JP2562379B2 - Drive controller for thermal printer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer, and more particularly to history control for controlling heat generation according to the driving results of its heat generating elements.

[Conventional technology]

Conventionally, in a thermal printer, a method of controlling energy applied to a heat generating element by using a heat sensitive element has been used. As an example of this, there is JP-A-63-202471.

Also in the conventional embodiment, a control method has been adopted in which both the thermistor for detecting the ambient temperature and the thermistor for detecting the temperature of the thermal head are provided and the applied energy is controlled based on the thermistor.

[Problems to be Solved by the Invention]

In these conventional examples, the detection of the substrate temperature of the thermal head and the control of the detection of the ambient temperature are not in harmony with each other, and it is extremely difficult to maintain a uniform print quality in a wide temperature range.

Further, particularly in a thermal transfer printer, not only the printing paper but also the ink ribbon is affected by the ambient temperature, and therefore fine control is required to correct the temperature detection of the thermal head with the ambient temperature.

However, in the conventional example, the control method suitable for the thermal transfer printer has not been established.

Further, in the conventional ambient temperature correction method, a plurality of thermistors of heat-sensitive resistance elements must be arranged, which is expensive.

An object of the present invention is to eliminate such a conventional problem,
It is an object of the present invention to provide a drive control device for a thermal printer, which responds finely to changes in ambient temperature and has good print quality in a wide temperature range.

[Means for solving the problem]

The present invention detects a base material temperature or a heat sink temperature of a thermal head having a plurality of heat generating elements, controls the applied energy of the thermal head according to the detected temperature, and further corrects the applied energy according to the ambient temperature. In a printer, a thermal resistance element disposed in contact with the base material or heat sink of the thermal head, and a head temperature for detecting the resistance value change of the thermal resistance element to detect the temperature of the base material or heat sink of the thermal head. A detection unit, a time detection unit for detecting whether or not the drive suspension time of the thermal head has exceeded a predetermined time, and the time detection unit. When the detection result exceeds the predetermined time, the temperature of the thermal head Ambient temperature detection means that recognizes the ambient temperature as the ambient temperature and the head temperature detected by operating the head temperature detection means during the printing operation. And a correction control unit that corrects the applied energy to the heating element of the thermal head based on the detection result of the ambient temperature detection unit. , The ambient temperature detecting means is operated prior to the printing operation of a predetermined printing unit, and thereafter the head temperature detecting means is operated during the predetermined printing operation to control the energy applied to the heat generating element according to the ambient temperature and the head temperature. It is a drive control device for a thermal printer characterized by the above.

〔Example〕

FIG. 12 is a characteristic diagram showing the relationship between the energizing pulse width and the temperature change of the thermal head due to the change of ambient temperature. The vertical axis shows the pulse width ratio when the pulse width at 25 ° C is 1.
It shows a wide temperature.

41 is an ideal characteristic curve showing a change in pulse width with respect to a change in ambient temperature, which is almost a straight line. From 51
Reference numeral 59 denotes a characteristic curve showing the optimum change characteristic of the pulse width with respect to the temperature change of the thermal head. Since the temperature of the thermal head does not naturally become lower than the ambient temperature in the initial stage of operation, it starts from the ambient temperature.

This characteristic curve is a plot of the points where the best print quality is obtained while changing the ambient temperature from 0 ° C to 5 ° C. Actually, the pulse width changes continuously with changes in the ambient temperature. Is.

 From this characteristic curve, the following can be seen.

The rate of change of the applied energy with respect to the temperature change by the thermistor equipped with the thermal head is smaller than the rate of change of the applied energy with respect to the change of the ambient temperature.

As the ambient temperature rises, it is necessary to reduce the applied energy almost linearly.

With respect to the temperature rise during driving of the thermal head, it is necessary to gradually increase the rate at which the applied energy is reduced as the temperature rise advances.

, The ratio of the applied energy that starts driving the thermal head from the ambient temperature and decreases as the temperature of the thermal head increases (reduction rate p) is the ratio of the applied energy that decreases with the ambient temperature as the starting point. It is smaller than the ratio (reduction rate q) at least in the range of 20 ° C or higher.

That is, the relationship of p <q must be maintained when the thermal head is driven from any position of the ambient temperature.

An embodiment of the drive control device of the thermal printer that is optimal for such characteristics will be described in detail below.

FIG. 1 is a schematic diagram showing the configuration of an embodiment of a terminal printer using a drive control device for a thermal printer according to the present invention.

