Title:
PROJECTION TYPE DISPLAY DEVICE
Document Type and Number:
WIPO Patent Application WO/1994/022042
Kind Code:
A1
Abstract:
A projection type display device (1) comprises an illumination optical system (2A), a color separation system (4) for separating white light (W) entering from the optical system (2A) into color beams (R, G, B); three liquid crystal panels (5R, 5G, 5B) for modulating the respective color beams; a waveguide system (9) disposed on the optical path of the beam (G), which is the longest of all the paths of the separated beams that enter the three light valves; a dichroic prism (6) for combining the beams modulated through the liquid crystal panels; and a projection lens (7) for projecting the combined light on a screen (8). The illumination optical system (2A) is equipped with a uniform illumination optical device (3) which converts white light to a uniform rectangular beam. The dichroic prism as an optical element having symmetry of rotation with respect to the axis of the projection optical system is used for the color synthesis system, and the uniform illumination optical device for suppressing the unevenness in color and illuminance is assembled in the illumination optical system. Accordingly, the display device has high illumination efficiency with less unevenness in color and illuminance.
Inventors:
NAKAYAMA TADAAKI (JP)
ITOH YOSHITAKA (JP)
YAJIMA AKITAKA (JP)
ITOH YOSHITAKA (JP)
YAJIMA AKITAKA (JP)
Application Number:
PCT/JP1994/000419
Publication Date:
September 29, 1994
Filing Date:
March 16, 1994
Export Citation:
Assignee:
SEIKO EPSON CORP (JP)
NAKAYAMA TADAAKI (JP)
ITOH YOSHITAKA (JP)
YAJIMA AKITAKA (JP)
NAKAYAMA TADAAKI (JP)
ITOH YOSHITAKA (JP)
YAJIMA AKITAKA (JP)
International Classes:
G03B21/14; G03B21/20; G03B33/12; H04N9/31; H04N5/74; (IPC1-7): G02F1/13; G02F1/1335
Foreign References:
| JPH0486725A | 1992-03-19 | |||
| JPH04234016A | 1992-08-21 | |||
| JPH0225016A | 1990-01-26 | |||
| JPH0267312U | 1990-05-22 | |||
| JPS6346490A | 1988-02-27 | |||
| JPS63121821A | 1988-05-25 | |||
| JPH0194985U | 1989-06-22 | |||
| JPS62237485A | 1987-10-17 | |||
| JPS63116123A | 1988-05-20 | |||
| JPH03152526A | 1991-06-28 |
Other References:
SHUNSUKE KOBAYASHI, "Display Technology Series Color Liquid Crystal Display", December 14, 1990 (14.12.90), Sangyo Tosho, p. 111-113.
See also references of EP 0646828A4
See also references of EP 0646828A4
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