JP6366931B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device capable of suppressing adverse effects due to heat generation of a light emitting device constituting a backlight device.

  A liquid crystal display device includes a liquid crystal display panel in which liquid crystal is sealed between two transparent substrates including a transparent electrode and a color filter through an alignment film, and a backlight that irradiates light from the back side of the liquid crystal display panel The display device of the liquid crystal display panel by applying a voltage to the transparent electrode to displace the molecular arrangement of the liquid crystal and changing the transmittance of light emitted from the backlight device. Is displayed.

  Due to the structure of the backlight device, the liquid crystal display device has a direct type in which a light emitting device serving as a light source is disposed on the back side of the liquid crystal display panel, and a light emitting device on the edge side of the light guide plate disposed on the back surface of the liquid crystal display panel. It is roughly classified into the edge light type to be arranged. The edge light type liquid crystal display device has an advantage that the thickness can be reduced as compared with the direct type, and recently, the liquid crystal display device employing the edge light type backlight device is becoming mainstream. In addition, as a light emitting device as a light source, there are a cathode tube and an LED (Light Emitting Diode), but an LED with low power consumption tends to be used.

  By the way, in order to increase the luminance of the display surface of the liquid crystal display panel, the light emitting device needs to emit light with high luminance. However, in the edge light type backlight device, the light emitting device is concentrated on the edge side of the light guide plate. For this reason, there is a possibility that the light emitting device becomes hot when the light is emitted with high luminance. Therefore, when an LED is used for the light emitting device, the LED is not high in heat resistance, so that there is a problem of damage due to heat during high luminance light emission. Therefore, in the high-brightness type liquid crystal display device, a direct-type backlight device has to be employed, and there is a problem that it is difficult to reduce the thickness.

  In order to apply an edge-light type backlight device to a high-brightness type liquid crystal display device, overheating prevention means of the light-emitting device is required. Patent Document 1 describes a technique for preventing overheating in a light emitting device of an edge light type backlight device. Patent Document 1 describes a structure in which a plurality of LEDs that are light emitting devices are classified into two or more groups, and each group is mounted on a different constituent member. Specifically, each of the plurality of LEDs disposed on the side of the light guide plate is alternately mounted on the front cover and the rear cover. According to Patent Document 1, such a configuration can increase the heat dissipating area per LED and increase the heat dissipating efficiency, so that a heat dissipating member such as a heat sink can be omitted, and the liquid crystal display device can be made thinner and lighter. It is supposed to be able to plan.

  FIG. 2 is a cross-sectional view showing a schematic configuration of a main part of a conventional liquid crystal display device 200, and shows a conventional example in which an overheating prevention technique for the light emitting device 27 of the edge light type backlight device 23 is different. In the figure, the surface corresponding to the display surface side of the liquid crystal display device 200 is referred to as “front surface”, and the opposite surface opposite to this is referred to as “back surface”.

  2 includes a liquid crystal display panel 21, an optical sheet 22 such as a polarizing sheet disposed on the back side of the liquid crystal display panel 21, and an edge light disposed on the back side of the optical sheet 22. Type backlight device 23, heat spreader 30 disposed on the back side of the backlight device 23, backlight chassis 25 covering the back surface of the heat spreader 30, and support unit for supporting the rear surface of the edge of the liquid crystal display panel 21 The panel chassis 28 having 28a and the front bezel 29 having the panel pressing portion 29a for pressing the front surface of the edge of the liquid crystal display panel 21 are provided.

  The backlight device 23 includes a light guide plate 26 and a light emitting device 27 disposed in the vicinity of the edge of the light guide plate 26, and a reflection sheet 24 is provided on the back surface of the light guide plate 26. The light emitting device 27 includes a light emitting element 27a made of an LED and a control board 27b. Further, although not shown in the figure, a control unit is provided for processing the image data and performing voltage control of the liquid crystal display panel 21 and luminance control of the backlight device 23.

  In the conventional example of FIG. 2, a heat spreader 30 in which an edge portion 30 a is in contact with or close to the control board 27 b of the light emitting device 27 is disposed between the light guide plate 26 and the backlight chassis 25. The heat spreader 30 absorbs and diffuses the heat generated in the light emitting device 27 to prevent overheating of the light emitting device 27. The heat spreader 30 is formed with large and small raised portions 31 and 32, and the raised portions 31 and 32 are brought into contact with the reflection sheet 24 provided on the back surface of the light guide plate 26 to support the light guide plate 26. Yes.

JP 2009-37212 A

  The present inventors have obtained knowledge that a liquid crystal display device having an edge light type backlight device may cause the following problems in addition to the problem that the light emitting device is damaged by overheating. It was. First, in the light guide plate, the light emitted from the light emitting device is not normally incident on the light guide plate as a result of being heated by the heat generation of the light emitting device and causing deformation such as elongation and warpage due to thermal expansion. There is a problem that efficiency is lowered and light leakage occurs.

