6.3. Using description and drawings to interpret the claims
6.3.3 Interpretation of ambiguous terms or confirmation of the text of a claim
Many decisions which use the description and drawings to interpret the claims concern the interpretation of relative, ambiguous or unclear terms or cite the description merely to confirm the most obvious interpretation of the text of a claim (e.g. T 23/86, OJ 1987, 316; T 16/87, OJ 1992, 212; T 50/90; T 952/90; T 439/92; T 458/96; T 717/98; T 556/02; T 1089/11; T 2145/13; T 694/20).
In several decisions the boards have stated that terms used in patent documents should be given their normal meaning in the relevant art, unless the description gives them a special meaning (see e.g. T 1321/04, T 25/15, T 1844/15, T 2030/20 in which the element "dip tube" was attributed a wider meaning in the light of the description. According to the established case law, the patent document may be its own dictionary (see e.g. T 311/93, T 523/00, T 1192/02, T 61/03, T 1321/04, T 620/08, T 2480/11, T 1817/14; see also in this chapter II.A.6.3.5). On this basis, the board in T 500/01 held that, a claim, the wording of which is essentially identical to a claim as originally filed, can nevertheless contravene the requirements of Art. 123(2) EPC if it contains a feature whose definition has been amended in the description in a non-allowable way (see also chapter II.E.1.14.4 "Amendment of definitions or removal of examples"). In T 1360/13 the board held that any change in the description or drawings may have an influence on the understanding of a claimed feature, in particular when it must be considered ambiguous in view of a piece of prior art or an allegedly infringing product, and may thus lead to a broadening of the extent of the protection conferred. Any information in the description and/or drawings of a patent directly related to a feature of a claim and potentially restricting its interpretation could not be removed from the patent without infringing Art. 123(3) EPC. An example can be seen in T 953/22 where amendments to a drawing modified the claimed subject-matter, even if the wording of the claims remained unamended. See also chapters II.E.2.4.2 "Deletion of feature from description where claim remains unchanged" and II.E.2.4.5 "Deletion or replacement of drawings".
According to the board in T 458/96, when the technical content of the claims and the description clearly establish how an invention operates, these features cannot be disregarded for the purposes of assessing patentability by interpreting them merely as defining an intended use.
In T 1023/02 the invention was based on the recognition that the genes for a specific viral protein (ICP34.5) expressed in infected cells determine the ability of herpes simplex viruses to destroy central nervous system tissue. The respondent argued that a post-published document revealed the existence of an ORF-P gene coincident with but anti-sense to the ICP34.5 gene. Therefore, in view of the term "only", the claim had to be interpreted as requiring that the first method step did not interfere with the expression of this ORF-P gene. The board, however, pointed out that it was apparent from the description that the patentee had not envisaged the existence of this gene. The skilled reader would therefore, in the light of the description, not interpret the subject-matter of claim 1 in the way advocated by the respondent. Accordingly post-published knowledge of further technical details and/or complications could not justify this interpretation.
In T 1409/16 the board considered that both "exclusive disjunctions" and "inclusive disjunctions" could be expressed by the "either [...] or" wording. The fact that another expression ("and/or") was used (in the sense of an inclusive "or") in another claim of the contested patent was not, as such, a compelling reason for concluding that the "either [...] or" wording used in the claim in question must have a different meaning, i.e. that it expressed an exclusive "or". There was no absolute obligation to use a fully coherent terminology for expressing given features if the latter could be expressed in different ways. The person skilled in the art reading the patent would certainly not conclude that the "either [...] or" wording of claim 1 expressed an exclusive "or", since this would mean that the exemplified (hence particularly preferred) embodiments would be excluded from the ambit of the claim. The board held that the "either [...] or" wording could only be considered as expressing an exclusive "or" in cases where the two situations referred to were, due to their very nature, mutually exclusive, i.e. incompatible with each other.
In T 439/22 the board held that the person skilled in the art would understand the term "gathered sheet", when read in isolation, as defining a sheet folded along lines to occupy a tridimensional space. Accordingly, when assigning this usual meaning to the term, the claimed subject-matter would have to be regarded as novel. However, if the same term was read in a broader but still technically meaningful manner in view of the definition given in the description, the claimed subject-matter would lack novelty. In light of the divergent case law of the boards of appeal regarding claim interpretation, the board decided to refer questions to the Enlarged Board. The second and third questions address the consultation of the description and figures when interpreting the claims to assess patentability as well as whether a definition or similar information on a term used in the claims which is explicitly given in the description may be disregarded when interpreting the claims to assess patentability and, if so, under what conditions (see in this chapter II.A.6.3.1).
- G 0001/24
In G 1/24 the Enlarged Board ("EBA") considered the points of law referred to it by Technical Board of Appeal 3.2.01 in T 439/22 of 24 June 2024. The first question was whether Art. 69(1), second sentence, EPC and Art. 1 of the Protocol on the Interpretation of Article 69 EPC are to be applied to the interpretation of patent claims when assessing the patentability of an invention under Art. 52 to 57 EPC. The second question concerned whether the description and figures are to be consulted when interpreting the claims to assess patentability and, if so, whether this may 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 third and final question was whether a definition or similar information on a term used in the claims, which is explicitly given in the description, can be disregarded when interpreting the claims to assess patentability and, if so, under what conditions.
The EBA confirmed that the departments of the EPO were required to interpret patent claims when assessing the patentability of an invention under Art. 52 to 57 EPC. As regards Question 1, the EBA held that there was no clear legal basis, in terms of an article of the EPC, for claim interpretation when assessing patentability. Article 69 EPC and Art. 1 of the Protocol were arguably only concerned with infringement actions and therefore were not entirely satisfactory as a basis for claim interpretation when assessing patentability. Article 84 EPC could also be criticised as an alternative legal basis as it addresses the content of the patent application and is formal in nature without providing guidance on how to interpret claims. It only sets out an instruction to the drafter of what needs to be in the claims and an instruction to the EPO to determine whether the claims meet that purpose. The EBA considered, however, that there was an existing body of case law of the Boards of Appeal which applied the wording of the aforementioned provisions in an analogous way to the examination of patentability under Art. 52 to 57 EPC, and from which the applicable principles of claim interpretation could be extracted.
The EBA further held it a settled point in the case law of the Boards of Appeal that the claims are the starting point and the basis for assessing the patentability of an invention under Art. 52 to 57 EPC.
As regards Question 2, the EBA stated that the description and any drawings must always be consulted when interpreting the claims, and not just in the case of unclarity or ambiguity. In adopting this position, the EBA rejected the case law of the Boards of Appeal that sees no need to refer to the descriptions and drawings when interpreting a claim, unless the claim is unclear or ambiguous. It found that this case law was contrary to the wording, and hence the principles, of Art. 69 EPC. It was also contrary to the practice of both the national courts of the EPC contracting states and the UPC. Moreover, from a logical point of view, the finding that the language of a claim is clear and unambiguous was an act of interpretation, not a preliminary stage to such an interpretative act.
Question 3 was held inadmissible by the EBA, which considered it to be encompassed by Question 2.
The EBA also referred to the harmonisation philosophy behind the EPC and noted that the case law of the UPC Court of Appeal on claim interpretation appeared to be consistent with the above conclusions. It further highlighted the importance of the examining division carrying out a high quality examination of whether a claim fulfils the clarity requirements of Art. 84 EPC, and stated that the correct response to any unclarity in a claim was amendment.
The order by the EBA in G 1/24 reads as follows: "The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC. The description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention under Articles 52 to 57 EPC, and not only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation."