JP2014179343A - Backlight device and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backlight device and a liquid crystal display device that are simplified in manufacture while heat radiation measures are taken on a light source.SOLUTION: A backlight device includes: a light guide plate 12 which emits incident light from an end face to a front side; a light source 14a which irradiates the end face with light; a rear chassis 9 which is provided on a rear side of the light guide plate; and a heat radiation member 8a which is provided on the rear side of the rear chassis and radiates heat from the light source while the light source is held at a place extended toward the end face. The heat radiation member has a chassis holding part which determines the position of the rear chassis, and the heat radiation member has chassis contact parts 38a-38c which come into partial contact with the rear of the rear chassis at a plurality of places other than places for fixation to the rear chassis.

Description

  The present invention relates to a backlight device and a liquid crystal display device, and more particularly to a backlight device and a liquid crystal display device having a heat dissipation structure for radiating heat from a backlight light source.

  In recent years, liquid crystal display devices such as flat-screen televisions have been increased in screen size. For example, products having screen sizes of 60 type, 70 type, and 80 type are on the market. In such a liquid crystal display device, an LED (Light Emitting Diode) instead of a conventional fluorescent tube is used as a backlight light source. In addition, the use of liquid crystal display devices is not limited to televisions, but is diversifying, such as PC (personal computer) monitors and digital signage (electronic signage). With this, LEDs also have higher brightness (high output). Things are required.

  In the above-mentioned liquid crystal display device, the amount of heat generated increases as the brightness of the LED increases, so it is necessary to take measures for heat dissipation of the LED. For example, Patent Document 1 describes a structure in which an LED substrate on which an LED serving as a heat source is disposed is attached to an aluminum heat radiating member called a heat sink (also referred to as a heat spreader) to dissipate the heat of the LED. Patent Document 2 describes a structure in which a heat radiating member is provided behind a rear chassis (also referred to as a backlight chassis) provided on the back side of the light guide plate.

JP 2009-217206 A JP2011-253769A

  However, Patent Document 1 does not show the fixing of the rear chassis. On the other hand, Patent Document 2 shows that the rear chassis is connected to the heat radiating member with a guide roller, but the position of the rear chassis is not determined until the guide roller is used, and the heat radiating member is pressed against the rear chassis. It is necessary to keep. For this reason, there exists a problem that it is difficult to manufacture the backlight apparatus which comprises a liquid crystal display device.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a backlight device and a liquid crystal display device that facilitate manufacturing while taking measures for heat radiation of a light source.

In order to solve the above-mentioned problems, the first technical means of the present invention includes a light guide plate that emits incident light from an end face to the front side, a light source that emits light toward the end face, and a rear surface of the light guide plate. A rear chassis provided on the side, and a heat dissipating member that is provided on the rear side of the rear chassis, holds the light source at a portion extending toward the end surface, and dissipates heat from the light source. The heat dissipating member has a chassis holding portion that determines the position of the rear chassis.
And the said heat radiating member has a chassis contact part which contacts the back surface of the said back chassis partially in multiple places other than a fixed location with this back chassis.

  According to a second technical means, in the first technical means, the rear chassis has a protrusion on the rear surface of the rear chassis, and the fixing member is inserted from the rear surface side of the heat radiating member at the protrusion. It is fixed to the heat radiating member.

  The third technical means is a liquid crystal display device equipped with the backlight device of the first or second technical means.

  According to the present invention, the heat dissipating member holding the light source is provided on the opposite side of the light guide plate with the back chassis interposed therebetween, and the heat from the light source can be efficiently dissipated. And since a back chassis is positioned quickly by the chassis holding part of a heat radiating member and position shift can be prevented, manufacture of a backlight apparatus becomes easy.

