Display device

• US 8,531,387 B2
• Filed: 05/04/2011
• Issued: 09/10/2013
• Est. Priority Date: 08/27/2009
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Park, Sangtae, Kim, Minchul, Kim, Sungwoo, Jung, Bupsung, Seo, Buwan, Ko, Myounghwa, Bae, Seungchoon, Kwon, Soonhyung
• Primary Examiner(s): SHERMAN, STEPHEN G
• Application Number:
  US13/100,950
• Publication Number:
  US 20110205256A1
• Time in Patent Office: 860 Days
• Field of Search: 345 87-104, 345/204, 345/690, 349 61- 71
• US Class Current: 345/102
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity
• CPC Class Codes: G02F 1/133612 Electrical details
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 2202/28 Adhesive materials or arrangements
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix

Abstract

According to an embodiment of the present invention, a display device includes a backlight unit that is divided into a plurality of blocks and is driven by the divided blocks, and includes at least one optical assembly, a display panel positioned over the backlight unit, a controller that outputs local dimming values corresponding to brightness of the blocks of the backlight unit, in accordance with an image displayed in the display panel, and a BLU driver that controls brightness of the blocks of the backlight unit using the local dimming values.

Claims

1. A display device comprising:

a backlight unit that is divided into a plurality of blocks and is driven by the divided blocks, and includes a plurality of optical assemblies;

a display panel positioned over the backlight unit;

a controller that outputs local dimming values corresponding to brightness of the blocks of the backlight unit, in accordance with an image displayed in the display panel; and

a BLU driver that controls brightness of the blocks of the backlight unit using the local dimming values,

wherein each of the plurality of optical assemblies includes;

a first layer;

a plurality of light sources that are formed on the first layer and emit light; and

a reflective layer that is disposed above the first layer,

wherein the BLU driver receives the local dimming values and outputs a plurality of driving signals, and the driving signals control the brightness of two or more blocks among the blocks of the backlight unit respectively,

wherein each of the plurality of optical assemblies is combinable with the other, and the backlight unit is formed by combining the plurality of optical assemblies, and

wherein a light emitting surface of one of the light sources is formed in a direction crossing the first layer, and at least two of the light sources emit light in different directions from each other.

2. The display device according to claim 1, wherein the display panel is divided into a plurality of regions and the controller adjusts the brightness of the blocks in the backlight unit which correspond to the regions, in accordance with luminance of the regions of the display panel.

3. The display device according to claim 2, wherein the controller includes:

an image analyzing unit that measures an average picture level of an image; and

a brightness determining unit that determines the local dimming values for each block of the backlight unit, using the measured average picture level of the image.

4. The display device according to claim 3, wherein the brightness determining unit determines the brightness of a light source included in the blocks of the backlight unit which correspond to a first region, using the average picture level of the image and an average picture level of the first region in the display panel.

5. The display device according to claim 3, further comprising:

a pixel compensator that adjust a luminance level of an input image signal, using the measured average picture level of the image; and

a panel driver that drives the display panel in response to the image signal outputted from the pixel compensator.

6. The display device according to claim 1, wherein the BLU driver receives the local dimming values for each block from the controller, using SPI (Serial Peripheral Interface) communication.

7. The display device according to claim 1, wherein the first layer is a substrate with the light sources mounted thereon.

8. The display device according to claim 1, wherein the each of the plurality of optical assemblies further includes a second layer disposed above the first layer to cover the light sources, and

wherein the second layer includes silicon-based or acryl-based resin.

9. The display device according to claim 1, wherein the each of the plurality of optical assemblies further includes a second layer disposed above the first layer to cover the light sources, and

wherein the second layer includes a plurality of dispersed particles.

10. The display device according to claim 1, wherein the each of the plurality of optical assemblies further includes a second layer disposed above the first layer to cover the light sources, and

wherein the display device further comprises light-shielding patterns that are formed on the second layer to correspond to positions of the light sources.

11. The display device according to claim 10, wherein at least one of the light-shielding patterns has a reflectance that decreases outwardly from a portion of the at least one of the light-shielding patterns corresponding to a center portion of a corresponding light source.

12. The display device according to claim 10, wherein a center of at least one of the light-shielding patterns is disposed a predetermined distance from a center of the corresponding light source in a first direction.

13. The display device according to claim 1, wherein the each of the plurality of optical assemblies further includes a second layer disposed above the first layer to cover the light sources, and

wherein the second layer is 0.1 to 4.5 mm thick.

14. The display device according to claim 1, wherein the light sources included in the each of the plurality of optical assemblies are driven in two or more divided blocks.

15. The display device according to claim 1, wherein the light sources included in a first light source array and a light sources included in the second light source array emit light in different directions from each other.

16. The display device according to claim 1, wherein the each of the plurality of optical assemblies further includes a second layer disposed above the first layer to cover the light sources,

wherein the display device further comprises at least one reflection layer between the first layer and the second layer, and

wherein the reflection layer includes at least a first portion and a second portion having different reflectances.

17. The display device according to claim 16, further comprising:

a plurality of patterns formed on the reflection layer,

wherein the reflection layer includes an area in which a density of the patterns increases.

18. A display device, comprising:

a backlight unit that is divided into a plurality of blocks and is driven by the divided blocks, and includes a plurality of optical assemblies;

a display panel positioned over the backlight unit;

a first controller that outputs local dimming values corresponding to brightness of the blocks of the backlight unit, in accordance with an image displayed in the display panel; and

a BLU driver that controls brightness of the blocks of the backlight unit using the local dimming values,

wherein each of the plurality of optical assemblies includes;

a first layer;

a plurality of light sources that are formed on the first layer and emit light; and

a reflective layer that is disposed above the first layers,

wherein the BLU driver includes a driving unit, and the driving unit includes a second controller that receives local dimming values from the first controller and a plurality of driver ICs that output driving signals for controlling the brightness of the two or more blocks respectively,

wherein each of the plurality of optical assemblies is combinable with the other, and the backlight unit is formed by combining the plurality of optical assemblies, and

wherein a light emitting surface of one of the light sources is formed in a direction crossing the first layer, and at least two of the light sources emit light in different directions from each other.

19. The display device according to claim 18, wherein the second controller outputs the local dimming values inputted in parallel, and then transmits the local dimming values for each block to the driver ICs.

20. The display device according to claim 18, wherein the driver ICs transmit driving signal to the light sources included in n blocks, using n channels, and n represents a number.

21. The display device according to claim 18, wherein the BLU driver includes a plurality of the driving units.

22. The display device according to claim 18, wherein the light sources included in the each of the plurality of optical assemblies are driven in two or more divided blocks.