Display device

Abstract

To provide a display device.SOLUTION: A display device comprises: a display panel having a display section including an organic electroluminescent element, and a chassis having a front surface in contact with the display section and a rear surface opposite the front surface; a heat reflective member having a first surface facing a rear surface and a second surface on the opposite side of the first surface, superimposed on the rear surface, the second surface having a thermal emissivity lower than that of the rear surface; and a heating element installed opposite the second surface and overlapping the heat reflective member.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a display device. [Background technology]

[0002] In a typical display device, a circuit board for operating the display device is disposed on the back side of the display panel. For example, Patent Document 1 discloses a display device in which a drive circuit board is disposed opposite the back side of the display panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-194543 Summary of the Invention [Problem to be solved by the invention]

[0004] During operation of the display device, the circuit board generates heat, which is transferred to the rear surface of the display panel by thermal radiation and heat transfer through the air between the circuit board and the rear surface of the display panel, causing a local rise in the temperature of the display panel in the area facing the circuit board.

[0005] Some display panels use organic electroluminescence elements (hereinafter referred to as organic EL elements) as display elements, and display images by arranging multiple organic EL elements in a plane. Organic EL elements deteriorate more rapidly when exposed to high temperatures. As a result, organic EL elements in areas where the temperature of the display panel has risen locally due to the circuit board deteriorate faster than organic EL elements in other areas. This can cause a localized decrease in display quality in areas of the deteriorated organic EL elements, making the difference in display quality from other areas more noticeable; this can lead to so-called burn-in, which reduces display quality and makes the difference in display quality from other areas more noticeable.

[0006] Therefore, in consideration of the above-mentioned problems, the present disclosure aims to provide a display device that makes it difficult for radiant heat emitted by a heating element arranged on the back side of the display panel to be transmitted to the display panel, thereby mitigating local temperature increases in the display panel near the heating element. [Means for solving the problem]

[0007] A display device according to one embodiment of the present disclosure includes a display panel having a display unit including an organic electroluminescent element and a chassis having a front surface in contact with the display unit and a back surface opposite the front surface; a heat-reflecting member having a first surface facing the back surface and a second surface opposite the first surface, the heat-reflecting member being superimposed on the back surface and having a lower thermal emissivity on the second surface than the back surface; and a heating element being positioned opposite the second surface and superimposed on the heat-reflecting member. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a display device according to a first embodiment. [Figure 2] 1 is a schematic diagram of a display device according to a first embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIGS. 1 and 2. [Figure 4] FIG. 2 is an exploded view of the display device according to the first embodiment. [Figure 5] 1 is a plan view showing the positional relationship between a chassis, a heat reflecting member, and a heat generating element according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5. [Figure 7] 10 is a plan view showing a part of a chassis, a heat reflecting member, and a heat generating element according to a first modification of the first embodiment. FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 7. [Figure 9] 10 is a plan view showing a part of a chassis, a heat reflecting member, and a heat generating element according to a second modification of the first embodiment. FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along the line XX in FIG. 9. [Figure 11]FIG. 10 is a plan view showing the positional relationship between a chassis, a heat reflecting member, and a heat generating element according to a second embodiment. [Figure 12] FIG. 12 is a cross-sectional view taken along the line XII-XII in FIG. [Figure 13] 10 is a plan view showing a part of a chassis, a heat reflecting member, and a heat generating element according to a first modification of the second embodiment. FIG. [Figure 14] 10 is a plan view showing a part of a chassis, a heat reflecting member, and a heat generating element according to a second modification of the second embodiment. FIG. [Figure 15] FIG. 15 is a cross-sectional view taken along the line XV-XV in FIG. 14. [Figure 16] 1 and 2. FIG. 3 is a cross-sectional view showing a part of a chassis, a heat-reflecting member, and a heat-generating element according to a third embodiment, taken along the same line as the cross-section III-III in FIGS. [Figure 17] 1 and 2. FIG. 3 is a cross-sectional view showing a part of a chassis, a heat-reflecting member, and a heat-generating element according to a fourth embodiment, taken along the same line as the cross-section III-III in FIGS. [Figure 18] FIG. 10 is a cross-sectional view taken along the same line as the III-III cross section in FIGS. 1 and 2 according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, identical or similar elements are designated by the same reference numerals, and duplicate descriptions will be omitted. Furthermore, the embodiments described below do not unduly limit the content of the present disclosure described in the claims, and not all of the configurations described in the embodiments are necessarily essential as means for solving the problems of the present disclosure.

