JP2018130910A - Image forming device having power-saving mode, and control method and program thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress unneeded power supply in a situation in which an image forming apparatus is returned from a power-saving mode in response to data transfer from an external device through a communication interface.SOLUTION: An image forming apparatus having an operation mode and a power-saving mode whose power consumption is lower than in the operation mode includes: return processing means for receiving transfer data from an external device through a communication interface and instructing return from the power-saving mode to the operation mode; and power control means for making a shift from the power-saving mode to the operation mode according to the instruction. The operation mode includes a first operation mode in which image formation is possible, and a second operation mode in which power consumption is lower than in the first operation mode and image formation is impossible, and the power control means determines whether to make a shift to the first operation mode or make a shift to the second operation mode on the basis of information showing a connection state of the communication interface during the power-saving mode.SELECTED DRAWING: Figure 6

Description

  The present invention relates to control of an image forming apparatus when returning from a power saving mode to an operation mode.

  Recent image forming apparatuses have a function of receiving and printing image data together with a print instruction from an external apparatus such as a PC via a communication interface. Further, recent image forming apparatuses have a function of shifting to a power saving mode in which a part of power supply is stopped when not used for a predetermined time, and reducing power consumption as much as possible without impairing user convenience. have. When the mode is shifted to the power saving mode, power supply to a printer unit, a scanner unit, or the like that consumes relatively large power is stopped. Patent Document 1 relates to mode transition control of an image forming apparatus, and prevents input data from being lost until the mode is changed from the power saving mode to the operation mode according to the change in the connection state of the communication interface. Techniques to do this are disclosed.

JP 2007-148594 A

  Until now, when there is data transfer from an external device via a communication interface during the power saving mode, processing for immediately returning to an operation mode (normal power state) in which printing processing is possible has been performed. This was intended to speed up the print output, but even if the received transfer data has contents that do not require print processing, a printer unit with high power consumption will be activated, and as a result, In some cases, power was wasted.

  An image forming apparatus having an operation mode and a power saving mode with lower power consumption than the operation mode, receiving transfer data from an external device via a communication interface, and switching from the power saving mode to the operation mode A return processing means for instructing a return; and a power control means for shifting from the power saving mode to the operation mode according to the instruction. The operation mode includes a first operation mode capable of image formation, and A second operation mode in which power consumption is lower than in the first operation mode and image formation is impossible, and the power control means is configured to perform the first operation based on information indicating a connection state of the communication interface during the power saving mode. It is determined whether to shift to one operation mode or to the second operation mode.

  According to the present invention, it is possible to suppress unnecessary power supply in a scene where the image forming apparatus is returned from the power saving mode in response to data transfer from the external apparatus via the communication interface.

1 is a diagram illustrating a configuration example of a printing system. The figure explaining the structure of a controller. The block diagram showing the electric power supply / stop state to each main part in MFP at the time of a 1st operation mode. The block diagram showing the electric power supply / stop state to each main part in MFP at the time of a 2nd operation mode. The block diagram showing the electric power supply / stop state to each main part in MFP at the time of the power saving mode based on Example 1. FIG. 5 is a flowchart illustrating details of mode transition control according to the first embodiment. 6 is a timing chart for explaining a return operation from the power saving mode. 6 is a timing chart for explaining a return operation from the power saving mode. The flowchart which shows the flow of a return process. FIG. 10 is a block diagram showing a power supply / stop state to main parts in the MFP in the power saving mode according to the second embodiment. 10 is a flowchart illustrating details of mode transition control according to the second embodiment. The figure explaining the internal structure of the transfer data in USB protocol.

  Hereinafter, the present invention will be described in detail according to preferred embodiments with reference to the accompanying drawings. In addition, the structure shown in the following Examples is only an example, and this invention is not limited to the structure shown in figure.

