printer

Abstract

To provide a printer that can contribute to suppressing power supply to an external instrument connected thereto through a connector from being started, more surely than before, in an unintended state of a power source.SOLUTION: A printer comprises: a USB connector that is connected with an external instrument; a PD circuit configured to execute negotiation with the external instrument connected to the USB connector, in accordance with a USB-PD standard; and a processor. The processor executes a power supply-starting process of starting power supply to the external instrument while outputting, to the PD circuit, a source setting instruction for switching a role of the printer with respect to the external instrument from a sink to a source (S10).SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a printer. [Background technology]

[0002] The printer in Patent Document 1 includes a USB interface with a connector and a current detection unit, and supplies power to an external device via the USB interface. When the printer receives an instruction to perform image processing while supplying power to the external device, it supplies power to the external device. If the difference between the minimum and maximum current values ​​detected by the interface within a certain period exceeds a threshold, the printer outputs an instruction to the USB interface to limit power supply to the external device. If the difference between the minimum and maximum current values ​​detected by the current detection unit during power supply to the external device does not exceed a threshold, the printer does not output an instruction to the USB interface to limit power supply to the external device. Under the USB-PD standard, the printer negotiates with the external device connected via the connector, and sets the power supply direction and the amount of power to be supplied based on the negotiation results. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-144301 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional printers described above, as a result of negotiation with an external device connected via a connector, power supply to the external device may start in an unintended power state (for example, when an AC adapter is not connected to the printer).

[0005] An object of the present invention is to provide a printer that contributes to more reliably preventing power supply to an external device connected via a connector from starting in an unintended power state than in the past. [Means for solving the problem]

[0006] A printer according to one aspect of the present invention includes a USB connector to which an external device is connected, a PD circuit configured to negotiate with the external device connected to the USB connector in accordance with the USB-PD standard, and a processor. The processor outputs a source setting instruction to the PD circuit to switch the printer's role relative to the external device from sink to source depending on the power supply status, and executes a power supply start process to start supplying power to the external device. According to the USB-PD standard, when the printer's role relative to the external device is sink, the printer does not supply power to the external device. The power supply start process executed by the printer's processor outputs a source setting instruction to start supplying power to the external device when the power supply status becomes an intended status (e.g., when an AC adapter is connected to the printer), while maintaining the printer's role as sink in an unintended power supply status. This contributes to more reliably preventing power supply to the external device from being started in an unintended power supply status (e.g., when the AC adapter is not connected to the printer) than in conventional methods.

[0007] The processor of the printer according to this aspect may, in the power supply start process, output the source setting instruction to the PD circuit to start power supply to the external device if the connection state between the printer and the AC adapter satisfies a source setting condition. In this case, the power supply start process executed by the processor of the printer outputs the source setting instruction according to the connection state between the printer and the AC adapter, thereby contributing to more reliably preventing power supply to an external device from being started when the connection state between the printer and the AC adapter is not intended, compared to conventional methods.

[0008] The processor of the printer according to this aspect may perform the power supply start process when the AC adapter is connected to the printer while the external device is connected to the printer via the USB connector, assuming that the source setting condition is met. When the AC adapter is connected to the printer while the external device is connected to the printer via the USB connector, this indicates that the printer can stably supply power to the external device using the AC adapter as a power source. The power supply start process executed by the printer's processor automatically switches the printer's role with respect to the external device from sink to source when the printer can stably supply power to the external device, thereby contributing to starting power supply to the external device.

[0009] The processor of the printer according to this aspect may perform the power supply start process when the external device is connected to the printer via the USB connector while the AC adapter is connected to the printer, assuming that the source setting condition is met. When the external device is connected to the printer via the USB connector while the AC adapter is connected to the printer, this is a case in which the printer can stably supply power to the external device using the AC adapter as a power source. The power supply start process executed by the printer's processor automatically switches the printer's role with respect to the external device from sink to source when stable power can be supplied from the printer to the external device, thereby contributing to starting power supply to the external device.

[0010] The printer according to this aspect further includes a print head and a transport unit that transports a medium, and the processor drives the print head and the transport unit to execute a print process that prints on the medium. If the connection status between the printer and the AC adapter satisfies the source setting condition during the print process, the power supply start process may output the source setting instruction to the PD circuit to start power supply to the external device after the print process is completed. If power supply is started during the print process, the power supplied to the print head may become temporarily unstable, potentially resulting in a deterioration in print quality. The power supply start process executed by the printer's processor contributes to preventing a deterioration in print quality due to power supply to an external device being started during the print process.

[0011] The printer according to this aspect further includes a print head, and the processor may, during the power supply start process, if the connection status between the printer and the AC adapter satisfies the source setting condition while the print head is being driven, output the source setting instruction to the PD circuit to start power supply to the external device after the print head has finished being driven. If power supply is started while the print head is being driven, the power supplied to the print head may become temporarily unstable, potentially resulting in a deterioration in print quality. The power supply start process executed by the printer's processor helps to prevent a deterioration in print quality caused by power supply to an external device being started while the print head is being driven.

[0012] The printer according to this aspect further includes a transport unit that transports media, and the processor may, during the power supply start process, if the connection status between the printer and the AC adapter satisfies the source setting condition while the transport unit is in operation, output the source setting instruction to the PD circuit to start power supply to the external device after the transport unit has finished operating. If power supply is started while the transport unit is in operation, the power supplied to the transport unit may become temporarily unstable, which may result in a deterioration in transport accuracy. The power supply start process executed by the printer's processor starts power supply to the external device after the transport unit has finished operating if the connection status between the printer and the AC adapter satisfies the source setting condition while the transport unit is in operation, thereby contributing to preventing a deterioration in transport accuracy due to starting power supply to the external device.

[0013] The printer according to this aspect further includes a cutting blade for cutting the medium, and the processor further executes a cutting process after the printing process, in which the cutting blade is driven to cut the medium while the transport unit is stopped, and the power supply start process may include outputting the source setting instruction to the PD circuit to start power supply to the external device after the printing process ends and when the disconnection process is executed if the connection status between the printer and the AC adapter satisfies the source setting condition during the printing process. The power supply start process executed by the printer's processor starts power supply to the external device after the printing process ends and when the disconnection process is executed if the connection status between the printer and the AC adapter satisfies the source setting condition during the printing process. Therefore, the power supply start process contributes to starting power supply to the external device without degrading print quality and transport quality.

