JPS6332167B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device, and an object of the present invention is to provide a highly reliable ECD that can withstand a wide range of operating temperatures.

In recent years, electrochromic materials (hereinafter referred to as EC materials) are used to reversibly display arbitrary characters, symbols, patterns, etc. by changing colors through electrical control using patterned display electrodes. Research on electronic display devices (hereinafter referred to as ECDs) is becoming more active.

For example, using transition metal oxides as EC materials
ECDs generally have a cell structure in which an electrolyte is held in a sandwich-like structure by a display electrode in which an EC material is patterned on a transparent electrode such as In ₂ O ₃ or SnO ₂ provided on a transparent substrate, and a counter electrode. Then, a DC voltage is applied between the display electrode and the counter electrode, and electricity is applied to the EC layer to cause coloring or decolorization, thereby making it possible to display a pattern. There are two types of electrolytes that make up the ECD: solid electrolytes and liquid electrolytes, and liquid electrolytes are generally used because they have excellent response characteristics when erasing a display.

Conventionally, liquid electrolytes include aqueous solutions and organic solvents, such as nonpolar solvents such as propylene carbonate, γ-butyllactone, and dimethylformamide, but each system has the following drawbacks. In other words, due to the expansion of the electrolyte as the temperature rises (for example, in the case of propylene carbonate, the volume expands by 1.04 times at 75°C when 20°C is 1), the internal pressure of the cell increases and the cell seal or Liquid leakage occurred from the liquid injection sealing part, or the cell itself was damaged, and the operating temperature range of the ECD cell was limited to around +50°C in the high temperature range.

The present invention eliminates such drawbacks and provides a method for manufacturing an ECD that does not cause liquid leakage or cell damage even when used at higher temperatures than conventional ones, for example, about 90°C. .

The present invention will be described below with reference to the drawings and embodiments.

The figure is a cross-sectional view of an ECD cell according to an embodiment of the present invention. In the figure, a transparent electrode 2 made of In ₂ O ₃ etc. (resistance approximately 20 Ω/□, light transmittance 80
%), and a WO ₃ film (5000 Å) 3 is provided thereon by vapor deposition. The back substrate 4 is held parallel to the display electrode 3 via a spacer 7 to form a cell, and inside thereof, a light scattering plate 6 made of TiO ₂ and a counter electrode 5 made mainly of carbon are installed. The inlet 8 is provided in the spacer 7 of approximately 1-2 mm. The manufacturing method for this cell is to adhere the contact surfaces between the back substrate 4, spacer 7, and transparent substrate 1 with thermoplastic adhesive in advance, and then use the reduced pressure method (the inside of the cell is evacuated in advance, and then the injection port is closed). An electrolytic solution 10 containing propylene carbonate as a main component was injected from the injection port 8 by a method of dipping in an electrolytic solution and leaking it to normal pressure. After injection, the cell was placed in an oven at 80°C for 10 to 20 minutes with the injection port 8 facing upward, and the injection port 8 was sealed with thermoplastic resin while the cell temperature was 80°C. Furthermore, the adhesive portion was covered with epoxy resin 9 for reinforcement.

For comparison, we created ECD cells that were sealed at room temperature after injection using the same cell as above, and each was kept at -10℃.
(8 hours) to 80℃ (8 hours), the results showed that conventional cells sealed at room temperature leaked or broke within 24 hours (1 day).
The cell of the present invention had durability of one month or more.

According to the present invention, after injecting the electrolyte,
Since the injection port is sealed at the highest temperature within the operating temperature range, the cell that has returned to room temperature has a margin for temperature, and even if the temperature during use rises above room temperature, the injection port will not be sealed. Since the temperature at that time is within that range, even if the electrolytic solution expands, the cell will allow it to expand, and there will be no leakage or damage to the cell.

The electrolytic solution of the ECD cell of the present invention is not limited to the examples, but can be applied to all liquid systems such as aqueous solutions and organic solvents. However, it goes without saying that by sealing at the highest temperature within the required operating temperature range, a cell that can withstand any operating temperature range can be created.

As described above, by using the ECD of the present invention, it is possible to complete a highly reliable ECD that can withstand a wide operating temperature range, and its effects are significant.

[Brief explanation of the drawing]

The figure is a structural sectional view showing one embodiment of the present invention. 1... Transparent substrate, 2... Transparent electrode, 3...
Display electrode, 4... Back substrate, 5... Counter electrode, 6... Light scattering plate, 7... Spacer, 8... Inlet.

Claims (1)

[Claims] 1. A method for manufacturing a display device, in which an electrolytic solution and a pair of electrodes in contact with the electrolytic solution are provided in a container, and an injection port for the electrolytic solution is formed in the container, wherein the electrolytic solution is placed in the container. A method for manufacturing a display device, comprising sealing the injection port at a temperature higher than room temperature after injection.