JP2007188725A - Inorganic distributed electroluminescent display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inorganic distributed electroluminescent display device capable of preventing a leakage current even when the inorganic distributed electroluminescent display device having a large area such as A0-A2 size is attached to a conductive wall surface. <P>SOLUTION: This inorganic distributed electroluminescent display device is composed of: an inorganic distributed electroluminescent element 10 having a first conductive film 121, a phosphor layer 122 and a back electrode 123 in that order; and a conductive film 30 with an insulation layer comprising an electrical insulation layer 31 and a second conductive film 32 arranged on the back electrode 123 side in that order; its front side and back side are covered with moistureproof films 11 and 13, respectively; and the second conductive film 32 is grounded when used. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention particularly relates to measures against electric leakage of a large-capacity inorganic electroluminescence (inorganic EL) display device that is used by being installed on a wall, a cylinder, a floor, a ceiling, or the like.

  Electroluminescent elements are divided into inorganic electroluminescent elements and organic electroluminescent elements such as particle-dispersed elements in which phosphor particles are dispersed in a high dielectric material, and thin-film elements in which a phosphor thin film is sandwiched between dielectric layers. Broadly divided. The present invention mainly relates to a particle-dispersed inorganic electroluminescence device.

FIG. 5 is a longitudinal sectional view of a conventional EL display device using a particle-dispersed electroluminescence element.
In the figure, reference numeral 50 denotes a conventional EL display device comprising a moisture-proof film 51, a dispersive electroluminescence element 52, and a moisture-proof film 53. The EL element 52 includes a transparent conductive film 521, a phosphor layer / reflection insulating layer 522, and a back electrode 523 in this order.

  As described above, the dispersive electroluminescence element 52 is fluorescent between a pair of conductive electrode films 521-523, at least one of which is light transmissive, in a high dielectric polymer such as a polymer having a fluoro rubber or a cyano group. The device is provided with a light emitting layer 522 comprising body powder, and further provided with a dielectric layer comprising a ferroelectric powder such as barium titanate in a high dielectric polymer to prevent dielectric breakdown. It is the normal form.

  Since the particle-dispersed electroluminescent element 52 does not use a high-temperature process at the time of element configuration, (1) a flexible material structure using a plastic substrate is possible, and (2) relatively without using a vacuum apparatus. It can be manufactured at low cost with a simple process, and (3) it has the feature that the emission color of the element can be easily adjusted by mixing a plurality of phosphor particles having different emission colors. Therefore, it is widely applied to backlights and display elements.

  The particle-dispersed electroluminescent element 52 is characterized by its ability to emit light uniformly over a large area, and as a film-like light source, it is thin, lightweight, and can be bent to some extent, so that it can be bent in a simple manner. It can be installed on walls, columns, floors, ceilings, etc., and their use is expected more and more in the future.

  However, the particle-dispersed electroluminescent element 52 itself is a capacitive load element, as can be inferred from the above-described configuration that it has a pair of conductive electrode films 521-523, and in order to emit light with sufficient luminance. It is necessary to apply an AC voltage having an effective value of 100 V or more and 400 Hz or more. For this reason, an inverter power source for driving this is required.

In addition, the conventional particle-dispersed electroluminescent elements were not supposed to be large-capacity devices such as walls, cylinders, floors, and ceilings. Assuming a large-capacity element to be installed on the wall, there is a possibility that stray capacitance will become a problem between the element itself, which is a capacitive load, and the wall or cylinder, floor, ceiling, etc. However, depending on the type of inverter power supply, I have noticed that an unexpected leakage current may occur.
As a result of investigating the cause, it was found that a leakage current appears particularly in the case of a drive circuit provided with an LC filter on the inverter output side.

