KR101683890B1 - Backlight unit and display appratus having the same - Google Patents

Abstract

The embodiment relates to a backlight unit and a display device having the backlight unit.
A backlight unit according to an embodiment includes a bottom cover having projections and recesses alternately arranged on a bottom surface thereof; A first radiating plate disposed in a concave portion of the bottom cover; A light emitting diode arrayed on one side of the bottom cover, and a second heat dissipation plate contacting the first heat dissipation plate; And a light emitting module for reflecting the light guide plate disposed on the bottom cover.

Description

BACKLIT UNIT AND DISPLAY APPARATUS HAVING THE SAME [0002]

The embodiment relates to a backlight unit and a display device having the same.

As information processing technology has developed, display devices such as LCD, PDP, and AMOLED have been widely used. Of these display devices, the LCD requires a backlight unit capable of generating light in order to display an image.

Embodiments provide a backlight unit having a plurality of heat dissipation plates disposed on a bottom cover and a display device having the same.

Embodiments provide a backlight unit having a plurality of heat dissipation plates having different thermal conductivity to dissipate heat generated from a light emitting module and a display device having the same.

Embodiments provide a backlight unit in which a plurality of heat pipes are arranged obliquely on a bottom cover and a display device having the backlight unit.

A backlight unit according to an embodiment includes a bottom cover; A plurality of first heat dissipation plates disposed on the bottom cover; A light emitting module disposed on at least one side of the bottom cover and including a plurality of light emitting diodes, a substrate on which the plurality of light emitting diodes are arranged, and a second heat dissipating plate to which the substrate is attached and which conducts heat to the first heat dissipation plate; And a light guide plate disposed on the bottom cover.

A display device according to an embodiment includes: a bottom cover; A plurality of first heat dissipation plates disposed on the bottom cover; A light emitting module disposed on at least one side of the bottom cover and including a plurality of light emitting diodes, a substrate on which the plurality of light emitting diodes are arranged, and a second heat dissipating plate to which the substrate is attached and which conducts heat to the first heat dissipation plate; And a backlight unit including a light guide plate disposed on the bottom cover; An optical sheet on the light guide plate; And a display panel on the optical sheet.

The embodiment can improve the heat dissipation efficiency of the light emitting module.

The embodiment can eliminate the thermal problem of the light emitting diode.

The embodiment can improve the heat radiation efficiency in the backlight unit.

The embodiment can secure the reliability and stability of the backlight unit.

1 is an exploded perspective view of a display device according to an embodiment.
Fig. 2 is a partial side sectional view showing the engaged state of Fig. 1. Fig.
3 is a plan view showing a heat pipe arrangement according to the embodiment.
4 is a perspective view illustrating an example of coupling between the heat pipe and the light emitting module according to the embodiment.
5 is a cross-sectional view taken along line I-I 'of FIG.

In the description of the embodiments, it is described that each substrate, frame, sheet, layer or pattern is formed "on" or "under" each substrate, frame, sheet, In the present case, "on" and "under" all reflect plates that are "directly" or "indirectly" formed. In addition, the upper or lower reference of each component is described with reference to the drawings. The size of each component in the drawings may be exaggerated for the sake of explanation and does not mean the size actually applied.

FIG. 1 is an exploded perspective view showing a display device according to an embodiment, and FIG. 2 is a partial side sectional view showing a coupled state of the backlight unit of FIG.

1 and 2, a display device 1 includes a display panel 10 on which an image is displayed, and a backlight unit 20 that provides light to the display panel 10. [

The backlight unit 20 includes a light guide plate 22 for providing a surface light source to the display panel 10, a reflection plate 23 for reflecting the leakage light, a light emitting module 30 for providing light in the edge region, And a bottom cover 40 for forming a lower outer appearance of the display device 1. [

Although not shown, the display device 1 includes a panel supporter for supporting the display panel 10 from the lower side, a tower for supporting the periphery of the display panel 1 and forming a rim of the display device 1, Cover.

