Corning Incorporated v Optix Australia Limited
[1999] APO 46
•2 August 1999
OFFICIAL NOTICE
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Application : No. 661135 in the name of CORNING INCORPORATED
Title: Method and Apparatus for Drawing Optical Fibres
Action: Opposition by OPTIX AUSTRALIA LIMITED under Section 59 of the Patents Act 1990
Decision: Issued .
Abstract
The invention relates to the production of an optical fibre which is drawn from a glass preform heated in a furnace. During the drawing process, a boundary layer of inert gas introduced into the furnace forms adjacent to the fibre which is utilised to symmetrically cool the fibre to a temperature at which its viscosity is high enough to prevent or minimise the generation of differential stresses which can induce fibre bow. This temperature is defined as the "strain point" of the fibre.
The term "strain point" was at the relevant date well recognised in the art as a means of describing the variation in viscosity of a glass with temperature. However, the temperature range said by the specification to correspond to the presently defined strain point extends beyond the conventionally defined strain point of any known glass, and consequently the use of this term was alleged to cause ambiguity.
It was found that the specification had properly invoked the dictionary principle to ascribe a particular meaning to the term "strain point" which prevailed over its conventional meaning (cf Kornelis' Kunsthars Producten Industrie BV v W R Grace & Co 28 IPR 471).
On this basis the specification did not contravene section 40; nor was there for practical purposes any prior disclosure of cooling a drawn fibre to the "strain point" as that term was to be understood in the context of the present specification. The prior disclosure relied on may have provided a "signpost" upon the road to the invention, but it did not take the reader to the "precise destination" (per General Tire & Rubber Co v Firestone Tyre & Rubber Co Ltd [1972] RPC 457). The invention was accordingly found to be novel.
PATENTS ACT 1990
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Re:Patent Application No.661135 in the name of CORNING INCORPORATED and opposition by OPTIX AUSTRALIA LIMITED under Section 59 of the Patents Act 1990
BACKGROUND
Patent application 661135 was filed on 27 April 1993 by Corning Incorporated (Corning) claiming priority from United States patent application 877626 which was filed on 1 May 1992. The present application was advertised accepted on 13 July 1995.
Optix Australia Limited (Optix) filed a notice of opposition to the grant of a patent on 13 October 1995 followed by a statement of grounds and particulars on 16 January 1996. The statement includes the following paragraphs:
"The ambiguities and other Section 40 problems listed here are not deemed to be an exhaustive list, the opponent reserves the right to raise further Section 40 allegations against the opposed specification."
"The opponent also reserves the right to amend the particulars of the opposition as further prior art and relevant information comes to light during the preparation and service of the evidence in respect of this opposition."
On 17 April 1996 a deputy commissioner refused to give directions sought by Corning under regulation 5.10(1) to negate the reservation of rights expressed in these paragraphs. Optix served its evidence in support of the opposition on 12 April 1996. On 19 April 1996 Corning filed a request for leave to amend the complete specification of the present application. Leave was granted and advertised on 7 November 1996, and the amendments subsequently allowed.
Service of the evidence in answer was completed on 18 April 1997 after Corning had been granted a number of extensions of time pending final determination of the request to amend. On 15 May 1997 Optix filed a notice of intention to serve evidence in reply, and duly served that evidence after the grant of an extension of time to 18 October 1997.
On 19 December 1997 Corning applied under regulation 5.10(4) to serve further evidence on the grounds that it wished to address new technical evidence which had allegedly been introduced by the evidence in reply. The application was allowed, but in acceding to a request by Optix a delegate of the Commissioner directed that evidence in response to the further evidence should be filed within 3 months of the date of service of the latter. The further evidence was eventually served on 29 June 1998, and evidence in response on 14 September 1998.
The matter came to hearing in Melbourne on 9 February 1999. Corning was represented by Mr Raymond Evans, assisted by Ms Michelle Hedges, of Phillips Ormonde & Fitzpatrick, Melbourne, and Optix by Mr AJF Ward, of Griffith Hack, Melbourne. Mr Akihhiko Mizutani, a declarant for Optix, was also in attendance.
THE SPECIFICATION
The specification commences by indicating that the invention relates to a method and apparatus for drawing an optical waveguide fibre from an optical waveguide preform.
The specification states that it has long been recognised that dimensional variations in optical waveguide fibres significantly impact optical properties, and as early as 1978 it was acknowledged that fibre diameter variations would need to be reduced to compete with traditional copper twisted wire pairs in the telecommunications market.
Methods and devices for drawing optical waveguide fibres from optical waveguide preforms are apparently well known in the art. The devices typically consist of a heat source for softening the preform, a fibre diameter measurement device, a unit for applying protective coatings to the fibre, and a fibre take up unit. The cleanliness of these devices has been improved by the introduction of gas flows into the heat source or furnace. This gas flow flushes fine particles produced in the draw furnace which can adhere to the fibre and reduce fibre strength. The gas flow also prevents updrafts of ambient air from entering the furnace. However, the introduction of the gas causes diameter variations in the fibre if the gas is not uniformly heated when it reaches the tip of the preform from which fibre is drawn.
