EP0372905A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Projection-type liquid crystal display apparatus
Assignee: Sharp Corp
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Filing: 1989-12-05
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Granted: —
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Expires: 2009-12-05
Abstract
Abstract A projection-type liquid crystal display apparatus using liquid crystal cells as light polarizing devices. This apparatus makes a polarization control of one of the two linearly polarized light components perpendicular to each other separated by the polarized light separating device (3) through the first liquid crystal cell (5P) and of the other of the two through the second liquid crystal cell (5S). The liquid crystal cells (5P, 5S) transmit through directly a linearly polarized light component incident upon pixel portions corresponding to bright pixels of an image to be projected on the screen (10), while they transmit through the one incident upon pixel portions corresponding to dark pixels of the image as converting it into the other linearly polarized light component. This apparatus composes the first linearly polarized light penetrating through pixel portions of the first liquid crystal cell (5P) corresponding to bright pixels of the image and the second linearly polarized light penetrating through pixel portions of the second liquid crystal cell (5S) corresponding to the same bright pixels as the above-mentioned bright pixels through a polarized light composing device (7) and projects the composed light on the screen (10) through an optical device (9).
Inventors
- 👤 Hisashi Atarashi
- 👤 Yutaka Takafuji
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 23:22
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3141; H04N9/315; H04N9/3167
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
283 words
A projection-type liquid crystal display apparatus comprising; means (3) for separating a light emitted from a light source (1) into two linearly polarized light components perpendicular to each other, a first liquid crystal cell (5P) which is located at the middle of a light path of a first linearly polarized light component out of the two linearly polarized light components, transmits through directly the first linearly polarized light component incident upon a pixel portion corresponding to a first display data out of two kinds of display data indicating light to be or not to be transmitted, and transmits through the first linearly polarized light component incident upon a pixel portion corresponding to a second display data as converting it into the second linearly polarized light component, a second liquid crystal cell (5S) which is located at the middle of the light path of the second linearly polarized light component out of the two linearly polarized light components, transmits through directly the second linearly polarized light component incident upon a pixel portion corresponding to the first display data out of two kinds of display data indicating light to be or not to be transmitted, and transmits through the second linearly polarized light component incident upon a pixel portion corresponding to the second display data as converting it into the first linearly polarized light component, means (7) for composing the first and second linearly polarized light components penetrating through a pixel portion corresponding to either of the first and second display data, out of pixel portions of the first and second liquid crystal cells (5P, 5S), and optical means (11) for projecting a light composed by the polarized light composing means on a screen (10).
Claim 2
Dependent Claim
283 words
A projection-type liquid crystal display apparatus comprising; means (3) for separating a light emitted from a light source (1) into two linearly polarized light components perpendicular to each other, a first liquid crystal cell (5P) which is located at the middle of a light path of a first linearly polarized light component out of the two linearly polarized light components, transmits through directly the first linearly polarized light component incident upon a pixel portion corresponding to a first display data out of two kinds of display data indicating light to be or not to be transmitted, and transmits through the first linearly polarized light component incident upon a pixel portion corresponding to a second display data as converting it into the second linearly polarized light component, a second liquid crystal cell (5S) which is located at the middle of the light path of the second linearly polarized light component out of the two linearly polarized light components, transmits through directly the second linearly polarized light component incident upon a pixel portion corresponding to the first display data out of two kinds of display data indicating light to be or not to be transmitted, and transmits through the second linearly polarized light component incident upon a pixel portion corresponding to the second display data as converting it into the first linearly polarized light component, means (7) for composing the first and second linearly polarized light components penetrating through a pixel portion corresponding to either of the first and second display data, out of pixel portions of the first and second liquid crystal cells (5P, 5S), and optical means (11) for projecting a light composed by the polarized light composing means on a screen (10).
Claim 3
Dependent Claim
25 words
A projection-type liquid crystal display apparatus according to claim 1, wherein the first and second liquid crystal cells (5P, 5S) are twisted-nematic liquid crystal cells.
