A federal judge has sided with DeLorme Publishing in its contentious patent-infringement battle with a Virginia company over the Yarmouth-based mapmaker’s line of hand-held emergency satellite communication devices.

U.S. District Court Judge Leonie Brinkema ruled Thursday that a patent claimed by Virginia-based BriarTek is invalid because there were multiple examples of similar products that pre-dated BriarTek’s patent application, according to a filing in the Eastern District court in Virginia. BriarTek had accused DeLorme, famous for its Maine Atlas and Gazetteer, of infringing on the disputed patent.

“The patent is invalid basically because someone else had invented it first,” Peter Brann, DeLorme’s attorney, said Thursday. “Obviously, this is a complete and sweet victory for DeLorme, who, from day one, did not think this patent was valid. It’s nice to have a federal judge confirm that.”

The judge’s decision, however, does not bring DeLorme’s patent troubles to an end. A related patent-infringement case between the two companies is pending as a U.S. International Trade Commission ruling is appealed. The outcome of that case has the potential to derail DeLorme’s evolution from a publisher of printed maps to a technology company that sells mapping software and the satellite communication devices in question, which are sold under the inReach brand. The inReach devices currently make up half of the company’s $20 million in annual revenue, said CEO Mike Heffron.

The patent fight began in August 2012 when BriarTek filed a complaint with the ITC that DeLorme was infringing on a patent that BriarTek received in 2011 for a “Global Bidirectional Locator Beacon and Emergency Communications System.” At the time, DeLorme was importing the inReach devices from overseas, triggering BriarTek’s complaint to the ITC. DeLorme then began manufacturing the devices in Yarmouth, but used components that it imported.

In June 2014, an ITC judge ruled that DeLorme was inducing infringement by consumers who bought the devices and levied a $6.2 million civil penalty against the company. DeLorme contested the penalty and appealed the decision to the U.S. Court of Appeals for the Federal Circuit. That appeal is pending, but Brann believes Brinkema’s ruling that the patent is invalid “mortally wounds” the ITC’s case.

BriarTek’s attorney disagreed. “The Virginia ruling has no impact on the ITC appeal,” John Fuisz wrote in an email. “The Virginia order as it currently stands does not remove the violation, the fine or the pending consent order.”

Fuisz said he had already alerted the ITC that BriarTek plans to appeal the Virginia decision “so that the government can move forward with the matter and collect the $6.2 million fine.”

Heffron, DeLorme’s CEO, said the company intends to grow its inReach business, even though it could be exposed to further fines from the ITC. The company, which was founded in 1976, has more than 80 employees at its Yarmouth headquarters.

“Our hope is once we get out from under legal costs, we plan to expand that business and continue to grow in Maine,” Heffron said Thursday morning.

Heffron could not say exactly how much this legal battle has cost the company, but said the lawyer fees alone are in the “seven figures.” He said the other cost is the time and energy spent by the company’s employees during the battle, which he said is probably equivalent to what it cost to pay the lawyers.

“It has been significant for us, especially for a small business,” Heffron said.

Confident that the company has done nothing wrong, Heffron said the experience hasn’t caused him to make any changes at DeLorme. Rather, he said, it has underscored a glaring need for the United States to revamp its patent-approval system.

“It’s pretty clear we’ve gotten away from the requirement to demonstrate a unique invention before a patent is issued,” Heffron said. “Patents are supposed to be issued for unique and novel innovations that no one has ever thought of before, not just a new presentation of a group of ideas that were previously developed.”