1 is a thermal head having a plurality of heat generating elements 1a, 2 is a head drive circuit for driving this thermal head, 3 is head control for controlling the heat generation amount of a thermal head inserted between the CPU 4 and the thermal head for each dot Each circuit (hereinafter abbreviated as HCU) is shown.

Reference numeral 15 is a reference value generating means for generating a reference value of the energization time of the heat generating element, which is a thermistor 1b which is a kind of a heat sensitive element for detecting the substrate temperature or the heat sink temperature of the A / D converter 15a and the thermal head 1 and a resistor The main component 15b is used to convert the potential Vt at the voltage dividing point between the thermistor 1b and the resistor 15b into a detected digital signal, and a binary code is generated in synchronization with a command from the CPU 4. The capacitor 15c is installed to stabilize the output potential Vt.

Reference numeral 12 is a ROM, 13 is a RAM, 17 is a data bus, 18 is an address bus, 14 is a timer circuit built in the CPU 4, and 20 is a power supply Vh input terminal.

CPU4 indicates an 8-bit CPU as an example.
It has a terminal 8, an I / O port, a timer circuit 14, and the like. The timer circuit has at least built-in timer units 14a and 14b that can operate independently.

Numeral 9 is a retriggerable one-shot timer circuit for detecting a relatively long time, and has a resistor 9a and a capacitor 9b and constitutes a pause time detecting means for detecting whether or not a predetermined pause time of printing has elapsed. A general product name such as 555 is used. It can be seen from the OUT terminal and the output level that a predetermined time has elapsed from the time when the print operation was completed because it was connected to the I / O port of CPU4 and a trigger was always applied during the print operation.
The detection time is set by the time constant of the resistor and the capacitor.

The HCU 3 functions as a type of peripheral of a CPU as a unit circuit, and is assigned to a specific address on a memory map like the ROM 12 and the RAM 13. The decoder 16 is connected to the terminal 7 for accessing this unit circuit.
Reference numeral 5 is a data input terminal connected to the data bus 17, and 6 is an address input terminal for inputting the lower 2 bits of the address bus.

Reference numeral 19 denotes an interface for inputting print data, which is used not only for inputting data but also for inputting a print mode. A command given by software from the printer interface or the like is also a kind of print mode detection means.

FIG. 2 is a head control circuit of the drive control device according to the present invention.
FIG. 3 is a detailed circuit diagram of HCU3.

The data input terminal 5 can input 8-bit data D _{0 to} D ₇ in parallel.

Reference numerals 21 to 29 denote data latch circuits each holding 8-bit data. Reference numerals 21 to 23 denote head driving signal data of H _{0 to} H ₇ , 24 to 26 data of H _{8 to} H ₁₅ , and 27 to 27. 29 is H ₁₆ ~
And latches the data of H _23, respectively.

For example, the head drive output has 24 output terminals H _{0 to} H ₂₄ for driving a 24-dot thermal head.

Reference numeral 31 is a latch circuit group that holds one dot row of the current head data, 32 is one dot row of the past data one time before, and 33 is one dot row of the past data two times before. The respective latch circuit groups are shown.

Reference numeral 30 is an address decoder, which has a function of storing head data in 8-bit units in accordance with address information output from the CPU and receiving a data signal in a current-carrying section that determines a current-carrying time to the thermal head. ,
As an example, the data latch circuits 21, 24 and 27 can be selected by the bit information of the lower 3 bits A0, A1 and A2 of the address data.

At the same time as the head drive data is output from the CPU 4 to the data bus, the ▲ ▼ signal is output.
The terminal is accessed and the data is transferred to each of the data latch circuits 21, 24 and 27 according to the information of the lower 3 bits of the address bus. Then, the already stored data is shifted to the right in FIG. 2, for example, the data in the data latch circuit 21 is shifted to the data latch circuit 22 and sequentially held as the past data.

34 is an energization period pulse generation circuit that demodulates an interval data signal modulated into a periodic signal from the CPU 4 as an energization period pulse. The binary counter 35 and the inverter 35a, AND
It consists of circuit 35b. Reference numeral 9 is a clock input terminal of the binary counter, and 10 is a reset input terminal, which is connected to the address decoder 30. The clock input is a pulse signal transferred with a variable cycle, and the energization section pulse generation circuit 34 selectively extracts this cycle to create a section pulse.

