WO2019069400A1

WO2019069400A1 - Display device

Info

Publication number: WO2019069400A1
Application number: PCT/JP2017/036149
Authority: WO
Inventors: 弘樹深井
Original assignee: 堺ディスプレイプロダクト株式会社
Priority date: 2017-10-04
Filing date: 2017-10-04
Publication date: 2019-04-11

Abstract

A display device (1) according to an embodiment comprises: a display panel (2) having a display surface (2a) on which an image is displayed and a rear surface (2b) that is the opposite surface to the display surface (2a); a heating element (3) disposed at the edge of the display panel (2) or in the vicinity of the edge; and a heat diffusion member (4) that diffuses heat generated by the heating element (3). The heat diffusion member (4) is provided with a plate-shape heat-dissipating part (4b) extending toward the outer side of the display panel (2) so as to be away from the heating element (3).

Description

Display device

The present invention relates to a display device.

In recent years, liquid crystal display devices are widely used as display devices for various electronic devices, and adoption of organic EL display devices for smartphones and the like is also expanding. In these display devices, a desired image is displayed by a combination of light having a color and brightness selected for each pixel. In the liquid crystal display device, light from the light source is blocked for each pixel, and depending on the degree of light blocking, display is performed from the brightest state (white) to the darkest state (black). Then, in order to improve the display quality, it is considered to increase the contrast ratio which is the ratio of the maximum luminance (white) to the minimum luminance (black). For example, in Patent Document 1, in order to suppress a decrease in contrast ratio, the spacer is disposed such that a predetermined region around the spacer disposed between the array substrate and the counter substrate overlaps the light shielding portion of the black matrix. ing.

JP, 2016-218128, A

The inventor has found that a reduction in contrast ratio can occur regardless of the factors disclosed in US Pat.

Then, an object of this invention is to provide the display apparatus which can suppress the fall of the contrast ratio newly discovered.

A display device according to an embodiment of the present invention includes a display panel having a display surface on which an image is displayed and a back surface opposite to the display surface, and a heating element disposed at or near an edge of the display panel. A heat diffusion member for diffusing heat generated by the heat generating body, the heat diffusion member including a plate-like heat dissipation portion extending toward the outside of the display panel so as to be away from the heat generating body It is characterized by

According to the embodiment of the present invention, it is possible to suppress the decrease in contrast ratio caused by the heat generated in the heating element.

It is a front view which shows an example of the display apparatus of Embodiment 1 of this invention. FIG. 2 is a cross-sectional view taken along line II-II of FIG. It is an enlarged view of the III section in FIG. It is an enlarged view of the heat generating body arrange | positioned in the display apparatus shown by FIG. 1, and its periphery. FIG. 3 is a perspective view showing an example of a heat diffusion member according to the display device of Embodiment 1. 5 is a side cross-sectional view showing another example of the display device of Embodiment 1. FIG. 5 is a side cross-sectional view showing another example of the display device of Embodiment 1. FIG. 5 is a side cross-sectional view showing another example of the display device of Embodiment 1. FIG. FIG. 7 is a side cross-sectional view showing another example of the arrangement of heating elements in the display device of Embodiment 1. FIG. 6 is a front view showing an example in which the display device of Embodiment 1 is provided with a housing. FIG. 8B is a top view of the display illustrated in FIG. 8A. It is a figure which shows an example of the cross section in the IX-IX line of FIG. 8A. It is a figure which shows the other example of the cross section in the IX-IX line of FIG. 8A. It is a figure which shows the other example of the cross section in the IX-IX line of FIG. 8A. It is a figure which shows typically the example of the display panel in the conventional display apparatus, and a heat sink.

The inventors of the present invention have found that heat may be transferred from the heat sink to the display panel from the heat sink to which the heat generated inside the display device should be transferred to the outside, resulting in a reduction in the contrast ratio in the liquid crystal display device. I found it. As shown in FIG. 10, in the conventional liquid crystal display device 100 including the edge light type backlight module, the end surface (light incident surface) of the light guide plate 105 disposed on the back surface of the liquid crystal display panel 101 is opposed. A plurality of light emitting diodes (LEDs) 102 serving as light sources are disposed. The LEDs 102 are disposed on the heat sink 103 via a substrate (not shown) so that the temperature of the LEDs 102 does not exceed the upper limit of the allowable operating temperature due to heat generation during light emission. The heat dissipation plate 103 is disposed along the back surface of the light guide plate 105 (opposite to the surface facing the liquid crystal display panel 101) from the vicinity of one side of the light guide plate 105 facing the LED 102. The inventor has found that heat is transmitted from the heat sink 103 to the liquid crystal display panel 101 via the light guide plate 105.

The liquid crystal display panel 101 generally has a laminated structure including a glass plate, a polarizing plate, an alignment film, a color filter, and the like. Each of these components has a different coefficient of thermal expansion. Therefore, when the temperature rises, the liquid crystal display panel 101 may be warped due to the difference in the thermal expansion coefficient of each component. A liquid crystal display panel is configured by providing an air gap between two glass plates and injecting a liquid crystal material into the air gap. The variation in the gap causes the transmittance of the liquid crystal layer to fluctuate, and in particular the unevenness of the brightness occurs in the black screen display. The air gap between the glass plates is generally called cell gap. When the liquid crystal panel is thermally warped due to the temperature rise, the external force causes fluctuation in the cell gap, and the transmittance of the liquid crystal layer fluctuates to cause unevenness in lightness. In addition, in the liquid crystal display panel, two polarizing plates are attached to the front and back of the panel so that their polarization axes are perpendicular to each other. Occurs. The inventors of the present invention have found that such unevenness in brightness due to the warp of the liquid crystal display panel 101 and light leakage due to expansion of the polarizing plate can occur in the liquid crystal display panel 101. Then, as a result, the inventor has found that the contrast ratio of the liquid crystal display device 100 can be reduced. Furthermore, in the arrangement of the conventional heat dissipation plate 103, since the distance between the heat dissipation plate 103 and the liquid crystal display panel 101 is narrow, the present inventor efficiently dissipates heat from the surface of the heat dissipation plate 103 facing the liquid crystal display panel 101. I found it not.

Hereinafter, the display device of the present invention will be described with reference to the drawings. The materials, shapes, sizes, relative positional relationships, and the like of the components in the embodiments described below are merely illustrative. The display device and the method of manufacturing the display device of the present invention are not to be interpreted in a limited manner by these.

Embodiment 1
FIG. 1 shows a front view of the display device 1 of Embodiment 1, and FIG. 2 shows a cross-sectional view taken along the line II-II of FIG. Further, FIG. 3 shows an enlarged view of a portion III in FIG. 2, and FIG. 4 shows an enlarged view of a portion where the heating element 3 is disposed in the display device 1 shown in FIG. . As shown in FIGS. 1 to 4, the display device 1 according to the first embodiment includes a display surface 2 a on which an image (including an image) is displayed and a display panel 2 having a back surface 2 b opposite to the display surface 2 a. A heating element 3 disposed in the vicinity of the edge of the display panel 2 and a heat diffusion member 4 for diffusing the heat generated by the heating element 3 are provided. Further, in the example of FIGS. 1 to 4, the display device 1 further includes the light guide plate 5 disposed to face the back surface 2 b of the display panel 2.

