JP2014038757A - Large-sized organic electroluminescent device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a large-sized light-emitting device with good appearance as a product and with good uniformity and excellent visibility, by reducing luminance unevenness in individual organic EL panels and luminance unevenness of the whole of the light-emitting device that is generated when forming the large-sized light-emitting device by arranging a plurality of organic EL panels.SOLUTION: The large-sized organic electroluminescent device includes not only a diffusion member on organic EL panels, but also a display that displays information by emitting light to the outside from the large-sized organic electroluminescent device, which has a specific layer structure with a film having a diffusion function.

Description

  The present invention relates to a large-sized organic electroluminescent device, and preferably to an organic light-emitting device used for a vehicle guidance sign installed on a highway, a service area, a parking area, a general road, or the like.

  Electroluminescence such as LED (light emitting diode) and organic EL (organic light emitting diode = OLED) in recent years has low power consumption, and is expected to be used for road traffic facilities that require a large number of light sources. In particular, since LEDs are excellent in characteristics such as high efficiency and long life, their use has been accelerated as a light source for road signs such as traffic lights, road shoulders and warnings in tunnels.

  The organic EL is also expected to be used as a road sign by taking advantage of the fact that it is a thin surface light emission with respect to the LED which is a point light source and is as efficient as the LED (Patent Document 1, Patent Document) 2). In particular, the organic EL formed on the flexible substrate is expected to have high safety as a road sign, taking advantage of the characteristic that it does not break and does not generate fragments. Furthermore, since it is surface light emission, visibility is very high and it is suitable as a label | marker.

  On the other hand, various studies are currently being conducted on the organic EL from the viewpoint of increasing the size, and for example, Patent Document 3 can easily increase the size of the organic EL panel and the mass production of the large panel. The technology is described. However, such a large organic EL panel still has problems to be realized from the viewpoint of film uniformity, luminance unevenness, life, and the like.

JP 2001-272937 A JP 2004-270443 A JP 2011-091093 A

As described above, there are many technical problems in increasing the size of the organic EL panel. However, there is a demand for large light emitting devices using organic EL. Therefore, the present inventors have studied to make a large light-emitting device by arranging a plurality of organic EL panels, and there is a considerable difference in luminance among the individual organic EL panels, and the light-emitting device as a whole is uniform. It has been found that there is a problem of lacking. Furthermore, the difference in luminance generated in each organic EL panel and the problem that when the organic EL panels are arranged side by side, non-light emitting portions between the panels cause uneven luminance in the entire light emitting device. did.
The present invention reduces uneven brightness in individual organic EL panels and brightness unevenness of the entire light-emitting device, which occurs when a large light-emitting device is formed by arranging a plurality of organic EL panels, and provides a large-scale light emission that is uniform and excellent in visibility. It is an object to provide an apparatus.

As a result of intensive studies to solve the above problems, the present inventors have a display unit that transmits light emitted from a light emitting unit including a plurality of organic EL panels arranged in the casing and emits the light to the outside of the casing. In a large organic electroluminescent device, a diffusion member is provided on the light emitting surface side of the light emitting portion of the organic EL panel, and a diffusion function is also provided in a display portion that emits light from the large organic electroluminescent device to display information. It has been found that the above-mentioned problems can be solved by providing the present invention, and the invention has been completed.

The outline of the present invention is as follows.
The present invention relates to a casing capable of emitting light from at least a part thereof, a light emitting unit disposed in the casing and including a plurality of organic EL panels, and light transmitted from the light emitting unit disposed in the casing. And an organic electroluminescent device including a display unit that emits light to the outside of the casing, wherein the organic electroluminescent device includes a diffusing member between the light emitting unit and the display unit, and the plurality of organic EL devices The panel has a non-light-emitting portion between the organic EL panels, and the display unit is formed by laminating at least a transparent substrate and a film having a diffusion function, or at least has a diffusion function. It is an organic electroluminescent apparatus which has a base material.

The diffusion member is a diffusion film, and is preferably provided in contact with the light emitting surface of the light emitting unit, and the diffusion film is preferably provided by being laminated on each of the plurality of organic EL panels.
The plurality of organic EL panels preferably have an area of 1000 to 500,000 mm ² .

The display unit is preferably formed by laminating at least a transparent substrate and a film having a diffusion function.
In the display section, the film having the diffusion function is a white colored film, and further includes a colored film other than white, and the colored film other than white is red, orange, yellow, green, blue, indigo. Preferably, the film is one or more colored films selected from the group consisting of violet, purple, and black.
The display unit is preferably laminated in the order of a transparent substrate, a white colored film, and a colored film other than white from the light emitting unit side. The organic electroluminescent device of the present invention is preferably a road sign.

  According to the present invention, even when a plurality of organic EL panels are arranged to form a large light emitting device, the difference in luminance generated in each organic EL panel is reduced, and the appearance as a light emitting device is preferable. It is possible to provide a uniform light-emitting device with reduced luminance unevenness and excellent visibility. In particular, the organic electroluminescent device of the present invention is suitably used as a light emitting device for road signs because it has a white colored diffusion film and a colored film other than white in the display section and is large.

