JP5779894B2 - Communication apparatus and image processing apparatus - Google Patents

Description

  The present invention relates to a communication apparatus that performs power saving control, and an image processing apparatus including the communication apparatus.

  Conventionally, communication apparatuses and image processing apparatuses having a communication function are widely known. Among these communication devices and image processing devices, there are devices that reduce power consumption of their own devices by performing power saving control. For example, Patent Document 1 below describes an image forming apparatus that controls itself so as to stop energization of some units while data processing is not performed. An image forming apparatus described in Patent Literature 1 below receives a variety of packets including a print job from an external device via a network, and responds to the received packet. And a printer for executing.

  In this image forming apparatus, power is supplied to the main communication unit and the printer in the standby mode (normal mode), and power supply to the main communication unit and the printer is stopped in the power saving mode (deep sleep mode). . For this reason, since the image forming apparatus disclosed in Patent Document 1 cannot respond by the main communication unit in the power saving mode, the image forming apparatus includes a sub communication unit (packet processing unit) that performs a response on behalf of the main response unit. In the power saving mode, the sub-communication unit responds by proxy when receiving a packet that allows proxy response, and activates the main response unit and printer unit when receiving a packet that cannot be proxy response such as a print job. Let

JP 2009-151537 A

  In the image forming apparatus described in Patent Document 1, energization to the main control unit is stopped when shifting from the standby mode to the power saving mode. For this reason, the main communication unit shuts down each file before it is de-energized, and writes the data stored in the volatile memory to the storage. Migration processing including processing is performed. This transition process varies depending on the configuration of the main communication unit, but generally takes about 1 second to 1 minute.

  During the execution of the migration process, there is a possibility that a packet is transmitted from an external device to the own device. For example, when a packet for making a request such as a job request or an information request is transmitted, it is necessary to respond to these packets. However, the main communication unit may not be able to respond during execution of the migration process. In addition, during the transition process, since the transition to the power saving mode has not yet been completed, a proxy response cannot be performed by the sub communication unit. In other words, even if the sub response unit is configured to perform a proxy response during the migration process, it is natural that the sub response unit cannot respond to a packet for which the proxy response is impossible. For this reason, if a packet is transmitted from an external device while the migration process is being performed, the packet cannot be responded and the packet may be lost.

  Accordingly, the present invention has been made to solve the above-described problems, and a communication device capable of preventing a loss of a packet transmitted from an external device during execution of a transition process to a power saving mode, and the communication device An object of the present invention is to provide an image processing apparatus including a communication device.

  A communication apparatus according to the present invention includes a power control unit that performs transition control of a power mode including a standby mode and a power saving mode in which power consumption is smaller than the standby mode, and a first communication unit that receives a request packet from an external device In the standby mode, a response packet is returned to the request packet received by the first communication unit. In the power saving mode, energization of at least a part is stopped by the power control unit, so that the response packet A second communication unit that makes it impossible to reply, and the first communication unit receives a request packet while the second communication unit is executing the process of shifting from the standby mode to the power saving mode. If received, the request packet is held, and after returning to the standby mode, the held request packet is output to the second communication unit, and the second communication unit receives the first communication unit. Accordingly, characterized in that return a response packet to the output request packet.

  According to the communication device of the present invention, when a request packet is received from an external device in the standby mode, a response packet is returned by the second communication unit. In the power saving mode, power saving can be achieved by stopping energization of at least a part of the second communication unit. On the other hand, when the request packet transmitted from the external device to the own device is received while the second communication unit is executing the transition process from the standby mode to the power saving mode, the request packet is received by the first communication unit. Retained. Then, after the own device returns to the standby mode, the held request packet is output from the first communication unit to the second communication unit. A response packet to the output request packet is returned by the second communication unit. Thereby, a response packet to the request packet received during the execution of the migration process can be returned. Therefore, it is possible to prevent a loss of packets transmitted from the external device during the execution of the transition process to the power saving mode.

  In the communication device according to the present invention, when the first communication unit holds the request packet and the transition process by the second communication unit is completed, the first communication unit outputs a return instruction for returning the power mode to the standby mode, The power control unit returns the power mode to the standby mode in accordance with the return instruction output by the first communication unit, and the second communication unit responds to the request packet output by the first communication unit after the return. It is preferable to send a packet back.

