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US4936656A Expired / Lapsed US ⏱️ 0.0 years remaining

Video projector

Assignee: Panasonic Holdings Corp
•
Filing: 1988-03-18
•
Granted: 1990-06-26
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Expires: 2008-03-18
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Abstract

Abstract A video projector utilizes a reflective liquid crystal light valve of the active matrix system and a polarizing beam splitter. An active matrix array circuit of the light valve has pixel electrodes arranged in a matrix mattern. The pixel electrodes each has a reflective surface for reflecting a light beam and protects corresponding switch elements from the light beam. There are provided at least two switch elements for each of the pixel electrodes so as to enhance the redundancy of the array circuit. Further, each pixel electrode is provided with a suitable additional capacitance.

Inventors

  • 👤 Ichiro Yamashita
  • 👤 Mamoru Takeda
  • 👤 Yoshito Miyatake
  • 👤 Yoneharu Takubo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 15:43
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/13624; H; H04; H04N; H04N5/00; H04N5/74; H04N5/7416; H04N5/7441; G02F1/136213

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 347 words
A video projector comprising: a reflective type liquid crystal light valve for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a video signal; a light source for generating a light beam; and an optical means for linearly polarizing the light beam from the light source, and for leading the linearly polarized light beam to the light valve, and for projecting the modulated light beam reflected from the light valve onto a screen to form a visible image on the screen, wherein the light valve comprises: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrate; wherein said active matrix array circuit includes: a plurality of scanning lines for supplying a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the video signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the video signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein a capacitance is formed between each of the pixel electrodes and one of the plurality of scanning lines which is different from the scanning lines for controlling the at least two switching elements connected to the each pixel electrode.
Claim 2
Dependent Claim 347 words
A video projector comprising: a reflective type liquid crystal light valve for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a video signal; a light source for generating a light beam; and an optical means for linearly polarizing the light beam from the light source, and for leading the linearly polarized light beam to the light valve, and for projecting the modulated light beam reflected from the light valve onto a screen to form a visible image on the screen, wherein the light valve comprises: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrate; wherein said active matrix array circuit includes: a plurality of scanning lines for supplying a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the video signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the video signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein a capacitance is formed between each of the pixel electrodes and one of the plurality of scanning lines which is different from the scanning lines for controlling the at least two switching elements connected to the each pixel electrode.
Claim 3
Dependent Claim 81 words
A video projector as in claim 1, wherein, if each of the plurality of scanning lines is designate by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to two switching elements which are respectively controlled by the (n-1)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to an (n-2)-th scanning line.
Claim 4
Dependent Claim 81 words
A video projector as in claim 1, wherein, if each of the plurality of scanning lines is designate by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to two switching elements which are respectively controlled by the (n-2)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to an (n-1)-th scanning line.
Claim 5
Dependent Claim 50 words
A video projector as in claim 1, wherein each of the at least two switching elements connected to each of the pixel electrodes has on each of its terminal portions an area to be cut off, when defective, by laser trimming so as to be separated from the array circuit.
Claim 6
Dependent Claim 26 words
A video projector as in claim 4, wherein the second substrate is transparent at a wave length of a laser beam used for the laser trimming.
Claim 7
Dependent Claim 374 words
A video projection comprising: a plurality of reflective type liquid crystal light valves each for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a video signal; a light source for generating a light beam; and an optical means for splitting the light beam from the light source into a plurality of light beams having different wave lengths from one another, and for linearly polarizing the split light beams, and for leading the linearly polarized light beams respectively to the plurality of light valves, and for projecting the modulated light beams from the light valves onto a screen to form a visible image on the screen; wherein each of the light valves comprises: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrates, wherein said active matrix array circuit includes: a plurality of scanning lines for supplying a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the video signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the video signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein a capacitance is formed between each of the pixel electrodes and one of the plurality of scanning lines which is different from the scanning lines for controlling the at least two switching elements connected to the each pixel electrode.
Claim 8
Dependent Claim 374 words
A video projection comprising: a plurality of reflective type liquid crystal light valves each for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a video signal; a light source for generating a light beam; and an optical means for splitting the light beam from the light source into a plurality of light beams having different wave lengths from one another, and for linearly polarizing the split light beams, and for leading the linearly polarized light beams respectively to the plurality of light valves, and for projecting the modulated light beams from the light valves onto a screen to form a visible image on the screen; wherein each of the light valves comprises: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrates, wherein said active matrix array circuit includes: a plurality of scanning lines for supplying a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the video signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the video signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein a capacitance is formed between each of the pixel electrodes and one of the plurality of scanning lines which is different from the scanning lines for controlling the at least two switching elements connected to the each pixel electrode.
Claim 9
Dependent Claim 81 words
A video projector as in claim 6, wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to two switching elements which are respectively controlled by the (n-1)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to an (n-2)-th scanning line.
Claim 10
Dependent Claim 81 words
A video projector as in claim 6, wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning lines is connected to two switching elements which are respectively controlled by an (n-2)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to the (n-1)-th scanning line.
Claim 11
Dependent Claim 50 words
A video projection as is claim 6, wherein each of the at least two switching elements connected to each of the pixel electrodes has on each of its terminal portions as area to be cut off, when defective, by laser trimming so as to be separated from the array circuit.
Claim 12
Dependent Claim 26 words
A video projector as in claim 9, wherein the second substrate is transparent at a wave length of a laser beam used for the laser trimming.
Claim 13
Dependent Claim 282 words
A reflective type liquid crystal light valve for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a modulation signal, comprising: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrate; wherein said active matrix array circuit includes: a plurality of scanning lines for supplying a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the modulation signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the modulation signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein a capacitance is formed between each of the pixel electrodes and one of the plurality of scanning lines which is different from the scanning lines for controlling the at least two switching elements connected to the each pixel electrode.