Although not shown in detail, the display panel 10 includes a lower substrate 12 and an upper substrate 11 that are bonded together to hold a uniform cell gap so as to face each other, and a liquid crystal layer interposed between the two substrates. Layer (not shown). A plurality of gate lines and a plurality of data lines intersecting the plurality of gate lines are formed on the lower substrate 12. A thin film transistor (TFT) is formed in a crossing region between the gate lines and the data lines . Color filters may be formed on the upper substrate 11. The structure of the display panel 10 is not limited thereto, and the display panel 10 may have various structures. As another example, the lower substrate 12 may include a color filter as well as a thin film transistor. In addition, the display panel 10 may have various structures according to a method of driving the liquid crystal layer.

Although not shown, a gate driving printed circuit board (PCB) for supplying a scan signal to a gate line is formed at an edge of the display panel 10, a data driving printed circuit board (PCB) May be provided.

A polarizing film (not shown) may be disposed on at least one of the upper side and the lower side of the display panel 10. An optical sheet 21 is disposed under the display panel 10 and the optical sheet 21 can be included in the backlight unit 20 and includes at least one prism sheet and / . The optical sheet 21 may be removed, but is not limited thereto.

The diffusing sheet diffuses the incident light evenly, and the diffused light can be converged on the display panel by the prism sheet. Here, the prism sheet may be selectively formed using a horizontal or vertical prism sheet, one or more roughness enhancing films, or the like. The types and the number of the optical sheets 21 may be added or deleted within the technical scope of the embodiments, but the invention is not limited thereto.

The backlight unit 20 is an edge type backlight type and includes a light guide plate 22, a reflection plate 23 below the light guide plate 22 and an edge side light emitting module 30 of the light guide plate 22.

The light emitting modules 30 may be disposed on opposite sides of the bottom cover 40, and the light emitting diodes 34 facing each other may be arranged on the same line or in a jig. However, the light emitting module 30 may be disposed on one side or all sides of the bottom cover 40, but is not limited thereto.

The light emitting module 30 includes a plurality of light emitting diodes 34, a module substrate 32 on which the light emitting diodes 34 are disposed, and a second heat dissipating plate 36.

The plurality of light emitting diodes 34 are arranged at a predetermined pitch, and at least one of the light emitting diodes 34 emits light of at least one color such as white, red, green, and blue. The embodiment may use a light emitting diode that emits light of at least one color or a combination of light emitting diodes that emit a plurality of colors.

The light emitting diodes 34 may be arranged in at least one row, but are not limited thereto. The light emitting diodes 34 mounted on the module substrate 32 may be arranged at regular intervals or may be arranged at irregular intervals.

The light emitting diodes 34 are mounted on the front surface of the module substrate 32. The module substrate 32 may be an FR-4 substrate, a metal substrate (MCPCB), a ceramic substrate, a flexible printed circuit board, or the like. The module substrate 32 may have a long bar shape.

The module substrate 32 may be erected in a direction perpendicular to the bottom surface of the bottom cover 40 and the LED 34 may be disposed on the front surface of the module substrate 32. Here, the module substrate 32 may be disposed parallel to the bottom surface of the bottom cover 40, but the present invention is not limited thereto.

The light guide plate 22 may be formed in a polygonal shape including at least four sides as long as the upper surface and the upper surface of the surface light source are formed, but the present invention is not limited thereto.

The light emitting diodes (34) are arranged to face at least one side of the light guide plate (22). In the following embodiments, the light emitting module 30 including the light emitting diodes 34 is disposed on both sides of the light guide plate 22.

Light is incident on both side surfaces of the light guide plate 22. The light guide plate 22 is made of a transparent material and includes one of acrylic resin such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), and polyethylene naphthalate . The light guide plate 22 may be formed by an extrusion molding method.

A scattering pattern (not shown) may be formed on the upper surface or the lower surface of the light guide plate 22. The scattering pattern is formed in a predetermined pattern to diffuse irregularly incident light, thereby improving light uniformity on the entire surface of the light guide plate 22. A scattering agent may be added to the inside of the light guide plate 22, but the present invention is not limited thereto.