  According to this configuration, when the migration process is completed with the request packet held, a return instruction is output. Thereby, when the transition process is completed and the mode is shifted to the power saving mode, a return instruction is output, and the own device returns from the power saving mode to the standby mode. Then, the held request packet is output from the first communication unit to the second communication unit, and a response packet to the output request packet is returned by the second communication unit. Thereby, when a request packet is received during the execution of the migration process, it is possible to return the device to the standby mode after the completion of the migration process and immediately respond to the request packet.

  In the communication device according to the present invention, when the first communication unit receives a request packet that can be responded by the first communication unit while the migration process is being performed in the second communication unit, the response packet When a request packet that cannot be answered by the first communication unit is received, it is preferable to hold the request packet.

  According to this configuration, when a request packet that can be responded to by the first communication unit is received during execution of the migration process, a response packet is returned. Thereby, it is possible to respond to the request packet that can be responded by the first communication unit even during the execution of the migration process. On the other hand, when a request packet that cannot be answered by the first communication unit is received, the request packet is held. As a result, a response can be made when returning, so that packet loss can be prevented.

  In the communication device according to the present invention, when the first communication unit receives a request packet that can be responded by the first communication unit in the power saving mode, the first communication unit returns a response packet, and the first communication unit does not respond. When a possible request packet is received, a return instruction for returning the power mode to the standby mode is output, and the power control unit returns the power mode to the standby mode according to the return instruction output by the first communication unit, The second communication unit preferably returns a response packet to the request packet received in the power saving mode by the first communication unit after returning.

  According to this configuration, in the power saving mode, when a request packet that can be responded to by the first communication unit is received, a response packet is returned. Thereby, it is possible to respond to a request packet that can be answered by the first communication unit without returning the second communication unit even in the power saving mode. On the other hand, when a request packet that cannot be answered by the first communication unit is received, a return instruction is output, and the own apparatus is returned to the standby mode. Thus, even when a request packet that cannot be responded to by the first communication unit is received in the power saving mode, the second communication unit can be activated to return a response packet.

  In the communication device according to the present invention, the second communication unit outputs a switching instruction to switch the communication control mode of the first communication unit to the transition control mode when starting the transition process to the first communication unit. When the transition process is completed, a switching instruction for switching the communication control mode of the first communication unit to the normal control mode is output to the first communication unit, and the first communication unit receives from the second communication unit When a switching instruction for switching to the transition control mode is output, the communication control mode is switched to the transition control mode. When a switching instruction for switching to the normal control mode is output, the communication control mode is switched to the normal control mode, and transition control is performed. When a request packet is received in the mode, the request packet is retained. When the request packet is retained when switching to the normal control mode, a return instruction is issued to the second communication unit. It is preferable to.

  According to this configuration, the communication control mode of the first communication unit is switched to the shift control mode by the switching instruction output when the shift process by the second communication unit is started, and is received in the shift control mode. The request packet is held by the first communication unit. That is, while the second communication unit is executing the transition process, the communication control mode of the first communication unit becomes the transition control mode, and the received request packet is held by the first communication unit. In addition, the communication control mode of the first communication unit is switched to the normal control mode by a switching instruction that is output after the transition process by the second communication unit is completed. That is, after the transition processing by the second communication unit is completed, the own device shifts to the power saving mode, and the communication control mode of the first communication unit is switched to the normal control mode. When the request packet is held in the first communication unit when the mode is switched to the normal control mode, a return instruction is output to the second communication unit, and the own device returns to the standby mode. Therefore, when a request packet is received during the transition process, it is possible to output a return instruction and return the host apparatus to the standby mode at the timing when the host apparatus transitions to the power saving mode. In other words, the request packet received from when the switching instruction is output when the transition process is started until the switching instruction is output after the transition process is completed is retained, Immediately after the switching instruction is output, the return instruction can be output.

  An image processing apparatus according to the present invention includes the above-described communication device and a processing unit that performs image processing. The first communication unit receives a request packet for requesting image processing from an external device. The image processing is performed according to the request packet.

