Apple Inc. and Google LLC are scowling at an inventor who claims the emoji buttons on their mobile phones infringe his patent on a universal keyboard.

Princeps Interface Technologies LLC sued the tech goliaths in Delaware earlier this summer, asserting a single patent on a universal keyboard developed by inventor Timothy Higginson. Princeps also sued Samsung Electronics Co., Motorola Mobility LLC and Asus Computer International.

But Google spotted a problem: The company to whom Higginson originally assigned the rights, Yuvee Inc., was dissolved in March 2018. In April of this year Yuvee sought to assign the patent-in-suit, No. 6,703,963, to Princeps. But Princeps wasn't created until May. "Thus, on the date they attempted to transfer the patent rights, neither Yuvee nor Princeps (the purported assignee) existed," Google stated in a motion to dismiss filed by Morris, Nichols, Arsht & Tunnell partner Brian Egan.

Princeps voluntarily dismissed its complaints earlier this month. But just to make sure they don't reappear, Google and Apple have sued for a declaratory judgment of non-infringement. And they've done it in the Northern District of California, on the theory that Princeps, despite being a Delaware company, established minimum contacts with the Northern District by suing Asus there.

Princeps argues that the '963 patent, first applied for in 2001, taught "automating and customizing the process of entering data into small profile input devices by dynamically utilizing user specified control combinations." By way of claim charts, its suits targeted the use of the emoji "domain control" that is used in Apple and Google mobile phones to call up a list of emojis.

But, Google argues in its DJ complaint, "The Gboard keyboard characters are not input keys simultaneously displayed with the alleged associated domain control in the accused Google products as required by at least claim 1" of the '963 patent.

"For example," Apple adds in its complaint, "the Emoji symbol (i.e., accused as being a domain control) does not appear simultaneously with Emoji characters (i.e., accused as being input keys)."

Desmarais partners John Desmarais and Paul Bondor lead Google's team in San Francisco and were co-counsel in the Delaware suit. Apple is represented by a Shook, Hardy & Bacon team featuring partner B. Trent Webb and Delaware counsel from Potter Anderson & Corroon.

Princeps Interface was represented in Delaware by Timothy Devlin and Patrick Delaney of the Devlin Law Firm in Delaware and California in the original, now-dismissed actions. Also providing counsel were Jeffrey Toler, who recently joined McDonnell Boehnen Hulbert & Berghoff, and Seth Wiener of the Law Offices of Seth W. Wiener.