JPS63242566A - Thermal transfer type printer - Google Patents

Abstract

PURPOSE:To make it possible to prevent printed density from becoming ununiform due to deficient heat generation, by detecting a cooling condition of a thermal head, and variably controlling the length of the next auxiliary heating period according to the cooling condition. CONSTITUTION:During an auxiliary heating period DELTAT, a heating current at a power source voltage +Vcc is applied only to the heat generating resistors corresponding to first data of not less than '1', namely, the resistors for transferring according to the first data, thereby performing auxiliary heating. Therefore, the first data at a white level is maintained as white, and transferring is not effected. By appropriately presetting an auxiliary heating preset value for a density at a level higher than the white level by one level, it is possible to achieve an optimum rise of transfer density. At the time of the next printing, the preset value is corrected according to variations in a cooling period, based on an auxiliary heating data value read from a correction table memory 21. Even when the cooling period is varied, the auxiliary heating preset value is corrected from the auxiliary heating data value obtained from the memory 21, whereby the auxiliary heating period DELTAT is variably controlled to an optimum value, so that printed density is prevented from becoming ununiform.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thermal transfer printing device, and is particularly applicable to a thermal transfer printing device that prevents unevenness of print length of 1 m.

Conventional printing devices (hard copy devices) for technical terminals include wire dot type, inkjet type, and thermal transfer type printing devices. A thermal transfer printing device uses an ink film (or ink ribbon), for example, which is a polyester film (or ribbon) with a thickness of 5 to 6 μm, on which a thermal ink is applied, and records the ink surface on the front side of this ink film. A thermal head is placed in contact with the paper and placed on the back side, and current is passed through the thermal head to generate heat, sublimating the ink on the ink film at the position corresponding to the thermal head and transferring it to the recording paper. This thermal head has a plurality of heat-generating resistors arranged in a row, and a current is sequentially applied to each heat-generating resistor.

The density, which determines the gradation of printed characters, figures, pictures, etc., is determined according to the transfer density and area of each dot on the recording paper to which the spine ink has been transferred. The transfer density and area of the ink dots are determined by the energization time of the rFi current applied to each heating resistor and the energization energy corresponding to the level of the applied voltage.

However, the relationship between the print density in the thermal transfer printing device and the time for passing current through the heating resistor (recording time) is not linear, and there is a density error between the 11 degrees that Kiku wants to obtain and the density that is actually obtained. The disadvantage was that it caused

Therefore, in Japanese Patent Application No. 60-49119, the present applicant proposed a thermal transfer gradation control device that corrects the relationship between density and recording time to be a straight line or a predetermined curve, and controls printing density. Proposed. Such a thermal transfer Ill adjustment control device converts, for example, an analog video signal into a digital signal (image data), sends this to a data storage device such as a semiconductor memory, determines addresses for the required number of pixels, and then stores it. , read out according to the address sent from the address counter, and output it to the grayscale data comparison circuit.

This density data comparison circuit uses - reference density data sent from the data counter (data indicating the minimum density at the beginning of R).
and the image data of the same number as the heating resistors read out from the data storage 127 sequentially, and if the value of the image data is equal to or larger than [F\I1 degree data, the shift register circuit For example, a high level output signal is supplied to the gate circuit via the gate circuit, and if the density data is smaller than the reference density data, a 0-level output signal is supplied to one input terminal of the gate circuit. The gradation data comparison circuit then compares the second standard density data from the one with the lowest density with the image data of the same number as the heating resistors sequentially read out from the data storage device in the same manner as above. , sends a high level or low level signal to one input terminal of the gate circuit in the same manner as above. Thereafter, the above operation is repeated in the same manner as above until the reference density data reaches the maximum density.

On the other hand, the correction circuit is supplied with the reference ga data and corrects it using a correction table in which correction data is stored in advance so that the recording time and density have a linear relationship. As a result, the correction circuit supplies to the other input terminal of the gate circuit a heating pulse whose pulse width changes for each unit of the reference concentration data based on the correction data.

Therefore, the heating pulse passes through only the gate circuit to which the high level signal is input to one input terminal.
Make the corresponding heating resistor generate heat. In this way,
A heating pulse is applied to the plurality of heating resistors for a time corresponding to the concentration, causing a pulsed current to flow, thereby controlling the gradation.

