JPH06183048A - Thermal printer - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a thermal printer, and an object thereof is to provide a thermal printer capable of high-speed and high-quality printing and capable of arbitrarily setting power consumption. A print head in which a plurality of heating elements are divided into a predetermined number of printing blocks, a driving unit that energizes the heating elements in each of the printing blocks and drives the print head, and a predetermined print data A counting means for counting the number of the heating elements simultaneously energized in the print head based on the printing block unit; and a distribution determining means for determining the distribution of the heating elements energized simultaneously by the counting means. Based on the distribution of the current-carrying heating elements per dot line, a plurality of printing blocks are simultaneously driven by the driving means in accordance with a preset simultaneous current-carrying pattern so that the thermal paper in contact with the heating elements of the printing blocks is colored. To configure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer, and more particularly to, for example, a battery-operated line dot type thermal printer.

[0002]

BACKGROUND OF THE INVENTION In recent years, from the viewpoint of quietness, maintainability, high speed, etc., printing is performed by electrically heating a print head corresponding to characters and figures on a thermal paper that develops color when heat is sensed, so-called, There are many thermal printers available. Of these thermal printers, battery-powered thermal printers are roughly classified into two groups: low-voltage (about 5V) serial thermal printers and high-voltage (about 12V) line thermal printers. In general, a thermal printer operating at a low voltage has a low printing speed, and a thermal printer having a high printing speed requires a high voltage.

That is, in a small portable device or the like, 4.5
Since it is driven at a low voltage such as a battery drive of about V to 6.5 V or a single 5 V power supply, high-speed printing cannot be performed. Therefore, for example, a thermal printer capable of high-speed printing at a low voltage of about 5V is required.

[0004]

2. Description of the Related Art A driving voltage applied to a heating resistor element in a conventional print head (hereinafter referred to as a thermal head) of this type of thermal printer is relatively high at about 12 to 24 V, and a power source used also has a current capacity. The large commercial power source was mainly used. In such a thermal printer, the heat energy supplied to the thermal paper by the heating resistance element of the thermal head is

[0005]

[Equation 1]

Is approximated by The applied voltage V
_{The set} and the saturation voltage V _sat have a relationship of V _set >> V _sat , and the generated heat energy ε is proportional to the square of the applied voltage V _set and the energization time t, and is inversely proportional to the resistance value R of the heating resistance element. In particular, since the voltage is proportional to the square of the applied voltage V _set , if the voltage is high, the energization time t can be shortened and the resistance value R can be increased.

That is, the energization time t is closely related to the printing speed. If the energization time t is short, the energization cycle can be shortened, so that the printing speed can be increased, and if the resistance value R is large, the power consumption can be kept small. Because you can
A high-voltage drive type thermal printer can perform high-speed printing with relatively low power consumption without using a special method.

The driving of the thermal head will be described below. FIG. 25 shows the basic configuration of a general line type thermal head. The thermal head of this line thermal printer is roughly divided into a head unit 101, a drive unit 102, and a control unit 103. The head unit 101 and the drive unit 1
Reference numeral 02 is composed of five print blocks B0 to B4 obtained by dividing the heating resistance element 104 of 320 dots per dot line into every 80 dots, and the driving unit 102 includes the driving transistor 105 for driving each heating resistance element 104. It is configured.

The control unit 103 controls the print blocks B0 to B4.
Latch circuit 106 for outputting a drive control signal to drive transistor 105 for each, and shift register 1
It is composed of 07. FIG. 26 shows a drive waveform of a typical thermal head. In the above configuration, when printing on a predetermined thermal paper, first, the drive transistor 105 is driven at a predetermined timing by the latch circuit 106 based on the predetermined data in the shift register 107, and the heat generating resistance element 104 in the print block B0. However, for example, 12V
The printing block B is energized with a high voltage for about a predetermined time.
Printing is performed on the thermal paper position corresponding to the position of 0, and then the paper is slightly fed.