FIG. 6 is a circuit diagram for explaining the cause of leakage current when the conventional EL display device of FIG. 5 is AC driven.
In the figure, 50 is the EL display device shown in FIG. 5, 60 is the EL drive housing, 60A is the EL drive circuit (driver), 60B is the output filter, 61 is the commercial AC power supply (100V), and 90 is the conductive wall surface. This assumes a wall placed in an atmosphere where condensation occurs. The EL drive circuit 60A includes a rectifying circuit that rectifies commercial alternating current to convert it into direct current, a smoothing circuit that smoothes the rectified pulsation voltage, an inverter that converts the output of the smoothing circuit into alternating current, and a frequency band of 1 kHz to 2 kHz of the inverter output. Is included.

<Reason why leakage current may occur>
The leakage current is considered to occur as follows.
When the EL drive circuit 60A is connected to a 100V commercial AC power supply 61, the EL front panel 521, which is a conductive film, and the EL back panel 523, which is a back electrode, pass through an output filter 60B in the EL drive circuit 60A. Between the two and the light emission display. However, since the EL panel is large, a large distributed capacitance (capacitor) is formed between the back electrode 523 and the conductive wall surface 90, and an operator (person) touches the EL driving device housing 60 there. Then, the charge stored in the distributed capacity flows from the earth to the capacitor of the output filter 60B in the EL driving device housing 60 through a person, and a closed loop is formed to return to the back electrode 523. Will flow.

  In order to achieve high brightness, the voltage and frequency are preferably set to 100 V or higher and 1 KHz or higher, respectively, but in that case, the leakage current tends to increase. When installed on a ceiling or the like, since it is often required to obtain high visibility and a relatively large amount of light, there is a demand for a tendency to increase the drive voltage and frequency.

  Various power source technologies have been disclosed as means for compensating for a decrease in luminance due to deterioration of the electroluminescence element. For example, as a method of compensating for brightness due to device deterioration, in order to compensate for the decrease in the amount of current due to the decrease in capacity due to deterioration, the current is compensated by increasing the voltage and frequency by detecting the current, thereby suppressing the decrease in brightness. To be done. In such a case, the voltage and frequency typically rise to 200 V or more and 1 KHz or more with respect to the initial set value, and the above-described problem of leakage current cannot be ignored.

  In addition, for example, in the case of a pulse wide modulation (Pulse Wide Modulation) type power supply, for example, an alternating current of 10 KHz or more is used as a basic transmission frequency for outputting a driving frequency of about 1 KHz. Often, however, leakage currents due to this high frequency are likely to occur.

  In addition, the leakage current increases as the area of the element increases or the capacity of the element increases. Therefore, in order to realize light emission in a large area, high luminance, and light emission life extension, which are the characteristics of the dispersion type electroluminescent element, it is necessary to solve the above problems.

On the other hand, as an inorganic dispersion type electroluminescence display device having a configuration similar to that of the present invention, there is one described in Patent Document 1.
Japanese Patent Laid-Open No. 2001-230083

FIG. 7 is a longitudinal sectional view of the thin electroluminescent lamp described in Patent Document 1 and a diagram showing how to drive it. This thin electroluminescent lamp is not suitable for a liquid crystal backlight and is intended to provide a thin electroluminescent lamp with a reduced noise level, and is manufactured as follows.
First, a transparent electrode layer 43 such as ITO is formed on the back surface of an insulating transparent film 42 made of PET or the like having a thickness of 100 to 200 μm by sputtering to a thickness of 300 to 500 mm. The light-emitting layer 44 dispersed in the film is printed to a thickness of 35 to 45 μm, and a first insulating layer (reflective insulating layer) 45 in which a white high dielectric material such as barium titanate is dispersed in a fluororesin is formed thereon. A back electrode layer 46 made of a conductive paste such as silver or carbon is printed thereon to a thickness of 10 to 15 μm, and the same material as that of the first insulating layer 45 is printed thereon with a thickness of 10 to 20 μm. A second insulating layer 47 having the same thickness is printed and formed, and a back shield electrode layer 48 made of a conductive paste such as silver or carbon is printed thereon to a thickness of 10 to 20 μm, and a fluorine rubber or the like is formed thereon. The Go The protective layer / vibration damping layer 49 is screen-printed with a film thickness (for example, about 100 μm) sufficiently thicker than the light emitting layer 44 and the first insulating layer 45 using a material having elastic elasticity or a material having rigidity such as epoxy resin. And completed.