It is a conceptual diagram showing the structural member of the organic electroluminescent apparatus of this invention. It is a conceptual diagram showing the light emission part which the organic electroluminescent apparatus of this invention is equipped with which consists of several organic EL panel. It is a conceptual diagram in the case of providing a diffusing member in the organic EL panel of the light emitting unit of the present invention. It is a conceptual diagram in case a diffusion member is provided so that the whole light emission surface of the light emission part of this invention may be covered. It is a conceptual diagram at the time of using the diffusion member of this invention as a panel. It is a conceptual diagram at the time of using the organic electroluminescent panel which provided the diffusion member in the light emission part of the organic electroluminescent apparatus of this invention. It is a conceptual diagram showing the cross section of the display part with which the organic electroluminescent apparatus of this invention is provided. It is a conceptual diagram showing the general structure (layer structure) of organic EL.

Hereinafter, the present invention will be described in detail while showing specific embodiments, but it is needless to say that the present invention is not limited to the illustrated specific embodiments.
The organic EL light emitting device of the present invention includes a casing, a light emitting unit disposed in the casing, and a display unit that emits light emitted from the light emitting unit to the outside (FIG. 1).

1. Casing The casing stores and holds the organic EL panel, which is a light emitting unit, and has a role of protecting the organic EL panel from heat, rain, wind, flying objects, and the like from the outside. The casing is not particularly limited as long as light can be emitted from at least a part thereof, and the size of the casing may be appropriately determined according to the required size of the light emitting device. Moreover, the material is not particularly limited as long as the organic EL panel can be protected from the heat, rain, wind, flying objects, and the like from the outside. Further, when the organic EL light emitting device is installed at a high position from the ground, the casing is preferably a light material.

  Examples of the material constituting such a casing include metal plates such as aluminum and steel, and hardened plastic plates such as acrylic plates. In particular, metal plates such as aluminum and steel are used from the viewpoint of safety against collisions with birds, stepping stones, vehicles, etc. (debris will not scatter), light weight, resistance to cracking, and ease of wiring and mounting on wall structures. preferable.

  The casing only needs to be able to emit light from the light emitting unit from at least a part of the casing, but it is preferable that one surface of the casing can emit light and the other surface does not have light transmittance. With such an embodiment, light emission is only in one direction, and luminance is improved. Moreover, the aspect which can open | release light of a casing may be sufficient, and in such a case, a casing is sealed by the below-mentioned display part, and an organic EL panel will be protected from an external factor.

  The shape of the casing is not particularly limited, and can be appropriately selected within the range used as the light emitting device. Examples thereof include a rectangular shape and a cylindrical shape. In addition, the display area is preferably large from the viewpoint of visibility, and the thickness is preferably thin from the viewpoint of installation area.

2. Light-emitting part The light-emitting part with which the organic electroluminescent apparatus of this invention is provided is arrange | positioned in a casing, and contains a some organic EL panel. In the present invention, in order to increase the size of the organic electroluminescent device, a plurality of organic EL panels are arranged to form a light emitting unit. The organic electroluminescent device of the present invention is characterized in that a diffusion member described later is provided on the light emitting surface side of the light emitting portion. The plurality of organic EL panels are usually installed in the casing after being fixed to the base material, and each organic EL panel has a non-light-emitting portion between the organic EL panels.

The size of the light emitting part is preferably smaller than the size of the casing, and the distance from the end of the light emitting part to the side surface of the casing is usually 1 cm or more, preferably 2 cm or more, more preferably 5 cm or more, usually 20 cm or less, Preferably it is 15 cm or less, more preferably 10 cm or less. When it is at least the lower limit value, it is difficult for heat to be generated in the casing, and the light emitting performance of the organic EL panel is difficult to deteriorate. Moreover, since it is below an upper limit, the fall of the peripheral part brightness | luminance of a display part can be suppressed, and the fall of visibility can be prevented.
The shape of the light emitting part is generally equal to the distance from the end of the light emitting part to the side surface of the casing according to the shape of the casing, but there is a part where the distance from the end of the light emitting part to the side surface of the casing is different. In some cases, the distance means an average distance.

FIG. 2 is a conceptual diagram of the light emitting unit 2 provided in the organic electroluminescent device of the present invention. The light emitting unit 2 has a plurality of organic EL panels 4 arranged on a substrate 5. In the present invention, luminance unevenness generated in each organic EL panel 4 is eliminated by using a diffusion member described later. In addition, the plurality of organic EL panels 4 have non-light emitting portions 2b in which no light emitter exists on both sides (including not only the horizontal direction but also the vertical direction) of each organic EL panel. The non-light emitting portion 2b is necessary when sealing the organic EL panel, and is inevitably present when arranging a plurality of organic EL panels as a light emitting portion. In the present invention, the light emitting unit 2 has such a non-light emitting part 2b, and thus the problem that luminance unevenness occurs in the entire light emitting device is devised by devising the layer structure of the display unit described later. To solve.

2-1. Organic EL panel An organic electroluminescent device (organic EL) panel uses an organic light-emitting material and generates excitons by passing an electric current through the organic light-emitting material layer. A light-emitting panel including an organic electroluminescent element that emits (both fluorescent and phosphorescent light) is used. In the present invention, the light-emitting panel is particularly sealed in a sealing material such as a sealing film.

2-2. Organic electroluminescent element Although the structure of the organic electroluminescent element used for this invention is not specifically limited, A general structure is demonstrated with reference to FIG.
FIG. 8 is a schematic cross-sectional view showing a structural example of an organic electroluminescent device. In FIG. 8, 41 is a substrate, 42 is an anode, 43 is a hole injection layer, 44 is a hole transport layer, 45 is a light emitting layer, 46 represents a hole blocking layer, 47 represents an electron transport layer, 48 represents an electron injection layer, and 49 represents a cathode. Even if it does not include an injection layer, a transport layer, or the like, a layer having other functions may be included, and each constituent layer may be a single layer or a plurality of layers.