[0010] <Embodiment 1> FIG. 1 is a schematic diagram of a display device 100 according to a first embodiment of the present disclosure. The lower left, upper right, upper left, lower right, upper, and lower sides of FIG. 1 correspond to the front, rear, right, left, upper, and lower sides of the display device 100, respectively. A planar view refers to a viewpoint when the top, bottom, left, and right directions are considered to be planes. The display device 100 of the present disclosure includes a display panel 400 and a housing 700. In FIG. 1, the front surface of the display device 100 is the main surface of the display panel 400, which is the surface on which an image is displayed. In the present disclosure, for example, the surface on which an image is displayed is rectangular and is installed so that the long sides extend in the left-right direction and the short sides extend in the up-down direction.

[0011] 2 is a schematic diagram of the display device 100 according to the first embodiment of the present disclosure, and is a diagram of the display device 100 viewed from a different viewpoint than that of FIG. 1. The lower left, upper right, upper left, lower right, upper, and lower sides of FIG. 2 respectively correspond to the left, right, front, rear, upper, and lower sides of the display device 100. As shown in FIG. 2, the display device 100 of the present disclosure has a housing 700 attached to it so as to cover the rear side of the display panel 400.

[0012] Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1 and Fig. 2. Fig. 4 is an exploded view of the display device 100, taken from the same perspective as Fig. 2. As can be seen from Figs. 3 and 4, the display device 100 has a structure in which a space 702 is provided between the display panel 400 and the housing 700.

[0013] <Display panel> 3, the display panel 400 has a structure in which a display unit 200 and a chassis 300 are stacked on top of each other. The display unit 200 includes a plurality of organic EL elements 201 as light-emitting elements. Although not shown, for example, the display unit 200 has a structure in which the plurality of organic EL elements 201 are disposed between a glass layer on which TFTs (thin film transistors) are formed and a sealing material layer.

[0014] The chassis 300 is a plate-like member that contacts the rear side of the display unit 200. The chassis 300 has a front surface 301 that contacts the display unit 200 and a back surface 302 on the opposite side. The chassis 300 has the function of serving as a support member that supports the display unit 200 so that it does not bend, and the function of absorbing heat generated when the organic EL element 201 emits light from the organic EL element 201 and diffusing the heat throughout the chassis 300 by thermal conduction to increase the in-plane temperature uniformity of the display unit 200. Therefore, the chassis 300 preferably has high strength and high thermal conductivity. For example, the chassis 300 is preferably a plate member made of a metal material such as iron or aluminum.

[0015] <Heat reflecting material> 3 and 4, a heat reflecting member 500 is provided on the rear surface 302. The heat reflecting member 500 has a first surface 501 facing the rear surface 302 and a second surface 502 opposite the first surface. As will be described in detail later, the second surface 502 of the heat reflecting member 500 has a lower thermal emissivity than the rear surface 302 of the chassis 300.

[0016] <Heater> The heating element 600 is a circuit board for operating the display device 100. In the present disclosure, an example configuration in which the display device 100 has three heating elements 600 is shown, and the three heating elements 600 are a power supply board 601, a display signal control board 602, and an operation control board 603. The power supply board 601 is a circuit board having a power supply circuit that generates a DC voltage necessary for operating the display device 100 from an externally supplied AC power source. The operation control board 603 is a circuit board on which a CPU, memory, and the like are mounted for controlling the operation of various functions of the display device 100, and is generally also referred to as a main board. The display signal control board 602 is a circuit board having a signal control circuit that controls the operation of the multiple organic EL elements 201 based on an externally input video signal and displays an image on the display surface of the display unit 200. It should be noted that the heating element 600 is not limited to the three boards mentioned above, and for example, the power supply board 601 may be divided into two boards: an inverter circuit board that converts AC to DC, and a transformer circuit board that converts the magnitude of the DC voltage, or may be a single circuit board that integrates multiple functions.

