Printing device, printing device control method and program

Abstract

To reduce frequencies of writing on a nonvolatile memory during operation of a printing device to reduce influences of the frequencies of the writing on a service life of the printing device.SOLUTION: A printing device according to one embodiment of the present invention comprises: a wired interface; a power storage part that is charged with electric power supplied through the wired interface; a volatile first memory; a non-volatile second memory; and writing means that executes writing-processing for writing data stored in the first memory on the second memory, using electric power charged into the power storage part, which determines whether the writing processing should be executed or not, on the basis of at least either of amounts of electric power supplied through the wired interface and residual charged electric power in the power storage part.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a printing device, and more particularly to a printing device that operates on power supplied from a wired interface terminal and charged in a power storage unit such as an electric double layer capacitor. [Background technology]

[0002] Conventional printing devices have non-volatile memory that can retain its contents even if power is not supplied to the device, and the non-volatile memory is used to retain various setting values, data used to control the operation of the device, etc. An example of non-volatile memory is a semiconductor storage device such as a flash memory.

[0003] Although flash memory can retain its stored contents even when the power is turned off, there is a limit to the number of times each memory element can be rewritten. Information such as various setting values ​​and operation control data stored in non-volatile memory must be kept up to date even in the event of an unexpected power outage, and is changed as needed while the printer is in operation. However, the number of times non-volatile memory is rewritten affects the product's lifespan, so it is necessary to keep the number of rewrites as small as possible.

[0004] As a technique to meet this need, Patent Document 1 discloses a technique in which the number of writes per area is counted so that the number of writes does not exceed an upper limit, and the area to be written to is changed when a specified value is exceeded. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-65550 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in Patent Document 1, it is necessary to change the area every time the specified value is exceeded, which causes problems in that the control becomes complicated and the storage capacity of the non-volatile memory increases.

[0007] In view of the above problem, an object of the present disclosure is to reduce the number of times data is written to non-volatile memory while a printing device is in operation, and to reduce the impact of the number of times data is rewritten on the lifespan of the printing device. [Means for solving the problem]

[0008] One embodiment of the present invention is a printing device having a wired interface, a power storage unit which is charged with power supplied via the wired interface, a volatile first memory, a non-volatile second memory, and a writing means which executes a writing process to write data stored in the first memory to the second memory using the power charged in the power storage unit, wherein the printing device determines whether or not to execute the writing process based on at least one of the amount of power supplied via the wired interface and the remaining charge of the power storage unit. Effect of the Invention

[0009] According to the present disclosure, it is possible to reduce the number of times data is written to non-volatile memory during operation of a printing device, and to reduce the impact of the number of times data is rewritten on the lifespan of the printing device. [Brief description of the drawings]

[0010] [Figure 1] Block diagram showing the configuration of the printer's control system [Diagram 2] Block diagram showing the configuration of the printer's power supply system [Diagram 3] Table showing power supply for each connection standard [Figure 4] 1 is a flowchart showing the process executed by the CPU 311 of the printer 300. [Diagram 5] Flowchart showing the process when updating stored data [Figure 6]Flowchart showing the process when the USB cable is unplugged [Figure 7] Flowchart showing the processing contents of writing to non-volatile memory [Figure 8] 1 is a flowchart showing the process executed by the CPU 311 of the printer 300. [Figure 9] Flowchart showing the process when updating stored data [Figure 10] Flowchart showing the process when a change in the power supply state is detected DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described in detail. Note that the components described in the following embodiments are merely examples, and are not intended to limit the scope of the technical features of the present disclosure.

[0012] [First embodiment] <Printer configuration> 1 is a block diagram showing the configuration of a control system of a printer 300 according to this embodiment. In the following, a so-called multifunction printer that incorporates a printing mechanism 301 and a reading mechanism 302 in the same housing and supports multiple functions such as a copy function is adopted as the printer 300, and a case where this embodiment is applied to the multifunction printer is described. Note that the printer may also be referred to as a "printing device."

[0013] Printer 300 has a main board 310 that controls the entire device, and various units such as a wireless LAN unit 304 and a short-range wireless communication unit 305. A microprocessor-type CPU 311 is disposed on main board 310. CPU 311 operates according to a control program stored in a ROM-type (i.e. non-volatile) program memory 313 connected via an internal bus 312, and according to the contents stored in a RAM-type (i.e. volatile) data memory 314.

