JPH0578917B2 - - Google Patents

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a display device in which an excited luminescent material such as a rare earth element or a transition metal element is encapsulated in an aluminum anodic oxide film to produce electric field excited luminescence. More specifically, the present invention relates to a display device having a characteristic in its electric field excitation structure.

``Prior Art'' A luminous element is a luminous element in which a phosphor such as a rare earth element such as eurobium or terbium is activated and encapsulated in a porous film obtained by anodizing a high-purity aluminum plate or foil. , was previously proposed by the applicant of the present application in JP-A-60-182689 and JP-A-60-205989. As a means of activating and encapsulating a phosphor in a porous film formed by anodizing, the porous film is immersed in a phosphor salt solution such as a europium salt solution or a terbium salt solution, and then re-anodized. method can be adopted. In such a method, in order to prevent the phosphor sealed in the porous film from leaking out, the pores filled with the phosphor are sealed, and the fluorescent material inside the pores of the porous film is sealed. In order to increase the amount of encapsulation and stability, it is also possible to perform a secondary anodic oxidation treatment at a lower voltage after the first anodization treatment step to form even finer encapsulation holes at the bottom of each hole.

In addition to ultraviolet rays or electron beams, electric field excitation means or the like can be used as a means for excitation of luminescence of such a luminescent element. In the case of electric field excitation means, for example, a high purity aluminum plate 2A as shown in FIG. As described above, a so-called Nesa glass 4 having a transparent electrode 5A formed thereon is arranged on the film 3 of the light-emitting element 1 having a porous light-emitting film 3 in which a fluorescent material is encapsulated, and a gap between the aluminum plate 2A and the transparent electrode 5A is arranged. By applying an alternating current voltage E to the phosphor, it is possible to emit light in, for example, orange, red, or yellow-green depending on the type of activated encapsulated phosphor.

"Problems to be Solved by the Invention" When constructing a display device using such a light emitting element, if the transparent electrode 5A is simply formed in close contact with the porous light emitting film 3 as described above, the transparent electrode 5A Since abnormal discharge occurs between the light-emitting film 3 and the light-emitting film 3, causing dielectric breakdown of the film 3, the light-emitting element 1 is destroyed in a short period of time, making it extremely difficult to expect stable light-emitting operation. The problem is that the brightness is also low. Further, such a display device has the disadvantage that characters, symbols, figures, etc. to be displayed are greatly restricted due to the structure of the uniform transparent electrode 5A.

"Means for Solving the Problems" Therefore, the present invention provides a display device in which a transparent electrode is provided on a luminescent element in which an excited luminescent material is enclosed in an aluminum anodic oxide film. The electrode and the transparent electrode are arranged in a mutual matrix electrode structure, and insulating spacers forming a number of display gaps corresponding to the matrix electrode structure are provided between the light emitting element and the transparent electrode. The object of the present invention is to provide a display device capable of displaying arbitrary light emission such as characters, symbols, or figures by selectively applying an excitation voltage to a matrix electrode. A structure may also be adopted in which an insulating resin such as phenolic resin is filled between the strip electrodes to be provided on the light emitting element side in order to increase the mechanical strength of the light emitting element.

``Example'' Hereinafter, the present invention will be described in further detail according to the illustrated embodiment. In FIGS. 1 to 3, the same reference numerals as in FIG. A large number of narrow band-shaped electrodes 2 are provided on the back surface of the porous light-emitting coating 3 of the body element 1, and the transparent electrodes 5 on the side of the Nesa glass 4 are also provided in a large number of band-shaped electrodes perpendicular to the band-shaped electrodes 2 as shown in the figure. The two electrodes 2 and 5 constitute a mutual matrix electrode structure. Reference numeral 7 denotes an insulating spacer interposed between the porous power generation wide coating 3 and the transparent electrode 5, in which a large number of display gaps 6 formed corresponding to the matrix electrode structure are arranged. be. The gap between the porous luminescent film 3 and the transparent electrode 5 formed by each display gap 6, and thus the thickness of the spacer 7, can be from several μm to several tens of μm, for example, from 2 to 19 μm, preferably from 5 μm to 5 μm. It can be set to about 18 μm. Such a spacer 7 is not limited to the method of constructing it separately as in this example, but can be formed by, for example, an insulating metal oxide film such as aluminum oxide or titanium oxide by sputtering, or an insulating polymer by screen printing or photolithography. It is also possible to form a film or the like directly on the porous luminescent coating 3.