However, in the thermal transfer printing apparatus, at the minimum density and a density level close to it (hereinafter referred to as the "white level"), and at the maximum density and a level close to it (hereinafter referred to as the "black level"), approximately Density cannot be reproduced linearly, resulting in overexposure and underexposure phenomena.

As a method of correcting the above-mentioned overexposure, there has been a method in which electricity is supplied in advance only to the heating resistor to be transferred to perform heat replenishment.

According to this method, it was possible to reproduce the density linearly from the white level to the halftone level, but due to the heat of the heating resistor, the halftone level to the black level was easily crushed into black, and the linear density was not reproduced. It was impossible to reproduce.

In addition, as a method for correcting the blackout, there is a method of controlling the amount of electricity applied to the heating resistor for each density, such as in the thermal transfer gradation control device proposed by the applicant of the present invention. According to this method, linear density reproduction was obtained for almost every density, but there were problems such as that linear density reproduction was impossible at the white level.

Therefore, the present applicant proposed the above-mentioned method by reheating only the heat-generating resistor to be transferred and controlling the energization time of each heat-generating resistor for each unit of printing density in the previous patent application 1986-117996@. We proposed a thermal transfer gradation control device that solved the problem. Such thermal transfer gradation control! l The device includes a control counter that generates and outputs a signal corresponding to a preset reheating time, and a minimum density (minimum printed density) during the reheating time according to the signal supplied from the control counter.
Means for generating reference concentration data that holds a value indicating the temperature and changes sequentially from the minimum concentration to the value indicating the maximum concentration in a short time after the elapse of the reheating time, and the reference concentration data including the reference concentration data during the reheating time. Means for generating control data by comparing the input data to be transferred with the input data to be transferred and indicating which heat generating resistor should flow current among the heat generating resistors in a row of plural heat generating resistors for each unit of density, and the reference density data. a correction data generation circuit that is supplied with correction data and outputs correction data set so that the relationship between the pre-stored recording density and the reference density data becomes a straight line or a predetermined curve, in accordance with the input reference density data; The correction data and aiIIall data are each supplied, and the time according to the value of the correction data! , 1J111 data shows means for passing current through the heat generating resistor.

The control counter maintains the reference concentration data at a value indicating the minimum concentration during the reheating time.

Therefore, the &1Jtllll data generating means causes a current to flow only through the heating resistor to which input data having a value greater than the minimum density is to be transferred, thereby reheating it.

In addition, since the standard 11 degree data changes sequentially from the minimum concentration to the maximum concentration in a short time after the reheating time has elapsed, the control data generation means is used to transfer the input data for each unit of concentration. A current is passed through the resistor. A current is passed through this heating resistor for a set time based on the correction data supplied from the correction data generation circuit, so that the relationship between the B concentration and the reference concentration data becomes a straight line or a predetermined curve. , generates a fever.

As a result, according to the thermal transfer gradation control device described above, only the heating resistor to be transferred is heated, so it is possible to obtain the optimum density characteristic in the highlight area, and the period of the data transfer pulse can be changed from the conventional one. Since the recording time is much shorter than that, the recording time can be shortened, and the energization time of each heating resistor can be adjusted for each degree of heating so that the recording time and density have a substantially linear relationship. As a result, the density can be controlled almost linearly from the highlight area up to a maximum of 11iWA without causing the blackout described above even at high density areas, and it is possible to achieve high image quality in printing. It has its features.

Problems to be Solved by the Invention Regarding the transport speed of the recording paper, the state of transport by the recording paper transport means is not necessarily constant, and fluctuations in motor rotation, variations in mechanical power transmission characteristics, slippage of the recording paper, etc. also occur. Although it is controlled to be constant, it actually fluctuates. The pitch between lines printed on recording paper can be virtually controlled by controlling the timing of current application to the thermal head in accordance with the output of an encoder that detects the transport speed (transfer amount) of recording paper with high precision. It is possible to keep it constant. However, current technology cannot eliminate fluctuations in the transport speed of the recording paper.

Therefore, if the timing of current application to the thermal head is variable & Q controlled in order to keep the above-mentioned pitch constant according to fluctuations in the transport speed of the recording paper, the length of the cooling time between two consecutive energization periods will vary. . FIG. 6(a) shows the energization control pulse for controlling the energization to the thermal head, and FIG. 6(b)
1 shows a current supply start pulse that instructs the start and end of current supply to the thermal head, and FIG.

