Printing apparatus, control method, storage medium, and computer program product

Abstract

The invention relates to a printing apparatus, a control method, a storage medium, and a computer program product. A printing apparatus configured to perform printing on a printing medium by using a printing unit includes: a power storage unit capable of storing power fed from an external power supply connected via a USB cable; a measurement unit capable of measuring time based on the power from the power storage unit; a control unit configured to execute a predetermined process based on a measurement result of the measurement unit; and a limiting unit capable of limiting the power fed from the power storage unit. In a period in which power feeding from the external power source is stopped, the limiting unit limits power feeding to at least units other than the measuring unit in accordance with a stored power amount of the power storage unit, and the measuring unit continues measuring.

Description

Technical Field

[0001] The present invention relates to a printing device, a control method, a storage medium, and a computer program product. Background Art

[0002] Japanese Patent Application Laid-Open No. 2017-205945 discloses an inkjet printing device that operates by using power from an external power source connected via a USB cable or the like, and can charge an auxiliary power source by using the external power source and also use the power of the auxiliary power source during operation.

[0003] In the printing device as described above, capping is performed on a print head in which nozzles for ejecting ink are formed. During the capping process, the surface on which the nozzles are formed is covered with a cap and protected to suppress the ink in the nozzles from drying out. It should be noted that even in the capped state, the ink in the nozzles gradually dries out, and the inkjet performance in the nozzles may deteriorate. Therefore, in the printing device as described above, after a certain period of time, a maintenance operation for maintaining and restoring the inkjet performance in the nozzles to the optimal state is performed.

[0004] Therefore, the printing device is provided with a timer for measuring the time elapsed since the completion of the most recent maintenance operation. The power from the external power source is used as the power for driving the timer. In addition, a dedicated battery for the timer is also provided to supply power to the timer in the case where the USB cable is unplugged and the power supply from the external power source is stopped. This increases the production cost of the printing device. Summary of the Invention

[0005] The present invention is proposed in view of the above problems, and provides a technique capable of supplying power to a timer after stopping the power supply from an external power source while suppressing an increase in cost.

[0006] The present invention provides a printing device configured to perform printing on a print medium by using a printing unit, the printing device including: a power storage unit capable of storing power fed from an external power source connected via a USB cable; a measurement unit capable of measuring time based on the power from the power storage unit; a control unit configured to perform a predetermined process based on a measurement result of the measurement unit; and a restriction unit capable of restricting the power fed from the power storage unit, wherein, during a period when the power supply from the external power source is stopped, the restriction unit restricts the power supply to units other than at least the measurement unit according to the stored power amount of the power storage unit, and the measurement unit continues to measure.

[0007] According to the present invention, it is possible to feed power to the timer after stopping the power feed from the external power supply while suppressing an increase in cost.

[0008] Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a block diagram illustrating the configuration of a power feed system of a printing apparatus;

[0010] Figure 2 is a block diagram illustrating the functional configuration of a timer;

[0011] Figure 3 is a schematic configuration diagram of a printing mechanism in a printing apparatus;

[0012] Figures 4A to 4E is a diagram illustrating the power feed state of the configuration of the power feed system in various states;

[0013] Figure 5 is a diagram illustrating the change in the stored electric charge of an EDLC over time;

[0014] Figure 6 is a flowchart illustrating the processing content of a measurement process;

[0015] Figure 7 is a flowchart illustrating the processing content of a determination process;

[0016] Figure 8 is a diagram illustrating the setting content executable by a user; and

[0017] Figure 9 is a diagram of the change in the stored electric charge of an EDLC over time in each setting. DETAILED DESCRIPTION

[0018] Exemplary embodiments of a printing apparatus, a control method, a storage medium, and a computer program product will be described below with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the present invention, and not all combinations of features described in these embodiments are essential for the solution of the present invention. In addition, the positions, shapes, etc. of the constituent elements described in the embodiments are merely examples and are not intended to limit the present invention to these positions, shapes, etc.

[0019] (First Embodiment)

[0020] First, with reference to Figures 1 to 7A printing apparatus according to a first embodiment will be described. The printing apparatus according to the present embodiment includes a universal serial bus (USB) connector into which a USB cable can be inserted and removed therefrom, and is configured to be connectable to various devices. By inserting a USB cable connected to an external device such as a PC terminal, a mobile terminal, a mobile battery, or an external power adapter into the USB connector, the external device and the printing apparatus can be connected to each other. In addition, the printing apparatus is configured to operate using power fed from an external device connected to the USB cable as described above. In the present specification, an external device that feeds power to the printing apparatus via the USB cable is referred to as an external power source. As described above, in the present embodiment, the USB connector serves as a connection portion that can be connected to an external power source via the USB cable.

[0021] <Configuration of the power feeding system of the printing apparatus>

[0022] Figure 1 FIG. is a block diagram illustrating the configuration of the power feeding system of the printing apparatus according to the present embodiment. The printing apparatus 10 according to the present embodiment includes an electric double layer capacitor (EDLC) 12 that can be charged and feed power, and a charger 14 configured to control the fed power. In addition, the printing apparatus 10 includes a DC-DC1 (boost) 16 and a DC-DC2 (buck) 18. The DC-DC1 (boost) 16 is a boost circuit configured to boost the power supply voltage fed from the charger 14, and the DC-DC2 (buck) 18 is a buck circuit configured to step down the voltage output from the DC-DC1 16. In addition, the printing apparatus 10 includes a motor driver 20 and a head driver 22. The motor driver 20 is configured to drive various motors to operate various configurations of the printing mechanism (to be described later), and the head driver 22 is configured to drive a print head 304 (to be described later). In addition, the printing apparatus 10 includes a power key 34 that can be operated by a user in an operation unit (not shown) and a timer 36 configured to measure time. It should be noted that in the printing apparatus 10, the operation unit including the power key 34 may include parts such as a display unit (not shown) capable of displaying various types of information, a speaker (not shown) capable of outputting voice guidance, a warning sound, and the like.

[0023] In the printing apparatus 10, the power supply voltage VBUS fed from an external power supply via the USB connector 24 connected by a USB cable and the power supply voltage VBAT fed from the EDLC 12 as an auxiliary power supply are fed to the charger 14. In the charger 14, the power supply voltage VSYS and the power supply voltage VACC are generated based on the power supply voltages VBUS and VBAT, and the generated power supply voltages VSYS and VACC are output. The charger 14 is a unit having functions of performing power control, EDLC discharge control, charging control, remaining battery level management, and abnormal operation protection. Further, the charger 14 is connected to the main ASIC 28 via a control serial bus.