The X, Y, Z shown in the figures are intended as X-direction defining a horizontal plane and Z-direction defining a Y-direction and a vertical direction unless otherwise stated herein. That is, in the display device 1, the long axis direction of the display surface 2a is the X direction, the short axis direction is the Z direction, and the thickness direction is the Y direction. In addition, the display device 1 at the time of use is arranged such that the display surface 2a is along the XZ plane.

The heat diffusion member 4 includes a heat receiving portion 4 a for receiving the heat generated by the heating element 3 and a plate-like heat radiating portion 4 b connected to the heat receiving portion 4 a. The plate-like heat radiating portion 4 b extends from the heat receiving portion 4 a to the outside of the display panel 2 so as to be away from the heating element 3. The heat diffusion member 4 may be a single plate, and in this case, the heat receiving portion 4a is a portion of the heat diffusion member 4 thermally connected to the heating element 3, and a single plate heat It may be an end or a central portion of the diffusion member 4. As described above, the “heat radiating portion” is a portion to which heat transmitted from the heat generating body 3 is transferred by heat conduction in a direction away from the heat generating body 3, and the heat transferred is a heat diffusion member by convection and radiation. It is the part that dissipates to the 4 circumference. Therefore, almost all parts of the heat diffusion member 4 excluding the part receiving the heat from the heat generating element 3 (heat receiving part 4a) can be the heat releasing part 4b.

In the plate-like heat radiating portion 4b, one end thereof is connected to the heat receiving portion 4a thermally connected to the heating element 3 disposed in the vicinity of the edge portion of the display panel 2, and the other end is the other end. The end is located at the distal end of the heating element 3. When the heat diffusion member 4 is a rectangular single plate, one of the two opposing sides thereof is located as a heat receiving portion 4a at a distance where the heat transfer of the heat generating element 3 can be realized, and the other side is from the heat generating element 3 A heat dissipation portion 4b may be formed to extend to the outside of the display panel 2 so as to be spaced apart (see FIGS. 6A and 6C). Alternatively, the heat dissipation portion 4b may be formed between a portion (heat receiving portion 4a) thermally connected to the heating element 3 between the two opposing sides (the heat receiving portion 4a) and the two sides (see FIG. 6B). Of course, the heat diffusion member 4 may not be a single plate, and may be L-shaped in cross section as shown in FIG. 7.

In the heat diffusion member 4, there may not be a clear structural difference between the heat receiving portion 4 a and the heat radiating portion 4 b, and the heat diffusion member 4 as a single member has relatively high heat absorption. The region where the heat dissipation is relatively low and the region where the heat absorption is relatively low and the heat dissipation is relatively high correspond to the heat receiving portion 4a and the heat radiating portion 4b, respectively.

Here, “heat generating body” is not a member that intentionally generates heat in the display device 1 but means a member that generates heat as a result. As a heat generating body arrange | positioned in the vicinity of the edge of the display panel 2, the light source for backlights of a transmissive liquid crystal display device is illustrated, for example. In the example of FIGS. 1 to 4, the display device 1 is a transmission type liquid crystal display device of edge light type, and in this example, the light emitting element used as a light source corresponds to the heating element 3. The light emitting element as the heating element 3 may be a light emitting diode (LED), a semiconductor element such as a laser diode, or a cold cathode tube. Further, as a heating element disposed at the edge of the display panel 2, for example, a semiconductor integrated circuit device that generates a drive signal for the display panel is exemplified (for example, a driver 32 described later with reference to FIG. 7).

Further, “near the edge of the display panel” means a position at a distance that allows heat to be transmitted from the display panel without passing through other members (a distance at which a thermal connection is established). "The edge of the display panel" means a frame area (an area where no image or video is displayed) in the display panel.

Also, “heat transfer” is used as a general term for heat transfer, “heat conduction (or simply“ conduction ”)”, “convection” and “radiation” are each a form of heat transfer, “heat conduction” "Means heat transfer without movement of matter," "convection" means heat transfer provided by a flow of matter, and "radiation" means heat transfer provided by an electromagnetic wave. Further, “diffusion” used for heat is mainly used for heat transfer from the heat receiving part 4 a generated inside the heat diffusion member 4 to an arbitrary place in the heat releasing part 4 b. Also, the "dissipation" of heat is used for the heat transfer from the surface of the heat diffusion member 4 to the air around it, or the heat transfer to the external material via the air.

As shown in FIG. 3, the light exit surface 5 b of the light guide plate 5 faces the back surface 2 b of the display panel 2, and the light entrance surface 5 a of the light guide plate 5 faces the heating element (light emitting element) 3. There is. The light emitting element 3 is thermally connected to the heat diffusion member 4. Here, “thermal connection” is an indirect connection (via air or some member) even if it is a direct connection (a state of direct physical contact) as long as heat transfer is realized. ) May be. In the example of FIGS. 1 to 4, the light emitting element 3 is mounted on the surface of the substrate 6 directly connected to the heat diffusion member 4. That is, the light emitting element 3 is indirectly connected to the heat diffusion member 4.

As described above, in the present embodiment, since the light emitting element 3 is thermally connected to the heat diffusion member 4, the heat generated by the light emitting element 3 is transferred to the heat receiving portion 4 a of the heat diffusion member 4. In the heat diffusion member 4, the heat transmitted from the light emitting element 3 is transmitted to the heat radiating portion 4b connected to the heat receiving portion 4a, and is transmitted by heat conduction in the heat radiating portion 4b, and from any surface of the heat radiating portion 4b It is dissipated to the outside. As a result, the temperature rise of the light emitting element 3 is suppressed.

The heat radiating portion 4 b extends from the heat receiving portion 4 a toward the outside of the display panel 2. Therefore, the heat dissipated from the surface of the heat radiating portion 4 b is difficult to be transmitted to the display panel 2. Note that “extends to the outside of the display panel 2” means that the heat radiating portion 4 b is on the YZ plane in each drawing so that the heat radiating portion 4 b does not approach the display panel 2 too much and does not block the display image. It means extending in a predetermined direction. Here, the “predetermined direction” is an angle θ (see FIG. 3) having the heat receiving portion 4a between the heat receiving portion 4a and the straight line extending in the + Z direction (that is, parallel to the back surface 2b of the display panel 2). The orientation is 30 ° or more and 270 ° or less. In other words, when the back surface 2b is parallel to the vertical direction as in the example of FIG. 3, the "predetermined direction" when the heat radiating portion 4b is behind the display panel 2 is based on the heat receiving portion 4a- It is an orientation having an elevation angle of 90 ° or more and 60 ° or less (an elevation angle of 0 ° or more and 60 ° or less, or a depression angle of 0 ° or more and 90 ° or less). Further, when the heat radiating portion 4b is present in front of the display panel 2 (see FIG. 6A), an elevation angle (0.degree. Or more, -90.degree. Or more and 0.degree. Or less) with respect to the heat receiving portion 4a. It is a direction having a depression angle of 90 ° or less). The “YZ plane” is a plane perpendicular to the display panel 2 including the vertical direction. The heat dissipating portion 4 b may have either or both of a refracting portion and a bending portion as long as it extends in a direction satisfying this condition. The heat radiating portion 4b extends in a direction in which the angle θ with the heat receiving portion 4a at the apex on the YZ plane is preferably 45 ° or more and 270 ° or less, more preferably 60 ° or more and 270 ° or less ing.