As is clear from FIG. 6(C), when the cooling period is shortened, the thermal head is not completely cooled down at the end of the cooling period, and therefore generates more heat than necessary during the next reheating period. Furthermore, if the cooling period becomes longer, the heat-sensitive head will be overcooled at the end of the cooling period, resulting in insufficient heat generation during the next reheating period.

For this reason, with conventional thermal transfer printing devices, the pitch between lines printed on the recording paper can be kept constant and controlled even if the transport speed of the recording paper changes, but due to fluctuations in the transport speed, the cooling period of the thermal head The length fluctuates, and due to insufficient cooling or overcooling of the thermal head, the heat generation of the thermal head becomes more than necessary (overheating) or insufficient in the next reheating period, and the density of the printed dots changes as shown in Figure 7. There was a problem in that unevenness occurred.

Therefore, the present invention solves the above problem by detecting insufficient cooling or overcooling of the thermal head by measuring four cooling periods, and variably controlling the length of the next reheating period based on the detection results. The purpose of the present invention is to provide a thermal transfer printing device that solves the problem.

Means for Solving the Problems The thermal transfer printing apparatus according to the present invention includes a measuring means for measuring four cooling periods in the dark during the first dot printing period, which consists of a heating period, a transfer period, and a cooling period of the thermal head. and a reheating period control means for variably controlling the length of the reheating period during the second dot printing II following between the first dot printing 111 based on the measurement results of the measuring means.

From the measurement result of the action measuring means, it is possible to detect the cooling state of the thermal head, that is, whether it is undercooled or overcooled. Since the reheating period fAII control means variably controls the length of the next reheating period depending on the cooling state of the thermal head, it is possible to prevent the thermal head from generating more heat than necessary or insufficient heat generation.

In this specification, thermal transfer recording refers to thermal recording in which recording is performed by chemically changing the recording paper itself due to heat generation, thermal recording using heat-melting transfer paper, and thermal recording using sublimation transfer paper. Thermal recording shall include everything that performs recording by applying geothermal heat.

Embodiment FIG. 1 shows a circuit diagram of an embodiment of a thermal transfer printing apparatus according to the present invention. In the figure, a thermal head 1 includes n heating resistors R1 formed in a row on a ceramic substrate. The configuration of this thermal head 1 is the same as that of a conventional thermal transfer printing device, and for example, as shown in FIG.
It extends in the width direction of the ink film 2. In FIG. 3, an ink film 2 serving as a transfer paper has a polyester film 3 coated with heat-melting ink 4 to a predetermined thickness on the surface thereof. The recording paper 5 is conveyed along with the ink film 2 in the direction of the arrow by the roller 6, with its recording surface facing the ink 4 surface of the ink film 2. A thermal head 1 is provided facing the roller 6 and is in contact with the back surface of the ink film 2.

The ink 4 of the ink film 2 corresponding to the energized heat generating resistor among the heat generating resistors R1 to Rn of the thermal head 1 is melted and transferred onto the recording paper 5. After passing through the thermal head 1, the ink film 2 is guided in a 0-rough direction and separated from the recording paper 5, and is placed on a take-up spool (not shown).
The used ink film 2a is wound up. The transferred ink 4a remains on the printed recording paper 5a. For convenience of illustration, the transferred ink 4a is shown as having a large area, but it actually consists of a collection of small dots.

Reference numeral 8 denotes a high-viscosity encoder, which detects the rotation of the roller 6 to obtain the transport speed (transfer amount) of the recording paper 5, and outputs an energization synchronization pulse.

Therefore, even if the transport speed of the recording paper 5 fluctuates, a well-known circuit (not shown) generates an energization start pulse as shown in FIG. By controlling the energization period, it is possible to keep the pitch between lines printed on the recording paper 5 constant.

One dot is formed by a negative heating resistor, and the size of the negative dot is determined by the time for which electricity is applied to the heating resistor (or the level of voltage applied). The shading, or gradation, of the printed figure is determined according to the size of each dot.

Returning to FIG. 1 again, the TV signal generator ff
An analog video signal supplied from 10 is converted into a digital signal by an analog/digital (A/D) converter 11ff11, and sent to a data storage device M12 for storage. On the other hand, the address counter 13 receives a constant frequency reference clock signal from a terminal 14 and a second clock signal from a terminal 15.
An energization start pulse a as shown in Figure <A) is supplied.

