Lighting unit and liquid crystal display device including the lighting unit

• US 20030016205A1
• Filed: 07/17/2002
• Published: 01/23/2003
• Est. Priority Date: 07/19/2001
• 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: Shiomi, Makoto, Kawabata, Masae
• Granted Patent: US 6,870,525 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133608 including particular frames or supporting means
• CPC Class Codes: G09G 2310/0232 Special driving of display border areas
• 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 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• 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
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

A lighting unit includes a reflector, a plurality of light-emitting elements and a controller. The light-emitting elements are respectively provided on the reflector for a plurality of light-emitting regions. The controller supplies a periodic drive signal to each of the light-emitting elements, thereby defining a state of the light-emitting element. The lighting unit illuminates a display panel including a light modulating layer with light that has been emitted from the light-emitting elements. The controller supplies drive signals of substantially different types to at least two of the light-emitting elements.

Claims

1. A lighting unit comprising:

a reflector;

a plurality of light-emitting elements, which are respectively provided on the reflector for a plurality of light-emitting regions; and

a controller for supplying a periodic drive signal to each of the light-emitting elements, thereby defining a state of the light-emitting element,

wherein the lighting unit illuminates a display panel including a light modulating layer with light that has been emitted from the light-emitting elements, and

wherein the controller supplies drive signals of substantially different types to at least two of the light-emitting elements.

2. The lighting unit of claim 1, further comprising at least one partition on the reflector, the light-emitting regions being defined by the at least one partition.

3. The lighting unit of claim 1, wherein the controller supplies a drive signal, having first and second signal intensities within one period, to each of the light-emitting elements, the light-emitting element being controlled to change into a first state responsive to the drive signal having the first signal intensity and into a second state responsive to the drive signal having the second signal intensity, respectively, the second state having an emission intensity lower than that of the first state.

4. The lighting unit of claim 3, wherein the controller controls the light-emitting elements to the first or second state at mutually different points of times.

5. The lighting unit of claim 3, wherein the second state is a zero-luminance state.

6. The lighting unit of claim 3, wherein the second state is a reduced-luminance state.

7. The lighting unit of claim 3, wherein the controller supplies drive signals, which have the first signal intensity for mutually different percentages of the one period thereof, to the at least two light-emitting elements, respectively.

8. The lighting unit of claim 3, wherein the controller supplies drive signals, having mutually different maximum signal intensities, to the at least two light-emitting elements, respectively.

17. The lighting unit of claim 2, wherein the at least one partition is elongated in a predetermined direction.

9. A lighting unit comprising:

a reflector;

at least one partition, which is provided on the reflector to define a plurality of light-emitting regions;

a plurality of light-emitting elements, which are respectively provided on the reflector for the light-emitting regions;

a controller for supplying a drive signal to each of the light-emitting elements, thereby defining a state of the light-emitting element; and

a plurality of detectors, which are respectively provided for the light-emitting regions to detect luminances of the light-emitting regions.

10. The lighting unit of claim 9, wherein the controller changes the drive signals to be supplied to the light-emitting elements in accordance with outputs of the detectors.

11. The lighting unit of claim 9, wherein the controller supplies a drive signal, having first and second signal intensities within one period, to each of the light-emitting elements, the light-emitting element being controlled to change into a first state responsive to the drive signal having the first signal intensity and into a second state responsive to the drive signal having the second signal intensity, respectively, the second state having an emission intensity lower than that of the first state.

12. The lighting unit of claim 11, wherein the controller controls the light-emitting elements to the first or second state at mutually different points of times.

13. The lighting unit of claim 11, wherein the second state is a zero-luminance state.

14. The lighting unit of claim 11, wherein the second state is a reduced-luminance state.

15. The lighting unit of claim 11, wherein the controller supplies drive signals, which have the first signal intensity for mutually different percentages of the one period thereof, to at least two of the light-emitting elements, respectively.

16. The lighting unit of claim 11, wherein the controller supplies drive signals, having mutually different maximum signal intensities, to at least two of the light-emitting elements, respectively.

18. A liquid crystal display device comprising:

a liquid crystal panel that includes a pair of substrates and a liquid crystal layer sandwiched between the substrates; and

the lighting unit of claim 17, which is provided behind the liquid crystal panel,

wherein multiple gate lines are arranged substantially parallelly to each other on one of the two substrates, and

wherein a direction in which the gate lines extend is substantially parallel to a direction in which the at least one partition extends.

19. The lighting unit of claim 9, wherein the at least one partition is elongated in a predetermined direction.

20. A liquid crystal display device comprising:

a liquid crystal panel that includes a pair of substrates and a liquid crystal layer sandwiched between the substrates; and

the lighting unit of claim 19, which is provided behind the liquid crystal panel,

wherein multiple gate lines are arranged substantially parallelly to each other on one of the two substrates, and

wherein a direction in which the gate lines extend is substantially parallel to a direction in which the at least one partition extends.