It is a figure which shows an example of the external appearance of the liquid crystal display device containing the backlight apparatus by this invention. It is a figure which shows the state which removed the back cabinet from the liquid crystal display device shown in FIG. It is a figure which shows an example of the state which decomposed | disassembled the internal structure of the liquid crystal display device shown in FIG. It is a figure when the state which removed the back cabinet from the liquid crystal display device shown in FIG. 1 is seen from diagonally back. It is a figure which shows the cross section of the upper end part of the liquid crystal display device shown in FIG. It is a figure which shows the cross section of the upper end part of the liquid crystal display device shown in FIG. It is a figure which shows the cross section of the lower end part of the liquid crystal display device shown in FIG.

Hereinafter, preferred embodiments according to a backlight device and a liquid crystal display device of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram showing an example of the appearance of a liquid crystal display device including a backlight device according to the present invention. 1A shows a state in which the liquid crystal display device is viewed from the front, FIG. 1B shows a state in which the liquid crystal display device is viewed from the back, and FIG. 1C shows the liquid crystal display device viewed from the left side. Indicates the state. In the figure, 1 is a liquid crystal display device, 2a to 2d are front frames, 3 is a liquid crystal panel, 4 is a stand, 5 is a back cabinet, 6 is a power cord lead-out portion, and 7 is an operation button portion.

  In FIG. 1, the liquid crystal panel 3 has a configuration in which liquid crystal is sandwiched between two glass substrates, and the alignment state of liquid crystal molecules constituting the liquid crystal is controlled so that the light guide plate 12 shown in FIG. It has a function as an optical shutter for controlling transmission / blocking of emitted light. Further, the front frames 2a to 2d are provided around the liquid crystal panel 3, and have a frame structure in which the front cabinet is divided into four parts in the up, down, left, and right directions in order to reduce the mold manufacturing cost of the front cabinet. The front frames 2a to 2d are made of a metal such as an aluminum alloy, for example, instead of a resin in order to improve design.

  The back cabinet 5 made of resin covers the back side of the backlight device to be described later, and a stand 4 for supporting the liquid crystal display device 1 is attached to the lower side thereof. The rear cabinet 5 is formed with a power cord lead-out portion 6 for pulling out the power cord from the inside of the liquid crystal display device 1. In addition, an operation button unit 7 for operating the liquid crystal display device 1 is provided on the left side surface of the liquid crystal display device 1.

FIG. 2 is a diagram illustrating a state where the rear cabinet is removed from the liquid crystal display device illustrated in FIG. 1. In a state in which the rear cabinet 5 is removed, the heat spreaders 8a and 8b, the backlight chassis 9, the heat spreaders 8a and 8b, the center seal fixed to the rear side of the backlight chassis 9, the auxiliary metal frame assembly 19a, and the like can be seen.
The heat spreaders 8a and 8b function as a heat radiating member for radiating heat of the LED light source, and are made of, for example, an aluminum alloy having high heat radiating performance. The heat spreaders 8 a and 8 b extend in the left-right direction of the liquid crystal display device 1 and are arranged at the upper and lower ends of the back surface of the backlight chassis 9. The backlight chassis 9 is formed of, for example, a metal such as iron and is positioned on the heat spreaders 8a and 8b as will be described later. The backlight chassis 9 corresponds to the rear chassis of the present invention.

  The lengths of the heat spreaders 8a and 8b in the left-right direction are set substantially equal to the horizontal length of the liquid crystal panel 3. On the other hand, the length of the heat spreaders 8a and 8b in the vertical direction is set to about 150 mm when the screen size is 70 inches and the material of the heat spreaders 8a and 8b is aluminum, for example. This length can be appropriately determined by calculating the area required for heat dissipation with respect to the heat generation amount of the LED corresponding to the screen size. As will be described later, since the heat spreaders 8a and 8b are arranged on the back side of the backlight chassis 9, the heat radiation area can be increased. For this reason, a higher heat dissipation effect can be obtained.