Similarly, printing blocks B1, B2, B
The heating resistance elements 104 in B3 and B4 are sequentially energized to print on the thermal paper position corresponding to each position of the printing blocks B1, B2, B3 and B4, and the printing of one dot line is completed.

[0011]

However, since such a conventional thermal printer is configured to energize at a high voltage of about 12V for a predetermined time, for example, a line at a low voltage of about 5V is used. When printing is performed every time, good printing density cannot be obtained, and as a result, there is a problem that high-speed printing cannot be performed.

This is as shown in the above equation [Equation 1]:
To obtain the required amount of heat generation at a low voltage, it is necessary to lower the resistance value R and increase the current value, but the applied voltage Vset
In order to reduce, the resistance value R of the heating resistance element must be reduced or the energization time t must be increased. However, increasing the energization time t generally increases the printing cycle and reduces the printing speed. Therefore, the energization time t cannot be set too large in order to realize high-speed printing.

Therefore, it is conceivable to reduce the resistance value R of the heating resistance element. However, there is a limit in reducing the resistance value R of the heating resistance element due to the head material, and the resistance value R of the heating resistance element is limited. If the resistance value R is small, a large current will flow. Therefore, when a battery is used, it causes a voltage drop due to the internal impedance of the battery and a print failure due to the loss in the head due to the common conductor in the head. Problem occurs.

Therefore, as a special case, when the capacity of the power supply used is large to some extent, for example, the printing block B is used.
There may be a method in which 0, B1 and print blocks B2, B3 are simultaneously energized, but in this case, the current value consumed becomes large. Therefore, in a thermal printer that uses a battery as the main power source, reduction processing is applied to the data to be printed in order to suppress the current consumption, and the current consumption is suppressed by reducing the number of heating elements that are energized at the same time, The print rate in the print block is calculated, and when the print rate exceeds a predetermined value, the print block is divided and simultaneous energization is performed to suppress the current consumption.

However, the method of suppressing the current consumption by reducing the number of heating elements simultaneously energized by the reduction process is very effective for the only proposition of current suppression, but instead of being able to reduce the current consumption, The print quality is deteriorated, and it is difficult to use it particularly for printing that requires high print quality such as bar codes. Further, in the method of obtaining the print rate in the print block and further dividing the print block based on the print rate, only the print rate of any one of the print blocks is high and the print rate of the other print blocks is Even if it is low, the energizing task of energizing the printing block with a high printing rate uniquely divides the other printing blocks, and is not efficient in terms of speeding up. Further, in order to further divide one print block, it is necessary to increase the number of times of data transfer to the shift register, and the energization processing time per dot line due to the transfer processing time becomes long, which is also a factor that hinders high speed printing. Becomes

Further, as described above, since the main power source is a battery, low power consumption is a prerequisite, but the actual allowable power is not uniform in actual operation and the It is desirable that it can be changed according to the system or application.

[0017]

It is therefore an object of the present invention to provide a thermal printer capable of high-speed and high-quality printing and capable of arbitrarily setting power consumption.

[0018]

In order to achieve the above object, a thermal printer according to the present invention has a print head in which a plurality of heating elements are divided into a predetermined number of printing blocks, and a heating element is provided for each printing block. Driving means for energizing and driving the print head, counting means for counting the number of the heating elements simultaneously energized in the print head for each printing block based on predetermined print data, and counting by the counting means Distribution determining means for determining the distribution of the heating elements that are simultaneously energized, and based on the distribution of the energizing heating elements per dot line, a plurality of printing blocks are formed by the driving means according to a preset simultaneous energization pattern. It is configured to be driven at the same time so that the thermal paper in contact with the heating element of the printing block is colored.

In this case, it is preferable to set the number of the heating elements and the number of printing blocks that are simultaneously energized according to the current capacity of the power source used and the required printing quality.
Further, in the printing block, a driving command is given to the driving means for transporting the thermal paper instead of the powering command to the printing block in which the heating element to be energized does not exist, so that the thermal paper can be moved in a short time. Transporting is effective.

