JP2003094703A - Thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal printer capable of eliminating waste of thermosensitive paper by narrowing a margin part produced in the thermosensitive paper, and executing a high quality printing operation without generation of slack in the thermosensitive paper even in the case the thermosensitive paper is replaced by new one. SOLUTION: In this thermal printer comprising a thermosensitive paper 4, a conveyance roller 8 for conveying the thermosensitive paper 4 in the arrow C conveyance direction, an ink ribbon 15 coated with an ink to be thermally transferred onto the thermosensitive paper 4, and a power source (not shown) for supplying the electric power at least to the driving source of the conveyance roller 8, a first thermal head 5 capable of executing a first printing operation by developing the color of a thermosensitive paper 4 being conveyed by the conveyance roller 8 and a second thermal head 9 capable of executing a second printing operation by thermally transferring an ink by pressing the ink ribbon 15 against the thermosensitive paper 4 are provided such that the thermosensitive paper 4 is conveyed by a predetermined amount in the arrow D paper discharging direction by rotating the conveyance roller 8 in one direction (clockwise direction) at the time of replacing the thermosensitive paper 4 or switching on the power source.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer, and more particularly to a thermal printer that performs thermal transfer printing by color-developing a thermal paper and transferring the ink of an ink ribbon to the thermal paper that has been colored.

[0002]

2. Description of the Related Art Conventionally proposed thermal printers store roll-shaped thermal paper in a paper storage unit, and a first thermal head is provided downstream of the paper storage unit in the transport direction of the thermal paper and a first thermal head. A first platen roller, which is in pressure contact with the first thermal head via a thermal paper, is provided. Further, a second thermal head and a second platen roller capable of coming into contact with and separating from the second thermal head are arranged on the downstream side of the first thermal head in the thermal paper transport direction. The thermal head makes it possible to transfer the ink from the ink ribbon to the thermal paper.

Further, a transport roller and a pressure roller which are in pressure contact with each other are disposed downstream of the second platen roller in the direction of transport of the thermal paper. The thermal paper is pressed and nipped between the transport roller and the pressure contact roller, and the transport roller is driven to rotate, whereby the first thermal head and the first thermal head
The platen and the thermal paper located between the second thermal head and the second platen roller can be conveyed in the paper discharge direction. Further, a paper cover that can open and close the paper storage unit is provided above the paper storage unit that stores the thermal paper, and this paper cover prevents dust and the like from entering the paper storage unit. Further, the sheet cover has a transport roller and first and second platen rollers pivotally supported,
In conjunction with opening and closing of the paper cover, the transport roller can be brought into and out of contact with the pressure contact roller, and the first and second platen rollers can be brought into and out of contact with the first and second thermal heads.

Further, a sheet cutting device is provided downstream of the conveying roller and the pressure contact roller in the conveying direction of the thermal paper so that the thermal paper printed by the first and second thermal heads can be cut. Has become. In such a conventionally proposed thermal printer, by selectively heating the heating element of the first thermal head, for example, black characters or the like are colored on the thermal paper to enable thermal printing. In addition, the second thermal head is lowered on the thermal paper after thermal printing by the first thermal head, and an ink ribbon having ink of a color such as cyan is pressed and thermally transferred to the thermal paper. It is possible to print two colors of black and cyan.

Further, the printed thermal paper is conveyed to a paper cutting device, and the printed page is cut and discharged. When the thermal paper stored in the paper storage section is used up, the paper cover on the paper storage section is opened and closed.
In conjunction with the opening and closing of the paper cover, the transport roller and the first and second platen rollers are moved upward to replace the thermal paper with a new one.

[0006]

However, in the conventionally proposed thermal printer, when the thermal paper is replaced with a new thermal paper and the paper storage unit is closed with the paper cover, the first platen roller causes the first platen roller to move to the first position. The thermal head is brought into pressure contact with the conveying roller by the pressure roller via the exchanged thermal paper. However, at the time of each pressure contact, slack may occur in the thermal paper between the first thermal head and the transportation roller. there were. At this time, the second thermal head is in the up state and is separated from the second platen roller.

