WO2014069572A1

WO2014069572A1 - Liquid crystal display device

Info

Publication number: WO2014069572A1
Application number: PCT/JP2013/079556
Authority: WO
Inventors: 伸一植松
Original assignee: シャープ株式会社
Priority date: 2012-11-05
Filing date: 2013-10-31
Publication date: 2014-05-08

Abstract

The present invention prevents heat from flowing into a front surface frame and an optical sheet while narrowing the frame section of a screen. A liquid crystal display device (1) is provided with: an optical sheet (10) that is arranged on the rear surface side of a liquid crystal panel (3); a light guide plate (12) that guides light from an LED substrate (14b) toward a liquid crystal panel (3); a backlight chassis (9); a front surface frame (2c) that is provided around the liquid crystal panel (3); an intermediate chassis (11e) that is inserted between the peripheral edge section of the optical sheet (10) and the peripheral edge section of the light guide plate (12) and that forms an air layer (16) between the optical sheet (10) and the light guide plate (12); and a heat spreader (8b) that is provided to the outside of the backlight chassis (9), that holds the LED substrate (14b) in a position facing the upper and low ends of the light guide plate (12), and that dissipates heat from the LED substrate (14b). The intermediate chassis (11e) comprises an extended section (111e) that extends between the front surface frame (2c) and the heat spreader (8b).

Description

Liquid crystal display

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

In recent years, liquid crystal display devices such as flat-screen televisions have been increased in screen size, and products with screen sizes of, for example, 60 type, 70 type, and 80 type have been sold. In such a liquid crystal display device, instead of a conventional fluorescent tube, an LED (Light-Emitting Diode) 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-described liquid crystal display device, the amount of heat generated increases as the brightness of the LED increases, so it is necessary to take measures against heat dissipation of the LED. In other words, heat insulation and heat dissipation measures are required for members that are thermally affected by heat generated from the LEDs. 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.

In addition, the liquid crystal display device is usually provided with an optical sheet that acts on the light emitted from the backlight light source and converts the characteristics of the light, and the liquid crystal panel is illuminated by the light emitted from the optical sheet. .

Examples of the optical sheet include a microlens sheet that makes light as perpendicular as possible to the liquid crystal panel to improve the front luminance of the liquid crystal panel, and condenses the light in the same manner as the microlens sheet toward the liquid crystal panel. An irradiating prism sheet (called a brightness enhancement sheet or the like) is used.

The optical sheet is made of resin, and when the heat dissipated from the LED used as the backlight light source is transmitted to the optical sheet through the members around the substrate on which the LED is installed, the optical sheet is thermally affected. It may be deformed. Then, the apparent optical characteristics in the plane change (flare), and the quality of the display image displayed on the liquid crystal panel is lowered. In particular, it is necessary to adopt a structure in which the optical sheet is not affected by the thermal effect due to the increase in the amount of heat generated with the recent increase in luminance of the backlight light source.

Regarding other techniques related to the heat insulating structure of liquid crystal panel members, for example, Patent Document 2 discloses a liquid crystal display device having a structure for preventing damage and wrinkles due to the thermal influence of an optical sheet. In this liquid crystal display device, an end portion of a panel guide for holding the liquid crystal panel is inserted between the light guide plate and the liquid crystal panel. An optical sheet is disposed on the light guide plate, and a gap is provided between the optical sheet and the liquid crystal panel. An interval maintaining / heat blocking member is provided between the light guide plate and the back side of the panel guide. This spacing maintaining / heat blocking member blocks the heat generated by the light source lamp provided on the side of the light guide plate so that the optical sheet disposed on the light guide plate is not thermally affected. .

A conventional heat dissipation structure using a heat spreader will be described with reference to FIG. FIG. 9 is a view showing a cross section of the upper end portion of a liquid crystal display device having a conventional heat dissipation structure, in which 100 denotes the liquid crystal display device. The liquid crystal display device 100 includes a decorative member 101, a front frame 102, a liquid crystal panel 103, an optical sheet 104, a light guide plate 105, a reflection sheet 106, a rear chassis (also referred to as a backlight chassis) 107, a heat spreader 108, and an LED substrate 109. . The front frame 102 is made of, for example, an aluminum alloy, and is disposed around the liquid crystal panel 103 with the spacer member S11 interposed therebetween, and functions as a front cabinet of the liquid crystal display device 100. A decorative member 101 is attached to the top surface of the front frame 102.

On the back side of the liquid crystal panel 103, an optical sheet 104, a light guide plate 105, and a reflection sheet 106 are provided in this order. The optical sheet 104 has functions such as uniformizing the light emitted from the light guide plate 105 and improving the luminance in the front direction. The light guide plate 105 is made of a transparent resin such as acrylic, and emits light incident from the backlight light source to the liquid crystal panel 103. The reflection sheet 106 has a function of reflecting light that does not enter the light guide plate 105 out of light emitted from the backlight light source and makes the light enter the light guide plate 105.