  Next, in the optical sheet, the temperature rises only in the vicinity of the light emitting device that has reached a high temperature, and as a result of local expansion, wrinkles are generated in the optical sheet, and the transmitted light becomes non-uniform, resulting in display. There is a problem that the image is uneven. In addition, there is a problem that the light guide plate that has been thermally deformed such as warpage presses the optical sheet, and the degree of freedom of thermal expansion and movement of the optical sheet is limited, so that the optical sheet is also wrinkled and the display image can be uneven. is there. Further, in the liquid crystal display panel, when the heat of the light emitting device is transmitted and the temperature of the liquid crystal display panel rises, the characteristics of the liquid crystal display panel change and the luminance of the black image increases, resulting in unevenness of the display image. In addition, the contrast ratio is relatively lowered, so that the display quality of the image is deteriorated.

  Patent Document 1 does not consider the above-described problems other than the damage of the light emitting device. That is, the above-mentioned problem cannot be solved. In addition, since the conventional liquid crystal display device described in Patent Document 1 employs a complicated structure in which LEDs classified into two or more groups are mounted on different components, it is difficult to manufacture the liquid crystal display device. There is a problem that increases the cost of the display device.

  The conventional liquid crystal display device 200 shown in FIG. 2 also does not take measures against the above-described problems other than the prevention of overheating of the light emitting device 27, and thus causes the following problems. The heat spreader 30 has a configuration in which the edge portion 30 a is in contact with or close to the light emitting element 27 a and the raised portions 31 and 32 are in contact with the reflection sheet 24. For this reason, the heat of the light emitting device 27 that has absorbed heat at the edge portion 30 a is diffused throughout the heat spreader 30, and the heat is transmitted to the light guide plate 26 through the reflection sheet 24 through the raised portions 31 and 32. . As a result, the light guide plate 26 is deformed to be stretched or warped due to thermal expansion, so that the positional relationship between the light emitting surface of the light emitting device 27 and the light incident surface of the light guide plate 26 is displaced, and light is incident. There is a problem that the efficiency is lowered and the designed luminance cannot be obtained.

  In addition, since the reflective sheet 24 is locally heated to cause partial thermal expansion, wrinkles are generated in the reflective sheet 24 and the light reflection state becomes uneven. Further, the heat of the light emitting device 27 is also transmitted to the optical sheet 22 through the light guide plate 26, and the optical sheet 22 is locally heated and partially thermally expanded. As a result, the optical sheet 22 is wrinkled. There is a problem that the light transmission state becomes non-uniform.

  An object of the present invention is to provide a liquid crystal display device which can prevent overheating of a light emitting device with a simple configuration and can prevent the heat generated by the light emitting device from adversely affecting the light guide plate and the optical sheet. .

The present invention provides a liquid crystal display panel having a display surface;
A light emitting unit disposed on the back side opposite to the display surface of the liquid crystal display panel;
A flat light guide plate disposed on the back side of the liquid crystal display panel so as to face the liquid crystal display panel, wherein the light emitting unit is configured such that light emitted from the light emitting unit is incident from an end surface of the light guide plate A light guide plate that is disposed in the vicinity of the light guide plate and emits light incident from an end surface thereof from a surface facing the liquid crystal display panel;
Between the liquid crystal display panel and the light guide plate, a flat optical sheet disposed to face the liquid crystal display panel and the light guide plate;
A first support for supporting the light guide plate;
A second support for supporting the liquid crystal display panel and the optical sheet;
The first support member is provided on the light guide plate from a plate-like base portion provided opposite to the back surface of the light guide plate opposite to the surface facing the liquid crystal display panel, and an outer peripheral edge of the base portion. A peripheral wall projecting in the direction of approach,
The second support covers an outer peripheral edge of the optical sheet,
The second support body includes a support main body portion, a first peripheral wall contact portion protruding from the support main body portion so as to contact a first surface of the peripheral wall portion facing the space surrounded by the peripheral wall portion, A second peripheral wall contact portion projecting from the support main body so as to contact a second surface opposite to the first surface of the peripheral wall portion, and the first peripheral wall contact portion and the A liquid crystal display device configured to sandwich the peripheral wall portion with a second peripheral wall contact portion .

Further, in the present invention, the support main body portion has a frame shape surrounding an end surface of the outer peripheral edge portion of the optical sheet,
The second support is
The liquid crystal display panel protrudes from the support main body so as to be interposed between the outer peripheral edge of the liquid crystal display panel and the outer peripheral edge of the optical sheet, and the outer peripheral edge of the liquid crystal display panel extends from the optical sheet side. A first protrusion to support;
It protrudes from the support main body so as to be interposed between the outer peripheral edge of the optical sheet and the outer peripheral edge of the light guide plate, and contacts the outer peripheral edge of the light guide plate from the optical sheet side. a second projecting portion further includes a,
The optical sheet is supported by sandwiching both sides in the thickness direction of the outer peripheral edge of the optical sheet by the first protrusion and the second protrusion.

