JP2006084977A - Display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display apparatus capable of securing display characteristics by increasing heat radiation efficiency as much as possible. <P>SOLUTION: An organic EL display is constituted that an organic EL panel 3 is stored in a housing 1 with heat conductivity and coupled to the housing through a heat conducting material 2 with heat conductivity. When the organic EL panel 3 generates heat, the heat is conducted to the housing 1 through the heat conducting material 2 and then dissipated from the housing 1 to the outside (into an atmosphere around the organic EL display). In this case, sufficient heat dissipation efficiency is obtained since the housing 1 and heat conducting material 2 both have sufficient heat conductivity and then the organic EL panel 3 hardly accumulates heat. Consequently, light emission efficiency of the organic EL panel 3 is secured, so luminance of an image hardly decreases and the image hardly has luminance unevenness, so that the luminance of the image can be secured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device such as an organic EL display that displays an image using an organic electroluminescence (EL) phenomenon, for example.

  In recent years, an organic EL display that displays an image using an organic EL phenomenon has attracted attention as one of flat panel displays. This organic EL display is a self-luminous display that utilizes the light-emitting phenomenon of the organic EL element, and is excellent in that it has a wide viewing angle and low power consumption.

  The organic EL display mainly has a configuration in which a driving panel and a sealing panel are arranged to face each other, and the driving panel and the sealing panel are bonded to each other through an adhesive layer. The drive panel is provided with a plurality of thin film transistors (TFT) and a plurality of organic EL elements for image display on one surface of a substrate. This organic EL element has, for example, a stacked structure in which a lower electrode layer, an organic layer, and an upper electrode layer are stacked in this order from the side closer to the substrate. The organic layer includes, for example, a light emitting layer that generates light for image display and a hole transport layer, an electron transport layer, and the like for emitting light from the light emitting layer.

  In this organic EL display, as described above, excellent display characteristics can be obtained from the viewpoint of viewing angle and power consumption. On the other hand, heat storage during image display is a problem in display characteristics. Specifically, in the organic EL display, when heat is generated based on the organic EL phenomenon, that is, the light emission phenomenon of the light emitting layer of the organic EL element, the ambient temperature of the organic EL element is increased by storing the heat. If it rises too much, the luminous efficiency is lowered due to the thermal degradation of the light emitting layer, which is the light emitting source, and the luminance of the image is lowered. In addition, in this case, if a temperature difference occurs in the display area of the organic EL display, the light emission efficiency varies in the display area, resulting in uneven brightness in the image. In an organic EL display, in general, the central region of the display region is likely to be heated to a high temperature due to factors such as a circuit configuration, for example, so that the luminance tends to partially decrease in the central region. Of course, the problem related to the heat storage of the organic EL display is not preferable from the viewpoint of display characteristics as described above, and is also not preferable from the viewpoint of handling of the user who uses the organic EL display.

Several techniques have already been proposed for heat storage measures aimed at improving the luminance of the organic EL display, that is, heat dissipation measures for suppressing heat storage. Specifically, for example, an organic EL display provided with various heat radiation components in the vicinity of the organic EL element, specifically between a drive panel and a sealing panel is known (for example, Patent Documents 1 to 3). 4). In this organic EL display, the heat dissipation efficiency of heat generated in the organic EL element is improved by utilizing the heat dissipation action of various heat dissipation components.
JP 2003-022891 A JP 2003-007450 A JP 2004-047458 A JP 2004-119277 A

  By the way, in order to ensure the display characteristics of the organic EL display, it is necessary to improve the heat dissipation efficiency of the heat generated in the organic EL element as much as possible in order to ensure the luminance of the image. However, in the conventional organic EL display, the heat dissipation efficiency is not yet sufficient due to the heat dissipation mechanism of the heat generated in the organic EL element, so there is room for improvement in terms of the heat dissipation efficiency. In this case, especially considering the promotion of the market spread of organic EL displays, not only the display characteristics are ensured as described above, but also the durability and versatility are ensured and the thickness is reduced. It is also important to plan.

  The present invention has been made in view of such problems, and an object thereof is to provide a display device capable of ensuring display characteristics by improving the heat dissipation efficiency as much as possible.

