3.2.3 Overlapping scope of protection

In T 1391/07 the board noted that the practice of prohibition of "double patenting" was confined to patents and applications relating to the same invention as defined by the subject-matter of the corresponding claims and therefore confined to claims conferring notionally the same scope of protection. It saw no basis for extending this practice to cover claims not defining the same subject-matter but conferring – as in the case before it – a scope of protection overlapping with each other only partially in the sense that some, but not all of the embodiments notionally encompassed by one of the claims would also be encompassed by the other one of the claims. In particular, the lack of legitimate interest of an applicant in obtaining two patents for the same subject-matter – as invoked by the Enlarged Board in decisions G 1/05 date: 2007-06-28 (OJ 2008, 271) and G 1/06 (OJ 2008, 307) – cannot be invoked when the scopes of protection conferred by the respective subject-matters overlap only partially with each other as there is no manifest objective reason to deny the legitimate interest of the applicant in obtaining a protection different from – although partially overlapping with – that of the parent patent already granted. Accordingly, the board concluded that the mere fact that the scope of protection notionally conferred by the claim in suit would partially overlap with that of the granted parent patent did not prejudice the grant of a patent (see also T 587/98, OJ 2000, 497; T 877/06, T 1491/06, T 2461/10, T 2563/11, T 1780/12).

In T 1252/16 the board noted that, contrary to the view adopted in T 307/03 (see in this chapter II.G.3.3.1), according to established case law, any prohibition of double patenting only applied to the "same subject-matter" and did not extend to claims that conferred a scope of protection overlapping each other only partially (citing T 2461/10).

On the relevance of the scope of protection for the issue of double patenting, see however also e.g. T 1780/12 and T 2563/11 (point 2.11 of the Reasons).