JP2001334695A - Thermal transfer printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermal transfer printer in which high quality printing can be ensured constantly even if the width of an ink ribbon or a sheet to be used is altered. SOLUTION: An optimal drive force for traveling an ink ribbon is preset based on the width information of an ink ribbon and a sheet, an optimal drive force is acquired by retrieving set information based on the width information of a sheet being carried on a sheet carrying passage and the width information of an ink ribbon, and then the drive force of the ink ribbon is regulated such that the ink ribbon is driven with the optimal drive force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer capable of adjusting a driving force for running an ink ribbon.

[0002]

2. Description of the Related Art In a thermal transfer printer, a thermal head and a platen roller are arranged opposite to each other with a paper transport path therebetween, and an ink ribbon is interposed between the paper transported in the paper transport path and the thermal head. This is for printing. The ink ribbon is wound around a ribbon sending roller, and the ink ribbon sent from the ribbon sending roller passes between the paper and the thermal head and is wound around the ribbon winding roller.

On the other hand, a thermal transfer printer is provided with a ribbon winding motor for driving a ribbon winding roller to rotate in one direction and a ribbon feeding motor for rotating a ribbon feeding roller in a direction opposite to the ribbon winding roller. Have been.
Then, a constant drive voltage is applied to each of the ribbon take-up motor and the ribbon delivery motor (however, there is a relation of “drive voltage of the ribbon take-up motor”> “drive voltage of the ribbon delivery motor”), and the ribbon is taken up. By rotating the roller with a stronger force than the ribbon delivery roller, the ink ribbon travels with tension applied.

In a thermal transfer printer in which a line thermal head and a platen are opposed to each other in a width direction orthogonal to the direction of conveyance of a sheet conveyed in one direction along a sheet conveyance path, a plurality of types of sheets having different widths are known. May be appropriately selected and used. In this case, an ink ribbon suitable for the paper width is selected from a plurality of types having different widths and used.

[0005]

However, in the conventional thermal transfer printer, the voltages applied to the ribbon winding motor and the ribbon sending motor are fixed unless the setting information is manually changed. For this reason, depending on the width of the ink ribbon and the width of the paper to be used, the balance of the force applied to the ink ribbon may be lost, and wrinkles may be generated on the ink ribbon, thereby deteriorating the print quality.

In order to prevent this kind of deterioration in print quality, it is necessary to manually adjust the voltages applied to the ribbon take-up motor and the ribbon delivery motor each time the width of the ink ribbon or paper used is changed. In addition, the user has to perform complicated work.

The present invention has been made in view of such circumstances, and an object thereof is to provide a thermal transfer printer which can always perform high-quality printing even when the width of an ink ribbon or paper used is changed. It is assumed that.

[0008]

According to a first aspect of the present invention, a thermal head and a platen roller are arranged to face each other with a sheet conveying path interposed therebetween, and a thermal head and a sheet conveyed along the sheet conveying path are disposed between the thermal head and the platen roller. In a thermal transfer printer that performs thermal transfer printing with an ink ribbon interposed therebetween, means for determining a driving force for running the ink ribbon based on the width information of the ink ribbon and the width information of the paper and driving the ink ribbon with the driving force Is provided. More specifically, as in the invention described in claim 2 of the present application, a storage means for setting and storing the optimum driving force for running the ink ribbon on the condition of the width information of the ink ribbon and the width information of the paper, and is transported along the paper transport path. Searching means for searching the setting information stored by the storage means from the width information of the paper to be printed and the width information of the ink ribbon to obtain the optimum driving force; and ink based on the optimum driving force obtained by the searching means. Drive control means for driving the ribbon. More specifically, as in the invention as set forth in claim 3 of the present application, a storage means for setting and storing the optimum driving force for running the ink ribbon on condition of the width information of the ink ribbon and the width information of the paper, and transports the paper in the paper transport path. Paper width detecting means for detecting the width of the paper to be printed, ribbon width detecting means for detecting the width of the ink ribbon, paper width information detected by the paper width detecting means, and an ink ribbon detected by the ribbon width detecting means Search means for searching the setting information stored by the storage means from the width information and obtaining the optimum driving force; and drive control means for driving the ink ribbon based on the optimum driving force obtained by the search means. It is provided with.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a thermal transfer printer that performs color printing by superimposing four colors of yellow, magenta, cyan, and black.