It has been found that the presence in the draw furnace of a gas such as helium may stabilise the temperature at the tip of the preform. During the drawing process, a boundary layer of helium (or other gas used in the furnace) forms adjacent to the fibre surface. This boundary layer will travel with the fibre through the exit of the furnace and provide substantially symmetric temperatures around the circumference of the fibre so long as the layer remains intact.
The specification next expresses Corning's belief that the disruption of the boundary layer by currents in the ambient atmosphere contributes to differential cooling which in turn can lead to fibre bending or "bow", or diameter oscillations. The specification continues as follows:
"We believe that bow results from differential cooling of the fiber before the viscosity of the cladding layer of the fiber is high enough to substantially prevent differential stresses in the drawn fiber. As a fiber cools, the cladding layer cools rapidly relative to the core region. This rapid cooling of the cladding layer induces high tensile stresses into the cladding layer of the fiber. Any differential cooling of the cladding layer before the viscosity is high enough to minimize differential stresses in the cladding layer will result in tensile stresses which are not uniformly distributed around the circumference of the fiber, thereby inducing bow."
This bow causes difficulty when the fibre is spliced to other fibres (particularly in ribbon fibre applications), resulting in high loss splices which are detrimental to the overall performance of an optical fibre-based telecommunications system. Furthermore, the diameter oscillations act to conceal an imperfection in the fibre known as an "airline" which is a hole identified by a sudden change of small magnitude in fibre diameter.
The invention seeks to overcome or at least alleviate one or more of the problems discussed above.
The specification ends with sixteen claims in all, of which the independent claims read as follows:
"1. An apparatus for drawing an optical waveguide fiber having minimal fiber bow, from an optical waveguide preform said fiber including a cladding having a strain point as herein defined, said apparatus including:
a) a furnace including a muffle having an inner diameter, for heating one end of
said preform to its softening temperature;b) means for drawing said fiber;
c) means for supporting said preform in said furnace which provide for relative
movement between said preform and said muffle; andd) means for symmetrically cooling said fiber to said strain point as it is being
drawn from said heated end of said preform to reduce fiber bow caused by
differential cooling of said fiber, said means including:(i) an upper muffle extension connected to an upper part of said muffle in a
manner sufficient to provide a gas tight seal against an ambient atmosphere
exterior to said furnace, said upper muffle extension including an inlet for
allowing an inert gas to enter into a top region of said upper muffle
extension;(ii) a tube sealingly connected to a lower part of said muffle in a manner
sufficient to provide a gas tight seal against said ambient atmosphere,
such that in use, an unobstructed flow of a boundary layer of said gas
is provided adjacent said fiber as it is being drawn, said boundary layer
cooling substantially symmetrically and thereby circumferentially
cooling said fiber in a substantially symmetrical manner, as said fiber and
said boundary layer travel through said tube; and(iii) a flow isolator connected to said tube at a bottom opening thereof for
isolating said drawn fiber and said boundary layer of gas from said
ambient atmosphere until said fiber is at or below said strain point.7. An apparatus for drawing an optical waveguide fiber having minimal fiber bow from an optical waveguide preform, said fiber including a cladding having a strain point as herein defined, said apparatus including:
a) a furnace including a muffle having an inner diameter, for heating one end of said
preform to its softening temperature;b) means for drawing said fiber;
c) means for supporting said preform in said furnace which provide for relative
movement between said preform and said muffle; andd) means for symmetrically cooling said fiber to said strain point as it is being drawn
from said heated end of said preform to reduce fiber bow caused by differential
cooling of said fiber, said means includingi) an upper muffle extension connected to an upper part of said muffle in a manner
sufficient to provide a gas tight seal against an ambient atmosphere exterior to
said furnace, said upper muffle extension including an inlet for allowing an inert
gas to enter into a top region of said upper muffle extension;ii) a tube having an outside diameter less than the inner diameter of said muffle, and
having an open upper end and an open lower end wherein said open upper end
extends into an open lower end of said muffle such that in use, an
unobstructed flow of a boundary layer of said gas is provided adjacent said fiber
as it is being drawn through said muffle and said tube through the bottom
opening of said tube, said boundary layer cooling substantially symmetrically
and thereby circumferentially cooling said fiber in a substantially symmetrical
manner, as said fiber and said boundary layer travel through said tube; andiii) a flow isolator located in the open lower end of said tube for isolating said
drawn fiber and said boundary layer of gas from said ambient atmosphere
until said fiber is at or below said strain point.11. A method for drawing optical waveguide fiber having minimal fiber bow, from an optical waveguide preform, said fiber including a cladding having a strain point as herein defined, said method having the steps of:
heating one end of said preform to its softening temperature in a furnace;
exposing said heated preform to an inert gas atmosphere in the furnace;
drawing said fiber from the heated end of said preform into a cooling chamber attached to the furnace and out a fiber outlet of said cooling chamber, said cooling chamber fluidly communicating with the furnace, wherein a uniform boundary layer of said inert gas is adjacent the fiber as it is being drawn, said uniform boundary layer cooling substantially symmetrically, and thereby circumferentially cooling said fiber to said strain point in a substantially symmetrical manner, as said fiber and said boundary layer travel through said cooling chamber; and
isolating said inert gas atmosphere in said cooling chamber from an ambient atmosphere outside of said furnace by constricting the opening at the fiber outlet of said cooling chamber and by utilizing the inert gas flow between the furnace and the cooling chamber."
