JP2025151806A - Printing device and method for controlling printing device - Google Patents

Abstract

To appropriately control the conveying speed.
[Solution] The printer 1 includes a drive motor 152, a transport roller 153 driven by the drive motor 152 and transporting the recording medium P, a recording head 151 that prints on the recording medium P, a first calculation unit 111 that calculates a first current amount QA which is the amount of current consumed by the recording head 151, a second calculation unit 112 that calculates a second current amount QB which is the amount of current consumed by the drive motor 152, an addition unit 113 that adds the first current amount QA and the second current amount QB to calculate a total current amount QT, and a speed control unit 115 that controls the transport speed V of the recording medium P based on the total current amount QT.
[Selected Figure] Figure 1

Description

This disclosure relates to a printing device and a method for controlling a printing device.

Patent document 1 describes a method of calculating the number of print dots for the next line of print data, calculating the amount of current consumed by the head from the number of print dots, selecting a print speed associated with a current consumption threshold value corresponding to the amount of current consumed, and determining this as the print speed to be used.

JP 2018-51888 A

However, when printing, the printer drives the carry motor at the same time as the head, and the current consumption of the carry motor must also be taken into account. Therefore, the technology described in Patent Document 1 could potentially overprotect the power supply, resulting in a decrease in printing speed.

One aspect of a printing device that solves the above problem is a printing device that includes a drive motor, a transport roller driven by the drive motor to transport a recording medium, a recording head that prints on the recording medium, a first calculation unit that calculates a first current amount that is the amount of current consumed by the recording head, a second calculation unit that calculates a second current amount that is the amount of current consumed by the drive motor, an adder that adds the first current amount and the second current amount to calculate a total current amount, and a transport speed control unit that controls the transport speed of the recording medium based on the total current amount.

FIG. 1 is a diagram illustrating an example of the configuration of a printer according to an embodiment. 10 is a diagram showing an example of a first table. 10 is a diagram showing an example of a second table. 10 is a flowchart showing an example of processing by a control unit.

This embodiment will be described below with reference to the drawings.

First, the configuration of a printer 1 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of a printer 1 according to the first embodiment.
As shown in FIG. 1 , the printer 1 includes a control unit 11 , an operation mechanism 12 , a display mechanism 13 , a power supply mechanism 14 , a printing mechanism 15 , and a print medium container 16 .
The control unit 11 controls the operation of each unit of the printer 1. The operation mechanism 12, the display mechanism 13, the power supply mechanism 14, and the printing mechanism 15 are each configured to be able to communicate with the control unit 11.
The printer 1 corresponds to an example of a "printing device."

The control unit 11 includes a processor 11A such as a CPU (Central Processing Unit) and memory 11B such as a ROM (Read Only Memory). Memory 11B stores the control program PG.

The processor 11A may be configured with multiple processors or may be configured with a single processor.
The processor 11A may be hardware programmed to implement the functions of each unit described below. That is, the processor 11A may be configured with the control program PG installed as a hardware circuit. In this case, the processor 11A may be configured with, for example, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or the like.
In the following description, the processor 11A executes the control program PG to realize various functions of the control unit 11.

Memory 11B has a non-volatile storage area that stores programs and data in a non-volatile manner. Memory 11B may include, for example, a ROM, HDD (Hard Disk Drive), or SSD (Solid State Drive) as the non-volatile storage area. Memory 11B may also include a volatile storage area that serves as a work area for temporarily storing programs executed by processor 11A and data to be processed. Memory 11B may also include, for example, RAM (Random Access Memory) as the volatile storage area.

In this embodiment, the processor 11A executes the control program PG to control each part of the printer 1, but this is not limited to this. The control unit 11 may, for example, include an ASIC, and the ASIC may execute processing using implemented functions. The control unit 11 may also, for example, include a signal processing circuit, and the signal processing circuit may execute processing by performing signal processing.

The operation mechanism 12 includes input means such as operation switches and a touch panel provided on the printer 1, detects user operations on the input means, and outputs detection signals corresponding to the operations to the control unit 11. The control unit 11 executes processing corresponding to the user operations based on input from the operation mechanism 12.

