Apple is doubling down on its legal assault against HTC.
According to Foss, Apple is claiming that five patents are being illegally used, including one used for scrolling operations, another for programmable tactile touch-screen displays, and one for a double-sided touch-sensitive panel, all of which are used in another complaint against Samsung.
The other relates to the ability to scroll, zoom, and rotate content on a screen, while the last references "portable computers."
Apple wasn't immediately available to comment on the complaint.
HTC expressed its disappointment with the further legal entanglement.
HTC is dismayed that Apple has resorted to competition in the courts rather than the market place," said Grace Lei, general counsel for the company. "HTC continues to vehemently deny all of Apple's past and present claims against it and will continue to protect and defend its own intellectual property as it has already done this year."
HTC has had success with its early embrace of the Android mobile operating system and was the first company that Apple targeted legally in regard to Android. When Apple filed its first complaint and a parallel lawsuit in March, Apple alleged that HTC was illegally using 20 patents related to the iPhone.
The complaint is another sign that the competitive pressures are getting to Apple. While the iPhone itself remains a blockbuster smartphone, the number of Android smartphones has overtaken it in the U.S.
HTC is considered the most vulnerable legally of the Android partners because it lacks a robust portfolio of patents that act as a potential shield. Earlier this month, HTC purchased S3 Graphics, largely because of a collection of patents that the ITC administrative law judge recently determined were used illegally by Apple.
An ITC administrative law judge has already recommended siding with HTC in that case, although the ruling is only a recommendation; the six-member commission will make the ultimate ruling this fall.
Over the past few years, technology companies have been increasingly using the ITC as a means of settling their disputes. The ITC process of review is often quicker than a traditional lawsuit filed in a district court, and the threat to ban the importation of products is often enough to force settlements.
Apple has been busy on the litigation front. Last week, Apple filed a complaint with the ITC against Samsung, seeking an injunction against the importing of key Android smartphones and tablets into the U.S. The complaint alleges that five technical patents and two design patents are illegally used by Samsung in its Android products. Samsung also has an ITC complaint against Apple.
Updated at 10:04 a.m. PT: Added comment from HTC and additional background on ITC cases. Updated at 12:52 p.m. PT: Added details of the patents in dispute found in the ITC complaint.
Correction at 10:37 a.m. PT: This story initially misstated Grace Lei's title. She is general counsel at HTC.