JPS58105217A - Display - Google Patents

Abstract

PURPOSE:To obtain a device which has a picture or a signal pattern of optional size especially, can be operated by low voltage, and is capable of storing and erasing easily, by providing an electrode on both faces of a laminated body which has laminated an electrochromic (EC) film, a solid electrolytic film and an optical resistance film in order. CONSTITUTION:On a film 4 of a glass substrate covered with a transparent conductive film 4, a WO3 film (EC film) 1 is formed, and a solid electrolytic film 2 having a good ionic conductive property is formed by sputtering an amorphous lithium compound such as niobic acid lithium, etc. on the surface of the film 1 at a low temperature. Subsequently, when the film 2 is heated, it is crystallized and its ionic conductive property is deteriorated, therefore, it is cooled and an optical resistance film 3 of CdS, etc. is sputtered, and a transparent electrode 5 is formed by sputtering ITO to the film 3, by which ECD is obtained. To this ECD, laser light is irradiated like an image from the electrode 5 side, to the EC film side, voltage is applied negative, and a picture 7 is stored. When the voltage is applied in the opposite direction, it is erased instantaneously. In this way, it is possible to obtain ECD which is capable of storing for hundreds of hours, and also ultraviolet rays and infrared rays, too.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device, and in particular, it is an object of the present invention to provide a display device in which the size can be arbitrarily selected and one image or signal pattern can be stored and erased. .

Conventionally, photographic plates that utilize chemical reactions such as silver salts, magnetic disks that utilize electromagnetic effects, optical disks, and the like have been used to store images or signal patterns. However, these had the disadvantage that they could not be easily stored and erased, so it was not possible to realize a practical device that was capable of storing and erasing data.

The inventors have discovered the basic principle of a new memorizable and erasable display device with a thin film multilayer structure and a new thin film material to realize this structure, and based on these discoveries, they have developed a new image-type display device. Invented the memory device.

The basic structure of the display device according to the present invention is as shown in FIG.
It is characterized by a thin film multilayer structure in which a solid electrolyte film 2 and a photoresistance film 3 are sequentially laminated.

The solid electrolyte membrane 2 is, for example, a transparent thin film.

Ionic conductivity is 10-2 to 1o-6Ω-1d1 at room temperature
It is of a certain degree. The color of the ECC 10 changes due to the entrance of conductive ions from the solid electrolyte membrane 2, for example, from transparent to colored.

FIG. 2 is for explaining the specific operating principle of the display device according to the present invention. In the figure, KOO12
Transparent electrode films 4 and 6 are respectively provided on the surface of the photoresistance film 3, and a DC voltage is applied between these electrodes M4 and M6. In this case, so that the electrical resistance of the photoresistance film 3 becomes sufficiently high,
Place it in a place that blocks light from outside. Here, for example, when the surface 6 of the electrode film 60 is irradiated with the light pattern 7, the resistance of the photoresistance film 3 in the part under the pattern 7 irradiated with light decreases, and the solid electrolyte film 2 and the ECC 10 in this part have a large DC voltage. It takes. As a result.

A light change in the same pattern as the light pattern 7, for example a colored pattern, occurs in the ECC10. This colored pattern is related to the conductive ions from solid electrolyte #2 entering the Re membrane 1, and unless a reverse voltage is applied, the number of conductive ions in the order of several hundred
The pattern does not disappear over time. In other words, a one-image type memory can be realized by simply applying an optical image or signal pattern to be stored to the photoresistance film 3 and applying an external DC voltage between the photoresistance film 3 and the ICC film 1. . Moreover, erasing of an image can be easily performed by applying a reverse bias DC voltage.

In this case, one aspect of the present invention is that a display device having a multilayer structure with a memory function can be formed on any substrate such as glass or an organic film substrate by vapor deposition technology.

Large screen memory can also be realized. However, the device according to the present invention does not necessarily require a substrate, as long as it can maintain the multilayer structure described above.

Although there are organic thin films as the above-mentioned EC film, inorganic thin films, especially metal oxide thin films are preferred due to their long-term stability.

For example, tungsten oxide, iridium oxide, molybdenum oxide, and nickel oxide are effective.

As solid electrolyte membranes, silver salt glass and the like have conventionally been known, but in addition to silver salts, rhidium compounds can be used, especially amorphous rhidium compounds formed by sputter deposition, such as amorphous rhidium niobate, tantalate, and titanate. , rhidium vanadate, rhidium zirconate, etc. have a faster response and are more effective than silver salts.

As a photoresistance film, it is only necessary that the electrical resistance changes drastically upon irradiation with light, and 8e is a material that has been widely used in the past.

X-ray o image (7) Memory contains 060, 0elS
, Ca5e, CdTe.

Thin films of compounds such as ZnO, ZnS, Zn8e, etc. (7) are effective. In addition, ■ such as Si and Go
family, such as Pb8e and pbr (iDN-VI compounds,
■-■ compounds such as Gamut and Garb are effective for storing infrared images.