[0014] In addition to the above-mentioned memories, the main board 310 has a non-volatile memory 315 that can retain contents even when power is cut off. By writing various settings and data to the non-volatile memory 315, the CPU 311 can continue to operate based on the same settings and data when power is supplied again after the power is turned off. An example of such a non-volatile memory 315 is a semiconductor storage device such as a flash memory. If a flash memory is used, it is possible to retain stored contents even when power is cut off, but there is often a limit to the number of times each memory element can be rewritten. For this reason, it is necessary to design the device by considering the timing at which writing is performed to the non-volatile memory, taking into account the product life of the device. In general, it is expected that the unit price of a storage device with a higher guaranteed number of rewrites will be higher.

[0015] The CPU 311 can read an original document by controlling the reading mechanism 302 via the reading mechanism control circuit 317, and store the image data obtained by the reading in the data memory 314. The CPU 311 can also print an image on a recording medium based on the image data in the data memory 314 by controlling the printing mechanism 301 via the printing mechanism control circuit 316.

[0016] The CPU 311 performs wireless LAN communication with other communication terminal devices by controlling the wireless LAN unit 304 via the wireless LAN communication control circuit 319. The CPU 311 also controls the short-range wireless communication unit 305 via the short-range wireless communication control circuit 320, thereby enabling the CPU 311 to detect a connection with another short-range wireless communication terminal and transmit and receive data to and from the other short-range wireless communication terminal.

[0017] The CPU 311 controls the operation unit control circuit 318 to display the status of the printer 300 on the operation panel 303, display a function selection menu, and accept operations from the user. The CPU 311 operates the USB interface 306 via the USB communication control circuit 321, and can perform USB communication with another terminal device connected via a USB cable. The CPU 311 controls the power control circuit 322 to grasp and control (increase, decrease, or reduce) the amount of power supplied from the USB interface 306, and also grasp and control (increase, decrease, or reduce) the amount of power stored in the power control circuit. Note that FIG. 1 shows a form in which the printer has a USB interface connector and is supplied with power via a USB cable connected to the USB interface connector, but this embodiment is not limited to this. This embodiment can also be applied to a form in which the printer has another wired interface terminal other than a USB connector and is supplied with power via the wired interface terminal and the cable of the other wired interface. Note that a specific example of another wired interface can be a wired LAN.

[0018] 2 is a block diagram showing the configuration of a power supply system of the printer 300. The printer 300 receives a power supply voltage V BAT The printer 300 can be driven by inputting the power supply V from the USB interface 306 to the charger IC 601, and the power supply system via the charger IC 601 controls the power supply in the printer 300. BUS The charger IC 601 charges the EDLC 606 with the current supplied thereto. At the same time, the charger IC 601 outputs a voltage from the EDLC 606 to the DC-DC converter (boost) 602. Details of the charger IC 601 and the EDLC 606 at this time will be described later. In the present application, the electric double layer capacitor (EDLC) 606 is referred to as a "power storage unit."

[0019] The DC-DC converter (boosting) 602 is a boosting circuit for boosting the voltage from the Charger IC 601. The boosted voltage is used by a Motor Driver 604 to drive the motors of the reading mechanism and the printing mechanism, and is also used by a Head Driver 605 as a driving power source for the head. In this way, the DC-DC converter (boosting) 602 is responsible for driving a relatively large load.

[0020] The DC-DC converter (step-up) 602 is connected to a DC-DC converter (step-down) 603. The DC-DC converter (step-down) 603 is a step-down circuit that generates a logic power supply voltage used by the ASIC 611, the program memory (Flash ROM) 313, and the data memory (DDR) 314. Here, the ASIC 611 is a custom IC including the CPU 311 and peripheral circuits. The charger IC 601 is an IC that has a function for controlling an input current via the USB interface 306, as well as controlling charging of the EDLC 606 and protecting it from abnormal operation. The charger IC 601 communicates with the ASIC 611 connected thereto via a control serial bus 612. Here, the control serial bus 612 constitutes a part of the internal bus 312. In this embodiment, communication is performed using a universal asynchronous receiver transmitter (UART) method.

[0021] The Charger IC 601 judges the input current according to the external device (e.g., a PC terminal) that is the supply source. In this embodiment, the charger IC 601 judges the input current according to the USB-BC (USB Battery Charge) standard (hereinafter referred to as BC judgement) and the USB-PD (USB Power Delivery) standard (hereinafter referred to as CC judgement). The ASIC 611 receives the results of the BC judgement and the CC judgement from the Charger IC 601, and determines the thresholds of the charge current, full charge, and overdischarge voltage of the Charger IC 601, and sets the determined thresholds in the Charger IC 601.

