According to highest court judicature, an embodiment departing from the literal sense of a patent claim may nevertheless infringe the scope of protection of the patent, if the requirements of an “equivalent patent infringement” are fulfilled:
- same effect, i.e. the departing embodiment shall solve the inventive problem with modified means which, however, objectively have essentially the same effect;
- obviousness, i.e. the discovery of the modified means having essentially the same effect shall not exceed the ordinary skill; and
- orientation towards the patent claim, i.e. the considerations of the skilled person shall be oriented towards the meaning of the patent claim such that the skilled person will consider the departing embodiment with its modified means as an solution being equivalent to the actual solution.
The latter requirement is not fulfilled, if an “implicit waiver of equivalent means” is at hand, as described in the headnote of the “Okklusionsvorrichtung”- decision (BGH, Judgement of May 10, 2011 – X ZR 16/09): „If a description discloses several possibilities of achieving a certain technical effect, wherein only one of these possibilities is comprised by the patent claim, the use of the other possibilities generally does not constitute a patent infringement with equivalent means.”
Simply put: If the patent is silent on equivalent means not being claimed, the proprietor may from the viewpoint of equivalence take action against these means. If, however, the patent description discloses the equivalent means, this is interpreted as an intentional waiver of these unclaimed equivalent means, as, otherwise, the proprietor could have chosen a more appropriate (broader) claim wording.
In his recent decision of November 7, 2013 (file number: 2 U 29/12) the Higher Regional Court Düsseldorf clarified that such an “implicit waiver of equivalent means” for the purpose of negating an equivalent patent infringement may exists only, if the patent specification indicates that the applicant waives the inclusion of the equivalent means into the scope of protection. It is not sufficient for negating an equivalent patent infringement, if the patent specification merely mentions the equivalent means in a different context. This holds true even if the equivalent means has been obvious for the applicant.