The LED substrate 109 is a substrate on which LEDs serving as backlight light sources are arranged, and is fixed to the heat spreader 108 with a double-sided tape or the like. The heat spreader 108 is made of, for example, an aluminum alloy having a T-shaped cross section, and fixes the LED substrate 109 on which the LEDs are arranged at positions facing the incident surfaces formed on the upper and lower ends of the light guide plate 105. A backlight chassis 107 is provided on the back side of the heat spreader 108. The backlight chassis 107 is made of, for example, iron and has a function of dissipating heat from the heat spreader 108 to the back side.

The backlight chassis 107 is convex in the direction of the liquid crystal panel 103, and the liquid crystal panel 103, the optical sheet 104, the light guide plate 105, and the reflection sheet 106 are sandwiched between the backlight chassis 107 and the front frame 102. Is fixed in close contact. Specifically, as shown in FIG. 9, the backlight chassis 107 is fixed to the front frame 102 with screws 110 with the heat spreader 108 and the spacer member S12 interposed therebetween.

JP 2009-98310 A JP 2008-181150 A

Due to the recent emphasis on design, the number of models in which the front frame 102 is made of metal such as aluminum instead of resin is increasing. For this reason, there is a problem that heat generated by the LED is transmitted to the front frame 102 via the heat spreader 108 and the front frame 102 becomes hot. Further, the heat is transmitted to the light guide plate 105 and thermally affects the optical sheet 104 in contact with the light guide plate 105.
Specifically, as shown in FIG. 9, since the front frame 102 and the heat spreader 108 are in contact with each other at the contact C, the heat generated in the LED substrate 109 is transferred from the heat spreader 108 to the front frame 102 through the contact C. Further, the heat is transmitted from the front frame 102 to the light guide plate 105 through the first restraining protrusion 102a, and the heat is transmitted to the optical sheet 104 in contact with the light guide plate 105. A path through which heat is transmitted at this time is indicated by a dotted line in FIG.

The lens sheet and the brightness enhancement film constituting the optical sheet 104 are thin sheets and are easily affected by heat. That is, since the optical sheet 104 is in close contact with the light guide plate 105, heat is transmitted from the light guide plate 105, and the sheet may be thermally deformed. Such thermal deformation of the optical sheet 104 is not desirable because it causes the display quality of the liquid crystal display device to deteriorate.

Further, the front frame 102 is formed with a first presser protrusion 102 a and a second presser protrusion 102 b toward the center of the screen of the liquid crystal panel 103. The first pressing protrusion 102 a is provided to sandwich the light guide plate 105 and the reflection sheet 106 between the backlight chassis 107 and the front frame 102. Further, the second presser protrusion 102b sandwiches the liquid crystal panel 103, the optical sheet 104, the light guide plate 105, and the reflection sheet 106 between the backlight chassis 107 and the front frame 102 via the spacer member S11. Is provided.

Therefore, as shown in FIG. 9, it can be seen that the liquid crystal panel 103 must be disposed closer to the center than the light guide plate 105 by the amount that the first presser protrusion 102a protrudes. That is, in order to hold the light guide plate 105 by the first pressing protrusion 102 a, it is necessary to make the horizontal and vertical lengths of the light guide plate 105 longer than the horizontal and vertical lengths of the liquid crystal panel 103. When the horizontal and vertical lengths of the light guide plate 105 are increased, the second pressing protrusion 102b for sandwiching the liquid crystal panel 103 needs to be elongated toward the center. Increasing the length of the second presser protrusion 102b means that a so-called frame portion (peripheral portion of the screen) of the liquid crystal display device is widened.

As described above, the conventional heat dissipation structure has a problem of heat inflow to the front frame and the optical sheet and a problem that the frame portion of the screen becomes wide.
Regarding the optical sheet, heat generated by the backlight light source is transmitted to the optical sheet through various members, which deteriorates the optical characteristics of the optical sheet and impairs display quality. In particular, due to the increase in heat generation accompanying the recent increase in brightness of the backlight light source, the above-mentioned problems are regarded as important.

In the heat dissipation structure described in Patent Document 1, the heat sink that holds the LED substrate and the first aluminum frame (front frame) are fixed via the second frame (heat insulating member). Since the aluminum lower chassis holding the heat sink is in direct contact with the first frame (front frame), the heat of the heat sink is transferred to the first frame (front frame) via the lower chassis. Therefore, the above problems cannot be solved.

Further, the liquid crystal display device of Patent Document 2 has a configuration in which an interval maintaining / blocking member for blocking heat flowing from the lamp (backlight light source) to the optical sheet side is provided, as described above. The heat generated from the LED serving as the backlight light source is transmitted to the front chassis through the heat spreader and is not transmitted to the light guide plate to affect the thermal effect on the optical sheet.

The present invention has been made in view of the above circumstances, and provides a liquid crystal display device having a heat dissipation structure capable of narrowing a frame portion of a screen while preventing heat from flowing into a front frame or an optical sheet. With the goal.
A further object of the present invention is to provide a liquid crystal display device capable of maintaining high display quality by suppressing the thermal influence on the optical sheet due to heat generated by the light source.

