20-Year Delay in Asserting Claim for Correction of Inventorship Does Not Result in Laches

02/28/2013 / John A. Kvinge

Under U.S. patent law, an individual that believes he or she was incorrectly omitted as a named inventor on a patent can bring a lawsuit under 35 U.S.C. § 256 to request correction of inventorship. However, the equitable doctrine known as “laches” provides a defense to this claim. Laches may result when an allegedly omitted inventor unreasonably delays in filing suit and the delay causes material prejudice to the defendant. Because laches is an affirmative defense, the defendant generally bears the burden of proof. However, laches is somewhat unique in that a presumption of laches applies if there has been more than a six year delay between the time the unnamed inventor knew or should have known that he or she was not named as an inventor in the patent, and the time he or she brings suit under § 256.
A Federal Circuit case in the last few months addressed the question of whether the six-year period for the presumption of laches begins running prior to the issuance date of the patent, if the unnamed inventor should have known prior to issuance that he or she was not named as an inventor in the patent application. The case, Hor v. Chu, Case No. 2011-1540, involved a patent for high-temperature superconducting materials. The invention was developed at the physics research laboratory at the University of Houston between November 1986 and March 1987, by Professor Paul Chu, with assistance from graduate assistants Dr. Pei-Herng Hor and Ruling Meng. The nature of the students’ assistance was a point of dispute, with each side claiming that it first suggested the use of various elements in the composition. 
On January 12, 1987, Professor Chu filed the first patent application for the composition.  On March 26, 1987, Professor Chu filed a continuation-in-part (“CIP”) application. Both Hor and Meng claimed that no one ever told them they would be listed as inventors in the applications. Both applications eventually issued as patents years later – the parent application issued as a patent on June 6, 2006, and the CIP application issued as a patent on May 4, 2010. Professor Chu was the sole inventor listed on both patents.
Hor filed suit in December 2008, and was joined by Meng in March 2010. Professor Chu moved for summary judgment, claiming that Plaintiffs’ § 256 claims were barred by the doctrine of laches because Hor and Meng should have known in 1987 that they were not named as inventors in the applications. Because over twenty years had passed between the time Hor and Meng purportedly should have known that they were not named as inventors, and the filing of the lawsuit, the district court concluded that Plaintiffs’ claims challenging inventorship were lached.
On appeal, the Federal Circuit evaluated the language of § 256, and concluded that the laches period for inventorship actions does not begin to run before the issuance date of the patent. Section 256 only allows actions to correct inventorship of an issued patent. Thus, if the period began to run before the patent issued, the six year period could expire before the unnamed inventor had any opportunity to challenge inventorship through §  256. The Federal Circuit rejected an argument that alternative methods of correcting inventorship in a pending application under sections 116 and 135 provide an adequate substitute for § 256. 
Accordingly, because less than two years had passed between the parent patent’s issuance and the filing of the lawsuit, the Federal Circuit held that laches did not apply, and Hor and Meng were free to pursue their inventorship claim. It now appears that no matter how long an application has been pending, the laches period for challenging inventorship under § 256 does not begin to run until the date the patent issues.
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