Justice, USPTO file briefs opposing Microsoft's bid to change the burden of proof in patent challenges

The federal government has weighed in on a legal question in i4i LLP's patent infringement case against Microsoft, supporting i4i's position that the law for proving patent challenges shouldn't be changed.

The Toronto-based company filed 22 amicus, or "friend of the court," briefs from various companies, venture capitalists and two federal agencies. The briefs all argue against Microsoft's Supreme Court appeal to revise the burden of proof in patent challenges, according to an announcement issued by i4i on Monday.

The 33-page March amicus filing (PDF) by attorneys at theJustice Department and U.S. Patent and Trademark Office simply concludes that "the decision of the court of appeals [in the i4i v. Microsoft case] should be affirmed."

Microsoft lost on appeal in a lower court after a jury awarded i4i more than $290 million in damages in a case involving i4i's custom XML technology. i4i's patent was considered to have been "willfully infringed" in older versions of Microsoft Word.

Microsoft is currently arguing at the Supreme Court that the standard of proof is too high to disprove a patent in cases where the U.S. Patent and Trademark Office lacked prior-art information. The company has its own supporters for that position, including amicus-brief backing from Apple, Google, GM, Verizon and the Electronic Frontier Foundation, among others.

Microsoft also recently backed Congressional efforts aimed at revising U.S. patent laws. Senate Bill S.23, or the "America Invents Act," was passed by the Senate last week, with deliberations in the House still pending.

i4i provides links to all 22 amicus-brief filers here. Seven former military officers also weighed in against revising the standard of proof in patent disputes. That brief (PDF) concluded that "to lower the standard [of proof in patent cases] risks military preparedness and morale."

The Supreme Court is scheduled to hear oral arguments in the case on April 18, with a decision expected by the end of June.