[0017] <Case> The housing 700 is a member that covers the rear of the display device 100, covers the rear surface 302, and has an inner surface 701 that faces the rear surface 302. The heating element 600 is attached to the inner surface 701 of the housing 700 in a position facing the second surface 502. A space 702 is provided between the rear surface 302 and the second surface 502 and the inner surface 701 and the heating element 600. In other words, the second surface 502 and the heating element 600 are spaced apart, and the space 702 exists between them.

[0018] Fig. 5 is a plan view showing the positional relationship between the chassis 300, the heat-reflecting member 500, and the heat-generating element 600 according to the first embodiment. Fig. 6 is a cross-sectional view taken along the line VI-VI in Fig. 5. As can be seen from Figs. 3 and 6, the heat-generating element 600 is disposed opposite the second surface 502, and overlaps with the heat-reflecting member 500 in a plan view seen from the inner surface 701 side. The heat-reflecting member 500 is disposed on the second surface 502.

[0019] 5 and 6, the heat reflecting member 500 has, in a plan view, a first region 503 that overlaps with the heat generating element 600 and a second region 504 that does not overlap with the heat generating element 600. In other words, in a plan view seen from the inner surface 701 side, the heat reflecting member 500 is provided in an area that is larger than the area that overlaps with the heat generating element 600.

[0020] In the present disclosure, the heat reflecting member 500 is provided on the back surface 302 at a position overlapping the heating element 600 in a plan view seen from the inner surface 701 side. Heat generated by the heating element 600 during operation of the display device 100 is transferred to the heat reflecting member 500 and the chassis 300 by heat transfer via the air in the space 702 and heat radiation (thermal radiation) transmitted by heat rays emitted from the heating element 600. Therefore, at positions corresponding to the first region 503 overlapping the heating element 600 in a plan view seen from the inner surface 701 side and the nearby second region 504, the amount of heat transferred to the chassis 300 is greater by both heat transfer and heat radiation than at other positions. The heat transferred to the chassis 300 is transferred to the display unit 200 by thermal conduction, causing the temperature of the organic EL element 201 to rise. Here, the second surface 502 of the heat reflecting member 500 has a lower thermal emissivity than the back surface 302 of the chassis 300, and therefore reflects a larger proportion of the heat rays radiated from the heat generating element 600. Therefore, in the region where the heat reflecting member 500 is present, the amount of heat transferred by thermal radiation from the heat generating element 600 is reduced. Therefore, in the display unit 200, the amount of heat transferred from the heat generating element 600 in the first region 503 and the second region 504 is reduced in a plan view seen from the inner surface 701 side, and a local increase in the temperature of the organic EL element 201 can be suppressed. This makes it possible to suppress the progression of local deterioration of the organic EL element 201 and mitigate degradation of display quality due to the occurrence of local burn-in.

[0021] For example, if the chassis 300 is made of iron, the thermal emissivity of the back surface 302 is 50%, and if the heat-reflecting member 500 is made of aluminum, the thermal emissivity of the second surface 502 is 10%. In this case, if the heat-reflecting member 500 has a thermal emissivity of 80%, the amount of heat transferred by thermal radiation from the heating element 600 to the second surface 502 is approximately 22% of that to the back surface 302, thereby reducing the amount of heat transferred. Note that the heat-reflecting member 500 only needs to use a material for at least the second surface 502 that has a lower thermal emissivity than the back surface 302. For example, if the chassis 300 is made of a metal material such as iron, which is commonly used, the thermal emissivity of the back surface 302 is approximately 40% to 60%. Specific materials that can be used for the heat-reflecting member 500 include, for example, a glossy aluminum plate, a tin-plated plate, and a silver-plated plate, each of which has a thermal emissivity of approximately 5% to 20%.

