Reflector and reflection-type LCD device using the same
View Patent ↗A reflector for a reflection-type LCD device is provided, which reflects efficiently incident light to the viewer's side and that suppresses the change of color tone. The reflector comprises a roughened surface having a protrusion pattern. The protrusion pattern gives inclination angle to the surface according to a specific distribution where a first component with an inclination angle value of 0° is 15% or less in area and a second component with an inclination angle value from 2° to 10° is 50% or greater in area. The protrusion pattern gives a variation range of chromaticity coordinates (x, y) on a chromaticity diagram dependent on an angle of view. The variation range is limited in a circle on the chromaticity diagram. The circle has a radius of approximately 0.05 and a center at a point corresponding to white color.
1. A reflector for a reflection-type LCD device, comprising:
a roughened surface having a protrusion pattern;
the protrusion pattern giving a variation range of chromaticity coordinates (x, y) on a chromaticity diagram dependent on an angle of view; and
the variation range being limited in a circle on the chromaticity diagram, where the circle has a radius of approximately 0.05 and a center at a point corresponding to white color.
2. The reflector according to claim 1 , further comprising
protrusions arranged in such a way that depressed areas are formed among adjoining ones of the protrusions;
a first bumpy layer formed to cover the protrusions; and
a base layer of the reflector formed on the first layer;
wherein each of the depressed areas has a closed geometric shape;
and wherein the first layer has a bumpiness generated by the protrusions;
and wherein the base layer has a bumpiness corresponding to the bumpiness of the first layer, thereby forming the protrusion pattern of the surface of the reflector.
3. The reflector according to claim 2 , wherein the closed geometric shape of each of the depressed areas is like one selected from the group consisting of triangle, rectangular, and ellipse.
4. The reflector according to claim 2 , wherein the first bumpy layer has a minimum height d and the protrusions have an inter-center distance L, where the minimum height d and the inter-center distance L have a relationship of (1/15)≦(d/L).
5. The reflector according to claim 1 , wherein the protrusion pattern gives a specific distribution of inclination angle values to the surface;
and wherein when incident light is irradiated to the surface of the reflector, bright regions with specific extent are generated, each of which has an inclination angle value within a range from 2° to 6°.
6. The reflector according to claim 5 , wherein when minimum and maximum distances between the protruding bright region and the adjoining depressed bright region are defined as L min and L max , respectively, and a mean distance between the protruding and depressed bright regions is defined as L mean =(L min +L max )/2, a relationship of
( L min −L max ) L mean ≧0.2
is established.
7. The reflector according to claim 2 , wherein the closed geometric shape of each of the depressed areas is like one selected from the group consisting of triangle, rectangular, and ellipse.
8. A reflection-type LCD device comprising one of the reflectors according to claim 1 .