JP6989139B2 - Thermal printer, printing method, and printing control program - Google Patents

Description

The present invention relates to a thermal printer, a printing method, and a print control program, and more particularly to a thermal printer, a printing method, and a print control program for printing print data on paper using a thermal head.

A thermal printer that prints print data on paper using a thermal head is known. Generally, in a thermal printer, a plurality of heat generating elements arranged in at least one row on a thermal head are selectively generated to generate heat for printing. Heat generation is performed by applying a drive pulse to the thermal head for a certain period of time. Further, in the thermal printer, printing is performed by applying an applied energy amount set corresponding to the printing speed, the external temperature, the thermal paper to be used, or the thermal transfer ribbon and the receiving paper to the thermal head.

In addition, the thermal type used in thermal printers includes a heat-sensitive type that uses special paper (heat-sensitive paper) that senses heat and develops color, and a heat-sensitive ink that is used as a ribbon to melt the ink into paper (plain paper). There is a thermal transfer type that develops color.

For example, Patent Document 1 discloses a "thermal printer" that prints a binary image using a thermal head in which heating elements are arranged in a row. The thermal printer disclosed in Patent Document 1 includes an image memory for storing bitmap data for printing, and a printing unit for printing the bitmap data for printing stored in the image memory. In Patent Document 1, when a specific pattern that should generate jaggies is detected from the bitmap data, a dot pattern that suppresses the jaggies is added to the bitmap data for printing stored in the image memory.

Further, Patent Document 2 discloses a "thermal printer" that corrects the deviation of the printing paper position due to a change in ambient temperature. The thermal printer disclosed in Patent Document 2 has a thermal head, a platen, a motor (stepping motor), a temperature sensor (thermistor), and a motor control unit. The thermal head prints on printing paper (thermal paper). The platen is arranged so as to face the thermal head with the printing paper (heat-sensitive paper) sandwiched between them, and conveys the printing paper (heat-sensitive paper). The motor (stepping motor) drives the platen to rotate. The temperature sensor (thermistor) is installed near the platen. The output of the temperature sensor (thermistor) is input to the motor control unit to control the rotation of the motor. The motor control unit controls the amount of rotation of the motor according to the output of the temperature sensor.

Further, Patent Document 3 discloses a "printing apparatus" capable of performing variable division printing without printing omissions. The printing apparatus disclosed in Patent Document 3 includes an input unit, a display unit, a thermal head, a thermista, a half-cut mechanism, a full-cut mechanism, a platen roller, a tape width detection switch, a control unit, a ROM (Read Only Memory), and a RAM ( Random Access Memory), display unit drive circuit, head drive circuit, transfer motor drive circuit, stepping motor, cutter motor drive circuit, and cutter motor are provided.

The thermal head is a print head that has a plurality of heat generating elements and prints on a printing medium. The platen is a transport unit that transports the printed medium. A thermistor is embedded in the thermal head. The thermistor is a measuring unit that measures the temperature of the thermal head.

The control unit controls the operation of each unit of the printing apparatus by expanding the program stored in the ROM into the RAM and executing the program. The control unit is a head control unit that controls the thermal head via the head drive circuit, generates a strobe signal and print data, and supplies the strobe signal and print data to the head drive circuit. The control unit is a transport control unit that controls the platen roller, and is a cut control unit that controls the cut mechanism. The ROM stores a print program for printing on a print medium and various data (for example, fonts and the like) necessary for executing the print program. The ROM also functions as a storage medium in which a program readable by the control unit is stored. The RAM functions as an input data memory for storing various information (print information) about printing. The RAM also functions as a print data memory for storing data (print data) indicating a pattern of print contents to be formed on a print medium, which is generated based on print information.

The head drive circuit energizes or de-energizes a plurality of heat generating elements based on the strobe signal and print data. More specifically, the head drive circuit energizes or de-energizes a plurality of heat generating elements based on print data during a period (energization control period) in which the strobe signal (control signal) is ON. The thermal head is a print head having a plurality of heat generating elements arranged in the main scanning direction. In the thermal head, the heat generating element is selectively energized by the head drive circuit according to the print data during the energization control period of the strobe signal supplied from the control unit, so that the ink ribbon is heated by the heat generating element and heat transfer is performed. Prints on the printing medium.

The transport motor drive circuit drives the stepping motor. The stepping motor drives the platen roller. The platen roller is rotated by the power of the stepping motor to convey the printed medium in the longitudinal direction (secondary scanning direction or conveying direction) of the printed medium. The stepping motor is a transport motor for transporting the printed medium in the transport direction, and the transport means for transporting the print medium in the transport direction includes a stepping motor.