  According to the image processing apparatus of the present invention, when a request packet for requesting image processing is received from an external device in the standby mode, a response packet is returned and image processing is performed. On the other hand, when a request packet is received while the second communication unit is executing the migration process, the request packet is held by the first communication unit. Then, after returning to the standby mode, the held request packet is output from the first communication unit to the second communication unit, and a response packet for the output request packet is returned by the second communication unit. The Thereby, a response packet to the request packet received during the execution of the migration process can be returned. Therefore, it is possible to prevent a loss of packets transmitted from the external device during the execution of the transition process to the power saving mode.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to prevent the loss of the packet transmitted from the external device during execution of the transfer process to power saving mode.

1 is a block diagram illustrating a configuration of an MFP according to an embodiment. FIG. 10 is a flowchart illustrating a migration process performed by a back end unit included in an MFP. It is a sequence diagram which shows a response process in case the front end part receives the request packet which cannot respond during execution of a transfer process. It is a sequence diagram which shows a response process when a front end part receives the request packet which cannot respond in a power saving mode.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. First, with reference to FIG. 1, an MFP (Multifunction Peripheral) 1 will be described as an example of an image processing apparatus according to the present embodiment. The MFP 1 includes the communication device according to the present embodiment. FIG. 1 is a block diagram showing the configuration of the MFP 1.

  The MFP 1 is a multifunction machine that executes image processing including printing, scanning, FAX (facsimile), and IFAX (Internet FAX). The MFP 1 is a network multifunction device that receives a job request transmitted from a personal computer (PC) 3 via a LAN (local area network) 90 and executes the above-described image processing.

  This MFP 1 has a function of shifting its own power mode for power saving, and when there is no job request for a predetermined time, the power mode is shifted from a standby mode capable of image processing to a power saving mode. To do. In the power saving mode, energization of each processing unit that performs image processing and a part of the NIC 14 is stopped. In this power saving mode, since energization to a part of the NIC 14 is stopped, the MFP 1 cannot respond when receiving a packet such as a job request, and therefore returns to the standby mode and responds.

  Subsequently, each component constituting the MFP 1 will be described. The MFP 1 includes a printer 10, a scanner 11, an NCU (Network Control Unit) 12, a modem 13, and a NIC (Network Interface Card) 14 in order to execute the above-described image processing.

  In this embodiment, the printer 10 is a printer that performs printing by an electrophotographic method. The scanner 11 is constituted by a CCD or the like, and optically reads a document to generate image data. Further, the image data of the document read by the scanner 11 is printed by the printer 10, so that copying is performed. The NCU 12 is connected to the modem 13 and controls the connection between the modem 13 and the public telephone line (PSTN) 91. In the MFP 1, FAX transmission / reception is performed by the NCU 12 and the modem 13.

  The NIC 14 controls data transmission / reception performed via the LAN 90. Further, the NIC 14 transmits an electronic mail attached with image data via the Internet connected to the LAN 90. Thereby, transmission of I-FAX is performed. The I-FAX is received by acquiring image data from the email received by the NIC 14. The acquired image data may be printed by the printer 10 or displayed on a display such as a personal computer (PC) 3.

  In order for each of the above components to perform image processing, the MFP 1 includes a codec 15 and an image storage unit 16. The codec 15 encodes and compresses the image data generated by the scanner 11 and decodes the encoded and compressed image data. The image storage unit 16 stores image data encoded and compressed by the codec 15, FAX data, I-FAX data, print data transmitted from the PC 3, and the like.

  The MFP 1 also includes an operation unit 17 for accepting operations from the user and a Web server 18 for the user to perform operations using the PC 3. The operation unit 17 includes various keys that receive operations from the user and a display that displays various information. The Web server 18 executes a THHP task in response to a request from a Web browser installed on the PC 3. As a result, web pages for performing various operations are displayed on the display of the PC 3. Then, an operation input from the user via the PC 3 is received by the Web server 18 via the NIC 14. Therefore, the user can use the PC 3 to perform operations such as job requests and various settings. The PC 3 corresponds to an external device described in the claims.