[0024] The printing apparatus 10 is configured to be driven by the power supply voltage VSYS generated in the charger 14, and the charger 14 performs power control on the printing apparatus 10. The power supply voltage VSYS output from the charger 14 is fed to the DC-DC1 16 via the VSYS_SW 26. The VSYS_SW 26 can be controlled by the main ASIC 28 described later, and controls the feeding of the power supply voltage VSYS to the DC-DC1 16.

[0025] The power supply voltage VSYS output from the VSYS_SW 26 is boosted to a predetermined voltage value (24V in this embodiment) in the DC-DC1 16, fed from the DC-DC1 16 to the motor driver 20, and used to drive various motors. Further, the boosted power supply voltage VSYS is fed from the DC-DC1 16 to the head driver 22 and used to drive the print head 304. Further, the boosted power supply voltage VSYS is fed from the DC-DC1 16 to the DC-DC2 18, and is stepped down to a plurality of voltage values in the DC-DC 18. In this embodiment, 3.3V, 1.8V, and 1.1V voltages are generated in the DC-DC2 18, and the generated 3.3V, 1.8V, and 1.1V voltages are fed to corresponding configurations, specifically, the main ASIC 28, the DDR memory 30, and the flash ROM 32, respectively.

[0026] The main ASIC 28 controls the operation of the entire printing apparatus. The main ASIC 28 is activated by receiving power feeding, and starts operating based on a program stored in the flash ROM 32. The main ASIC 28 that has started operating can receive inputs from the power key 34 and an operation unit (not shown), and can perform various operations in the printing apparatus 10 based on operations from the user. As described above, in this embodiment, the main ASIC 28 is configured to function as a control unit that controls the printing apparatus.

[0027] The main ASIC 28 can obtain the remaining power information related to the power stored in the EDLC 12 (specifically, the stored power, also simply referred to as "remaining power" hereinafter) via the charger 14. In addition, the main ASIC 28 is connected to the timer 36 and can obtain the time measured by the timer 36. In addition, the main ASIC 28 outputs a control command to the timer 36 and controls various operations such as the start and stop of operations and the initialization (reset) of measured values using the output control command. The timer 36 is connected to the charger 14 and is directly fed the power supply voltage VACC from the charger 14. As described above, in this embodiment, the timer 36 functions as a measurement unit that measures time.

[0028] The EDLC 12 is a storage battery and discharges in response to an instruction from the charger 14 according to the load of the printing device 10. For example, in the printing operation of the printing device 10, when the charger 14 determines that the power supply voltage VBUS from the USB connector 24 is insufficient and the printing operation cannot be performed, the power supply voltage VBAT of the EDLC 12 is used to perform the printing operation. The charging control is executed based on an instruction output from the main ASIC 28 to the charger 14 via the control serial bus. In this embodiment, the EDLC 12 functions as a power storage unit that can store the power fed from an external power supply and can feed the stored power.

[0029] <Function configuration of the timer>

[0030] Next, the function configuration of the timer 36 will be described. Figure 2 It is a block diagram showing the function configuration of the timer 36.

[0031] The timer 36 operates by receiving the power supply voltage VACC from the charger 14. The timer 36 includes a pulse oscillator 202 configured to periodically output pulses and a pulse counter 204 configured to count the number of pulses output from the pulse oscillator 202. In addition, the timer 36 includes a logic unit 206 configured to calculate the elapsed time based on the count value in the pulse counter 204, and an I / F unit 208 capable of outputting the calculation result in the logic unit 206 to the main ASIC 28.

[0032] The logic unit 206 can have a form in which time and date are used as the time count or a form in which the pulse count value itself is used as the time count, and can have any form as long as the logic unit 206 can measure time. In addition, the I / F unit 208 receives a control command output from the main ASIC 28. In the timer 36, based on these control commands, control is performed over the oscillation state of the pulse oscillator 202 that controls the start and stop of the operation of the timer 36 and the reset of the count value of the pulse counter 204. It should be noted that in this embodiment, when the count value of the pulse counter 204 is reset, the measured value of the logic unit 206 is also reset. In a state where the power supply voltage VACC is fed from the charger 14, the timer 36 continues to operate after receiving a control command for starting the operation until the timer 36 receives a control command for stopping the operation.

[0033] <Configuration related to the printing mechanism of the printing device>

[0034] Next, the configuration related to the printing mechanism in the printing device 10 will be described. Figure 3 It is a schematic configuration diagram of the printing mechanism in the printing device 10.

[0035] The printing device 10 includes a conveyance unit 302 and a print head 304. The conveyance unit 302 is configured to convey the print medium M in the Y direction, and the print head 304 is configured to perform printing on the print medium M conveyed by the conveyance unit 302 by ejecting ink onto the print medium M. In addition, the printing device 10 includes a carriage 306 in which the print head 304 is mounted and the carriage 306 is movable in a direction (X direction) intersecting (orthogonal in this embodiment) the conveyance direction (Y direction) of the print medium M conveyed by the conveyance unit 302. In addition, the printing device 10 includes a maintenance unit 308 that can perform a maintenance operation for maintaining and restoring the inkjet performance at the nozzles configured to eject ink in the print head 304 to an optimal state.

[0036] The print head 304 is configured to be able to eject multiple types of inks that are different from each other. A plurality of nozzles for ejecting each ink are arranged side by side in a direction intersecting the X direction to form a nozzle array. In this embodiment, the print head 304 is configured to be able to eject four types of inks: black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. It should be noted that the number and types of inks ejected from the print head 304 are not limited to the above.

[0037] The carriage 306 is slidably disposed on a guide shaft 310 extending in the X direction and is connected to a carriage motor 314 via a belt 312. Accordingly, the carriage 306 can reciprocate in the X direction by driving of the carriage motor 314. Therefore, the print head 304 mounted in the carriage 306 is configured to be movable in the X direction from one side to the other side and from the other side to one side via the carriage 306. In a printing operation, while causing the carriage 306 to scan in the X direction, drive pulses are applied to the print head 304 to eject ink from the print head 304 onto a print medium M, thereby performing printing for one scan operation on a print surface Mp of the print medium M.

[0038] The conveyance unit 302 includes a conveyance roller 318 and a conveyance motor 320. The conveyance roller 318 is configured to convey the print medium M, and the conveyance motor 320 is configured to drive the conveyance roller 318. It should be noted that although the conveyance roller 318 and the print medium M are shown separated from each other in the Z direction for ease of understanding in Figure 3 , actually the print medium M abuts against the conveyance roller 318 in the Z direction. The conveyance unit 302 drives the conveyance motor 320 to convey the print medium M in the Y direction using the conveyance roller 318.