FIG. 3 is a diagram showing an example of a state in which the internal structure of the liquid crystal display device shown in FIG. 1 is disassembled. The front frames 2a to 2d described with reference to FIG. 1 are assembled as one frame member by frame fastening brackets 2e _{1 to} 2e ₄ arranged at four corners, and are fixed around the liquid crystal panel 3.
On the back side of the liquid crystal panel 3, an optical sheet 10, a light guide plate 12, a reflective sheet 13, and a backlight chassis 9 are provided in this order.

  The optical sheet 10 is composed of, for example, two microlens sheets and one brightness enhancement sheet, and has functions such as uniformizing the light emitted from the light guide plate 12 and improving the brightness in the front direction. Have. The light guide plate 12 is formed of a transparent resin such as acrylic, and emits light from the LED light source to the liquid crystal panel 3 positioned on the front side. The reflection sheet 13 has a function of reflecting light that is not incident on the light guide plate 12 out of light emitted from the LED light source and causing the light to enter the light guide plate 12.

The backlight chassis 9 is provided on the back side of the reflection sheet 13, holds the light guide plate 12 and the reflection sheet 13, and functions as a mounting base for these. The heat spreaders 8 a and 8 b are provided on the back side of the backlight chassis 9.
The heat spreader 8a holds the bar-shaped LED substrate 14a on which the LED light source is arranged at a position facing the incident surface formed at the upper end of the light guide plate 12, and has a function of radiating heat from the LED substrate 14a. Have. The heat spreader 8b has a function of holding the bar-shaped LED substrate 14b and dissipating heat from the LED substrate 14b at a position facing the incident surface formed at the lower end of the light guide plate 12.

The heat spreaders 8a and 8b and the LED substrates 14a and 14b are fixed by a double-sided tape or the like. The light guide plate 12, the reflection sheet 13, the LED substrates 14a and 14b, the backlight chassis 9, and the heat spreaders 8a and 8b correspond to the backlight device of the present invention.
Here, the heat from the LED boards 14a and 14b is radiated by the heat spreaders 8a and 8b. However, in the present invention, the heat spreader 8a is provided in order to easily release the heat generated in the LED boards 14a and 14b to the outside of the backlight device. , 8b is focused on the rear side of the backlight chassis 9.

  The liquid crystal display device 1 includes intermediate chassis 11a to 11f formed of plastic or the like. The intermediate chassis 11 a to 11 f are disposed between the peripheral portion of the optical sheet 10 and the peripheral portion of the light guide plate 12. In this example, an intermediate chassis with six divisions is shown, but for example, four divisions may be used, and the number of divisions is not particularly limited.

  FIG. 4 is a view of the state in which the rear cabinet is removed from the liquid crystal display device shown in FIG. 1 when viewed obliquely from behind. 5 is a cross-sectional view of the portion X (upper end portion of the liquid crystal display device 1) of FIG. 4 when viewed from the side, and FIG. 6 is an enlarged view of the portion X1 of FIG. 7A is a cross-sectional view of the Y portion (lower end portion of the liquid crystal display device 1) in FIG. 4 when viewed from the side, and FIG. 7B is a cross-sectional view of Y1 in FIG. 7A. It is an enlarged view of a part.

First, as shown in FIG. 5, the heat spreader 8a has one end bent toward the liquid crystal panel 3, and an LED substrate 14a is provided on the inner surface of the bent portion.
Here, the heat spreader 8a and the backlight chassis 9 are in partial contact with each other, and heat transmitted from the heat spreader 8a to the backlight chassis 9 is reduced.

  Specifically, the other end side of the heat spreader 8a extends downward from the holding position of the LED substrate 14a, and the heat dissipating fins 28a to 28c that can come into contact with the outside air in the back cabinet 5 are provided on the back surface of the heat spreader 8a. Is formed. Among them, the heat radiating fin 28 a is arranged at a position closest to the LED substrate 14 a and is configured by, for example, three protrusions extending in the left-right direction of the liquid crystal panel 3. The radiating fin 28b is disposed below the radiating fin 28a and has the same shape as the radiating fin 28a. For example, the radiating fin 28b includes five protrusions. The radiating fin 28c is disposed below the radiating fin 28b and has the same shape as the radiating fins 28a and 28b. For example, the radiating fin 28c includes 14 protrusions.