The cutter motor drive circuit drives the cutter motor. The half-cut mechanism and the full-cut mechanism are operated by the power of a cutter motor to half-cut or full-cut the printed medium. The full cut is an operation of cutting the base material of the printing medium together with the release paper along the width direction, and the half cut is an operation of cutting only the base material along the width direction.

Patent Document 4 discloses a "printing apparatus" capable of high-quality printing that can cope with fluctuations in paper characteristics and print density. The printing apparatus disclosed in Patent Document 4 includes an interface, a system control unit, a print control unit, a thermal head, a drive control unit, a stepping motor, and an ink sheet transfer motor. The print control unit controls the thermal head. The drive control unit controls the stepping motor and the ink sheet transfer motor. The printing apparatus transfers the ink of the ink sheet to the paper by the thermal head, the stepping motor, and the ink sheet transport motor to perform printing. The thermal head has a length in a direction intersecting the paper transport direction, and printing is performed for each line corresponding to the length direction.

The interface can communicate with the information terminal and receives and acquires print information from the information terminal. The print information includes image data to be printed and information related to paper characteristics such as paper size.

The system control unit comprehensively controls each component of the printing device such as the print control unit and the drive control unit based on the print information received by the interface. The system control unit processes the image data and the paper size information included in the print information to generate a plurality of print data for each line. The system control unit controls the print control unit based on the print data, and controls the drive of the thermal head via the print control unit. The system control unit controls the drive control unit based on the print data, and controls the stepping motor and the ink sheet transfer motor via the drive control unit.

The drive control unit outputs a drive current based on the control signal output from the system control unit to the stepping motor. The drive control unit controls the drive of the stepping motor by the drive current calculated by the system control unit. The drive control unit controls the ink sheet transfer motor that winds up the ink sheet based on the signal output from the system control unit.

The stepping motor is rotationally driven by a drive current supplied from the drive control unit. The drive current supplied to the stepping motor can be adjusted by a control signal output from the system control unit to the drive control unit.

The print control unit generates drive data for the thermal head based on the print data generated by the system control unit, and outputs the drive data to the thermal head. The thermal head prints on paper based on the drive data output by the print control unit.

The system control unit includes a CPU (Central Processing Unit) and a storage unit, and print information can be input from the interface. The storage unit includes, for example, a non-volatile memory such as a flash memory and a temporary storage memory such as a RAM (Random Access Memory). The non-volatile memory stores a correction table, a control program related to printing, various initial values, and the like. In the temporary storage memory, for example, print information, print data, drive data, drive current being calculated, and the like are temporarily stored.

The paper mounted on the printing apparatus is sandwiched between the pinch roller and the grip roller. The grip roller is connected to a stepping motor controlled by a drive control unit, and is rotated by the driving force of the stepping motor. The paper is conveyed in the paper conveying direction by the rotation of the grip roller.

The ink sheet is supplied together with the paper between the thermal head and the pinch roller facing the thermal head. The ink sheet is supplied between the thermal head and the pinch roller by rotating the ink sheet transfer motor controlled by the drive control unit. The paper is crimped and heated by a thermal head and a pinch roller together with the ink sheet, and as a result, an image is printed on the paper.

The thermal head is arranged so as to have a longitudinal direction in a direction intersecting the paper transport direction. The thermal head prints line by line corresponding to its longitudinal direction. That is, the printing apparatus prints a plurality of print data for each line while transporting the paper for each line.

Japanese Unexamined Patent Publication No. 2000-037896 Japanese Unexamined Patent Publication No. 2001-205834 Japanese Unexamined Patent Publication No. 2018-103432 Japanese Unexamined Patent Publication No. 2018-138339

However, Patent Documents 1 to 4 have the following problems.

In the thermal printer (printing apparatus) disclosed in Patent Documents 1 to 4, it is possible to control the balance of the applied energy to be applied to the thermal head in order to clearly distinguish between the black portion and the white portion for printing. Have difficulty. Further, the balance control is largely due to the cooling characteristics of the thermal head itself, and may be influenced by the characteristics of the thermal head itself.

Further, in the thermal printer (printing apparatus) disclosed in Patent Documents 1 to 4, the print data is characters or the like in the white portion included in the black portion, and when the white area portion is particularly small, the black portion is used. The white part may be crushed due to the residual heat of the applied energy during printing.

