Claim interpretation in Europe – G1/24

The Enlarged Board of Appeal (EBoA) of the European Patent Office (EPO) has recently issued its decision on G1/24. This eagerly awaited decision (on which over 30 amicus curiae briefs were filed by third parties) looks at whether the interpretation of patent claims should focus solely on the wording of the claims themselves, or whether the accompanying description and drawings should also be used to interpret the claims.

The EBoA has decided that the claims are the starting point and the basis for assessing the patentability of an invention, and that the description and drawings shall always be consulted to interpret the claims (and not only if the skilled person finds a claim to be unclear or ambiguous when read in isolation). The findings of this important decision are likely to significantly shift how patent claims are interpreted in examination and opposition proceedings before the EPO, and bring EPO practice into closer alignment with that of national courts and the Unitary Patent Court.

Background

The decision stems from an opposition filed against European Patent EP3076804, granted to Philip Morris Products S.A on 31 July 2019, for a “heated aerosol-generating article” intended for use with an electrically operated aerosol-generating device.

A key feature of claim 1 of this patent is that the article comprises an “aerosol-forming substrate comprising a gathered sheet of aerosol-forming material”. The electrically operated device heats, rather than burns, the aerosol-forming substrate (for example, tobacco) to produce an aerosol that is inhaled by the user.

Claim 1:

1. A heated aerosol-generating article (1000, 2000) for use with an electrically-operated aerosol-generating device (3010) comprising a heating element (3100), the aerosol-generating article comprising an aerosol-forming substrate (1020, 2020) radially encircled by a sheet of thermally-conductive material (1222, 2222), in which the aerosol-forming substrate comprises a gathered sheet of aerosol-forming material circumscribed by a wrapper, the wrapper being the sheet of thermally-conductive material which acts as a thermally-conducting flame barrier for spreading heat and mitigating against the risk of a user igniting the aerosol-forming substrate by applying a flame to the aerosol-generating article.

Fig. 2 of patent:

Yunnan Tobacco International opposed the patent, arguing that prior art document D1, which describes a “spirally wound” tobacco sheet, anticipates claim 1 because a spirally wound sheet is equivalent to a “gathered” sheet. To support this, Yunnan Tobacco drew attention to paragraph [0035] of the patent, which defines “gathered” as a sheet that is “convoluted, folded, or otherwise compressed or constricted substantially transversely to the cylindrical axis of the rod”. They argued that this definition includes the spirally wound configuration of D1 because spiral winding constitutes a form of transverse constriction relative to the cylindrical axis and therefore falls within the scope of the claim.  In other words, when the claim term “gathered” is interpreted based on the accompanying description, the term is broad enough to encompass spirally wound sheets and therefore lacks novelty over D1.

Conversely, Philip Morris argued that “gathered” has a well-established meaning in the technical field of the patent and a skilled person would understand that the spirally wound sheet of D1 is not gathered. Therefore, the claim is novel over D1.

In first instance proceedings, the Opposition Division sided with Philip Morris, agreeing that the term “gathered” has a clear and established meaning in the relevant technical field, and that a rolled/spirally wound sheet as disclosed in D1 is not a gathered sheet within the meaning of claim 1. In particular, the Opposition Division held that the term “gathered” implies that the sheet is geometrically modified into a more complex shape in analogy to “gathering” used as a sewing technique. The Opposition Division cited the below image from the Wikipedia entry on this sewing technique:

Source: https://en.wikipedia.org/wiki/Gather_(sewing)

Claim 1 was therefore found to be novel over D1 (and also patentably distinct from other cited prior art) and the opposition was rejected.

Conflicting approaches to claim interpretation

Yunnan Tobacco appealed the Opposition Division’s decision to reject the opposition. The appeal, filed on 30 April 2020, again focused on the interpretation of “gathered”. The Board of Appeal noted that the outcome of the case hinged on whether the description is to be taken into account even when interpreting a claim for which the wording is clear, and that there was diverging case law on whether the description should be taken into account.

(1) Construction based on the ‘classical’ approach (Article 84 EPC):

A first line of decisions, such as T 056/21 and T 0169/20, adhere to what the Board has referred to as the “classical approach” to claim interpretation. This approach has been more widely adopted by the EPO. In T 0169/20 it was found that Article 84 of the European Patent Convention (EPC) and related rules exclusively govern claim interpretation during examination. Article 84 EPC stipulates that the claims define the scope of protection:

Article 84 EPC: The claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description.

