Image display device

• US 20030063062A1
• Filed: 03/20/2002
• Published: 04/03/2003
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Yamamoto, Tsunenori, Tsumura, Makoto, Inuduka, Tatsuki
• Granted Patent: US 7,142,188 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines

Abstract

A multi-color display system suppressed in deterioration in resolution and increase in power consumption or deterioration in brightness. The multi-color display system includes n types of spectrum selecting means; m types of light sources each having different spectral distribution; light source controlling means for controlling in a time-division basis emissions from the m types of light sources; color light sources generated by the light source controlling means and the n types of spectrum selecting means, the number of the color light sources being not less than n+1 but not more than n×m; and a light valve for controlling a transmittance or a reflectance in accordance with image information.

Claims

1. An image display device comprising:

n types of spectrum selecting means;

m types of light sources each having different spectral distribution;

light source controlling means for controlling in a time-division basis emissions from the m types of light sources;

color light sources generated by the light source controlling means and the n types of spectrum selecting means, the number of the color light sources being not less than n+1 but not more than n×

m; and

a light valve for controlling a transmittance or a reflectance in accordance with image information.

2. The image display device according to claim 1, wherein in combination the color light sources with the light valve, a shape which is formed by coordinates on a chromaticity diagram for output light, the output light being generated by the display device, is a polygon whose vertex is in the shape of a convexity.

3. The image display device according to claim 1 or claim 2, wherein the spectrum selecting means are color filters each of which is disposed for each of pixels.

4. The image display device according to claim 3, wherein a wavelength band to be selected depending on each of the color filters includes a maximum value of brightness of the light sources, and a band of each of the light sources is narrower than the wavelength band of each of the color filters.

5. The image display device according to any one of claims 1 to 4, further comprising

a function for switching between a mode for lighting all the m types of light sources and a mode for selectively lighting the light sources.

6. The image display device according to claims 1 to 5, wherein the light valve is an active matrix type liquid crystal display device.

7. The image display device according to claim 6, wherein display voltages are written for all the pixels when the m types of light sources for irradiating the active matrix type liquid crystal display device are not lit.

8. The image display device according to claim 7, wherein the liquid crystal display panel has a function of changing display of all the pixels simultaneously.

9. The image display device according to claim 7 or claim 8, further comprising

a memory for storing image data in each of the pixels in the liquid crystal display panel in the format of digitized information obtained by converting a voltage value or multivalue;

and

a strobe function for writing a voltage or a current value to each of the pixels in accordance with the information stored in the memory;

whereby the function of changing display of all the pixels simultaneously is achieved.

10. The image display device according to claim 6, wherein a plurality of array light sources is aligned in a scanning direction for image rewriting of the active matrix type liquid crystal display device, and lighting of the light sources are scrolled in synchronization with the rewrite scanning.

11. The image display device according to any one of claims 1 to 10, wherein a display mode of the liquid crystal is an inplane switching mode.

12. The image display device according to any one of claims 1 to 11, wherein each of the light sources is a laser light source or an emission diode.

13. The image display device according to any one of claims 1 to 11, wherein each of the light sources is a light source that uses an emission generated by irradiating a fluorescent material with ultraviolet rays.

14. The image display device according to any one of claims 1 to 11, wherein a spectral wavelength or a spectral distribution of each of the light sources to be used for image display is controlled based on instructions from a viewer of the image display device, light source information on a location where an image is captured, instructions from a creator of the image, or light source information on a location where the image display device is viewed.