[0014] If the connection state between the printer and the AC adapter satisfies the source setting condition during execution of the printing process, the processor of the printer according to this aspect may output the source setting instruction to the PD circuit to start power supply to the external device between print jobs after the printing process ends and before the next printing process is executed in the power supply start process. The power supply start process executed by the printer processor starts power supply to the external device between print jobs, which contributes to preventing the power supply start process from interfering with the printing process.

[0015] The printer according to this aspect further includes a wireless communication interface, and the processor further executes an acceptance process for receiving a print instruction that instructs execution of the print process via the wireless communication interface, and if the connection status between the printer and the AC adapter satisfies the source setting condition during execution of the print process, the power supply start process may output the source setting instruction to the PD circuit to start power supply to the external device after the print process based on the print instruction accepted via the wireless communication interface is completed and between print jobs until the next print instruction is accepted via the wireless communication interface. The power supply start process executed by the printer's processor starts power supply to the external device between print jobs, thereby contributing to preventing the power supply start process from interfering with the print process.

[0016] The processor of the printer according to this aspect may further execute a power supply termination process by outputting a sink setting instruction to the PD circuit to switch the role between the printer and the external device from source to sink depending on the state of the power source, and terminating power supply to the external device. The power supply termination process executed by the printer processor contributes to automatically terminating power supply to the external device depending on the state of the power source.

[0017] The processor of the printer according to this aspect may output the sink setting instruction to the PD circuit and terminate power supply to the external device when an OFF instruction to turn off the power is acquired as the power supply state in the power supply termination process. The power supply termination process executed by the processor of the printer contributes to automatically terminating power supply to the external device when an OFF instruction is acquired.

[0018] In the power supply termination process, the processor of the printer according to this aspect may output the sink setting instruction to the PD circuit and terminate power supply to the external device when the AC adapter is disconnected from the printer as the power supply state. If the AC adapter is disconnected from the printer while the printer is connected to the AC adapter and supplying power to the external device, the power supplied to the printer may become temporarily unstable. The power supply termination process executed by the printer's processor automatically terminates power supply to the external device when the AC adapter is disconnected from the printer, thereby contributing to preventing the power supplied to the printer from becoming temporarily unstable.

[0019] The printer according to this aspect further includes a print head and a transport unit that transports a medium, and the processor drives the print head and the transport unit to further execute a print process that prints on the medium. In the power supply termination process, if the power supply state meets the condition for outputting the sink setting instruction during execution of the print process, the power supply termination process may output the sink setting instruction to the PD circuit and terminate power supply to the external device after the print process is completed. If the power supply state meets the condition for outputting the sink setting instruction during execution of the print process, the power supplied to the printer may become temporarily unstable. The power supply termination process executed by the printer's processor automatically terminates power supply to the external device after the print process is completed if the power supply state meets the condition for outputting the sink setting instruction during execution of the print process, thereby contributing to preventing temporary instability in the power supplied to the printer during execution of the print process.

[0020] The printer according to this aspect further includes a print head and a transport unit that transports a medium, and the processor drives the print head and the transport unit to perform a print process that prints on the medium, and if an OFF instruction to turn off the power is received during the print process, the processor may further perform a power OFF process to turn off the power of the printer after the print process is completed. The power OFF process executed by the printer's processor helps to avoid turning off the power while the print process is being executed.

[0021] The PD circuit of the printer according to this aspect may set the initial role of the printer to the sink during the negotiation with the external device. The PD circuit of the printer contributes to preventing power supply to the external device from starting in an unintended power state. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a perspective view of the printer 1 with the cover 22 closed, viewed from above and to the front right. [Figure 2] FIG. 2 is a partial cross-sectional view taken along the line 2-2 in FIG. [Figure 3] 2 is a block diagram showing the electrical configuration of the printer 1. FIG. [Figure 4] 10 is a flowchart of a print control process. [Figure 5] 10 is a flowchart of a power supply start control process. [Figure 6] FIG. 2 is an explanatory diagram of the transition of rolls in the printer 1. [Figure 7] 10 is a flowchart of a power supply end control process. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are used to explain technical features that can be adopted by the present invention. In other words, the configurations and the like shown in the drawings are merely illustrative examples and are not intended to limit the present invention.

[0024] The physical configuration of the printer 1 will be described with reference to Figures 1 and 2. Hereinafter, the upper left, lower right, lower left, upper right, upper, and lower in Figure 1 will be referred to as the front, rear, right, left, upper, and lower of the printer 1, respectively. Note that in this embodiment, the up-and-down direction is used for convenience of explanation and is not limited to the vertical direction.

[0025] As shown in Figures 1 and 2, the printer 1 is a thermal printer that prints on a medium P. In this embodiment, the medium P is a long print tape whose length in the transport direction is longer than its width. The width direction is the left-right direction, and the transport direction is the forward direction. The printer 1 includes a housing 20 and an input unit 25. The housing 20 includes a main body 21 and a cover 22. The main body 21 is a roughly rectangular box-shaped body extending in the front-rear direction and forms the lower part of the housing 20. The main body 21 opens upward. The cover 22 is a roughly rectangular box-shaped body extending in the front-rear direction and forms the upper part of the housing 20. The cover 22 is rotatable around an axis extending in the left-right direction at the upper rear end of the main body 21. Figure 1 shows the cover 22 in a closed state, covering the opening of the main body 21 from above. Although not shown, when the cover 22 is opened, the cover 22 opens the opening of the main body 21 upward.

[0026] 2, an outlet 24 is formed at the front end of the housing 20. The outlet 24 is a gap between the front wall of the main body 21 and the front wall of the cover 22, and extends in the left-right direction. The printed medium P is discharged from the housing 20 through the outlet 24.

[0027] 1, the input unit 25 is provided at the upper end of the cover 22. The input unit 25 is a switch that receives input of various information and instructions, and outputs them to the CPU 30 (described later). The input unit 25 includes a power button.

[0028] As shown in FIG. 2, the printer 1 includes a transport unit 5 and a print head 6 inside a housing 20. The transport unit 5 is provided at the upper front end of the main body 21. The transport unit 5 is disposed between the front end of the main body 21 and the front end of the support mechanism 10 in the front-to-rear direction. The transport unit 5 is a cylinder with an axis extending in the left-to-right direction, and is provided in the main body 21 so as to be rotatable around the axis.

[0029] The print head 6 prints on the medium P. The print head 6 is a plate-like member extending in the left-right direction, and is attached to the cover 22 from below. In this embodiment, the print head 6 is a thermal head having multiple heating elements. The printer 1 prints on the medium P by selectively activating the multiple heating elements of the print head 6 to generate heat.