Similarly, in T 056/21 it was held that the EPC does not require applicants to amend the description to align with the claims. The Board emphasised that the claims define the scope of protection, while the description provides context and details. Requiring amendment of the description was deemed to lead to unnecessary changes and not enhance legal certainty.

In these earlier decisions, the claims were treated as self-contained, with the description used only in exceptional circumstances (e.g. ambiguous claims) and never to override clear claim language. This was the approach followed by the Opposition Division in the first instance proceedings of the present case: it was held that the term “gathered” has an ordinary meaning that is not anticipated by the spirally wound sheet of D1.

(2) Construction based on the description and drawings (Article 69 EPC):

A second line of decisions adopt the opposite view. For example, in T 1473/19, the Board held that Article 69 EPC (and the accompanying Protocol on the interpretation of Article 69 EPC) apply during examination and opposition proceedings. Article 69 EPC requires that the description and drawings are used to interpret the claims:

Article 69(1) EPC: The extent of the protection conferred by a European patent or a European patent application shall be determined by the claims. Nevertheless, the description and drawings shall be used to interpret the claims.

In T 1473/19 it was decided that claims must therefore be read in light of the description and drawings, including when claim validity is at issue, such as in cases of added subject-matter.

An argument against adopting this second approach is that Article 69 EPC refers to the extent of protection of the claims, whereas examination and opposition proceedings at the EPO are only ever concerned with assessing the validity of the claims. This is in contrast with national courts and the Unitary Patent Court (UPC), where the extent of protection of the claims is at issue, and these courts do interpret the claims in view of the description and drawings (as required by Article 69 EPC). However, this argument itself raises a concern with adopting the first “classical approach”: namely that a patentee could potentially argue for a relatively narrow interpretation during proceedings before the EPO (arguing that a claim term has a clear meaning and thus the description and drawings do not need to be consulted), and then argue for a different (and potentially broader) interpretation of the same claim term based on the description and drawings during proceedings before national courts or the UPC.

These conflicting approaches to claim interpretation outlined above presented a challenge for the Board of Appeal, which acknowledged the divergent case law on using the description and drawings to interpret claims. Both the Opposition Division and the Board of Appeal noted that the ordinary meaning of “gathered”, understood analogously to sewing techniques like pleating or bunching, was narrower than the definition provided in the patent description. Given the divergence in the case law and the importance of the issues, the Board referred the following questions to the EBoA.

The questions referred to the EBoA

Question 1: Application of Article 69(1) EPC during examination:

Is Article 69(1), second sentence EPC and Article 1 of the Protocol on the Interpretation of Article 69 EPC to be applied on the interpretation of patent claims when assessing the patentability of an invention under Articles 52 to 57 EPC?

Question 2: Role of the description and drawings:
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?

Question 3: Definitions in the description:

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?

Arguments at oral proceedings

In the discussion of Questions 1 and 2 at the oral proceedings held by the EBoA, Yunnan Tobacco argued for a new “diamond standard” approach to claim construction, emphasising that claims should be interpreted in light of the description and drawings to ensure the scope of protection aligns with the inventor’s disclosed technical contribution, as required by Article 69 EPC. Philip Morris, on the other hand, maintained the primacy of claim wording, arguing that claims should be interpreted independently of the description, as stipulated by Article 84 EPC, to maintain legal certainty. They cautioned against allowing the description to broaden claim scope, citing potential inconsistencies with established case law like G 2/12. Meanwhile, the EPO President argued that the description is a tool to clarify ambiguous claim terms but should not redefine them, aligning with the principle of claims being as self-contained as possible.

With regards to Question 3, Yunnan Tobacco argued that definitions in the description are critical for clarifying the intended meaning of claim terms and should not be disregarded. In their view, doing so would introduce legal uncertainty and undermine the applicant’s ability to define technical language within the application. In contrast, Philip Morris maintained that if a claim term is clear on its face, there is no need to refer to the description, arguing for strict claim primacy and against importing meanings from the description absent ambiguity. The EPO President concurred, acknowledging that while the description can offer valuable context, any specialised meaning intended by the applicant must be expressly set out in the claims.

