©busracavus/iStock

With decision T 439/22 of 24 June 2024, a referral was made to the Enlarged Board of Appeal at the European Patent Office (EPO) seeking to clarify the legal basis for interpreting patent claims for the purpose of assessing patentability; whether and under which circumstances the description and drawings may be taken into account when interpreting a patent claim; and, finally, the extent to which a patent can serve as its own dictionary.

According to decision T 439/22, the referral questions are as follows:
1. Are Article 69 (1), second sentence EPC (Extent of protection; “. . . the description and drawings shall be used to interpret the claims”) and Article 1 of the Protocol on the Interpretation of Article 69 EPC (“Article 69 should not be interpreted as meaning that . . . the description and drawings being employed only for the purpose of resolving an ambiguity found in the claims”) to be applied to the interpretation of patent claims when assessing the patentability of an invention under Articles 52 to 57 EPC?

2. May the description and drawings 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?

3. May a definition of or similar information on a term used in the claims that is explicitly given in the description be disregarded when interpreting the claims to assess patentability; and, if so, under what conditions?

“Lipase” Case in Japan
These questions are familiar to many Japanese patent practitioners, including the author of this article. This is because in the landmark decision “Lipase,” the Supreme Court in Japan needed to address similar questions 33 years ago, in 1991. While facing a situation similar to the one the EPO is currently facing with G1/24, the Supreme Court stated that when the claimed subject matter is compared with the relevant prior art for the purpose of assessing novelty and inventive step, the claimed subject matter must be determined based on the terms used in a claim in question, with the proviso that the description and drawings may be taken into account when doing so only under special circumstances, e.g., a) when the technical meaning of a term in the claim cannot be understood directly and unambiguously from the term itself, or b) when it is self-evident that the claim includes an error in light of the description and drawings.

In the “Lipase” case, even though the disputed claims merely refer to “lipase” (an enzyme that break down triglycerides into free fatty acids and glycerol), the first instance court interpreted the scope thereof when assessing novelty and inventive step such that the “lipase” was limited to “Ra lipase,” a particular type of lipase, since they believed that only “Ra lipase” was supported by the description and drawings. However, the first instance court’s interpretation was found to be unjustifiable by the Supreme Court for the above reasons, based on the Supreme Court’s finding that the term “lipase” as such is sufficiently clear.

For better understanding, it may be useful to further refer to the official commentary on this landmark decision, which states that the purpose of this decision is to clarify that interpreting a claim to assess novelty and inventive step whereby an additional technical feature that is only disclosed in the description or drawings has been incorporated into the claim is only acceptable under exceptional situations. For the sake of completeness, the same commentary added that in contrast to the above, for the purpose of understanding the claimed subject matter from a technical point of view, it is always acceptable to take into account the description as well as the drawings. The reason therefor is that in many cases, a claim tends to be somewhat difficult to understand in isolation, as it is usually drafted in such a way that only the necessary elements of the invention have been summarized therein, and thus some guidance in the description or drawings is required to fill the gap.

In comparison with G1/24, it should be noted that in the “Lipase” decision, the Court made it clear that the above rationale is applicable only when assessing novelty and inventive step, whereas G1/24 appears to also need to deal with situations in which other aspects, such as patent eligibility and industrial applicability, are assessed.

The Third Point in the Referral Questions of G1/24
In the “Lipase” case, the description in suit does not include any definition of or similar information on the term “lipase”; rather, the description states that “Ra lipase” is preferred. Thus, the “Lipase” case may not directly deal with the third point in the referral questions in G1/24, namely, the extent to which a patent can serve as its own dictionary. However, some court decisions in Japan following the “Lipase” case already appear to answer this particular legal question. For example, in H13 (Gyo-ke) No. 346, the Tokyo High Court needed to deal with an issue concerning whether or not the support requirement is met when a term used in a claim in question is unclear (and thus the claim is considered to be unsupported), but a clear definition of the term is explicitly given in the description. The Applicant argued that in light of the “Lipase” decision, the claim should be interpreted while taking the definition in the description into account if the claim is unclear when read in isolation, as is the case for the present case. In response to this argument, the Court, while not denying that taking a definition given in the description into account may be acceptable when assessing novelty and inventive step in light of the “Lipase” decision, stated that doing so is not acceptable when assessing claim requirements. The court added that a claim should be drafted whereby the meaning is clear from the wording of the claim alone as much as possible. Thus, it can be concluded that in Japan, taking a definition given in the description into account when interpreting claims to assess novelty and inventive step is acceptable under the conditions given in the “Lipase” decision.

Already Addressed, or Another Referral?
In view of the above analysis of the “Lipase” decision, as well as the developments afterwards, it seems at least on the face of it that the referral questions in G1/24 were already addressed in Japan as follows:

1. The principles “. . . the description and drawings shall be used to interpret the claims” and “. . . the description and drawings being employed only for the purpose of resolving an ambiguity found in the claims” may be applied to the interpretation of patent claims when assessing the novelty and inventive step of an invention.

2. The description and drawings may be consulted when interpreting the claims to assess novelty and inventive step, and this may be done only under special circumstances, e.g., when the technical meaning of the term in the claim cannot be understood directly and unambiguously from the term as such, or when it is self-evident that the claim includes an error in light of the description and drawings.

3. A definition of or similar information on a term used in the claims that is explicitly given in the description may be disregarded under the following conditions.
a) When interpreting the claims to assess novelty and inventive step, the above may be disregarded only when the above special circumstances do not exist.
b) When interpreting the claims to assess other aspects including patent eligibility, industrial applicability, support, and enablement etc., the above should always be disregarded.

In this context, it is intriguing to note that the case underlying G1/24 (“Heated aerosol”) concerns a situation in which it is disputed whether the term “gathered sheet” used in the claims should be given its usual meaning in the art, or whether it should be read in a broader but still technically meaningful manner in view of the definition given in the description. Thus, one might consider this case to be outside the scope of the “Lipase” decision, as the point at issue in the “Heated aerosol” case is whether it is acceptable to broaden the claim scope, rather than limit it, as is the case in the “Lipase” decision. In this context, it is true that the “Lipase” decision is often explained in legal articles, textbooks, and the like as concerning situations in which a claim in question is “too broad,” and there is a need to narrow it down in some way to come to a sensible conclusion. However, at the same time, it may still be said that in both the “Lipase” case and the “Heated aerosol” case, the issue is equally about whether it is acceptable to incorporate additional technical features that are only disclosed in the description into a claim in dispute when interpreting the scope thereof, regardless of whether doing so leads to limitation or broadening of the claim, and thus both of these cases are in the same category in which the “Lipase” decision governs. Alternatively, since, to the best of our knowledge, such a legal question (i.e., in what conditions a term used in a claim can be read in a broader than the usual meaning in the art but still technically meaningful manner in view of the definition given in the description) at the very least does not appear to be directly addressed by high-level courts in Japan in a strict sense, we might need another referral to the high-level courts.