JP2016119362A - Transparent organic EL display device - Google Patents

Abstract

An object of the present invention is to provide a transparent organic EL display device which is excellent in transparency and heat dissipation and is inexpensive. A transparent organic EL display device 1 of the present invention includes a transparent organic EL panel 2 and a heat dissipation sheet 3 laminated on the transparent organic EL panel 2. The heat dissipation sheet 3 is a transparent film 6 provided with a fine metal wire 7 on at least one surface. Moreover, it is preferable that the positions of the wiring 5 of the transparent organic EL panel 2 and the fine metal wires 7 of the heat dissipation sheet 3 coincide with each other in the stacking direction of the transparent organic EL panel 2 and the heat dissipation sheet 3. [Selection] Figure 1

Description

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

  The organic EL display device includes elements expected for a display device such as high definition, high response speed, high contrast, wide viewing angle, and thinness, and is the next generation display device that follows liquid crystal display devices and plasma panel display devices. It is attracting attention 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 emit light when an electric current is passed through an organic material are arranged on a substrate such as a glass plate and arranged in a lattice pattern. 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, the heat storage of the organic EL panel during image display is a problem. That is, heat generated from the organic EL element during image display may be deteriorated and the characteristics such as light emission efficiency and luminance may be deteriorated.
Thus, an organic EL display device in which a heat dissipation member is stacked on an organic EL panel has been proposed (for example, Patent Document 1). In this organic EL display device, heat generated in the organic EL panel can be radiated to the outside through the heat radiating member due to the heat radiating action of the heat radiating member.

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

JP 2013-21357 A

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

  As a result of diligent research to solve the above-mentioned problems, the present inventor uses a transparent film provided with a thin metal wire on at least one surface as a heat radiating member, thereby reducing 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 radiating sheet laminated on the transparent organic EL panel, and the heat radiating sheet is provided with a thin metal wire on at least one surface. It is an organic EL display device characterized by being 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 electroluminescent display apparatus. It is a top view of a heat dissipation sheet.

  Hereinafter, preferred embodiments of a transparent organic EL display device of the present invention will be described with reference to the drawings. Note that this embodiment shows one embodiment of the present invention and does not limit the present invention. Further, in this embodiment, the shape, combination, etc. of each component can be modified according to design requirements and the like without departing from the gist of the present invention. In addition, the drawings are illustrated so that the respective constituent members can be easily understood, and are different in size from the actual constituent members.

Embodiment 1 FIG.
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, a transparent organic EL display device 1 includes a transparent organic EL panel 2 and a heat dissipation sheet 3 laminated on the transparent organic EL panel 2. A casing 4 is disposed at the peripheral edge of the laminate of the transparent organic EL panel 2 and the heat dissipation sheet 3.
In FIG. 1, only the characteristic part of the transparent organic EL display device 1 of the present embodiment is illustrated, and various members known in the technical field can be further provided. Moreover, since structures other than the characteristic part of the transparent organic electroluminescence display 1 of this Embodiment are well-known in the said technical field, detailed description is abbreviate | omitted.

The transparent organic EL panel 2 is not particularly limited, and a transparent organic EL panel 2 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, the transparent organic EL elements constituting the pixels are usually 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. In this way, 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, and a gate of a driving TFT is connected to the switching TFT to select the selected scanning line. The transparent organic EL element is driven by turning on the switching TFT and inputting a data signal from the signal line to the driving TFT.

Here, in this specification, the scanning lines and data lines of the transparent organic EL panel 2 are collectively referred to as “wiring 5”. In the transparent organic EL panel 2, the wirings 5 are arranged in a lattice shape.
In FIG. 1, only the wiring 5 is illustrated among the members constituting the transparent organic EL panel 2, and 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 a thin metal wire 7 provided on at least one surface of the transparent film 6.
It does not specifically limit as the transparent film 6, A well-known thing can be used in the said technical field. The transparent film 6 is generally a film formed from a transparent resin. Examples of the transparent resin include polyester resin, polystyrene, polyimide, polyamide, polysulfone, polycarbonate, polyvinyl chloride, polyethylene, polypropylene, and copolymers thereof, as well as silicone resin, phenol resin, epoxy resin, ABS resin, and the like. . These can be used alone or in combination of two or more. Of the transparent resins, polyethylene terephthalate (PET), silsesquioxane (SSQ), and a liquid crystal polymer are preferably used from the viewpoints of cost, heat resistance, mechanical properties, and the like. Here, the “liquid crystal polymer” in the present specification is a polymer having liquid crystallinity and means a polymer having a mesogenic group such as parahydroxybenzoic acid.

