Allsop Inc v Bintang Ltd

[1989] FCA 428

Re: ALLSOP INC. AND COMMUNICATIONS POWER INCORPORATED (AUST.) PTY.
LIMITED
And: BINTANG LIMITED; PETER ROBERT STANTON; GOLDRING AUDIO INDUSTRIES
PTY. LIMITED AND CLURAT PTY. LIMITED
No. G1190 of 1988
FED No. 428
(1989) AIPC para 90-615
Patents
15 IPR 686

COURT

IN THE FEDERAL COURT OF AUSTRALIA

NEW SOUTH WALES DISTRICT REGISTRY
GENERAL DIVISION
Bowen C.J.(1), Beaumont(1) and Burchett(1) JJ.

CATCHWORDS

Patents - infringement - two patents for devices for cleaning the playing head of a cassette player - whether the respondents' "Flexibar" device replicates mechanical means, described in first patent, by which action of cassette player is converted to cleaning action - whether "Flexibar" device involves "a lever arm pivotally mounted in the container for reciprocating motion" - whether a "lever arm" is an essential integer of appellants' first patent - observations as to construction of claims in a complete specification - meanings of "lever", "pivotally", "mounted", "reciprocating".

Patents - counter-claim for revocation of second of appellants' patents - obviousness - application of test stated by Aickin J. in The Wellcome Foundation Ltd v. VR Laboratories (Aust) Pty Ltd (1981) 148 CLR 262, 270 - discussion of characteristics possessed by hypothetical "worker in the field" and of the nature of "inventiveness" - principles relating to "obviousness" - question of fact - relevance of known need/longfelt demand for, and substantial commercial success of, claimed invention.

Patents Act 1952 s.100(1)(e)

HEARING

SYDNEY

#DATE 8:8:1989

Counsel for the Appellants: Mr K.R. Handley Q.C. with Mr D.M. Yates

Solicitors for the Appellants: Norbert Lipton & Sankey

Counsel for the Respondents: Dr J. Emmerson Q.C. with

Mr G.C. Lindsay and Mr J.T. Gleeson

Solicitors for the 1st and 3rd
Respondents: Freehill, Hollingdale & Page

Solicitors for the 2nd and 4th Respondents: Dunhill Morgan

ORDER

The appeal be dismissed with costs.

NOTE: Settlement and entry of orders is dealt with in Order 36 of the Federal Court Rules.

JUDGE1

Allsop Inc., the first appellant, is the patentee of Letters Patent No. 522073 ("the first patent") and Letters Patent No. 539569 ("the second patent"). The patented invention is, in the case of the first patent, entitled "a cleaner for a cassette player". The second is similarly entitled. The first appellant and its licensee, Communications Power Incorporated (Aust.) Pty. Limited, the second appellant, instituted proceedings in the Supreme Court of New South Wales against Bintang Limited, the first respondent, and Peter Robert Stanton, the second respondent, seeking (inter alia) declarations: (1) that the distribution and sale by the first respondent of an audio cassette cleaner known as the "THC-83" infringed the second patent; and (2) that the manufacture and sale by the second respondent and the distribution and sale by the first respondent of another audio cassette cleaner, known as the "Flexibar Head Cleaner", infringed the first and second patents. After the institution of the proceedings, Goldring Audio Industries Pty. Limited, the third respondent, and Clurat Pty. Limited, the fourth respondent, were added as defendants upon the footing that: (1) the claims made against the first respondent were deemed to be made against the third respondent; and (2) the claims made against the second respondent were deemed to be made against the fourth respondent. In their defences, the respondents denied the infringements alleged. They also alleged that the second patent was invalid because it was obvious, it was not novel, and the claims made were not fairly based on the matters disclosed in the specification. On the same grounds, the respondents, by counter-claim, sought an order that the second patent be revoked.

1. In the Supreme Court, it was not seriously disputed that the device THC-83 would have infringed the second patent if it had been valid. Cohen J. held: (1) that the making and sale of the Flexibar device did not infringe the first patent; and (2) that the second patent was invalid. Accordingly, he ordered that the appellants' summons be dismissed, and that the second patent be revoked. The appellants now appeal from these orders.
   Appeal against the dismissal of the claims of infringement of the
   first patent by the making and sale of the Flexibar

2. The first patent is for a term of sixteen years commencing on 28 June 1978, with a priority date of 30 June 1977. According to the specification, the invention relates to a device for cleaning the playing head of a cassette player, and also for cleaning the pinch roller and capstan of the cassette player. The invention, it is claimed,
   

"avoids the disadvantages of the prior art and, in particular, provides an automatic cleaner ... . It is merely necessary to insert the cleaner ... into the recess of the cassette player for the cleaner to clean the playing head, capstan and pinch roller of the cassette player."

