UK claim interpretation: “purposive construction” Peter Hale

Kilburn & Strode Established in 1906 Total staff fee earners 18 partners 17 IT and electronics professionals 14 life sciences professionals

Peter Hale Degree in Communication Engineering UK and EPO Attorney Qualified Patent Attorney Litigator Partner - Kilburn & Strode

Bill Neobard - Partner Degree in Electrical & Electronic Engineering Member of Institution of Electrical Engineers (“IEE”) UK and EPO Attorney Partner Kilburn & Strode Former Patent Office Senior Examiner

Ron Camp Degree in Electronic Engineering Member of IEE UK and EPO Attorney Senior Associate - Lead LGE prosecuting attorney Former Patent Office Senior Examiner

Claim Interpretation - Background Claim construction historically: Old UK approach – claim broadly and interpret a hard boundary (pre 1980) German approach – claim the “thing” (narrowly) and interpret a soft penumbra or “cloud” around the claim

EPO Claim Interpretation European Patent Convention (“EPC”) had to reconcile these two positions: Article 69 EPC “The extent of protection conferred by a European patent or European patent application shall be determined by the terms of the claims. Nevertheless, the description and drawings shall be used to interpret the claims.”

EPO Claim Interpretation The Protocol on the Interpretation of Article 69 EPC “The Protocol”: Article 69 should not be interpreted in the sense that the extent of 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...

EPO Claim Interpretation …Neither should it be interpreted in the sense 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 patentee has contemplated…

EPO Claim Interpretation …On the contrary, it is to be interpreted as defining a position between these extremes which combines a fair protection for the patentee with a reasonable degree of certainty for third parties.

EPO Claim Interpretation The Protocol a diplomatic solution – vague UK courts “That’s what we have been doing all the time” German courts “That’s what we have been doing all the time” National courts look to EPO for guidance – this was no great help and did not converge courts on interpretation

EPO Claim Interpretation In December 2007 “EPC 2000” comes into force Many changes – which we will come back and tell you about! Includes change to The Protocol appears to enable German courts to interpret narrowly (like UK) while still allowing for variants

EPO Claim Interpretation The Protocol Article 2 (EPC 2000) adds: “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.” ???“due account”??? We have to wait and see…

UK Claim Interpretation Claim interpretation must be: A question of law Based on a reading of patent as a whole Be sensible Be “purposive” not literal, ie. “in conformity with the stated object of the invention”

The Catnic case Approach to interpretation based on House of Lords case Catnic v. Hill & Smith [1982] (“Catnic”) Patent granted under “old” UK Patents Act 1949 but interpretation not affected by move from claims under common law to statute law of “new” UK Patents Act 1977.

The Catnic case A metal support for a wall above (e.g.) a door frame (a “lintel”) Claimed as a box structure with a back plate extending “vertically”

The Catnic case Infringement had a back plate that was 6-8 degrees out of vertical

The Catnic case House of Lords held that there was no good reason why patentee would want to limit claim strictly to the vertical – purposive approach – what was the job the invention is designed to do?

The Improver case Court of Appeal case Improver v Remington [1990] Judge Hoffman set out 3 questions based on “purposive construction” from Catnic – “The Protocol Questions”: 1.Does the variant have a material effect on the way the invention works? If yes, the variant is outside the claim. If no- 2.Would this (that the variant had no material effect) have been obvious at the date of publication of the patent to the reader skilled in the art. If no, the variant is outside the claim. If yes-

The Improver case 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. Used a lot since then in more or less the same format-15 years since the Improver case took a fundamental look at claim interpretation, and 25 years since Catnic.

Kirin Amgen v TKT case House of Lords case Kirin Amgen v TKT [2005] Infringement of patent to erythropoietin. Issue of interpretation of “host cell” in the claim – was it limited to host for exogenous DNA or did it also cover virally promoted DNA in the cell – the infringement? Started out using Protocol Questions…

Kirin Amgen v TKT case Problem was that the second Protocol question did not work. The technical field was new and fast moving – expert witness said he was “surprised” the hosting technique worked! Would this (that the variant had no material effect) have been obvious at the date of publication of the patent to the reader skilled in the art? If no, the variant is outside the claim. How can you decide on “obviousness” of the variant when skilled person had no knowledge of the field which was new? So, Protocol Question #2 was seen to fail

Kirin Amgen v TKT case Lord Hoffman (same judge but now a Lord!) gave main judgment and commented: Article 69 of the European Patent Convention (EPC) indicates that the scope of protection is determined by the claims Protocol is for interpreting Art 69 and not claims Protocol makes it clear that a literal interpretation of the meaning of the claims is not acceptable (old UK style) Neither is the use of the claims as a mere guide to the scope of protection conferred (German style) These principles are part of UK Patents Act and so also apply to claim construction in this country and are consistent with Catnic case. (“That’s what we have been doing all the time”)

Kirin Amgen v TKT case What matters is the question asked by the Protocol: “What would the person skilled in the art have understood the patentee to have intended to mean by the language used in the claim?” Hoffman’s Protocol Questions on purposive construction from the Improver case are not legal rules, but guidelines which may be used in suitable cases to assist the court. In some cases, particularly cases involving a rapidly-evolving, high technology field, the questions may not be appropriate. Equivalents can be a guide to claim construction only (see EPC 2000)

Kirin Amgen v TKT case “Purposive construction does not mean that one is extending or going beyond the definition of technical matter for which the patentee seeks protection in the claims. The question is always what the skilled person in the art would have understood the patentee to be intending the language of the claims to mean. And for that purpose, the language he has carefully chosen is usually of critical importance.” (Hoffman)

Kirin Amgen v TKT case “No doubt there will be patent lawyers who are dismayed at the notion that the Protocol Questions do not provide an answer in every case. They may feel cast adrift on a sea of interpretive uncertainty. But that is the fate of all who have to understand what people mean by using language.” (Hoffman)

Conclusion Claim interpretation must be: A question of law Based on a reading of patent as a whole Be sensible Be “purposive” not literal, ie. “in conformity with the stated object of the invention”

Has anything changed? Thank you