[0030] A cutter unit 50 is removably attached to the front end of the housing 20. The cutter unit 50 includes a unit housing 51, a cutting blade 54, a fixed blade 55, and, as shown in FIG. 3, a cutter motor 57. The unit housing 51 is shaped like a rectangular parallelepiped box. A passage opening 56 is formed in the unit housing 51, penetrating the unit housing 51 in the front-to-rear direction. The rear end of the passage opening 56 is located in front of the discharge opening 24.

[0031] The cutting blade 54 and the fixed blade 55 are housed in the unit housing 51 and are arranged at the rear end of the unit housing 51. The fixed blade 55 is arranged above the passage opening 56 and is fixed to the unit housing 51. The cutting edge provided at the lower end of the fixed blade 55 extends in the left-right direction. The cutting edge of the fixed blade 55 is exposed to the passage opening 56 from below.

[0032] The cutting blade 54 is disposed below the passage opening 56 and extends in the left-right direction. A blade is formed on the upper end of the cutting blade 54. The cutting blade 54 is movably supported by the unit housing 51 at a retracted position where it is retracted below the passage opening 56, and an entry position where it enters the passage opening 56. The cutter motor 57 is housed in the unit housing 51 and moves the cutting blade 54 between the retracted position and the entry position. The printer 1 moves the cutting blade 54 from the retracted position to the entry position. The printer 1 cuts the medium P discharged from the discharge opening 24 between the cutting blade 54 and the fixed blade 55.

[0033] The electrical configuration of the printer 1 will be described with reference to Figure 3. The printer 1 includes a battery unit 71 and a main unit 72. The battery unit 71 includes a charging circuit 36, a battery 62, and an attachment section 88. The charging circuit 36 ​​charges the battery 62 based on power from an AC adapter 101 attached to the attachment section 88. Power from the AC adapter 101 or the battery 62 is supplied to a drive section 80. The drive section 80 can print on a medium P based on power from the AC adapter 101 or the battery 62. The battery 62 is, for example, a lithium-ion battery or an electric double layer capacitor.

[0034] The main unit 72 includes an OR circuit 85, a logic DCDC converter (hereinafter referred to as "logic DCDC") 86, a USB power supply DCDC converter (hereinafter referred to as "power supply DCDC") 81, a FET 83, a USB connector 82, a PD circuit 84, and a drive unit 80.

[0035] The OR circuit 85 switches the power supply path to the external device 100 depending on whether the battery 62 and the AC adapter 101 are connected. For example, when only the AC adapter 101 is connected, the OR circuit 85 switches the power supply path so that power is supplied from the AC adapter 101. For example, when only the battery 62 is connected, the OR circuit 85 switches the power supply path so that power is supplied from the battery 62. When the AC adapter 101 and the battery 62 are connected, the OR circuit 85 switches the power supply path so that power from the AC adapter 101 is supplied to the drive unit 80, while power from the AC adapter 101 is supplied to the battery 62. The switching of the power supply path by the OR circuit 85 is performed automatically, but may be set by the user.

[0036] The logic DCDC 86 converts the input voltage from the AC adapter 101 or the battery 62 into an output voltage (for example, 3.3 V) for driving the drive unit 80.

[0037] The power supply DCDC 81 converts the input voltage from the AC adapter 101 or the battery 62 into an output voltage (for example, 9 V, 5 V, etc.) suitable for supplying power to the external device 100. The power converted by the power supply DCDC 81 is supplied to the external device 100.

[0038] An external device 100 is connected to the USB connector 82. The USB connector 82 is a connection port for connecting to the external device 100 via a cable 98 that complies with the USB-PD (USB Power Delivery) standard. The external device 100 is a USB device.

[0039] The PD circuit 84 is configured to execute negotiation in accordance with the USB-PD standard with the external device 100 connected to the USB connector 82. The PD circuit 84 is capable of communicating with the CPU 30. The PD circuit 84 is capable of controlling the value of the output voltage from the power supply DCDC 81. The PD circuit 84 executes negotiation in accordance with the USB-PD standard with the external device 100 via the USB connector 82. The PD circuit 84 controls the power supply from the power supply DCDC 81 to the external device 100 by controlling the on / off of the FET 83. For example, when the FET 83 is turned on, power is supplied to the external device 100 via the USB connector 82 and the cable 98. In other words, the PD circuit 84 can supply power supplied based on the power of the AC adapter 101 or the battery 62 to the external device 100.

[0040] The drive unit 80 includes a CPU 30, a ROM 31, a RAM 32, a storage device 33, and an input / output interface (I / O) 34. The CPU 30, the ROM 31, the RAM 32, and the storage device 33 are electrically connected to the I / O 34. The CPU 30 is a processor that controls the printer 1. The ROM 31 stores various setting information. The RAM 32 temporarily stores various information. The storage device 33 is non-volatile.

[0041] The I / O 34 is connected to drive circuits 37 and 40, a motor driver 38, an input unit 25, and a wireless communication interface (hereinafter referred to as wireless communication IF) 17. The drive circuit 37 controls the drive of the print head 6 in response to instructions input from the CPU 30. The drive circuit 40 controls the drive of the cutter motor 57 in response to instructions input from the CPU 30. The motor driver 38 controls the drive of the carry motor 53 in response to instructions input from the CPU 30. The input unit 25 inputs detection results to the I / O 34. The wireless communication IF 17 is a communication interface capable of performing short-range wireless communication compliant with, for example, the Bluetooth (registered trademark) standard. The communication standard of the wireless communication IF 17 is not limited to the Bluetooth (registered trademark) standard, and other short-range wireless communication standards such as NFC may also be used. The wireless communication IF 17 may be configured to communicate with external devices in accordance with, for example, the WFD (abbreviation for Wi-Fi Direct (registered trademark)) standard established by the Wi-Fi Alliance.

[0042] The print control process by printer 1 will be described with reference to FIG. 4. Hereinafter, steps are abbreviated as S. After the power is turned on, CPU 30 reads a program for executing the print control process stored in ROM 31 into RAM 32. CPU 30 executes the print control process having the following steps in accordance with instructions contained in the program read into RAM 32. Various data obtained during the print control process is stored in RAM 32 as appropriate. When an AC adapter 101 is connected to printer 1, printer 1 uses AC adapter 101 as its power source, regardless of whether a battery 62 is installed. When an AC adapter 101 is not connected to printer 1, printer 1 uses battery 62 as its power source.