In the liquid crystal display device of the present invention, the light guide plate and the optical sheet are spaced apart from each other.
In the liquid crystal display device of the present invention, at the outer peripheral edge of the optical sheet sandwiched between the first protrusion and the second protrusion, the end of the edge of the optical sheet and the support body There is a gap in the surface direction of the optical sheet between them .

According to the present invention, a liquid crystal display device includes a liquid crystal display panel, a light emitting unit disposed on the back side of the liquid crystal display panel for emitting light, a light guide plate, an optical sheet, a second support member, the . The light guide plate is a flat member disposed on the back side of the liquid crystal display panel so as to face the liquid crystal display panel, and is close to the light emitting unit so that the light emitted from the light emitting unit enters from the end face of the light guide plate The light incident from the end face is emitted from the surface facing the liquid crystal display panel. The optical sheet is a flat plate member disposed between the liquid crystal display panel and the light guide plate so as to face the liquid crystal display panel and the light guide plate, and previously determines light incident from the surface facing the light guide plate. The light is converted into light having optical characteristics, and the converted light is emitted from the surface facing the liquid crystal display panel.

The second support supports the liquid crystal display panel and the optical sheet, and covers an outer peripheral edge of the optical sheet. The second support member is a structure for supporting the liquid crystal display panel and the optical sheet, having supporting lifting body portion, the first protrusion and the second protrusion. The support main body is a frame-shaped portion that surrounds the end surface of the outer peripheral edge of the optical sheet. The first protruding portion is a portion protruding from the support main body portion so as to be interposed between the outer peripheral edge portion of the liquid crystal display panel and the outer peripheral edge portion of the optical sheet, and the outer peripheral edge portion of the liquid crystal display panel Is supported from the optical sheet side. The second projecting portion is a portion projecting from the support main body so as to be interposed between the outer peripheral edge of the optical sheet and the outer peripheral edge of the light guide plate, and guides the outer peripheral edge of the optical sheet. While supporting from the optical plate side, it contacts the outer peripheral edge of the light guide plate from the optical sheet side to suppress deformation of the light guide plate.
The 2nd support body is supporting the optical sheet by pinching | interposing the outer-periphery edge part of an optical sheet in the clearance gap between a 1st protrusion part and a 2nd protrusion part. According to this structure, there is no pressure on the optical sheet from either the light guide plate side or the liquid crystal display panel side, and the surface of the optical sheet is formed in the gap between the first protrusion and the second protrusion. Since the optical sheet can be supported in a state where free thermal expansion and free movement are ensured only in the direction, wrinkles can be prevented from occurring in the optical sheet, and the direction perpendicular to the surface of the optical sheet The optical sheet can be appropriately supported by restricting the movement of the optical sheet to the optical sheet.

In the liquid crystal display device of the present invention, the second protrusion provided between the outer peripheral edge of the optical sheet and the outer peripheral edge of the light guide plate is in contact with the outer peripheral edge of the light guide plate from the optical sheet side. Since the deformation of the light guide plate is suppressed, even if the light guide plate thermally expands due to heat generation of the light emitting part and rises to the optical sheet side, the rise of the light guide plate is suppressed and the end surface of the outer peripheral edge of the light guide plate It is possible to suppress the occurrence of a positional deviation between the light emitting unit and the light emitting unit. As a result, the light emitted from the light emitting unit can be normally incident into the light guide plate, and a decrease in light incident efficiency can be suppressed and light leakage can be prevented.

In addition, the second protrusion provided between the outer peripheral edge of the optical sheet and the outer peripheral edge of the light guide plate is in contact with the outer peripheral edge of the light guide plate from the optical sheet side to suppress the deformation of the light guide plate. Therefore, it is possible to prevent the optical sheet from being thermally deformed such as warp due to heat generation of the light emitting part from suppressing the optical sheet, thereby preventing the thermal expansion and freedom of movement of the optical sheet from being limited, As a result, generation of wrinkles in the optical sheet can be suppressed, and unevenness in the display image can be prevented.
Since there is a gap in the surface direction of the optical sheet between the end of the optical sheet and the support main body at the outer peripheral edge of the optical sheet sandwiched between the first protrusion and the second protrusion, optical Even when the sheet is thermally expanded, there is a margin until the end of the edge of the optical sheet comes into contact with the support body. For this reason, generation | occurrence | production of the wrinkle of the optical sheet at the time of thermal expansion can be prevented more appropriately.

