JPH1016188A - Device for heating and transferring sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a device for heating and transferring a sheet capable of decreasing a fall of temperature at the surface of heat-pressing rollers at the time of passing and heat transferring a sheet assembly through a pair of heat pressing rollers. SOLUTION: The sheet heating and transferring device is such that a sheet assembly C consisting of a transfer sheet S formed with images and printing paper P each being superimposed on a metallic ancillary sheet M is passed through a pair of heat-pressing rollers 20, 21, and images of the transfer sheet S is heat transferred to printing paper P, in which a thermosensor 23 is brought in touch with the end part of the heat pressing roller 21 being in contact with the metallic ancillary sheet M in order that an input electric power of a heater lamp disposed within the heat pressing roller is controlled in terms of signals of the temperature sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet assembly in which a transfer sheet on which an image is formed and a printing paper are superimposed on a metal auxiliary sheet, and is passed between a pair of heat-pressing rollers. The present invention relates to a sheet-body heat transfer apparatus for thermally transferring a sheet to a printing paper.

[0002]

2. Description of the Related Art When an image is digitally processed and the digital data is transferred to a transfer sheet by a printer, an image having a rich color tone is reproduced and a sharp image quality can be realized. If the image of this transfer sheet is offset printed, the color tone of the printed matter will be slightly different from the color tone of the transfer sheet, so in order to accurately grasp the final finished image, A color-proofed print sample is required.

[0003] As a device for producing such a print sample, a sheet heat transfer device has recently been receiving attention. As described above, this sheet-body heating transfer apparatus is a sheet assembly in which a transfer sheet on which an image is formed and a printing paper are superimposed on a metal auxiliary sheet made of, for example, an aluminum plate having a thickness of about 0.3 mm. Is carried in from a carry-in entrance formed in the casing along the carry-in table, and is passed between a pair of heat-pressing rollers arranged inside the casing to thermally transfer the image of the transfer sheet to the actual printing paper. When an image is formed on a transfer sheet by digital data using an ink ribbon coated with a thin film containing a pigment that matches the hue of the ink, when the image on the transfer sheet is thermally transferred to actual printing paper, it is extremely faithful to the actual printed matter. A stable printing sample can be stably finished.

[0004]

In such a sheet heating transfer apparatus, the pair of heating and pressing rollers are soft rollers in which the surface of a core roller made of a metal pipe is covered with a soft synthetic resin such as silicon rubber. Although a heat lamp is arranged, in order to obtain a print sample that is faithful to the actual printed matter, the heat-pressing roller presses the transfer sheet to the printing paper and heat-transfers it. It is necessary that the surface temperature be as uniform as possible without change. For this reason, it is necessary to control the input power of the heater lamp disposed in the heating and pressing roller by measuring the temperature of the heating and pressing roller with the temperature sensor.

As described above, the heat-pressing roller is a soft roller in which the surface of a core roller made of a metal pipe is covered with a soft synthetic resin such as silicon rubber. There is also a time lag before it travels to the temperature sensor, and the temperature sensor is in contact with the exposed core roller at the end of the thermocompression roller, but there is also a time lag caused by the positional relationship between the position of this temperature sensor and the surface of the thermocompression roller. . That is, there is a time lag between the time when the temperature of the heating and pressing roller is measured by the temperature sensor to control the input power of the heater lamp arranged in the heating and pressing roller and the time when the surface temperature of the heating and pressing roller is actually controlled. . Therefore, when the sheet assembly is passed between the pair of heat-pressing rollers for thermal transfer, the heat of the heat-pressing roller is taken away by the sheet assembly, but due to this time lag, the surface temperature of the heat-pressing roller is greatly reduced. ,
There is a problem that a portion that cannot be transferred occurs.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sheet heat transfer apparatus capable of reducing a decrease in the surface temperature of a heat pressure roller when a sheet assembly is transferred between a pair of heat pressure rollers. With the goal.

