JPH06203956A - Manufacture of dispersion type electroluminescent element - Google Patents

Abstract

PURPOSE:To provide a dispersion type electroluminescent element having a long life and small power consumption even when a large luminance gradient is given thereto by providing an optional luminance gradient in a light emitting part at segment and pattern emission. CONSTITUTION:In a dispersion type electroluminescent element (EL) consisting of a moisture-proof layer 1, a water supply layer 2, a transparent electrode layer 3, a light emitting layer 4, a back plate layer 5, and a reflecting insulating layer 6, an optional luminance gradient is provided on a light emitting part at segment and pattern emission. Thus, the luminance gradient can be given without shortening the life nor increasing the power consumption. The optional luminance gradient is preferably provided on the light emitting part by etching or coating the electrode 3 or the electrode 5 to give a field strength difference between both electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a dispersion type electroluminescence device (hereinafter referred to as "EL").

[0002]

2. Description of the Related Art Current EL is, as shown in FIG. 1, an aluminum foil of a back electrode layer 5 in which an aluminum foil having a thickness of 100 μ is laminated with an aluminum foil having a thickness of 30 μ and sodium hydroxide is used as shown in FIG. Water is etched with a 1: 1 weight ratio solution, and barium titanate or the like is dispersed in an organic binder at a 1: 4 weight ratio to form a paint, which is applied by screen printing to a dry film thickness of 25μ. And 80 ℃
The coating is prepared by drying in a drying oven at ˜90 ° C. for 3 hours to form a reflective insulating layer 6, on which a phosphor such as zinc sulfide activated with copper is dispersed in an organic binder in a weight ratio of 1: 3. And apply this to a dry film thickness of 60μ by screen printing.
The light emitting layer 4 is laminated and formed by drying in a drying oven at a temperature of 100 ° C to 100 ° C for 24 hours, and then the transparent electrode layer 3 and the light emitting layer 4 are superposed and thermocompression-bonded by a heat roller at 170 ° C. The product is wrapped in the moisture-proof layer 1 from above and below and thermocompression-bonded with a heat roller at 130 ° C. to obtain a product. In FIG. 1, 2 is a water replenishing layer and 6 is a reflective insulating layer. In FIG. 2, 7 is a terminal and 8 is a character light emitting part.

The EL having the above-mentioned structure is characterized in that the luminance surface is uniform in light emission, and the degree of unevenness in luminance is within ± 5%. If further unevenness in luminance occurs, heat is generated in the power supply section of the EL. Since there is a problem that the element is destroyed by the high temperature heat that is generated, it is important to improve the quality of the product by configuring so as not to cause the uneven brightness.

On the other hand, as one application of the EL, there is a case where a product in which the visibility is improved by providing an arbitrary brightness gradient in the light emitting portion at the time of segment and pattern light emission.

[0005]

However, the above-mentioned conventional E
In L, if a brightness gradient is provided to improve visibility, heat generation shortens the life of the EL, and power consumption increases, which is not practical.

On the other hand, there are many demands for products having a large brightness gradient as means for improving the visibility.

It is an object of the present invention to provide a method for manufacturing an EL which has a brightness gradient and is improved in visibility without shortening the life or increasing the power consumption.

[0008]

The method of manufacturing an EL according to the present invention is as follows.

1. A method for manufacturing a dispersive electroluminescent device, characterized in that in a dispersive electroluminescent device comprising at least a transparent electrode, a light emitting layer, a reflective insulating layer and a back electrode, an arbitrary brightness gradient is provided in a light emitting portion during segment and pattern light emission. .

2. As a means for providing the brightness gradient, the transparent electrode or the back electrode may be etched to provide a difference in electric field strength between the two electrodes to provide an arbitrary brightness gradient in the light emitting portion. The back electrode may be coated to provide a difference in electric field strength between the two electrodes to provide an arbitrary brightness gradient in the light emitting portion.

[0011]

The present invention will be described in more detail with reference to the following examples.

Example 1 (Etching method) An aluminum foil for a back electrode in which a 30 μm-thick aluminum foil was laminated on a 100 μm-thick polyester film was used as shown in FIGS.
Etching with a solution of 1 gravity ratio, barium titanate or the like dispersed in an organic binder at a ratio of 1: 4 by weight to form a paint, and a material having a dry film thickness of 25μ is applied by screen printing. A reflective insulating layer is formed by drying in a drying oven at 80 ° C to 90 ° C for 3 hours, and a phosphor such as zinc sulfide activated by copper is dispersed in an organic binder at a ratio of 3: 1 by weight. And dry it by screen printing to a film thickness of 60μ
And then dried in a drying oven at 90 ° C. to 100 ° C. for 24 hours to form a laminated light emitting layer.