G 1/24 – The decision

In the decision, the EBoA has summarised that the two conflicting positions on claim interpretation are based on either Article 69 EPC (and the accompanying Protocol) or Article 84 EPC. However, interestingly, the EBoA considers that neither Article 69 nor 84 EPC are “entirely satisfactory” as a legal basis for claim interpretation when assessing patentability. The EBoA notes that Article 69 EPC and the Protocol are only concerned with infringement actions before national courts and the UPC. On the other hand, Article 84 EPC concerns the content of the application and does not mention the invention or provide guidance on how to interpret the claims, instead only providing an instruction of what needs to be in the claims. The EBoA therefore concludes that there is in fact no clear basis in the EPC for claim interpretation when assessing patentability and that therefore, strictly speaking, Question 1 should be answered negatively. Nevertheless, the EBoA reasoned that there is an existing body of case law of the Boards of Appeal from which the relevant principles of claim interpretation can be extracted.

Following from the above, the EBoA decided that in respect of Question 2:

• 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 any drawings are always referred to when interpreting the claims, and not just in case of unclarity or ambiguity.

The EBoA rejected the diverging case law in which the description and drawings are only consulted when a claim term is unclear or ambiguous, i.e. the “classical approach”. The EBoA noted that this would be contrary to Article 69 EPC and also the practice of national courts and the UPC.  Furthermore, the assessment that the language of a claim is clear or ambiguous is itself an act of interpretation, not a preliminary stage to such an interpretative act.

It was noted that it would be “a most unattractive proposition” that the EPO deliberately adopts a principle of claim interpretation that is contrary to the practice of the tribunals that are downstream of the patents that it grants. In this regard, the EBoA cited the harmonisation philosophy behind the EPC that was raised in the earlier decisions of G5/83 and G3/08, wherein it was held to be incumbent upon the EPO, and particularly its Boards of Appeal, to take into consideration the decisions and expressions of opinion of courts and intellectual property offices in the contracting states of the EPC. The Board referred to the current case law of the UPC, including NanoString Technologies v 10x genomics (ORD_595990/2023, which we reported on here), and noted that its decision in the present case that the description and any drawings are always referred to when interpreting the claims (and not only if the claims are unclear or ambiguous) is consistent with this UPC case law.

Regarding Question 3, the EBoA held that this is encompassed within Question 2, and therefore is inadmissible because an answer is not required for the Referring Board to reach a decision on the case before it.

Conclusion

The use of the “classical approach” to claim interpretation at the EPO is widespread and therefore it will be interesting to see the consequences of rejecting this approach and whether this will significantly increase the complexity of the examination procedure. In fact, the EBoA highlighted the importance of the examining division carrying out a high quality examination of whether patent claims fulfil the clarity requirements of Article 84 EPC, and noted that the correct approach to any unclarity in a claim is amendment.

It is worth remembering that the contracting states to the EPC have a large number of different official languages, and that via the London Agreement many countries have agreed to only require translation of the claims (and not the description) into their own official language. The decision therefore means that in cases where the translated claims have a first interpretation but a second broader interpretation is “hidden” in the (untranslated) description, this second interpretation should (in principle) have been considered by the EPO before deciding to grant the patent. This should therefore give greater clarity to third parties.

Following the decision, it may be that EPO examiners are now likely to scrutinise the description even more closely upon allowance of an application, particularly where embodiments in the description do not fall within the ordinary scope of the claims. In these situations, examiners may insist on stricter revisions to align description and drawings with claim language, potentially increasing revisions to ensure full consistency and avoid ambiguity or scope issues in future. This requirement can already be quite onerous for applicants, and there will potentially be a separate EBoA referral on T 0697/22 regarding whether such description amendments are necessary.

Patentees should take extra care in view of the decision when drafting the description and preparing the associated drawings, to ensure that these are consistent with the intended scope of the terms used in the claims. Meanwhile, parties should consider reviewing their pending cases before the EPO in light of the decision, to check whether there are any arguments around interpretation based on the description or drawings that could result in a favourable outcome. For example, in post-grant opposition proceedings, an Opponent may be able to argue that the claims lack novelty or inventive step based on a broader/different interpretation of a claim term relying on the description or drawings (e.g. if the Opposition Division has previously interpreted the claims more narrowly based on the rejected “classical approach”).

The decision should ultimately provide greater consistency in claim construction, with the aim of avoiding patent claims from being interpreted differently at the EPO and before national courts and the UPC.