When slack occurs in the thermal paper between the first thermal head and the transport roller, the positional accuracy of thermal transfer printing in which the second thermal head is moved down to thermally transfer the ink of the ink ribbon cannot be obtained. However, there is a risk that misalignment may occur between the image printed by thermal printing in the first printing and the image printed by thermal transfer in the second printing, resulting in defective printing. Also, the thermal paper after printing is cut by the paper cutting device, but the margin from the leading edge of the next printed page to the first printed line of the next page is long, and the thermal paper is cut. There was a problem that was wasted.

The present invention has been made in view of the above-mentioned points, and reduces the margin of the thermal paper to reduce the waste of the thermal paper, and even if the thermal paper is replaced with a new thermal paper. An object of the present invention is to provide a thermal printer capable of high-quality printing without causing slack in the paper.

[0009]

As a first means for solving the above problems, a thermal printer according to the present invention comprises a thermal paper, a transport roller capable of transporting the thermal paper in a predetermined transport direction, and the thermal paper. An ink ribbon having a transferable ink applied to a sheet of paper and a power source capable of supplying power to at least a driving source of the carrying roller are provided, and the thermal paper carried by the carrying roller is colored to perform the first printing. The thermal paper is provided with a first thermal head and a second thermal head capable of performing second printing by pressing the ink ribbon onto the thermal paper transported by the transport roller to transfer the ink. At the time of replacement or when the power source is turned on, the transport roller is rotated in one direction to transport the thermal paper by a predetermined amount in the paper discharge direction.

As a second means for solving the above-mentioned problems, there is provided a paper storage portion capable of storing the thermal paper,
By disposing a paper cover that can be opened and closed above the paper storage unit, and replacing the thermal paper and closing the paper cover,
The transport roller is configured to rotate in the one direction.

As a third means for solving the above-mentioned problems, the conveying roller is composed of a platen roller to which the first and second thermal heads can come into pressure contact, and the first thermal head is always down. Then, the second thermal head is brought into pressure contact with the carrying roller, and the second thermal head can be moved up and down to come into contact with and separate from the carrying roller via the ink ribbon.

As a fourth means for solving the above-mentioned problems, a thermal paper, a transport roller capable of transporting the thermal paper in a predetermined transport direction, and an ink coated with an ink transferable to the thermal paper. A ribbon, and color the heat-sensitive paper conveyed in the conveyance direction by the conveyance roller to develop a first color.
First thermal head capable of printing and a second thermal head capable of second printing by pressing the ink ribbon onto the thermal paper conveyed in the conveyance direction by the conveyance roller to transfer the ink And a paper cutting device capable of cutting the thermal paper to a predetermined length on the downstream side of the carrying roller in the carrying direction. By reversing in the opposite direction to the direction, by rotating the conveying roller in the one direction, it is possible to convey the thermal paper to the paper cutting device side, and by reversing the conveying roller,
The thermal paper can be back-fed in a direction away from the paper cutting device, and the thermal paper is formed by cutting at least the trailing edge of the page after printing is aligned with the paper cutting device and cut. Further, the front end of the next page before printing is configured to be back-fed to the vicinity of the transport roller.

As a fifth means for solving the above-mentioned problems, the back feed of the thermal paper cuts the trailing edge of the page after the printing is finished, or starts printing on the next page. The configuration is performed immediately before.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermal printer of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic diagram illustrating a thermal printer of the present invention, FIG. 2 is a schematic diagram illustrating a printing operation of the thermal printer of the present invention, and FIG. 3 is a schematic diagram illustrating replacement of thermal paper according to the present invention. FIG. 4 is a schematic diagram for explaining the exchange of the ink ribbon according to the present invention.