[0043] As shown in FIG. 4, the CPU 30 determines whether a print instruction to execute printing has been detected (S51). The user operates the input unit 25 to input a print instruction to the printer 1. The print instruction may be input from an external device via the wireless communication IF 17. The print instruction includes print data and cutting information indicating whether to cut the medium P after printing. If a print instruction is not detected via the input unit 25 or the wireless communication IF 17 (S51: NO), the CPU 30 returns the process to S51. If a print instruction is detected (S51: YES), the CPU 30 drives the print head 6 and the transport unit 5 to execute a printing process to print on the medium P (S52). Specifically, the CPU 30 outputs a control signal to the motor driver 38. The motor driver 38 outputs a drive current corresponding to the control signal received from the CPU 30 to drive the transport motor 53 and rotate the transport unit 5. This causes the medium P to be pulled out from the roll. The printer 1 outputs a control signal to the drive circuit 37. The drive circuit 37 controls the print head 6 to selectively heat the multiple heating elements. The portions of the medium P that are heated by the heating elements develop color. The printer 1 repeats the conveyance of a predetermined amount of medium P by the conveyance unit 5 and the selective generation of heat by the print head 6. In this way, printing is performed on the medium P. The printed medium P is discharged to the outside of the housing 20 through the discharge port 24. The medium P is inserted through the passage port 56.

[0044] The CPU 30 determines whether to cut the medium P based on the cutting information included in the print instruction (S53). If the medium P is to be cut (S53: YES), the CPU 30 executes a cutting process after the print process, driving the cutting blade 54 to cut the medium P while the transport unit 5 is stopped (S54). Specifically, the CPU 30 stops the transport unit 5 when the medium P is transported to the cutting position and outputs a control signal to the drive circuit 40. The drive circuit 40 outputs a drive current according to the control signal received from the CPU 30 to drive the cutter motor 57, which moves the cutting blade 54 up and down. As a result, the printer 1 cuts the medium P discharged from the discharge port 24 between the cutting blade 54 and the fixed blade 55. If the medium P is not to be cut (S53: NO), or following S54, the CPU 30 determines whether to turn off the power (S55). If the power is not to be turned off (S55: NO), the CPU 30 returns the process to S51. If the power is to be turned off (S55: YES), the CPU 30 ends the print control process.

[0045] The power supply start control process executed by the printer 1 will be described with reference to Figures 5 and 6. Hereinafter, step will be abbreviated as S. After the power is turned on, the CPU 30 reads a program for executing the power supply start control process stored in the ROM 31 into the RAM 32. The CPU 30 executes the power supply start control process, which has the following steps, in accordance with instructions contained in the program read into the RAM 32. Various data obtained during the power supply start control process is stored in the RAM 32 as appropriate.

[0046] The CPU 30 determines whether the external device 100 is connected to the USB connector 82 (S1). If the external device 100 is not connected to the USB connector 82 (S1: NO), the CPU 30 returns the process to S1. If the external device 100 is connected to the USB connector 82 (S1: YES) in a state in which the battery 62 is being used as a power source as in state G1 of FIG. 6, the CPU 30 detects the external device 100 (S2), and the PD circuit 84 executes negotiation with the external device 100 via the USB connector 82 in accordance with the USB-PD standard.

[0047] The CPU 30 determines whether the negotiation with the external device 100 by the PD circuit 84 is complete (S3). If the negotiation is complete, the PD circuit 84 notifies the CPU 30 of the negotiation result. If the negotiation is not complete (S3: NO), the CPU 30 returns the process to S3. If the negotiation is complete (S3: YES), the PD circuit 84 sets the initial value of the roll of the printer 1 to sink (S4).

[0048] The CPU 30 determines whether the AC adapter 101 is connected to the attachment portion 88 (S5). S5 is a process for determining whether the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition. In this embodiment, the CPU 30 determines that the source setting condition is satisfied when the AC adapter 101 is connected to the printer 1 while the external device 100 is connected to the printer 1 via the USB connector 82 (S5: NO followed by S5: YES). The CPU 30 also determines that the source setting condition is satisfied when the external device 100 is connected to the printer 1 via the USB connector 82 while the AC adapter 101 is connected to the printer 1 (S5: YES without passing through S5: NO).

[0049] As in state G3 in FIG. 6, when the AC adapter 101 is not connected to the attachment portion 88 (S5: NO), the CPU 30 waits in S5 until the AC adapter 101 is connected. As in state G4, when the AC adapter 101 is connected to the attachment portion 88 (S5: YES), the CPU 30 determines whether it is time to start power supply to the external device 100. The power supply start timing may be determined as appropriate. The power supply start timing may be a timing determined by at least one of the following first to sixth start conditions. The first to sixth start conditions may be combined within a range that does not cause contradictions.

[0050] The first start condition is a condition in which, if the connection status between the printer 1 and the AC adapter 101 satisfies the source setting condition while the printing process of S52 is being executed (S5: YES), the CPU 30 does not determine that it is time to start supplying power while the printing process is being executed (S6: NO), but determines that it is time to start supplying power after the printing process being executed has ended (S6: YES).

[0051] The second start condition is that if the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition while the printing process of S52 is being executed (S5: YES), the CPU 30 does not determine that it is time to start supplying power while the printing process is being executed (S6: NO), but determines that it is time to start supplying power after the printing process being executed has ended and when the disconnection process of S54 is being executed (S6: YES).

[0052] The third start condition is that if the connection status between the printer 1 and the AC adapter 101 satisfies the source setting condition while the printing process of S52 is being executed (S5: YES), the CPU 30 does not determine that it is time to start supplying power while the printing process is being executed (S6: NO), but determines that it is time to start supplying power between the print jobs after the printing process currently being executed has ended and before the next printing process is executed (S6: YES).

[0053] The fourth start condition is a condition in which, if the connection status between the printer 1 and the AC adapter 101 satisfies the source setting condition while the printing process of S52 is being executed (S5: YES), the CPU 30 does not determine that it is time to start power supply while the printing process is being executed (S6: NO), but determines that it is time to start power supply after the printing process based on the printing instruction accepted via the wireless communication IF 17 is completed and between printing jobs until the next printing instruction is accepted via the wireless communication IF 17 (S6: YES).

[0054] The fifth start condition is a condition in which, if the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition while the print head 6 is being driven (S5: YES), the CPU 30 does not determine that it is time to start power supply while the print head 6 is being driven (S6: NO), but determines that it is time to start power supply after driving of the print head 6 has finished (S6: YES). Under the fifth start condition, even if printing processing is being executed, the power supply start timing may be set when the print head 6 is not being driven.