The display mechanism 13 includes a display panel such as multiple LEDs (Light Emitting Diodes) and an LCD (Liquid Crystal Display), and, under the control of the control unit 11, turns the LEDs on, off, and blinks in a predetermined manner, displays information on the display panel, etc.

The power supply mechanism 14 supplies power to the peripheral device 2 .
The peripheral device 2 includes, for example, a barcode scanner, a card reader, and the like.
The power supply mechanism 14 includes, for example, a first USB (registered trademark) (Universal Serial Bus) terminal 141 , a second USB (registered trademark) terminal 142 , a third USB (registered trademark) terminal 143 , and a fourth USB (registered trademark) terminal 144 .
Each of the first USB (registered trademark) terminal 141, the second USB (registered trademark) terminal 142, the third USB (registered trademark) terminal 143, and the fourth USB (registered trademark) terminal 144 supplies power to the peripheral device 2 via a USB (registered trademark) cable.

The peripheral devices 2 include, for example, a first peripheral device 21, a second peripheral device 22, a third peripheral device 23, and a fourth peripheral device 24.
The first USB (registered trademark) terminal 141 is configured to be connectable to, for example, the first peripheral device 21. The second USB (registered trademark) terminal 142 is configured to be connectable to, for example, the second peripheral device 22. The third USB (registered trademark) terminal 143 is configured to be connectable to, for example, the third peripheral device 23. The fourth USB (registered trademark) terminal 144 is configured to be connectable to, for example, the fourth peripheral device 24.
The first USB (registered trademark) terminal 141, the second USB (registered trademark) terminal 142, the third USB (registered trademark) terminal 143, and the fourth USB (registered trademark) terminal 144 correspond to examples of "connection terminals."
The first peripheral device 21, the second peripheral device 22, the third peripheral device 23, and the fourth peripheral device 24 correspond to an example of "a plurality of peripheral devices."

The power supply mechanism 14 includes a current sensor SA. The current sensor SA detects a peripheral current value AS, which is the current value of the current supplied from the power supply mechanism 14 to the peripheral device 2. In other words, the peripheral current value AS is the current value consumed by the peripheral device 2. The current sensor SA outputs the detected peripheral current value AS to the control unit 11.
The current sensor SA corresponds to an example of a "current detection unit."

In this embodiment, the current sensor SA detects the peripheral current value AS, but this is not limiting. Instead of using the current sensor SA, current consumption values corresponding to each type of connected peripheral device 2 may be pre-stored in memory 11B, and the control unit 11 may detect the type of peripheral device 2 connected to the "connection terminal." The peripheral current value AS may then be obtained from the current consumption values corresponding to each type of peripheral device 2 pre-stored in memory 11B, depending on the type of peripheral device 2 connected to the "connection terminal." This configuration corresponds to an example of a "current detection unit."

The printing mechanism 15 executes a printing function under the control of the control unit 11. The printing mechanism 15 prints characters, images, etc. on a recording medium P such as printing paper under the control of the control unit 11. The recording medium P is, for example, thermal paper.
The printing mechanism 15 includes a recording head 151, a drive motor 152, and a transport roller 153 as components related to printing.

The recording head 151 is, for example, a thermal head, that is, in this embodiment, the printer 1 is a thermal printer.
The recording head 151 has a plurality of heating elements. The heating elements generate heat when energized. An image is formed on the recording medium P by applying heat from the recording head 151 to the recording medium P.

The drive motor 152 drives the transport roller 153. The drive motor 152 is, for example, a DC motor.
The transport roller 153 is disposed opposite the recording head 151. With the recording medium P sandwiched between the transport roller 153 and the recording head 151, the recording medium P is transported by the rotation of the transport roller 153.

The print medium storage unit 16 is configured to be able to store recording media P. For example, a roll of long recording media P is stored in the print medium storage unit 16, and the recording media P is pulled out from the roll and transported by the drive motor 152 onto a transport path (not shown). The print medium storage unit 16 may also be configured to collect the printed matter, which is the recording media P, after printing.

Next, the functional blocks of the control unit 11 of the printer 1 will be described.
The control unit 11 includes a first calculation unit 111, a second calculation unit 112, an addition unit 113, a speed determination unit 114, a speed control unit 115, a print data storage unit 116, and a table storage unit 117. When the processor 11A executes the control program PG, the processor 11A functions as the first calculation unit 111, the second calculation unit 112, the addition unit 113, the speed determination unit 114, and the speed control unit 115. When the processor 11A executes the control program PG, the memory 11B functions as the print data storage unit 116 and the table storage unit 117.

