Peter J. Janssen

Design aspects of a scrolling color LCoS display

Abstract The Philips scrolling color liquid crystal on silicon (LCoS) architecture is a very attractive approach towards affordable large area displays. The color sequential nature coupled with high resolution brings demands on speed and bandwidth. Design requirements and solutions tailored to address scrolling color LCoS demands are presented. We have implemented high quality displays based on silicon backplanes employing a mixed digital–analog construction, high speed FPGA based drive electronics, a thin nematic liquid crystal cell, and a scanning stripe optical engine. Despite challenging demands we have found many opportunities to exploit available technologies in our system designs.

18.2: Galvanic Activity in Reflective LCDs

Reflective LC displays using an internal reflector are inherently asymmetric. This asymmetry affects the electro-optic behavior of the LC and has been identified as the major cause of flicker. In this paper we report experiments which associate this flicker with electrochemical activity within the LCD itself.

Fast-responding liquid crystal light-valve technology for color-sequential display applications

A color sequential projection system has some distinct advantages over conventional systems which make it uniquely suitable for consumer TV as well as high performance professional applications such as computer monitors and electronic cinema. A fast responding light-valve is, clearly, essential for a good performing system. Response speed of transmissive LC lightvalves has been marginal thus far for good color rendition. Recently, Sevchenko Institute has made some very fast reflective LC cells which were evaluated at Philips Labs. These devices showed sub millisecond-large signal-response times, even at room temperature, and produced good color in a projector emulation testbed. In our presentation we describe our highly efficient color sequential projector and demonstrate its operation on video tape. Next we discuss light-valve requirements and reflective light-valve test results.

64.1: Invited Paper: A Light Guide Engine for Single‐Panel LCoS

Using light guide components we have developed a new scrolling-color engine for single panel LCoS projection. Light guides allow for lossless delivery of light leading to a simpler and more compact system. Engine design and construction based on a single 0.87-inch diagonal LCoS panel is described.

A single-panel LCoS engine based on light guides

— By using light-guide components, a new scrolling-color engine for single-panel LCoS projection has been developed. Light guides allow for loss-less delivery of light leading to a simpler and more-compact system. Engine design and construction based on a single 0.88-in.-diagonal LCoS panel is described. Separate results with a multilayer optical film Cartesian PBS show that a significant improvement in system efficiency is possible.

Contrast improvements for scrolling-color LCoS

A scrolling-color LCoS (liquid-crystal-on-silicon) display must exhibit both fast speed and high contrast. These requirements drive design choices for the liquid crystal and optics of the image kernel. The input director was aligned to the incoming polarization and a compensated 45TN0 effect was choosen. Contrast demands place tight requirements on interfacial reflections. A wire-grid PBS can achieve high contrast and can simplify the system construction. With attention to the above, we report a sequential contrast of 800:1 at the viewing screen. With a 90TN0 effect, the contrast can be increased even further, but with some penalty in light efficiency. With this effect, sequential contrast of 2000:1 was measured.