The specification defines the term "strain point" as being the temperature at which the fibre cladding has a viscosity that is high enough to minimise, or substantially prevent, fibre bow due to differential stresses.
The specification contains a detailed discussion of preferred aspects of the invention which are described with reference to a single sheet of drawings. The flow isolator shown by these may for example comprise shutters or an adjustable iris. The specification explains that moving the flow isolator into close proximity to the fibre will substantially isolate the tube or extension at the lower part of the muffle from the ambient atmosphere to thereby prevent differential cooling of the fibre before the viscosity of the cladding layer of the fibre is high enough to minimise or substantially prevent differential stresses therein.
STATEMENT OF GROUNDS AND PARTICULARS
The statement of grounds and particulars lists four grounds of opposition: non-compliance with paragraph 18(1)(a) (manner of manufacture), paragraph 18(1)(b)(i) (novelty), paragraph 18(1)(b)(ii) (inventive step) and section 40 of the Act, and provides a number of particulars in support of each ground. In essence, the statement sets out the case for Optix
in the following terms:
1) The claimed invention is not a manner of manufacture, is not novel, and does not involve an
inventive step having regard to the following documents:
Japanese patent applications 1-275443, 1-192741, 1-192740 and 62-246837;
United States patents 5160359, 5059229, 4988374, 4763427, 4594088, 4514205, 4437870, 4400190, 4208200, 4154592 and 4126436;
European application 0321182;
Australian patent 605656; and
An article entitled "Optical Fiber Drawing Techniques" by Montierth published in 1978 in Optical Spectra at pages 42 to 48
2) The claims do not define the invention and are unclear due to a number of listed ambiguities.
THE EVIDENCE
Evidence in Support
The evidence filed in support of the opposition consists of statutory declarations by:
Susumu Noji with Exhibits SN-1 to SN-6
Antony John Fowler Ward with Exhibits AJFW-1 to AJFW-3
Mr Noji states that from 1983 to 1993 he was employed by Sumitomo Electric Industries of Japan (Sumitomo), and between 1990 and 1993 was the manager of its optical fibre plant. In 1994 he was seconded to Optix as Technical Manager.
Mr Noji exhibits a number of the prior art documents in the name of Sumitomo which are listed in the statement of grounds and particulars.
Evidence in Answer
The evidence in answer consists of statutory declarations by:
Professor David John Booth with Exhibits DJB1 to DJB10
Ron Bailey with Exhibits RB-1 and RB-2
Tony Cargnelutti
Ngaire Ann Pettit-Young
Suresh T. Gulati with Exhibit STG-1
Professor Booth is presently the Director of the Optical Technology Research Laboratory at Victoria University. He has acquired considerable experience in Australia as a researcher and lecturer in the fields of lasers and applied optics generally, and has worked continuously in the field of fibre optics since 1988. Professor Booth provides a brief but instructive overview of glass technology.
Ms Pettit-Young and Mr Cargnelutti attest to the public availability before the relevant date of the various textbooks referred to in evidence by Professor Booth.
Mr Bailey states that from 1990 he has been employed as Fabrication Manager with Australian Photonics CRC/OFTC where he is involved in the manufacture of fibre preforms and various types of optical fibres. He is also responsible for the maintenance and operation of fibre drawing apparatus. Mr Bailey is generally supportive of Professor Booth's evidence.
Dr Gulati joined Corning in 1967 as a senior research scientist in mathematics and mechanics. In 1974 he became a research associate in physical properties, advancing to senior research associate in 1979. He was named a Corning research fellow in 1983 and his research duties involve glass blanks which are to be used in the manufacture of optical fibres.
Evidence in Reply
The evidence in reply consists of statutory declarations by:
Ichiro Yoshimura with Exhibit IY-1
Susumu Noji
Mark G Sceats with Exhibits MGS-1 and MGS-2
Dr Sceats has held the position of Chief Executive Officer of Australian Photonics Cooperative Research Centre since 1994. He has many years of interdisciplinary research experience, and is the senior author of a number of commissioned review articles, more recently in the area of optical fibre technology. After some theoretical discussion of glass technology, Dr Sceats sets out his replies to a number of questions put to him by Mr Ward.
Mr Yoshimura was between 1985 and 1992 involved with the research and development of optical fibre drawing and is in fact named as inventor by JP 1-275443 which, as I have indicated above, is a document listed in the statement of grounds and particulars.
Further Evidence
The further evidence filed by Corning consists of statutory declarations by:
Suresh T. Gulati with Exhibits STG2 to STG5
Professor David John Booth with Exhibits DJB11 to DJB14
Evidence in Response
The evidence filed by Optix in response to the further evidence consists of a statutory declaration by Akihiko Mizutani.