The print data storage unit 116 stores print data DP in advance. The print data DP is transmitted to the recording head 151 by the control unit 11. The recording head 151 then forms an image corresponding to the print data DP on the recording medium P.

The table storage unit 117 stores a first table TBL1 and a second table TBL2 in advance. The first table TBL1 is a table that associates the peripheral current value AS with one table selected by the speed determination unit 114 from a plurality of tables.
The first table TBL1 will be further described with reference to FIG.

The second table TBL2 is a table that associates a current consumption threshold THA, which is a threshold corresponding to the added current QT, with the target speed VT. The target speed VT is a target value for the conveying speed V. The added current QT is calculated by the adder 113.
The second table TBL2 will be further described with reference to FIG.

The first calculation unit 111 calculates a first current amount QA, which is the amount of current consumed by the recording head 151. The first calculation unit 111 calculates the first current amount QA based on the print data DP. The first current amount QA is, for example, the amount of current consumed by the recording head 151 when the recording head 151 prints one line of the print data DP. The first calculation unit 111 calculates the first current amount QA, for example, using the following equation (1):
QA=(Vh/(((Rt+Rd)/N)+Rfet))×TE (1)

Here, voltage value Vh indicates the voltage value of the voltage supplied to the print head 151. Resistance value Rt indicates the resistance value of each of the multiple heating elements arranged in the print head 151. Resistance value Rd indicates the resistance value of a driver resistor connected in series with each of the multiple heating elements arranged in the print head 151. Number N indicates the number of heating elements to be energized among the multiple heating elements arranged in the print head 151. Resistance value Rfet indicates the resistance value of an FET (Field Effect Transistor) that switches each of the multiple heating elements arranged in the print head 151 ON and OFF. Time TE indicates the time during which electricity is applied to the multiple heating elements arranged in the print head 151 when printing one line.
The unit of the first current amount QA is, for example, (A×μsec).

The second calculation unit 112 calculates a second current amount QB, which is the amount of current consumed by the drive motor 152. The second calculation unit 112 calculates the second current amount QB based on, for example, the applied voltage value Vm to the drive motor 152, the on-time Dp of PWM (Pulse Width Modulation) control, the rotation speed Nr of the drive motor 152, and the transport time TF, which is the time it takes for the transport roller 153 to transport the recording medium P a transport amount corresponding to one line of the print data DP.
The second calculation unit 112 calculates the second current amount QB using, for example, the following equation (2).
QB=((Vm×Dp/Dmax−Ke×Nr)/
(Rm+Rmd)×Dp/Dmax)×TF (2)

Here, the time Dmax is the time for one cycle of PWM control. The coefficient Ke is the back electromotive force constant (V/rps) of the drive motor 152. The resistance value Rm is the resistance value of the resistor of the drive motor 152. The resistance value Rmd is the resistance value of the driver resistor of the drive motor 152.
The second current amount QB is expressed in units of (A×μsec), for example.

The adder 113 adds the first current amount QA and the second current amount QB to calculate the total current amount QT. That is, the adder 113 calculates the total current amount QT using the following equation (3).
QT=QA+QB (3)

The speed determination unit 114 refers to the first table TBL1 and selects one table from among the multiple tables based on the peripheral current value AS. Then, the speed determination unit 114 refers to the second table TBL2 corresponding to the selected table and determines the conveyance speed V of the recording medium P to be the target speed VT corresponding to the added current amount QT.
The processing of the speed determination unit 114 will be further described with reference to FIGS.

The speed control unit 115 controls the transport speed V of the recording medium P. The speed control unit 115 controls the transport speed V of the recording medium P, for example, based on the added current amount QT. The speed control unit 115 controls the transport speed V of the recording medium P by the transport roller 153 to the target speed VT determined by the speed determination unit 114, for example, by PWM controlling the drive motor 152.
The speed control unit 115 corresponds to an example of a "conveyance speed control unit."

