turn yellow, magenta, and cyan—the three basic colors used for most color printing. And in 2005—with Polaroid in the midst of bankruptcy proceedings—that technology, plus a team of 44 researchers from the lab, was spun off to create Zink. (The research operation and Polaroid’s inkless-printing patents were purchased for an undisclosed sum by Robert White, an executive at Petters Group Worldwide in Minneapolis, and a group of private investors. Petters Group itself went on to buy most of Polaroid’s other assets.)
Herchen, one of the Zink’s Polaroid veterans who made the jump when the company was formed, explains that when the Zink paper passes through a special Zink printer, it comes in contact with a thermal print head that applies hundreds of millions of tiny heat pulses. “By adjusting the temperature and the timing of each pulse,” Herchen says, “the printer controls which crystals are melted”—and therefore which exact color, out of a range of millions, will appear at each pixel.
But as simple as it sounds, it took a couple more years to make the technology work, according to Herchen. The previous existence of high-resolution thermal print heads and the electronics to drive them meant that half the problem was already solved. But the chemistry of the color crystals was another matter. “The most difficult part was efficient color conversion—-controlling the amount of color you get when the crystals are melted,” Herchen says. “Another challenge was to make the images stable after you’ve formed them… Also, there’s one color that forms at a high temperature [yellow], one that’s intermediate [magenta], and one that’s low [cyan], and it’s important that these temperatures be fairly well separated from each other. That took some doing.”
And so did coming up with the software to precisely control the print heads in Zink’s system, which bristle with 300 heating elements per inch. Producing a single pixel of yellow, for instance, means heating a single element to a high temperature for just long enough to melt the yellow crystals in the paper’s top layer—but not long enough for the heat to dissipate to the middle or bottom layers. Producing a more complex color might require delivering two or three different pulses in quick succession, at different temperatures and durations, all while the paper is moving quickly past the print head. Zink “relied pretty heavily” on Alps Electric of Japan for help solving the control problem, Herchen says.
The company showed off its first working prototype at the Demo conference in Desert Palms, CA, last January, then spent 2007 transferring its technology to manufacturing partners, including Taiwan-based FoxConn, the world’s largest contract electronics manufacturer.
Zink’s plan had always been to license its intellectual property rather than to actually build anything, says Caswell. But then came the Konica-Minolta deal. “We needed to get the paper manufactured in scale, and we were looking for factories that could do thin-film coating,” Caswell says. “We found a Konica-Minolta plant that was a perfect match in North Carolina. But when we said ‘Would you like to be a partner?’ they said ‘You’re half a year too late—we’re in the process of liquidating.’ We convinced them to stall the process while we went to see if we could afford to buy the facility. And by July 2 we had our own plant, along with 62 people who were previously Konica-Minolta employees.”
That roughly doubled the company’s employee base. And it made Zink into a full-fledged manufacturer. But the company is still a very different place from its birth parent, Polaroid, Caswell says.
“The Polaroid model was very successful for decades, but it was tightly integrated from end to end, from inventing the IP to