  Further, the method for forming the constituent layers is not particularly limited, for example, a dry film forming method such as a vacuum deposition method or a sputtering method, or a spin coating method, a dip coating method, a die coating method, a bar coating method, a blade coating method, Examples of the wet coating method include a roll coating method, a spray coating method, a capillary coating method, an ink jet method, a screen printing method, a gravure printing method, and a flexographic printing method.

  The substrate material of the organic electroluminescence device is not particularly limited, but glass plates such as quartz glass, alkali-free glass and soda lime glass, metal plates and metal foils such as aluminum and steel, polyethylene terephthalate, polyolefin, polymethacrylate, polyethylene Examples thereof include plastic films and sheets such as naphthalate, polyimide, polycarbonate, and polyether sulfone. In particular, from the viewpoint of safety against collisions with birds, stepping stones, vehicles, etc. (debris will not scatter), light weight, resistance to cracking, and easy wiring and mounting, aluminum and steel metal sheets, metal foil, plastic films, etc. In the case of a sheet or glass, it is preferable to use a thin and flexible substrate.

  The thickness of the substrate is not particularly limited and can be freely set according to the purpose, but is usually 0.1 mm or more, preferably 0.5 mm or more, more preferably 1 mm or more, and usually 4 mm or less, preferably 3 mm or less, more preferably 2 mm or less.

  The anode material of the organic electroluminescent device is not particularly limited, but is a metal such as aluminum, gold, silver, nickel, palladium, platinum or an alloy thereof, a metal oxide such as zinc oxide of indium and / or tin, or copper iodide. And metal halides such as carbon black, or conductive polymers such as poly (3-methylthiophene), polypyrrole, and polyaniline. When the substrate is a conductive material, the substrate and the anode may be the same.

Although the cathode material of an organic electroluminescent element is not specifically limited, Metals, such as tin, magnesium, indium, calcium, aluminum, silver, or those alloys are mentioned. Moreover, in order to suppress the reflection of the light from the outside which arises at the time of light extinction of organic EL, a cathode can also be made into a rough surface.

  The light emitting layer of the organic electroluminescent element may contain a compound having a hole transporting property (hole transporting compound) or a compound having an electron transporting property (electron transporting compound) in addition to the light emitting material. preferable. For example, a material using a light-emitting material as a dopant material and a hole transporting compound, an electron transporting compound, or the like, or a mixture thereof as a host material can be used.

  The light emitting material of the light emitting layer is not particularly limited, and may be a fluorescent light emitting material or a phosphorescent light emitting material. From the viewpoint of internal quantum efficiency, a phosphorescent material is preferred. In addition, although a fluorescent light emitting material and a phosphorescent light emitting material may be used in combination, the light emission efficiency as an element is greatly affected by the efficiency of the fluorescent light emitting material. All are preferably phosphorescent materials. The ratio of the light emitting material in the light emitting layer is not particularly limited, but is usually 0.05% by weight or more and usually 35% by weight or less.

  The molecular weight of the light emitting material is not particularly limited, but is usually 10,000 or less, preferably 5000 or less, more preferably 4000 or less, still more preferably 3000 or less, and usually 100 or more, preferably 200 or more, more preferably 300 or more, and further. Preferably it is the range of 400 or more.

  The thickness of the light emitting layer is not particularly limited, but is usually 3 nm or more, preferably 5 nm or more, most preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less, and most preferably 70 nm or less.

  In addition to the above-described constituent layers, the materials, forms, and adjustment methods of the hole injection layer, hole blocking layer, electron injection layer, protective layer, etc. are not particularly limited. Moreover, you may have a structure other than this, The material, form, and preparation method can use suitably what is used as an organic electroluminescent element.

2-3. Sealing material In this invention, organic EL means the thing of the state which sealed the above-mentioned organic electroluminescent element.
The method for sealing the organic electroluminescent element is not particularly limited as long as it can be sealed so as to cover the light emitting region, and usually using a thermoplastic resin, a wet laminating method, a dry laminating method, a hot melt laminating method, Examples of the sealing method include an extrusion laminating method and a heat laminating method. Since the luminescent material may be deteriorated by heat treatment, a method capable of sealing at a temperature of 110 ° C. or lower is preferable.

  The type of the sealing material is not particularly limited, and for example, a polymer material that exhibits a buffering function and that does not scatter fragments when damaged is preferable, and is a source of deterioration of organic electroluminescent elements such as ultraviolet rays, oxygen, and moisture. More preferably, the polymer material contains an additive or the like that suppresses intrusion.

  Moreover, in order to suppress deterioration due to ultraviolet rays or heat, an ultraviolet absorber, an antioxidant, a light stabilizer, or the like may be added to the sealing material. The amount of these additives is not particularly limited, but is preferably 1000 ppm or less. If it is the said range, while being able to suppress degradation by an ultraviolet-ray or a heat | fever, the characteristic of resin can be maintained.

The thickness of the sealing material is usually 200 μm or more, preferably 300 μm or more, more preferably 4 μm.
It is 00 μm or more, usually 1 mm or less, preferably 800 μm or less, more preferably 600 μm or less. If it is the said range, the penetration | invasion of deterioration sources, such as an ultraviolet-ray, oxygen, a water | moisture content, will be suppressed and the buffer function which protects an element can be obtained.

