JPS5923436B2 - Method of manufacturing an electroluminescent lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electroluminescent lamp, and more particularly to a method for manufacturing an electroluminescent lamp with uniform voltage resistance characteristics in which electrode spacing is regulated.

Conventionally, an electroluminescent lamp having a structure in which a light emitter layer or an insulator layer is sandwiched between a pair of electrodes has, for example, a front electrode layer of a transparent conductive film, a light emitter layer, an insulator layer, Ag paste, etc. on a transparent insulating substrate. A structure in which a back electrode layer and a protective layer made of a resin material are sequentially laminated is manufactured. However, these phosphor layers and insulator layers are usually formed by coating a transparent conductive film on an insulating substrate with a coating solution in which phosphor powder or high dielectric particles are suspended in a solution of a polymeric organic material as a binder. Although it can be obtained by laminating and depositing the film by spraying or screen printing, it has been difficult to form a film with a constant thickness. For this reason, there were drawbacks such as variations in the voltage resistance characteristics of the product9 and poor voltage resistance. In particular, in small electroluminescent lamps that operate on pulse drive from a battery power source, the luminescent layer and insulator layer are made of extremely thin films (~20 μm) in order to keep the operating voltage as low as possible.
However, in the conventional method described above, the light emitter layer and the insulator layer themselves have an irregular uneven shape.
It has the disadvantage that it is difficult to form a thin film and is prone to voltage breakdown defects and short-circuit defects. The present invention was proposed in view of the above, and in addition to regulating the electrode spacing to a constant spacing,
Provided is a manufacturing method that stably supplies an electroluminescent lamp with extremely low operating voltage by reducing the electrode spacing.

The method of the present invention employs a free-standing phosphor layer in which phosphor powder is dispersed in a thermoplastic resin material and softens upon heating.

This luminescent layer is then applied to a hot press machine, and the luminescent layer is pressed and deformed using an electrode body or an electrode jig having uneven portions, and the thickness of the resulting concave portions of the luminescent layer becomes a predetermined electrode spacing. It is regulated as follows. Next, an outline of the present invention will be described.

First, the phosphor layer is obtained by thoroughly kneading a phosphor powder of, for example, zinc sulfide and a thermoplastic resin powder of high dielectric vinylidene fluoride, and then hot-rolling the mixture to eliminate most pinholes and pores. It is in the form of a thin film sheet that does not contain any substances. This luminescent layer itself has sufficient elastic modulus and rigidity, and can be freely handled. However, it is difficult to form the self-supporting light emitter layer formed in this way to be thin enough (for example, 20 μm or less) to be used as it is in an electroluminescent lamp. Furthermore, even if formed into a thin film, it is easily damaged and difficult to handle in the manufacturing process. Therefore, the luminescent layer having such a structure is applied to a hot press machine and heated and formed using an electrode jig or an electrode body having uneven portions. Therefore, the luminescent layer is pressed and shaped into a certain shape by the convex portions of these electrode jigs or electrode bodies, and the thickness of the luminescent layer in the pressed concave portions, that is, the electrode spacing, is constant, resulting in uniform pressure characteristics. An electroluminescent lamp can be obtained. Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a luminescent layer 1 that is softened by heating press used in the present invention, in which a fluorescent powder 1a is made of a transparent thermoplastic resin material 1.
It is distributed in 6. To manufacture the luminescent layer 1 having such a structure, for example, 50% by volume of the transparent thermoplastic resin material 16 powder of vinylidene fluoride is thoroughly mixed with the phosphor powder 1a of zinc sulfide, and this kneaded product is prepared. This is rolled by a roll heated to a high temperature using a calendar molding machine to obtain a sheet-like luminescent material layer having a relatively uniform thickness of about 50 to 100 μm. Then, the phosphor powder 1a is uniformly embedded in the thermoplastic resin material 1b, resulting in a phosphor layer 1 with a smooth surface containing almost no pores or pinholes. Since the light emitting layer 1 is a relatively thick and flexible thin film layer having sufficient elastic modulus and rigidity, it can be easily handled by itself. Next, as shown in FIG. 2, the light emitting layer 1 is
Both surfaces are placed in a high-temperature press 2 to form electrode surfaces. ″
Heat molded so that the spacing between the surfaces is constant. That is, the high-temperature press machine 2 includes an upper mold 3 and a lower mold 4, and is equipped with a heating mechanism and a hydraulic mechanism (not shown) to maintain the mold temperature at a predetermined temperature and to keep the upper mold 3 at a predetermined temperature. It is designed so that it can be moved up and down to pressure mold the light emitting layer 1. A jig 5 in which a large number of protrusions of a certain height (indicated by symbol A) are formed is placed on the lower mold 4 of the high-temperature press machine 2, and a press thickness (indicated by symbol A) is placed on this jig 5. A light-emitting layer 1 formed to be slightly thicker is set as shown in FIG. Then, the upper mold 3 is lowered as shown by the arrow while being heated to a temperature of about 200° C. at which the luminescent layer 1 can be softened. Then, the luminescent layer 1 is pressed by the upper mold 3, and the lower surface side of the luminescent layer 1 is pressed and deformed by the protrusions 6 of the jig 5, and an uneven surface 7 corresponding to the protrusions 6 of the jig 5 is formed. Ru. Therefore, the distance C between the flat surface 8 pressed by the upper mold 3 on the upper surface side of the light emitting layer 1 and the uneven surface 7 on the lower surface side pressed and shaped by the jig 5 is determined by the press thickness B and the jig. The difference in height A of the protrusions of No. 5 (as shown by symbol C-B-A) is formed at regular intervals. Further, this interval C can be freely set by changing the height A of the protrusion of the jig 5. Next, the light emitter layer 1 formed with a constant interval C has its uneven surface 7
After that, a back electrode 9 of a conductive layer such as an Al deposited film or Ag paste was formed using a vacuum deposition method or a screen printing method, and finally a transparent conductive film 10 was formed on the resin as shown in FIG. After the film 11 is placed on the flat surface 8 of the light-emitting layer 1, it is sandwiched between double-sided plastic outer skins 12 and 13 and bonded under heat and pressure to obtain an electroluminescent lamp 14.

