Backlight unit and display device including backlight unit

• US 10,365,513 B2
• Filed: 01/11/2019
• Issued: 07/30/2019
• 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:
  US16/245,692
• Publication Number:
  US 20190163017A1
• Time in Patent Office: 200 Days
• 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 display device includes a display panel; a light source; a frame at a rear of the display panel; and a reflecting sheet between the display panel and the frame, the reflecting sheet having a rectangular shape with a first long side, a second long side opposite the first long side, a first short side adjacent to the first long side and the second long side, and a second short side opposite the first short side. Further, the reflecting sheet includes a first horizontal area along the first long side, and a first vertical area along the first short side. In addition, at least one of the first horizontal area and the first vertical area includes a first area including a plurality of first dots, a second area including a plurality of second dots and a third area including a plurality of third dots.

Claims

1. A display device comprising:

a display panel;

a light source;

a frame at a rear of the display panel; and

a reflecting sheet between the display panel and the frame, the reflecting sheet having a rectangular shape with a first long side, a second long side opposite the first long side, a first short side adjacent to the first long side and the second long side, and a second short side opposite the first short side,

wherein the reflecting sheet includes a first horizontal area along the first long side, and a first vertical area along the first short side,

wherein at least one of the first horizontal area and the first vertical area includes;

a first area including a plurality of first dots, a second area including a plurality of second dots and a third area including a plurality of third dots,

wherein the second area is between the first area and the third area,

wherein a size of the first dots in the first area is the same, a size of the second dots in the second area is the same, and a size of the third dots in the third area is the same, and

wherein the size of the first dots in the first area is greater than the size of the second dots in the second area, and the size of the second dots in the second area is greater than the size of the third dots in the third area.

2. The display device of claim 1, wherein the first area of the first horizontal area is closest to the first long side of the reflecting sheet, the second area of the first horizontal area is farther from the first long side of the reflecting sheet than the first area, and the third area of the first horizontal area is the farthest from the first long side of the reflecting sheet among the first area, the second area and the third area of the first horizontal area.

3. The display device of claim 1, wherein the first area of the first vertical area is a closest area to the first short side of the reflecting sheet, the second area of the first vertical area is farther from the first short side of the reflecting sheet than the first area, and the third area of the first vertical area is the farthest area from the first short side of the reflecting sheet among the first area, the second area and the third area of the first vertical area.

4. The display device of claim 1, wherein the first vertical area further includes a fourth area including a plurality of fourth dots next to the third area, and the fourth area is the farthest area from the first short side of the reflecting sheet among the first area, the second area, the third area, and the fourth area of the first vertical area.

5. The display device of claim 4, wherein a size of the fourth dots in the fourth area is the same, and the size of the fourth dots in the fourth area is smaller than the size of the third dots in the third area.

6. The display device of claim 4, wherein a width of the third area is greater than a width of the second area of the first vertical area.

7. The display device of claim 6, wherein the width of the third area is greatest among the first area, the second area, the third area, and the fourth area of the first vertical area.

8. The display device of claim 1, wherein a width of the first horizontal area is different from a width of the first vertical area.

9. The display device of claim 8, wherein the width of the first vertical area is greater than the width of the first horizontal area.

10. The display device of claim 1, wherein the frame includes a bottom and a sidewall extending from the bottom,

wherein the reflecting sheet includes a first sheet part and a second sheet part extending from the first sheet part toward the sidewall of the frame, and

wherein the first horizontal area and the first vertical area are formed in the second sheet part of the reflecting sheet.

11. The display device of claim 1, wherein the size of the first, second and third dots gradually changes in a direction from an outside of the reflecting sheet to an inside of the reflecting sheet.

12. The display device of claim 1, wherein a border line between the first area and the second area of the first horizontal area is straight, and

wherein a border line between the second area and the third area of the first horizontal area is straight.

13. The display device of claim 12, wherein a border line between the first area and the second area of the first vertical area is straight, and

wherein a border line between the second area and the third area of the first vertical area is straight.

14. The display device of claim 1, wherein the first vertical area has a different shape than the first horizontal area.

15. The display device of claim 1, wherein the reflecting sheet includes a second horizontal area along the second long side, and a second vertical area along the second short side,

wherein at least one of the second horizontal area and the second vertical area includes:

a first area including a plurality of first dots, a second area including a plurality of second dots and a third area including a plurality of third dots, and

wherein the second area is between the first area and the third area.

16. The display device of claim 1, wherein a first distance between the first area of the first horizontal area and the first area of the first vertical area is shorter than a second distance between the second area of the first horizontal area and the second area of the first vertical area.