Further, the counting means sets the number of heating elements simultaneously energized in the print head in a single print block unit and two adjacent print block units, or in a single print block unit. Counting in units of two adjacent print blocks and units of three or more adjacent print blocks, normalizing the number of energization heating elements in the print blocks into pattern data of a predetermined number of bits, and based on the normalized pattern data It is preferable to read a previously stored energization pattern and look up the driving sequence.

[0021]

According to the present invention, a plurality of printing blocks are simultaneously driven by the driving means in accordance with the preset simultaneous energization pattern based on the distribution of the energization heating elements per dot line, and the current capacity of the power supply to be used and necessary Since the number of the heating elements and the number of printing blocks that are simultaneously energized are set according to the printing quality, the printing speed can be increased and any power consumption can be set.

When there is no print block to be energized, the drive command is given instead of the energization command and the printing process is skipped, so that the overall printing speed is increased. Further, the energization pattern stored in advance is read out based on the normalized pattern data, and the driving sequence is looked up to further increase the overall printing speed.

That is, it is possible to obtain a high-speed and high-quality printing and a thermal printer in which power consumption can be arbitrarily set.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 24 are views showing an embodiment of a thermal printer according to the present invention, FIG. 1 is a block diagram showing the overall configuration of the present embodiment, and FIG. 2 is a block showing the configuration of a thermal head in the present embodiment. It is a figure.

First, the structure will be described. As shown in FIG. 1, the line thermal printer of this embodiment has an MPU (Micr
Processing Unit) 1, mechanism drive circuit 2, print ratio measuring circuit 3 as counting means, print block energization judging circuit 4 as distribution judging means, interface circuit 5, A
The / D conversion module 6, the RAM 7, the ROM 8, the thermal head 9, and the stepping motor 10 are included.

The MPU 1 performs the main control of the printer, and the mechanism driving circuit 2 energizes the print block of the thermal head and drives the stepping motor 10. The print ratio measuring circuit 3 counts the number of heating resistance elements 104 that are simultaneously energized in print block units, and stores the count result in the RAM 7.

The print block energization determination circuit 4 includes a print block selection determination circuit 4a and a print block energization control circuit 4
b, which is counted by the printing rate measuring circuit 3 to obtain R
Based on the count value stored in the AM7, the high speed and the energization current are optimized, and the printing blocks to be energized simultaneously are selected. Here, a method of determining the energization pattern performed by the print block selection determination circuit 4a will be specifically described with reference to FIG. FIG. 3 is a diagram showing a processing concept in the print block selection determination circuit.

In FIG. 3, a is a heating resistance element 10 in a state in which one dot line is counted by the printing rate measuring circuit 3.
The distribution of four numbers is shown, and N0 to N4 in the distribution a indicate the number of heating resistance elements 104 to be energized in each of the print blocks B0 to B4. In the following description, the number of simultaneously energized print blocks when energizing a plurality of print blocks is 2 as a condition for determining the energization pattern, and the maximum number of heat generation resistance elements 104 that can be energized is 64 dots as an allowable current limit. And

In the judgment processing, first, the print blocks B0 to B
The number N0 to N of the heat generating resistance elements 104 in 4 to be energized
Each of No. 4 is divided into a case (Nx = 0) where there is no heating resistance element 104 to be energized and a case (Nx ≠ 0) where there is. In FIG. 3, b is information of the number of heat generating resistance elements 104 in the print blocks B0 to B4 after performing case classification, and is “0” when there is no heat generating resistance element 104 to be energized, and “when there is”. Assuming that the information indicated by b in FIG. 3 is derived from arbitrary print data as 1 ″, the heat generating resistance element 104 energized in two adjacent print blocks.
The maximum number of heating elements that can be energized (in this case,
64), and as a result of the comparison, if it exceeds the maximum number of heating resistance elements, it is set to "1", and if it is equal to or less than the maximum number of heat generation resistance elements, it is set to "0", and the information indicated by c in FIG. It

Here, in c in FIG. 3, the numbers N0 and N
When the sum of 1 and the sum of the numbers N1 and N2 are larger than 64 dots, the print blocks B0 and B1 and the print blocks B1 and B2 should be energized at the same time according to the limitation condition of the maximum number of heat generating resistance elements. Cannot be done, and the sum of the numbers N2 and N3 is
Since N3 = 0, N2 + N3 ≦ 64 is inevitably established, and the print blocks B2 and B3 can be energized simultaneously. Since N4 = 0, the print block B4
In, there is no need for energizing operation.

