1. Under the settled legal precedent of the BGH [Bundesgerichtshof = Federal Court of Justice], an interpretation of patent claims is always required – even if the philological wording of the claim appears to be clear. This applies not only to infringement actions (see only BGH GRUR 1986, 803 – Formstein; BGH GRUR 2002, 515 – Schneidmesser I), but also to actions for nullity (see most recently GRUR 2012, 1124 – Polymerschaum I). Significantly, two of the cases to be discussed here, namely the “Rotorelemente” and “Zugriffsrechte” decisions, were issued in actions for nullity.
2. One of the basic principles of patent law is that, in doubtful cases, the terms used in the patent specification are to be defined within the context of the patent specification and therefore independently, since every patent specification constitutes its own lexicon (BGH GRUR 1999, 909 – Spannschraube; BGH 2005, 754 – werkstoffeinstückig). This principle applies, in particular and especially, when the interpretation of a term on the basis of the “patent’s own lexicon” leads to an understanding that differs from the customary understanding in the specialised area.
3. The “patent’s own lexicon” is decisively provided in the description. The meaning of the terms used in the patent claims are to be defined based on the understanding derived from the description. This makes the interplay between the claims and the description especially clear: Under Art. 69 EPC and its protocol on interpretation and under the corresponding national practice in accordance with § 14 PatG [Patentgesetz = Patent Act], the principle of the primacy of the patent claim applies, according to which, when there are contradictions between the claim and the description, the claim takes precedence, since the claim – and not the description – defines and limits the protected subject matter – i.e. the monopoly conferred by the administrative act granting the patent (see only BGH GRUR 2011, 701 – Okklusionsvorrichtung). On the other hand, the technical meaning of the patent claim is controlling in determining the subject matter of the patent – and not merely its wording on a purely philological level – since the description is to be utilised to determine the meaning of the claim (see BGH GRUR 2015, 875 no. 16 – Rotorelemente). How this “hermeneutic circle” between the philological wording of the claim and the technical information provided in the description is to be resolved is the subject matter of the three decisions to be discussed.
4. In the “Zugriffsrechte” case, the interpretation of a claim was to be reviewed, which, in the opinion of the Federal Court of Justice, was contrary to the two embodiments described in the patent specification (see nos. 26 + 40). The Federal Court of Justice rejected the interpretation. It stated that an interpretation of the patent claim, which has as its result that none of the embodiments described in the patent specification are covered by the subject matter of the patent, can only be considered if other possible interpretations, which at least result in the inclusion of part of the embodiments, must be eliminated or if there is sufficiently clear evidence in the patent claim that something that, in large part, differs from the specification is actually being claimed (headnote and no. 26). Ultimately, in this case, the Federal Court of Justice came to the conclusion that the patent claim – still – demonstrated with sufficient clarity that both embodiments with the features described in the patent specification were covered (no. 46).
5. Such an interpretation of the claim, which finds the description and its embodiments to be in conformity, is especially clear in the “Kreuzgestänge” decision: There the headnote provided by the Federal Court of Justice states: If several embodiments are presented as being “according to the invention” in the description of a patent, then, in doubtful cases, the terms used in the patent claim are to be understood such that all of the embodiments can be used to “flesh them out”. Moreover, the BGH determined in the decision (no. 22) that patent specifications are to be read in a reasonable relationship and, in doubtful cases, the patent claim is to be understood such that no contradictions between the statements in the description and the pictorial representations in the drawings arise, because patent specifications constitute their own lexicon of the terms used therein and ultimately only the connotations arising from the patent specification are controlling.
6. This raises the question of what is the limit of a “reasonable” interpretation of a claim and a description in terms of their cohesiveness when individual embodiments or parts thereof are no longer compatible with the claim, e.g., based on a limitation imposed in the granting proceedings, i.e. when the well-known set of facts in the “Okklusionsvorrichtung” case exists. Here the BGH confirmed the principles of the “Okklusionsvorrichtung” decision (GRUR 2011, 701) in the “Kreuzgestänge” decision. The Court stated: Only if and to the extent that the teaching of the patent claim cannot be brought into conformity with the description and the drawings and an unresolvable contradiction remains, may those components of the description that find no expression in the patent claim be omitted in determining the subject matter of the patent (no. 22 and headnote).