  In the electroluminescent lamp 41, the transparent electrode layer 43 and the back shield electrode layer 48 are short-circuited or grounded together, and an AC voltage source is connected between the transparent electrode layer 43 and the back electrode layer 46. The piezoelectric effect generated in the first insulating layer 45 and the second insulating layer 47 by applying an alternating electric field in reverse phase between the back electrode layer 46 and between the back electrode layer 46 and the back shield electrode layer 48. In addition to canceling the distortion caused by the vibration, the vibration is attenuated by the vibration damping layer 49 to reduce noise.

As described above, the thin electroluminescent lamp described in Patent Document 1 appears to have a configuration similar to that of the present invention described later, but the first insulating layer 45 and the second insulating layer 47 are made of the same material and have the same thickness. On the other hand, the second insulating layer of the present invention should not be made of the same material as the first insulating layer (ferroelectric material) (if it is a ferroelectric material, a large distributed capacitance is formed). Therefore, the effect of the present invention is not achieved).
The usage (driving method) also applies an alternating electric field of opposite phase between the transparent electrode layer 43 and the back electrode layer 46 and between the back electrode layer 46 and the back shield electrode layer 48 as described above. Yes (the usage of the present invention is driven only between the transparent electrode layer 43 and the back electrode layer 46. The back shield electrode layer 48 is grounded, which will be described later), and its effect is also noise cancellation (the effect of the present invention is prevention of leakage).
Therefore, although the thin electroluminescent lamp described in Patent Document 1 is partially similar in configuration, the thin electroluminescent lamp described in Patent Document 1 cannot prevent leakage.

  The present invention has been made in view of the above circumstances, and solves the problems in the conventional display device described above. A particle-dispersed electroluminescent element that realizes a large area, high luminance, and long life is obtained by using conductive columns, walls, or the like. An object of the present invention is to provide a safe inorganic dispersion type electroluminescence display device in which leakage current does not flow even when installed on a floor, a ceiling, or the like.

In order to solve the above-mentioned problem, the invention according to claim 1 relates to an inorganic dispersion type electroluminescence display device, and an inorganic dispersion type electroluminescence element having a first conductive film, a phosphor layer, and a back electrode in this order; It is characterized by comprising a conductive film with an insulating layer comprising an electrical insulating layer and a second conductive film provided in this order on the back electrode side.
The invention described in claim 2 is the inorganic dispersion type electroluminescence display device according to claim 1, wherein the first conductive film and the second conductive film are covered with a moisture-proof film.
The invention according to claim 3 relates to an inorganic dispersion type electroluminescence display device, comprising an inorganic dispersion type electroluminescence element having a first conductive film, a phosphor layer, and a back electrode in this order, and the first conductivity. Insulation comprising a first moisture-proof film and a second moisture-proof film covering the film and the front and back electrodes, respectively, and an electrical insulation layer and a second conductive film provided in this order on the second moisture-proof film side And a conductive film with a layer.
According to a fourth aspect of the present invention, in the inorganic dispersed electroluminescence display device according to any one of the first to third aspects, the first conductive film is transparent.
The invention according to claim 5 is the inorganic dispersion type electroluminescence display device according to any one of claims 1 to 4, wherein the second conductive film is used while being grounded.

According to the inorganic dispersion type electroluminescence display device of the first aspect, the leakage current of the inorganic dispersion type electroluminescence display device can be prevented by grounding the second conductive film.
According to the inorganic dispersion type electroluminescence display device of the second aspect, since it is covered with the moisture-proof film, it can be used even in a poor environment with much moisture.
According to the inorganic dispersion type electroluminescence display device of claim 3, leakage current can be easily prevented by adding a conductive film with an insulating layer to a conventional electroluminescence element.
According to the inorganic dispersion type electroluminescence display device of the fourth aspect, since the first conductive film is transparent, it can be used as a bright backlight.
According to the inorganic dispersion type electroluminescence display device of the fifth aspect, since the second conductive film is grounded, the leakage current of the inorganic dispersion type electroluminescence display device can be prevented.