The gate circuit 37 (G0) of FIG. 2 mixes the output signal of the energization section pulse generation circuit 34 and the drive data of the memory circuit and outputs a head drive signal to the heat generating element, which corresponds to the past drive data. It comprises a first gate circuit 38, a second gate circuit 40 corresponding to the present drive data, and a third gate circuit 39 for applying a preheating pulse according to the past drive history. Energization intervals t3, t2, t1 are sub-energization intervals corresponding to past drive data and are input to the first gate circuit, and energization intervals t0 are main energization intervals corresponding to current drive data and second gate circuit. Entered in. T2 in the sub energization section is also input to the third gate circuit for the preheating pulse.

FIG. 3 is an explanatory view showing the relationship between the address data and the function, and the three data latch circuits can be selectively accessed by the information of the lower 2 bits when A2 = 0. After the data is set, when a predetermined address is accessed and a pulse is input to the energization signal input terminals 9 and 10, the heating element is energized.

FIG. 4 is a timing chart showing the input / output waveforms of this energization section pulse generation circuit, and 41 is the input waveform of the interrupt input to the CPU from the timer that determines the printing cycle of the printer, generally using the built-in timer of the CPU. It uses internal interrupt enable.

42 shows the input waveform of the clock input terminal 9. The clock input signal has a cycle that changes sequentially. When the binary counter 35 receives this clock after reset input, it is converted into a 4-bit code. This is converted into output waveforms of 43 to 46 by the inverter 35a and the AND circuit 35b. 43 is the output waveform of the 36a terminal, 44 is the 36b terminal, 45 is
Reference numeral 46 of the 36c terminal indicates the output waveform of the 36d terminal, and the pulse widths thereof are t3, t2, t1, and t0, respectively. These pulse widths are the energizing time of the heating element, and are given to the heating element as an energizing section corresponding to the past drive history.

FIG. 5 is an explanatory diagram showing a method of energizing the thermal head of the drive control device according to the present invention, in which 51, 52 and 53 are memory circuits.
Shows the data in 31, 32, and 33, respectively, 51 is the current, 52
Indicates the data of the previous time, and 53 indicates the data of the previous time. 54 to 58 show the output waveform of the head drive signal,
54 shows the output waveform of the H ₀ terminal, 57 shows the output waveform of the H ₇ terminal, and 58 shows the output waveform of the H ₁₀ terminal.

In FIG. 5, 53 is shown as data at the start of printing. Energization The first time energization is ON and all dots are energized for the entire energization time.
The section is applied as a preheat pulse. This preheating pulse only raises the substrate temperature of the thermal head and does not form dots.

If the energization data of its own heat generating element is on at the timing one before, the t3 section shown by the shaded area is reduced (shown in the output waveform 54), and if there is drive data at the timing two before, the t2 section is generated. If it is reduced (shown in output waveform 57) and is continuous, then the t3 + t2 interval is reduced (shown in output waveform 54). When both adjacent dots are energized ON in the previous driving result, the t1 section is reduced (shown in the output waveform 56). When the data to be compared for all reductions is ON data and the current data is ON, only the t0 section is energized ON. Conversely, when the data to be compared for the reduction is the off data and the current data is off, a preheating pulse is given. The gate circuit 37 performs such comparison of drive data and selection of energization sections.

By forming the head control circuit 2 as a gate array into one chip, a thermal printer having an extremely simple configuration can be realized. This is an extremely important factor when incorporated in not only a terminal printer using a thermal printer but also a miniaturization-oriented device such as a portable world processor.

In the present embodiment, as an example, the past data is stored up to twice before, but it is possible to increase the number of energization sections to 4 times and 5 times by setting this to 3 times and 4 times. By doing so, more detailed history control can be realized.

FIG. 6 shows the temperature T of the thermistor 1b of the reference value generating means 15 of the thermal printer driving device of the present invention and the potential Vt of the voltage dividing point.
It is a characteristic diagram showing the relationship with
A characteristic curve 61 is shown when Rth is 50 kΩ and the resistance value of the resistor 15b is Rk = 25 kΩ, where Rth is the reference value of ° C.

The A / D converter used in the present embodiment is one that outputs an 8-bit binary code. The A / D converter converts this potential into a digital value and outputs it. The number that can be decomposed with 8 bits is 255, and if the maximum detection voltage is 4 volts [V], a resolution of 15.7 mV can be obtained in one step. The maximum detection voltage can be easily set using the Vmax setting pin of the A / D converter.

Since the characteristic curve 61 is non-linear, the temperature range is different for each voltage section. However, the CPU 4 can detect the temperature of the thermal head by detecting this potential with a binary code, and can set the optimum energization condition according to the printing conditions such as the printing mode.

