One evening in November at an impromptu gathering of reporters at the Comdex computer trade show, Bill Gates, chairman of Microsoft Corp., enthusiastically described a breakthrough technology for improving the readability of text on the flat-panel color displays used on laptop computers.
The technique, which he said would be added to Microsoft's Windows operating system next year, is known as Cleartype, and it makes text on a portable computer almost as readable as a newspaper or a book, Gates said.
Such an advance could be the key to shifting the balance from text on paper to computer screens, he said, helping to popularize electronic books and making online publications legible enough to read directly from a computer screen for long periods without eye strain.
No one disputes that Cleartype represents a crucial step in the evolution of the information age and could mean an economic bonanza for the computer, Internet and publishing industries.
But Gates' portrayal of the underlying technology as a Microsoft innovation has set off an intense debate among some computer researchers.
The company says Cleartype is the result of work done by Bill Hill, a Microsoft researcher who joined Gates on stage for the Las Vegas introduction of the technology. Hill, the company says, discovered a fundamental new approach to rendering type by inventing algorithms that draw upon the basic physics of human vision.
But within hours of the introduction, the Internet was buzzing with claims that Cleartype was suspiciously similar to approaches developed many years earlier by researchers at Apple Computer, IBM, Xerox Corp. and elsewhere.
No one is suggesting that Microsoft intentionally violated the patent rights of any other company or individual. The major reason for the industry's fascination is that the issue speaks to a theme that winds through the government's landmark antitrust case against Microsoft being tried in federal court.
In testimony by executives of Netscape Communications Corp. and Sun Microsystems Inc., Microsoft has been portrayed as a high-technology opportunist that often copies and absorbs the innovations of other, smaller companies but seldom invents much on its own.
That perception is not new. Despite spending almost $3-billion a year on research and development, Microsoft is frequently portrayed as a company distinguished by its ability to capitalize on the ideas of others.
Indeed, Microsoft became the giant of the industry by purchasing another company's operating system and licensing it to IBM for its first personal computer. And Gates once defended Microsoft from accusations that his company borrowed the look and feel of the Windows operating system from Apple's Macintosh by insisting that both companies borrowed a graphical interface pioneered at Xerox's legendary Palo Alto Research Center.
This time, however, Microsoft insists that "the techniques we've developed are significantly different than the claims for prior art of which we're aware," said Dick Brass, a Microsoft vice president for technology development who is leading the company's electronic-book development.
But John Seeley Brown, director of the Palo Alto Research Center, is one of a group of researchers who do not see it that way.
"They may have found a minor twist," Brown said, "but the idea of how the eye perceives color based on the display of sub-pixels is where we started this game."
Microsoft has refused to disclose details about Cleartype, saying it did not want to compromise the patent protection it seeks.
During his impromptu Comdex chat with reporters, though, Gates divulged that Hill and a small group of Microsoft researchers had been able to take advantage of the fact that on a liquid crystal display, or LCD, each picture element, or pixel, consists of three separate sub-pixels, of different colors. When all three are switched on simultaneously, the viewer is tricked into seeing a single white pixel because the individual sub-pixels are too tiny for the eye to resolve.
This means that LCDs should be able to render type fonts as much as three times the actual screen resolution, making them far sharper and easier to read.
The stairstep edges of lines on a typical computer screen give fonts a jagged appearance, so smoothing type has long been a quest of software designers. Most settle for one of a variety of techniques known as anti-aliasing or hinting. The most common technique is to paint pixels along a character's edge in shades of gray, which essentially smudges the characters' borders to make them appear less jagged.
Microsoft says its sub-pixel approach is "an unprecedented innovation in font display technology" and Gates called it a "leap forward" in screen sharpness.
Other industry researchers acknowledge that the Cleartype technology will make screens sharper, but insist that the underlying concepts have been known for decades.
"The thing that I objected to is they made such a big deal out of it," said Steve Gibson, a software developer who wrote programs for the Apple II personal computer. "I'm afraid they are going to try to claim it as their own."