9.21.1 Foreseeable disadvantageous or technically non-functional modifications

In some decisions the subject-matter was found not to involve an inventive step, when the invention was the result of a foreseeable disadvantageous modification of the closest prior art (T 119/82, OJ 1984, 217; T 155/85, OJ 1988, 87; T 939/92, OJ 1996, 309; T 72/95; T 694/13, T 2313/22).

The board in T 119/82 (OJ 1984, 217) had already found that disadvantageous modifications did not involve an inventive step if the skilled person could clearly predict these disadvantages, if their assessment was correct and if these predictable disadvantages were not compensated by any unexpected technical advantage. More recently, the board in T 2197/09 confirmed that inventive step cannot be acknowledged on the basis of a purely disadvantageous modification of the closest prior art.

In T 2465/19 the board found that distinguishing feature i) did not represent an arbitrary modification of the device of D1 having only foreseeable disadvantages, but rather represented an alternative solution to a known problem. The board accepted that the application did not explicitly mention any particular additional advantage or surprising beneficial effect. However, it could not be said to have only disadvantages with respect to D1. Nor could this feature be said to be arbitrary. The board noted with reference to Headnote II of G 2/21 (OJ 2023, A85) that the technical effect of an invention over the closest prior art need not be explicitly stated in the application, as long as it was derivable from the original application, in particular since the closest prior art may not have been known to the applicant when drafting it. (see also chapter I.D.4.1).