In order to solve the above-mentioned problems, a first technical means of the present invention includes an optical sheet disposed on the back side of a liquid crystal panel, and light from a light source provided on the back side of the optical sheet to the liquid crystal panel. A liquid crystal display device comprising: a light guide plate that emits light; a rear chassis provided on the back side of the light guide plate; and a front frame provided around the liquid crystal panel, the peripheral portion of the optical sheet, An intermediate chassis that is inserted between a peripheral portion of the light guide plate and forms an air layer between the optical sheet and the light guide plate, and provided on the outer side of the rear chassis, facing the upper and lower ends of the light guide plate. A heat radiating member that holds the light source at a position and dissipates heat generated from the light source, and the intermediate chassis has an extending portion that extends between the front frame and the heat radiating member. It is what

The second technical means is characterized in that, in the first technical means, the front frame and the heat radiating member are made of metal.

According to a third technical means, in the first or second technical means, the heat dissipating member has a flange, and the front frame and the flange sandwich the extended portion extended from the intermediate chassis. And, it is fixed integrally by a fixing member on the back side of the front frame.

According to a fourth technical means, in any one of the first to third technical means, the horizontal and vertical lengths of the light guide plate are equal to or less than the horizontal and vertical lengths of the liquid crystal panel. It is a feature.

The fifth technical means includes a light source, a light guide plate that diffuses and emits light from the light source, an optical sheet that acts on the light emitted from the light guide plate to convert optical characteristics, and the optical And a liquid crystal panel for displaying an image by modulating light emitted from the sheet, wherein heat dissipation from the substrate on which the light source is disposed is transmitted to the optical sheet via a member constituting the liquid crystal display device. An intermediate chassis is provided as a part of the member in the conduction path that conducts toward the substrate, and a resin spacer member is disposed on the path through which heat is conducted from the intermediate chassis to the optical sheet. It is characterized by.

A sixth technical means is the fifth technical means, wherein the spacer member is provided between the intermediate chassis and the optical sheet, between the intermediate chassis and the light guide plate, and between the intermediate chassis and the liquid crystal panel. It is characterized by being provided between.

A seventh technical means is the sixth technical means, wherein the light guide plate holds the light source substrate on which the light source is disposed, and dissipates heat generated from the light source substrate, and is connected to the heat radiating member. A rear chassis disposed on the rear side of the liquid crystal panel and a front frame provided so as to surround the liquid crystal panel, and the heat dissipation member, the intermediate chassis, and the front frame are integrally fixed, The light guide plate, the optical sheet, and the liquid crystal panel are held between a chassis and an end portion of the liquid crystal panel, and a part of the intermediate chassis includes a peripheral portion of the optical sheet and a peripheral portion of the light guide plate. And an air layer having a predetermined interval is formed between the optical sheet and the light guide plate.

The eighth technical means is the seventh technical means, characterized in that the spacer member is further provided between the front frame and the liquid crystal panel.

According to the present invention, an air layer is formed by inserting an intermediate chassis between the optical sheet and the light guide plate, and the intermediate chassis is extended between the heat radiating member (heat spreader) and the front frame. The frame portion of the screen can be narrowed while preventing heat from flowing into the front frame and the optical sheet.
In addition, according to the present invention, it is possible to provide a liquid crystal display device capable of suppressing a thermal influence on the optical sheet due to heat generated by the light source and maintaining high display quality.

It is a figure which shows an example of the external appearance of the liquid crystal display device 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 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 an example of the state which looked at the lower end part of the liquid crystal display device shown in FIG. 1 from diagonally backward. 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 lower 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 upper end part of the liquid crystal display device with the conventional heat dissipation structure.

Hereinafter, preferred embodiments of the 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 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 (front cabinets), 3 is a liquid crystal panel, 4 is a stand (support), 5 is a back cabinet, 6 is a power cord lead-out section, and 7 is an operation button section. Indicates.

In FIG. 1, the liquid crystal panel 3 has a configuration in which liquid crystal is sandwiched between two glass substrates, and is emitted from a light guide plate (not shown) by controlling the alignment state of liquid crystal molecules constituting the liquid crystal. It functions as an optical shutter that controls transmission / blocking of the transmitted 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 upper, lower, 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.

A resin-made rear cabinet 5 is provided with a stand 4 for supporting the liquid crystal display device 1, and a power cord lead-out portion 6 for drawing a power cord from the inside of the liquid crystal display device 1 is formed. 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 view showing a state in which the rear cabinet 5 is removed from the liquid crystal display device 1 shown in FIG. In a state in which the rear cabinet 5 is removed, the

heat spreaders

8a and 8b, the rear chassis (hereinafter referred to as the backlight chassis) 9, and the center seal and auxiliary metal frame assembly 9a are visible. The

heat spreaders

8a and 8b function as a heat radiating member for radiating heat generated by the LED light source, and are made of, for example, an aluminum alloy having high heat radiating performance. The backlight chassis 9 is made of, for example, a metal such as iron, and

heat spreaders

8 a and 8 b are fixed to the upper and lower ends of the back surface of the backlight chassis 9. The center seal and auxiliary metal frame assembly 9a are fixed to the back side of the backlight chassis 9 and the

heat spreaders

8a and 8b.

