NV Philips Gloeilampenfabrieken v Mirabella International Pty Ltd

Re: NV PHILIPS GLOEILAMPENFABRIEKEN and PHILIPS LIGHTING PTY LIMITED And:
MIRABELLA INTERNATIONAL PTY LIMITED and NV PHILIPS GLOEILAMPENFABRIEKEN
No. G351 of 1991
FED No. 493
Patents
(1992) AIPC 90-903 (extract)

COURT

IN THE FEDERAL COURT OF AUSTRALIA

NEW SOUTH WALES DISTRICT REGISTRY
GENERAL DIVISION
Wilcox J.(1)

CATCHWORDS

Patents - Patent concerning low-pressure mercury vapour discharge lamp - Infringement - Respondent's lamps use luminescent material comprising a mixture of three luminescent compounds - Integer of claims that luminescent material used in lamp have a specified maximum short term decrease - Whether evidence established the short term decrease of respondent's lamps - Construction of patent claims - Whether limited to a lamp containing a single luminescent material - Validity of patent - Revocation - Rules governing applications under 1990 Act for revocation of 1952 Act patent - Sufficiency of description - Failure of patent to specify luminescent materials - Fair basing - Whether specification of suitable characteristics of known material for known use constitutes an "invention" or a "manner of new manufacture" - Utility - Novelty.

Patents Act 1990, ss.7, 18, 40, 138, 230, 233(4), Schedule 1 Dictionary.

Patents Act 1952, ss.6, 40, 100.

Acts Interpretation Act 1901, s.15AB

HEARING

SYDNEY

#DATE 14:7:1992

Counsel for the Applicant: R Ellicott QC and

D Ryan

Solicitors for the Applicant: Sly and Weigall

Counsel for the Respondent: A Bennett

Solicitors for the Respondent: Williams Niblett

ORDER

The Court orders that:

1. The Application be dismissed.

2. It be declared that patent no. 523847 is invalid.

3. Patent no. 523847 be revoked.

4. The applicants pay the costs of the respondent in relation to both the principal proceeding and the Cross-claim.
Note: Settlement and entry of orders is dealt with in Order 36 of the Federal Court Rules.

JUDGE1

This case concerns a patent (no. 523847) issued to NV Philips Gloeilampenfabrieken ("NV Philips"), the first applicant, on 27 January 1983. NV Philips is a Netherlands corporation having its headquarters at Eindhoven, in that country. The patent was granted under the Patents Act 1952 for a term of 16 years commencing on 21 August 1978, the first anniversary of the filing in the Netherlands of a basic application in respect of the same article. The patent describes the invention as a "low-pressure mercury vapour discharge lamp". In some of its manifestations it may take the form of a compact, long-life, energy-efficient light globe. The second applicant, Philips Lighting Pty Limited, is an Australian subsidiary of the first applicant.

The respondent, Mirabella International Pty Limited, distributes in Australia compact lamps which are known as Mirabella PLC-E type lamps ("Mirabella lamps"). These lamps, apparently imported from China, are similar in appearance to Philips' compact lamps, ("Philips' lamps"). The applicants say that Mirabella lamps infringe NV Philips' patent. They claim a declaration to that effect together with an injunction restraining the respondent from making, causing to be made, importing, selling, offering for sale or, by way of trade, distributing Mirabella lamps in Australia. They also seek an order for the delivery up for destruction, or destruction under their supervision, of all Mirabella lamps in the possession or control of the respondent, together with damages or an account of profits. These claims are contested by the respondent, which denies infringement. In addition, the respondent challenges the validity of the patent. Five grounds were mentioned in its Cross-claim: failure to comply with the requirements of s.40 of the Patents Act 1990; lack of novelty; that the subject of the patent is not an invention or manner of manufacture; obviousness; and lack of utility. Obviousness is no longer pressed. The other grounds are maintained. The respondent claims a declaration that the patent is invalid and an order for revocation.
So far as I am aware, this is the first case in which it has been necessary to consider the implications for the revocation of 1952 Act patents of the replacement of that Act by the 1990 Act. During the course of the case, differences on that question emerged between counsel. As this is a matter of general significance to the case, it seems desirable to discuss it in principle before embarking upon the facts.
The effect of the 1990 Act on the revocation of 1952 Act patents
The Patents Act 1952 was repealed by s.230 of the 1990 Act. However, the 1990 Act contains some transitional and savings provisions: see Chapter 23. Those provisions include s.233 which relevantly provides:

"233.(1) Subject to this Chapter and the Regulations, this Act applies in relation to a standard patent or a petty patent granted under the 1952 Act as if the patent had been granted under this Act.

(2) A patent mentioned in subsection (1) does not have effect in any place in which it did not have effect immediately before the commencing day.

(3) ...

(4) Objection cannot be taken to a patent mentioned in subsection (1), and such a patent is not invalid, so far as the invention is claimed in any claim, on any ground that would not have been available against the patent under the 1952 Act."

I think that the purpose of subs.(4) is clear. It is to ensure that a person who obtained a patent under the 1952 Act would not be exposed, by the repeal of that legislation and the substitution of the 1990 Act, to an attack on the validity of the patent which would not otherwise have been available. But s.233(4) does not provide that a challenge to validity must be made under the 1952 Act. Leaving aside for the moment the meaning in this context of the word "ground", and subject to one qualification, it is clear that, after the commencement of the 1990 Act, a person who challenges the validity of a patent granted under the 1952 Act must do so under the 1990 Act, relying upon a ground available under that Act which is also a ground of invalidity under the 1952 Act.
The qualification to which I refer arises out of reg. 23.26(1) of the Patents Regulations 1991. That sub-regulation provides that the 1952 Act applies to an action or proceeding, made or started under that Act and not finally dealt with or determined before the commencing day, in which the validity of a patent is disputed or which concerns infringement of a patent. The present action was instituted on 5 July 1991, after the commencement of the 1990 Act. Accordingly, reg. 23.26 has no application to it; this is not a proceeding started under the 1952 Act. The qualification may be ignored. In order to obtain a revocation order in this case, the respondent must make out at least one ground of invalidity under the 1990 Act which is also a ground of invalidity under the 1952 Act.
Against this background, I turn to the statutory provisions relating to the grounds of invalidity alleged by the respondent. Section 40 of the 1990 Act sets out the formal requirements for provisional specifications and complete specifications. We are here concerned with a complete specification. Accordingly, subss. (2), (3) and (4) apply. They read:

"(2) A complete specification must:

(a) describe the invention fully, including the best method known to the applicant of performing the invention; and

(b) where it relates to an application for a standard patent - end with a claim or claims defining the invention; and

(c) where it relates to an application for a petty patent - end with a single claim, or a single independent claim and not more than 2 dependent claims, defining the invention.

(3) The claim or claims must be clear and succinct and fairly based on the matter described in the specification.

(4) The claim or claims must relate to one invention only."

In the present case the respondent alleges two infringements of s.40: that the complete specification does not describe the invention fully (subs.(2)(a)) and that the claims of the complete specification are not fairly based on the matter described in the specification (subs.(3)).
The equivalent provisions of the 1952 Act, also in s.40, were indistinguishable in substance.

"40.(1) A complete specification -

(a) shall fully describe the invention,

including the best method of performing the invention which is known to the

applicant; and

(b) shall end with a claim or claims defining the invention.

...

(2) The claim or claims shall be clear and succinct and shall be fairly based on the matter described in the specification."

The matter of novelty is treated differently by the 1990 Act than by the 1952 Act. Under the 1952 Act lack of novelty was a ground for revocation: see s.100(1)(g). In express terms, this is not so under the 1990 Act. However, s.138(1) of that Act entitles the Minister, or any other person, to apply to a "prescribed court" for a revocation order. This Court is a "prescribed court": see the definition of that term in the Dictionary contained in Schedule 1 to the Act. The available revocation grounds are set out in s.138(3). They include "that the invention is not a patentable invention" (para. (b)). The term "patentable invention" is defined by the Dictionary as meaning "an invention of the kind mentioned in section 18". Section 18 reads:

"18.(1) Subject to subsection (2), a patentable invention is an invention that, so far as claimed in any claim:

(a) is a manner of manufacture within the meaning of section 6 of the Statute of Monopolies; and

(b) when compared with the prior art base as it existed before the priority date of that claim:

(i) is novel; and

(ii) involves an inventive step; and

(c) is useful; and

(d) was not secretly used in the patent area before the priority date of that claim by, or on behalf of, or with the authority of, the patentee or nominated person or the patentee's or nominated person's predecessor in title to the invention.

(2) Human beings, and the biological processes for their generation, are not patentable inventions."

It will be noted that it is an essential feature of a patentable invention that, when compared with the prior art base as it existed before the priority date of the claim, the invention be novel. Accordingly, lack of novelty deprives an invention of the status of being a "patentable invention" and constitutes a ground for revocation under s.138(3)(b).
Turning to the third ground of objection, that the subject of the patent is not an invention or manner of manufacture, the situation is somewhat similar. Section 100(1)(d) of the 1952 Act made it a ground of revocation that the invention claimed in the specification "is not an invention within the meaning of this Act". Section 6 defined the word "invention", for the purposes of the Act but subject to any indication of a contrary intention, as meaning "any manner of new manufacture the subject of letters patent and grant of privilege within section 6 of the Statute of Monopolies, and includes an alleged invention". It is difficult to see that the concluding words of this definition were intended to apply to the use of "invention" in s.100(1)(d). Those words would render the paragraph nugatory; any claimed invention is an alleged invention. I think that the better view is that, in s.100(1)(d), "invention" meant a patentable manner of new manufacture. This view is consistent with that expressed by the Full High Court in Commissioner of Patents v Microcell Limited (1959) 102 CLR 232. That case arose under the 1903 Act. The Commissioner had refused to accept the respondent's application on the ground that it was not for an invention. The respondent argued that the Commissioner was not entitled to reject the application on that ground; the application alleged an invention and this was enough to bring it within the definition of "invention". The Full Court rejected that argument, saying (at 246): "It must be enough to warrant rejection that it should be clear on its face that the specification discloses no inventive step".
The distinction that I have mentioned is brought out in the 1990 Act. The Dictionary to that Act contains a definition of "invention" corresponding to that in the 1952 Act; that is, including an "alleged invention". But s.18 requires that a "patentable invention" be a manner of manufacture within the meaning of s.6 of the Statute of Monopolies; that is, a true invention. It follows that there is no material difference between the substance of the ground of revocation available under the old Act and that of the ground available under the new.
Under the 1952 Act it was a ground of revocation that the invention, as claimed in the relevant specification, "was obvious and did not involve an inventive step having regard to what was known or used in Australia on or before the priority date of (the) claim": see s.100(1)(e). The 1990 Act deals with the same subject matter by a combination of s.18, which requires a "patentable invention" to be one that "involves an inventive step", and s.7(2). The latter provision relevantly reads:

"(2) For the purposes of this Act, an invention is to be taken to involve an inventive step when compared with the prior art base unless the invention would have been obvious to a person skilled in the relevant art in the light of the common general knowledge as it existed in the patent area before the priority date of the relevant claim ..."