Claim 4
Dependent Claim
25 words
A projection-type liquid crystal display apparatus according to claim 1, wherein the first and second liquid crystal cells (5P, 5S) are provided with color filters.
Claim 5
Dependent Claim
47 words
A projection-type liquid crystal display apparatus according to claim 1, wherein the first and second liquid crystal cells (5P, 5S) respectively include three liquid crystal cells each of which handles individually one incident primary color light of the linearly polarized light component separated into three primary colors.
Claim 6
Dependent Claim
26 words
A projection-type liquid crystal display apparatus according to claim 4, wherein the linearly polarized light component is separated into the three primary colors through dichroic mirrors.
Claim 7
Dependent Claim
31 words
A projection-type liquid crystal display apparatus according to either of claims 1, wherein the first and second liquid crystal cells have a function to give the transmitted light a variable tone.
Claim 8
Dependent Claim
54 words
A projection-type liquid crystal display apparatus according to either of claims 1, wherein the polarized light composing means (7) is a polarized light beam splitter which composes the first linearly polarized light component penetrating through the first liquid crystal cell and the second linearly polarized light component penetrating through the second liquid crystal cell.
Claim 9
Dependent Claim
55 words
A projection-type liquid crystal display apparatus according to either of claims 1, wherein the polarized light composing means (7) is a polarized light beam splitter which composes the second linearly polarized light component penetrating through the first liquid crystal cell and the first linearly polarized light component penetrating through the second liquid crystal cell (S).
Claim 10
Dependent Claim
23 words
A projection-type liquid crystal display apparatus according to claim 7 or 8, wherein the polarized light beam splitter (7) is of plate type.
Claim 11
Dependent Claim
23 words
A projection-type liquid crystal display apparatus according to claim 7 or 8, wherein the polarized light beam splitter (7) is of cube type.
Claim 12
Dependent Claim
21 words
A projection-type liquid crystal display apparatus according to either of claims 1, wherein the optical means (11) is a projection lens.
Claim 13
Dependent Claim
20 words
A projection-type liquid crystal display apparatus according to either of claims 1, wherein the screen (10) is of non-transparent type.
Claim 14
Dependent Claim
20 words
A projection-type liquid crystal display apparatus according to either of claims 1, wherein the screen (10) is of transparent type.
Claim 15
Dependent Claim
120 words
A liquid crystal display device having a liquid crystal imaging means for controlling light from a light source in accordance with image data, wherein there is provided means for dividing randomly polarized light from said source into first and second sub-beams of linearly polarized light, said sub-beams having different respective axes of polarization, said liquid crystal imaging means comprising first and second liquid crystal cells arranged in the paths of said respective first and second sub-beams, and operable to control the state of polarization of the respective said sub-beams, in accordance with said image data, and means for recombining the polarization-controlled sub-beams, in such a way as to form a composite beam which is intensity modulated according to the image.
Claim 16
Dependent Claim
120 words
A liquid crystal display device having a liquid crystal imaging means for controlling light from a light source in accordance with image data, wherein there is provided means for dividing randomly polarized light from said source into first and second sub-beams of linearly polarized light, said sub-beams having different respective axes of polarization, said liquid crystal imaging means comprising first and second liquid crystal cells arranged in the paths of said respective first and second sub-beams, and operable to control the state of polarization of the respective said sub-beams, in accordance with said image data, and means for recombining the polarization-controlled sub-beams, in such a way as to form a composite beam which is intensity modulated according to the image.
Claim 17
Dependent Claim
47 words
A display device according to claim 14 wherein each said liquid crystal cell is a twisted nematic cell operable to transmit first selected portions of the respective sub-beam directly without alteration of polarization and second selected portions with rotation of polarization to that of the other sub-beam.
Claim 18
Dependent Claim
23 words
A display device according to claim 14 or claim 15 wherein said dividing means and said recombining means comprise respective polarizing beam splitters.
References Cited (Backward Citations)
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