[0039] During the process of printing on the print medium M based on a job, a printing operation is performed on the print medium M conveyed to a print start position by the conveyance unit 302. The printing operation performs printing for one scan operation by ejecting ink from the print head 304. Thereafter, the conveyance unit 302 performs a conveyance operation of conveying the print medium M by a predetermined amount, and then performs the printing operation again. As described above, the printing apparatus 10 performs printing on the print medium M based on a job by repeatedly and alternately performing the printing operation for one scan operation and the conveyance operation of a predetermined amount.

[0040] The maintenance unit 308 is disposed in a moving area of the carriage 306 and outside a printing area of the print medium M in the X direction through the print head 304. The maintenance unit 308 includes a cover portion 322 configured to abut against (seal) the print head 304 to protect a nozzle surface 304a of the print head 304. Although detailed description and illustration are omitted, the maintenance unit 308 includes various well-known maintenance components such as a suction unit configured to set the inside of the cover portion 322 to a negative pressure and a wiping unit configured to wipe the nozzle surface 304a. The nozzle surface 304a is a surface of the print head 304 facing the print surface Mp of the conveyed print medium M and is a surface on which nozzles for ejecting ink are formed.

[0041] During the sealing process of the cover portion 322, the print head 304 is moved to a position where the nozzle surface 304a faces the cover portion 322 of the maintenance unit 308 (a standby position described later) (see Figure 3the dotted line part in (), and then lift the cover portion 322. In this embodiment, the print head 304 stands by at a standby position where the nozzle surface 304a faces the cover portion 322 at a timing such as when no printing operation is performed. Capping after the completion of printing based on a job can protect the nozzle surface 304a and suppress the evaporation of the liquid component of the ink from the nozzle and the thickening of the ink in the nozzle due to evaporation.

[0042] It should be noted that even with such capping, when a long time has passed in the capped state, the liquid component of the ink will evaporate from the nozzle and the like, and the ejection performance of the ink from the nozzle will deteriorate. In addition, the ambient temperature, heat generation in the constituent components of the printing apparatus 10, etc. will also cause evaporation to occur during the printing operation. Therefore, in the maintenance unit 308, for example, maintenance operations for maintaining and restoring the ejection characteristics to an optimal state are performed at the following predetermined timings: for example, in the preparation operation after job input and in the initialization process of predetermined constituent components such as the initialization process of the origin position of the print head 304. The maintenance operations include various well-known processes: for example, a suction discharge process in which the suction unit is driven in the capped state to set the inside of the cover portion 322 to a negative pressure and forcibly suck the ink from the nozzle, and a wiping process in which the wiping unit wipes the nozzle surface 304a. Although in this embodiment, the cover portion 322 is configured to be included in the maintenance unit 308, the present disclosure is not limited thereto. The cover portion 322 may be provided separately from the maintenance unit 308 including the suction unit, the wiping unit, etc.

[0043] <State of the configuration of the power feeding system>

[0044] In the printing apparatus 10, during the printing process based on a job, due to the ambient temperature where the printing apparatus 10 is installed, heat generation in the constituent members, etc., the liquid component of the ink in the nozzle evaporates in the nozzles where no ink is ejected. In addition, in the printing apparatus 10, when no printing based on a job is performed, the cover portion 322 caps the print head 304 located at the standby position. However, even in the capped state, the liquid component of the ink will evaporate in the nozzle, only at a slower rate than when the print head 304 is not capped.

[0045] Therefore, the printing apparatus 10 is configured to perform a maintenance operation at a predetermined timing such as at the moment of initializing the constituent components of the printing mechanism when the time elapsed since the most recent maintenance operation reaches or exceeds a predetermined time Tp. It should be noted that the printing apparatus 10 obtains the time elapsed since the most recent maintenance operation by using the timer 36. The timer 36 is driven by the power supply voltage VACC output from the charger 14.

[0046] As described above, the power supply voltage VBUS is fed from an external power supply connected to the printing apparatus 10 via a USB cable to the charger 14, and in the case where the USB cable is unplugged, for example, the power supply voltage VBAT is fed from the EDLC 12 serving as an auxiliary power supply to the charger 14. Therefore, in the case where the USB cable is unplugged and the stored power of the EDLC 12 reaches or falls below a certain amount, there is a possibility that the timer 36 cannot measure time because the power feed from the charger 14 stops, and the maintenance operation cannot be performed at an appropriate timing.

[0047] Therefore, in the present embodiment, according to the power-on or power-off of the printing apparatus 10, the connection or disconnection of the USB cable, and the stored power of the EDLC 12, the power feed to some components of the power feed system is restricted, thereby allowing the timer 36 to measure a time equal to or longer than a predetermined time Tp. It should be noted that the predetermined time Tp is, for example, the time from the most recent maintenance operation to the next maintenance operation, and is determined experimentally according to the type of ink and the like.

[0048] The power feed to each component of the power feed system according to the power-on or power-off of the printing apparatus 10, the connection or disconnection of the USB cable (i.e., whether there is power feed from an external power supply), and the stored power of the EDLC 12 will be described below. Figures 4A to 4E FIG. is a diagram showing the state of the power feed to each component of the power feed system according to the power-on or power-off of the printing apparatus 10, the connection or disconnection of the USB cable, and the stored power of the EDLC 12. It should be noted that in Figures 4A to 4E , in the case where the configuration is in a state of feeding power or a state where power can be fed (the "ON" state), the block diagram representing each configuration is shown as a hollow block, and in the case where the configuration is in a state of not feeding power or a state where power cannot be fed (the "OFF" state), the block diagram representing each configuration is shown as a block with an "×".

[0049] = First State =

[0050] As Figure 4A shown in, in the first state where the power of the printing apparatus 10 is on and the USB cable is connected, power is fed from an external power supply via the USB connector 24. Therefore, the charger 14 charges the EDLC 12, and in the case where the power load increases due to a printing operation or the like, power is also fed to the VSYS_SW 26 by receiving the power feed from the EDLC 12. Therefore, the components of the power feed system are fed with power and are in the "ON" state. In addition, since the power of the printing apparatus 10 is on, the main ASIC 28 is in an operating state, and various operations such as a printing operation can be performed.