The heat diffusion member 4 is disposed along the upper side, the left side, or the right side of the display panel 2 when the display device 1 is used, as described later with reference to reference numerals 41 to 43 in FIG. May be When the heat diffusion member 4 is disposed along the upper side of the display panel 2, the angle θ is between the straight line extending vertically downward (−Z direction) from the heat receiving portion 4 a and the extending direction of the heat releasing portion 4 b in the YZ plane. Of the heat receiving portion 4a of the When the heat diffusion member 4 is disposed along the left side or the right side of the display panel 2, the angle θ is the + X direction from the heat receiving portion 4 a in the XY plane (a plane perpendicular to the display panel 2 including the horizontal direction) Alternatively, the angle between the straight line extending in the X direction and the extending direction of the heat radiating portion 4b is a vertex at the heat receiving portion 4a.

As described above, in the conventional liquid crystal display device 100 (see FIG. 10), the heat dissipation plate 103 for diffusing the heat generated by the LED 102 is disposed along the back surface of the light guide plate 105. Most of the heat sink plate 103 faces the back surface of the light guide plate 105. Such a shape and arrangement of the heat dissipation plate 103 ensure the surface area necessary to obtain the heat dissipation performance required of the heat dissipation plate 103, and reduce the overall thickness of the liquid crystal display device 100 including the heat dissipation plate 103. It is thought that the intention was adopted. However, it has not been recognized until now that the heat of the heat dissipation plate 103 can be transferred to the liquid crystal display panel 101 via the light guide plate 105 and that such heat transfer affects the liquid crystal display panel 101. . In such a situation, the inventor has found that heat can be transferred from the heat sink 103 to the liquid crystal display panel 101, and a reduction in contrast ratio can occur due to such heat transfer.

In the example of FIGS. 1 to 4, the heat dissipation part 4 b of the heat diffusion member 4 extends from the heat receiving part 4 a in a direction at which the angle with the back surface 2 b of the display panel 2 is approximately 90 °. It also extends along a substantially perpendicular direction. Specifically, the heat radiating portion 4 b extends from the heat receiving portion 4 a in a direction in which the back surface 2 b of the display panel 2 faces (hereinafter, the direction in which the back surface 2 b faces is also referred to as “rearward”). Neither surface of the heat radiating portion 4 b is opposed to the display surface 2 a or the back surface 2 b of the display panel 2. Even when the display panel 2 exists directly in front of any one of the surfaces of the heat dissipation portion 4 b (hereinafter referred to as the surface S), the surface S is parallel to the display surface 2 a or the back surface 2 b of the display panel 2 There is no. Therefore, the heat dissipated from the heat radiating portion 4 b is difficult to be transmitted to the light guide plate 5 and the display panel 2. Therefore, the temperature of the display panel 2 does not easily rise. Therefore, in the display panel 2, the warping due to the difference in the thermal expansion coefficient between the components is hard to occur, and the light leakage hardly occurs. In addition, since temperature unevenness in the display panel 2 is also less likely to occur, it is considered that display unevenness due to temperature characteristics of liquid crystal molecules or temperature characteristics of a drive circuit for driving the display panel 2 is also less likely to occur. Therefore, while the fall of contrast ratio is suppressed, the image of the outstanding display quality can be obtained.

In addition, since the heat radiating portion 4 b extends from the heat receiving portion 4 a to the outside of the display panel 2, even if the heat receiving portion 4 a is disposed in the vicinity of the display panel 2, the heat radiating portion 4 b Are separated from the display panel 2. Therefore, the air around the heat dissipation portion 4b can freely flow. Therefore, high heat dissipation can be obtained by convection (natural convection and / or forced convection). Moreover, unlike the conventional heat sink disposed opposite to the display panel 2, the thickness T 4 of the heat diffusion member 4 is increased without increasing the thickness of the portion provided with the display panel 2 in the display device 1 can do. That is, the thermal conductivity and thermal capacity of the thermal diffusion member 4 can be enhanced by thickening the thermal diffusion member 4 without causing an increase in the thickness of the portion where the image is displayed. As a result, the heat generated by the heating element 3 can be efficiently diffused.

In the example shown in FIG. 2, the heat diffusion member 4 having a length L4 (see FIG. 1) = 1544 mm, a width W4 = 60 mm and a thickness T4 = 10 mm is provided on the 70-type (1539 mm wide × 866 mm long) display panel 2 It is combined. As shown in the examples described later, using the heat diffusion member 4 of this size, improvement of the contrast ratio of the display panel 2 is obtained, and the temperature of the heating element (light emitting element) 3 (see FIG. 3) Can be maintained below the upper limit value. The ratio of the length (height) H2 in the vertical direction of the display panel 2 to the width W4 and the thickness T4 of the heat diffusion member 4 in FIG. 2 is the height (height) H2 of the 70-inch display panel described above; The ratio of the width W4 = 60 mm and the thickness T4 = 10 mm of the thermal diffusion member 4 is substantially the same (in FIG. 1, the thickness of the thermal diffusion member 4 is emphasized so that the thermal diffusion member 4 can be easily recognized) ing). That is, as shown in FIG. 2, the heat diffusion member protrudes from the back surface 2b of the display panel 2 by a slight length compared to the size of the display panel 2 (the height H2 of the display panel 2 in FIG. 2). The inventors of the present invention have found that the use of No. 4 can achieve both the required heat dissipation and the improvement of the contrast ratio.

The heat diffusion member 4 provided with the heat dissipating part 4 b extending from the heat receiving part 4 a toward the outside of the display panel 2 does not significantly increase the size of the display device 1 as shown in FIG. 2. In addition, a support portion (stand) for supporting the display panel 2, an acoustic member such as a speaker, and / or an operation panel including a switch for operation may be provided at the peripheral edge of the display panel 2. Therefore, the heat diffusion member 4 can be contained in or combined with these members. By doing so, the increase in size of the display device 1 can be avoided. That is, the display device 1 according to the present embodiment includes the heat diffusion member 4 including the heat receiving portion 4 a and the heat radiating portion 4 b extending from the heat receiving portion 4 a toward the outside of the display panel 2. In terms of surface as well, it can be provided with sufficient merchantability as a flat display.

As shown in FIG. 1, in the present embodiment, the display panel 2 has a rectangular front shape, and the display surface 2 a is directed forward. In the example of FIG. 1, the heat diffusion member 4 is disposed along the lower side of the rectangular display panel 2. The front shape of the display panel 2 is not limited to a rectangle, and may be, for example, a square. The display device 1 is disposed along the upper side, the left side, and the right side of the display panel 2 instead of or in addition to the heat diffusion member 4 disposed along the lower side of the display panel 2. One or more heat diffusion members 41 to 43 may be provided. That is, the heat diffusion member 4 may be disposed along any one or more of the four sides of the display panel 2 having a rectangular shape. For example, when the display panel 2 is installed so that the display surface 2a is parallel to the vertical direction, the heat diffusion is performed along one or more of the lower side, the upper side, and the left and right sides of the display panel 2 A member 4 may be provided. The display panel 2 and the heat diffusion member 4 may be housed inside the housing 10 including a frame-shaped bezel portion surrounding the display panel 2.

