LCD comprising a light separating element including a cholesteric liquid crystal sheet
AssigneeKabushiki Kaisha Toshiba
InventorsKazuki Taira, Yoshinori Higuchi
Life of this patent
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Abstract
A display device having an emitter, a direct-view display screen, a light-guiding member for guiding illumination light emitted from the emitter to the direct-view display screen, a light separating element for separating the illumination light selectively into a first and second polarized light component and transmitting the first light component and reflecting the second light component, a light converting member for converting the reflected second light component to a first light component, a reflecting plate for returning the converted first light component to the light separating element, and a half-wave film for rotating the vibration direction of the first polarized light component, thereby obtaining the illumination light.
Claims9
A display device comprising:
- an emitter,
- a direct-view display screen,
- a light separating element including a cholesteric liquid crystal sheet for selectively separating illumination light emitted from said emitter into a first and second polarized light components and transmitting the first polarized light component and reflecting the second light component, and
- a reflecting member for converting the reflected second light component to a first light component and returning it to said light separating element.
A display device comprising:
- an emitter,
- a direct-view display screen,
- a light-guiding member for guiding an illumination light emitted from said emitter to said direct-view display screen, wherein said light-guiding member has a surface having projections and depressions inclined to the incident side, formed on the opposite side to said direct-view display screen of said light-guiding member, with a light incident angle approximately equal to Brewster's angle which is represented by the following formula:
- .theta..sub.B =tan.sup.-1 (n.sub.2 /n.sub.1)
- wherein n.sub.1 is a refractive index of the incident side medium and n.sub.2 is a refractive index of the emitting side medium;
- a light separating element for separating the illumination light selectively into a first and second polarized light components and transmitting the first light component and reflecting the second light component,
- a conversion/reflection member for converting the reflected second light component to a first light component and returning it to said light separating element, and
- a light converting means for converting a vibration direction of said first light component transmitted through said light separating element into another vibration direction, thereby obtaining the illumination light.
A display device comprising:
- an emitter,
- a liquid crystal panel,
- a light separating element including a cholesteric liquid crystal sheet for selectively separating illumination light emitted from said emitter into a first and second polarized light components and transmitting the first polarized light component and reflecting the second light component, and
- a reflecting member for converting the reflected second light component to a first light component and returning it to said light separating element.
A display device comprising:
- an emitter,
- a liquid crystal panel,
- a light separating element including a cholesteric liquid crystal sheet for selectively separating illumination light emitted from said emitter into a first and second polarized light components and transmitting the first polarized light component and reflecting the second light component,
- a quarter-wave film interposed between said light separating element and said liquid crystal panel, and
- a reflecting member for converting the reflected second light component to a first light component and returning it to said light separating element.
Dependencies are inferred from the claim text.