[0007]

In order to achieve the above object, the present invention provides a sheet assembly in which a transfer sheet on which an image is formed and a printing paper are overlapped on a metal auxiliary sheet by a pair of heating devices. In a sheet heating and transferring apparatus that heat-transfers an image of a transfer sheet to a printing paper by passing between transfer rollers, a temperature sensor is brought into contact with an end of a pair of heating and pressing rollers that contacts a metal auxiliary sheet. Then, based on the signal of the temperature sensor, the input power of the heater lamp arranged in the heating and pressing roller is controlled.

[0008]

Embodiments of the present invention will be specifically described below with reference to the drawings. In FIG. 1, a carry-in table 11 and a carry-out table 13 are attached to both sides of a casing 10. Then, the casing 1 at the base end of the loading table 11
A carry-in port 12 is formed at 0 and a carry-out port 14 is formed at the casing 10 at the base end of the carry-out stand 13. Also,
In the casing 10, guide plates 15, 15, 15 at the same level as the carry-in table 11 and the carry-out table 13 are arranged.

A pair of heat-press rollers 20 and 21 and a pair of discharge rollers 30 and 3 are disposed between the guide plate 15 and the guide plate 15.
1 are rotatably arranged in a state where they are pressed against each other. The heat-press rollers 20 and 21 and the discharge rollers 30 and 31 are synchronously driven to rotate in the direction of the arrow by a chain 41 wound around a sprocket attached to the output shaft of the drive motor 40. I have.

The heat-press rollers 20, 21 and the discharge rollers 30, 31 are soft rollers whose core rollers made of a metal pipe are covered with a soft synthetic resin, for example, silicone rubber. Inside,
As the heater lamp 22, a rod-shaped halogen bulb having a rated power of 1360 W is arranged. The heat-pressing rollers 20 and 21 are covered with the roller cover 16 so that the heat of the heat-pressing rollers 20 and 21 does not adversely affect other electric control components disposed in the casing 10. .

An exhaust fan 50 is provided at the bottom of the casing 10.
When the exhaust fan 50 is operated, the cooling air is sucked from the carry-in port 12 and enters the roller cover 16 as shown by the arrow, and enters the heating and pressing rollers 20 and 2.
1 is cooled. Heating pressure roller 20,
The cooling air that has cooled the cooling air 21 is exhausted by an exhaust fan 50 from an exhaust hole formed at the bottom of the casing 10.

As shown in FIG. 2, the sheet assembly C includes a metal auxiliary sheet M made of an aluminum plate having a thickness of, for example, 0.3 mm, and a transfer sheet S on which an image is formed by digital data and a printing paper P. It is superimposed on. In this example, the sheet assembly C is provided with a casing 10 along the loading stand 11 with the metal auxiliary sheet M facing downward.
Is carried in from the carry-in port 12 formed in the first place. When the leading end of the sheet assembly is inserted between the pair of heating and pressing rollers 20 and 21, the sheet assembly is pressed in a heated state by the pair of rotating heating and pressing rollers 20, 21. The images are sequentially conveyed while being thermally transferred to the printing paper. The sheet assembly guided by the guide plate 15 is further conveyed by the discharge rollers 30 and 31 and discharged from the discharge port 14. That is, in this example,
During the thermal transfer, the metal auxiliary sheet M is in contact with the lower thermocompression roller 21, and the transfer sheet S is in contact with the upper thermocompression roller 20.

Here, at the time of thermal transfer, the heat pressing roller 2
The temperature of the heating and pressing roller is measured by a temperature sensor so that the input power of the heater lamp 22 disposed in the heating and pressing roller 20, 21 is controlled so that the surface temperature of the heating and pressing roller 21 is kept as constant as possible without changing. Need, but above all,
It is necessary to keep the temperature of the upper heat-press roller 20 in contact with the transfer sheet S from changing. Therefore, in the present invention, as shown in FIG. 2 and FIG.
The lower heat-press roller 2 in contact with the metal auxiliary sheet M
1 is brought into contact with the core roller 21a exposed from the end. The thyristor control of the input power of the heater lamp 22 is performed based on the signal of the temperature sensor 23.