As described above, the light emitting diode (LED) is exemplified as the light emitting element 3 as a heating element. For example, as shown in FIG. 4, a plurality of light emitting diodes are arranged as light emitting elements 3 in a row along one side (the lower side of the display panel 2 in the example of FIG. 4) of the display panel 2. That is, the plurality of light emitting elements 3 are preferably arranged to face the light incident surface 5 a over the entire length of the light incident surface 5 a of the light guide plate 5 in the longitudinal direction. By disposing the light emitting element 3 in such a manner, light can be incident over substantially the entire surface of the light incident surface 5a. A plurality of light emitting elements 3 may be arranged in a line along each of two or more sides of the display panel 2. In this case, the substrate 6 and the heat are opposed to each side of the display panel 2. A diffusion member 4 may be provided.

As shown in FIG. 3, the light guide plate 5 has, at its end face, a light entrance surface 5 a on which the light from the light source is incident. The light advancing from the light incident surface 5a to the end face opposite to the light incident surface 5a while repeating total reflection, is emitted from the light exit surface 5b to the display panel 2. Preferably, the light incident surface 5a and the light exit surface 5b are substantially orthogonal to each other. In the example of FIG. 3, the light emitting surface 5 b of the light guide plate 5 is provided with a diffusion layer 52. The light emitting surface 5 b of the light guide plate 5 is opposed to the back surface 2 b of the display panel 2 via the diffusion layer 52. The diffusion layer 52 diffuses the light emitted from the light guide plate 5 so as to be emitted at a wide emission angle. Although not shown, the light guide plate 5 is provided with a diffuse reflection pattern and a reflection layer on the opposite surface 5c of the light exit surface 5b. The light guide plate 5 is made of, for example, a translucent synthetic resin such as acrylic or polycarbonate, or glass. Further, the diffusion layer 52 may be made of, for example, a resin film such as a PET film or a PC film including a diffusion member such as milk semi-acrylic resin or plastic beads.

The substrate 6 is preferably made of a thermally conductive material. This is because the heat of the light emitting element 3 can be well diffused inside the substrate 6. In that respect, the substrate 6 may be understood as part of the heat spreading member 4. For example, an example of the substrate 6 is a wiring board in which a conductor pattern is formed on a plate made of alumina, aluminum nitride, silicon nitride or the like. The substrate 6 may be a metal base substrate or the like provided with a wiring layer formed through an insulating layer on a base layer formed of copper, aluminum or the like. When the display device 1 is a liquid crystal display device, the light of the light emitting element 3 can be efficiently incident to the inside of the light guide plate 5 by the configuration shown in FIG. 3 and FIG. The heat can be efficiently transmitted to the heat diffusion member 4.

As shown in FIG. 3, the length (width) W6 of the substrate 6 in the thickness direction of the display panel 2 is from the distance from the display surface 2 a of the display panel 2 to the opposite surface 5 c of the light output surface 5 b of the light guide plate 5. Too long. That is, in the example of FIG. 3, the contact area between the substrate 6 and the thermal diffusion member 4 is larger than in the case where the width W6 of the substrate 6 is, for example, about the same as the thickness of the light guide plate 5. Therefore, the heat transferred from the light emitting element 3 to the substrate 6 and transferred also in the direction perpendicular to the thickness direction in the substrate 6 can be well transferred to the heat diffusion member 4. On the other hand, in the above-described conventional liquid crystal display device 100 (see FIG. 10), the heat dissipation plate 103 disposed in the vicinity of one side of the light guide plate 105 is curved toward the back surface of the light guide plate 105. In such a configuration, only a substrate having a short length in the thickness direction of the liquid crystal display panel 101 can be used as a substrate (not shown) on which the LED 102 is mounted. However, in the example of FIG. 3, since the heat radiating portion 4 b of the heat diffusion member 4 linearly extends from the heat receiving portion 4 a toward the outside of the display panel 2, the large substrate 6 with the width W 6 can be used. The temperature rise of the light emitting element 3 can be further suppressed.

In the example shown in FIGS. 1 to 4, the display device 1 further includes an auxiliary member 11. The auxiliary member 11 is fixed to the edge of the back surface 2 b of the display panel 2 via the light guide plate 5. As shown in FIGS. 3 and 4, the auxiliary member 11 is disposed along the back surface 2 b of the display panel 2. The auxiliary member 11 is provided to increase the rigidity of the display panel 2. Preferably, as shown in FIG. 4, the auxiliary member 11 covers substantially the entire side of the display panel 2 and the light guide plate 5 (the lower side in the example of FIG. 4) at the edge of the display panel 2 and the light guide plate 5. Provided as. The auxiliary member 11 suppresses deformation of the display panel 2 and the light guide plate 5. In the present embodiment, the heat dissipation part 4 b of the heat diffusion member 4 extends from the heat receiving part 4 a toward the outside of the display panel 2, so the heat diffusion member 4 is used to suppress deformation of the display panel 2 and the light guide plate 5. It can be difficult to do. However, by providing the auxiliary member 11, the rigidity of the display panel 2 and the light guide plate 5 can be enhanced, and the deformation thereof can be further reduced.

Auxiliary member 11 can be formed using any metal such as, for example, aluminum or stainless steel. However, preferably, the auxiliary member 11 is formed using a material having a low thermal conductivity so that the heat of the heat diffusion member 4 is not transferred to the light guide plate 5 and the display panel 2 as much as possible. The auxiliary member 11 may be formed of any resin such as engineering plastic, and the material of the auxiliary member 11 is not particularly limited thereto. Further, in the examples of FIGS. 3 and 4, the auxiliary member 11 is a cylindrical body having a substantially rectangular cross-sectional shape in a cross section perpendicular to the long axis direction, but the auxiliary member 11 has a cross-sectional shape other than rectangular. It may be a rod-like body having no hollow portion. The auxiliary member 11 may also have a generally U-shaped or C-shaped cross-sectional shape. The auxiliary member 11 may be connected to the light guide plate 5 using any bonding means such as an adhesive.

As shown in FIG. 3, the auxiliary member 11 is fixed to the heat diffusion member 4 via the connection member 12. The heat diffusion member 4 and the light guide plate 5 are fixed to each other using the auxiliary member 11 and the connection member 12. The connecting member 12 has a first fixing surface 121 directed substantially parallel to the back surface 2 b of the display panel 2 and a second fixing surface 122 substantially orthogonal to the first fixing surface 121. The auxiliary member 11 may be fixed to the first fixing surface 121 of the connecting member 12 using any fixing means, and the heat diffusion member 4 may be fixed to the second fixing surface 122 using any fixing means. In the example of FIG. 3,

bolts

12 a and 12 b are respectively used as fixing means for the auxiliary member 11 and the connecting member 12 and as fixing means for the heat diffusion member 4 and the connecting member 12. The material of the connecting member 12 is not particularly limited, but preferably, the same material as the auxiliary member 11 is used as the material of the connecting member 12. Further, the shape of the connection member 12 is not limited to the shape shown in FIG. 3 as long as the heat diffusion member 4 and the light guide plate 5 can be connected.

