LIGHTING SYSTEM AND DISPLAY DEVICE EQUIPPED WITH THE SAME

• US 20100134395A1
• Filed: 04/16/2008
• Published: 06/03/2010
• Est. Priority Date: 04/20/2007
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Takata, Yoshiki
• Application Number:
  US12/596,742
• Publication Number:
  US 20100134395A1
• Time in Patent Office: Days
• US Class Current: 345/89
• CPC Class Codes: G02F 1/133604 with lamps
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 1/133622 Colour sequential illumination
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/2022 using sub-frames
• 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 display apparatus that can perform even a high quality moving picture display and provides improved color purity, and an illumination device used in the display apparatus are provided. The display apparatus includes: an illumination device (3) that includes a first light source (31G) that emits light of a first color and a second light source (31RB) that emits light of a second color complementary to the first color; a gate driver (24) that sequentially selects each of scanning lines GL at a cycle of 0.5 frames; a source driver (23) that, at a first half of one frame time period, writes a data signal into each of pixels of the first color, and at a latter half thereof, writes a data signal into each of pixels of the other two colors; and a switch circuit (26) that, at the first half of one frame time period, switches on the first light source while switching off the second light source, and at the latter half of the time period, switches on the second light source while switching off the first light source.

Claims

1. An illumination device used as a backlight of a display apparatus, comprising:

a first light source that emits light of a first color; and

a second light source that emits light of a second color complementary to the first color,

wherein each of the first light source and the second light source is a fluorescent tube having a cold cathode or a hot cathode,

an amount of light emitted by the first light source is smaller than an amount of light emitted by the second light source, and

the first light source and the second light source can be controlled so as to be switched on independently of each other.

2. The illumination device according to claim 1,

wherein a plurality of the first light sources and a plurality of the second light sources are provided and arranged so as to alternate with each other one by one or in sets of a plural number of the first or second light sources.

3. The illumination device according to claim 1,

wherein an amount of electric power supplied to the first light source is smaller than an amount of electric power supplied to the second light source.

4. The illumination device according to any claim 1,

wherein an amount of electric current fed through the first light source is smaller than an amount of electric current fed through the second light source.

5. The illumination device according to claim 1,

wherein the first light source has an inner diameter larger than an inner diameter of the second light source.

6. The illumination device according to claim 1,

wherein a gas pressure inside the first light source is higher than a gas pressure inside the second light source.

7. The illumination device according to claim 1,

wherein the light of the first color has a spectrum principally in a wavelength region of green, and

the light of the second color has a spectrum principally in wavelength regions of red and blue.

10. The illumination device according to claim 1,

wherein the light of the first color has a spectrum principally in a wavelength region of blue, and

the light of the second color has a spectrum principally in wavelength regions of red and green.

8-9. -9. (canceled)

11. A display apparatus, comprising:

a display element that includes;

scanning lines and data lines that are arranged in a matrix form;

a switching element that is connected to each of the scanning lines and a corresponding one of the data lines;

a pixel portion that performs a gradation display in accordance with a data signal written from the corresponding one of the data lines when the switching element is brought to an ON state based on a signal of the each of the scanning lines; and

color filters that are arranged so as to correspond to the pixel portions and include at least filters of three colors that exhibit a white color when mixed;

an illumination device that outputs plane-shaped light to the display element and includes a first light source that emits light of a first color that is one of the three colors and a second light source that emits light of a second color complementary to the first color, and in which each of the first light source and the second light source is a fluorescent tube having a cold cathode or a hot cathode, and an amount of light emitted by the first light source is smaller than an amount of light emitted by the second light source;

a scanning line driving portion that sequentially supplies a selection signal to each of the scanning lines at a cycle of half a time period in which one image is displayed in the display element;

a data line driving portion that, at one of a first half and a latter half of the time period in which one image is displayed in the display element, supplies a data signal to be written into each in a group of pixel portions among the pixel portions that corresponds to the color filter of the first color to a corresponding one of the data lines, and at an other of the first half and the latter half of the time period, supplies a data signal to be written into each in groups of pixel portions among the pixel portions that correspond respectively to the color filters of two colors among the three colors other than the first color to a corresponding one of the data lines; and

a light source driving portion that, at the one of the first half and the latter half of the time period in which one image is displayed in the display element, switches on the first light source while switching off the second light source, and at the other of the first half and the latter half of the time period, switches on the second light source while switching off the first light source.

12. The display apparatus according to claim 11,

wherein a plurality of the first light sources and a plurality of the second light sources are provided and arranged so as to alternate with each other one by one or in sets of a plural number of the first or second light sources.

13. The display apparatus according to claim 11,

wherein an amount of electric power supplied to the first light source is smaller than an amount of electric power supplied to the second light source.

14. The display apparatus according to claim 11,

wherein an amount of electric current fed through the first light source is smaller than an amount of electric current fed through the second light source.

15. The display apparatus according to claim 11,

wherein the first light source has an inner diameter larger than an inner diameter of the second light source.

16. The display apparatus according to claim 11,

wherein a gas pressure inside the first light source is higher than a gas pressure inside the second light source.

17. The display apparatus according to claim 11,

wherein the light of the first color has a spectrum principally in a wavelength region of green, and

the light of the second color has a spectrum principally in wavelength regions of red and blue.

20. The display apparatus according to claim 11,

wherein the light of the first color has a spectrum principally in a wavelength region of blue, and

the light of the second color has a spectrum principally in wavelength regions of red and green.

21. The display apparatus according to claim 11,

wherein at one of the first half and the latter half of the time period in which one image is displayed in the display element, the data line driving portion supplies a data signal for causing each in the groups of pixel portions among the pixel portions that correspond respectively to the color filters of two colors among the three colors other than the first color to perform a black gradation display to a corresponding one of the data lines, and at an other of the first half and the latter half of the time period in which one image is displayed in the display element, the data line driving portion supplies a data signal for causing each in the group of pixel portions among the pixel portions that corresponds to the color filter of the first color to perform a black gradation display to a corresponding one of the data lines.

22. The display apparatus according to claim 11,

wherein in the illumination device, a plurality of the first light sources and a plurality of the second light sources are provided so that a longitudinal direction of the first and second light sources is parallel to an extending direction of the scanning lines, and

at one of the first half and the latter half of the time period in which one image is displayed in the display element, the light source driving portion switches on the plurality of the first light sources successively in an order of arrangement so as to be synchronized with an application of the selection signal to each of the scanning lines, and at an other of the first half and the latter half of the time period in which one image is displayed in the display element, the light source driving portion switches on the plurality of the second light sources successively in an order of arrangement so as to be synchronized with the application of the selection signal to each of the scanning lines.

23. The display apparatus according to claim 11,

wherein an interpolation data generating portion further is provided that generates a data signal to be supplied to one of the data lines at the latter half of the time period in which one image is displayed in the display element by performing interpolation between a data signal to be supplied to the one of the data lines in said time period and a data signal to be supplied to the one of the data lines in a time period subsequent to said time period.

18-19. -19. (canceled)