Apple alleges patent violations by a rival

Still, it shows Apple’s get-tough strategy as significant competitors emerge.

“We can sit by and watch competitors steal our patented inventions, or we can do something about it,’’ Apple CEO Steve Jobs said.

Apple said HTC has infringed on 20 of its patents covering aspects of the iPhone’s user interface and hardware. Several relate to the technology behind touchscreens, including one that lets a device’s screen detect more than one finger touch at a time, allowing the user to zoom in or out by spreading fingers apart or pinching them together, for instance.

Google was not named as a defendant.

When the iPhone came out in 2007, it changed the smartphone landscape by introducing a stylish, easy-to-use device. Apple later followed with an application store that extended the capabilities of the device far beyond just making phone calls, checking e-mails, and surfing the Web.

Apple is seeking unspecified damages and court orders to block US sales of HTC’s Android phones and other products that Apple says violate its patents.

The complaints were filed with the US International Trade Commission, which has the power to block imports, and US District Court in Wilmington, Del.

HTC spokeswoman Linda Mills said the company learned of the lawsuits yesterday through media reports and has not reviewed Apple’s claims.

“HTC values patent rights and their enforcement but is also committed to defending its own technology innovations,’’ Mills said.

Apple itself faces litigation over the iPhone and other products from the Finnish cell phone maker Nokia Corp., which Apple has countersued.