A View from David Zax
A Paper-Like Display Showing Color Video
Another innovation from Japan Display. Could it catch on?
Japan Display, the entity that pools resources from Sony, Toshiba, and Hitachi that I wrote about last week, has showed off another neat display at FPD International 2012, and again the Japanese-savvy Diginfo has the scoop (and video). The display is a paper-like LCD that can show video. On top of that, the display is low-power, relatively speaking. The results could be of great use to device makers who want to simulate a paper-like experience while adding the capabilities of color video.
In a press release, Japan Display pointed to the two novel technologies at play here: first, “an optical property optimization adopting a newly-developed scattering layer,” and second, a method for reducing power consumption when displaying still images.
First, let’s talk about that “newly-developed scattering layer.” Japan Display calls that a Light Control Layer. Most LCDs would simply reflect light, like a mirror–think of an iPad when it’s turned off, say. By adding the layer, a Japan Display rep told Diginfo, “the display collects light to some extent, in the direction of the user’s eyes, making it look similar to paper.” Japan Display asserts that “ordinary digital paper” can’t achieve the same good color levels of its own display.
And how about that second feature that reduces power consumption? Japan Display has a name for that, too: Memory in Pixels. The technology here is straightforward enough: the display has electric circuits built in, which can retain signals. “With a still picture, once the data has been written, it can be retained,” said Japan Display’s Kazunori Yamaguchi, “so power consumption is extremely low.” Unfortunately, Diginfo doesn’t present further explication of the SRAM tech at work here; expect details to emerge as the device nears the market. In its press release, Japan Display touted power consumption of 3mW for a still image.
And when exactly will the device come to market? Japan Display has developed two versions of the tech–one that has a lower color purity (5 percent of the NTSC color gamut), yet achieves good brightness (a 40 percent reflection rate), and then another with better color purity (36 percent coverage of the NTSC color gamut) that’s dimmer. The first one is ready to go to the mass market as soon as device makers say so; with the latter, Japan Display wants to do some more R&D, presumably to figure out how to boost brightness while retaining that high color gamut.
The quest for an e-reader display (or e-reader-like display) that shows color video is of chief importance to device makers. Last year, TR’s Tom Simonite looked at an intriguing reflective display called Mirasol; Qualcomm acquired the startup that made the tech in 2004. The Kyobo e-reader was the first to use Mirasol tech. But when the screen reportedly didn’t live up to the excitement that had surrounded it, the e-reader went on a clearance sale.
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