Patent EP0573989A2 successfully refreshed from Google Patents.
EP0573989A2
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EP
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Driving method for spatial light modulator
Assignee: Panasonic Holdings Corp
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Filing: 1993-06-09
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Granted: —
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Expires: 2013-06-09
Abstract
Abstract In a spatial light modulator used in a projection type display, holographic television set or the like and having a configuration of at least a photo-conductive layer with rectification and a ferroelectric liquid crystal layer provided between a pair of transparent electrodes and a side of the photo-conductive layer facing to a CRT, plural units of driving signals including at least an erasing pulse and a writing voltage period are applied between the transparent electrodes in one frame cycle of the CRT. <IMAGE>
Inventors
- 👤 Yukio Tanaka
- 👤 Akio Takimoto
- 👤 Koji Akiyama
- 👤 Yasunori Kuratomi
- 👤 Junko Asayama
- 👤 Hisahito Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 23:26
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/001; G09G3/003; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/135; G09G3/002
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
87 words
A method for driving a spatial light modulator, comprising: providing a spatial light modulator having an output comprising a photo-conductive layer with rectification and a ferroelectric liquid crystal layer provided between a pair of transparent electrodes, with a side of the photo-conductive layer facing forward a light information inputting device; and applying plural units of a driving signal between said pair of transparent electrode during each frame cycle of the light information inputting device, so that output light intensity on the entire output face is substantially uniform.
Claim 2
Dependent Claim
41 words
The driving method for a spatial light modulator in accordance with claim 1, wherein a ratio of a length of said unit of driving signal to a length of each said frame cycle is in a range from 1.5 to 1000.
Claim 3
Dependent Claim
30 words
The driving method for a spatial light modulator in accordance with claim 2, wherein said unit of driving signal consists of an erasing voltage period and a writing voltage period.
Claim 4
Dependent Claim
58 words
The driving method for a spatial light modulator in accordance with claim 3, wherein said erasing voltage is in a range from +2 V to +30 V and said writing voltage is in a range of -30 V to +2 V, wherein a direction of the voltage which biases said photo-conductive layer forward is defined to be positive.
Claim 5
Dependent Claim
43 words
The driving method for a spatial light modulator in accordance with claim 2, wherein said unit of driving signal consists of a series of an erasing voltage period, a first lower voltage period, a writing voltage period and a second lower voltage period.
Claim 6
Dependent Claim
33 words
The driving method for a spatial light modulator in accordance with claim 5, wherein a length of said second lower voltage period is longer than a length of said second lower voltage period.
Claim 7
Dependent Claim
75 words
The driving method for a spatial light modulator in accordance with claim 6, wherein said erasing voltage is in a range from +2 V to +30 V, said writing voltage is in a range of -30 V to -2 V and voltage of said second lower voltage period is in a range from -2 V to +2 V, wherein a direction of the voltage which biases said photo-conductive layer forward is defined to be positive.
References Cited (Backward Citations)
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