[0022] The EDLC 606 is an electric double layer capacitor. The EDLC 606 controls charging from the Charger IC 601 according to instructions from the ASIC 611, and supplies the power supply voltage V BAT Power is supplied by the EDLC606 power supply voltage V BAT The charger IC 601 can transmit various information related to power supply to the ASIC 611. The printer 300 uses this information to perform various controls. For example, when the printer 300 is in a printing operation, the power supply voltage V BAT When the power supply voltage V BAT It instructs the ChargerIC601 to control charging until the power supply voltage V BAT When the ASIC 611 receives a notification that the power consumption has reached a certain threshold, the ASIC 611 can perform control to resume the print operation. If the USB cable is unplugged during operation while power is being supplied from the USB interface 306, or if power supply from the USB interface 306 is stopped, the Charger IC 601 notifies the ASIC 611 so that an operation to deal with the power supply stop can be started immediately.

[0023] <Power supply amount for each connection standard> Figure 3 is a table showing the amount of power supply for each connection standard. BC1.2 is based on the USB-BC (Battery Charge) standard, and defines a method for determining whether the USB port is a charging USB port (CDP) by electrically determining it using the D+ and D- signal lines for USB data communication. In addition, in the case of a standard USB port that is not a charging port, communication based on the USB standard is performed after this detection is completed, and it is possible to determine the USB version during this process. On the other hand, USB Type-C defines the Power Delivery standard, and the amount of power supply can be notified by communication via the CC pin. Note that the Power Delivery standard also allows the supply voltage to be controlled from 5V to 48V, but in this figure the maximum power is listed as the value when 5V is supplied.

[0024] <Executing processing according to the event type> In the following embodiment, an example will be described in which data is not always written to the non-volatile memory immediately when saved data is updated, but is written to the non-volatile memory only when the USB is removed.

[0025] Fig. 4 is a flowchart showing the process executed by CPU 311 of printer 300. The series of processes shown in the flowchart in Fig. 4 are performed by CPU 311 reading program data stored in program memory 313 into data memory 314 and executing the read data. The process in Fig. 4 starts when logic power is supplied to ASIC 611 and the power is turned on.

[0026] In step S400, CPU 311 reads out data stored in non-volatile memory 315 to a stored data buffer area on data memory 314. At this time, if any data has been encrypted and stored in non-volatile memory 315, it performs decryption processing as necessary, and makes the data unencrypted in the stored data buffer area of ​​data memory 314. Note that hereinafter, "step S~" will be abbreviated to "S~" for simplicity.

[0027] In S401, the CPU 311 clears a flag (hereinafter, referred to as an unwritten flag) indicating that the latest data that has not been written to the non-volatile memory 315 is in the saved data buffer area. After that, the CPU 311 repeatedly executes the loop process from S402 to S410 until it transitions to a power-off state or the logic power supply to the ASIC 611 is cut off.

[0028] During execution of the loop processing, in S403, the CPU 311 waits for the occurrence of an event to be processed.

[0029] In S404, the CPU 311 determines the type of the event that has occurred, and the subsequent processing of S404 is so-called event-driven processing in which processing is performed according to the type of the event that has occurred.

[0030] The process subsequent to S404 will be specifically described below. If the event is the detection of a power-off operation, the process proceeds to S405, and the power is turned off. As a result, the CPU 311 exits the repeat loop in S410 and ends the process in this figure. If the event is the detection of a USB cable being inserted, the process proceeds to S406, and a USB communication connection establishment process after the USB is inserted is executed. If the event is the detection of a USB cable being removed, the process proceeds to S407, and a process at the time of USB removal is executed. The contents of the process at the time of USB removal will be described later (see FIG. 6). If the event is the reception of a job from an external device such as a smartphone via USB or wireless LAN, the process proceeds to S408, and a process for executing the job is executed. The process at the time of job execution is determined by the contents notified by the job, and a print job, a scan job, or other process is executed as appropriate. If the event is something else, a process according to the event that occurred in S409 is executed.

[0031] <Saved data update process> Fig. 5 is a flowchart showing the process contents when updating stored data. The series of processes shown in the flowchart in Fig. 5 is performed by CPU 311 reading program data stored in program memory 313 into data memory 314 and executing the read data.