1. The consistory clause is in these terms:
   "According to the present invention there is provided a
   

device for automatically cleaning the playing head and tape engaging drive members of a cassette player having a sprocket drive and a recess able to receive a cassette tape in a playing position, said device comprising: a container adapted to be retainable within the recess in a cleaning position, a lever arm pivotally mounted in the container for reciprocating motion, means at one end of the lever arm to receive cleaning means to engage a surface of the playing head, drive means positioned in said container to receive said drive sprocket in driving relationship, a cam member having a substantially circular configuration being connected to said drive means for rotation about an axis offset from the center (sic) of the cam member, said cam member having a circumferential groove formed in a closed loop positioned eccentrically relative to the center of rotation of said cam member, and cam follower means on said lever arm and means for maintaining the lever arm in constant driving engagement with said groove of said cam member so that as said cam member rotates about its axis of rotation, said cam member causes said lever arm to reciprocate with a continuous motion from side to side across said playing head." (Emphases added)

1. There follow examples of embodiments of the invention, with detailed descriptions and appropriate figure drawings. Figure 1 is a plan view showing a first embodiment of the invention:
   
   

DIAGRAM OMITTED

A second embodiment is shown in Figure 4:

DIAGRAM OMITTED

1. Claim 1 claims a device in terms of the description of the invention in the consistory clause.

2. Claim 2 is in these terms:
   "A device as claimed in claim 1, including further
   

cleaning means comprising: a first cleaning portion mounted in said container so that with said container positioned in the recess (what is this recess is made plain by the consistory clause set out above), said first cleaning portion is located adjacent said capstan and in cleaning engagement with said capstan, a second cleaning portion mounted in said container so that when said container is positioned in said recess, said second cleaning portion is located adjacent said pinch roller, with said second cleaning portion being movably mounted for movement toward and away from said pinch roller, spring means arranged to yieldingly urge said second cleaning portion towards said pinch roller and into cleaning engagement with the pinch roller, with said spring means yielding sufficiently to permit said second cleaning portion to be positioned at various cleaning locations to accommodate variations in size and position of pinch rollers of various cassette players."

1. Claims 3 and 4 are not presently relevant. Claims 5, 6, 7 and 8 are as follows:
   "5. A device as claimed in any one of claims l to 4,
   

wherein the means for maintaining the lever arm in constant driving engagement with the cam member comprises a spring.

6. A device as claimed in claim 5, wherein said lever

arm is mounted by slot means for linear movement relative to a center of rotation of said lever arm towards said playing head, said spring being arranged not only to urge said lever arm into engagement with said cam member, but also to urge said lever arm toward said playing head to maintain proper engagement with said playing head.

7. A device as claimed in claim 6, wherein said lever

arm has means for resiliently biasing said one end of the lever arm towards said playing head.

8. A device as claimed in claim 7, wherein said

biasing means comprises a resilient loop integral with the lever arm."

1. Cohen J. found (and in order to appreciate many of the arguments it is essential to understand these facts) that common to all cassette players are: first, two spindles, one of which is the driving spindle when the play button is activated; secondly, a playing head, made of metal and slightly curved, which is moved into contact with the tape when the player is operating; and, thirdly, a capstan and pressure roller which are engaged with the tape to control the pressure for the winding of the tape. In some models there is an erase head. There are also auto-s devices. Some cause the player to stop when the wind-off spindle is not revolving; in others, pressure on the tape from the wind-off spindle causes the machine to stop. Some players (particularly those designed for use in motor cars) have an auto-reverse mechanism by which, once the tape reaches the end, the machine reverses so that what was the free-running wind-off spindle becomes the drive spindle. This requires a capstan and a pressure roller on both sides.

2. It is plain that the inventor of the first patent had some of these features in mind. The deviser of the respondents' Flexibar perhaps had all of them in mind. The Flexibar shares with the first patent the concept of mimicking a cassette in order to utilize the cassette player's own operation for the purpose of cleaning it. The dispute on this aspect of the case concerns the mechanical means by which the action of the cassette player is converted to a cleaning action. The respondents contend, and his Honour held, that the Flexibar does not involve "a lever arm pivotally mounted in the container for reciprocating motion," as specified in the patent, and that this is an essential integer which, having not been taken, denies infringement.
   

Illustrative Drawings of Flexibar cleaner showing

(1) the mechanism; (2) a separate representation of the T-bar

DIAGRAM OMITTED

1. The debate about this issue makes it necessary to examine the construction and working of the Flexibar. That is most easily done by reference to the illustrations attached to these reasons, which we have drawn from photo-copies of parts of an exhibit. The first illustration shows a view of the working parts of the Flexibar as they lie flat, enclosed in their clear plastic container, which is of the size and shape of a cassette. At the top can be seen three cleaning pads, the centre one for the playing head of the cassette player and the other two for the capstan and pinch roller of an auto-reverse cassette player (in other models there will only be one capstan and pinch roller on one side, though in some models there may be an erase head to be cleaned on the opposite side). The cleaning pads are attached to a roughly T-shaped piece of plastic (referred to as a "T-bar") so constructed, with a crescent-shaped piece at the intersection of the stem and the arms of the T, as to provide some flexibility in the arms. The T-bar bearing the cleaning pads is constrained, at a number of points, so that it can move only to a limited degree. At the base of the stem of the T, where it overlies the intersection of two cogged wheels, there is on one side a pin (invisible in the first illustration because concealed by the T-bar itself) which is inserted into a groove in the wheel on that side. When the wheel turns, the pin follows the groove, describing an eccentric circle in relation to the wheel. This arrangement of the wheel is known as a cam, and the pin as a cam follower. The pin can be seen in the second illustration, which shows the T-bar removed from the cassette and turned over. The pin is shown as a circle in the bottom right hand corner of the second illustration. The other supports of the T-bar are, first, four pins (shown in the first illustration as heavy dots), one above and one below each arm of the T, which are affixed to the case of the cassette, and secondly, two sloping "ramps", also affixed to the casing of the cassette, at the extremity of either arm.

