Liquid crystal display

• US 20050212992A1
• Filed: 01/12/2005
• Published: 09/29/2005
• Est. Priority Date: 03/29/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Nakanishi, Kunifumi
• Granted Patent: US 7,570,319 B2
• Time in Patent Office: Days
• US Class Current: 349/61
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white

Abstract

A primary object of the present invention is to provide a liquid crystal display device being capable of displaying an image with large color reappearance area and a genuine hue and chroma, while controlling a displacement of white chromaticity caused by changes of viewing angles. The device includes: a light source; a back light controlling a luminous intensity distribution from the light source; and a liquid crystal display panel controlling a transmission rate of light from the back light. The maximum intensity of a light emitting spectrum of the back light is in a range of 510 nm to 530 nm in a wavelength range of 500 nm to 550 nm, wherein the liquid crystal panel includes a red color filter transmitting red components, a green color filter transmitting green components and a blue color filter transmitting blue components, and a transmit spectrum of the green color filter includes a half value of a maximum transmitting rate of 500 nm to 590 nm in a wavelength range. The change of the transmit spectrum between viewing angle of 0° and 60° is within 20% from front direction in a wavelength range of 500 nm to 600 nm.

Claims

1. A liquid crystal display device comprising:

a light source;

a back light controlling a luminous intensity distribution from said light source; and

a liquid crystal display comprising liquid crystal display panel;

wherein said liquid crystal display panel is provided in a light emitting side of said back light and controls a transmission rate from said back light;

wherein a maximum intensity of a light emitting spectrum of said back light is in a range of 510 nm to 530 nm in a wavelength range of 500 nm to 550 nm;

wherein said liquid crystal panel comprises a red color filter, which transmits red components, a green color filter, which transmits green components and a blue color filter, which transmits blue components, and a transmit spectrum of said green color filter comprises a half value of a maximum transmitting rate of 500 nm to 590 nm in a wavelength range.

3. The liquid crystal display device of claim 1, wherein in said liquid crystal panel has a relative change of the transmit spectrum within 20% from front direction, between a viewing angle change of 0°

and 60°

in a wavelength range of 500 nm to 600 nm.

5. The liquid crystal display device of claim 3, wherein in said liquid crystal display panel controls a transmittance through applying a lateral electric field to liquid crystal by an electrode being located under a substrate and parallel rotates liquid crystal molecules on the substrate.

7. The liquid crystal display device of claim 1, wherein said liquid crystal display comprises the light source in said back light;

said light source being a cold cathode tube.

9. The liquid crystal display device of claim 1, wherein said liquid crystal display comprises the light source in said back light;

said light source being a light emitting diode.

11. The liquid crystal display device of claim 3, wherein said liquid crystal display panel employs a vertical alignment mode while aligning liquid crystal molecule vertically to the two glass substrates, alignment of the liquid crystal molecules is controlled through applied voltage between said two glass substrates.

13. The liquid crystal display panel of claim 3, wherein said liquid crystal display employs optically compensated birefringence mode while bent aligned molecules being between the two glass substrates, alignment of the liquid crystal molecules is controlled through applied voltage between said two glass substrates.

15. The liquid crystal display device of claim 1, wherein the light source of said back light is a thermal cathode tube.

17. The liquid crystal display device of claim 1, wherein the light source of said back light is an electroluminescence.

19. The liquid crystal display device of claim 1, wherein the light source of said back light is a fluorescent display tube.

2. A liquid crystal display device comprising:

a light source;

a back light controlling a luminous intensity distribution of light from said light source; and

a liquid crystal display comprising liquid crystal display panel;

wherein said liquid crystal panel is provided in a light emitting side and controls a transmission rate from said back light;

wherein a maximum intensity of a light emitting spectrum of said back light is in a range of 510 nm to 520 nm in a wavelength range of 500 nm to 550 nm;

wherein said liquid crystal panel comprises a red color filter which transmits red components, a green color filter which transmits green components and a blue color filter which transmits blue components, and a transmit spectrum of said green color filter comprises a half value of a maximum transmitting rate of 500 nm to 590 nm in a wavelength range.

4. The liquid crystal display device of claim 2, wherein in said liquid crystal panel has a relative change of the transmit spectrum within 20% from front direction, between a viewing angle change of 0°

and 60°

in a wavelength range of 500 nm to 600 nm.

6. The liquid crystal display device of claim 4, wherein in said liquid crystal display panel controls a transmittance through applying a lateral electric field to liquid crystal by an electrode being located under a substrate and parallel rotates liquid crystal molecules on the substrate.

8. The liquid crystal display device of claim 2, wherein said liquid crystal display comprises the light source in said back light;

said light source being a cold cathode tube.

10. The liquid crystal display device of claim 2, wherein said liquid crystal display comprises the light source in said back light;

said light source being a light emitting diode.

12. The liquid crystal display device of claim 4, wherein said liquid crystal display panel employs a vertical alignment mode while aligning liquid crystal molecule vertically to the two glass substrates, alignment of the liquid crystal molecules is controlled through applied voltage between said two glass substrates.

14. The liquid crystal display panel of claim 4, wherein said liquid crystal display employs optically compensated birefringence mode while bent aligned molecules being between the two glass substrates, alignment of the liquid crystal molecules is controlled through applied voltage between said two glass substrates.

16. The liquid crystal display device of claim 2, wherein the light source of said back light is a thermal cathode tube.

18. The liquid crystal display device of claim 2, wherein the light source of said back light is an electroluminescence.

20. The liquid crystal display device of claim 2, wherein the light source of said back light is a fluorescent display tube.