  In addition, as for the back surface of the heat spreader 8a which has the radiation fins 28a-28c, it is desirable to perform the black alumite process on the surface part, for example. By generating a black film of aluminum oxide on the back surface of the heat spreader 8a, the emissivity is increased and the heat dissipation effect can be further enhanced.

  On the other hand, on the front surface of the heat spreader 8a, chassis contact portions 38a to 38c are formed that extend along the LED board 14a and increase in contact area as the distance from the LED board 14a increases. The chassis contact portion 38a is located on the opposite side of the heat radiation fin 28a, protrudes toward the liquid crystal panel 3, and contacts the back surface of the backlight chassis 9. The chassis contact portion 38b is located on the opposite side of the heat radiating fin 28b and protrudes toward the liquid crystal panel 3 side. Similarly to the chassis contact portion 38a, the chassis contact portion 38b contacts the back surface of the backlight chassis 9. However, the chassis contact portion 38b contacts the back surface of the backlight chassis 9 in a wider range than the contact area with the chassis contact portion 38a. Yes.

The chassis contact portion 38c is located on the opposite side of the heat radiation fin 28c, protrudes toward the liquid crystal panel 3, and contacts the back surface of the backlight chassis 9 in the same manner as the chassis contact portions 38a and 38b. However, the chassis contact portion 38c is in contact with the back surface of the backlight chassis 9 in a wider range than the contact area with the chassis contact portions 38a and 38b.
Thus, the radiation fins 28a to 28c are formed on the back side of the chassis contact portions 38a to 38c, and the thickness of the backlight device can be reduced. The contact areas of the chassis contact portions 38a to 38c with the backlight chassis 9 are increased as the distance from the LED substrate 14a increases. For this reason, in the backlight chassis 9 in contact with the heat spreader 8a, high temperature portions are not locally formed, low temperature portions are formed over a wide range, and high and low temperature unevenness is eliminated. Further, the influence on the optical sheet 10 is reduced.

  In addition, the backlight chassis 9 can be positioned in front of the heat spreader 8a having the chassis contact portions 38a to 38c. Specifically, as shown in FIG. 6, the heat spreader 8a has chassis holding portions 48a and 48b protruding toward the liquid crystal panel 3 in the vicinity of the holding position of the LED substrate 14a. For example, the chassis holding portions 48 a and 48 b are provided at intervals slightly wider than the thickness of the backlight chassis 9, and extend in the left-right direction of the liquid crystal panel 3.

  On the other hand, at the upper end of the backlight chassis 9, a bent portion 9 a protrudes in a direction away from the liquid crystal panel 3 and is formed along the left-right direction of the liquid crystal panel 3. The end portion of the bent portion 9a is engaged with the chassis holding portions 48a and 48b when the liquid crystal display device 1 is assembled as will be described later. Thereby, the backlight chassis 9 is supported by the heat spreader 8a.

  Next, the lower side of the liquid crystal display device 1 has the same configuration, and as shown in FIG. 7A, the heat spreader 8b and the backlight chassis 9 are partially in contact with each other, and the back from the heat spreader 8b. The heat transmitted to the light chassis 9 is reduced. One end side of the heat spreader 8b is bent toward the liquid crystal panel 3, and the LED substrate 14b is provided on the inner surface of the bent portion. In FIG. 7, 17 is a substrate shield, 18 is a source substrate, and 20 is a source substrate holder.

  The other end side of the heat spreader 8b extends upward from the holding position of the LED substrate 14b, and radiating fins 28d to 28f are formed on the back surface of the heat spreader 8b. The heat dissipating fins 28d are arranged at positions closest to the LED substrate 14b, and include, for example, three protrusions extending in the left-right direction of the liquid crystal panel 3. The radiating fin 28e is disposed above the radiating fin 28d and has the same shape as the radiating fin 28d. For example, the radiating fin 28e includes five protrusions. The radiation fins 28f are disposed above the radiation fins 28e and have the same shape as the radiation fins 28d and 28e. For example, the radiation fins 28f include 14 protrusions. In addition, it is desirable that the back surface of the heat spreader 8b having the radiation fins 28d to 28f is also subjected to, for example, black alumite treatment on the surface portion.

