EP0072124A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Light-modulating device comprising a multigate light valve
Assignee: Xerox Corp
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Filing: 1982-07-22
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Granted: —
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Expires: 2002-07-22
Abstract
Abstract To obtain a more uniform optical output from an electro-optic light valve (17), the lengths of the electrodes (18) for the light valve are selected in accordance with a function which is inversely related to the predicted and/or measured, data-independent variations in the uncompensated or incompletely compensated optical output of the light valve, thereby compensating for such variations.
Inventors
- 👤 Robert A. Sprague
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 21:07
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/29; G02F1/31; G02F1/315; G02F1/01; G02F1/03; G02F1/0305; G02F1/0316; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1238; G06K15/1242; G06K15/1252
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
118 words
A multi-gate light valve (12) for spatially modulating a light beam (24), said light valve including an electro-optic element (17) positioned to be illuminated by said light beam, said electro-optic element having a predetermined optical axis a plurality of electrodes (18) intimately associated with said electro-optic element, said electrodes extending lengthwise of said optical axis, and means (62) for applying data samples to at lest every other one of said electrodes, whereby localized electric fields are created within said electro-optic element to spatially modulate said light beam in accordance with said data samples; characterised in that the electrodes are of different effective lengths selected to compensate at least partially for data-independent, spatial non-uniformities in said modulated light beam.
Claim 2
Dependent Claim
118 words
A multi-gate light valve (12) for spatially modulating a light beam (24), said light valve including an electro-optic element (17) positioned to be illuminated by said light beam, said electro-optic element having a predetermined optical axis a plurality of electrodes (18) intimately associated with said electro-optic element, said electrodes extending lengthwise of said optical axis, and means (62) for applying data samples to at lest every other one of said electrodes, whereby localized electric fields are created within said electro-optic element to spatially modulate said light beam in accordance with said data samples; characterised in that the electrodes are of different effective lengths selected to compensate at least partially for data-independent, spatial non-uniformities in said modulated light beam.
Claim 3
Dependent Claim
28 words
A valve as claimed in claim 1, wherein the lengths of said electrodes are preselected to compensate for predictable, data-independent, spatial energy variations in said modulated light beam.
Claim 4
Dependent Claim
43 words
A valve as claimed in claim 1 or 2, wherein said electrodes are supported on a separate substrate (28) and are held closely adjacent said electro-optic element, whereby electric fringe fields are proximity coupled into said electro-optic element to modulate said light beam.
Claim 5
Dependent Claim
83 words
A valve as claimed in claim 3, wherein said electro-optic element has a reflecting surface (21), said light beam is applied to said electro-optic element at a grazing angle of incidence relative to said surface and is brought to a wedge-shaped focus thereon for total internal reflection therefrom, said substrate is an integrated circuit having a metallised layer patterned to define said electrodes, and said integrated circuit is immediately adjacent said reflecting surface to proximity couple said fringe fields into said electro-optic element.
Claim 6
Dependent Claim
34 words
A valve as claimed in any preceding claim, each of said electrodes is individually addressable; said data samples are differentially encoded for application to said electrodes, and said electro-optic element is an electro-optic crystal.
Claim 7
Dependent Claim
29 words
A valve as claimed in any preceding claim, the lengths of the electrodes are trimmed after fabrication in order to compensate for measured variations in said modualted light beam.
References Cited (Backward Citations)
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