Further, according to the present invention, the second support is in contact with the first peripheral wall protruding from the support main body so as to contact the first surface of the peripheral wall facing the space surrounded by the peripheral wall of the first support. And a second peripheral wall contact portion projecting from the support main body portion so as to contact the second surface opposite to the first surface of the peripheral wall portion, the first peripheral wall contact portion and the second peripheral wall contact portion It is comprised so that a surrounding wall part may be clamped with a surrounding wall contact part. As a result, the bonding strength between the second support and the first support can be increased. As a result, the force by which the second protrusion of the second support member presses the outer peripheral edge of the light guide plate from the optical sheet side is the force that rises to the optical sheet side of the light guide plate that is thermally deformed by the heat generation of the light emitting unit. In order not to lose, it is possible to reinforce the pressing force of the second protrusion against the light guide plate. Therefore, even if the light guide plate is thermally expanded due to heat generation of the light emitting part, the second protrusion can more reliably prevent the light guide plate from rising, so that the end surface of the outer peripheral edge of the light guide plate and the light emitting part Can be prevented from occurring, and as a result, it is possible to suppress a decrease in light incident efficiency of light emitted from the light emitting portion into the light guide plate.

  According to the invention, in the liquid crystal display device, the light guide plate and the optical sheet are spaced apart from each other. As a result, a space is formed between the light guide plate and the optical sheet, and the heat generated by the light emitting portion is generated through the light guide plate by utilizing the heat insulation effect of the air layer in the space, and the liquid crystal display panel. It becomes difficult to be transmitted to. Therefore, it is possible to prevent the temperature of the liquid crystal display panel from rising due to the heat of the light emitting part, and to prevent the characteristics of the liquid crystal display panel from changing. As a result, unevenness in the displayed image or contrast It can be prevented that the ratio is relatively lowered and the display quality of the image is deteriorated.

  In addition, by forming a space between the light guide plate and the optical sheet, it is possible to increase the distance between the light emitting unit and the optical sheet that are disposed in proximity to the end surface of the outer peripheral edge of the light guide plate. Therefore, it is possible to suppress the portion of the optical sheet adjacent to the light emitting portion from being thermally expanded locally, and as a result, it is possible to suppress the occurrence of wrinkles on the optical sheet and prevent unevenness in the display image. can do.

It is sectional drawing which shows schematic structure of the principal part of the liquid crystal display device 100 which concerns on one Embodiment of this invention. It is sectional drawing which shows schematic structure of the principal part of the conventional liquid crystal display device.

  FIG. 1 is a cross-sectional view showing a schematic configuration of a main part of a liquid crystal display device 100 according to an embodiment of the present invention. In the following description, the surface corresponding to the display surface side of the liquid crystal display panel 1 is referred to as “front surface”, and the opposite surface opposite to this is referred to as “back surface”.

  The liquid crystal display device 100 of the present embodiment is a device that displays an image on a display surface by outputting image information in a television or a personal computer. The liquid crystal display device 100 includes a liquid crystal display panel 1, an optical sheet 2, an edge light type backlight device 3 including a light guide plate 6, a reflective sheet 4, a backlight chassis 5 as a first support, and a light emitting device as a light emitting unit. 7, a panel chassis 8 as a second support, a front bezel 9 as a frame, and a heat spreader 10 as a heat absorbing member. Further, although not shown, the liquid crystal display device 100 is provided with a control unit including a microcomputer that performs electric control such as voltage control of the liquid crystal display panel 1 and luminance control of the backlight device 3.

  The liquid crystal display panel 1 is supported by a panel support portion 8b of a panel chassis 8 described later. The liquid crystal display panel 1 includes two substrates and is formed in a rectangular plate shape when viewed in the thickness direction. The liquid crystal display panel 1 includes a switching element such as a TFT (Thin Film Transistor), and liquid crystal is injected into a gap between two substrates. In the liquid crystal display panel 1, the light emitted from the light emitting device 7 of the backlight device 3 disposed on the back side on the other side in the thickness direction on the side opposite to the display surface on the one side in the thickness direction is the light guide plate 6 and optical. By irradiating the sheet 2 as a backlight, a display function is exhibited. The two substrates are provided with drivers (source drivers) for driving the pixels in the liquid crystal display panel 1, various elements, and wirings.

  The optical sheet 2 is disposed in parallel with the liquid crystal display panel 1 so as to face the back surface opposite to the display surface of the liquid crystal display panel 1. The optical sheet 2 converts light emitted from a light guide plate 6 described later into light having predetermined optical characteristics, and emits the converted light toward the liquid crystal display panel 1. Specifically, the optical sheet 2 directs the traveling direction of the light reaching from the back side through the light guide plate 6 to the front side. In the light guide plate 6, in order to prevent the luminance from being biased in the surface direction, the traveling direction of light includes many components in the surface direction as vector components. On the other hand, the optical sheet 2 converts the traveling direction of light containing a lot of vector components in the plane direction into the traveling direction of light containing many components in the thickness direction. The optical sheet 2 is formed with a large number of lens or prism-shaped portions arranged side by side in the surface direction, thereby reducing the diffusivity of light traveling in the thickness direction. Therefore, the luminance can be increased in the display by the liquid crystal display device 100.

