T 0296/93 (HBV antigen production) 28-07-1994

Reasons for the Decision

1. Admissibility and other procedural questions

The appeal is admissible.

The submissions by respondent II and by the appellant on 10 August 1994 and 16 August 1994 respectively, are disregarded because they were filed after closing of the debate (in this respect see decision T 595/90, OJ EPO 1994, 695, in particular point 1 of the reasons) and, what is more, after the announcement of the decision (see G 12/91, OJ EPO 1994, 285, points 2 and 3).

2. Admissibility of intervention (Article 105 EPC)

2.1 The board firstly observes that the opposition division, through its announcement of the decision on 28 October 1992 to revoke the patent, had effectively severed itself from the case, and therefore could not take any decision on the intervention matter. Had no appeal been lodged against the decision to revoke, the intervention would have had no standing at all (see G 4/91, OJ EPO 1993, 707). This matter therefore must be dealt with by the board. In G 1/94 (OJ EPO 1994, 787), the Enlarged Board of Appeal further established that an intervention at the appeal stage is admissible.

2.2 Article 105(1) EPC reads as follows:

"In the event of an opposition to a European patent being filed, any third party who proves that proceedings for infringement of the same patent have been instituted against him may, after the opposition period has expired, intervene in the opposition proceedings if he gives notice of intervention within three months of the date on which the infringement proceedings were instituted. The same shall apply in respect of any third party who proves both that the proprietor of the patent has requested he cease alleged infringement of the patent and that he has instituted proceedings for a court ruling that he is not infringing the patent."

2.3 In the negotiations leading up to the adoption of the EPC, the question of intervention was raised in 1971 in Working Group I, which decided to propose the introduction of such an opportunity for third persons to enter into opposition proceedings, the object being to make it possible for an alleged infringer to avoid having to defend himself before a national court although central opposition proceedings were still pending before the EPO (BR/144/71, points 75 to 77).

In subsequent meetings to discuss further details, proposals were made to ensure that interventions would not lead to delays of the opposition proceedings (BR 168/72, BR 169/72, and BR 177/72). These time considerations led to a fixed period of three months after the institution of infringement proceedings before a national court.

In preparation for the Munich Diplomatic Conference in 1973, the Swiss delegation proposed a separate possibility to intervene in a situation where no infringement action had been instituted by the patentee but he had requested - for example in an ordinary letter - a third party to stop infringing the patent and the third party had initiated proceedings for a court ruling that he was not infringing the patent (M/31, 28 May 1973). This proposal was adopted by the Conference (M/PR/I, page 51), although one delegation questioned whether this further opportunity would not indeed cause delays in the opposition proceedings.

2.4 The board cannot agree with the intervener that the above- cited travaux préparatoires indicate a right to choose at will which starting point for calculating the time period for intervention to invoke.

The second possibility of intervention was only introduced to make it possible at all for a third party to enter the centralised proceedings before the EPO, although no formal infringement action had been raised. The situation for this second category of interveners is in fact identical to the first, with the very important difference that he otherwise could not avail himself of the centralised EPO proceedings. This was not considered justified in the case where a patentee chooses not to start a court action, thereby preempting the intervener. The latter would then have to institute national proceedings himself, proceedings which could prove to be needless, ie if the patent were later to be revoked by the EPO.

2.5 The provision of the institution of court actions as starting dates for the calculation of the time periods for intervention guarantees an indisputable official date. As the appellant rightly pointed out, it is not customary in procedural law that a party which wants to avail itself of a time limit also holds the means by which the starting point for its calculation can be controlled.

The principle behind Article 105 EPC is that, as soon as any court action has been brought, the sole available period for intervention starts running. Any other interpretation would open the possibility of abuse of the intervention opportunity by the filing of national invalidity actions in order simply to trigger a new time limit under Article 105 EPC, regardless of earlier circumstances.

2.6 Consequently, the board finds that the two alternatives offered under Article 105(1), first and second sentences, EPC respectively, are mutually exclusive for the same case of infringement. With regard to the same patent, an alleged infringer can only belong to one category, the decisive factor being which court action was the first to be instituted.

2.7 In the present case, therefore, the time period for intervention was triggered by the writ of summons of 1 July 1992. Not having been filed within three months of that date, the notice of intervention does not meet the requirements of Article 105(1), first sentence, EPC, and must therefore be rejected as inadmissible.

3. Formal allowability of the amended claims (Article 123(2) and (3) EPC)

4. Entitlement to priority (Article 87 EPC)

5. The citability of document (3)

6. Novelty (Article 54 EPC)

7. Inventive step (Article 56 EPC)