JP3652042B2 - Electroluminescence structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electroluminescence structure for preventing noise of electroluminescence.
[0002]
[Prior art]
In recent years, with the development of information processing equipment, expectations for higher display quality flat panel displays are increasing. Flat panel displays include liquid crystal (LCD), plasma (PDP), electroluminescence (EL), fluorescent display tube (VFD), etc. Recently, there is an EL display that can be colored and has excellent display quality. Attention has been paid.
[0003]
Many cellular phones and the like are provided with EL light emitting elements so that the numeric buttons can be seen well at night. Since these portables are used while being carried, a DC dry battery is used for driving. Since the EL light-emitting element requires an AC power supply, the EL light-emitting element is used by converting a DC power supply of a dry battery to an AC power supply and further connecting to an inverter that boosts the voltage.
[0004]
In the basic configuration of the AC drive type thin film EL element, a light emitting layer is disposed between two electrodes via an insulating layer. When an AC voltage is applied between the electrodes and the electric field strength in the light emitting layer exceeds a certain value, the light emission central atom in the light emitting layer is excited, and light emission having a wavelength unique to this atom is obtained. Therefore, characteristics such as light emission luminance and light emission color of the EL light emitting element are substantially determined by the light emitting layer.
[0005]
FIG. 3 is a cross-sectional view showing the structure of a conventional general EL light emitting device. In FIG. 3, the EL layer 10 has a transparent electrode (ITO electrode) layer 1 formed on the top surface, 2 a light emitting layer, 3 an insulating layer, and 4 a back electrode layer. From both the electrode layers 1 and 4, a transparent electrode lead terminal 5a and a back electrode lead terminal 6a are disposed at the ends. The entire surface excluding a part of both the lead terminals 5a and 6a is covered with a transparent moisture-proof sheet 7. Further, the transparent electrode lead terminal 5 a and the back electrode lead terminal 6 a are connected to an inverter 9 by a lead wire or a flexible cable 8. By applying an alternating voltage from the inverter 9 to the transparent electrode layer 1 and the back electrode layer 4, the light emitting layer 2 emits light to illuminate surrounding display members and the like. The required AC voltage varies depending on the application, but is generally used in a voltage range of about 35 to 150V.
[0006]
However, in the above EL structure, since the EL layer and the inverter are separate structures, they must be handled via the connection line, and the mounting layout structure in the equipment, that is, the inverter placement location and the lead wire or cable Design considerations are required for the routing of wires. In addition, load is applied to the inverter and wiring during assembly and maintenance. Furthermore, it is expensive. Further, since the wire is bent by the lead wire or the cable wire, a conduction failure is likely to occur at the joint portion between the lead terminal and the connection wire. When these times increase, the joint part peels off or the cable wire breaks, which causes a conduction failure. In addition, various unexpected problems can occur during handling during work. Furthermore, there was a limit to the miniaturization of the device itself.
[0007]
Therefore, in order to solve the above-mentioned problem, the present applicant has applied for “Electroluminescence and its manufacturing method” (application date, December 26, 1996). The outline will be described with reference to FIG.
[0008]
As shown in FIG. 4, 7 is a transparent moisture-proof sheet made of a transparent plastic film, and on the lower surface thereof, ITO powder is made into a paint and a transparent electrode layer (ITO electrode) 1 is formed by screen printing. The light emitting layer 2 formed on the lower surface of the transparent electrode layer 1 is formed by printing with a fluorescent matrix and a paint containing a metal or halogen element activator. The insulating reflective layer 3 is formed by printing with a paint containing barium titanate. On the lower surface of the insulating reflective layer 3, the back electrode layer 4 is formed by coating conductive powder and screen printing. A second insulating layer 12 is formed by screen printing so as to cover the through-hole 11 looking into the lower surface of the back electrode layer 4 and the side surfaces of the light emitting layer 2, the insulating reflection layer 3 and the back electrode layer 4. The back electrode terminal 6 electrically connected to the back electrode layer 4 through the through-hole 11 formed in the second insulating layer 12 and the side surface of the second insulating layer 12 from a part of the lower surface of the transparent electrode layer 1. Further, a transparent electrode terminal 5 that extends to a part of the lower surface and is electrically connected to the transparent electrode layer 1 is formed by screen printing.
