JPH05134612A - Image display device - Google Patents

Abstract

PURPOSE:To provide the image display device of a large screen for which a planar thermal head of a relatively small size is used and which is inexpensive and is high in display speed within a required range. CONSTITUTION:The thermal head 1 is movable to the arbitrary position of the display screen which is the large screen and, therefore, the image displaying of the display screen 16 of A0 size or more can be made by the thermal head 1 of about an A3 size. The required display range is covered by the size of the thermal head 1 and since there is no need for moving the thermal head 1, the display speed is high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device which can be used for computer-aided design, that is, CAD or the like.

[0002]

2. Description of the Related Art Conventionally, polyester as a heat-sensitive recording material whose transparency reversibly changes depending on temperature,
A material having a heat-sensitive layer in which a resin such as polyamide is dispersed with an organic low molecular weight substance such as higher alcohol and higher fatty acid is disclosed in, for example, JP-A-54-119377 and JP-A-55-1.
It is known from Japanese Patent No. 54198. Recording with this recording material, that is, image formation and erasing is performed by utilizing the change in transparency depending on the temperature of the heat sensitive layer, and a recorded image is obtained as a transparent image on a white background or as a white image on a colorless background.

Further, a heat-sensitive recording material used as an image display device is disclosed in Japanese Patent Application Laid-Open No. 57-212481. In this, an image is displayed using a linear thermal head with an endless belt-shaped heat sensitive body.

[0004]

However, in order to obtain an image on a large screen required for CAD or the like by using a linear thermal head, a long thermal head is required, which is expensive. The time to change the display also takes time because it is necessary to drive the endless belt-shaped heat sensitive body.

The present invention has been made to solve the above-mentioned problems, and by using a relatively small planar thermal head, it is inexpensive and has a large display speed within a required range. It is an object of the present invention to provide an image display device.

[0006]

In order to achieve this object, the image display device of the present invention has a display screen of a heat sensitive body whose transparency reversibly changes depending on temperature, and a transparency of the heat sensitive body. It comprises a thermal head for changing and a moving means for moving the thermal head on the back surface of the display screen.

[0007]

According to the present invention having the above structure, the moving means moves the thermal head for changing the transparency of the heat sensitive body on the back surface of the display screen by the heat sensitive body, so that the image is formed on the entire display screen by the thermal head. Is displayed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, the change in transparency depending on the temperature of the heat sensitive body will be described with reference to FIG. In FIG. 4, the heat sensitive element is, for example, T0.
It is cloudy and opaque at room temperature below. This is T1-T
It becomes transparent when heated to a temperature between 2 and remains transparent even if the temperature is returned to T0 or lower in this state. Further heating to a temperature of T3 or higher results in a semitransparent state between the maximum transparency and the maximum opacity. Next, when this temperature is lowered, the first cloudy opaque state is restored without taking the transparent state again.
When this opaque state is heated to a temperature between T0 and T1 and then cooled to room temperature, that is, a temperature of T0 or lower, a state between transparent and opaque, that is, translucent can be obtained. ..

[0012] Further, the transparent material that has become transparent at room temperature is heated to a temperature of T3 or higher again and returned to room temperature, and returns to the cloudy opaque state again. That is, it can take both opaque and transparent forms at room temperature and intermediate forms thereof.

Therefore, for example, after heating the entire layered heat-sensitive member having such a heat-sensitive body to a temperature of T3, it is cooled to a normal temperature of T0 or lower to make it opaque, and then this is partially heated by a thermal head or the like between T0 and T1. By heating to that temperature to make the portion transparent or semi-transparent, a colored image is formed by disposing the layered coloring member on the back surface of the layered heat-sensitive member.

The layered heat-sensitive member can be formed by, for example, heating and melting a resin base material and an organic low-molecular substance, mixing them, and molding them into a sheet.

As the resin base material, a material having good transparency, mechanical stability, and good moldability is used. For example, it is polyester or polyacrylate.

