International Conference on Judicial Protection of IPR Chengdu, China September 9-11 2009

Claim Interpretation and the Doctrine of Equivalence in the UK Christopher Floyd Judge of the Patents Court Royal Courts of Justice, London, UK

Why claim interpretation matters Claims define the monopoly granted by the patent So define what is (and by implication what is not) an infringemen Also need to be interpreted for validity purposes For most patent actions, claim interpretation is the most important issue.

An example Claim 1: A wheeled vehicle for conveying a passenger having two wheels: a forward wheel, and a rear wheel to which brakes may be applied.

Figure 1

The alleged infringement

Questions of interpretation Did the patentee intend to limit the claim to vehicles with only two wheels? Must the forward and rear wheels be in-line? If two wheels is not a limit what about:

What about?

Pre-EPC Before the European Patent Convention, two approaches to claim interpretation said to exist Strict literalism Loose “purposive” interpretation

In the UK a claim was either infringed Literally Pursuant to the doctrine of taking the essence (or the “pith and marrow”) of the claim The latter doctrine was of limited application It applied only to “inessential integers” of the claim

In other countries the doctrine of infringement by taking the essence of an invention is called “infringement by equivalents” or the “doctrine of equivalents”. In the United Kingdom it was also treated as a doctrine which permitted protection outside the terms of a claim.

A doctrine of equivalents To extend protection to things falling outside the claims which perform the same function in the same way to achieve the same result “necessary to prevent sharp practice” per Lord Reid in Van der Lely v Bamfords [1963] RPC 605 @ 607 “to temper unsparing logic and prevent an infringer from stealing the benefit of the invention” per Judge Learned Hand in Royal Typewriter Co Remington Rand 168 2 F2nd 691,692

Law reviewed in Catnic The pre EPC law in the UK was reviewed by the House of Lords in Catnic v Hill & Smith Held that there was a single or unitary approach to construction of patent claims It had always been so (really?)

The Catnic case A steel lintel for building purposes The rear element was to “extend vertically” D’s lintel was 6o from vertical Held that it infringed the claim by applying “purposive construction”

Purposive construction A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge. The question in each case 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.

The question, of course, does not arise where the variant would in fact have a material effect upon the way the invention worked. Nor does it arise unless at the date of publication of the specification it would be obvious to the informed reader that this was so. Where it is not obvious, in the light of then-existing knowledge, the reader is entitled to assume that the patentee thought at the time of the specification that he had good reason for limiting his monopoly so strictly and had intended to do so, even though subsequent work by him or others in the field of the invention might show the limitation to have been unnecessary. It is to be answered in the negative only when it would be apparent to any reader skilled in the art that a particular descriptive word or phrase used in a claim cannot have been intended by the patentee, who was also skilled in the art, to exclude minor variants which, to the knowledge of both him and the readers to whom the patent was addressed, could have no material effect upon the way in which the invention worked."

The EPC Governs grant of a bundle of patents for contracting states Contains provisions governing scope of protection

Article 69 Article 69 Extent of protection (1) The extent of the protection conferred by a European patent … shall be determined by the claims. Nevertheless, the description and drawings shall be used to interpret the claims.

The Protocol Protocol on the Interpretation of Article 69 EPC of 5 October 1973 Article 1 General principles Article 69 should not be interpreted as meaning that the extent of the protection conferred by a European patent is to be understood as that defined by the strict, literal meaning of the wording used in the claims, the description and drawings being employed only for the purpose of resolving an ambiguity found in the claims. Nor should it be taken to mean that the claims serve only as a guideline and that the actual protection conferred may extend to what, from a consideration of the description and drawings by a person skilled in the art, the patent proprietor has contemplated. On the contrary, it is to be interpreted as defining a position between these extremes which combines a fair protection for the patent proprietor with a reasonable degree of legal certainty for third parties.

Kirin Amgen “Purposive construction” does not mean going beyond the definition of the technical matter for which the patentee seeks protection in the claims. “The question is always what the person skilled in the art would have understood the patentee to be using the language of the claim to mean”

Doctrine of equivalents rejected House of Lords in Kirin Amgen said that both “pith and marrow in UK” and US doctrine of equivalence were attempts by the courts “to give to the patentee the full extent of the monopoly which the person skilled in the art would reasonably have thought that he was claiming” The courts felt unable to give that scope of protection because of “literalism”

Two ways forward Adhere to literalism and adopt a separate doctrine of infringement by equivalence Abandon literalism and interpret the claim so as to give it the scope which the person skilled in the art would have understood the patentee to be claiming The Protocol, as it stood, forbade the first of these courses, as it failed to determine the protection by the scope of the claims

How to deal with equivalents Courts following Catnic had developed guideline rules for dealing with equivalents Explained in Improver Corporation v Remington

The Improver Analysis (1)  Does the variant have a material effect upon the way the invention works? If yes, the variant is outside the claim. If no (2)  Would this (ie that the variant had no material effect) have been obvious at the date of publication of the patent to a reader skilled in the art? If no, the variant is outside the claim. If yes? (3)  Would the reader skilled in the art nevertheless have understood from the language of the claim that the patentee intended that strict compliance with the primary meaning was an essential requirement of the invention? If yes, the variant is outside the claim. On the other hand, a negative answer to the last question would lead to the conclusion that the patentee was intending the word or phrase to have not a literal but a figurative meaning (the figure being a form of synecdoche or metonymy) denoting a class of things which include the variant and the literal meaning, the latter being perhaps the most perfect, best-known or striking example of the class."

Is PC in accordance with the Protocol? The House of Lords said PC was in accordance with the Protocol The Protocol outlaws literalism So does PC It says one should not go outside the claims It says one should combine a fair protection for the patentee with a reasonable degree of certainty for third parties

How is this to be achieved How is this to be achieved? The claims must be construed in a way which attempts, so far as is possible in an imperfect world, not to disappoint the reasonable expectations of either side. What principle of interpretation would give fair protection to the patentee? Surely, a principle which would give him the full extent of the monopoly which the person skilled in the art would think he was intending to claim. And what principle would provide a reasonable degree of protection for third parties? Surely again, a principle which would not give the patentee more than the full extent of the monopoly which the person skilled in the art would think that he was intending to claim. Indeed, any other principle would also be unfair to the patentee, because it would unreasonably expose the patent to claims of invalidity on grounds of anticipation or insufficiency. Lord Hoffmann Kirin Amgen at [47]

The Protocol as amended Article 2 Equivalents For the purpose of determining the extent of protection conferred by a European patent, due account shall be taken of any element which is equivalent to an element specified in the claims.

Is PC in accordance with the amended Protocol? The House of Lords’ view was that Article 69 prevented equivalence from extending protection outside the claims So the amendment to the Protocol, which is a Protocol on the interpretation of Article 69 cannot be understood as authorising a scope of protection wider than the claims But that does not mean that equivalence does not form an important part of arriving a a construction of the claims

Claim interpretation: law and fact The English approach is to regard the interpretation of claims as a matter of law But the question of law is to be decided against a background of fact: the common general knowledge Thus different conclusions may be reached on the same patent, because the evidence of common general knowledge is different

Thank You