US4728174A — Electron beam addressed liquid crystal light valve

Claim 1

Independent Claim 159 words

A liquid crystal light valve (LCLV) adapted to be addressed by a scanning electron beam, comprising: a liquid crystal layer adapted to be addressed by a readout optical beam, a flat electrically resistive membrane supported in proximity to the liquid crystal layer on the opposite side thereof from the readout beam, a layer of partially conductive material supported by the membrane and adapted to be addressed by the electron beam, the accumulation of electric charge in the partially conductive material from the electron beam producing a voltage across the liquid crystal, means for collecting charge received by the partially conductive layer as a result of electron beam scanning of the layer, and circuit means connected to dissipate charge received by the collecting means from the partially conductive layer, the resistance of at least one of the liquid crystal light valve layers being high enough to produce a substantially AC voltage across the liquid crystal following each electron beam scan.

Claim 2

Dependent Claim 159 words

A liquid crystal light valve (LCLV) adapted to be addressed by a scanning electron beam, comprising: a liquid crystal layer adapted to be addressed by a readout optical beam, a flat electrically resistive membrane supported in proximity to the liquid crystal layer on the opposite side thereof from the readout beam, a layer of partially conductive material supported by the membrane and adapted to be addressed by the electron beam, the accumulation of electric charge in the partially conductive material from the electron beam producing a voltage across the liquid crystal, means for collecting charge received by the partially conductive layer as a result of electron beam scanning of the layer, and circuit means connected to dissipate charge received by the collecting means from the partially conductive layer, the resistance of at least one of the liquid crystal light valve layers being high enough to produce a substantially AC voltage across the liquid crystal following each electron beam scan.

Claim 3

Dependent Claim 42 words

The LCLV of claim 1, wherein the collecting means comprises a conductive matrix disposed on the partially conductive layer and dividing that layer into pixel elements, the conductive matrix being adapted to receive electrical charge from the partially conductive layer pixel elements.

Claim 4

Dependent Claim 39 words

The LCLV of claim 2, wherein a transparent electrode is provided on the opposite side of the liquid crystal layer from the partially conductive layer, the electrode being connected to provide a voltage reference for the liquid crystal layer.

Claim 5

Dependent Claim 19 words

The LCLV of claim 3, the circuit means comprising a mutual connection between the conductive matrix and transparent electrode.

Claim 6

Dependent Claim 14 words

The LCLV of claim 4, wherein the conductive matrix and transparent electrode are grounded.

Claim 7

Dependent Claim 22 words

The LCLV of claim 4, the circuit means comprising an AC power supply connected between the conductive matrix and the transparent electrode.

Claim 8

Dependent Claim 40 words

The LCLV of claim 1, further comprising a mirror disposed on the opposite side of the liquid crystal layer from the readout beam and adapted to reflect a readout beam received from the liquid crystal layer back through that layer.

Claim 9

Dependent Claim 26 words

The LCLV of claim 1, wherein the partially conductive layer has a bulk resistance in the order of about 10 10 -10 13 ohms per square.

Claim 10

Dependent Claim 214 words

A liquid crystal light valve (LCLV) adapted to be addressed by a scanning electron beam, comprising: a liquid crystal layer adapted to be addressed by a readout optical beam, a layer of partially conductive material supported in proximity to the liquid crystal layer on the opposite side thereof from the electron beam, and adapted to be addressed by the readout beam, the accumulation of electrons in the partially conductive layer from an electron beam scan producing a voltage across the liquid crystal, a grid of conductive material disposed on the partially conductive layer and adapted to receive electron leakage from the partially conductive layer, the grid dividing the partially conductive layer into a series of pixel elements with grid material surrounding the pixel elements to receive electron leakage therefrom, and circuit means connected to discharge the grid of electrons leaked from the partially conductive layer, the dimensions and materials for the various elements being selected, relative to the electron beam scanning rate, to produce an electron leakage rate from the partially conductive layer pixels into the grid that is fast enough to substantially dissipate electrons delivered to the pixels during an electron beam scan prior to the next scan, but slow enough for the liquid crystal to produce an image for a readout beam.

Claim 11

Dependent Claim 214 words

A liquid crystal light valve (LCLV) adapted to be addressed by a scanning electron beam, comprising: a liquid crystal layer adapted to be addressed by a readout optical beam, a layer of partially conductive material supported in proximity to the liquid crystal layer on the opposite side thereof from the electron beam, and adapted to be addressed by the readout beam, the accumulation of electrons in the partially conductive layer from an electron beam scan producing a voltage across the liquid crystal, a grid of conductive material disposed on the partially conductive layer and adapted to receive electron leakage from the partially conductive layer, the grid dividing the partially conductive layer into a series of pixel elements with grid material surrounding the pixel elements to receive electron leakage therefrom, and circuit means connected to discharge the grid of electrons leaked from the partially conductive layer, the dimensions and materials for the various elements being selected, relative to the electron beam scanning rate, to produce an electron leakage rate from the partially conductive layer pixels into the grid that is fast enough to substantially dissipate electrons delivered to the pixels during an electron beam scan prior to the next scan, but slow enough for the liquid crystal to produce an image for a readout beam.