The term "patent area" is defined in the Dictionary to include not only Australia but also the Australian continental shelf, the waters above the continental shelf and the airspace above both Australia and the continental shelf.

An invention which fails to involve an inventive step is not a "patentable invention" and is, therefore, revocable under s.138(3)(b).
Finally, lack of utility was a ground for revocation under the 1952 Act: see s.100(1)(h). Under the 1990 Act a "patentable invention" is required to be useful: see s.18(1)(c). If it is not, any patent granted over the invention may be revoked under s.138(3)(b).
I earlier set to one side the meaning of the word "ground", where used in s.233(4) of the 1990 Act. Counsel for the applicants accept that, in a broad way, there is some equivalence between the relevant revocation provisions of the two statutes. But they submit that equivalence is not enough. They say that a 1952 Act patent may be revoked under the 1990 Act only where the two statutes provide an identically worded ground of revocation; if there is any difference in wording, the 1990 Act "ground" would not have been available under the 1952 Act.
There are two aspects to counsel's argument. First, they point out that many of the grounds of revocation specified under s.100 of the 1952 Act are not now distinct grounds of revocation; they are caught up by the definition of "patentable invention" in s.18 and the provision in s.138(3)(b) of a ground of revocation "that the invention is not a patentable invention". Conceding that, under the 1990 Act, a patent which, for example, is not novel may be revoked under s.138(3)(b) because of that fact, counsel say that this is a different "ground" of revocation than that provided by s.100(1)(g): "that the invention ... was not novel in Australia on the priority date of (the) claim". The 1990 "ground" is that "the invention is not a patentable invention". The second proposition is that, even where there is no difference between the name of the relevant ground in the two Acts, any variation between them concerning the elements of that ground, or the factual matters which need to be established, results in the 1990 Act ground being one that would not have been available under the 1952 Act. As counsel put the matter in their submissions: "There must be a precise agreement in the integers of invalidity under whatever heading is used"; and this irrespective of whether or not the critical integer or different factual matters have any significance in the particular case.
Counsel for the respondent disputes these propositions. She says that it is enough that the basis upon which the patent is revocable under the 1990 Act - for example, because it fails in some respect to satisfy the s.18 definition of "patentable invention" - is also a basis of revocation under the 1952 Act. Counsel not only argues that it does not matter that there is a change in statutory structure, so that what is a specific ground of revocation in the 1952 Act, such as lack of novelty, is merely the basis for a more widely-stated ground in the 1990 Act. She says that, provided that the same description is used, it does not matter that there is a difference between the elements that must be proved under the two Acts or the relevant factual material.
Fundamental to the issues raised by these submissions is the meaning of the word "ground" in s.233(4). Does this refer to the particular statutory provision under which revocation may be ordered, so that any difference in the statutory provision means a difference in the ground? Or does the word refer to the factual basis for revocation, however that basis may be translated into legal effect? I think that the latter interpretation was intended. As counsel for the applicants agree, if they are correct in their submission that the word "ground" refers to the particular statutory provision, the 1990 Act has profoundly changed Australian patent law. For example, revocability of a patent granted in respect of an invention which is not novel or not useful is a notion as old as patent law itself. On the view put by counsel, and merely because of the passage of the 1990 Act, these grounds are now inapplicable to patents issued under the 1952 Act. Examples could be multiplied. Most of the grounds of revocation listed in the old s.100(1) are now not distinct grounds of revocation. They merely enable the claim that the particular invention is not a "patentable invention". On counsel's argument it would not matter that a particular invention was demonstrated to be, for example, not novel, not useful or obvious; and, therefore, capable of revocation under s.138(3)(b). Because of the passing of the 1990 Act, the court could not revoke the patent on such a ground. A provision designed to ensure that 1952 Act patent-holders would not suffer from the replacement of that Act by the 1990 Act would confer a benefit on those of them whose patents were vulnerable to revocation; to the disadvantage of people interested in challenging their statutory monopolies. It is true that the anomaly would not last forever. But it would last until the expiry of all 1952 Act patents, a considerable time. Given these consequences, the Court should accept the applicants' interpretation of the word "ground" only if satisfied that this is the clear meaning of the word in its statutory context or if investigation of relevant extrinsic material shows that it was intended to be so construed. As I have indicated, in my opinion, in the context of s.233(4), the word "ground" is ambiguous. It is legitimate to look to the legislative history in order to resolve that ambiguity: see s.15AB of the Acts Interpretation Act 1901.

The 1989 Bill which became the Patents Act 1990 grew out of a report supplied to the Government by the Industrial Property Advisory Committee ("IPAC"). The Government's response to the report, tabled by the Minister for Science, Mr Barry Jones, indicated that the Government accepted most of the committee's recommendations. It rejected some others. In tabling the response on 28 November 1986, Mr Jones commented that "the report does not suggest that there is an immediate need for change, nor that there is a need for radical change, in the Australian patent system". "Precipitate change", he said, "would invite disruption for Australian users of the system". The Government accepted IPAC's recommendation to broaden the prior art base against which issues of novelty and obviousness were to be determined, for both standard and petty patents. There was no other recommendation concerning grounds of revocation.
Mr Jones moved the second reading of the 1989 Bill on 1 June 1989. In doing so, he again referred to the IPAC report. He said that the Bill was intended to implement the Government's response to that report and commented upon its form: "It is a splendid piece of drafting and a Bill that is notably easy to read". The Minister gave no hint of a Government intention to affect the entitlement of people to challenge 1952 Act patents. See House of Representatives Debates, 1 June 1989 at 3479-3483.
Mr Jones presented an explanatory memorandum to the House. A supplementary explanatory memorandum was later circulated, whilst the Bill was before the Senate. In the present context, these documents - like Mr Jones' comments - are chiefly notable for what they do not say. The explanatory memorandum identifies the purpose of the legislation as the implementation of the Government's response to the IPAC report. In para.2 it says:

"Apart from improvements on a variety of administrative matters, ranging from examination of patent applications to enforcing patents in the courts, the Bill implements a number of policy measures. Notably, the Bill strengthens the standards of patentability for standard patents by testing inventions for novelty and inventive step against prior disclosures anywhere in the world rather than just in Australia. Other policy changes were also outlined in the Government's response to IPAC's report."

