Liquid crystal display device with a plurality of diffusion reflectors

• US 7,345,720 B2
• Filed: 05/27/2004
• Issued: 03/18/2008
• Est. Priority Date: 06/04/2003
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Noguchi, Koji
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): Kim; Richard H
• Application Number:
  US10/855,156
• Publication Number:
  US 20040263727A1
• Time in Patent Office: 1,391 Days
• Field of Search: 349113-114, 349/106
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133555 Transflectors

Abstract

A transflective liquid crystal display device, improved in luminance and contrast to improve the viewability and the color reproducibility in color display better, having scattering diffusion reflectors formed at a first transparent substrate and a transparent window formed at the first transparent substrate surrounding the diffusion reflectors in an unevenness distribution. Since the easily regular reflecting regions around the diffusion reflectors are formed with the transparent window, both the reflectance of diffused and reflected front light and the transmittance of back light can be improved.

Claims

1. A liquid crystal display device comprising:

a first transparent substrate;

a second transparent substrate facing said first transparent substrate in spaced-apart relationship;

a color filter formed at said second transparent substrate and passing light; and

a liquid crystal layer between said first transparent substrate and said second transparent substrate,

wherein,

said first transparent substrate comprises a plurality of diffusion reflectors projecting from a surface of said first transparent substrate for diffusing and reflecting front light incident from said second transparent substrate side via said color filter and said liquid crystal layer, said diffusion reflectors being formed in an uneven distribution across the surface of the first transparent substrate and being spaced apart from each other along said first transparent substrate,

said first transparent substrate provides a transparent window for passing light surrounding said diffusion reflectors at portions from which said diffusion reflectors do not project,

said color filter is formed with color filter apertures formed so as to pass light at positions facing said diffusion reflectors, and

each one of said plurality of diffusion reflectors is formed by a first reflecting underlayer formed on said first transparent substrate in said uneven distribution, a second reflecting underlayer formed on the first reflecting underlayer and having a curved upper surface, and a projecting curved third reflecting layer formed on the second reflecting underlayer.

2. A liquid crystal display device as set forth in claim 1, wherein a first distance of said liquid crystal layer between said second transparent substrate and said diffusion reflectors is smaller than a second distance of said liquid crystal layer between said second transparent substrate and said transparent window.

3. A liquid crystal display device as set forth in claim 1, wherein said first distance is a half of said second distance.

4. A liquid crystal display device as set forth in claim 1, wherein said diffusion reflectors are formed at parts with diffusion reflection apertures so as to pass light.

5. A liquid crystal display device as set forth in claim 1, further comprising:

another color filter formed at said first transparent substrate and passing back light incident from a direction facing said front light such that the plurality of diffusion reflectors is formed between the color filter formed at said second transparent substrate and the another color filter formed at said first transparent substrate.

6. A liquid crystal display device comprising a plurality of pixels, each of which comprises:

a first transparent substrate or portion thereof;

a second transparent substrate or portion thereof facing said first transparent substrate in spaced-apart relationship;

a color filter formed at said second transparent substrate and passing light; and

a liquid crystal layer between said first transparent substrate and said second transparent substrate,

wherein,

said first transparent substrate or portion thereof comprises a plurality of diffusion reflectors projecting from a surface of said first transparent substrate for diffusing and reflecting front light incident from said second transparent substrate side via said liquid crystal layer, said diffusion reflectors being formed in an uneven distribution across the surface of the first transparent substrate and being spaced apart from each other along said first transparent substrate,

said first transparent substrate or portion thereof provides a transparent window for passing light surrounding said diffusion reflectors at portions from which said diffusion reflector do not project,

said color filter is formed with color filter apertures formed so as to pass light at positions facing said diffusion reflectors, and

each one of said plurality of diffusion reflectors is formed by a first reflecting underlayer formed on said first transparent substrate in said uneven distribution, a second reflecting underlayer formed on the first reflecting underlayer and having a curved upper surface, and a projecting curved third reflecting layer formed on the second reflecting underlayer.

7. A liquid crystal display device as set forth in claim 6, further comprising:

another color filter formed at said first transparent substrate and passing back light incident from a direction facing said front light, such that the plurality of diffusion reflectors is formed between the color filter formed at said second transparent substrate and the another color filter formed at said first transparent substrate.