[0032] The series of processes shown in the flowchart of FIG. 5 are executed by the CPU 311 of the printer 300 when data to be stored in the non-volatile memory 315 is updated in association with various operations of the printer 300. For example, the timing of execution varies widely, such as when an operation is performed on the operation panel, or when the printer 300 is operated by the job execution process of S408 and the state is changed. In order to safely store data, it is preferable to execute the processes shown in FIG. 5 executed by the CPU 311 of the printer 300 when no other processes are being executed, for example, when other processes (such as job execution processes) have ended. Examples of other processes referred to here include processes for executing jobs received from external devices. Note that, since multiple tasks may be executed in parallel by multitasking, the processes shown in FIG. 5 may be executed in parallel with other processes such as job execution and communication operations.

[0033] When updating the stored data, first in S500, the CPU 311 of the printer 300 reflects the data to be updated in the stored data buffer area provided in the data memory 314. The stored data buffer area is an area for reading out and using data stored in the non-volatile memory 315 into a work area on the data memory 314. Information encrypted and stored in the non-volatile memory 315 is decrypted when it is read out into the stored data buffer area, and the data held in the stored data buffer area becomes unencrypted information.

[0034] At the time of performing S500, the information stored in non-volatile memory 315 and the information stored in the saved data buffer area do not match, so in the next S501, CPU 311 sets an unwritten flag. The unwritten flag indicates that the latest data that has not been written to non-volatile memory 315 is in the saved data buffer area, and is defined as a program variable of data memory 314.

[0035] In the next step S502, the CPU 311 checks the power supply state and judges whether the USB power supply amount is equal to or greater than a first threshold. If the judgment result in this step is true, the process proceeds to step S503, whereas if the judgment result is false, the process proceeds to step S505. The USB power supply amount refers to the amount of power supplied via the USB interface 306. The power supply state to be checked in this step may refer to the results of the BC judgment and CC judgment detected by the power supply control circuit when the USB is inserted, and the type and current value of the USB power supply may be acquired. Whether or not the USB power supply amount equal to or greater than a predetermined threshold is secured may be determined by directly using the results of the BC judgment and CC judgment, or by deriving and using the current value that is actually being supplied. Although the case where the power supply amount is quantitatively judged has been described, the control may be performed by using the judgment of whether or not the USB power supply is being performed.

[0036] In S503, the CPU 311 determines whether the remaining charge (also called the charge amount) of the ELDC 606 is equal to or greater than a predetermined second threshold. The process of this step is performed to determine whether there is enough power remaining to complete the process of writing the contents of the saved data buffer area to the non-volatile memory 315, regardless of when the USB power supply is interrupted. If the determination result of this step is true (i.e., the remaining charge is equal to or greater than the second threshold), the printer 300 can continue to operate, and the series of processes ends. On the other hand, if the determination result of this step is false (i.e., the remaining charge is not equal to or greater than the second threshold), the process proceeds to S504.

[0037] In S504, the CPU 311 temporarily stops other operations in the printer 300 and waits for the necessary amount of electric power to be charged. By this step, the remaining charge amount of the ELDC 606 becomes at least equal to or greater than the second threshold value. Note that when charging in this step, as described above, operations other than the charging operation are temporarily stopped, and this temporarily stopped operation may be part or all of the operations in the printer 300.

[0038] In S505, the CPU 311 executes a writing process to the non-volatile memory 315 (hereinafter referred to as the non-volatile memory writing process). This is a process of writing the contents of the save data buffer area to the non-volatile memory 315, and the details will be described later (see FIG. 7).

[0039] When the non-volatile memory writing process is performed in S505, since the contents of the save data buffer area are reflected in the non-volatile memory 315, in subsequent S506, the CPU 311 clears the unwritten flag.

[0040] Note that in this figure, a form is shown in which after S504, the process proceeds to S505 and the non-volatile memory writing process is immediately performed, but the form is not limited to this. If power can be secured to safely perform the non-volatile memory writing process even when other operations are performed in S504, it is also possible not to perform the immediate writing at the timing of S505.

[0041] <USB removal process> FIG. 6 is a flowchart showing the processing contents when the USB cable is removed. This process shows the processing contents related to the non-volatile memory update process among the USB removal processes executed as a sub-flow of S407 in FIG. 4. Note that the series of processes shown in the flowchart of FIG. 6 are performed by the CPU 311 reading the program data stored in the program memory 313 into the data memory 314 and executing the read data.