  The sealing material preferably has a light transmittance of 380 nm or less of 15% or less, and more preferably 8% or less. If it is the said range, deterioration of the luminescent material etc. by an ultraviolet-ray can be suppressed.

2-4. Area / Thickness of Organic EL Panel In the present invention, each of the organic EL panels usually has an area of 1,000 mm ² or more, and preferably has an area of 5,000 mm ² or more. On the other hand, the upper limit is not particularly limited, the area of the normal 500,000 ² or less, it is preferable that the area of 80,000 ² or less. The larger the area of each organic EL panel, the fewer organic EL panels required to make a large light-emitting device, and the smaller the proportion of non-light-emitting parts that exist between the panels, resulting in less uneven brightness It becomes. However, as the area of the organic EL panel becomes larger, there is a problem that luminance unevenness in each panel is more likely to occur. Therefore, in the present invention, it is preferable to use the organic EL panel having the above area range.

  The organic EL panels each preferably have a thickness of 5 mm or less, more preferably 3 mm or less, even more preferably 2 mm or less, and particularly preferably 1 mm or less. preferable. Although a minimum is not specifically limited, Usually, it is 0.1 mm or more. By setting it as such thickness, it becomes possible to set it as the organic electroluminescent apparatus which is easy to construct by becoming thin and light.

2-5. Diffusion member of light emitting part The light emitting part of the organic electroluminescence device of the present invention is characterized by comprising a diffusion member on the light emitting surface side. The diffusion member can reduce luminance unevenness of the organic EL panel and further luminance unevenness of the entire display unit. The diffusion member may be provided between the light emitting unit and the display unit in the casing, and may be provided so as to be in contact with the light emitting surface, or may be provided with a space from the light emitting surface. The diffusing member may be used in the form of a film, or may be used as a panel separately from the organic EL panel, but it is preferably used in the form of a film in consideration of reducing the thickness of the entire light emitting device.

  As a method of providing the diffusing member so as to be in contact with the light emitting surface, each of the sealed organic EL panels may be covered with the diffusing member, or the function of diffusing the resin used for sealing the organic electroluminescent element It is good also as a diffusing member. Or you may provide so that the whole light emission surface of a light emission part may be covered with a diffusion member. The method of providing the diffusing member so as to be in contact with the light emitting surface in this manner is preferable from the viewpoint of waterproofing and dustproofing.

  Further, for example, the diffusing member can be made into a single member by making it into a panel, and can be provided in a manner detachable from the light emitting portion. By making the diffusing member into a panel and making it detachable, there are advantages such as easy maintenance of the light emitting part. As a paneling method, a diffusing member can be laminated on a transparent substrate, or a substrate having a diffusing function can be used as a panel. Such a panel can be used by being fixed to the casing at an arbitrary position between the light emitting unit and the display unit.

The diffusing member of the light emitting part of the present invention preferably has a parallel light transmittance and a total light transmittance within a specific range. The parallel light transmittance is usually 85% or less, preferably 75% or less, more preferably 65% or less, particularly preferably 50% or less, usually 15% or more, preferably 20% or more, more preferably 30% or more. It is. The total light transmittance is usually 99% or less, preferably 95% or less, more preferably 90% or less, and usually 20% or more, preferably 25% or more, more preferably 35% or more. Within the above range, it is possible to eliminate luminance unevenness in each organic EL panel.

The parallel light transmittance and the total light transmittance are values measured in accordance with JIS K 7105 “Testing methods for optical properties of plastics”, and are in the relationship of the following equations.
T _p = T _t −T _d
(T _t : Total light transmittance (%) T _d : Diffuse transmittance (%) T _p : Parallel light transmittance (%))
T _t = 100−R−A
(T _t : Total light transmittance R: Total light reflectance A: Absorption rate)

  The material of the light diffusing member is not particularly limited, and examples thereof include acrylic resins, polycarbonate resins, polyester resins, polyolefin resins, polyurethane resins, and silicone resins. From the viewpoint of transparency and strength, acrylic resins and polycarbonate resins are particularly preferable, and acrylic resins are more preferable.

  When the diffusion film is used as a diffusion member of the light emitting part, the material is, for example, an acrylic resin synthesized from (meth) acrylic acid ester (methyl acrylate, ethyl acrylate, etc.); polytetrafluoroethylene, polychloro Trifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, perfluoroalkoxy fluororesin, ethylene tetrafluoride / hexafluoropropylene copolymer, ethylene / tetrafluoroethylene copolymer (ETFE), ethylene / chlorotrifluoroethylene copolymer Fluorine hydrocarbon resins such as polymers; polycarbonates synthesized from polyhydric alcohols such as hydroquinone, resorcin, and bisphenol A and carbonates such as bisalkyl carbonates, bisaryl carbonates, and phosgene. In particular, fluorine-based hydrocarbon resins and acrylic resins are preferable, and ETFE and acrylic resins are more preferable.

The thickness of the diffusion film is usually 50 μm or more, preferably 80 μm or more, more preferably 100 μm or more, and usually 500 μm or less, preferably 400 μm or less, more preferably 300 μm or less, and even more preferably 200 μm or less. When it is in the above range, the generation of wrinkles and the like during cost and lamination can be suppressed.
When using a panelized diffusion member, the diffusion film having the above thickness may be laminated on a transparent substrate having a thickness of 1 mm or more and 5 mm or less, or the thickness of the diffusion member may be 1.5 mm or more and 4 mm or less. it can.

