JPH08142364A - Thermal recording apparatus - Google Patents

Abstract

PURPOSE: To provide a thermal recording apparatus capable of outputting a high-grade sublimable dye image not only to special paper but also to plain paper and preventing the output of recording paper in a wet state by bringing a pressure contact roller into contact with recording paper under pressure up to the rear end thereof. CONSTITUTION: A dyeing layer 3b is formed on an intermediate transfer medium 2 and a sublimable dye image 15 is formed on the dyeing layer 3b and, thereafter, the dyeing layer 3b having the sublimable dye image 15 formed thereon is thermally transferred to recording paper 12 by a pressure contact roller 8. At the time of the transfer of the dyeing layer 3b to the recording paper 12, the pressure roll 8 is certainly brought into contact with the recording paper 12 under pressure up to the rear end part thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal recording apparatus which is used in a copying machine, a fax machine, a printer or the like, and which outputs a desired image or characters on a recording paper according to an electric signal.

[0002]

2. Description of the Related Art In recent years, as a recording system used in printers and the like, a sublimation type thermal recording system using a thermal head and an ink sheet holding a sublimable dye, as disclosed in JP-A-1-275163, has been proposed. It has been put to practical use.

An example of a conventional thermal recording apparatus using this thermal recording system will be described below. FIG. 8 is a block diagram of a conventional thermal recording device using a sublimable dye. In FIG.
Reference numeral 112 is a recording paper in which a dyeing layer is provided on a thick base material such as synthetic paper, and 104 is a thermal head having a large number of heating elements 105 arranged in rows in the width direction of the recording paper 112. . Reference numeral 103 is an ink sheet, and a dye layer 103c containing a sublimable dye is applied on a film-shaped substrate 103a. The thermal head 104 is the ink sheet 10
The dye layer 103c of No. 3 and the dye layer 103c are pressed against the platen 117 together with the recording paper 112.

In this state, the platen 117 and the recording paper 11
2 and the ink sheet 103 are respectively moved in the directions of the arrows to heat the heating element 105 in accordance with the recording signal, heat the sublimable dye of the dye layer 103c in the portion facing the heating element 105, and the dyeing layer of the recording paper 112. Move to. By this operation, the sublimable dye image 115 can be obtained on the recording paper 112. Further, by using the dye layer 103c containing sublimable dyes of three colors of Y, M, and C, a high-definition full-color image can be obtained.

[0005]

However, in the conventional recording apparatus using the sublimable dye, it is necessary to use the special paper as the recording paper, and it is impossible to output the desired recording paper. Further, since this special paper is expensive, it has a drawback of high running cost.

Further, an intermediate transfer medium, a dyeing layer sheet supporting a dyeing layer, a dye layer sheet supporting a dye layer, a thermal head, and a transfer means including a heat roll are used, and the intermediate transfer medium is temporarily used. A sublimation dye image was formed by forming a dyeing layer on the transfer medium, forming a sublimable dye image on the dyeing layer, and then pressing a heat roll against the intermediate transfer medium through a recording paper. A method is also conceivable in which the dyeing layer is thermally transferred onto recording paper to obtain output. With this method, it is not necessary to use special paper, and a sublimable dye image can be obtained even on plain paper. However, the following problems will occur unless the method of pressing the heat roll onto the intermediate transfer medium through the recording paper and the material of the surface of the heat roll are sufficiently taken into consideration. When the recording paper is pressed against the intermediate transfer medium with a hot roll, the water contained in the recording paper is squeezed, and the water moves to the rear part of the recording paper.
After thermally transferring the rear end of the dyeing layer to the recording paper, if the heat roll is separated from the intermediate transfer medium in a state where the rear end of the recording paper has not been pressed against the intermediate transfer medium, the recording paper can be separated. The part becomes wet. The fact that the recording paper is output in a wet state is a very low degree of perfection of the device, and even if the recording paper dries after that, there are many cases where wrinkled areas become wrinkled. ,
The output image is of low quality.

In view of the above-mentioned conventional problems, the present invention provides not only a full-color image using a sublimable dye on special paper, but also
The present invention provides a thermal recording device capable of outputting even on plain paper. Further, the present invention provides a stable thermal recording apparatus of a process in which the rear end of the recording paper is not output in a wet state.