[0055] The sixth start condition is a condition in which, if the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition while the transport unit 5 is being driven (S5: YES), the CPU 30 does not determine that it is time to start power supply while the print head 6 is being driven (S6: NO), but determines that it is time to start power supply after the drive of the transport unit 5 has finished (S6: YES). Under the sixth start condition, the power supply start timing may be set even if the print process is being executed and the transport unit 5 is not being driven. Under the sixth start condition, the power supply start timing is not set when the transport unit 5 is being driven, even if the print process is not being executed.

[0056] If it is not the timing to start power supply (S6: NO), the CPU 30 returns the process to S6. If it is the timing to start power supply (S6: YES), the CPU 30 outputs an ON signal to the power supply DCDC 81 (S8). After waiting for 250 ms (S9), the CPU 30 outputs a source setting instruction to the PD circuit 84 to switch the role of the printer 1 relative to the external device 100 from sink to source depending on the power supply status, and executes power supply start processing to start power supply to the external device 100 (S10). In this embodiment, if the connection status between the printer 1 and the AC adapter 101 satisfies the source setting condition (S5: YES), the CPU 30 outputs the source setting instruction to the PD circuit 84 at the power supply start timing to start power supply to the external device 100 (S10).

[0057] In response to receiving the source setting instruction from the CPU 30, the PD circuit 84 negotiates with the external device 100 and starts a role swap to change the role of the printer 1 from sink to roll (S11). The CPU 30 determines whether the role swap is successful (S14). If the negotiation is completed, the PD circuit 84 outputs the negotiation result to the CPU 30. If the role swap is successful (S14: YES), the PD circuit 84 sets the role of the printer 1 from sink to source (S15), as shown in state G4 of FIG. 6. In this case, power supply from the power supply DCDC 81 to the external device 100 begins. If the source setting fails (S14: NO), the CPU 30 outputs an OFF signal to the power supply DCDC 81 (S16). The PD circuit 84 maintains the role of the printer 1 as sink (S17). In this case, power supply from the power supply DCDC 81 to the external device 100 does not begin. After S15 or S17, the CPU 30 starts the power supply end control process, and then ends the power supply start control process.

[0058] The power supply termination control process executed by the printer 1 will be described with reference to FIG. 7. In the power supply termination control process, a sink setting instruction is output to the PD circuit 84 to switch the role between the printer 1 and the external device 100 from source to sink depending on the power supply state, and power supply termination process is executed to terminate power supply to the external device 100. Hereinafter, steps are abbreviated as S. When the power supply start control process ends, the CPU 30 reads a program for executing the power supply termination control process stored in ROM 31 into RAM 32. The CPU 30 executes the power supply termination control process, which has the following steps, in accordance with the instructions included in the program read into RAM 32. Various data obtained during the power supply termination control process is stored in RAM 32 as appropriate.

[0059] The CPU 30 determines whether the power button has been pressed based on the detection result of the input unit 25 (S21). The user presses the power button to turn off the power of the printer 1. If the power button has been pressed (S21: YES), the CPU 30 determines whether printing processing is currently being executed (S22). If printing processing is currently being executed (S22: YES), the CPU 30 waits in S22 until the printing processing is completed.

[0060] If a print process is not being executed (S22: NO), and if an OFF instruction to turn off the power supply is acquired as the power supply state (S21: YES), the CPU 30 outputs a sink setting instruction to the PD circuit 84 to switch the role between the CPU 30 and the external device 100 from source to sink, and ends power supply to the external device 100 (S23). If the power supply state satisfies the condition for outputting a sink setting instruction during print process execution (S22: YES), and after the print process is completed (S22: NO), the CPU 30 outputs the sink setting instruction to the PD circuit 84 to end power supply to the external device 100 (S23). The CPU 30 outputs an OFF signal to the power supply DCDC 81 (S24). In response to acquiring the OFF signal from the CPU 30, the power supply DCDC 81 stops power supply to the external device 100.

[0061] The CPU 30 starts processing to turn off the power to the main unit 72 of the printer 1 (S25). In this embodiment, if the CPU 30 receives an OFF instruction to turn off the power during printing processing (S22: YES), it executes power OFF processing (S25) to turn off the power to the printer 1 after the printing processing is completed (S22: NO).

[0062] In response to receiving the sink setting instruction, the PD circuit 84 negotiates again with the external device 100 (S26) and sets the role of the printer 1 to sink (S27). By processing S27, the printer 1 ends power supply from the power supply DCDC 81 to the external device 100. The CPU 30 then ends the power supply end processing.

[0063] If the power button is not pressed (S21: NO), the CPU 30 determines whether the AC adapter 101 has been removed from state G4 in FIG. 6 (S31). If the AC adapter 101 has been removed (S31: YES), the CPU 30 determines whether a print process is being executed (S32). If a print process is being executed (S32: YES), the CPU 30 waits in S32 until the print process is completed.

[0064] If a print process is not being executed (S32: NO), the CPU 30 outputs a sink setting instruction to the PD circuit 84 (S33). In this embodiment, if the power supply state satisfies the condition for outputting a sink setting instruction during print process execution (S31: YES), and after the print process is completed (S31: NO), the CPU 30 outputs the sink setting instruction to the PD circuit 84 and stops power supply to the external device 100 (S33). After waiting for 1 second (S34), the CPU 30 outputs an OFF signal to the power supply DCDC 81 (S35). In response to receiving the OFF signal from the CPU 30, the power supply DCDC 81 stops power supply to the external device 100.

[0065] In response to receiving the sink setting instruction, the PD circuit 84 negotiates again with the external device 100 (S36) and sets the role of the printer 1 to sink (S37), as shown in state G3. By the processing of S37, the printer 1 stops power supply from the power supply DCDC 81 to the external device 100.

[0066] If the AC adapter 101 has not been removed (S31: NO), the CPU 30 determines whether the external device 100 has been removed from the USB connector 82 (S41). If the external device 100 has not been removed from the USB connector 82 (S41: NO), the CPU 30 returns the process to S21. If the external device 100 has been removed from the USB connector 82 (S41: YES), the CPU 30 outputs an OFF signal to the power supply DCDC 81 (S42). This returns the role of the printer 1 to the initial value of sink, as shown in state G2. Following S37 or S42, the CPU 30 activates the power supply start control process, and then ends the power supply end control process.

