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US 7,405,780 B2Granted
Liquid-crystal display
AssigneeDai Nippon Printing Co., Ltd.
InventorKeiji Kashima
Life of this patent
Estimating the term…
Abstract
In a liquid-crystal display (10), unpolarized light from a light source (12) passes through a linear polarization separation layer (14) and strikes a liquid-crystal cell (16). The liquid-crystal cell (16), in response to an applied electrical field, changes the direction of a director, so as to change the direction of the electrical field oscillation vector of the incident linearly polarized light by substantially 0 to 90°, this light then striking a dichroic linear polarization layer (18) on the surface, whereby only a component coincident with the polarization transmission axis thereof is allowed to exit to the outside. The dichroic linear polarization layer (18) transmits 50% of this incident light, and absorbs the remaining 50%.
Claims8
A liquid-crystal display comprising:
- a dichroic polarizing layer having one of a function whereby of the incident light, a light component having circular polarization of one direction, either right or left, is transmitted, and a component of another circular polarization direction is absorbed, and a function whereby one linearly polarized light component is transmitted and a linearly polarized light component perpendicular thereto is absorbed;
- a liquid-crystal cell including a liquid crystal layer that shifts the phase of light passing therethrough and electrodes for applying an electrical field to said liquid-crystal layer, whereby one of circularly polarized light and linearly polarized light incident after being transmitted through said dichroic polarizing layer is converted to the other before it exits the other side or is not converted but the liquid-crystal cell also has one function of a function that changes the ellipticity of the light if exiting as circularly polarized light or changes the direction of polarization of the light if it is exiting as linearly polarized light;
- and
- a polarization separation layer having one of a function of transmitting a light component having circular polarization of one direction, either right or left, and reflecting a component of the other circular polarization direction, and a function of transmitting one linearly polarized light component and reflecting another component having a polarization direction perpendicular thereto, these being disposed in this sequence as seen from the observation side, wherein light is caused to be incident from either said dichroic polarizing layer or said polarization separation layer side;
- wherein said dichroic polarizing layer is a dichroic circular polarizing layer which, of incident light transmits a circularly polarized light component of one direction, either right or left, and absorbs a circularly polarized light component of the other direction, said liquid-crystal layer having a retardation value that causes a phase shift in the transmitted light that is substantially π/2, said liquid-crystal cell converting the incident circularly polarized light to linearly polarized light before it exits from the opposite side, by applying an electrical field from said electrodes to said liquid-crystal layer so as to change the orientation of the directors thereof, thereby causing a change in the polarization axis of the linearly polarized light, said polarization separation layer being made a linear polarization separation layer that, of the incident light thereto, transmitting a light component of one linear polarization and reflecting another linearly polarized light component having polarization perpendicular thereto.
2 more elements
A liquid-crystal display comprising:
- a dichroic polarizing layer having one of a function whereby of the incident light, a light component having circular polarization of one direction, either right or left, is transmitted, and a component of another circular polarization direction is absorbed, and a function whereby one linearly polarized light component is transmitted and a linearly polarized light component perpendicular thereto is absorbed;
- a liquid-crystal cell including a liquid crystal layer that shifts the phase of light passing therethrough and electrodes for applying an electrical field to said liquid-crystal layer, whereby one of circularly polarized light and linearly polarized light incident after being transmitted through said dichroic polarizing layer is converted to the other before it exits the other side or is not converted but the liquid-crystal cell also has one function of a function that changes the ellipticity of the light if exiting as circularly polarized light or changes the direction of polarization of the light if it is exiting as linearly polarized light;
- and
- a polarization separation layer having one of a function of transmitting a light component having circular polarization of one direction, either right or left, and reflecting a component of the other circular polarization direction, and a function of transmitting one linearly polarized light component and reflecting another component having a polarization direction perpendicular thereto, these being disposed in this sequence as seen from the observation side, wherein light is caused to be incident from either said dichroic polarizing layer or said polarization separation layer side;
- wherein the dichroic polarizing layer is a dichroic circular polarizing layer which, of incident light transmits one circularly polarized light component and absorbs another circularly polarized light component, said liquid-crystal cell having the effect of shifting a linearly polarized light phase of incident light substantially by −π/2 to +π/2, when said electrical field is applied to said liquid-crystal layer from said electrodes so as to change the retardation value thereof, and the polarization separation layer being a linear polarization separation layer that, of the incident light thereto, transmits a light component of one linear polarization and reflects another linearly polarized light component having polarization perpendicular thereto.
2 more elements
A liquid-crystal display comprising:
- a dichroic circular polarizing layer which, of incident light transmits a circularly polarized light component of one direction, either right or left, and absorbs a circularly polarized light component of the other directions;
- and
- a liquid crystal cell, including a liquid crystal layer that shifts the phase of light passing therethrough, and electrodes for applying an electric field to said liquid crystal layer, these being disposed in this sequence as seen from the observation side, wherein said liquid-crystal cell having the effect of shifting a circularly polarized light phase of incident light substantially by 0 to π, wherein said electrical field is applied to said liquid-crystal layer from said electrodes so as to change a retardation value thereof.
Dependencies are inferred from the claim text.