[0008]

In order to solve the above-mentioned problems, a thermal recording apparatus of the present invention comprises an intermediate transfer medium, a dyeing layer sheet having a dyeing layer on a film-shaped substrate, and a film-shaped dyeing layer sheet. A dye layer sheet having a dye layer containing a sublimable dye on a substrate, a dyeing layer forming means for forming a dyeing layer of the dyeing layer sheet on an intermediate transfer medium, and a dye layer of the dye layer sheet selectively. Thermal image forming means for forming a sublimable dye image on the dyeing layer formed on the intermediate transfer medium by heating, and the dyeing layer formed on the intermediate transfer medium by pressure contact with the intermediate transfer medium via the recording paper. And a transfer means for thermally transferring to the recording paper together with the sublimable dye image formed thereon, and after pressing the intermediate transfer medium and the transferring means through the recording paper, until the rear end of the recording paper is pressed. Has a configuration in which the intermediate transfer medium and the transfer means are not separated from each other. .

Further, the transfer means is composed of a pressure contact roll provided with means for heating and maintaining a desired temperature, and the surface which is in pressure contact with the intermediate transfer medium through the recording paper has a thermal conductivity of 0.0.
It is formed of a substance of 8 to 5 W / m · ° C.

Preferably, the dyeing layer sheet and the dyeing layer sheet are those in which a dye layer and the dyeing layer are applied face-sequentially to a film-shaped substrate, and the thermal image forming means is a thermal head. This thermal head is also used as a dyeing layer forming means. The dyeing layer forming portion uses an intermediate transfer medium containing at least silicone rubber.

[0011]

As described above, the present invention forms a dyeing layer on an intermediate transfer medium, records a sublimable dye image on the dyeing layer, and further forms a dyeing layer on which the sublimable dye image is recorded. Since it is a method of thermal transfer to recording paper, it is possible to output a high-definition full-color image not only on special paper but also on plain paper.

In addition, after the intermediate transfer medium and the transfer means are pressed against each other via the recording paper, the intermediate transfer medium and the transfer means are not separated from each other until the rear end of the recording paper is completely pressed. Therefore, the water in the recording paper can be discharged from the rear end of the recording paper to the outside of the recording paper. Therefore, it is possible to provide a stable thermal recording apparatus of the process in which the rear end of the recording paper is not output in a wet state.

Further, the transfer means is composed of a pressure contact roll provided with means for heating and keeping a desired temperature, and the surface which is in pressure contact with the intermediate transfer medium through the recording paper has a thermal conductivity of 5 W /
Since it is formed of a substance having a temperature of m · ° C. or less, when the moisture released from the recording paper comes into contact with the pressure roll, it is possible to prevent the moisture from abruptly evaporating and generating an abnormal sound. Further, since the thermal conductivity is 0.08 W / m · ° C. or higher, heat can be satisfactorily transferred to the recording paper, whereby the dyeing layer can be satisfactorily transferred to the recording paper.

[0014]

EXAMPLE A thermal recording apparatus according to an example of the present invention will be described below.
This will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an intermediate transfer drum made of metal, on the surface of which an intermediate transfer medium 2 made of silicone rubber having a proper releasability is provided, and a driving means (not shown). ) To rotate at a desired speed. Silicone rubber has a hardness of 20 to 70 degrees and a film thickness of 0.1 m
The thickness of m to 2 mm is preferably used, but in the present embodiment, a hardness of 50 degrees and a film thickness of 0.4 mm is used.

In the present embodiment, the intermediate transfer medium 2 is formed of silicone rubber having a proper releasability, but it may be a silicone rubber holding an adhesive material, and has a proper releasability. As long as it is held, for example, a fluorine-based polymer material, a silicone-based polymer material,
PET or polyimide resin may be used.

