Cantor Colburn's October/November 2026 Ideas on Intellectual Property Law newsletter
Who knows what, and when?
Third-party product sale triggers patent’s on-sale bar
U.S. patent law includes many provisions that ensure patents are granted only to truly new inventions that the public couldn’t have been privy to before the filing of the patent application. One of these is the “on-sale bar,” which generally invalidates patents for products that had already been available for sale. The bar applies even, it turns out, if the products don’t disclose the patented invention’s functional details. This article reviews a case governed by the laws before the America Invents Act of 2011 (AIA) was passed. A short sidebar covers what evidence was required to prove the on-sale bar applied under pre-AIA law.
Definitive Holdings v. Powerteq, No. 24-1761, April 14, 2026, Fed. Cir.
Corrected inventorship doesn’t change patent invalidity finding
The owner of a patent can seek correction of the listed inventors at any time after a patent has issued. But a recent case makes clear that this leniency regarding corrections doesn’t provide the patent owner a second bite at the apple after the Patent Trial and Appeal Board has found the patent invalid. This article summarizes the case and the court’s findings.
Implicit, LLC v. Sonos, Inc., No. 20-1173, -1174, March 9, 2026, Fed. Cir.
Establishing exclusivity in the rights to copyrighted work
To bring a copyright infringement lawsuit, a party must possess an exclusive right in the work under the Copyright Act. This article discusses what happens when multiple parties have such an exclusive right in a single copyright — so multiple parties can sue for infringement of that copyright.
Great Bowery Inc. v. Consequence Sound LLC, No. 24-12482, -1174, May 5, 2026, 11th Cir.
A single DuPont factor can defeat trademark opposition
Trademark opposition proceedings often turn on the likelihood of confusion between two marks based on an analysis of 13 so-called DuPont factors (named for the case in which they were first enumerated). But the factors don’t have to be weighted equally. In fact, the U.S Court of Appeals for the Federal Circuit has repeatedly stated that each factor’s weight may vary from case to case, and courts aren’t required to consider every factor in every case. This article examines a recent case in which a single factor weighing against confusion proved decisive.
Fuente Marketing, Ltd. v. Vaporous Technologies, LLC, No. 24-1460, April 8, 2026, Fed. Cir.