In this embodiment, the second calculation unit 112 calculates the second current amount QB, which is the amount of current consumed by the drive motor 152 during the transport time TF, which is the time it takes for the transport roller 153 to transport the recording medium P a distance corresponding to one line of the print data DP, but the embodiment is not limited to this. The second calculation unit 112 may also calculate the average value of the second current amount QB, which is the amount of current consumed by the drive motor 152 during the transport time TF, which is the time it takes for the transport roller 153 to transport the recording medium P a distance corresponding to a predetermined number NP of lines of the print data DP. In this case, the addition unit 113 adds the first current amount QA and the average value of the second current amount QB to calculate the total current amount QT.

The predetermined number NP is an integer equal to or greater than 2. The larger the predetermined number NP, the simpler the processing of the second calculation unit 112. The smaller the predetermined number NP, the more accurately the added current amount QT can be calculated.
For example, the second calculation unit 112 may determine the predetermined number NP according to the transport speed V of the recording medium P. For example, the second calculation unit 112 may set the predetermined number NP to a larger value as the transport speed V of the recording medium P increases. In this case, the predetermined number NP can be set appropriately.

Next, the first table TBL1 will be described with reference to FIG. 2. FIG. 2 is a diagram showing an example of the first table TBL1.
As shown in FIG. 2, the first table TBL1 associates the peripheral current value AS with a selection table TS, which is a table selected by the speed determination unit 114.
For example, when the peripheral current value AS is equal to or less than 1.0 A, the speed determination unit 114 selects table A as the selection table TS.
Also, for example, when the peripheral current value AS is greater than 1.0 A and equal to or less than 1.5 A, the speed determination unit 114 selects table B as the selection table TS.
Also, for example, if the peripheral current value AS is greater than 1.5 A and less than or equal to 2.0 A, the speed determination unit 114 selects table C as the selection table TS.

In this embodiment, as shown in FIG. 2, a case will be described in which the speed determination unit 114 selects from three table options: Table A, Table B, and Table C, but the embodiment is not limited to this. The more table options the speed determination unit 114 selects from, the more likely it is that the speed determination unit 114 will be able to set the target speed VT to an appropriate value. The fewer table options the speed determination unit 114 selects from, the more simplified the processing of the speed determination unit 114 can be.

Next, the second table TBL2 will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the second table TBL2.
3, the second table TBL2 is a table that associates the target speed VT with a current consumption threshold THA. The current consumption threshold THA is shown as a current consumption threshold TH1 when the speed determination unit 114 selects table A as the selection table TS, a current consumption threshold TH2 when the speed determination unit 114 selects table B as the selection table TS, and a current consumption threshold TH3 when the speed determination unit 114 selects table C as the selection table TS. The current consumption threshold THA is a threshold for the added current QT.

The speed determination unit 114 determines the target speed VT, for example, in the following manner.
That is, when the speed determination unit 114 selects table B as the selection table TS, the current consumption threshold TH2 is selected as the current consumption threshold THA corresponding to table B.
The speed determination unit 114 then compares the added current amount QT calculated by the adding unit 113 with the current consumption threshold TH2. Specifically, the speed determination unit 114 selects, from the current consumption thresholds TH2, a current consumption threshold TH2 that is equal to or greater than the added current amount QT and that is closest to the added current amount QT, with reference to Fig. 3. Furthermore, the speed determination unit 114 determines, with reference to Fig. 3, the target speed VT corresponding to the selected current consumption threshold TH2 as the target value of the conveying speed V.

For example, if the speed determination unit 114 selects table B as the selection table TS and the added current amount QT is "10,500 (A x μsec)," then, with reference to FIG. 3, it selects "11,000 (A x μsec)" from the current consumption threshold TH2. Then, with reference to FIG. 3, the speed determination unit 114 determines the target speed VT corresponding to "11,000 (A x μsec)" to be "52 (mm/sec)."

For example, if the speed determination unit 114 selects table C as the selection table TS and the added current amount QT is "10,500 (A x μsec)," then, with reference to FIG. 3, it selects "11,500 (A x μsec)" from the current consumption threshold TH3. Then, with reference to FIG. 3, the speed determination unit 114 determines the target speed VT corresponding to "11,500 (A x μsec)" to be "41 (mm/sec)."

