JP6427408B2 - Transparent organic EL display - Google Patents

Description

  The present invention relates to a transparent organic EL display device.

  Organic EL display devices are equipped with elements expected for display devices such as high definition, high response speed, high contrast, wide viewing angle, thin, etc., and are the next generation display devices following liquid crystal display devices and plasma panel display devices Has been noted as. An organic EL panel used in an organic EL display device is an electrode in which light emitting elements (organic EL elements) using electroluminescence that emits light when current flows in an organic material are disposed on a substrate such as a glass plate and arranged in a grid An image can be displayed by controlling the light emitting element by (wiring).

While the organic EL display device has various advantages as described above, heat storage of the organic EL panel at the time of image display is a problem. That is, when the heat generated from the organic EL element during image display is stored, the organic EL element may be degraded, and the characteristics such as the light emission efficiency and the luminance may be lowered.
Then, the organic electroluminescence display which laminated | stacked the thermal radiation member on the organic electroluminescent panel is proposed (for example, patent document 1). In the organic EL display device, the heat generated by the organic EL panel can be dissipated to the outside through the heat dissipation member by the heat dissipation function of the heat dissipation member.

By the way, in recent years, among organic EL display devices, a transparent organic EL display device ("transmission type organic EL display device" which is transparent when not emitting light and can display an image by emitting light when current flows) It is also called attention). In addition to the characteristics required for a general organic EL display device, this transparent organic EL display device must have high transparency when not emitting light. Specifically, in the transparent organic EL display device, the transparency of the heat dissipation member should be high.
However, since a general organic EL display device uses a metal plate such as an Al plate as a heat dissipation member, this heat dissipation member can not be used for a transparent organic EL display device. It is also conceivable to use a transparent material with high thermal conductivity (for example, diamond, sapphire, transparent ceramic, etc.) as a heat dissipation member, but such transparent materials are not practical because they are expensive. Furthermore, although it is conceivable to use a transparent plastic such as PMMA or PET as a heat dissipation member, the transparent plastic is not practical because its thermal conductivity is about 1/100 compared to metals such as Al and Cu.

Unexamined-Japanese-Patent No. 2013-21357

  The present invention has been made to solve the problems as described above, and it is an object of the present invention to provide a transparent organic EL display device which is excellent in transparency and heat dissipation, and is inexpensive.

  As a result of intensive studies to solve the above problems, the present inventor uses a transparent film provided with metal fine wires on at least one surface as a heat dissipation member, thereby suppressing the cost of the transparent organic EL display device. It has been found that both transparency and heat dissipation can be achieved.

  That is, the present invention is a transparent organic EL display device having a transparent organic EL panel and a heat dissipation sheet laminated on the transparent organic EL panel, wherein the heat dissipation sheet is provided with metal thin lines on at least one surface. Organic EL display device characterized in that it is a transparent film.

  According to the present invention, it is possible to provide a transparent organic EL display device which is excellent in transparency and heat dissipation and is inexpensive.

It is an expanded sectional view in the edge part periphery of a transparent organic electroluminescence display. It is a figure for demonstrating the light transmittance of a transparent organic electroluminescence display. It is a top view of a heat dissipation sheet.

  Hereinafter, preferred embodiments of the transparent organic EL display device of the present invention will be described using the drawings. Note that this embodiment shows one aspect of the present invention, and does not limit the present invention. Further, in this embodiment, the shapes, combinations, and the like of the constituent members can be modified according to the design request and the like without departing from the spirit of the present invention. Further, the drawings are illustrated so that each component can be easily understood, and the size and the like are different from actual components.

Embodiment 1
FIG. 1 is an enlarged cross-sectional view around the edge of the transparent organic EL display device of the present embodiment. In FIG. 1, the transparent organic EL display device 1 has a transparent organic EL panel 2 and a heat dissipation sheet 3 laminated on the transparent organic EL panel 2. In addition, a housing 4 is disposed at the periphery of the laminate of the transparent organic EL panel 2 and the heat dissipation sheet 3.
In addition, in FIG. 1, only the characteristic part of the transparent organic electroluminescence display 1 of this Embodiment is shown in figure, and it can further provide various members well-known in the said technical field. Moreover, since the structure other than the characteristic part of the transparent organic electroluminescence display 1 of this Embodiment is well-known in the said technical field, detailed description is abbreviate | omitted.