  In order to accept operations such as job requests and various settings from the user via the PC 3, the NIC 14 transmits and receives various packets to and from the PC 3. The NIC 14 has a back end portion 21 and a front end portion 22. The front end unit 22 has a PHY circuit for transmitting and receiving packets, and outputs the received packet to the back end unit 21. The back end unit 21 includes a MAC circuit, and the back end unit 21 has a response function as the NIC 14 in the standby mode. In the power saving mode, the power supply to the back end unit 21 is stopped, and the network response by the back end unit 21 becomes impossible. In the present embodiment, the back end unit 21 functions as the second communication unit described in the claims, and the front end unit 22 functions as the first communication unit.

  The back-end unit 21 is physically configured by a CPU that performs calculations, a ROM that stores programs for causing the CPU to execute each process, a RAM that temporarily stores various data such as calculation results, and the like. Yes. In the standby mode, the back end unit 21 inputs a packet received by the front end unit 22, and analyzes the input packet.

  The PC 3 transmits request packets for making various requests to the MFP 1. The request packet includes a request packet for making a job request. The request packet for performing the job request is transmitted when the user requests the MFP 1 for a job such as a print job, a scan job, a FAX job, or an I-FAX job via the PC 3. Here, a case where a print job request is made will be described as an example. This job request is called a PC print request in the sense of a print request from the PC.

  The PC 3 transmits a PC print request to the MFP 1 before transmitting data packets such as print data and print setting data to the MFP 1. This PC print request is a SYN packet designating the 9100th port for receiving print data. The SYN packet is a packet that requests establishment of a session in order to transmit data in TCP / IP. That is, the SYN packet designating the 9100th port is a packet requesting permission for session establishment and print data transmission, and functions as a request packet.

  The back-end unit 21 analyzes the input PC print request and returns a SYN / ACK packet that permits session establishment. The back end unit 21 permits the transmission of print data by setting the window size of the SYN / ACK packet to be returned to a value greater than or equal to a predetermined value. The SYN / ACK packet in which the window size is set to a predetermined value or more is a packet that satisfies the request of the PC print request (request packet) transmitted from the PC 3, and functions as a response packet.

  The back end unit 21 outputs a response packet to the front end unit 22, and the front end unit 22 returns the response packet to the PC 3. After the response packet is returned, an ACK packet is transmitted from the PC 3 to the MFP 1, and a session is established between the MFP 1 and the PC 3. That is, a session is established between the MFP 1 and the PC 3 by the TCP / IP three-way handshake. After the session is established, a data packet including print data and print setting data is transmitted to the MFP 1. Based on this data packet, the printer 10 executes a print job. For this reason, the printer 10 functions as a processing unit described in the claims.

  When a scan job, FAX job, or I-FAX job request is made, a SYN packet designating a specified port is used as a PC scan request, PC-FAX request, or PC-IFAX request, as with a print job. , Transmitted from the PC 3 to the MFP 1. Then, after the back end unit 21 returns a response packet to this request packet, a session is established, and a data packet is transmitted from the PC 3 to the MFP 1.

  Based on the data packet, a scan job, a FAX job, or an I-FAX job is executed by the scanner 11, the NCU 12, the modem 13, and the NIC 14. The scanner 11 performs a scan job, and thus functions as a processing unit described in the claims. Since the NCU 12 and the modem 13 perform a FAX job, they function as a processing unit described in the claims. Further, since the NIC 14 performs an I-FAX job, it functions as a processing unit described in the claims.

  The request packet includes an SNMP packet, an ICMP packet, an ARP packet, and the like in addition to the request packet for requesting the job. The SNMP packet is a packet that requests status information of the MFP 1 by SNMP (Simple Network Management Protocol). The status information is information including job accumulation status, presence / absence of paper in the paper cassette, presence / absence of toner, and the like. When the SNMP packet is input, the back-end unit 21 returns a packet including the requested status information as a response packet.

  The ICMP packet is a packet for requesting a response from the other party in order to confirm the connection status by ICMP (Internet Control Message Protocol). When the ICMP packet is input, the back-end unit 21 returns a packet including the requested connection information as a response packet.