(System configuration)
FIG. 1 is a diagram illustrating a configuration example of a printing system according to the present embodiment. The MFP 100 is an image forming apparatus generally called a multi function peripheral, and has a plurality of functions such as a PDL print function and a copy function. The MFP 100 includes a controller 101, an operation unit 102 on which a user performs various input operations, a scanner unit 103 that is an image input device, and a printer unit 104 that is an image output device. The operation unit 102, the scanner unit 103, and the printer unit 104 are each connected to the controller 101, and the controller 101 controls the operation of each unit. The controller 101 is connected to the client PC 120 via a predetermined communication interface, which is a USB (Universal Serial Bus) in this embodiment. When printing an electronic document or the like created on the client PC 120, the user creates a print job and transmits it via USB, and instructs the MFP 100 to print. In the following description, USB will be described as an example, but the communication interface is not limited to this. For example, IEEE 1394 (FireWire / i.LINK) or Serial ATA (SATA) may be used. The controller 101 is connected to a LAN (Local Area Network) and communicates with the client PC 110 and the print server 111. The user can similarly create a print job on the client PC 110 and instruct the MFP 100 to print. At this time, the print job is provided to the MFP 100 via the print server 111.

  Next, the configuration of the controller 101 will be described with reference to FIG. The controller 101 includes a CPU 201, a ROM 202, a RAM 203, an HDD 204, a power control unit 205, an image processing unit 206, and various interfaces (I / F), and is connected to each other via a system bus. The various I / Fs include a scanner I / F 207, a printer I / F 208, a USB I / F 209, a network I / F 210, and an operation unit I / F 211. The CPU 201 is an arithmetic processing unit that performs main control, and each function of the MFP 100 is realized by executing various programs stored in the ROM 203 and the HDD 204. The ROM 202 stores a boot program necessary for system startup. A RAM 203 is a readable / writable memory for providing a work area as a main storage unit of the CPU 201, and is also used as an image memory for temporarily storing image data to be internally processed. The HDD 204 is a nonvolatile memory, and stores operating system and application programs, setting value data and user data that need to be retained even after the MFP 100 is turned off.

  The power control unit 205 controls the power supply to each unit (switches on / off) according to the operation state of the MFP 100. Specifically, based on the control signal received from the CPU 201 via the system bus, power supply control is performed by transmitting a control signal to the power supply device 220 that is a power supply unit. Further, the power control unit 205 can detect the presence or absence of connection of the client PC 120 based on the potential of a power supply line 330 described later. The power supply device 220 is connected to the commercial power supply 221 and supplies power to each unit of the MFP 100 based on a control signal received from the power control unit 205. The power supply device 220 is always energized as long as it is connected to the commercial power supply 221 and can supply power. The power supply device 220 includes a power supply circuit for outputting DC power to each part of the MFP 100.

  The image processing unit 206 performs correction, processing, editing, and the like on the input image data, and performs image processing such as color conversion, filtering, and resolution conversion to obtain image data to be subjected to printing processing in the printer unit 104. Generate. In addition, a scanner I / F 207, a printer I / F 208, and a USB I / F 209 are connected to the image processing unit 206. A scanner I / F 207 connects the scanner unit 103 and the controller 101, a printer I / F 208 connects the printer unit 104 and the controller 101, and a USB I / F 209 connects the client PC 120 and the controller 101. The MFP 100 receives the print job from the client PC 120 via the USB I / F 209 with the client PC 120 as a host and itself as a device. The USB cable used for connection with the client PC 120 has a power supply line separately from the signal line, and the power control unit 205 and the USB IF 209 are connected by the power supply line 330. The image processing unit 206 can detect the presence or absence of disconnection of the USB connection during the power saving mode by monitoring the potential change of the power supply line 330. In addition, the image processing unit 206 receives data transfer from the client PC 120 and also performs a return process from the power saving mode to the operation mode.

  The network I / F 210 is an interface for connecting to a LAN. The operation unit I / F 211 is an interface for performing input / output with the operation unit 102 configured by a liquid crystal touch panel or the like. The CPU 201 outputs image data to be displayed to the operation unit 102 via the operation unit I / F 211. The operation unit I / F 211 transmits data input by the user via the operation unit 102 to the CPU 201.