  The method for imparting the above-mentioned characteristics for reducing the parallel light transmittance to the material of the diffusing member of the light emitting part is not particularly limited, but in addition to utilizing the original characteristics of the resin used, for example, forming an uneven structure on the surface of the member And a method of appropriately roughening the surface of the member, a method of foaming the member, a method of dispersing filler (inorganic particles such as silicon oxide, titanium oxide, aluminum oxide, zirconium oxide) inside the resin of the member. From the viewpoint of translucency, a method of forming an uneven structure on the surface of the member and a method of foaming the member are preferable.

  Although the color of the diffusing member of the light emitting part is not particularly limited, it is preferably colorless or cloudy because organic EL is used as the light source of the light emitting device.

  The diffusion member of the light emitting part of the organic electroluminescent device of the present invention will be described with reference to FIGS. FIG. 3 shows an embodiment in which a diffusion film is provided as a diffusion member on the organic EL panel 4 of the light emitting unit 2 of the present invention. In the organic EL panel 4 of FIG. 3, a diffusion film 60 is laminated on the light emitting surface. By adopting such an aspect, maintenance such as replacement of individual organic EL panels becomes easy.

  In FIG. 4, the entire light emitting surface of the light emitting unit 2 is covered with the diffusion film 60. By setting it as such an aspect, construction of a diffusion member becomes easy.

  FIG. 5 is an example of a case where a diffusion panel 61 in which a diffusion member is panelized is installed in the light emitting unit 2. The panelized diffusion panel 61 can be fixed and used at an arbitrary position between the light emitting unit 2 and the display unit.

  FIG. 6 shows an embodiment of an organic electroluminescent device in the case where the organic EL panel 4 in which the diffusion film 60 is laminated on the light emitting surface is used for the light emitting unit 2. The light emitting unit 2 is provided at an arbitrary position of the casing 1, and light emitted from the light emitting unit 2 passes through the display unit 3. Due to the diffusion film 60, luminance unevenness is reduced.

3. Display part The display part with which the organic electroluminescent apparatus of this invention is provided permeate | transmits the light which a light emission part emits, and discharge | releases light outside a casing. The display unit of the present invention is formed by laminating at least a transparent substrate and a film having a diffusion function (hereinafter also referred to as a diffusion film of the display unit), or has at least a substrate having a diffusion function. Furthermore, the display part of 3 layer structure can also be comprised with the transparent base material, the white colored film which has a spreading | diffusion function, and the colored film other than white. Moreover, the display part of 2 layer structure can also be comprised with the base material which has a spreading | diffusion function, and colored films other than white.
In addition, in order to obtain higher visibility, optical characteristics such as diffusibility and transparency of a film having a diffusion function and / or a substrate having a diffusion function can be adjusted. Considering the ease of adjusting the diffusion function as the display portion, it is preferable to have two or more layers having a diffusion function. Even if a film having a diffusion function of one or more layers is laminated on a base material having a diffusion function, two or more films having a diffusion function may be laminated on a transparent base material. It is preferable to laminate a film having At this time, at least one layer of the base material having a diffusion function and / or a film having the diffusion function is preferably white, more preferably two or more layers are white, and all the layers are white. Is more preferable.
When two or more layers of white films having a diffusion function are used, the optical characteristics of the plurality of white films may be different or the same.
The reason and mechanism of the display unit in the present invention is not clear, but by having such a layer structure, luminance unevenness caused by non-light-emitting portions existing between the organic EL panels constituting the light-emitting unit is reduced. be able to.

3-1. Transparent base material The transparent base material transmits light emitted from the organic EL panel of the light emitting part, and is a base material for forming the light emitting part of the present invention into a layer structure. Moreover, in the case where the surface (part) from which light can be emitted is open in the casing, it is necessary to seal the casing with a transparent base material to protect the stored organic EL panel from external factors. . In such a case, the transparent substrate is exposed to sunlight or rainwater, and is installed in a harsh outdoor environment where a collision such as a bird or a stepping stone may occur. What is excellent in is preferable. Specific examples include glass plates such as quartz glass, alkali-free glass and soda lime glass, and plastic plates such as acrylic plates and polycarbonate. In particular, plastic plates such as acrylic plates are preferred from the viewpoint of safety against collisions with birds, stepping stones, vehicles, etc. (debris will not scatter), light weight and resistance to cracking, and easy wiring and mounting. It is preferable to use a thin-walled flexible base material.

  The transparent substrate is required to transmit light emitted from the organic EL panel, and the total light transmittance is usually 75% or more, preferably 80% or more, more preferably 85% or more, and further preferably 87% or more. In particular, it is preferably 92% or more, particularly preferably 95% or more, and usually 99% or less.

  The thickness of the transparent substrate is not particularly limited, but it is preferably thinner from the viewpoint of thinning the entire light emitting device, and preferably has a certain thickness in order to have sufficient weather resistance. Moreover, it is preferable that it has a certain thickness also from the viewpoint of elimination of luminance unevenness, and is usually 0.2 mm or more, preferably 1 mm or more, more preferably 1.5 mm or more, further preferably 2 mm or more, particularly preferably. It is 3 mm or more, usually 50 mm or less, preferably 20 mm or less, more preferably 10 mm or less, and further preferably 5 mm or less.

