The Enlarged Board of Appeal of the European Patent Office (EPO) has just issued a decision concerning the interpretation of claims in a European patent. Given the importance of this issue in patent litigation, this decision was highly anticipated.
Context
Clarity of patent claims under the European Patent Convention (EPC)
To be granted by the EPO, a European patent must meet several requirements. In particular, the claims must be clear in themselves (Article 84 EPC).
The purpose of this requirement is to provide legal certainty to third parties, enabling them to reliably determine the scope of the patent, which is defined by the claims (Article 69 EPC).
Interpreting claims in post-grant proceedings
The validity of a European patent can be challenged after grant through procedures such as opposition before the EPO or revocation actions before national courts or the Unified Patent Court (UPC).
In such post-grant proceedings, various grounds can be invoked to revoke the patent, including lack of novelty or inventive step of the claimed subject matter. However, lack of clarity is not among these grounds.
In these proceedings, the way claims are interpreted plays a decisive role: depending on whether the claims are interpreted broadly or narrowly, the conclusion on novelty or inventive step may differ.
One might think that interpreting a claim should not be difficult since the EPO has verified the clarity of the claims before granting the patent.
However, despite the EPO's examination, ambiguous terms may remain in the claims of granted European patents. In this regard, we observe that EPO examiners are far less strict and rigorous than examiners from other offices (notably the US and China), especially concerning the clarity of dependent claims, which are often examined with less attention than independent claims.
The interpretation of ambiguous terms in post-grant proceedings generally raises significant difficulties.
The case T0439/22: starting point of decision G1/24
In case T 0439/22, which led to the present decision, a Board of Appeal questioned how to interpret the expression "gathered sheet" claimed in patent EP3076804. The patent proprietor argued that it should be given the meaning commonly used in the relevant field, in which case the invention would be novel; the opponent argued that the definition provided in the patent description, which was broader, should be used, in which case the invention would not be novel.
Over the years, divergences have emerged in the body of previous decisions by Boards of Appeal on this issue. The Boards disagreed on the legal basis for interpreting claims (Article 84 vs. Article 69 EPC) and on the conditions under which the description and drawings can be used to interpret the claims.
It is due to these divergences that the Board in case T 0439/22 decided to refer the matter to the Enlarged Board of Appeal.
The questions asked and the answers provided
| Question | Answer |
| 1.Should Article 69(1), second sentence EPC and Article 1 of the Protocol on the Interpretation of Article 69 EPC be applied to the interpretation of patent claims when assessing the patentability of an invention under Articles 52 to 57 EPC? | No. Articles 69 and 84 EPC are not relevant legal bases. |
| 2.May the description and figures be consulted when interpreting the claims to assess patentability, and if so, may this be done generally or only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation? | The description and any drawing arealwaysreferred to when interpreting the claims, and not just in the case of unclarity or ambiguity. |
| 3.May a definition or similar information on a term used in the claims which is explicitly given in the description be disregarded when interpreting the claims to assess patentability, and if so, under what conditions? | No answer, as the question is deemed inadmissible. |
Consequences of decision G1/24
Systematic referral to the description in claim interpretation
The answer to question 2 should put an end to the practice of some Boards of Appeal of simply ignoring the description and drawings when interpreting claims.
In its decision, the Enlarged Board of Appeal makes no secret of its intention to align with the case law of the UPC and national courts. On paper, this alignment is welcome, as it strengthens the overall coherence of the European patent legal system.
Consequences of the lack of explicit answer to question 3
To justify the inadmissibility of question 3, the Enlarged Board briefly stated that it is "encompassed" in question 2. In other words, the Enlarged Board claims that by answering question 2, it also answers question 3.
This reasoning seems difficult to understand.
Formally, question 2 was general, closed, and concerned the possibility of referring to the description and drawings (as a whole) to interpret claims. In contrast, question 3 was more specific, partly open, and asked under what conditions a definition in the description could be disregarded (which presupposes that the description is to be referred to).
Even though the wording of question 3 does not explicitly mention the potential conflict between a definition in the patent description and another definition accepted in the relevant field, it is clear that the Board of Appeal in case T 0439/22 asked question 3 so that the Enlarged Board could help resolve this conflict.
The answer to question 2 (in paragraphs 14 to 21 of decision G1/24) is completely silent on such a conflict.
Ultimately, decision G1/24 does not provide explicit assistance to the Board in case T0439/22. Based on the answer to question 2, we already know that the definition of "gathered sheet" in the description of patent EP3076804 must be "referred to" However, given the lack of an answer to question 3, it is difficult to predict whether this definition should be preferred over the (narrower) definition used in the relevant field.
That said, it is possible that some Boards will interpret decision G1/24 in the following way: since the Enlarged Board suggests that its answer to question 2 also answers question 3, this must mean that a definition provided in the description should systematically be applied to interpret the claims. In other words, "referring to the description" would mean applying its content.
Conclusion
Decision G1/24 confirms the necessity of taking the description and drawings of a patent into consideration to interpret its claims when examining their validity.
However, this decision leaves users somewhat unsatisfied, as it does not provide an explicit answer on how to resolve a conflict between multiple definitions of a claimed term, one of which is provided in the description.
This is unfortunate, as divergences between Boards of Appeal on this issue are likely to persist.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