First, an embodiment of the thermal printer of the present invention will be described with reference to FIGS. 1 and 2. In the upper right portion of the housing 1 in the figure, a substantially L-shaped paper cover indicated by a chain double-dashed line is shown. 2 are provided. The paper cover 2 is the first support shaft 1
It can rotate in the direction of arrow A with a as a fulcrum. Further, a substantially hexagonal ribbon holder 3 as shown by a chain double-dashed line is arranged on the upper left side in the figure of the housing 1. The ribbon holder 3 is rotatable in the direction of arrow B with the second support shaft as a fulcrum. Below the paper cover 2, a paper storage portion 1c is formed inside the housing 1, and the thermal paper 4 wound in a roll shape on the core rod 4a is stored therein. The thermal paper 4 can be colored black, for example, and can be transported in the transport direction indicated by arrow C. Further, a first thermal head 5 composed of a line head is arranged in the transport path of the thermal paper 4. On the first thermal head 5, a plurality of heating elements (not shown) are formed in line in the width direction of the thermal paper 4.

The first thermal head 5 is fixed to a head mounting base 6, and the head mounting base 6 is axially supported by the rotation center of a rotatable guide roller 7. The first thermal head 5 is elastically urged toward the transport roller 8 to be described later so that it can constantly be pressed against the transport roller 8. On the side of the first thermal head 5 that faces the heating elements, a conveying roller 8 made of a platen roller is arranged. The conveying roller 8 is geared to a stepping motor or the like which is a drive source, and is rotatably supported by the sheet cover 2. And the transport roller 8
Is rotated in the clockwise direction at the time of printing, and can be rotated in the counterclockwise direction after the completion of printing.

The thermal paper 4 is guided by the guide roller 7 and is conveyed in the conveying direction of the arrow C by the clockwise rotation of the conveying roller 8, and the first thermal head 5 in the pressure contact state and the conveying roller. The first thermal head 5 is transported to the downstream side of the first thermal head 5. The thermal paper 4 transported in the transport direction indicated by the arrow C is capable of performing the first thermal printing by causing the first thermal head 5 to develop, for example, black characters and the like.

A second thermal head 9 is arranged on the downstream side of the first thermal head 5 in the carrying direction of arrow C. This second thermal head 9
Like the first thermal head 5, it is composed of a line head, and a plurality of heating elements (not shown) are formed in the width direction of the thermal paper 4 on the side facing the transport roller 8. The second thermal head 9 is fixed to a rotating arm 11 that can rotate about a supporting shaft 10 as a fulcrum. Then, the second thermal head 9 is rotated by the rotation arm 11 about the support shaft 10 as a fulcrum, so that the second thermal head 9 is in a down state where it is pressed against the conveyance roller 8 as shown in FIG. 1, or as shown in FIG. The up state is set apart from the transport roller 8.

The second thermal head 9 is lowered onto the thermal paper 4 on which the first printing has been performed by the first thermal head 5, and the ink ribbon 15 described below is pressed against the thermal paper 4 to eject the ink on the ink ribbon 15. The second transfer, which is thermal transfer printing, is possible by performing thermal transfer. A pair of rotatable pinch rollers 1 are provided on the left and right sides of the second thermal head 9 in the figure.
2 is pivotally supported by the rotating arm 11. Also, thermal paper 4
On the downstream side of the second thermal head 9 in the conveyance direction, a rotatable pressure contact roller 13 is arranged in pressure contact with the conveyance roller 8. The thermal paper 4 transported between the transport roller 8 and the pressure contact roller 13 can be transported in the paper discharge direction indicated by the arrow D by the clockwise rotation of the transport roller 8.