From the above calculation results, the optimum energization pattern becomes a pattern shown by d or e in FIG.
In FIG. 3, in d and e, the ● symbol for each print block indicates the energization operation for one print block, and the ■ symbol indicates the non-energization operation, and the elliptical symbol written across the two print blocks is 2. The simultaneous energization operation for two adjacent print blocks is shown.

Here, the energization period is the same for the ● symbol and the elliptical symbol, and the ■ symbol may be 0 in principle if only the thermal head is focused on. 3, the d and e energization patterns are temporally equivalent. However, normally, the thermal printer also drives the stepping motor 10 which conveys the paper at the drive timing of the printing block, so that if the symbol (4) is 0, the stepping motor 10 cannot rotate normally. However, the maximum drive cycle of the stepping motor 10 is sufficiently shorter than the energization cycle of the heating resistor element 104 of the thermal head, and may be about 1/2 to 1/4 of the head energization cycle. Ellipse symbol period T0
In the case of 1/2, the energization pattern of d in FIG. 3 has a temporal advantage over the energization pattern of e in FIG.

The interface circuit 5 is for inputting commands and data from the host computer, and the A / D conversion module 6 is for measuring the drive voltage and the substrate temperature of the thermal head 9. RAM7
Is a memory that stores a count value of the number of heating resistance elements 104 that are energized at the same time, which is counted by the printing rate measuring circuit 3, and the ROM 8 is a non-volatile memory that stores in advance program codes and parameters for controlling the MPU 1. is there.

The thermal head 9 is, as shown in FIG.
The head unit 101, the driving unit 102, the control unit 103, the print ratio measuring circuit 3, the print block selection determining circuit 4a and the print block energizing control circuit 4b included in the print block energizing determining circuit 4, and the heating resistor element 104.
Is electrically heated to cause the heat-sensitive paper in contact with the heating resistance element 104 to develop color.

The stepping motor 10 is a drive source for carrying the thermal paper. Next, the operation will be described. When printing is performed, print data is first transferred to a shift register for inputting print data in synchronization with the transfer synchronization signal CLK, as in the conventional driving method. In this case, the print ratio measuring circuit 3
Thus, the print data is converted into the number of heating resistance elements 104 to which electricity is applied.

The print data is generally transferred in 1-byte (8-bit) units. At this time, the conversion data of the number of heating resistance elements 104 to be energized corresponding to the 1-byte print data is set in advance, Normally, the conversion data is read using the print data itself as an offset. In this way, the print data is converted into the number of heating resistance elements 104 that are energized, and the number of heating resistance elements 104 that are simultaneously energized in printing block units (64 bits × 5 in this case) is counted and stored.

After the print data for one dot line has been transferred, the latching and energizing operations are performed. In this embodiment, the print block unit counts simultaneously by the print ratio measuring circuit 3 after the transfer of the print data is completed. The number of heat generating resistance elements 104 to be energized is read into the print block energization determination circuit 4 via the RAM 7, the drive time spent for one dot line is minimum, and energization of the print block is such that the set allowable current is not exceeded. The pattern is determined, and control information is given to the print block power supply control circuit 4b by the power supply pattern, whereby the print block power supply control circuit 4b outputs the data latched from the shift register 107 to the latch circuit 106 by the signal LA. Signal STB
The drive transistor 105 is driven based on 0 to STB4, the heating resistor element 104 is energized, and printing is performed.

