JPS592900B2 - thermal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device that obtains an image by heating a display medium with a heating element, and a heat-sensitive display device that is formed by stacking and integrating a plurality of heat-sensitive sheets coated with a heat-sensitive material as a display medium. The object of the present invention is to obtain a thermal display device that can obtain extremely fine color images by using this method.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a heat-sensitive display body formed in the shape of an endless band, which includes a driving pulley 3 connected to a motor 2 and two driven pulleys 4 and 5.
It is supported by being wrapped around it, and is moved in the direction of arrow A in synchronization with an external signal.

Reference numeral 6 denotes a heating element such as a thermal head used in a thermal printer, which is installed in the width direction of the thermal display 1 at the position of the driven pulley 4 which also serves as a platen, and is in contact with the surface of the thermal display 101. ing.

T is a cooler composed of, for example, a Peltier element and a metal piece, and is installed in the middle of the transfer path of the heat-sensitive display 1.
The cooling portion is in contact with the surface of the heat-sensitive display body 1. 8 is a heat insulator for keeping the heat-sensitive display body 1 at a certain temperature;
15 For example, it is composed of a heater, a fan, etc.

Reference numeral 9 denotes a transparent glass window, which is provided on the cover 10 of the device in order to view the display surface of the heat-sensitive display 1.

FIG. 2 is a partially enlarged view showing the structure of the thermosensitive display body 1.
20 heat sheet 1 made by coating a transparent sheet with a heat-sensitive material
1 and 12 and a base 13 colored white or another color are joined to form a three-layer integrated structure. Heat sensitive sheet 11
and No. 12 use heat-sensitive materials with different color and temperature-transmittance change characteristics. As the heat-sensitive material, a known thermochromic material25 is used. There are many types of thermochromic materials, but they all have the property of becoming transparent at a certain temperature. FIG. 3 is a diagram showing the temperature versus transmittance change characteristics of the heat-sensitive display body 1 with the above-described configuration, where the curve a shows the characteristics of the heat-sensitive sheet 11, and the curve b shows the characteristics of the heat-sensitive 30 sheet 12. There is. As is clear from this figure, the heat-sensitive sheets 11 and 12 have reversibility and hysteresis characteristics in their temperature-versus-transmittance change characteristics.Therefore, if the heat-sensitive display body 1 is kept at the temperature Ts, for example, the heat-sensitive sheet 11 is made transparent. If desired, the transparency of the heat-sensitive sheet 11 can be maintained by setting the temperature to 35 Twl and then returning it to the holding temperature Ts. Heat sensitive sheet 1
If it is desired to make both 1 and 12 transparent, the temperature may be set to Tw2 and then returned to the holding temperature T8. In Figure 2, A
indicates the area where the background color of the heat-sensitive sheet 11 is displayed;
Further, B indicates an area where the heat-sensitive sheet 11 is made transparent by applying a temperature of Tw to the heat-sensitive display body 1, and the ground color of the heat-sensitive sheet 12 is displayed.
By adding the temperature TW2 to , the heat-sensitive seaports 1 and 12 are made transparent and the area where the base color is displayed is shown. Therefore, in FIG. 1, the heat-sensitive display body 1 is kept at a temperature T8 by a heat insulator 8, and the heat-generating body 6 is turned on in accordance with image information.
When a temperature of TW1 or TW2 is given, an image can be displayed using the color of the heat-sensitive sheets 11, 12 or the base 13, or a combination of these colors.

The displayed image can be erased by transporting the thermal display body 1 by the motor 2, sending the image to the position of the cooler 7, cooling it to a temperature below T8, and then moving the image to the cooler 7. 8 to maintain the temperature at T8, it can be returned to a displayable state again. In addition, although the above-mentioned embodiment explained the case where three-color display is performed, it is possible to increase the number of heat-sensitive sheets, set the ground colors to blue, yellow, red, and black, and set the base color to white to respond to each color signal. If you control the temperature of the heating element using
It becomes possible to easily display a color image.

In addition, in the above-mentioned embodiment, the base is integrated with the heat-sensitive sheet to constitute the heat-sensitive display body, but it is also possible to construct the heat-sensitive display body only with the heat-sensitive sheet and install a plate-shaped base behind the display area. As explained above, the present invention is capable of forming an endless strip by stacking and integrating a plurality of heat-sensitive sheets of different colors using a heat-sensitive material having reversibility and hysteresis characteristics in terms of temperature versus transmittance change characteristics. A display image can be obtained by forming a heat-sensitive display body and controlling the heating temperature of a heating element that gives an image to the heat-sensitive display body according to color information. There is an effect that a thermal display device capable of displaying a color image can be realized.

Also, the display resolution depends on the resolution of the cells of the heating element, and is approximately 10 lines/M7! Since it is possible to obtain up to about L, extremely fine color images can be obtained and can be used in various display fields.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, FIG. 2 is a partially enlarged view showing the structure of a heat-sensitive display, and FIG. 3 is a diagram showing the change in transmittance versus temperature of a heat-sensitive sheet. 1...Thermal display body, 2...Motor, 3
...1 driving pulley, 4,5...driven pulley, 6...heating element, 7...cooler,
8... Heater, 9... Transparent glass window,
10...Cover 11,12...Thermosensitive sheet, 13...Base.

Claims (1)

[Claims] 1. By coating a transparent sheet with a heat-sensitive material having reversibility and hysteresis characteristics in its temperature-transmittance change characteristics to form a plurality of heat-sensitive sheets with different colors, which are then stacked and integrated. An endless strip-shaped thermal display, a driving pulley and a driven pulley that support the thermal display, a heating element that provides an image in contact with the thermal display, and a heating element that cools the thermal display to erase the image. A thermal display device comprising a cooler and a heat insulator that maintains the thermal display body at a constant temperature. 2. Claim 1, characterized in that the temperature-transmittance change characteristics of the heat-sensitive sheets coated with the heat-sensitive material are different.
Thermal display device described in Section 1.