The transparent organic EL panel 2 is not particularly limited, and those known in the art having a driving method such as a passive matrix type or an active matrix type can be used.
In the passive matrix type transparent organic EL panel 2, generally, transparent organic EL elements constituting pixels are arranged in a matrix. A transparent organic EL element is provided at the intersection of a plurality of row electrodes (scanning lines) and a plurality of column electrodes (data lines), and a voltage corresponding to a data signal is applied between the selected row electrodes and the plurality of column electrodes. Thus, the transparent organic EL element is driven.
On the other hand, in the active matrix type transparent organic EL panel 2, a switching thin film transistor (TFT) is provided at the intersection of a plurality of scanning lines and a plurality of data lines, the gate of the driving TFT is connected to this switching TFT, and the selected scanning line The switching TFT is turned on to input a data signal from the signal line to the driving TFT to drive the transparent organic EL element.

Here, in the present specification, the scanning lines and the data lines of the transparent organic EL panel 2 are collectively referred to as “wiring 5”. In the transparent organic EL panel 2, the wires 5 are arranged in a lattice.
In addition, in FIG. 1, only the wiring 5 is illustrated among the members which comprise the transparent organic electroluminescent panel 2, and the other members are not illustrated.

The heat dissipation sheet 3 laminated on the transparent organic EL panel 2 plays a role of radiating heat generated in the transparent organic EL panel 2.
The heat dissipation sheet 3 includes a transparent film 6 and fine metal wires 7 provided on at least one surface of the transparent film 6.
The transparent film 6 is not particularly limited, and those known in the art can be used. The transparent film 6 is generally a film formed of a transparent resin. Examples of transparent resins include polyester, polystyrene, polyimide, polyamide, polysulfone, polycarbonate, polyvinyl chloride, polyethylene, polypropylene and copolymers thereof, as well as silicone resin, phenol resin, epoxy resin, ABS resin, etc. . These can be used alone or in combination of two or more. Among transparent resins, polyethylene terephthalate (PET), silsesquioxane (SSQ), and liquid crystal polymer are preferably used from the viewpoints of cost, heat resistance, mechanical properties and the like. Here, in the present specification, the “liquid crystal polymer” is a polymer having liquid crystallinity and means a polymer having a mesogenic group such as parahydroxybenzoic acid.

  The thickness of the transparent film 6 is not particularly limited, but is preferably 20 μm to 500 μm, more preferably 30 μm to 400 μm, and still more preferably 40 μm to 300 μm.

  It does not specifically limit as a metal which comprises the metal fine wire 7, Various metals, such as an alkali metal, an alkaline earth metal, a transition metal, can be used. Examples of metals include aluminum, nickel, zinc, iron, tin, titanium, molybdenum, gold, silver, copper, and their alloys. These can be used alone or in combination of two or more.

The line width of the thin metal wire 7 is not particularly limited, but is preferably equal to or less than the line width of the wiring 5 of the transparent organic EL panel 2. By doing so, the visibility of the metal thin line 7 can be reduced, so the transparency of the transparent organic EL display device 1 can be improved.
Specifically, the line width of the metal fine wire 7 is generally 30 μm or less, preferably 0.1 μm to 25 μm, more preferably 1 μm to 20 μm, and still more preferably 2 μm to 10 μm. When the line width of the thin metal wire 7 exceeds 30 μm, the transparency of the heat dissipation sheet 3 may be impaired.

  The heat dissipating sheet 6 made of the above material is high in thermal conductivity, light in weight, flexible, and inexpensive. Therefore, by using the heat dissipation sheet 3, it is possible to obtain the lightweight and flexible transparent organic EL display device 1 at low cost.

In the transparent organic EL display device 1 of the present embodiment, the positional relationship between the wires 5 of the transparent organic EL panel 2 and the metal thin wires 7 of the heat dissipation sheet 3 in the stacking direction of the transparent organic EL panel 2 and the heat dissipation sheet 3 is particularly It is not limited and may be appropriately adjusted according to the characteristics required of the transparent organic EL display device 1.
For example, when higher transparency is required for the transparent organic EL display device 1, as shown in FIG. 1, the wiring 5 of the transparent organic EL panel 2 and the wiring 5 of the transparent organic EL panel 2 and the heat dissipation sheet 3 are stacked. It is preferable to make the positions of the heat dissipation sheet 3 and the metal thin wires 7 coincide with each other. With such a configuration, the transparency can be maximized.