FIG. 1 is a schematic configuration diagram of a thermal transfer printer according to the present embodiment. The thermal transfer printer has a first head 1 for black, a second head 2 for yellow, a third head 3 for magenta, and a cyan head. Fourth heads 4 are sequentially arranged along the sheet transport path 5. Further, platen rollers 6, 7, 8, and 9 are arranged at positions facing the first to fourth heads 1, 2, 3, and 4 with the transport path 5 interposed therebetween.

Each of the first to fourth heads 1, 2, 3, and 4 is a line thermal head in which a plurality of heating resistors are arranged on an end face, and ribbon magazines 10, 11, 1, and 1 are provided in the vicinity thereof.
2, 13 are set detachably. Each of the ribbon magazines 10, 11, 12, and 13 includes a ribbon delivery roller 10a, 11a, 12a, 13a and a ribbon take-up roller 10b, 11b, 12b, 13b, respectively.
The unused ink ribbons 10c, 11c, 12c, and 13c wound around a, 12a, and 13a are sent out to the first to fourth heads 1, 2, 3, and 4, and the first to fourth heads 1 and 2,
Ink ribbons 10c, 11c, 12 after 2, 3, and 4
c, 13c to the ribbon winding rollers 10b, 11b, 12
b, 13b. And the first
In the vicinity of the head 1, a ribbon width sensor 1 comprising an optical transmission sensor for detecting the width of the ink ribbon 10c running in the ribbon cassette 10 set in the vicinity thereof.
4 are provided.

One end of the transport path 5 is a sheet supply port 5a, and the other end is a sheet discharge port 5b. A pair of paper transport rollers 15a and 15b, which are transposed across the paper, a paper width sensor 16 composed of an optical transmission sensor capable of detecting the leading edge of the paper and the width of the paper, A paper end sensor 17 composed of an optical transmission sensor capable of detection and a paper holder 18 are provided. A paper 19 which is a continuous roll paper is wound around a paper holder 18.
By nipping and transporting the sheets a and 15b, the sheet is transported on the transport path 5 toward the sheet discharge port 5b.

In such a configuration, usually, the first head 1
, A ribbon magazine 10 with a black ink ribbon 10 c is set, near the second head 2, a ribbon magazine 11 with a yellow ink ribbon 11 c is set, and near the third head 3. Has a ribbon magazine 12 provided with a magenta ink ribbon 12c.
Is set, and a ribbon magazine 13 having a cyan ink ribbon 13c is set near the fourth head 3. In this case, each of the ink ribbons 10c, 11
The widths of c, 12c, and 13c are uniquely determined by the width of the paper 19, and the user can use the ink ribbons 10c, 11c, 12c, and 13 of each color having a width corresponding to the width of the paper 19 to be used.
The ribbon magazines 10, 11, 12, and 13 provided with c are set respectively.

In this embodiment, four types of ink ribbons having a ribbon width of 110 mm, 90 mm, 70 mm and 50 mm can be used. When the paper width is 85 mm to 105 mm, an ink ribbon having a ribbon width of 110 mm is used. When the paper width is from 65 mm to 85 mm, an ink ribbon having a ribbon width of 90 mm is used. When the paper width is from 45 mm to 65 mm, an ink ribbon having a ribbon width of 70 mm is used, and the paper width is 25 mm.
The description is continued on the assumption that an ink ribbon having a ribbon width of 50 mm is used when the width is from 50 mm to 45 mm.

FIG. 2 is a block diagram showing a main circuit configuration of the thermal transfer printer according to the present embodiment. In the thermal transfer printer, a CPU (Central Process) is used as a main control unit.
singUnit) 21. Also, an RO in which program data of processing performed by the CPU 21 and the like are stored in advance.
M (Read Only Memory) 22, RA in which various memory areas such as a print buffer for expanding print data are formed
M (Random Access Memory) 23, a PC interface 24 for controlling data communication with a personal computer having data for printing, and various sensors such as the ribbon width sensor 14, the paper width sensor 16, and the paper end sensor 17. Sensor interface 25 for capturing signals
It has.

