Garmin Ltd. has filed two lawsuits against European rival TomTom Inc., claiming the company is using Garmin-patented technology in its GPS devices.

In the suits, filed earlier this month in U.S. District Court in Madison, Wis., Olathe-based Garmin says TomTom has infringed on five Garmin U.S. patents protecting technology used in Garmin’s Global Positioning System devices.

All the patents covered in the lawsuits are aimed at making GPS navigators easier to use.

“One of our hallmarks is ease of use,” said Garmin spokesman Ted Gartner, adding that the company’s history in the GPS field means it has “amassed a significant stable of patents” in the consumer and aviation markets.

Amsterdam-based TomTom denied Garmin’s allegations.