Even as it acknowledged that it "rarely remands the issue of claim construction," U.S. Court of Appeals for the Federal Circuit did just that. Nazomi Communications, Inc. v. ARM Holdings, PLC, Case No. 04-1101 (Fed. Cir. Apr. 11, 2005) (Fogel, J.).

The district court granted partial summary judgment of non-infringement to ARM on Nazomi’s patent for a Java hardware accelerator used to translate source code written in Java bytecodes into native instructions for a CPU. In its opinion, the district court did not actually construe the asserted claims or analyze the infringing product vis-à-vis specific claim limitations. Instead, in what the Federal Circuit termed a "terse seven-page order," the district court concluded that the accused device practiced the prior art and, therefore, was either invalid or not infringed. Applying the old axiom that patents should be construed to preserve their validity, the district court concluded that "[i]t follows necessarily that the claims of the patent must reach a different type of hardware solution [than the prior art] to be valid, and that the solution of the prior art does not infringe."

Pointing out the error in "putting the validity cart before the claim construction horse" and cautioning "against the nonviable ‘practicing the prior art’ defense" applied by the district court, the Federal Circuit held the district court’s analysis to be incorrect. It also held that the record created by the district court was "inadequate" to permit the Federal Circuit itself to come up with a proper claim construction or make an independent judgment as to the propriety of summary judgment because the district court did not "supply the basis for its reasoning sufficient for a meaningful review." The decision was vacated and remanded.

Practice Note: In part because of the different burdens of proof regarding infringement (preponderance) and invalidity (clear and convincing), as well as potential equivalents issues, the Federal Circuit routinely insists that there is no such thing as a "practicing the prior art" defense to literal infringement. Rather, in every case, the district court must construe the claims and then apply that construction in an infringement and/or validity analysis.

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