Cybor Corp. v. FAS Technologies, Inc

The Federal Circuit recently held, in Cybor Corp. v. FAS Technologies, Inc. (1998), that patent claim construction should be reviewed de novo because it is a question of law. Because de novo review enables the Federal Circuit to ignore the claim constructions of district courts, the Cybor decision likely will serve to sustain or increase the rate of claim construction reversals on appeal. The Federal Circuit unwisely decided Cybor because it misinterpreted prior case law on the issue and ignored the factual inquiries that are common in claim construction proceedings. Instead, the Federal Circuit should have adopted a mixed review standard for claim construction that grants deference to those parts of a judge's claim construction that are based upon findings of fact. For all other aspects of claim construction, the court should apply a de novo standard of review.