T 0099/85 (Diagnostic Agent) of 23.10.1986

1. If a document does not contain details of the size of particles (here: particles of a filler in a film) a specific size range is not implicitly disclosed if it is common knowledge among persons skilled in the art that particles whose size lies clearly outside this range may also be used for the known purpose (here: as a filler).

2. In order to assess inventive step, the problem must be defined objectively in such a way that it does not partially anticipate the solution (with reference to T 229/85, OJ EPO 1987,237).

3. In the opposition proceedings there is no reason officially to insist on a change in the wording of the claim simply because one feature in the preamble to a two-part claim does not belong to the state of the art (Rule 29(1)(a) EPC).