Next, the main processing of the control unit 11 in this embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing an example of the main processing of the control unit 11.
As shown in FIG. 4, in step S101, the control unit 11 acquires a peripheral current value AS from the current sensor SA.
Next, in step S103, the speed determination unit 114 refers to the first table TBL1 based on the peripheral current value AS and selects one table from among the plurality of tables.
Next, in step S105, the first calculation unit 111 calculates the first current amount QA, which is the amount of current consumed by the print head 151. The first calculation unit 111 calculates the first current amount QA, for example, using the above formula (1).

Next, in step S107, the second calculator 112 calculates the second current amount QB, which is the amount of current consumed by the drive motor 152. The second calculator 112 calculates the second current amount QB, for example, using the above formula (2).
Next, in step S109, the adder 113 adds the first current amount QA and the second current amount QB to calculate the total current amount QT. The adder 113 calculates the total current amount QT using, for example, the above formula (3).
Next, in step S111, the speed determination unit 114 refers to the second table TBL2 corresponding to one of the tables selected in step S103, and determines the target value of the conveying speed V of the recording medium P to be the target speed VT corresponding to the added current amount QT.

Next, in step S113, the speed control unit 115 controls the conveying speed V of the recording medium P to the target speed VT.
Next, in step S115, the control unit 11 determines whether printing of the print data DP is completed.
If the control unit 11 determines that printing of the print data DP is not complete (step S115; NO), the process returns to step S101. If the control unit 11 determines that printing of the print data DP is complete (step S115; YES), the process then ends.

Step S105 corresponds to an example of a "first calculation step."
Step S107 corresponds to an example of a "second calculation step."
Step S109 corresponds to an example of an "addition step."
Step S113 corresponds to an example of a "transport control step."

[3. Structure and Effects]
As described above with reference to Figures 1 to 4, the printer 1 according to this embodiment includes a drive motor 152, a recording head 151 that prints on a recording medium P, a transport roller 153 that is driven by the drive motor 152 and transports the recording medium P toward the recording head 151, a first calculation unit 111 that calculates a first current amount QA that is the amount of current consumed by the recording head 151, a second calculation unit 112 that calculates a second current amount QB that is the amount of current consumed by the drive motor 152, an addition unit 113 that adds the first current amount QA and the second current amount QB to calculate a total current amount QT, and a speed control unit 115 that controls the transport speed V of the recording medium P based on the total current amount QT.

With this configuration, the first current amount QA, which is the amount of current consumed by the recording head 151, and the second current amount QB, which is the amount of current consumed by the drive motor 152, are added together to calculate the total current amount QT, and the transport speed V of the recording medium P is controlled based on the total current amount QT. Therefore, the transport speed V can be controlled appropriately.

In addition, in the printer 1 according to this embodiment, the recording head 151 is a thermal head, and the first calculation unit 111 calculates the first current amount QA based on the print data DP.

With this configuration, the first current amount QA, which is the amount of current consumed by the thermal head, is calculated based on the print data DP, so the first current amount QA can be calculated appropriately.

The printer 1 according to this embodiment also includes USB terminals 141-144 capable of supplying power to multiple peripheral devices 21-24, and a current detection unit that detects a peripheral current value AS, which is the current value consumed by the peripheral devices 21-24 connected to the USB terminals 141-144. The speed control unit 115 controls the transport speed V based on the added current amount QT and the peripheral current value AS.

With this configuration, the conveying speed V is controlled based on the added current amount QT and the peripheral current value AS, allowing the conveying speed V to be controlled appropriately.

In addition, in the printer 1 according to this embodiment, the current detection unit is a current sensor SA.

With this configuration, the current sensor SA detects the peripheral current value AS, allowing for accurate detection of the peripheral current value AS.

The printer 1 according to this embodiment also includes a table storage unit 117 that stores multiple tables A-C that associate and store the additional current amount QT with the target speed VT, and a speed determination unit 114 that selects one table from the multiple tables A-C based on the peripheral current value AS and references the selected table to determine the transport speed V to the target speed VT that corresponds to the additional current amount QT, and a speed control unit 115 that controls the transport speed V to the target speed VT determined by the speed determination unit 114.