  The ARP packet is a packet for requesting a response to inquire about the MAC address by ARP (Address Resolution Protocol). When an ARP packet is input, the back-end unit 21 returns a packet including its own AMC address as a response packet.

  The back-end unit 21 that performs the network response described above is deenergized in the power saving mode. Thereby, power saving can be achieved. On the other hand, since the back end unit 21 cannot perform a network response, the front end unit 22 functions in the power saving mode.

  The front-end unit 22 is physically configured by a CPU that performs calculations, a ROM that stores programs for causing the CPU to execute each process, a RAM that temporarily stores various data such as calculation results, and the like. Yes. The front end unit 22 functions as a proxy for the back end unit 21 in the power saving mode in order to realize power saving. Therefore, in order to reduce power consumption and cost, a CPU, ROM, and RAM having relatively low specifications. Is used.

  For this reason, the communication function of the front end unit 22 is restricted by the back end unit 21, and the front end unit 22 cannot make a proxy response to some request packets. Request packets that can be subjected to a proxy response by the front end unit 22 of the present embodiment are SNMP packets, ICMP packets, ARP packets, and the like. The request packet for which proxy response is impossible is a job request or the like.

  The front end unit 22 of this embodiment includes a determination unit 221 and a proxy response unit 222 in order to make a proxy response to a request packet. The determination unit 221 determines whether a proxy response is possible, that is, whether a response packet can be returned. The proxy response unit 222 returns a response packet when the determination unit 221 determines that a proxy response is possible.

  In the present embodiment, the proxy response unit 222 stores the response packet generated by the backend unit 21 in advance in the standby mode as proxy response information in association with the request packet. Packets stored as proxy response information include SNMP packets, ICMP packets, ARP packets, and the like. When the determination unit 221 receives a packet after shifting to the power saving mode, the determination unit 221 determines whether a proxy response is possible based on the proxy response information.

  Specifically, the determination unit 221 determines that a response is possible when the received packet matches any request packet stored as proxy response information. On the other hand, when the received packet does not match any request packet stored as proxy response information, the determining unit 221 determines that a response is impossible. For example, the determination unit 221 calculates a CRC (Cyclic Redundancy Check) value of the request packet and compares it with the CRC value of each request packet stored as proxy response information. Thereby, the determination unit 221 determines whether or not the received packet matches any request packet stored as proxy response information.

  When the determination unit 221 determines that a response is possible, the proxy response unit 222 returns a response packet associated with the request packet that matches the received packet. When the determination unit 221 determines that the response is impossible, the return instruction output unit 223 included in the front end unit 22 outputs a return instruction for returning the own device to the standby mode. As a result, energization of each component including the back end unit 21 is started, and the own device returns to the standby mode. The front end unit 22 outputs the received request packet to the back end unit 21 after the back end unit 21 returns to the standby mode, that is, starts up. The returned back end unit 21 generates a response packet for the request packet output from the front end unit 22 and returns it.

  Since the front-end unit 22 does not store a job request such as a PC print request as proxy response information, when the job request is received in the power saving mode, the front-end unit 22 determines that a response is impossible. Therefore, when a job request is received, a return instruction is output, and the own device returns to the standby mode. Then, the job is executed.

  The MFP 1 includes a control unit 19 for controlling each component in an integrated manner. The control unit 19 is physically configured by a CPU that performs calculations, a ROM that stores programs for causing the CPU to execute each process, a RAM that temporarily stores various data such as calculation results, and the like. . The control unit 19 includes a power control unit 20 as a functional component.

  The power control unit 20 shifts its own power mode by controlling energization of the components of the MFP 1. The power control unit 20 functions as a power control unit described in the claims. When the MFP 1 is turned on, the power control unit 20 sets the power mode to the standby mode and supplies power to all the components of the MFP 1. The standby mode is a state in which all jobs can be executed.