A paper cutting device 14 is disposed downstream of the pressure roller 13 in the paper discharge direction indicated by the arrow D of the thermal paper 4. This paper cutting device 14 completes printing by aligning the fixed blade 14a with the rear edge 4c of the page 4b after printing of the thermal paper 4 and sliding the movable blade inside the case 14b toward the fixed blade 14a. Next page 4b
Is cut so that it can be separated from the thermal paper 4.
Then, the page 4b after printing, which is separated from the thermal paper 4, can be discharged to the outside of the housing 1. Also,
The leading end portion 4d of the next page before printing, which is formed by cutting the page 4b after printing is completed, by rotating the transport roller 8 in one direction (clockwise direction) and in the opposite direction (counterclockwise direction). , The conveying roller 8 with which the pressure roller 13 is in pressure contact
It is designed to feed back to the vicinity.

The paper cutting device 14 not only cuts the page 4b after printing is completed, but also when the thermal paper 4 is replaced with a new one, the thermal paper 4 not to be printed is provided on the downstream side of the paper cutting device 14. A predetermined amount is conveyed and cut. That is, the thermal paper 4 is configured to cut at least the rear end portion 4c of the page 4b after printing is completed by aligning it with the paper cutting device 14. Therefore, the heat-sensitive paper 4 after replacement can be surely cued out, and the size from the leading end of the heat-sensitive paper 4 to the first print line can be made constant.

Further, as shown in FIG. 2, an ink ribbon 15 is supplied between the second thermal head 9 in the up state and the carrying roller 8. This ink ribbon 15
Is a side on which one surface coated with ink of a desired color faces the transport roller 8 and the other surface not coated with ink is guided by the pair of pinch rollers 12 to form the heating element of the thermal head 9. Can be slid on. And
When the second thermal head 9 is moved down and brought into pressure contact with the transport roller 8, the ink ribbon 15 is brought into pressure contact with the thermal paper 4 and the ink of the desired color is thermally transferred to the thermal paper, thereby enabling the second printing. Has become.

The ink ribbon 15 has a winding core 16 wound at one end and a supply core 17 wound at the other end, and a winding bobbin (not shown) in the ribbon holder 3 and a supply bobbin. (Not shown) is engaged and mounted.
In addition, the supply core 17 has an unused ink ribbon 1
5 is wound, and the ink ribbon 15 is pulled in the winding direction of the arrow F by the rotation of the winding core 16 in the direction of the arrow E and can be wound around the winding core 16.

The take-up core 16 is engaged with a take-up bobbin (not shown) capable of slip rotation to bring down the second thermal head 9 so that the ink of the ink ribbon 15 is applied to the thermal paper 4. During the second printing of thermal transfer printing, the ink ribbon 15 is rotated while the winding bobbin is slippingly rotated.
Is wound on the winding core 16. Therefore, a predetermined tension is applied to the ink ribbon 15 between the second thermal head 9 and the take-up core 16 during the second printing, and the ink ribbon 15 is slackened during the second printing. Will not occur.

The printing operation on the thermal paper 4 by the thermal printer of the present invention as described above will be explained with reference to FIG. 2. The thermal paper 4 fed between the conveying roller 8 and the pressure contact roller 13 is When the transport roller 8 rotates in the clockwise direction, the transport roller 8 is transported in the paper discharge direction indicated by the arrow D. At the same time, by selectively energizing a plurality of heating elements of the first thermal head 5 that is in pressure contact with the thermal paper 4, the thermal paper 4 is caused to develop color, for example, black characters or the like are printed. 1 is printed. Further, the first thermal head 5 is kept in pressure contact with the transport roller 8 via the thermal paper 4 even during the standby for the first printing. Therefore, a mechanism for moving up / down the first thermal head 5 is unnecessary, and the structure of the thermal printer of the present invention can be simplified.

The thermal paper 4 which is undergoing the first printing by the first thermal head 5 is rotated in the clockwise direction of the carrying roller 8 so that the second thermal head 9 and the carrying roller 8 are in the up state. Pass through. Then, the second thermal head 9 is moved down onto the thermal paper 4 on which the first printing has been performed, the ink ribbon 15 is pressed against the thermal paper 4, and the ink having a color different from that of the first printing, such as cyan, is used. Is thermally transferred to perform second printing. In the second printing in which the ink of a color such as cyan is transferred by heat, for example, one-point printing of a store name, a product logo, or the like can be performed to make the characters printed in the second printing stand out.