As the organic low molecular weight substance, alkanol;
Alkane diols; halogen alkanols or halogen alkane diols; alkyl amines; alkanes; alkenes; alkynes; halogen alkanes; halogen alkenes; halogen alkynes; cycloalkanes; cycloalkynes; cycloalkenes; saturated or unsaturated mono- or dicarboxylic acids or their esters, Amides or ammonium salts; saturated or unsaturated halogen fatty acids or their esters, amides or ammonium salts; allylcarboxylic acids or their esters, amides or ammonium salts; halogenallylcarboxylic acids or their esters, amides or ammonium salts Thioalcohol; thiocarboxylic acid or its ester, amine, or ammonium salt; carboxylic acid ester of thioalcohol, etc. It is.

The structure of the image forming apparatus embodying the present invention is as follows.
As shown in FIG. 1, a display screen 16 composed of the layered heat-sensitive member and the layered colored member and a back surface of the display screen 16 are closely attached to
A planar thermal head 1 of about 3 sizes is provided. The fixed plate 4 supporting the thermal head 1 is vertically movably guided by vertical bars 8 and 9 and is fixed to a vertical wire 6. The vertical wire 6 is wound around the pulleys 5 and 6.

The vertical frame 10 supporting the vertical bars 8 and 9 and the pulleys 5 and 7 is guided by horizontal bars 11 and 12 so as to be movable left and right, and is fixed to a horizontal wire 15. The horizontal wire 15 is wound around the pulleys 13 and 14. Horizontal bars 11, 12 and pulleys 13, 14
Are supported by a body frame (not shown).

The structure of the thermal head 1 is composed of horizontal stripe wirings Y1 and Y printed on a polyimide film shown in FIG.
2. ． ． And heating elements Y11, Y12. ． ． , Vertical stripes X1, X2. ． ． And heating elements X11 and X1
2. ． ． By overlapping the surfaces of the heating elements, the grid-shaped intersections generate heat. For example, when a voltage is applied between X1 and Y1, a current flows through X11 and Y11 to generate Joule heat.

Next, the operation of this embodiment will be described. Using the transparency change due to the temperature of the heat sensitive body described above, the thermal head 1 is controlled by the control circuit (not shown), and the display screen 1
Display the image on 6.

Display screen 1 outside the range of the thermal head 1
In order to display an image on 6, the thermal head 1 is moved as follows.

The thermal head 1 is moved to a predetermined vertical position by rotating the pulley 5 by a motor (not shown) to move the fixing plate 4 in the vertical direction via the vertical wire 6.

Next, the pulley 13 is rotated by a motor (not shown) to move the vertical frame 10 in the horizontal direction via the horizontal wire 15 to move the thermal head 1 to a predetermined horizontal position.

After moving the thermal head 1 to a predetermined position,
The thermal head 1 is controlled by a control circuit (not shown),
The image is displayed on the display screen 16.

Therefore, the thermal head 1 can be moved to an arbitrary position on the display screen 16 which is a large screen.
An image of the display screen 16 of A0 or more can be displayed by the thermal head 1 of about the size. Further, the required display range can be covered by the size of the thermal head 1, and since the thermal head 1 does not need to be moved, the display speed is high.

[0024]

As is clear from the above description,
According to the image display device of the present invention, since the thermal head can be moved to an arbitrary position on the display screen, it is possible to display an image on a large-screen display screen with a small planar thermal head. Further, the required display range can be covered by the size of the thermal head, and since the thermal head and the display screen do not need to be moved, the display speed of the required display range is high.

[Brief description of drawings]

FIG. 1 is a diagram showing an image display device embodying the present invention.

FIG. 2 is a pattern diagram of a thermal head.

FIG. 3 is a pattern diagram of a thermal head.

FIG. 4 is a graph showing the thermoreversibility of a heat sensitive body.

[Explanation of symbols]

 1 Thermal head 5 Pulley 6 Vertical wire 13 Pulley 15 Horizontal wire 16 Display screen

Claims (1)

[Claims] 1. A display screen using a thermosensitive element whose transparency reversibly changes depending on temperature, a thermal head for changing the transparency of the thermosensitive element, and a moving means for moving the thermal head on the back surface of the display screen. An image display device equipped with.