The through hole 12c provided in the first fixing surface 121 to insert the bolt 12a should have a shape orthogonal to the light incident surface 5a of the light guide plate 5 when it is combined with the light guide plate 5 through the auxiliary member 11 in its opening shape. It may be a slot having a longitudinal direction parallel to the direction. Further, the through hole 12d provided in the second fixing surface 122 for inserting the bolt 12b is parallel to the thickness direction of the light guide plate 5 when it is combined with the light guide plate 5 through the auxiliary member 11 in its opening shape. It may be an elongated hole having a longitudinal direction. By providing the through

holes

12 c and 12 d as described above, the light emitting element 3 can be easily positioned at a desired position with respect to the light incident surface 5 a when the light guide plate 5 and the heat diffusion member 4 are fixed.

The heat diffusion member 4 is formed using a material having a high thermal conductivity. The heat diffusion member 4 preferably contains any one or more of aluminum, copper and ceramics. When the heat diffusion member 4 contains any of these materials, the heat transmitted from the heating element 3 such as a light emitting element can be widely diffused in the heat diffusion member 4 and efficiently dissipated to the outside. However, the heat diffusion member 4 may be formed of a material having other substances as main components. Also, on the surface of the thermal diffusion member 4, a high emissivity film (not shown) made of Al ₂ O ₃ , AlTiN, graphite or the like is used by sputtering or evaporation to enhance heat transfer by radiation. It may be formed. In addition, an alumite treatment may be applied to the surface of the heat diffusion member 4 in order to enhance the heat dissipation by radiation.

Preferably, a thickness T4 of the plate-shaped heat radiation portion 4b of the heat diffusion member 4 is 1 mm or more and 5 mm or less. When the heat radiating portion 4 b has a thickness in this range, the heat transmitted from the light emitting element 3 is widely diffused in the heat diffusion member 4 and efficiently dissipated to the outside, and further, the bezel portion of the display device 1 There is also no significant increase in width. However, the thickness T4 of the heat dissipation portion 4b is not necessarily limited to the thickness in this range. The thickness T4 of the heat dissipation portion 4b may be thicker than the thickness of the display panel 2 and / or the thickness of the light guide plate 5 in order to ensure good heat diffusion.

Another example of the heat diffusion member 4 in the present embodiment is schematically shown in FIG. 5 together with the display panel 2. In the example of FIG. 5, the heat dissipation portion 4 b of the heat diffusion member 4 has a surface 4 d in which a plurality of fins 4 c are aligned. Thus, the heat diffusion member 4 may be provided with a plurality of fins 4c arranged in parallel. The provision of the plurality of fins 4 c increases the surface area of the heat diffusion member 4, and as a result, the amount of heat dissipated from the heat diffusion member 4 to the outside increases. Therefore, the temperature rise of the light emitting element 3 (see FIG. 4) is further suppressed. Although not shown, the substrate 6 (see FIG. 4) is connected to the surface of the heat dissipation part 4b opposite to the surface 4d, and the light emitting element 3 is mounted on the substrate 6.

The fins 4c are preferably provided on the surface 4d opposite to the surface facing the light guide plate 5 in the heat diffusion member 4 when the light guide plate 5 and the heat diffusion member 4 are connected as in the example of FIG. . The fins 4 c extend from the surface 4 d in a direction in which the surface 4 d faces away from the display panel 2. Each of the plurality of fins 4 c has a plate-like shape, and two opposing surfaces (hereinafter referred to as “principal surface 4 ca”) other than the end surfaces of the plate-like fins 4 c It is provided to be substantially parallel to the thickness direction. The plurality of fins 4 c are parallel to each other with the main surfaces 4 ca facing each other in the direction in which one side of the display panel 2 facing the heat diffusion member 4 extends. When the plurality of fins 4c are provided in this manner, as described later, when an air flow is generated using a fan or the like in the thickness direction of the display panel 2 (see FIG. 9B), heat is very effectively generated. It can be dissipated to the surroundings. The plurality of fins 4 c may be arranged in parallel in the thickness direction of the display panel 2 in a direction in which the main surfaces 4 ca of the respective fins 4 c are substantially parallel to the display panel 2.

The fins 4c are formed of, for example, a material containing at least one of aluminum, copper, and ceramics, and preferably formed integrally with the heat dissipation portion 4b using the same material as the heat dissipation portion 4b. However, the fins 4c may be formed using a material different from that of the heat dissipation portion 4b, and the fins 4c may be individually formed and then fixed to the surface 4d using an adhesive or the like.

In the present embodiment, the heat radiating portion 4b of the heat diffusion member 4 may extend from the heat receiving portion 4a in a direction other than the rear of the display panel 2 unlike the example of FIGS. 6A to 6C show an example of the heat dissipating part 4b extending in a direction other than the rear of the display panel 2 as such. 6A to 6C show cross sections at the same position as the cross sectional view shown in FIG. 3 in each example. 6A to 6C, the same components as those shown in FIG. 3 are assigned the same reference numerals as the reference symbols shown in FIG. 3, and the description thereof is appropriately omitted in the following description. .

In the example shown in FIG. 6A, the heat radiating portion 4b is substantially in the direction in which the display surface 2a of the display panel 2 faces (hereinafter, the direction in which the display surface 2a faces is also referred to as "forward") with respect to the display surface 2a. It extends vertically from the heat receiving portion 4a. The heat diffusion member 4 is connected to the light guide plate 5 using a connection member 12 having an L-shaped cross-sectional shape. Also in the example of FIG. 6A, as in the example of FIG. 3 and the like, the heat radiating portion 4b does not extend along the display surface 2a and the back surface 2b of the display panel 2 and faces the heat receiving portion 4a toward the outside of the display panel 2. It extends from Therefore, the heat diffusion member 4 diffuses inside toward the end 4 ba and the heat dissipated from the heat diffusion member 4 to the outside is difficult to be transmitted to the display panel 2. Therefore, the decrease in contrast ratio of the display device 1 can be prevented. The connecting member 12 is preferably formed using a material having a low thermal conductivity, similarly to the auxiliary member 11 and the connecting member 12 in the example of FIG. 3.

As shown in FIG. 6A, when the heat diffusion member 4 is provided, the heat radiation portion 4b existing between the display surface 2a and the user (not shown) who views the display surface 2a is used for any use. May be For example, as described later, a housing (not shown) covering the heat diffusion member 4 is provided, and the surface of the housing covering the surface 4 e facing the display panel 2 in the heat radiating portion 4 b An operation panel or the like provided with a switch or the like may be provided.

