The following information is true and accurate at the time of publication.
February 19, 2003
Sony develops "SXRD", a display device capable of generating high resolution, high contrast images of film quality smoothness
for upcoming use in both front-projectors and rear-projection TVs
Tokyo, Japan - Sony Corporation today announced the development of SXRD (Silicon X-tal*1 Reflective Display), a liquid crystal display device for use in projectors, which achieves a panel contrast of over 3000:1 with high resolution of Full HDTV(1920Hx1080V)jusing a silicon backplane. Its main features are outlined below.
*1 Abbreviation of "Crystal"
<High Resolution Picture Quality>
The outstanding picture quality generated by SXRD is due to the large number of pixels contained within the image area of the device. For this to be achieved both the size of each individual pixel and the space between pixels has been minimized. The combination of radically designed Silicon Driving Circuit technology and novel Silicon Wafer Process Technology, coupled with new Liquid Crystal Device technology, has enabled 2,000,000 pixels with a pitch of 9um to be arranged just 0.35um apart (Diagram1-a). This is the world's smallest inter-pixel spacing*2 thus delivering full HDTV (1920Hx1080V, 16:9 widescreen format) within an image area measuring a mere 0.78 inches diagonally across.
In comparison to high temperature Poly-Silicon liquid crystal devices, this represents a 2.4- fold increase in pixel density, and a 10-fold improvement in inter-pixel spacing.
These advances have facilitated the achievement of a high-grade, high-resolution picture quality previously unseen on fixed-pixel projection devices, with outstanding cinematic quality and image smoothness that can be enjoyed free from the grainy "mesh" effect noticeable on conventional projectors.
*2 Current data, based on Sony research
<High Contrast and Rapid Response Time>
In Sony's SXRD device the liquid crystal cell gap measures less than 2um, far thinner than conventional high temperature Poly-Silicon liquid crystal or LCOS(Liquid Crystal On Silicon)devices (Diagram1-b). Furthermore, in place of the TN(Twisted Nematic)liquid crystal commonly used in projection devices, Sony's unique "Vertically Aligned Liquid Crystal" materials, whereby the liquid crystal molecules are aligned vertically to the cell substrates have been used. The materials have been developed to provide good driving voltages and high quality optical properties, even in such thin cells, ensuring high contrast images that would otherwise be unachievable with conventional TN devices (Diagram1-b).
These innovations have made a high panel contrast level of 3000:1, and very rapid 5 milli-second response time a reality. This represents an approximately threefold increase over conventional projector contrast levels.
Sony has overcome the long-standing challenge of incorporating an inorganic alignment layer to the liquid crystal cell, enabling the alignment technology of vertically aligned liquid crystals which has been problematic until now. This inorganic material has successfully replaced the organic polyimide film previously used to align the liquid crystal. This innovation has greatly improved alignment layer durability, ensuring the longevity of the high-resolution, high-grade features of the SXRD device.
<Combined High Product Quality and Production Efficiency>
With conventional projection devices, in order to ensure uniform cell gap, the substrates must be assembled one at a time in a piecemeal fashion. At the same time, spacers such as beads or posts known as "columns" would also need to be inserted within the display area of the liquid crystal cell. However, in the case of the SXRD device, through the development of Planarization Technology of Silicon Backplane, and alignment layer fabrication process, Sony has established a means of assembling entire wafers, even without the use of spacers (Diagram 2). Thus many panels are created at once in unison. This process has significantly reduced dust ingress, while simultaneously improving both picture quality and production efficiency.
The features and capabilities of the"SXRD"technology make it ideal for use in front projectors and rear projection TVs of home theater dimensions, capable of delivering the high resolution, high-grade content that is becoming increasingly prevalent. The move towards content of this nature is set to continue with the forthcoming launch of terrestrial digital broadcasting in the near future. Sony aims to introduce front projectors and rear projection products incorporating this technology to the market within the next fiscal year.