With this configuration, one table is selected from multiple tables A-C based on the peripheral current value AS, and the conveying speed V is determined to the target speed VT corresponding to the added current amount QT by referring to that one table, thereby allowing the conveying speed V to be determined appropriately.

In addition, in the printer 1 according to this embodiment, the drive motor 152 is a DC motor, and the speed control unit 115 controls the transport speed V by PWM controlling the drive motor 152, and the second calculation unit 112 calculates the second current amount QB based on the applied voltage value Vm to the drive motor 152, the on time Dp of the PWM control, the rotation speed Nr of the drive motor 152, and the transport time TF, which is the time it takes for the transport roller 153 to transport the recording medium P a transport amount corresponding to one line of the print data DP.

This configuration allows the second current amount QB, which is the amount of current consumed by the drive motor 152, to be calculated appropriately.

In addition, in the printer 1 according to this embodiment, the second calculation unit 112 calculates the average value of the second current amount QB for a predetermined number NP of lines of the print data DP, and the addition unit 113 adds the first current amount QA and the average value of the second current amount QB to calculate the total current amount QT.

With this configuration, by setting the predetermined number NP to an appropriate value, it is possible to reduce the load on the control unit 11 while calculating an appropriate added current amount QT.

In addition, in the printer 1 according to this embodiment, the second calculation unit 112 determines the predetermined number NP based on the transport speed V.

With this configuration, the predetermined number NP is determined based on the conveying speed V, allowing the predetermined number NP to be set to an appropriate value.

The control method for the printer 1 according to this embodiment is a method for controlling the printer 1, which includes a drive motor 152, a transport roller 153 driven by the drive motor 152 to transport the recording medium P, and a recording head 151 that prints on the recording medium P, and includes a first calculation step of calculating a first current amount QA, which is the amount of current consumed by the recording head 151, a second calculation step of calculating a second current amount QB, which is the amount of current consumed by the drive motor 152, an addition step of adding the first current amount QA and the second current amount QB to calculate a total current amount QT, and a transport control step of controlling the transport speed V of the recording medium P based on the total current amount QT.

The control method for the printer 1 according to this embodiment achieves the same effects as the printer 1 according to this embodiment.

This embodiment shows one aspect and can be modified and adapted as desired without departing from the spirit and scope of the invention.

In this embodiment, the "printing device" is described as a printer 1, but this is not limiting. The "printing device" may also be, for example, a copier. The "printing device" may also be, for example, a multifunction peripheral.

In this embodiment, the drive motor 152 is a DC motor, but the embodiment is not limited to this. The drive motor 152 may also be an AC motor.

In this embodiment, the recording head 151 is described as a thermal head, but the embodiment is not limited to this. The recording head 151 may also be, for example, a head that ejects ink.

In this embodiment, the "connection terminal" is described as a USB (registered trademark) terminal, but the embodiment is not limited to this. Some or all of the "connection terminals" may be, for example, serial terminals. In this case, power is supplied to the peripheral device 2 via a serial cable.

In this embodiment, a case is described in which the processor 11A of the printer 1 executes the control program PG stored in the memory 11B, but the embodiment is not limited to this. The control program PG can also be configured as a recording medium on which it is recorded so as to be readable by a computer, or as a transmission medium for transmitting the control program PG.
The recording medium may be a magnetic or optical recording medium or a semiconductor memory device, and examples of the recording medium include portable or fixed recording media such as a flexible disk, HDD, CD-ROM (Compact Disk Read Only Memory), DVD (Digital Versatile Disk), Blu-ray (registered trademark) Disc, magneto-optical disk, flash memory, and card-type recording medium.
The recording medium may be a non-volatile storage device such as a RAM, ROM, or HDD that is an internal storage device provided in the printer 1.

The functions of the printer 1's control unit 11 may be realized by one or more processors or semiconductor chips. The control unit 11 may also be configured to include a co-processor such as a SoC (System-on-a-Chip), MCU (Micro Control Unit), or FPGA. The control unit 11 may perform various controls by using both the CPU and the co-processor in cooperation with each other, or by selectively using one of the two.

The processing units in the flowchart in Figure 4 are divided according to the main processing content to make it easier to understand the processing of the printer 1's control unit 11, and there are no limitations on how the processing units are divided or their names. The processing units in the flowchart may be divided into more processing units depending on the processing content. One processing unit may also be divided so that it includes more processes. The order of the processing may be changed as appropriate as long as it does not interfere with the intent.

