Claim interpretation using the description: Potential referral to the EPO Enlarged Board of Appeal
The role of the description in the interpretation of the claims of a patent or patent application by the European Patent Office (EPO) has been a much-discussed issue in several recent EPO decisions1. In the ongoing appeal case T 439/22, the EPO Board of Appeal (“the Board”) has indicated that, due to diverging EPO case law on this issue, they intend to refer questions to the Enlarged Board of Appeal to clarify if, and under what circumstances, the description of a patent specification can be used to interpret the language of a claim. An interlocutory decision from the Board, including the referred questions, is expected to be issued on 10 June 2024.
Appeal Case T 0439/22
As highlighted by their preliminary opinion, the Board believes the outcome of this case depends on if the description can be used to interpret the language of the claims. A key term in the claims of the patent in question, EP30768042, is at face value deemed clear. However, if this term is viewed in light of the description, a much broader interpretation of the term would be favoured. This broader interpretation could result in the claimed invention being found to lack novelty over a prior art disclosure. The case therefore hangs on how the language of the claim is interpreted.
In its preliminary opinion, the Board emphasised that it believes a referral to the Enlarged Board of Appeal is required due to a divergence in recent EPO case law regarding use of the description to interpret claim features in the assessment of patentability. The Board highlighted one line of case law, exemplified by T 1473/193, requiring consideration of the description for claim interpretation, with basis for this approach to be found in Article 69 EPC. A second line of case law highlighted by the Board, exemplified by T 169/204, only allows use of the description for claim interpretation in exceptional cases where the language of the claims require clarification, with basis for this approach found in Article 84 EPC. However, although not discussed by the Board in their preliminary opinion, both cases stress the principle of the primacy of the claims, where the wording of the claims takes precedence in respect of claim interpretation.
Claim interpretation at the EPO
The two divergent lines of case law highlighted by the Board are based on different Articles of the European Patent Convention (EPC) either referencing Article 84 or 69 EPC.
Article 84 EPC requires that ‘the claims shall define the matter for which protection is sought.’ This has been used in certain lines of case law (e.g. T 0256/195 and T 169/20) to require that the claims should be interpreted on their own merits, without or with limited recourse to the description. However, it is unclear if Article 84 necessarily provides a statutory restriction on the use of the description to interpret the claims, or instead sets out the principle of the primacy of the claims while still allowing for interpretation using the description in certain circumstances.
In contrast, Article 69 EPC provides that ‘the extent of the protection conferred by a European patent, or patent application shall be determined by the claims. Nevertheless, the description and drawings shall be used to interpret the claims.’ This has been used in other lines of case law (e.g. T 1473/19) to require that that the claims should be interpreted in light of the description and drawings. However, from the language used in Article 69, it appears the Article determines claim interpretation in post-grant infringement proceedings rather than in proceedings before the EPO.
Additionally, there is no consistent approach to in what circumstances the description should be used to interpret the claims. The Protocol on the Interpretation of Article 69 EPC defines a large range of positions for the extent of protection, as being between at one extreme ‘defined by the strict, literal meaning of the wording used in the claims’ and the other extreme that ‘the claims serve only as a guideline’. Following the Protocol, national courts and the Unitary Patent Court (UPC) generally appear to take the description into account when interpreting the claims, even in cases where the claims themselves are deemed clear at face value. However, favouring a body of EPO case law which includes T 1473/19, recently the EPO has used the description to interpret the claims only when the claims themselves are unclear, even in cases where the claims themselves are seemingly clear but contradict the description.
The Board in T 439/22 appears to consider that the difference in approach between the EPO and national courts results in a point of law of fundamental importance, as it should be a general principle that claims are interpreted in a consistent manner through both pre-grant and post-grant proceedings to avoid broadening the scope of claims post grant.
Referral to the Enlarged Board of Appeal
The Board in the present case therefore intends to refer questions to the Enlarged Board of Appeal to ensure uniform application of the law within the Boards of Appeal, and because of the apparent divergence in case law between the Boards of Appeal and national courts.
The questions the Board intends to refer to the Enlarged Board of Appeal have not yet been published, and it is not known if the Enlarged Board of Appeal will accept the referral. However, in our view it would be useful if the following questions were referred to the Enlarged Board of Appeal:
1. Does Article 69 EPC allow for use of the description in the interpretation of a feature of a claim of a European patent application or a European patent for the assessment of patentability?
2. Does Article 84 EPC allow for use of the description in the interpretation of a feature of a claim of a European patent application or a European patent for the assessment of patentability?
3. If the answer to either of the first or second question is yes, can the description be used in the interpretation of a feature of a claim for the assessment of patentability where the feature of the claim is deemed clear from the wording of the claim alone, and would the answer to this question be different where the feature of the claim as interpreted by the wording of the claim alone would be inconsistent with the embodiments disclosed in the description?
4. Would any of the answers to the above questions be different where the approach as espoused by the answers to the above questions is contradictory to the approaches to the interpretation of a feature of a claim taken by national courts of EPC Contracting States and/or the Unitary Patent Court?
This possible referral promises to clarify the approach taken by the EPO towards claim interpretation. We await confirmation of the referred questions and news on whether the Enlarged Board of Appeal will accept the referral.
______