2. When the Flexibar is inserted into a cassette player, the drive or wind-on spindle of the player will operate in one of the two wheels, whichever is on that side of the cassette player. It does not matter which, since the wheels are intermeshed so that, either way, both will rotate. The rotation of the wheel, in the eccentrically circular groove of which the cam follower is inserted, will cause the T-bar to be alternately pulled to one side, and pushed to the other, as the cam revolves. Since the pushing and pulling act at the base of the stem of the T, it is obvious there will be a tendency towards a tilting of the T-bar, but the four pins will constrain it so that it cannot tilt except within the tolerances of the fit of the T-bar between the pins. It will therefore slide from side to side with each alternate pulling and pushing from the cam. As the end of each arm moves outwards, it will be deflected by the "ramp" at that end so as to apply some pressure to the cleaning pad on that side. The central pad will move from side to side across the face of the playing head of the cassette player. At the extremity of each movement, there will be an instant of time before the friction between the pad and the playing head can be overcome, in which the T-bar will tilt fractionally, or rotate about the point of contact, until any tolerance between the guide pins is taken up and the T-bar commences its linear slide.

3. The question raised by the appeal, in respect of the alleged infringement of the first patent, is whether the respondents, in their Flexibar cleaner, have taken the integer "a lever arm pivotally mounted in the container for reciprocating motion". But in order to answer that question, it is necessary first to construe claim one of the specification of the patent. The principles of construction to be applied are not in doubt. In Populin v. H.B. Nominees Pty Ltd (1982) 59 FLR 37 at 42-43, it was said in the joint judgment of Bowen C.J., Deane and Ellicott JJ.:
   "The complete specification must not be read in the
   

abstract but in the light of common knowledge in the art before the priority date bearing in mind that what is being construed is a public instrument which must, if it is to be valid, define a monolopy in such a way that it is not reasonably capable of being misunderstood (see generally Welch Perrin & Co. Pty Ltd v. Worrel (1961) 106 CLR 588 at 610). The essential features of the product or process for which it claims a monopoly are to be determined not as a matter of abstract uninformed construction but by a common-sense assessment of what the words used convey in the context of then-existing published knowledge."

1. Put differently, the specification should, generally speaking, be given a purposive construction, rather than a purely literal one: Populin (supra) at 43; The Decor Corporation Pty Ltd v. Dart Industries Inc. (Lockhart, Sheppard & Foster JJ., unreported, 18 November 1988), per Sheppard J. at 12.

2. In the present case, the relevant framework of knowledge is perhaps most clearly shown by the complete specification itself. It says:
   "There have been proposals to clean the playing head to
   

tape players. Generally speaking, they rely on a hand operated lever extending through a cartridge. At one end of the lever there is a cleaning pad that contacts the tape playing head. At the other end of the lever, which extends through the back of the cartridge and out of the recess, there is a handle so that the cleaning pad can be reciprocated across the tape playing head. ... One prior art device discloses a cartridge-type cleaner where a reciprocating lever arm having a cleaning pad thereon is moved back and forth by a cam driven by the sprocket of the player to clean the playing head. There are also cleaning pads to clean the capstan of the player. However, there is a continuing need for improvement in such devices."

The specification goes on to claim, for the invention the subject of the patent, the merit of automatic cleaning of playing head, capstan and pinch roller.

1. In general, an understanding of the meanings of the words "lever", "pivotally", "mounted" and "reciprocating", as ordinary English words, may be assumed. However, as these words are clearly used in the specification in their mechanical sense, so far as that sense differs from common usage, it is desirable to set out the appropriate dictionary definitions, which have been taken from the Shorter Oxford English Dictionary, 3rd edition, 1980 reprint. The mechanical meaning of lever is "name for a rigid structure of any shape (normally a straight bar) fixed at one point called the fulcrum, and acted on at two other points by two forces, tending to cause it to rotate about the fulcrum". The dictionary adds: "The force to be resisted by the use of the lever is called the weight, and the force applied for this purpose the power. Levers are said to be of the first, second, or third kind or order according as the fulcrum, the weight, or the power is midmost of the three." "Pivotally" means "as on a pivot", and "pivot" relevantly means "a short shaft or pin, forming the fulcrum and centre on which something turns or oscillates; a pintle, gudgeon." Both the last two words evoke pins on which things turn, as in the case of the pintle in a hinge, or the gudgeon of an axle. (In the 1989 2nd ed. of The Oxford English Dictionary, vol. XIII, "pivot" is relevantly defined as: "A short shaft or pin, usually of metal and pointed, forming the fulcrum and centre on which something turns or oscillates; as the pin of a hinge, the end of an axle or spindle, or the arbor on which the hands of a timepiece turn; a pintle, gudgeon".) The relevant meaning of "mounted" is "set up for use, as cannon". Cf. Martin Engineering Co. v. Matflo Engineering Pty Ltd (1987) 17 FCR 132 at 139. The mechanical meaning of "reciprocate" is "to move backwards and forwards", from which "reciprocating" has the meaning "that reciprocates; specifically in Mechanics (of machines etc.) having a reciprocating part or parts".