Reference numeral 3 is an ink sheet which is a combination of a dyeing layer sheet and a dye layer sheet. Details of the ink sheet 3 are shown in FIG. The ink sheet 3 has a film thickness of 3 to
The dyeing layer 3b and the dye layer 3c are applied on a base material 3a made of a PET film having a thickness of about 9 μm. Polyvinyl butyral resin is used for the dyeing layer 3b. The dye layer 3c is composed of at least a sublimable dye and a binder. As the sublimable dye, disperse dyes, oil-soluble dyes, basic dyes and the like are used. Polyester, acrylic styrene resin, or the like is used as the binder. The ink sheet 3 has a dyeing layer 3b and Y, M, and C dye layers 3c formed in a frame-sequential manner. In addition, the back surface of the base material 3a is subjected to a heat resistant slip treatment.

A thermal head 4 serves as both a dyeing layer forming means and a thermal image forming means.
The heating elements 5 that generate heat when energized are formed in rows. Reference numeral 6 denotes a thermal head separating / contacting lever, which supports the thermal head 4 so as to be capable of separating / contacting the intermediate transfer medium 2.
Reference numeral 7 is a spring for pressing the thermal head 4 against the intermediate transfer medium 2.

Reference numeral 8 is a pressure roller made of metal, and a coating layer 9 is formed on the outer peripheral surface of the pressure roller 8. The coating layer 9 has a thickness of 0.5 mm, a rubber hardness of 50 degrees, and a thermal conductivity of 0.
2W / m · ° C silicone rubber is used. Although silicone rubber is used for the coating layer 9 in the present embodiment, if the thermal conductivity is 0.08 to 5 W / m.degree. C. and the heat resistance is good, for example, fluororubber, fluororesin, polyimide. Etc. are also preferably used. Pressing roll 8 is lever 1
The recording paper 12 is rotatably supported by 0 and the spring 11.
The intermediate transfer medium 2 can be pressed against the intermediate transfer medium 2 at a desired pressure. Reference numeral 13 is a halogen lamp for heating the press contact roll 8 to keep it warm. Reference numeral 14 denotes a thermistor for detecting the surface temperature of the coating layer 13, which is connected to a temperature control means (not shown). The halogen lamp 13 is turned on and off in accordance with the temperature detected by the thermistor 14, and the surface of the coating layer 9 is desired. Control to the temperature of. The pressure contact roll 8, the coating layer 9, the lever 10, the spring 11, the halogen lamp 13, and the thermistor 14 constitute a transfer unit. Further, in FIG. 3, reference numeral 15 denotes a sublimation dye image formed on the dyeing layer 3b formed on the intermediate transfer medium 2.

Next, the operation of the thermal recording apparatus configured as described above will be described with reference to the drawings.

First, in FIG. 1, when the power of the apparatus is turned on, the halogen lamp 13 emits light. Thereafter, according to the temperature detected by the thermistor 14, the halogen lamp 13 is repeatedly turned on and off, whereby the pressure roll 8 is pressed.
The surface of the upper coating layer 9 can be heated and kept at a preset temperature. The set temperature of the coating layer 9 varies depending on the material of the intermediate transfer medium 2, the material of the dyeing layer 3b, the pressure contact force of the pressure roller 8 with respect to the intermediate transfer medium 2, etc., but is set to 150 ° C. in this embodiment.

Next, the thermal head 4 is attached to the ink sheet 3
The intermediate transfer drum 1 is pressed against the intermediate transfer drum 1 via the intermediate transfer drum 1 and is held at a position where the dyeing layer 3b of the ink sheet 3 contacts the intermediate transfer medium 2. In this state, the intermediate transfer drum 1 is rotated in the direction of the arrow shown, and the ink sheet 3 is run in the direction of the arrow shown so that the relative speed to the intermediate transfer medium 2 becomes zero. The peripheral speed of the intermediate transfer drum 1 is 10 mm / s
It is set to ec. At this time, a control unit (not shown) gives a drive signal to the thermal head 4 to heat the heating element 5 at the tip of the thermal head 4. By this heat, the adhesive force between the intermediate transfer medium 2 and the dyeing layer 3b can be made larger than the adhesive force between the dyeing layer 3b and the base material 3a. Therefore, the dyeing layer 3b of the ink sheet 3 can be formed on the intermediate transfer medium 2. In the present embodiment, the thermal head 4 was caused to generate heat when the dyeing layer 3b was formed. However, if the adhesive force between the intermediate transfer medium 2 and the dyeing layer 3b is sufficient at room temperature, it is not always necessary to generate heat. Absent.

