Substrate with cholesteric layer and display having the substrate

• US 20040051830A1
• Filed: 07/07/2003
• Published: 03/18/2004
• Est. Priority Date: 11/07/2001
• Status: Active Grant

• Current Assignee: Dai Nippon Printing Company Limited
• Original Assignee: Dai Nippon Printing Company Limited
• Inventors: Kashima, Keiji
• Granted Patent: US 7,256,847 B2
• Time in Patent Office: Days
• US Class Current: 349/115
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 2201/343 cholesteric liquid crystal reflector
• CPC Class Codes: G02F 2203/09 transflective

Abstract

In view of the above problems of the prior art, the present invention has been made, and an object of the present invention is to provide a board, which is free from coloring, has high color tone quality, can realize a bright display screen, and imposes no significant restriction on the provision of an electric circuit, and a display device comprising the board, and further provides a liquid crystal display board, which is excellent in color contrast between transmission display and reflection display, and a semi-transmission color liquid crystal display device comprising the liquid crystal display board. A board according to the invention comprises a light transparent substrate and a cholesteric layer provided on the substrate and provided with an optical window of a predetermined pattern.

Claims

1. A board comprising a light transparent substrate and a cholesteric layer provided on the substrate and provided with an optical window of a predetermined pattern.

2. The board according to claim 1, characterized in that the reflectance of circularly polarized light from the cholesteric layer is 90 to 100%.

3. A semi-transmission liquid crystal display device comprising the board according to claim 1 or 2.

4. The semi-transmission liquid crystal display device according to claim 3, wherein an electric circuit is provided on the cholesteric layer in its light transparent substrate side.

5. The semi-transmission liquid crystal display device according to claim 3 or 4, which further comprises a first color filter layer provided on the upper part of or above the cholesteric layer and a second color filter layer provided on the upper part of or above the optical window portion.

6. The semi-transmission liquid crystal display device according to claim 5, wherein the second color filter layer is provided in the optical window portion in the cholesteric layer.

7. The semi-transmission liquid crystal display device according to claim 3 or 4, wherein a color filter layer is provided on the upper part of or above the cholesteric layer and the light transmittance of the color filter layer in its portion corresponding to the optical window portion is higher than the light transmittance of the color filter layer in its optical window-free portion.