  When the usage is not performed for a predetermined time, the power control unit 20 shifts the power mode to the power saving mode and stops energization of each component except for a part of the NCU 12 and the front end unit 22. The reason why power is supplied to a part of the NCU 12 is to detect a FAX call. If the NCU 12 detects a FAX call in the power saving mode, the NCU 12 outputs a return instruction. Further, as described above, when the front end unit 22 receives a request packet that cannot be responded in the power saving mode, the front end unit 22 outputs a return instruction. In the power saving mode, when a return instruction is output from the NCU 12 or the front end unit 22 in the power saving mode, the power control unit 20 starts energizing all the components and returns the power mode to the standby mode.

  In the standby mode, when the usage is not performed again for a predetermined time (for example, 15 minutes), the power mode again shifts to the power saving mode. As described above, the MFP 1 normally makes several transitions from the standby mode to the power saving mode within one day. In the present embodiment, when the standby mode is shifted to the power saving mode, the energization of the back end unit 21 is stopped except for the backup DRAM included in the back end unit 21. Power is supplied to the backup DRAM to perform self-refresh, but the power consumption is relatively small, and power saving can be realized.

  The back end unit 21 needs to perform a transition process from the standby mode to the power saving mode before the energization is stopped. The migration process includes a shutdown process. This shutdown process is a process for performing normal and quick return to the standby mode after the transition to the power saving mode. The shutdown process performed by the back-end unit 21 according to the present embodiment includes a process of closing a file and writing data to a backup DRAM. In this embodiment, the backup DRAM is a DDR memory, and the data transfer rate is relatively fast, so the time required for the migration process is about 1 to 2 seconds.

  The back end unit 21 cannot make a network response during the execution of the migration process. Therefore, in order to cope with a case where a request packet is transmitted from the PC 3 during the execution of the migration process, the back end unit 21 causes the front end unit 22 to function during the execution of the migration process.

  Here, the control mode of the front end unit 22 in the power saving mode described above is referred to as a normal control mode, and the control mode during execution of the shift process is referred to as a shift control mode. When starting the transition process, the back-end unit 21 issues a switching instruction for switching the communication control mode of the front-end unit 22 to the transition control mode. When the switching instruction for switching to the transition control mode is output from the back end unit 21, the front end unit 22 switches the communication control mode to the transition control mode. Accordingly, the front end unit 22 performs communication control in the transition control mode during the execution of the transition process.

  The determination unit 221 of the front end unit 22 determines whether or not the front end unit 22 can respond when a packet is detected in the transfer control mode, that is, during the execution of the transfer process by the back end 21. The determination as to whether or not the response is possible is the same as the above-described determination in the power saving mode. The front end unit 22 determines that the response is possible if a request packet that matches the received packet is stored in the proxy response information. If it is determined and not stored, it is determined that the response is impossible.

  When the determination unit 221 determines that a response is possible, the proxy response unit 222 returns a response packet in the same manner as in the power saving mode. That is, a response packet stored as proxy response information is returned. If the determination unit 221 determines that the response is impossible, the back end unit 21 that is executing the migration process cannot be restored, and the packet holding 224 of the front end unit 22 holds the request packet. That is, the packet holding unit 224 stores the request packet. Since the proxy response unit 222 does not store the job request as proxy response information, when the job request is received, it is determined that the response is impossible, and the packet holding unit 224 holds the job request.

  After the transition process is completed, the back end unit 21 issues a switching instruction for switching the communication control of the front end unit 22 from the transition control mode to the normal control mode. The front end unit 22 switches the communication control mode to the normal control mode when a switching instruction for switching to the normal control mode is output from the back end unit 21. Thereby, in the power saving mode, the communication control mode of the front end unit 22 becomes the normal control mode. When the migration process is completed in a state where the request packet is held by the packet holding unit 224, the return instruction unit 223 of the front end unit 22 outputs a return instruction. In response to this return instruction, the MFP 1 returns to the standby mode. The return to the standby mode can be performed relatively quickly, on the order of several hundred msec.

  After returning to the standby mode, the packet holding unit 224 outputs to the back-end unit 21 when there is a held request packet. Then, the back end unit 21 that has returned returns a response packet to the output request packet, and then the job is executed.

  Subsequently, the operation of the MFP 1 will be described. With reference to FIG. 2, the migration process by the back end unit 21 will be described. FIG. 2 is a flowchart showing the migration process by the backend unit 21. This transition process is performed when the back-end unit 21 inputs an instruction to shift to the power saving mode from the control unit 19.

