The use of technical means for carrying out a method for performing mental acts, partly or entirely without human intervention, might, having regard to Art. 52(3) EPC 1973, render such a method a technical process or method and therefore an invention within the meaning of Art. 52(1) EPC 1973 (T 38/86, OJ 1990, 384; see also T 258/03, OJ 2004, 575).

In T 471/05 the board pointed out that claim 1 merely formulated a series of mathematical and optical abstract concepts without properly requiring a physical, technical implementation. It followed that the subject-matter for which protection is sought was the mere "design" of an optical system and encompasses purely abstract and conceptual implementations excluded from patent protection pursuant to Art. 52(1), (2) and (3) EPC 1973. More particularly, the claimed method could be carried out as a purely mental act or as a purely mathematical design algorithm and, consequently, encompasses embodiments falling within the category of methods for performing mental acts as such and within the category of mathematical methods as such both expressly excluded from patent protection under Art. 52(2)(a) and (c) EPC 1973 in conjunction with Art. 52(3) EPC 1973.

The board stated that the criteria for technical character of a claimed invention discussed in decision T 619/02 (OJ 2007, 63) implicitly presupposed that the claimed subject-matter defining the matter for which protection is sought related to a physical entity or a physical activity. It could not be denied that the method defined in claim 1 of the main request could be carried out using some physical means and that such implementations of the claimed method constitute physical, technical activities not excluded from patent protection (see for instance decisions T 914/02, and T 258/03, OJ 2004, 575). Nonetheless, contrary to the appellant's contention, the claimed method did not require the use of technical means and the method was not restricted to physical, technical implementations, and the fact that the claimed method encompassed non-excluded implementations such as those mentioned above did not overcome the fact that the claimed method also encompassed excluded subject-matter (T 914/02, and T 388/04, OJ 2007, 16; see also T 453/91, T 930/05). Thus, as long as the claimed design method was not confined to physical, technical implementations, the claimed subject-matter encompassed embodiments excluded from patentability under Art. 52(1) to (3) EPC 1973 and was not entitled to patent protection under the EPC. The board also stated that the mere presence in the claim of such purely conceptual technical considerations did not overcome the conclusion above that the claim merely formulated a sequence of mathematical and optical concepts without properly requiring a technical or even a physical implementation. In particular, a purely mental implementation of the claimed method remains a mental act as such within the meaning of Art. 52(2) and (3) EPC 1973 even if the mental act involves conceptual technical considerations as already concluded in decision T 914/02 in which a method claim involving technical considerations and encompassing technical embodiments was refused on the grounds that the invention as claimed could still be exclusively performed by purely mental acts. In view of the above the subject-matter defined in claim 1 of the main request was excluded from patent protection under Art. 52(1), (2) and (3) EPC 1973.

In T 603/89 (OJ 1992, 230) the invention consisted of an apparatus for and a method of learning how to play a keyboard instrument, where numbers corresponding to notes on a sheet of music also appeared on the keys. The technical feature claimed was the marking of the keys. Patentability was ruled out by Art. 52(2)(c) and (d) EPC 1973. Since the key markings were merely known technical features, the contribution made by the claimed invention to the working of the teaching apparatus lay solely in the content of the information displayed, not in the apparatus itself. The invention was not based on a technical problem, but on an improvement to a teaching method, which was equivalent to an improvement to a method for performing mental acts.