JPH08183093A - Heater and thermal transfer method - Google Patents

Abstract

PURPOSE: To obtain a heater capable of preventing deterioration of a heating performance in continuously heating a thermally bonding material by a heating drum. CONSTITUTION: When an image-receiving material 11 as a thermally bonding material and image-receiving paper 33 as a material to be bonded in an overlapped state are heated by a heating drum 37 being rotated to be bonded to each other, the temperature of the heating drum 37 by heating is detected, and the rotating speed of the heating drum 37 is lowered correspondingly to the temperature decrease for uniformizing the total heating value at the time of heating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for superposing a heat-adhesive material and a material to be adhered and heating them by a rotating heating drum to bond the heat-adhesive material and the material to be adhered to each other. The present invention relates to a heat transfer method using an apparatus.

[0002]

2. Description of the Related Art A heating device called a laminator using a heat-adhesive material is provided with a sheet-like heat-adhesive material and an adherend material which are superposed on each other by a heating drum which is heated to a desired temperature and has a constant rotation speed. There is a heating system.

[0003]

When the peripheral length of the heating drum is shorter than the length of the thermal bonding material in the conveying direction, the heating drum heats one thermal bonding material by rotating a plurality of times. However, while the heat-adhesive material and the adherend material are superposed and heated, the heating drum is in contact with the heat-adhesive material and the adherent material, and in some cases, a carrier for conveying them by sandwiching them. The heat of the drum decreases as the number of revolutions increases. That is, even if the heating drum has a predetermined temperature during the first heating, the temperature decreases during the second heating, and further decreases during the third heating, and the heating performance gradually decreases accordingly. To do. Such a decrease in heating performance due to a decrease in the temperature of the heating drum causes a decrease in adhesiveness. The image quality deteriorates significantly.

Therefore, in order to prevent the deterioration of the heating performance due to the temperature decrease of the heating drum, it is conceivable to provide a temperature control means for the heating drum. However, since the response speed of the temperature increase is slow, the second rotation and thereafter. The temperature drop cannot be compensated for when heating. An object of the present invention is to provide a heating device and a heat transfer method capable of preventing the deterioration of the heating performance during continuous heating.

[0005]

The above object according to the present invention is achieved by the following constitution. (1) In a heating device that superimposes a heat-bonding material and a material to be bonded and heats them by a rotating heating drum to bond the heat-bonding material and the material to be bonded to each other, corresponding to the number of rotations of the heating drum. The heating device is configured to reduce the rotation speed of the heating drum. (2) Means for detecting the temperature of the heating drum in a heating device for superposing the heat-adhesive material and the material to be adhered and heating them by a rotating heating drum to bond the heat-adhesive material and the material to be adhered And a control unit that controls the heating drum to rotate at a low speed when the temperature of the heating drum decreases, in response to the temperature decrease. (3) The heat-adhesive material is a heat-sensitive recording image-receiving material, the material to be adhered is an image-receiving material, and (1) or (2) above.
A heating transfer method for transferring an image formed on the heat-sensitive recording image-receiving material onto the image-receiving material by the heating device according to.

[0006]

According to the heating device and the heat transfer method having the above-mentioned constitution, when the temperature of the heating drum is lowered due to the progress of rotation when heating is performed, the rotation speed of the heating drum is corresponding to the temperature drop of the heating drum. Since the heating speed is controlled to be low, the heating time becomes long even if the heating temperature is lowered, the total amount of heat required for heating is made substantially uniform, and deterioration of heating performance due to continuous heating can be prevented in advance.

Suitable thermal adhesive materials in the present invention include a thin film peeling type thermal recording material and a thermal recording image receiving material having thermal adhesiveness described in Japanese Patent Application No. 5-263695. The coloring material layer of the thermal recording material has a coloring material content of 40.
The layer thickness is 0.2 μm to 1.0 μm at a weight% or more, and the coloring material content is high even though the layer thickness is thinner than the conventional coloring material layer. Therefore, the color material layer has a small shearing force (force capable of peeling the color material layer) due to the layer thickness, and can be peeled in the form of fine dots. Moreover, since the coloring material layer has a much higher coloring material content than in the conventional case, a high density can be obtained even if the coloring material layer is peeled off with fine dots and transferred to the image receiving material. The content of the coloring material of 40% by weight or more means that the amount of the coloring material per unit area is significantly larger than that of the conventional one. in this way,
When the amount of coloring material per unit area is large, even a minute dot can express a gradation by coloring at a predetermined density, and the gradation range is widened.