More specifically, in printing using a thermal head, if the application time to the thermal head is extended for a long time, the black density increases and clear black characters are obtained. However, in this case, while the black part stands out, on the contrary, the residual heat when printing the black part remains in the white part, and "tailing" and "outline characters, logos, and delicate white horizontal lines are crushed. "May occur. Here, "tail pulling" means that the black part is mixed in the white part.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thermal printer, a printing method, and a print control program capable of clearly printing a difference between black and white.

In order to achieve the above object, as one aspect of the present invention, the thermal printer has a plurality of heat generating elements arranged in the main scanning direction and prints on a printing medium; the temperature of the thermal head. A temperature detecting means for detecting; a stepping motor for transporting the printed medium in a transport direction orthogonal to the main scanning direction; the stepping motor having a variable step angle; the thermal head and the stepping motor. A thermal printer comprising; a receiving means for receiving the original image data and a signal indicating a print density from a higher-level device; the original image data is N (in the transport direction). N is a stretching means that is stretched by a factor of 2) to generate stretched image data; a determining means that determines the applied energy applied to the thermal head based on the temperature of the thermal head and the print density. And; a determination means for determining whether or not the white portion included in the original image data is crushed by the application by the determined applied energy; the determination result of the determination means indicates that the white portion is crushed. If this is the case, the white portion included in the stretched image data is expanded and edited by a predetermined (M / N) dot (1 ≦ M <N) in the transport direction to obtain extended edited image data. An editing means; a head control means that selects one of the stretched image data and the extended edited image data according to the determination result and supplies the selected image data as print data to the thermal head according to the determined applied energy. With a motor control means for driving the stepping motor at a fine step angle (θ / N) obtained by multiplying the original step angle θ required for printing one dot of the original image data by (1 / N); To prepare for.

As another aspect of the present invention, the printing method executed by the controller is a printing method in a thermal printer, and the thermal printer has a plurality of heat generating elements arranged in the main scanning direction and prints on a printing medium. ; A temperature detecting means for detecting the temperature of the thermal head; a stepping motor for transporting the printed medium in a transport direction orthogonal to the main scanning direction, wherein the step angle is variable. The printing method performed by the controller including a stepping motor; a receiving step of receiving the original image data and a signal indicating the print density from the host device; N (N is 2) in the transport direction of the original image data. A decompression step that generates stretched image data by decompressing (the above integers) times; and a determination step that determines the applied energy to be applied to the thermal head based on the temperature of the thermal head and the print density; A determination step for determining whether or not the white area included in the original image data is crushed by the application with the determined applied energy; when the determination result of the determination step indicates that the white area is crushed. In addition, an extended editing step of obtaining extended editing image data by expanding and editing the white portion included in the expanded image data by a predetermined (M / N) dot (1 ≦ M <N) in the transport direction. A head control step in which one of the stretched image data and the extended edited image data is selected according to the determination result, and the selected image data is supplied as print data to the thermal head according to the determined applied energy. It includes a motor control step for driving the stepping motor at a fine step angle (θ / N) obtained by multiplying the original step angle θ required for printing one dot of image data by (1 / N).

As another aspect of the present invention, the print control program is a print control program that controls printing of a thermal printer by a computer, and the thermal printer has a plurality of heat generating elements arranged in the main scanning direction. A thermal head that prints on a printing medium; a temperature detecting means for detecting the temperature of the thermal head; a stepping motor for transporting the printing medium in a transport direction orthogonal to the main scanning direction, and a step. The printing control program includes the stepping motor having a variable angle; and a receiving procedure for receiving the original image data and a signal indicating the print density from the host device to the computer; the original image data in the transport direction. The stretching procedure for generating stretched image data by stretching N (N is an integer of 2 or more) times; determines the applied energy to be applied to the thermal head based on the temperature of the thermal head and the print density. The determination procedure for determining whether or not the white portion included in the original image data is crushed by the application by the determined applied energy; the determination result of the determination procedure is that the white portion is crushed. In the case of indicating that, the blank portion included in the stretched image data is expanded and edited by a predetermined (M / N) dot (1 ≦ M <N) in the transport direction, and the expanded edited image data is printed. A head that selects one of the stretched image data and the extended edited image data according to the determination result and supplies the selected image data as print data to the thermal head according to the determined applied energy. Control procedure; Motor control that drives the stepping motor at a fine step angle (θ / N) obtained by multiplying the original step angle θ required for printing one dot of the original image data by (1 / N). To execute the procedure and;

According to the present invention, it is possible to clearly print the difference between white and black.