[0022] 5 and 6 , the heat reflecting member 500 preferably overlaps only a portion of the back surface 302 in a plan view from the inner surface 701 side, and an area where the back surface 302 is exposed is provided. At positions of the back surface 302 corresponding to the first area 503 and the second area 504 covered by the heat reflecting member 500, most of the heat rays from the heating element 600 to the chassis 300 are reflected toward the heating element 600. Therefore, at these positions, heat transfer by thermal radiation is small, and heat transfer from the heating element 600 to the chassis 300 is mainly due to heat transfer by the air in the space 702. Therefore, at the positions of the chassis 300 corresponding to the first area 503 and the second area 504 in a plan view from the inner surface 701 side, heat is mainly transferred by heat transfer. Conversely, in a plan view from the inner surface 701 side, the amount of heat transferred from the heat generating element 600 by heat conduction is small at positions farther from the heat generating element 600, but the absence of the heat reflecting member 500 results in an increase in heat due to thermal radiation. This reduces the difference in the amount of heat transferred from the heat generating element 600 to the chassis 300 between the portion covered with the heat reflecting member 500 and the portion not covered, thereby preventing local temperature differences from occurring in the plurality of organic EL elements 201. This further suppresses the progression of local degradation of the organic EL elements 201 and alleviates degradation of display quality due to the occurrence of local burn-in.

[0023] In the first embodiment, a partial region 505 having a higher thermal emissivity than the second surface 502 may be provided in a part of the second region 504. For example, as shown in FIG. 5 , the outer edge of the heat reflecting member 500 may have a wavy outline in a plan view seen from the inner surface 701 side. In this case, the second region 504 corresponds to the region between the first region 503 and a virtual rectangular region connecting the vertices of the outer edge of the heat reflecting member 500. In the wavy portion of the second region 504, the heat reflecting member 500 is not disposed, and the partial region 505 is a portion where the back surface 302 of the chassis 300 is exposed. In other words, in FIG. 5 , the partial region 505 is a region where the heat reflecting member 500 has been partially removed. Because the back surface 302 has a higher thermal emissivity than the second surface 502, the partial region 505 also has a higher thermal emissivity than the second surface 502. With this configuration, the amount of heat transferred from the heat generating element 600 to the chassis 300 by heat radiation is in the order of: area where the heat reflecting member 500 is not disposed > second area 504 > first area 503. Furthermore, the amount of heat transferred from the heat generating element 600 to the chassis 300 by heat conduction is in the order of: area where the heat reflecting member 500 is not disposed < second area 504 < first area 503. Therefore, for heat transferred by both heat radiation and heat conduction, the difference in the amount of heat transferred from the heat generating element 600 to the chassis 300 between the first area 503, the second area 504, and the area not covered by the heat reflecting member 500 is smaller, further suppressing the occurrence of local temperature differences among the multiple organic EL elements 201. This further suppresses the progression of localized deterioration of the organic EL elements 201, thereby mitigating the degradation of display quality due to the occurrence of localized burn-in.

[0024] In the second region 504, in a plan view from the inner surface 701 side, the proportion of the area occupied by the partial region 505 may increase with increasing distance from the heat generating element 600. For example, in FIG. 5 , in a plan view from the inner surface 701 side, the outer edge of the heat reflecting member 500 has a wavy outline, and the area of ​​the region where the heat reflecting member 500 is disposed decreases toward the outside of the outline, and the area of ​​the partial region 505 where the heat reflecting member 500 is not disposed increases. This makes it possible, in a plan view from the inner surface 701 side, for the amount of heat transferred by thermal radiation to increase with increasing distance from the heat generating element 600. Therefore, the change in the amount of heat transferred to the chassis 300 depending on the distance from the heat generating element 600 can be made more gradual, and the occurrence of local temperature differences in the plurality of organic EL elements 201 can be further suppressed.

[0025] <Modification 1 of Embodiment 1> Fig. 7 is a plan view showing a part of the chassis 300, the heat-reflecting member 500, and the heat-generating element 600 according to a first modification of the first embodiment. Fig. 8 is a cross-sectional view taken along the line VIII-VIII in Fig. 7. In the first modification of the first embodiment, the structure of the partial region 505 differs from that of the first embodiment. Note that, for the entire heat-reflecting member 500, it is sufficient that the arrangement pattern shown in Fig. 7 is repeated along the outer edge of the heat-reflecting member 500.