  First, in step S <b> 101, a switching instruction for instructing to switch the communication control mode of the front end unit 22 to the transition control mode is output from the back end unit 21 to the front end unit 22. In a succeeding step S102, it is determined whether or not it is possible to shift to the power saving mode. For example, when the back-end unit 21 is executing communication processing or data backup processing, it is determined that the shift to the power saving mode is impossible. In this case, in step S103, the transition process to the power saving mode is stopped, and the transition process ends.

  On the other hand, when it is determined that the shift to the power saving mode is possible, the process of step S104 is performed next. In step S104, the back-end unit 21 is shut down. In step S105, it is determined whether or not the shutdown process has been completed until the shutdown process is completed. After the shutdown process is completed, the process of step S106 is performed.

  In step S <b> 106, a switching instruction that instructs to switch the communication control mode of the front end unit 22 to the normal control mode is output from the back end unit 21 to the front end unit 22. Thereafter, in step S107, the power supply to the back end unit 21 is stopped, and the transition to the power saving mode is completed. By performing the above processing, the communication control mode of the front end unit 22 can be switched to the transition control mode during execution of the transition process by the back end unit 21.

  Subsequently, a processing procedure of response processing according to the power mode by the MFP 1 will be described. First, with reference to FIG. 3, the response process when the front end unit 22 receives a request packet that cannot be responded during the execution of the migration process will be described. FIG. 3 is a sequence diagram showing response processing when the front-end unit receives a request packet that cannot be responded during execution of migration processing.

  First, in step S <b> 111, an instruction to shift to the power saving mode is input to the back end unit 21. Thereby, the migration process of the back end unit 21 is started. In step S112, an instruction to switch to the transition control mode is output from the back end unit 21 to the front end unit 22. In step S <b> 113, a response indicating that the request has been accepted is output from the front end unit 22 to the back end unit 21. As a result, the communication control mode of the front end unit 22 is switched to the transition control mode. Thereafter, in step S114, the back-end unit 21 performs a shutdown process.

  If an SNMP packet is transmitted from the PC 3 to the MFP 1 during execution of the migration process (S115), the front-end unit 22 determines whether the received request packet (SNMP packet) is a response request packet. Since the SNMP packet is a responsive packet, the response packet is returned from the front end unit 22 to the PC 3 in the subsequent step S116. That is, a proxy response is executed.

  If a PC print request is transmitted from the PC 3 to the MFP 1 during execution of the migration process (S117), the front end unit 22 determines whether the received request packet (PC print request) is a request packet that can be responded to. Is judged. Since the PC print request is an unresponsive packet, the received request packet (PC print request) is held in the subsequent step S118.

  On the other hand, after the shutdown process of the back end unit 21 is completed, an instruction to switch to the normal control mode is output from the back end unit 21 to the front end unit 22 in step S119. In step S120, a response indicating that the request has been accepted is output from the front end unit 22 to the back end unit 21. As a result, the communication control mode of the front end unit 22 is switched to the normal control mode. In step S121, the transition to the power saving mode is completed.

  On the other hand, in S122, the front end unit 22 determines that the migration process has been completed with the request packet held. In this case, in a subsequent step S123, a return instruction is output from the front end unit 22 to the back end unit 21. In step S124, energization of the back end unit 21 is started, and the own device returns to the standby mode. In step S <b> 125, the held PC print request is output from the front end unit 22 to the back end unit 21. Subsequently, in step S126, a response packet to the output PC print request is returned by the back-end unit 21. Thereafter, the print data is transmitted to the MFP 1 and a print job is executed.

  Next, with reference to FIG. 4, a response process when the front end unit 22 receives a request packet that cannot be responded in the power saving mode will be described. FIG. 4 is a sequence diagram showing a response process when the front end unit receives a request packet that cannot be responded in the power saving mode.

