Backlight unit and display device including backlight unit

• US 9,740,047 B2
• Filed: 10/30/2015
• Issued: 08/22/2017
• Est. Priority Date: 10/31/2014
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Oh, Sewon, Kim, Eunseok
• Primary Examiner(s): Guharay, Karabi
• Application Number:
  US14/928,621
• Publication Number:
  US 20160123555A1
• Time in Patent Office: 662 Days
• Field of Search: 349 58
• CPC Class Codes: F21V 7/04 Optical design
• 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 1/133608 including particular frames or supporting means
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity

Abstract

A backlight unit is discussed, which includes a frame including a bottom and a sidewall extending from the bottom; at least one substrate located on the frame, and a plurality of light sources mounted on the at least one substrate; and a reflecting sheet located on the at least one substrate, wherein the reflecting sheet includes: a first sheet part located on the bottom, the first sheet part including a plurality of holes corresponding to the plurality of the light sources, and a plurality of first dots; and a second sheet part extended from the first sheet, the second sheet part including a plurality of second dots, wherein the plurality of first dots are positioned adjacent to at least one of the plurality of holes.

Claims

1. A backlight unit comprising:

a frame including a bottom and a sidewall extending from the bottom;

at least one substrate located on the frame, and a plurality of light sources mounted on the at least one substrate; and

a reflecting sheet located on the at least one substrate,

wherein the reflecting sheet comprises;

a first sheet part located on the bottom, the first sheet part including an outer area having a plurality of outermost holes and an inner area having a plurality of inner holes corresponding to the plurality of the light sources;

a second sheet part extended from the first sheet part;

a plurality of first dot areas on the first sheet part, and respectively having a ring-shaped dot area being adjacent to and aligned with at least one of the outermost holes; and

a plurality of second dot areas on the second sheet part,

wherein the respective ring-shaped dot areas are only arranged on some of the outermost holes.

2. The backlight unit of claim 1, wherein at least one of the inner holes includes the ring-shaped dot area.

3. The backlight unit of claim 1, wherein sizes of the plurality of first dot areas are the same as each other.

4. The backlight unit of claim 1, wherein the first dot areas have dots of different sizes.

5. The backlight unit of claim 1, wherein the ring-shaped dot areas surround respective remaining outermost holes excluding at least one of the outermost holes adjacent to a corner of the reflecting sheet.

6. The backlight unit of claim 1, wherein, in the outer area, first holes adjacent to a first side of the reflecting sheet are symmetric with second holes adjacent to a third side of the reflecting sheet.

7. The backlight unit of claim 1, wherein dot sizes of the plurality of first dot areas are the same as each other and dot densities of the plurality of first dot areas are the same as each other.

8. The backlight unit of claim 1, wherein at least one of dot sizes and dot densities of the first dot areas are different from each other.

9. The backlight unit of claim 1, wherein the at least one substrate comprises a plurality of substrates, and

wherein the reflecting sheet further comprises at least one cut part corresponding to at least one connection portion between the plurality of the substrates.

10. The backlight unit of claim 1, wherein areas between adjacent first dot areas are absent of dots.

11. The backlight unit of claim 1, wherein a first dot area of the plurality of first dot areas is located between the at least one of the outermost holes and the second dots and is aligned with a center axis of the at least one of the outermost holes.

12. The backlight unit of claim 1, wherein a first dot area of the plurality of first dot areas forms a ring shape or an oval ring-shape.

13. The backlight unit of claim 1, wherein non-dot areas exist between adjacent first dot areas, and

wherein the non-dot areas are aligned with a mid portion between adjacent outermost holes.

14. The backlight unit of claim 1, wherein the ring-shaped first dot areas are disposed adjacent to respective ones of the outermost holes excluding corner outermost holes.