  The backlight device 3 is an edge light type having a light guide plate 6 and a light emitting device 7 disposed in the vicinity of the end surface of the outer peripheral edge of the light guide plate 6. On the back surface of the light guide plate 6, a reflection sheet 4 that reflects incident light toward the liquid crystal display panel 1 is provided. In the present embodiment, the light-emitting device 7 includes a light-emitting element 7a composed of LEDs arranged close to the end face of the outer peripheral edge of the light guide plate 6, and a control board 7b on which the light-emitting element 7a is mounted. . Note that a plurality of light emitting devices 7 may be provided along the outer peripheral edge of the light guide plate 6 or a plurality of light emitting elements 7a mounted on a single control board 7b as a unit. Good.

  The light guide plate 6 is disposed in parallel with the optical sheet 2 and opposed to the back surface of the optical sheet 2 opposite to the front surface facing the liquid crystal display panel 1. The light guide plate 6 is made of a translucent resin material and is a rectangular plate-like (in this embodiment, a rectangular plate-like) member. The light guide plate 6 emits light emitted from the light emitting device 7 and incident from the end face of the outer peripheral edge from the front surface which is one surface in the thickness direction facing the back surface of the optical sheet 2.

  In the liquid crystal display device 100 of this embodiment, the heat spreader 10 is provided on the back side of the backlight device 3, that is, on the back side of the outer peripheral edge of the light guide plate 6. This heat spreader 10 is intended to prevent overheating of the light emitting device 7 by absorbing and diffusing the heat generated in the light emitting device 7. The heat spreader 10 is disposed to face the back of the outer peripheral edge of the light guide plate 6 (disposed on a base 5a of the backlight chassis 5 described later), and one outer peripheral edge of the heat spreader base 10a. A heat absorbing portion 10b that rises perpendicularly from the heat spreader base portion 10a in the direction approaching the light guide plate 6; Have.

  In the heat spreader 10, the heat absorbing portion 10 b is interposed between a base portion 5 a of the backlight chassis 5 described later and the light emitting device 7, and supports the light emitting device 7 in contact with or close to the control board 7 b of the light emitting device 7. The heat absorbing portion 10b absorbs heat generated in the light emitting device 7. Further, in the heat spreader 10, the raised portions 10c and 10d are provided in contact with the reflection sheet 4 provided on the back surface of the light guide plate 6, and are configured to support the light guide plate 6 from the back side. Moreover, the heat spreader 10 is manufactured with the material excellent in heat conductivity, for example, copper, copper alloy, aluminum, aluminum alloy etc. are used.

  The backlight chassis 5 is formed so as to cover the heat spreader 10 from the back side and further cover the light guide plate 6 from the back side, and is configured to support the central portion of the light guide plate 6 from the back side. The backlight chassis 5 is opposed to the rear surface of the light guide plate 6 and has a plate-like base portion 5a on which a light guide plate support portion 5aa for supporting the central portion of the light guide plate 6 from the rear side is formed, and an outer peripheral edge of the base portion 5a And a peripheral wall portion 5 b protruding from the base portion 5 a to the same side as the light guide plate support portion 5 aa, that is, vertically projecting toward the liquid crystal display panel 1.

  The outer peripheral edge of the base portion 5 a of the backlight chassis 5 is provided in contact with the back surface of the heat spreader base portion 10 a of the heat spreader 10, and the light guide plate support portion 5 aa formed at the center portion of the base portion 5 a is the center of the light guide plate 6. In this section, the light guide plate 6 is provided in contact with the reflective sheet 4 provided on the back surface of the light guide plate 6 and is configured to support the light guide plate 6 from the back surface side.

(First embodiment)
In the liquid crystal display device 100 according to the first embodiment of the present invention, the panel chassis 8 is a structure that supports the liquid crystal display panel 1 from the back side and supports the optical sheet 2 from the back side. A panel chassis base 8a, a panel support 8b, and a light guide plate deformation suppressing portion 8c.

  The panel chassis base portion 8a surrounds the end surface of the outer peripheral edge of the optical sheet 2 and has a rectangular frame shape along the outer peripheral edge of the liquid crystal display panel 1 so as to protrude on both sides in the thickness direction with respect to the optical sheet 2. The liquid crystal display panel 1 is formed and brought into contact with the tip of the outer peripheral edge of the liquid crystal display panel 1 from the back side.

  The panel support portion 8 b is a portion that protrudes along the back surface of the liquid crystal display panel 1 in a direction from the inner peripheral edge portion on the front surface side of the panel chassis base portion 8 a toward the center side of the liquid crystal display panel 1. The panel support portion 8b is provided between the outer peripheral edge portion of the liquid crystal display panel 1 and the outer peripheral edge portion of the optical sheet 2, and is in contact with the back surface of the outer peripheral edge portion of the liquid crystal display panel 1. 1 is supported from the back side (optical sheet 2 side).