  In the display device according to the present invention, a display panel is housed in a heat-conducting housing provided with an image display opening so that the display direction faces the opening, and the display panel is thermally conductive. It is connected to the housing via a base material having

  In the display device according to the present invention, the display panel is housed inside a case having thermal conductivity, and the display panel is connected to the case via a base material having thermal conductivity. When heat is generated, the heat is conducted to the casing through the base material, and then is radiated from the casing to the outside (in the atmosphere around the display device). In this case, since sufficient heat dissipation efficiency is obtained based on the fact that both the casing and the base material have sufficient thermal conductivity, both the casing and the base material have sufficient thermal conductivity. Compared with the case where sufficient heat dissipation efficiency cannot be obtained due to the lack of the property, it is difficult to store heat in the display panel. Accordingly, the luminance of the image is ensured because the luminance of the image is less likely to be lowered and luminance unevenness is less likely to occur in the image based on ensuring the light emission efficiency of the display panel.

  According to the display device of the present invention, the display panel is housed inside the thermally conductive casing, and the display panel is connected to the casing via the base material having thermal conductivity. Therefore, it is difficult to store heat in the display panel because sufficient heat dissipation efficiency is obtained. Therefore, since the luminance of the image is ensured based on ensuring the light emission efficiency of the display panel, the display characteristics can be ensured by improving the heat dissipation efficiency as much as possible.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, the configuration of an organic EL display as a display device according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2 show the configuration of an organic EL display, FIG. 1 shows a cross-sectional configuration, and FIG. 2 shows a perspective configuration. FIG. 1 shows a cross-sectional configuration along the line II shown in FIG. 2, and FIG. 2 shows a state in which a series of components constituting the organic EL display are separated from each other.

  The organic EL display according to the present embodiment displays an image using an organic EL phenomenon, for example, and is mounted on a portable electronic device such as a PDA (Personal Digital Assistant). For example, as shown in FIGS. 1 and 2, the organic EL display includes an organic EL panel 3 in a housing 1 provided with an image display opening 1P so that a display direction 3D faces the opening 1P. And the organic EL panel 3 is connected to the housing 1 via the heat transfer material 2.

  The housing 1 is a container for housing the organic EL panel 3 and physically protecting the organic EL panel 3 from the outside, and has a substantially box-shaped structure provided with the opening 1P described above. In particular, the casing 1 has thermal conductivity, that is, the casing 1 dissipates heat generated in the organic EL panel 3 together with the protection function described above, and specifically, the casing 1 heats itself as a heat dissipation path. It also has a heat dissipation function that plays a role in dissipating heat. For example, the housing 1 includes a heat conductive material such as an aluminum-based material, and specifically includes aluminum (Al) or an alloy containing aluminum. As this “alloy containing aluminum”, for example, aluminum copper alloy (AlCu), aluminum manganese alloy (AlMn), aluminum silicide (AlSi), aluminum magnesium alloy (AlMg), aluminum magnesium silicide (AlMgSi), or aluminum zinc A magnesium alloy (AlZnMg) etc. are mentioned. Among these aluminum-based materials, aluminum has low specific gravity (can be reduced in weight), high specific strength (high physical durability), excellent corrosion resistance (hard to rust), and excellent recyclability (recyclable) Since the electrical conductivity is high (easy to ground) and the thermal conductivity is high (easy to dissipate heat), it is preferable as the constituent material of the housing 1 from the viewpoint of the protection function and the heat radiation function. In addition to the series of advantages described above, the advantages of aluminum include a point that is hard to be magnetized, easily reflects light and heat, easy to process, and has a beautiful finish during processing. Of course, some alloys containing aluminum have the same advantages as aluminum, so alloys having the same advantages as aluminum are also preferable as the constituent material of the housing 1.

  In this housing 1, for example, the inner dimension (inner dimension) is larger than the outer dimension (outer edge dimension) of the organic EL panel 3 in order to facilitate the housing of the organic EL panel 3 inside the casing 1. ing. Thus, a gap 1G is provided between the housing 1 and the organic EL panel 3. The gap 1G is used as a clearance when the organic EL panel 3 is housed in the housing 1. In addition, the structure of the housing | casing 1 other than the above-mentioned characteristic can be set freely.

  The heat transfer material 2 has thermal conductivity, that is, a base material that conducts heat generated in the organic EL panel 3 to the casing 1 by connecting the organic EL panel 3 to the casing 1 as a base. It is. The heat transfer material 2 includes, for example, a heat conductive resin, a resin containing heat conductive particles, or a heat conductive material such as graphite. Examples of the “thermal conductive resin” include silicone rubber, acrylic rubber, or ethylene propylene rubber, and examples of the “resin containing thermal conductive particles” include gold (Au) particles dispersed therein. Silicone rubber etc. which were made are mentioned.