  Next, mode transition control of the MFP 100 will be described. The MFP 100 is broadly divided into two types of modes: an operation mode in which the device is used and a power saving mode in which the device is not used. Further, the operation mode is divided into a first operation mode in which print processing is possible and a second operation mode in which print processing is impossible but data processing and communication processing are possible. 3 to 5 are block diagrams showing power supply / stop states to main components in the MFP 100 in each mode. The mode transition control is performed by a control signal from the CPU 201 or a microcomputer (not shown) as a USB controller in the image processing unit 206. Specifically, by rewriting a register value in the power control unit 205 with a control signal, the switches 304, 305, and 315 to 320 are turned on / off to control power supply to each unit.

  In the case of the first operation mode shown in FIG. 3, power is supplied to all the main units in the apparatus such as the controller 101, the operation unit 102, the scanner unit 103, and the printer unit 104. Therefore, in this first operation mode, the user can use all functions of the MFP 100 such as scanning and printing. On the other hand, in the second operation mode shown in FIG. 4, power is supplied to the controller 101, but power supply to each major part with high power consumption is stopped. That is, the supply of power to the operation unit 102, the scanner unit 103, and the printer unit 104, which are indicated by hatching in FIG. 4, is stopped. Therefore, in the second operation mode, initialization processing necessary for data reception via LAN or USB and re-establishment of USB connection can be performed, but functions such as scanning and printing cannot be used.

  Further, in the power saving mode shown in FIG. 5, the power supply to the CPU 201 and the HDD 208 in the controller 101 is also cut off (switches 315 and 316 are off). As is clear from FIG. 5, in the power saving mode, in addition to the scanner unit 103 and the printer unit 104, the CPU 201 and the HDD 204 are also indicated by diagonal lines, and the power supply to these is also stopped. Here, in the image processing unit 206, only half of the blocks are hatched. This means that in the image processing unit 206, there are a part where the power supply is maintained and a part where the power supply is stopped. That is, the power supply is continued without turning off the switch 320 itself, and the microcomputer in the image processing unit 206 can detect reception of transfer data from the client PC 120 via the USB I / F 209. When reception of the transfer data is detected, a signal (hereinafter referred to as “notification signal”) 340 notifying that is transmitted from the microcomputer to the power control unit 205. In response to the notification signal 340, the power control unit 205 performs power control for shifting to the first operation mode or the second operation mode. While maintaining the power supply for performing such control, the power supply to a module (for example, a clock distribution circuit) that does not require operation in the image processing unit 206 is interrupted by, for example, clock gating.

  Note that when the external device is connected only via the network I / F 210 and not connected via the USB I / F 209, the power supply to the image processing unit 206 is also stopped (the switch 320 is also turned off). In this case, power supply to the network I / F 210 is maintained, and transfer data from the client PC 110 and the server 111 can be received. Whether the power supply to the image processing unit 206 is continued or stopped in the power saving mode is determined based on whether the client PC 120 is normally connected via the USB I / F 209 at the time of shifting to the power saving mode. The In the following, based on the configuration in which the client PC 120 is connected via the USB I / F 209, the mode transition for determining the power supply state at the return depending on whether or not the USB connection is disconnected during the power saving mode. Control will be described.

(Details of mode transition control)
FIG. 6 is a flowchart illustrating details of mode transition control (power control) according to the present embodiment. First, in step 601, the transition control from the first operation mode to the power saving mode is executed when the condition for shifting to the power saving mode is satisfied. Specifically, based on a control signal from the CPU 201 that turns off the switch 305 and the switches 315 to 319, the power control unit 205 stops supplying power to the printer unit 104 and the CPU 201. As a condition for shifting to the power saving mode, there are a case where the power saving button on the operation unit 102 is pressed and the MFP 100 is not operated for a predetermined time.