FIG. 6B shows an example of the heat diffusion member 4 having the heat dissipating part 4 b extending from the heat receiving part 4 a both toward the front and the back of the display panel 2. The heat radiating portion 4 b has a first end 4 ba 1 which is a tip of a portion of the display panel 2 extending to the front, and a second end 4 ba 2 which is a tip of a portion of the display panel 2 extending to the rear doing. The substrate 6 on which the light emitting element 3 is mounted as a heating element is connected to a substantially middle portion between the first end 4 ba 1 and the second end 4 ba 2 of the heat diffusion member 4. The heat diffusion member 4 is fixed to the light guide plate 5 using the connecting member 12 so that the light emitting element 3 faces the light incident surface 5 a of the light guide plate 5. Also in the example of FIG. 6B, the heat dissipated to the outside from the heat diffusion member 4 is difficult to transfer to the display panel 2. Therefore, the decrease in contrast ratio of the display device 1 can be prevented. Further, in the example of FIG. 6B, the protrusion amount of the heat diffusion member 4 from the display surface 2a or the back surface 2b of the display panel 2 is small while securing the same heat capacity in the heat diffusion member 4 as the example of FIG. can do.

6C, the display apparatus 1 provided with the heat-diffusion member 4 juxtaposed with the display panel 2 is shown. The heat radiating portion 4 b extends from the heat receiving portion 4 a along a direction substantially parallel to the display surface 2 a of the display panel 2. That is, the heat dissipation part 4 b may extend in the direction in which the side surface of the display panel 2 faces. Also in the example of FIG. 6C, the heat dissipated from the heat diffusion member 4 to the outside is difficult to be transmitted to the display panel 2. Therefore, the decrease in contrast ratio of the display device 1 can be prevented. In the example of FIG. 6C, the heat diffusion member 4 is disposed such that the side surface 4 f faces the display panel 2 and faces the light incident surface 5 a of the light guide plate 5. The substrate 6 on which the light emitting element 3 is mounted is connected to the side surface 4 f of the heat diffusion member 4. The heat diffusion member 4 is fixed to the light guide plate 5 using a connecting member 12 having a generally S-shaped cross-sectional shape so that the light emitting elements 3 face the light incident surface 5 a of the light guide plate 5.

The heat dissipating part 4b may extend in any direction facing the outside of the display panel 2 without limiting to the examples shown in FIGS. 3 and 6A to 6C. Further, as in the example of FIG. 6B, when the heat dissipation part 4b extends to both the front and the rear of the display panel 2, the length of the front extending may be different from the length of the rear extending. In addition, as described above, the light emitting element 3 as a heating element may be provided along an arbitrary side of the display panel 2 having, for example, a rectangular front shape, and the heat diffusion member 4 accordingly corresponds to the display panel. It may be provided on each of the upper side, lower side, and left and right sides of 2. As such, even when the heat diffusion member 4 is provided on any side of the display panel 2, the heat dissipation part 4 b can be provided to extend in an arbitrary direction facing the outside of the display panel 2.

Although the display device 1 according to the embodiment has been described mainly using the example in which the display device 1 is a liquid crystal display device including the light guide plate 5 in the above description, the display device 1 is, for example, an organic EL It may be a display device, and in that case, the display panel 2 may be an organic EL display panel. The organic EL display panel is configured of an organic EL element that emits light of luminance according to the drive current. Therefore, if the organic EL element does not emit light with the luminance as intended based on the selected current value, the contrast ratio may be reduced. In general, the luminance of the organic EL element tends to decrease at high temperatures. Furthermore, a field effect thin film transistor (TFT) that controls energization of the organic EL element can also have temperature characteristics with respect to the threshold of the voltage between the gate and the source or the on resistance between the drain and the source. Therefore, when the organic EL display device includes a heating element and the heat of the heating element is transmitted to the organic EL display panel, the organic EL element may not emit light with the intended brightness. In that case, the contrast ratio may decrease. However, the organic EL display device is provided with the heat diffusion member 4 including the heat receiving portion 4 a and the heat releasing portion 4 b extending from the heat receiving portion 4 a toward the outside of the display panel 2 as in the present embodiment. It is considered that such a reduction in contrast ratio is avoided also in In the organic EL display device, for example, a semiconductor integrated circuit device such as a driver for supplying a drive current to the organic EL element can be a heating element.

A driver 32 as a heating element in the present embodiment is schematically shown in FIG. 7 together with the display panel 2 and the heat diffusion member 4. FIG. 7 shows an example in which the display device 1 is an organic EL display device, and a driving current is supplied to the organic EL elements in the display panel 2 through the driver 32. As shown in FIG. 7, a driver 32 as a heating element in this example can be disposed at the edge of the display panel 2.

In the example of FIG. 7, the display panel 2 includes a display layer 2 d constituted by a plurality of organic EL elements, and a TFT substrate 2 c provided with a plurality of thin film transistors (TFTs) for controlling energization to the organic EL elements. There is. The driver 32 is a bare chip semiconductor integrated circuit device, and is mounted in a face-down manner on a wiring pattern (not shown) formed on the surface of the TFT substrate 2c. A thermally conductive layer 13 is provided on the back surface 32 a of the driver 32 (the opposite surface of the chip surface on which terminal pads and the like not shown are formed). The surface of the heat conduction layer 13 opposite to the surface in contact with the driver 32 is in contact with the heat diffusion member 4, and the driver 32 is indirectly connected to the heat diffusion member 4 via the heat conduction layer 13.

The heat conduction layer 13 is formed using a conductive or insulating material. The driver 32 and the heat diffusion member 4 are thermally connected via the heat conduction layer 13, and an amount of heat that can contribute to suppression of temperature rise of the driver 32 can be transferred from the driver 32 to the heat diffusion member 4 . The heat conductive layer 13 has, for example, a sheet-like or gel-like form, and preferably has a thermal conductivity of 1 W / (m · K) or more, more preferably 5 W / (m · K) or more. ing. The heat conduction layer 13 may be made of, for example, graphite or a silicone resin or an acrylic resin to which particles such as alumina are added.

In the example of FIG. 7, the heat diffusion member 4 has an L-shaped cross-sectional shape. The heat dissipating part 4 b extends from the heat receiving part 4 a toward the outside of the display panel 2 as in the heat dissipating part 4 b of the heat diffusion member 4 shown in FIG. 3 and the like. Therefore, also in the structure illustrated in FIG. 7, the heat transferred from the driver 32 to the heat diffusion member 4 is effectively dissipated to the outside from the surface of the heat dissipation part 4 b, while being transferred to the display panel 2. hard. Thus, the heating element (driver 32) may be at the edge of the display panel 2, and the heating element is connected to the heat diffusion member 4 via, for example, the heat conduction layer 13 having good heat conductivity. It may be done.

In the display device 1 according to the present embodiment, the heat diffusion member 4 may have a high temperature because the heat generated by the heating element such as the light emitting element 3 is transmitted. Therefore, it is preferable that the display device 1 includes a housing that accommodates at least the heat diffusion member 4 so that the user does not touch the heat diffusion member 4 at high temperature. As an example of such a display device 1, FIG. 8A shows a front view of the display device 1 provided with a housing 10, and FIG. 8B shows a top view of the display device 1 shown in FIG. 8A. FIG. 9A shows a cross-sectional view taken along line IX-IX of FIG. 8A. In FIGS. 8A and 8B and FIGS. 9A to 9C, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the repeated description of the components is appropriately omitted. .

