EP0512842A2
Expired / Lapsed
EP
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Light-light transfer method by use of spatial light modulator and its display apparatus
Assignee: Victor Company of Japan Ltd
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Filing: 1992-05-08
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Granted: —
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Expires: 2012-05-08
Abstract
Abstract A light-light transfer method by use of a spatial light modulator realizes an image display at high efficiency of light without causing undesirable residual image. The spatial light modulator is constituted to include two electrodes and at least a photoconductive layer member and a photo-modulation layer member used in a birefringence operating mode both being sandwiched between the two electrodes. A writing light is entered from the photoconductive layer member side so that its exposure value varies from the minimum exposure value to the maximum exposure value in a condition that a predetermined operation voltage is supplied between the two electrodes. In this instant, a voltage applied between both ends of the photo-modulation layer member corresponds to a voltage obtained by subtracting a voltage drop amount, occurring in the photoconductive layer member due to an incidence of the writing light, from said predetermined operation voltage applied in advance between said two electrodes. An operational condition of the spatial light modulator is set so that the voltage applied between both ends of the photo-modulation layer member becomes a voltage monotonously exceeding a voltage value corresponding to an extreme value of a degree of photo-modulation in a characteristic curve showing a relationship between an applied voltage and a degree of photo-modulation in the photo-modulation layer member, at thetiming the writing light of the maximum exposure value is entered into the spatial light modulator.
Inventors
- 👤 Toshio Konno
- 👤 Shintaro Nakagaki
- 👤 Ichiro Negishi
- 👤 Tetsuji Suzuki
- 👤 Fujiko Tatsumi
- 👤 Ryusaku Takahashi
- 👤 Keiichi Maeno
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 10:48
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/001; G09G3/002; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/135; G09G3/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
220 words
A light-light transfer method by a spatial light modulator including two electrodes and at least a photoconductive layer member and a photo-modulation layer member used in a birefringence operating mode both being sandwiched between the two electrodes; when a writing light is entered from the photoconductive layer member side in such a manner that its exposure value varies from the minimum exposure value to the maximum exposure value in a condition that a predetermined operation voltage is supplied between the two electrodes; within a voltage applied between both ends of the photo-modulation layer member which value corresponds to a voltage obtained by subtracting a voltage drop amount, which occurs in the photoconductive layer member as a monotonous changing condition due to an incidence of the writing light, from said predetermined operation voltage applied in advance between said two electrodes; setting an operational condition of the spatial light modulator in such a manner that, at the timing the writing light of the maximum exposure value is entered into the spatial light modulator, a voltage applied between both ends of the photo-modulation layer member.becomes a voltage monotonously exceeding a voltage value corresponding to an extreme value of a degree of photo-modulation in a characteristic curve showing a relationship between an applied voltage and a degree of photo-modulation in the photo-modulation layer member.
Claim 2
Dependent Claim
54 words
A light-light transfer method in accordance with claim 1 in which an electric power source supplying voltage between two electrodes is controlled so as to change its frequency and/or its voltage so as to change an impedance of the photoconductive layer member in accordance with a changing range of intensity of the light-emitting element.
Claim 3
Dependent Claim
74 words
A light-light transfer method in accordance with claim 1 or 2 in which the intensity of light emitted from the light-emitting element is controlled in such a manner that, when a writing light corresponding to a peak gradation of image information is applied to the spatial light modulator, the voltage applied between both ends of the photo-modulation layer member exceeds an extreme point at which an intensity of reading-out light takes an extreme value.
Claim 4
Dependent Claim
338 words
A display apparatus comprising: a light-emitting element array including N pieces of light-emitting element disposed in at least one row so as to correspond to a plurality of N pieces of picture elements; an emitting means for emitting said N pieces of light-emitting elements on the basis of information from respectively corresponding picture elements; a spatial light modulator including two electrodes and at least a photoconductive layer member and a photo-modulation layer member used in a birefringence operating mode both being sandwiched between the two electrodes; an image-forming means for image-forming said lights, which are in a condition of being simultaneously deflected after emitted together from said respective light-emitting elements, on a photoconductive layer element in a spatial light modulator, when a writing light deflected by said deflecting means is entered from the photoconductive layer member side in such a manner that its exposure value varies from the minimum exposure value to the maximum exposure value in a condition that a predetermined operation voltage is supplied between the two electrodes, within a voltage applied between both ends of the photo-modulation layer member which value corresponds to a voltage obtained by subtracting a voltage drop amount, which occurs in the photoconductive layer member as a monotonous changing condition due to an incidence of the writing light, from said predetermined operation voltage applied in advance between said two electrodes, by setting an operational condition of the spatial light modulator in such a manner that, at the timing the writing light of the maximum exposure value is entered into the spatial light modulator, a voltage applied between both ends of the photo-modulation layer member becomes a voltage monotonously exceeding a voltage value corresponding to an extreme value of a degree of photo-modulation in a characteristic curve showing a relationship between an applied voltage and a degree of photo-modulation in the photo-modulation layer member; and a projecting means for reading out information written in the spatial light modulator by a reading-out light and projecting them on a screen by a projection-optics system.
Claim 5
Dependent Claim
64 words
A display apparatus in accordance with claim 4 in which said N pieces of light-emitting element are actuated by a driving circuit so that the N pieces of light-emitting element can simultaneously emit lights with intensities respectively modulated in response to each information of the N pieces of picture element arrayed on one straight-line of an image to be displayed within a predetermined intensity.
Claim 6
Dependent Claim
84 words
A display apparatus in accordance with claim 4 or 5 in which said N pieces of light-emitting element disposed in a row in the light-emitting element array can be actuated by a driving circuit so that the N pieces of light-emitting element can respectively emit light with a constant intensity but modulated by a time width instead of modulated by intensity itself in accordance with corresponding information of the N pieces of picture element arrayed on one straight-line of the image to be displayed.
Claim 7
Dependent Claim
46 words
A display apparatus according to claim 4, 5 or 6 and further comprising a deflecting means for simultaneously deflecting light emitted from respective light-emitting elements of said light-emitting element array in a direction normal to a line-up direction of light emitted from said respective light-emitting elements.
References Cited (Backward Citations)
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