It is a side sectional view which shows the schematic hardware structure of the thermal printer which concerns on embodiment of this invention. It is a block diagram which shows the schematic structure of the thermal printer shown in FIG. It is a figure which shows an example of the memory area of the print control program and RAM stored in ROM used in the thermal printer shown in FIG. FIG. 3 is a block diagram showing an example of a functional configuration of a controller used in the thermal printer shown in FIG. 2. It is a flowchart for demonstrating the operation of the thermal printer shown in FIG. It is a figure which shows an example of the original image data which is used in the thermal printer shown in FIG. 4, and is stored in the 1st print data edit memory area of a RAM. It is a figure which shows an example of the data which stretched 4 times in the transport direction from the original image data shown in FIG. It is a figure which shows an example of the expanded image data which is stored in the 2nd print data edit memory area of a RAM used for the thermal printer shown in FIG. It is a figure which shows an example of the extended edit image data stored in the 3rd print data edit memory area of a RAM used for the thermal printer shown in FIG.

The features of the present invention will be described. The present invention suppresses character crushing and line crushing in "non-applied areas" that appear in the print range when black areas are continuously printed (black solid), and white and black in "non-applied areas". Provide a method for clearly printing the difference between the two. Here, the "non-printing part" means, for example, "small outline characters and logos, and a delicate white outline portion".

That is, in the present invention, first, when the thermal printer receives image data such as a desired print bitmap, the print data is expanded so that the print data can be printed on paper with higher definition by software. Subsequently, in the present invention, for the white part, the image data is re-edited so that the white part is enlarged by the amount corresponding to the applied energy, and the white part is applied to the thermal head as print data. As a result, the applied energy is increased, the heat generated when black is applied suppresses the crushing of the white portion due to the residual heat applied to the white portion, and the difference between black and white is clearly printed.

Embodiments of the present invention will be described with reference to the drawings.

[Embodiment]
The thermal printer 100 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a side sectional view showing a schematic hardware configuration of the thermal printer 100, and FIG. 2 is a block diagram showing a schematic configuration of the thermal printer 100.

The illustrated thermal printer 100 communicates with a host device 200 and prints print data on a heat-sensitive paper (printed medium) M using a thermal head 172, such as a printer device, an ATM (automatic teller's machine), or a POS (point of sales). ) It is a printer device for printing detailed slips of terminals and the like.

As shown in FIG. 1, the thermal paper (printed medium) M is fed from the roll paper 12 onto the transport road surface 14. A first transport roller 16 and a second transport roller 17 are arranged on the transport road surface 14. A thermal head 172, a platen 182, and a cutter 184 are arranged between the first transfer roller 16 and the second transfer roller 17. The unwound thermal paper (printed medium) M passes between the thermal head 172 and the platen 182. Upon passing through this, the thermal paper (printed medium) M is heated by the thermal head 172, so that print data is printed on the thermal paper (printed medium) M.

The thermal head 172 has a plurality of heat generating elements arranged in the main scanning direction, and prints on the thermal paper (printed medium) M.

As shown in FIG. 2, the thermal printer 100 includes a controller 105, an interface 140, a thermistor 174, a stepping motor 176, and a cutter motor 178 in addition to the thermal head 172, the platen 182, and the cutter 184. ing.

The thermistor 174 is provided in close proximity to or embedded in the thermal head 172. The thermistor 174 serves as a temperature detecting means for detecting the temperature of the thermal head 172.

The interface 140 is a part that communicates with the host device 200. The controller 105 controls the thermal head 172, the stepping motor 176, and the cutter motor 178, as will be described later. The controller 105 includes a CPU (Central Processing Unit) 110, a ROM (Read-Only Memory) 120, a RAM (Random Access Memory) 130, a head drive circuit 150, and a motor drive circuit 160.

The CPU 110 controls and functions the thermal printer 100 by reading data received via the interface 140 (described later) and a print control program (described later) stored in the ROM 120 described later onto the RAM 130 and executing processing. It is an arithmetic unit that realizes.

The ROM 120 is a rewritable non-volatile memory that stores a print control program described later. The non-volatile memory comprises, for example, EPROM (Erasable Programmed Read-Only Memory).

The RAM 130 is a volatile memory that temporarily holds a print control program read from the ROM 120, data received via the interface 140, and the like, and is used as a work area of the CPU 110.

The head drive circuit 150 energizes or de-energizes a plurality of heat generating elements of the thermal head 172 based on print data supplied from the CPU 110, which will be described later. The motor drive circuit 160 drives the stepping motor 176 and the cutter motor 178 based on a drive command to be described later, which is supplied from the CPU 110.