From September 1995 to March 1998 Mr Mizutani held the position of Consultant Engineer with Optix, and is currently its Technical Manager. He worked with Sumitomo between 1985 and 1995 in the production of optical fibres.
I will refer to the substance of the evidence where appropriate in my decision.
DECISION
Procedural Issues
During the course of the hearing a number of procedural issues arose which I will now consider in their turn.
Grounds of opposition
At the commencement of the hearing I pointed out that although the statement of grounds and particulars had invoked the grounds of opposition available under paragraphs 18(1)(a) and 18(1)(b)(ii), Optix could not rely on either ground in the absence of any material facts on which they were based (Mobay Corp v The Dow Chemical Company Co 24 IPR 379). In response Mr Ward advised that Optix would only be pursuing the grounds of want of novelty and non-compliance with section 40.
As a further issue, I noted that the offending wording identified for the latter ground does not appear in the claims in their current form, ie. as amended following acceptance of the application. Mr Ward agreed but indicated that Optix still wished to avail itself of this ground of opposition for the reason that the use of the term "strain point" in the amended claims gave rise to matters of construction not present at the time of acceptance. Indeed it is evident from the material before me that the interpretation to be placed on this term in the context of the amended specification is also central to the remaining ground of opposition pursued.
Admissibility of certain evidence
Mr Ward advised that in arguing the opposition ground of want of novelty Optix intended to rely on JP 1-275443 (the '443 specification) alone.
Mr Evans submitted that the English translation of this document which is exhibited to the Noji and Ward declarations served as evidence in support (see exhibit SN-6 or AJFW-3) has not been properly verified, and therefore was not admissible as evidence.
I am not convinced by this line of argument since although neither exhibit is accompanied by a related certificate of verification, the fact that these documents have been put before me by way of declaratory evidence is, in my opinion, sufficient proof that either may be regarded as an accurate translation from the Japanese language.
Weight of evidence
It is clear from the material before me that the issues to be decided go to the construction of the present specification and also the '443 specification.
The construction of a specification is ultimately the responsibility of the Commissioner's delegate hearing the matter. However, to quote from Blanco White, Fourth Edition, 2-201:
"As with any other document, questions of construction of a patent specification, arising in legal proceedings, are for the court to decide as a matter of law; for this purpose the court must first instruct itself as to the technical matters involved, so as to place itself in the position of one acquainted with the art concerned - in the position, that is, of a person to whom the specification is addressed."
Mr Evans submitted that a number of declarants were not qualified to comment on the state of the art in Australia before the priority date and, as a consequence, their evidence so far as it relates to issues of construction should be weighted accordingly. Specifically, only Professor Booth and Mr Bailey for Corning, and Dr Sceats for Optix, belonged to the category of skilled worker in the art in Australia.
This was not disputed by Mr Ward and in any event I find myself in agreement with Mr Evans since the evidence of Messrs Noji and Mizutani indicates that neither declarant acquired experience in the art in Australia until well after the priority date, while Dr Gulati's experience seems to have been confined to the United States. Mr Yoshimara also lacks relevant experience in Australia but I do not think his evidence can be entirely disregarded as argued by Mr Evans given the former's role as inventor of the subject matter disclosed by the '443 specification.
Substantive Issues
I now turn to the grounds of opposition which Optix wishes to pursue, namely, want of novelty and non-compliance with section 40. Given the general tenor of the submissions put to me at the hearing it is in my opinion appropriate to consider whether the specification complies with section 40 before proceeding to the question of novelty.
Section 40
Mr Ward firstly took me to the specification prior to amendment where in the independent claims it was said that the fibre is cooled to a temperature at which the cladding layer of the fibre is high enough to substantially prevent differential stresses in the cladding layer. He also drew attention to a number of the dependent claims which stated that the fibre is cooled to a specified range of exit temperatures.
Mr Ward submitted that it was not clear if the exit temperature now defined by the reference to "strain point" lies within this range, or whether the new definition was intended to embrace some other temperature.
For his part Mr Evans submitted that as "strain point" was a term of art its use in the amended specification did not lead to any ambiguity.
There seems no doubt from the evidence that the term "strain point" is well recognised in the relevant field. As explained by Professor Booth, a number of standard or fixed points have been defined to aid in the description of the variation in viscosity of a glass with temperature. These points include both "strain point" and "softening point", and are essentially defined in terms of the temperature at which a particular viscosity is achieved. The softening point corresponds to a viscosity of 107.6 Poise and the strain point to 1014.5 Poise. Professor Booth further explains that the strain point of a glass is qualitatively defined as the temperature below which the rate of cooling can be increased (for example by exposure to ambient atmosphere) without introducing thermal stress.
However on my understanding of the matter, Mr Ward's real concern does not turn on whether "strain point" may be regarded as a term of art, but instead resides in the contention that the meaning ascribed to this term by the present specification does not equate with the conventional meaning as understood by those skilled in the art of glass technology.
As already mentioned, the specification defines the term "strain point" as being the temperature at which the fibre cladding has a viscosity that is high enough to minimise, or substantially prevent, fibre bow due to differential stresses. According to Professor Booth and Mr Bailey, this definition is not inconsistent with the conventional definition and thus in its present context "strain point" would represent a temperature which is similar in value to that which corresponds to the conventionally-defined strain point.
