The EPO Enlarged Board of Appeal has announced that, while the claims are the basis for assessing the patentability of an invention, the description and drawings must always be consulted to interpret the claims.
Background
Until now, there has been diverging case law on the correct way to interpret claim language at the EPO, with differing views on the extent to which the description and drawings should be used to interpret the claims – should the claims always be interpreted in light of the description and drawings, should the description and drawings only be referred to if the claims are unclear or ambiguous, or should the claims be interpreted in isolation?
Claim interpretation
Having found that there is no clear legal basis, in terms of an article of the EPC, for claim interpretation when assessing patentability, the Enlarged Board issued two guiding principles:
- The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC.
- The description and drawings are always referred to when interpreting the claims, and not just when the claims are deemed unclear or ambiguous when read in isolation.
These guiding principles aim to align EPO examination practice with the current case law of the Unified Patent Court (UPC).
Lessons
Today’s decision emphasises the need for care to be taken when drafting and amending the description and drawings, as well as the claims, as information provided in the description and drawings may have a substantial impact on the patentability of the claims.
The decision also highlights the need to consider fully the potential ramifications of any description amendments requested by an EPO examiner during prosecution – which are becoming increasingly prevalent – to avoid any unforeseen impact on the validity of the claims.