  The heat transfer material 2 has, for example, a sheet-like structure. That is, since the organic EL panel 3 is connected to the housing 1 via the heat transfer material 2 having a sheet-like structure and a large area, the presence of the heat transfer material 2 causes the organic EL panel 3 and the housing 1 to be connected. A large area heat conduction path is secured between them.

  In particular, the heat transfer material 2 has, for example, adhesiveness, that is, the organic EL panel 3 is attached to the housing 1 using the adhesiveness of the heat transfer material 2. The heat transfer material 2 having adhesiveness is, for example, a single layer structure of the above-described heat conductive material, and the heat conductive material itself may have adhesiveness, or heat conduction. The adhesive material layer has a laminated structure in which an adhesive layer is provided on both surfaces, and the adhesive layer may have adhesiveness.

  As this heat transfer material 2, for example, a commercially available heat transfer sheet can be used. Specifically, “Siloxane-free thermally conductive adhesive sheet (trade name: EFCO TM sheet)” manufactured by Furukawa Electric Co., Ltd., "High thermal conductive silicone rubber sheet (trade name: TC series)" manufactured by Shin-Etsu Chemical Co., Ltd., "Heat dissipation sheet (trade name: PGS graphite sheet)" manufactured by Matsushita Electronic Parts Co., Ltd., "Transmission" manufactured by Fujikura Co., Ltd. “Heat sheet (trade name: cool sheet)” or “Heat radiation gel sheet (trade name: MasaSheet GT / GS)” manufactured by Nitto Kako Co., Ltd. can be used. Among these, the “siloxane-free thermally conductive adhesive sheet” is one in which the heat transfer sheet itself has adhesiveness.

  As described above, the organic EL panel 3 is a display panel that displays an image using the organic EL phenomenon, and the display direction 3D faces the opening 1P of the housing 1. Here, for example, as shown in FIG. 1, the housing 1 is arranged so that the opening 1 </ b> P faces upward, so the display direction 3 </ b> D of the organic EL panel 3 also faces upward. The organic EL panel 3 includes, for example, a drive panel 10 for image formation and a sealing panel 20 for image display. For example, the drive panel 10 has a larger panel size than the sealing panel 20 so that an electrode pad (not shown) for electrical connection is exposed even when the driving panel 10 is bonded to the sealing panel 20. is doing. In FIG. 2, a region surrounded by a one-dot chain line represents a display region 3 </ b> R that is a substantial image display range of the organic EL panel 3.

  Next, a detailed configuration of the organic EL panel 3 will be briefly described with reference to FIG. FIG. 3 shows an enlarged cross-sectional configuration of the organic EL panel 3.

  In the organic EL panel 3, for example, as shown in FIG. 3, the drive panel 10 and the sealing panel 20 are disposed to face each other, and the drive panel 10 and the sealing panel 20 are attached to each other via the adhesive layer 30. It has a combined configuration.

  The drive panel 10 has a configuration in which a plurality of combinations of three organic EL elements 12R, 12G, and 12B are arranged on one surface of the drive substrate 11. An insulating layer 13 is embedded between the organic EL elements 12R, 12G, and 12B, and these organic EL elements 12R, 12G, and 12B are covered with a protective layer.

  The driving substrate 11 is a circuit board provided with TFTs (not shown) for driving the organic EL elements 12R, 12G, and 12B. For example, the driving substrate 11 is formed on one surface of a substrate made of an insulating material such as glass. The electronic component including the above-described TFT is provided.

  The organic EL elements 12R, 12G, and 12B generate light of three colors (R (Red), G (Green), and B (Blue)) corresponding to the three primary colors of light as image display light. Specifically, the organic EL element 12R generates red light LR, the organic EL element 12G generates green light LG, and the organic EL element 12B generates blue light LB. Each of these organic EL elements 12R, 12G, and 12B has a configuration in which the organic layer 122 is sandwiched between the lower electrode layer 121 and the upper electrode layer 123, for example. The organic layer 14 includes, for example, a light-emitting layer (a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer) as a light source of each color, and a hole transport layer, an electron transport layer, and the like for emitting the light-emitting layer. It has the laminated structure containing.

  The lower electrode layer 121 and the upper electrode layer 123 are, for example, at least one metal selected from the group including silver (Ag), aluminum (Al), magnesium (Mg), calcium (Ca), and sodium (Na), or It is comprised with the alloy containing the metal.