7. Due to the narrowing of the set of cases in which an “unresolvable contradiction” between the description and the granted claim exists, this principle runs into a “chicken or the egg problem” when an attempt is made to put it into practice: It is often difficult to determine solely from the granted patent whether an embodiment or parts thereof are not covered by the subject matter of the patent claim, e.g. because the patent claim was limited in the granting proceedings, or whether a (limited) claim can – and should – be interpreted such that it covers the embodiment. This was particularly clear in the “Okklusionsvorrichtung” case (GRUR 2011, 701 and the remarks of Kühnen in this regard).
In the “Okklusionsvorrichtung” decision (no. 25), the BGH did not address whether the patent application can be used as an interpretation aid to resolve this “chicken or the egg problem”. The sensitivity of this question is evident from the fact that the protocol on interpretation in Art. 69 EPC does not permit the use of occurrences in the granting proceedings as a “source” for the interpretation of a patent claim (see BGH GRUR 2002, 51 – Kunststoffrohrteil).
The Federal Court of Justice has now given indications of how to resolve this “chicken or the egg problem” in its “Rotorelemente” decision: There, the question to be examined was whether the subject matter of the granted claim had been impermissibly expanded as compared to the original disclosure. In this regard, the Federal Court of Justice determined that the content of the original documents or the published application could not be consid-ered in the interpretation. The patent claim cannot be interpreted based on the original disclosure nor may its meaning be determined by comparing the wording of the claim with differing formulations in the application (no. 17). However, when it is doubtful whether the patent claim and the specification can be placed in a reasonable relationship with each other, the “history of the claim” can be utilised. In the decided case, use of the history of the claim was permitted to clarify whether the claim protected subject matter that deviated from what was disclosed in the description or fell short of this (no. 17). For practical purposes, one can infer that, e.g., the patent application can be used as an interpretation aid to recall the “history of the claim” (see also, in particular, Meier-Beck, GRUR 2012, 1177, 1181, regarding the “history of the limitations” as an interpretation aid).
8. The requirement of a “reasonable interpretation” of patent claims, i.e. the development of an overall understanding of the patent claims and the description intended to explain them, which is to be as reasonable and consistent as possible, becomes graphic in the “Rotorelemente” decision (see no. 32 thereof):
The subject matter of the action for nullity there was a device to manufacture rotor ele-ments. The elements had so-called pole sections and so-called base frames. The device to manufacture these rotor elements had a punch assembly. On a purely philological level, this punch assembly had a first punching element, according to the granted claim, which was used to punch out the parts of the base frame sections at first grasp. A second punching element was then used to punch out the pole sections. However, in the opinion of the Federal Court of Justice, it was evident from the overall content of the description and the additional Patent Claims 2 – 6 that, when formulating the granted Claim 1, the base frame sections and the pole sections were interchanged (see nos. 18 and 22). Therefore, the Federal Court of Justice came to the conclusion that, contrary to its wording, the claim should be read to mean that the first punching element makes (at least) parts of the pole sections available for punching and the second punching element makes the base frame sections available for punching (no. 18).
Accordingly, the BGH’s headnote stated: In determining the meaning of a patent claim, wording that is clear per se is not controlling if an interpretation of the claim utilising the description and the additional patent claims reveals that two terms used in the patent claim should be interchanged with each other. As its rationale, the BGH stated as follows (no. 16): The principle that, if there are contradictions between the claim and the description, the claim should take precedence, does not mean that no understanding of the patent claim may emerge from the description and the drawings, which diverges from what the mere wording of the claim states. The function of the description is to explain the protected invention. Therefore, in doubtful cases, an understanding of the description and the claim is required that does not bring the parts of the patent specification into contradiction with each other, but interprets them as related parts of a reasonable whole.
Thereby the BGH builds on earlier decisions (BGH GRUR 2008, 887, no. 21 – Momentan-pol II; BGH GRUR 2009, 653, no. 16 – Straßenbaumaschine) in which it had already held that professionals must strive to give the patent a reasonable interpretation.
9. The “Rotorelemente” decision is, of course, characterised in that the philological wording of the granted claim was diametrically opposed to the technical meaning of the description. This may have led the Federal Court of Justice to make a “rectifying interpretation” based on the description. The decision is not an isolated case (see Meier-Beck, GRUR 2012, 1177, 1181 with reference to BGH Mitt. 2002, 176 – Signal- und Gegensprechanlage). In summary, it can be stated that a rectifying interpretation of the claim based on the description is possible if the philological wording of the claim is “obviously incorrect” in light of the technical meaning imparted by the description. Due to the requirement of legal certainty and the primacy of the claim, a careful examination must be made to determine whether the “Rotorelemente” decision can be generalised beyond the decided set of cases.
