• The Protocol Questions

    Not a Doctrine of Equivalents

    We are often asked whether UK law recognizes a "Doctrine of Equivalents". The answer is that patent claims must be construed according to the Protocol on Interpretation of Article 69 of the European Patent Convention, which seeks to balance fair protection for the patentee with a reasonable degree of certainty for third parties. In applying the Protocol, the Courts of the United Kingdom have adopted a so-called purposive construction of claims, derived from a decision of the House of Lords (Catnic v Hill & Smith [1982] RPC 183) concerning a patent granted under the now-obsolete Patents Act 1949. In 1989, the Patents Court in Improver v Remington [1990] FSR181 reformulated the Catnic decision as three questions, and these three questions are now recognised as the standard for applying the Protocol. These questions, variously referred to as the "Catnic", "Improver" or "Protocol" questions are set out on below in a flow chart.

    When using these questions, the Court is looking to see whether a variant on a feature specified in a claim falls within the scope of the claim. It might be thought that a variant would be expected to include equivalents. However, in practice, this does not appear to be the case. Indeed, the Courts are very careful not to use the term "equivalents", as this is not a doctrine by which the natural language can be ignored and something else can be substituted in its place. In Amersham Pharmacia Biotech v Amicon (unreported), Lord Justice Aldous stated “I do not believe that the Protocol introduced into our law a doctrine of infringement by equivalent effect by use of a different mechanism. That may be for the future.”

     

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    Contrast with Germany?

    The first two questions are questions of fact requiring enquiry into the evidence. The third question is a question of law for the Court. It has been debated whether this approach contrasts with laws of other countries in Europe, and especially whether the third Protocol Question is unique to the interpretation of the Protocol applied by the Courts of England (see e.g. PLG Research v Ardon [1995] RPC 287 in which the Court of Appeal admitted that the interpretation applied is not as closely in conformity with the Protocol on Interpretation as that of the Courts of Germany). This question (together with the second Question) serves to fulfil the second limb of the Protocol requirement, i.e. that the terms of the claims should be interpreted so as to provide a “fair degree of protection for third parties”. Regardless of whether this is an approach that is particular to the English Courts or whether the tendency is turning towards reliance on the Protocol itself rather than the three Protocol Questions, we shall see below that in the United Kingdom, defendants who might otherwise be found to infringe are sometimes “off the hook” as a result of this question.

     

    Doctrine of Equivalents is Coming

    During the Diplomatic Conference of November 2000 on amendment to the European Patent Convention it was proposed that the Protocol on Interpretation of Article 69 should be amended by the introduction of a new Article 2. The originally proposed new article said:

    (1) For the purpose of determining the extent of protection conferred by a European patent, due account shall be taken of means which at the time of the alleged infringement are equivalent to the means specified in the claims.

    (2) A means shall generally be considered as being equivalent if it is obvious to a person skilled in the art that using such means achieves substantially the same result as that achieved through the means specified in the claim.

    But the conference adopted a final wording that was considerably watered-down (see Special edition No. 4 of the EPO Official Journal 2001):

    For the purposes 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.

    This and other amendments to the EPC (the "EPC 2000") will enter into force two years after ratification by 15 contracting states. So far only the four new states that ratified this year have ratified the new text. It is expected that it will take another couple of years for the necessary minimum 11 further states to ratify. So the new text with its amended protocols is not likely to come into force before 2005. When it eventually comes into force, it will apply to patents granted on applications filed after that time.

     

    Comment

    When the amended Protocol comes into force it will firmly establish a doctrine of equivalents in Europe. But the revised text does not go so far as was originally proposed to the Diplomatic Conference. The new text merely requires that “due account” is taken of any element which is equivalent to an element specified in the claims. One could well say that the present Protocol Questions do indeed take “due account” of such elements. In this newsletter we explore how the UK Court of Appeal would not at present go so far as the proponents of a Doctrine of Equivalents would have liked to have gone in the draft amendment of the Protocol put before the Diplomatic Conference.

    One way or another, unless the House of Lords has an opportunity to reconsider the matter, Catnic and the various formulations of the Protocol Questions derived from Catnic are likely to be with us for a very long time.