T 0409/90 (Avalanche photodiodes) of 29.01.1991

I. The invention which is the subject of the priority document has to be determined from a consideration of the priority document as a whole, as read by a skilled person (cf. point 2.3(a) of the Reasons for the Decision).

II. When considering what is disclosed by a claim of a priority document it is relevant that the purpose of the claim is to define the protection which is sought. The fact that a claim in a priority document is broad enough to cover specific subject- matter claimed for the first time in a European patent application cannot by itself be sufficient evidence that such subject-matter has already been disclosed in the priority document so as to establish identity of invention for the purpose of claiming priority under Article 87 EPC (cf. point 2.3(a) of the Reasons for the Decision).