A reflection pattern may be formed on the lower surface of the light guide plate 22, and the reflection pattern may reflect light leaking to the lower portion of the light guide plate 22, which may improve the light efficiency.

A reflection plate 23 may be provided under the light guide plate 22. The light emitted from the light emitting diode 34 is incident on the side surface of the light guide plate 22 and the light incident on the side surface of the light guide plate 22 is guided inside the light guide plate 22. At this time, the light leaked to the reflection plate 23 is reflected by the reflection plate 23, and then is emitted through the upper surface of the light guide plate 22. This is because the light leaked to the lower portion of the light guide plate 22 is re-incident on the light guide plate 22, thereby preventing problems such as lowering of light efficiency, lowering of optical characteristics, and occurrence of dark portions.

2, the reflection plate 23 may be disposed closer to the module substrate 32 than the light guide plate 22. This may reflect light leaked out of the light emitted from the light emitting diode 34 I can do it.

The bottom cover 40 is opened on the upper side and the optical sheet 21, the light guide plate 22 and the reflection plate 23 can be accommodated therein.

A plurality of protrusions 41 may be disposed on the bottom surface of the bottom cover 40 and recesses 42 may be disposed between the plurality of protrusions 41. The plurality of protrusions 41 may be arranged in a direction in which the light emitting diodes 34 are arranged. The projecting portion 41 may be inclined at an angle with respect to the axial direction of the light emitted from the light emitting diode 34 (the X axis direction in FIG. 3) or the vertical axis direction from one side of the bottom cover 40 .

1 and 3, a concave portion 42 and a protruding portion 41 are alternately arranged on the bottom surface of the bottom cover 40. The protruding portion 41 is formed on the bottom surface of the bottom cover 40, That is, the upper surface of the concave portion 42.

The width of the concave portion 42 disposed between the protruding portions 41 may be formed to correspond to the width of the first heat radiation plate 60.

 The recess 42 and the protrusion 41 may be disposed on both sides of the bottom surface of the bottom cover 40 and symmetrical with respect to the X axis of the bottom cover 40.

The projecting portion 41 of the bottom cover 40 may be inclined and the inclined direction may be inclined in the Y-axis direction with respect to the X-axis. The recess 42 and the protrusion 41 may be inclined at an inclination angle? In the range of 3 to 45 degrees with respect to the X axis perpendicular to the inward direction from one side of the bottom cover 40 . The first heat radiation plate 60 coupled to the recess 42 may be disposed further on the inside of the bottom cover 40 than both sides of the bottom cover 40 .

The second heat dissipation plate 36 and the first heat dissipation plate 60 are disposed between the bottom cover 40 and the reflection plate 23.

1, 3, and 4, a first heat dissipating plate 60 is disposed on both sides of the bottom cover 40, and a second heat dissipating plate 36 is disposed on an outer side of the first heat dissipating plate 60. [ .

The first heat dissipation plate 60 is disposed on both sides of the bottom surface of the bottom cover 40 and the second heat dissipation plate 36 is included in the light emitting module 30. The first heat dissipation plate 60 and the second heat dissipation plate 36 are in contact with each other and can radiate heat from the entire surface. The first heat-dissipating plate 60 includes a heat pipe, and the second heat-dissipating plate 36 may include a metal plate having a high thermal conductivity.

The first heat dissipation plate 60 is slantingly coupled to the recess 42 of the bottom cover 40.

A supporting groove 43 is formed in the protrusion 41 of the bottom cover 40 and a fixing plate 45 is coupled to the supporting groove 43. A threaded hole 54 is formed in the support groove 43 and the fixing plate 45 and the fixing plate 45 is fastened to the bottom cover 40 using screws 72 in FIG. The fixing plate 45 fixes and prevents the plurality of first heat dissipating plates 60 coupled to the recesses 42.

A screw hole 51 is formed in a predetermined region of the second heat dissipating plate 36 and the second heat dissipating plate 36 is fastened to the bottom cover 40 using the screw 71. Here, although the screw is used as an example of the fastening member in the embodiment, various fastening means such as a hook and a rivet may be used, but the present invention is not limited thereto.

