JPS58100173A - Electrochromic display element - 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 The present invention provides an electrochromic display device in which a transparent display substrate is placed on the front side and a background material is provided behind it. The present invention relates to an electrochromic display element having a structure in which fixed patterns such as the above are installed. As is well known, an electrochromic display element is a display element that applies reversible color development, decolorization, or color change phenomenon (electrochromism) accompanying an electrochemical reaction. Although many substances exhibiting electrochromism are known, a substance using WO3 will be explained below as an example. Electrochromic display elements are expected to be put to practical use because they are less dependent on viewing angle than liquid crystal display elements and can provide clearer displays.

Taking advantage of the characteristics of these electrochromic display elements,
In order to enhance the display function and decorativeness, display elements are often used in which fixed patterns such as letters, symbols, or images are arranged to coordinate with the pattern of the display electrodes, and display is performed along with the fixed patterns. . For example, there is a wristwatch with a bone display showing the day of the week as shown in FIG. In Figure 1, the day of the week characters such as Sun, Mon, Tue, etc. are arranged in a fixed pattern, and the necessary day of the week designation is displayed by coloring one of the rectangular display electrodes placed close to each character. specify. The decorativeness can be further enhanced by coloring the day in red, the earth in blue, the other days in black, etc. Conventionally, such fixed patterns have been printed on the outer surface of the display substrate or on the surface of the background material.The specific structure of the latter is disclosed in Japanese Patent Application Laid-Open No. 1002-3. However, these structures have the following disadvantages: when imprinting a fixed pattern on the background material, it is difficult to align the pattern with the pattern on the display substrate; If the background material is something like a porous ceramic plate, using something like a paint as the printing ink will make it difficult to obtain dimensional accuracy due to expansion and contraction. As a result, an unnecessary gap is created between the background material and the display substrate, and air bubbles may enter this gap, or gas released from the adhesive when bonding the display substrate and the back substrate may enter. It is said that when a fixed pattern is printed on the outer surface of a display substrate, parallax will occur due to the thickness of the substrate, and the display quality will deteriorate due to scratches and dirt on the printed pattern. There are drawbacks.

The present invention has been made in order to improve the above-mentioned drawbacks, and an object of the present invention is to provide an electrochromic display element that has no parallax, is easy to align, and has a structure in which the display substrate and the background material are in close contact with each other. Return.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below according to embodiments with reference to the drawings.

FIG. 1 is an explanatory diagram showing the manufacturing process order of an electrochromic display element according to an embodiment of the present invention.

ITO film (Sn0
A transparent conductive film consisting of an In2O3'' film doped with In2O2 is provided (FIG. 1). By etching this transparent conductive film, patterns for display electrodes and their leads are formed (jJ, bell in Figure 2).

Etching methods include wet etching and dry etching, and resists include photoresists and printing resists. In this example, the resist is ER-yo/
Rc (manufactured by Tamura Seisakusho) was screen printed and wet etched using a FeC15 hydrochloric acid solution. Next, as a fixed pattern '3, an inorganic pigment is mixed with a frit made by pasting low-melting glass powder with a solvent, such as ts-OJl, 3C manufactured by Nippon Electric Glass Co., Ltd., and screen-printed (see Fig. 2 (C).
)).

Inorganic pigments include the following, and multicolor printing can be performed if necessary.

Red: Gunmetal, mixture of selenium oxide and iron oxide, red lead.

Cadmium red yellow Antimony dioxide, barium yellow, cadmium yellow Green: Chrome Oshi side green Blue: Cobalt pull - Purple: Mixture of gunmetal and cobalt oxide, cobalt violet Black: Iron black Next display Protects the transparent conductive film on the lead part of the heavy box In order to do this, 5i02 is provided as an insulating film by CVD on the entire surface of the display substrate (FIG. 1(D)). At this time, the display substrate is heated to about 50° C., so the previously printed frit and pigment shield are fused to the substrate. Next, a lift-off resist is provided on the insulating film in the lead portion of the display electrode (FIG. 1(E)).

Bunny Height S (manufactured by Nippon Graphite Industries) was used as the lift-off resist. After baking this lift-off resist j, the insulating film on the display area is dry etched using CF and gas to expose the transparent conductive film (FIG. 2(F)). On top of this, WO3 is vacuum-deposited as an electrochromic layer (Fig. 1 (G)), and this is immersed in dilute hydrochloric acid to remove the lift-off resist j and the WO3 thereon to obtain the desired display substrate (second Figure (H)).

In the manufacturing process of the display substrate mentioned above, it is necessary to perform printing three times in total: printing a resist for etching the transparent conductive film, printing a fixed pattern using a mixture of frit and pigment, and printing a resist for lift-off. For these mutual alignments, the accuracy can be easily maintained by using the same jig.

A dish-shaped glass plate as a rear substrate 2 is bonded to the manufactured display substrate using an adhesive r. At this time, a flexible sheet-like background material 2 and a counter electrode IO are enclosed in the internal space. As the background material 2, a material in which a pigment is embedded in a porous fluororesin sheet, such as Fluorobor (manufactured by Sumitomo Electric), is used. The reason for embedding the pigment is that fluororesin alone is insufficient in whiteness, hiding rate, etc. as a background. By changing the pigment, it is possible to create a colored background other than white. By using a flexible sheet-like material as the background material, the display substrate and background material can be brought into close contact even if there is a bulge in the fixed pattern of frit provided on the display substrate, and air bubbles can be prevented between them. In addition to preventing the intrusion of the electrochromic layer, it also acts as a gasket against the gas generated when the adhesive ♂ is cured, thereby preventing deterioration of the electrochromic layer. Counter electrode t
n and t-1, a mixture of Mn0p and graphite powder and pressure molded into a sheet shape is used. Finally, as an electrolyte/
A solution of M-LiC No. 04 and butyrolactone is injected under vacuum, impregnated into the porous background material 2, and the injection port is sealed, thereby producing the electrochromic display element shown in FIG. 1 (1).

In the above example, the fixed pattern 3 was printed after forming the transparent conductive film, but the invention is not necessarily limited to this, and it may be printed before forming the transparent conductive film. You can print it later. It is clear that the effects of the present invention are not impaired in either case.

As explained in detail above, according to the present invention, parallax does not occur between the fixed pattern and the display electrode in an electrochromic display element having a fixed pattern of characters, symbols, images, etc. for enhancing display function decoration. Furthermore, a display device having a good display effect in which the background material and the display substrate are in close contact can be obtained.

[Brief explanation of the drawing]

Figure 7 is a plan view illustrating the basic configuration of an electrochromic display element having a fixed pattern. FIG. 1 is a cross-sectional configuration diagram showing an electrochromic display element according to an embodiment of the present invention in the order of manufacturing steps. K...Front substrate, J...Transparent conductive film, 3: Fixed pattern, D...Insulating film, 5: Lift-off resist,
N...electrochromic layer, 7...rear substrate,
g...adhesive, glue...background material, IO...counter electrode. Agent Patent Attorney Aihiko Fukushi Figure 1

Claims (1)

[Claims] 1. A fixed pattern is printed on the inner surface of a display substrate in parallel with an electrochromic layer, and a sheet-like flexible member is brought into close contact with the contact surface of the substrate to serve as a background material. Characteristic electrochromic display elements. 2. The electrochromic display element according to claim 1, wherein the fixed pattern is formed by printing a frit containing a pigment. 3. The electrochromic display element according to claim 1, wherein the flexible member is a fluororesin with a pigment embedded therein. 4. The electrochromic display element according to claim 1 or 3, wherein the flexible member is impregnated with an electrolytic solution of the electrochromic layer.