  The light guide plate deformation suppressing portion 8 c is a portion that protrudes along the front surface of the light guide plate 6 in a direction from the inner peripheral edge portion on the back side of the panel chassis base portion 8 a toward the center side of the light guide plate 6. The light guide plate deformation suppressing portion 8c is provided between the outer peripheral edge portion of the optical sheet 2 and the outer peripheral edge portion of the light guide plate 6, and the outer peripheral edge portion of the optical sheet 2 from the back side (light guide plate 6 side). While supporting, it contacts the outer-periphery edge part of the light-guide plate 6 from the optical sheet 2 side, ie, contacts the outer-periphery edge part of the light-guide plate 6 from the front side, and suppresses deformation of the light-guide plate 6.

(Second Embodiment and Third Embodiment)
In the liquid crystal display device 100 according to the second embodiment of the present invention, the panel chassis 8 further includes a first peripheral wall contact portion 8d and a second peripheral wall contact portion 8e. In the second embodiment, the first peripheral wall contact portion 8d is a portion protruding along the peripheral wall portion 5b of the backlight chassis 5 in a direction away from the liquid crystal display panel 1 from the central portion on the back side of the panel chassis base portion 8a. It is. 8 d of 1st surrounding wall contact parts are provided in contact with the 1st surface (inner surface) of the surrounding wall part 5b which faces the space enclosed by the surrounding wall part 5b. The second peripheral wall contact portion 8e is a portion protruding along the peripheral wall portion 5b of the backlight chassis 5 in a direction away from the liquid crystal display panel 1 from the outer peripheral edge portion on the back side of the panel chassis base portion 8a. . The second peripheral wall contact portion 8e is provided in contact with a second surface (outer surface) opposite to the first surface of the peripheral wall portion 5b. In the third embodiment, the first peripheral wall contact portion 8 d is provided in contact with the first surface of the peripheral wall portion 5 b and in contact with the heat absorbing portion 10 b of the heat spreader 10. The panel chassis 8 having the first peripheral wall contact portion 8d and the second peripheral wall contact portion 8e as described above sandwiches the peripheral wall portion 5b of the backlight chassis 5 by the first peripheral wall contact portion 8d and the second peripheral wall contact portion 8e. Is configured to do.

  The panel chassis 8 supports the liquid crystal display panel 1 by the panel support portion 8b, suppresses the deformation of the light guide plate 6 by the light guide plate deformation suppression portion 8c, and the peripheral wall by the first peripheral wall contact portion 8d and the second peripheral wall contact portion 8e. By firmly holding the portion 5b and suppressing the occurrence of a positional shift between the light emitting device 7 and the end surface of the outer peripheral edge of the light guide plate 6, the light from the light emitting device 7 to the light guide plate 6 can be prevented. In order not to decrease the light incident efficiency, it is required to have rigidity and strength.

(Fourth embodiment)
In the fourth embodiment, the panel chassis 8 contacts the heat spreader 10 at the first peripheral wall contact portion 8d. Since the panel chassis 8 supports the liquid crystal display panel 1, the optical sheet 2, and the light guide plate 6, the heat absorbed by the heat spreader 10 is not transmitted to the liquid crystal display panel 1, the optical sheet 2, and the light guide plate 6. It is preferable to be configured as described above. Therefore, in the fourth embodiment, the panel chassis 8 is formed of a material having excellent heat insulation. As a material excellent in heat insulation constituting the panel chassis 8, PC (polycarbonate) resin, ABS (acrylonitrile-butadiene-styrene) resin, or glass fiber reinforced resin obtained by adding glass fiber to these resins is used. It is done.

  The front bezel 9 is a member for covering the front surface of the outer peripheral edge portion of the liquid crystal display panel 1 and covering the outer surface of the second peripheral wall contact portion 8 e that is the outermost surface of the panel chassis 8. The front bezel 9 is formed in a rectangular frame shape, and covers the outer peripheral edge portion of the liquid crystal display panel 1 from the front side, thereby holding the liquid crystal display panel 1 and the outer peripheral edge portion of the panel pressing portion 9a. The panel chassis covering portion 9b is formed to extend along the second peripheral wall contact portion 8e of the panel chassis 8 and covers the outer surface of the second peripheral wall contact portion 8e. In the liquid crystal display device 100 of this embodiment, the liquid crystal display panel 1 is sandwiched between the panel pressing portion 9a of the front bezel 9 and the panel support portion 8b of the panel chassis 8, and the panel chassis covering portion 9b is the second peripheral wall contact portion 8e. The panel chassis base 8a is fixed to cover the outer surface, and the panel chassis 8 is fixed as a whole.