<Embodiment 1>
FIG. 1 is a cross-sectional view of an inorganic dispersion type electroluminescence display device according to Embodiment 1 of the present invention.
In the figure, 10 is an EL display device according to Embodiment 1 of the present invention, 11 is a moisture-proof film, 12 is an EL element, and in the order of the transparent conductive film 121, the phosphor layer / reflective insulating layer 122, and the back electrode 123 from the front side. 13 is a moisture-proof film.
The above is the same configuration as that of the conventional apparatus (FIG. 5). Further, according to Embodiment 1 of the present invention, a PET (polyethylene terephthalate) film 31 is formed between the back electrode 123 and the moisture-proof film 13 on the back electrode 123 side. And the conductive film 30 with an insulating layer which consists of the conductive film 32 in the moisture-proof film 13 side is inserted. In the figure, each component is illustrated separately in order to make it easy to understand, but in actuality, these components are integrally formed in close contact with each other. This is attached to the wall surface 90.
The wall surface 90 is conductive (contains a case where a material containing a conductive material is used, a metal mesh for giving strength is used, or an atmosphere where condensation is likely to occur). If there is, there is a possibility that a leakage current flows as described in the conventional apparatus.

<How to use>
Therefore, according to the present invention, after the EL display device 10 according to the first embodiment of the present invention is attached to the wall surface 90, the conductive film 32 provided according to the first embodiment of the present invention is grounded. .

<Reason why leakage current does not occur>
FIG. 2 is a circuit diagram for AC driving the EL display device of FIG.
In the figure, 10 is the EL display device shown in FIG. 1, 60 is an EL drive housing, 60A is an EL drive circuit (driver), 60B is an output filter, 61 is a commercial AC power supply (100V), and 90 is a conductive wall surface. This assumes a wall placed in an atmosphere where condensation occurs. The EL drive circuit 60A includes a rectifying circuit that rectifies commercial alternating current to convert it into direct current, a smoothing circuit that smoothes the rectified pulsation voltage, an inverter that converts the output of the smoothing circuit into alternating current, and a frequency band of 1 kHz to 2 kHz of the inverter output. Is included. 30 is a conductive film with an insulating layer provided according to the present invention, 32 is a second conductive film, and the second conductive film 32 is grounded.

<Reason why leakage current does not occur in FIG. 2>
When the EL drive circuit 60A is connected to a 100V commercial AC power supply 61, the EL front panel 521, which is a conductive film, and the EL back panel 523, which is a back electrode, pass through an output filter 60B in the EL drive circuit 60A. Between the two and the light emission display. On the other hand, even if the EL panel is large, since the second conductive film 32 provided on the back electrode 523 via the insulating layer is grounded, it is distributed between the back electrode 52 and the conductive wall surface 90. Therefore, even if the operator (person) touches the EL driving device housing 60 there is no charge, the leakage current does not flow to the person.

<Embodiment 2>
FIG. 3 is a cross-sectional view of an inorganic dispersion-type electroluminescence display device according to Embodiment 2 of the present invention.
In the figure, 20 is an EL display device according to Embodiment 2 of the present invention, 11 is a moisture-proof film, 12 is an EL element, and in order of the transparent conductive film 121, phosphor layer / reflective insulating layer 122 and back electrode 123 from the front side. 13 is a moisture-proof film.
Each of the above components are integrally formed. This is the same as the conventional apparatus (FIG. 5). According to Embodiment 2 of the present invention, when this EL display device 20 is attached to the conductive wall surface 90, the conductive film 30 with an insulating layer comprising the PET (polyethylene terephthalate) film 31 and the conductive film 32 is provided. Is characterized in that the PET film 31 side is interposed on the moisture-proof film 13 side and the conductive film 32 is grounded.