[0051] In the first state, Timer 36 is powered by Charger 14 and can measure time, and Main ASIC 28 can obtain the measured value in Timer 36. In addition, in the first state, since power is fed to Main ASIC 28, the user can operate to turn off the power of the printing device 10 by the power key 34 connected to Main ASIC 10. It should be noted that when the power of the printing device 10 is turned on and the USB cable is disconnected, for example, it is prompted in the operation unit or the like to connect to an external power source using the USB cable, and the printing device 10 is connected to the external power source. Therefore, the same state as Figure 4A is achieved.

[0052] =Second State=

[0053] As Figure 4B shown, in the second state where the power of the printing device 10 is turned off and the USB cable is connected, power is fed from an external power source via USB connector 24. Charger 14 feeds power to VSYS_SW26 by receiving power feed from the external power source. Therefore, the components constituting the power feed system are fed with power and are in the "ON" state. In addition, since the power of the printing device 10 is turned off, Main ASIC 28 is in the standby state and in a waiting state with restricted operation. Therefore, in the second state, the power consumption is lower than that in the first state. Timer 36 is powered by Charger 14 and can measure time, and Main ASIC 28 can obtain the measured value in Timer 36. In the second state, since power is fed to Main ASIC 28, the user can operate to turn on the power of the printing device 10 by the power key 34.

[0054] =Third State=

[0055] As Figure 4C shown, in the following third state, the power stored in the EDLC 12 as an auxiliary power source is consumed: the power of the printing device 10 is turned off; the USB cable is disconnected; and the stored power of the EDLC 12 is equal to or greater than a predetermined amount Tm. In the third state, since the stored power of the EDLC 12 is equal to or greater than the predetermined amount Tm (which will be described later), Charger 14 receives the power feed from the EDLC 12 and feeds power to VSYS_SW 26. Therefore, the components constituting the power feed system are fed with power and are in the "ON" state. Since the power of the printing device 10 is turned off, Main ASIC 28 is in the standby state and in a waiting state with restricted operation.

[0056] In the third state, the timer 36 is powered by the charger 14 and can measure time, and the main ASIC 28 can obtain the measured value in the timer 36. In addition, in the third state, since power is fed to the main ASIC 28, the user can operate the power button 34 to turn on the power of the printing device 10. The main ASIC 28 detects the remaining power information (stored power) of the EDLC 12 via the charger 14. When the stored power of the EDLC 12 (i.e., the remaining power in the EDLC 12) decreases and is lower than a predetermined amount Tm, the printing device 10 switches to the fourth state.

[0057] = Fourth State =

[0058] As Figure 4D shown, in the following fourth state, the power stored in the EDLC 12 is consumed: the power of the printing device 10 is turned off; the USB cable is disconnected; and the stored power of the EDLC 12 is greater than or equal to "0" (or an amount corresponding to "0") and less than the predetermined amount Tm. It should be noted that "0" or an amount corresponding to "0" is the lower limit value at which the components of the power feeding system can operate. In the fourth state, since the stored power of the EDLC 12 has decreased and is lower than the predetermined amount Tm, the power feeding to components other than the timer 36 is restricted to prioritize the power feeding to the timer 36, and the power feeding is dedicated to the timer 36.

[0059] Specifically, the main ASIC 28 detects the remaining power information of the EDLC 12 via the communication line 402. When the main ASIC 28 determines that the stored power of the EDLC 12 is less than the predetermined amount Tm, the main ASIC 28 stops the power feeding of the VSYS_SW 26 via the control line 404. This control from the main ASIC 28 causes the VSYS_SW 26 to restrict the power feeding from the charger 14 to the DC-DC1 16. Therefore, the power feeding to the DC-DC2 18 and the main ASIC 28 stops, and the DC-DC1 16, DC-DC2 18, and the main ASIC 28 enter the "OFF" state where no power is fed. As described above, in this embodiment, the VSYS_SW 26 functions as a restricting unit that can restrict the power feeding to the main ASIC 28.

[0060] In the fourth state, since the main ASIC 28 is in the "OFF" state and cannot operate, the main ASIC 28 cannot receive the operation of the user via the power button 34, and the loaded program is also in a reset state. At the same time, the power feed from the charger 14 to the timer 36 continues, and the timer 36 can measure time. It should be noted that in the fourth state, since the main ASIC 28 cannot operate, the main ASIC 28 cannot obtain the measured value in the timer 36. As described above, in the fourth embodiment, the power feed to the DC-DC1 16, DC-DC2 18, and the main ASIC 28 is stopped, and the power consumption in the power feed system is suppressed to ensure the power to be fed to the timer 36. Therefore, the power can be ensured to be fed to the timer 36 for a long time.

[0061] = Fifth State =

[0062] As Figure 4E shown, in the following fifth state, the power feed to all components of the power feed system is stopped: the power of the printing device 10 is turned off; the USB cable is disconnected; and the stored power of the EDLC 12 is "0" (or an amount corresponding to "0"). The reduction of the stored power of the EDLC 12 causes the stored power to be lower than the stored power at which the charger 14 and the timer 36 can operate, and these configurations are also not fed with power and enter the "OFF" state. In the case where the timer 36 enters the "OFF" state, the timer 36 cannot continue time measurement, the count value of the pulse counter 204 is reset, and the calculation result in the logic unit 206 is initialized (reset) based on the reset of the count value. In other words, the measured values measured so far disappear.

[0063] = Main ASIC Transitions from "OFF" State to "ON" State =

[0064] Although illustrations are omitted, during the recovery process from the fourth state and the fifth state (i.e., when the main ASIC 28 transitions from the "OFF" state to the "ON" state), the printing apparatus 10 needs to be in a state where the USB cable is connected to the USB connector 24 and power is fed from an external power source. After connecting the USB cable to the USB connector 24, the power fed from the external power source is fed to the charger 14. Therefore, the charger 14 feeds power to the VSYS_SW 26 and the timer 36. In addition, power fed from the external power source is fed to the VSYS_SW 26 via the control line 406, thereby activating the VSYS_SW 26. The VSYS_SW 26 activated by the power feed from the control line 406 feeds the power fed from the charger 14 to the DC-DC1 16. Specifically, the restriction on the power feed from the charger 14 to the DC-DC1 16 by the VSYS_SW 26 is cancelled. Then, power is fed from the DC-DC1 16 to the main ASIC 28 via the DC-DC2 18. The DC-DC1 16, the DC-DC2 18, and the main ASIC 28 enter the "ON" state, and the timer 36 enters a state where time measurement can be performed.

