HIGH-EFFICIENCY LIGHT VALVE PROJECTORS AND HIGH-EFFICIENCY LASER-LIGHT SOURCES

Citation
We. Glenn et al., HIGH-EFFICIENCY LIGHT VALVE PROJECTORS AND HIGH-EFFICIENCY LASER-LIGHT SOURCES, SMPTE journal, 106(4), 1997, pp. 210-216
Citations number
5
Categorie Soggetti
Instument & Instrumentation",Telecommunications,"Photographic Tecnology
Journal title
ISSN journal
00361682
Volume
106
Issue
4
Year of publication
1997
Pages
210 - 216
Database
ISI
SICI code
0036-1682(1997)106:4<210:HLVPAH>2.0.ZU;2-6
Abstract
The optical efficiency of an active matrix liquid crystal display (AML CD) light valve projector is determined by the optical design, the met hod of modulation, and the efficiency of the light source. This paper describes a new projector with an efficient modulation technique, whic h can employ unpolarized light by using a unique diffraction grating f ormed in a liquid crystal panel. The technique uses a Schlieren optica l system and has been tested with xenon arcs, metal halide arcs, and e fficient solid-state laser light sources. The optical system reduces l aser speckle significantly when highly coherent baser sources are used All source combinations exceeded 3 lm/W for white light projection pe rformance, and the experimental results of the combinations are discus sed. This modulation technique obtains a high contrast ratio with smal ler panels than can be achieved with rotation-of-polarization light va lve projectors.