As shown in FIGS. 8A, 8B and 9A, the housing 10 has a support 10a for supporting the display panel 2 so that the display surface 2a of the display panel 2 is oriented in a predetermined direction. In addition, the housing 10 has a bezel portion 10 c surrounding the display panel 2 in a frame shape at the edge of the display panel 2. The housing 10 also covers the back surface 2 b of the display panel 2. The housing 10 accommodates the heat diffusion member 4 therein. In the example of FIG. 8A and FIG. 9A, the thermal diffusion member 4 is disposed along one side of the display panel 2 which is the lower side when the display device 1 is used. The heat diffusion member 4 may be provided on each side of the display panel 2 which is the upper side, the left side, or the right side when the display device 1 is used, as indicated by reference numerals 41 to 43 in FIG. 8A. In that case, the casing 10 is provided which can accommodate the heat diffusion members 41 to 43 disposed along the sides in the bezel portion 10c. In FIG. 9A, reference numeral 14 denotes a driver mounting substrate on which a driver (not shown) for supplying a driving signal to the display panel 2 is mounted. Further, reference numeral 15 denotes a flexible printed wiring board (FPC) which electrically connects the circuit in the driver mounting substrate 14 and the internal circuit of the display panel 2.

The support portion 10 a functions as a stand for raising the display panel 2 at a predetermined angle with respect to the installation surface B (see FIG. 9A) of the display device 1. As shown in FIG. 9A, the heat diffusion member 4 is accommodated inside the support portion 10a. By accommodating the heat diffusion member 4 inside the support portion 10 a, the influence of the heat diffusion member 4 on the outer shape of the display device 1 can be reduced. In the example of FIG. 8A, the support portion 10 a is formed over substantially the entire side of the display panel 2 which is the lower side when the display device 1 is used.

The housing 10 is formed using any material. The housing 10 is preferably formed using an insulating material having high thermal conductivity. For example, the housing 10 is formed using a main material including an insulating resin and an additional material having a thermal conductivity higher than the main material. Examples of the main material include resins such as polystyrene, polycarbonate and acrylonitrile butadiene styrene. In addition, as the auxiliary material, it is mainly referred to as a so-called filler, and an additive material dispersed in the main material is exemplified, and fine particles formed of alumina, aluminum nitride, silicon nitride etc. are exemplified as the auxiliary material . However, the material of the housing 10 is not limited to these.

When the housing 10 has the preferable thermal conductivity as described above, as shown in FIG. 9A, in the inside of the housing 10, a part or all of the surface of the heat dissipation part 4b in the heat diffusion member 4 Is preferably thermally connected to the inner wall of the housing 10. In the example of FIG. 9A, a part of the surface of the heat dissipation portion 4b is in contact with the inner wall of the housing 10. When the surface of the heat dissipation portion 4 b is thermally connected to the housing 10, more heat may be transmitted from the heat dissipation portion 4 b to the outside. The heat radiating portion 4b and the inner wall of the housing 10 may be connected indirectly via a heat conductive sheet or the like that can constitute the heat conductive layer 13 (see FIG. 7) described above.

In the example of FIG. 9A, the support portion 10a of the housing 10 has a recess 10a1 on the lower surface facing the installation surface B on which the display device 1 is installed. The heat dissipation portion 4 b of the heat diffusion member 4 is in contact with the inner wall of a portion of the housing 10 that forms the bottom surface of the recess 10 a 1. The recess 10 a 1 can be a space that can be flowed by air, which is secured between the installation surface B and the housing 10 when the display device 1 is used. Therefore, the heat transmitted from the heat diffusion member 4 to the housing 10 can be efficiently dissipated. In the present embodiment, the heat dissipation portion 4 b of the heat diffusion member 4 and the inner wall of the housing 10 do not necessarily have to be thermally connected.

Another example of the display device 1 of the present embodiment provided with the housing 10 is shown in FIG. 9B. In the example of FIG. 9B, the display device 1 further includes a fan 16 that generates an air flow around the heat dissipation portion 4 b of the heat diffusion member 4. The fan 16 receives power supply such as electric power, for example, and causes the surrounding air to flow by rotating a plurality of blades fixed to the drive shaft. By operating the fan 16, forced convection can be generated around the heat dissipation portion 4b, and as a result, the heat dissipation of the heat dissipation portion 4b can be enhanced.

Furthermore, the heat diffusion member 4 shown in FIG. 9B is provided with a plurality of fins 4c having a main surface 4ca parallel to the thickness direction of the display panel 2 similarly to the heat diffusion member 4 shown in FIG. The fan 16 is fixed to the housing 10 at a position facing the end surface 4cb of the fins 4c (a surface other than the two main surfaces 4ca of the plate-like (hexahedral) fins 4c). In the example of FIG. 9B, the fan 16 is also provided at a position facing the end 4ba remote from the light emitting element 3 (heating element) in the heat radiating portion 4b. By arranging the fan 16 at such a position, it is possible to generate an air flow flowing along the main surface 4ca of the fin 4c. Therefore, the heat transferability by convection from the heat diffusion member 4 can be further enhanced. The fan 16 may be provided at a position different from the position illustrated in FIG. 9B. Further, when the display device 1 includes the fan 16, the heat diffusion member 4 may not necessarily include the fins 4 c.

As described above, the heat diffusion member 4 is preferably accommodated in the housing 10 in order to prevent the user from touching the high temperature heat diffusion member 4. However, if any necessity arises, for example, if the inside of the case becomes extremely hot because there is no ventilation inside or outside the case 10, as shown in FIG. The opening 10b may be provided. When the opening 10 b is provided at a position where the heat diffusion member 4 can be partially exposed in the housing 10, it is preferable that the exposed portion of the heat diffusion member 4 be provided with a protective member 17 covering the exposed portion. . Although an epoxy resin, a silicone resin, an acrylic resin, etc. are illustrated as a material of the protection member 17, The material of the protection member 17 is not limited to these. As a material of the protective member 17, one having a low thermal conductivity is preferable from the viewpoint of user protection against heat. The thermal conductivity of the material forming the protective member 17 is preferably 0.3 W / (m · K) or less.

〔Example〕
Implementation conditions
The contrast ratio improvement action and the heat radiation performance of the heat diffusion member 4 by the display device 1 of Embodiment 1 were confirmed using a display device having a structure similar to the structure exemplified in FIGS. 1 to 4 (Example 1) ). As the display panel 2, a 70-type transmissive liquid crystal panel was used. As the heat diffusion member 4, an aluminum plate having a length L4 = 1544 mm, a width W4 = 60 mm, and a thickness T4 = 10 mm was used. As the substrate 6, a base layer made of an aluminum plate having a thickness of 0.8 mm, an insulating layer having a thickness of 0.16 mm formed on the base layer using an epoxy resin, and an insulating layer using a copper alloy Three metal base substrates having a wiring layer formed thereon were used. And a light emitting diode was used as a heating element. Three metal base substrates each mounted with 84 light emitting diodes were connected on the surface of the aluminum plate as the heat diffusion member 4. Then, a power of 153.594 W was applied to a total of 252 light emitting diodes as power capable of emitting light of luminance required for the liquid crystal display panel, and the display quality of the liquid crystal display panel was confirmed. Further, for comparison, in the conventional liquid crystal display device 100 illustrated in FIG. 10, power was applied to the same number of light emitting diodes as the light emitting diodes used in Example 1 described above under the same conditions as Example 1 ( Comparative example 1).

