With ruling T 439/22, several questions regarding the interpretation of patent claims for the assessment of substantive patentability have been referred to the Enlarged Board of Appeal of the European Patent Office (EPO). The referral is pending as G 1/24 and, in particular, raises the question of whether the description and figures can be consulted when interpreting claims, and, if so, whether a patent can serve as its own dictionary. The answer to these questions was considered decisive for the outcome of T 439/22 in view of the following fact pattern: The description of the opposed patent provided a specific definition for one of the terms in claim 1; this definition was broader than that commonly used in the art; when interpreting the claims on the basis of the broader definition, the subject matter claimed was anticipated by the prior art, whereas when interpreting the claims on the basis of the more narrow definition commonly used in the art, the subject matter claimed was not anticipated. In this case, the assessment of novelty therefore hinges on whether the specific definition provided in the description of the patent at issue or the interpretation based on common general knowledge should be applied by the skilled person. Divergent case law of the Boards of Appeal on these aspects of claim interpretation was identified and as a result, the case had to be referred to the Enlarged Board of Appeal to ensure uniform application of the law on this point of fundamental importance.
“Virtue lies in the middle ground.” (Jose Rizal) – provisions of the European Patent Convention (EPC) on claim interpretation
The claims of a European Patent have to be interpreted in proceedings before the EPO as well as in infringement proceedings before the UPC or the national Courts. The EPC provides specific provisions for interpreting claims to determine the extent of protection. According to § 69 EPC and its Protocol, the extent of protection conferred by a European Patent is determined by using the description and drawings to interpret the claims. This implies that neither a strict, literal meaning of the wording used in the claims should be relied upon for interpretation, nor should the claims be considered to serve merely as a guideline for inferring the extent of protection from the description and drawings. On the contrary, the claims should be interpreted as resulting from a middle ground between these two extremes indicated in Article 1 of the Protocol on the Interpretation of § 69 EPC. In this manner, a combination of fair protection for the patent proprietor can be combined with a reasonable degree of legal certainty for third parties.
The EPC itself does not contain explicit instructions for interpreting claims to assess substantive patentability. However, at least the Guidelines for Examination in the EPO (Part F, Chapter IV, Point 4.2) stipulate that the meaning of the claim should be clear from the wording of the claim alone. This approach is clearly distinct from the middle ground rationale stipulated in the specific provisions of Article 69 EPC and its Protocol for infringement proceedings before European Courts. Instead of consulting the description and drawings for interpreting the claims, the EPO’s 1st instance divisions are encouraged to rely on the literal meaning of the wording used in the claims alone.
The situation for appeal proceedings before the EPO is less clear-cut. As indicated above and extensively discussed in T 439/22, the case law of the Boards of Appeal on claim interpretation, in particular with regard to the question whether the description and figures can be consulted when interpreting the claims, diverges:
“Diversity: The art of thinking independently together.” (Malcolm Forbes) – case law of the Boards of Appeal on claim interpretation
In T 439/22, the referring Board identified 100 previous appeal rulings dealing with claim interpretation since 2008. The rulings were found to diverge on the following points:
On a formal level, the rulings were assigned to one of three different categories in view of the legal basis for claim construction specified therein:
- The majority of the rulings (52%) held that, in assessing substantive patentability, Article 69 EPC and its Protocol must not be applied, because the explicit reference therein to the “extent of protection conferred” precludes these provisions from being used for any other purpose than for determining the “extent of protection conferred”.
- A significant number of rulings (26%) held that, in assessing substantive patentability, Article 69 EPC and its Protocol must be applied, because these provisions provide the only basis for construing claims in the EPC at all and consequently, should be applied over the whole realm of the EPC including the assessment of substantive patentability.
- The remaining rulings (22%), although dealing with claim interpretation in assessing substantive patentability, did not specify any legal basis for doing so.
On a substantive level, the rulings evaluated were found to diverge on the question whether it is a prerequisite that the claim wording when read in isolation is found to be unclear or ambiguous for taking the figures and description into account when construing a patent claim:
- There are rulings that take the description and figures into consideration in any case when construing a claim.
- Other rulings take the description into consideration without raising the question of potential ambiguities in the claims.
- Still other rulings leave the question unanswered stating that, even when consulting the description and figures, neither limiting features should be read into the claim, nor should an existing feature in a claim be disregarded with reference to information given only in the description.
- Finally, some rulings state that the claims should essentially always be interpreted on their own, i.e., without consulting the description and figures at all.
Ultimately, the rulings evaluated were also found to diverge regarding the extent to which definitions given in the description for certain terms may influence the interpretation of these terms used in the claims (i.e., extent to which a patent can serve as its own dictionary):
- Some rulings state that the patent as a legal document may be its own dictionary and rely on the finding that the EPC does not require that terms used in different patents always have the same meaning.
- Many rulings underline that the support of the description should not be used to restrict or modify the subject-matter of the invention as claimed beyond what a skilled person would understand when reading the wording of the claims (known as the principle of the primacy of the claims).
- Even where a claim was found to be unclear, some rulings follow this approach.
- Some rulings postulate that claims should always be construed on their own merits without taking anything from the description.
- Other rulings disregard information, including definitions, in the description if the claim read on its own is found to be clear.
- Some rulings disregard definitions and other information from the description only if they are found to contradict the ordinary meaning of terms used in the claim.
- Several rulings hold that, where this is possible, any mismatch between claims and a definition in the description should be resolved by amending the claims.
In a nutshell, in T 439/22, the referring Board’s evaluation revealed that the case law of the Boards of Appeal on claim interpretation diverges in various directions in at least three dimensions. Thus, a ruling from the Enlarged Board is required, in particular when taking into account that the claim construction of the EPO has to be viewed within the greater context of the European Patent protection system as a whole.
“To put everything in balance is good, to put everything in harmony is better.” (Victor Hugo) – G 1/24 provides an opportunity to pave the way for a coherent approach to claim interpretation by the EPO and by European Courts
All stakeholders must have a vital interest in a patent system that applies the same interpretation of claims in examination, opposition and infringement proceedings. Otherwise, European Patents could be granted or maintained in view of prior art embodiments, which were not found to fall within the claims in the assessment of substantive patentability by the EPO, whereas the same embodiment would be considered to represent literal infringement of the patent. Similarly, embodiments described in the prior art could be found to anticipate the subject matter claimed, even though the scope of protection provided by the claims does not encompass these embodiments. Both scenarios would be very dissatisfactory.
As explained above, in infringement proceedings before European Courts claim interpretation is based on the specific provisions of Article 69 EPC and its Protocol, i.e., a middle ground practice, which interprets the claims on the basis of the description and the drawings. The referral ruling, T 439/22, cites a number of rulings from national Courts and the UPC, which conclude that the description and the drawings must always be used as aids for the interpretation of a patent claim and not only to resolve ambiguities in a patent claim. Applying the same legal standard in the proceedings before the EPO appears to be the only way to achieve the required coherence in claim interpretation before the EPO and European Courts.
It remains to be seen whether the Enlarged Board will use the opportunity to provide a significant contribution towards harmonized claim interpretation. Until then, the EPO’s 1st instance divisions will continue with business-as-usual. The President of the EPO has decided that proceedings should continue while referral G 1/24 is pending, meaning that 1st instance divisions will continue to apply the above indicated practice set out in the Guidelines for Examination in the EPO.
Author
Dr. Albrecht von Menges
Uexküll & Stolberg, Hamburg
Patent Attorney, Partner