  When a transparent substrate is provided with a diffusion function to provide a diffusion function, the diffusion function is achieved by adding a function of scattering visible light to the transparent substrate in the same manner as the diffusion film of the display unit described later. The base material which has can be obtained.

3-2. Diffusion film of display part, base material having diffusion function The diffusion film of display part and the base material having a diffusion function transmit light emitted from the organic EL panel of the light emitting part, and as a large organic electroluminescent device as a whole It has a function to reduce luminance unevenness. Although the said film and base material should just have a diffusion function at least, by making it white, it can also be used not only as a use as a light-emitting device but as a display color of various label | markers.

In the present invention, white means that in the XYZ color system, the values of the chromaticity coordinates x and y are usually 0.2 or more, preferably 0.25 or more, more preferably 0.3 or more, and usually 0.45 or less. , Preferably 0.42 or less, more preferably 0.38 or less, and most preferably 0.35 or less.
In the present invention, the values of X, Y and Z in the XYZ color system can be measured by a colorimetric color difference meter ZE-2000 manufactured by Nippon Denshoku Industries Co., Ltd.
In the XYZ color system, chromaticity coordinates x, y, and z are defined by the following equations.

  The diffusion film of the display unit is not particularly limited as long as it is a light transmissive film having a function of scattering visible light. Examples of the light transmissive film include films of polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), and the like. The diffusion film of the display unit is exposed to sunlight and rain water in the same way as the transparent base material, and is installed in a harsh outdoor environment where collisions such as birds and stepping stones can occur. What is excellent is preferable and it can also be set as the film which has a function which prevents scattering of a fragment, when a transparent base material is damaged.

In addition, as a method for imparting a function of scattering visible light to a light transmissive film or a transparent substrate, for example, a method of forming a concavo-convex structure on the surface of a film or a transparent substrate, or a surface of a film or a transparent substrate Examples thereof include a method of appropriately roughening, a method of foaming a film or a transparent substrate, a method of incorporating fillers (inorganic particles such as silicon oxide, titanium oxide, aluminum oxide, and zirconium oxide) in the film or transparent substrate. Among these, from the viewpoint of improving the visibility by increasing the diffusibility, a method in which a filler is contained in the film or the transparent substrate is preferable, and as the filler, titanium oxide or silicon oxide is particularly preferable.

  The diffusion film of the display unit or the substrate having a diffusion function is preferably one having parallel light transmittance, total light transmittance, and diffuse transmittance within a specific range. The parallel light transmittance is usually 50% or less, preferably 40% or less, more preferably 20% or less, and even more preferably 10% or less. The lower limit is not particularly limited, but is usually 1% or more, preferably It is 3% or more, more preferably 5% or more. The total light transmittance is usually 25% or more, preferably 35% or more, more preferably 45% or more, and is usually 100% or less, preferably 99% or less, more preferably 95% or less. The diffuse transmittance is usually 10% or more, preferably 20% or more, more preferably 30% or more, and is usually 50% or less, preferably 60% or less, more preferably 70% or less. Within the above range, it is possible to eliminate luminance unevenness in the display unit.

  Although the thickness of the diffusion film of the display part is not particularly limited, it is usually 10 μm or more, preferably 30 μm or more, more preferably 50 μm or more, and usually 5 mm or less, preferably 300 μm or less, from the viewpoint of maintaining the function of scattering visible light. More preferably, it is 150 μm or less.

3-3. Colored film other than white Colored film other than white transmits light emitted from the organic EL panel of the light emitting part, and includes a diffusion film of the display part or a substrate having a diffusion function, and a colored film other than white. Characters and patterns can be displayed by arrangement.

  In the present invention, the term “other than white” refers to all colors other than white, and examples include red, orange, yellow, green, blue, indigo, purple, black, and gray. In addition, intermediate colors composed of these colors, such as peach, yellow green, and blue green, are also included.

  When the organic EL light emitting device of the present invention is used as a road sign, the color of the colored film other than white is preferably red, orange, yellow, green, blue, purple, and green is particularly high in terms of visibility. preferable. In the present invention, green means that in the XYZ color system, the value of the chromaticity coordinate x is usually 0.05 or more, preferably 0.1 or more, more preferably 0.15 or more, and most preferably 0.2 or more. In general, it is 0.4 or less, preferably 0.35 or less, more preferably 0.3 or less, and the value of the chromaticity coordinate y is usually 0.4 or more, preferably 0.5 or more, more preferably 0.55. These are usually 0.8 or less, preferably 0.75 or less, more preferably 0.7 or less.

  The colored film other than white is preferably one having parallel light transmittance and total light transmittance within a specific range from the viewpoint of eliminating luminance unevenness in the display unit. The parallel light transmittance is usually 1% or more, preferably 5% or more, more preferably 10% or more, most preferably 20% or more, usually 50% or less, preferably 45% or less, more preferably 40% or less. Yes, most preferably 35% or less. The total light transmittance is usually 10% or more, preferably 15% or more, more preferably 20% or more, most preferably 40% or more, and usually 60% or less, preferably 55% or less, more preferably 50% or less. And most preferably 45% or less. In the same way as the diffusion film and transparent substrate of the display unit, considering that it is installed in a harsh outdoor environment where it can be exposed to sunlight and rainwater and can collide with birds, stepping stones, etc., it is weather and impact resistant. A superior one is preferred. These can also use what is marketed. As the light transmissive film, polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene (PE), polypropylene (PP), Examples thereof include films such as polystyrene (PS).