  Under the power saving mode, in step 602, the power control unit 205 monitors the potential fluctuation of the power supply line 330 connected to the USB I / F 209. When the connection with the client PC 120 is disconnected due to disconnection of the USB cable or the like, the potential of the power supply line 330 is lowered, so it is possible to detect whether the USB connection is disconnected or not by monitoring this potential state. . Note that the potential of the power supply line 330 decreases due to the cable disconnection or the shutdown of the client PC 120. In other words, not only physical disconnection such as disconnection of the USB cable but also electrical disconnection is included in the “disconnection” here. In this case, whether or not the potential of the power supply line 330 has decreased is determined by whether or not the normal potential (for example, 5 V) has dropped to a predetermined threshold value (for example, 0.7 V) or less. If a potential drop in the power supply line 330 is detected, the process proceeds to step 603. On the other hand, if no potential drop is detected, the process proceeds to step 604.

  In step 603, the power control unit 205 stores information (for example, a flag) indicating the potential drop of the power supply line 330 in the internal register as information indicating the connection state with the client PC 120 in the power saving mode. This potential drop information is also information indicating the insertion / removal state of the USB cable. In this embodiment, it is determined whether or not the USB connection with the client PC 120 has been disconnected in the power saving mode based on the presence or absence of the flag as the potential drop information, and whether the transition to the first operation mode is performed. It is determined whether to move to.

  In step 604, the presence or absence of data transfer from the client PC 120 is monitored by the microcomputer in the image processing unit 206. The transfer data is a so-called print job (print instruction data in PDL format), and a command that instructs execution of initialization processing (enumeration) for establishing a USB connection between the host and the device. There is. If transfer data from the client PC 120 is detected, the process proceeds to step 605. On the other hand, if transfer data is not detected, the process proceeds to step 606.

  In step 605, the aforementioned notification signal 340 is sent to the power control unit 205 by the microcomputer in the image processing unit 206 in response to data transfer from the client PC 120.

  In step 606, the power control unit 205 monitors whether the notification signal 340 has been received. If the notification signal 340 is received from the image processing unit 206, the process proceeds to step 607. On the other hand, when the notification signal 340 has not been received, the process returns to step 602 and the power saving mode is continued. Note that the monitoring processing in steps 602, 604, and 606 is executed at predetermined intervals (for example, every several hundred msec).

  In step 607, whether to shift to the first operation mode or to shift to the second operation mode is determined based on the potential decrease information stored in the internal register of the power control unit 205. If there is a potential drop during the power saving mode, the USB connection is temporarily interrupted, so an initialization process is required to establish the connection again. Therefore, when the potential drop information exists, it can be estimated that the transfer data from the client PC 120 is an instruction command for the initialization process. Therefore, in this case, the controller 101 is activated to shift to the second operation mode in which the printer unit 104 and the like are not activated. On the other hand, if there is no potential drop during the power saving mode, the USB connection is maintained even during the power saving mode, and it is estimated that the transfer data from the client PC 120 is a print job. Therefore, when there is no potential drop information, the printer unit 104 is shifted to the first operation mode that activates the printer unit 104 and the like. In this embodiment, if a flag as potential drop information is held, the process proceeds to step 608. On the other hand, if the flag is not held, the process proceeds to step 609.

  In step 608, the power control unit 205 executes the transition control to the second operation mode based on the determination that the transfer data from the client PC 120 is an instruction command for initialization processing for re-establishing the USB connection. Is done. Specifically, power supply to the CPU 201 and the HDD 204 is resumed based on a control signal for turning on the switches 315 and 316 from the microcomputer in the image processing unit 206. Then enumeration to establish a USB connection is performed.

  In step 609, based on the determination that the transfer data from the client PC 120 is a print job, the power control unit 205 executes control for shifting to the first operation mode. Specifically, based on a control signal for turning on the switches 305 and 315 to 319 from the microcomputer in the image processing unit 206, power supply to each unit in the apparatus including the printer unit 104 is resumed. Then, print processing according to the print job is executed.