  FIG. 2 is a view for explaining the light transmittance of the transparent organic EL display device 1. As shown in FIG. 2A, by aligning the positions of the wires 5 of the transparent organic EL panel 2 and the thin metal wires 7 of the heat dissipation sheet 3 in the stacking direction of the transparent organic EL panel 2 and the heat dissipation sheet 3, It is possible to increase the proportion of the part through which light (represented by the arrow) is transmitted. As a result, the transparency of the laminate of the transparent organic EL panel 2 and the heat dissipation sheet 3 can be improved. On the other hand, when the positions of the wires 5 of the transparent organic EL panel 2 and the metal thin wires 7 of the heat dissipation sheet 3 are not matched, as shown in FIG. 2B, the ratio of the part transmitting light decreases. As a result, the transparency of the laminate of the transparent organic EL panel 2 and the heat dissipation sheet 3 is not sufficiently improved.

  When the positions of the wires 5 of the transparent organic EL panel 2 and the thin metal wires 7 of the heat dissipation sheet 3 coincide in the stacking direction of the transparent organic EL panel 2 and the heat dissipation sheet 3, the wires 5 of the transparent organic EL panel 2 Moire may occur due to the interference between the metal and the metal thin wires 7 of the heat dissipation sheet 3. Therefore, when it is required to prevent the occurrence of moiré, the positions of the wires 5 of the transparent organic EL panel 2 and the metal thin wires 7 of the heat dissipation sheet 3 in the stacking direction of the transparent organic EL panel 2 and the heat dissipation sheet 3 You may shift it. Specifically, the thin metal wires 7 of the heat dissipating sheet 3 may be disposed at an angle to the wires 5 of the transparent organic EL panel 2. In this case, although the light transmittance of the transparent organic EL display device 1 is lowered, the transparency of the transparent organic EL display device 1 is maintained within a practicable range.

  FIG. 3 is a top view of the heat dissipation sheet 3 (a top view of the heat dissipation sheet 3 as viewed from the side on which the thin metal wires 7 are provided). The metal thin wires 7 of the heat dissipation sheet 3 may be linear, but may be grid-like as shown in FIG. 3. By using the grid-like metal thin wires 7, the proportion of the conductive metal thin wires 7 can be increased, so that the thermal conductivity of the heat dissipation sheet 3 can be improved.

  Although the aperture ratio of the heat dissipation sheet 3 is not particularly limited, it is preferably 60% or more, more preferably 70% to 95%, and still more preferably 80% to 90%. If the opening ratio of the heat dissipation sheet 3 is less than 60%, the transparency of the heat dissipation sheet 3 may be reduced. Here, in the present specification, the "aperture ratio of the heat dissipation sheet 3" refers to the ratio of the area of the portion where the thin metal wire 7 is not provided to the entire area of the transparent film 6 where the thin metal wire 7 is provided. means.

  It does not specifically limit as a manufacturing method of the thermal radiation sheet 3 which has the above characteristics, The method well-known in the said technical field can be used. For example, after the metal thin wires 7 are formed in advance, the heat dissipation sheet 3 can be manufactured by attaching the metal thin wires 7 to the transparent film 6 using an adhesive or the like. The heat dissipation sheet 3 can also be manufactured by directly bonding the thin metal wire 7 to the transparent film 6 using a method such as thermocompression bonding. Furthermore, after forming a metal film on the transparent film 6 by a dry process such as a CVD method or a PVD method, or a plating method, the metal film is processed into a predetermined shape (for example, grid shape) by a dry or wet etching process. The heat dissipating sheet 3 may be manufactured by

The thin metal wires 7 of the heat dissipation sheet 3 are preferably provided on the surface of the transparent film 6 on the transparent organic EL panel 2 side. By providing the thin metal wires 7 of the heat dissipation sheet 3 on the transparent organic EL panel 2 side, the heat generated in the transparent organic EL panel 2 can be efficiently dissipated.
In addition, the thin metal wires 7 of the heat dissipation sheet 3 may be provided on both sides of the transparent film 6. By providing the metal thin wires 7 of the heat dissipation sheet 3 on both sides of the transparent film 6, the thermal conductivity of the heat dissipation sheet 3 is further improved, and the heat generated in the transparent organic EL panel 2 can be dissipated more efficiently.