The thickness of the colored film other than white is not particularly limited, but is usually 15 μm or more, preferably 20 μm or more, more preferably 50 μm or more, further preferably 70 μm or more, and usually 600 μm or less, preferably 400 μm or less, more preferably 300 μm or less. More preferably, it is 200 μm or less, particularly preferably 150 μm or less.

3-4. Layer Configuration The configuration of the display unit of the present invention will be described with reference to the drawings.
FIG. 1 is a conceptual diagram showing an organic EL light emitting device of the present invention, and FIG. In the upper part of FIG. 7, the diffusion film 32 of the display unit and the colored film 33 other than white are laminated on the transparent substrate 31. In the upper part of FIG. 7, the diffusion film 32 of the display unit is visually recognized for a portion where the colored film 33 other than white is not present, and the white colored film 32 is visually recognized in the colored film 33 other than white. Is done.

  In the lower part of FIG. 7, a colored film 33 other than white is laminated on a base material 34 having a diffusion function. In the lower part of FIG. 7, the base material 34 having a diffusion function is visually recognized in the same manner as in the upper part of FIG. 7, and the diffusion function is provided in the non-white colored film 33. The base material 34 which has has white and is visually recognized. As a result, an arrow as shown in the display unit 3 of FIG.

  The layer configuration of the display unit 3 is not particularly limited with respect to the stacking order, but when used as a road sign, it is preferable to use a color film 33 other than white as the outermost layer. In the case of a road sign, it is assumed that the organic EL panel does not emit light in the daytime. In this case, when the transparent substrate 31 is present in the outermost layer, the display may not be visible due to reflection by the outermost layer. This is because sex exists. Preferably, the display unit is configured by laminating the transparent substrate 31, the diffusion film 32 of the display unit, and the colored film 33 other than white in this order.

  In addition, when one surface of the casing is manufactured from a light-transmitting plastic or the like, the plastic surface can be used as a transparent substrate of the display unit or a substrate having a diffusion function.

Luminance of the organic electroluminescence device of the present invention is usually 200 cd / m ² or more, preferably 300 cd / m ² or more, more preferably 400 cd / m ² or more, usually 3000 cd / m ² or less, preferably 2000 cd / m ² Hereinafter, it is more preferably 1000 cd / m ² or less.
The above range is preferable when used as a road sign because it is not too dazzling for the driver even if the light source is directly visually recognized, and brightness that can be visually recognized even in poor visibility such as at night. Moreover, the lifetime of the luminescent label itself can be extended by appropriately suppressing the luminance.

Even when the organic electroluminescent device of the present invention is increased in size, there is no luminance unevenness. Preferably, there is no luminance unevenness in a region having an area of 80% from the center of the display portion. In the present invention, there is no luminance unevenness. In the same color region of the display unit, the ratio between the maximum value and the minimum value of the luminance is 0.85 or more, preferably 0.90 or more, more preferably 0.95 or more. That means.
Therefore, the organic electroluminescent device of the present invention can be used as general lighting, but since it has a colored film in the display portion, it is preferably used as a light emitting device for display and used as a road sign. It is more preferable.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited only to an Example.

<Example 1>
(Manufacture of display part)
A transparent substrate 1 mm thick acrylic resin plate (total light transmittance 92%), a white colored film having a diffusion function 50 μm thick diffusion film 1 (white polyvinyl chloride film: XYZ color system) X = 0.36, y = 0.34, z = 0.29, parallel light transmittance 2%, total light transmittance 48%, diffuse transmittance 45%), and a white portion is formed on a part thereof. A green display film 1 made of polyvinyl chloride with a thickness of 50 μm as a colored film other than the above (x = 0.25, y = 0.63, z = 0.12 in the XYZ color system, parallel light transmittance 16%, all A display portion is obtained by laminating a light transmittance of 24%.

(Manufacture of light emitting part and casing)
An organic EL panel (width 50 mm × length 100 mm) on which a diffusion film 2 having a thickness of 100 μm (acrylic resin, parallel light transmittance 15%, total light transmittance 60%) is bonded at intervals of 5 mm (non-light emitting portion) A light-emitting part is obtained by arranging 5 sheets horizontally and 4 sheets vertically (20 sheets in total).
The light emitting part is placed on the bottom of an aluminum casing (aluminum thickness 1 mm, inner dimension 30 cm (vertical) × 45 cm (horizontal) × 15 cm (depth), opening size 27 cm (vertical) × 40 cm (horizontal)). Install.

(Production of organic electroluminescent device)
The light emitting part and the display part are fixed to the casing to obtain the marker 1 using the organic electroluminescent device. The distance between the surface of the light emitting part of the marker 1 (the light emitting side surface of the organic EL panel) and the back of the display part (the surface of the acrylic resin plate) is 20 mm.

<Example 2>
A green display film 2 made of polyvinyl chloride with a thickness of 50 μm as a colored film other than white (x = 0.19, y = 0.51, z = 0.31 in the XYZ color system, parallel light transmittance of 12%, The label 2 is obtained in the same manner as in Example 1 except that the total light transmittance 18%) is used.