Next, the operation of forming the sublimable dye image 15 on the dyeing layer 3b formed on the intermediate transfer medium 2 will be described with reference to FIG. In FIG. 3, the dyeing layer 3 in which the Y-colored portion of the dye layer 3c of the ink sheet 3 is formed on the intermediate transfer medium 2
The intermediate transfer medium 2 and the ink sheet 3 are moved in the same position as when the dyeing layer 3b is formed. At this time, a control unit (not shown) gives a drive signal to the thermal head 4, and the thermal head 4 is driven according to the image pattern.
The heating element 5 is heated. As a result, the dye layer 3c is heated, the sublimable dye of the dye layer 3c is thermally diffused and transferred to the dyeing layer 3b formed on the intermediate transfer medium 2, and the Y-color sublimable dye image 15 is transferred to the dyeing layer 3b. Is obtained. Furthermore, by performing the same operation for the dye layers 3c of M and C colors,
Sublimation dye images 15 of three colors Y, M and C can be obtained on the dyeing layer 3b.

Next, the operation of transferring the dyeing layer 3b having the sublimable dye image 15 formed thereon to the recording paper 12 will be described with reference to FIG. First, the recording paper 12 is conveyed by a paper feeding means (not shown). In this state, as shown in FIG. 4, the pressure roller 8 heated and kept in heat is pressed against the intermediate transfer medium 2 via the recording paper 12 to dye and form the sublimable dye image 15 on the intermediate transfer medium 2. The layer 3b can be thermally transferred to the recording paper 12. At this time, the pressure contact force of the pressure contact roll 8 to the intermediate transfer medium 2 is configured to be a linear pressure of 2 kgf / cm. With this pressure contact force, the intermediate transfer drum 1
Peripheral speed of 10 mm / sec, heating temperature 1 of the coating layer 9
At 50 ° C., the dyeing layer 3b could be satisfactorily transferred onto the recording paper 12 having a Bekk smoothness of 3 seconds and a thickness of 150 μm. At this time, since the intermediate transfer medium 2 is made of flexible silicone rubber, the silicone rubber can be made to follow the irregularities on the surface of the recording paper 12. As a result, the dyeing layer 3b could be made to closely follow the irregularities of the recording paper 12, and an output with good fixability could be obtained.

Next, the state of the water content of the recording paper 12 during the transfer operation of the dyeing layer 3b to the recording paper 12 will be described with reference to FIGS. 5, 6 and 7. Figure 5
FIG. 6 is a partially enlarged view showing a state in which a pressure roller 8 is pressed against the intermediate transfer medium 2 via a recording paper 12. Here, 16 represents moisture. The moisture 16 in the recording paper 12 was substantially evenly present in the recording paper 12 before being pressed against the intermediate transfer medium 2. However, when the moisture 16 is pressed against the intermediate transfer medium 2 by the pressing roll 8, the water 16 Is the pressure contact roll 8 and the intermediate transfer medium 2
Since it is difficult to pass through the nip between and, it will be in a state of accumulating in front of the nip. At this time, it is considered that most of the moisture 16 in the recording paper 12 moves in the state of water vapor, not in the liquid state, and a considerable amount of the moisture 16 does not pass through the nip and moves to the rear portion of the recording paper 12. To go. Further, it is considered that a certain amount of the water 16 becomes water vapor and moves to the outside of the recording paper 12. Further, by heating from the surface of the recording paper 12 opposite to the surface on which the dyeing layer 3b is transferred, the moisture 16 easily accumulates on the side of the recording paper 12 to which the dyeing layer 3b is transferred.

Next, a case where the pressure roller 8 is not completely pressed to the rear end of the recording paper 12 will be described with reference to FIG. FIG. 6 is a partially enlarged view showing a state in which the pressure roll 8 is separated from the intermediate transfer medium 2 from the state of FIG. In FIG. 6, it goes without saying that the pressing roller 8 is separated from the intermediate transfer medium 2 after the transfer of the dyeing layer 3b to the recording paper 12 is completely completed. Recording paper 12 in the state of FIG.
When the pressure contact with the intermediate transfer medium 2 is released, the water accumulated in front of the nip between the pressure contact roll 8 and the intermediate transfer medium 2 stops moving in that state. The surface to which 3b is transferred becomes wet.
The fact that the recording paper 12 is output in a wet state does not directly adversely affect the image portion, but it is a low degree of perfection as an apparatus. Further, even if the recording paper 12 output in a wet state dries thereafter, the wet portion becomes a paper wrinkle state, resulting in a low quality output image.

