US4783146A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal print bar
Assignee: Xerox Corp
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Filing: 1987-01-20
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Granted: 1988-11-08
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Expires: 2007-01-20
Abstract
Abstract A linear array of liquid crystal shutters mounted near a photoreceptor surface and arranged transversely to the direction of travel of the photoreceptor surface, an array of thin film transistors connected to the array of liquid crystal shutters for electrically driving the shutters and logic means connected to the array of thin film transistors selectively pulsing the liquid crystal shutters to selectively expose the photoreceptor surface a line at a time. The system further includes circuit means for producing an electric field between the opposed electrodes of each of the liquid crystal shutters to prevent passage of light through the shutters and means for selectively de-energizing each of the pairs of electrodes for predetermined time period in response to the receipt of input data signals.
Inventors
- 👤 Joseph F. Stephany
- 👤 Andras I. Lakatos
- 👤 Virgil J. Hull
- 👤 Alain E. Perregaux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:22
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1238; G06K15/1242; G06K15/1252
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
183 words
Apparatus for projecting data on a photoreceptor surface comprising: drive means for moving the photoreceptor surface, a linear, optical writing station arranged transversely to the direction of travel of the photoreceptor surface including an array of liquid crystal devices mounted adjacent to the photoreceptor surface, said liquid crystal devices being arranged along two parallel lines with the location of the liquid crystal devices of the second line being staggered relative to the location of the liquid crystal devices of the first line, said array extending over a linear extent equivalent to the width of said photoreceptor surface onto which data is to be projected, an array of thin film transistors connected to the array of liquid crystal devices for electrically driving said devices, a source of light for projecting light onto said liquid crystal devices, means to focus said light onto the photoreceptor surface from the liquid crystal device, and logic means electrically connected to the array of thin film transistors for selectively pulsing said array of liquid crystal devices whereby said photoreceptor surface is selectively exposed by light from said light source.
Claim 2
Dependent Claim
183 words
Apparatus for projecting data on a photoreceptor surface comprising: drive means for moving the photoreceptor surface, a linear, optical writing station arranged transversely to the direction of travel of the photoreceptor surface including an array of liquid crystal devices mounted adjacent to the photoreceptor surface, said liquid crystal devices being arranged along two parallel lines with the location of the liquid crystal devices of the second line being staggered relative to the location of the liquid crystal devices of the first line, said array extending over a linear extent equivalent to the width of said photoreceptor surface onto which data is to be projected, an array of thin film transistors connected to the array of liquid crystal devices for electrically driving said devices, a source of light for projecting light onto said liquid crystal devices, means to focus said light onto the photoreceptor surface from the liquid crystal device, and logic means electrically connected to the array of thin film transistors for selectively pulsing said array of liquid crystal devices whereby said photoreceptor surface is selectively exposed by light from said light source.
Claim 3
Dependent Claim
15 words
The apparatus of claim 1 wherein said thin film transistors are amorphous or polycrystalline silicon.
Claim 4
Dependent Claim
16 words
The apparatus of claim 1 wherein said photoreceptor surface is exposed a line at a time.
Claim 5
Dependent Claim
107 words
An improved control for a liquid crystal image bar for use in a printer of the type having a moving photoconductive member, comprising: first and second glass substrates, a first plurality of transparent electrodes being located on the first glass substrate and a second plurality of transparent electrodes being located on the second glass substrate, polarizers being positioned on each of the glass substrates, an illuminating means for directing light towards one of the polarizers, an alternating voltage source, and multiplexed array of thin film transistors connected between the voltage source and the electrodes to selectively pulse said electrodes to form an image on the photoconductive member.
Claim 6
Dependent Claim
107 words
An improved control for a liquid crystal image bar for use in a printer of the type having a moving photoconductive member, comprising: first and second glass substrates, a first plurality of transparent electrodes being located on the first glass substrate and a second plurality of transparent electrodes being located on the second glass substrate, polarizers being positioned on each of the glass substrates, an illuminating means for directing light towards one of the polarizers, an alternating voltage source, and multiplexed array of thin film transistors connected between the voltage source and the electrodes to selectively pulse said electrodes to form an image on the photoconductive member.
Claim 7
Dependent Claim
69 words
The control of claim 4 including circuit means for energizing the electrodes on the second glass substrate from the voltage source to produce an electric field between the first plurality and the second plurality of electrodes in order to prevent the passage of light through the image bar, and means for selectively de-energizing each of the plurality of electrodes on the second glass substrate for a predetermined time period.