This assertion does not, however, take account of the omission by the conventional definition of strain point discussed by Professor Booth of any specific reference to fibre bow. Moreover, in referring to the temperature utilised to give effect to the present invention, the specification on page 10 states:
"As the boundary layer flows through extension 30, it gradually cools in a substantially symmetric manner, thereby cooling fiber 11 in a substantially symmetric manner. We believe that fiber 11 need only be cooled to a temperature in the range of 1000 to 1300oC to ensure that the viscosity of the cladding layer of the fibre is high enough to substantially prevent differential stresses in the cladding layer of the fibre."
and continues on page 11 as follows:
"We believe that substantially symmetric cooling of the fiber will minimize the differential stresses induced in the fiber, thereby minimizing bow due to differential stresses."
The clear inference to be drawn from these statements is that the temperature represented by the presently defined strain point is between 1000oC and 1300oC. The issue which then emerges, and which is central to Mr Ward's line of attack, is that this temperature range is said by Optix to go beyond the strain point of any known glass found in the cladding of optical fibres.
Professor Booth has argued that as the strain point of a glass is dependent on its composition, absolute values of temperature said to correspond to this point are largely meaningless without knowing the composition of the glass. This variation in strain point with composition is corroborated by exhibit DJB6 and also Dr Sceats who notes that while pure silica glass which is used in the cladding of most optical fibres has a strain point of 1108oC, the strain point of germanosilicate glass occurs at a considerably lower temperature.
The present specification does not refer to any particular glass composition and there was some debate between the parties as to whether it could be implied that a pure silica glass was envisaged, in which case the temperature range of 1000oC to 1300oC disclosed by the specification would fall outside the conventional strain point of 1108oC, or whether this discrepancy simply pointed to the use of a glass which had been doped with additives.
It is common ground that the characteristics of an optical fibre having a pure silica cladding may be modified through the addition of a variety of dopants including oxides of germanium, boron or fluorine. However, Dr Sceats goes on to say that when any of these additives are substituted for silicon, the viscosity of the resultant multicomponent glass is lowered at all temperatures such that the strain point is lower than that for silica glass. Dr Sceats has restated this evidence as indicated below when responding to the following question which was put to him by Mr Ward:
"Are there any glasses commonly used in optical fibres that have strain points between 1100oC and 1300oC?
The strain points of glasses used in optical fibres are less than 1108oC. I am not aware of any glasses used in optical fibres which have strain points above 1108oC."
I consider Dr Sceats' evidence in this regard to be prima facie credible given his standing as an independent expert witness as acknowledged by Mr Evans, and it is also relevant to note here that this evidence has not been challenged by any of the declarants for Corning even though they have had the opportunity to do so.
On this basis I conclude that the practice of doping the cladding of optical fibres would not lead to an increase in strain point above 1108oC, since the uncontested evidence of Dr Sceats establishes that the only known effect of this practice is to reduce the strain point to a temperature below that for pure (ie. undoped) silica glass. Accordingly, I find that the term "strain point" does not in the conventional language of glass technology embrace the full temperature range disclosed by the present specification.
However, this is not to say that "strain point" as presently used is necessarily misleading since it is well settled in patent law that the ordinarily recognised meaning of words appearing in a claim may not be their true meaning when read in the light of a dictionary found elsewhere in the specification. The nature of this so-called dictionary principle is reflected in British Thomson-Houston Company Ld vCorona Lamp Works Ld 39 RPC 49 at 67, where Viscount Haldane said:
"We have to scan the Specification with the closeness which is required in the case of any instrument conferring a monopoly, but, subject to this, all we can legitimately do is apply the ordinary rules for the construction of written instruments. One of these, which is relevant in the case before us, is that the instrument must be read as a whole. The Claiming Clauses, for example, are not to be taken as standing in complete isolation. For if the Patentee has used in these clauses expressions which he has already adequately interpreted in the body of his Specification, he is entitled to refer to the Specification as a dictionary in which the meaning of the words he uses has been defined."
It must be clear that the specification is setting up a dictionary: see for example Minerals Separation North American Corporation v NorandaMines Ltd 69 RPC 81 and Kornelis' KunstharsProducten Industrie BVv W R Grace & Co 28 IPR 471. Although the latter case relates to the allowability of amendments under section 102, it is nevertheless of particular assistance in the present circumstances where the primary issue is essentially the same, namely, whether the specification has plainly indicated that a special meaning is to apply which prevails over the ordinary meaning of "strain point".
The invention claimed in Kornelis' was a method of producing a closure cap which involved exposing the cap to heating by microwave energy. It was urged against the applicant that the amendments sought to be made were not allowable since they would have the effect of introducing claims to a frequency range not normally described by the word "microwave". The applicant argued in response that the specification provided its own dictionary, making plain that the meaning of "microwave" embraced heating which utilised the frequencies in dispute.