The printing operation will be described in detail below. First,
When the MPU 1 receives a print command from the host through the interface circuit 5, the print data of one dot line unit is expanded on the RAM 7, and if the latch operation of the previous dot line in the thermal head 9 is completed, the printing is performed. The print data expanded on the RAM 7 is sequentially transmitted to the rate measuring circuit 3.

Then, in the print ratio measuring circuit 3, while the print data synchronized with the transfer clock is transferred to the shift register in the thermal head 9, the number of energized heat generating resistance elements is counted for each print block and temporarily stored in the RAM 7. After the evacuation and the transfer of the print data of all the one dot lines and the counting of the number of energization heat generating resistance elements are completed, the print rate energization determination circuit 4 causes the print block energization determination circuit 4 to start the next operation TR.
0 is issued.

At this time, in the print block energization determination circuit 4, the count result written in the RAM 7 by the print ratio measurement circuit 3 is read out, the print block energization pattern optimization calculation is performed, and the calculation result is stored in the RAM 7. It is written, and the energization start trigger TR is applied to the mechanism drive circuit 2.
1 is issued. In the mechanism drive circuit 2, the stepping motor 10 is driven and the print data in the shift register is latched by the latch signal line, and R
The intentional energization pattern written on the AM 7 is read and the print block is energized. At the same time, in the MPU 1, the A / D conversion module 6 measures the voltage of the driving voltage and the substrate temperature of the thermal head 9 is measured by the thermistor connection line, and the thermal energy supplied from the heating resistance element of the thermal head 9 to the thermal paper is supplied. The current is converted into time and the energization time parameter is transmitted to the mechanism drive circuit 2. The mechanism drive circuit 2 controls the energization time based on the received parameters.

Here, an example of the optimization calculation in the print block energization determination circuit 4 is shown in FIGS. 4 to 10 and 11 to 2.
2 shows. 4 to 10 are arithmetic means when the maximum number of print blocks that can be simultaneously energized is set to 2, FIG.
1 to 22 are arithmetic means when the maximum number of print blocks that can be simultaneously energized is set to 3.

In FIGS. 4 to 10 and 11 to 22, the maximum number of heat generating resistance elements that can be energized simultaneously is limited to 64 dots, but the maximum number of heat generating resistance elements is changed from the host computer. Is issued as a command, the user can freely set the maximum energization current according to the power supply capacity used, and the optimum energization pattern is obtained from the number of energization heating resistance elements counted by the printing rate measurement circuit 3. In this case, it may be generated by a certain algorithm operation, but the addition judgment result of the print block is normalized to several bits, and the energization pattern stored in advance in the memory is looked up using the normalized bit data as an offset. Therefore, the energization pattern can be generated easily at high speed.

FIG. 23 is a block diagram of the lookup means when the maximum number of print blocks that can be simultaneously energized is set to 3, FIG. 23 (a) is a bit structure of normalized bit data, and FIG. 23 (b). Indicates the value structure of the energization pattern. The value data is stored in advance in the memory as described above, and the normalized bit data × 2 is added as an offset word to the storage start address of the value data, and 2-byte value data is obtained from the added address. As a result, the energization pattern is generated.

Further, the normal value data is stored in the ROM 8, but in this case, the maximum number of print blocks that can be energized is fixed and cannot be changed. Therefore, if the user wants to change the maximum number of print blocks that can be energized, the storage location is set to RAM7.
It is also possible to deal with generating the lookup table of the value data assigned above by an algorithm. In this case, the capacity of the RAM 7 becomes large, but the degree of freedom for setting the maximum number of energization printing blocks is expanded, and the generation speed of the energization pattern is no different from that in the case where the ROM 8 is arranged.