The vertical length of the

heat spreaders

8a and 8b is 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. Further, since the

heat spreaders

8a and 8b are arranged on the back surface of the backlight chassis 9, the heat radiation area can be increased as compared with the conventional one (FIG. 9). 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 1 shown in FIG. 1 is disassembled. The liquid crystal display device 1 includes metal front frames 2a to 2d as a front cabinet. These four front frames 2a to 2d are assembled as one frame member by _four frame fastening brackets 2e ₁ to 2e ₄ and 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, and a reflection sheet 13 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 made of acrylic resin, polycarbonate resin, cycloolefin resin (COP) or the like, and diffuses light incident from the backlight light source and emits the light toward the liquid crystal panel 3. A reflection sheet 13 is installed on the back side of the light guide plate 12 to reflect the light leaked from the back side surface of the light guide plate 12 and return it to the front to increase the light utilization efficiency.

The backlight chassis 9 is provided on the back side of the light guide plate 12 and the reflection sheet 13 and holds the light guide plate 12 and the reflection sheet 13. The

heat spreaders

8a and 8b are provided outside the backlight chassis 9 and hold the

LED boards

14a and 14b on which the LED light sources are arranged at positions facing the incident surfaces formed on the upper and lower ends of the light guide plate 12, and the LED boards. The heat generated from 14a and 14b is dissipated. The

heat spreaders

8a and 8b and the

LED substrates

14a and 14b are fixed with a double-sided tape or the like.

Further, the liquid crystal display device 1 includes intermediate chassis 11a to 11f formed of plastic or the like. The intermediate chassis 11a to 11f are provided in a path through which heat radiation from the

LED substrates

14a and 14b on which LEDs serving as light sources are arranged is conducted toward the optical sheet 10 through members constituting the liquid crystal display device 1. It is made of a material such as resin or rubber, and itself has a heat insulating property. In this example, the intermediate chassis is divided into six parts, but it may be divided into four parts, for example, and the number of divisions is not particularly limited. These intermediate chassis 11 a to 11 f are inserted between the peripheral edge of the optical sheet 10 and the peripheral edge of the light guide plate 12.

FIG. 4 is a view showing a cross section of the upper end portion of the liquid crystal display device 1 shown in FIG. As described above, the liquid crystal display device 1 (upper side) includes the front frame 2a, the liquid crystal panel 3, the optical sheet 10, the intermediate chassis 11a, the light guide plate 12, the reflection sheet 13, the backlight chassis 9, the heat spreader 8a, and the LED substrate. 14a. Between the front frame 2a and the liquid crystal panel 3, between the liquid crystal panel 3 and the intermediate chassis 11a, between the intermediate chassis 11a and the optical sheet 10, and between the intermediate chassis 11a and the light guide plate 12, respectively, such as urethane Spacer members S1, S2, S3, S4 are arranged. The optical sheet 10 is formed by fitting a plurality of holes (not shown) formed along the periphery of the optical sheet 10 and ribs (not shown) formed in the intermediate chassis 11a to 11f. Fixed.

The main object of the present invention is to narrow the frame portion of the screen while preventing heat from flowing into the front frame and the optical sheet. As a configuration for this purpose, the liquid crystal display device 1 includes an intermediate chassis 11a and a heat spreader 8a. The intermediate chassis 11 a is inserted between the peripheral edge of the optical sheet 10 and the peripheral edge of the light guide plate 12, and forms an air layer 16 between the optical sheet 10 and the light guide plate 12. The thickness of the air layer 16 is about 3 mm. The heat spreader 8a is provided outside the backlight chassis 9, holds the LED substrate 14a at a position facing the incident surface formed at the upper and lower ends of the light guide plate 12, and dissipates heat generated from the LED substrate 14a. The intermediate chassis 11a includes an extending portion 111a that extends between the front frame 2a and the heat spreader 8a.

More specifically, the heat spreader 8a has a flange 81a, and the front frame 2a and the flange 81a of the heat spreader 8a sandwich the extended portion 111a extended from the intermediate chassis 11a. It is integrally fixed on the back side by a fixing member such as a screw 15a. In addition, about a fixed location, the four corners of the liquid crystal display device 1 shall be fixed, for example. By fixing the screws in the depth direction from the back as described above, the strength of the housing can be secured, and furthermore, the screws can be hidden, which is desirable from the viewpoint of design.

Here, the heat generated by the LED board 14a on which the LED serving as the heat source is disposed is radiated by the heat spreader 8a. However, by arranging the heat spreader 8a outside the backlight chassis 9, the light guide plate 12 and the optical sheet 10 can be heated. Heat can be made difficult to transmit. It is desirable that the heat spreader 8a and the backlight chassis 9 are partially in contact with each other. Thereby, it is possible to reduce the heat transmitted from the heat spreader 8a to the backlight chassis 9.

