Steve, here it is from the rctech.com website:

RCT and Epson Settle Patent Infringement Suit

Tucson, AZ - Jan 15, 2001

Research Corporation Technologies and Japan-based Seiko Epson Corporation have settled a patent infringement lawsuit RCT brought against Epson in July 2000.

RCT claimed Epson uses RCT's patented technology for halftoning color and gray-scale images in a variety of its inkjet printers.

Through constructive discussions and because Epson recognizes the value of RCT's technology, both parties agreed to settle the matter. RCT granted Epson a license to RCT's patents for the Blue Noise Mask halftoning technology developed by Kevin Parker and Theophano Mitsa at the University of Rochester in New York. RCT settled a similar lawsuit against the Hewlett-Packard Company in December 1999.

"We are pleased with the settlement and look forward to a mutually rewarding relationship with Seiko Epson," said RCT President Gary M. Munsinger. "Our Blue Noise Mask team expects to conclude a number of licenses over the coming months. To remain competitive, players in the printer and related industries should seriously consider this technology."

The Blue Noise Mask is the first halftoning method to combine high quality with virtually instantaneous halftoning. "Blue noise" refers to an unstructured pattern with small low-frequency-noise components that produces visually appealing arrangements of dots. Blue Noise Mask provides superior images, free of image artifacts and moiré patterns, at faster speeds.

Besides this, I have it on authority from a few different developers. Epson doesn’t even assemble many of their printers, for them to license this code doesn’t surprise me a bit. It works well, why reinvent the wheel.

And about Colorbyte’s screening technology which is better than what Epson uses, Graeme wrote:

“It's certainly not easy to get screening patterns better than what Epson manages, since they have had a lot of time and opportunity to figure their own device out. The handling multiple dot sizes is a bit of a trick.”

Colorbyte doesn’t have Epson’s resources either but they manage to do it better, especially with the 4000 and its triple-shot dot. In fact Colorbyte has exactly one person responsible for the development of these better screens, color engine, separate B+W pipeline, along with all of their other technologies. I think it is fair to say he is probably a talented person.

Cris Daniels