JPS6078425A - Photosensitive display device - 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 that utilizes light irradiation.

Conventional Structures and Problems Conventionally, electrochromic devices, photochromic devices, etc. have been cited as devices that exhibit color changes. Electrochromic elements produce and erase color by applying an electric field, and form colored patterns depending on the shape of the electrodes. Therefore, it was difficult to easily write and display data directly from the outside, and it was only used as a simple display. In addition, photochromic elements are
Although it shows color changes using light, it requires a light source with a different wavelength for erasing, making the configuration complicated.

Further, examples of conventional display boards on which information can be written directly include blackboards and whiteboards. These could not be written without direct contact with the display board. Also, therefore,
There is a limit to large areas, and when the area becomes large, erasing must be done manually, which takes time and becomes difficult. Also, chalk etc. do not have enough trust and are inconvenient because the surrounding area needs to be darkened.

In addition, there has not been a display board that can withstand use as a display board on which information can be written directly without contact.

Based on the discovery of a display material that changes color when irradiated with light and can be erased by heat or electric field, the inventors have discovered that it is possible to write directly on a large screen with no contact or contact, and it is easy to write on a large area. invented a photosensitive display device that could be erased instantly.

OBJECTS OF THE INVENTION An object of the present invention is to provide a photosensitive display device that can be easily written and erased.

Structure of the Invention The present invention provides a display body having a two-layer structure of a color-forming layer and an ion source provided in close contact with the color-forming layer, by irradiating light with an irradiation light source. It is characterized by causing and displaying changes.

The inventors discovered that when a two-layer structure consisting of a color-forming layer and an ion supply source provided in close contact with the color-forming layer is used as a display body, irradiation with light generates oxidation, and applying an electric field to the display causes oxidation. discovered that the display was instantly erased by the movement of ions from the color-forming layer.Also, when irradiated with light, an electric field was applied to the display body in a direction that would cause the ions to move to the color-forming layer, to the extent that they would not be moved by the electric field alone. The inventors have confirmed that if added, the color will change even under low-intensity light. However, if an electric field is applied in the direction in which the ions move to the coloring layer to the extent that the ions cannot be moved by the electric field alone, a clear display can be maintained for a much longer time. Further, the coloring layer is a sputtered film of a mixed oxide of lithium and tungsten in an argon atmosphere, and the ion source is a sputtered film of a mixed oxide of lithium and tungsten in an argon/oxygen atmosphere. It was confirmed that it is particularly effective as a photosensitive display material of the present invention. In addition, by providing a pair of electrodes sandwiching the two-layer structure, at least one of which is transparent to the irradiation light beam, it is possible to apply an electric field to the two-layer structure and to irradiate the light beam. It was possible to cause a color change.

Furthermore, when coloring by irradiating light, the wavelength is 500 nm.
The inventors have confirmed that the color change is particularly effective when ultraviolet light of m is used. According to the present invention, a light and simple marking jig such as a light ben can be realized by guiding the laser beam through a fiber or the like. Furthermore, by using an ITO film as an electrode that is transparent to ultraviolet light, the color changes more effectively than when ultraviolet light is used. In addition, we confirmed that the display can be easily erased by applying heat without using electrodes, and by providing a flat heating element that is in thermal contact with the display, large screens can be displayed instantly. will be deleted. It has been confirmed that the use of a sputtered film of a mixed oxide of lithium and tungsten as a display material is particularly effective.

DESCRIPTION OF EMBODIMENTS FIG. 1 shows a first embodiment of a display portion of a photosensitive display panel of the present invention. The coloring layer 1 and the ion source 2 are placed in close contact and sandwiched between electrodes 3 and 4 that are transparent to ultraviolet light. Although this four-layer structure is formed on the substrate 5, the substrate 6 is not necessarily required as long as it is mechanically stable, and either one of the electrodes may be transparent to ultraviolet light. Further, the electrodes 3 and 4 are not necessarily required as long as a sufficient electric field is applied to the two-layer structure of the coloring layer 1 and the ion source 2. When a sputtered film of a mixed oxide of lithium and tungsten in an argon atmosphere is used as the coloring layer 1, and a sputtered film of a mixed oxide of lithium and tungsten in an argon/oxygen atmosphere is used as the ion source 2, the coloring layer A negative potential is applied to the electrode 4 on the side, and a positive potential is applied to the electrode 3 on the ion supply source side, to the extent that no color develops due to the energy of the electric field.

