T 2174/16 - Broader dependent claim

 Key points

• Claim 1 as granted specifies particles of at least 20 nm*, dependent claim 3 as granted specifies at least 15 nm; in opposition the patentee combines claims 1 and 3. The questions is whether this is permitted under Art. 123(3) ?
• The feature at issue is actually the ' span value' of the particles, but this is not relevant for the decision.
• The Board: “Since the lower limit of the span value in claim 1 of the main and first auxiliary requests is lower than that in granted independent claim 1, and its dependent claims, namely 15 nm instead of about 20 nm, the scope of protection which would be conferred by claim 1 of the main and first auxiliary requests is broader than the scope of protection conferred by the claims as granted, such that the requirements of Article 123(3) EPC are not satisfied (also see T1702/12; point 4 of the reasons).”
• “The Board points out that establishing the scope of protection is a question of law. Indeed, scope of protection is an issue which is typically decided by a judge in infringement proceedings. Thus the claims are not only to be read with the understanding of the technically skilled person, but also by the lawyer, and their scope has to be established accordingly. The overall purpose of the provisions of Article 123(3) EPC is primarily a legal purpose, namely legal certainty for third parties that they will not be confronted with broader claims after amendments made in opposition. Therefore the principle of legal certainty which is of upmost importance with regard to scope of protection conferred by the patent as granted must be taken into account and the general principle that a claim drafted as dependent claim contains all the features of the independent claim to which it refers must normally apply, as far as possible with a reasonable claim interpretation.”

 T 2174/16 -

https://www.epo.org/law-practice/case-law-appeals/recent/t162174eu1.html

decision text omitted.