Liquid crystal display device having improved cooling efficiency

• US 10,191,328 B2
• Filed: 11/11/2014
• Issued: 01/29/2019
• Est. Priority Date: 06/13/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Sung Ki, Kim, Won-nyun
• Primary Examiner(s): Nguyen, Lauren
• Application Number:
  US14/538,053
• Publication Number:
  US 20150062489A1
• Time in Patent Office: 1,540 Days
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0085 Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64
• CPC Class Codes: G02F 1/133382 Heating or cooling of liquid crystal cells other than for activation, e.g. circuits or arrangements for temperature control, stabilisation or uniform distribution over the cell
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133628 with cooling means

Abstract

A liquid crystal display device includes a liquid crystal display panel, a light guide plate disposed on a lower part of the liquid crystal display panel, an LED circuit substrate disposed along at least one side of the light guide plate to accommodate an LED on a front surface thereof, and a heat transmission member having a first part that faces a lower surface of the light guide plate and a second part that is extendedly bent from the first part and faces the LED circuit substrate.

Claims

1. A backlight unit, comprising:

a light guide element to guide light to a liquid crystal display panel;

a circuit substrate;

a plurality of light emitting diodes (LEDs) on the circuit substrate to emit the light toward the light guide element;

a first heat transmission member formed with both a first portion and a second portion, the first portion formed along a direction opposite a longitudinal axis of the light guide element and facing at least one of the plurality of LEDs and the circuit substrate and the second portion integrally extending from a longitudinal end portion of the first portion along a direction opposite a longitudinal axis of the first portion and parallel to the light guide element;

a second heat transmission member configured to be coupled to the first heat transmission member, the second heat transmission member formed to accommodate the light guide element, the circuit substrate and the plurality of LEDs and the second heat transmission member having a first portion and a second portion, the first portion and the second portion of the second heat transmission member being disposed parallel to the first portion and the second portion of the first heat transmission member, respectively;

an intervening element disposed between the circuit substrate and the first portion of the first heat transmission member to receive heat from the plurality of LEDs through the circuit substrate and transmit the received heat to the second heat transmission member through the first heat transmission member; and

a reflection element disposed between the light guide element and the second portion of the first heat transmission member to reflect the light toward the liquid crystal display panel through the light guide element,

wherein the first heat transmission member and the second heat transmission member are made from a metallic material, and

wherein a surface area of the second portion of the second heat transmission member which is parallel to the light guide element is larger than a corresponding surface area of the second portion of the first heat transmission member which integrally extends from the longitudinal end portion of the first portion and is parallel to the light guide element.

2. The backlight unit of claim 1, wherein the first heat transmission member has an L-shape and is disposed along a side portion of the light guide element.

3. The backlight unit of claim 1, wherein a section of the first heat transmission member has an L-shape.

4. The backlight unit of claim 1, wherein the first portion of the first heat transmission member is disposed along a side portion of the light guide element, and

the circuit substrate faces the first portion of the first heat transmission member via the intervening element.

5. The backlight unit of claim 4, wherein the second portion of the first heat transmission member further extends from and is bent with respect to the first portion and faces at least one of the light guide element and the reflection element.

6. The backlight unit of claim 4, wherein the second portion of the first heat transmission member extends from and is bent with respect to the first portion and disposed along a bottom portion of the light guide element to contact the reflection element.

7. The backlight unit of claim 1, wherein the first heat transmission member is in thermal contact with at least one of the plurality of LEDs and the circuit substrate.

8. The backlight unit of claim 1, wherein the intervening element has a thin plate shape.

9. The backlight unit of claim 1, wherein the intervening element has a stripe-shape.

10. The backlight unit of claim 1, wherein the intervening element has a shape of the circuit substrate.

11. The backlight unit of claim 1, wherein the intervening element adheres the circuit substrate to the first heat transmission member.

12. The backlight unit of claim 1, wherein the intervening element is in thermal contact with the circuit substrate and the first heat transmission member.

13. The backlight unit of claim 1, wherein the intervening element has a form of a thermally conductive medium having a high heat transfer coefficient.

14. The backlight unit of claim 1, wherein the second heat transmission member contacts at least a portion of the first heat transmission member.

15. The backlight unit of claim 1, wherein the first heat transmission member and the second heat transmission member are an inner heat transmission member and an outer second heat transmission member, respectively.

16. The backlight unit of claim 1, wherein a size of the reflection element is larger than a size of the light guide element.

17. The backlight unit of claim 1, wherein the plurality of LEDs and the light guide element are spaced at a predetermined interval.

18. The backlight unit of claim 1, wherein the circuit substrate is made of metal.

19. The backlight unit of claim 1, wherein at least one of the first heat transmission member and the second heat transmission member is made of metal.

