Liquid crystal display device and method for manufacturing the same

• US 20040207783A1
• Filed: 12/22/2003
• Published: 10/21/2004
• Est. Priority Date: 12/26/2002
• Status: Active Grant

• Current Assignee: Citizen Holdings Co., Ltd.
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Togashi, Seigo
• Granted Patent: US 7,221,417 B2
• Time in Patent Office: Days
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133516 Methods for their manufacture, e.g. printing, electro-deposition or photolithography
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate

Abstract

A liquid crystal display device comprises: first and second transparent substrates; a liquid crystal that is enclosed between the first and second transparent substrates; a first color filter that is formed on either the first or second transparent substrate; a light reflective layer that has a plurality of openings and that is formed on the second transparent substrate toward the liquid crystal; and a second color filter that is formed on the second transparent substrate on the side opposite to the liquid crystal. The second color filter is fabricated by forming a layer of a color photosensitive material such as a photosensitive emulsion and illuminating and coloring this layer by light transmitting through the first color filter using the reflective layer as an exposure mask. As a result, a second color filter, that has a color dot pattern the same as that of the first color filter, is formed by one exposure and developing process.

Claims

1. A liquid crystal display device, comprising:

first and second transparent substrates;

a liquid crystal that is enclosed between said first and second transparent substrates;

a first color filter that is formed on either said first or second transparent substrate;

a light reflective layer that has a plurality of openings and that is formed on said second transparent substrate toward the liquid crystal; and

a second color filter that is formed on said second transparent substrate on the side opposite to said liquid crystal.

2. A liquid crystal display device according to claim 1, wherein said second color filter is formed by illuminating and coloring a color photosensitive material applied on said second transparent substrate on the side opposite to said liquid crystal by light transmitting through said first color filter and by using said reflective layer as an exposure mask.

3. A liquid crystal display device according to claim 1, wherein said first color filter is formed on said light reflective layer of said second substrate.

4. A liquid crystal display device according to claim 1, wherein said first and second color filters have substantially equal optical densities.

5. A liquid crystal display device according to claim 1, wherein said first color filter is formed of a plurality of dots comprised of colors of red, green and blue and the center of each dot of said first color filter agrees with the center of said openings of said light reflective layer.

6. A liquid crystal display device according to claim 1, wherein said color photosensitive material comprises a photosensitive emulsion.

7. A liquid crystal display device according to claim 1, wherein a backlight device is disposed below a surface of said second transparent substrate and on the side opposite to said liquid crystal.

8. A method for manufacturing a liquid crystal display device, comprising the steps of:

forming a reflective layer having a plurality of openings and then a first color filter on a second transparent substrate, sequentially;

applying a color photosensitive material on a surface of said second transparent substrate on the side opposite to that on which said reflective layer is formed;

forming a second color filter that has a color dot matrix pattern same as that of said first color filter by illuminating said color photosensitive material from above said first color filter through the openings of said reflective layer;

disposing a first transparent substrate opposed to the surface of said second transparent substrate on which said first color filter is formed; and

filling a liquid crystal between said first and second transparent substrates.

11. A method for manufacturing a liquid crystal display device according to claim 8, wherein said first color filter is formed by a photolithography, a printing, an electrodeposition or an inkjet method.

12. A method for manufacturing a liquid crystal display device according to claim 8, wherein said color photosensitive material is a photosensitive emulsion and the step of forming said second color filter comprises the step of developing said photosensitive emulsion that has been exposed.

9. A method for manufacturing a liquid crystal display device, comprising the steps of:

forming a reflective layer having a plurality of openings and then a first color filter on a second transparent substrate sequentially;

disposing a first transparent substrate through a sealing member opposite to, and above, a surface of said second transparent substrate on which said reflective layer and first color filter are formed;

applying a color photosensitive material on a surface of said second transparent substrate on the side opposite to that on which said first color filter is formed;

forming a second color filter by illuminating said color photosensitive material from above said first transparent substrate through said first color filter, said openings provided on said reflective layer and said second transparent substrate and coloring the material; and

filling a liquid crystal between said first and second transparent substrates.

13. A method for manufacturing a liquid crystal display device according to claim 9, wherein said first color filter is formed by a photolithography, a printing, an electrodeposition or an inkjet method.

14. A method for manufacturing a liquid crystal display device according to claim 9, wherein said color photosensitive material is a photosensitive emulsion and the step of forming said second color filter comprises the step of developing said photosensitive emulsion that has been exposed.

10. A method for manufacturing a liquid crystal display device, comprising the steps of:

forming a reflective layer having a plurality of openings and then a first color filter on a second transparent substrate sequentially;

disposing a first transparent substrate through a sealing member opposite to and above a surface of said second transparent substrate on which said reflective layer and first color filter are formed;

filling a liquid crystal between said first and second transparent substrates;

applying a color photosensitive material to a surface of said second transparent substrate on the side opposite to said liquid crystal; and

forming a second color filter by illuminating said color photosensitive material from above said first transparent substrate through said liquid crystal, said first color filter, said openings provided on said reflective layer and said second transparent substrate and coloring the material.

15. A method for manufacturing a liquid crystal display device according to claim 10, wherein said first color filter is formed by either a photolithography, printing, electrodeposition or inkjet method.

16. A method for manufacturing a liquid crystal display device according to claim 10, wherein said color photosensitive material is a photosensitive emulsion and the step of forming said second color filter comprises the step of developing said photosensitive emulsion that has been exposed.