As described above, the air layer 16 is formed between the optical sheet 10 and the light guide plate 12 by inserting the intermediate chassis 11 a between the optical sheet 10 and the light guide plate 12. And since this air layer 16 functions as a heat insulation layer which interrupts the heat_generation | fever in LED board 14a, it becomes possible to make it difficult for a heat | fever to be transmitted to the optical sheet 10. FIG. The intermediate chassis 11a has an extending portion 111a, and the heat spreader 8a has a flange 81a. Then, by inserting the extended portion 111a extending from the intermediate chassis 11a between the front frame 2a and the flange 81a of the heat spreader 8a, it is possible to make it difficult for heat generated by the LED board 14a to be transmitted to the front frame 2a. It becomes possible. That is, since both the front frame 2a and the heat spreader 8a are made of metal, the heat from the heat spreader 8a is transferred to the front frame 2a by inserting the intermediate chassis 11a having a relatively low thermal conductivity between these members. It becomes difficult to convey.

Further, in the heat dissipation structure of FIG. 9 described above, the first presser protrusion 102a is required to tightly fix the liquid crystal panel 103, the optical sheet 104, and the light guide plate 105. However, in the heat dissipation structure of FIG. Since the optical sheet 10 and the light guide plate 12 are separated from each other by the chassis 11a, the first pressing protrusion 102a can be eliminated. Since the light guide plate 12 is held by the intermediate chassis 11a instead of the first presser protrusion 102a, the horizontal and vertical lengths of the light guide plate 12 are equal to or less than the horizontal and vertical lengths of the liquid crystal panel 3. It becomes possible to do. Then, by shortening the horizontal and vertical lengths of the light guide plate 12, the length of the portion corresponding to the frame of the front frame 2a can be shortened, so that the frame portion of the screen can be narrowed (narrowed frame). It becomes possible.

As described above, the intermediate chassis 11a has a non-contact structure in which the optical sheet 10 and the light guide plate 12 are separated from each other, whereby the horizontal and vertical lengths of the light guide plate 12 are set in the horizontal and vertical directions of the liquid crystal panel 3. Since it can be less than the length, the frame portion of the screen can be narrowed.

FIG. 5 is a diagram showing an example of a state where the lower end portion of the liquid crystal display device 1 shown in FIG. 1 is viewed obliquely from the rear. In this example, screws for fixing the four corners are omitted. The liquid crystal display device 1 (lower side) includes a front frame 2c, a liquid crystal panel 3, an optical sheet 10, an intermediate chassis 11e, a light guide plate 12, a reflection sheet 13, a backlight chassis 9, a heat spreader 8b, and an LED substrate 14b. The basic configuration is the same as the configuration of the upper end portion shown in FIG. 4, and is between the front frame 2c and the liquid crystal panel 3, between the liquid crystal panel 3 and the resin frame 11e, and between the resin frame 11e and the optical sheet. 10, spacer members S5, S6, S7, and S8 such as urethane are disposed between the resin frame 11c and the light guide plate 12, respectively.

FIG. 6 is a view when the rear cabinet 5 is removed from the liquid crystal display device 1 shown in FIG. FIG. 7A is a cross-sectional view of the portion X in FIG. 6 (the lower end portion of the liquid crystal display device 1) as viewed from the side. FIG. 7B is an enlarged view in which a Y portion in FIG. 7A is enlarged. In FIG. 7, 17 is a substrate shield, 18 is a source substrate, and 19 is a source substrate holder. It is assumed that the substrate shield 17, the source substrate 18, and the source substrate holder 19 are not provided on the upper end side of the liquid crystal display device 1.

As shown in FIG. 7A, the heat spreader 8b is fixed to the backlight chassis 9 with screws 15c. Note that the upper end side of the liquid crystal display device 1 has a substantially similar configuration. That is, the heat spreader 8b (lower side) in FIG. 7A and the heat spreader 8a (upper side) in FIG. 4 are both fixed to the backlight chassis 9 with screws from the back. In addition, the

heat spreaders

8a and 8b are both provided with heat radiation fins at a plurality of locations in order to perform more efficient heat radiation.

In FIG. 7B, as with the upper side of the liquid crystal display device 1, the intermediate chassis 11 e is inserted between the optical sheet 10 and the light guide plate 12, thereby allowing air between the optical sheet 10 and the light guide plate 12. Layer 16 is formed. And since this air layer 16 functions as a heat insulation layer which interrupts the heat_generation | fever in LED board 14b, it becomes possible to make it difficult for a heat | fever to be transmitted to the optical sheet 10. FIG. The intermediate chassis 11e has an extending portion 111e, and the heat spreader 8b has a flange 81b. Then, by inserting the extended portion 111e extending from the intermediate chassis 11e between the front frame 2c and the flange 81b of the heat spreader 8b, it is possible to make it difficult for heat generated by the LED board 14b to be transmitted to the front frame 2c. It becomes possible. That is, since both the front frame 2c and the heat spreader 8b are made of metal, the heat from the heat spreader 8b is transferred to the front frame 2c by inserting the intermediate chassis 11e having a relatively low thermal conductivity between these members. It becomes difficult to convey.

