In Arendi S.A.R.L. v. Apple Inc., Appeal No. 2015-2073, the Federal Circuit reversed the PTAB’s finding that certain claims were obvious, holding that it was not obvious to supply a missing claim limitation using “common sense” alone.

Arendi asserted the ’843 Patent against Apple, who then filed an IPR petition on obviousness grounds, arguing that a prior art reference taught all but one claim limitation. The PTAB found the claims invalid as obvious and used common sense to supply the missing claim limitation.

The Federal Circuit reversed, noting that common sense is normally applied in the context of a motivation to combine references, not to supply missing claim elements. Moreover, in the rare cases when missing elements are supplied by common sense, the limitations are unusually simple and the technology particularly straightforward. Here, the missing claim limitation was essential to the claim-at-issue. Finally, the Court noted that unsupported assertions of common sense, without any reasoning or analysis of the evidence, are improper.