2. The appellants' argument examined minutely, as separate expressions, the words "lever arm" and the words "pivotally mounted". But "a common-sense assessment of what the words used convey" demands that they be read in their context - "a lever arm pivotally mounted in the container for reciprocating motion" - and indeed in their extended context, which indicates that the cleaning means will be "at one end of the lever arm", and that the reciprocating motion for which the lever arm is to be pivotally mounted is "a continuous motion from side to side across said playing head".

3. Counsel's dismemberment of the statement in the claim into its component words led him to submit that it could be regarded as embracing something which could be a lever, although not functioning as such. But this is to drain language of all meaning - a non-functional lever is like a non-functional beam; it is simply a length of rigid material. What differentiates a lever from a beam, or a host of other lengths of material, is its function as a lever. When one speaks - as counsel instanced - of a crow-bar as a lever, one is thinking of it as designed and destined for that use - not simply as an iron bar. And here a "lever arm" is spoken of as "pivotally mounted ... for reciprocating motion". That inevitably suggests function - as indeed the word which in English is "lever" has done since the time of Archimedes.

1. Putting the requirement of a lever to one side as fulfilled non-functionally by the relatively rigid structure of the T-bar, counsel suggested that this could be regarded as pivotally mounted (though not in order to act as a lever) within the meaning of the claim by virtue of its capacity to tilt, or, as he put it, to "rock", at the beginning of each new sideways movement, in the manner already described. This was perhaps the fundamental argument put on this aspect of the case. It necessitated a reading of the word "pivotally", not so much as an adverb describing the manner of mounting of the T-bar, but almost as if it were an adjective indicating that the T-bar had the quality of being capable of pivoting. For when friction at the playing head causes the T-bar to rock fractionally, the only pivoting involved is of the T-bar on the contact point at the playing head. It has nothing to do with any pivotal mounting (unless the cam follower pin is the relevant pivotal mounting - which was disclaimed at the hearing), and the only extent to which the mounting contributes is that its tolerances do not actually prevent the minute movement occurring. Still less can it be said that what happens demonstrates a lever arm pivotally mounted in the container, since the point of the pivoting which occurs is outside the container and at the playing head. There is, of course, no pivot in the ordinary sense, on which the lever arm is mounted, and, if the draftsman meant to express no more than a capacity to rotate, the description "pivotally mounted" is surplusage, since the word "lever" necessarily involves that capacity.

2. Assuming the argument could get past these obstacles, it would meet the words "for reciprocating motion". They express the purpose of the patentee's requirement that the lever arm be pivotally mounted in the container. But if the presence of the tolerances of the pins, permitting the T-bar to tilt upon its meeting frictional forces at the playing head, enables the T-bar to be described as pivotally mounted, it is not so "for reciprocating motion". There is no reciprocation of the uni-directional tilting or rocking of the T-bar, which merges, upon the overcoming of friction, into the sideways sliding for which the device was plainly designed. A tilt the other way only occurs about a different point of rotation, a different "pivot", at the other side of the playing head, when the cleaning pad is ready to slide back.

3. The word "for" expresses purpose. If pivotal mounting, in some loose sense, is to be seen in the ability of the T-bar to pivot to the extent indicated, the purpose is not reciprocating motion; it is (if there be any purpose) the initiation of linear motion. But the fact is that the tilting or rocking motion is not purposeful at all. The expert whose evidence was accepted by the learned trial judge, Professor Morton, made this quite clear. He said:
   "(T)he rocking motion is something which is undesirable
   

from the point of view of the cleaner. The action which is predicated on this design is in fact a transverse movement from side to side and the rocking action occurs only because the device can never be manufactured to perfect tolerances. Therefore one could never have the two pins in very close proximity to this cross member simply because of the difficulties of ever making things exactly; and the only reason it rocks is because there always has to be some clearance provided between these pins, and the smaller that clearance can be made, and the smaller angle of rotation they allow, then the better from the point of view of the cleaner."

1. A further fundamental problem, already touched upon, confronting the appellants' argument is that the minuscule pivoting at the playing head is not a lever action. The T-bar is no more a lever, as it pivots about a point on the playing head, than is a post as it pivots about a point on the ground when it is being uplifted at one end in order to drop it into a posthole. Neither is levering anything. It is true, as Prof. Morton acknowledged, that the components of a lever system - applied force, lever, fulcrum and load - are present when the T-bar, at the end of its minute arc, subjects the guide pin to a load upon contacting it; but the force, of course, is not applied to move the guide pin, and it would simply not be an appropriate use of language to describe the T-bar as acting, at that instant, as a lever, nor to describe the T-bar, on that account, by the word "lever". As soon might the post be called a lever because the workman slides it slowly into the hole by pulling at the top, in order to apply frictional pressure to the bottom against the far side of the hole, the "fulcrum" being the near edge of the hole. Yet the draftsman of the specification refers to "a lever arm". If he had not meant to refer to an arm acting as a lever, it is difficult to comprehend the adjectival use of the word "lever". The expression "lever arm" is used five times in claim one. It reflects the recital of the prior art, and also the preferred embodiments of the invention described in the specification, all of which appear to be describing lever mechanisms. Because they are lever mechanisms, in which the end of the lever bearing the cleaning pad describes an arc, they all appear to have the disadvantage of reduced contact at either extremity of the playing head being cleaned, for which some of them attempt to compensate by the use of a spring.

