Toshiaki Narusawa

A 1M‐pixel full‐color projection display using nematic‐cholesteric phase‐transition liquid crystals

— A 1M-pixel full-color projection display with a very simple optical system using a conventional overhead projector has been developed. This display uses the nematic-cholesteric phase-transition liquid-crystal display and a micro-color-filter. Moreover, the micro-color-filter can be placed outside the liquid-crystal panel. This simple configuration provides a high-performance low-cost color electronic overhead projector. This projection display uses a 9M-pixel nematic-cholesteric phase-transition black-and-white liquid-crystal panel to enable gray shades by spatial dither, resulting in a full-color projection display. A 12:1 contrast ratio and 2.2-ms line-addressing time is achieved.

Photoconduction of Copper Phthalocyanine-Binder Photoconductor Sensitized with Poly-N-vinylcarbazole

A nontoxic organic photoconductor for near infrared light has been developed. It consists of poly-N-vinylcarbazole (PVCz) dispersed in a copper phthalocyanine (CuPc)-binder resin system. PVCz has been selected from among several electron donating compounds that are considered to be able to reduce the induction period (TN) that is a typical imperfection of the binary system. The optimum mixing ratio of the three components (CuPc, PVCz, and a binder resin) was determined after examining film-forming ability, charge acceptance, and exposure energy for half-decay of the surface potential (E1/2). The photoconductor, composed of E-crystal form of CuPc (40 wt/%), PVCz (10 wt/%), and a polyester binder resin (50 wt/%), has an E1/2 of 3.2 , ¿J/cm2 at a light of 760 nm. It has a charge acceptance of 800 V, in accordance with the p-type. conduction of CuPc, when a positive surface charge is used.