The explanatory memorandum goes on to indicate that "the text of the Patents Act has been thoroughly redrafted and re-arranged to modernise its language and avoid unnecessary complexity". Paragraph 29, dealing with cl.18 of the Bill on patentable inventions, indicates that the term "manner of manufacture" "invokes a long line of UK and Australian court decisions. It means little more than that an invention must belong to the useful arts rather than the fine arts". Paragraph 199, dealing with cl.136 of the Bill (which became s.138 of the Act), does no more than paraphrase the language of the clause.
When the Bill was introduced into Parliament, it lacked the transitional Chapter 23. These provisions were introduced by way of Government amendment and were referred to in the supplementary explanatory memorandum. That document refers to cl.229 of the Bill, which became s.233 of the Act. But it is not informative. The only comment on subclause (4) is that it "ensures that such a patent (that is, a 1952 Act patent) cannot be attacked under the Bill on any ground that would not have been available against the patent under the repealed Act".
In the whole of this material there is no suggestion of any intention to make any significant change to the rules relating to revocation. It is impossible to believe that the result contended for by counsel was intended by the Government; and it does not appear that the Parliament relevantly departed from the Government's Bill. Counsel for the applicants say that these matters are irrelevant; if the result for which they contend flows from the language used by the Parliament, it does not matter that it was unintended by the Government and the Parliament. I agree, of course. But the submission depends upon the language used in the statute being free from ambiguity. If there is ambiguity, the failure of the Government to allude to such a major change in the existing law, and major derogation from the rights of those persons who might wish to challenge a 1952 Act patent, is significant.
The second proposition advanced by counsel for the applicants, dealing with variations in the elements of the relevant ground or the factual matters needing to be established, has more limited consequences. It would not exclude revocation under the 1990 Act on virtually all the grounds mentioned in the old s.100(1). But it would exclude revocation on some of them, including novelty and obviousness. The factual material on which an objection of novelty may be based is different under the 1990 Act than under the 1952 Act. For standard patents, it has been broadened from information published in Australia at the priority date of the claim to information publicly available anywhere in the world. Obviousness is affected by the expansion, however theoretically, of the defined "patent area": compare ss.18 and 7(2) of the 1990 Act with s.100(1)(e) of the 1952 Act. It seems to me unlikely that the Parliament intended to protect 1952 Act patent-holders from challenge on these grounds. Once again, there is nothing in the legislative history to so suggest. I do not think that the mere fact that the 1990 Act changed the elements of a particular ground of revocation, or the evidence needed to make it good, means that this ground is now unavailable against a 1952 Act patent.
At the same time, I have difficulty with the respondent's submission that, so long as the 1990 Act used the same descriptive word as in the 1952 Act, the Court is now concerned only with the elements specified in the 1990 Act and the evidence relevant under the 1990 Act. Such an approach seems to cut against the policy, apparent in s.233(4), of ensuring that 1952 Act patent-holders are not rendered more vulnerable to challenge by the passing of the 1990 Act. In the case, for example, of novelty, a challenge may be easier under the 1990 Act than under the corresponding 1952 provision. There may have been relevant information publicly available overseas but not published in Australia. It would seem inconsistent with the object of s.233(4) to allow the 1990 Act to expose the patent-holder to a revocation not previously available.
I think that the purpose of s.233(4) is to maintain the existing rights of 1952 Act patent-holders, but no more. That purpose may be achieved by an interpretation that requires an applicant for revocation under the 1990 Act to establish, not only the facts needed to make out the relevant ground under the 1990 Act, but also facts that would have led to revocation upon an equivalent basis under the 1952 Act. That interpretation means that, whilst 1952 Act patents remain in contention, there must be a dual inquiry, the Court testing the facts against the invoked ground of invalidity, however described, in each Act. If the proved facts satisfy the requirements of each Act, s.233(4) permits revocation under the 1990 Act of the 1952 Act patent; but not otherwise.
The compact low-pressure mercury vapour discharge lamp
A low-pressure mercury vapour discharge lamp is a fluorescent lamp. Fluorescent lamps have been in widespread use for many years. In terms, this case is not restricted to any particular form of low-pressure mercury vapour discharge. The patent does not exclude the possibility of its application to a lamp having the shape and dimensions of the conventional fluorescent lamp. But, in reality, the case is concerned with a particular type of low-pressure mercury vapour discharge lamp, a "compact lamp". I say this because it is an integer of each of the claims that the lamp have a column discharge of at least 500 watts per square metre. This would be an unusual and unnecessary loading for a conventional fluorescent lamp. On the evidence, it is essential for a compact lamp.
The most obvious differences between a compact lamp and a conventional fluorescent lamp are size and shape. Whereas the conventional lamp is long and thin (typically a metre or more in length by 3-4cm in diameter) the compact lamp is small and comparatively squat. Sometimes it is straight; sometimes curved, like an incandescent light globe. But, regardless of shape and size, the principle behind a compact lamp is the same as that behind a conventional fluorescent lamp. The essence of its operation is its ability to convert electrical energy into light by the production of radiation lying within that part of the radiation spectrum which is visible to the human eye.
I should explain in more detail. The compact lamp consists of a glass tube, the inner surface of which is coated with a luminescent material, containing two electrodes. Both Philips lamps and Mirabella lamps use luminescent material comprising a mixture of fluorescent salts, called "phosphors". Each phosphor is a separate chemical compound. The tube is filled with an inert rare earth gas, usually argon, and some mercury. Electrical energy is applied between the electrodes, creating an electrical discharge in the inert gas and heating the tube. The heat vaporises the mercury. The atoms of mercury vapour absorb energy from the free electrons of the gas discharge, exciting them to high energy levels and causing them to emit radiation. This initial radiation is mostly in the form of ultraviolet rays invisible to the human eye. However, the initial radiation is immediately absorbed by the phosphors, causing the phosphors to emit longer wavelength radiation which is visible to humans. The colour of the emitted radiation (light) depends upon the choice of phosphors. Generally speaking, it will be desired to have a white light rather than one that is bluish or pinkish in hue. It has been common for many years for manufacturers of fluorescent lamps to procure this result by combining phosphors that would, separately, emit red, green or blue light and whose combined emission appears as white light.
Phosphors vary in their efficiency in converting ultraviolet radiation into visible light; a matter which is, of course, critical to their suitability for use in fluorescent lamps. That efficiency is expressed in terms of lumens per watt. A lumen is a measure of radiant power evaluated according to the ability of the light source to produce the visible sensation of light. The number of watts indicates, of course, the electrical input. Efficiency is reduced by degradation of the phosphor or if energy is lost in heat. Most phosphors degrade in time, but at differing rates. Some phosphors have a high efficiency but degrade quickly, others a lower efficiency but a longer life. The light produced by a lamp is called luminous flux and measured in lumens. If a particular phosphor is efficient, so that it produces a high number of lumens per watt, the luminous flux will be high.
Before turning to the subject patent, four particular aspects of compact lamp design should be mentioned. The first is wall-loading. The term "wall-loading" is used to describe the ratio between the electrical power input to the lamp and the area of the inside surface of the lamp. It follows that compact lamps, because of their smaller size, have a higher wall-loading than conventional lamps that use the same wattage. A lamp with a high wall-loading is often called a "highly-loaded" lamp.
Secondly, using the same phosphors, a compact lamp is less efficient than a conventional fluorescent lamp. This is a result of the lamp's smaller size. There are two aspects of the matter: there is an increase in the proportion of energy which is expended at the electrodes to sustain the discharge and, thus, lost as heat; and there is a greater proportion of ion recombination at the wall of the tube. The smaller the diameter of the tube, the more readily will ions diffuse to the walls and recombine. Their recombination energy is largely expended as heat, rather than used to produce visible light.
Thirdly, the radiation from a low-pressure mercury vapour discharge lamp occurs primarily at two wavelengths: 185 nanometres ("nm") and 254 nm. Radiation at 185 nm has a degrading effect on phosphors, leading to a loss of luminous flux. This loss is often called "short term decrease" or "STD", the name stemming from the fact that the loss occurs within the first few minutes after the lamp is switched on. Although the evidence on the matter is sparse, I gather that STD is not cumulative. It persists whilst the lamp is illuminated and recurs, to about the same extent and from about the same base, when the lamp is next switched on. But, of course, the effect of STD is to reduce the lamp's operating efficiency. Some phosphors are more resistant to STD than others, hence it is important to select phosphors whose characteristics include high STD resistance.
Radiation at 245nm does not degrade phosphors. Indeed, it seems to have a beneficial effect, apparently by absorbing some of the 185nm radiation. Accordingly, it is desirable to design the lamp in such a manner as to minimise 185nm radiation and maximise 245nm radiation. A problem about compact lamps, compared with conventional fluorescent lamps, is that their smaller size leads to an increase in the 185nm/245nm ratio; thus increasing the problem of phosphor degradation.
Finally, there is a problem of electro-negativity ("e.n"). This phenomenon was described by Professor Linus Pauling, who in 1945 compiled a list of the e.n of all known elements, as "the power of an atom in a molecule to attract electrons to itself". The combination of cations (the positively charged mercury ions) suitable for a compact lamp must have a relatively low electro-negativity in order to resist degradation of the phosphor by the mercury atoms.
The patent specification
The patent specification commences with the following statement:

"The invention relates to a low-pressure mercury vapour discharge lamp having a vacuum-tight radiation-permeable envelope provided with a luminescent layer, a gas filling comprising mercury and a rare gas, and means for maintaining a column discharge in the gas filling, the power consumed by the column being at least 500 W per m2 surface area of the luminescent layer."

The specification then outlines the principle underlying low-pressure mercury vapour discharge lamps, their physical descriptions and manner of operation. Reference is made to conventional fluorescent lamps, the statement being made that the 40 watt T-12 lamp (a lamp 1.2 metres in length and 37 mm in diameter) generally has a wall-loading of about 300 watts per square metre ("W/m2").
The specification then says that low-pressure mercury vapour discharge lamps have already been made, wherein a higher wall-loading, of 500 W/m2, is applied. This is said to have been done "with the object of obtaining small and compact lamps". Reference is then made to German and United States patents disclosing small lamps with wall-loadings of 2,500 W/m2 and 25,000 W/m2 respectively.
The specification then turns to the prior art:

"A great drawback of the prior art lamps with a relatively high wall load is that the efficiency of the lamp, that is to say the radiant flux or luminous flux of the useful radiation emitted by the luminescent layer ... appears to have a low value. In particular this efficiency is considerably lower than that of the normal lamp (for example the 40 W/T12-lamp). This drawback is especially felt with the compact lamps and is one of the reasons that this lamp type, which might offer great advantages for practical applications, for example as a substitute for normal incandescent lamps, has as yet not been introduced. The reason why it appeared to be impossible to produce lamps having a high power input per unit volume and with an efficiency comparable to that of the normal lamps was not understood. Also known insights as regards the optimum mercury vapour pressure ... and means for controlling the mercury vapour pressure (amalgams etc) did not lead to the desired result. It has, therefore, been considered that producing a compact lamp, for example by reducing the diameter whilst maintaining the electric power supplied must inevitably be accompanied by loss in efficiency."

Continuing, the specification deals with the object of the invention:

"... to provide low-pressure mercury vapour discharge lamps which in operation has (sic) a high density of the consumed power and a high radiation efficiency, so that on the one hand compact lamps with an efficiency substantially equal to that of the normal low-pressure mercury vapour discharge lamps and, on the other hand, lamps having high current densities with an improved radiation efficiency become available."

The substance of claim 1, with one variation to which I will come, is then set out. It is followed by this description of the course of investigations:

"During the investigations which led to the invention, it was found that an efficient conversion of the electric power into ultra-violet radiation is possible in a highly loaded lamp. It was surprisingly found that the efficiency of this conversion can be substantially equal to that of the normal 40W/T12 lamp. It was found to be a prerequisite that the electron temperature in the highly loaded lamp assumes a value which is not lower, and is, preferably higher than that in the normal lamp. Various measures are possible to achieve this. Starting, for example, from the normal lamp, the required high electron temperature is maintained if the discharge tube has a smaller diameter, while the electric power supplied to the lamp is kept substantially constant. Compared to the normal lamps, the electric field strength is then higher, the lamp current is lower and the wall load is higher than in the normal lamps. Experiments showed that said high efficiency of the conversion into ultra-violet radiation can also be obtained with very low diameters of the discharge tube (from one to a few mm). Another measure which makes it possible to maintain a high electron temperature is to reduce the rare gas pressure in the lamp whilst increasing the supplied electric power. Compared to the normal lamps the lamp current is then considerably greater and the electric field strength is substantially the same or is somewhat lower. The wall load in these lamps is of course higher.

It was furthermore found that with an efficient production of ultra-violet radiation in highly loaded lamps, there is not only a high ultra-violet radiation density at the wall but also the share of the radiation having a wavelength of 185nm is relatively higher than in normal lamps. This unexpectedly high ratio between the 185nm radiation and the 254 nm radiation combined with the increased density of the total ultra-violet radiation produced results in the 185 nm-load of the wall of such lamps being considerably higher than in normal lamps."

The specification then identifies the invention:

"The invention is based on the recognition that failure of the prior art lamps with high wall load is not due to a low efficiency of the conversion into ultra-violet radiation, as has been generally assumed so far, but is due to the luminescent materials used. The invention provides suitable luminescent materials as a measure for obtaining efficient, highly loaded lamps. Consequently, the present invention opens the way to an entirely new lamp type, namely the compact low-pressure mercury vapour discharge lamp which can replace the normal incandescent lamp which is used in very great numbers. As the efficiency of the low-pressure mercury vapour discharge lamp is approximately 5 times greater than that of the incandescent lamp, a very considerable saving in energy is possible." (Emphasis added).

