T 0472/92 - Public prior use / Level of proof "up to the hilt"- #51

Citation rank: 51
No. of citations: 92

This appeal case concerns alleged public prior use. In the underlying case, the Opposition Division rejected an opposition based entirely on public prior use attacks. The opponent appealed. The Technical Board of Appeals then had to evaluate, i.a., the evidence presented in support of the alleged public prior use.

The Board referred to an earlier decision, T 270/90, which also concerned public prior use. In T 270/90, the Board used the same standard of proof as is normally applied with any other objection under Article 100 EPC, namely the "balance of probability". T 270/90, however, concerned a case of public prior use, in which both parties had more or less the same access to the evidence relating to the public prior use. With regard to T 270/90, the Board in T 472/92 stated:

"[...] In that case [T 270/90], the Board expressly refused to accept a submission that the much more rigorous standard of "beyond all reasonable doubt" should apply, even if, as was the case there, both parties were able to access and to adduce evidence relating to the decisive issue of confidentiality of the transactions alleged to constitute prior public use." (point 3.1 of the reasons)

The Board in T 472/92 reaffirmed the approach of T 270/90 for cases in which both parties have access to the relevant evidence. The Board, however, remarked:

"[...] in the majority of prior public use cases practically all the evidence in support of an alleged prior public use lies within the power and knowledge of the opponent, so the patentee seldom has any ready, or indeed any access to it at all. All he can, in practice, do is to challenge that evidence by pointing out any inconsistencies contained in it or to draw attention to any gaps in the chain of commercial transactions that needs to be established by the opponent in order to succeed on this ground." (point 3.1 of the reasons)

The Board found that, in such cases where all evidence is in the hands of the opponent,

"... the opponent must prove his case up to the hilt, for little if any evidence will be available to the patentee to establish the contradictory proposition that no prior public use had taken place"(still point 3.1 of the reasons, emphasis added)

Regarding the manner in which public prior use must be proven "up to the hilt", the Board stated that the following facts must be proven:

   (a) the date on which the prior use occurred ("when" issue),
   (b) exactly what was in prior use ("what" issue), and
   (c) the circumstances surrounding the prior use (e.g., issue of confidentiality).

These criteria are nowadays regularly applied by Examination/Opposition Divisions and Appeal Boards in public prior use cases. They also entered into the Guidelines, currently at: G-IV, 7.2.

In the case at hands, the opponent-appellant failed to prove, i.a., that an alleged delivery of products falling under the claims, from the opponent to a joint-venture partner of the opponent, was not under a confidentiality agreement (see "(c)", above).

For this reason alone, the Board concluded that the public prior use attack had to fail.

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Headnote I:

Although the standard of proof is the same for all objections covered by Article 100 EPC (cf. T 270/90, OJ EPO 93, 725), in those prior public use cases, where practically all the evidence in support of an alleged prior public use lies within the power and knowledge of the Opponent, the latter has to prove his case up to the hilt (Reasons 3.1).

The full text of the decision can be found here.