Germany: Claim interpretation if preamble equates to state of the art

When interpreting a patent claim, it must be taken into account that a patent's doctrine seeks to distinguish itself from the state of the art described in it. If the specification equates to known prior art with the claim's preamble, the features of the characterising portion of the patent shall – in case of doubt – not be regarded as being understood according to features which are found in the state of the art from which they currently should have been distinguished. (Guiding principle of the Court)

PatG § 14; EPÜ Art. 69; BGH X ZR 16/17 (BPatG) – Scheinwerferbelüftungssystem

The defendant was the proprietor of European patent 0 764 811, relating to headlamps of motor vehicles with a ventilation system, which had meanwhile expired. An action for annulment will continue to be admissible owing to the fact that a declaration of invalidity of the patent in dispute opened up the possibility for the plaintiff to bring an action for restitution against its judgment.

The description of the patent in dispute was adapted in the course of the grant procedure to note that the expert was aware of a ventilation system, according to the preamble of independent patent claim 1 from a French patent application belonging to the state of the art. In the course of the grant procedure claim 1 was changed into a two-part form. The characteristic part of claim 1 of the patent in dispute provides, inter alia, that the ventilation system forms a labyrinth, with a twofold change of direction of the ventilation path.

The plaintiff asserts that such a labyrinth, with a twofold change of direction, is shown in the French patent application cited, which is why the subject matter of the patent at issue is not patentable owing to a lack of novelty, or at least due to a lack of inventive step. The BPatG dismissed the request.

The nullity appeal was directed against this judgement and the plaintiff continued to seek the full nullity of the patent in dispute.

The BGH rejected the appeal.Consequently, in nullity proceedings a novelty attack based on prior art cited in the patent specification might, in case of doubt, not be successful if the prior art in the patent is equated with the preamble of the claim as explained in this decision. On the other hand, a restrictive interpretation of the claims can be made in equivalent cases for infringement proceedings

Volker Tegeder

Maiwald Patentanwalts- und Rechtsanwaltsgesellschaft mbHElisenhof, Elisenstr 3D-80335, Munich, GermanyTel: +49 89 74 72 660 Fax: +49 89 77 64 24info@maiwald.euwww.maiwald.eu