In considering this question Burchett J emphasised the importance of using the body of the specification as a context for the understanding of an expression in a claim. The point made here was that this approach did not seek to impermissibly vary or qualify the plain meaning of the claim by adding glosses drawn from other parts of the specification, but instead followed the accepted rule that in interpreting a claim the specification must be read as a whole (see Décor Corporation PtyLtd v Dart Industries Inc 13 IPR 385 and BTH v Corona cited above).
When these principles are applied to the construction of the present specification there can be no doubt that the term "strain point" is to be understood in a special sense throughout the specification, including the claims.
On amended page 7a the term is defined for the purpose of the specification as being the temperature at which the fibre cladding has a viscosity that is high enough to minimise, or substantially prevent, fibre bow due to differential stresses. According to Professor Booth, this explicit definition involves a "very similar" concept to the conventional definition of strain point. Although there is evidence to support this view, the distinction remains that the strain point of a glass is not conventionally defined in terms of fibre bow. This difference alone would appear significant given Professor Booth's admission that he was not aware of the bowing effect.
However, if anything more were needed to compel the reader to adopt a special meaning, the specification between pages 10 and 12 states that in performing the invention the fibre is cooled to a temperature in the range of 1000oC to 1300oC to ensure that the viscosity of the cladding layer is high enough to minimise or substantially prevent fibre bow due to differential stresses. Thus when the definition in the earlier part of the specification is read in the light of these later statements it seems plain beyond further argument that "strain point" is used in the present context as including a temperature range not ordinarily described by that term. In stating this I have not overlooked the fact that a temperature of 1000oC could conceivably be representative of the conventional strain point of a glass to which one or more dopants have been added. However, I am also satisfied on the evidence that the upper limit (viz. 1300oC) of this temperature range is considerably higher than the conventional strain point of any known glass, whether doped or otherwise.
Accordingly, I find that the intention to use the term "strain point" in a way which overrides its recognised meaning as a term of art has been made plain to those who read the specification.
Mr Ward raised the further argument that the result "to substantially prevent differential stresses in the cladding layer" specified by the accepted claims had subsequently been expanded by amendment to include the alternatives "to minimise, or substantially prevent, …" (emphasis added) in the claims now under consideration. While this appears to be a criticism of the amendment itself, which of course is not a valid ground of objection in the present proceeding, it is in my opinion clear from the specification (see pages 2, 3 and 11) that both alternatives are fairly contemplated by the invention.
In view of the foregoing, I hold that Optix has not established the ground of non-compliance with section 40.
Novelty
The test for novelty is whether an alleged anticipation is the same in substance as the claim in suit so that the alleged anticipation would, if the patent were valid, constitute an infringement (NicaroHoldings Pty Ltd v Martin Engineering (1990) 91 ALR 513). This test is commonly referred to as the reverse infringement test which was formulated by Aiken J in Meyers Taylor Pty Ltd v Vicarr
Industries Ltd (1977) CLR 228.
As already mentioned, the ground of want of novelty was pursued by Optix only on the basis of the '443 specification.
This specification discloses with reference to Fig 1 an optical fibre draw furnace having a cylindrical partition wall which extends below a core pipe or muffle. A disk-like shutter is installed in the lower end of the partition wall which comprises a central outlet for discharging a drawn fibre from the furnace body, and a series of further outlets in its outer periphery. The shutter is divided into a pair of shutter portions which can be opened or closed to (presumably) vary the size of the central outlet in like manner to an adjustable iris. The specification refers to the introduction of an inert gas or air into an upper region of the muffle and thus, contrary to the submissions of Mr Evans, provides "clear and unmistakable directions" (per Flour Oxidising Co Ltd v Carr & Co Ltd 25 RPC 428) to use inert gas as an alternative to air. I believe this interpretation to be consistent with what the specification would convey to the skilled reader since Corning's own declarants have indicated that an inert gas atmosphere is commonly employed in the field of the invention.
Although not entirely clear on the matter, it seems from the '443 specification that the inert gas flows along the fibre to be discharged through the peripherally located outlets in the shutter without the occurrence of turbulent flow so as to prevent dust particles from adhering to the fibre, thereby reducing its strength. The elimination of turbulent flow also allows the fibre to cool to below the softening temperature before being discharged through the central shutter opening which the specification says decreases fluctuations in outside diameter. By way of example, the fibre may be cooled by the gas flow to a temperature of 1000oC or 1200oC.
Mr Noji has submitted in evidence that the partition wall and shutter disclosed by the '443 specification operate in similar fashion to the tube and flow isolator, respectively, of the claimed invention. I agree but this similarity does not lead to the overall "structural equivalence" pressed by Mr Ward since the '443 specification fails to disclose the upper muffle extension characterised by apparatus claims 1 and 7. Furthermore, the partition wall is not sealingly connected nor extends into the lower end of the muffle as individually required by these claims. I am, however, conscious of the fact that method claim 11 makes no reference to any of the aforementioned features.
The evidence for Optix also focuses on the statement made in the '443 specification that the drawn fibre is cooled to below the softening temperature.