The stepping motor 176 drives the platen 182. The platen 182 is rotated by the power of the stepping motor 176, and conveys the heat-sensitive paper (printed medium) M in the longitudinal direction (secondary scanning direction or conveying direction) thereof. This transport direction is a direction orthogonal to the main scanning direction. That is, the stepping motor 176 is a transport motor for transporting the thermal paper (printed medium) M in the transport direction. The stepping motor 176 shown in the figure is a motor having a variable step angle.

The cutter motor 178 drives the cutter 184. The cutter 184 moves up and down by the power of the cutter motor 178 to cut the thermal paper (printed medium) M.

FIG. 3 is a diagram showing an example of a print control program stored in the ROM 120 and a memory area of the RAM 130.

The ROM 120 stores a print data editing program 122, a head control program 124, and a motor control program 126 as print control programs. The print data editing program 122 is a program for editing the original image data received from the host device 200 via the interface 140 as described later. The head control program 124 is a program for controlling the head drive circuit 150, as will be described later. The motor control program 126 is a program for controlling the motor drive circuit 160, as will be described later.

In reality, the CPU 110 executes a predetermined process according to the program stored in the ROM 120, but in the following, it is also described that the program simply executes the predetermined process.

The RAM 130 has a first print data editing memory area 132, a second print data editing memory area 134, and a third print data editing memory area 136 as memory areas.

The first print data editing memory area 132 is an area for storing the original image data sent from the host device 200 via the interface 140. The original image data is, for example, image data such as a bitmap. The second print data editing memory area 134 is a stretched image data obtained by stretching the original image data in order to print the print data to be printed on the heat-sensitive paper (printed medium) M with higher definition. A memory area for saving. The third print data editing memory area 136 is a memory area for storing the extended editing image data obtained by further re-editing the stretched image data with respect to the white portion.

Subsequently, the functional configuration of the controller 105 will be described with reference to FIG. As shown in FIG. 4, the controller 105 includes a main control unit 300, a RAM 130, a head drive circuit 150, and a motor drive circuit 160.

The main control unit 300 controls each component of the thermal printer 100 (controller 105). The main control unit 300 includes, for example, a combination of the CPU 110 and the ROM 120 shown in FIG.

The main control unit 300 functionally includes a receiving means 310, an expanding means 320, an applied energy determining means 330, a white portion crushing determining means 340, an extended editing means 350, a head control means 360, and a motor control means 370. ..

The receiving means 310 receives the original image data and the signal indicating the print density from the host device 200 via the interface 140. The receiving means 310 stores the received original image data in the first print data editing memory area 132 of the RAM 130. Specific examples of the original image data will be described later.

The stretching means 320 stretches the original image data stored in the first print data editing memory area 132 N times in the transport direction to generate the stretched image data. Here, N is an integer of 2 or more, and is equal to, for example, 4. The stretching means 320 stores the generated stretched image data in the second print data editing memory area 134 of the RAM 130. Specific examples of the stretched image data will also be described later.

The applied energy determining means 330 determines the applied energy to be applied to the thermal head 172 based on the temperature of the thermal head 172 and the print density.

The white-out portion crushing determination means 340 determines whether or not the white-out portion crushed in the original image data is crushed by the application by the determined applied energy. Here, whether or not the white portion is crushed is incorporated in the head control program 124 as a parameter in consideration of the characteristics of the thermal head 172 at the time of development of the thermal printer 100.

When the determination result of the white-out portion crushing determination means 340 indicates that the white-out portion is crushed, the extended editing means 350 moves the white-out portion included in the stretched image data to a predetermined position (M / N) in the transport direction. ) The above-mentioned extended-edited image data is obtained by extended-editing by the number of dots. Here, M is an integer of 1 or more and N or less. The extended editing means 350 stores the extended editing image data in the third print data editing memory area 136 of the RAM 130. Specific examples of the extended edited image data will also be described later.

The head control means 360 selects one of the stretched image data and the extended edited image data according to the above-mentioned constant result, and uses the selected image data as print data according to the applied energy determined above, and the thermal head via the head drive circuit 150. Supply to 172.

The motor control means 370 has a fine step angle (θ / N) obtained by multiplying the original step angle θ required for printing one dot of the original image data by (1 / N), via the motor drive circuit 160. Drives the stepping motor 176. The original step angle θ is, for example, 3.6 degrees. Therefore, when N is equal to 4, the fine step angle (θ / N) is equal to 0.9 degrees.

The motor control means 370 also controls the cutter motor 178 via the motor drive circuit 160.

Next, the relationship between the print control program stored in the ROM 120 shown in FIG. 3 and each means of the main control unit 300 shown in FIG. 4 will be described.