The occupied capacity of the value data generated in FIGS. 11 to 22 and 23 requires 8 Kbytes because the normalized bit data is 12 bits, and is required for other control program codes and parameters. Since there is a fear of giving a constraint, the following processing can be considered as a means to avoid this. That is, first, the normalized bit data includes a case where a contradiction occurs between the addition operation results. For example, in FIG. 23 (a), B0 + B1 and B1 + are obtained from the two-block addition operation result
When both B2 are 1, B0 + B1 + B2, which is the result of the 3-block addition operation, cannot be 0. Therefore, the consistency of the block distribution pattern, the two-block addition operation result, and the three-block addition operation result is confirmed, the bit module in which the inconsistency occurs is masked, the number of bits of the bit data is reduced, and By not storing inconsistent value data, the actual value data occupation capacity can be significantly reduced.

Therefore, in the conventional thermal head,
As shown in FIG. 26, since one print block is sequentially energized with the same energization cycle regardless of the presence or absence of the heating resistance element 104 to be energized, assuming that the energization cycle for one print block is T0, one dot line The time required is 5x
However, in the present embodiment, as shown in FIG. 24, a plurality of print blocks are energized at the same time, and the stepping motor 10 is driven at a high speed during non-energization operation.
The time required to drive the dot line is 3 × T0, and the speed can be increased by about 1.3 times that of the conventional one. It is clear that the difference in the required time becomes larger as the printing rate becomes lower, and the difference in the printing speed appears remarkably at the printing rate in the normal printer actual operation of about 10 to 20%. . In this case, since the maximum number of energization heat generating elements does not exceed 64 dots as in the conventional case, the maximum current can be suppressed to the level of the conventional case.

Further, although the maximum number of print blocks that can be simultaneously energized is 2 as a condition for determining the energization pattern in the above description of the operation, it is also possible to expand to 3 or more, and simultaneous energization is performed. Since the maximum number of heat generating resistance elements can be increased if the power supply on the user side has a margin, in this case, the speed can be further increased. Note that the larger the maximum number of print blocks that can be energized simultaneously, the faster the printing speed. However, if the paper feed step for one dot line is the number of steps corresponding to the number of print blocks, stepping is performed while energizing multiple print blocks. This causes a problem that the motor 10 is driven. In such a case, the maximum number of printing blocks that are energized simultaneously can be changed, and both the printing speed and the printing quality can be changed according to the operation mode of the user.

That is, in the present embodiment, printing is performed at high speed without increasing the energization current, and is comparable to the high-voltage drive thermal printer used as a stabilized power supply even at a low drive voltage such as battery drive. No printing speed can be achieved. Further, since the current can be changed according to the capability of the power supply used by the user, it is possible to provide a thermal printer having a high degree of freedom.

In the embodiment shown in FIG. 1, the printing rate measuring circuit 3 and the printing block simultaneous energization judging circuit 4 are illustrated as independent elements, but they do not necessarily have to be independent and two circuits are required. Integrated,
Alternatively, the MPU 1 may be substituted. Moreover, the calculation means in FIGS. 4 to 10 and FIGS. 11 to 22 is merely an example, and other energization patterns may exist as long as the processing concept is the same.

Furthermore, in the present invention, as an example, the thermal head 9 having a total of 320 dots of 64 dots × 5 blocks is used.
However, the present invention is not limited to this, and it goes without saying that the total number of heating resistance elements included in the thermal head, the number of divisions into print blocks, and the like are arbitrary depending on the given device and purpose. Absent.

[0051]

According to the present invention, a plurality of printing blocks are simultaneously driven in accordance with a preset simultaneous energization pattern based on the distribution of the energization heating elements per dot line, and the current capacity of the power supply to be used and the required amount are required. Since the number of the heating elements and the number of printing blocks that are simultaneously energized can be set according to the printing quality, the printing speed can be increased and any power consumption can be set.

When there is no print block to be energized, the printing process is skipped by giving a drive command instead of the energization command, so that the overall printing speed can be increased and further normalized. The overall printing speed can be further increased by reading a previously stored energization pattern based on the pattern data and looking up the drive sequence.

Therefore, it is possible to provide a high-speed and high-quality printing and a thermal printer in which power consumption can be arbitrarily set.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a thermal head in this embodiment.

FIG. 2 is a block diagram showing a main configuration of an embodiment of the present invention.