FIG. 7 is an A / D of the driving device of the thermal printer of the present invention.
It is explanatory drawing of the 1st data table in a memory | storage means which shows the correlation of the output code of a converter, and the basic pulse width of energization time, the thermistor temperature table 71, Vt output value table 7
2, A / D converter output value, that is, reference value table 73,
Reference pulse width ratio table 74, reference pulse width table 75,
It consists of the standard value of standard pulse width of 76.

The relationship between the tables 73 and 74 and the prescribed value 76 of the reference pulse width are stored in the ROM as the first data table 77. Therefore, the CPU can set the reference pulse width by detecting the output code of the A / D converter as the reference value. The reference pulse width TW is obtained from the specified value 76 of the reference pulse width and the ratio. The standard value of the pulse width ratio of 1.00 is based on the case of 25 ° C.

Table 73 is written in hex code, but ROM
It is burned with a binary code inside the table. Actually, the accuracy of the table is further subdivided into temperature steps, and the code table 73 and the reference pulse width table 74 are held as data in units of 1 ° C. However, it is also possible to hold it in units of 10 ° C and approximate it between them with a straight line to complement them. The characteristic of the ratio of the reference pulse width can be optimized by experimenting with the heat storage characteristic of the thermal head of the printer.

In the method that uses a pulse generator circuit that includes a thermistor, it is generally difficult to match the circuit characteristics to this optimum characteristic, but in the method that uses the A / D converter, the temperature characteristic curve can be changed freely. You can see that you can choose.

FIG. 8 is an explanatory diagram showing an example (second data table) of the ratios of the energized sections, where 81, 82, and 83 are print modes,
Reference numerals 84, 85 and 86 show the ratios of the energized sections in the respective modes.

The ratio of the energized section is shown as 100 with the reference pulse width being t0 at one time of thermal transfer. The pulse width ratio is changed according to the printing mode such as the type of ink ribbon or the type of printing paper. These reference ratios are set as a third data table in the ROM 12, and the output value of the reference value generating means 15 and the first data table in the ROM and the second data table are set according to the print mode.
It is possible to easily obtain the pulse width of each energization section from the values of the data table of 3 and the value of the third data table. As an example, if the reference pulse width TW has a pulse width t0 and the ambient temperature is 25 ° C., then t3 = 80 × t0 / 100.

As described above, the reference pulse width can be set to a value that determines the main energization section t0, but it can also be determined by dividing the total energization time by the ratio of energization sections.

The printing modes are not limited to those listed here, and there are many combinations such as monochrome ink bottles, color ribbons, and printing speeds.

FIG. 9 is an explanatory view showing a second data table in the storage means showing the correction coefficient of the pulse width depending on the ambient temperature,
The reference pulse width at that time can be obtained by multiplying the correction coefficient of FIG. 9 according to the ambient temperature by setting 25 ° C. to 1. For example, if the ambient temperature is 30 ° C, it can be calculated as 0.95 x 0.95 from the ratio of the reference pulse width of the ambient temperature 25 ° C and the correction coefficient of 30 ° C.

The A / D converter that detects the head temperature is used to detect the ambient temperature, and if the pause time of the head exceeds a predetermined time by the pause time detection means, the head temperature detected immediately before the printing operation becomes the ambient temperature. Mostly approximated.
The predetermined value of the dwell time varies depending on the size of the thermal head, and generally, in a serial type thermal head, it almost reaches the ambient temperature in about 3 to 5 minutes. However, since the line type thermal head takes about 20 to 30 minutes, it is necessary to set the predetermined value of the rest time depending on the size of the head.

[Operation] The printing operation will be described with reference to FIGS. 10 and 11.

FIG. 10 is a flow chart of the printing operation of the drive control device for the thermal printer of the present invention.

Prior to the start of printing, the pause time detecting means detects whether it is the first printing after the power is turned on (step 101) or whether a sufficient time has passed from the previous printing. (Step 102) If it is the first printing or the idle time is sufficient, the A / D converter is operated to detect the ambient temperature. (Step 103) First, the correction value of the pulse width is obtained from the ambient temperature from the second data table and stored in a predetermined address of the RAM. If it is not the first print, this value is updated. (Step 104) After that, the thermal head is driven while detecting the head temperature at every predetermined cycle. (Step 105, Step 1
06) It is possible to easily obtain the pulse width of each energization section from the output value of the reference value generating means 15 and the correction value obtained from the values of the first data table and the second data table in this ROM. .