  It is preferable that the peripheral part of the heat dissipation sheet 3 is in contact with the case 4 of the transparent organic EL display device 1. With such a configuration, the heat generated in the transparent organic EL panel 2 can be efficiently dissipated from the housing 4 via the heat dissipation sheet 3.

  It is preferable that the thin metal wires 7 of the heat dissipation sheet 3 be blackened. By blackening the fine metal wires 7 of the heat dissipation sheet 3, it is possible to prevent reflection and improve the visibility and the contrast. The method for blackening treatment is not particularly limited, and methods known in the art can be used.

  The heat dissipation sheet 3 may be in direct contact with the transparent organic EL panel 2 or may be in contact via an adhesive layer. Here, in the present specification, the "adhesive layer" means a layer obtained by applying and curing an adhesive. The adhesive is not particularly limited, and those known in the art can be used.

  The transparent organic EL panel 2 may be sandwiched between the two heat dissipation sheets 3 using two heat dissipation sheets 3. In such a configuration, the heat dissipation sheet 3 disposed on the back surface of the transparent organic EL panel 2 functions as a heat dissipation member, while the heat dissipation sheet disposed on the surface of the transparent organic EL panel 2 functions as a conductive film . Therefore, it is possible to obtain the transparent organic EL display device 1 having the electromagnetic wave shielding function or the touch panel function.

When sandwiching the transparent organic EL panel 2 between two heat dissipation sheets 3, it is preferable that a transparent high radiation film be formed on the surface of the heat dissipation sheet 3 (conductive film) on the image display side. By forming a transparent high radiation film, reflection can be prevented and visibility and contrast can be improved. Here, in the present specification, the "high radiation film" means a film having an emissivity of 0.8 or more.
The transparent high radiation film can be formed using a transparent high radiation material. The transparent high-radiation material is not particularly limited, and materials known in the art can be used. An example of the transparent high radiation material is "Uniquel" series of Joint Ink Co., Ltd.

  The transparent organic EL display device of the present embodiment having the above configuration is excellent in transparency and heat dissipation, and is inexpensive.

  1 transparent organic EL display device, 2 transparent organic EL panel, 3 heat radiation sheet, 4 housings, 5 wiring, 6 transparent film, 7 metal thin line.

Claims (9)

A transparent organic EL display device having a transparent organic EL panel and a heat dissipation sheet laminated on the transparent organic EL panel,
The heat radiation sheet, Ri transparent film der the thin metal wires are provided on at least one surface,
The line width of the thin metal wire is equal to or less than the line width of the wiring of the transparent organic EL panel,
The position of the wiring of the said transparent organic EL panel and the metal thin wire of the said heat dissipation sheet correspond in the lamination direction of the said transparent organic EL panel and the said heat dissipation sheet, The transparent organic EL display characterized by the above-mentioned . The transparent organic EL display device according to claim 1 , wherein the metal thin line is a grid-like metal thin line. The transparent organic EL display device according to any one of claims 1 and 2 , wherein an aperture ratio of the heat dissipation sheet is 60% or more. The transparent organic EL display device according to any one of claims 1 to 3 , wherein the metal thin line is provided on the surface of the transparent film on the transparent organic EL panel side. The said thin metal wire is provided in the both surfaces of the said transparent film, The transparent organic electroluminescence display as described in any one of the Claims 1-4 characterized by the above-mentioned. The transparent organic EL display device according to any one of claims 1 to 5 , wherein a peripheral portion of the heat dissipation sheet is in contact with a casing of the transparent organic EL display device. The transparent organic EL display device according to any one of claims 1 to 6 , wherein the metal thin line is blackened. The transparent organic EL display device according to any one of claims 1 to 7 , wherein the transparent organic EL panel is sandwiched between two heat dissipation sheets. 9. The transparent organic EL display device according to any one of claims 1 to 8 , wherein a transparent high radiation film is formed on the surface of the heat dissipation sheet on the image display side.

Images