Reflective liquid crystal display device
View Patent ↗A reflective LCD device having a CLC color filter includes a holographic film to increase a luminance and viewing angle. Due to the holographic film, light incident to the CLC film has not only a small incident angle but also a small reflection angle. Therefore, a wavelength variation decreases. Further, since the holographic film diffuses the reflected light, a chromaticity variation also decreases. Since the reflective LCD device of the present invention further includes the diffusion film on the holographic film, the incident light can have a wide range of incident angle and the reflected light can be further diffused.
1. A reflective cholesteric liquid crystal (CLC) display device, comprising:
a first substrate;
an absorption layer on the first substrate;
a cholesteric liquid crystal (CLC) color filter over the absorption layer;
a first electrode on the cholesteric liquid crystal (CLC) color filter;
a second substrate spaced apart from the first substrate;
a second electrode on the rear surface of the second substrate;
a retardation layer on the front surface of the second substrate;
a polarizer on the retardation layer;
a holographic film on the polarizer, the holographic film for reducing an angle of light incident to the polarizer; and
a liquid crystal layer between the first electrode and the second electrode.
2. The device according to claim 1 , wherein the holographic film diffracts the incident light to have an incident angle of less than about 20 degrees.
3. The device according to claim 1 , further comprising a diffusion film on the holographic film.
4. The device according to claim 1 , wherein the second substrate includes a thin film transistor that applies a signal to the second electrode.
5. The device according to claim 1 , wherein the first substrate includes a thin film transistor that applies a signal to the first electrode.
6. The device according to claim 1 , wherein the second substrate includes a transparent insulating material.
7. The device according to claim 1 , wherein the first substrate includes a transparent material.
8. The device according to claim 1 , wherein the first substrate includes an opaque material.
9. The device according to claim 1 , further comprising a first alignment layer on the absorption layer.
10. The device according to claim 1 , wherein the reflected light from the cholesteric liquid crystal color filter layer shows one of red, green, and blue in each pixel region.
11. The device according to claim 1 , wherein the first electrode includes a transparent conductive material.
12. The device according to claim 1 , wherein the second electrode includes a transparent conductive material.
13. A reflective cholesteric liquid crystal (CLC) display device, comprising:
a first substrate;
a second substrate;
an absorption layer formed on the first substrate;
a first alignment layer formed on the absorption layer;
a cholesteric liquid crystal color filter layer formed on the first alignment layer;
a first electrode formed on the cholesteric liquid crystal color filter layer;
a second alignment layer formed on the first electrode;
a second electrode formed on the second substrate;
a third alignment layer formed on the second electrode;
a liquid crystal layer interposed between the second alignment layer and the third alignment layer;
a retardation layer formed on the second substrate;
a polarizer formed on the retardation layer;
a holographic film disposed on the polarizer; and
a diffusion film formed on the holographic film.
14. The device according to claim 13 , wherein the holographic film diffracts the incident light to have an incident angle of less than about 20 degrees.
15. The device according to claim 13 , wherein the second substrate includes a thin film transistor that applies a signal to the second electrode.
16. The device according to claim 13 , wherein the first substrate includes a thin film transistor that applies a signal to the first electrode.
17. The device according to claim 13 , wherein the second substrate includes a transparent insulating material.
18. The device according to claim 13 , wherein the first substrate includes a transparent material.
19. The device according to claim 13 , wherein the first substrate includes an opaque material.
20. The device according to claim 13 , wherein the first alignment layer includes a polymer.
21. The device according to claim 13 , wherein the reflected light from the cholesteric liquid crystal color filter layer shows one of red, green, and blue in each pixel region.
22. The device according to claim 13 , wherein the first electrode includes a transparent conductive material.
23. The device according to claim 13 , wherein the second electrode includes a transparent conductive material.
24. A method of manufacturing a reflective cholesteric liquid crystal (CLC) display device, comprising:
forming a first substrate;
forming an absorption layer on the first substrate;
forming a cholesteric liquid crystal (CLC) color filter on the absorption layer;
forming a first electrode on the cholesteric liquid crystal (CLC) color filter;
forming a second substrate spaced apart from the first substrate;
forming a second electrode on the rear surface of the second substrate;
forming a retardation layer on the front surface of the second substrate;
forming a polarizer on the retardation layer;
forming a holographic film on the polarizer, the holographic film for reducing an angle of light incident to the polarizer; and
forming a liquid crystal layer between the first electrode and the second electrode.
25. A method of manufacturing a reflective cholesteric liquid crystal (CLC) display device, comprising:
forming a first substrate;
forming a second substrate;
forming an absorption layer on the first substrate;
forming a first alignment layer on the absorption layer;
forming a cholesteric liquid crystal color filter layer on the first alignment layer;
forming a first electrode on the cholesteric liquid crystal color filter layer;
forming a second alignment layer on the first electrode;
forming a second electrode on the second substrate;
forming a third alignment layer on the second electrode;
forming a liquid crystal layer interposed between the second alignment layer and the third alignment layer;
forming a retardation layer on the second substrate;
forming a polarizer on the retardation layer;
forming a holographic film disposed on the polarizer; and
forming a diffusion film on the holographic film.
26. The device according to claim 9 , wherein the first alignment layer includes a polymer.