Claim 8
Dependent Claim
125 words
Apparatus for projecting data on a photoreceptor surface comprising: drive means for moving the photoreceptor surface, a linear, optical writing station arranged transversely to the direction of travel of the photoreceptor surface including an array of liquid crystal devices mounted adjacent to the photoreceptor surface, an array of thin film transistors connected to the array of liquid crystal devices for electrically driving said devices, a source of light for projecting light onto said liquid crystal devices, means to focus said light onto the photoreceptor surface from the liquid crystal device, and logic means electrically connected to the array of thin film transistors for selective pulsing of said array of liquid crystal devices whereby said photoreceptor surface is selectively exposed by light from said light source.
Claim 9
Dependent Claim
125 words
Apparatus for projecting data on a photoreceptor surface comprising: drive means for moving the photoreceptor surface, a linear, optical writing station arranged transversely to the direction of travel of the photoreceptor surface including an array of liquid crystal devices mounted adjacent to the photoreceptor surface, an array of thin film transistors connected to the array of liquid crystal devices for electrically driving said devices, a source of light for projecting light onto said liquid crystal devices, means to focus said light onto the photoreceptor surface from the liquid crystal device, and logic means electrically connected to the array of thin film transistors for selective pulsing of said array of liquid crystal devices whereby said photoreceptor surface is selectively exposed by light from said light source.
Claim 10
Dependent Claim
65 words
The apparatus of claim 6 wherein said liquid crystal devices are arranged along two parallel lines with the location of the liquid crystal devices of the second line being staggered relative to the location of the liquid crystal devices of the first line, said array extending over a linear extent equivalent to the width of said photoreceptor surface onto which data is to be projected.
Claim 11
Dependent Claim
18 words
The apparatus of claim 7 wherein the first line comprises odd bits and the second line even bits.
Claim 12
Dependent Claim
34 words
The apparatus of claim 7 wherein the first line comprises a first density of bits and the second line comprises a second density of bits, said first density being different from said second density.
Claim 13
Dependent Claim
32 words
The apparatus of claim 7 including means to selectively deenergize a liquid crystal device of said array of liquid crystal devices for a predetermined period of time to expose said photoreceptor surface.
Claim 14
Dependent Claim
211 words
Apparatus for projecting data on a photoreceptor surface comprising: drive means for moving the photoreceptor surface, a linear, optical writing station arranged transversely to the direction of travel of the photoreceptor surface including on array of liquid crystal devices mounted adjacent to the photoreceptor surface, said liquid crystal devices being arranged along two parallel lines with the location of the liquid crystal devices of the second line being staggered relative to the location of the liquid crystal devices of the first line, said array extending over a linear extent equivalent to the width of said photoreceptor surface onto which data is to be projected, the first line comprising a first density of bits and the second line comprising a second density of bits, said first density being different from said second density, an array of thin film transistors connected to the array of liquid crystal devices for electrically driving said devices, a source of light for projecting light onto said liquid crystal devices, means to focus said light onto the photoreceptor surface from the liquid crystal device, and logic means electrically connected to the array of thin film transistors for selective pulsing said array of liquid crystal devices whereby said photoreceptor surface is selectively exposed by light from said light source.
Claim 15
Dependent Claim
211 words
Apparatus for projecting data on a photoreceptor surface comprising: drive means for moving the photoreceptor surface, a linear, optical writing station arranged transversely to the direction of travel of the photoreceptor surface including on array of liquid crystal devices mounted adjacent to the photoreceptor surface, said liquid crystal devices being arranged along two parallel lines with the location of the liquid crystal devices of the second line being staggered relative to the location of the liquid crystal devices of the first line, said array extending over a linear extent equivalent to the width of said photoreceptor surface onto which data is to be projected, the first line comprising a first density of bits and the second line comprising a second density of bits, said first density being different from said second density, an array of thin film transistors connected to the array of liquid crystal devices for electrically driving said devices, a source of light for projecting light onto said liquid crystal devices, means to focus said light onto the photoreceptor surface from the liquid crystal device, and logic means electrically connected to the array of thin film transistors for selective pulsing said array of liquid crystal devices whereby said photoreceptor surface is selectively exposed by light from said light source.
References Cited (Backward Citations)
US3438057A
Cited
US3850517A
Cited
US3936172A
Cited
US3967893A
Cited
US4386352A
Cited
US4385292A
Cited
US4403217A
Cited
US4545672A
Cited
US4653859A
Cited
US4697910A
Cited
US4692779A
Cited
US4595259A
Cited
US4636817A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-08 | 1992-05-09 | 1992-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-08 | 1996-05-09 | 1996-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-08 | 2000-05-09 | 2000-11-08 | $7700.00 | Window Closed / Lapsed |