The engagement of the overlapped portions of the second heat dissipation plate 36 and the first heat dissipation plate 60 by the screws 71 can be made firm.

The heat generated from the light emitting module 30 is conducted to the second heat dissipating plate 36 and the second heat dissipating plate 36 conducts heat to the first heat dissipating plate 60, The one heat-dissipating plate 60 dissipates the conducted heat. Accordingly, heat emitted from the light emitting diode 34 can be effectively dissipated through the second heat dissipation plate 36 and the first heat dissipation plate 60.

The first heat dissipation plate 60 will be described in detail as follows.

The first heat-dissipating plate 60 may be formed of, for example, a heat pipe. The heat pipe includes a fluid filled therein. The heat pipe may have a rectangular plate shape having a longer length in the lateral direction than in the longitudinal direction. Here, the term " lateral direction " refers to a lateral direction when the display device is disposed at a predetermined position, and the longitudinal direction refers to a longitudinal direction. The heat pipes can be arranged in an inclined manner so that the cooling flow can be efficiently performed. For example, the heat pipes are formed to be symmetrical in the left and right direction with respect to the vertical center line, and are arranged to be inclined. The heat pipe is a material having good thermal conductivity and can be used as a metal material such as copper or stainless steel. The fluid is vaporized by the conducted heat and is moved in the opposite direction of the heat pipe by a pressure difference. The fluid may be distilled water, ethanol, methanol or the like, and the fluid material may be appropriately selected depending on the operating temperature. The opposite side of the heat pipe is maintained in a vacuum state, and after the heat of the gas is discharged, it is returned to the fluid through a condensation process. That is, the heat pipe performs heat dissipation (or evaporation) through the surface of the heat pipe while repeating condensation and vaporization. The fluid can be returned by gravitational field, and the heat pipe is arranged at a predetermined slope. That is, the first heat dissipation plate 60 can be used as a convection heat transfer element, and heat generated from the light emitting diode 34 can be dissipated in a natural convection manner without using any additional power.

With the first heat dissipating plate 60 having such a structure, the light generated in the light emitting module 30 is transferred to the plurality of heat pipes. The heat transferred to the heat pipes is cooled in the planar direction of the bottom cover 40 along the heat pipe.

5 is a cross-sectional view taken along line I-I 'of FIG. 4 and 5, the coupling structure of the second heat dissipation plate will be described.

The second heat dissipation plate 36 includes a mount portion 36B, a first support portion 36A, a second support portion 36C, and a heat conduction portion 36D. The mounting portion 36A is disposed perpendicularly to the bottom surface of the bottom cover 40, and the rear surface of the module substrate 32 is attached to the front surface of the mounting portion 36A. The first support portion 36A is bent in the lateral direction of the bottom cover 40 at the upper end of the mounting portion 36B and is coupled to the upper side of the bottom cover 40. [ The first support portion 36A is coupled to the upper side of the bottom cover 40 to reduce the flow of the second heat dissipation plate 36. [

The second support portion 36C is bent in a direction opposite to the bending direction of the first support portion 36A from the mounting portion 36B so as to be in contact with the bottom surface of the bottom cover 40. [ The second support part 36C is in close contact with the bottom surface of the bottom cover 40 to support the light emitting module 30 and conduct thermal conduction through the bottom cover 40. [

The heat conduction part 36D extends from the second support part 36C in a stepped manner toward the inner side of the bottom cover 40 and is disposed on the first heat radiation plate 60. [ The heat conduction part 36D overlaps the first heat radiation plate 60 and may be bonded to the first heat radiation plate 60 by an adhesive member 75. [ The adhesive member 75 may include a thermally conductive grease or a thermally conductive tape as an adhesive having high thermal conductivity.

A plurality of first heat radiation plates 60 are disposed on the bottom surface of the bottom cover 40 of the backlight unit 20 so as to be transmitted from the light emitting module 30 disposed in the edge area of the bottom cover 40 It is possible to effectively dissipate heat that has been generated. Further, heat transferred from the light emitting module (30) can be dissipated more quickly by using a heat pipe which is the first heat dissipating plate (60).