It seems to be common ground that the phrase "as a measure for" in the emphasised sentence of this extract is synonymous with "as a means of". So the essence of the claimed invention is that it "provides suitable luminescent materials" as a means of obtaining efficient, highly loaded lamps. Although, according to the specification, the investigators surprisingly discovered that it is possible to convert electric power into ultra-violet radiation as efficiently in a highly loaded lamp as in a normal 40W/T12 lamp, and although the authors describe how this can be done, this discovery and information is not part of their claimed invention. Rather, in describing the invention, they start from the position that there is equal conversion efficiency between a 40W/T12 lamp and a highly loaded lamp and address the question why, in that situation, highly loaded lamps are less efficient in producing visible light. The problem, they say, lies in the luminescent materials that have been used. The solution is to select suitable luminescent materials and the purpose of the invention is to guide that choice; thus opening the way for a new type of lamp, the compact low-pressure mercury vapour discharge lamp.
The specification turns to embodiments. It is said that, in a lamp according to the invention, "a luminescent material is used which is, on the one hand, highly resistant against 185 nm radiation, that is to say it has only a very slight decrease in the luminous flux (on excitation by 254 nm radiation) owing to irradiation by 185 nm rays and which, on the other hand, has a high mercury resistance". No luminescent material is identified. The specification goes on to set parameters for acceptable short-term decrease of the luminous flux of the material when it is irradiated for 15 minutes "by radiation having wavelengths of mainly 185 nm and 254 nm with a radiation density between 150 and 500 W/m2 and with a ratio of 185 nm power to 254 nm power between 0.20 and 0.40". The specification refers to an apparatus for measuring this short-term decrease which is described and illustrated later in the document. The specification stipulates that the STD after 15 minutes "shall not be more than 5%". The embodiment proceeds to deal with electro-negativity, stating that "the luminescent material must not only satisfy the requirement as regards the short-term decrease but also the requirement for a higher degree of mercury resistance." It is said that it has "been found that the luminescent layer in highly loaded lamps is exposed to a much greater number of collisions with excited mercury atoms and mercury ions than is the case in normal lamps ... A measure of the mercury resistance of a luminescent material is found in the electro-negativity (e.n) of the cations of the luminescent material". After stating that "it is now clear that mercury ... will attack luminescent materials whose cation has e.n >1.9" the embodiment specifies an e.n of not more than 1.4, measured according to the Pauling table.
It is not necessary to detail all the remaining embodiments. A number reflect the various claims without identifying any particular luminescent material as meeting the specified criteria or being otherwise suitable for use in compact lamps. However, at page 13, the specification refers to an embodiment containing as luminescent material "a red luminescing, trivalent europium - activated rare earth metal oxide having a composition defined by the formula Ln2o3:pEu3+, where Ln represents at least one of the elements Y, Gd and Lu and where 0.01< p
0.20. These luminescent oxides, which are known per se, appear to have a very small short-term decrease and are highly resistant to mercury, so that they can be used with great advantage in lamps according to the invention". The compound referred to in this embodiment is generally known as "YOX".
The next embodiment refers to a group of luminescent aluminates, known per se under the sobriquet "CAT". It is said that these materials have a small short-term decrease and a good mercury resistance.
The following embodiment contains a reference to a further group of luminescent aluminates, known per se and often called "BAM". They are said to have very low short-term decrease and good mercury resistance.
The statement is then made that:

"The luminescent layer in a lamp according to the invention may contain a luminescent material from the group consisting of bivalent europium-activated strontium tetraborate, lead-activated barium disilicate, bivalent europium-activated strontium chlorophosphate with an apatite crystal structure, gadolinium metaborate activated by cerium and terbium and gadolinium borate activated by trivalent bismuth and trivalent europium."

It is said that these materials have an excellent STD and that their mercury resistance "is very favourable".
The specification then refers to two diagrams. Figure 1 illustrates "a low-pressure mercury vapour discharge lamp according to the invention". Figure 2 is a diagrammatic representation of the apparatus for measuring STD. Both diagrams are described at length. It is important to note that the STD specified in the claims (5% and 3%) is the decrease in luminosity of the luminescent material when measured by the particular apparatus in the way prescribed in this embodiment.
The specification refers to some tables. Table I sets out the electro-negativity, STD and luminous flux of ten different compounds, including YOX, CAT and BAM, as measured in discharge tubes with an inside diameter of 10.3mm. The specification comments: "It is clear that reducing the diameter, which results in highly loaded lamps, in accordance with the invention, is not accompanied by a loss in column efficiency".
Table II sets out measurements of the luminous flux of lamps, of 7.8, 10.3 and 14.5mm inside diameter, containing "a blue luminescing material", BAM, after various numbers of hours of operation. Table III conveys similar information concerning YOX, a red luminescing material. Example 17 gives the same information for CAT, a green luminescing material, but only in respect of a 7.8mm tube. There is information in Tables IV and V (examples 18 to 26) regarding a mixture of YOX and CAT. Examples 27, 28, 29 provide some information about a mixture of YOX, CAT and BAM.
At the end of this section of the specification the words appear:

"It is clear that the abovementioned embodiments only serve to illustrate the invention.

On the basis of the requirements formulated in this description as regards short term decrease and mercury resistance and by means of the methods described for determining these properties, a person skilled in the art can easily ascertain which luminescent materials are suitable for use in lamps according to the invention. Furthermore it should be noted that a luminescent material which, for example, does not satisfy the requirements imposed on the short-term decrease can be made suitable, for example by optimizing the preparation of this material. It is possible that a luminescent material becomes sufficiently resistant to attack by mercury by coating the material with a protective layer."

The claims to the invention follow. Because of its central importance to the argument, I set out claim 1 in full:

"1. A low-pressure mercury vapour discharge lamp having a vacuum-tight, radiation-permeable envelope bearing a luminescent layer and containing a gas filling comprising mercury and a rare gas, and means for maintaining a column discharge in the gas filling, the power consumed during operation by the column discharge being at least 500 W per m2 surface area of the luminescent layer, wherein the luminescent layer contains a luminescent material which has the property of having at 254 nm-excitation a luminous flux which, after the material has been subjected for 15 minutes to ultraviolet radiation consisting substantially of the wavelengths 185 and 254 nm, having a radiation density between 150 and 500 W/m2 and having a ratio of 185 nm power to 254 nm power between 0.20 and 0.40, is not more than 5% lower than the initial luminous flux of the material at 254 nm excitation and measured under identical circumstances, and wherein the combination of cations (as hereinbefore defined) in the luminescent material has an electro-negativity of not more than 1.4."

Claim 2 refers to a lamp as claimed in Claim 1, but with an STD of not more than 3%, rather than the 5% mentioned in Claim 1.
Claim 3 refers to a lamp, as claimed in Claim 1 or Claim 2:

"wherein an electric field strength of 150 to 1000 V/m (volts per metre) is maintained in the column discharge during operation of the lamp".

It is common ground between the parties that this claim envisages a compact lamp, the stipulated electric field strength being only appropriate to such a lamp.The earlier claims do not mention electric field strength.

Claim 4 refers to a lamp, as claimed in Claim 3, "wherein the envelope has a tubular shape, whose cross-section perpendicular to the axis of the tube is substantially circular and whose inside diameter is from 3 to 15mm".
Claim 5 refers to a lamp, as claimed in Claim 1 or Claim 2, wherein an electric current of a current density of at least 0.5 A/cm2 (amps per square centimetre) is maintained in the column discharge during operation of the lamp.
Claims 6, 7, 8 and 9 each claim a lamp as claimed in any one of Claims 1 to 5 wherein a particular luminescent material is used: in the case of Claim 6, YOX; in the case of Claim 7, CAT; in the case of Claim 8, BAM; and in the case of Claim 9 a compound from the group described above immediately before my reference to the diagrams.
Infringement
The applicants do not claim that the respondent has infringed any of Claims 6 to 9. The reason for this is that the luminescent material used in the respondent's lamp does not correspond with the material mentioned in any one of those claims. They say that the respondent's luminescent material is a mixture of YOX, CAT and BAM, the three phosphors separately referred to in Claims 6, 7 and 8. But they accept that a mixture of the three phosphors is a different luminescent material from any of them individually and is therefore different from the relevant integer in any of these three claims.
However, in relation to Claims 1 to 5 the applicants press their claim of infringement. There is no issue about formal matters. By a series of affidavits which it is unnecessary to detail, the applicants establish the sale in Australia by the respondent of Mirabella lamps, their transmission by Philips personnel to Eindhoven for testing, the taking of samples of the phosphor mixture from two Mirabella lamps, and the making of various tests. The applicants' case, on infringement, is that the tests show that Mirabella lamps have all the characteristics specified in Claim 1 of their patent. They also suggest that the lamps have the additional features required in each of Claims 2, 3 and 4. There does not seem to be any significant dispute about the last-mentioned matter; but it is not important to determine whether or not it is correct. The case has been fought on the basis that, if Mirabella lamps infringe Claim 1 and the patent is valid, the first applicant is entitled to relief. The respondent says that under no circumstances is the second applicant entitled to relief, it being neither the patentee nor an exclusive licensee. This proposition is not disputed. It seems to me correct.
The undisputed evidence establishes that the Mirabella lamps are properly described as "low-pressure mercury vapour discharge lamps" and that they have the structural characteristics required by Claim 1: a vacuum-tight, radiation permeable envelope containing electrodes able to introduce and maintain a column discharge in a gas filling. It is also clear that the gas filling of the lamps comprises mercury and a rare gas and that the power consumed during operation is not less than 500 W/m2 of the surface area of the luminescent layer. The contest on infringement revolves entirely around the properties of the Mirabella luminescent layer.
Evidence of the composition of the Mirabella phosphors was provided by Ms L M C Vugts and Mrs A P Mouws-van Rossum, both chemical analysts employed by NV Philips at Eindhoven. Mrs Mouws-van Rossum extracted from a Mirabella lamp (identified as lamp 113-1) a sample of the luminescent powder. She subjected it to analysis by a technique known as X-ray diffraction ("XRD") and found that it consisted of a mixture of YOX, CAT and BAM together with a slight excess of aluminium oxide. Subsequently, she carried out a similar analysis on a sample of the luminescent material taken from a Philips' compact lamp. This material was also a mixture of YOX, CAT and BAM, apparently without any impurities. The weight to weight ratios of both samples were fairly comparable: in the case of the Philips lamp being 51% YOX, 40% CAT and 9% BAM, in the case of Mirabella, 41%, 37% and 8% with 10% aluminium oxide and a 4% silicate impurity. Ms Vugts carried out a different type of analysis called X-ray fluorescence analysis ("XRF"). She applied this technique to both samples and was able to construct a table of the weight to weight ratios of their constituent oxides.
Mr M M H Janssen is an employee of NV Philips working in the field of spectroradiometry. He measured the spectral powder distribution ("SPD") of four Mirabella lamps, numbers 113-1, 113-2, 133 and 154. SPD measurement is a procedure for determining the optical properties of lamps. It is carried out by means of a Cary monochromator, an apparatus which measures the visible emission spectrum of lamps, giving the radiation energy (in watts) for each interval of 1 nm on the wavelength scale. The results enable determination of optical properties such as colour point, colour temperature, colour rendering index, total luminous flux and total energy of the visible radiation. Mr Janssen reported the SPD results to Dr H C G Verhaar, the chief expert witness relied upon by the applicants in this proceeding. In 1985 Dr Verhaar received a docorandus degree in chemistry from the State University of Utrecht. (Judging by Dr Verhaar's explanation, a docorandus degree would be roughly equivalent to a master's degree in Australia). In the following year, he commenced employment with NV Philips, working in the field of luminescent materials. Although there are some points of difference between Dr Verhaar and the respondent's expert witnesses, on matters immaterial to anything I have to determine, no general attack is made upon Dr Verhaar's competence or experience. I am satisfied that he is well read and experienced on the subject of luminescent materials in general and, in particular, in relation to phosphors suitable for use in low-pressure mercury vapour discharge lamps. Dr Verhaar also had the reports of Ms Vugts and Mrs Mouws-van Rossum. Basing himself upon all this material, Dr Verhaar said that the luminescent material used in the Mirabella lamps was a mixture of YOX, CAT and BAM. He also said that, since each of these three phosphors has an electro-negativity of less than 1.4, the mixture necessarily also had an e.n of less than 1.4. In actual fact, he said he calculated the electro-negativity of the particular mixture, having regard to the weighted average of the three components, at 1.1. Finally, Dr Verhaar measured the STD of the powder taken from two Mirabella lamps, following the procedure, and using the equipment, prescribed by the patent. Each of five measurements showed an STD less than 5%. The measurements ranged from 1.4% to 3.4%, with a mean value of 2.2%. Dr Verhaar stated that this figure was 95% reliable, within a tolerance of plus or minus 0.7%.
On its face, Dr Verhaar's evidence establishes that the luminescent materials in the Mirabella lamps possess all the features referred to in Claim 1. Moreover, as there is a 95% probability that the STD was less than 3%, the evidence suggests they also satisfy the requirements of Claim 2. Mr Harry Nienhus, an electrical engineer employed by NV Philips, calculated the electrical field strengths of the Mirabella lamps. One of the four lamps (no. 113-1) had a minimum field strength of only 139.2 V/m, a figure outside the range of 150-1000 volts per metre required by Claim 3. Mr Nienhus discarded this result as "unrealistically low". Referring to the minimum field strengths, 182.7 and 152.7 V/m, of two other lamps (113-2 and 154), he opined that the "field strength in lamp 113-1 exceeds 150 V/m". I do not understand the justification for jettisoning the inconvenient lamp 113-1 result. But it does not matter. Whether or not lamp 113-1 was one of them, at least some of the Mirabella lamps infringe the electric field strength integer of Claim 3. The same statement may be made of Claim 4. This claim differs from Claim 3 only in its requirement of a particular envelope configuration, a requirement satisfied by the Mirabella lamps.
The respondent called no evidence in response to the applicants' evidence concerning infringement, save that one of its experts, Dr J G Thompson, a Research Fellow in the School of Chemistry at the Australian National University, questioned the sufficiency of the evidence said to support Mrs Mouws-van Rossum's XRD analysis. He said that it was not demonstrated that the Philips phosphors used for comparative purposes by Mrs Mouws-van Rossum "are of the same composition as the equivalent Mirabella phosphors". Accordingly, in his view, the interpretations of the XRD analysis made by both Mrs Mouws-van Rossum and Dr Verhaar are unjustified.
Dr Thompson's criticism was not taken up in Dr Verhaar's affidavit in reply. It seems to me to be justified. But this does not lead me to discard Dr Verhaar's opinion as to the composition - and therefore the e.n - of the Mirabella factors. Dr Verhaar's opinion was based also on Ms Vugt's XRF analysis, which escaped criticism by Dr Thompson save for a complaint that she had not reported the experimental errors in the analysis, and Mr Janssen's SPD results, which were not challenged at all. Neither Ms Vugts nor Mr Janssen was required for cross-examination. It was not put to Dr Verhaar, who was cross-examined, that Ms Vugts' work was unreliable. The composition of the Mirabella luminescent material was virtually common ground. In support of its case of lack of novelty, Mirabella sought to show, indirectly, that its luminescent material was a mixture of YOX, BAM and CAT. Dr Thompson went to pains to demonstrate that Mirabella CAT and Mirabella YOX were identical to the CAT and YOX described respectively in two articles published prior to the patent: "A Survey of a Group of Phosphors, Based on Hexagonal Aluminate and Gallate Host Lattices" by J M P J Verstegen published in the Journal of the Electrochemical Society (1974) vol 121, no. 12 at 1623-1627 ("first Verstegen") and "A New Generation of 'Deluxe' Fluorescent Lamps, Combining an Efficacy of 80 Lumens/W or More with a Colour Rendering Index of Approximately 85" by J M P J Verstegen, D Radielovic and L E Vrenken, a paper given at a conference in July 1974 and published in the Journal of the Illuminating Engineering Society in January 1975 ("second Verstegen"). In the course of that demonstration, Dr Thompson expressed the opinion that the CAT used by Philips in its lamps was identical to the CAT described in first Verstegen - and, therefore, that used by Mirabella - and that the YOX used by Philips was identical to the YOX described in second Verstegen - and, therefore, that used by Mirabella. Dr Thompson said that the BAM described in both Verstegen articles "fall within the range of compounds included in Philips BAM". The only identicality not propounded by Dr Thompson was that of Mirabella BAM with the BAM described in the articles; and, therefore, with Philips BAM.

