Illuminating device with primary color LED and fluorescent light sources, and liquid crystal display device

• US 7,810,979 B2
• Filed: 06/02/2005
• Issued: 10/12/2010
• Est. Priority Date: 06/02/2004
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Oku, Takashi
• Primary Examiner(s): Negron; Ismael
• Application Number:
  US11/143,115
• Publication Number:
  US 20050269560A1
• Time in Patent Office: 1,958 Days
• Field of Search: 362/613, 362/228, 362/231, 362/601, 362/611, 362/614, 362/97.3, 362/240, 362/246, 362/249.02, 349/68
• US Class Current: 362/613
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: H05B 35/00 Electric light sources using a combination of different types of light generation

Abstract

An illumination device including a first light source for emitting light of a first primary color, a second light source for emitting light of a second primary color, and a third light source for emitting light of a third primary color, wherein the first light source is a light emitting diode, the second light source is a fluorescent tube, and the third light source is either a light emitting diode or a fluorescent tube. The illumination device generates white light by mixing the light emitted by the first, second and third light sources. A liquid crystal panel is illuminated with the white light generated by the illumination device.

Claims

1. An illuminating device comprising:

a first light source, including a plurality of light emitting diodes, for emitting light of a wavelength band showing a first primary color;

a second light source, including a blue fluorescent tube, for emitting light of a wavelength band showing a second primary color that predominantly includes light substantially within a blue wavelength band;

a third light source, including a green fluorescent tube for emitting a light of a wavelength band showing a third primary color that is substantially within a green wavelength band;

an optical waveguide for mixing light emitted from said first, second and third light sources to generate a white light; and

a diffusion member that diffuses the white light.

2. The illuminating device according to claim 1, further comprising:

wherein the optical waveguide guides a light incident from an end face and reflecting from one entire main surface toward said diffusion member,

wherein at least the first light source is disposed on one end face of the optical waveguide and the second light source is disposed on another end face of the optical waveguide perpendicular to said one end face where the first light source is disposed,

the first primary color light emitted from the first light source, the second primary color light emitted from the second light source, and the third primary color light emitted from the third light source are incident on the optical waveguide, the optical waveguide guides the incident first primary color light, the second primary color light and the third primary color light while fully reflecting the incident lights to mix the colors and generate the white light, and emits the generated white light from one entire main surface.

3. The illuminating device according to claim 1, wherein the first primary color is a red color, and the first light source is a plurality of red light emitting diodes for emitting a light of a wavelength band showing a red color.

4. The illuminating device according to claim 1, wherein the first, second and third light sources are disposed so as to face the optical waveguide.

5. The illuminating device according to claim 1, wherein the first, second and third light sources are disposed in a substantially identical plane.

6. An illuminating device comprising:

a first light source, including a plurality of light emitting diodes, for emitting light of a wavelength band showing a first primary color that predominantly includes light substantially within a red wavelength band;

a second light source, including a blue fluorescent tube, for emitting light of a wavelength band showing a second primary color that predominantly includes light substantially within a blue wavelength band;

a third light source, including a plurality of green light emitting diodes for emitting light of a wavelength band showing a third primary color that predominantly includes light substantially within a green wavelength band;

a color mixer, separate from fluorescent tubes, for mixing light of the first primary color and the third primary color to a light with a yellow wavelength band; and

an optical waveguide for mixing light emitted from said second light source and said color mixer to generate a white light.

7. The illuminating device according to claim 6, wherein

the optical waveguide guides a light incident from an end face and reflecting from one entire main surface toward a diffusion member,

wherein at least the first light source is disposed on one end face of the optical waveguide and the second light source is disposed on another end face of the optical waveguide perpendicular to said one end face where the first light source is disposed,

the first primary color light emitted from the first light source, the second primary color light emitted from the second light source, and the third primary color light emitted from the third light source are incident on the optical waveguide, the optical waveguide guides the incident first primary color light, the second primary color light and the third primary color light while fully reflecting the incident lights to mix the colors and generate the white light, and emits the generated white light from one entire main surface.

8. The illuminating device according to claim 6, wherein the first, second and third light sources are disposed so as to face the optical waveguide.

9. The illuminating device according to claim 6, wherein the first, second and third light sources are disposed in a substantially identical plane.

10. A liquid crystal display device having a transmission type liquid crystal panel, and an illuminating device for illuminating the liquid crystal panel from one main surface side, wherein the illuminating device comprises:

a first light source for emitting light of a wavelength band showing a first primary color;

a second light source for emitting light of a wavelength band showing a second primary color that predominantly includes light substantially within a blue wavelength band; and

a third light source for emitting light of a wavelength band showing a third primary color, where

the first light source is a plurality of light emitting diodes,

the second light source is a blue fluorescent tube,

the third light source is green fluorescent tube for emitting a third primary color that is green, and

an optical waveguide for mixing together light emitted from the first light source, the second light source, and the third light source,

wherein the illuminating device generates a white light by mixing the light of the wavelength band showing the first primary color the light of the wavelength band showing the second primary color and the light of the wavelength band showing the third primary color and illuminates the liquid crystal panel with the generated white light.

11. The liquid crystal display device according to claim 10, wherein

the optical waveguide guides the light incident from the end face while fully reflecting the light and emitting the light from one entire main surface,

the first light source, the second light source and the third light source are disposed on the end face of the optical waveguide, and

the first primary color light emitted from the first light source, the second primary color light emitted from the second light source, and the third primary color light emitted from the third light source are incident on the optical waveguide from the end face, the optical waveguide guides the incident first primary color light, the second primary color light and the third primary color light while fully reflecting the incident lights to mix the colors and generate a white color, and emits the generated white color from one entire main surface.

12. A liquid crystal display device having a transmission type liquid crystal panel, and an illuminating device for illuminating the liquid crystal panel from one main surface side, wherein the illuminating device comprises:

a first light source, including a plurality of light emitting diodes, for emitting light of a wavelength band showing a first primary color that predominantly includes light substantially within a red wavelength band; and

a second light source, including a blue fluorescent tube, for emitting light of a wavelength band showing a second primary color that predominantly includes light substantially within a blue wavelength band; and

a third light source, including a plurality of light emitting diodes, for emitting light of a wavelength band showing a third primary color that predominantly includes light substantially within a green wavelength band; and

a color mixer, separate from fluorescent tubes, that mixes light emitted from the first light source and light emitted from the third light source to produce light of a yellow color, and

an optical waveguide for mixing together light emitted from the second light source and the color mixer,

wherein the illuminating device generates a white light by mixing the light of the wavelength band showing the first primary color, and the light of the wavelength band showing the second primary color and the light of the wavelength band showing the third primary color, after having been mixed in the color mixer, to illuminate the liquid crystal panel with the generated white light.

13. The liquid crystal display device according to claim 12, wherein

the illuminating device includes a optical waveguide for guiding the light incident from the end face while fully reflecting the light and emitting the light from one entire main surface, the first light source, the second light source and the third light source are disposed on the end face of the optical waveguide, and

the first primary color light emitted from the first light source, the second primary color light emitted from the second light source, and the third primary color light emitted from the third light source are incident on the optical waveguide from the end face, the optical waveguide guides the incident first primary color light, the second primary color light and the third primary color light while fully reflecting the incident lights to mix the colors and generate a white color, and emits the generated white color from one entire main surface.

14. The illuminating device according to claim 12, wherein the first, second and third light sources are disposed so as to face the optical waveguide.

15. The illuminating device according to claim 12, wherein the first, second and third light sources are disposed in a substantially identical plane.