FIG. 3 is a diagram showing a processing concept in a print block selection determination circuit.

FIG. 4 is a diagram for explaining a calculation unit when the maximum number of print blocks that can be simultaneously energized is set to 2;

FIG. 5 is a diagram for explaining a calculation unit when the maximum number of print blocks that can be simultaneously energized is set to 2;

FIG. 6 is a diagram for explaining a calculation unit when the maximum number of print blocks that can be energized simultaneously is set to 2;

FIG. 7 is a diagram for explaining a calculation unit when the maximum number of print blocks that can be simultaneously energized is set to 2;

FIG. 8 is a diagram for explaining a calculation unit when the maximum number of print blocks that can be energized simultaneously is set to 2;

FIG. 9 is a diagram illustrating a calculation unit when the maximum number of print blocks that can be energized simultaneously is set to 2;

FIG. 10 shows the maximum number of print blocks that can be simultaneously energized is 2
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 11 shows the maximum number of printing blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 12 shows the maximum number of print blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 13 shows the maximum number of printing blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 14 shows the maximum number of print blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 15 shows the maximum number of printing blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 16 shows the maximum number of print blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 17 shows the maximum number of print blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 18 shows the maximum number of print blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 19 shows the maximum number of printing blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 20 shows the maximum number of printing blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 21 shows the maximum number of print blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 22 shows the maximum number of print blocks that can be simultaneously energized is 3
FIG. 6 is a diagram for explaining a calculation unit when set to “1”.

FIG. 23 shows the maximum number of print blocks that can be simultaneously energized is 3
FIG. 3 is a block diagram of a lookup unit when set to.

FIG. 24 is a waveform diagram showing drive waveforms of the thermal head of the embodiment.

FIG. 25 is a diagram showing a basic configuration of a conventional line-type thermal head.

FIG. 26 is a waveform diagram showing drive waveforms of a conventional thermal head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 MPU 2 Mechanism drive circuit 3 Print ratio measuring circuit (counting means) 4 Print block energization determination circuit (distribution determination means) 4a Print block selection determination circuit 4b Print block energization control circuit 5 Interface circuit 6 A / D conversion module 7 RAM 8 ROM 9 thermal head 10 stepping motor 101 head unit 102 drive unit 103 control unit 104 heating resistor element 105 drive transistor 106 latch circuit 107 shift register

Claims (5)

[Claims] 1. A print head comprising a plurality of heating elements divided into a predetermined number of printing blocks, drive means for energizing the heating elements for each printing block and driving the print head, and predetermined printing. Counting means for counting the number of heating elements simultaneously energized in the print head based on the data in units of the printing blocks, and distribution determining means for determining the distribution of the heating elements simultaneously energized counted by the counting means. ,, based on the distribution of the energized heating element per dot line,
A thermal printer characterized in that a plurality of printing blocks are simultaneously driven by the driving means in accordance with a preset simultaneous energization pattern, and the thermal paper in contact with the heating elements of the printing blocks is colored. 2. The thermal printer according to claim 1, wherein the number of the heating elements and the number of printing blocks that are simultaneously energized are set according to the current capacity of the power source used and the required printing quality. . 3. In the printing block, a driving command is given to a driving means for transporting the thermal paper instead of the powering command to the printing block in which the heating element to be energized does not exist, and the thermal paper is driven. The thermal printer according to claim 1, wherein the thermal printer is conveyed in a short time. 4. The counting means indicates the number of heating elements simultaneously energized in the print head in a single print block unit.
And counting in units of two adjacent printing blocks, normalizing the number of energization heating elements in the printing block to a predetermined number of bits of pattern data, and reading out a pre-stored energization pattern based on the normalized pattern data, 4. The thermal printer according to claim 1, wherein the driving sequence is looked up. 5. The counting means indicates the number of heating elements simultaneously energized in the print head in a single print block unit.
And two adjacent print block units, and three adjacent print blocks
The thermal printer according to claim 4, wherein the counting is performed for each printing block.