Nokia today expanded its legal attack against rival Apple to the iPad, alleging that Apple's tablet and iPhone violate five Nokia patents, federal court documents show.
The patents, which cover signal-to-noise modulation, geo-location and antenna technologies, are different than the 17 patents Nokia has claimed Apple infringed in two earlier federal lawsuits.
"We have taken this step to protect the results of our pioneering development and to put an end to continued unlawful use of Nokia's innovation," said Paul Melin, Nokia's general manager for patent licensing, in a statement Friday.
The filing is the latest in the legal hostilities between Nokia and Apple. In October 2009, Nokia claimed Apple infringed 10 of its patents related to wireless technologies used in the iPhone. Apple countersued in December , charging Nokia with violating 13 of its patents.
Also in December, Nokia followed its first lawsuit with another that alleged Apple infringed seven additional patents .
Both companies have filed complaints with the U.S. International Trade Commission (ITC), asking that their rival be barred from importing infringing products. The ITC has approved both complaints, and will investigate.
Apple is embroiled in other legal battles over its mobile products. The company faces an ITC investigation prompted by a complaint by Eastman Kodak that the iPhone infringes on several of its camera patents. In March, Apple sued handset maker HTC , charging the Taiwanese company with violating numerous patents. HTC manufactures several phones powered by Google 's Android mobile operating system.
Apple began selling the iPad 3G on April 30.
"Apple's unauthorized use of the patents-in-suit in its products at the time of their sale allows it to charge less for its products because it does not have to recover the costs of development of the technology used in the device," Nokia's lawsuit said. "This allows it to obtain market share that it would otherwise not be able to obtain were its products to bear the costs for the patented technology."
According to research firm IDC, Nokia is the world's leading handset maker, with an estimated 39% of the global smartphone market in the first quarter of 2010. By comparison, Apple held the No. 3 spot -- also behind BlackBerry-maker RIM -- and controlled a 16% share .
Nokia's lawyers asked that Apple be barred from infringing the patents, and that the company be forced to pay an unspecified amount in damages.
Nokia and Apple did not reply to requests seeking comment.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld . Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is firstname.lastname@example.org .
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