On the other hand, the image receiving material has a cushion layer and an image receiving layer layered on a support. The cushion layer has a softening temperature of 80 ° C. or less and a thickness of 3 to 100 as measured by a Vicat method (specifically, a polymer softening point measuring method according to American Material Testing Method ASTMD-1235).
μm, and can be deformed by pressing. In addition,
The image receiving layer can also be deformed following the deformation of the cushion layer.

Specific examples of the material having a softening temperature of 80 ° C. or less as measured by the Vicat method for the cushion layer include polyolefins such as polyethylene and polypropylene, ethylene and vinyl acetate, and ethylene and ethylene copolymers such as acrylate. ,PVC,
Vinyl chloride copolymers such as vinyl chloride and vinyl acetate, polyvinylidene chloride and its copolymers, polystyrene, styrene copolymers such as styrene and (meth) acrylic acid ester, polyvinyltoluene, vinyltoluene and (meth) acrylic acid Vinyltoluene copolymers such as esters, poly (meth) acrylic acid esters, copolymers of (meth) acrylic acid esters such as butyl (meth) acrylate and vinyl acetate, acetic acid copolymer nylon, copolymer nylon, N -It is preferable to select at least one of polyamide resins such as alkoxymethylated nylon, polybutadiene, polyisoprene and their copolymers (rubber-based polymers), and organic polymer substances such as chlorinated rubber. (Japan Plastics Industry Federation, All Japan Plastics Industry Association ed., Industrial Committee issued, it is possible to softening temperature by the issued Oct. 25, 1968) is to use an organic polymer material of less than or equal to about 80 ℃.
It is also possible to add various plasticizers compatible with the high molecular weight substance to these organic high molecular weight substances to lower the substantial softening point. Furthermore, it is also possible to substantially lower the softening point to 80 ° C. or lower by adding a plasticizer compatible with an organic polymer substance having a softening point of 80 ° C. or higher. In addition, in these organic polymer substances, a substantial softening point is set to 8 in order to adjust the adhesive force with the support or the photosensitive layer.
It is also possible to add various polymers, adhesion improvers or surfactants, and release agents within the range not exceeding 0 ° C.

As an example, when an ethylene-vinyl acetate copolymer is used as a cushion layer on a polyethylene terephthalate film, the addition of a trace amount of polyethylene chloride is particularly effective. The thickness of the intermediate layer is not particularly limited as long as the total thickness with the thickness of the image receiving layer is about 8 μm or more, but preferably the cushion layer has a thickness of 3 μm to 100 μm.
Particularly preferably, it is 10 μm to 50 μm.

This cushion layer may be prepared by dissolving the above-mentioned polymer in a suitable solvent and coating it on a support, or by forming a layer previously formed on another temporary support by a method such as coating and melt extrusion. It may be transferred onto a support.

[0012]

EXAMPLES Examples of a heating apparatus to which the present invention is applied will be described below with reference to FIGS. The present invention is applied to the heat transfer apparatus shown in FIG. 1. However, in describing the embodiments, the structure and operation of the printer will be described with reference to FIGS. 6 and 7 for easy understanding of the invention. First, a description of a heat transfer device and a comparative example will be given with reference to FIGS. 1 to 5. FIG. 6 schematically shows the configuration of the printer 1, in which a toner sheet 5, which is a heat-sensitive recording material, is wound between the rollers 3a and 3b, and one roller 3a moves to the thermal head 7 during image formation. It is sent out toward and is wound around the other roller 3b. The roller 9 has a heat-sensitive image-receiving material 11 having thermal adhesiveness.
The sheet-shaped image receiving material 11 having a length of 1 unit is sent out to the upper right in FIG. Image receiving material 1
1 is supplied from the paper feed cassette 2. The thermal head 7 descends so as to come into contact with the platen roller 13 as shown in the figure during image formation, but is positioned upward during standby.

At the time of printing, one sheet of the image receiving material 11 is fed by the guide member 15 and the roller pair 17 into the reversing guide portion 19 formed in a slit shape and a curved shape as shown by an arrow A. Next, the roller pair 17 is once controlled to stop rotating, and then the roller pair 17 is rotationally driven in the opposite direction. As a result, the moving direction of the image receiving material 11 is changed from the arrow A to the arrow B, and the image receiving material 11 is sent out onto the guide plate 21 and conveyed to the lower side of the thermal head 7.