While the second thermal head 9 is waiting for the second printing, the second thermal head 9 is separated from the conveying roller 8 and the winding of the ink ribbon 15 around the winding core 16 is stopped. Therefore, wasteful consumption of the ink ribbon 15 can be reduced. When the second thermal head 9 is down to perform the second printing, the take-up bobbin (not shown) causes the take-up roller 16 to slip and rotate while the second printing is completed. Ink ribbon 15
Is wound around the winding roller 16. Therefore, even if the ink ribbon 15 may adhere to the thermal paper 4 in the second printing, the adhered ink ribbon 15 can be smoothly and smoothly separated from the thermal paper 4.

When the second printing is completed, the second thermal head 9 is moved up to convey the printed thermal paper 4 in the paper discharge direction indicated by the arrow D, and the ink ribbon to the take-up core 16 is also printed. Stop winding of 15. Then, the thermal paper 4 on which the first and second printing has been completed is pressed by the pressing roller 10
Page 4 after the printing is completed
b The rear end portion 4c is connected to the cutter portion 14a of the paper cutting device 14.
Align and cut. Then, the page 4b after printing is separated from the thermal paper 4 and discharged to the outside.

In addition, the leading end portion 4d of the next page before printing, which is formed by cutting by the sheet cutting device 14, reverses the carrying roller 8 (counterclockwise direction) to the vicinity of the carrying roller 8 where the pressure contact roller 13 is located. Back feed to. As a result, the thermal paper 4 can reduce the blank area from the first print line of the next page to the leading end 4d.
Further, the back feed of the thermal paper 4 is performed after cutting the rear end portion 4c of the page 4b after printing or just before starting printing on the next page. As a result, the thermal paper 4 can reduce the blank area from the first print line of the next page to the leading end 4d.

When the thermal paper 4 in use is lost and the thermal paper 4 is to be replaced with a new one, the paper cover 2 is changed from the state shown in FIGS. 1 and 2 to the first spindle as shown in FIG. 1
Rotate in the direction of arrow A using a as a fulcrum to move the paper storage unit 1
Open above c. Then, the transport roller 8 separates from the pressure contact roller 13, and the gear connection with the stepping motor (not shown) that is the drive source of the transport roller 8 is released. Then, the used core rod 4a located in the paper storage unit 1c is taken out, and a new thermal paper 4 is loaded into the paper storage unit 1c.
, And the paper cover 2 is rotated in the direction opposite to the arrow A to close the paper storage unit 1c.

Then, the paper cover 2 turns on a detection switch (not shown) to rotate the carrying roller 8 in one direction which is the clockwise direction. The rotation of the carrying roller 8 causes the thermal paper 4 to be carried by a predetermined amount in the paper discharge direction indicated by the arrow D. At the time of exchanging such thermal paper 4, the thermal paper 4 between the first thermal head 5 and the pressure roller 13 which may be generated at the time of exchange by transporting the thermal paper 4 by a predetermined amount in the paper discharge direction. Can be loosened.

By removing this slack, it is possible to eliminate the positional deviation of the characters etc. printed in the second printing,
High-quality printing with no deviation between the first printing and the second printing is possible. Further, the thermal head of the present invention has a power source (not shown) capable of supplying power to at least the driving source of the transport roller 8, and even when the power source is turned on, as in the case of replacing the thermal paper 4. The thermal paper 4 may be conveyed by a predetermined amount in the paper discharge direction.

When the used ink ribbon 15 is used up and is replaced with a new ink ribbon 15, the ribbon holder 3 is moved from the state shown in FIGS. 1 and 2 to the second spindle as shown in FIG. It is rotated in the direction of arrow B using 1b as a fulcrum. A second thermal head 9 is attached to the ribbon holder 3, and the second thermal head 9 is largely separated from the transport roller 8 as the ribbon holder 3 rotates. Then, the used ink ribbon 15 wound around the winding core 16 and the supply core 17 are taken out from the ribbon holder 3. After that, ribbon holder 3
In addition, the supply core 17 on which the ink ribbon 15 before use is wound
And the winding core 16 is mounted. Then, the winding core 1
6 is engaged with the winding bobbin, and the supply core 17 is engaged with the supply bobbin.