[0067] In the above embodiment, the printer 1, CPU 30, transport unit 5, print head 6, USB connector 82, PD circuit 84, external device 100, and wireless communication IF 17 are each an example of the printer, processor, transport unit 5, print head 6, USB connector, PD circuit, external device, and wireless communication interface of the present invention. The process of S10 is an example of the power supply start process of the present invention. The process of S52 is an example of the printing process of the present invention. The process of S54 is an example of the disconnection process of the present invention. The processes of S23 and S33 are each an example of the power supply end process of the present invention. The process of S25 is an example of the power OFF process of the present invention. The process of S51 is an example of the reception process of the present invention.

[0068] The printer 1 of the above embodiment includes a USB connector 82 to which an external device 100 is connected, a PD circuit 84 configured to execute negotiation in accordance with the USB-PD standard with the external device 100 connected to the USB connector 82, and a CPU 30. The CPU 30 outputs a source setting instruction to the PD circuit 84 to switch the role of the printer 1 relative to the external device 100 from sink to source depending on the state of the power supply, and executes a power supply start process to start supplying power to the external device 100 (S10). Under the USB-PD standard, when the role of the printer 1 relative to the external device 100 is sink, the printer 1 does not supply power to the external device 100. The power supply start process executed by the CPU 30 of the printer 1 supplies power to the external device 100 by outputting a source setting instruction when the power state becomes the intended state (for example, when the AC adapter 101 is connected to the printer 1), but by setting the role of the printer 1 to sink in an unintended power state (for example, when the AC adapter 101 is not connected to the printer 1), this contributes to more reliably preventing power supply to the external device 100 from starting in an unintended power state than in the past.

[0069] If the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition (S5: YES) during the power supply start process, the CPU 30 outputs a source setting instruction to the PD circuit 84 to start supplying power to the external device 100 (S10). The power supply start process executed by the CPU 30 of the printer 1 outputs a source setting instruction depending on the connection state between the printer 1 and the AC adapter 101, thereby contributing to more reliably preventing power supply to the external device 100 from being started when the connection state between the printer 1 and the AC adapter 101 is not intended, compared to conventional methods.

[0070] When the AC adapter 101 is connected to the printer 1 while the external device 100 is connected to the printer 1 via the USB connector 82 (S5: YES after S5: NO), the CPU 30 performs a power supply start process (S10), assuming that the source setting condition is met. When the AC adapter 101 is connected to the printer 1 while the external device 100 is connected to the printer 1 via the USB connector 82, this means that the printer 1 can stably supply power to the external device 100 using the AC adapter 101 as a power source. The power supply start process executed by the CPU 30 of the printer 1 automatically switches the role of the printer 1 with respect to the external device 100 from sink to source when stable power supply from the printer 1 to the external device 100 is possible, thereby contributing to starting power supply to the external device 100.

[0071] When the external device 100 is connected to the printer 1 via the USB connector 82 while the AC adapter 101 is connected to the printer 1 (S5: YES without passing through S5: NO), the CPU 30 performs a power supply start process (S10), assuming that the source setting condition is met. When the external device 100 is connected to the printer 1 via the USB connector 82 while the AC adapter 101 is connected to the printer 1, this means that stable power supply from the printer 1 to the external device 100 is possible using the AC adapter 101 as a power source. The power supply start process executed by the CPU 30 of the printer 1 automatically switches the role of the printer 1 with respect to the external device 100 from sink to source when stable power supply from the printer 1 to the external device 100 is possible, thereby contributing to starting power supply to the external device 100.

[0072] The printer 1 includes a print head 6 and a transport unit 5 that transports the medium P. The CPU 30 drives the print head 6 and the transport unit 5 to execute a print process that prints on the medium P (S52). If the power supply start timing is set by the first start condition, during the power supply start process, if the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition (S5: YES, S6: NO), and after the print process is completed (S6: YES), the CPU 30 outputs a source setting instruction to the PD circuit 84 to start power supply to the external device 100 (S10). If power supply is started during the print process, the power supplied to the print head 6 may become temporarily unstable, potentially resulting in a deterioration in print quality. The power supply start process executed by the CPU 30 of the printer 1 helps prevent deterioration in print quality due to the start of power supply to the external device 100 during the print process.

[0073] The printer 1 includes a print head 6. When the power supply start timing is set by the fifth start condition, if the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition during the power supply start process, the CPU 30 outputs a source setting instruction to the PD circuit 84 to start power supply to the external device 100 (S10) after the print head 6 has finished driving (S6: YES). If power supply is started while the print head 6 is driving, the power supplied to the print head 6 may become temporarily unstable, potentially resulting in a deterioration in print quality. The power supply start process executed by the CPU 30 of the printer 1 helps to prevent deterioration in print quality caused by starting power supply to the external device 100 while the print head 6 is driving.

[0074] The printer 1 includes a transport unit 5 that transports a medium P. When the power supply start timing is set by the sixth start condition, if the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition during the power supply start process while the transport unit 5 is in operation (S5: YES, S6: NO), the CPU 30 outputs a source setting instruction to the PD circuit 84 to start supplying power to the external device 100 after the transport unit 5 has finished operating (S6: YES) (S10). If power supply is started while the transport unit 5 is in operation, the power supplied to the transport unit 5 may become temporarily unstable, potentially resulting in a deterioration in transport accuracy. The power supply start process executed by the CPU 30 of the printer 1 starts supplying power to the external device 100 after the transport unit 5 has finished operating if the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition during the transport unit 5 in operation. This contributes to preventing a deterioration in transport accuracy due to the start of power supply to the external device 100.

[0075] The printer 1 is equipped with a cutting blade 54 that cuts the medium P. After the printing process (S52), the CPU 30 executes a cutting process in which the cutting blade 54 is driven to cut the medium P while the transport unit 5 is stopped (S54). When the power supply start timing is set by the second start condition, if the connection state between the printer 1 and the AC adapter 101 during the printing process satisfies the source setting condition (S5: YES, S6: NO), the CPU 30 outputs a source setting instruction to the PD circuit 84 to start power supply to the external device 100 after the printing process has ended and when the cutting process is being executed (S6: YES) (S10). The power supply start process executed by the CPU 30 of the printer 1 starts power supply to the external device 100 after the printing process has ended and when the cutting process is being executed if the connection state between the printer 1 and the AC adapter 101 during the printing process satisfies the source setting condition. Therefore, the power supply start process contributes to starting power supply to the external device 100 without degrading the print quality and transport quality.