The functional units shown in Figure 1 indicate functional configurations, and the specific implementation form is not particularly limited. It is not necessary to implement hardware that corresponds to each functional unit individually; it is also possible to configure a single processor to execute a program to realize the functions of multiple functional units. Some of the functions realized by software in the above-described embodiments may be implemented as hardware, or some of the functions realized by hardware may be implemented as software. In addition, the specific detailed configurations of the other units of the printer 1 may also be changed as desired without departing from the spirit of the invention.

1...Printer (printing device), 11...Control unit, 11A...Processor, 11B...Memory, 111...First calculation unit, 112...Second calculation unit, 113...Adder, 114...Speed determination unit, 115...Speed control unit (conveying speed control unit), 116...Print data storage unit, 117...Table storage unit, 14...Power supply mechanism, 141...First USB terminal (connection terminal), 142...Second USB terminal (connection terminal), 143...Third USB terminal (connection terminal), 144...Fourth USB terminal (connection terminal), 15...Printing mechanism, 151... Recording head, 152...drive motor, 153...transport roller, 2...peripheral device, 21...first peripheral device, 22...second peripheral device, 23...third peripheral device, 24...fourth peripheral device, AS...peripheral current value, DP...print data, NP...predetermined number, P...recording medium, PG...control program, QA...first current amount, QB...second current amount, QT...additional current amount, SA...current sensor, TBL1...first table, TBL2...second table, TH1, TH2, TH3, THA...current consumption threshold, V...transport speed, VT...target speed.

Claims (9)

A drive motor;
a transport roller driven by the drive motor to transport a recording medium;
a recording head for printing on the recording medium;
a first calculation unit that calculates a first current amount that is a current amount consumed by the recording head;
a second calculation unit that calculates a second current amount that is the amount of current consumed by the drive motor;
an adder that adds the first current amount and the second current amount to calculate a sum current amount;
a conveyance speed control unit that controls a conveyance speed of the recording medium based on the added current amount;
A printing device comprising: the recording head is a thermal head,
the first calculation unit calculates the first current amount based on print data;
The printing device of claim 1 . a connection terminal capable of supplying power to a plurality of peripheral devices;
a current detection unit that detects a peripheral current value that is a current value consumed by the peripheral device connected to the connection terminal;
Equipped with
the conveying speed control unit controls the conveying speed based on the added current amount and the peripheral current value.
The printing device of claim 1 . The current detection unit is a current sensor.
The printing device according to claim 3 . a table storage unit that stores a plurality of tables that store the added current amount and the conveying speed in association with each other;
a speed determination unit that selects one table from the plurality of tables based on the peripheral current value, and determines a target speed, which is a target value of the conveying speed, as a conveying speed corresponding to the added current amount by referring to the one table;
the conveying speed control unit controls the conveying speed to the target speed determined by the speed determination unit.
The printing device according to claim 3 . The drive motor is a DC motor,
the conveying speed control unit controls the conveying speed by PWM control of the drive motor,
the second calculation unit calculates the second current amount based on a voltage value applied to the drive motor, an on-time of the PWM control, a rotation speed of the drive motor, and a transport time that is a time required for the transport roller to transport the recording medium a transport amount corresponding to one line of print data;
The printing device according to any one of claims 1 to 5. the second calculation unit calculates an average value of the second current amount for a predetermined number of lines of the print data,
the adder calculates the added current amount by adding the first current amount and an average value of the second current amount.
The printing device according to claim 6. The second calculation unit determines the predetermined number in accordance with the conveying speed.
The printing device according to claim 7. A drive motor;
a transport roller driven by the drive motor to transport a recording medium;
a recording head for printing on the recording medium;
A method for controlling a printing device, comprising:
a first calculation step of calculating a first current amount that is a current amount consumed by the recording head;
a second calculation step of calculating a second current amount that is the current amount consumed by the drive motor;
an addition step of adding the first current amount and the second current amount to calculate a total current amount;
a conveyance control step of controlling a conveyance speed of the recording medium based on the added current amount;
A method for controlling a printing device, comprising: