Sony Corporation (Tokyo, Japan) (www.sony.net) recently announced the development of SXRD (Silicon X-tal Reflective Display), a liquid crystal on silicon (LCOS) device for use in projectors. The news reinforced its plans for the technology generating a lot of attention, interest and speculation.

Many SXRD product details, including price, haven't been finalized, but Sony has specified the 0.78-inch SXRD microdisplay has 1920 x 1080 resolution, 3,000:1 contrast ratio and 65% reflectivity. The SXRD was developed and will be manufactured internally.

The SXRD will co-exist with the grating light valve (GLV), with similar specs, because it is smaller and further along in development, according to Sony. Sony is not saying if the new technology will first appear in front projectors or rear-projection TV first, but a roll out in Japan initially seems likely. We suspect a series of high-end front projectors will be developed aimed home theater, custom install and maybe even digital cinema applications. Apparently, Sony has produced several prototype front projectors that it has shown to custom install dealers on a limited basis. A rear-projection TV set offering 1080p seems probable too.

The panel itself features a 9µm pixel pitch and minimizes the space between pixels (0.35µm). In comparison to HTPS panels used in Sony's Cineza front projectors and Grand Wega LCD-RPTVs, this represents a 2.4- fold increase in pixel density, and a 10-fold improvement in inter-pixel spacing. The pixel aperture, or fill factor is 92%, similar to LCOS devices from Hitachi, Three-Five Systems and others. It is also similar to DLP. This pixel aperture is much lower in transmissive HTPS devices. These advances should allow the SXRD panel to achieve a high-resolution picture with outstanding cinematic quality and image smoothness that can be enjoyed free from the grainy "mesh" effect noticeable on conventional HTPS projectors.

Sony has been developing LCOS technology for some time, initially pursuing a ferroelectric LCOS technology. The new device features a vertically aligned nematic (VAN) LC, where the liquid crystal molecules are aligned vertically to the cell substrates. This is a similar LC mode as is used by JVC in their high-performance D-ILA LCOS device. The cell gap in the SXRD device measures less than 2µm, thinner than transmissive HTPS or most LCOS devices. The SXRD materials have been developed to accept good driving voltages and high quality optical properties, even in such thin cells. These innovations have enabled the combination of very high 3000:1 contrast and very rapid 5-msec response time.

Most surprising about the panel is the contrast, which can be heavily influenced by the testing method, particularly the f-number and wavelength. We made a number of attempts to clarify how this measurement was made, but Sony did not respond to our inquiries.

Sony has overcome the long-standing challenge of incorporating an inorganic alignment layer to the liquid crystal cell, enabling vertically aligned liquid crystals. This inorganic thin-film material has successfully replaced the organic polyimide film previously used to align the liquid crystal. This innovation greatly improves alignment layer durability and longevity of the device.
Sony has established a means of wafer-scale assembly that apparently includes integral spacer technology to help ensure a uniform cell gap. The silicon backplanes are fabricated in a silicon foundry using a 0.35-micron process, but the foundry was not identified. This wafer-scale cell assembly process will significantly reduced dust contamination and impurities, while improving picture quality, yield and production cost, thus making it suitable for high efficiency, panel mass production, says Sony. All LCOS developers has struggled to move the technology into mass production, so perhaps Sony will have better luck. We will be watching.

Sony, Jeena Choi, 201-476-8121, jeena.choi@am.sony.com

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Insight Media, Annmarie Gabisch, 203-831-8464, Annmarie@insightmedia.info