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).

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 his 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.