The print data editing program 122 stored in the ROM 120 functions as a receiving means 310, an expanding means 320, a white portion crushing determining means 340, and an extended editing means 350 of the main control unit 300.

The head control program 124 stored in the ROM 120 works in combination with the applied energy determining means 330 of the main control unit 300 and the head control means 360. That is, the head control program 124 has a function of calculating and controlling the energy applied to the thermal head 172 from the temperature of the thermal head 172 and the desired black print density.

The motor control program 126 stored in the ROM 120 functions as the motor control means 370 of the main control unit 300. That is, the motor control program 126 has a function of controlling the stepping motor 176.

As described above, the combination of the print data editing program 122, the head control program 124, and the motor control program 126 works as the print control program.

Next, the operation of the thermal printer 100 will be described with reference to FIGS. 5 to 9. In the following, it will be described that N is equal to 4, M is equal to 1, and the original step angle θ is 3.6 degrees.

First, the receiving means 310 of the main control unit 300 receives the original image data desired to be printed in a bitmap format or the like from the host device 200 (step S101 in FIG. 5). Then, the receiving means 310 stores the original image data in the first print data editing memory area 132 of the RAM 130.

FIG. 6 is a diagram showing an example of original image data. The illustrated original image data is composed of bitmap data having 4 dots in the horizontal direction (main scanning direction) and 7 dots in the vertical direction (conveying direction: sub-scanning direction), and is data with 1 dot white. More specifically, as shown in FIG. 6, in the original image data, the 1st to 3rd dots are made of solid black, the 4th dot is made of white, and the 5th to 7th dots are made of solid black. It is image data.

Subsequently, the expanding means 320 of the main control unit 300 transfers the original image data stored in the first print data editing memory area 132 in the transport direction (vertical direction) 4 as a preparation for editing into higher-definition print data. It stretches twice (step S102 in FIG. 5). The stretching means 320 stores the resulting stretched image data in the second print data editing memory area 134 of the RAM 130.

More specifically, the stretching means 320 first obtains data obtained by stretching the original image data four times in the transport direction, as shown in FIG. 7, and then, as shown in FIG. 8, the first of each dot. Stretched image data is obtained with the areas other than the lines shown in white being outlined.

Next, the applied energy determining means 330 of the main control unit 300 determines the applied energy to be applied to the thermal head 172 from the temperature detected by the thermistor 174 provided in the thermal head 172 and the print density instructed by the host device 200. It is determined (step S103 in FIG. 5).

At that time, the white-out portion crushing determination means 340 of the main control unit 300 first determines whether or not there is a white-out portion by FW (firmware) by searching the original image data from the upper end to the lower end. Then, when it is recognized that the white part is present, the white part crush determination means 340 determines whether or not the applied energy to be applied may invade the crush of the white part (FIG. 5). Step S104).

When it is determined that the applied energy amount may invade the crushing of the white-out portion (Y in step S105 in FIG. 5), the extended editing means 350 of the main control unit 300 has the second white-out portion. The stretched image data stored in the print data editing memory area 134 of the above is finely expanded and edited in a white area (step S106 in FIG. 5). The extended editing means 350 stores the resulting extended edited image data in the third print data editing memory area 136 of the RAM 130.

FIG. 9 is a diagram showing an example of extended edited image data. As is clear from FIG. 9, the extended editing image data is data obtained by expanding and editing the white outline of the 4th dot in the transport direction by (1/4) dots and expanding it to the 5th dot-1 portion. Along with this, the solid black that was in the 5th dot-1 part has been moved to the 5th dot-2 part.

Subsequently, the head control means 360 and the motor control means 370 of the main control unit 300 refer to the head drive circuit 150 and the motor drive circuit 160 for the extended editing image data stored in the third print data editing memory area 136, respectively. A print instruction and a drive instruction are given to (step S107 in FIG. 5). More specifically, the head control means 360 sends a print instruction to the head drive circuit 150 to supply the extended edited image data according to the applied energy determined as the print data. The motor control means 370 has a fine step angle θ / 4 (0.9) obtained by multiplying the original step angle θ (3.6 degrees) required for printing one dot of the original image data by (1/4). A drive instruction for driving the stepping motor 176 is sent to the motor drive circuit 160.

According to the above print instruction and drive instruction, the head drive circuit 150 and the motor drive circuit 160 print on the thermal paper (printed medium) M by driving the thermal head 172 and the stepping motor 176.