The address counter 13 and the data counter 16I are started by the energization start pulse a that arrives at time tl, respectively. The control counter 17 is loaded with a preset reheating preset value from the reheating preset source 18 in response to the energization start pulse a.

This reheating preset value is a value that determines the reheating period (time), which will be described later, and includes the period of pulse b shown in FIG. It is determined by the pressing force of the
4" is selected.

Further, the heating period is selected to be a time during which pixel data for one line is repeatedly read out an integral number of times.

On the other hand, the reference clock signal from terminal 14 is sent to counter 19.
is also supplied and counted. This counter 19 is reset by a pulse i obtained by inverting the pass Ti start pulse a from the terminal 15 using an inverter 20. That is, the counter 19 counts the reference clock signal during the cooling period for the thermal head 1 in FIG. 6(b). counter 1
The output count value of 9 is supplied to the correction table storage memory 21. The correction table storage memory 21 is stored in the correction table storage memory 21 as shown in FIG.
) Based on the characteristics shown in FIG. By specifying the read address using the output count value, the reheating data value corresponding to the variation in the cooling period is read out. The reheating data value is supplied to the reheating preset ji 18, and the preset reheating preset value of the reheating preset source 18 is corrected according to the variation in the cooling period.

The control counter 17 is generated based on the reference clock signal from the address counter 13 as shown in FIG. 2(B).
The pulse b shown in Fig. 2 (
As shown in C), a low level signal C is supplied to the data counter 16 to stop its H1 counting operation. Therefore, the value of the standard a degree data d shown in FIG. 2(D) supplied from the data counter 16 to the grayscale data comparison circuit 22 is
The hit value [0] during the above-mentioned time ΔT (heating period) is maintained at the value [0, 1] indicating the minimum m degrees of whiteness.

The period of the pulse b is selected to be shorter than the period of the output pulse of a conventional address counter, for example, about 1710.

The address counter 13 inputs the first address to the data storage device upon receiving the energization start pulse a. Send to 112. The data storage device 12 sends first data (the first data of the image data from the A/D conversion device 11) corresponding to this first address to the grayscale data comparison circuit 22. The density data comparison circuit 22 compares the first data with reference density data (hereinafter referred to as "second data") "0" indicating the minimum density from the data counter 16, and determines that the first data is the second data. If the data is greater than the data "0", 1111111 data "1" is sent to the shift register 23, and if they are equal, the control data "01" is sent to the shift register 23.

In this way, when the first address is completed, the address counter 134. i sequentially 2゜3,・
..., sends the n-th address to the data storage device 12,
The data storage Vt'r 112 transfers the first data corresponding to the 2nd to nth addresses each time to the grayscale data comparison circuit 2.
2 sequentially. Here, the first data from the 1st to nth addresses are the respective heating resistors R of the thermal head 1.
This corresponds to the image data printed by 1 to RTl. The gray data comparison circuit 22 compares the first data and second data rOJ roughly corresponding to the 2nd to nth addresses, and transfers the control data rOJ or "1" to the shift register 23 in the same manner as above. send to The n-stage shift register 23 sequentially takes in n-bit control data corresponding to the first to nth addresses supplied from the m original data comparison circuit 22, and sends it to the latch circuit 24.

When the address counter 13 finishes counting the 1st to nth addresses, the data counter 16 and the latch circuit 2 use the pulse b shown in FIG. 2(B) as a data transfer pulse.
4 and the control counter 17. At the same time as this data transfer pulse b is sent, the data counter 16
The heating pulse e shown in Fig. 2 (E) is applied to the address counter 1.
3 and one input terminal of the AND circuit 25 and the AND circuit 26.

On the other hand, a reference zero signal is supplied from the terminal 14 to one end of the AND circuit 25, and at the same time as the heating pulse e is input from the data counter 16, the pulses are shifted from 1 to
Output to the register 23 and register 1 to 1 of the address counter 13.
The n-bit control data corresponding to the n-th address is transferred from the shift register 23 to the latch circuit 24. When the data transfer pulse b is received, the latch circuit 21 latches the Lll control data supplied from the shift register 23 and sends it to one input terminal of each of the gate circuits 01 to GTI.