Sputter deposition is effective for forming the six films in the display device of the present invention, and sputter deposition at low temperatures is particularly effective for forming the amorphous thridium compound thin film of the solid electrolyte film. Sputter deposition is also effective in realizing a multilayer structure.

Furthermore, the inventors discovered that there is a more effective configuration in the present invention, and invented a display device with another new configuration.

FIG. 3 is a sectional view of this display device. In the figure,
Three-layer electrodes each having an insulating layer 10 between conductive layers 8.9 are disposed on both sides of the thin film multilayer structure consisting of a CC10 solid electrolyte membrane 2 and a photoresistance membrane 3. For the insulating layer 10, a sputtered thin film of 8i02, for example, is used. A voltage is applied to the outer conductive layer 9 so as to have a reverse bias than that of the inner conductive layer 8. The magnitude of the voltage is such that it is the voltage applied to the ECC 10 solid electrolyte membrane 2, or such that a reverse bias voltage is applied to the inner conductive layer 8. In this case, the photoresistance film 3 is formed thick.

With such a configuration, the difference in voltage applied to the Xa film 1 and the solid electrolyte film 2 between the portions irradiated with light and the portions not irradiated becomes large, and the contrast of the stored signals becomes clearer. .

Next, one embodiment of the present invention will be specifically described.

Example 1 On a glass substrate whose surface is coated with a transparent conductive film.

A tungsten oxide film is formed to a thickness of about 1 μm.

The tungsten oxide film is formed by high-frequency sputter deposition in an oxygen atmosphere using a tungsten oxide target. Next, a lithium niobate film is similarly formed by high frequency sputter deposition. This film has poor ionic conductivity unless it is in an amorphous state, so it is necessary to keep the formation temperature low. The inventors set the formation temperature to liquid nitrogen temperature, used a magnetron type sputtering device with rhidium niobate as a target, sputtered at a sputtering power of 100 W for 1 hour, and sputtered to a thickness of 1000 to 2000 mm with good ion conductivity. An amorphous lydium niobate film was obtained. Further, CdS is sputter-deposited thereon.

During this formation, if heat is applied to the previously deposited lithium niobate film, recrystallization occurs.

Since the amorphous property deteriorates and the ionic conductivity deteriorates, it is necessary to perform sputtering while cooling.

The CdS film has a thickness of about 2 μm, and an ITO film is sputter-deposited thereon to form a transparent electrode.

In this device, a voltage of 2V is applied between the electrodes so that the side in contact with the EC membrane is negative, and 0. The area irradiated with the IW laser light was memorized as blue. 0.
When irradiated with IW laser light for 170.5 seconds, a contrast ratio of 1:2.5 was obtained.

Furthermore, the memory retention time has been confirmed to be over 200 hours.0 was erased instantly by applying a voltage of 4V in the reverse direction.

Example 2' In Example 1, before depositing the tungsten oxide film, an 8i02 film and an ITO film with a thickness of approximately 2,000 people were sputter-deposited, and tungsten oxide and lithium niobate were deposited thereon in the same manner as in Example 1. .

The CdS and ITO films are stacked, and then an 8i0+ film and an ITO film are stacked thereon in the same manner. In this case, C6S has a thickness of 3
It was called μ theory. Now - 6V to the outer pair of electrodes.

When a voltage of 4 V was applied to the inner pair of electrodes and a laser beam of 0.111 W was irradiated for 0.5 seconds, the contrast ratio was 1:2.7 under the same conditions as in Example 1.

It was instantly erased when the voltage inside was turned off. and 1
Memory retention time when both voltages are turned off at the same time is 20
It has been confirmed that the time is 0 hours or more.

As is clear from the above description, the display device according to the present invention can store images and signal patterns at low voltage.

It is erasable, does not require matrix operations, and features real-time operation. Furthermore, images and signal patterns can be stored two-dimensionally over a large area for any light wavelength ranging from ultraviolet to infrared.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part showing the basic structure of a display device according to the present invention, and FIGS. 2 and 3 are cross-sectional views showing a typical structure of a display device according to the present invention. 1... Electrochromic membrane, 2...
・Solid electrolyte membrane, 3...Photoresistance film, 4.6...
...Electrode, 8゜9...Conductive layer, 10...
...Insulating layer.

Claims (4)

[Claims] (1) A display device comprising a thin film multilayer structure in which at least an electrochromic film, a solid electrolyte film, and a photoresistance film are sequentially laminated, and a means for applying a voltage to the thin film multilayer structure. (2) The display device according to claim 1, wherein the electrochromic film is made of a metal oxide thin film. (3) The display device according to claim 1, wherein the solid electrolyte membrane is composed of an amorphous thridium compound membrane. (4) Photoresistance film made of I-Vl compound, Group II semiconductor IV-V
2. The display device according to claim 1, characterized in that the display device is made of at least one of a compound I and a sodium chloride compound. (2) A voltage applying means is applied to both sides of the thin film multilayer structure consisting of an electrochromic film, a solid electrolyte film, and a photoresistance film.
each is placed. 2. The display device according to claim 1, wherein the display device is a three-layer electrode with an insulating layer interposed between two conductive layers.