Further, the front frame 2c and the flange 81b of the heat spreader 8b are integrally fixed by a fixing member such as a screw 15b on the back side of the front frame 2c with the extending portion 111e of the intermediate chassis 11e and the board shield 17 interposed therebetween. ing. Thus, the strength of the housing can be secured by fixing the screws in the depth direction from the back.

As described above, the liquid crystal display device according to the present invention includes an optical sheet disposed on the back side of the liquid crystal panel, and a light guide provided on the back side of the optical sheet and emitting light from a light source to the liquid crystal panel. A liquid crystal display device comprising an optical plate, a back chassis provided on the back side of the light guide plate, and a front frame provided around the liquid crystal panel, wherein the optical sheet includes a peripheral portion of the optical sheet and the light guide plate An intermediate chassis that is inserted between the peripheral portion and forms an air layer between the optical sheet and the light guide plate; and provided on the outer side of the rear chassis, at a position facing the upper and lower ends of the light guide plate. A heat radiating member that holds the light source and dissipates heat generated from the light source, and the intermediate chassis has an extending portion that extends between the front frame and the heat radiating member. Thereby, the frame portion of the screen can be narrowed while preventing heat from flowing into the front frame and the optical sheet.

Further, the front frame and the heat radiating member may be made of metal. Thereby, even when the front frame is made of aluminum, for example, and the design is improved, heat inflow to the front frame and the optical sheet can be more effectively prevented.

The heat dissipating member has a flange, and the front frame and the flange are integrally formed by a fixing member on the back side of the front frame with the extended portion extending from the intermediate chassis interposed therebetween. It may be fixed. As a result, the strength of the housing can be ensured, and further, since the screw can be hidden, the design can be improved.

The horizontal and vertical lengths of the light guide plate may be equal to or less than the horizontal and vertical lengths of the liquid crystal panel. Thereby, the frame part of a screen can be narrowed.

Next, the configuration for suppressing the thermal influence on the optical sheet due to the heat generated by the light source will be further described.
FIG. 8 is a view showing a cross section of the upper end portion of the liquid crystal display device 1 shown in FIG. 1, and shows the configuration of the same portion as FIG. As described above, the liquid crystal display device 1 (upper side) includes the front frame 2a, the liquid crystal panel 3, the optical sheet 10, the intermediate chassis 11a, the light guide plate 12, the reflection sheet 13, the backlight chassis 9, the heat spreader 8a, and the LED substrate. 14a.

The heat spreader 8a to which the LED substrate 14a is fixed is bent toward the inner side in the vertical direction at the rear side end portion of the LED substrate 14a, and is stretched for a predetermined length. The backlight chassis 9 is fixed to the heat spreader 8a on the front side (the liquid crystal panel 3 side) of the heat spreader 8a.
The intermediate chassis 11 a extends between the front frame 2 a and the heat spreader 8 a, and a part of the intermediate chassis 11 a is inserted between the peripheral edge of the optical sheet 10 and the peripheral edge of the light guide plate 12.

The front frame 2a and the flange 81a formed on the heat spreader 8a are integrally fixed by a fixing member such as a screw 15a from the back side with an extending portion (flange) 111a extending from the intermediate chassis 11a interposed therebetween. ing. In addition, about a fixed location, the four corners of the liquid crystal display device 1 shall be fixed, for example. By fixing the screws in this way from the back to the front, it is possible to ensure the strength of the casing, and furthermore, the screws can be hidden, which is desirable from the viewpoint of design.

With this configuration, the heat spreader 8a, the intermediate chassis 11a, and the front frame 2a are integrally fixed, and the reflective sheet is sequentially formed between the backlight chassis 9 and the front frame 2a fixed to the heat spreader 8a in order from the backlight chassis 9 side. 13, the light guide plate 12, the optical sheet 10, and the liquid crystal panel 3 are stacked and held. At this time, the intermediate chassis 11a is disposed between the heat spreader 8a and the front frame 2a, and a part of the intermediate chassis 11a is inserted between the peripheral portion of the optical sheet 10 and the peripheral portion of the light guide plate 12, thereby allowing optical An air layer 16 having a predetermined interval is formed between the sheet 10 and the light guide plate 12. The space between the air layers 16 is about 3 mm, for example. The optical sheet 10 is configured such that a plurality of holes (not shown) formed along the periphery of the optical sheet 10 are engaged with ribs (not shown) formed in the intermediate chassis 11a to 11f. Fixed.