[0042] In S600, the CPU 311 determines whether the unwritten flag is set. If the determination result in this step is true, the process proceeds to S601. If the determination result is false, however, there is no need to perform a write process to the non-volatile memory 315, and the process ends.

[0043] In S601, the CPU 311 executes a non-volatile memory write process. This is a process for writing the contents of the saved data buffer area to the non-volatile memory 315, and will be described in detail later (see FIG. 7).

[0044] When the non-volatile memory write process is performed in S601, the contents of the saved data buffer area are reflected in the non-volatile memory 315, so in the following S602, the CPU 311 clears the unwritten flag.

[0045] <Non-volatile memory write process> FIG. 7 is a flowchart showing the specific contents of the non-volatile memory write process. This process is executed as a subflow of S505 in FIG. 5 or S601 in FIG. 6. Since the non-volatile memory 315 is composed of a semiconductor storage device such as a flash memory, data cannot be rewritten in units of bits or bytes, and data must be erased and written in units of storage blocks such as 512 bytes or 1K bytes. The non-volatile memory write process in this figure shows the process contents as a combination of the write process in units of blocks and the data encryption process. The series of processes shown in the flowchart in FIG. 7 are performed by the CPU 311 reading the program data stored in the program memory 313 into the data memory 314 and executing the read data.

[0046] First, in S700, the CPU 311 reads out data to be updated that is stored in a predetermined block of the non-volatile memory 315 into the data memory 314.

[0047] In S701, the CPU 311 performs the necessary decryption process. Note that the data stored in the non-volatile memory 315 is partially or entirely encrypted as necessary, and the description of the encryption algorithm is omitted here. The data may be encrypted in units of storage blocks in the non-volatile memory 315, or only arbitrary data defined in the storage data buffer area may be encrypted.

[0048] In S702, the CPU 311 merges the decrypted data on the data memory 314 with the updated data in the saved data buffer area.

[0049] In S703, the CPU 311 performs necessary encryption processing on the data that has been merged in S702. With this step, preparation of the data to be written to the non-volatile memory 315 is completed.

[0050] In S704, the CPU 311 performs interrupt inhibition processing, and controls so that other operations are not executed in parallel while writing to the non-volatile memory 315. Note that, although the case where the exclusive processing is performed by the interrupt inhibition processing is shown here, the exclusive processing may be performed by a semaphore or other method. Also, if the writing control of the non-volatile memory 315 can be managed, it is possible to configure so that the exclusive processing does not necessarily have to be implemented. After S704, the writing process for each storage block to the non-volatile memory 315 is executed.

[0051] In S705, the CPU 311 performs block erasure of the storage block in the non-volatile memory 315. Specifically, it is sufficient to issue an erase command defined for each non-volatile memory 315 device.

[0052] In S706, the CPU 311 writes data to a storage block in the non-volatile memory 315. Specifically, it is sufficient to issue a block write command defined for each device in the non-volatile memory 315. When writing to the necessary storage blocks is completed in S706, the process proceeds to S707.

[0053] In S707, the CPU 311 performs interrupt permission processing, ends the exclusive control, and ends the non-volatile memory write processing.

[0054] <Effects of this embodiment> By controlling as described above, when power is being supplied from the USB, writing to the non-volatile memory 315 is not performed, and when the USB is removed, the remaining charging power is used to write unupdated data that has not been written to the non-volatile memory 315. This makes it possible to reduce the number of writes to the non-volatile memory, and to reduce the impact of the number of writes on the lifespan of the device. Furthermore, by reducing the number of write processes to the non-volatile memory during operation, it is also possible to reduce the impact of the write process time on the operating speed of the printer 300.

[0055] [Second embodiment] Hereinafter, as the second embodiment, a case will be described in which a change in the power supply state is monitored and, based on the monitoring result, writing is performed to the non-volatile memory 315. Note that, hereinafter, the description of the contents common to the above will be omitted as appropriate, and the description will focus on the contents different from the above.

[0056] 8 is a flowchart showing the process executed by the CPU 311 of the printer 300. This process starts when logic power is supplied to the ASIC 611 and the power is turned on. The overall process configuration is similar to that of the first embodiment (see FIG. 4), so only the different parts will be described.