The constituent material of the organic layer 122 is as follows, for example. That is, the light emitting layer (light emitting layer for generating red LR) in the organic EL element 12R is, for example, 2,6-bis [(4′-methoxydiphenylamino) styryl] -1,5-dicyanonaphthalene (BSN). Are mixed with a red light emitting material such as 4,4′-bis (2,2-diphenylvinyl) biphenyl (DPVBi). The light emitting layer (light emitting layer for generating green light LG) of the organic EL element 12G is configured to include a green light emitting material such as DPVBi mixed with coumarin 6. The light emitting layer (light emitting layer for generating blue LB light) in the organic EL element 12B is, for example, 4,4′-bis [2, {4- (N, N-diphenylamino) phenyl} vinyl] biphenyl ( And a blue light emitting material such as DPVBi mixed with DPAVBi). Note that the hole transport layer is, for example, a hole such as 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA) or α-naphthylphenyldiamine (α-NPD). For example, the electron transport layer includes an electron transport material such as 8-hydroxyquinoline aluminum (Alq ₃ ).

The insulating layer 13 electrically isolates (insulates) the organic EL elements 12R, 12G, and 12B, and narrows the emission ranges of the light beams LR, LG, and LB emitted from the organic EL elements 12R, 12G, and 12B. For example, it includes an organic insulating material such as polyimide and an inorganic insulating material such as silicon oxide (SiO ₂ ).

The protective layer 14 is for protecting the organic EL elements 12R, 12G, and 12B. For example, the protective layer 14 is a passivation film made of a light transmissive dielectric material such as silicon oxide (SiO ₂ ) or silicon nitride (SiN). is there.

  On the other hand, the sealing panel 20 has a configuration in which the color filter 22 is provided on one surface of the sealing substrate 21.

  The sealing substrate 21 leads the outside of the organic EL panel 3 by transmitting the light LR, LG, LB generated in the organic EL elements 12R, 12G, 12B. For example, the sealing substrate 21 is made of an insulating material such as glass. It is configured. That is, the organic EL panel 3 is, for example, a top that displays an image by emitting light LR, LG, LB generated in the organic EL elements 12R, 12G, 12B upward, that is, through the sealing panel 20 to the outside. It has an emission type structure.

  The color filter 22 guides the light LR, LG, and LB generated in the organic EL elements 12R, 12G, and 12B to the outside of the organic EL panel 3 and causes the outside light to enter the inside of the organic EL panel 3. This is to ensure contrast by absorbing the reflected light when reflected by the EL elements 12R, 12G, 12B and the like. The color filter 22 includes three regions arranged corresponding to the organic EL elements 12R, 12G, and 12B, that is, a red region 22R, a green region 22G, and a blue region 22B. The red region 22R, the green region 22G, and the blue region 22B are configured to include, for example, resins mixed with red, green, and blue pigments, respectively.

  The adhesive layer 30 is used to bond the drive panel 10 and the sealing panel 20 to each other, and includes an adhesive material such as a thermosetting resin, for example.

  Next, the operation of the organic EL display will be described with reference to FIGS. FIG. 4 is a diagram for explaining a heat conduction path in the organic EL display. In FIG. 4, (A) shows a planar configuration of the heat transfer material 2, (B) shows a cross-sectional configuration of the heat transfer material 2, and (C) shows the heat conduction path in detail. The cross-sectional structure of the housing | casing 1 is shown.

  In this organic EL display, as shown in FIG. 3, three organic EL elements 12R, 12G, and 12B are driven using TFTs (not shown) provided on the driving substrate 11 of the driving panel 10, That is, when a voltage is applied between the lower electrode layer 121 and the upper electrode layer 123, the holes supplied from the hole transport layer in the organic layer 122 of each of the organic EL elements 12R, 12G, and 12B Since the electrons supplied from the electron transport layer are recombined in the light emitting layer, each of the organic EL elements 12R, 12G, and 12B generates light. Specifically, the organic EL element 12R generates red light LR, the organic EL element 12G generates green light LG, and the organic EL element 12B generates blue light LB. When the combined light of these three colors of light LR, LG, and LB is guided to the outside through the sealing substrate 21 of the sealing panel 20, the combined light is visually recognized by the user as an image. Images are displayed based on the light beams LR, LG, and LB.