Further, first to fourth heads 1, 2, 3,
4, a platen roller 6, 7, 8, 9 and a sheet transport roller 15a, 1
A platen controller 27 that controls driving of a platen motor (not shown) that rotates the first and fourth heads 1, 2, 3, and 4.
A solenoid controller 28 that controls the driving of a solenoid mechanism (not shown) that moves up and down to contact and separate from 7, 8, 9; and ink ribbons 10c, 11c,
12c, 13c ribbon delivery rollers 10a, 11a, 1
2a, 13a and ribbon winding rollers 10b, 11b, 1
A ribbon motor controller 29 for controlling the driving of ribbon motors 31 to 38, which are DC motors for rotating 2b and 13b, respectively, is provided. And CP
The U21 is connected to the ROM 22, RAM 23, PC interface 24, sensor interface 25, and controllers 26, 27, 28, and 29 by bus lines 30, such as an address bus and a data bus, to form a control circuit of the thermal transfer printer. ing.

Incidentally, the ribbon motor 31 is a motor for rotating the ribbon delivery roller 10a of the ribbon magazine 10 provided with the black (K) ink ribbon, and the ribbon motor 32 is a ribbon winding roller 10b of the ribbon magazine 10. Is a motor for rotating. The ribbon motor 33 is a motor for rotating the ribbon delivery roller 11a of the ribbon magazine 11 provided with the yellow (Y) ink ribbon, and the ribbon motor 34 is for rotating the ribbon take-up roller 11b of the ribbon magazine 11. It is a motor. The ribbon motor 35 is a motor for rotating the ribbon delivery roller 12a of the ribbon magazine 12 provided with a magenta (M) ink ribbon.
6 is a ribbon take-up roller 12b of the ribbon magazine 12
Is a motor for rotating. Also, the ribbon motor 37
Is a motor for rotating the ribbon delivery roller 13a of the ribbon magazine 13 provided with a cyan (C) ink ribbon, and the ribbon motor 38 is a motor for rotating the ribbon winding roller 13b of the ribbon magazine 13.

The thermal transfer printer having such a configuration is particularly suitable for the printer shown in FIG.
As shown in the figure, each of the ribbon winding rollers 10b, 11b, 1
Ribbon motors 32, 34, 3 for rotating 2b, 13b
A voltage setting table 41 in which drive voltages of so-called winding voltages 6, 6 and so-called winding voltages and driving voltages of ribbon motors 31, 33, 35, 37 for rotating the ribbon sending rollers 10a, 11a, 12a, 13a, so-called sending voltages, are set in advance. RO
M22. By the way, in this embodiment,
The winding voltage is 15V and the sending voltage is 10V.

Further, as shown in FIG. 4, the upper limit value and the lower limit value of the corresponding paper width with respect to the ribbon width of the usable ink ribbon, and the winding voltage and feeding when using the paper of the corresponding paper width. In the ROM 22, correction values tables 42, 43, 44, and 45 in which respective correction amounts of the voltage are set in advance are formed.

In this embodiment, the ribbon width 1
For a 10 mm ink ribbon, the correction value table 4
As shown in FIG. 2, the winding voltage correction amount when the paper width of 105 mm to 95 mm is used and the sending voltage correction amount are both ± 0 V, and the winding voltage when the paper width of 94 mm to 85 mm is used. The correction amount and the transmission voltage correction amount are -1 V and -0.5 V, respectively. In other words, when using paper having a paper width of 105 mm to 95 mm, by setting the winding voltage to 15 V and the sending voltage to 10 V, the force applied to the ink ribbon may be balanced and wrinkles may occur on the ink ribbon. No, paper width 94mm-85
In the case of using paper of mm, by setting the winding voltage to 14 V and the sending voltage to 9.5 V, the force applied to the ink ribbon is balanced and wrinkles do not occur on the ink ribbon.

For an ink ribbon having a ribbon width of 90 mm, as shown in the correction value table 43, a paper width of 8 mm is used.
The winding voltage correction amount and the sending voltage correction amount when using paper of 4 mm to 75 mm are -2 V and -1 V, respectively, and the winding voltage correction amount and sending voltage correction when using paper with a paper width of 74 mm to 65 mm. The amounts are -3V and -1.5V, respectively. That is, a sheet width of 84 mm to 75 mm
In the case of using paper having a width of 7 mm, the winding voltage is set to 13 V and the sending voltage is set to 9 V, so that the force applied to the ink ribbon is balanced so that the ink ribbon does not wrinkle, and the paper width is reduced from 74 mm to When 65 mm paper is used, the winding voltage is set to 12 V, and the sending voltage is set to 8.
By setting the voltage to 5 V, the force applied to the ink ribbon is balanced and the ink ribbon does not wrinkle.