Further, the ink ribbon 15 housed in the ribbon holder 3 and drawn around to the second thermal head 9 side.
Has one surface coated with ink facing outward, and the other surface not coated with ink is the second thermal head 9
Slidably contact with. Then, the ribbon holder 3 accommodating the ink ribbon 15 is rotated in the direction opposite to the arrow B to close the upper left portion of the housing 1. Such a second thermal head 9 when the ribbon holder 3 closes the housing 1
Is in an up state in which it is separated from the conveyance roller 8 and is in a standby state for the second printing. The winding core 16 at this time is
The rotation is stopped and the ink ribbon 15 is not wound. Therefore, wasteful consumption of the ink ribbon has been reduced.

Further, the thermal printer of the present invention can perform the first printing or the second printing individually on the thermal paper 4 and can also perform the first printing and the second printing simultaneously. It has become. That is, the first and second
The thermal heads 5 and 9 can perform the first printing and / or the second printing on the thermal paper 4.

In the embodiment of the present invention, the conveying roller 8 is composed of the platen roller, but the platen roller and the conveying roller 8 are formed separately, and the thermal paper 4 is formed.
The conveyance roller and the pressure contact roller are arranged on the downstream side of the platen roller in the conveyance direction of No. 1, and the thermal paper 4 in which the first and second thermal heads 5 and 9 are in pressure contact with the platen roller is sandwiched between the conveyance roller and the pressure contact roller. Then, the thermal paper 4 may be pulled by rotationally driving the transport roller. Alternatively, the conveying roller 8 shown in FIG. 1 may be rotatable, and the pressure contact roller 13 may be rotationally driven to pull the thermal paper 4. In this case, the pressing roller 13 constitutes a carrying roller, and any one of the carrying roller 8 and the pressing roller 13 may be rotationally driven. Further, the first thermal head 5 has been described as being in a state of being constantly lowered and in pressure contact with the transport roller 8, but it may be capable of being moved up / down (contactable / separable to the transport roller 8).

[0037]

As described above, in the thermal printer of the present invention, when the thermal paper is exchanged or the power is turned on, the conveying roller pressed by the pressing roller is rotated in one direction to eject the thermal paper. Since the predetermined amount is conveyed in the paper direction, even if the thermal paper is loosened between the first thermal head and the pressure contact roller, this looseness can be removed. Therefore, it is possible to eliminate the positional deviation of characters or the like printed in the second printing, and it is possible to perform high-quality printing with no deviation between the first printing and the second printing.

Further, there is provided a paper storage portion capable of storing thermal paper, and a paper cover which can be opened and closed is provided above the paper storage portion. When the thermal paper is replaced and the paper cover is closed, the conveyance rollers are moved. Since it is rotated in one direction, it is possible to eliminate the positional deviation of characters or the like printed in the second printing. Further, since the transport roller is automatically rotated in association with opening and closing of the paper cover, it is possible to provide a thermal printer having good operability.

Further, since the first thermal head is always down to come into pressure contact with the carrying roller, and the second thermal head is up / down to come into contact with and separate from the carrying roller via the ink ribbon. The first thermal head does not require an up / down mechanism and can have a simple structure. In addition, the second thermal head can stop the winding of the ink ribbon when the second printing is on standby and up, thereby reducing wasteful consumption of the ink ribbon.

Further, the thermal paper is cut by aligning the trailing edge of the page after printing with the paper cutting device, and the leading edge of the next page before printing formed by this cutting is near the conveying roller. Since it is back-fed up to, it is possible to reduce the margin that can be formed at the tip of the next page,
Waste of thermal paper can be reduced.