2. Yet another difficulty with the appellants' submission, that the T-bar may be seen as a lever arm within the meaning of claim one, is that claim one describes "means at one end of the lever arm to receive cleaning means to engage a surface of the playing head". If the T-bar is a lever arm, the cleaning means to engage the playing head can only be found at the intersection of the two parts forming the T-bar, which cannot be described as "at one end". To treat the T-bar as a lever pivoting at the point of contact with the playing head upon force being applied by the cam follower pin, the load being at one of the guide pins, requires the intersection of the two parts of the T to be between the load and the point of application of force; it is at an intermediate point, or as it is put in the Oxford dictionary (ubi cit. supra) "midmost of the three", not at an end. An alternative version of the appellants' argument, which was pressed at the hearing below but only faintly upon the appeal, was that the T-bar could be regarded as a lever turning upon the guide pin as a fulcrum. This would place the load at the playing head, that is, between the application of force by the cam follower pin and the fulcrum at the guide pin. It is impossible to reconcile either formulation of the appellants' case with the language of the specification which places the cleaning means "at one end of the lever arm". The language of the specification is consistent with the view that the patent concerns a lever mechanism, pivoting (at a point between the cam and the playing head) so that the cleaning means at the end of the lever arm can describe an arc across the face of the playing head in order to clean it. Specifically as regards the alternative version of the argument, the highly qualified expert accepted by the trial judge, Prof. Morton, gave unequivocal evidence that the operation of the Flexibar does not involve rotation about a guide pin as a fulcrum. What it does involve is linear sliding against the pin.

3. The consistent tenor of Prof. Morton's evidence was that the patent is fundamentally different in principle from the mechanics of the Flexibar in that the patent describes a lever and pivot mechanism, whereas the Flexibar involves neither lever nor pivot, its mechanism converting the motion involved into a linear or sliding movement. So far as Prof. Morton's view depends upon his reading of the patent, it cannot, of course, be accepted unless the court reads the patent in the same way, or in a way consistent with Prof. Morton's reasoning. The construction of the complete specification is for the court. But attention has already been drawn to a number of considerations which support an understanding of the patent as referring to a true lever mechanism, and not to anything working in the way in which the Flexibar works. Nevertheless, counsel for the appellants submitted that "the substantial idea disclosed by the specification and made the subject of a definite claim has been taken and embodied in" the Flexibar (Olin Corporation v. Super Cartridge Co. Pty Ltd (1977) 14 ALR 149 at 157). He attempted to make this good upon the footing that the movements of the mechanism of the Flexibar involve an arm "which gives the result of claim one". He submitted that the adjective "lever" is not an essential integer of the claim.

4. Reliance was placed by counsel on the decision of the House of Lords in Catnic Components Limited v. Hill & Smith Limited (1982) RPC 183. However, in that case at 243 Lord Diplock made it plain that the question is:
   "whether persons with practical knowledge and experience
   

of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way the invention worked."

A variant which would inevitably have a material effect upon the way the invention worked is expressly excluded by his Lordship's formulation of the question. A change from a lever describing an arc, as it pivots, to an apparatus with no lever, but producing a linear movement, cannot be described as having "no material effect upon the way the invention worked". It must not be overlooked that, at 242-243 in introducing the passage quoted, Lord Diplock emphasized:

"My Lords, a patent specification is a unilateral

statement by the patentee, in words of his own choosing, addressed to those likely to have a practical interest in the subject matter of his invention (i.e. 'skilled in the art'), by which he informs them what he claims to be the essential features of the new product or process for which the letters patent grant him a monopoly. It is those novel features only that he claims to be essential that constitute the so-called 'pith and marrow' of the claim."

(See also Populin's case (supra) at 42-43.) This statement of the law should be read remembering that a claim is required to "provide a workable standard suitable to the intended use": Minnesota Mining and Manufacturing Company v. Beiersdorf (Australia) Limited (1980) 144 CLR 253 at 274. Section 40 of the Patents Act 1952 requires that a claim "shall be clear and succinct and shall be fairly based on the matter described in the specification", and refers to a claim as "defining the invention".

1. In the light of what the draftsman was required to do, and having regard to all the considerations which have been mentioned, it is impossible to regard the adjective "lever" as expressing an inessential integer, nor can the expression "pivotally mounted" be regarded as capable of being satisfied by something less than mounting on a pivot. It follows that the respondents did not take all of the essential features or integers of the patentee's claim, and that is fatal to the allegation of infringement: Olin Corporation case (supra) at 157. In Populin v. H.B. Nominees Pty Ltd (supra) at 42 a "fundamental rule" was said to be "that there will be no infringement unless the alleged infringer has taken all of the essential features or integers of the patentee's claim".