[0057] In S804, the type of event is determined. If the event is an event notifying the ASIC 611 of a change in the power supply state from the Charger IC 601, the process proceeds to S806, where the CPU 311 executes a process at the time of a change in the power supply state. BATThe charge state can be acquired by setting the charger IC 601 in advance as a state that notifies the ASIC 611 when the state changes or when the USB power supply is notified by the BC judgment or CC judgment. The USB power supply refers to the power supply via the USB interface 306. The process when the power supply state changes will be described later in detail (see FIG. 10). The process contents for other events can be the same as those in the first embodiment, and therefore the description will be omitted here.

[0058] Fig. 9 is a flowchart showing the process contents when updating stored data. This process is executed by CPU 311 of printer 300 when data to be stored in non-volatile memory 315 is updated in accordance with various operations of printer 300. The series of processes shown in the flowchart of Fig. 9 is executed by CPU 311 reading program data stored in program memory 313 into data memory 314 and executing the read data.

[0059] When updating the saved data, first in S900, CPU 311 reflects the data to be updated in a saved data buffer area provided in data memory 314. At this point, the information saved in non-volatile memory 315 and the information stored in the saved data buffer area do not match. Therefore, in the next S901, CPU 311 sets an unwritten flag.

[0060] In S902, the CPU 311 checks the power supply state and judges whether the remaining charge of the EDLC 606 is secured at a predetermined value or more, more specifically, whether the remaining charge is equal to or greater than a predetermined third threshold. If it is judged in this step that the remaining charge is equal to or greater than the third threshold, the process during power supply state fluctuation is terminated. On the other hand, if it is judged in this step that the remaining charge is not equal to or greater than the third threshold, the process proceeds to S903. Note that the third threshold is preset to a value that is actually required for the CPU 311 to perform a write process to the non-volatile memory 315 plus a certain margin. In this way, it is possible to guarantee that there is enough power remaining for the CPU 311 to perform a write process to the non-volatile memory 315 when it is detected that the remaining charge has fallen below a predetermined value in the process during power supply fluctuation described below. The remaining charge is detected via the Charger IC 601 as the power supply voltage V BAT It can be obtained by obtaining

[0061] In S903, the CPU 311 executes a non-volatile memory write process. This is a process for writing the contents of the saved data buffer area to the non-volatile memory 315, and is the same as in the first embodiment (see FIG. 7).

[0062] When the non-volatile memory write process is performed in S903, the contents of the saved data buffer area are reflected in the non-volatile memory 315, so in the following S904, the CPU 311 clears the unwritten flag.

[0063] 10 is a flowchart showing the contents of the process when a change in the power supply state is detected (referred to as a process at the time of change in the power supply state). This process is executed as a subflow of S806 in FIG.

[0064] In S1000, the CPU 311 determines whether the unwritten flag is set. If the determination result in this step is true, the process proceeds to S1001. On the other hand, if the determination result in this step is false (i.e., if the unwritten flag is not set), there is no need to perform the write process to the non-volatile memory 315, and the power supply state change process is terminated.

[0065] In S1001, the CPU 311 checks the power supply state and determines whether the remaining charge of the EDLC 606 has fallen below a predetermined fourth threshold. If the determination result in this step is true, the process proceeds to S1002. On the other hand, if the determination result in this step is false (i.e., if the remaining charge has not fallen below the predetermined fourth threshold), writing does not need to be performed until the next power supply state change event, and the power supply state change process is terminated.

[0066] In S1002, the CPU 311 executes a non-volatile memory write process. This process is similar to that in the first embodiment (see FIG. 7), and therefore a description thereof will be omitted here.

[0067] When the non-volatile memory write process is performed in S1002, the contents of the saved data buffer area are reflected in the non-volatile memory 315, so in the following S1003, the CPU 311 clears the unwritten flag.

[0068] <Effects of this embodiment> By controlling as described above, when the remaining charge of the EDLC 606 is sufficient, writing to the non-volatile memory 315 is not performed. When it is detected that the remaining charge of the EDLC 606 has fallen below a predetermined value, the remaining charging power is used to write unupdated data that has not been written to the non-volatile memory 315. This makes it possible to reduce the number of writes to the non-volatile memory, and to reduce the effect of the number of writes on the lifespan of the printer 300. Furthermore, by reducing the number of write processes to the non-volatile memory during operation, it is also possible to reduce the effect of the write process time on the operating speed of the printer 300.