[0026] As shown in FIG. 7 , in Modification 1 of Embodiment 1, in a plan view from the inner surface 701 side of the second region 504, a heat-reflecting member 500 is disposed on the side closer to the heat-generating element 600, while a plurality of first covering members 507 are disposed instead of the heat-reflecting member 500 on the side farther from the heat-generating element 600. The first covering members 507 are formed of a material with lower emissivity than the back surface 302 and may be made of the same material as the heat-reflecting member 500, or may be a covering layer or masking member with lower emissivity than the back surface 302. Examples of covering layers and masking members that can be used for the first covering members 507 include aluminum foil, a coating film made of a radiant heat-reducing paint containing a powder of a metal such as aluminum, silver, chromium, or nickel and a solvent, and the like, and their thermal emissivity is approximately 2% to 25%. Therefore, the portion of the second region 504 where the heat-reflecting member 500 and the first covering members 507 are not disposed and the back surface 302 is exposed is the partial region 505. 7, for example, in the second region 504, the number of first covering portions 507 gradually decreases with increasing distance from the heating element 600 in a plan view seen from the inner surface 701 side. Therefore, the proportion of the area occupied by the partial regions 505 increases toward the outside of the heat reflecting member 500. As a result, in a plan view seen from the inner surface 701 side, the amount of heat transferred by thermal radiation increases with increasing distance from the heating element 600. Therefore, it is possible to make the change in the amount of heat transferred to the chassis 300 depending on the distance from the heating element 600 more gradual, and to further suppress the occurrence of local temperature differences in the plurality of organic EL elements 201.

[0027] <Modification 2 of Embodiment 1> Fig. 9 is a plan view showing a part of the chassis 300, the heat-reflecting member 500, and the heat-generating element 600 according to a second modification of the first embodiment. Fig. 10 is a cross-sectional view taken along the line XX in Fig. 9. In the second modification of the first embodiment, the structure of the partial region 505 differs from that of the first embodiment. Note that, for the entire heat-reflecting member 500, it is sufficient that the arrangement pattern shown in Fig. 9 is repeated along the outer edge of the heat-reflecting member 500.

[0028] 9 and 10 , in Modification 2 of Embodiment 1, heat-reflecting member 500 is disposed over the entire second region 504 in a plan view from the inner surface 701 side. A second covering portion 508 having a wavy shape in a plan view from the inner surface 701 side is disposed on the heat-reflecting member 500 at the outer edge far from the heat-generating element 600. Second covering portion 508 is formed of a material with a higher emissivity than second surface 502. It may be the same material as chassis 300, or it may be a covering layer or masking member with a higher emissivity than second surface 502. Examples of covering layers and masking members that can be used for second covering portion 508 include a coating of oil-based paint, vinyl tape, and hard rubber, and their thermal emissivity ranges from approximately 85% to 95%. Therefore, the portion of second region 504 where second covering portion 508 is disposed is partial region 505. In other words, the partial region 505 is a region of the second surface 502 that is covered with a material having a higher thermal emissivity than the second surface 502. As shown in FIG. 9 , for example, in the second region 504, the area of ​​the second covering portion 508 gradually increases with increasing distance from the heating element 600 in a plan view from the inner surface 701 side. Therefore, the proportion of the area occupied by the partial region 505 increases toward the outside of the heat-reflecting member 500. As a result, the amount of heat transferred by thermal radiation increases with increasing distance from the heating element 600 in a plan view from the inner surface 701 side. Therefore, the amount of heat transferred to the chassis 300 can change more gradually depending on the distance from the heating element 600, and local temperature differences among the multiple organic EL elements 201 can be further suppressed. Note that, in a plan view from the inner surface 701 side, the shape of second covering portion 508 is not limited to a wavy shape, and any shape is possible as long as the area of ​​second covering portion 508 gradually increases with increasing distance from heating element 600 in a plan view from the inner surface 701 side. Also, second covering portion 508 does not need to be integral, and multiple second covering portions 508 may be provided in second region 504.

[0029] <Embodiment 2> Fig. 11 is a plan view showing a part of the chassis 300, the heat reflecting member 500, and the heat generating element 600 according to the second embodiment of the present disclosure. Fig. 12 is a cross-sectional view taken along the line XII-XII in Fig. 11. The second embodiment differs from the first embodiment in the shape and arrangement of the partial region 505.