For an ink ribbon having a ribbon width of 70 mm, as shown in the correction value table 44, the paper width 6
The winding voltage correction amount and the sending voltage correction amount when using the paper of 4 mm to 55 mm are -4 V and -2 V, respectively, and the winding voltage correction amount and the sending voltage correction when the paper width of 54 mm to 45 mm are used. The amounts are -5V and -2.5V, respectively. That is, a sheet width of 64 mm to 55 mm
mm paper, the winding voltage is set to 11 V and the sending voltage is set to 8 V, so that the force applied to the ink ribbon is balanced and the ink ribbon does not wrinkle. When 45 mm paper is used, the winding voltage is set to 10 V and the sending voltage is set to 7.
By setting the voltage to 5 V, the force applied to the ink ribbon is balanced and the ink ribbon does not wrinkle.

For an ink ribbon having a ribbon width of 50 mm, as shown in the correction value table 45, a sheet width of 4 mm is used.
The winding voltage correction amount and the sending voltage correction amount when using paper of 4 mm to 35 mm are set to -6 V and -3 V, respectively, and the winding voltage correction amount and sending voltage correction when using a paper width of 34 mm to 25 mm. The amounts are -7V and -3.5V, respectively. That is, a sheet width of 44 mm to 35 mm
mm paper, the winding voltage is 9V,
By setting the sending voltage to 7V, the force applied to the ink ribbon is balanced and wrinkles are not generated on the ink ribbon. When using a sheet having a sheet width of 34 mm to 25 mm, the winding voltage is set to 8V, By setting the sending voltage to 6.5 V, the force applied to the ink ribbon is balanced and the ink ribbon does not wrinkle.

Thus, the thermal transfer printer is operated when the power is turned on and when the ribbon magazines 10, 11, 1
When the sheets 2 and 13 are replaced and when the paper 19 is replaced, the CPU 21 executes the ink ribbon drive control processing shown in the flowchart of FIG.

That is, when the CPU 21 starts this ink ribbon drive control process, first, ST (step) 1
As a result, the signal of the ribbon width sensor 14 is fetched via the sensor interface 25, and the ribbon width of the ink ribbon 10C provided in the ribbon magazine 10 is detected. Also, as ST2, the signal of the paper width sensor 16 is also fetched via the sensor interface 25, and the paper holder 1 is read.
The paper width of the paper 19 wound around 8 is detected.

Next, ST3 is read from the ROM 22 as ST3.
Correction value tables 42, 4 for the ribbon width detected in
3, 44 or 45 is read, and it is determined whether or not the range of the corresponding sheet width set in the correction value table includes the sheet width detected in ST2. Here, if the paper width detected in ST2 is not included in the range of the corresponding paper width, an error occurs because the width of the ink ribbon is inappropriate for the width of the paper to be used, and the printing process is disabled.

If the paper width of the paper 19 to be used is included in the range of the corresponding paper width in ST3, the winding voltage correction amount of the corresponding paper width to which the paper width belongs is acquired in ST4. Then, in ST5, it is determined whether the winding voltage correction amount is ± 0V. Here, when the winding voltage correction amount is other than ± 0 V, the winding voltage setting value is read from the voltage setting table 41 of the ROM 22 in ST6, and the winding voltage setting value is corrected by the winding voltage correction amount. Before giving it to the ribbon motor controller 29. When the winding voltage correction amount is ± 0 V, the winding voltage setting value read from the voltage setting table 41 of the ROM 22 is given to the ribbon motor controller 29 without correction.

Next, in step ST7, the transmission voltage correction amount of the corresponding sheet width to which the sheet width belongs is acquired. And ST8
It is determined whether or not the transmission voltage correction amount is ± 0 V. Here, when the transmission voltage correction amount is other than ± 0 V, at step ST9, the transmission voltage setting value is read from the voltage setting table 41 of the ROM 22, the transmission voltage setting value is corrected by the transmission voltage correction amount, and then the ribbon motor is corrected. This is given to the controller 29. When the transmission voltage correction amount is ± 0 V, the transmission voltage setting value read from the voltage setting table 41 of the ROM 22 is given to the ribbon motor controller 29 without correction.

