US5130830A
Expired / Lapsed
US
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Spatial light modulator and spatial light modulating apparatus with alignment film having particular conductance
Assignee: NTT Inc
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Filing: 1990-02-26
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Granted: 1992-07-14
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Expires: 2010-02-26
Abstract
Abstract A spatial light modulator has a photoconductive layer deposited on one glass substrate having a transparent electrode. A first liquid crystal alignment film is formed on the photoconductive layer. A second liquid crystal alignment film is formed on another glass substrate having another transparent electrode. A ferroelectric liquid crystal is filled between the first and second liquid crystal alignment films.
Inventors
- 👤 Seiji Fukushima
- 👤 Takashi Kurokawa
- 👤 Takashi Kozawaguchi
- 👤 Shinji Matsuo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:42
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/135; G02F1/137; G02F1/139; G02F1/141
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
88 words
A spatial light modulator comprising: a photoconductive film deposited on one glass substrate having a transparent electrode; a first liquid crystal alignment film deposited on said photoconductive film; a second liquid crystal alignment film deposited on another glass substrate having another transparent electrode; and a ferroelectric liquid crystal filled between said first and second liquid crystal alignment film; wherein said first and second liquid crystal alignment films have an electric conductance of 10 -6 S/cm 2 or above in a direction perpendicular to a plane of the films.
Claim 2
Dependent Claim
88 words
A spatial light modulator comprising: a photoconductive film deposited on one glass substrate having a transparent electrode; a first liquid crystal alignment film deposited on said photoconductive film; a second liquid crystal alignment film deposited on another glass substrate having another transparent electrode; and a ferroelectric liquid crystal filled between said first and second liquid crystal alignment film; wherein said first and second liquid crystal alignment films have an electric conductance of 10 -6 S/cm 2 or above in a direction perpendicular to a plane of the films.
Claim 3
Dependent Claim
30 words
A spatial light modulator according to claim 1, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal having a spontaneous polarization of less than 20 nC/cm 2 .
Claim 4
Dependent Claim
25 words
A spatial light modulator according to claim 1, further including reflection film means sandwiched between said photoconductive film and said first liquid crystal alignment film.
Claim 5
Dependent Claim
17 words
A spatial light modulator according to claim 3, wherein said reflection film means comprises a dielectric mirror.
Claim 6
Dependent Claim
21 words
A spatial light modulator according to claim 3, wherein said reflection film means comprise metal light blocking films arranged like islands.
Claim 7
Dependent Claim
26 words
A spatial light modulator according to claim 3, wherein said reflection film means includes a laminated body comprising a dielectric mirror and metal light blocking films.
Claim 8
Dependent Claim
110 words
A spatial light modulating apparatus comprising: a spatial light modulator having a photoconductive film deposited on one glass substrate having a transparent electrode; a first liquid crystal alignment film deposited on said photoconductive film; a second liquid crystal alignment film deposited on another glass substrate having another transparent electrode; a ferroelectric liquid crystal filled between said first and second liquid crystal alignment films; and driving power source means for applying a control pulse to said transparent electrodes on said glass substrates such that the product of a pulse width and an applied voltage exceeds the threshold value of the self-retaining property of said ferroelectric liquid crystal during a writing operation.
Claim 9
Dependent Claim
110 words
A spatial light modulating apparatus comprising: a spatial light modulator having a photoconductive film deposited on one glass substrate having a transparent electrode; a first liquid crystal alignment film deposited on said photoconductive film; a second liquid crystal alignment film deposited on another glass substrate having another transparent electrode; a ferroelectric liquid crystal filled between said first and second liquid crystal alignment films; and driving power source means for applying a control pulse to said transparent electrodes on said glass substrates such that the product of a pulse width and an applied voltage exceeds the threshold value of the self-retaining property of said ferroelectric liquid crystal during a writing operation.
