In order not to unnecessarily limit the protection of an invention, it may be useful to initially formulate the claims conferring protection as broadly as possible. This is to ensure adequate and sufficient protection for the applicant against the use of the invention by third parties.

However, according to §21 (1) No. 2 Patent Law, § 34 (4) Patent Law and Art. 83 EPC, the invention of a patent application must be disclosed in such a clear and complete manner that a person skilled in the art can carry it out. According to established case law, this is fulfilled if the person skilled in the art is able to carry out the teaching of the patent claim on the basis of the overall disclosure over the entire claimed scope of the invention without inventive step and without unreasonable effort. In particular, the requirement to disclose the patent teaching over the entire claimed area can be problematic in the case of a broad claim drafting.

In the decision X ZR 15/19 of 17.12.2020 - concerning an action for revocation against the German part of a European patent - the Federal Supreme Court held that, under certain aspects, sufficient disclosure is present even if, despite a broad claim wording, ways of carrying out the invention that can be reworked are indicated only in partial areas of the claimed field.

The patent in suit underlying the decision concerned the production of amino acids by means of fermentation using genetically modified microorganisms, and the patent specification in suit was mainly concerned with certain amino acids.

With regard to the ground for invalidity of lack of disclosure, the applicant for revocation objected that the patent in suit did not disclose an increased production with regard to all claimed amino acids and that a large number of amino acids existed which were covered by the scope of protection, but which were not disclosed in detail.

In response to this objection, the Federal Supreme Court clarified that the requirement of practicability of an invention was already deemed to be fulfilled if a general solution scheme was provided to the skilled person. It was sufficient if at least one reworkable way of carrying out the invention was disclosed. It was by no means necessary for all embodiments covered by the patent claim to be disclosed in an executable manner. Even a generalised patent claim - as in the present case - could satisfy the requirement of sufficient disclosure, provided that the protection claimed extended within the range that the skilled person would take from the description and the embodiments as the most general form of the technical teaching that solved the problem underlying the invention.

Based on these requirements for sufficient disclosure of an invention, the action was dismissed.