Laitram Corp. v. NEC Corp.

Laitram Corp. (plaintiff) held a patent for a high-speed printer. Patent claim 1 disclosed the printing apparatus, stating that it was an electro-optical apparatus for printing alphanumeric characters at high speed. Claim 2 disclosed the method for printing using the apparatus. In 1989, Laitram sued NEC Corp. and NEC Information Systems, Inc. (collectively, NEC) (defendants) for patent infringement. While the suit was pending, a third party initiated a reexamination proceeding with the Patent and Trademark Office (PTO), contesting the patent’s validity. The PTO concluded that claims 1 and 2 were invalid for obviousness and anticipation based on prior art. Laitram then amended claims 1 and 2, adding limitations addressing speed, type quality, and direction of movement. Regarding type quality, the amendments clarified that the apparatus and method were for printing “type-quality” alphanumeric characters, meaning characters with a certain clarity and sharpness. The PTO allowed the amended patent claims, concluding that the reexamined claims sufficiently distinguished the invention from prior art. The infringement suit between Laitram and NEC then resumed. The district court granted a partial summary judgment stating that amendments during reexamination were per se, or automatic, substantive changes to the patent’s scope and Laitram’s damages would therefore be limited to NEC printer sales after the PTO’s allowance of the reexamined claims. The Federal Circuit reversed, holding that amendments during a reexamination proceeding were not per se substantive changes and a court instead needed to consider the particular facts. On remand, the district court concluded that the reexamined claims were substantively identical to the original claims, in part because although type quality was not mentioned in the original claims, it was mentioned in the original patent description, meaning the part of the patent that provided general context for the invention. The court therefore concluded that Laitram was entitled to damages for NEC printer sales both before and after the claim amendments. NEC appealed.