T1791/16 – Clarity in opposition proceedings
In decision T 1791/16 dated 22 June 2021, the Board of Appeal decided that if a granted claim is unambiguous or unclear, all technically reasonable interpretations of said claim must be considered. If a single technically reasonable interpretation of the claim contains subject matter that extends beyond the content of the application as filed, the claim is considered to add matter to the application as filed and an objection to said claim may validly be raised in opposition under Article 100(c) EPC.
The claims of a pending European patent application must comply with the requirements of Article 84 EPC.
Article 84 EPC recites:
The claims shall define the matter for which protection is sought. They shall be clear and concise and supported by the description.
If a claim of a pending European patent application is deemed to not fulfil the requirements of Article 84 EPC, in any way, the examiner responsible for said application will most likely raise a clarity objection. In response to the clarity objection, the applicant will be required to amend the claim in question or submit convincing arguments in support of the clarity of said claim, for the application to proceed to grant.
However, once a patent has been granted on a European patent application, there is no provision for third parties to object to a granted claim on the ground of lack of clarity. The grounds for opposition of a granted European patent are set out in Article 100 EPC.
Article 100 EPC recites:
Opposition may only be filed on the grounds that:
- the subject-matter of the European patent is not patentable under Articles 52 to 57;
- the European patent does not disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art;
- the subject-matter of the European patent extends beyond the content of the application as filed, or, if the patent was granted on a divisional application or on a new application filed under Article 61, beyond the content of the earlier application as filed.
In other words, the claims of a granted European patent may only be objected to for failing to meet the requirements of patentability (Article 52(1) EPC[i]), for lacking sufficiency (Article 83 EPC[ii]), or for containing added subject matter (Articles 123(2) EPC[iii], 76(1) EPC[iv], and 61(1)(b) and 61(2) EPC[v]). There is no provision in the EPC for opposing a claim of a granted European patent on the ground of lack of clarity (Article 84 EPC).
However, clarity objections may validly be raised against amended claims filed during opposition proceedings under Article 101(3)(a) EPC[vi].
Occasionally, where a granted claim lacks clarity in the form of lacking support in the description as filed, said claim may validly be opposed under Article 100(b) EPC. For example, a granted claim may be so broad that it both lacks support and is not sufficiently disclosed such that a person skilled in the art is able to carry out the subject matter of said claim[vii].
Recent decision T1791/16 shows that a granted claim lacking clarity may, under certain circumstances, also be objected to under Article 100(c) EPC.
Decision T1791/16 dealt with an appeal against the decision of the opposition division to revoke European patent number EP 1611541 for failure to comply with the requirements of Article 123(2) EPC3.
The patent in suit concerned multispectral imaging biometrics and claim 1 was directed to a sensor system for obtaining multispectral image data for use in biometric authentication or identification.
During prosecution of the application, the proprietor had amended the last feature of the system of claim 1 to refer to comparing “skin features” rather than comparing “multispectral images”. The appellant (patent proprietor) and the respondent (opponent) disagreed on what was to be understood by the last feature of claim 1 as amended during prosecution: the respondent put forward a first interpretation of the last feature of claim 1 and alleged that said feature so interpreted lacked basis in the application as filed; and the appellant countered with a second interpretation of the last feature of claim 1, arguing that the respondent’s interpretation of claim 1 was unreasonable based on the disclosure of the application as filed.
The Board of Appeal (herein “the Board”) considered the interpretation of the last feature of claim 1 put forward by the respondent and found this interpretation to be a technically reasonable one on the basis of application as filed[viii], which, according to the Board, did not make clear what was meant by “skin features”[ix]. The Board agreed that the last feature of claim 1, so interpreted as put forward by the respondent, lacked basis in the application as filed[x].
The Board did not exclude the second interpretation of the last feature of claim 1, put forward by the appellant, from also being technically reasonable. The Board concluded that the last feature of claim 1 could reasonably be interpreted in various ways. The Board considered that, in the interest of legal certainty on the subject matter covered by a granted claim, all technically reasonable interpretations of said claim must be considered. If one of those interpretations contains matter that extends beyond the content of the application as originally filed, it must be concluded that a breach of Article 100(c) EPC has occurred8.
Accordingly, the Board upheld the decision of the opposition division to revoke the patent for infringing Article 123(2) EPC3.
While it may be desirable, from the perspective of obtaining the greatest scope of protection, to allow claims to grant in their broadest possible form, decision T1791/16 highlights the danger of allowing ambiguous claims to grant, which may reasonably be interpreted in a variety of ways. If just one interpretation of a granted claim extends beyond the content of the application as filed, that claim is open to being objected to under Article 100(c) EPC.
Whether an interpretation of a claim is considered technically reasonable must be considered on a case by case basis. In decision T1791/16, contradictory statements in the description, regarding the meaning of the term “skin features”, led to the Board finding this term to be ambiguous and considering the respondent’s interpretation of claim 1 to be technically reasonable.
When drafting patent applications, it is important to ensure that the meaning of all terms used in the claims is clearly and unambiguously defined in the description.
Furthermore, applicants should always review allowed claims for any ambiguities that may not have been picked up by the examiner prior to grant.
[i] Article 52(1) EPC: European patents shall be granted for any inventions, in all fields of technology, provided that they are new, involve an inventive step and are susceptible of industrial application.
[ii] Article 83 EPC: The European patent application shall disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art.
[iii] Article 123(2) EPC: The European patent application or European patent may not be amended in such a way that it contains subject-matter which extends beyond the content of the application as filed.
[iv] Article 76(1) EPC: A European divisional application shall be filed directly with the European Patent Office in accordance with the Implementing Regulations. It may be filed only in respect of subject-matter which does not extend beyond the content of the earlier application as filed; in so far as this requirement is complied with, the divisional application shall be deemed to have been filed on the date of filing of the earlier application and shall enjoy any right of priority.
[v] Article 61 EPC: If by a final decision it is adjudged that a person other than the applicant is entitled to the grant of the European patent, that person may, in accordance with the Implementing Regulations:
(a) prosecute the European patent application as his own application in place of the applicant;
(b) file a new European patent application in respect of the same invention; or
(c) request that the European patent application be refused.
[vi] Article 101(3)(a) EPC: If the Opposition Division is of the opinion that, taking into consideration the amendments made by the proprietor of the European patent during the opposition proceedings, the patent and the invention to which it relates
- meet the requirements of this Convention, it shall decide to maintain the patent as amended, provided that the conditions laid down in the Implementing Regulations are fulfilled
[vii] Guidelines D-III, 5
[viii] No 11 of the reasons for decision T1791/16
[ix] No 9 of the reasons for decision T1791/16
[x] No 10 of the reasons for decision T1791/16