FIG. 11 is an explanatory diagram showing the timing when the head is driven, which will be described in detail below. T ₀ , T ₁ and T ₂ indicate energization periods, which are determined by a timer for determining the energization periods, and also serve as basic clocks for a step motor or the like (not shown) for moving the head in addition to the energization periods.

Access the reference value generating means 15 in synchronization with the energization cycle,
Detect the output code of the A / D converter. The reference pulse width TW according to the temperature of the thermal head is obtained by referring to the first data table, and the energization section t0 is calculated by multiplying the ambient temperature correction coefficient obtained at the beginning of the printing operation by the third data table. t1 …… Calculates tn. In the next timing cycle, the pulse width values of the main energizing section and the sub-energizing section to the heating element corresponding to this are counted alternately using the timer circuits 14a and 14b with the built-in CPU, and the HCU of the HCU is synchronized with this output time. It outputs as a periodic signal by accessing a predetermined address. As an example, after setting t3 to the timer circuit 14a, t2 is set to the timer circuit 14b while the timer circuit 14a is operating, and when the counting operation of the timer circuit 14a is finished, the timer circuit 14b is activated and t1 is set to the timer circuit 14b. It is a procedure. By using a plurality of timer circuits in this way, highly accurate time can be obtained and accurate energization control can be performed without being affected by the processing speed of the CPU. Furthermore, the timer output process also uses the internal interrupt function of the CPU to minimize the delay time. Thus, the CPU 4 equipped with a plurality of timer circuits also serves as the energization section data output means. The reading of the pulse width TW is performed at every predetermined cycle of the head drive, and by accommodating the temperature of the thermal head which changes from moment to moment, heat accumulation can be prevented and good print quality can be realized.

During the printing operation, basically, the pulse width can be set to the optimum value at this time by operating the A / D converter every dot period and detecting the temperature of the thermal head. However, in the low-speed printing mode in which the printing speed is slow, the temperature rise of the thermal head is not so rapid, so that it does not have to be one dot cycle. In addition, the CPU4 outputs the energization signal by varying the total energization time and the width of the energization section according to the type of ink ribbon and the type of paper and outputs the energization signal, so read the data table corresponding to these printing modes. It is converted into a periodic signal and output.

According to this example, the value of the energization section can be easily obtained by obtaining the reference pulse width from the reference value detected by the A / D converter and calculating it at a predetermined ratio.

In this embodiment, the pause time detecting means is explained as a one-shot timer, but a CPU built-in timer may be used.

The energization section data generating means centering on the CPU and the energization section pulse generating means 34 constitute the energization section signal generating means.

〔The invention's effect〕

According to the present invention, it is possible to improve the printing quality of a thermal printer over a wide range of ambient temperatures, and it is possible to provide a very useful thermal printer.

By detecting the ambient temperature and the temperature of the thermal head, it became possible to drive the thermal head at a higher speed, and it was possible to respond to faster printing.

The ambient temperature can be detected without arranging two thermistors, and fine control is possible with due consideration given to the difference in printing characteristics due to the difference in thermal transfer ink ribbons, and various ink ribbons such as color ribbons and multi-time ribbons. Can be supported by one model.

As described above in detail, the drive control device of the thermal printer according to the present invention can be applied to all types of printers that print using a heat generating element and is extremely useful.

By referring to the table in the ROM, the temperature of the thermal head is substantially detected in real time, which enables extremely precise thermal control.

As described above in detail, the drive control device of the thermal printer according to the present invention can be applied to all types of printers that print using a heat generating element and is extremely useful.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the construction of an embodiment of a terminal printer using a drive control device for a thermal printer according to the present invention. FIG. 2 is a detailed circuit diagram of the head control circuit HCU3 of the drive control device of the present invention. FIG. 3 is an explanatory diagram showing the relationship between the address data and the function of the head control circuit of the present invention. FIG. 4 is an explanatory diagram showing input / output waveforms of the energization section pulse generation circuit of the drive control device of the present invention. FIG. 5 is an explanatory diagram showing a method of energizing the thermal head of the drive control device of the present invention. FIG. 6 is a characteristic diagram showing the relationship between the temperature T of the thermistor 1b of the reference value generating means 15 of the driving device of the thermal printer of the present invention and the potential Vt of the voltage dividing point. FIG. 7 is an explanatory diagram showing the correlation between the output value of Vt of the driving device of the thermal printer of the present invention, the output value of the A / D converter, and the reference pulse width of the energization time. FIG. 8 is an explanatory diagram showing an example of a ratio of energization intervals of the drive control device of the present invention. FIG. 9 is an explanatory diagram showing a second data table in the storage means showing the correction coefficient of the pulse width depending on the ambient temperature. FIG. 10 is a flow chart of the printing operation of the drive control device for the thermal printer of the present invention. FIG. 11 is an explanatory diagram showing the timing when the head is driven. FIG. 12 is a characteristic diagram showing the relationship between the energizing pulse width and the change in ambient temperature and the change in temperature of the thermal head. 1 ... Thermal head 1b ... Thermistor 2 ... Head drive circuit 31, 32, 33 ... Memory circuit 4 ... CPU 15 ... Reference value generating means 19 ... Rest time detecting means 14a, 14b ... Timer circuit 34 ...... Section pulse generation circuit 37 …… Gate circuit 77 …… First data table 84, 85, 86 …… Second data table

