Apple has sued HTC claiming 20 patent violations relating to iPhone and other technology, including the iPhone's multitouch functionality.
The company filed two suits concurrently, with the US International Trade Commission (ITC) and the US District Court in Delaware, on Tuesday. Apple chief Steve Jobs said in a statement that "competitors should create their own original technology, not steal [Apple's]".
"We can sit by and watch competitors steal our patented inventions, or we can do something about it. We've decided to do something about it," Jobs said.
Taiwan-based HTC, which makes numerous Android and Windows Mobile handsets that have been named in the suits, responded by saying it was unable to comment on the validity of Apple's claims, as it only learned of the suits on Tuesday through the media.
"HTC values patent rights and their enforcement but is also committed to defending its own technology innovations," the company said.
Apple sued HTC over 10 patents in the ITC case, and 10 separate patents in the Delaware case.
The multitouch patent — US Patent 7,479,949, awarded to Apple at the start of 2009 — covers gestures such as pinch-to-zoom and swipe-to-scroll, and is named in the Delaware filing. Until recently, HTC Android phones sold in the US had multitouch disabled, but in February Google issued an update for the Nexus One 'Google phone' that enabled such functionality for US users.
Other patents named in the Delaware filing include those for 'unlocking a device by performing gestures on an unlock image', 'list scrolling and document translation, scaling, and rotation on a touchscreen display', and 'object-oriented graphic system'.
The patents listed in the ITC filing include, among others: 'Message protocol for controlling a user interface from an inactive application program' and 'Real-time signal processing system for serially transmitted data'.
Apple is also involved in a legal battle with Nokia over patents, some of which — such as the list-scrolling patent — are also named in the suits launched against HTC on Tuesday.