At this time, the extended editing image data stored in the third print data editing memory area 136 is image data that has been stretched four times so that high-definition printing can be performed by the processing up to that point, so that the head drive circuit The 150 and the motor drive circuit 160 output the extended edited image data to the thermal head 172 so that the printing can be performed with four times the fineness, and print the data.

When it is determined that the applied energy amount does not have the possibility of invading the collapse of the white portion (N in step S105 in FIG. 5), the head control means 360 and the motor control means 370 of the main control unit 300 are second. For the stretched image data stored in the print data editing memory area 134 of the above, print instructions and drive instructions are given to the head drive circuit 150 and the motor drive circuit 160, respectively (step S107 in FIG. 5). Therefore, the head control means 360 sends a print instruction to the head drive circuit 150 to supply the stretched image data according to the applied energy determined as the print data.

Next, the effect of this embodiment will be described.

The first effect is that in printing using the thermal head 172, it is possible to print clearly black and white on outline characters, logos, horizontal lines and the like in solid black. The reason for this is that since the edited image data that slightly expands the white part is printed, some cooling effect of the residual heat of the thermal head 172 is expected, and the white part is expanded to some extent as the print data. Therefore, the white range becomes easy to recognize, and the crushing becomes difficult to recognize. In addition, the difference in the print result from the original image data to the extended edited image data, which is a concern at this time, is also finely re-edited, but the print difference is so small that humans can recognize it. However, it is not recognized.

The second effect is realized by controlling the balance of the applied energy amount to clarify the applied part (black printing) and the non-applied part (white) in the printing using the thermal head 172. Is easy to control.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto. For example, the present invention also includes a form in which a part or all of the embodiments described above are appropriately combined, and a form in which the embodiment is appropriately modified.

In the above embodiment, the example of editing the original image data by a program is shown, but it may be realized by searching the data to be stored in the memory by the hardware.

Further, in the above embodiment, an example in which the original image data is stretched four times is shown, but the stretching accuracy may be any degree depending on the desired fineness and the like. That is, N may be 2 or more.

Further, in the above embodiment, an example of expanding the white portion by 1/4 dot is shown, but if the applied energy is large and the expansion by 1/4 dot is insufficient, 2/4 dot or 3/4 dot or 3/4 dot expansion is shown. The white portion may be expanded to 4 dots.

In the above embodiment, for example, the print control program executed by the main control unit 300 of the thermal printer 100 is stored in the ROM 120 or the like in advance. However, the present invention is not limited to this, and by implementing a print control program for executing the above-mentioned various processes on an existing general-purpose computer, a framework, a workstation, or the like, the thermal according to the above-described embodiment is provided. It may function as a device corresponding to the printer 100.

The method of providing such a program is arbitrary, and is stored and distributed in, for example, a computer-readable recording medium (flexible disc, CD (Compact Disc) -ROM, DVD (Digital Versatile Disc) -ROM) or the like. Alternatively, the program may be stored in a storage on a network such as the Internet and provided by downloading the program.

The present invention can be applied to a printer device that prints using a thermal head.

12 Roll paper 14 Transport road surface 16 First transport roller 17 Second transport roller 100 Thermal printer 105 Controller 110 CPU
120 ROM
122 Print data editing program 124 Head control program 126 Motor control program 130 RAM
132 First print data editing memory area 134 Second print data editing memory area 136 Third print data editing memory area 140 Interface 150 Head drive circuit 160 Motor drive circuit 172 Thermal head 174 Thermistor (temperature detecting means)
176 Stepping motor 178 Cutter motor 182 Platen 184 Cutter 200 Upper device 300 Main control unit 310 Receiving means 320 Stretching means 330 Applied energy determination means 340 Whiteout part crushing judgment means 350 Extended editing means 360 Head control means 370 Motor control means M Heat-sensitive paper (Printed medium)

Claims (9)