In considering what effect should be given to Dr Thompson's criticisms of Mrs Mouws-van Rossum's XRD analysis report, it is pertinent to take into account not only the other material considered by Dr Verhaar but also the fact that no evidence was adduced by the respondent concerning the composition of its luminescent material. It is true, as counsel for the respondent emphasises, that the applicants bear the onus of persuading the Court, upon a balance of probabilities, that the respondent has infringed the patent. But, to the extent that this involves proof of the composition of the respondent's luminescent material, I must take into account the principle in Jones v Dunkel (1959) 101 CLR 298. The composition of its luminescent material is a subject within the knowledge of the respondent or its supplier. The respondent was peculiarly well placed to call evidence about the matter. It chose not to do so. The proper inference from this circumstance is that the respondent believed that evidence concerning the composition of its luminescent material would not assist its case on infringement. This inference, in turn, supports the conclusion that, despite Dr Thompson's criticisms of the XRD analysis, there is no sufficient reason to reject Dr Verhaar's opinion about the composition of the Mirabella luminescent material.
The respondent puts two other matters in relation to infringement. The first concerns the STD tests undertaken by Dr Verhaar. Counsel rightly says that it is an essential integer of each of the claims of the patent that the luminescent material have an STD not exceeding a specified value (5% or 3%) when tested by means of the method and apparatus prescribed by the patent. Unless the Mirabella luminescent material is shown to have been so tested, the infringement claim is not made out. She then puts nine matters: there is no evidence as to the treatment of the Mirabella lamps between the time of their manufacture and their purchase by Philips Lighting for transmission to Eindhoven; there is "no evidence to negate the inference that the lighting of the lamp itself interferes with the STD test;" the procedure of heating the luminescent material, undertaken by Dr Verhaar, does not dispel the potential error from contamination and loss of efficacy from previous burning; the initial decrease when the lamp is turned on differs from the STD as defined in the patent, both in terms of measurement and stability; the material scraped from the Mirabella lamps for testing includes impurities such as electrode materials, carbon or mercury which may interfere with the STD test but there is no evidence as to their effect; the repairing effect of 254 nm radiation has not been measured; the presence of non-phosphor oxides in the Mouws-van Rossum test might affect the STD test results; an error of +0.7 in a mean result of 2.2 represents a potential error of 31.8%; and the experimental error possibilities admitted by Dr Verhaar in cross-examination are inconsistent with a reliability of 95% and a demonstration of an STD not exceeding 3%.
The first comment that should be made about these submissions is that there is no evidence from Mirabella as to the significance of any of the mentioned matters. Counsel for the applicants not unnaturally emphasise this point. In relation to some of the matters, Mirabella was in a position to adduce relevant evidence; so its failure to do so suggests that evidence would not have damaged the applicants' case concerning the STD tests. But in this connection it is necessary to remember that the STD limit stipulated by the patent depends upon the use of the particular apparatus described in the patent. This is apparently special Philips' equipment, not generally available on the market. There is no evidence that Mirabella had access to such equipment, or as to what would be involved in manufacturing, and testing the reliability of, its own equipment. Given the unusual nature of the prescribed STD test, I do not think that I should assume that Mirabella could have conducted its own tests and provided evidence concerning the results.
My second general comment about counsel's nine points is that some of them seem to overlook that the patent specification provides its own STD test. The relevant integers in the claims are not to be read as requiring a maximum 5% or 3% STD when STD is determined by some other method, even some more usual and/or scientifically respectable method. In relation to the issue of infringement, the respondent must take the patent specification as it is, with all the inconveniences and illogicalities (if any) of measuring STD in accordance with a particular method and using particular equipment. To the extent that some of the criticisms point to limitations of the prescribed test, they are irrelevant to the present issue.
Notwithstanding my reservation about Mirabella's ability to conduct its own STD tests, a number of the matters raised by counsel may be disposed of speedily. As to the first objection: it cannot matter whether there was a change in the STD potential between the time of manufacture of the Mirabella lamps and their purchase by Philips personnel. The first applicant is entitled to complain of the sale of a Mirabella lamp having characteristics (including STD) which, at the time of sale, reproduced the patent integers. The second and sixth matters overlap. Counsel says that there is no evidence whether the Mirabella lamps, whose luminescent material was tested, had previously been lit. This is so. But, if previous lighting matters, this is a criticism of the test itself. There is no evidence that it does matter. The case was conducted on the supposition that STD is not cumulative; that, at the moment of illumination, the efficacy of the lamp is much the same as at the moment of any earlier illumination. If this supposition is correct, it would not matter that it is not known whether the Mirabella lamps were illuminated prior to the luminescent material being removed for STD testing. Similarly, the statement that the repairing effect of 254nm radiation has not been measured is true but irrelevant; the prescribed STD test does not require this step.
Counsel's third point arises out of Dr Verhaar's evidence that, after the luminescent material was removed from the Mirabella lamps, it was heated to 400oC for half an hour. Dr Verhaar said in his affidavit that this thermal treatment "removes traces of mercury that may be present on the phosphor particles, and also restores small efficacy losses, resulting from STD, in case a lamp has burned for some time". Counsel says that it is not established that this procedure would restore efficacy losses. I do not accept that view. It was Dr Verhaar's opinion that the thermal treatment would have that effect. He was not contradicted about the matter.
The fourth matter raised by counsel has some relevance to one of her objections to validity. It does not, in my opinion, raise a point regarding infringement. It is really a criticism of the selected test. In his affidavit Dr Verhaar referred to the method of measuring STD:

"20. Because according to the invention, the luminous flux of which the decrease is to be measured is the luminous flux produced by excitation of the luminescent material solely at 254nm, the S TD of the luminescent materials cannot be measured by studying the operation of the Defendant's lamps. Operation of the lamp necessarily exposes the material to radiation of various wavelengths, and particularly to a mixture of 254 and 185nm. To determine the STD as defined in the patent, it is necessary to expose the material in question to radiation only at 254nm and to determine the luminous flux produced, then to expose the material to the prescribed mixture of 254 and 185nm radiation for the prescribed time, and then again to expose the material only to 254nm radiation under identical conditions as initially, and determine the luminous flux then produced. A further reason why the STD cannot be measured by studying lamp operation is that when a gas discharge lamp is first turned on, some time must elapse while the lamp warms up. During this time the discharge increases in its output, so the lamp brightness actually increases."