[0065] <Change in the stored charge of the EDLC>

[0066] Next, the change in the stored charge of the EDLC 12 over time around the moment when the USB cable for connecting to the external power source is unplugged (i.e., around the moment when the power feed from the external power source stops) will be described. Figure 5 It is a graph showing the change in the stored charge of the EDLC 12 over time around the moment when the USB cable for connecting to the external power source is unplugged.

[0067] In the first state where the power of the printing apparatus 10 is turned on, the printing apparatus 10 can perform various operations including maintenance operations under the control of the main ASIC 28. Although it will be described in detail later, in this embodiment, when performing a maintenance operation, the measured value in the timer 36 is initialized and then time measurement is started again. In Figure 5 the point T1 represents the timing of performing the maintenance operation.

[0068] When the power of the printing apparatus 10 is turned off from the first state by operating the power button 34, the printing apparatus 10 transitions to the second state. In Figure 5Among them, the point T2 indicates the timing when the power supply of the printing device 10 is turned off. Then, when the USB cable is unplugged from the USB connector 24, the printing device 10 switches to the third state. Since the EDLC 12 is charged in the first state and the second state, at the moment when the USB cable is unplugged, sufficient power equal to or greater than the predetermined amount Tm is stored in the EDLC 12. In Figure 5 Among them, the point T3 indicates the timing when the USB cable is unplugged. In the third state, since power is fed to the components constituting the power feeding system, the power of the EDLC 12 is consumed, and the stored power of the EDLC 12 decreases over time.

[0069] The main ASIC 28 monitors the stored power of the EDLC 12, and when the stored power of the EDLC 12 is lower than the predetermined amount Tm, the printing device 10 switches to the fourth state. In Figure 5 Among them, the point T4 indicates the timing when the stored power of the EDLC 12 reaches the predetermined amount Tm. In the fourth state, VSYS_SW 26 stops feeding power to the DC-DC1 16, DC-DC2 18, and the main ASIC 28 for power feeding, and the DC-DC1 16, DC-DC2 18, and the main ASIC 28 are in the "OFF" state. Therefore, in the fourth state, the power consumption of the EDLC 12 is lower than that in the third state, and the stored power of the EDLC 12 slowly decreases.

[0070] The predetermined amount Tm, which is the threshold for switching from the third state to the fourth state, is set such that the timer 36 can measure a time equal to or longer than the predetermined time Tp from after completing the most recent maintenance operation, and the predetermined time Tp is the time interval for performing the maintenance operation. Specifically, the predetermined amount Tm is set such that the time elapsed from completing the most recent maintenance operation reaches the predetermined time Tp during which power can be fed to the timer 36 in the fourth state. For example, the predetermined amount Tm satisfies the following formula (1). It should be noted that the symbols in the following formula (1) are as follows: Tm is the predetermined amount Tm, Co is the power consumption of the timer 36 per unit time, Tp is the predetermined time Tp, and El is the time elapsed from the maintenance operation (current value).

[0071] Tm≥Co×(Tp-El) … (1)

[0072] Setting the predetermined amount Tm as described above allows the timer 36 to measure a time longer than the predetermined time Tp from after completing the most recent maintenance operation, and the predetermined time Tp is the time interval for performing the maintenance operation. In Figure 5 Among them, the point T5 indicates the timing when the predetermined time Tp has elapsed from the point T1 of completing the most recent maintenance operation. Specifically, the time elapsed from the point T1 to the point T5 corresponds to the predetermined time Tp.

[0073] After transitioning to the fourth state, the stored power of the EDLC 12 decreases over time, and when the stored power of the EDLC 12 reaches "0" or an amount corresponding to "0", the printing device 10 transitions to the fifth state. In the fifth state, the printing device 10 enters the "ALL OFF" state where power feeding to all components of the power feeding system is stopped. In Figure 5 FIG., point T6 indicates the timing when the stored power of the EDLC 12 reaches "0" or an amount corresponding to "0". In the fifth state, the driving of the timer 36 is stopped as described above, and with this stop, the count value of the pulse counter 204 is reset, and the measured value of the logic unit 206 is initialized, i.e., set to "0".

[0074] In the fourth and fifth states, power is not fed to the main ASIC 28. Therefore, in the fourth and fifth states, the power of the printing device 10 cannot be turned on by operating the power button 34. Connecting a USB cable to connect the printing device 10 to an external power source enables the operation of the power button 34. Therefore, in the period after point T4, the printing device 10 is connected to the external power source to activate the main ASIC 28. As described later, the activated main ASIC 28 refers to the measurement result of the timer 36 and determines whether to continue the time measurement of the timer 36 based on the measurement result.

[0075] In the present embodiment, in the fourth state, power consumption in the power feeding system is suppressed, and the driving time of the timer 36 is ensured to be longer than a predetermined time Tp starting from the most recent maintenance operation. Therefore, at the stage of transitioning to the fifth state, a predetermined time Tp has elapsed since the most recent maintenance operation. Therefore, if the measured value of the timer 36 is reset at the time point when a USB cable is connected and power is fed from an external power source, it means that a predetermined time Tp has elapsed since the most recent maintenance operation, and there is no need to measure time.

[0076] <Measurement Process>

[0077] In the above configuration, when the maintenance operation is completed, the printing device 10 performs a measurement process of measuring the time elapsed since the maintenance operation. Figure 6 FIG. is a flowchart showing the detailed processing content of the measurement process. The main ASIC 28 performs the Figure 6 series of processes shown in the flowchart of FIG. by loading the program code stored in the flash ROM 32 onto the DDR 30 and executing the program code. Another option is, Figure 6All or part of the functions of the steps can be performed by hardware such as another ASIC or circuit. In this specification, the symbol S in each process description in the flowchart means a step in the flowchart.

[0078] In the case of starting the measurement process, first, in S602, the main ASIC 28 initializes the measured value of the timer 36. In S602, the pulse counter 204 of the timer 36 is reset, thereby initializing the measured value of the logic unit 206. Next, in S604, the main ASIC 28 starts the time measurement of the timer 36. Thereafter, in S606, the main ASIC 28 determines whether the main ASIC 28 is in the standby state.