On the other hand, the address counter 13 is reset by the arrival of the heating pulse e and sequentially counts addresses 1 to n again in response to the energization start pulse a. The counter 13 causes the data storage device 12 to repeatedly read n pieces of first data on the same line, and the second data is held at "0". The data of the above values [0, 1] and the gray data comparison circuit 2
2, the magnitudes are repeatedly compared.

Therefore, during the reheating period Δ■, when the first data is ``1'' or more, a heating current is applied by the power supply voltage +Vcc only to the heating resistor to be transferred according to the first data, and the heat is reheated. Therefore, the first data of the own level is held as white and is not transferred, and the rise of the transfer density is optimized by setting the above-mentioned reheating preset value optimally in advance for the density above the white level. be able to. At the time of the next printing, the reheating preset value is corrected according to the change in the cooling period using the reheating data value from the correction table storage memory 21.

After that, at time t2 when the control counter 17 has finished counting the pulses B by the reheating preset value, the pulse C becomes high level, and the data counter 16 starts counting operation and performs the same operation as above. After performing this once for the first data for one line, the next incoming pulse b is multiplied by Jl at time t3, and the second pulse shown in FIG. Indicates the second density from the smallest data and increases to 1 value [1-1.

As a result, the gray data comparison circuit 22 sequentially compares the n pieces of first data for the same line with the second data having the value "1". Also when the second data is "1", the shift register 23. Latch circuit 24. AND circuit 2
5 etc. perform the same operation as above, and gate circuits 01 to G
The latched control data is sent to one input terminal of each TI.

On the other hand, the correction table storage memory 27 is supplied with the second data "01" shown in FIG. The data corrected using the corrected correction table is sent to the pulse generator 28.The pulse generator 28 is at a high level for a predetermined period including the reheating period ΔT according to the incoming correction data, and after this Jlflfm. generates a pulse f shown in FIG. 2(F) whose pulse width gradually changes and outputs it to the other input terminal of the AND circuit 26.AN
The D circuit 26 generates a pulse q shown in FIG. 2(G) based on the incoming heating pulse e and pulse f, and sends it to the other input terminal of each of the gate circuits 01 to GT+.

The above pulse q has a time of 11tI as shown in FIG. 2(G).
Thereafter, a predetermined period including the reheating period ΔT (i.e., a period from time t1 to t3 when the second data d is "0") has a predetermined pulse width, and after this m period, the correction table is Depending on the data content of the correction data read out from the memory memory 27, the pulse width is decreased by, for example, one cycle.

Each of the gate circuits G+-Gn outputs a gate signal obtained by gate processing the pulse q and n-bit control data supplied from the latch circuit 24 to an NPN transistor T+.
~TT+ is supplied to each base, and the switching is controlled. Current is passed only through the heating resistor connected to the collector side of the turned-on transistor among the transistors 1 to 1, which generates heat.

Moreover, after time t2, the second data output from the data counter 16 is rO,1,r in synchronization with pulses b and e.
IJ, r2J, .
If it is equal to or smaller than the second data, control data [0] is output. This 1°0” or “1”
The energization time of the heating current flowing through the heat generating resistor changes according to the control data of , and the pulse width of the pulse q, thereby performing gradation recording of data for one line.

After that, when the next start pulse a comes in, the address counter 13 and the data counter 16 are each reset, and the data counter 16 again changes the second data sequentially as shown from time t1 onward in FIG. 2(D). Then, the same operation as above is performed, and the gradation recording of the first data for the next one line is performed.

In this way, as shown in FIG. 4, the number of gradation levels vs. density characteristic according to this embodiment is calculated as follows: lli! Compared to the iwJ number vs. density characteristic ■, linear density control in highlight areas is possible, and compared to the gradation number vs. density characteristic ■ when only the above-mentioned skipping correction is performed, from midtones to black level. Linear concentration control is possible. Therefore, according to this embodiment, substantially linear density control can be performed from the number of gradations "0" to rmJ, that is, from the white level to the black level. Also, the period of pulse b is 1/10 of the conventional one.
Since it is only a small amount, the recording time can be shortened. Furthermore, even if there is a variation in the cooling period, the 1st reheating preset is corrected by the reheating data value from the correction table storage memory 21, so that the 6 reheating periods can be optimally varied.
Therefore, uneven printing density will not occur.

In this way, each time the data counter 16 finishes counting from 1 to m times, one line is recorded on the recording paper 5, and after the recording of this one line is completed, the data counter 16 counts from 1 to m again. Start counting.