Note that the shape of the protrusions 6 of the jig 5 can be freely chosen, such as slit-like or island-like, but the spacing between adjacent protrusions 6 should be approximately equal to the spacing C of the light-emitting layer 1 or within several times at most. It is desirable to do so. FIG. 4 shows another embodiment of the present invention, an electroluminescent lamp in which a metal ball-shaped electrode body 15 is implanted into a light-emitting layer 1 with its end face exposed, which is manufactured in the same manner as in the above embodiment. An assembly 16 is shown.

The assembly part 16 having such a structure can be freely adjusted by changing the distance C between the light emitting layers 1 and the size A of the metal balls of the electrode body 15 using the high temperature press 2 in the same manner as in the above embodiment. It can be set to . In this case, since the electrode body 15 is used to press and deform the luminescent layer 1, there is no need for a molding jig 5 or for forming electrodes to be adhered to the uneven surface 7 of the luminescent layer 1. Therefore, the exposed surface of the electrode body 15 of the assembly part 16 is coated with Ag paste to connect the electrode body 15, and a transparent conductive film is formed on the other surface in the same manner as in the previous example to create an electric field with a regulated electrode spacing. You can get a luminous lamp. FIG. 5 shows still another embodiment of the present invention, which is an assembly of an electroluminescent lamp in which an electrode body 17 having a step is implanted into a light emitting layer 1 manufactured in the same manner as in the above embodiment with its end surface exposed. Part 18 is shown.

In the electrode body 17, a plurality of convex portions 19 are combined to form a display portion for displaying, for example, characters or figures, and concave portions 20 constitute segment electrodes forming respective lead portions. In the assembly part 18 having such a structure, the distance C between the light emitting layers 1 can be freely set by changing the height A of the convex portion 19 of the electrode body 17, in the same way as in the previous embodiment. As described above, the present invention uses a hot press machine to press a self-supporting relatively thick luminescent layer that softens upon heating with an electrode jig or an electrode body having uneven parts. Since the surface of the luminescent layer is deformed to form an uneven surface that corresponds to the electrode jig or electrode body, the electrode spacing is regulated, uniform voltage resistance characteristics and low voltage driving are achieved, resulting in electroluminescence with excellent characteristics. You can get light.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a light-emitting layer used in the electroluminescent lamp of the present invention, FIG. The figure is a cross-sectional view of a main part of an electroluminescent lamp for explaining the method of the present invention, FIG. FIG. 7 is a cross-sectional view of a main part of an assembly of an electroluminescent lamp according to yet another embodiment. DESCRIPTION OF SYMBOLS 1... Luminescent layer, 1a... Fluorescent powder, 1b... Thermoplastic resin material, 2... Heat press machine, 7... ...Uneven surface, 9, 15, 17...
... Electrode body, 12, 13 ... Resin outer cover, 1
4...Electroluminescent lamp.

Claims (1)

[Claims] 1. In an electroluminescent lamp in which an electrode body is attached to both sides of a self-supporting luminescent layer made of a thermoplastic resin material with phosphor powder dispersed therein, and both outer surfaces of the electrode body are further covered with a resin jacket, the above-mentioned A method for manufacturing an electroluminescent lamp, comprising forming an uneven surface on one surface of a light emitting layer by hot pressing.