Further, since the back-feed of the thermal paper is performed after cutting the trailing edge of the page after printing or immediately before starting printing on the next page, the thermal paper should be surely back-fed. As a result, the margin portion formed at the tip of the next page can be surely reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a thermal printer of the present invention.

FIG. 2 is a schematic diagram illustrating a printing operation of the thermal printer of the present invention.

FIG. 3 is a schematic view for explaining replacement of thermal paper according to the present invention.

FIG. 4 is a schematic view for explaining replacement of an ink ribbon according to the present invention.

[Sharp sign]

1 case 1c Paper storage 2 Paper cover 3 Ribbon holder 4 thermal paper 4a core rod 4b Page after printing 4c rear end 5 First thermal head 6 head mount 7 Guide roller 8 Conveyor rollers 9 Second thermal head 10 spindles 11 rotating arm 12 pinch rollers 13 Pressure roller 14 Paper cutting device 15 Ink ribbon 16 winding core 17 Supply core

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B41J 15/16 B65H 35/06 15/20 B41J 3/20 117A B65H 35/06 109Z F term (reference) 2C058 AB04 AB17 AC07 AE09 AF06 AF15 AF51 AF53 DA10 DA22 LB17 LC02 2C059 BB05 BB10 BB11 2C060 BA01 BC03 BC04 BC12 BC22 BC72 BC84 CB02 2C065 AA01 AB01 CZ06 CZ09 DA03 DA26 DA34 DA37

Claims (5)

[Claims] 1. A thermal paper, a transport roller capable of transporting the thermal paper in a predetermined transport direction, an ink ribbon coated with an ink that can be transferred to the thermal paper, and a power supply to at least a drive source of the transport roller. A first thermal head capable of performing the first printing by coloring the thermal paper transported by the transport roller, and the thermal ribbon transported by the transport roller by pressing the ink ribbon with pressure. A second thermal head capable of performing second printing by transferring the ink is provided, and when the thermal paper is replaced or the power is turned on, the transport roller is rotated in one direction. A thermal printer characterized in that the thermal paper is conveyed by a predetermined amount in the paper discharge direction. 2. A paper storage unit that can store the thermal paper, and a paper cover that can be opened and closed above the paper storage unit is provided. When the thermal paper is replaced and the paper cover is closed, The thermal printer according to claim 1, wherein the transport roller is configured to rotate in the one direction. 3. The transport roller comprises a platen roller to which the first and second thermal heads can come into pressure contact, and the first thermal head is constantly down and comes into pressure contact with the transport roller, The thermal printer according to claim 1 or 2, wherein the thermal head can be moved up and down to contact and separate from the transport roller via the ink ribbon. 4. A thermal paper, a transport roller capable of transporting the thermal paper in a predetermined transport direction, and an ink ribbon coated with ink that can be transferred to the thermal paper. The transport roller is provided in the transport direction. A first thermal head capable of performing the first printing by developing color of the conveyed thermal paper and the thermal ribbon conveyed by the conveying roller in the conveying direction with the ink ribbon pressed to transfer the ink. A second thermal head capable of printing 2 is disposed, and a paper cutting device capable of cutting the thermal paper at a predetermined length is provided downstream of the carrying roller in the carrying direction. The rotation of the carrying roller can be reversed in one direction and in the opposite direction to this one direction, and by rotating the carrying roller in the one direction, the thermal paper can be carried to the paper cutting device side, and the carrying By rotating the rollers in the reverse direction, the thermal paper can be back-fed in the direction away from the paper cutting device, and the thermal paper is aligned with the paper cutting device at least at the rear end of the page after printing is completed. A thermal printer characterized by being cut, and the front end of the next page before printing formed by this cutting is fed back to the vicinity of the conveying roller. 5. The back feed of the thermal paper is performed after cutting the trailing edge of the page after the printing is finished, or immediately before starting printing on the next page. Item 4. The thermal printer according to item 4.