  On the other hand, on the front surface of the heat spreader 8b, chassis contact portions 38d to 38f are formed that extend along the LED board 14b and increase in contact area as the distance from the LED board 14b increases. The chassis contact portion 38d is located on the opposite side of the heat radiating fins 28d, protrudes toward the liquid crystal panel 3, and contacts the back surface of the backlight chassis 9. The chassis contact portion 38e is located on the opposite side of the heat radiation fin 28e and protrudes toward the liquid crystal panel 3 side. Similar to the chassis contact portion 38d, the chassis contact portion 38e contacts the back surface of the backlight chassis 9, but contacts the back surface of the backlight chassis 9 in a wider range than the contact area with the chassis contact portion 38d. Yes.

The chassis contact portion 38f is located on the opposite side of the heat radiating fins 28f and protrudes toward the front side. Like the chassis contact portions 38d and 38e, the chassis contact portion 38f contacts the back surface of the backlight chassis 9, The contact portion 38f is in contact with the back surface of the backlight chassis 9 in a wider range than the contact area with the chassis contact portions 38d and 38e.
Thus, the radiation fins 28d to 28f are formed on the back side of the chassis contact portions 38d to 38f, and the thickness of the backlight device can be reduced. The contact areas of the chassis contact portions 38d to 38f with the backlight chassis 9 are increased as the distance from the LED substrate 14b increases. For this reason, in the backlight chassis 9 in contact with the heat spreader 8b, the high temperature portion is not locally formed, the low temperature portion is formed over a wide range, and the high and low temperature unevenness is eliminated. Further, the influence on the optical sheet 10 is reduced.

In addition, the backlight chassis 9 can be positioned in front of the heat spreader 8b having the chassis contact portions 38d to 38f. As shown in FIG. 7B, the heat spreader 8b has a chassis holding portion 48c that protrudes toward the liquid crystal panel 3 and extends in the left-right direction in the vicinity of the holding position of the LED substrate 14b.
On the other hand, a bent portion 9 d is formed at the lower end of the backlight chassis 9. The bent portion 9 d protrudes in a direction away from the liquid crystal panel 3 and is formed along the left-right direction of the liquid crystal panel 3.

  When the liquid crystal display device 1 is assembled, the position of the bent portion 9a of the backlight chassis 9 is set to the chassis holding portions 48a and 48b shown in FIG. 6, and the position of the bent portion 9d is set to the chassis holding portion 48c shown in FIG. To match each. When the inner side of the bent portion 9a is engaged with the chassis holding portion 48b and the inner side of the bent portion 9d is engaged with the chassis holding portion 48c, the backlight chassis 9 is connected to the chassis holding portions 48a to 48c of the heat spreaders 8a and 8b. The position of the backlight chassis 9 with respect to the heat spreaders 8a and 8b is determined by being supported by the chassis contact portions 38a to 38f.

  As described above, the heat spreaders 8a and 8b holding the LED boards 14a and 14b are provided on the opposite side of the light guide plate 12 with the backlight chassis 9 interposed therebetween, and heat from the LED boards 14a and 14b is transferred into the rear cabinet 5. Can efficiently dissipate heat in the atmosphere. Since the backlight chassis 9 is quickly positioned by the chassis holding portions 48a, 48b, 48c and the like and can be prevented from being displaced, the liquid crystal display device 1 including the backlight device can be easily manufactured.

