Sanho Corp. v. Kaijet Tech. Int’l Ltd
Authored by: Jeremy J. Gustrowsky
A recent Federal Circuit decision clarifies an important rule for inventors: selling your invention privately—even without a confidentiality agreement—does not count as “publicly disclosing” it for the purposes of blocking later-filed patent applications from being used as prior art against you. This issue came up in a dispute over U.S. Patent No. 10,572,429, which covers a port extension device for laptops and other electronics. The patent owner, Sanho Corporation, argued that a private sale of its “HyperDrive” device before a competitor’s patent application should have shielded it from being used as prior art.
The court disagreed. The key legal question was whether a private, non-confidential sale of a product that embodies an invention is enough to be considered a “public disclosure” under 35 U.S.C. § 102(b)(2)(B). This section of the patent law provides an exception: if the inventor publicly discloses the invention before someone else files a patent application, that later application can’t be used as prior art. However, the court made it clear that “publicly disclosed” means more than just making a sale—it requires that the invention is actually made available to the public in a way that teaches them about the invention.
In this case, the sale was a private transaction between the inventor and Sanho, arranged through private messages and with no evidence that the features of the invention were shared with the public. There was no public announcement, no demonstration, and no evidence that anyone other than the buyer learned about the invention’s details. The court emphasized that the purpose of the “public disclosure” exception is to reward inventors who share their inventions with the public, not those who keep them private—even if they are selling the product.
For inventors and companies, the takeaway is clear: if you want to protect yourself from later-filed patent applications being used against you, you need to make a true public disclosure of your invention—such as publishing details, showing it at a public event, or otherwise making it accessible to the public. Private sales alone, even if not confidential, simply don’t count as a public disclosure.