[0009]
An inverter 9 is provided on the lower surface side of the second insulating layer 12 and is connected to the back electrode terminal 6 and the transparent electrode terminal 5 so as to be integrally joined and fixed. A transparent coating layer 13 is formed over the entire surface of the inverter 9 except for a part of the inverter input terminal 9a by a dipping method.
[0010]
[Problems to be solved by the invention]
However, the above-described EL light emitting device has the following problems. That, 35～150V as described above the back electrode layer and the transparent electrode layer, voltage of several tens to several KH _Z is applied. As a result, the electric field of the electrode causes an inductive current to be generated in a nearby inverter circuit, causing a problem of radiation noise.
[0011]
The present invention has been made in view of the above-described conventional problems. The object of the present invention is to cut off an induced current generated by applying an AC voltage between electrodes in a structure in which an EL layer and an inverter are integrated, thereby reducing noise. It is an object of the present invention to provide an electroluminescence structure which prevents generation and realizes downsizing and high reliability of equipment.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the electroluminescence structure of the present invention has a light emitting layer having a transparent electrode layer covered with a transparent moisture-proof sheet on the top surface and a back electrode layer on the bottom surface with an insulating reflective layer interposed therebetween. Insulating sandwiched between two electrodes and having a through hole on the bottom surface of the back electrode layer to look into the bottom surface of the back electrode layer so as to cover the side surfaces of the light emitting layer, the insulating reflective layer, and the back electrode layer A layer, a back electrode terminal electrically connected to the back electrode layer in the through hole formed in the insulating layer, and a part of a lower surface of the transparent electrode layer extending to a side surface and a part of the lower surface of the insulating layer. A transparent electrode terminal formed and electrically connected to the transparent electrode layer; and an inverter disposed integrally and fixedly arranged on the lower surface side of the insulating layer with the back electrode terminal and the transparent electrode terminal; Inverter of the inverter A transparent coating layer formed on the entire surface excluding a part of the input terminal, and an AC voltage is applied from the inverter to the transparent electrode terminal and the back electrode terminal disposed on the two electrode layers. In the electroluminescence structure in which the light emitting layer emits light when applied, the transparent electrode layer has a large shape protruding from the light emitting layer, and the insulating layer has a recess formed in a portion covering the side surface. the transparent electrode terminals are formed by extending from the lower surface of the protruding portion of the transparent electrode layer to a part of the concave inner surface and a lower surface of the insulating layer, between the back electrode layer and the insulating layer And from the lower surface side of the back electrode layer, another insulating layer each having a through hole and a conductive metal layer are laminated, the upper surface side of the conductive metal layer is insulated by the other insulating layer, and the conductive layer It is characterized in that the lower surface side and side surface side insulating genera layer were performed in the insulating layer.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The structure of electroluminescence in the present invention will be described below with reference to the drawings. 1 and 2 relate to the structure of an EL which is a preferred embodiment of the present invention, FIG. 1 is a partial sectional view of an EL light emitting element, and FIG. 2 is a partially cutaway perspective view of an EL layer. In the figure, the same members as those in the prior art are denoted by the same reference numerals.
[0015]
1 and 2, the configuration of the EL light emitting element 30 will be described. As shown in FIG. 1, reference numeral 7 denotes a transparent moisture-proof sheet made of a transparent plastic film. On the lower surface, a transparent electrode layer (ITO electrode) 1 is formed by screen-printing ITO powder. The light emitting layer 2 formed on the lower surface of the transparent electrode layer 1 is formed by printing with a fluorescent matrix and a paint containing a metal or halogen element activator. The insulating reflective layer 3 is formed by printing with a paint containing barium titanate. On the lower surface of the insulating reflective layer 3, the back electrode layer 4 is formed by coating conductive powder and screen printing. A first insulating layer 15 is formed on the lower surface of the back electrode layer 4 by screen printing, and a conductive metal layer 16 having a through hole 11 through which the lower surface of the back electrode layer 4 is viewed through the first insulating layer 15. Form.
[0016]
The conductive metal layer 16 is preferably a metal foil having excellent conductivity, such as an aluminum foil or a copper foil. In order to prevent the conductive metal layer 16 from being electrically connected to the back electrode layer 4, the first insulating layer 15 is interposed between the back electrode layer 4 and at the same time, adhesion between the two is made of glass or Use of adhesives such as plastic balls is good. Needless to say, the grounding effect of the conductive metal layer 16 is further increased. The conductive metal layer 16 functions as a shield material that blocks induced current due to alternating current.
