Smartphone maker BlackBerry is reviving a legal battle against a startup co-founded by Ryan Seacrest, saying its iPhone keyboard rips off the design from BlackBerry phones' physical keyboards.



BlackBerry won a preliminary injunction last year against Typo Products' first keyboard.

Read MoreApplewins patent for virtual reality goggles



But Typo released a second-generation keyboard in December. Called the Typo2, it is a case that gives iPhones a physical keyboard below the touch screens.

In a federal lawsuit filed Monday, BlackBerry said Typo is still infringing on BlackBerry's patents, including those related to design, backlighting and typing automation technologies.

Seacrest started Typo with entrepreneur Laurence Hallier in 2013. The company declined to comment on the lawsuit.

Read MoreThe REAL battle Apple's waging

Physical keyboards remain one of BlackBerry's signature features, even as the phone's popularity has waned.