[0079] In the case where the main ASIC 28 determines in S606 that the main ASIC 28 is not in the standby state (i.e., in the operating state), the determination in S606 is made again. At the same time, in the case where the main ASIC 28 determines in S606 that the main ASIC 28 is in the standby state, the process proceeds to S608, and the main ASIC 28 determines whether power is fed from an external power source. In S608, the main ASIC 28 determines whether to feed the power supply voltage VBUS to the charger 14. In this determination, in the case where the main ASIC 28 determines to feed the power supply voltage VBUS to the charger 14, the main ASIC 28 determines that power is fed from an external power source. In the case where the main ASIC 28 determines not to feed the power supply voltage VBUS to the charger 14, the main ASIC 28 determines that power is not fed from an external power source.

[0080] In the case where the main ASIC 28 determines in S608 that power is fed from an external power source, the process returns to S606. At the same time, in the case where the main ASIC 28 determines in S608 that power is not fed from an external power source, the process proceeds to S610, and the main ASIC 28 obtains the stored charge amount of the EDLC 12 at this timing. As described above, the main ASIC 28 can obtain the remaining charge amount information of the EDLC 12 via the charger 14. Therefore, in S610, the main ASIC 28 obtains the stored charge amount of the EDLC 12 based on the obtained remaining charge amount information.

[0081] Next, in S612, the main ASIC 28 determines whether the stored power of the EDLC 12 is equal to or greater than a predetermined amount Tm. In the case where the main ASIC 28 determines in S612 that the stored power of the EDLC 12 is equal to or greater than the predetermined power, the process returns to S606. Meanwhile, in the case where the main ASIC 28 determines in S612 that the stored power of the EDLC 12 is less than the predetermined amount Tm, the process proceeds to S614, and the main ASIC 28 stops the power feed through the VSYS_SW 26. Accordingly, power is not fed to the main ASIC 28, and the main ASIC 28 becomes inoperable.

[0082] The process of S614 causes the printing apparatus 10 to enter the fourth state, and stops the power feed to the DC-DC1 16, the DC-DC2 18, and the main ASIC 28 through the VSYS_SW 26. Meanwhile, the power feed to the timer 36 continues. It should be noted that in the case where the fourth state continues and the stored power of the EDLC 12 decreases to "0" or an amount corresponding to "0", the printing apparatus 10 transitions to the fifth state, stops the power feed to all components of the power feed system, and initializes (resets) the measured value of the timer 36.

[0083] Then, in the case where a USB cable is connected to the USB connector 24 in the fourth state and the fifth state, power is fed from an external power source to the charger 14 and the VSYS_SW 26. In addition, the power feed from the external power source causes the VSYS_SW 26 to cancel the restriction on the power feed to the DC-DC1 16, thereby feeding power to the DC-DC1 16, the DC-DC2 18, and the main ASIC 28. In the case where the main ASIC 28 is fed power and enters the "ON" state, the main ASIC 28 refers to the measurement result of the timer 36.

[0084] Therefore, at the timing of activating the main ASIC 28 after stopping the power feed through VSYS_SW 26 in S614, the process proceeds to S616, and the main ASIC 28 determines whether to initialize the measured value of the timer 36. In the case where the main ASIC 28 determines not to initialize the measured value of the timer 36 in S616, the main ASIC 28 determines to enter the "ON" state in the fourth state where the time measurement of the timer 36 continues, and the process returns to S606. Therefore, after the process of S616, the time measurement in the timer 36 also continues. At the same time, in the case where the main ASIC 28 determines to initialize the measured value of the timer 36 in S616, the main ASIC 28 determines that the main ASIC 28 enters the "ON" state in the fifth state where the timer 36 is stopped, assuming that a time equal to or longer than the predetermined time Tp has elapsed, and terminates the measurement process. It should be noted that in the case where the maintenance operation starts during the measurement process, the executed measurement process is forcibly terminated.

[0085] <Determination process>

[0086] At a predetermined timing (such as at the moment of initializing a predetermined component of the printing mechanism), the printing apparatus 10 executes a determination process for determining to execute a maintenance operation based on the measurement result of the timer 36. Then, in the printing apparatus 10, based on the result of the determination process, the maintenance operation of the maintenance unit 308 is executed. In this section, the determination process for determining to execute a maintenance operation based on the measurement result of the timer 36 is described. Figure 7 is a flowchart showing the detailed processing content of the determination process. The main ASIC 28 performs Figure 7 a series of processes shown in the flowchart by loading the program code stored in the flash ROM 32 onto the DDR 30 and executing the program code. As another option, Figure 7 all or part of the functions of the steps in

[0087] can be executed by hardware such as another ASIC or circuit.

[0088] Meanwhile, when the main ASIC 28 determines in S704 not to initialize the measurement value, the process proceeds to S708, and the main ASIC 28 determines whether the measurement value is equal to or greater than a predetermined time Tp. When the main ASIC 28 determines in S708 that the measurement value is equal to or greater than the predetermined time Tp, the process proceeds to S706. Meanwhile, when the main ASIC 28 determines in S708 that the measurement value is less than the predetermined time Tp, the process proceeds to S710, and the main ASIC 28 determines not to perform a maintenance operation and terminates the determination process.

[0089] <Operation and effect>

[0090] As described above, in the printing apparatus 10 according to the present embodiment, when the power is turned off and no power is fed from an external power source, if the stored power of the EDLC 12 is lower than a predetermined amount Tm, the power feed to some configurations other than the timer 36 is stopped. This ensures that power can be fed from the EDLC 12 to the timer 36, and allows the timer 36 to exceed a predetermined time Tp from the time of the most recent maintenance operation to perform time measurement, where the predetermined time Tp is the time interval for performing a maintenance operation. Therefore, in the printing apparatus 10, there is no need to provide a dedicated battery for the timer 36, and power can be fed to the timer 36 after unplugging the cable while suppressing an increase in cost and ensuring the function of performing a maintenance operation.

[0091] (Second Embodiment)

[0092] Next, reference will be made to Figure 8 and Figure 9 to describe a printing apparatus according to a second embodiment. In the following description, components that are the same as or corresponding to those in the printing apparatus according to the first embodiment described above are denoted by the same reference numerals as those used in the first embodiment, and detailed descriptions of these components will be omitted.

[0093] In the first embodiment described above, the power feed to the main ASIC 28 is stopped at the timing when the stored power of the EDLC 12 is lower than a predetermined amount, so that the driving time of the timer 36 exceeds a predetermined time Tp from the most recent maintenance operation. When the printing apparatus enters the fourth state where the power feed to the main ASIC 28 is stopped, the printing apparatus 10 cannot be activated unless a USB cable is connected to reactivate the main ASIC 28 by power feed from an external power source and the power key 34 is set to an operable state. For example, users who frequently use the printing apparatus 10 may find such specifications inconvenient. Therefore, if the timing of transitioning to the fourth state can be delayed and the state where the power key 34 is available can be maintained for a long time, it is expected to improve the convenience of users who frequently use the printing apparatus.