In terms of infringement, it does not matter that, to use counsel's words, "the initial decrease when the lamp is turned on is different to the STD as defined in the patent". The patent specifies a specific method of measuring STD. If the STD of the Mirabella lamps, measured in accordance with that method, is less than 5%, the relevant integer of Claim 1 is satisfied. In relation to infringement, it does not matter whether or not this measure has any relationship to the practical operation of the lamps.
As to the fifth matter; Dr Verhaar conceded that impurities might affect the test results but he thought that the precautions he took were sufficient to ensure that they would not in fact do so. He was neither challenged nor contradicted on that matter. The same comment applies to the seventh matter raised by counsel: the impurities present in the Mirabella luminescent material, as analysed by Mrs Mouws-van Rossum.
The eighth point is correct, as a matter of arithmetic. But it leads nowhere. Even if one assumes the maximum positive error, lifting the mean average STD of 2.2% to 2.9%, the result is still below the 5% required by Claim 1 and even the 3% required by Claim 2.
The final point of the nine arises out of some evidence of Dr Verhaar in cross-examination. Dr Verhaar said that he calculated, but by reference to only one phosphor, "an experimental effect" of about 1%. This potential error is, apparently, in addition to the variation figure of +0.7%. It apparently stems from the smallness of the sample measured. Counsel interprets Dr Verhaar's reference to one percent as meaning that his maximum figure of 2.9% might more accurately be 3.9%. I am not certain that this is what he meant, as distinct from saying that there might be a one percent variation in the measured STD - that is, +1% of 2.2%. But assuming counsel is right, as she herself says, this would provide no comfort to her client in relation to the infringement of Claim 1; it would only mean that Claim 2 is not shown to be infringed.
Despite my reservations about the application of Jones v Dunkel to this aspect of the case, I do not think that there is substance in any of the nine points listed by counsel in support of her submission that the applicants have not proved that Mirabella's lamps answer the STD requirements of Claim 1.
Counsel puts one other matter in connection with infringement. It involves a question of construction of the patent which is not free from difficulty. Counsel says that, upon their proper interpretation, Claims 1 to 5 each claim only a lamp with a single luminescent material; a "luminescent material" being a single phosphor, a single chemical compound. She argues that it is not an infringement of the patent to put out lamps which use a mixture of three luminescent materials. Claim 1 speaks of a lamp having a luminescent layer which "contains a luminescent material" with defined STD and e.n values. Claims 2 to 5 each pick up that portion of Claim 1.
Counsel for the respondent concedes that the word "contains" is ambiguous; it may mean "comprises", it may mean "includes". But she says that this ambiguity is resolved by resort to the body of the specification where it is made plain that "contains" means "comprises"; and as the patent uses the singular indefinite article, it is referring to a lamp which comprises a single luminescent material. In support of her submission that "contains" means "comprises", counsel refers to page 6 of the specification where there is a description paragraph closely corresponding to Claim 1, but with the difference that it says "the luminescent layer comprises a luminescent material" having the designated characteristics. She also refers to some of the embodiments. One refers to a lamp which "contains as luminescent material", YOX; another to a lamp which "contains a luminescent aluminate", CAT; another to a lamp that "contains a luminescent aluminate", BAM. Counsel suggests that, in each of these contexts, the word "contains" clearly means "comprises". Only one luminescent material is envisaged.
I think it is correct that, in Claim 1, "contains" means "comprises". In addition to the points made by counsel for the respondent, it seems to me that any other interpretation creates a practical difficulty. It is plainly critical to the invention, as described in the patent, that the luminescent layer have an STD and e.n within the values specified in the claims. If the layer's STD or e.n values exceed those specified, it will degrade and the lamp lose luminous flux. It is therefore not enough to specify that the layer include a luminescent material within the designated values. That would not guarantee that the layer itself will be within the designated values; the low STD or e.n value of the luminescent material might be negated or swamped by characteristics of other components in the layer. For the patent to make sense, it seems to me necessary to read it as specifying the maximum values of the layer itself. This is only achieved if one reads the reference to the layer containing a luminescent material with the specified values as comprising such a material.
As it seems to me, the more important question is the meaning of the words "luminescent material". If a mixture having luminescent qualities may be "a luminescent material", within the meaning of the patent, the mixture used in Mirabella lamps falls within the requirement of Claim 1 for a "luminescent layer (which) contains a luminescent material" of the designated values.
Claim 1, read alone, is not inconsistent with the view that "a luminescent material" may be a mixture of phosphors, provided that the mixture, considered as a whole, meets the claim's STD and electro-negativity requirements. The same may be said of Claims 2 to 5, each of which simply pick up the relevant Claim 1 requirement. But when one reaches Claim 6 it becomes apparent that the particular luminescent material then under discussion is not a mixture. It is a particular compound, YOX. Similar statements may be made about Claims 7 and 8, each of which refer to a single compound, CAT and BAM respectively. Claim 9 refers to a "luminescent layer (which) comprises at least a luminescent material of the group consisting of" certain compounds. This claim treats each separate compound as a luminescent material, the totality of which comprise a group of luminescent materials.
The wording of Claims 6 to 9 tends to suggest that, when using the words "luminescent material", the authors of the patent had in mind a single luminescent compound; that is, a single phosphor. But the position is far from clear. A person who merely reads the claims will, in my judgment, be left uncertain whether the term "a luminescent material" was intended to extend to a mixture of luminescent materials. Accordingly, reference may be made to the body of the specification to resolve the matter: see Interlego AG v Toltoys Pty Ltd (1973) 130 CLR 461 at 479 and Rosedale Associated Manufacturers Ltd v Carlton Tyre Saving Co Ltd (1960) RPC 59 at 69. When that reference is made, one finds several examples of the use of the same words, "a luminescent material", without any indication whether or not they may refer to a mixture of compounds. The body of the specification repeats, as embodiments, the substance of the various claims, reproducing the same ambiguity as in the claims themselves. At page 16 the patentees commence the passage that describes the invention itself, with reference to figure 1, and the apparatus for measuring STD, with reference to figure 2. During the course of the latter description, at page 19, the patentees say: "In the manner described above, the short-term decrease of a number of luminescent materials was determined. Table I lists the results of these measurements for a number of luminescent materials which are suitable for use in lamps according to the invention". As I have already indicated, Table I lists ten different compounds. Each compound is treated as a luminescent material. None of the items in the table is a mixture.
The references in examples 11-17 to various compounds each one of which is described as "a ... material", are, perhaps, neutral. But the discussion concerning examples 18, 19 and 20 is revealing. It refers to "a mixture of two luminescent materials, namely (YOX) and (CAT)". In other words, each of these two compounds is "a luminescent material"; the mixture of the two is not itself "a luminescent material". Similarly, examples 27, 28 and 29 relate to "a mixture of three luminescent materials, consisting of 54% by weight of (YOX), 36.5% by weight of (CAT) and 9.5% by weight of (BAM)".
It is, of course, a fundamental of patent law that the width of the claim and the specification is not enlarged or limited by the stated embodiments. The purpose of inserting embodiments in the specification is merely illustrative; to assist the reader to understand the nature of the invention and the form that it might take. The fact that a particular manifestation of the invention is not within a stated embodiment does not mean that it is deprived of protection if it falls within the claim and specification, fairly construed. However, it is not inconsistent with these principles to use the embodiments to clarify an ambiguity in the claims and elsewhere in the body of the specification. The embodiments are part of the specification and the specification must be read as a whole. Any part of the specification may provide the dictionary for particular words. There is a conceptual difference between allowing the scope of the embodiments to affect the ambit of the claims and allowing the language of the embodiments to clarify their meaning. In the present case, it seems to me that the embodiments do clarify the language of the claims, and earlier portions of the body of the specification, in relation to the term "a luminescent material". They show that the patentees used that term to refer only to a single compound. When they wished to refer to a mixture of luminescent compounds they used other language.
So far as I can see, the patentees might just as well have referred to a mixture of luminescent materials in their claims. Provided that, as a whole, it met the specified STD and e.n standards, a mixture of phosphors would serve as well as a single phosphor. But the patentees did not. That is the critical point. As Lord Parker said in Fellows v Thomas William Lench Ltd (1917) 34 RPC 45 at 55: "(A) claiming clause operates as a disclaimer of what is not specifically claimed". See also Shave v H V McKay Massey Harris Pty Ltd (1935) 52 CLR 701 at 709-710 and Electric and Musical Industries Ltd v Lissen Ltd (1938) 56 RPC 23 at 39.
In my opinion, on their proper interpretation, each of the five claims, in respect of which infringement is alleged, relates to a lamp whose envelope bears a luminescent layer comprising a single chemical compound with defined properties. None of them extends to a lamp whose envelope bears a luminescent layer comprising a mixture of luminescent compounds. The luminescent layer in the respondent's lamps comprises a mixture of three compounds. Accordingly, the lamps do not infringe the patent. The principal proceeding should be dismissed.
The cross-claim
The conclusion just expressed is sufficient to dispose of the original dispute between the parties. But the respondent seeks revocation of the patent. That relief is only available if it establishes one or more of the grounds of invalidity alleged in its Further Amended Cross-claim; establishing matter which would make out the relevant ground under both the 1952 Act and the 1990 Act, as stated above. Revocation could become important if, during the life of the patent, the respondent marketed a lamp that contains a single phosphor. Accordingly, I should deal with revocation. Moreover, the respondent argues invalidity as an answer to the applicants' claim of infringement, if all other answers fail. The possibility that I am wrong in regard to the meaning of "luminescent material" is a further reason for dealing with the patent's validity.
Section 40: sufficiency of description and fair basing

"If stainless steel and its properties were known, and many kinds of articles had been made of it, it would not be possible for a man to claim a monopoly for making kitchen sinks of stainless steel merely because he was the first man who ever thought of doing this."

In referring further to the judgment of Morton J., the members of the High Court emphasised his use of the word 'merely". They went on, at 249:

"Many valid patents are for new uses of old things. But it is not an inventive idea for which a monopoly can be claimed to take a substance which is known and used for the making of various articles, and make out of it an article for which its known properties make it suitable, although it has not in fact been used to make that article before."

Turning to the facts of the case before them, their Honours stated at 250 that the specification did not disclose "more than a new use of a particular known product". The specification contained "no suggestion of novelty in relation to the article to be manufactured or the material to be used". The properties of the materials to be used in the manufacture of the articles were well known, as was the fact that those properties made them especially suitable for use in the articles.
The Full Court differed from the view expressed at first instance by Menzies J. His Honour had been influenced by two affidavits referring to factors which had previously caused a general view that the intended materials were not suitable for the intended articles. But the Full Court was unimpressed by this, pointing out that no new discovery in relation to suitability was claimed. At 251 their Honours concluded:

"We have in truth nothing but a claim for the use of a known material in the manufacture of known articles for the purpose of which its known properties make that material suitable. A claim for nothing more than that cannot be subject matter for a patent, and the position cannot be affected either by the fact that nobody thought of doing the thing before, or by the fact that, when somebody did think of doing it, it was found to be a good thing to do."