  FIG. 7 is a timing chart for explaining the return operation from the power saving mode. The horizontal axis represents the passage of time. Both figures show the relationship between the power state of the MFP 100 and each step of the flow of FIG. 6 described above.

  FIG. 7 shows a case where the operation mode returns to the second operation mode. First, the MFP 100 transitions to the power saving mode (S601). Then, when the USB cable is disconnected during the power saving mode, a potential decrease is detected (Yes in S602), and the potential decrease information is held in the internal register of the power control unit 205 (S603). After that, it is assumed that the power saving mode is continued and the USB cable is inserted again. Then, data transfer of the USB connection establishment request is performed from the client PC 120 to the MFP 100. Upon receiving this data transfer (Yes in S604), the image processing unit 206 sends a notification signal 340 (S605), and the power control unit 205 receives it (Yes in S606). At this time, since the power control unit 205 holds the potential drop information (Yes in S607), the transition control from the power saving mode to the second operation mode is performed (S608). In this second operation mode, the printer unit 104 is not activated and enumeration is executed with lower power consumption.

  FIG. 8 shows a case where the operation mode returns to the first operation mode. First, the MFP 100 transitions to the power saving mode (S601). Then, during the power saving mode, the client PC 120 performs print job data transfer. Upon receiving this data transfer (Yes in S604), the image processing unit 206 sends a notification signal 340 (S605), and the power control unit 205 receives it (Yes in S606). At this time, since the USB cable is not disconnected during the power saving mode, the power control unit 205 does not hold the potential decrease information (No in S607). Therefore, transition control from the power saving mode to the first operation mode is performed (S609). In the first operation mode, the printer unit 104 is activated and printing processing is executed promptly.

  Next, return processing from the power saving mode will be described. FIG. 9 is a flowchart showing the flow of return processing. This process is executed by the CPU 201.

  In step 901, it is determined whether or not potential drop information is held in the internal register of the power control unit 205. If the voltage drop information is held, the process proceeds to step 902 to perform processing for establishing a USB connection. On the other hand, if the voltage drop information is not held in the register, the USB connection is normally established, and the process is exited.

  In step 902, enumeration for establishing a USB connection is performed under the second operation mode. Needless to say, when a standard other than USB is adopted as the communication interface, initialization processing corresponding to the standard is executed. When the initialization process is finished, in step 903, the potential drop information held in the register of the power control unit 205 is reset. The above is the content of the return process.

  As described above, according to the present exemplary embodiment, when the disconnection of the connection via the communication interface with the client PC is detected during the power saving mode of the image forming apparatus, the information is retained. After that, when data is transferred from the client PC, the return mode (power state) is determined depending on whether or not the connection is disconnected during the power saving mode. In other words, if the connection is disconnected during the power saving mode, it is determined that the transfer data is an instruction instruction for initialization processing for establishing the connection, and the printer unit 104 is shifted to the second operation mode that does not start up. To do. On the other hand, if the connection is not disconnected, it is determined that the transfer data is a print job, and the process proceeds to the first operation mode in which the printer unit 104 is activated. As a result, when returning from the power saving mode triggered by data transfer from the client PC, the power supply to the printer unit 104 with high power consumption can be limited to the case where the printing process is actually performed. .

  In the first embodiment, if there is a disconnection of the USB connection during the power saving mode, the information is retained, and the information is referred to when returning with the data transfer as an opportunity to return to the first operation mode. It was decided whether to return to the two operation mode. Next, a mode in which the contents transferred from the client PC 120 are analyzed to determine whether to return to the first operation mode or to return to the second operation mode will be described as a second embodiment. The description common to the first embodiment will be omitted or simplified, and the following description will focus on the differences.