  When an image is displayed on the organic EL display, as shown in FIGS. 1 to 3, heat is generated based on the light emission phenomenon of the organic EL elements 12 </ b> R, 12 </ b> G, and 12 </ b> B in the organic EL panel 3. Based on the configuration in which the organic EL panel 3 is connected to the housing 1 via the heat transfer material 2, heat generated in the organic EL panel 3 is conducted to the housing 1 via the heat transfer material 2. Then, heat is radiated from the housing 1 to the outside (in the atmosphere around the organic EL display).

  Specifically, first, when the heat generated in the organic EL panel 3 is conducted to the heat transfer material 2, as shown in FIG. 4A, the amount of heat in the surface of the heat transfer material 2 (in the XY plane). Heat diffuses so that the distribution is uniform. More specifically, in an organic EL display, heat is generally concentrated in the central region of the display region 3R (see FIG. 2) of the organic EL panel 3, but heat is concentrated in the central region of the display region 3R. Even if concentrated, as shown in FIG. 4A, the thermal conductivity of the heat transfer material 2 is used to conduct heat HA concentrated in the central region of the display region 3R so that it spreads radially. That is, since heat is preferentially conducted from the relatively high temperature central region toward the relatively low temperature peripheral region, the heat HA is diffused in the surface of the heat transfer material 2. In addition, when the heat generated in the organic EL panel 3 is conducted to the heat transfer material 2, generally, heat tends to concentrate on the corner region of the heat transfer material 2, but the heat is concentrated on the corner region. However, as shown in FIG. 4 (A), using the thermal conductivity of the heat transfer material 2, heat HB concentrated in the corner region of the heat transfer material 2 is conducted so as to spread to the periphery, That is, since heat is preferentially conducted from the relatively high temperature corner region toward the relatively low temperature peripheral region, the heat HB is also diffused in the surface of the heat transfer material 2.

  Subsequently, the heat conducted to the heat transfer material 2 is dissipated by being conducted from the heat transfer material 2 to the housing 1. Specifically, as shown in FIGS. 4B and 4C, the heat HC conducted to the heat transfer material 2 is transferred to the housing 1 by using the entire surface of the heat transfer material 2 as a conduction path. When conducted, as shown in FIG. 4C, the heat HD conducted to the housing 1 using the thermal conductivity of the housing 1 uses the entire housing 1 as a heat dissipation path. Heat is released to the outside. Thereby, the heat generated in the organic EL panel 3 is radiated to the outside by utilizing the thermal conductivity of both the housing 1 and the heat transfer material 2.

  In the organic EL display according to the present embodiment, an organic EL panel 3 is housed inside a case 1 having thermal conductivity, and the organic EL panel 3 is provided via a heat transfer material 2 having thermal conductivity. The display characteristics can be ensured by improving the heat dissipation efficiency as much as possible for the following reasons.

  FIG. 5 shows a configuration of an organic EL display as a comparative example with respect to the organic EL display according to the present embodiment, and shows a cross-sectional configuration corresponding to FIG. The organic EL display of this comparative example includes a casing 101 provided with an opening 101P instead of the casing 1 provided with an opening 1P, and an adhesive 102 instead of the heat transfer material 2. Except for the point, it has the same configuration as the organic EL display according to the present embodiment. The casing 101 is made of, for example, a material that is generally widely used as an exterior application for the purpose of physically protecting the organic EL panel 3, for example, stainless steel (for example, SUS) that has a particularly high specific strength. It is comprised by. The adhesive 102 is a material that is generally widely used for bonding, for example, for the purpose of adhering the organic EL panel 3 to the housing 1, and specifically, a double-sided tape containing an acrylic adhesive. It is comprised by.

  In the organic EL display of this comparative example (see FIG. 5), since the organic EL panel 3 is connected to the housing 101 via the adhesive 102, when heat is generated in the organic EL panel 3, the heat is transferred to the adhesive. Heat is dissipated by conduction to the housing 101 via 102. However, in this case, sufficient heat dissipation is caused by the fact that neither the stainless steel constituting the housing 101 nor the acrylic pressure-sensitive adhesive constituting the adhesive material 102 has sufficient thermal conductivity. Since efficiency cannot be obtained, heat is easily stored in the organic EL panel 3. Specifically, the temperature difference (the difference between the highest temperature and the lowest temperature) in the display region 3R in the case of the comparative example reaches about 5 ° C. to 7 ° C. or more. As a result, the organic EL elements 12R, 12G, and 12B are likely to be thermally deteriorated. As a result, the light emission efficiency of the organic EL panels 12R, 12G, and 12B is likely to be reduced. Therefore, uneven brightness tends to occur in the image, that is, it is difficult to ensure the brightness of the image.