Counsel for the present respondent contends that Microcell is apposite to the facts of this case. She concedes that the present facts are a little more complicated, in that the patentees have accepted two limitations in their claims (a maximum STD and maximum e.n) which were not already well-known parameters of a useful phosphor. But she says that this does not matter. Pointing out that the specification makes no claim for a compact lamp per se, she suggests that this might have been what the patentees would have wished to claim, but were unable to do so because of the anticipation of that invention in articles published by members of NV Philips' own research staff; "so it (NV Philips) tried to obtain the monopoly by the back-door by not claiming compact lamps as such and referring only to characteristics". Whether or not this is so, counsel says that this is simply a case, like Microcell, where there is "nothing more than a claim for the use of a known material (a phosphor) in the manufacture of known articles (low-pressure mercury vapour discharge lamps) for the purpose for which its known properties (luminescence) make that material suitable". She says that, as in Microcell, it is immaterial that, until recently, it was generally thought that there were problems in using the material for the desired purpose.
Insisting that the introduction of STD and e.n limitations does not amount to a discovery which takes the case outside Microcell, counsel points out that there is no suggestion in either the patent or the evidence that these figures (5% and 3% STD and 1.4 e.n) are other than arbitrary. Counsel concedes that the realisation that the problem about compact lamps lay, not in the efficiency of their conversion of electrical energy into ultra-violet radiation, but in the efficiency of the phosphor, may have been a break-through in the development of compact lamps. But she says that this discovery was not patentable. Neither was the idea of using particular phosphors for low-pressure mercury vapour discharge lamps, including compact lamps. All the phosphors referred to in this case (certainly the three used by Mirabella) were already known to be highly efficient luminescents.
All that Philips did, says counsel, was to experiment amongst phosphors known to have suitable luminescent and visible spectrum qualities and determine STD and e.n parameters which could be met by some of them, being limits which would not lead to significant loss of luminous flux. These limits were then adopted for the purposes of the patent. Counsel says that there is nothing magical about an STD of 5% (or 3%). STD is a well-known phenomenon of all fluorescent lights; obviously, the lower STD the better. But there is no suggestion that a phosphor with an STD of 6% or 10% would be ineffective as a light. It would be a less efficient light. It may, therefore, be less commercially attractive, but it would not lack utility. Similar, if a selected phosphor had an e.n of more than 1.9, it would be attacked by the mercury ions, leading to a further loss of luminous flux. This might be commercially important but would not render the lamp useless.
In support of her submissions on this aspect of the case, counsel draws attention to answers given by Dr Verhaar in response to some questions I asked him in an endeavour to understand the significance of the claimed STDs. I asked Dr Verhaar whether one could obtain the same efficacy by taking a more efficient phosphor and accepting an STD higher than 5%. He replied that, as far as he knew, the phosphors applied in fluorescent lamps and compact fluorescent lamps "are chosen as being the phosphors with the highest efficiencies ... (a)nd most of these and maybe all that are applied to compact lamps have the lowest STD values". The evidence then proceeded:

"So, does that mean that - and I suppose this is only common sense - you seek out the most efficient phosphor as a starting point, you want to get the one that is going to give you the best luminescence when you first charge the lamp and then you discard those which have a high STD?- --That is correct, your Honour, and we look at phosphor, it is only at a certain point when you want to perform lamp tests, when you actually want to make a few experimental lamps that you determine the STD. At that point you determine other properties of the material that are of interest for the actual application in the lamp but first you try to do your best and reach an interesting efficiency and if not across the bridge yet, no, but an interesting efficiency and then you measure the STD and some other parameters that may bother you in operation of the lamp and then you will see if the experimental lamp making should be carried out or not and if the STD is all right. You say well, let's make a few lamps and see what comes out and if there occur no other problems from that moment on but say that the phosphor cannot withstand the lamp making process, in the lamp making process there is a step in which the lamps are heated to 600 degrees centigrade, for instance, and some phosphors do not survive this step, but you make these lamps and you judge their performance. If you don't say well, either the efficiency has to be raised to a high level to compete with the phosphors presently in use, your fault is on the efficiency. Yes. Now, if you take this hypothetical situation that there simply was not a phosphor known that had an STD as low as 5 per cent - say that the best one that you could get was say, 10 per cent?---Yes. Yet you still wanted to end up with the same luminous flux as you get with the present phosphors at 5 per cent, could you do that by increasing the wall loading?---I think, your Honour, if you speak in terms of luminous efficacy, which means lumens as per watts - - - Well, obviously not, it would be more watts, wouldn't it?---If you just increase the wattage of a lamp, the power of a lamp, evidently more light will come out. It depends on the STD and the change in the ratio of 185 to 254, if it is also the efficacy of the energy aspects, the energy friendliness of the lamp which also increases or stays at the same level.

So the answer is yes you can do it, but it would be less energy efficient because it will use more electricity to get the same degree of luminosity?---That is correct, your Honour."

In responding to the respondent's submissions on this aspect of the case, counsel for the applicants point to evidence showing that, at the priority date, compact fluorescent lamps were not in manufacture. Accordingly, they submit, at least insofar as Claims 3 and 4 are concerned, Microcell is inapplicable. Further, they say, in Microcell the relevant properties were well known, "here they were not". They go on:

"There is simply no evidence that the STD properties of any particular phosphor or class of phosphor were well known, or known at all, in Australia at the priority date. There is, further, no evidence that the property of some phosphors having an electronegativity as defined in the specification, of 1.4 or less, was relevant to their behaviour under the sorts of conditions to be encountered in a compact lamp or in a 'highly loaded' lamp."

I do not think that the fact that compact lamps were not in production at the priority date is material to the present question. Neither, as I read the report of the case, were Microcell's rocket projectors. The Court's discussion about new stainless steel products confirms that the circumstance that the relevant article has not previously been manufactured is not decisive of the question of invention or new manufacture.
The other response made by counsel for the applicants is more significant. I think everyone would agree that, if a person discovered a new property in a known material which, for the first time, made it apparent that the material was suitable for a new use, the discovery would amount to an invention and the claim of the patent would be for a manner of new manufacture. But that is not this case. The present patent does not claim the discovery by the patentees of any new property of phosphors, making them suitable for use in highly loaded low-pressure mercury vapour discharge lamps. The luminescent qualities of phosphors had long been known. Indeed, it is the applicants' case on sufficiency of description - which I accept - that the luminescent qualities of the relevant phosphors were so well-known that it was unnecessary to identify the phosphors to be selected for STD testing and e.n evaluation. A mere skilled technician would know which to try. Nor does the patent claim that the patentees discovered that phosphors are subject to STD. This inherent characteristic of phosphors was well-known. Similarly, it was known that mercury ions would attack substances with a higher e.n than mercury (1.9) and zinc, which has an e.n of 1.6. (The only explanation of the patent's selection of 1.4 as the appropriate e.n limit was to stipulate a figure lower than that of zinc.)
The contribution to the art claimed by the patentees - in relation to Claims 1 to 5, the only contribution they claim - is to specify desirable STD and e.n limits for phosphors used in highly loaded lamps. They make no claim that a phosphor whose STD or e.n exceeds one or both of those limits will be unsuitable for use in a highly-loaded lamp; it is just that the lamp will be less efficient than a conventional fluorescent lamp and, presumably, less competitive with incandescent lamps. Neither the patent nor the evidence suggests that the STD and e.n values stipulated in the patent reflect any discovery or new scientific insight by the patentees; rather they were figures chosen to reflect the patentees' judgment as to the degree of efficiency-loss from these two causes which would be commercially acceptable. No doubt the choices were carefully calculated, and I do not doubt that phosphors meeting those parameters have enabled Philips to market a successful product; but the stipulated figures are arbitrary, in the non-pejorative sense of depending upon the will or discretion of the patentees.
During the course of their oral submissions, counsel for the applicants described Claim 1 as "a statement of the criteria to be met by manufacturers to achieve a vendible product. The patent tells people how to make the lamp. They know about phosphors but this tells them in two important respects"; that is, STD and e.n. In support of that position, counsel pointed to evidence establishing that, since the priority date, compact highly-loaded lamps have begun to be manufactured and, especially in recent years, have sold in significant numbers.
There is no doubt about the increasing use of compact highly-loaded lamps. There is some dispute as to its cause. There is evidence that a major factor in the growing popularity of compact lamps is the higher cost of electricity, making their energy-efficiency more important to purchasers. But, be that as it may and accepting the success of the Philips product, it seems to me that it is not an invention, or a manner of new manufacture, for someone to specify the criteria required to be met, in the manufacture of a known product from known materials, in order to achieve vendibility. As was said by Dixon C.J., Kitto and Windeyer JJ. in National Research Development Corporation v Commissioner of Patents (1959) 102 CLR 252 at 262: "Unless invention is found in some new method of using the material or some new adaptation of it so as to serve the new purpose, no valid patent can be granted".
My view about this aspect of the case may be illustrated by an example adapted from one given in argument. Suppose someone invents a new type of motor car engine, the AB engine, which operates on principles different to those of the familiar internal combustion engine. This invention is obviously patentable, whether or not it is competitive with the internal combustion engine. But, suppose further that, as it stands, the AB is not competitive with the internal combustion engine because of poor fuel economy and exhaust emission levels unsatisfactory to regulatory authorities. Someone, the original inventor or somebody else ("O"), tackles these problems and finds that by the use of one of the new CD group of materials its performance can be improved. In fact, with some (but not all) the new materials, the engine will achieve an economy level of X and an emission value of Y, at which standards it is highly competitive with the internal combustion engine. But this inventor does not expressly claim, or even expressly calculate, X or Y. A different person ("P") then claims a patent over all AB engines using a material within the CD group which achieve X and Y. P does not specify which CD materials are likely to achieve that result; that choice is left to the skilled addressee, CD materials being by then well-known within the industry. Could it be said that P's contribution amounts to an "invention" or "manner of new manufacture"? All that P has done is to calculate, and claim a monopoly over, the area of commercial application of the real invention, or series of inventions. If, as the example postulates, O and P are different people, P's action would probably be regarded as outrageous piracy. If O and P were the same person, there would be no such feeling. Nonetheless, this would not affect the conclusion that the final step was not inventive. The inventive work had been previously performed; the problems had already been solved. The last step was no more than a specification of minimum commercial criteria.
The application of this example will be obvious. The AB engine is the compact lamps, the CD group of materials the new phosphors. The factors X and Y are equivalent to STD and e.n. The evidence suggests that much of the work in developing the new phosphors was performed by NV Philips' personnel. The authors of the three most significant pre-priority date articles concerning suitable phosphors were all NV Philips personnel. For all I know, Philips personnel may also have been involved in the discovery that the problem of compact lamp efficiency lay in the area of phosphor choice rather than poor energy conversion. To the extent that Philips personnel were engaged in these important earlier discoveries, it would be understandable if people within NV Philips regard the compact lamp, as it stands, as their invention. But, for reasons not explained by the evidence, no patent was granted over the earlier steps, which were truly inventive. The only patent which has been granted relates to the final step, which merely delineates the commercial boundaries of the inventions already made.
In my opinion, the suggestion that the invention claimed in the patent is not an "invention" or a "manner of new manufacture", is well-founded. The invention is not a "patentable invention" within s.18 of the 1990 Act. Being also within s.100(1)(d) of the 1952 Act, the patent is susceptible to revocation under s.138(3)(b) of the 1990 Act. I propose to so order.
Inutility and lack of novelty
Having regard to the conclusion just expressed, it is not strictly necessary for me to deal with the final two grounds of revocation. I do not propose to do so at normal length, especially as the evidence arising out of the respondent's claim of lack of novelty is both complex and lengthy. However, as both issues were fully argued, I propose to express shortly the conclusions I have reached on these issues.
So far as lack of utility is concerned, it is helpful to begin by reminding oneself of the meaning of that expression in this context. The concept is explained in Terrell on Patents (para. 5.39) in this way:

"Inutility, in the sense in which what word is used in modern patent law and practice, is concerned solely with the scope of the claim, and means that the claim covers a mechanism or a process which is useless for the purposes indicated by the patentee i.e. which does not produce the result or one of the results claimed in the specification. A patent would also be void for inutility if the invention was useless for any purpose whatsoever, but this is a circumstance which is unlikely to occur in practice."