Claim 14
Dependent Claim 282 words
A reflective type liquid crystal light valve for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a modulation signal, comprising: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrate; wherein said active matrix array circuit includes: a plurality of scanning lines for supplying a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the modulation signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the modulation signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein a capacitance is formed between each of the pixel electrodes and one of the plurality of scanning lines which is different from the scanning lines for controlling the at least two switching elements connected to the each pixel electrode.
Claim 15
Dependent Claim 81 words
A light valve as in claim 11, wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to two switching elements which are respectively controlled by the (n-1)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to an (n-1)-th scanning line.
Claim 16
Dependent Claim 81 words
A light valve as in claim 11, wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to two switching elements which are respectively controlled by an (n-2)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to an (n-1)-th scanning line.
Claim 17
Dependent Claim 50 words
The light valve as in claim 11, wherein each of the at least two switching elements connected to each of the pixel electrodes has on each of its terminal portions an area to be cut off, when defective, by laser trimming so as to be separated from the array circuit.
Claim 18
Dependent Claim 26 words
A light valve as in claim 14, wherein the second substrate is transparent at a wave length at a laser beam use for the laser trimming.
Claim 19
Dependent Claim 382 words
A video projection comprising: a reflective type liquid crystal light valve for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a video signal; a light source for generating a light beam; and an optical means for linearly polarizing the light beam from the light source and for leading the linearly polarized light beam to the light valve, and for projecting the modulated light beam reflected from the light valve onto a screen to form a visible image on the screen, wherein the light valve comprises: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrates; wherein said active matrix array circuit includes: a plurality of scanning lines for supply a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the video signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the video signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to the two switching elements which are respectively controlled by the (n-1)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to an (n-2)-th scanning line.
Claim 20
Dependent Claim 382 words
A video projection comprising: a reflective type liquid crystal light valve for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a video signal; a light source for generating a light beam; and an optical means for linearly polarizing the light beam from the light source and for leading the linearly polarized light beam to the light valve, and for projecting the modulated light beam reflected from the light valve onto a screen to form a visible image on the screen, wherein the light valve comprises: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrates; wherein said active matrix array circuit includes: a plurality of scanning lines for supply a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the video signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the video signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to the two switching elements which are respectively controlled by the (n-1)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to an (n-2)-th scanning line.
Claim 21
Dependent Claim 409 words
A video projection comprising: a plurality of reflective type liquid crystal light valves each for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a video signal; a light source for generating a light beam; and an optical means for splitting the light beam from the light source into a plurality of light beams having different wave lengths form one another, and for linearly polarizing the split light beams, and for leading the linearly polarized light beams respectively to the plurality of light valves, and for projecting the modulated light beams from the light valves onto a screen to form a visible image on the screen; wherein each of the light valve comprises: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrates, wherein said active matrix array circuit includes: a plurality of scanning lines for supply a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the video signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the video signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to the two switching elements which are respectively controlled by the (n-2)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to an (n-1)-th scanning line.
Claim 22
Dependent Claim 409 words
A video projection comprising: a plurality of reflective type liquid crystal light valves each for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a video signal; a light source for generating a light beam; and an optical means for splitting the light beam from the light source into a plurality of light beams having different wave lengths form one another, and for linearly polarizing the split light beams, and for leading the linearly polarized light beams respectively to the plurality of light valves, and for projecting the modulated light beams from the light valves onto a screen to form a visible image on the screen; wherein each of the light valve comprises: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrates, wherein said active matrix array circuit includes: a plurality of scanning lines for supply a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the video signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the video signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to the two switching elements which are respectively controlled by the (n-2)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to an (n-1)-th scanning line.
Claim 23
Dependent Claim 316 words
A reflective type liquid crystal light valve for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a modulation signal, comprising: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrate; wherein said active matrix array circuit includes: a plurality of scanning lines for supplying a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the modulation signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the modulation signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to two switching elements which are respectively controlled by an (n-2)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to the (n-1)-th scanning line.
Claim 24
Dependent Claim 316 words
A reflective type liquid crystal light valve for reflecting a light beam being incident thereon while modulating the polarization of the light beam according to a modulation signal, comprising: a transparent first substrate having on a surface thereof a transparent electrode; a second substrate having an active matrix array circuit on a surface thereof opposing the transparent electrode; and a liquid crystal layer interposed between the first and second substrate; wherein said active matrix array circuit includes: a plurality of scanning lines for supplying a control signal; a plurality of signal lines arranged to intersect the scanning lines for supplying the modulation signal; a plurality of pixel electrodes opposing the transparent electrode and being arranged in a matrix to correspond to respective intersecting points of the scanning and signal lines; and a plurality of switching elements for applying the modulation signal on the signal lines to the pixel electrodes selectively according to the control signal on the scanning lines, the pixel electrodes each having on a surface opposing the transparent electrode a reflective surface for reflecting the light beam being incident thereon from the first substrate side of the light valve and covering the switching elements so that the incident light beam does not reach the switching elements, each of the pixel electrodes being connected to at least two of the switching elements which are respectively controlled by at least two of the scanning lines which are different from each other, and wherein, if each of the plurality of scanning lines is designated by a sequential number n in a sequential order thereof, then each of the pixel electrodes disposed between an (n-1)-th scanning line and an n-th scanning line is connected to two switching elements which are respectively controlled by an (n-2)-th scanning line and the n-th scanning line, and the capacitance connected to the each pixel electrode is connected to the (n-1)-th scanning line.

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