20. The backlight unit of claim 1, wherein the light guide element indirectly contacts the first heat transmission member.

21. A display device, comprising:

a liquid crystal display panel;

a light guide element to guide light to the liquid crystal display panel;

a circuit substrate;

a plurality of light emitting diodes (LEDs) on the circuit substrate to emit the light toward the light guide element;

a first heat transmission member formed with both a first portion and a second portion, wherein;

the first portion is disposed along a direction opposite a longitudinal axis of the light guide element; and

the second portion is disposed along a bottom portion of the light guide element and which extends from and is bent with respect to the first portion, the second portion integrally extending from a longitudinal end portion of the first portion along a direction opposite a longitudinal axis of the first portion and parallel to the light guide element;

a second heat transmission member configured to be coupled to the first heat transmission member, the second heat transmission member formed to accommodate the light guide element, the circuit substrate and the plurality of LEDs and the second heat transmission member having a first portion and a second portion, the first portion and the second portion of the second heat transmission member being disposed parallel to the first portion and the second portion of the first heat transmission member, respectively;

an intervening element disposed between the circuit substrate and the first portion of the first heat transmission member to receive heat from the plurality of LEDs through the circuit substrate and transmit the received heat to the second heat transmission member through the first heat transmission member; and

a reflection element disposed between the light guide element and the second portion of the first heat transmission member to reflect the light toward the liquid crystal display panel through the light guide element,

wherein the first heat transmission member and the second heat transmission member are made from a metallic material, and

wherein a surface area of the second portion of the second heat transmission member which is parallel to the light guide element is larger than a corresponding surface area of the second portion of the first heat transmission member which integrally extends from the longitudinal end portion of the first portion and is parallel to the light guide element.

22. The display device of claim 21, wherein the second portion of the first heat transmission member contacts the reflection element.

23. The display device of claim 21, wherein a section of the first heat transmission member has an L-shape.

24. The display device of claim 21, wherein the intervening element has a thin plate shape.

25. The display device of claim 21, wherein the intervening element adheres the circuit substrate to the first portion of the first heat transmission member.

26. The display device of claim 21, wherein the intervening element has a shape of the circuit substrate.

27. The display device of claim 21, wherein the second heat transmission member has an L-shape and contacts the first heat transmission member.

28. The display device of claim 21, wherein the first heat transmission member and the second heat transmission member are an inner heat transmission member and an outer second heat transmission member, respectively.

29. The display device of claim 21, wherein a size of the reflection element is larger than a size of the light guide element.

30. The display device of claim 21, wherein the plurality of LEDs and the light guide element are spaced at a predetermined interval.

31. An apparatus comprising:

a display device, the display device comprising;

a liquid crystal display panel;

a light guide element to guide light to the liquid crystal display panel;

a circuit substrate;

a plurality of light emitting diodes (LEDs) on the circuit substrate to emit the light toward the light guide element;

a first heat transmission member formed with both a first portion and a second portion wherein;

the first portion disposed along a direction opposite a longitudinal axis of the light guide element; and

the second portion disposed along a bottom portion of the light guide element and which extends from and is bent with respect to the first portion, the second portion integrally extending from a longitudinal end portion of the first portion along a direction opposite a longitudinal axis of the first portion and parallel to the light guide element;

a second heat transmission member configured to be coupled to the first heat transmission member, the second heat transmission member formed to accommodate the light guide element, the circuit substrate and the plurality of LEDs and the second heat transmission member having a first portion and a second portion, the first portion and the second portion of the second heat transmission member being disposed parallel to the first portion and the second portion of the first heat transmission member, respectively;

an intervening element disposed between the circuit substrate and the first portion of the first heat transmission member to receive heat from the plurality of LEDs through the circuit substrate and transmit the received heat to the second heat transmission member through the first heat transmission member; and

a reflection element disposed between the light guide element and the second portion of the first heat transmission member to reflect the light toward the liquid crystal display panel through the light guide element,

wherein the first heat transmission member and the second heat transmission member are made from a metallic material, and

wherein a surface area of the second portion of the second heat transmission member which is parallel to the light guide element is larger than a corresponding surface area of the second portion of the first heat transmission member which integrally extends from the longitudinal end portion of the first portion and is parallel to the light guide element.

32. The apparatus of claim 31, wherein the second portion of the first heat transmission member contacts the reflection element.

33. The apparatus of claim 31, wherein the intervening element adheres the circuit substrate to the first portion of the first heat transmission member.

34. The apparatus of claim 31, wherein the intervening element has a shape of the circuit substrate.

35. The apparatus of claim 31, wherein the second heat transmission member has an L-shape and contacts the first heat transmission member.

36. The apparatus of claim 31, wherein a size of the reflection element is larger than a size of the light guide element.

37. The apparatus of claim 31, wherein the plurality of LEDs and the light guide element are spaced at a predetermined interval.