<Reason why leakage current does not occur>
FIG. 4 is a circuit diagram for AC driving the EL display device of FIG.
In the figure, 20 is an EL display device shown in FIG. 3, 60 is an EL drive housing, 60A is an EL drive circuit, 60B is an output filter, 61 is a commercial AC power supply (100V), and 90 is a conductive wall surface.
When the EL drive circuit 60A is connected to a 100V commercial AC power supply 61, the EL front panel 521, which is a conductive film, and the EL back panel 523, which is a back electrode, pass through an output filter 60B in the EL drive circuit 60A. Between the two and the light emission display. On the other hand, even if the EL panel is large, since the second conductive film 32 provided on the back electrode 523 via the moisture-proof film and the insulating layer is grounded, the back electrode 52 and the conductive wall surface 90 Therefore, even if the operator (person) touches the EL driving device housing 60 there is no charge, the leakage current does not flow to the person.

Below, the preferable aspect of the electroluminescent element of this invention is described.
<Phosphor particles>
The phosphor particles are described in Japanese Patent Application Nos. 2004-223781, 2004-230991, 2004-186626, 2005-053653, 2005-053415, 2004-346837, 2005-0454456, and the like. The phosphor particles for electroluminescence can be preferably used.

<Transparent conductive film>
With respect to the transparent conductive film, those described in Japanese Patent Application No. 2005-053565, Japanese Patent Application Laid-Open No. 2005-302508, Japanese Patent Application No. 2004-208791, Japanese Patent Application No. 2004-254116, Japanese Patent Application No. 2005-197234, and the like can be preferably used.

<Wavelength conversion fluorescent dye>
With respect to the wavelength conversion fluorescent dye, those described in Japanese Patent Application Nos. 2004-315982 and 2004-316405, and methods of use can be preferably used.

  In addition, in the element configuration of the present invention, a substrate, a reflective insulating layer, various protective layers, a filter, a light scattering reflection layer, and the like can be provided as necessary. In particular, regarding the substrate, a transparent resin sheet can be used for the flexible substrate in addition to the glass substrate or the ceramic substrate.

<Power supply>
Usually, the dispersion type electroluminescence element is driven by alternating current. Typically, it is driven using an AC power source of 50 Hz to 3 KHz at 100 V or higher. When the area is small, the luminance increases almost in proportion to the applied voltage and frequency. The electroluminescent device of the present invention can be driven at a high frequency even with a large size of 0.1 m ² or more, and can have high luminance. In that case, driving at 500 Hz to 5 KHz is preferable, and driving at 1 KHz to 3 KHz is more preferable.
When driving under such conditions is possible, it is possible to emit light with high brightness.
It is important for the element of the present invention to emit light with a high luminance of 200 cd / m ² or more. When the color temperature is 200 cd / m ² or less, the high color temperature of the present invention shifts to red due to the influence of external light and cannot exhibit a preferable white color. More preferably, it is preferably 300 cd / m ² or more, and particularly preferably 500 cd / m ² or more.
Examples of preferred embodiments of the power source of the present invention include Japanese Patent Application No. 2005-0442, Japanese Patent Application No. 2005-04443, Japanese Patent No. 3236236, Japanese Patent Application Laid-Open No. 2005-62524, Japanese Patent Application Laid-Open No. 6-225546, Japanese Patent Application Laid-Open No. 7-65952, Japanese Patent Application Laid-Open No. 7-170760, JP-A-8-45663, JP-A-8-250280, JP-A-9-322560, and the like.