[0076] When the power supply start timing is set by the third start condition, if the connection state between the printer 1 and the AC adapter 101 satisfies the source setting condition during the power supply start process (S5: YES, S6: NO), the CPU 30 outputs a source setting instruction to the PD circuit 84 to start power supply to the external device 100 (S10) between print jobs after the print process ends and before the next print process is executed (S6: NO). The power supply start process executed by the CPU 30 of the printer 1 starts power supply to the external device 100 between print jobs, which helps to prevent the power supply start process from interfering with the print process.

[0077] The printer 1 includes a wireless communication IF 17. The CPU 30 executes a reception process to receive a print instruction that instructs execution of a print process via the wireless communication IF 17 (S51). When the power supply start timing is set by the fourth start condition, if the connection state between the printer 1 and the AC adapter 101 during execution of the print process satisfies the source setting condition (S5: YES, S6: NO), the CPU 30 outputs a source setting instruction to the PD circuit 84 to start power supply to the external device 100 (S10) after the print process based on the print instruction received via the wireless communication IF 17 is completed and between print jobs until the next print instruction is received via the wireless communication IF 17 (S6: YES). The power supply start process executed by the CPU 30 of the printer 1 starts power supply to the external device 100 between print jobs, thereby contributing to preventing the power supply start process from interfering with the print process.

[0078] The CPU 30 outputs a sink setting instruction to the PD circuit 84 to switch the role between the printer 1 and the external device 100 from source to sink depending on the state of the power supply, and causes the PD circuit 84 to execute a power supply termination process to terminate power supply to the external device 100 (S23 or S33). The power supply termination process executed by the CPU 30 of the printer 1 contributes to automatically terminating power supply to the external device 100 depending on the state of the power supply.

[0079] If an OFF instruction to turn the power off is acquired as the power supply state during the power supply termination process (S21: YES), the CPU 30 outputs a sink setting instruction to the PD circuit 84 to terminate power supply to the external device 100 (S23). The power supply termination process executed by the CPU 30 of the printer 1 contributes to automatically terminating power supply to the external device 100 when an OFF instruction is acquired.

[0080] In the power supply termination process, if the power supply state indicates that the AC adapter 101 is disconnected from the printer 1 (S31: YES), the CPU 30 outputs a sink setting instruction to the PD circuit 84 to terminate power supply to the external device 100 (S33). If the AC adapter 101 is disconnected from the printer 1 while the printer 1 is supplying power to the external device 100 while the AC adapter 101 is connected to the printer 1, the power supplied to the printer 1 becomes temporarily unstable. The power supply termination process executed by the CPU 30 of the printer 1 contributes to preventing the power supplied to the printer 1 from becoming temporarily unstable by automatically ending the power supply to the external device 100 when the AC adapter 101 is disconnected from the printer 1.

[0081] The printer 1 includes a print head 6 and a transport unit 5 that transports the medium P. The CPU 30 drives the print head 6 and the transport unit 5 to execute a print process that prints on the medium P (S52). If the power supply status satisfies the condition for outputting a sink setting instruction during the print process, the CPU 30 outputs a sink setting instruction to the PD circuit 84 and terminates power supply to the external device 100 (S23 or S33) after the print process is completed (S22: YES or S32: YES). If the power supply status satisfies the condition for outputting a sink setting instruction during the print process, the power supplied to the printer 1 becomes temporarily unstable. The power supply termination process executed by the CPU 30 of the printer 1 contributes to preventing temporary instability of the power supplied to the printer 1 during the print process by automatically terminating power supply to the external device 100 after the print process is completed if the power supply status satisfies the condition for outputting a sink setting instruction during the print process.

[0082] The printer 1 includes a print head 6 and a transport unit 5 that transports the medium P. The CPU 30 drives the print head 6 and the transport unit 5 to execute a print process that prints on the medium P (S52). If the CPU 30 receives an OFF instruction to turn the power OFF during the print process, it executes a power OFF process that turns the printer 1 OFF after the print process is completed (S25). The power OFF process executed by the CPU 30 of the printer 1 helps to avoid turning the power OFF while the print process is being executed.

[0083] The PD circuit 84 sets the initial role of the printer 1 to sink in negotiation with the external device 100. The PD circuit 84 of the printer 1 helps to prevent power supply to the external device 100 from starting in an unintended power state.

[0084] The present invention can be implemented in various forms, and may be realized in the form of, for example, a printing program executed by a processor of a printer, a non-transitory computer-readable medium storing a printing program, or a printer control method.

[0085] (A) The configuration of the printer 1 may be changed as appropriate. The printer 1 may or may not include a cutter unit 50 that cuts the medium P. The cutter unit 50 may be permanently attached to the printer 1. The type of printer 1 may be changed as appropriate, and may be an inkjet printer or a label printer. The location of the transport unit 5 may be changed as appropriate depending on the configuration of the print head 6, and it does not have to be located opposite the print head 6. The transport unit 5 may be a transport roller or a transport belt. There may be multiple transport units 5. The medium P may be changed as appropriate, and may be, for example, tape that is not wound into a roll, or fanfold paper. The number of USB connectors 82 may be two or more.

[0086] (B) A program including commands for executing the print control process, power supply start control process, and power supply end control process may be stored in a storage device of the printer 1 before the CPU 30 executes the program. Therefore, the program acquisition method, acquisition path, and device that stores the program may each be changed as appropriate. The program executed by the CPU 30 may be received from another device via a cable or wireless communication and stored in the storage device. The other device may include, for example, a PC or a server connected via a network.

[0087] (C) The steps of the print control process, power supply start control process, and power supply end control process are not limited to being executed by the CPU 30, and some or all of them may be executed by other electronic devices (for example, ASIC). The steps of the print control process, power supply start control process, and power supply end control process may be distributed and processed by multiple electronic devices (for example, multiple CPUs). In other words, the processor of the printer 1 may be multiple electronic devices. The order of the steps of the print control process, power supply start control process, and power supply end control process may be changed, steps may be omitted, or steps may be added, as necessary. The following modifications may be made to the print control process, power supply start control process, and power supply end control process as appropriate.

[0088] The source setting conditions may be changed as appropriate. If the printer 1 is equipped with a removably mounted power supply battery for supplying power to the external device 100, the source setting conditions may be determined to be satisfied when the power supply battery is mounted and has stored enough power to supply power.

[0089] The conditions for setting the power supply start timing may be changed as appropriate and are not limited to the first to sixth start conditions. For example, the printer 1 may obtain remaining battery information for the external device 100 and determine whether to prioritize power supply to the external device 100 based on the remaining battery power. The conditions for setting the power supply start timing may be selectable by the user from among multiple candidates. The CPU 30 may omit the processing of S6, and if the source setting conditions are met (S5: YES), output a source setting instruction to the PD circuit 84 to start power supply to the external device 100 (S10).