2. Accordingly, the appeal against the dismissal of the claims of infingement of the first patent by the making and sale of the Flexibar cleaner should be dismissed.
   Appeal against order revoking the second patent

3. The ground on which the second patent was revoked was the ground stated in s.100(1)(e) of the Patents Act, "that the invention, so far as claimed in any claim of the complete 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 that claim".

4. The priority date of the second patent is 24 October 1980, and its term is sixteen years from 9 October 1981. The complete specification of the second patent commences with a statement of the nature of the invention and the problems it was intended to overcome, as follows:
   

"The present invention relates to cassettes containing devices for cleaning the driving and/or recording elements of tape recorders. The following have already been proposed:

- loading of these cassettes with a short length of

slightly abrasive cleaning tape, but, since this tape has a thickness much greater than that of a normal recording and/or playback tape, it involves the risks of damaging or putting out of adjustment some of the tape recorder members foreseen (sic) for guiding, driving and recording/playing back the tape:

- cassettes containing a device actuated by one of the

take-up, take-off spool shafts (German Utility Model 6,928,925 of July 22nd, 1969 in the name of BECKER AUTORADIOWERK GmbH), but since cassettes of this type have only one working side (take-up spool) their great disadvantages are:

- that they cannot be used on 'bi-directional' units.

In fact, these are generally equipped on each of the spools with an automatic stop device, such as described in the applicant's Belgian Patent No. 672,331 of November 16th, 1965, and since, in a cassette of this type, the feeding spool is not driven, the automatic stop device associated with it immediately monitors either the stopping of the unit or the ejection of the cassette,

- that they require close attention by users when

introduced into one-way units, since such a cassette must always be positioned in such a way that the spool operating the cleaning device is placed on the winding spool spindle. In fact, if this rule is not observed, no cleaning takes place and the cassette is immediately ejected if the unit is equipped with a mechanical stop, or the unit is further switched off if it is equipped with an automatic stop device of the type described in the applicant's Belgian Patent mentioned above. Since most users are unaware of this kind of technical problem, they will conclude from this that their cleaning cassette is completely out of order.

The object of the present invention is, therefore, to overcome these disadvantages and to suggest a device which is simple, unexpensive (sic) and effective, whatever the type of cassette player it is used on and type of automatic stop same is equipped with."

The complete specification continues to describe the invention in terms which are repeated in claim one. Claim one reads:

"A cleaning device for cleaning a head of a tape cassette player, where said player has a cassette receiving area to receive a tape cassette in a playing position, and a pair of spaced spindles to engage first and second spools of said tape cassette, which spindles are at predetermined spindle locations in said cassette receiving area, said device comprising:

(a) a cassette housing adapted to be inserted in said cassette receiving area in an operating location;

(b) a drive system comprising:

(i) a first drive member rotatably mounted in said cassette housing at a first drive location where, with said housing in its operating position, said first drive member engages said first spindle in drive relationship so as to be rotatable with said first spindle;

(ii) a second drive member rotatably mounted in said cassette housing at a second drive location where, with the housing in its operating position, said second drive member engages said second spindle in drive relationship so as to be rotatable with said second spindle;

(iii) an interconnecting drive means operatively engaging said first and second drive members in a manner that rotational movement of one of said first and second drive members causes the other of said first and second drive members to rotate;

(c) a cleaning member having a cleaning portion positioned to engage the head of the player, said cleaning member being mounted in said housing to be drawn on a cleaning path by which said cleaning portion wipes against the head of the player; whereby when either spindle of the player is rotated under power from the player, the drive member engaging that spindle is caused to rotate to ensure that the other of the spindles is rotating, and the cleaning member is caused to move in a path to clean the head of the player."

Claims two to nine inclusive merely add various elaborations, such as the specification in claim two of a third wheel member, operatively engaging the first and second wheel members, as the interconnecting drive means required by claim one. It is unnecessary to set out these further claims, which all depend on the validity of claim one.

1. It is apparent that the essence of the claimed invention is the idea of a second drive member to engage the second spindle of the tape cassette player, so as to avoid the problems arising from previous devices which engaged only one spindle, and the idea of providing an interconnection between the two drive means, so that, whichever engaged the driving spindle, the other would also rotate. Two things would follow from this device: the cleaner would work whatever the way round it was inserted in the cassette player, and auto-stop mechanisms depending on the failure of the wind-off spindle to rotate would not be triggered. Auto-stop mechanisms depending on the application of pressure to the tape when it is fully unwound or jams would not be triggered either, but they created no particular problem for the prior art referred to in the complete specification.

2. The test of obviousness was stated by Aickin J. in The Wellcome Foundation Limited v. VR Laboratories (Aust.) Proprietary Limited (1981) 148 CLR 262 at 270:
   "It is as well to bear in mind that the question of
   

obviousness involves asking the question whether the invention would have been obvious to a non-inventive worker in the field, equipped with the common general knowledge in that particular field as at the priority date, without regard to documents in existence but not part of such common general knowledge. The question is not whether it was or would have been obvious to the inventor or to some other particular worker in the field ... ."

At 286 he added:

"What is important is that the patent itself should

involve an inventive step, whether or not it was consciously taken by the patentee and whether or not it appeared obvious to the patentee himself. The test is whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not."