[0069] [Third embodiment] In the above-mentioned embodiment, in the stored data update process, the non-volatile memory write process (S505, S903) is performed based on whether the amount of USB power supply is equal to or greater than a predetermined threshold (S502 in FIG. 5) or whether the remaining charge of the EDLC 606 is equal to or greater than a predetermined threshold (S902 in FIG. 9). In contrast, in the present embodiment, in order to reduce the impact on the device operation speed due to writing to the non-volatile memory during operation, a determination step is added to determine whether a job operation is being executed, and based on the determination, it is determined whether to perform the non-volatile memory write process.

[0070] Below, as a variation of the stored data update process according to the first embodiment, a form in which it is determined whether or not to perform non-volatile memory write processing based on whether or not a job operation is being executed will be described with reference to FIG. 5.

[0071] In this embodiment, a determination step is added before S502 in the saved data update process shown in Fig. 5 to determine whether a job operation is being executed. If the determination result of this determination step is true (i.e., if a job operation is being executed), the saved data update process is terminated, whereas if the determination result is false (i.e., if a job operation is not being executed), the process proceeds to S502. In addition, after the job execution process of S408 in Fig. 4 is terminated, a process equivalent to the USB removal process (see Fig. 6) may be added and executed.

[0072] In the above embodiment, a determination step for determining whether or not a job operation is being executed is added to the stored data update process of the first embodiment, but the present invention is not limited to this embodiment. For example, similarly to the second embodiment (see FIG. 9), a determination step for determining whether or not a job operation is being executed may be added before S902, and based on the determination result of this determination step, it may be determined whether or not to perform non-volatile memory write processing.

[0073] The present disclosure can also be realized by a process in which a program for implementing one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that implements one or more functions.

[0074] [Technical Features of the Disclosure] The present disclosure includes the following configurations.

[0075] (Configuration 1) A printing device having a wired interface, a power storage unit which is charged with power supplied via the wired interface, a volatile first memory, a non-volatile second memory, and a writing means which executes a writing process to write data stored in the first memory to the second memory using the power charged in the power storage unit, wherein the printing device determines whether or not to execute the writing process based on at least one of the amount of power supplied via the wired interface and the remaining charge of the power storage unit. (Configuration 2) A printing device as described in configuration 1, characterized in that the writing process is not executed while a process other than the writing process is being executed, and when the execution of the other process is completed, it is determined whether or not to execute the writing process based on at least one of the amount of power supply and the remaining charge. (Configuration 3) The printing device according to configuration 1 or 2, wherein the other processes include a process of executing a job received from an external device. (Configuration 4) The printing device according to any one of configurations 1 to 3, further comprising: determining whether or not to execute the writing process based on the amount of power supply and the remaining charge. (Configuration 5) The printing device according to any one of configurations 1 to 4, wherein the writing process is executed when the amount of power supply is not equal to or greater than a first threshold value. (Configuration 6) The printing device according to any one of configurations 1 to 5, characterized in that when the amount of power supply is equal to or greater than the first threshold and the remaining charge is equal to or greater than a second threshold, the writing process is not executed. (Configuration 7) A printing device described in any one of configurations 1 to 6, characterized in that when the power supply amount is greater than or equal to the first threshold and the remaining charge amount is not greater than or equal to the second threshold, the writing process is executed after charging the storage unit. (Configuration 8) A printing device described in any one of configurations 1 to 7, characterized in that when charging the storage unit when the power supply amount is greater than or equal to the first threshold and the remaining charge amount is not greater than or equal to the second threshold, some or all of the operation of the printing device is temporarily suspended. (Configuration 9) A printing device according to any one of configurations 1 to 8, further comprising a determination means for determining whether a job operation is being executed before determining whether the power supply amount is greater than or equal to the first threshold. (Configuration 10) The printing device according to any one of configurations 1 to 9, wherein the other processes include a power supply state change process that is executed when the power supply state changes. (Configuration 11) A printing device described in any one of configurations 1 to 10, characterized in that if the remaining charge is equal to or greater than a third threshold, the writing process is not executed, and if the remaining charge is not equal to or greater than the third threshold, the writing process is executed. (Configuration 12) A printing device described in any one of configurations 1 to 11, characterized in that, in the processing when the power supply state changes, if it is determined that the remaining charge has fallen below a fourth threshold, the writing process is executed, and if it is determined that the remaining charge is not below the fourth threshold, the writing process is not executed. (Configuration 13) The printing device according to any one of configurations 1 to 12, wherein the writing process includes a process of encrypting all or a part of the data. (Configuration 14) The printing device according to any one of configurations 1 to 13, wherein the wired interface is a USB interface. (Configuration 15) The printing device according to any one of configurations 1 to 14, wherein the wired interface is a wired LAN. (Control Method 1) A control method for a printing device having a wired interface, a power storage unit which is charged with power supplied via the wired interface, a volatile first memory, a non-volatile second memory, and a writing means which executes a write process to write data stored in the first memory to the second memory using the power charged in the power storage unit, the control method being characterized in that it is determined whether or not to execute the write process based on at least one of the amount of power supplied via the wired interface and the remaining charge of the power storage unit. (Program 1) A control method for a printing device having a wired interface, a power storage unit which is charged with power supplied via the wired interface, a volatile first memory, a non-volatile second memory, and a writing means which executes a writing process to write data stored in the first memory to the second memory using the power charged in the power storage unit, the control method being characterized in that it is determined whether or not to execute the writing process based on at least one of the amount of power supplied via the wired interface and the remaining charge of the power storage unit. [Explanation of symbols]