It will be recalled from the evidence of Professor Booth that in addition to "strain point", the term "softening point" is used to describe the variation in viscosity of a glass with temperature. The viscosities corresponding to these points differ significantly (by approximately 107 poise) such that the temperature represented by the softening point of any glass is considerably higher than that represented by its strain point.
Optix relies on this known relationship to support the contention that because the fibre is in accordance with the '443 specification cooled to a temperature below the softening temperature, it must exit the furnace at a temperature approaching the strain point. This is demonstrated (it is said) by the overlap between the exit temperatures of 1000oC and 1200oC disclosed by the '443 specification and the presently disclosed exit temperature range of 1000oC to 1300oC.
In response the declarants for Corning consistently point to the lack of any express disclosure of cooling to a temperature at or below the strain point, notwithstanding the overlap in exit temperatures which they assert is inconclusive in the absence of information regarding the glass compositions involved. As stated for example by Mr Bailey:
"… the disclosure in JPA'443 of actual temperature values does not by itself indicate whether the strain point has been reached because the value of the strain point for a particular glass is dependent on glass composition … In fact, the clear implication in JPA'443 is that the strain point is not reached prior to exiting the furnace because JPA'443 is concerned only with cooling to below the softening point."
To take the last point first, the case put by Optix seems to equate "softening temperature" referred to in the '443 specification with the term of art "softening point". Mr Yoshimura (the inventor associated with this specification) has declared that:
"In referring to 'softening temperature', I did not mean the precise 'softening point' as used in glass science …"
However, the relevant consideration here is not what the inventor meant, but rather what the addressee would have understood him to mean (per Osram Lamp Works Ltd v Pope's Electric Lamp Co Ltd 34 RPC 369). In the present circumstances even the declarants for Corning have exchanged "softening point" for "softening temperature" in their evidence without any attempt to distinguish one term from the other, which leads me to conclude that these terms are recognised as having the same meaning in the field of glass technology.
Moving to the next point made by Optix, I have already referred to the dependency of strain point on glass composition and there is evidence from both parties to show that the addition of dopants may reduce the strain point of a glass to below the exit temperature of 1000oC disclosed by the '443 specification. Nevertheless, there is nothing in either the present specification or the '443 specification to suggest that their disclosures relate to different glass compositions, or indeed that anything other than pure silica glass was envisaged.
Whatever the situation may be, I do not believe that this line of argument assists either party since it is based on the conventional meaning of "strain point" which, as I have previously found, is displaced by the dictionary meaning given to that term by the present specification.
This brings me to the overlap in exit temperatures which Optix submits "points to both disclosures producing the same result".
In essence this submission goes to the question of whether for the purposes of practical utility the information contained in the '443 specification is equal to that provided by the present specification (per Hill v Evans (1862) 31 LJ Ch 457). The concept of "practical utility" was also considered in General Tire & Rubber Co v Firestone Tyre & Rubber Co Ltd [1972] RPC 457 at 485-6 where it was said:
" … 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 … 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."
One implication of this requirement is that an earlier document will only deprive a subsequent invention of novelty if it achieves the same result as the later invention (see eg. Beecham Group Ltd's (Amoxycillin) Application [1980] RPC 261).
According to Professor Booth, the problem to which the '443 specification is directed is not the same as that addressed by the present specification since:
"The JPA'443 document is directed to reducing fluctuations in the diameter and to enhance tensile strength of optical fibres. On the other hand the opposed specification is directed to reduction or elimination of fibre bow. While variations in fibre bow may affect fibre diameter, it is not the same as variations in fibre diameter. The existence of fibre bow can detrimentally affect other fibre properties, as is discussed in the opposed application."
This evidence has been confirmed by Mr Bailey. Dr Sceats has surprisingly said nothing on the matter and thus in pursuing this ground of opposition Optix principally relies on the uncorroborated evidence of Mr Nori. The main thrust of Mr Nori's analysis of the '443 specification is found in his evidence in reply as follows:
"7. … it is quite clear from a number of disclosures in JP'443 that non-turbulent or uniform cooling is envisaged. There are many references to uniform gas flow and no turbulent flow and it is clear to me and I believe that it would be clear to others skilled in this art that this type of flow is the very laminar or boundary layer flow that produces symmetrical cooling of the kind referred to by the applicant's declarants.
8. If JP'443 produces symmetrical cooling the only remaining concern is that the fibre is cooled sufficiently so that the differential stresses are not created once it escapes to the atmosphere. Whilst JP'443 makes no reference to strain point, there are frequent references to cooling the fibre to a temperature below the softening temperature. This disclosure coupled with … exit temperatures of 1000oC and 1200oC clearly points, in my opinion, to the fibre exiting the apparatus at a temperature that is sufficiently low to prevent differential stresses and bow.
9. On page 4 lines 8 to 11 of the opposed application, I note the following passage:
'We believe that the disruption of the boundary layer by currents in the ambient
atmosphere contributes to the differential cooling which can lead to fibre bow
or diameter oscillation.'The applicant's declarants argue that JP'443 only relates to diameter oscillation. However, I note that the patent applicant appears to be inferring that the differential cooling is relevant to either of fibre bow or diameter oscillation. I thus fail to see how the patent applicant can argue that the Sumitomo apparatus has no relevance to fibre bow."