What is required of a patent, for it to be useful, is stated by Lahore and others at para. 1.5.072 of their work "Patents, Designs and Trade Marks Law" in this way:

"What is required is that the invention should enable the addressee to achieve the result claimed by the patentee as being attainable through the use of that invention. If the claimed invention provides a product or process better than what was previously known, as good but cheaper, an alternative method of achieving an old result or it gives the public a useful choice, that is enough. It is not necessary that the invention should be a commercial success unless that is promised by the patentee and it is immaterial, for the purposes of judging utility, that the invention has never been used; it is enough that it could have been."

Logically, the issue of utility does not arise unless the patent is formally valid - meaning, amongst other things, that it sufficiently describes the invention - and describes something which is in truth an invention and a manner of new manufacture. So I approach this issue on that basis, notwithstanding my contrary opinion about the last matter. That means that I have to consider the arguments of counsel on utility on the basis that the mere designation of maximum STD and e.n values constitutes an invention.

The first argument of counsel, in relation to lack of utility, depends upon the fact that Claims 1 to 5 of the patent specification do not identify any particular phosphor. As counsel says, there are many phosphors which would satisfy the patent's STD and e.n requirements which would not be useful for the stated purpose of providing a satisfactory low-pressure mercury vapour discharge lamp. The STD test, she says, teaches nothing about the choice of a suitable luminescent material. Referring to the evidence of Dr Verhaar, already quoted, she says that it is merely one of a series of parameters applied when a particular phosphor is being considered for use in an experimental lamp. Moreover, the patent teaches nothing about phosphor preparation. A phosphor which has acceptable STD when properly prepared may exceed the specification's requirements when poorly prepared. Finally, STD measurement requires special apparatus which may not be available to the addressee.
I do not think that the last submission has any substance. The patent specification describes the apparatus, thus enabling its reproduction by others. It is not a valid objection that it may be difficult or expensive to do this. If someone wishes to use the invention according to the patent - and for this purpose, as explained above, I assume that there is an invention - this is the price to be paid. It may not be worth paying that price; it may be better to forego the benefit of the invention. But, as the extract from Lahore makes plain, utility does not depend upon the commercial attractiveness of the invention.
The two earlier points have more substance. But it seems to me that both are heavily undercut by my view that the specification sufficiently describes the invention. It will be remembered that I expressed the opinion that a skilled addressee would know which phosphors, amongst the range of known phosphors, have the necessary qualities, sufficient luminescence and appropriate visual spectrum, to make them worth testing and would appreciate the necessity for proper preparation. If those views are correct, they also answer the submission now being discussed. Approaching the matter on the basis - contrary to my own opinion - that the patent describes an invention, I reject the contention that it lacks utility.
In relation to novelty, and approaching the matter on the same basis, I reach a similar conclusion. It is true that the evidence establishes the publication before the priority date of a great deal of relevant information. The authors of the paper I previously called "Verstegen 2" referred to the discovery of "a new class of phosphors based on hexagonal aluminate host lattices". They said that "several representatives" of this class were suited to application in fluorescent lamps. The identified phosphors included BAM, CAT and YOX. Reference was made to the "new generation" lamps enabled by the new phosphors, which would be superior both in luminous output and color rendering capability. The authors claimed that an advantage of the new phosphors was their high efficiency at elevated temperatures, making them suitable for high-loaded lamps in which the mercury pressure is amalgam-regulated. The lamp according to the invention is such a lamp. Verstegen 1 gives considerable further detail about the phosphors, as does a 1976 article by another NV Philips' employee, Mr L E Vrenken. Mr Vrenken specifically mentions BAM, CAT and YOX as being "well suited for application in fluorescent lamps". He also makes the point that the new phosphors are suitable for compact lamps:

"The use of the new phosphors is not restricted to 40W T12 lamps. An advantage of the rare earth activated phosphors is their high efficiency at elevated temperatures, which makes them suitable for those situations where the bulb wall temperature is relatively high e.g. with normal lamps in closed luminaires or with highly loaded lamps".

Inasmuch as the essence of the claimed invention is the selection of suitable luminescent material, counsel for the respondent asks: what more was required? She agrees that none of the articles informed the reader that the recommended phosphors had an STD of less than 5% (or 3%) and an e.n of less than 1.4. But she says that this does not matter; whether or not the user was aware of those characteristics he or she would have selected a luminescent material which in fact complied with the requirements of the patent.
The three articles to which I have referred were all available in Australia before the priority date. At the trial there was some discussion about whether they could be read together, for the purposes of the contest on novelty. Counsel for the respondent finally said that she did not seek to do this. Even so, but for two matters, I would be of the opinion that the claimed invention was anticipated by either Verstegen 2 or the Vrenken article, read alone. A reader of either of these articles would clearly understand that the new class of phosphors - and, in particular, BAM, CAT and YOX - were suitable luminescent materials for use in fluorescent lamps, including "highly-loaded" lamps.
Counsel for the applicants submit that a patent is anticipated only where the prior art gives "precise instructions that must inevitably produce the invention in question". Reference is made to General Tyre and Rubber Company v Firestone Tyre and Rubber Company Ltd (1972) RPC 457. In that case, at 485-486, Sachs L.J., on behalf of the United Kingdom Court of Appeal, said in relation to novelty:

"If the prior inventor's publication contains a clear description of, or clear instructions to do or make, something that would infringe the patentee's claim if carried out after the grant of the patentee's patent, the patentee's claim will have been shown to lack the necessary novelty, that is to say, it will have been anticipated. The prior inventor, however, and the patentee may have approached the same device from different starting points and may for this reason, or it may be for other reasons, have so described their devices that it cannot be immediately discerned from a reading of the language which they have respectively used that they have discovered in truth the same device; but if carrying out the directions contained in the prior inventor's publication will inevitably result in something being made or done which, if the patentee's patent were valid, would constitute an infringement of the patentee's claim, this circumstance demonstrates that the patentee's claim has in fact been anticipated. If, on the other hand, the prior publication contains a direction which is capable of being carried out in a manner which would infringe the patentee's claim, but would be at least as likely to be carried out in a way which would not do so, the patentee's claim will not have been anticipated, although it may fail on the ground of obviousness. To anticipate the patentee's claim the prior publication must contain clear and unmistakable directions to do what the patentee claims to have invented: ... A signpost, however clear, upon the road to the patentee's invention will not suffice. The prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee."

Counsel for the applicants point out that none of the prior publications reveal:

(a) the STD or e.n characteristics required by the patent;

(b) the actual wall loading that could be expected in a compact lamp;

(c) how the phosphors referred to in the article alleviate or cure what had traditionally been regarded as a discharge problem; or

(d) the quantum of 185nm radiation to be expected in a compact lamp.

It seems to me that none of points (a), (c) and (d) furnish an answer to the respondent's case on novelty. As to (a), it is true that none of the prior publications specifies an STD or e.n requirement. But, insofar as BAM, CAT and YOX are concerned, this would not matter. They each happen to comply with the STD and e.n criteria specified in the patent. Their use in a 500W/m2 low-pressure mercury vapour discharge lamp, otherwise complying with the description in Claim 1, would furnish an excellent example of what Sachs L.J. called approaching "the same device from different starting points." By carrying out the instructions offered by either Verstegen 2 or the Vrenken article, to use one or more of the phosphors BAM, CAT and YOX, a person would inevitably use a luminescent material with an STD of less than 5%, indeed less than 3%, and an e.n of less than 1.4.
As to (c) and (d) above, it is not to the point that the user may not understand these things; the use of BAM, CAT or YOX or a mixture of two or more of them, would constitute a "reverse infringement" of the relevant integer of the patent.
However, it seems to me that counsel have a good argument in relation to point (b). In that connection, it should be noted that a "highly-loaded" lamp does not necessarily have a wattage to surface area ratio as high as 500 W/m2. The expert evidence establishes that the term is often applied to lamps with a loading as low as 400 W/m2. Although readers of Verstegen 2 or the Vrenken article, seeing the words "highly-loaded", might reasonably speculate that the new phosphors would be suitable for use in 500 W/m2 lamps, they are not told that fact in terms. To apply the words of Sachs LJ, this is a case where there is a clear "signpost upon the road to the patentee's invention", but the flag is not planted at the precise destination.
My second reason for rejecting the respondent's argument relating to novelty arises out of the fact that the phosphors referred to in the three articles are not limited to BAM, CAT and YOX. It would not be right to test anticipation by the facts of this case. The relevant question is whether an implementer of the teaching contained in one of the prior publications would "inevitably" breach the subject patent. If that person used BAM, CAT or YOX, or a mixture of two or more of them, in a 500 W/m2 lamp, the patent would be breached. But, although these three phosphors take the limelight, there are other phosphors amongst the group discussed in the article. As I understand the evidence, they do not all have STD and e.n characteristics within the claims of the patent. So a person could implement the teaching of the prior publication but not transgress the limits of the monopoly claimed in this patent.
In summary, I am of the opinion that the applicants have not established that the respondent has infringed patent no. 523847. I propose to dismiss the Application. Pursuant to the Cross-claim, I propose to declare the patent invalid and order that it be revoked. The applicants must pay the respondent's costs, both of the principal proceeding and the Cross-claim.

[1992] FCA 493

14 JULY 1992