SAN FRANCISCO — Monday was not a $1 billion day in the San Jose courtroom of U.S. District Judge Lucy Koh.

For Japanese computer company Fujitsu, it was a $0 day. Unlike Apple, which walked away from trial with a record patent verdict in August, Fujitsu and the company’s lawyers at Covington & Burling weathered a total loss in a patent trial against three rivals over the wireless networking cards inserted into computers for on-the-go Internet access.

After a 10-day trial, the eight-member jury sided with Belkin Inc., D-Link Corp., and NetGear Inc., deeming Fujitsu’s claims under a patent for a “card type input/output interface device” to be invalid. The jury, which began deliberating Friday, also found the defendants had not caused infringement by selling routers and access points that were compatible with wireless interface cards. Lead Belkin attorney David Enzminger of Winston & Strawn in Los Angeles told jurors a computer industry group published draft specifications for cards that would connect users to the Internet prior to Fujitsu’s first patent application in 1991. Moreover, at least one company prior to 1990 sold a wireless communication card that connected individual computers to printers and other devices through a network, he said.

“We felt the patent was invalid and Fujitsu actually hadn’t invented what they claimed to have invented,” Enzminger said in an interview Monday. “Our defense was an invalidity defense.”

The jury found the defendants proved by clear and convincing evidence that each claim raised by Fujitsu was anticipated by prior art and would have been obvious to a person of ordinary skill in the art as of April 1991.

Despite the quick verdict, Enzminger said the jury fully grappled with the complicated issues in the case. Three members of the jury spoke with lawyers after the verdict, he said.

“They were very hardworking,” he said. “They dug down surprisingly deeply. They spent a lot of time going through documentary evidence.”

Monday’s jury verdict dealt with a subset of products Fujitsu accused of infringing on its ’769 patent. Overall, Fujitsu sought roughly $20 million in damages from the defendants, Enzminger said.

Robert Fram, lead lawyer for Fujitsu and co-chair of Covington’s IP litigation group, didn’t respond to messages. A Fujitsu spokesman said the company would review its next steps. D-Link was represented by solo practitioners S.J. Christine Yang of Orange County and Duncan Palmatier of Moscow, Idaho.

In an email, Netgear General Counsel Andrew Kim gave credit to the company’s outside legal team, led by Reed Smith partner John Bovich.