Incidentally, the structure of the thermal head 1 may be as shown in FIG. 5. In the figure, the same parts as in Fig. 3 are given the same reference numerals.
The explanation will be omitted. The recording paper 5 is wound and fixed around the outer periphery of the platen 31 by a clamper 30. The encoder 8a detects the rotational speed (rotation angle) of the platen 31 via the belt 32, and generates the energization synchronization pulse.

In the example of FIG. 3, the recording paper 5 may be continuous paper, but the
In the illustrated example, the recording paper 5 is fixed to the platen 31 one by one.

It goes without saying that the present invention can also be applied to color printers.

Note that the analog video signal supplied from the TV signal generator 10 may be an information signal of images such as other characters and figures.

In addition, although the above embodiment describes the case where the relationship between 28 hours and the density is a straight line, the relationship between the recording time and the density may be a predetermined curve.

Effects of the Invention As described above, according to the present invention, only the transfer heating resistor is heated, so it is possible to obtain the optimum density characteristic in the highlight area, and the period of the data transfer pulse can be changed from the conventional one. Since it is considerably shorter than that, it is possible to shorten the recording time.Furthermore, the energization time of each heating resistor can be controlled for each concentration so that the recording time and concentration have a nearly linear relationship. Therefore, it is possible to perform almost linear +11 scale control from the highlight area to the maximum number of gradations without causing the aforementioned black-out even at high density levels, and it is possible to achieve high image quality in printing. , by measuring the length of the cooling period of the thermal head, insufficient cooling or overcooling of the thermal head is detected, and the length of the reheating period is variably controlled based on the detection results. Since the period is fixed, it has the advantage of effectively preventing unevenness in printing density caused by excessive heat generation or insufficient heat generation of the thermal head caused by fluctuations in the cooling period.

[Brief explanation of the drawing]

FIG. 1 is a circuit system diagram showing an embodiment of the thermal transfer printing apparatus according to the present invention, FIG. 2 is a signal waveform diagram for explaining the operation of the circuit system shown in FIG. FIG. 4 is a schematic perspective view of an example of a main part of a thermal transfer printing device, FIG. 4 is a diagram showing an example of the tone number vs. density characteristic between the device of the present invention and a conventional device, and FIG. 5 is a diagram to which the device of the present invention can be applied. A schematic perspective view of another example of the main parts of a thermal transfer printing device, FIG. 6 is a diagram for explaining the driver I/printing period, and FIG. 7 is a diagram for explaining unevenness in printing density that occurs in a conventional device. It is. 1... Thermal head, 12... Data storage device, 13
...Address counter, 14.15...Terminal, 16
... Data counter, 17... Control counter, 18... Heat supplementary preset source, 19... Counter, 21... Correction table storage memory, 23... Shift register, 24... Latch circuit , 25.26...
AND circuit, 27... Correction table storage memory, 28
...Pulse generator, GI-GTl...Gate circuit,
R1~RT+...Heating resistor, T+-Tn...Transistor. Patent applicant: Victor Japan Co., Ltd. Figure 3 Figure 5 Figure 7

Claims (2)

[Claims] (1) The application time of the current applied to each of the heat-generating resistors arranged in a line that constitutes the thermal head is individually controlled according to the print density, and the printing of each dot on the recording paper is controlled individually. , a heat replenishment period in which the corresponding heating resistor of the thermal head is energized to reheat it, and a transfer period in which dots are printed on recording paper by thermal transfer by energizing the corresponding heating resistor. In a thermal transfer printing device that performs dot printing during a dot printing period consisting of a cooling period for cooling a heating resistor, a measuring means for measuring a cooling period during the first dot printing period, and a measuring means for measuring a cooling period during the first dot printing period, and a 1. A thermal transfer printing apparatus comprising a heating period control means for variably controlling the length of a heating period during a second dot printing period following a first dot printing period. (2) The measuring means includes a counter that counts a reference clock signal of a constant frequency during the cooling period during the first dot printing period, and the reheating period control means A storage means that stores in advance heat replenishment data as a correction table for correcting overheating or insufficient heat generation of the corresponding heating resistor that occurs during the reheating period during the second dot printing period due to fluctuations, The length of the reheating period during the second dot printing period is variably controlled by reheating data read out from the correction table by specifying a readout address of the storage means based on the count value of the counter. A thermal transfer printing device according to claim 1.