Liquid crystal display having particular irregularity controlling structure
View Patent ↗The invention relates to a reflective or reflective/transmissive liquid crystal display having a light-reflecting layer and provides a low-cost light crystal display having high controllability of the thickness of a liquid crystal layer. The liquid crystal display has a wrinkly irregular layer having a wrinkly irregular surface formed such that it follows irregularity controlling structures on a glass substrate. The liquid crystal display also has a plurality of holding protrusions which are formed to protrude from an opposite glass substrate and which hold the two substrates so as to leave a predetermined gap between them. The holding protrusions which have substantially the same length are formed at predetermined intervals such that they contact the tops of convexes of the wrinkly irregular layer, which makes it possible to control the thickness of the liquid crystal layer into agreement with a design value easily.
1. A liquid crystal display, comprising:
a wrinkly irregular layer having a wrinkly irregular surface formed on a substrate;
an opposite substrate provided opposite to a side of the substrate on which the wrinkly irregular layer is formed;
a liquid crystal layer sealed between the substrate and the opposite substrate;
an irregularity controlling structure formed under the wrinkly irregular layer on the substrate for controlling the orientation of a irregularities of the wrinkly irregular layer; and
a holding protrusion formed on either concaves or convexes of the wrinkly irregular layer for holding the substrate and the opposite substrate with a predetermined gap left between them,
wherein the irregularity controlling structure is formed from a material which is different from the wrinkly irregular layer in thermal deformation charcteristics.
2. A liquid crystal display according to claim 1 , wherein the holding protrusion is formed to protrude from the opposite substrate.
3. A liquid crystal display according to claim 1 , wherein the holding protrusion is formed to protrude from the wrinkly irregular layer.
4. A liquid crystal display according to claim 1 , wherein the holding protrusion controls the alignment of the liquid crystal.
5. A liquid crystal display according to claim 1 , wherein the wrinkly irregular layer is formed of a photosensitive resin such as a novolac type positive resist.
6. A liquid crystal display according to claim 1 , further comprising a light-reflecting layer formed on the wrinkly irregular layer so as to follow the irregularities and reflect an incident light from the side of the opposite substrate.
7. A liquid crystal display according to claim 6 , wherein the light-reflecting layer is formed also between the holding protrusion and the wrinkly irregular layer.
8. A liquid crystal display according to claim 1 , further comprising a gate bus line formed on the substrate, a drain bus line formed so as to intersect the gate bus line with an insulation film interposed between them, and a pixel region formed at each intersection between the gate bus line and the drain bus line, wherein the irregularity controlling structure is formed of the same material as the gate bus line and/or the drain bus line.
9. A liquid crystal display according to claim 8 , wherein the irregularity controlling structure is formed in the same layer as the gate bus line and/or the drain bus line.
10. A liquid crystal display according to claim 8 , further comprising a light source which is provided on the side of the substrate, the pixel region having a reflective area in which the light-reflecting layer is formed and a transmissive area which transmits light emitted from the light source.
11. A liquid crystal display according to claim 1 , wherein the liquid crystal has negative dielectric constant anisotropy and is vertically aligned when no voltage is applied.
12. A liquid crystal display according to claim 1 , wherein a plurality of said holding protrusions are formed only on the convexes of the wrinkly irregular layer.
13. A liquid crystal display according to claim 1 , wherein the irregularity controlling structure is formed directly on the substrate.