  Although the thickness of the transparent film 6 is not specifically limited, Preferably it is 20 micrometers-500 micrometers, More preferably, it is 30 micrometers-400 micrometers, More preferably, they are 40 micrometers-300 micrometers.

  It does not specifically limit as a metal which comprises the metal fine wire 7, Various metals, such as an alkali metal, alkaline-earth metal, and a transition metal, can be used. Examples of metals include aluminum, nickel, zinc, iron, tin, titanium, molybdenum, gold, silver, copper, and alloys thereof. 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 in this way, since the visibility of the thin metal wire 7 can be reduced, the transparency of the transparent organic EL display device 1 can be improved.
Specifically, the line width of the fine metal wire 7 is generally 30 μm or less, preferably 0.1 μm to 25 μm, more preferably 1 μm to 20 μm, and further 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 material as described above has high thermal conductivity, is light and flexible, and is inexpensive. Therefore, by using the heat dissipation sheet 3, the transparent organic EL display device 1 that is lightweight and flexible can be obtained at low cost.

In the transparent organic EL display device 1 of the present embodiment, the positional relationship between the wiring 5 of the transparent organic EL panel 2 and the thin metal wire 7 of the heat radiating sheet 3 in the stacking direction of the transparent organic EL panel 2 and the heat radiating sheet 3 is particularly It is not limited, What is necessary is just to adjust suitably according to the characteristic requested | required of the transparent organic electroluminescent display apparatus 1. FIG.
For example, when higher transparency is required for the transparent organic EL display device 1, the wiring 5 of the transparent organic EL panel 2 in the stacking direction of the transparent organic EL panel 2 and the heat dissipation sheet 3, as shown in FIG. It is preferable to match the position of the heat dissipation sheet 3 with the fine metal wires 7. With such a configuration, the transparency can be improved to the maximum.

  FIG. 2 is a view for explaining the light transmittance of the transparent organic EL display device 1. As shown in FIG. 2A, in the stacking direction of the transparent organic EL panel 2 and the heat radiating sheet 3, by matching the positions of the wiring 5 of the transparent organic EL panel 2 and the metal thin wire 7 of the heat radiating sheet 3, The proportion of the portion through which light (represented by arrows) can be increased. As a result, it becomes possible to improve the transparency of the laminated body of the transparent organic EL panel 2 and the heat dissipation sheet 3. On the other hand, when the positions of the wiring 5 of the transparent organic EL panel 2 and the fine metal wires 7 of the heat-dissipating sheet 3 are not matched, as shown in FIG. 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.

  In addition, when the position of the wiring 5 of the transparent organic EL panel 2 and the metal thin wire 7 of the heat dissipation sheet 3 are matched in the stacking direction of the transparent organic EL panel 2 and the heat dissipation sheet 3, the wiring 5 of the transparent organic EL panel 2 is aligned. And moire may occur due to interference between the heat dissipation sheet 3 and the fine metal wires 7. Therefore, when it is required to prevent the occurrence of moire, the positions of the wiring 5 of the transparent organic EL panel 2 and the fine metal wires 7 of the heat radiating sheet 3 are arranged in the stacking direction of the transparent organic EL panel 2 and the heat radiating sheet 3. It may be shifted. Specifically, the fine metal wires 7 of the heat radiating sheet 3 may be arranged at an angle with respect to the wiring 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 in a practical range.

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

  The aperture ratio of the heat dissipation sheet 3 is not particularly limited, but is preferably 60% or more, more preferably 70% to 95%, and still more preferably 80% to 90%. If the aperture ratio of the heat dissipation sheet 3 is less than 60%, the transparency of the heat dissipation sheet 3 may be reduced. Here, in this specification, the “opening ratio of the heat dissipation sheet 3” refers to the ratio of the area of the portion where the fine metal wires 7 are not provided to the total area of the surface of the transparent film 6 where the fine metal wires 7 are provided. means.