Next, the case where the pressure roller 8 is completely pressed to the rear end of the recording paper 12 will be described with reference to FIG.
FIG. 7 is a partially enlarged view showing a state immediately after the rear end of the recording paper 12 is completely pressed. In FIG. 5, the moisture 16 that has accumulated in front of the nip between the pressure roller 8 and the intermediate transfer medium 2 moves to the trailing edge of the recording paper 12 one after another, and finally from the trailing edge of the recording paper 12 to the recording paper 12. Is released to the outside. In this state, the recording paper 12 has no water 16 accumulated therein, and even if the pressure roller 8 is separated from the intermediate transfer medium 2, the recording paper 12 is not output in a wet state. Also,
Immediately after the press contact of the rear end of the recording paper 12 is finished, the press roll 8
And the water 16 collected before the nip between the intermediate transfer medium 2 and
Since it comes into direct contact with the coating layer 9 of the pressure roll 8,
Evaporates in a short time. Further, even when the water 16 accumulated in the nip between the pressure roller 8 and the intermediate transfer medium 2 is large and does not evaporate in a short time, the water 16 is not formed on the intermediate transfer medium 2 to form the dyeing layer 3b. Since it can be easily retained at the position, it is possible to easily realize a configuration in which the water 16 does not affect the output image at all.

Further, the importance of the thermal conductivity of the coating layer 9 will be described. When the thermal conductivity of the coating layer 8 is low, it is difficult to transfer heat to the recording paper 12 during the transfer operation of the dyeing layer 3b to the recording paper 12, and it is necessary to increase the heat retention temperature of the coating layer 9. The heat retention temperature of the coating layer 9 is preferably as low as possible within a range in which the dyeing layer 3b can be satisfactorily transferred to the recording paper 12 from the viewpoints of increase in temperature inside the apparatus, power consumption, heat resistance of various materials, and the like. As a result of an experiment conducted from this point of view, the thermal conductivity of the material of the coating layer 9 had to be 0.08 W / m · ° C or higher. When the thermal conductivity of the coating layer 9 is high, the coating layer 9 is directly in contact with the moisture 16 collected before the nip between the pressure roller 8 and the intermediate transfer medium 2 immediately after the pressure contact after the recording paper 12 is finished. At this time, the water 16 rapidly changes to water vapor, and an abnormal sound is generated. The abnormal sound itself does not directly affect the output image, but is not preferable for the device. Therefore, as a result of conducting an experiment from the viewpoint of whether or not an abnormal sound is generated, the thermal conductivity of the material of the coating layer 9 needs to be 5 W / m · ° C or less. Therefore,
In this embodiment, since the thermal conductivity is sufficiently taken into consideration, the dyeing layer 3b can be satisfactorily transferred to the recording paper 12 and the generation of abnormal sound can be prevented.

In this way, it is possible to obtain a high-quality full-color image on recording paper other than special paper, which could not be obtained by the conventional thermal recording method using a sublimable dye. Therefore, the running cost can be reduced. Further, it is possible to provide a thermal recording device in which no abnormal sound is generated and the recording paper is not output in a wet state.

Although the intermediate transfer drum 1 is used in this embodiment, a belt-shaped substrate on which the intermediate transfer medium 2 is formed can also be preferably used.

Further, in this embodiment, the dyeing layer 3b and Y, M,
Ink sheet 3 on which C dye layer 3c is formed in a frame-sequential manner
However, the dyeing layer 3b and the dye layers 3c of Y, M, and C may be formed on different sheets, and the dye layers 3c of Y, M, and C may be different from each other. It may be formed on a sheet.

[0032]

INDUSTRIAL APPLICABILITY As described above, the present invention forms a dyeing layer on an intermediate transfer medium, records a sublimable dye image on the dyeing layer, and further dyes the sublimable dye image. Since the layers are thermally transferred to the recording paper, it is possible to output a high-definition full-color image not only on special paper but also on plain paper.