Thereafter, the CPU 21 starts the control of the normal printing process. In this printing process, the ribbon motor controller 29 controls each of the ribbon winding motors 32, 34, 3
6 and 38 are driven forward by the winding voltage given from the CPU 21, respectively.
The ribbon winding rollers 10b, 11b, and 12 are driven to rotate in reverse by the sending voltage supplied from the CPU 21.
b, 13b to ribbon sending rollers 10a, 11a, 12
a, 13a, the ink ribbons 10c, 11c,
12c and 13c are run.

Here, the CPU 21 operates the paper width sensor 16.
Information of the paper 19 detected by the sensor and the ribbon width sensor 1
A search means for searching the setting information stored in the correction value tables 42, 43, 44, and 45 from the width information of the ink ribbon 10c detected by the control unit 4 to obtain an optimum driving force, and based on the optimum driving force. Ink ribbon 10c, 1
Drive control means for driving 1c, 12c and 13c.

Incidentally, specifically, the ink ribbons 10c,
11c, 12c, and 13c, and the ribbon delivery roller 10
a, 11a, 12a, 13a and ribbon winding roller 10
By detecting the angular velocities b, 11b, 12b, and 13b, the winding diameters on the ribbon sending side and the winding side are determined, and the optimum driving force is further adjusted according to the winding diameter of the ink ribbon.

In the present embodiment configured as described above, for example, the ink ribbons 10c and 11 having a width of 110 mm are provided.
c, 12c, 13c, and a paper 19 having a width of 100 mm.
When printing is performed on the ribbon winding motors 32, 34, 36, and 38, the winding voltage set value 15 V is set according to the setting information of the sheet width 105 mm to 95 mm stored in the correction value table 42. The applied voltage is applied as it is, and the set output voltage of 10 V is applied to each ribbon sending motor 31, 33, 35, 37 as it is. At this time, the force applied to the ink ribbon is balanced, and wrinkles do not occur on the ink ribbon, so that good print quality can be obtained.

On the other hand, when the ink ribbons 10c, 11c, 12c and 13c each having a width of 110 mm are used, 90
When printing is performed on paper having a width of 1 mm, the winding voltage set value 1 is set for each of the ribbon winding motors 32, 34, 36, and 38.
5 V is applied as it is, and each ribbon sending motor 31, 3
If the sending voltage set value of 10 V is applied to 3, 35, and 37 as it is, the force applied to the ink ribbon becomes unbalanced, and wrinkles may occur on the ink ribbon. On the other hand, in the present embodiment, the correction value table 42
In the ribbon winding motors 32, 34, 36, and 38, the winding voltage set value 15V was corrected by the corresponding winding voltage correction amount -1V according to the setting information of the paper width 94 mm to 85 mm stored in. 14V is applied to the ribbon feeding motors 31, 33, 35, and 37, and 9.5V obtained by correcting the sending voltage set value 10V by the corresponding sending voltage correction amount -0.5V is applied. The balance of the forces applied to the print is obtained, and good print quality is obtained.

As described above, according to the present embodiment, the sheet width sensor 16 is provided as a sheet width detecting means for detecting the width of the sheet 19 conveyed in the sheet conveying path 5, and the width of the ink ribbon 10c is detected. A ribbon width sensor 14 is provided as ribbon width detecting means. Also, the ink ribbons 10c, 10c,
The correction value tables 42, 43, and 4 serve as storage means for setting and storing the optimum driving force for running the wheels 11c, 12c, and 13c.
4, 45 are provided. Thus, the CPU 21 stores the width information of the paper 19 detected by the paper width sensor 16 and the width information of the ink ribbon 10c detected by the ribbon width sensor 14 in the correction value tables 42, 43, 44, and 45. The optimal driving force is obtained by retrieving the setting information on the ink ribbons 10c, 11c, 1 with the optimal driving force.
Since the driving force of the ink ribbon is automatically adjusted so that the ink ribbons 2c and 13c run, high-quality printing can always be performed even when the width of the ink ribbon or paper used is changed.

In the above-described embodiment, the width of the ink ribbon and the width of the paper are detected by the sensors to obtain the width information of the ink ribbon and the width of the paper.
The ink ribbon width information and the paper width information are input from a personal computer connected via the C interface 24, and the driving force of the ink ribbon is adjusted based on the input ink ribbon width information and the paper width information. The present invention includes those that do.