[0076] 300 Printers 306 USB Interface 314 Data Memory 315 Non-volatile memory 606 EDLC

Claims

1. A wired interface; a power storage unit that is charged with power supplied via the wired interface; a volatile first memory; a second non-volatile memory; a write means for executing a write process of writing data stored in the first memory to the second memory by using the power stored in the power storage unit; A printing device having: determining whether to execute the writing process based on at least one of the amount of power supplied via the wired interface and the remaining charge of the power storage unit; A printing device comprising:

2. The write process is not executed while a process other than the write process is being executed, when the execution of the other process is completed, determining whether or not to execute the writing process based on at least one of the amount of power supply and the remaining charge amount; 2. The printing device according to claim 1.

3. The other processing includes a processing for executing a job received from an external device.

3. The printing device according to claim 2.

4. determining whether or not to execute the writing process based on the amount of power supply and the remaining charge amount; 4. The printing device according to claim 3.

5. If the amount of power supply is not equal to or greater than a first threshold, the write process is executed.

5. The printing apparatus according to claim 4.

6. When the amount of power supply is equal to or greater than the first threshold and the remaining charge is equal to or greater than a second threshold, the writing process is not executed.

6. The printing apparatus according to claim 5.

7. When the amount of supplied power is not equal to or greater than the first threshold and the remaining charge amount is not equal to or greater than the second threshold, the power storage unit is charged and then the writing process is executed.

7. The printing apparatus according to claim 6.

8. when the amount of supplied power is not equal to or greater than the first threshold and the remaining charge amount is not equal to or greater than the second threshold, a part or all of the operation of the printing device is temporarily stopped when charging the power storage unit.

8. The printing apparatus according to claim 7.

9. The power supply control device further includes a determination unit that determines whether a job operation is being performed before determining whether the amount of power supply is equal to or greater than the first threshold.

9. The printing apparatus according to claim 8.

10. The other processing includes a power supply state change processing that is executed when the power supply state changes.

4. The printing apparatus according to claim 2 or 3.

11. If the remaining charge amount is equal to or greater than a third threshold, the writing process is not executed, When the remaining charge amount is not equal to or greater than the third threshold value, the writing process is executed.

11. The printing device according to claim 10.

12. When it is determined that the remaining charge amount is below a fourth threshold in the power supply state change process, the writing process is executed, and when it is determined that the remaining charge amount is not below the fourth threshold, the writing process is not executed.

12. The printing device according to claim 11.

13. The writing process includes a process of encrypting a part or all of the data.

4. The printing device according to claim 1, wherein the printing device is a printer.

14. The wired interface is a USB interface.

4. The printing device according to claim 1, wherein the printing device is a printer.

15. The wired interface is a wired LAN.

4. The printing device according to claim 1, wherein the printing device is a printer.

16. A wired interface; a power storage unit that is charged with power supplied via the wired interface; a volatile first memory; a second non-volatile memory; a write means for executing a write process of writing data stored in the first memory to the second memory by using the power stored in the power storage unit; A method for controlling a printing device having determining whether to execute the writing process based on at least one of the amount of power supplied via the wired interface and the remaining charge of the power storage unit; A control method comprising:

17. A program for causing a computer to execute the method according to claim 16.

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