After that, the transparent electrode film and the light emitting layer are superposed and thermocompression-bonded with a heat roller at 170 ° C., further wrapped with a moisture-proof film from above and below, and thermocompression-bonded with a heat roller at 130 ° C. 1000V, 400Hz for this EL element
Table 1 shows the initial luminance and the contrast inside and outside the light emission shown in FIG.

[0014]

[Table 1]

Next, in order to measure the visibility of the EL element on the photopic brightness and the scotopic brightness, a white light fluorescent lamp was used.
The EL of Example 1 was prepared by making a 0 lx and 5 lx light environment.
Table 2 shows the effect when the device is driven to emit light at 100 V and 400 Hz.

[0016]

[Table 2]

Contrast = bright area brightness-dark area brightness / bright area brightness Contrast light emitting part external to light emitting part internal ratio Contrast 10 lx environment same as above Contrast 10 lx environment light emitting part external to non-light emitting part ratio In FIG. 10 is the inside of the light emitting portion, 11 is a non-electrode portion, and 12 is an electrode portion in FIG.
b = 2: 1 and a = 0.3 mm.

Example 2 (Coating method) On an aluminum foil for a back electrode having a thickness of 100 µ, beads and the like were dispersed in an organic binder in a weight ratio of 1: 3 to form a paint, and the reverse plate of Figs. 2 and 3 was prepared. It is applied by screen printing to a dry film thickness of 50μ, and then dried in a drying oven at 80 ° C to 90 ° C for 3 hours to form an inter-electrode electric field strength difference layer, on which an organic binder barium titanate is formed. And the like are dispersed in a 1: 4 weight ratio to form a paint, and a film thickness of dryness is 2 by screen printing.
It is applied to 5μ and dried in a drying oven at 80 ° C to 90 ° C for 3 hours to form a reflective insulating layer, and a fluorescent substance such as zinc sulfide activated with copper is added to the organic binder in a weight ratio of 1: 3. It is dispersed in a ratio to form a coating material, which is applied by screen printing to a dry film thickness of 60 μm, and then dried in a drying oven at 90 ° C. to 100 ° C. for 24 hours to form a laminated light emitting layer.

After that, the transparent electrode film and the light emitting layer were superposed and thermocompression-bonded with a heat roller at 170 ° C., further wrapped with a moisture-proof film from above and below, and thermocompression-bonded with a heat roller at 130 ° C. Table 3 shows the initial luminance and contrast of the outside and inside of the light emission shown in FIG. 3 when the EL device was driven and emitted at 100 V and 400 Hz.

[0020]

[Table 3]

Next, in order to measure the visibility of the EL element on the photopic luminance and the scotopic luminance, a white fluorescent lamp was used to measure the visibility.
The EL of Example 2 was prepared under a light environment of 0 lx and 5 lx.
Table 4 shows the effect when the device is driven at 100 V and 400 Hz.

[0022]

[Table 4]

Note. 1) lx: looks

[Brief description of drawings]

FIG. 1 is a structural diagram of an EL.

FIG. 2 is an EL light emission pattern diagram.

FIG. 3 is an external internal view of a light emitting unit.

FIG. 4 is an internal electrode diagram of a light emitting unit.

[Explanation of symbols]

 1 Moisture-proof layer 2 Water replenishment layer 3 Transparent electrode layer 4 Light-emitting layer 5 Back electrode layer 6 Reflective insulating layer 7 Lead terminal 8 Character light-emitting part 9 Light-emitting part outside 10 Light-emitting part 11 Non-electrode part 12 Electrode part

Claims (3)

[Claims] 1. A dispersion type electroluminescent device comprising at least a transparent electrode, a light emitting layer, a reflective insulating layer and a back electrode, wherein a desired brightness gradient is provided in a segment and a light emitting part at the time of pattern light emission. Manufacturing method of electroluminescent element. 2. The dispersed electroluminescence according to claim 1, wherein the transparent electrode or the back electrode is etched to provide a difference in electric field strength between the two electrodes to provide an arbitrary brightness gradient in the light emitting portion. Device manufacturing method. 3. The dispersion type electroluminescence according to claim 1, wherein a transparent electrode or a back electrode is coated to provide a difference in electric field strength between the two electrodes to provide an arbitrary brightness gradient in a light emitting portion. Device manufacturing method.