[0090] The process in which the CPU 30 outputs a sink setting instruction to the PD circuit 84 to switch the role between the printer 1 and the external device 100 from source to sink depending on the power supply state may be modified or omitted as appropriate. The conditions under which the power supply state outputs a sink setting instruction may be modified as appropriate. The sink setting instruction may be output in response to an instruction from the user input via the input unit 25. For example, even if the process of S23 is omitted, when power supply from the power supply DCDC 81 to the external device 100 is stopped in the process of S24, renegotiation is started in S26, and the role of the printer 1 is returned to the initial value of sink in S27. Similarly, even if the process of S33 is omitted, when power supply from the power supply DCDC 81 to the external device 100 is stopped in the process of S35, renegotiation is started in S36, and the role of the printer 1 is returned to the initial value of sink in S37.

[0091] The initial role value of the printer 1 may be set by the user. The initial role value of the printer 1 may be source. In this case, for example, the role may be set to source once in negotiation when the external device 100 is connected, and then automatically reset to sink at a predetermined timing. The predetermined timing may be, for example, a timing after a predetermined time has elapsed since the role was set to source. The predetermined timing may be, for example, a timing when an instruction from the user is obtained under the condition that the external device 100 is not connected to the USB connector 82 of the printer 1. [Explanation of symbols]

[0092] 1: Printer, 5: Conveyor, 6: Print head, 17: Wireless communication IF, 30: CPU, 82: USB connector, 84: PD circuit, 100: External device, P: Media

Claims

1. 1. A printer comprising: a USB connector for connecting an external device; a PD circuit configured to execute negotiation in accordance with the USB-PD standard with the external device connected to the USB connector; Processor and Equipped with The processor: A power supply start process in which a source setting instruction for switching the role of the printer with respect to the external device from sink to source is output to the PD circuit according to the state of the power supply, and power supply to the external device is started. A printer characterized by performing the above.

2. The processor:

2. The printer according to claim 1, wherein, in the power supply start process, if the connection state between the printer and the AC adapter satisfies a source setting condition, the source setting instruction is output to the PD circuit to start power supply to the external device.

3. The processor:

3. The printer according to claim 2, wherein when the AC adapter is connected to the printer while the external device is connected to the printer via the USB connector, the power supply start process is performed as a case where the source setting condition is satisfied.

4. The processor:

3. The printer according to claim 2, wherein when the AC adapter is connected to the printer and the external device is connected to the printer via the USB connector, the power supply start process is performed as a case where the source setting condition is satisfied.

5. A print head; a conveying unit that conveys the medium; Further provided with The processor: further executing a printing process for printing on the medium by driving the print head and the transport unit; 3. The printer according to claim 2, wherein, in the power supply start process, if the connection state between the printer and the AC adapter satisfies the source setting condition while the printing process is being executed, the source setting instruction is output to the PD circuit after the printing process is completed, thereby starting power supply to the external device.

6. Further comprising a print head, The processor:

3. The printer according to claim 2, wherein, in the power supply start process, if the connection state between the printer and the AC adapter satisfies the source setting condition while the print head is being driven, the source setting instruction is output to the PD circuit after driving of the print head has finished, thereby starting power supply to the external device.

7. Further comprising a transport unit that transports the medium, The processor:

3. The printer according to claim 2, wherein, in the power supply start process, if the connection state between the printer and the AC adapter satisfies the source setting condition while the transport unit is being driven, the source setting instruction is output to the PD circuit after the drive of the transport unit has ended, thereby starting power supply to the external device.

8. Further, a cutting blade for cutting the medium is provided. The processor: After the printing process, a cutting process is further performed in which the cutting blade is driven to cut the medium while the conveying unit is stopped; 6. The printer according to claim 5, wherein, in the power supply start process, if the connection state between the printer and the AC adapter satisfies the source setting condition while the printing process is being executed, after the printing process is completed and when the disconnection process is being executed, the source setting instruction is output to the PD circuit to start power supply to the external device.

9. The processor:

6. The printer according to claim 5, wherein, in the power supply start process, if the connection state between the printer and the AC adapter satisfies the source setting condition while the printing process is being executed, the source setting instruction is output to the PD circuit to start power supply to the external device during a print job between the end of the printing process and before the next printing process is executed.

10. further comprising a wireless communication interface; The processor: further executing a receiving process for receiving a print instruction for instructing execution of the print process via the wireless communication interface; 6. The printer according to claim 5, wherein, in the power supply start process, if the connection state between the printer and the AC adapter satisfies the source setting condition while the printing process is being executed, after the printing process based on the print instruction accepted via the wireless communication interface is completed and between print jobs until the next print instruction is accepted via the wireless communication interface, the printer outputs the source setting instruction to the PD circuit to start power supply to the external device.

11. The processor:

2. The printer according to claim 1, further comprising: a power supply termination process that outputs a sink setting instruction to the PD circuit to switch the role between the printer and the external device from the source to the sink according to the state of the power supply, and terminates power supply to the external device.

12. The processor:

12. The printer according to claim 11, wherein, in the power supply termination process, when an OFF instruction to turn off the power supply is acquired as the state of the power supply, the sink setting instruction is output to the PD circuit, thereby terminating power supply to the external device.

13. The processor:

12. The printer according to claim 11, wherein, in the power supply termination process, when the power supply state is such that the AC adapter is disconnected from the printer, the sink setting instruction is output to the PD circuit, and power supply to the external device is terminated.

14. A print head; a conveying unit that conveys the medium; Further provided with The processor: further executing a printing process for printing on the medium by driving the print head and the transport unit; 12. The printer according to claim 11, wherein, in the power supply termination process, if the state of the power supply satisfies the condition for outputting the sink setting instruction while the printing process is being executed, the sink setting instruction is output to the PD circuit after the printing process is completed, thereby terminating the power supply to the external device.

15. A print head; a conveying unit that conveys the medium; Further provided with The processor: further executing a printing process for printing on the medium by driving the print head and the transport unit; The printer according to claim 11, wherein, if an OFF instruction to turn off the power supply is received during the printing process, a power OFF process to turn off the power supply of the printer is further executed after the printing process is completed.

16. 2. The printer according to claim 1, wherein the PD circuit sets the initial value of the role of the printer to the sink during the negotiation with the external device.

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