[0030] In the second embodiment, a partial region 505 having a higher thermal emissivity than the second surface 502 is provided in a part of the second region 504. In the second embodiment, as shown in, for example, FIGS. 11 and 12 , a plurality of openings 506 are provided in the outer edge portion of the heat reflecting member 500 in a plan view seen from the inner surface 701 side. In this case, the region between the outer edge portion of the heat reflecting member 500 and the first region 503 corresponds to the second region 504. The openings 506 in the second region 504 expose the back surface 302 of the chassis 300. In other words, the partial region 505 is the opening 506 in which the heat reflecting member 500 is partially removed. Because the back surface 302 has a higher thermal emissivity than the second surface 502, the partial region 505 also has a higher thermal emissivity than the second surface 502. With this configuration, the amount of heat transferred from the heat generating element 600 to the chassis 300 by heat radiation is in the order of: area where the heat reflecting member 500 is not disposed > second area 504 > first area 503. Furthermore, the amount of heat transferred from the heat generating element 600 to the chassis 300 by heat conduction is in the order of: area where the heat reflecting member 500 is not disposed < second area 504 < first area 503. Therefore, for heat transferred by both heat radiation and heat conduction, the difference in the amount of heat transferred from the heat generating element 600 to the chassis 300 between the first area 503, the second area 504, and the area not covered by the heat reflecting member 500 is smaller, further suppressing the occurrence of local temperature differences among the multiple organic EL elements 201. This further suppresses the progression of localized deterioration of the organic EL elements 201, thereby mitigating the degradation of display quality due to the occurrence of localized burn-in. In Figure 11, in a planar view from the inner surface 701 side, the partial regions 505 are arranged along the upper and lower edges of the heat-reflecting member 500, but the partial regions 505 may also be arranged along the left and right edges.

[0031] In the second region 504, in a plan view from the inner surface 701 side, the proportion of the area occupied by the partial regions 505 may increase with increasing distance from the heat generating element 600. For example, in FIGS. 11 and 12 , in a plan view from the inner surface 701 side, a plurality of partial regions 505 are provided in a direction toward the outer edge of the heat reflecting member 500, and the area of ​​the partial regions 505 increases with increasing distance from the outer edge of the heat reflecting member 500. This makes it possible, in a plan view from the inner surface 701 side, for the amount of heat transferred by thermal radiation to increase with increasing distance from the heat generating element 600. Therefore, it is possible to make the change in the amount of heat transferred to the chassis 300 depending on the distance from the heat generating element 600 more gradual, and to further suppress the occurrence of local temperature differences in the plurality of organic EL elements 201.

[0032] <Modification 1 of Embodiment 2> 13 is a plan view showing a part of the chassis 300, the heat-reflecting member 500, and the heat-generating element 600 according to Modification 1 of Embodiment 2. Modification 1 of Embodiment 2 differs from Embodiment 2 in the structure of the partial region 505. Note that, for the entire heat-reflecting member 500, it is sufficient that the arrangement pattern shown in FIG. 13 is repeated along the outer edge of the heat-reflecting member 500.

[0033] In the first modification of the second embodiment, in a plan view from the inner surface 701 side, the size of each of the plurality of openings 506 constituting the partial region 505 is the same, and the number of openings 506 arranged per unit area increases with increasing distance from the heat generating element 600. As a result, the area of ​​the partial region 505 increases with increasing distance from the outer edge of the heat reflecting member 500, and in a plan view from the inner surface 701 side, the amount of heat transferred by thermal radiation increases with increasing distance from the heat generating element 600. Therefore, the change in the amount of heat transferred to the chassis 300 depending on the distance from the heat generating element 600 can be made more gradual, and the occurrence of local temperature differences in the plurality of organic EL elements 201 can be further suppressed.

[0034] <Modification 2 of Embodiment 2> Fig. 14 is a plan view showing a part of the chassis 300, the heat-reflecting member 500, and the heat-generating element 600 according to Modification 2 of Embodiment 2. Fig. 15 is a cross-sectional view taken along the XV-XV line in Fig. 14. In Modification 2 of Embodiment 2, the structure of the partial region 505 differs from that of Modification 1 of Embodiment 2. Note that, for the entire heat-reflecting member 500, it is sufficient that the arrangement pattern shown in Fig. 9 is repeated along the outer edge of the heat-reflecting member 500.