Claims (3)

(57) [Claims] 1. A method of detecting a base material temperature or a heat sink temperature of a thermal head having a plurality of heat generating elements, controlling the applied energy of the thermal head according to the detected temperature, and further correcting the applied energy according to an ambient temperature. In a thermal printer, a thermal resistance element arranged in contact with the base material or heat sink of the thermal head, and a head for detecting the resistance value change of the thermal resistance element to detect the temperature of the base material or heat sink of the thermal head. A temperature detection means, a time detection means for detecting whether or not the drive rest time of the thermal head exceeds a predetermined time, and the time detection means, and when the detection result exceeds the predetermined time, the thermal head Ambient temperature detecting means for recognizing the temperature as its ambient temperature, and head temperature detected by operating the head temperature detecting means during printing operation. Control means for driving and controlling the heat-generating element of the thermal head according to the applied energy, and correction control means for correcting the energy applied to the heat-generating element of the thermal head based on the detection result of the ambient temperature detecting means. Then, the ambient temperature detecting means is operated prior to the printing operation of the predetermined printing unit, and thereafter the head temperature detecting means is operated during the predetermined printing operation to control the energy applied to the heating element according to the ambient temperature and the head temperature. A drive control device for a thermal printer, which is characterized by: 2. A drive control device for a thermal printer, wherein the drive history of the heat generating element is stored at least twice in the past and printing is performed while controlling the energization time of each of the heat generating elements based on the storage result. And a, a storage circuit for storing the current and past drive data of the heat generating element, and b, a main power supply section for outputting the current drive data for the power supply time of any heat generating element connected to the storage circuit. And a gate circuit for dividing and outputting to a plurality of sub-energization sections corresponding to past drive data, c, a heat-sensitive resistance element for detecting the temperature of the thermal head or a temperature of its heat sink, d, the heat-sensitive resistance element A reference value generating means for generating a reference value of an energization time to the heat generating element, the reference value generating means having an A / D converter for detecting a potential at a voltage dividing point with the resistor, and e, the time detecting means and the reference value. A correction value detecting means for recognizing the reference value as a correction reference value of the ambient temperature from the generating means; f, a data table showing the relationship between the reference value, the pulse width of the main energizing section and the pulse width of the sub energizing section. Storage means for storing as g, a storage means for storing the relationship between the correction reference value of the correction value detection means and the increase / decrease rate of the pulse width as a data table, h, the reference value and the correction reference value Energizing section signal generating means for determining the pulse width of each energizing section by referring to the data table in order to set the plurality of energizing sections in the gate circuit based on the detection result of and supplying the pulse width to the gate circuit as an energizing section signal. And a head drive circuit that turns on and off the power supply to the heat generating element in response to an output signal of the gate circuit. 3. A thermal printer in which the temperature of a base material or the temperature of a radiator plate of a thermal head equipped with a plurality of heat generating elements is detected and the applied energy of the thermal head is controlled in accordance with the detected temperature. A heat-sensitive resistance element arranged in contact with the material temperature or the heat dissipation plate, a storage means for detecting the temperature using the heat-sensitive resistance element prior to the printing operation of a predetermined printing unit, and storing this as the ambient temperature, and a predetermined printing The temperature of the thermal head itself is detected by using the thermal resistance element during operation, and means for determining the applied energy to the thermal head from the stored ambient temperature and the temperature of the thermal head, the ambient temperature And the temperature of the thermal head are detected by a single thermal resistance element, and the heating element is controlled by the applied energy that is optimal for those temperature conditions. Drive control apparatus for a thermal printer, characterized in that.