The Federal Circuit Court of Appeals has ruled that a claim for correction of inventorship under 35 U.S.C. § 256 accrues when the patent issues and not when the allegedly omitted inventors purportedly knew or should have known that they were not named inventors on the patent application. Hor v. Chu, No. 2011-1540 (Fed. Cir., decided November 14, 2012). So ruling, the court reversed the district court’s dismissal of the action on grounds of laches and equitable estoppel.

According to the Federal Circuit, the statute is clear that the laches clock does not begin to run, at the earliest, until the patent issues. The court also found that the lower court erred in granting summary judgment on the affirmative defense of equitable estoppel because the court raised the issue sua sponte. The defense should have been, but was not, pleaded by the patent holder.

The patents at issue involved research related to high temperature superconducting compositions; the patent holder was a professor of physics at the University of Houston, and the allegedly omitted inventors were a research assistant and independent materials scientist who was part of the professor’s research group. A concurring appeals court judge agreed with the majority’s statutory analysis, but, in the interest of more prompt resolution of inventorship issues, suggested that Congress amend the law to require earlier claim filing.