In the embodiment, the ribbon winding voltage and the ribbon sending voltage are set in advance in the voltage setting table 41, and the correction value tables 42, 43, 44,
In 45, the upper limit value and the lower limit value of the corresponding paper width and the respective correction amounts of the winding voltage and the sending voltage when using the paper of the corresponding paper width are set in advance with respect to the ribbon width of the ink ribbon, and the voltage setting is performed. By correcting the ribbon winding voltage and the ribbon sending voltage of the table 41 with the correction amounts of the correction value tables 42, 43, 44, and 45, the optimum driving force of the ink ribbon was determined and the ink ribbon was driven. The ribbon winding voltage and the ribbon sending voltage, which are the optimum driving force for running the ribbon, are set and stored under the conditions of the ink ribbon width information and the paper width information, respectively, and the paper width information detected by the paper width detecting means is stored. The ribbon winding voltage and the ribbon sending voltage, which are the optimum driving force, may be extracted from the ink ribbon width information detected by the ribbon width detecting means and driven.

The present invention is not limited to the color printer of the above-described embodiment, but can be applied to a monochrome thermal transfer printer having one thermal head.

[0038]

As described above in detail, according to the first to third aspects of the present invention, it is possible to provide a thermal transfer printer that can always perform high-quality printing even when the width of an ink ribbon or paper used is changed. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a thermal transfer printer according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a main part of the thermal transfer printer.

FIG. 3 is a configuration diagram of a voltage setting table stored in a ROM of the thermal transfer printer.

FIG. 4 is a configuration diagram of a correction value table stored in a ROM of the thermal transfer printer.

FIG. 5 is a flowchart showing a procedure of an ink ribbon drive control process executed by a CPU of the thermal transfer printer.

[Explanation of symbols]

 1, 2, 3, 4 ... first to fourth heads 5 ... paper transport path 6, 7, 8, 9 ... platen rollers 10, 11, 12, 13 ... ribbon magazines 10a, 11a, 12a, 13a ... ribbon delivery rollers 10b, 11b, 12b, 13b ... Ribbon winding rollers 10c, 11c, 12c, 13c ... Ink ribbon 14 ... Ribbon width sensor 16 ... Paper width sensor 19 ... Paper 21 ... CPU 31, 33, 35, 37 ... Ribbon sending motor 32 , 34, 36, 38 ... ribbon winding motor 41 ... voltage setting table 42, 43, 44, 45 ... correction value table

Claims (3)

[Claims] 1. A thermal head and a platen roller are arranged opposite to each other with a paper transport path interposed therebetween, and thermal transfer printing is performed by interposing an ink ribbon between the paper transported on the paper transport path and the thermal head. The thermal transfer printer according to claim 1, further comprising: means for determining a driving force for traveling the ink ribbon based on the width information of the ink ribbon and the width information of the paper, and driving the ink ribbon with the driving force. Thermal transfer printer. 2. A thermal head and a platen roller are opposed to each other with a paper transport path interposed therebetween, and thermal transfer printing is performed by interposing an ink ribbon between the paper transported on the paper transport path and the thermal head. Storage means for setting and storing an optimum driving force for running the ink ribbon on condition of the width information of the ink ribbon and the width information of the paper, and width information of the paper transported on the paper transport path. Searching means for searching the setting information stored by the storage means from the information and the width information of the ink ribbon to obtain an optimum driving force; and searching for the ink ribbon based on the optimum driving force obtained by the searching means. A thermal transfer printer, comprising: a drive control unit for driving. 3. A thermal head and a platen roller are opposed to each other with a paper transport path interposed therebetween, and thermal transfer printing is performed by interposing an ink ribbon between the paper transported in the paper transport path and the thermal head. In the thermal transfer printer, a storage unit for setting and storing an optimum driving force for running the ink ribbon on condition of the width information of the ink ribbon and the width information of the paper, and a width of the paper transported on the paper transport path. Paper width detecting means for detecting, ribbon width detecting means for detecting the width of the ink ribbon, paper width information detected by the paper width detecting means, and ink ribbon width information detected by the ribbon width detecting means A search means for searching the setting information stored in the storage means to obtain an optimum driving force, and an optimum drive obtained by the search means. Thermal transfer printer, characterized by comprising a drive control means for driving the ink ribbon on the basis of.