  FIG. 10 is a block diagram showing a power supply / stop state to each main part in the MFP in the power saving mode according to the present embodiment, corresponding to FIG. 5 described above. The difference from FIG. 5 is that the image processing unit 206 notifies the power control unit 205 of two types of notification signals according to the transfer data, specifically, either the first notification signal 1001 or the second notification signal 1002. It is a point that outputs. Here, the first notification signal 1001 is a signal output when the content of the transfer data is a print job, and is a notification signal corresponding to the first operation mode. On the other hand, the second notification signal 1002 is a signal that is output when the content of the transfer data is an instruction command for initialization processing (here, enumeration) for establishing a connection. It is a notification signal corresponding to the mode. FIG. 11 is a flowchart illustrating details of mode transition control (power control) according to the present embodiment. This will be described in detail below with reference to FIGS.

  First, in step 1101, the transition control from the first operation mode to the power saving mode is executed when the condition for shifting to the power saving mode is satisfied. Under the power saving mode, in step 1102, the microcomputer in the image processing unit 206 monitors the presence / absence of data transfer from the client PC 120. If data transfer is detected, the process proceeds to step 1103. If data transfer is not detected, the process proceeds to step 1106.

  In step 1103, the microcomputer in the image processing unit 206 analyzes the transfer data from the client PC 120 and determines whether it is a print job or an enumeration instruction command. FIG. 12 is a diagram for explaining the internal structure of transfer data in the USB protocol. Transfer data by USB is sent in a bundle of four types of packets: SOF packet, token packet, data packet, and handshake packet. Each packet includes information for identifying the contents of each packet, called PID. As shown in FIG. 12, when the transfer data is a print job, the PID of the token packet is “OUT”. On the other hand, when the transfer data is an enumeration instruction command, the PID of the token packet is “SETUP”. Whether the transfer data from the client PC 120 is a print job or an enumeration instruction command can be determined by whether or not a token packet with a PID of “SETUP” follows the SOF packet. As a result of the analysis, if the received transfer data is a print job, the process proceeds to step 1104. On the other hand, if the received transfer data is an enumeration instruction command, the process proceeds to step 1105.

  In step 1104, the first notification signal 1001 is sent to the power control unit 205 by the microcomputer in the image processing unit 206 in response to receiving the transfer data. In step 1105, the second notification signal 1002 is sent to the power control unit 205 by the microcomputer in the image processing unit 206 in response to receiving the transfer data.

  In step 1106, the power control unit 205 monitors whether any notification signal is received. If the first notification signal 1001 or the second notification signal 1002 is received from the image processing unit 206, the process proceeds to step 1107. On the other hand, if neither notification signal has been received, the process returns to step 1102 to continue the power saving mode.

  In step 1107, the power control unit 205 switches processing according to the received notification signal. Specifically, if the received notification signal is the first notification signal 1001, since the transfer data is a print job, the process proceeds to step 1108 to execute the transition control to the first operation mode. On the other hand, if the received notification signal is the second notification signal 1002, since the transfer data is an enumeration instruction command, the process proceeds to step 1109 to execute the transition control to the second operation mode.

  The above is the content of the mode transition control according to the present embodiment. In the present embodiment, as shown in FIG. 10, the first notification signal 1001 and the second notification signal 1002 are configured by separate communication lines, and input ports on the power control unit 205 side are provided correspondingly. ing. In the case of this configuration, the notification signal itself is the same (High / Low) and can be distinguished by which input port is High. However, the present embodiment is not limited to such a configuration. For example, a common input port may be used to distinguish the first notification signal and the second notification signal according to the content of the notification signal.

  As described above, in this embodiment, when receiving the transfer data, the image processing unit 206 transmits a notification signal that can identify whether the transfer data is a print job to the power control unit 205. Based on the received notification signal, the power control unit 205 shifts to the first operation mode when the transfer data related to the reception is a print job, and shifts to the second operation mode when the transfer data is not a print job. Even in this embodiment, at the time of return from the power saving mode triggered by data transfer from the client PC, the power supply to the printer unit 104 with large power consumption can be limited to the case where the printing process is actually performed. It becomes possible.

