A complaint for a (negative) declaratory judgment requires that the plaintiff has a legitimate interest (“Feststellungsinteresse”) in the requested declaratory finding by the competent court. A legitimate interest of the plaintiff in finding that a specific patent is not infringed may exist if the patent owner, despite its obligation to do so, does not respond to the question of the plaintiff whether a certain device falls under the scope of protection of the patent. In the present decision, the Dusseldorf Appeal Court clarifies that the patent owner who has filed a complaint against a company based on infringement of a different national part of a European patent generally is not obliged to answer the question by such company whether similar devices also infringe the German part of said European patent in Germany. Thus, the absence of a response from the patent owner generally does not create a legitimate interest for such company requesting a negative declaratory judgment.

In the case at hand, the patent owner had filed an infringement complaint in Turkey based on literal and equivalent infringement of the Turkish part of European Patent 1 392 575 against the manufacturer of sealing devices allegedly falling under the scope of protection of this patent. The manufacturer wrote several letters to the patent owner asking for a statement on whether its respective devices also infringed the German part of said European patent. The patent owner did not comment on the potential infringement of the German part of EP 1 392 575 but merely answered that he would not comment on any possible future activities and that he was not willing to spend money and time for the assessment of a theoretical infringement question. As a consequence, the manufacturer filed a complaint for a declaratory judgment of non-infringement against the patent owner with the Dusseldorf District Court.

As both parties declared the matter terminated before the Dusseldorf District Court had issued a declaratory judgment, the Dusseldorf Appeal Court only had to decide which party has to bear the statutory costs of the proceedings, i.e., which party would presumably have lost the case. The Appeal Court ordered that the plaintiff had to bear these costs because he did not have a legitimate interest in a declaratory judgment. Upon the appeal filed by the plaintiff, the Dusseldorf Appeal Court upheld the District Court’s decision for the following reasons:

Section 256 German Code of Civil Procedure stipulates that a complaint may be filed to establish the existence or non-existence of a legal relationship, i.e., for example the existence of a patent infringement, if the plaintiff has a legitimate interest in having the legal relationship established by a judicial ruling at the court’s earliest convenience. According to the established German case law, such legitimate interest is given if the defendant alleges to be entitled to a claim against the plaintiff.

In its grounds of the decision, the Dusseldorf Appeal Court explained in which situations such allegation by a patent owner to be entitled to a claim based on infringement providing for a legitimate interest in a declaratory judgment could be assumed. The Court distinguished between explicit allegations, e.g. in a warning letter, and so-called implied allegations (“konkludente Berühmung”),e.g., silence with respect to a question on the patent owner’s assessment of the infringement situation despite an obligation to respond. According to the Court, an implied allegation requires a behavior of the patent owner towards the plaintiff, which allows the clear conclusion that the patent owner alleges to be entitled to a claim against the plaintiff based on infringement of the patent.

Applying these principles to the case at hand, the Court stated that if the patent owner simply refuses to give a substantial answer to the question whether he regards a certain device to fall under the scope of protection of the patent, an explicit allegation is out of the question. An implied allegation would only allow a clear conclusion in the above sense if the patent owner was generally obliged to answer such question. According to the Dusseldorf Appeal Court, there is no such general obligation of the owner of a (European) patent to give an answer to such request. Following the established German case law, the Court explained that this was not only true if there were no legal relationships between the patent owner and the inquiring company prior to the inquiry, but also in case the inquiring company had already been sued for patent infringement by the patent owner and asked whether a modified device would still fall under the scope of protection of the patent.

Furthermore, the Dusseldorf Appeal Court added that there was also no obligation of the patent owner to provide an answer, even if the patent owner had already sued the inquiring company in another EPC member state based on infringement of a national part of a European patent a German counterpart of which is valid in Germany. This was easily understandable, as the Court explained, in case the wording of the claims of the national parts of the European patent in question was different which might result in a different scope of protection, or if the patent owner based his complaint on infringement under the doctrine of equivalence since the requirements of equivalent infringement depend on the respective national case-law and thus significantly vary between the different EPC member states. Therefore, filing such complaint does not allow the clear conclusion that the patent owner would automatically see himself entitled to a claim for patent infringement also in another EPC member state.

Finally, according to the Dusseldorf Appeal Court, a complaint based on literal infringement of another national part of a European patent – and refusing to answer to an inquiry regarding infringement with regard to the German part of the respective European patent – generally also does not constitute an implied allegation to be entitled to a claim in Germany. The Court explained that the mere conduct of the patent owner in one EPC member state does not constitute such implied allegation in another member state. In this context, the Court pointed to the general opinion that the European patent was a bundle of independent national patents which had to be considered individually. Only if additional circumstances were at hand, e.g. if the patent owner through respective comments or behavior showed that he deemed also the other national (here German) part of the European patent to be infringed, the plaintiff may have a legitimate interest in a declaratory judgment of non-infringement.

The present decision shows that, despite the pending referral to the CJEU regarding the requirements for successfully raising the compulsory license objection, German instance courts are still reluctant to use a less strict standard than in the “Orange-Book” decision – at least until a final decision is rendered by the CJEU. Thereby, the application of very strict requirements for a preliminary stay of enforcement measures complies with the practice of the instance courts, in this respect.

Following this approach, on the one hand, owners of SEPs presently may expect to be able to preliminary enforce a first instance judgment based on that SEP. On the other hand – in particular in view of the latest decision of the European Commission regarding Motorola Mobility’s violation of antitrust law by forcing Apple to sign an unfavourable license agreement by means of posing a threat of enforcing an injunction against Apple on the basis of a SEP – patent holders might need to consider risks of liability based on such enforcement in case the CJEU will significantly ease the requirements for raising the compulsory license objection.