As shown in FIG. 5, the backlight chassis 9 has a protruding portion 9b protruding in a direction away from the liquid crystal panel 3, and has a protruding portion 9c as shown in FIG.
As described above, once the position of the backlight chassis 9 with respect to the heat spreader 8a is determined, the fixing member shown between FIG. 5 and the fixing member located between the heat radiating fin 28b and the heat radiating fin 28c, for example, the fastening position of the screw 15b, The protrusion 9b contacts the front surface of the heat spreader 8a. When the screw 15b is inserted from the back side of the heat spreader 8a and the heat spreader 8a and the backlight chassis 9 are fastened, the backlight chassis 9 is fixed to the heat spreader 8a with screws.

  On the other hand, when the position of the backlight chassis 9 with respect to the heat spreader 8b is determined, the protruding portion 9c is located on the front surface of the heat spreader 8b at the fastening position of the screw 15c located above the radiation fin 28f, as shown in FIG. Contact. When the screw 15c is inserted from the back side of the heat spreader 8b and the heat spreader 8b and the backlight chassis 9 are fastened, the backlight chassis 9 is fixed to the heat spreader 8b with screws.

Thus, the backlight chassis 9 positioned by the chassis holding portions 48a to 48c can be securely fixed to the heat spreaders 8a and 8b using the screws 15b and 15c.
The reflective sheet 13 and the light guide plate 12 are attached to the fixed backlight chassis 9 in this order, and then the intermediate chassis 11a to 11f described with reference to FIG. 3 between the peripheral portion of the light guide plate 12 and the peripheral portion of the optical sheet 10. Is inserted, an air layer 16 having a thickness of about 3 mm is formed between the light guide plate 12 and the optical sheet 10 (non-contact structure). The optical sheet 10 is fixed by fitting a plurality of holes (not shown) formed along the peripheral edge portion thereof and ribs (not shown) formed in the intermediate chassis 11a to 11f. Thus, since the air layer 16 functions as a heat insulating layer that blocks the heat introduced to the heat spreaders 8a and 8b, it is possible to make it difficult to transmit this heat to the optical sheet 10.

  Subsequently, the liquid crystal panel 3 is overlaid on the optical sheet 10, and the peripheral portion of the liquid crystal panel 3 is pressed by the front frames 2a to 2d. As shown in FIG. 6, between the front frame 2a and the liquid crystal panel 3, between the liquid crystal panel 3 and the resin frame 11a, between the optical sheet 10 and the resin frame 11a, and between the resin frame 11a. Between the optical plate 12, spacer members S1, S2, S3, S4 such as urethane are respectively disposed. Further, as shown in FIG. 7B, between the front frame 2c and the liquid crystal panel 3, between the liquid crystal panel 3 and the resin frame 11e, between the optical sheet 10 and the resin frame 11e, the resin frame. Spacer members S5, S6, S7, and S8, such as urethane, are disposed between 11e and the light guide plate 12, respectively.

  As shown in FIG. 5, one end side of the heat spreader 8a extends upward in a hook shape, and the end portion of the intermediate chassis 11a can be sandwiched between the hook-shaped portion and the front frame 2a. The front frame 2a, the intermediate chassis 11a, and the heat spreader 8a are integrally fixed by screws 15a and the like from the back side of the heat spreader 8a. Further, as shown in FIG. 7A, one end side of the heat spreader 8b also extends downward in a hook shape, and the end portion of the intermediate chassis 11e can be sandwiched between the hook-shaped portion and the front frame 2c. The front frame 2c, the intermediate chassis 11e, and the heat spreader 8b are also fixed integrally using screws 15d inserted from the back side.

  Although the substrate shield 17 in FIG. 7B appears to be separated because of the cutting position, the substrate shield 17 may also be fixed with screws 15d on the heat spreader 8b side. In addition, with respect to the fixing points by the screws 15a and 15d, for example, the four corners of the liquid crystal display device 1 are fixed. In this way, by fixing the screws in the depth direction from the back, the strength of the housing can be secured, and furthermore, the screws can be hidden when viewed from the front of the liquid crystal display device 1. It is desirable from the viewpoint.

