The provision of Art 123(2) and (3) of the European Patent Convention (EPC) is to avoid that an applicant or proprietor improves the scope of the application or patent by way of amendments.
Various decisions of the European Patent Office (EPO) technical boards of appeal deal with this topic and have resulted in several referrals to the Enlarged Board of Appeal. A recent decision G2/10 of August 30, 2011 adds further case law and guidelines of how to comply with Art 123(2) and (3) EPC when amending the application during the substantive examination and the granted patent during opposition proceedings.
According to landmark decision G1/93 from the Enlarged Board of Appeal, a granted European patent, that contains subject matter which extends beyond the content of the application as filed and which subject matter also limits the scope of protection conferred by the patent, cannot be maintained in opposition proceedings unamended.
G1/93 provides generic guidance of how to make such amendments. In particular, G1/93 clarifies that if a limiting feature provides a technical contribution to the claims, the granted patent cannot be amended just by deleting the limiting features from the granted claims without violating Art 123(2) and (3) EPC. It is, however, allowable to replace the added subject matter with corresponding subject matter having proper basis in the application as filed. If the added subject matter does not limit the scope of the claim it can be removed.
Patent application, EPO