The lawsuits against Apple, Japan-based Sony, Taiwan-based HTC Corp, South Korea-based LG Electronics Inc and Samsung Electronics Co were filed in the U.S. District Court in Wilmington, Delaware.

The patent at issue relates to a computer graphics process that turns text and images into pixels to be displayed on screens.

According to the lawsuits, the defendants' infringing devices include Apple's iPhone and the HTC EVO4G, LG Thrill, Research in Motion Torch, Samsung Galaxy S and Galaxy S II, and Sony Xperia Play smartphones.

Graphics Properties said that unless the alleged infringements are halted, it will suffer irreparable harm. The lawsuits seek to stop the sale of infringing products and also seek reasonable royalties and other damages.

HTC spokeswoman Lori Rodney, LG spokesman John Taylor, Research in Motion spokeswoman Tenille Kennedy and Sony spokeswoman Sandra Genelius declined to comment on the substance of their companies' respective lawsuits. Apple and Samsung did not immediately respond to requests for comment.

Silicon Graphics filed for bankruptcy in 2009 and sold much of its operations to Rackable Systems Inc. The remaining operations are based in New Rochelle, New York, and are owned by private investment firms and other investors, according to the complaints.

The lawsuits are all in the U.S. District Court, District of Delaware. They are Graphics Properties Holdings Inc v. Apple Inc, No. 12-00385; Graphics Properties Holdings Inc v. HTC Corp et al, No. 12-00387; Graphics Properties Holdings Inc. v. LG Electronics Inc et al, No. 12-00389; Graphics Properties Holdings Inc v. Research in Motion Ltd et al, No. 12-00386; Graphics Properties Holdings Inc. v. Samsung Electronics Co et al, No. 12-00388; and Graphics Properties Holdings Inc v. Sony Corp et al, No. 12-00390.

(Reporting By Jonathan Stempel, Liana B. Baker and Sinead Carew in New York; Editing by Maureen Bavdek and John Wallace)

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