It is true that the present specification discusses the problem of diameter oscillation caused by differential cooling of the fibre by turbulent flow. However, it is abundantly clear that this is not the full extent of the adverse effects of differential cooling with which the specification is concerned.
As pointed out by Mr Evans, the aim of the present invention is ultimately to prevent or minimise the occurrence of fibre bow which results from differential cooling of the fibre before the viscosity of the cladding layer of the fibre is high enough to substantially prevent or minimise differential stresses in the fibre. The invention meets this objective by proposing even cooling about the circumference of the drawn fibre until the fibre reaches a temperature which corresponds to the "strain point" as defined by the present specification. This even cooling is in turn achieved by the use of an inert gas atmosphere to form a stable boundary layer which flows adjacent to and symmetrically cools the fibre.
Mr Noji and Mr Ward have both drawn attention to the following passage on page 7 of the '443 specification:
"… when the optical fiber is drawn with the inert gas … the inert gas forms a clean and uniform downward atmospheric gas flow … and is then discharged … without forming a turbulent flow. The optical fiber 11 thus drawn in such a [sic] atmospheric gas flow is cooled down to a point below the softening temperature …"
and argue that the "clean and uniform" gas flow disclosed by this passage is equivalent to the boundary layer generated in accordance with the present invention.
The disclosure of a boundary layer as such is not disputed on behalf of Corning. Mr Bailey, however, submits that there are no directions in the '443 specification to cool the boundary layer, and thereby the fibre, in a symmetrical manner. I agree that this feature is not explicitly disclosed by the '443 specification but note with interest the explanation on page 4 of the present specification that symmetrical cooling can occur "so long as the boundary layer remains intact". I have previously mentioned that the '443 specification aims in part to decrease variations in diameter by eliminating turbulent flow and this it does with the assistance of the shutter which prevents the ambient atmosphere from entering the exit end of the partition wall and disrupting the boundary layer. In other words, the shutter functions to maintain the boundary layer intact. This would appear to also be the purpose of the flow isolator employed by the present invention.
However, the '443 specification does not direct the reader to prevent disruption of the boundary layer so as to promote symmetrical cooling of the fibre, nor is there anything before me to suggest that maintaining the boundary layer intact will invariably lead to this result. The '443 specification simply states that the fibre is allowed to cool to a point below the softening temperature which falls well short of meeting the standard of disclosure required, and this failing is in my opinion reflected in Mr Noji's leading statement "If JP'443 produces symmetrical cooling …" (emphasis added).
This aside, it is particularly relevant to note that the present invention qualifies the step of symmetrical cooling as occurring until such time as the fibre cladding reaches a viscosity which substantially prevents or minimises differential stresses which cause the fibre to bend. This is assured by cooling the fibre to its strain point as defined for the purpose of the specification which is said to lie within the range of 1000oC to 1300oC.
The '443 specification teaches cooling to exit temperatures of 1000oC or 1200oC which Mr Yoshimura declares were chosen "because it was my understanding that the glass does not change its form below the softening temperature". However, Mr Yoshimura does not explain whether by "form" he is referring to the effects of thermal stress on the drawn fibre, or whether some other characteristic such as the fibre elongation normally associated with the conventional softening point of a glass (see exhibit DJB6) is meant. Critically, he does not say that either exit temperature was selected with a view to ensuring that the fibre was cooled to a temperature at which the cladding has a viscosity that is high enough to minimise or substantially prevent fibre bow due to differential stresses. Further to this, the '443 specification does not treat the "softening temperature" it discloses as being in any way related to the presently defined "strain point" which hardly seems surprising given its complete lack of recognition of the problem of fibre bow.
Based on the above I find that the '443 specification does not anticipate the claimed invention. To use the metaphorical language of General Tire, although this specification might provide a "signpost" upon the road to the invention, it does not take the reader to the "precise destination".
Accordingly, I hold that the ground of want of novelty has not been made out.
CONCLUSION
I have found that Optix has not succeeded on any of the grounds relied on. Accordingly, I dismiss the opposition and direct that application 661135 proceed to sealing, subject to any appeal being filed.
COSTS
The power of the Commissioner to award costs is discretionary, so I must take into account all relevant considerations (per American National Can Co v W R Grace & Co-Conn 29 IPR 292).
In actions before the Commissioner, costs usually follow the event. In the present case Corning amended the specification after the evidence in support had been filed which in my view is a prima facie acknowledgement of the validity of the opposition at that time. Mr Evans submitted that this did not warrant varying the normal approach since Optix had elected to pursue the opposition in the face of the amendments made to the specification. However, I am not persuaded by this line of argument since it is clear from my decision above that the amendments have raised substantial issues not found with the specification prior to amendment.
Consequently, I award costs against Corning up to and including the date of advertisement of allowance of the amendment, that is 27 March 1997, and against Optix thereafter.
O L Haggar
Delegate of the Commissioner of Patents
Patent attorneys for the applicant: Phillips Ormonde & Fitzpatrick, Melbourne
Patent attorneys for the opponent: Griffith Hack, Melbourne
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