17. The display device of claim 16, wherein the second distance is shorter than a third distance between the third area of the first horizontal area and the third area of the first vertical area.

18. The display device of claim 1, wherein the frame includes a bottom and a sidewall extending from the bottom,

wherein the reflecting sheet includes a first sheet part and a second sheet part extending from the first sheet part toward the sidewall of the frame, and

wherein the first horizontal dot area, the second horizontal dot area and the third horizontal dot area are formed in a horizontal part of the second sheet part, and

wherein the first vertical dot area, the second vertical dot area and the third vertical dot area are formed in a vertical part of the second sheet part.

19. A display device comprising:

a display panel;

a light source;

a frame at a rear of the display panel; and

a reflecting sheet between the display panel and the frame, the reflecting sheet having a rectangular shape with a first long side, a second long side opposite the first long side, a first short side adjacent to the first long side and the second long side, and a second short side opposite the first short side,

wherein the reflecting sheet includes;

a first horizontal dot area, a second horizontal dot area and a third horizontal dot area along the first long side, wherein the first horizontal dot area is closest to the first long side of the reflecting sheet, the second horizontal dot area is farther from the first long side of the reflecting sheet than the first horizontal dot area, and the third horizontal dot area is the farthest from the first long side of the reflecting sheet among the first horizontal dot area, the second horizontal dot area and the third horizontal dot area; and

a first vertical dot area, a second vertical dot area and a third vertical dot area along the first short side, wherein the first vertical dot area is closest to the first short side of the reflecting sheet, the second vertical dot area is farther from the first short side of the reflecting sheet than the first vertical dot area, and the third vertical dot area is the farthest from the first short side of the reflecting sheet among the first vertical dot area, the second vertical dot area and the third vertical dot area,

wherein a size of dots in the first horizontal dot area is the same, a size of dots in the second horizontal dot area is the same, and a size of dots in the third horizontal dot area is the same,

wherein a size of dots in the first vertical dot area is the same, a size of dots in the second vertical dot area is the same, and a size of dots in the third vertical dot area is the same,

wherein the size of the dots in the first horizontal dot area is greater than the size of the dots in the second horizontal dot area, and the size of the dots in the second horizontal dot area is greater than the size of the dots in the third horizontal dot area, and

wherein the size of the dots in the first vertical dot area is greater than the size of the dots in the second vertical dot area, and the size of the dots in the second vertical dot area is greater than the size of the dots in the third vertical dot area.

20. The display device of claim 19, wherein the reflecting sheet further includes a fourth vertical dot area next to the third vertical dot area, and the fourth vertical dot area is the farthest area from the first short side of the reflecting sheet among the first vertical dot area, the second vertical dot area, the third vertical dot area, and the fourth vertical dot area.

21. The display device of claim 20, wherein a size of dots in the fourth vertical dot area is the same, and the size of the dots in the fourth vertical dot area is smaller than the size of the dots in the third vertical dot area.

22. The display device of claim 20, wherein a width of the third vertical dot area is greater than a width of the second vertical dot area.

23. The display device of claim 22, wherein the width of the third vertical dot area is greatest among the first vertical dot area, the second vertical dot area, the third vertical dot area, and the fourth vertical dot area.

24. The display device of claim 19, wherein a width of the first, second and third horizontal dot areas is different from a width of the first, second and third vertical dot areas.

25. The display device of claim 24, wherein a width of the first, second and third vertical dot areas is greater than the width of the first, second and third horizontal dot areas.

26. The display device of claim 19, wherein a size of dots gradually changes from the first horizontal dot area, the second horizontal dot area and the third horizontal dot area in a direction from an outside of the reflecting sheet to an inside of the reflecting sheet, and

wherein a size of the dots gradually changes from the first vertical dot area, the second vertical dot area and the third vertical dot area in a direction from an outside of the reflecting sheet to an inside of the reflecting sheet.

27. The display device of claim 19, wherein a border line between the first horizontal dot area and the second horizontal dot area is straight, and

wherein a border line between the second horizontal dot area and the third horizontal dot area is straight.

28. The display device of claim 27, wherein a border line between the first vertical dot area and the second vertical dot area is straight, and

wherein a border line between the second vertical dot area and the third vertical dot area is straight.

29. The display device of claim 19, wherein a shape of the first, second and third horizontal dot areas is different than a shape of the first, second and third vertical dot areas.

30. The display device of claim 19, wherein the second horizontal dot area is between the first and third horizontal dot areas, and the second vertical dot area is between the first and third vertical dot areas.