The present invention is not limited to the above-described embodiment and the attached drawings, but is defined by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims, As will be described below.

The present invention relates to a liquid crystal display device and a liquid crystal display device using the same and a liquid crystal display device having the same. 41: protruding portion, 42: concave portion, 45: fixing plate, 60: first heat dissipating plate

Claims (11)

Bottom cover;
A plurality of first heat dissipation plates disposed on the bottom cover;
A light emitting module disposed on at least one side of the bottom cover and including a plurality of light emitting diodes, a substrate on which the plurality of light emitting diodes are arranged, and a second heat dissipating plate to which the substrate is attached and which conducts heat to the first heat dissipation plate; And
And a light guide plate disposed on the bottom cover,
Wherein the bottom cover includes a plurality of recesses in which the first heat dissipation plates are housed, respectively; And a plurality of projections projected on both sides of the recess,
A plurality of support grooves formed in protrusions of the bottom cover; And a fixing plate disposed on the upper surface of the support groove and the first heat radiation plate. Bottom cover;
A plurality of first heat dissipation plates disposed on the bottom cover;
A light emitting module disposed on at least one side of the bottom cover and including a plurality of light emitting diodes, a substrate on which the plurality of light emitting diodes are arranged, and a second heat dissipating plate to which the substrate is attached and which conducts heat to the first heat dissipation plate; And
And a light guide plate disposed on the bottom cover,
Wherein the second heat dissipation plate includes: a mounting portion having a rear surface of the substrate attached to the front surface; A first support portion bent from the upper end of the mount portion and extending to a side surface of the bottom cover; A second support portion bent toward an inner side of the bottom cover at a lower end of the mount portion and closely attached to a bottom surface of the bottom cover; And a heat conducting portion formed to be stepped from the second supporting portion and contacting the upper surface of the first heat dissipating plate. The backlight unit according to claim 1 or 2, wherein the first heat dissipation plate is disposed obliquely with respect to an axial direction extending vertically from one side of the bottom cover to the inside of the bottom cover. The backlight unit according to claim 3, wherein the first heat dissipation plate is inclined at a range of 3 to 45 degrees. The bottom cover according to claim 1 or 2, wherein the plurality of first heat-dissipating plates are disposed on both sides of the bottom surface of the bottom cover,
Wherein the light emitting module is disposed on both sides of the bottom cover. The backlight unit according to claim 1 or 2, wherein the first heat-dissipating plate includes a heat pipe in a fluid state and a vacuum state. [2] The apparatus of claim 1, further comprising: a hole formed in the support groove of the bottom cover, the fixing plate, and the second heat dissipation plate; And a fastening member fastened to the hole. delete Bottom cover; A plurality of first heat dissipation plates disposed on the bottom cover; A light emitting module disposed on at least one side of the bottom cover and including a plurality of light emitting diodes, a substrate on which the plurality of light emitting diodes are arranged, and a second heat dissipating plate to which the substrate is attached and which conducts heat to the first heat dissipation plate; And a backlight unit including a light guide plate disposed on the bottom cover;
An optical sheet on the light guide plate; And
And a display panel on the optical sheet,
The second heat dissipation plate is mounted on a front surface of the substrate, the front surface being perpendicular to the bottom surface of the bottom cover; A first support portion bent from the upper end of the mount portion and extending to a side surface of the bottom cover; A second support portion bent toward an inner side of the bottom cover at a lower end of the mount portion and closely attached to a bottom surface of the bottom cover; And a heat conduction part formed to be stepped from the second support part and in contact with the upper surface of the first heat dissipation plate. The display device of claim 9, wherein the first heat dissipation plate includes a heat pipe in a fluid state and a vacuum state, and the heat pipe is obliquely disposed on a bottom surface of the bottom cover. The display device of claim 9, wherein the second heat dissipation plate contacts the plurality of first heat dissipation plates and conducts heat generated from the light emitting diodes.

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