[0094] Therefore, in the present embodiment, the timing of stopping the power supply to the main ASIC 28 can be changed according to the usage frequency, that is, the timing of transitioning to the fourth state. Specifically, the stored power of the EDLC 12, which is the threshold for transitioning from the third state to the fourth state, can be changed through user settings. Figure 8 is a table showing the setting contents of the change threshold. In the present embodiment, as Figure 8 shown, three modes, "standard", "low (level 1)", and "low (level 2)", can be set. It should be noted that the modes that can be set are not limited to three modes, and can also be two, four, or more modes.

[0095] When set to "standard", similar to the first embodiment above, the threshold is a predetermined amount Tm. For example, such a setting is performed through a setting screen displayed on the display unit of the operation unit including the power key 34. Specifically, the main ASIC 28 displays a setting screen on the display unit and performs settings based on the user's operations on the operation unit so as to apply the setting contents selected by the user. As described above, in the present embodiment, the main ASIC 28 functions as a setting unit configured to set one mode from multiple modes. In the setting screen, a notification indicating that the "standard" setting is the recommended setting can be made.

[0096] When set to "low (level 1)", the threshold is lowered to a level lower than the predetermined amount Tm and set to the stored power amount Tm1. Lowering the threshold from the predetermined amount Tm to the stored power amount Tm1 allows the third state to be maintained for a long time. Therefore, when set to "low (level 1)", the main ASIC 28 is in an active state for a longer time than when set to "standard", and the state in which the power key 34 is available can be maintained for a long time. In addition, in the setting screen, a notification indicating that the "low (level 1)" setting is suitable for high-frequency use and a notification indicating that maintenance operations are sometimes performed at startup when the usage frequency is low can be made.

[0097] When set to "low (level 2)", the threshold is lowered to a level lower than the predetermined amount Tm and the stored power amount Tm1, and set to the stored power amount Tm2. Lowering the threshold from the predetermined amount Tm to the stored power amount Tm2 allows the third state to be maintained for a longer time than when set to "standard" or "low (level 1)". Therefore, when set to "low (level 2)", the main ASIC 28 is in an active state for a longer time than when set to the other two settings, and the state in which the power key 34 is available can be maintained for a long time. In addition, in the setting screen, a notification indicating that the "low (level 2)" setting is suitable for higher-frequency use and a notification indicating that maintenance operations are sometimes performed at startup when the usage frequency is low can be made.

[0098] It should be noted that in the case of setting "Low (Level 1)" or "Low (Level 2)", the threshold value used in S612 of the measurement process is set to the stored power amount Tm1 or the stored power amount Tm2, and other processes are the same as in the case of setting to "Standard" (i.e., as described in the above description of the first embodiment). In addition, the determination process is also the same as in the case of setting to "Standard".

[0099] Next, the change in the stored power amount of the EDLC 12 over time according to the above settings will be described. Figure 9 It is a graph showing the change in the stored power amount of the EDLC 12 over time according to the settings. Since the change in the case of setting to "Standard" is the same as the change in the content described in the above first embodiment, the description for "Standard" will be omitted.

[0100] In the case of setting to "Low (Level 1)", the stored power amount Tm1, which is the threshold value for transitioning from the third state to the fourth state, is less than the predetermined amount Tm. Therefore, the timing for transitioning from the third state to the fourth state (i.e., the timing to stop feeding power and the main ASIC 28 enters the "OFF" state) is a point P1 that is later than the point T4 corresponding to the predetermined amount Tm. Therefore, in the case of setting "Low (Level 1)", the timing for transitioning from the third state to the fourth state is delayed from the case of setting to "Standard", the "ON" state of the main ASIC 28 will last longer, and the state in which the power button 34 is available will be maintained longer.

[0101] In addition, in the case of setting to "Low (Level 2)", the stored power amount Tm2, which is the threshold value for transitioning from the third state to the fourth state, is less than the predetermined amount Tm and is even smaller than the stored power amount Tm1 that is less than the predetermined amount Tm. Therefore, the timing for transitioning from the third state to the fourth state is a point P2 that is later than the point T4 corresponding to the predetermined amount Tm and the point P1 corresponding to the stored power amount Tm1. Therefore, the timing for transitioning from the third state to the fourth state is further delayed compared to the cases of setting to "Standard" and "Low (Level 1)", the "ON" state of the main ASIC 28 will last longer, and the state in which the power button 34 is available will be maintained longer.

[0102] Note that, when set to "Low (Level 1)" or "Low (Level 2)", the power consumption per unit time in the fourth state is also the same as that in the case of being set to "Standard". Therefore, the stored power of the EDLC 12 reaches "0" or the value corresponding to "0" by an amount corresponding to the delay in the timing of transitioning to the fourth state, and the timing is at point P3 ("Low (Level 1)") or point P4 ("Low (Level 2)") earlier than point T6 in the case of being set to "Standard". In other words, the operation time of the timer 36 is shorter when set to "Low (Level 1)" than when set to "Standard", and the operation time is even shorter when set to "Low (Level 2)".

[0103] Therefore, when set to "Low (Level 2)", the timer 36 measures time only during the period Pr1 from point T1 to point P4. The period Pr1 is shorter than the period PR from point T1 to point T5 (i.e., the predetermined time Tp). Therefore, when set to "Low (Level 2)", the period in which the counting of the timer 36 terminates includes the timing when the elapsed time does not reach the predetermined time Tp. Therefore, there may be a case where the maintenance operation is not performed at an appropriate timing. However, since it is assumed that the user who sets "Low (Level 2)" often uses the printing device 10, it is desirable to use the printing device 10 during the operation of the timer 36 and suppress the execution of the maintenance operation at an inappropriate timing.

[0104] <Operation and Effect>

[0105] As described above, in the printing device 10 according to the present embodiment, the user can change the threshold for transitioning from the third state to the fourth state according to the usage frequency of the printing device 10. Therefore, in the present embodiment, in addition to the operations and effects of the first embodiment, it is possible to ensure a long power supply time to the main ASIC 28 and a long available time of the power button 34 connected to the main ASIC 28. This improves the convenience of the user 10 who often uses the printing device.

[0106] (Other Embodiments)

[0107] Note that the above-described embodiments can be modified as described in (1) to (6) below.