FIG. 4 qualitatively shows how the temperature changes during thermal transfer of the thermocompression rollers 20, 21.
The solid line curve is a characteristic curve of the lower thermocompression roller 21 contacting the metal auxiliary sheet M, and the dotted line curve is a characteristic curve of the upper thermocompression roller 20 contacting the transfer sheet S. The temperature at the start of the thermal transfer is T ₀ (for example, 170 ° C.). When the temperature decreases to T ₁ , the input power of the heater lamp 22 increases, and when the temperature increases again to T ₀ , the input power of the heater lamp 22 decreases. When performing control,
The lower heat-press roller 2 in contact with the metal auxiliary sheet M
1 is easier to release heat than the upper thermocompression roller 20 with which the transfer sheet S contacts, so that the temperature is greatly reduced, and the time when the temperature of the thermocompression roller 21 changes from T ₀ to T ₁ is represented by S ₁ . Assuming that the time when the temperature of the roller 21 changes from T ₀ to T ₁ is S ₂ , the relationship of S ₂ > S ₁ always holds.

Here, since the temperature sensor 23 is in contact with the lower heat-pressing roller 21 with which the metal auxiliary sheet M contacts, the input power of the heater lamp 22 is increased when the time S _{1 has} elapsed from the start of the thermal transfer. . If the temperature sensor 2
3 is the upper heat-press roller 20 with which the transfer sheet S contacts.
When the time S ₂ elapses from the start of the thermal transfer, the input power of the heater lamp 22 is increased.
Since S ₂ > S ₁ , the input power of the heater lamp 22 can be quickly increased by bringing the temperature sensor 23 into contact with the lower heating pressure roller 21 with which the metal auxiliary sheet M contacts. That is, since the input power of the heater lamp 22 can be quickly controlled, the temperature change of the upper heating and pressing roller 20 with which the transfer sheet S contacts is extremely small, and can be maintained at a substantially constant temperature.

[0016]

As described above, according to the present invention, a sheet assembly in which a transfer sheet on which an image is formed and a printing paper are overlapped on a metal auxiliary sheet is passed between a pair of heat-pressing rollers. In a sheet heating transfer apparatus for thermally transferring an image of a transfer sheet onto a printing paper, a temperature sensor is brought into contact with an end of a pair of heat-pressing rollers, which is in contact with a metal auxiliary sheet, and a temperature sensor. Since the input power of the heater lamp arranged in the heating and pressing roller is controlled based on the signal, it is possible to provide a sheet heating and transferring apparatus capable of reducing a decrease in the surface temperature of the heating and pressing roller. .

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a sheet heating transfer apparatus.

FIG. 2 is an explanatory diagram of a positional relationship between a seat assembly and a temperature sensor.

FIG. 3 is an explanatory diagram of a mounting position of a temperature sensor.

FIG. 4 is an explanatory diagram of a temperature characteristic curve of a thermocompression roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Casing 11 Carry-in board 12 Carry-in port 13 Carry-out stand 14 Carry-out port 15 Guide plate 16 Roller cover 20 Heat-pressing roller which a transfer sheet contacts 21 Heat-pressing roller which a metal auxiliary sheet contacts 22 Heat lamp 23 Temperature sensor 30, 31 Discharge Roller 40 Drive motor 50 Exhaust fan C Sheet assembly S Transfer sheet P Printing paper M Metal auxiliary sheet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Kushida 262 Kondo Tondobayashi, Gunma Prefecture Inside Gunma Ushio Electric Machinery Co., Ltd. 72) Inventor Yoshihiro Koyanagi 798 Miyadai, Kaisei-cho, Ashigarakami-gun, Kanagawa Prefecture Inside Fuji Photo Film Co., Ltd.

Claims (1)

[Claims] 1. A sheet assembly in which a transfer sheet on which an image is formed and a printing paper are superimposed on a metal auxiliary sheet are passed between a pair of heating and pressing rollers, and the image of the transfer sheet is thermally transferred to the printing paper. In the sheet heat transfer apparatus, a temperature sensor is brought into contact with an end of the heat-pressing roller that contacts the metal auxiliary sheet, of the pair of heat-pressing rollers, and the heat-pressing roller is inserted into the heat-pressing roller based on a signal from the temperature sensor. A sheet heating and transferring apparatus for controlling an input power of a heater lamp arranged.