The heat generated by the LED board 14a on which the LED serving as the heat source is efficiently radiated by the heat spreader 8a, but as indicated by the broken line arrow, the heat generated by the LED board 14a is conducted from the heat spreader 8a to the intermediate chassis 11a, Further, it is transmitted from the intermediate chassis 11 a to the optical sheet 10 via the liquid crystal panel 3, directly from the intermediate chassis 11 a, or from the intermediate chassis 11 a via the light guide plate 12. Alternatively, there is also heat that is transmitted from the intermediate chassis 11 a to the optical sheet 10 via the front frame 2 a and the liquid crystal panel 3. Alternatively, the heat generated in the LED substrate 14 a is transmitted from the heat spreader 8 a to the backlight chassis 9, and tries to be transmitted from the backlight chassis 9 to the optical sheet 10 via the reflection sheet 13 and the light guide plate 12.
The intermediate chassis 11a is made of a material such as resin or rubber, and is effective for imparting heat insulation properties. However, the intermediate chassis 11a is still not able to be completely insulated only by the intermediate chassis 11a, and the heat from the LED board 14a is generated. There is a possibility of affecting the optical sheet 10 through the intermediate chassis 11a.

As a configuration for preventing the optical sheet 10 from being affected by the heat generated by the LED, between the front frame 2a and the liquid crystal panel 3, between the liquid crystal panel 3 and the intermediate chassis 11a, and between the intermediate chassis 11a and the optical sheet 10. The spacer members S1, S2, S3, and S4 are disposed between the intermediate chassis 11a and the light guide plate 12, respectively. As the spacer members S1, S2, S3, and S4, a foamed resin member such as a foamed urethane resin, a resin member such as a PET sheet, or a combination of these can be used.

The heat transmitted from the LED board 14a to the intermediate chassis 11a and from the front frame 2a to the liquid crystal panel 3 can be insulated by the spacer member S1. Further, heat transmitted from the LED board 14a to the intermediate chassis 11a and further to the liquid crystal panel 3 can be insulated by the spacer member S2. Further, heat that is transmitted from the intermediate chassis 11a to the light guide plate 12 is insulated by the spacer member S4.

Also, the heat that is transmitted directly from the intermediate chassis 11a to the optical sheet 10 can be insulated by the spacer member S3. Here, when the spacer member S3 is in direct contact with the optical sheet 10, there is a possibility that the distortion cannot be released when the optical sheet 10 is slightly expanded / contracted due to a change in environmental temperature or the like. 10 can be arranged so as to be separated from each other by a minute interval. For example, when the optical sheet 10 is shaken toward the intermediate chassis 11a due to vibration or the like, the spacer member S3 is disposed, so that damage to the optical sheet 10 and changes in optical characteristics can be avoided.

In addition, by inserting the intermediate chassis 11 a between the optical sheet 10 and the light guide plate 12, an air layer 16 is formed between the optical sheet 10 and the light guide plate 12. The air layer 16 provides an effect of insulating heat that is transmitted from the backlight chassis 9 to the optical sheet 10 via the light guide plate 12.

As described above, by disposing the spacer members S1 to S4, the transmission path of the heat generated by the LED to the optical sheet 10 can be blocked, and the thermal influence on the optical sheet 10 can be suppressed. Further, the thermal effect from the light guide plate 12 to the optical sheet 10 can be suppressed by the air layer 16 between the optical sheet 10 and the light guide plate 12 formed by the intermediate chassis 11a.

Refer to Fig. 5 again. The basic configuration of the lower end portion of the liquid crystal display device 1 in FIG. 5 is the same as the configuration of the upper end portion shown in FIG. 8, and between the front frame 2c and the liquid crystal panel 3, the liquid crystal panel 3 and the intermediate chassis 11e. Between the intermediate chassis 11e and the optical sheet 10, and between the intermediate chassis 11c and the light guide plate 12, spacer members S5, S6, S7, and S8 such as foamed urethane are disposed. By these, the path | route through which the heat generated from the LED board 14b is transmitted to the optical sheet 10 can be blocked, and the thermal influence on the optical sheet 10 can be suppressed. Further, by inserting the intermediate chassis 11e between the optical sheet 10 and the light guide plate 12, an air layer 16 is formed between the optical sheet 10 and the light guide plate 12, and this air layer 16 is formed on the LED substrate 14b. Since it functions as a heat insulating layer that blocks heat generation, heat can be hardly transmitted to the optical sheet 10. *

The liquid crystal display device includes a light source, a light guide plate that diffuses and emits light from the light source, an optical sheet that acts on the light emitted from the light guide plate to convert optical characteristics, and light emitted from the optical sheet. And a liquid crystal panel that displays an image by modulating the light, and a conduction path through which heat radiation from the substrate on which the light source is disposed is conducted toward the optical sheet through a member constituting the liquid crystal display device An intermediate chassis may be provided as a part of the above member, and a resin spacer member may be disposed on a path through which heat is conducted from the intermediate chassis to the optical sheet. Thereby, the thermal influence on the optical sheet due to the heat generated by the light source can be suppressed, and high display quality can be maintained.