(Other examples)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

Claims (11)

An image forming apparatus having an operation mode and a power saving mode in which power consumption is lower than that of the operation mode,
A return processing means for receiving transfer data from an external device via a communication interface and instructing a return from the power saving mode to the operation mode;
In accordance with the instructions, power control means for shifting from the power saving mode to the operation mode;
With
The operation mode includes a first operation mode in which image formation is possible and a second operation mode in which power consumption is lower than that in the first operation mode and image formation is impossible.
The power control means determines whether to shift to the first operation mode or the second operation mode based on information indicating a connection state of the communication interface during the power saving mode.
An image forming apparatus. The information indicating the connection state is information indicating an insertion / extraction state of a cable used for connection between the external device and the communication interface,
The image forming apparatus according to claim 1, wherein the power control unit shifts to the second operation mode when the information indicating the insertion / removal state indicates that the cable is disconnected. The information indicating the connection state is information indicating a potential state of a power supply line connecting the power control unit and the communication interface,
The image forming apparatus according to claim 1, wherein the power control unit shifts to the second operation mode when the information indicating the potential state indicates a decrease in potential. When the return processing unit detects reception of transfer data, the return processing unit transmits a signal notifying the reception to the power control unit as the instruction,
The image forming apparatus according to claim 1, wherein the power control unit shifts to the first operation mode or the second operation mode in response to the signal to be notified. An image forming apparatus having an operation mode and a power saving mode in which power consumption is lower than that of the operation mode,
A return processing means for receiving transfer data from an external device via a communication interface and instructing a return from the power saving mode to the operation mode;
In accordance with the instructions, power control means for shifting from the power saving mode to the operation mode;
With
The operation mode includes a first operation mode in which image formation is possible and a second operation mode in which power consumption is lower than that in the first operation mode and image formation is impossible.
When the return processing unit receives the transfer data, the return processing unit transmits a notification signal capable of identifying whether the transfer data is a print job to the power control unit as the instruction.
The power control means shifts to the first operation mode based on the received notification signal when the transfer data related to the reception is a print job, and the first control mode when the transfer data related to the reception is not a print job. Transition to the two operation mode,
An image forming apparatus. The notification signal includes a first notification signal corresponding to a case where the transfer data is a print job and a second notification signal corresponding to a case where the transfer data is an instruction command for initialization processing of the communication interface. Including
The return processing means transmits either the first notification signal or the second notification signal to the power control means according to the received transfer data.
The image forming apparatus according to claim 5.   The image forming apparatus according to claim 1, wherein the communication interface is a USB. When transitioning to the second operation mode, enumeration to establish a USB connection is executed,
The image forming apparatus according to claim 7, wherein the power control unit resets information indicating the connection state when the enumeration is completed. An image forming apparatus control method having an operation mode and a power saving mode in which power consumption is lower than the operation mode,
A return processing step of receiving transfer data from an external device via a communication interface and instructing a return from the power saving mode to the operation mode;
In accordance with the instructions, a power control step for shifting from the power saving mode to the operation mode;
Including
The operation mode includes a first operation mode in which image formation is possible and a second operation mode in which power consumption is lower than that in the first operation mode and image formation is impossible.
In the power control step, based on information indicating a connection state of the communication interface during the power saving mode, it is determined whether to shift to the first operation mode or to the second operation mode.
A control method characterized by that. An image forming apparatus control method having an operation mode and a power saving mode in which power consumption is lower than the operation mode,
A return processing step of receiving transfer data from an external device via a communication interface and instructing a return from the power saving mode to the operation mode;
In accordance with the instructions, a power control step for shifting from the power saving mode to the operation mode;
Including
The operation mode includes a first operation mode in which image formation is possible and a second operation mode in which power consumption is lower than that in the first operation mode and image formation is impossible.
In the return processing step, when the transfer data is received, a notification signal capable of identifying whether the transfer data is a print job is transmitted to the power control unit as the instruction,
In the power control step, based on the received notification signal, when the transfer data related to the reception is a print job, the process is shifted to the first operation mode, and when the transfer data related to the reception is not a print job, Transition to the two operation mode,
A control method characterized by that.   A program for causing a computer to function as the image forming apparatus according to any one of claims 1 to 8.