<Example 3>
A green display film 3 made of polyvinyl chloride with a thickness of 50 μm as a colored film other than white (x = 0.28, y = 0.50, z = 0.22 in the XYZ color system, parallel light transmittance 33%, A label 3 is obtained in the same manner as in Example 1 except that 45% of the total light transmittance is used.

<Example 4>
A green display film 4 made of polyvinyl chloride and having a thickness of 50 μm as a colored film other than white (x = 0.26, y = 0.58, z = 0.16 in the XYZ color system, parallel light transmittance 2%, The label 4 is obtained in the same manner as in Example 1 except that the total light transmittance is 11%.

<Example 5>
A green display film 5 made of polyvinyl chloride and having a thickness of 50 μm as a colored film other than white (x = 0.24, y = 0.46, z = 0.29 in the XYZ color system, parallel light transmittance 4%, The label 5 is obtained in the same manner as in Example 1 except that the total light transmittance (21%) is used.

<Example 6>
Base material 1 having a diffusion function (thickness 2 mm, x = 0.32 in the XYZ color system, y = 0.32, z = 0.36, parallel light transmittance 3%, total light transmittance 41%) The indicator 6 is obtained in the same manner as in Example 1 except that the display unit produced by laminating the green display film 1 used in Example 1 as a colored film other than white is used.

<Example 7>
A label 7 is obtained in the same manner as in Example 6 except that the green display film 2 used in Example 2 is used as a colored film other than white.

<Example 8>
A label 8 is obtained in the same manner as in Example 6 except that the green display film 3 used in Example 3 is used as a colored film other than white.

<Example 9>
A label 9 is obtained in the same manner as in Example 6 except that the green display film 4 used in Example 4 is used as a colored film other than white.

<Example 10>
A marker 10 is obtained in the same manner as in Example 6 except that the green display film 5 used in Example 5 is used as a colored film other than white.

<Example 11>
The label 11 is obtained in the same manner as in Example 1 except that the diffusion film 1, the transparent base material, and the green film are laminated in this order from the light emitting part side (the diffusion film is laminated on the light emitting part side of the transparent base material).

<Example 12>
In manufacturing the light emitting part, organic EL panels (width 50 mm x length 100 mm) are arranged at 5 mm intervals (non-light emitting part), 5 by 4 horizontally (20 in total), and a diffusion film of 300 mm x 600 mm on top. The label | marker 12 is obtained like Example 1 except having laminated | stacked 2 and having obtained the light emission part.

<Comparative Example 1>
A label 13 is obtained in the same manner as in Example 1 except that the diffusion film 2 is not used.

<Comparative example 2>
A label 14 is obtained in the same manner as in Example 1 except that the diffusion film 1 is not used.

(Visibility evaluation method)
Visibility is evaluated by confirming the following items by visual observation at a distance of 5 m from a label using each organic electroluminescent device that emits light at 400 cd / m ² .
-Presence or absence of brightness unevenness (no brightness unevenness: ○, almost no brightness unevenness: △, brightness unevenness: x)
・ Luminance unevenness difference between colored part and white part (no brightness unevenness difference: ○, almost no brightness unevenness: △, brightness unevenness difference: x)
・ The sharpness of the boundary between the colored part and the white part when not emitting light (clearly recognizable border: ○, border recognizable: △, border blurred: ×)

DESCRIPTION OF SYMBOLS 1 Casing 2 Light emission part 2a Light emission part 2b Non-light emission part 3 Display part 31 Transparent base material 32 Diffusion film 33 of display part Colored film 34 Base material which has a diffusion function 4 Organic electroluminescent panel 41 Substrate 42 Anode 43 Hole injection layer 44 Positive Hole transport layer 45 Light emitting layer 46 Hole blocking layer 47 Electron transport layer 48 Electron injection layer 49 Cathode 5 Base material 60 Diffusion film 61 Diffusion panel

Claims (8)

A casing capable of emitting light from at least a part thereof,
A light emitting unit disposed in the casing and including a plurality of organic EL panels; and
An organic electroluminescent device comprising a display unit disposed in the casing and transmitting light emitted from the light emitting unit and emitting light to the outside of the casing,
The organic electroluminescent device has a diffusion member between the light emitting unit and the display unit,
The plurality of organic EL panels have a non-light emitting portion between the organic EL panels,
The said display part is an organic electroluminescent apparatus in which the film which has a transparent base material and a diffusion function at least is laminated | stacked, or has a base material which has a diffusion function at least.   The organic electroluminescent device according to claim 1, wherein the diffusion member is a diffusion film and is provided in contact with a light emitting surface of the light emitting unit.   The organic electroluminescence device according to claim 2, wherein the diffusion film is provided by being laminated on each of the plurality of organic EL panels. The organic electroluminescence device according to claim 1, wherein each of the plurality of organic EL panels has an area of 1000 to 500,000 mm ² .   The organic electroluminescent device according to claim 1, wherein the display unit is formed by laminating at least a transparent substrate and a film having a diffusion function.   In the display section, the film having the diffusion function is a white colored film, and further includes a colored film other than white, and the colored film other than white is red, orange, yellow, green, blue, indigo. The organic electroluminescent device according to claim 5, wherein the organic electroluminescent device is one or more colored films selected from the group consisting of violet, purple, and black.   The said display part is an organic electroluminescent apparatus of Claim 6 laminated | stacked in order of a transparent base material, a white colored film, and colored films other than white from the light emission part side.   The organic electroluminescent device according to any one of claims 1 to 7, which is a road sign.