Transflective liquid-crystal display device
AssigneeAlps Electric Co., Ltd.
InventorTakehiko Sone
Life of this patent
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Abstract
A liquid crystal layer is composed of a liquid crystal composition having a positive dielectric anisotropy, and the liquid crystal composition is sandwiched by a pair of transparent substrates while being twisted by 220 to 260 degrees. Also, in a liquid crystal display device having an optical compensating plate and a polarizer respectively formed above and below a liquid crystal cell, a transflector is formed on the inner surface of the transparent substrate of the liquid crystal cell, the transflector has a high-reflectivity film having a plurality of fine apertures therein, and the high-reflectivity film has a diffuse reflection surface, on the surface thereof, having a controlled reflected luminance characteristic.
Claims30
A transflective liquid-crystal display device comprising:
- a liquid crystal cell, the liquid crystal cell containing:
- a liquid crystal layer;
- a pair of mutually opposing transparent substrates sandwiching the liquid crystal layer;
- transparent electrodes and an alignment film formed close to an inner surface of one of the transparent substrates in that order;
- other transparent electrodes and another alignment film formed close to an inner surface of the other transparent substrate in that order;
- and
- a transflector disposed close to the one transparent substrate;
- a first optical compensating plate and a first polarizer formed close to an outer surface of the other transparent substrate in that order;
- a second optical compensating plate and a second polarizer formed close to an outer surface of the one transparent substrate in that order;
- and
- an illuminator that is disposed close to an outer surface of the second polarizer and which emits light toward the liquid crystal cell,
- wherein the liquid crystal layer contains a liquid crystal composition which has a positive dielectric anisotropy, which is twisted by about 220 to 260 degrees, and which is sandwiched by the pair of transparent substrates, and
- wherein the transflector contains a high-reflectivity film having a plurality of fine apertures therein and the high-reflectivity film contains a diffuse reflection surface, on the surface thereof, whose reflected luminance characteristic is controlled.
A method of fabricating a transflective liquid-crystal display device comprising:
- introducing a liquid-crystal layer between a first and a second transparent substrate and limiting the liquid crystal layer to having a liquid crystal composition of a positive dielectric anisotropy and which is twisted by about 220 to 260 degrees;
- forming a transflector on an inner surface of the first transparent substrate, forming a plurality of fine apertures in a high-reflectivity film of the transflector thereby forming a diffuse reflection surface on the transflector, controlling a reflected luminance characteristic of the diffuse reflection surface such that the diffuse reflection surface has a high reflected luminance region with a substantially flat portion, and planarizing the transflector by covering the fine apertures with a planarizing film;
- forming a first set of transparent electrodes and a first alignment film on an inner surface of the transflector, a first optical compensating plate and a first polarizer on an outer surface of the first transparent substrate, a second set of transparent electrodes and a second alignment film on an inner surface of the second transparent substrate, and a second optical compensating plate and a second polarizer on an outer surface of the second transparent substrate;
- and
- placing a backlight proximate to an outer surface of the second polarizer.
Dependencies are inferred from the claim text.