Further, after the intermediate transfer medium and the transfer means are pressed against each other via the recording paper, the intermediate transfer medium and the transfer means are not separated from each other until the rear end portion of the recording paper is pressed against each other. Therefore, the water in the recording paper can be discharged from the rear end of the recording paper to the outside of the recording paper. Therefore, it is possible to provide a stable thermal recording apparatus of the process in which the rear end of the recording paper is not output in a wet state.

Further, the transfer means is composed of a pressure contact roll provided with means for heating and maintaining a desired temperature, and the surface which is in pressure contact with the intermediate transfer medium through the recording paper has a thermal conductivity of 5 W /
Since it is formed of a substance having a temperature of m · ° C. or less, when the moisture released from the recording paper comes into contact with the pressure roll, it is possible to prevent the moisture from abruptly evaporating and generating an abnormal sound. Further, since the thermal conductivity is 0.08 W / m · ° C. or higher, heat can be satisfactorily transferred to the recording paper, whereby the dyeing layer can be satisfactorily transferred to the recording paper.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a thermal recording apparatus in an embodiment of the present invention.

FIG. 2 is a detailed view of an ink sheet in the same embodiment.

FIG. 3 is a schematic diagram showing an operation of forming a sublimable dye image in the example.

FIG. 4 is a schematic diagram showing a transfer operation of a dyeing layer onto recording paper in the example.

FIG. 5 is a partially enlarged view showing a state in which the pressure contact roll in the embodiment is in pressure contact with the intermediate transfer medium via the recording paper.

FIG. 6 is a partially enlarged view showing a state in which the pressure roller is separated from the intermediate transfer medium without completely pressing the pressure roller to the trailing edge of the recording paper in the embodiment.

FIG. 7 is a partial enlarged view showing a state in which the pressure contact roll is separated from the intermediate transfer medium after the pressure contact roll in the embodiment is completely pressure contacted to the trailing edge of the recording paper.

FIG. 8 is a schematic configuration diagram of a conventional thermal recording device.

[Explanation of symbols]

2 Intermediate transfer medium 3 Ink sheet (also serving as a dyeing layer sheet and dye layer sheet) 3a Substrate 3b Dyeing layer 3c Dye layer 4 Thermal head (having a sublimation recording means and a dyeing layer forming means) 5 Heating element 8 Pressure contact roll 9 Covering layer 13 Halogen lamp 14 Thermistor 15 Sublimable dye image

Claims (5)

[Claims] 1. An intermediate transfer medium, a dyeing layer sheet having a dyeing layer on a film substrate, a dye layer sheet having a dye layer containing a sublimable dye on a film substrate, and the dyeing. A dyeing layer forming means for forming a dyeing layer of a layer sheet on the intermediate transfer medium, and a dye layer of the dye layer sheet is selectively heated to sublimate into a dyeing layer formed on the intermediate transfer medium. Thermal image forming means for forming a volatile dye image and the intermediate transfer medium through pressure contact with a recording paper to record the dyeing layer formed on the intermediate transfer medium together with the sublimable dye image formed on the dyeing layer. A transfer means for thermally transferring to the paper, and after the intermediate transfer medium and the transfer means are pressed against each other via the recording paper, the intermediate transfer medium and the transfer means are pressed until the rear end of the recording paper is pressed. A thermal recording device characterized by not separating. 2. The transfer means is composed of a pressure contact roll provided with means for heating and maintaining a desired temperature, and the surface of the transfer means which is in pressure contact with the intermediate transfer medium through the recording paper has a thermal conductivity of 0.08 to 5.
The thermal recording apparatus according to claim 1, wherein the thermal recording apparatus is formed of a material having a W / m · ° C. 3. The thermal recording apparatus according to claim 1, wherein the thermal image forming means is a thermal head. 4. The thermal image forming means also serves as a dyeing layer forming means, and the dyeing layer sheet and the dye layer sheet are formed by applying a dyeing layer and a dye layer to a film-shaped substrate in a face-sequential manner. The thermal recording apparatus according to claim 3, wherein the thermal recording apparatus is provided. 5. The thermal recording apparatus according to claim 1, wherein the dyeing layer forming portion is an intermediate transfer medium containing at least silicone rubber.