[0017]
The light emitting layer 2, the insulating reflective layer 3, the back electrode layer 4, the first insulating layer 15, and the conductive metal layer 16 have a through hole 11 that looks into the bottom surface of the back electrode layer 4 on the bottom surface of the conductive metal layer 16. A second insulating layer 12 is formed by screen printing so as to cover the side surface of the first insulating layer 12. The through-holes 11 formed in the second insulating layer 12 are connected to the back electrode layer 4 from the back electrode terminal 6 and a part of the transparent electrode layer 1 from the lower surface of the second insulating layer 12. A transparent electrode terminal 5 which extends to part of the side surface and the lower surface and is electrically connected to the transparent electrode layer 1 is formed by screen printing (EL layer 14 in FIG. 2).
[0018]
An inverter 9 is provided on the lower surface side of the second insulating layer 12 and is connected to the back electrode terminal 6 and the transparent electrode terminal 5 so as to be integrally joined and fixed. A transparent coating layer 13 is formed over the entire surface of the inverter 9 except for a part of the inverter input terminal 9a by a dipping method.
[0019]
As described above, the preferred embodiment of the present invention has been described with reference to FIGS. 1 and 2. In the structure of the conventional general EL light emitting device shown in FIG. 3, an insulating layer is interposed on the lower surface side of the back electrode layer 4. Needless to say, the same effect can be obtained even if the conductive metal layer is provided.
[0020]
【The invention's effect】
As described above, according to the present invention, most of the EL light-emitting elements are formed by laminating the screen printing method, the EL layer and the inverter are integrally joined, and the back electrode layer and the second electrode are joined together. A conductive metal layer as a shield material is placed between the insulating layer and the first insulating layer, and a voltage is applied between the transparent electrode layer and the back electrode layer because of the structure that is fixed by the coating layer. By doing so, the induced current generated in the nearby inverter circuit is prevented and the generation of noise is prevented. As described above, it is possible to provide an electroluminescence structure that achieves downsizing and high reliability of equipment.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of an EL light emitting device according to an embodiment of the present invention.
FIG. 2 is a partially cutaway perspective view of an EL layer.
FIG. 3 is a partial cross-sectional view of a conventional EL light emitting device.
FIG. 4 is a partial cross-sectional view of an EL layer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transparent electrode layer 2 Light emitting layer 3 Insulating reflective layer 4 Back electrode layer 5 Transparent electrode terminal 6 Back electrode terminal 7 Transparent moisture-proof sheet 9 Inverter 11 Through hole 12 2nd insulating layer 13 Coating layer 14 EL layer 15 1st Insulating layer 16 Conductive metal layer 30 EL light emitting device

Claims (1)

The light emitting layer is sandwiched between two electrodes, a transparent electrode layer covered with a transparent moisture-proof sheet on the upper surface and a back electrode layer on the lower surface via an insulating reflective layer, and the lower surface of the back electrode layer An insulating layer having a through hole that looks into the lower surface of the back electrode layer so as to cover side surfaces of the light emitting layer, the insulating reflection layer, and the back electrode layer; and the back electrode layer in the through hole formed in the insulating layer A back electrode terminal that is electrically connected to the transparent electrode layer, and a transparent electrode terminal that extends from the lower surface of a part of the transparent electrode layer to the side surface and a part of the lower surface of the insulating layer, and is electrically connected to the transparent electrode layer; Formed over the entire surface excluding a part of the inverter input terminal of the inverter, and an inverter that is integrally joined and fixed to the back electrode terminal and the transparent electrode terminal on the lower surface side of the insulating layer With a transparent coating layer Is, by applying an AC voltage from the inverter to the for two arranged on the electrode layer to the transparent electrode terminals and the back electrode terminals, in the structure of the electroluminescence light emitting layer emits light, the transparent electrode layer The transparent layer has a large shape protruding from the light emitting layer, and the insulating layer has a recess formed in a portion covering the side surface, and the transparent electrode terminal extends from the lower surface of the protruding portion of the transparent electrode layer. wherein is formed by extending to a part of the concave inner surface and a lower surface, between the back electrode layer and the insulating layer, the lower surface side of the back electrode layer, other insulating layer and the conductive metal each having a through hole A layer is laminated, the upper surface side of the conductive metal layer is insulated by the other insulating layer, and the lower surface side and the side surface side of the conductive metal layer are insulated by the insulating layer. Elect Luminescence.

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