Backlight unit and liquid crystal display device

• US 20070058358A1
• Filed: 09/05/2006
• Published: 03/15/2007
• Est. Priority Date: 09/06/2005
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Moriyasu, Mitsuhiro, Chikazawa, Hideyuki
• Granted Patent: US 7,597,451 B2
• Time in Patent Office: Days
• US Class Current: 362/97.300
• CPC Class Codes: G09G 2310/0221 with use of split matrices G09G3/3644 and G09G3/3666 take precedence
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

[Problems]To provide a backlight unit capable of improving color purity of a prescribed emission color as well as obtaining a uniform emission colors in the entire device, and a liquid crystal display device comprising thereof. [Means for Solving Problems]

Backlight unit B comprises: a LED 13 for compensating emission intensity of red wavelength light of a fluorescent tube 11, being arranged in between each of a plurality of said fluorescent tubes 11 arrayed in up and down directions, and a LED 13a for compensating emission intensity of red wavelength light of a fluorescent tube 11a, being arranged in the outside of each of two fluorescent tubes 11a arranged in the outermost of a plurality of said fluorescent tubes 11.

Claims

1. A backlight unit comprising a first compensating light source for compensating emission intensity of a prescribed wavelength light of a fluorescent tube, being arranged in between each of a plurality of said fluorescent tubes arrayed in a prescribed direction, wherein said backlight unit further comprises a second compensating light source for compensating emission intensity of a prescribed wavelength light of said fluorescent tube, being arranged in the outside of each of two fluorescent tubes arranged in the outermost of said plurality of fluorescent tubes.

2. A backlight unit, according to claim 1, wherein emission intensity of said second compensating light source is lower than emission intensity of said first compensating light source.

3. A backlight unit, according to claim 1, wherein emission intensity of said second compensating light source is nearly half of emission intensity of said first compensating light source.

4. A backlight unit, according to claim 1, wherein said first compensating light source and/or said second compensating light source have a plurality of light-emitting elements arrayed in the longitudinal direction of said fluorescent tube.

5. A backlight unit, according to claim 2, wherein said first compensating light source and/or said second compensating light source have a plurality of light-emitting elements arrayed in the longitudinal direction of said fluorescent tube.

6. A backlight unit, according to claim 3, wherein said first compensating light source and/or said second compensating light source have a plurality of light-emitting elements arrayed in the longitudinal direction of said fluorescent tube.

7. A backlight unit, according to claim 4,

wherein a light source substrate in which said first and second compensating light sources are mounted is constituted to include a plurality of segmented substrates segmented in an array direction of said fluorescent tubes, and

wherein a relation:

X=(L+1)/N is satisfied, provided that L is the number of arrayed said fluorescent tubes, X is the number of light-emitting elements to be arrayed in a direction parallel to an array direction of said fluorescent tubes in said segmented substrate, and N is the number of said segmented substrates.

8. A backlight unit, according to claim 5,

wherein a light source substrate in which said first and second compensating light sources are mounted is constituted to include a plurality of segmented substrates segmented in an array direction of said fluorescent tubes, and

wherein a relation:

X=(L+1)/N is satisfied, provided that L is the number of arrayed said fluorescent tubes, X is the number of light-emitting elements to be arrayed in a direction parallel to an array direction of said fluorescent tubes in said segmented substrate, and N is the number of said segmented substrates.

9. A backlight unit, according to claim 6,

wherein a light source substrate in which said first and second compensating light sources are mounted is constituted to include a plurality of segmented substrates segmented in an array direction of said fluorescent tubes, and

wherein a relation:

X=(L+1)/N is satisfied, provided that L is the number of arrayed said fluorescent tubes, X is the number of light-emitting elements to be arrayed in a direction parallel to an array direction of said fluorescent tubes in said segmented substrate, and N is the number of said segmented substrates.

10. A backlight unit, according to claim 4,

wherein one or a plurality of inverter circuits for driving two of said fluorescent tubes are further comprised,

wherein a light source substrate in which said first and/or second compensating light sources are mounted is constituted to include a plurality of segmented substrates segmented in an array direction of said fluorescent tubes, and

wherein a relation:

X=(2M+1)/N is satisfied, provided that M is the number of said inverter circuits, X is the number of light-emitting elements to be arrayed in a direction parallel to an array direction of said fluorescent tubes in said segmented substrate, and N is the number of said segmented substrates.

11. A backlight unit, according to claim 5,

wherein one or a plurality of inverter circuits for driving two of said fluorescent tubes are further comprised,

wherein a light source substrate in which said first and/or second compensating light sources are mounted is constituted to include a plurality of segmented substrates segmented in an array direction of said fluorescent tubes, and

wherein a relation:

X=(2M+1)/N is satisfied, provided that M is the number of said inverter circuits, X is the number of light-emitting elements to be arrayed in a direction parallel to an array direction of said fluorescent tubes in said segmented substrate, and N is the number of said segmented substrates.

12. A backlight unit, according to claim 6,

wherein one or a plurality of inverter circuits for driving two of said fluorescent tubes are further comprised,

wherein a light source substrate in which said first and/or second compensating light sources are mounted is constituted to include a plurality of segmented substrates segmented in an array direction of said fluorescent tubes, and

wherein a relation:

X=(2M+1)/N is satisfied, provided that M is the number of said inverter circuits, X is the number of light-emitting elements to be arrayed in a direction parallel to an array direction of said fluorescent tubes in said segmented substrate, and N is the number of said segmented substrates.

13. A liquid crystal display device comprising a backlight unit according to claim 1.

14. A liquid crystal display device comprising a backlight unit according to claim 2.

15. A liquid crystal display device comprising a backlight unit according to claim 3.

16. A liquid crystal display device comprising a backlight unit according to claim 4.

17. A liquid crystal display device comprising a backlight unit according to claim 5.

18. A liquid crystal display device comprising a backlight unit according to claim 6.

19. A liquid crystal display device comprising a backlight unit according to claim 7.

20. A liquid crystal display device comprising a backlight unit according to claim 8.