The patent battle between Microsoft and the University of California's Eolas spin-off is heating up again, with each side pressing its case before the government.
UC and Eolas filed a response to the U.S. Patent and Trademark Office 11 weeks after a USPTO examiner issued preliminary findings in a re-examination of the Eolas browser patent.
Attorneys for the university and Eolas on Tuesday filed the 10-page response and two declarations in order to rebut the preliminary findings, which would invalidate the patent if formally endorsed. The findings appeared to tip the closely watched case in Microsoft's favor, acknowledging that the patent may have been wrongly granted. But they're far from the last word, legal experts said, since they came early in what will likely be a years-long process.
While Microsoft is not formally involved in the re-examination process, it is preparing its own appeal to a $521 million patent infringement decision it lost to the university and Eolas in federal district court last year.
A representative for the University of California expressed confidence the patent would prevail both in court and at the patent office.
"The court case was a slam dunk," said UC representative Trey Davis. "Part of the interest in the patent office re-examination is that Microsoft is using it essentially as a back door to win the case when they couldn't win it in court."
The federal district court jury ruled against Microsoft after agreeing with the school's contention that Microsoft's market-dominating Internet Explorer browser infringed on Eolas' patent describing how a browser can open plug-in applications.
In response, Microsoft proposed changes to IE that would bypass the patent but potentially hobble millions of Web pages. That prospect helped bring Web developers and the World Wide Web Consortium (W3C), a key standards body, to Microsoft's side.
The W3C asked that the patent office revoke the patent, and agency's director at the time, James Rogan, ordered the re-examination.
Microsoft declined to comment on UC's Tuesday filing to the USPTO, saying it had not yet had a chance to review the material. The software maker's filing next week will launch an appeals process that could wrap up this winter, said an attorney for UC.
An attorney for the university and Eolas expressed confidence in their prospects at the court of appeals.
"Every case we try, we do so knowing that it's likely to be appealed at the federal circuit," said the attorney, Marty Lueck. "We believe that the trial court made no errors of law and the jurors' verdict is supported by substantial evidence, so we believe we should win."
The substance of the university's response concerns examples of so-called prior art, or technology that predated a patent application that would prove it wasn't an original invention.
In its request for a re-exam, the patent office cited two examples of technology the office said was substantially similar to what the Eolas patent described. Both were published prior to the UC-Eolas patent by Web developer Dave Raggett.
Eolas also submitted two declarations, one by Eolas founder and patent inventor Mike Doyle, the other by Princeton University computer scientist Ed Felton, who was a lead prosecution witness for UC and Eolas at trial.