  Further, as described above, since the intermediate chassis is sandwiched between the heat spreaders 8a and 8b and the front frames 2a and 2c, heat from the LED boards 14a and 14b is hardly transmitted to the front frames 2a and 2c. Further, by adopting a non-contact structure in which the optical sheet 10 and the light guide plate 12 are separated by the intermediate chassis, the horizontal and vertical lengths of the light guide plate can be shorter than the horizontal and vertical lengths of the liquid crystal panel. Therefore, the frame portion of the screen can be narrowed.

  As mentioned above, although the Example was described, the backlight apparatus of this invention is the light guide plate which radiate | emits the incident light from an end surface to the front side, the light source which irradiates light toward the said end surface, and the back side of the said light guide plate A rear chassis provided on the rear chassis, and a heat radiating member that is provided on the rear surface side of the rear chassis and that holds the light source at a portion extending to the end face and dissipates heat from the light source. The member may include a chassis holding portion that determines a position of the rear chassis. Thus, the heat radiating member holding the light source is provided on the opposite side of the light guide plate across the rear chassis, and heat from the light source can be efficiently radiated. And since a back chassis is positioned quickly by the chassis holding part of a heat radiating member and position shift can be prevented, manufacture of a backlight apparatus becomes easy.

Moreover, the edge of the said back chassis may have the bending part bent to the back side of this back chassis, and the inner side of this bending part and the said chassis holding part may engage. Since the inside of the bent part of the rear chassis and the protruding part of the chassis holding part are engaged, it is possible to reliably prevent the rear chassis from being displaced.
The back chassis may have a protrusion on the back surface of the back chassis, and the protrusion may be fixed to the heat dissipation member using a fixing member inserted from the back side of the heat dissipation member. The rear chassis positioned by the chassis holding portion can be reliably fixed to the heat dissipation member using the fixing member.

Moreover, the said heat radiating member may have a chassis contact part which contacts the said back chassis, and a radiation fin in the back side of this chassis contact part. As a result, the thickness of the backlight device can be reduced, and in the rear chassis in contact with the heat radiating member, high temperature portions are not locally formed, and low temperature portions are formed over a wide range, resulting in high and low temperature unevenness. Is resolved.
Moreover, the liquid crystal display device carrying the backlight apparatus mentioned above may be sufficient. This facilitates the manufacture of the liquid crystal display device.

1 ... liquid crystal display device, 2 a to 2 d ... front frame, 2e ₁ ～2E ₄ ... frame fastening bracket, 3 ... liquid crystal panel, 4 ... stand, 5 ... rear cabinet, 6 ... power cord lead portion, 7 ... operation button unit, 8a, 8b ... heat spreader, 9 ... backlight chassis, 9a, 9d ... bent portion, 9b, 9c ... projection, 10 ... optical sheet, 11a-11f ... intermediate chassis, 12 ... light guide plate, 13 ... reflection sheet, 14a, 14b ... LED board, 15a-15d ... Screw, 16 ... Air layer, 17 ... Board shield, 18 ... Source board, 19a ... Center seal and auxiliary metal frame assembly, 20 ... Source board holder, 28a-28f ... Radiation fin, 38a ~ 38f ... chassis contact part, 48a-48c ... chassis holding part.

Claims (3)

A light guide plate for emitting incident light from the end face to the front side;
A light source that emits light toward the end surface;
A rear chassis provided on the back side of the light guide plate;
A heat dissipating member that is provided on the back side of the rear chassis, holds the light source at a portion extending toward the end surface, and dissipates heat from the light source;
The heat dissipating member has a chassis holding portion that determines the position of the rear chassis,
The said heat radiating member has the chassis contact part which contacts the back surface of the said back chassis partially in multiple places other than a fixed location with this back chassis. The backlight device according to claim 1,
The back chassis has a protrusion on the back surface of the rear chassis, and the protrusion is fixed to the heat dissipation member using a fixing member inserted from the back side of the heat dissipation member. Light equipment.   A liquid crystal display device comprising the backlight device according to claim 1.

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