(5th Embodiment and 6th Embodiment)
Further, in the liquid crystal display device 100 according to the fifth embodiment of the present invention, the liquid crystal display panel 1 and the optical sheet 2 are arranged apart from each other, corresponding to the thickness of the panel support portion 8b of the panel chassis 8. Yes. As a result, a first space S1 is formed between the liquid crystal display panel 1 and the optical sheet 2. Furthermore, in the liquid crystal display device 100 according to the sixth embodiment of the present invention, the light guide plate 6 and the optical sheet 2 correspond to the thickness of the light guide plate deformation suppressing portion 8c of the panel chassis 8 and are spaced apart from each other. Has been. As a result, a second space S2 is formed between the light guide plate 6 and the optical sheet 2.

  The liquid crystal display device 100 of the present embodiment configured as described above exhibits the operations and effects described below.

  The panel chassis 8 provided in the liquid crystal display device 100 according to the first embodiment described above includes a panel support 8b provided between the outer peripheral edge of the liquid crystal display panel 1 and the outer peripheral edge of the optical sheet 2. A light guide plate deformation suppressing portion 8c provided between the outer peripheral edge portion of the optical sheet 2 and the outer peripheral edge portion of the light guide plate 6, and the panel support portion 8b backs the outer peripheral edge portion of the liquid crystal display panel 1. Since the light guide plate deformation suppressing portion 8c comes into contact with the outer peripheral edge of the light guide plate 6 from the front side to suppress the deformation of the light guide plate 6, the light guide plate 6 is thermally expanded by the heat generated by the light emitting device 7. Even if it rises to the optical sheet 2 side (front side), the rise of the light guide plate 6 is suppressed, and the positional relationship between the end surface of the outer peripheral edge of the light guide plate 6 and the light emitting device 7 is shifted. Can be suppressed. As a result, the light emitted from the light emitting device 7 is normally incident into the light guide plate 6, and it is possible to suppress a decrease in light incident efficiency and to prevent light leakage.

  Further, the light guide plate deformation suppressing portion 8 c provided between the outer peripheral edge portion of the optical sheet 2 and the outer peripheral edge portion of the light guide plate 6 is arranged on the optical sheet 2 side (front side) at the outer peripheral edge portion of the light guide plate 6. Since the deformation of the light guide plate 6 is suppressed by contacting the optical sheet 2, it is possible to suppress the optical sheet 2 from being pressed by the light guide plate 6 that is thermally deformed such as warp due to the heat generation of the light emitting device 7. As a result, it is possible to prevent the optical sheet 2 from being wrinkled and to prevent the display image from being uneven.

  Further, the panel chassis 8 provided in the liquid crystal display device 100 according to the second embodiment, the third embodiment, and the fourth embodiment described above is in contact with the first peripheral wall that contacts the inner surface of the peripheral wall portion 5b of the backlight chassis 5. 8 d and a second peripheral wall contact portion 8 e that contacts the outer surface of the peripheral wall portion 5 b, and the peripheral wall portion 5 b is sandwiched between the first peripheral wall contact portion 8 d and the second peripheral wall contact portion 8 e. ing. Thereby, the coupling strength between the panel chassis 8 and the backlight chassis 5 can be increased. As a result, the force with which the light guide plate deformation suppressing portion 8 c of the panel chassis 8 presses the outer peripheral edge of the light guide plate 6 from the front side rises to the front side of the light guide plate 6 that is thermally deformed by the heat generated by the light emitting device 7. In order not to lose the force, the pressing force of the light guide plate deformation suppressing portion 8c against the light guide plate 6 can be reinforced. Therefore, even if the light guide plate 6 is thermally expanded due to heat generated by the light emitting device 7, the light guide plate deformation suppressing portion 8c can more reliably prevent the light guide plate 6 from rising, so that the outer peripheral edge portion of the light guide plate 6 can be prevented. The positional deviation between the end face of the light-emitting device 7 and the light-emitting device 7 can be suppressed from occurring, and as a result, the decrease in the light incident efficiency of the light emitted from the light-emitting device 7 into the light guide plate 6 can be suppressed. Can do.

  Furthermore, in the liquid crystal display device 100 according to the fifth and sixth embodiments described above, the first space S1 is formed between the liquid crystal display panel 1 and the optical sheet 2, and the light guide plate 6 and the optical sheet 2 are formed. A second space S2 is formed between the two. As a result, the heat generation effect of the air space in the first space S1 and the second space S2 is utilized to make it difficult for heat generated by the light emitting device 7 to be transmitted to the optical sheet 2 and the liquid crystal display panel 1 via the light guide plate 6. . Therefore, it is possible to prevent the temperature of the liquid crystal display panel 1 from increasing due to the heat transmitted from the light emitting device 7 and to prevent the characteristics of the liquid crystal display panel 1 from changing. As a result, the display image is uneven. It is possible to prevent the contrast ratio from being relatively lowered and the display quality of the image from being deteriorated.