Claim 12

Dependent Claim 25 words

The LCLV of claim 9, wherein the partially conductive layer has a bulk resistance in the order of about 10 7 -10 10 ohms cm.

Claim 13

Dependent Claim 39 words

The LCLV of claim 9, wherein a transparent electrode is provided on the opposite side of the liquid crystal layer from the partially conductive layer, the electrode being connected to provide a voltage reference for the liquid crystal layer.

Claim 14

Dependent Claim 19 words

The LCLV of claim 11, the circuit means comprising a mutual connection between the conductive grid and transparent electrode.

Claim 15

Dependent Claim 13 words

The LCLV of claim 12, wherein the grid and transparent electrodes are grounded.

Claim 16

Dependent Claim 21 words

The LCLV of claim 12, the circuit means comprising an AC power supply connected between the grid and the transparent electrode.

Claim 17

Dependent Claim 40 words

The LCLV of claim 9, further comprising a mirror disposed on the opposite side of the liquid crystal layer from the readout beam and adapted to reflect a readout beam received from the liquid crystal layer back through that layer.

Claim 18

Dependent Claim 18 words

The LCLV of claim 15, wherein the mirror is positioned between the liquid crystal layer and the membrane.

Claim 19

Dependent Claim 243 words

A liquid crystal light valve (LCLV) adapted to be addressed by a scanning electron beam, comprising: a liquid crystal layer adapted to be addressed by a readout optical beam, a flat, electrically resistive membrane supported in proximity to the liquid crystal layer on the opposite side thereof from the readout beam, a layer of partially conductive material supported by the membrane and adapted to be addressed by the electron beam, a conductive grid disposed on the partially conductive layer and dividing that layer into pixel elements, the conductive grid being adapted to receive electrical charge from the partially conductive layer pixel elements, and circuit means connected to dissipate charge received by the grid from the partially conductive layer as a result of electron beam scanning of the layer, the accumulation of electric charge in the partially conductive material due to an electron beam scan and the subsequent dissipation of the charge through the grid producing a voltage across the liquie crystal and a related liquid crystal current I LC in the form: ##EQU2## C LC =liquid crystal capacitance per pixel R LC =liquid crystal resistance per pixel C M =combined membrane partially conductive layer capacitance per pixel R M =effective combined membrane partially conductive layer sheet resistivity per pixel, C LC , R LC , C M and R M being selected to produce an AC voltage across the liquid crystal during a substantial portion of the time between the electron beam scans.

Claim 20

Dependent Claim 243 words

A liquid crystal light valve (LCLV) adapted to be addressed by a scanning electron beam, comprising: a liquid crystal layer adapted to be addressed by a readout optical beam, a flat, electrically resistive membrane supported in proximity to the liquid crystal layer on the opposite side thereof from the readout beam, a layer of partially conductive material supported by the membrane and adapted to be addressed by the electron beam, a conductive grid disposed on the partially conductive layer and dividing that layer into pixel elements, the conductive grid being adapted to receive electrical charge from the partially conductive layer pixel elements, and circuit means connected to dissipate charge received by the grid from the partially conductive layer as a result of electron beam scanning of the layer, the accumulation of electric charge in the partially conductive material due to an electron beam scan and the subsequent dissipation of the charge through the grid producing a voltage across the liquie crystal and a related liquid crystal current I LC in the form: ##EQU2## C LC =liquid crystal capacitance per pixel R LC =liquid crystal resistance per pixel C M =combined membrane partially conductive layer capacitance per pixel R M =effective combined membrane partially conductive layer sheet resistivity per pixel, C LC , R LC , C M and R M being selected to produce an AC voltage across the liquid crystal during a substantial portion of the time between the electron beam scans.

Claim 21

Dependent Claim 66 words

The LCLV of claim 17, wherein the membrane thickness is in the approximate range of 4-12 microns, the partially conductive layer thickness is in the approximate range of 3-10 microns, the liquid crystal layer thickness is in the approximate range of 1-25 microns, the sides of the pixels are approximately 0.1-1 mm. and the electron beam current is in the approximate range of 10 microamps-1 milliamp.

Claim 22

Dependent Claim 25 words

The LCLV of claim 17, wherein the partially conductive layer has a bulk resistance in the order of about 10 7 -10 10 ohms cm.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1991-03-01	1991-08-31	1992-03-01	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1995-03-01	1995-08-31	1996-03-01	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1999-03-01	1999-08-31	2000-03-01	$7700.00	Window Closed / Lapsed

Electron beam addressed liquid crystal light valve

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