However, in making its decision, the appeals court interpreted the patent more broadly, according to Mary Doyle, senior vice president and general counsel for palmOne. "The more broadly you construe a patent," she said, "the more broadly you're casting the net on prior art."

When evaluating a patent application, examiners consider evidence of whether a similar invention had been created, discussed or conceived of earlier than the applicant's. Prior art can include drawings, memos and articles in journals.

The broader interpretation allowed palmOne to present prior art that hadn't been considered when granting the patent, without claiming that Stamford, Conn.-based Xerox would have been aware of such prior art.

The palmOne legal team presented three pieces of prior art that convinced the judge to throw out the patent: an earlier Japanese patent, an article written in 1983, and Microsoft's Pen Windows product, released in the early 1980s.

"The trial court took great pains to author a decision this time that we believe would be very difficult to overturn on appeal," Doyle said. "Even were it overturned on appeal, the trial court went further to say the patent's validity must then be determined by a jury. Which is to say we won on all counts."