1. Although the hypothetical worker in the field must be assumed to be non-inventive, he must also be assumed to be "a person skilled in the art to which the invention related": Sunbeam Corporation v. Morphy-Richards (Australia) Pty Ltd (1961) 35 ALJR 212 at 218. Windeyer J. went on to refer to "scientific inventions, intricate mechanical arrangements, chemical processes, electrical and electronic devices and so forth", and added:
   "In these fields the persons skilled in the art are not
   

just skilled artisans. They are often trained engineers and scientists, who are well versed in the periodical literature of their subjects."

To the like effect is the remark of Diplock L.J. in Johns-Manville Corporation's Patent (1967) RPC 479 at 493, that the hypothetical "person versed in the art" may be a "highly qualified technologist in the research department" of a manufacturing company. The point made by Windeyer J. and Diplock L.J. simply recognizes the changes which have occurred in industry and technology during the course of this century. As Clark J., speaking for the Supreme Court of the United States, said in Graham v. John Deere Co. of Kansas City (1966) 383 US 1 at 19:

"The standard (ie the standard of the law of patents) has

remained invariable in this Court. Technology, however, has advanced - and with remarkable rapidity in the last 50 years. Moreover, the ambit of applicable art in given fields of science has widened by disciplines unheard of a half century ago. It is but an evenhanded application to require that those persons granted the benefit of a patent monopoly be charged with an awareness of these changed conditions. The same is true of the less technical, but still useful arts. He who seeks to build a better mousetrap today has a long path to tread before reaching the Patent Office."

1. While these statements indicate the extent of the knowledge to be attributed to the hypothetical skilled but uninventive worker in the field, it is clear law that the inventive element needed to sustain a patent may be quite small. As Aickin J. said in Meyers Taylor Pty Limited v. Vicarr Industries Limited (1977) 137 CLR 228 at 249:
   "It is trite law that a 'scintilla of inventiveness' is
   

sufficient and that 'no smallness or simplicity will prevent a patent being good' ... ."

And the cases abound in warnings against the seductive clarity of hindsight: Graham Hart (1971) Proprietary Limited v. S.W. Hart & Company Proprietary Limited (1978) 141 CLR 305 at 332; Wellcome Foundation case (supra) at 286. The two concepts, that the simplicity of an idea does not deny its inventiveness, and that the light of hindsight may be misleading, may have an interaction. For "there is all too easy and tempting a slope from the recognition of the simplicity of an idea to a conclusion, when someone else has already expressed it clearly, that there was nothing inventive about it": Martin Engineering Company v. Trison Holdings Pty Limited (unreported, Burchett J., 14 March 1989); and see the Meyers Taylor case (supra) at 243.

1. But although a simple idea may be inventive, it is essential for validity that there be inventiveness. Though small, it must be present. As was said in Graham v. John Deere Co. (supra) at 15 (footnote), there is a "requirement that the subject matter sought to be patented must be beyond the skill of the calling." The question, as Lord Herschell said in Vickers, Sons & Co. Limited v. Siddell (1890) 15 AC 496 at 502 is whether the subject of the patent "was so obvious that it would at once occur to anyone acquainted with the subject, and desirous of accomplishing the end, or whether it required some invention to devise it." In R.D. Werner & Co. Inc. v. Bailey Aluminium Products Pty Ltd (1989) 85 ALR 679 at 689, Lockhart J. said: "There must ... be some difficulty overcome, some barrier crossed". He cited a dictum of Cotton L.J. that "it must be a question of whether there is sufficient invention to justify a monopoly being granted by the Crown in the particular thing."

2. When the principles which surround that question have been stated, the question itself remains one of fact involving an evaluation of the claimed invention in the light of the evidence. It has been described as a "jury question": Wellcome Foundation case at 280. It is a question to which what was said by Gibbs C.J., albeit in a different context, in S.W. Hart & Co. Proprietary Limited v. Edwards Hot Water Systems (1985) 159 CLR 466 at 478 is applicable:
   "The nature of the issue, involving as it does matters of
   

impression, is one in which particular respect and weight should be given to the decision of the trial judge unless some error in his judgment has been demonstrated."

See also the comments of Brennan J. in the same case at 491.

1. Counsel for the appellant found fault with Cohen J's approach on the basis that he concentrated too much upon the ease with which anyone acquainted with mechanical devices would perceive the solution proposed by the patentee, and too little on the analysis of the problem, and the recognition of its nature, which would have had to precede the working out of a solution. He criticized the evidence of Prof. Morton, who was accepted by his Honour. Prof. Morton said he had solved the problem in three minutes, and that it presented no difficulty - prompting counsel to claim that the mere fact he was told the ways in which the prior art was said to have failed to function satisfactorily (that is, the absence in a one-wheel device of any means of causing the wind-off spindle to turn, with the result that the auto-stop mechanism was activated; and the even chance of a one-wheel device being inserted the wrong way round so as not to engage the drive spindle) suggested the answer to the problem. But if the answer could be so easily suggested, the question must be asked whether that solution did cross the boundary between a routine application of existing knowledge and practice to a new problem and a simple, yet truly inventive, idea.

