'Blue Noise Mask' Patents Cleared For Enforcement

The inventors of the "Blue Noise Mask," a display and printing technology that rapidly generates high-quality images developed at the University of Rochester in the late 1980s, are pleased that the patents for their technology will be able to be enforced in a lawsuit against Microsoft because of the recent decision of a federal appellate court.

The co-inventors of the Blue Noise Mask are Kevin J. Parker, dean of the School of Engineering and Applied Sciences, and his former graduate student, Theophano Mitsa, who is now an assistant professor of electrical and computer engineering at the University of Massachusetts, Dartmouth.

Research Corporation Technologies (RCT), a company that helps universities commercialize technology developed in their laboratories, owns the six U.S. patents and several international patents on the technology and enforces them for the benefit of itself, the University and the inventors. The Blue Noise Mask has been licensed to several companies, including Hewlett-Packard, Lexmark International, and Seiko-Epson.

In 2001, RCT sued Microsoft Corporation for infringing the Blue Noise Mask patents. In response, Microsoft alleged the inventors' subsequent research unrelated to the patents invalidated their original patent. In 2005, a Federal district court agreed with Microsoft. The federal appellate court in Washington, D.C., which handles appeals of all patent cases, just reversed that ruling, stating that the Rochester inventors' "experiments were not material to the patented invention and did not give rise to any disclosure obligation" and that the original lawsuit against Microsoft can continue. The appellate court further took the highly unusual step of directing that the case be assigned to a different trial court judge.

"We're happy to see the patent rights upheld," says Parker. "It's gratifying that the court came out so strongly against the tactics employed by Microsoft to delay the infringement trial."

Begun in the late 80s, the Blue Noise Mask was originally designed to improve ultrasound images. Until Blue Noise Mask technology, ultrasound diagnostic equipment was slow and plagued by distracting "noise." That noise could hamper a doctor's diagnosis, so Parker invented a process that involved "blue noise"—an unstructured yet visually pleasing halftone pattern, which improved the speed and quality of the printing process.

Parker, along with Mitsa, refined the Blue Noise Mask technology until it could create an improved image 45 times faster than the leading technology. The technology became the standard in the industry for image printing.

"This research is a great example of the unforeseen benefits of basic research at a university," Parker has previously noted.