  In addition, by forming the second space S2 between the light guide plate 6 and the optical sheet 2, the light emitting device 7 and the optical sheet 2 that are disposed close to the end surface of the outer peripheral edge of the light guide plate 6 are provided. Therefore, it is possible to suppress the portion of the optical sheet 2 that is close to the light-emitting device 7 from being locally thermally expanded, and as a result, it is possible to prevent the optical sheet 2 from wrinkling. Thus, the display image can be prevented from being uneven.

(Seventh embodiment)
In the liquid crystal display device 100 according to the seventh embodiment of the present invention, it is preferable that the light guide plate deformation suppressing portion 8 c of the panel chassis 8 is formed with a protruding portion that protrudes in the direction approaching the light guide plate 6. . Accordingly, the second space S2 formed between the light guide plate 6 and the optical sheet 2 can be made wider corresponding to the thickness of the light guide plate deformation suppressing portion 8c, and as a result, the second space. By utilizing the heat insulating effect of the air layer of S2, the effect that heat generated by the light emitting device 7 is not easily transmitted to the optical sheet 2 and the liquid crystal display panel 1 through the light guide plate 6 can be made more remarkable.

  As described above, the liquid crystal display device 100 according to the present embodiment can solve all of the conventional problems described above. Therefore, a high-brightness type liquid crystal that employs an edge-light type backlight device and achieves thinning. A display device can be provided. In addition, since the problem that the light emitting device 7 is damaged due to overheating and the heat generated by the light emitting device 7 adversely affects the light guide plate 6, the optical sheet 2, and the liquid crystal display panel 1, the display quality can be stabilized. it can.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2 Optical sheet 3 Backlight apparatus 4 Reflective sheet 5 Backlight chassis 5a Base part 5aa Light guide plate support part 5b Perimeter wall part 6 Light guide plate 7 Light-emitting device 7a Light-emitting element 7b Control board 8 Panel chassis 8a Panel chassis base part 8b Panel support Part 8c light guide plate deformation suppressing part 8d first peripheral wall contact part 8e second peripheral wall contact part 9 front bezel 9a panel pressing part 9b panel chassis covering part 10 heat spreader 10a heat spreader base part 10b heat absorption part 10c, 10d raised part 100 liquid crystal display device

Claims (4)

A liquid crystal display panel having a display surface;
A light emitting unit disposed on the back side opposite to the display surface of the liquid crystal display panel;
A flat light guide plate disposed on the back side of the liquid crystal display panel so as to face the liquid crystal display panel, wherein the light emitting unit is configured such that light emitted from the light emitting unit is incident from an end surface of the light guide plate A light guide plate that is disposed in the vicinity of the light guide plate and emits light incident from an end surface thereof from a surface facing the liquid crystal display panel;
Between the liquid crystal display panel and the light guide plate, a flat optical sheet disposed to face the liquid crystal display panel and the light guide plate;
A first support for supporting the light guide plate;
A second support for supporting the liquid crystal display panel and the optical sheet;
The first support member is provided on the light guide plate from a plate-like base portion provided opposite to the back surface of the light guide plate opposite to the surface facing the liquid crystal display panel, and an outer peripheral edge of the base portion. A peripheral wall projecting in the direction of approach,
The second support covers an outer peripheral edge of the optical sheet,
The second support body includes a support main body portion, a first peripheral wall contact portion protruding from the support main body portion so as to contact a first surface of the peripheral wall portion facing the space surrounded by the peripheral wall portion, A second peripheral wall contact portion projecting from the support main body so as to contact a second surface opposite to the first surface of the peripheral wall portion, and the first peripheral wall contact portion and the A liquid crystal display device configured to sandwich the peripheral wall portion with a second peripheral wall contact portion . The support main body has a frame shape surrounding an end surface of the outer peripheral edge of the optical sheet,
The second support is
The liquid crystal display panel protrudes from the support main body so as to be interposed between the outer peripheral edge of the liquid crystal display panel and the outer peripheral edge of the optical sheet, and the outer peripheral edge of the liquid crystal display panel extends from the optical sheet side. A first protrusion to support;
It protrudes from the support main body so as to be interposed between the outer peripheral edge of the optical sheet and the outer peripheral edge of the light guide plate, and contacts the outer peripheral edge of the light guide plate from the optical sheet side. a second projecting portion further includes a,
2. The liquid crystal according to claim 1, wherein the optical sheet is supported by sandwiching both sides in a thickness direction of an outer peripheral edge of the optical sheet by the first protrusion and the second protrusion. Display device.   The liquid crystal display device according to claim 1, wherein the light guide plate and the optical sheet are spaced apart from each other. In the outer peripheral edge of the optical sheet sandwiched between the first protrusion and the second protrusion, between the end of the edge of the optical sheet and the support main body, in the surface direction of the optical sheet The liquid crystal display device according to claim 2 , wherein a gap is provided.

Images