Optical assembly, backlight unit and display apparatus thereof

• US 8,672,498 B2
• Filed: 02/02/2010
• Issued: 03/18/2014
• Est. Priority Date: 08/27/2009
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Bae, Seung Choon, Kim, Sung Woo, Kwon, Soon Hyung, Jung, Bup Sung, Park, Sang Tae, Seo, Bu Wan
• Primary Examiner(s): SEMBER, THOMAS M
• Application Number:
  US12/698,886
• Publication Number:
  US 20110050735A1
• Time in Patent Office: 1,505 Days
• Field of Search: 362/29, 362/30, 362 971- 974, 362/297, 362/346, 362/237, 362/240, 362/241, 362/247, 362/249.02, 362/249.06, 362/23.12, 362/23.13, 362/23.19, 362/23.2
• US Class Current: 362/97.1
• 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: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity
• CPC Class Codes: G02F 1/133613 characterized by the sequence of light sources

Abstract

The present invention relates to an optical assembly, a backlight unit, and a display apparatus thereof. According to an embodiment of the present invention, an optical assembly includes a first layer, a plurality of light sources disposed over the first layer, a second layer that is disposed above the first layer and covering the plurality of light sources, and a pattern layer disposed above or in the second layer, wherein the pattern layer includes a plurality of patterns disposed at positions substantially corresponding to the light sources.

Claims

1. An optical assembly, comprising:

a first layer;

a plurality of light sources disposed over the first layer;

a second layer that is disposed above the first layer and covering the plurality of light sources; and

a pattern layer disposed above or in the second layer,

wherein the pattern layer includes a plurality of patterns, which are respectively corresponding to the plurality of light sources and are formed with a different material from the second layer by depositing, printing, or coating,

each of the plurality of patterns corresponds to one of the plurality of light sources that is located closest to said each of the plurality of patterns,

at least one of the light sources has a light emitting surface that faces a lateral direction and emits light to the side,

a center of at least one of the patterns is disposed a predetermined distance from a center of the corresponding closest light source in the lateral direction, and

a width of each of the plurality of patterns in the lateral direction is greater than a width of the corresponding closest light source in the lateral direction.

2. The optical assembly according to claim 1, wherein at least one of the light sources emits the light to the side at a predetermined orientation angle.

3. The optical assembly according to claim 1, wherein at least one of the patterns included in the pattern layer reflects at least part of light emitted from the plurality of light sources.

4. The optical assembly according to claim 1, wherein at least one of the patterns is formed on a transparent film and includes a plurality of dots.

5. The optical assembly according to claim 4, wherein a density of the plurality of dots for the at least one of the patterns decreases outwardly from a portion of the at least one of the patterns.

6. The optical assembly according to claim 5, wherein the portion of the at least one of the patterns corresponds to a center portion of the corresponding light source.

7. The optical assembly according to claim 1, wherein at least one of the patterns has a reflectance that decreases outwardly from a portion of the at least one of the patterns corresponding to a center portion of the corresponding light source.

8. The optical assembly according to claim 1, wherein at least one of the patterns has a portion that transmits at least part of a light emitted from the corresponding light source.

9. The optical assembly according to claim 1, wherein an outer edge portion of the at least one of the patterns is aligned with a light emitting surface of said corresponding light source.

10. The optical assembly according to claim 1, wherein the at least one of the patterns in its entirety is disposed a predetermined distance from a light emitting surface of said corresponding light source in the first direction.

11. The optical assembly according to claim 1, wherein an opening ratio of the pattern layer is at least 70%.

12. The optical assembly according to claim 1, wherein at least one of the patterns has one of a circle shape, a cylinder shape, an oval shape and a rectangle shape.

13. The optical assembly according to claim 1, wherein at least one of the patterns includes at least one of metal and metal oxide.

14. The optical assembly according to claim 1, wherein at least one of the patterns includes titanium dioxide (TiO₂).

15. The optical assembly according to claim 1, wherein at least one of the patterns is formed with pattern portions disposed above the corresponding light source, the pattern portions having a convex shape, a concave shape, a semicircle shape, or a triangle shape.

16. The optical assembly according to claim 1, wherein the second layer includes a plurality of particles.

17. The optical assembly according to claim 1, further comprising:

a third layer disposed above the second layer and the pattern layer,

wherein the third layer includes a plurality of particles.

18. The optical assembly according to claim 1, wherein a thickness of the second layer is approximately 0.1 to 4.5 mm.

19. The optical assembly according to claim 1, wherein the second layer encapsulates the plurality of light sources on the first layer.

20. A backlight unit, comprising:

at least one optical assembly of claim 1.

21. A display apparatus, comprising:

a backlight unit including at least one optical assembly of claim 1; and

a display panel positioned above the backlight unit,

wherein the backlight unit is divided into a plurality of blocks and is selectively drivable for the divided blocks.

22. The display apparatus according to claim 21, wherein the light sources of the backlight unit are disposed to correspond to a display region of the display panel.

23. The display apparatus according to claim 21, wherein the display panel is divided into a plurality of areas, and a luminance of light emitted from one of the blocks of the backlight unit corresponding to one of the areas is adjusted depending on a gray level peak value or a color coordinate signal of the areas.

24. An optical assembly, comprising:

a first layer;

a plurality of light sources disposed over the first layer; and

a second layer disposed above the first layer and covering the plurality of light sources, the second layer including a plurality of patterns respectively corresponding to the plurality of light sources for selectively reflecting light emitted from the plurality of light sources,

wherein each of the plurality of patterns corresponds to one of the plurality of light sources that is located closest to said each of the plurality of patterns,

the plurality of patterns are formed by depositing, printing, or coating,

at least one of the light sources has a light emitting surface that faces a lateral direction and emits light to the side,

a center of at least one of the patterns is disposed a predetermined distance from a center of the corresponding closest light source in the lateral direction, and

a width of each of the plurality of patterns in the lateral direction is greater than a width of the corresponding closest light source in the lateral direction.

25. The optical assembly according to claim 24, wherein the plurality of patterns are formed on the second layer or in the second layer.

26. The optical assembly according to claim 24, wherein a thickness of the second layer is approximately 0.1 to 4.5 mm.