Claim 10
Dependent Claim
40 words
A spatial light modulator according to claim 7, wherein said first an second liquid crystal alignment films have an electric conductance of 10 -6 S/cm 2 or above in a direction of a perpendicular of a plane of the films.
Claim 11
Dependent Claim
30 words
A spatial light modulator according to claim 7, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal having a spontaneous polarization of less than 20 nC/cm 2 .
Claim 12
Dependent Claim
24 words
A spatial light modulator according to claim 7, further including reflection film means sandwiched between said photoconductive film and said liquid crystal alignment films.
Claim 13
Dependent Claim
17 words
A spatial light modulator according to claim 10, wherein said reflection film means is a dielectric mirror.
Claim 14
Dependent Claim
26 words
A spatial light modulator according to claim 11, wherein said reflection film means is a laminated body comprising a dielectric mirror and metal light blocking films.
Claim 15
Dependent Claim
119 words
A spatial light modulating apparatus comprising: a spatial light modulator having a semiconductor substrate; a photodiode deposited on said semiconductor substrate; a dielectric mirror deposited on said semiconductor substrate, a first liquid crystal alignment film deposited on said dielectric mirror, a second liquid crystal alignment film deposited on a glass substrate having a transparent electrode, a ferroelectric liquid crystal filled between said first and second liquid crystal alignment films; and a driving power source for applying a control pulse between said glass substrate and said transparent electrode on said glass substrate such that the product of a pulse width and an applied voltage exceeds the threshold value of self-retaining property of said ferroelectric liquid crystal during a writing operation.
Claim 16
Dependent Claim
119 words
A spatial light modulating apparatus comprising: a spatial light modulator having a semiconductor substrate; a photodiode deposited on said semiconductor substrate; a dielectric mirror deposited on said semiconductor substrate, a first liquid crystal alignment film deposited on said dielectric mirror, a second liquid crystal alignment film deposited on a glass substrate having a transparent electrode, a ferroelectric liquid crystal filled between said first and second liquid crystal alignment films; and a driving power source for applying a control pulse between said glass substrate and said transparent electrode on said glass substrate such that the product of a pulse width and an applied voltage exceeds the threshold value of self-retaining property of said ferroelectric liquid crystal during a writing operation.
Claim 17
Dependent Claim
147 words
A spatial light modulating apparatus comprising: a spatial light modulator including, a photoconductive film deposited on one glass substrate having a transparent electrode, a dielectric mirror deposited on said photoconductive film, a first liquid crystal alignment film deposited on said dielectric mirror, a second liquid crystal alignment film deposited on another glass substrate having another transparent electrode, and a ferroelectric liquid crystal filled between said first and second liquid crystal alignment films an erase pulse light source for supplying an erase pulse for erasing data on said spatial light modulator; a read pulse light source for supplying a read pulse for reading data on said spatial light modulator; and a driving power source for applying a drive electric pulse to said spatial light modulator and supplying a sync signal to said erase pulse light source and said read pulse light source to ensure an intermediate gradation display.
Claim 18
Dependent Claim
147 words
A spatial light modulating apparatus comprising: a spatial light modulator including, a photoconductive film deposited on one glass substrate having a transparent electrode, a dielectric mirror deposited on said photoconductive film, a first liquid crystal alignment film deposited on said dielectric mirror, a second liquid crystal alignment film deposited on another glass substrate having another transparent electrode, and a ferroelectric liquid crystal filled between said first and second liquid crystal alignment films an erase pulse light source for supplying an erase pulse for erasing data on said spatial light modulator; a read pulse light source for supplying a read pulse for reading data on said spatial light modulator; and a driving power source for applying a drive electric pulse to said spatial light modulator and supplying a sync signal to said erase pulse light source and said read pulse light source to ensure an intermediate gradation display.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-14 | 1996-01-13 | 1996-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-14 | 2000-01-13 | 2000-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-14 | 2004-01-13 | 2004-07-14 | $7700.00 | Window Closed / Lapsed |