SP Technologies is suing Apple over a patent it claims is used in the touch-screen display of the iPhone.

The company claims Apple is aware of the patent, which was awarded to SP Technologies in 2004.

The patent describes a "method and medium for computer readable keyboard display incapable of user termination."

Filed last week in a plaintiff-friendly Texas court, the lawsuit - which claims "wilful and deliberate" infringement of the patent - demands royalties for each iPhone sold and an injunction against Apple to prevent it using the patent

Apple spokeswoman Natalie Kerris told Bloomberg the company doesn't comment on pending litigation.