[0035] 14 and 15 , in Modification 2 of Embodiment 2, heat-reflecting member 500 is disposed over the entire second region 504 in a plan view from the inner surface 701 side. At the outer edge far from heat-generating element 600, a plurality of second covering portions 508 are disposed on heat-reflecting member 500 in a plan view from the inner surface 701 side. Second covering portion 508 is formed of a material with a higher emissivity than second surface 502 and may be the same material as chassis 300, or may be a covering layer or masking member with a higher emissivity than second surface 502. Examples of covering layers and masking members that can be used for second covering portion 508 include oil-based paint coating, vinyl tape, and hard rubber, and their thermal emissivity ranges from approximately 85% to 95%. Therefore, the portion of second region 504 where second covering portion 508 is disposed is partial region 505. In other words, the partial region 505 is a region of the second surface 502 that is covered with a material having a higher thermal emissivity than the second surface 502. As shown in Fig. 14, for example, in a plan view from the inner surface 701 side, the multiple second covering portions 508 that make up the partial region 505 have the same size, and the number of second covering portions 508 arranged per unit area increases with increasing distance from the heating element 600. As a result, the area of ​​the partial region 505 increases with increasing distance from the outer edge of the heat-reflecting member 500, and the amount of heat transferred by thermal radiation increases with increasing distance from the heating element 600 in a plan view from the inner surface 701 side. Therefore, the amount of heat transferred to the chassis 300 can change more gradually depending on the distance from the heating element 600, thereby further suppressing local temperature differences in the multiple organic EL elements 201.

[0036] <Embodiment 3> 16 is a cross-sectional view showing a part of the chassis 300, the heat-reflecting member 500, and the heat-generating element 600 according to a third embodiment of the present disclosure, taken at the same position as the cross section III-III in Figures 1 and 2. The third embodiment differs from the first embodiment in the shape of the outer edge of the heat-reflecting member 500.

[0037] As shown in FIG. 16 , in the third embodiment, a portion of the second surface 502 in the second region 504 is inclined upward in a direction away from the heat generating element 600. In other words, a portion of the outer edge of the heat reflecting member 500 is bent away from the rear surface 302, resulting in a structure having an inclined portion 509 that is inclined upward. By adjusting the angle of the inclined portion 509, heat radiated from the heat generating element 600 as heat rays can be reflected in any direction. Although not shown, for example, by providing an opening in the housing 700 in the direction of the heat rays reflected by the inclined portion 509, a portion of the heat transmitted by thermal radiation can be released to the outside of the space 702. This reduces the total amount of heat transmitted from the heat generating element 600 to the chassis 300, thereby lowering the overall temperature of the plurality of organic EL elements 201. This suppresses deterioration of the plurality of organic EL elements 201 due to heat, thereby suppressing deterioration in display quality.

[0038] <Embodiment 4> 17 is a cross-sectional view showing a part of the chassis 300, the heat-reflecting member 500, and the heat-generating element 600 according to a fourth embodiment of the present disclosure, taken at the same position as the cross section III-III in Figures 1 and 2. The fourth embodiment differs from the first embodiment in that a heat diffusion member 800 is provided between the chassis 300 and the heat-reflecting member 500.

[0039] <Heat diffusion material> In the fourth embodiment, the heat diffusion member 800 is sandwiched between the back surface 302 and the first surface 501. The heat diffusion member 800 is made of a material having higher thermal conductivity than the heat reflecting member 500 and the chassis 300. For example, if the material of the heat diffusion member 800 is aluminum, graphite, or the like, the thermal conductivity is approximately 200 to 800 W / m·K. Furthermore, materials such as aluminum foil, copper foil, and a coating film made of radiant heat reducing paint that can be used as the heat reflecting member 500 have a thermal conductivity of approximately 200 W / m·K to 400 W / m·K. In contrast, metal materials such as iron, which are commonly used for the chassis 300, have a thermal conductivity of approximately 20 W / m·K to 50 W / m·K. Therefore, by using a material for the heat diffusion member 800 that has higher thermal conductivity than the heat reflecting member 500 and the chassis 300, the heat transmitted from the heat generating element 600 can be more easily diffused by the heat diffusion member 800 from high-temperature regions to low-temperature regions in a plan view seen from the inner surface 701 side, thereby making it possible to more uniform the temperature differences among the plurality of organic EL elements 201 included in the display unit 200. Therefore, it is more preferable that the heat diffusion member 800 cover the entire back surface 302 of the chassis 300.