On the other hand, as shown in FIG. 7, the toner sheet 5 is formed with four thermosensitive coloring portions of K (black), C (cyan), M (magenta), and Y (yellow) in a frame sequential manner.
Then, the toner sheet 5 is synchronized with the conveyance of the image receiving material 11.
Is also sent out, and the image receiving material 11 is provided below the thermal head 7.
And the toner sheet 5 are on top of each other. At this time, the image receiving material 11 and the K portion of the toner sheet 5 are positioned so as to overlap with each other, and are conveyed between the thermal head 7 and the platen roller 13 in an overlapped state.

In this state, the thermal head 7 descends, and the thermal head 7 comes into contact with the overlaid toner sheets 5 by the cooperation of the platen roller 13. An image signal including printing is supplied to the thermal head 7, the corresponding heating element generates heat to heat the toner sheet 5, and the heated K portion is transferred to the image receiving material 11. During this time, the toner sheet 5
The image receiving material 11 is continuously conveyed, and a K image corresponding to an image signal is sequentially formed on the image receiving material 11 with the conveyance. A peeling plate 23 is provided at the tip of the thermal head 7 so that the toner sheet 5 after image formation and the image receiving material 11 are peeled off. The toner sheet 5 is taken up by the take-up roller 3b.
The image receiving material 11 is conveyed to the left side of the figure by the action of the pair of feed rollers 25.

Then, when the conveyance of the recording data is completed, the toner sheet 5 is controlled to be stopped. Next, the thermal head 7 is driven upward, and then the feed roller 25 is rotationally driven in the opposite direction, so that the image receiving material 1
1 is conveyed in the direction opposite to that at the time of image formation. Image receiving material 11
Is again conveyed in the direction of arrow A in the reversing guide portion 19, and when it has returned to a predetermined position, the conveyance is stopped. The toner sheet 5 is idly fed to the leading position of the second color C. next,
It is conveyed in the direction of arrow B by the reverse rotation drive of the roller pair 17, and C of the toner sheet 5 is placed at the lower position of the thermal head 7.
Overlaid on the part. Then, the thermal head 7 descends, the same transfer as described above is performed on the portion C, and the toner sheet 5 is stopped at the time of recording for the length of the image data.

Then, when the thermal head 7 is driven upward, the image receiving material 11 is conveyed into the reversing guide portion 19 in the same manner as described above, and the image forming material 11 is prepared for the image formation of the next M portion. A color image is formed on the image receiving material 11 by performing the same image forming operation on the M portion and the Y portion. The image receiving material 11 on which a predetermined color image has been formed in this way, that is, the image receiving material 11 on which the image formation of the Y portion is completed, is conveyed again to the reversing guide portion 19 and taken out from the rear end 19a of the conveying guide portion 19.

It should be noted that the conveyance of the image receiving material 11 in the directions of arrows A and B, the superposition of the toner sheet 5 at a predetermined position, the vertical movement of the thermal head 7 and the heating operation are all performed by a control device (not shown). It is supposed to be done. Further, the image receiving material 11 after the image formation is turned over by the reversing guide portion 1.
Illustration of rollers and the like for sending out from the rear end 19a of 9 is also omitted.

Next, the thermal transfer device will be described with reference to FIGS. The heat transfer device 31 transfers the image formed on the image receiving material 11 to art paper, coated paper, high-quality paper,
The image is transferred to the image receiving paper 33 such as a PET film, a white PET film, a synthetic paper, etc. by heat. Therefore,
The image receiving material 11 corresponds to the thermal adhesive material in the present invention, and the image receiving paper 33 corresponds to the adhered material. When heat transfer is performed, as shown in FIG. 2, the image receiving paper 32 is superposed on the image receiving material 11 and sandwiched between the pair of heating drums 37 along the guide plate 35 shown in FIG. While being conveyed by the rollers, it is heated by the heat generated from the heating drum 37, and the image G is transferred onto the image receiving paper 33 by heating as shown in FIG.