A thermal head that has a plurality of heat generating elements arranged in the main scanning direction and prints on a printing medium, and a thermal head.
A temperature detecting means for detecting the temperature of the thermal head and
A stepping motor for transporting the printed medium in a transport direction orthogonal to the main scanning direction, the stepping motor having a variable step angle, and the stepping motor.
A controller that controls the thermal head and the stepping motor,
It is a thermal printer equipped with
The controller
A receiving means for receiving the original image data and a signal indicating the print density from the host device, and
A decompression means for generating decompressed image data by decompressing the original image data N (N is an integer of 2 or more) times in the transport direction.
A determination means for determining the applied energy applied to the thermal head based on the temperature of the thermal head and the print density, and
A determination means for determining whether or not the white portion included in the original image data is crushed by the application by the determined applied energy.
When the determination result of the determination means indicates that the white portion is crushed, the white portion included in the stretched image data is converted into a predetermined (M / N) dot (1 ≦ M) in the transport direction. <N) Extended editing means to obtain extended edited image data by performing extended editing by the amount of
A head control means that selects one of the stretched image data and the extended edited image data according to the determination result and supplies the selected image data as print data to the thermal head according to the determined applied energy.
A motor control means for driving the stepping motor at a fine step angle (θ / N) obtained by multiplying the original step angle θ required for printing one dot of the original image data by (1 / N).
A thermal printer equipped with. The thermal printer according to claim 1, wherein N is equal to 4 and M is equal to 1. When the determination result indicates that the white portion is crushed, the head control means selects the extended editing image data as the selected image data.
When the determination result indicates that the white portion is not crushed, the head control means selects the stretched image data as the selected image data.
The thermal printer according to claim 1 or 2. It is a printing method in a thermal printer.
The thermal printer is
A thermal head that has a plurality of heat generating elements arranged in the main scanning direction and prints on a printing medium, and a thermal head.
A temperature detecting means for detecting the temperature of the thermal head and
A stepping motor for transporting the printed medium in a transport direction orthogonal to the main scanning direction, the stepping motor having a variable step angle, and the stepping motor.
Equipped with
The printing method is
A reception step for receiving the original image data and a signal indicating the print density from the host device, and
A decompression step of expanding the original image data by N (N is an integer of 2 or more) times in the transport direction to generate decompressed image data, and a decompression step.
A determination step of determining the applied energy to be applied to the thermal head based on the temperature of the thermal head and the print density, and a determination step.
A determination step for determining whether or not the white portion included in the original image data is crushed by the application with the determined applied energy, and
When the determination result of the determination step indicates that the white area is crushed, the white area included in the stretched image data is converted into a predetermined (M / N) dot (1 ≦ M) in the transport direction. <N) An extended editing step to obtain extended editing image data by performing extended editing by the amount of
A head control step in which one of the stretched image data and the extended edited image data is selected according to the determination result, and the selected image data is supplied to the thermal head according to the determined applied energy as print data.
A motor control step for driving the stepping motor at a fine step angle (θ / N) obtained by multiplying the original step angle θ required for printing one dot of the original image data by (1 / N).
The printing method performed by the controller , including. The printing method performed by the controller according to claim 4, wherein N is equal to 4 and M is equal to 1. When the determination result indicates that the white portion is crushed, the head control step selects the extended editing image data as the selected image data.
When the determination result indicates that the white portion is not crushed, the head control step selects the stretched image data as the selected image data.
The printing method performed by the controller according to claim 4 or 5. A print control program that controls the printing of a thermal printer by a computer.
The thermal printer is
A thermal head that has a plurality of heat generating elements arranged in the main scanning direction and prints on a printing medium, and a thermal head.
A temperature detecting means for detecting the temperature of the thermal head and
A stepping motor for transporting the printed medium in a transport direction orthogonal to the main scanning direction, the stepping motor having a variable step angle, and the stepping motor.
Equipped with
The print control program is applied to the computer.
The reception procedure for receiving the original image data and the signal indicating the print density from the host device, and
A decompression procedure for generating decompressed image data by decompressing the original image data N (N is an integer of 2 or more) times in the transport direction, and a decompression procedure.
A determination procedure for determining the applied energy to be applied to the thermal head based on the temperature of the thermal head and the print density, and a determination procedure.
A determination procedure for determining whether or not the white portion included in the original image data is crushed by the application with the determined applied energy, and the determination procedure.
When the determination result of the determination procedure indicates that the white area is crushed, the white area included in the stretched image data is converted into a predetermined (M / N) dot (1 ≦ M) in the transport direction. <N) Extended editing procedure to obtain extended edited image data by performing extended editing by the amount, and
A head control procedure in which one of the stretched image data and the extended edited image data is selected according to the determination result, and the selected image data is supplied to the thermal head according to the determined applied energy as print data.
A motor control procedure for driving the stepping motor at a fine step angle (θ / N) obtained by multiplying the original step angle θ required for printing one dot of the original image data by (1 / N).
A print control program that executes. The print control program according to claim 7, wherein N is equal to 4 and M is equal to 1. When the determination result indicates that the white portion is crushed, the head control procedure selects the extended edited image data as the selected image data.
When the determination result indicates that the white portion is not crushed, the head control procedure selects the stretched image data as the selected image data.
The print control program according to claim 7 or 8.

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