JPS62128487A - Display apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" 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 enclosed in an aluminum anodic oxide film to produce electric field excited luminescence. More specifically, the present invention relates to a display device having an improved 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 europium or terbium is activated and sealed in a porous film obtained by anodizing a high-purity aluminum plate or foil. , the applicant of the present application first filed Japanese Patent Application Laid-Open No. 1986-
This was proposed in Japanese Patent Application Laid-open No. 182689 and Japanese Patent Application Laid-open No. 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 light-emitting element.
In the case of an electric field excitation means, as shown in FIG. 3, a transparent electrode is placed on a luminescent element 1 having a porous luminescent coating 3 in which a phosphor is encapsulated in a high-purity aluminum plate 2 as described above. By arranging the so-called Nesa glass 4 formed with 5 and applying an alternating current voltage E between the aluminum plate 2 and the transparent electrode 5, a color such as orange, red, yellow-green, etc., depending on the type of activated encapsulated phosphor, is formed. The light emitting operation can be performed.

"Problems to be Solved by the Invention" When constructing a display device using such a light emitting element, if the transparent electrode 5 is simply formed in close contact with the porous light emitting film 3 as described above, the transparent electrode 5 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.

"Means for Solving the Problems" The present invention has been made in consideration of the above circumstances, and for this reason, in the present invention, a display layer is provided between the porous light-emitting coating of the light-emitting element and the transparent electrode. The gap is provided so as to suitably prevent dielectric breakdown of the film due to abnormal discharge as described above, while continuing stable and uniform high-intensity light emitting operation. A protective film is provided on the electrode surface to prevent deterioration of the transparent electrode due to ion collisions associated with luminescent discharge, thereby providing a display device with a long life.

``Example'' Hereinafter, the present invention will be further explained with reference to the drawings. In FIGS. 1 and 2, the same reference numerals as in FIG. 3 represent the same components, and 7 represents the display gap 8. It is an insulating film to be formed between the porous light emitting film 3 and the transparent electrode 5, and 6 indicates a protective film deposited on the surface of the transparent electrode 50.

The insulating film 7 is made of an insulating film, such as a polyester film, having a thickness that allows the required display gap 8 to be formed, and is coated with desired gap characters 8A, 8B, etc. such as <M, N, etc., as shown in FIG. This can be formed by punching out and interposed therein like a spacer in the above manner. Instead of such a separate spacer structure, the insulating film 7 can be composed of an insulating metal oxide film such as aluminum oxide or titanium oxide that is directly deposited on the porous light emitting film 3 by sputtering or the like. An insulating polymer film formed by screen printing, 7# trithography, or the like may be used. The protective film 6 for preventing deterioration of the transparent electrode 5 can be composed of an insulating metal oxide film such as titanium oxide or aluminum oxide, and may be provided uniformly on the transparent electrode 5 as shown in the figure or in the display gap. 8 may be provided in the area corresponding to the shape shown in FIG. 2, for example. Of course, such a transparent electrode 5 has a gap character shape 8A as shown in FIG.

It is possible to adopt an electrode pattern of any shape that matches 8B, and in this case, the protective film 6 will be formed according to the electrode pattern.

Although the display gap 8 depends on the thickness of the insulating film 7, it can be set in the range of several micrometers to several tens of micrometers, for example, in the range of 2 to 19 micrometers, preferably in the range of 5 to 18 micrometers. In the display device having the display gap 8 formed in the above manner, when an AC voltage E of about 280 to 380 V, for example, is applied, uniform and high-intensity light emission can be achieved while suitably preventing the occurrence of abnormal discharge as in the conventional case. In addition, collisions of ions against the transparent electrode 5 due to the luminescent discharge operation within the display gap 8 are well prevented by the protective wlI film 6, and therefore, the transparent electrode 5 due to the electroluminescent display operation is
This means that the problem of deterioration can be solved suitably.

In addition to forming the display gap 8 with the interposition of the insulating film 7 as described above, it is also possible to form the display gap 8 in any gap pattern by directly digging down the porous light emitting film 3.

The light-emitting body to be enclosed in the porous light-emitting film 3 is not limited to the above-mentioned rare earth elements, but may be M n .

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 electrochemical method as described above, 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 light emitting film 3 can be peeled off from the aluminum plate 2 as a base material by a reverse electrolytic method.

"Effects of the Invention" As described above, the display device of the present invention forms a display gap between a light emitting element and a transparent electrode, and at the same time provides a protective film on the transparent electrode surface in this display gap region. Since the structure is configured as follows, it is possible to suitably prevent the occurrence of abnormal discharge as in the conventional case, and stably maintain a uniform and high-intensity light emitting operation. Since the collision of ions against the transparent electrode during the light emitting discharge operation performed within the display gap can be suitably prevented by the protective film formed on the electrode, deterioration of the transparent electrode can be prevented and long-life light emission can be achieved. The display function can be maintained.

[Brief explanation of drawings]

FIG. 1 is a conceptual partially enlarged sectional configuration diagram of a display device according to an embodiment of the present invention, FIG. 2 is a diagram illustrating means for forming a display gap, and FIG. 3 is a diagram illustrating a conventional structure. FIG. 3 is a similar partially enlarged cross-sectional configuration diagram of a display device. 1: Luminous element 2: Aluminum plate 3: Porous luminescent film 4: Nesa glass 5: Transparent electrode 6: Electrode protective film 7: Insulating film 8: Display gap

Claims (1)

[Claims] In a display device in which a transparent electrode is provided on a light-emitting element in which an excited light-emitting material is enclosed in an aluminum anodic oxide film, a display gap is provided between the light-emitting element and the transparent electrode, and at least the gap is A display device characterized in that a protective film is formed on the transparent electrode surface of the region.