[0040] <Embodiment 5> 18 is a cross-sectional view of a display device 100 according to a fifth embodiment of the present disclosure, taken along the same line as the cross section III-III in Figures 1 and 2. The fifth embodiment differs from the first embodiment in that a heating element 600 is attached to the rear surface 302 of the chassis 300.

[0041] 18, the heating element 600 is attached to the rear surface 302 via an attachment portion 303 or a fixture 304 at a position facing the rear surface 302 and the second surface 502. As a result, a space 702 is provided between the rear surface 302 and the second surface 502 and the inner surface 701 and the heating element 600. In other words, the rear surface 302 and the heating element 600 are separated by the attachment portion 303 or the fixture 304, and a part of the space 702 exists between them.

[0042] The attachment portion 303 is provided so as to protrude from the rear surface 302 and penetrate the heat reflecting member 500. In other words, the portion where the attachment portion 303 is present has a portion where the heat reflecting member 500 is not partially disposed. The attachment portion 303 may be, for example, a separate columnar part fixed to the rear surface 302, or may be an integral part of the chassis 300 where the rear surface 302 protrudes partially in a convex shape.

[0043] The fixture 304 is a member having a shape such that one side is fixed to the back surface 302 outside the heat reflecting member 500 in a plan view seen from the inner surface 701 side, and the other side is fixed to the heating element 600 in a region overlapping the heat reflecting member 500 in a plan view seen from the inner surface 701 side. The fixture 304 can be, for example, a Z-shaped metal fitting.

[0044] The present disclosure is not limited to the configurations of the above-described embodiments and modified examples, and may be replaced with a configuration that is substantially the same as the configurations shown in the above-described embodiments and modified examples, a configuration that has the same effect, or a configuration that can achieve the same purpose. [Explanation of symbols]

[0045] 100:Display device 200:Display section 201: Organic EL element 300: Chassis 301:Front 302: Back 303: Mounting part 304: Mounting fixture 400: Display panel 500: Heat reflecting material 501: Front page 502:Second side 503:First area 504:Second area 505: Partial area 506: Opening 507: First coating part 508: Second coating part 509: Inclined part 600: Heating element 601: Power supply board 602: Display signal control board 603: Motion control board 700: Cabinet 701:Inside 702: Space 800: Heat diffusion material

Claims

1. a display panel including a display unit including an organic electroluminescence element, and a chassis having a front surface in contact with the display unit and a rear surface opposite to the front surface; a heat reflecting member having a first surface facing the rear surface and a second surface opposite to the first surface, the heat reflecting member being disposed on the rear surface, the second surface having a lower thermal emissivity than the rear surface; a heat generating element disposed opposite the second surface and overlapping the heat reflecting member.

2. The display device according to claim 1 , wherein the heat reflecting member overlaps only a portion of the rear surface.

3. 2. The display device according to claim 1, wherein the heat generating element is at least one of a power supply board, a display signal control board, and an operation control board.

4. a housing covering the rear surface and having an inner surface facing the rear surface; the heating element is attached to the rear surface or the inner surface, The display device according to claim 1 , wherein there is a space between the rear surface and the second surface and between the inner surface and the heating element.

5. the heat reflecting member has a first region overlapping the heat generating element and a second region not overlapping the heat generating element, The display device according to claim 1 , wherein a partial area having a higher thermal emissivity than the second surface is provided in a part of the second area.

6. The display device according to claim 5 , wherein in the second region, the proportion of the area occupied by the partial region increases with increasing distance from the heat generating element.

7. 7. The display device according to claim 5, wherein the partial region is a region where the heat reflecting member is partially removed.

8. The display device according to claim 5 , wherein the partial region is a region of the second surface covered with a material having a higher thermal emissivity than the second surface.

9. the heat reflecting member has a first region overlapping the heat generating element and a second region not overlapping the heat generating element, The display device according to claim 1 , wherein in the second region, a portion of the second surface is inclined upward in a direction away from the heat generating element.

10. The display device according to claim 1 , further comprising a heat diffusion member sandwiched between the rear surface and the first surface, the heat diffusion member having a higher thermal conductivity than the heat reflection member and the chassis.

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