In the liquid crystal display device, the spacer member may be provided between the intermediate chassis and the optical sheet, between the intermediate chassis and the light guide plate, and between the intermediate chassis and the liquid crystal panel. Thereby, the specific structure of the position which arrange | positions a spacer member is provided, and the thermal influence to an optical sheet can be suppressed effectively.

In addition, the liquid crystal display device holds a light source substrate on which a light source is disposed and dissipates heat generated from the light source substrate, and a rear chassis connected to the heat dissipation member and disposed on the back side of the light guide plate A front frame provided so as to surround the periphery of the liquid crystal panel, and the heat dissipation member, the intermediate chassis, and the front panel are integrally fixed, and between the rear chassis and the end of the front panel, a light guide plate, The optical sheet and the liquid crystal panel are held, and a part of the intermediate chassis is inserted between the peripheral portion of the optical sheet and the peripheral portion of the light guide plate, and an air layer having a predetermined interval is formed between the optical sheet and the light guide plate. It may be what you are doing. Thereby, the thermal influence on the optical sheet can be suppressed by the air layer formed between the optical sheet and the light guide plate.

Further, the liquid crystal display device may be one in which a spacer member is further provided between the front member and the liquid crystal panel. Thereby, the thermal influence to an optical sheet can be suppressed more effectively.

1 ... liquid crystal display device, 2a ~ 2d ... 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 ... rear chassis (backlight chassis), 9a ... center seal and auxiliary bracket frame assembly, 10 ... optical sheet, 11a-11f ... intermediate chassis, 12 ... light guide plate, 13 ... reflective sheet, 14a, 14b ... LED substrate, 15a to 15c ... screw, 16 ... air layer, 17 ... substrate shield, 18 ... source substrate, 19 ... source substrate holder, 81a, 81b ... flange, 100 ... liquid crystal display device, 101 ... decorative member, 102 Front frame 102a Projection 103 Liquid crystal panel 104 Optical sheet 105 Light guide plate 106 Reflective sheet 107, backlight chassis, 108, heat spreader, 109, LED substrate, 110, screw, 111a, 111e, extending portion.

Claims

An optical sheet disposed on the back side of the liquid crystal panel, a light guide plate provided on the back side of the optical sheet and emitting light from a light source to the liquid crystal panel, and a rear chassis provided on the back side of the light guide plate And a liquid crystal display device comprising a front frame provided around the liquid crystal panel,
An intermediate chassis that is inserted between a peripheral portion of the optical sheet and a peripheral portion of the light guide plate, and forms an air layer between the optical sheet and the light guide plate;
A heat dissipating member that is provided outside the rear chassis, holds the light source at a position facing the upper and lower ends of the light guide plate, and dissipates heat generated from the light source;
The liquid crystal display device according to claim 1, wherein the intermediate chassis has an extending portion that extends between the front frame and the heat dissipation member.
2. The liquid crystal display device according to claim 1, wherein the front frame and the heat dissipation member are made of metal.
3. The liquid crystal display device according to claim 1, wherein the heat radiating member has a flange, and the front frame and the flange sandwich the extended portion extended from the intermediate chassis, and the front surface. A liquid crystal display device, which is integrally fixed by a fixing member on a back side of the frame.
4. The liquid crystal display device according to claim 1, wherein the horizontal and vertical lengths of the light guide plate are equal to or less than the horizontal and vertical lengths of the liquid crystal panel. Liquid crystal display device.
A light source, a light guide plate that diffuses and emits light from the light source, an optical sheet that acts on the light emitted from the light guide plate to convert optical characteristics, and modulates the light emitted from the optical sheet In a liquid crystal display device having a liquid crystal panel for displaying an image,
An intermediate chassis is provided as a part of the member in a conduction path in which heat radiation from the substrate on which the light source is disposed is conducted toward the optical sheet through a member constituting the liquid crystal display device. A resin spacer member is disposed on a path through which heat is conducted to the optical sheet.
The liquid crystal display device according to claim 5.
The liquid crystal display, wherein the spacer member is provided between the intermediate chassis and the optical sheet, between the intermediate chassis and the light guide plate, and between the intermediate chassis and the liquid crystal panel. apparatus.
The liquid crystal display device according to claim 6.
A heat radiating member that holds the light source substrate on which the light source is disposed and dissipates heat generated from the light source substrate;
A rear chassis connected to the heat dissipation member and disposed on the back side of the light guide plate;
A front frame provided so as to surround the periphery of the liquid crystal panel,
The heat dissipation member, the intermediate chassis, and the front frame are fixed integrally, and the light guide plate, the optical sheet, and the liquid crystal panel are held between the rear chassis and the end of the liquid crystal panel,
A part of the intermediate chassis is inserted between the peripheral edge of the optical sheet and the peripheral edge of the light guide plate, and an air layer having a predetermined interval is formed between the optical sheet and the light guide plate. A liquid crystal display device.
The liquid crystal display device according to claim 7.
The liquid crystal display device, wherein the spacer member is further provided between the front frame and the liquid crystal panel.