The heating drum 37 is provided with a halogen lamp 39 which is a heat source at the center thereof, and its temperature is kept at a predetermined temperature by a temperature control circuit (not shown). But,
When the heat transfer is performed, the heat of the heating drum 37 is removed, and the temperature is lowered at the time of the second heat transfer, and the transfer performance is also lowered. The halogen lamp 39 is provided with a temperature control circuit, but since the response speed of heat is slow, the second rotation, the third
The temperature rise of the halogen lamp 39 cannot keep up with the rotation and the subsequent heat transfer. Therefore, in this embodiment, the rotation speed of the heating drum 37 is controlled according to the temperature of the heating drum 37, and the heating time is adjusted according to the temperature. According to this configuration, since the amount of heat required for transfer can be made constant even if the heating temperature is decreased, it is possible to prevent the transfer performance from being deteriorated.

Next, the structure of the rotation control circuit 41 will be described. The rotation control circuit 41 includes a temperature detection element 43 such as a thermistor for detecting the temperature of the heating drum 37, a buffer amplifier 45, an amplification circuit 47 for amplifying a temperature signal, a motor drive circuit 49 including a current control transistor Tr, and a heating drum. The motor 37 is configured to rotate and drive 37.

The buffer amplifier 45 is assumed to have a linear correction function because the temperature characteristic of the thermistor is non-linear. The amplifier circuit 47 has an amplification factor α times O.
A control transistor Tr which is composed of a P-amplifier, a feedback circuit with a feedback factor of β, and a reference voltage Vref to amplify a minute temperature signal to form a motor drive circuit 49.
Is for driving. The motor drive circuit 49 is
A control transistor Tr is connected between the power source Vcc and the motor M, and the drive current of the motor M is controlled by the control transistor Tr.

In the case of performing heat transfer, the image receiving paper 33 is superposed on the image receiving material 11 and conveyed on the guide plate 35 shown in FIG. The image receiving material 11 is shown in FIG.
As shown in FIG.
And the image receiving layer 11c are formed, and the image G is formed on the surface of the image receiving layer 11c by the printer 1 described with reference to FIGS. 6 and 7. At the time of heat transfer, as shown in FIG. 2, the image G forming surface is superposed so as to be in contact with the image receiving paper 33, and is sandwiched by the heating drum 37 as described above. By the first thermal transfer of the heating drum 37, the image G is thermally transferred to the image receiving paper 33 as shown in FIG. Then, the heating transfer of the second rotation is performed.
The following rotation control of the motor M is performed in response to the decrease in temperature.

That is, when the temperature of the heating drum 37 is lowered by the first thermal transfer, this temperature drop is detected by the thermistor 43, and the temperature signal Vt obtained from the buffer amplifier 45 is lowered in level. The temperature signal Vt is amplified by the amplifier circuit 47, and the control signal Tr is driven by the output signal. However, since the level of the output signal is lowered, the control transistor Tr reduces the drive current of the motor M. As a result, the motor M shifts to low speed rotation,
The time width of one rotation of the heating drum 37 is extended. Therefore, at the time of the second heat transfer, the temperature of the heating drum 37 decreases, but the time width during which the image receiving material 11 and the image receiving paper 33 are heated by the heating drum 37 becomes longer, and the amount of heat to be transferred by heating is kept constant. To be done. Therefore, the transfer performance at the time of heat transfer becomes equivalent to that at the first time, and uniform heat transfer is performed.

When the second thermal transfer is performed,
The temperature of the heating drum 37 further decreases. However, the control of the drive current of the motor M from the temperature detection is performed in the same manner as described above,
Since the amount of heat required for the heat transfer is kept constant, the heat transfer after the third rotation can be favorably performed. On the other hand, 1
If the next heat transfer is not performed after the heat transfer of the rotation or the plurality of rotations is performed, the temperature of the heating drum 37 rises. In this case, the level of the temperature signal Vt obtained from the buffer amplifier 45 rises and the output signal of the amplifier circuit 47 also rises in level, so that the drive current of the motor M also increases. Therefore, the motor M shifts to high-speed rotation, but since the heat of the halogen lamp 39, that is, the heat of the heating drum 37 is controlled by the temperature control circuit, it does not change beyond a predetermined rotation speed. Even in this case, good heat transfer can be performed.

