The high court refused to adopt Microsoft's lower standard to replace the long-standing requirement that a defendant in a patent infringement case prove by clear and convincing evidence that a plaintiff's patent is invalid.
Microsoft had argued that a lower standard of proof involving a "preponderance of the evidence" would make some "bad" patents easier to invalidate while promoting innovation and competition.
The legal battle began in 2007 when i4i sued Microsoft. A federal jury awarded $290 million to i4i after finding that Microsoft, in 2003 and 2007 versions of Word, its word processing application, had infringed i4i's patent relating to text manipulation software.
The i4i dispute was over a method of processing electronic documents using embedded codes that provide instructions on how information appears. Word 2003 and 2007 use extensible markup language or XML, for encoding, and customize the XML in a way that closely held i4i contends infringes its patent.
On December 2099, a U.S. appeals court upheld the award, and the U.S. Patent and Trademark Office upheld the validity of the i4i patent.
In the meantime, Microsoft removed the contested features from its current software.
In appealing to the Supreme Court, Microsoft said it wanted a new trial. But the justices ruled against Microsoft.