2. Unless Prof. Morton's evidence is to be rejected (and no ground appears for overturning the trial judge's acceptance of him), the appellants' argument really must be that the perception of the true nature of the problem was the inventive step in this case (cf. the Wellcome Foundation case at 281). But is there any complexity, obscurity, or difficulty to justify so regarding that perception? It is at bottom impossible to imagine anyone skilled in the operation of audio tape playing machines and their cleaners known at the priority date, when confronted with the problem of a cleaner not functioning because it engaged only the drive sprocket (so that the auto-stop mechanism was triggered by virtue of the absence of any means of revolving the wind-off spindle), having any difficulty whatever in recognizing what had occurred. Similarly, if such a person had been told that customers using a one-wheel device had been confused by its failure to operate when inserted the wrong way round in a perfectly ordinary tape playing machine without an auto-reverse capability, he must have understood precisely what had happened. In the case of each of these problems, the machine had simply functioned in accordance with its design. The court is required by the law to postulate an unimaginative skilled worker in the field, but it is not required to postulate an ignorant one. What had happened, and the design features of tape playing machines which had caused it to happen, were both perfectly apparent.

3. The appellants relied on the proposition, discussed by Aickin J. in the Minnesota Mining and Manufacturing case (supra) at 297-298, that evidence of a known need at the priority date, and evidence that when introduced into the market the product "met that need, and had substantial commercial success", are "well recognized indications of inventiveness though they are not in themselves decisive." Evidence of that kind has been regarded as significant in a number of cases, including Martin Engineering Company v. Trison Holdings Pty Limited (supra). It is referred to as a relevant consideration in Graham v. John Deere Co. (supra) at 17-18, where a learned article, dealing with indicia of "nonobviousness", in 112 U Pa L Rev 1169 (1964) is cited. In the article ,at 1173-1174, it is pointed out:
   "Longfelt demand can be inferred by proof that a defect
   

existed, but the patentee must articulate the defect in need of solution. The more pronounced and persistent the defect, the stronger the inference of longfelt demand. Often, however, proper assessment of the magnitude of a defect will be hampered if the necessary evidence is unavailable or is highly technical. In such a case a court can turn to other sources within an industry for evidence showing that many skilled artisans have attempted to find a solution to the problem which the patent in question purports to solve. Such evidence shows indirectly the presence of a significant defect while serving as a simulated laboratory test of the obviousness of the solution to a skilled artisan.

The amount of research expended by the industry is an

important source of evidence and this can be measured in terms of man-hours. ...

The significance of a given period of time during which

a defect was present or even of a period of proven unsuccessful research can not be determined by a single absolute standard, for the speed of innovation varies from industry to industry. To create an inference of longfelt demand, the time the defect persisted should at least be longer than the average timelapse (preceding) the unpatented solutions of defects in the relevant art.

In receiving evidence of unsuccessful research, courts

must take care that such research was conducted under the same state of the art as that which confronted the patentee. It may be that an intervening innovation made that which the patentee accomplished obvious even though it was not obvious to prior unsuccessful researchers."

1. The argument about longfelt demand was put to the trial judge. He commented:
   "This argument assumes that attempts were being made to
   

overcome the problems which Prof. Morton had had described to him. There is no evidence as to when these problems were realised or if anyone tried to solve them before late 1980. The existence of an earlier device does not in itself indicate that it had observed disadvantages which had been the subject of attempts to remedy them. I do not consider that this submission overcomes the evidence of obviousness."

His Honour's comments are justified. The evidence did not indicate when auto-reverse audio tape players, with auto-s mechanisms operative upon the wind-off spindle failing to revolve, first appeared or first became common on the Australian market. Also, despite the assertion in the complete specification of the second patent about another difficulty in the prior art, it is not convincingly apparent that many persons using a cassette cleaner which did not trigger an auto-s mechanism, but merely failed to operate because inserted the wrong way round, would be unable to react just as persons often do when an audio tape is inserted the wrong way round - that is, remove the cassette and replace it the other way. There was some evidence suggesting this may have been a problem, but plainly the greater problem was the complete inability of a one-wheel device to work in the presence of an auto-stop mechanism of the kind mentioned. When that problem became apparent in Australia, or indeed anywhere else, as a problem affecting a significant number of customers of those who produced tape player cleaners, was simply not disclosed by the evidence. Consistently with what was disclosed, the claimed invention may have been developed immediately the problem became a matter of concern to the person who developed it, that is, as soon as tape players equipped with the relevant auto-stop device appeared, or their appearance became anticipated, in significant numbers on the market to be served. Although the appellants called evidence on the subject, their witness contented himself with saying that, as at October 1980, this auto-stop feature "was available" on the Australian market. He did not say it was common. By way of contrast, the same witness did examine the frequency of use at that time of the (for present purposes) irrelevant device which stops some tape players when there is an overload on the tape. He said that was not universal, but was not rare either.

1. In this state of the evidence, and having regard to the considerations which have been discussed, no ground appears for disturbing the trial judge's finding that the second patent is invalid for obviousness. It is unnecessary to pronounce upon the respondents' arguments that the second patent also lacked novelty and fair basis.

2. The appeal should be dismissed with costs.