<Conductive film for preventing leakage>
The conductive film or plate-like sheet for preventing leakage of the present invention is not particularly limited, but the insulation film or plate-like sheet is insulated so that the wall, pillar, floor, or ceiling to be installed is insulated. Is preferably arranged. In this case, for example, a configuration in which an aluminum film and a resin film such as polyethylene terephthalate are bonded together or the aluminum film is laminated with the resin film is preferable. If it is such a structure, the electroconductive sheet may be bonded together via the insulating film with respect to the back electrode (FIG. 1), More preferably, a back electrode and a back electrode are provided between a moisture-proof film and a back electrode. It may be insulated and incorporated (FIG. 3).
There is no particular limitation on the material having conductivity, and an aluminum film, a copper film, a conductive sheet formed of a conductive paste in which carbon, silver, copper, or the like is dispersed can be preferably used. When there is no limit to the weight that can be used, an aluminum plate, a stainless plate, a steel plate or the like may be used. A surface resistance of at least 1 Ω / m ² or less is required.
These conductive parts need to be connected to the ground wire of the output cord from the power source or to be grounded by other methods. A specific example is shown in FIG.

Example 1
<Invention: phosphor particle A>
25 g of zinc sulfide (ZnS) particle powder having an average particle diameter of 30 nm, 0.1 mol% of copper sulfate with respect to ZnS, 0.003 mol% of chloroauric acid, and 0.005 of Na ₂ [Pt (OH) ₆ ] An appropriate amount of NaCl, MgCl ₂ and ammonium chloride (NH 3 Cl) powder as fluxes and a magnesium oxide powder in a 20% by mass alumina crucible with respect to the phosphor powder are added to a dry powder added with mol%, and 2.0 ° C. at 1200 ° C. After baking for an hour, the temperature dropped. Thereafter, the powder was taken out and pulverized and dispersed with a ball mill. After further ultrasonic dispersion, 5 g of ZnCl ₂ and 0.05 mol% of copper sulfate were added to ZnS, and then 1 g of MgCl ₂ was added to prepare a dry powder, which was again put in an alumina crucible at 700 ° C. for 6 hours. Baked. At this time, firing was performed while flowing 10% oxygen gas as an atmosphere.

After firing, the particles are pulverized again, dispersed and settled in 40 ° C H2O, washed with the supernatant, washed with 10% hydrochloric acid, dispersed, settled and removed to remove unnecessary salts. And dried. Further, a 10% KCN solution was heated to 70 ° C. to remove Cu ions and the like on the surface.
Further, the surface layer corresponding to 10% by weight of the whole particles was removed by etching with 6N hydrochloric acid.
The particles thus obtained were further sieved to take out monodispersed and small-sized particles.
The phosphor particles thus obtained had an average particle size of 15.0 μm and a coefficient of variation of 31%. In addition, the particles were pulverized in a mortar, and fragments having a thickness of 0.2 μm or less were taken out and observed under an electron microscope under an acceleration voltage condition of 200 KV. A portion having 10 or more defects was included.
BaTiO ₃ fine particles having an average particle size of 0.02 μm are dispersed in a cyanoresin solution dissolved in an organic solvent at a ratio of 30% by mass, and applied on an aluminum sheet having a thickness of 100 μm so that the dielectric layer has a thickness of 30 μm. It dried for 1 hour at 120 degreeC using the warm air dryer.

The phosphor particle A is made to have x = 3.3 ± 0.3 y = 3.4 ± 0.3 in CIE chromaticity coordinates when emitting light of fluorescent dye FA-007 manufactured by Sinloihi Co., Ltd. and 300 cd / m ² , It was dispersed and kneaded in a cyanoresin solution having a concentration of 30 wt%, and applied on the dielectric layer so as to have a thickness of 60 μm.

(Formation of intermediate layer)
On the phosphor layer, using a coating solution in which BaTiO ₃ fine particles having an average particle size of 0.02 μm are dispersed in a cyanoresin solution in an amount 1/5 that of the dielectric layer, the coating is applied to a thickness of 2 μm. An intermediate layer was formed.