  In contrast, in the organic EL display (see FIG. 1) according to the present embodiment, since the organic EL panel 3 is connected to the housing 1 via the heat transfer material 2, heat is generated in the organic EL panel 3. When generated, the heat is radiated by conduction to the housing 1 via the heat transfer material 2. In this case, sufficient heat dissipation is based on the fact that both the aluminum-based material constituting the housing 1 and the heat transfer sheet constituting the heat transfer material 2 have sufficient thermal conductivity. Since efficiency is obtained, it becomes difficult to store heat in the organic EL panel 3. Specifically, the temperature difference in the display region 3R in the case of the present embodiment is about 1 ° C. As a result, the organic EL elements 12R, 12G, and 12B are less likely to be thermally deteriorated. As a result, the light emission efficiency of the organic EL panels 12R, 12G, and 12B is less likely to decrease, and thus the luminance of the image is less likely to decrease. Thus, luminance unevenness hardly occurs in the image, that is, it is possible to ensure the luminance of the image. Therefore, display characteristics can be ensured by improving the heat dissipation efficiency as much as possible.

  In particular, if the advantages of the organic EL display according to the present embodiment are supplemented, as described above, the organic EL elements 12R, 12G, and 12B are entirely formed on the basis that the heat dissipation efficiency is improved as much as possible. Since it is less likely to be thermally deteriorated, it is possible to suppress a decrease in the brightness of the entire image, and as shown in FIG. 4A, the heat HA conducted from the organic EL panel 3 to the heat transfer material 2 , HB is diffused so that the heat distribution is made uniform in the surface of the heat transfer material 2, it is possible to suppress the occurrence of uneven brightness in the image. In this case, since the heat dissipation efficiency is further improved, the organic EL elements 12R, 12G, and 12B are less likely to be thermally deteriorated. In particular, when displaying a white image (all of the organic EL elements 12R, 12G, and 12B). When the organic EL panels 12R, 12G, and 12B reach the maximum temperature, the display life of the organic EL display can be extended and the organic EL panel can be improved based on the improvement of the heat dissipation efficiency. Since the panel 3 is less likely to be heated, the handleability of the user who uses the organic EL display can be improved.

  Moreover, in this Embodiment, based on the structure by which the organic electroluminescent panel 3 is connected with the housing | casing 1 via the heat-transfer material 2, an organic electroluminescent display can be reduced in thickness easily for the following reasons.

  FIG. 6 shows a configuration of an organic EL display as another comparative example with respect to the organic EL display according to the present embodiment, and shows a cross-sectional configuration corresponding to FIG. The organic EL display of another comparative example has the same configuration as the organic EL display of the comparative example shown in FIG. 5 except that a heat sink 103 is provided instead of the housing 101. The heat sink 103 is a radiator for cooling the heat generated in the organic EL panel 3. For example, the heat sink 103 has a configuration in which a plurality of fins for heat dissipation are provided on a base plate.

  In the organic EL display of another comparative example (see FIG. 6), since the heat sink 103 is connected to the organic EL panel 3 through the adhesive material 102, the forced heat dissipation function of the heat sink 103 is used to The heat generated in the EL panel 3 is efficiently radiated. However, in this case, since the large heat sink 103 is mounted on the organic EL display, the organic EL display becomes thicker. The thickening of the organic EL display is a serious problem when the organic EL display is mounted on a portable electronic device such as a PDA. In addition, in this case, assuming an organic EL display manufacturing process, a mold having a complicated shape is required to form the heat sink 103 using a molding process. In particular, the formation size of the heat sink 103 is fixed. In order to increase the display size, it is necessary to form a plurality of heat sinks 103 and mount them on the organic EL display. This complicates the manufacturing process of the organic EL display, and the organic EL display Cost increases. In addition, the problem regarding the complexity of the manufacturing process of the organic EL display described above is not limited to the case where the heat sink 103 is mounted on the organic EL display, but a fan having an air cooling function is mounted on the organic EL display instead of the heat sink 103. This can occur in the same way.