When ultraviolet light 6 is irradiated there, the ultraviolet light passes through the ITO film 4 and gives energy to the two layers of sputtered films, causing the lithium ions to move and become colored. Color develops only. Excimer laser light was used as the ultraviolet light and was generated at approximately s om T /ca.

Note that a mercury lamp or the like may be used as the ultraviolet light, and it is preferable to guide the light through a fiber. By squeezing the light with a lens, it is possible to display minute details, and it is also possible to change the color over a large area. Furthermore, there is no viewing angle dependence and a display with high contrast can be achieved. Further, by leaving the electric field applied as it is, the display can be maintained clearly for a longer period of time than when no electric field is applied. By applying a reverse bias (a weak electric field of about 5 layers) during color development, the color can be erased instantly with a switch operation without easily raising dust. A difference of 10 dB or more was observed between the time of coloring and the time of decolorization for He-N and laser beam, and the decolorization was completely performed. According to FIG. 1, it is possible to create a display panel that is extremely lightweight, thin, and has a large area, and can be erased very easily, has a high contrast, and can display clear and fine details. And there is no problem with dirt.

FIG. 2 shows another embodiment of the photosensitive display panel of the present invention. A coloring layer 1 is provided on a flat heating element 7. The planar heating element 5 and the coloring layer 1 may be provided on the substrate 5, but the substrate 5 is not necessary as long as it is mechanically stable.

The coloring layer 1 is irradiated with ultraviolet light or the like to develop color. Any type of light, not just ultraviolet light, may be used, but light with higher energy is considered to be more effective. When erasing the entire screen, a flat heating element is used to apply heat and provide thermal energy to erase the entire screen. When erasing a portion, it is recommended to use a small iron or the like.

Effects of the Invention As described above, the present invention makes it easy to use fibers by using a display board that changes color when irradiated with light and a light source for irradiating light.
- allows for a display board that can be written on from the outside, both contactless and contactless, and that can be easily and instantly erased with the operation of a switch, making it possible to display on a large screen without staining or dust. In addition, it is possible to realize a light and thin photosensitive display panel that has low viewing angle dependence, has a large contrast, and is capable of performing very small fine writing at a driving voltage, and is therefore of great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of an embodiment of the photosensitive display plate of the present invention;
FIG. 2 is a schematic sectional view of another embodiment of the photosensitive display panel of the present invention. 1... Coloring layer, 2... Ion supply source,
3, 4...electrode, 5...substrate, 6...
...Light, 7...Erase surface heating element.

Claims (1)

[Scope of Claims] (1) A photosensitive display device characterized in that a display body having a coloring part is irradiated with light from an irradiation light source, and a color change is caused in the display body by the light irradiation. . (2) The photosensitive display device according to claim 1, wherein the coloring section has a two-layer structure including a coloring layer and an ion source provided in close contact with the coloring layer. (3) The photosensitive display device according to claim 1, wherein ultraviolet light having a wavelength of 500 nm or less is used as a light source for irradiation. (4) The photosensitive display device according to claim 1, wherein a light pen is used as a light source for irradiation. (6) The photosensitive display device according to claim 1, further comprising an erasing mechanism that applies an electric field to the two-layer structure. (6) The photosensitive display device according to claim 1, wherein an electric field is applied when the two-layer structure is irradiated with light. (a) The photosensitive display device according to claim 1, characterized in that a display holding mechanism by applying an electric field is added to the two-layer structure. (8) Using a sputtered film of a mixed oxide of lithium and tungsten in an argon atmosphere as the coloring layer, and a sputtered film of the above mixed oxide of lithium and tungsten in an argon/oxygen atmosphere as an ion supply source. A photosensitive display device according to claim 1, characterized in that: (9) A photosensitive display device according to claim 1, characterized in that a pair of electrodes, at least one of which is transparent to irradiation light, is provided with the two-layer structure sandwiched therebetween. (10) The photosensitive display device according to claim 8, characterized in that an ITO film is used as the electrode that is transparent to ultraviolet rays. (11) The photosensitive display device according to claim 1, further comprising an erasing mechanism that applies heat to the display body. (12) A plane in thermal contact with the display as an erasing mechanism;
Claim 10 characterized in that a heating element is provided.
The photosensitive display device described in . (13) A photosensitive display device according to claim 12, characterized in that a sputtered film of a mixed oxide of lithium and tungsten is used as the display body.