Hitachi Introduces Display Based on MEMS (Microelectromechanical Systems) Technology

Submitted by lalit on October 10, 2010 - 11:13pm.

Microelectromechanical Systems (MEMS) based displays are trying to replace the LCDs in portable electronics. Qualcomm has already shown their mirasol display technology based on MEMS earlier this year in sizes ranging from 3- to 7-inch. And now Hitachi is joining the bandwagon with their 2.5-inch display prototype based on MEMS. 

Hitachi is using Pixtronix’s Digital Micro Shutter system that combines thin-film transistor technology with MEMS for lower power consumption and better color reproduction. Unlike popular MEMS projections display applications that utilize reflective micro mirrors, the Pixtronix display architecture uses MEMS shutters, which are digitally actuated between a transmissive (open) or opaque (closed) state. When integrated with a backlight, this forms the basis for a direct- view display.

The Pixtronix display is a transmissive, field sequential color (FCS) display. Utilizing a tri-color LED backlight, the display provides a full color gamut 105% of NTSC (compared to 55% on LCD) and color depth for a rich and vibrant video experience (contrasted with direct view reflective MEMS displays). It has very low power consumption because of its unique optical train, which utilizes light recycling to achieve over 60% optical transmission. The Pixtronix display also has high contrast ratio through a wide viewing angle.

The Pixtronix display module consists of two joined components: a MEMS module and a backlight. The MEMS module comprises an active backplane with MEMS shutters built over it and a cover glass. The backplane and MEMS are fabricated using standard TFT processing with a simple digital circuit. Cell assembly and module integration are also accomplished using standard LCD processing tools. This allows production of these displays using the large installed base of LCD processing tools and manufacturing infrastructure.

The advantages offered by Pixtronix’s Digital Micro Shutter displays are lower production cost, as high cost LCD materials like liquid crystals, color filters and polarizers are not required; better image quality with 105% color gamut, 24 bit color depth, 170 degree viewing angle and 100 microsecond response time; and ultra low power consumption about 75% reduction from conventional LCD. Also the Pixtronix displays can be used without the backlight in reflective mode, just like e-ink displays to further reduce power consumption. And, yes the display offers full color reproduction in reflective mode also.

Hitachi says that Digital Micro Shutter displays should come to the market in second half of 2011 in up to 10-inch size. Initially, Hitachi will aim for smaller devices like cellphones and portable media players. Check out the video below showing how a conventional MEMS display works, which is slightly different from MEMS based Digital Micro Shutter display, but it gives you an idea about the technology.