In this decision the Court of Appeal confirms the revocation of EP 3 223 320 for added matter and dismisses Seoul Viosys’ appeal against the Düsseldorf Local Division.
The judgment is noteworthy for two points. First, the headnotes set out a clear framework for how translations of non-EPO-language PCT applications operate in added-matter analysis, including a prima facie presumption that the applicant’s own translation is correct and a corresponding shift of the burden of proof. Secondly, the Court clarifies that open claim wording such as “comprising” (“umfassend”) and the use of the singular (“eine Mesa”) do not, as a matter of claim interpretation, restrict the claim to a single mesa – even though, on the facts, this broader reading could not cure the added-matter defect.
Here, claim 1 defined a light-emitting diode “comprising” a first semiconductor layer, “a mesa” disposed on that layer, and further layers and electrodes.
On this basis, the Court reached two important conclusions:
First, “comprising” – rendered in the German reasons as “umfassend” – indicates that the claim lists mandatory elements but does not exclude the presence of further elements, unless the claim clearly requires a closed structure. The wording “umfassend” therefore leaves room for additional mesas and electrodes beyond those expressly recited. The description consistently speaks of “Mesas” and “a plurality of mesas”, and the technical teaching is directed to improving current spreading in multi-mesa flip-chip structures.
Secondly, the use of the singular “eine Mesa” is, in this context, not a numerical limitation to exactly one mesa, but an indefinite article in the usual claim-drafting sense of “at least one mesa”. The Court expressly rejects the Local Division’s view that references such as “the mesa” in later features restrict the claim to a single mesa. Rather, the skilled person reads these references as pointing back to at least one mesa required by the claim, without excluding additional mesas.
The Court thus held that claim 1, properly interpreted, covers LEDs with one mesa as well as LEDs with multiple mesas. The understanding of “umfassend” as open wording is therefore fully confirmed.
The headnotes of the decision address how the content of a non-EPO-language PCT application is to be determined for this exercise:
The international application in Korean is the “earlier application” for the purposes of Art. 138.1(c) EPC. However, where that application is not in an EPO official language, the content of the earlier application is determined primarily on the basis of the translation filed on entry into the European phase.
The translation requirement is not a purely formal or procedural step. By filing the translation, the applicant defines the text in the language of the proceedings on which the EPO conducts search and examination and against which Art. 123.2 EPC is assessed.
Because it is in the applicant’s own interest that the examination proceed on the basis of the “true” content of the application, a translation filed by the applicant is prima facie presumed to be an accurate rendering of the international application. Third parties and courts may rely on this translation.
If the proprietor later asserts that this translation is wrong and seeks to rely on a different version, the burden lies on the proprietor to prove the inaccuracy and to establish that, on the basis of a correct translation, the patent does not extend beyond the earlier application. Simply producing the original language text and a new translation is not enough; the Court indicates that, in a case such as this, one would expect at least a party expert on the specifics of the source language.