  On the other hand, in the organic EL display according to the present embodiment (see FIG. 1), the organic EL panel 3 is connected to the housing 1 via the heat transfer material 2, so Since the heat generated in the organic EL panel 3 is dissipated using the natural heat dissipating function, the heat dissipating efficiency when using the housing 1 is not equal to the heat dissipating efficiency when using the heat sink 103, Sufficient heat dissipation efficiency is obtained. In this case, since sufficient heat dissipation efficiency can be obtained by simply mounting the small casing 1 on the organic EL display, the organic EL display is thinned. The thinning of the organic EL display is an important advantage when the organic EL display is mounted on a portable electronic device such as a PDA. In addition, in this case, assuming the manufacturing process of the organic EL display, the mold necessary for forming the housing 1 using the molding process can be a simple shape. In addition to simplification, the cost of the organic EL display is reduced. Therefore, in this embodiment, the organic EL display can be easily thinned.

  Moreover, in this Embodiment, since the housing | casing 1 was comprised using the aluminum-type material excellent in workability, by utilizing the outstanding workability of the aluminum-type material, it is desired according to a use application. The housing 1 can be configured to have a shape.

  In the present embodiment, the heat transfer material 2 has adhesiveness, and the organic EL panel 3 is attached to the housing 1 by using the adhesiveness of the heat transfer material 2. In the manufacturing process of the organic EL display, it is not necessary to separately prepare an adhesive member such as a double-sided tape in order to carry out the dimensioning operation of the effective display area of the organic EL panel 3. Therefore, since it is possible to carry out the dimensioning operation of the effective display area of the organic EL panel 3 without using an adhesive member such as a double-sided tape, the organic EL display can be easily manufactured.

  Here, the difference between the organic EL display according to the present embodiment and the series of known organic EL displays described in the above “Background Art” will be described as follows. In other words, in any case, a series of known organic EL displays has a small heat dissipation component mounted between the drive panel and the sealing panel, and uses the heat dissipation action of the small heat dissipation component to dissipate heat. Therefore, sufficient heat dissipation efficiency cannot be obtained due to insufficient heat dissipation capacity of the heat dissipation component. In addition, in this case, since the drive panel and the sealing panel are not physically protected from the outside, for example, the durability against dropping or vibration during transportation is not sufficient, and versatility is also provided when used in various applications. not enough. On the other hand, in the organic EL display according to the present embodiment, the housing 1 is mounted on the organic EL panel 3 as a large heat-dissipating component, and heat is dissipated using the heat dissipating action of the large housing 1. Therefore, sufficient heat radiation efficiency can be obtained based on the fact that the heat radiation capacity of the housing 1 is sufficient. In addition, in this case, since the housing 1 performs the above-described heat dissipation function and also a protective function for physically protecting the organic EL panel 3 from the outside, the durability against drop or vibration during transportation is sufficient. In addition to being obtained, sufficient versatility for use in various applications is also obtained. Therefore, the organic EL display according to the present embodiment has advantages not only in terms of heat dissipation but also in terms of durability and versatility, compared to a series of known organic EL displays.

In the present embodiment, it is possible to further improve the heat dissipation efficiency by using the gap 1G provided between the housing 1 and the organic EL panel 3. Specifically, for example, as illustrated in FIG. 7, the heat transfer material 4 may be provided in the gap 1 </ b> G so as to be adjacent to both the housing 1 and the organic EL panel 3. This heat transfer material 4 has thermal conductivity, that is, a filler that conducts heat generated in the organic EL panel 3 to the housing 1 in the same manner as the heat transfer material 2 by being filled in the gap 1G. It is. The heat transfer material 4 includes, for example, a heat conductive resin or a resin containing heat conductive particles. Examples of the “thermal conductive resin” include a photo-curing resin such as an epoxy resin (for example, an ultraviolet (UV) curable resin), a natural curable resin such as a silicone resin, or a thermosetting resin. Examples of the “resin containing thermally conductive particles” include grease in which aluminum oxide (Al ₂ O ₃ ) particles are mixed with a liquid silicone resin. In particular, the heat transfer material 4 flows into the gap 1G in order to secure a heat conduction path via the heat transfer material 4 between the organic EL panel 3 and the housing 1, for example, by filling the gap 1G. It is preferable that the material is cured after being filled with the functional material. In this case, considering the stable mass productivity of the organic EL display, among the series of curable resins described above, a naturally curable resin that takes time to complete the curing reaction and a curing reaction to proceed. As a constituent material of the heat transfer material 4, a photocurable resin that can complete the curing reaction in a short time without requiring unnecessary heat is used rather than a thermosetting resin that requires unnecessary heat supply. Is preferred.

