Palm allowed to challenge Graffiti patent, says US court

The dispute arose in April 1997, when Xerox sued US Robotics - later acquired by 3Com – the then owner of Palm. Xerox claimed that the Graffiti handwriting-recognition technology used in popular PDA devices produced by Palm infringed a Xerox patent received in January of the same year.

Xerox alleged wilful infringement of its patent, entitled "Unistrokes for Computerised Interpretation of Handwriting", and sought to prevent Palm infringing the patent in the future, in addition to seeking damages.

Although the case was initially dismissed in 2002, Xerox's claims were reconsidered following an appeal. In December 2001, a US federal court ruled that Xerox had a valid and enforceable patent, which was infringed by Palm's Graffiti technology.

Palm appealed the ruling, in 2002, but was unsuccessful and was ordered to post a $50 million bond to Xerox. Palm requested a further appeal.

Yesterday, the US Court of for the Federal Circuit in Washington apparently upheld the original ruling, reasoning that it found "no error" in the lower court's infringement analysis. Nevertheless, the court sided with Palm's argument that the lower court had failed to establish whether Xerox's technology in question was unique and therefore valid.

The court has subsequently returned part of the case to the US District Court for the Western District of New York for further examination. This effectively gives Palm the opportunity to challenge the patent again.

If the validity of the Xerox patent is proved, Palm, which dominates the global market for PDAs, will be required to stop marketing devices with the handwriting recognition software in question.

Last month, Palm announced that it had abandoned its Graffiti handwriting recognition software to switch to a new system, a decision apparently prompted by the company's continuing legal wrangle with Xerox.