[0108] (1) In the above-described second embodiment, although the threshold for transitioning from the third state to the fourth state is set to be less than the threshold in the case of being set to "Standard" in each optional setting, the present disclosure is not limited thereto. The threshold in the optional setting can be set to be greater than the threshold in the case of being set to "Standard". This enables setting processing in which functions other than the timer 36 can be used in parallel with the timer 36 in the fourth state.

[0109] (2) Although not particularly described in the above embodiments, the printing apparatus 10 determines that the USB cable has been unplugged when the power supply voltage VBUS is stopped from being fed to the charger 14. The printing apparatus 10 may include a configuration for detecting the unplugging of the USB cable from the USB connector, and determines whether the USB cable has been unplugged based on the detection result of this configuration.

[0110] (3) Although in the above embodiments, the printing apparatus 10 is a so-called serial scanning type printing apparatus that uses a print head configured to eject ink while moving in a direction intersecting the conveyance direction of the print medium, the present disclosure is not limited thereto. The printing apparatus 10 may be a so-called full-line type printing apparatus that uses a long print head extending over the entire area of the printing region in the width direction of the print medium.

[0111] (4) Embodiments of the present invention can also be implemented by the following method, that is, a software (program) that executes the functions of the above embodiments is provided to a system or apparatus via a network or various storage media, and the computer or central processing unit (CPU) or microprocessing unit (MPU) of the system or apparatus reads and executes the program.

[0112] (5) Although in the above embodiments, the power supply to the main ASIC 28 and the like is stopped by the limitation of VSYS_SW 26, the power supply to the main ASIC 28, the motor driver 20, and the head driver 22 can also be stopped individually. In addition, the power supply to the display panel and the wireless communication unit can also be stopped.

[0113] (6) The above embodiments and the various forms described in (1) to (5) above can be appropriately combined.

[0114] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such variations as well as equivalent structures and functions.

Claims

1. A printing device, the printing device being configured to print on a printing medium by using a printing unit, the printing device comprising: a power storage unit capable of storing power fed from an external power source connected via a USB cable; a measuring unit capable of measuring time based on power from the power storage unit; a control unit configured to perform a predetermined process based on the measurement result of the measurement unit; as well as a limiting unit capable of limiting the power fed from the power storage unit, wherein During a period in which the power feeding from the external power source is stopped, The limiting unit limits the feeding of power to at least units other than the measuring unit according to the amount of power stored in the power storage unit, and The measuring unit continues measuring.

2. The printing device according to claim 1, wherein: The control unit controls the restriction unit to restrict power feeding to the control unit in a case where the stored power amount of the power storage unit is lower than a predetermined value.

3. The printing device according to claim 1 or 2, wherein: The restriction unit cancels the restriction in a case where the printing apparatus receives power feeding from the external power source after restricting power feeding to the control unit.

4. The printing device according to claim 1 or 2, wherein: When power feeding to the measuring unit is stopped, the measuring unit initializes the measured value.

5. The printing device according to claim 2, further comprising a maintenance unit capable of performing a maintenance operation of maintaining and restoring the inkjet performance of the printing unit, the printing unit being configured to print on the printing medium by inkjet, wherein The control unit determines execution of the maintenance operation based on the measurement result of the measurement unit.

6. The printing device according to claim 5, wherein: The predetermined value is set so that after the power feeding from the external power supply is stopped, before the stored power of the power storage unit reaches an amount that cannot drive the measuring unit, the time elapsed from the most recent maintenance operation reaches or exceeds a predetermined time, the predetermined time being a time interval for performing the maintenance operation.

7. A printing device according to any one of claims 2, 5, and 6, further comprising a setting unit capable of setting one of a plurality of different modes of the stored power of the power storage unit as a threshold value for the restriction unit to perform the restriction.

8. The printing device according to claim 7, wherein: The plurality of modes include a mode in which the threshold value is the predetermined value and a mode in which the threshold value is smaller than the predetermined value.

9. The printing device according to claim 5, wherein: In the case where the maintenance operation is completed, the control unit causes the measuring unit to initialize the measurement value and then start time measurement.

10. The printing device according to any one of claims 5, 6 and 9, wherein: The maintenance unit comprising a cover portion configured to cover a surface of the printing unit on which nozzles for ejecting ink are formed, and The cover portion is caused to cover the printing unit that does not perform printing.

11. The printing device according to claim 5, wherein: The control unit determines to perform the maintenance operation in a case where the measurement value of the measurement unit is equal to or greater than a predetermined time at a predetermined timing, the predetermined time being a time interval for performing the maintenance operation.

12. The printing device according to claim 5, wherein: In the case where the power feed to the measuring unit is stopped, the measuring unit initializes the measured value, and The control unit performs the maintenance operation while initializing the measurement value of the measurement unit at a predetermined timing.

13. The printing device according to claim 11 or 12, wherein: The predetermined timing includes the timing of initialization processing of constituent components of the printing apparatus or the timing of a preparation operation after a job input.

14. The printing device according to claim 1, further comprising a connection unit, a USB cable connected to the external power source can be inserted into and unplugged from the connection unit, and the connection unit can be connected to the external power source via the USB cable, wherein When the USB cable is plugged into the connection unit, the power feeding from the external power source is performed, and When the USB cable is unplugged from the connection unit, the power feeding from the external power source is stopped.

15. A control method of a printing apparatus, the printing apparatus including a measuring unit capable of measuring time by using power fed from a power storage unit capable of storing power fed from an external power source connected via a USB cable and operating to perform predetermined processing based on a measurement result of the measuring unit, the control method comprising: In the case where the power feeding from the external power source is stopped, the power feeding to the measuring unit is prioritized according to the storage amount of the power storage unit.

16. A non-transitory computer-readable storage medium storing a program for causing a computer to perform a control method of a printing apparatus, the printing apparatus including a measuring unit capable of measuring time by using power fed from a power storage unit capable of storing power fed from an external power source connected via a USB cable and operating to perform a predetermined process based on a measurement result of the measuring unit, the control method comprising: In the case where the power feeding from the external power source is stopped, the power feeding to the measuring unit is prioritized according to the storage amount of the power storage unit.

17. A computer program product comprising a program for causing a computer to perform a control process of a printing apparatus, the printing apparatus comprising a measuring unit capable of measuring time by using power fed from a power storage unit capable of storing power fed from an external power source connected via a USB cable and operating to perform a predetermined process based on a measurement result of the measuring unit, the control method comprising: In the case where the power feeding from the external power source is stopped, the power feeding to the measuring unit is prioritized according to the storage amount of the power storage unit.

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