[result]
In Comparative Example 1, while black display due to light leakage was observed at the corners of the display screen during “black” display, such a phenomenon was confirmed in the visual level in Example 1 It was not done. That is, in Example 1, it was confirmed that the decrease in the contrast ratio was suppressed. In Example 1, the temperature of the light emitting diode was only 62 ° C. at a room temperature of 24 ° C. It has been confirmed that the upper limit (for example, 35 ° C.) of the operating temperature range of the display can also be lower than the upper limit (for example, 75 ° C.) of the operating temperature range of the light emitting diode.

[Summary]
(1) The display device according to the first embodiment of the present invention includes a display panel having a display surface on which an image is displayed and a back surface opposite to the display surface, and arranged at or near an edge of the display panel And a heat diffusion member for diffusing the heat generated by the heat generation member, wherein the heat diffusion member is a plate-like member extending toward the outside of the display panel away from the heat generation member. It is characterized by having a heat radiation part.

According to the configuration of (1), it is possible to suppress the decrease in contrast ratio caused by the heat generated in the heating element.

(2) The display device further includes a light guide plate disposed facing the back surface of the display panel in the above (1), and a light exit surface of the light guide plate faces the back surface of the display panel The light incident surface of the light guide plate may be opposed to the light emitting element as the heating element, and the light emitting element may be connected to the heat diffusion member.

According to the configuration of (2), the light of the light emitting element can be efficiently incident on the display panel through the light guide plate, and the heat of the light emitting element as a heat generating element can be efficiently transmitted to the heat diffusion member it can.

(3) In the display device of the above (2), the light emitting element may be mounted on the surface of a substrate directly connected to the heat diffusion member.

According to the configuration of (3), the light emitting element can be efficiently disposed on the heat diffusion member.

(4) In the display device according to (3), the length of the substrate in the thickness direction of the display panel is greater than the distance from the display surface of the display panel to the surface opposite to the light exit surface of the light guide plate. It may be long.

According to the configuration of (4), the temperature rise of the light emitting element can be further suppressed.

(5) In the display device according to any one of the above (1) to (4), the heat radiating portion may extend along a direction substantially perpendicular to the display surface of the display panel.

According to the configuration of (5), it is possible to suppress the decrease in the contrast ratio caused by the heat generated in the heating element.

(6) In the display device according to any one of (1) to (4), the heat radiating portion may extend along a direction substantially parallel to the display surface of the display panel.

According to the configuration of (6), it is possible to suppress the decrease in the contrast ratio caused by the heat generated in the heating element.

(7) In the display device according to any one of the above (1) to (6), the heat dissipation unit may have a surface in which a plurality of fins are aligned.

According to the configuration of (7), the surface area of the heat diffusion member is increased, and as a result, the amount of heat dissipated from the heat diffusion member to the outside is increased. Therefore, the temperature rise of the heating element can be further suppressed.

(8) In the display device according to any one of the above (1) to (7), the heat diffusion member may contain one or more of aluminum, copper and ceramics.

According to the configuration of (8), the heat transmitted from the heating element can be widely diffused in the heat diffusion member, and the heat can be efficiently dissipated to the outside.

(9) In the display device according to any one of the above (1) to (8), a thickness of the heat dissipation portion may be 1 mm or more and 5 mm or less.

According to the configuration of (9), the heat transmitted from the heat generating element can be widely diffused in the heat diffusion member, and moreover, it can be avoided that the width or the like of the bezel portion of the display device is significantly increased.

(10) The display device according to any one of the above (1) to (9), further comprising: a housing that accommodates the heat diffusion member at least, the housing comprising a main material including an insulating resin and the main The heat sink may be formed using an auxiliary material having a thermal conductivity higher than that of the material, and part or all of the surface of the heat dissipation part may be thermally connected to the inner wall of the housing.

According to the configuration of (10), more heat can be transmitted to the outside from the heat radiating portion.

(11) In the display device of the above (10), the housing has a support portion for supporting the display panel so as to turn the display surface of the display panel in a predetermined direction, and the heat diffusion member supports the You may be accommodated in the inside of a part.

According to the configuration of (11), the influence of the heat diffusion member on the outer shape of the display device, for example, the increase in size can be reduced.

(12) In any one of the above (1) to (11), the display device is fixed to an edge portion of the display panel and disposed along the back surface of the display panel to suppress deformation of the display panel It may further include an auxiliary member.

According to the configuration of (12), deformation of the display panel 2 can be reduced.

DESCRIPTION OF SYMBOLS 1 display 2 display panel 2a display surface 2b back surface 3 light emitting element (heating element)
32 driver (heating element)
4, 41, 42, 43 Heat diffusion member 4a Heat receiving portion 4b Heat radiating portion 4c Fin 4d Surface 5 Light guide plate 5a Light incident surface 5b Light emitting surface 6 Substrate 10 Case 10a Support portion 11 Auxiliary member 12 Connecting member 16 Fan 17 Protective member T4 Thickness of heat diffusion member (heat radiation part) W6 Length of substrate in width direction of display panel (width)

Claims

A display panel having a display surface on which an image is displayed and a back surface opposite to the display surface;
A heating element disposed at or near an edge of the display panel;
A heat diffusion member for diffusing the heat generated by the heating element;
The display device, wherein the heat diffusion member includes a plate-like heat dissipation portion extending toward the outside of the display panel so as to be away from the heat generating member.
It further comprises a light guide plate disposed opposite to the back surface of the display panel,
The light exit surface of the light guide plate faces the back surface of the display panel,
The light incident surface of the light guide plate faces the light emitting element as the heating element,
The display device according to claim 1, wherein the light emitting element is connected to the heat diffusion member.
The display device according to claim 2, wherein the light emitting element is mounted on a surface of a substrate directly connected to the heat diffusion member.
The display device according to claim 3, wherein a length of the substrate in a thickness direction of the display panel is longer than a distance from the display surface of the display panel to a surface opposite to the light exit surface of the light guide plate.
The display device according to any one of claims 1 to 4, wherein the heat dissipation portion extends along a direction substantially perpendicular to the display surface of the display panel.
The display device according to any one of claims 1 to 4, wherein the heat dissipation portion extends along a direction substantially parallel to the display surface of the display panel.
The display device according to any one of claims 1 to 6, wherein the heat dissipation part has a surface in which a plurality of fins are aligned.
The display device according to any one of claims 1 to 7, wherein the heat diffusion member contains one or more of aluminum, copper and ceramics.
The display device according to any one of claims 1 to 8, wherein a thickness of the heat dissipation portion is 1 mm or more and 5 mm or less.
It further comprises a housing for housing at least the heat diffusion member,
The housing is formed using a main material including an insulating resin and an auxiliary material having a thermal conductivity higher than that of the main material,
The display device according to any one of claims 1 to 9, wherein a part or all of the surface of the heat dissipation part is thermally connected to the inner wall of the housing.
The housing has a support for supporting the display panel so that the display surface of the display panel is oriented in a predetermined direction.
The display device according to claim 10, wherein the heat diffusion member is housed inside the support portion.
The auxiliary member fixed to the edge of the said display panel and arrange | positioned along the said back of the said display panel, and suppressing a deformation | transformation of the said display panel is further equipped with any one of Claims 1-11. Display device.