The luminescent material to be enclosed in the porous luminescent film 3 is not limited to the rare earth elements mentioned above, but may include Mn,
One or two of transition element metals such as Co, Zn, or Ce, or an alloy thereof can be used as appropriate, and the encapsulation means include the above-mentioned electrochemical method, as well as direct injection into the porous film. A method of injecting the above-mentioned luminescent material by ion implantation is also suitable. Such a porous luminescent coating 3 can be peeled off from an aluminum plate as a base material by a reverse electrolytic method.

FIG. 2 shows an example of a method of forming the band-shaped electrode 2 provided on the light emitting element 1. This method involves applying a large number of resist materials 8 for etching on the aluminum plate 2A side of the light emitting element 1 constructed in the conventional manner. Etching can be carried out using an aqueous mercuric chloride solution, a methanol solution of bromine, or an anhydrous ether solution of hydrogen chloride, which can dissolve only the aluminum plate 2A without dissolving the porous luminescent coating 3 in this strip-shaped state. . In addition, as described above, the porous luminescent coating 3
If a peeled one is used, the strip-shaped electrode 2 can be appropriately formed thereon alone.

In such a display device, selective contact is made between the strip-shaped electrodes 2 and 5 constituting the matrix electrode.
By applying an AC voltage of about 280V to 380V, it is possible to display any characters, symbols, or figures in a matrix manner through the display gap 6 of the spacer 7. It becomes possible to maintain stable and uniform high-intensity light emitting display operation while suitably preventing the occurrence of such abnormal discharges.

As shown in FIG. 3, between the strip electrodes 2 on the side of the light emitting element 1, an insulating resin 9 such as a phenolic resin having a coefficient of thermal expansion equal to or close to that of the electrode material made of aluminum or the like is filled. Light emitter element 1
It is also preferable to configure the structure to increase the mechanical strength of the material. This type of electroluminescent display device using the porous light emitting film 3 has the following features in addition to the matrix display using the matrix electrode structure and the spacer 7:
A spacer 7 made of an insulating film and formed by punching out characters 6A, 6B, etc. as illustrated in FIG. 4 is provided between the porous luminescent coating 3 of the luminous element 1 shown in FIG. It is also suitable to interpose a luminescent display of a specific character, etc., but in such a display device, it is necessary to punch out the shape of the character, symbol, figure, etc. to be displayed on the spacer in advance. Compared to the present invention, which allows arbitrary matrix light-emitting display to be performed using a single spacer, display contents tend to be restricted. Therefore, the present invention is extremely advantageous in that it provides any matrix light emitting display function without changing the spacer.

"Effects of the Invention" As explained above, the display device of the present invention is an electric field excitation light emitting display device using a porous light emitting film in which a luminescent material is enclosed in an aluminum anodic oxide film. Since the electrodes for electric field excitation are formed in a matrix structure and the spacer is provided with a large number of gaps for light emitting display corresponding to the matrix electrodes, any matrix light emitting display can be performed using a single spacer. This allows the display function to be suitably enhanced. Further, in such a light emitting display operation, it is possible to suitably prevent the occurrence of abnormal discharge as in the conventional case, maintain a stable and uniform high luminance light emitting display operation, and provide a highly durable display device.

[Brief explanation of the drawing]

FIG. 1 is a conceptual exploded perspective view of a display device according to an embodiment of the present invention, FIG. 2 is a diagram illustrating a method of forming a strip electrode on the light emitting element of FIG. 1, and FIG. , a conceptual partial cross-sectional configuration diagram of a display device in which an insulating resin is filled between the strip electrodes of the light-emitting element in the display device shown in FIG. 1, and FIG. FIG. 5 is a conceptual partial cross-sectional configuration diagram of a conventional display device using a porous light emitting film. 1: Luminous element, 2A: Aluminum plate, 2:
Band-shaped electrode, 3: Porous luminescent film, 4: Nesa glass, 5: Transparent strip-shaped electrode, 6: Display gap,
7: Insulating spacer, 9: Insulating resin.

Claims (1)

[Scope of Claims] 1. In a display device in which a transparent electrode is provided on a luminescent element in which an excited luminescent material is enclosed in an aluminum anodic oxide film, the electrode of the luminescent element and the transparent electrode are mutually connected. A display device characterized in that the display device is configured to have a matrix electrode structure, and insulating spacers forming a large number of display gaps corresponding to the matrix electrode structure are provided between the light emitting element and the transparent electrode. . 2. The display device according to claim 1, wherein an insulating resin is provided between the strip electrodes of the light emitting element.