Saturday, December 11, 2010

Reflections on a reflective LCOS press release

A few days ago, a press release from one of the liquid crystal on silicon (LCOS) chip vendors landed in my inbox. Two things caught my interest:
1. That sometimes in 2012 (e.g. 13 to 24 months from today) they would release a display with 2048x1536 pixels.
2. That this chip would eventually power head-mounted displays that could serve as an alternative to achieving wide field of view and high resolution through multiple low-resolution displays.

I think Sensics is the only company that has tiled head-mounted displays as part of the product line, I took that as presenting a 2012 alternative to Sensics. If imitation is the most sincere form of flattery, than I and the rest of the Sensics team should take this press release with pride.

Other than pride, it gives us an opportunity to review the criteria we use for selecting the display chips that power our products. We are not married to a specific display technology, but strive the provide an excellent combination of panoramic field of view and high definition and a lightweight design. Panoramic field of view provide greater sense of immersion and heightened situational awareness. High definition provides more realistic images. Lightweight designs can be used for extended periods without neck strain or long-term health concerns. Customers have come to understand why all these attributes are important and want to go forward, not backward, with future HMDs.

Last time we made that choice, OLEDs were best for us and our customers as they offer unique advantages:
- Simpler optical design which translates into smaller, lighter products. OLEDs are self-emitting whereas LCOS is a reflective technology requiring an external light source and more complex optical path.
- Higher contrast. Because the external light source for LCOS shines even when the displays need to show black, the overall contrast in LCOS is typically much lower than OLED
- Faster switching and no motion blur. LCOS relies on an external light source an LCOS chip is typically lit by three alternating light sources. In contrast, OLED is faster and the colors are continuously lit.
- Lower power consumption which translates into less heat near and head and longer operation when used with a battery.
- Simpler drive electronics which make for smaller products.

LCOS chips do offer two advantages:
- Greater fill ratio, which is the percent of useful area in the chip.
- Ability to offer very high brightness if lit by a powerful lamp. This could be important for actual flight helmets that need to be used in direct sunlight but not as much for HMDs.

As part of the xSight and piSight product line, Sensics achieves panoramic field of view, high definition 1080P and light weight by optically tiling several 800x600 OLED displays. Tiling is getting better and better every year, and tiling HMDs could be introduced for 1280x1024 or even higher resolution OLEDs, effectively decreasing the number of tiles while maintaining all the other advantages of the tiled design.

BTW, the Sensics zSight is not tiled and offers a single-screen solution for those that prefer it.

Come late 2011, 2012 or whenever a higher-resolution LCOS chip is ready, Sensics will be more than happy to take a serious look at it and see if it could improve the customer experience relative to then-available alternatives. Until then, we're just glad to be on everyone's mind.

1 comment:

Anonymous said...

I just wanted to say "thanks" for your pioneering work in this field - like many folks I've been hoping to own decent 3D goggles for decades. If the resolution is ~800x600 and head-tracking response time is fast, I think i'd be happy with ~35 degree FOV, but one cannot be sure until one tries it.