JPS62128485A - 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 particularly, the present invention relates to a display device characterized by 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 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 Publication No. 1986-
This was proposed in JP-A No. 182689 and JP-A-60-20!5969. 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, etc. 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. 7, 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 8ii5 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 luminance is low.

``Means for Solving the Problems'' Therefore, the present invention provides an insulating film between the above-described luminescent element in which an excited luminescent material is encapsulated in an aluminum anodic oxide film and a transparent electrode provided on the element. Several μm to several tens of μm with an insulating polymer film or insulating metal oxide film interposed
The present invention provides a display device configured to achieve stable light emission operation and improvement in light emission brightness by forming a gap of m. Such a gap is formed by the above-mentioned inclusions according to the required characters, symbols, figures, etc. necessary for the display device, and the existence of this gap prevents the conventional abnormal discharge between the porous luminescent film and the transparent electrode. can be prevented and good light emission operation can be performed.

"Embodiments" Hereinafter, the present invention will be described in further detail based on the illustrated embodiments. In FIGS. 1 to 6, the same reference numerals as in FIG. 7 indicate the same components, and FIG. As shown in FIG. 2, a required gap 6 is formed between the porous light emitting film 3 and the transparent electrode 5. The relationship between the gap 6 and brightness is as shown in Figure 2, where the horizontal axis is the gap G (μK) and the vertical axis is the brightness B (cd/m"). The gap range can be set to about 2 to 19 μm, preferably about 5 to 18 μm.

Such a gap can be constructed, for example, by interposing an insulating film 7 such as a polyester film between the porous luminescent coating 3 and the transparent electrode 5 to provide a gap 8 within the above range, as shown in FIG. This gap 8 can be obtained, for example, by punching and forming an insulating film 7 on letters 8A, 8B such as M, N, etc., as shown in FIG.

Instead of interposing the insulating film 7, an insulating metal oxide film 9 such as aluminum oxide or titanium oxide is coated on the porous light emitting film 3 of the light emitting element 1 by sputtering or the like to a thickness of several μm or more as described above. Letter 8A was applied to a thickness of several tens of micrometers in the same manner as above.

It is also possible to configure a gap such as 8B to remain.

Similarly, such an insulating metal oxide film 9 can also be formed of an insulating polymer film formed by screen printing, photolithography, or the like. Note that the transparent electrodes to be formed on the Nesa glass 4 corresponding to the shapes of the gaps 8 such as the letters 8A and 8B as described above are also 5A as shown in FIG.

5B can be formed as appropriate. In the display device including the gap formed in the above manner,
When an alternating current voltage E of, for example, about 280 V to 380 V is applied, it is possible to suitably prevent the occurrence of abnormal discharge as in the conventional case, and it is possible to stably maintain uniform and high-intensity light emission.

The luminescent material to be enclosed in the porous luminescent film 3 is not limited to the rare earth elements mentioned above, but may be Mn1C.

One or two transition element metals such as Zn or Ce, or an alloy thereof can be used as appropriate, and the encapsulation means include the electrochemical method described above, as well as ion implantation directly into the porous film. A method of injecting a luminescent material as described above 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 according to the present invention encapsulates a light emitting body and forms a required gap between a photoporous light emitting film and a transparent electrode, and utilizes the gap to display characters and symbols. Or, since the structure is configured to perform a desired electroluminescence operation such as a figure, it is possible to suitably prevent dielectric breakdown of the porous luminescent film due to abnormal discharge as in the conventional case, and achieve stable and uniform high-intensity luminescence operation. It can be achieved. Therefore, it is possible to perform a stable display function for a long period of time.

[Brief explanation of drawings]

FIG. 1 is a conceptual partially enlarged cross-sectional configuration diagram of a display device in which a gap is provided between a porous light-emitting film and a transparent electrode according to the present invention, and FIG. 2 shows the gap and luminance of FIG. 1. Figure 3 is a partially enlarged cross-sectional view similar to the above when the gap is formed of an insulating film, and Figure 4 is a graph showing the relationship between the gap and the gap formed by punching out letters on the insulating film. FIG. 5 is a conceptual diagram of a light-emitting element showing an embodiment in which an insulating metal oxide film or polymer film is deposited on a porous light-emitting film to form a required display gap. FIG. 6 is a diagram showing an example in which the transparent electrode on the Nesa glass side is configured to correspond to the shape of the display gap, and FIG. 7 is a conceptual cross-sectional diagram of a conventional display device. be. E: Luminous element 2 @ Aluminum plate 3 ° Porous luminescent coating 4 ゛ Nesa glass 5 ° Transparent electrode 6.8:
Display gap 7 ° Insulating film 9 - Insulating gold M oxide film or polymer film Figure 1 Figure 2 G (, um) $ 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (5)

[Claims] (1) A display device configured to include a luminescent element in which an excited luminescent material is enclosed in an aluminum anodic oxide film, and means for forming a gap between a transparent electrode provided on the luminescent element. (2) The display device according to claim (1), wherein the gap is formed by interposing an insulating film. (3) The display device according to claim (1), wherein the gap is formed by interposing an insulating metal oxide film. (4) The display device according to claim (1), wherein the gap is formed by interposing an insulating polymer film. (5) The display device according to any one of claims (1) to (4), wherein the gap is configured to be several μm to several tens of μm.