38. A backlight unit, comprising:

a light guide element to guide light to a liquid crystal display panel;

a circuit substrate;

a plurality of light emitting diodes (LEDs) on the circuit substrate to emit the light toward the light guide element;

a heat transmission member receiving the light guide element, the circuit substrate and the plurality of LEDs, the heat transmission member being formed with both a first portion facing at least one of the plurality of LEDs and the circuit substrate and a second portion, the heat transmission member comprising;

a first heat transmission member including the first portion which is formed along a direction opposite a longitudinal axis of the light guide element and the second portion integrally extending from a longitudinal end portion of the first portion along a direction opposite a longitudinal axis of the first portion and parallel to the light guide element,

a second heat transmission member having a first portion and a second portion, the first portion and the second portion of the second heat transmission member being disposed parallel to the first portion and the second portion of the first heat transmission member, respectively;

an intervening element disposed between the circuit substrate and the first portion of the first heat transmission member, the intervening element being configured to receive heat from the plurality of LEDs through the circuit substrate and transmit the received heat to the second heat transmission member through the first heat transmission member; and

a reflection element disposed between the light guide element and the second portion of the first heat transmission member to reflect the light toward the liquid crystal display panel through the light guide element,

wherein a surface area of the second portion of the second heat transmission member which is parallel to the light guide element is larger than a corresponding surface area of the second portion of the first heat transmission member which integrally extends from the longitudinal end portion of the first portion and is parallel to the light guide element.

39. The backlight unit of claim 38, wherein the first portion of the heat transmission member is disposed along a side portion of the light guide element and faces the circuit substrate via the intervening element.

40. The backlight unit of claim 39, wherein the heat transmission member further has a second portion which extends from and is bent with respect to the first portion and faces at least one of the light guide element and the reflection element.

41. The backlight unit of claim 38, wherein the intervening element has a thin plate shape.

42. The backlight unit of claim 38, wherein the intervening element has a shape of the circuit substrate.

43. The backlight unit of claim 38, wherein the intervening element adheres the circuit substrate to the heat transmission member.

44. The backlight unit of claim 38, wherein a size of the reflection element is larger than a size of the light guide element.

45. The backlight unit of claim 38, wherein the plurality of LEDs and the light guide element are spaced at a predetermined interval.

46. The backlight unit of claim 38, wherein the circuit substrate is made of metal.

47. A backlight unit, comprising:

a light guide element to guide light to a liquid crystal display panel;

a circuit substrate;

a plurality of light emitting diodes (LEDs) on the circuit substrate to emit the light toward the light guide element;

a metallic heat transmission member receiving the light guide element, the circuit substrate and the plurality of LEDs, the metallic heat transmission member being formed with both a first portion facing at least one of the plurality of LEDs and the circuit substrate and a second portion, the metallic heat transmission member comprising;

a first heat transmission member including the first portion which is formed along a direction opposite a longitudinal axis of the light guide element and the second portion integrally extending from a longitudinal end portion of the first portion along a direction opposite a longitudinal axis of the first portion and parallel to the light guide element,

a second heat transmission member having a first portion and a second portion, the first portion and the second portion of the second heat transmission member being disposed parallel to the first portion and the second portion of the first heat transmission member, respectively;

a thermally heat conductive layer disposed between the circuit substrate and the first portion of the metallic heat transmission member, the thermally heat conductive layer being configured to receive heat from the plurality of LEDs through the circuit substrate and transmit the received heat to the second heat transmission member through the first heat transmission member; and

a reflection element disposed between the light guide element and the second portion of the first heat transmission member to reflect the light toward the liquid crystal display panel through the light guide element, and

a surface area of the second portion of the second heat transmission member which is parallel to the light guide element is larger than a corresponding surface area of the second portion of the first heat transmission member which integrally extends from the longitudinal end portion of the first portion and is parallel to the light guide element.

48. The backlight unit of claim 47, wherein the first portion of the heat transmission member is disposed along a side portion of the light guide element and faces the circuit substrate via the intervening element.

49. The backlight unit of claim 48, wherein the heat transmission member further has a second portion which extends from and is bent with respect to the first portion and faces at least one of the light guide element and the reflection element.

50. The backlight unit of claim 47, wherein the intervening element has a thin plate shape.

51. The backlight unit of claim 47, wherein the intervening element has a shape of the circuit substrate.

52. The backlight unit of claim 47, wherein the intervening element adheres the circuit substrate to the heat transmission member.

53. The backlight unit of claim 47, wherein a size of the reflection element is larger than a size of the light guide element.

54. The backlight unit of claim 47, wherein the plurality of LEDs and the light guide element are spaced at a predetermined interval.

55. The backlight unit of claim 47, wherein the circuit substrate is made of metal.