[SID] US Venture Unveils Low-power Transmissive MEMS Display

Jun 11, 2009
Tetsuo Nozawa, Nikkei Electronics
A 2.5-inch MEMS display prototype
A 2.5-inch MEMS display prototype
[Click to enlarge image]
Mark Halfman, vice president of Marketing at Pixtronix
Mark Halfman, vice president of Marketing at Pixtronix
[Click to enlarge image]

Pixtronix Inc unveiled a MEMS display developed with its proprietary technology at SID Display Week 2009.

Pixtronix gave a lecture on the display, "PerfectLight," in the symposium (lecture number: 37.4) and exhibited it at the exhibition site. The company has already prototyped a 2.5-inch QVGA (320 x 240 pixels) display that can display full-color video images.

"We have signed a contract with an Asian panel manufacturer," Pixtronix said. "The product will be released probably in 2010."

The MEMS display is composed of an LED backlight, two glass plates, MEMS shutters and a TFT substrate. The MEMS shutter measures about 160 x 160μm and features the maximum switching speed of 100μs. Although it is a transmissive display with a backlight, unlike LCDs, it does not use color filters or polarizing filters.

Digitally expressed gradation

The PerfectLight reproduces colors by blinking RGB LEDs in a time-divided manner while making them operate in conjunction with the MEMS shutters. Although the shutter has only two values, either open or closed, "the display can express gradation by changing the duty ratio and the number of times the shutter is opened and closed," Pixtronix said.

With this method, the PerfectLight can show 16.77 million colors (24 bits) and provide a color gamut of 145% NTSC, according to the company. It has a contrast ratio of 1,000:1 and a viewing angle of 170°.

The MEMS display's advantage over the existing transmissive displays is that it consumes less power. The power consumption of the new display is 1/4 of that of LCDs. In the case of the prototyped 2.5-inch display, it is about 45mW.

"LCDs can only utilize several percent of the light emitted by the backlight," the company said. "But the PerfectLight, which eliminates the use of color filters, etc, can use up to 60%."

Initially, the display will be targeted at car navigation systems, etc. Pixtronix plans to increase the number of pixels to 800 x 480 (WVGA) so that its applications can be expanded to smartphones, netbooks, notebook PCs and eventually to TVs.