[0026]

[Embodiment 1] Next, an embodiment will be described with reference to FIGS. When the length of the image receiving paper 33 is 500 mm and the heat transfer speed (laminating speed) is set to 15 mm / s, transfer failure (adhesion failure) occurs from 240 mm from the tip (at the third rotation) in the conventional configuration. occured. On the other hand, as shown in FIG. 4, the rotation of the heating drum 37 is changed by 15 times for the first rotation in response to the temperature decrease of the heating drum 37.
mm / s, 10 mm / s for the second rotation, 8 mm / s for the third rotation, and 5 mm / s for the fourth and subsequent rotations, good heat transfer could be performed from the leading edge to the trailing edge.

[0027]

[Embodiment 2] The rotation speed of the heating drum 37 is 10 mm / s.
When heat transfer was performed with a constant setting, as shown in the upper left part of FIG. 5, from the front end of the image receiving paper 33 to 120 mm (1
There was a slight graininess on the rotation eye). Also, the image receiving paper 3
From the position of about 480 mm (5th rotation) from the tip of 3,
As shown in the lower right of FIG. 5, transfer failure (adhesion failure) occurred. On the other hand, when the rotation speed is controlled in accordance with the temperature of the heating drum 37 as shown in this embodiment, good heat transfer without roughness or transfer failure can be achieved in the range shown in the central part of FIG. I was able to do it. The heating drum 3
The calculation formula for setting the rotation speed of No. 7 was obtained by the following formula. Rotation speed (mm / s) = temperature of heating drum (° C) / 2-
65. In this case, good heat transfer could be performed from the front end to the rear end of the image receiving paper 33.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. That is, the present invention can be applied not only to the heat transfer device 31 but also to a heat developing device in a recording device using a photothermographic material. The heat-adhesive material need not be a recording material, but may be a simple laminate material. Therefore, the present invention can also be applied to an apparatus for laminating sheet-like materials. When the heat-sensitive recording material is heated with a heating drum to develop a color, it can be applied to, for example, a heat-sensitive recording material based on diazo color development. Since the present invention can be applied to a material having a narrow temperature allowable range, it has an effect of widening the material design latitude and facilitating the material design as well as the design of the heat transfer device.

[0029]

As described above, in the heating device and the heat transfer method according to the present invention, the heat-adhesive material and the adherend material are superposed and heated by the rotating heating drum, and the heat-adhesive material and When adhering to the material to be adhered, the rotation speed of the heating drum is reduced corresponding to the temperature drop of the heating drum due to heating, the heating time is lengthened, and the total amount of heat during heating is made uniform. Therefore, even if the temperature of the heating drum decreases, the heating performance does not decrease, and good heating can be continued.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of a thermal transfer device that is an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of an image receiving material and the superposition of the image receiving paper.

FIG. 3 is a cross-sectional view of an image receiving material and an image receiving paper showing an example of image transfer.

FIG. 4 is a characteristic diagram showing the relationship between the temperature of the heating drum and the rotation speed of the heating drum.

FIG. 5 is a characteristic diagram showing the relationship between the temperature of the heating drum and the heating rate.

FIG. 6 is a configuration diagram showing the configuration and operation of the printer.

FIG. 7 is a plan view showing a superposition of a toner sheet and an image receiving material.

[Explanation of symbols]

 11 Image Receiving Material 31 Heat Transfer Device 33 Image Receiving Paper 35 Guide Plate 37 Heating Drum 39 Halogen Lamp 41 Rotation Control Circuit 43 Temperature Detecting Element 45 Buffer Amplifier 46 Amplifying Circuit 49 Motor Driving Circuit G Image M Motor

Claims (3)

[Claims] 1. A heating device for superposing a heat-adhesive material and a material to be adhered on each other and heating them by a rotating heating drum to bond the heat-adhesive material and the material to be adhered to each other. Correspondingly, the heating device is characterized in that the rotation speed of the heating drum is reduced. 2. A heating device for superposing a heat-adhesive material and a material to be adhered on each other and heating them by a rotating heating drum to bond the heat-adhesive material and the material to be adhered to each other, and detects the temperature of the heating drum. And a control means for controlling the heating drum to rotate at a low speed when the temperature of the heating drum decreases, in response to the temperature decrease. 3. The heat-sensitive adhesive material is a heat-sensitive recording image-receiving material, and the adherend material is an image-receiving material.
A heating transfer method for transferring an image formed on the heat-sensitive recording image-receiving material onto the image-receiving material by the heating device according to.