  In the organic EL display provided with the heat transfer material 4, as shown in FIGS. 4B and 4C, the heat HC generated in the organic EL panel 3 passes through the heat transfer material 2 to the housing 1. In addition to conduction, as shown in FIG. 7, heat HE generated in the organic EL panel 3 is also conducted to the housing 1 via the heat transfer material 4 by utilizing the heat conductivity of the heat transfer material 4. The heat dissipation efficiency can be further improved. Specifically, the heat conductivity when the heat transfer material 4 is provided in the gap 1G is approximately 12 to 13 times that of the heat conductivity when the heat transfer material 4 is not provided in the gap 1G. . In addition, in this case, since it becomes difficult for moisture to enter the organic EL panel 3 through the gap 1G based on the presence of the heat transfer material 4, the organic EL elements 12R, 12G, and 12B deteriorate due to the moisture. Since the heat transfer material 4 fulfills the above-described heat transfer function and also functions as a cushion to absorb the shake when the organic EL display shakes due to vibration during transportation, for example. The organic EL panel 3 can also be prevented from being damaged due to shaking.

  Although the display device of the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment, and the configuration of the display device of the present invention obtains the same effect as the above embodiment. Is freely deformable as long as possible. Specifically, in the above embodiment, the aluminum-based material is exemplified as the constituent material of the housing. However, the material is not necessarily limited to this, and other than the aluminum-based material as long as it has sufficient thermal conductivity. The materials may be used.

  In the above embodiment, the case where the display device of the present invention is applied to an organic EL display has been described. However, the present invention is not necessarily limited thereto, and the display device of the present invention is applied to other displays other than the organic EL display. It is also possible to apply. Even in this case, the same effect as the above embodiment can be obtained.

  The display device according to the present invention can be applied to various displays such as an organic EL display.

It is sectional drawing showing the cross-sectional structure of the organic electroluminescent display which concerns on one embodiment of this invention. FIG. 2 is a perspective view illustrating a perspective configuration of the organic EL display illustrated in FIG. 1. It is sectional drawing which expands and represents the cross-sectional structure of an organic electroluminescent panel. It is a figure for demonstrating the heat conduction path | route in the organic electroluminescent display which concerns on one embodiment of this invention. It is sectional drawing showing the cross-sectional structure of the organic electroluminescent display as a comparative example with respect to the organic electroluminescent display which concerns on one embodiment of this invention. It is sectional drawing showing the cross-sectional structure of the organic electroluminescent display as another comparative example with respect to the organic electroluminescent display which concerns on one embodiment of this invention. It is sectional drawing showing the modification regarding the structure of the organic electroluminescent display which concerns on one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Housing | casing, 1G ... Gap | interval, 1P ... Opening, 2, 4 ... Heat-transfer material, 3 ... Organic EL panel, 3D ... Display direction, 3R ... Display area, 10 ... Drive panel, 11 ... Substrate for drive, 12R, 12G, 12B ... Organic EL element, 13 ... Insulating layer, 14 ... Protective layer, 20 ... Display panel, 21 ... Substrate for sealing, 22 ... Color filter, 22R ... Red region, 22G ... Green region, 22B ... Blue region, DESCRIPTION OF SYMBOLS 30 ... Adhesive layer, 121 ... Lower electrode layer, 122 ... Organic layer, 123 ... Upper electrode layer, HA-HE ... Heat, LB ... Blue light, LG ... Green light, LR ... Red light, 3R ... Display area .

Claims (10)

A display panel is housed in a housing having thermal conductivity provided with an image display opening so that a display direction faces the opening.
The display panel is connected to the housing via a base material having thermal conductivity. The display device according to claim 1, wherein the casing includes aluminum (Al) or an alloy containing aluminum. The display device according to claim 1, wherein the base material includes a heat conductive resin, a resin containing heat conductive particles, or graphite. The display device according to claim 1, wherein the base material has a sheet-like structure. The base material has adhesiveness;
The display device according to claim 1, wherein the display panel is affixed to the casing using the adhesiveness of the base material. The display device according to claim 1, wherein a gap is provided between the housing and the display panel. The display device according to claim 6, wherein the gap is filled with a filler having thermal conductivity. The display device according to claim 7, wherein the filler includes a heat conductive resin or a resin containing heat conductive particles. The display device according to claim 8, wherein the filler is hardened after the gap is filled with a fluid material. The display device according to claim 1, wherein the display panel displays an image using an organic electroluminescence (EL) phenomenon.

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