  It does not specifically limit as a manufacturing method of the thermal radiation sheet 3 which has the above characteristics, A well-known method can be used in the said technical field. For example, the heat-dissipating sheet 3 can be manufactured by preparing the fine metal wires 7 in advance and then attaching the fine metal wires 7 to the transparent film 6 using an adhesive or the like. Moreover, the heat-radiation sheet 3 can also be manufactured by sticking the thin metal wire 7 directly to the transparent film 6 using a technique 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, a lattice shape) by a dry or wet etching process. The heat radiating sheet 3 may be manufactured.

The fine 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 wire 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.
Further, the fine metal wires 7 of the heat dissipation sheet 3 may be provided on both surfaces of the transparent film 6. By providing the thin metal wires 7 of the heat radiating sheet 3 on both surfaces of the transparent film 6, the heat conductivity of the heat radiating sheet 3 is further improved, and the heat generated in the transparent organic EL panel 2 can be radiated more efficiently.

  It is preferable that the heat dissipation sheet 3 is in contact with the casing 4 of the transparent organic EL display device 1 at the periphery. With such a configuration, the heat generated in the transparent organic EL panel 2 can be efficiently radiated from the housing 4 via the heat radiating sheet 3.

  The fine metal wires 7 of the heat dissipation sheet 3 are preferably blackened. By blackening the metal thin wire 7 of the heat radiating sheet 3, it is possible to prevent reflection and improve visibility and contrast. The blackening treatment method is not particularly limited, and methods known in the technical field can be used.

  The heat dissipation sheet 3 may be in direct contact with the transparent organic EL panel 2, but may be in contact with the adhesive layer. Here, in this specification, the “adhesive layer” means a layer obtained by applying and curing an adhesive. It does not specifically limit as an adhesive agent, A well-known thing can be used in the said technical field.

  The transparent organic EL panel 2 may be sandwiched between the two heat radiating sheets 3 using two heat radiating sheets 3. In such a configuration, the heat radiating sheet 3 disposed on the back surface of the transparent organic EL panel 2 functions as a heat radiating member, while the heat radiating sheet disposed on the surface of the transparent organic EL panel 2 functions as a conductive film. . Therefore, the transparent organic EL display device 1 with an electromagnetic wave shielding function or a touch panel function can be obtained.

When the transparent organic EL panel 2 is sandwiched between two heat radiating sheets 3, it is preferable that a transparent high radiation film is formed on the surface of the heat radiating sheet 3 (conductive film) on the image display side. By forming the transparent high radiation film, it is possible to prevent reflection and improve visibility and contrast. 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 technical field can be used. As an example of the transparent high radiation material, “Unicool” series of Joint Ink Co., Ltd. can be mentioned.

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

  DESCRIPTION OF SYMBOLS 1 Transparent organic electroluminescent display apparatus, 2 Transparent organic electroluminescent panel, 3 Heat radiation sheet, 4 Housing | casing, 5 wiring, 6 Transparent film, 7 Metal fine wire.

Claims (10)

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 transparent organic EL display device, wherein the heat-dissipating sheet is a transparent film provided with a thin metal wire on at least one surface.   2. The transparent organic material according to claim 1, wherein, in the stacking direction of the transparent organic EL panel and the heat dissipation sheet, the positions of the wiring of the transparent organic EL panel and the fine metal wires of the heat dissipation sheet coincide with each other. EL display device.   The transparent organic EL display device according to claim 1, wherein the thin metal wire is a lattice-like thin metal wire.   The transparent organic EL display device according to claim 1, wherein an opening ratio of the heat dissipation sheet is 60% or more.   The transparent organic EL display device according to any one of claims 1 to 4, wherein the thin metal wire is provided on a surface of the transparent film on the transparent organic EL panel side.   The transparent organic EL display device according to claim 1, wherein the thin metal wires are provided on both surfaces of the transparent film.   The transparent organic EL display device according to claim 1, wherein a peripheral portion of the heat dissipation sheet is in contact with a housing of the transparent organic EL display device.   The transparent organic EL display device according to claim 1, wherein the thin metal wires are blackened.   The transparent organic EL display device according to any one of claims 1 to 8, wherein the transparent organic EL panel is sandwiched between the two heat dissipation sheets.   The transparent organic EL display device according to claim 9, wherein a transparent high radiation film is formed on a surface of the heat dissipation sheet on the image display side.

Images