(Transparent conductive film)
A conductive film having a light transmittance of 88% with a surface resistance of 30 Ω / m ² deposited with ITO (indium zinc oxide) was prepared, and a cyanoresin was printed thereon to a thickness of 0.1 μm or less. After taking out the terminal for external connection from the transparent electrode part of the element and the aluminum back electrode part using a copper aluminum sheet having a thickness of 80 μm, the element is sandwiched with a GX film which is a moisture-proof film manufactured by Toppan Printing Co., Ltd. Thermocompression bonding was performed while vacuum degassing. The element size was quadrangular so that the light emitting area was 0.5 m ² .
The light-emitting element of the comparative example manufactured in this manner was used as Sample 1. Based on these samples, driving was performed under conditions of driving voltage and frequency of around 140 V and 1.5 KHz. The brightness was adjusted to 600 cd / m ² . On this EL element, photographs of people and vegetable salad (including broccoli and tomato), landscape (including red, yellow, green, blue flowers and plants, and blue sky) were printed on Fuji Photo Film's G color print. A transmissive print material was created and placed.
When this was sandwiched between polyethylene terephthalate transparent films with a thickness of 250 μm, grounded on a stainless steel wall, and the inverter power supply CVFT1-D200 made by Tokyo Seiden Co., Ltd. was used to drive at 140 V, 1.5 KHz, 1 mA Leakage current exceeding 100 was detected.
On the other hand, a conductive sheet containing a 20 μm thick aluminum film laminated with a 38 μm thick polyethylene terephthalate film was created, and the ground wire was drawn out from the end of the conductive sheet and connected to the ground terminal of a commercial power source. It was confirmed that the leakage current was 1 mA or less.

  The leakage current detection circuit used the method specified in the Electrical Appliance and Material Safety Law.

  As described above, according to the present invention, the second conductive film is provided on the back electrode side of the inorganic dispersion type electroluminescent display device via the insulator and the second conductive film is grounded. Even when an inorganic dispersion type electroluminescent display device having a large area is attached to a conductive wall surface, a stray capacitance is not formed between the back electrode and the conductive wall surface, so that leakage current can be prevented.

It is sectional drawing of the inorganic dispersion type electroluminescent display apparatus which concerns on Embodiment 1 of this invention. FIG. 2 is a circuit diagram for AC driving the EL display device of FIG. 1. It is sectional drawing of the inorganic dispersion type electroluminescent display apparatus which concerns on Embodiment 2 of this invention. FIG. 4 is a circuit diagram for AC driving the EL display device of FIG. 3. It is a longitudinal cross-sectional view of the conventional EL display apparatus using a particle-dispersed electroluminescent element. FIG. 6 is a circuit diagram for AC driving the conventional EL display device of FIG. 5. It is a figure which shows the longitudinal cross-sectional view of the thin electroluminescent lamp of patent document 1, and how to drive.

Explanation of symbols

10 EL display device 11 according to Embodiment 1 of the present invention Moisture-proof film 12 EL element 121 Transparent conductive film 122 Phosphor layer / reflective insulating layer 123 Back electrode 13 Moisture-proof film 20 EL display device 30 according to Embodiment 2 of the present invention Insulation Layered conductive film 31 PET (polyethylene terephthalate) film 32 Conductive film 60 EL driving device housing 60A EL driving circuit (driver)
60B Output filter 61 Commercial AC power supply 90 Conductive wall

Claims (5)

  An inorganic dispersion type electroluminescent element having a first conductive film, a phosphor layer and a back electrode in this order, an electrically insulating layer provided in this order on the back electrode side, and a second conductive film. An inorganic dispersion type electroluminescence display device comprising: an electrically conductive film with an insulating layer.   2. The inorganic dispersed electroluminescence display device according to claim 1, wherein the first conductive film and the second conductive film are covered with a moisture-proof film.   An inorganic dispersion-type electroluminescent device having a first conductive film, a phosphor layer, and a back electrode in this order, a first moisture-proof film and a second moisture-proof film covering the first conductive film and the front and back electrodes, respectively. An inorganic dispersion comprising: a film; and a conductive film with an insulating layer comprising an electrical insulating layer and a second conductive film provided in this order on the second moisture-proof film side Type electroluminescence display device.   The inorganic dispersed electroluminescence display device according to claim 1, wherein the first conductive film is transparent.   The inorganic dispersed electroluminescence display device according to claim 1, wherein the second conductive film is used while being grounded.

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