  In steps S131 to S136, processing similar to that in steps S111 to S116 described above is performed, and thus description thereof is omitted. In this sequence, during the execution of the migration process, a request packet that cannot be responded is not received, and the migration process is completed in a state where there is no held request packet. In step S137, an instruction to switch to the normal control mode is output from the back end unit 21 to the front end unit 22. In step S138, a response indicating that the request has been accepted is output from the front end unit 22 to the back end unit 21. As a result, the communication control mode of the front end unit 22 is switched to the normal control mode. In step S139, the transition to the power saving mode is completed.

  When a proxyable packet such as an SNMP packet is transmitted from the PC 3 to the MFP 1 after shifting to the power saving mode (S140), a response packet is returned from the front end unit 22 to the PC 3 in the subsequent step S141. That is, a proxy response is executed. Next, when a packet that cannot be substituted is received (S142), a return instruction is output from the front-end unit 22 to the back-end unit 21 in the subsequent step S143.

  In step S144, energization of the back end unit 21 is started, and the own apparatus returns to the standby mode. In step S145, the held PC print request is output from the front end unit 22 to the back end unit 21. Subsequently, in step S146, a response packet to the output PC print request is returned by the back-end unit 21. Thereafter, the print data is transmitted to the MFP 1 and a print job is executed.

  According to the MFP 1 according to the present embodiment described above, when a request packet that cannot be responded is received during the execution of the migration process, the received request packet is held by the front end unit 22. Then, after returning to the standby mode, the held request packet is output to the back-end unit 21. Then, a response packet for the output request packet is returned by the back-end unit 21. Thereby, a response packet to the request packet received during the execution of the migration process can be returned. Therefore, it is possible to prevent a loss of packets transmitted from the external device during the execution of the transition process to the power saving mode.

  When the transfer process is completed with the request packet held, a return instruction is output in the power saving mode after the transfer process is completed, and the own apparatus returns from the power saving mode to the standby mode. Thus, when a request packet is received during the execution of the migration process, it is possible to immediately return the device to the standby mode and respond to the request packet after the completion of the migration process.

  On the other hand, if a request packet that can be answered by the front end unit 22 is received during the execution of the migration process, a response packet is returned. As a result, it is possible to respond to a request packet that can be responded by the front end unit 22 even during execution of the migration process.

  In the power saving mode, when a request packet that can be answered by the front end unit 22 is received, a response packet is returned. Thereby, it is possible to respond to a request packet that can be answered by the front end unit 22 without returning the back end unit 21 even in the power saving mode. On the other hand, when a request packet that cannot be answered by the front end unit 22 is received, a return instruction is output, and the own device is returned to the standby mode. Thereby, even when a request packet that cannot be responded to by the front end unit 22 is received in the power saving mode, the back end unit 21 can be activated and a response packet can be returned.

  Furthermore, in this embodiment, the communication control mode of the front end unit 22 is switched to the transition control mode by the switching instruction output when the back end unit 21 starts the transition process, and the request packet received during the transition process. Is held by the front end portion 22. Then, when the backend unit 21 switches the communication control mode of the front end unit 22 to the normal control mode according to the switching instruction output after the completion of the migration process, and the request packet is held, the return instruction is output. Accordingly, when a request packet is received during the transition process, it is possible to output a return instruction and return the host apparatus to the standby mode at the timing when the host apparatus completely shifts to the power saving mode. In other words, the request packet received between the time when the switching instruction is output when the transition process is started and the time when the switching instruction after the completion of the transition process is output is held, and the own device is in the power saving mode. It is possible to output a return instruction immediately after the complete transition to (1).

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. In the above embodiment, the front end unit 22 is configured to be able to respond to some request packets such as an SNMP packet, an ICMP packet, and an ARP packet, but is not limited thereto. The front end unit 22 may not have a function of responding to the request packet. In this case, when the front end unit 22 receives a request packet during execution of the transition control, the front end unit 22 may be configured to hold all the request packets. In the above-described embodiment, the communication apparatus according to the present invention is applied to the MFP 1. However, the present invention is not limited to this.

1 MFP
10 Printer 11 Scanner 12 NCU
13 Modem 14 NIC
20 Power control unit 21 Back end unit 22 Front end unit

Claims (4)

A power control unit that performs transition control of a power mode including a standby mode and a power saving mode in which power consumption is smaller than the standby mode;
A first communication unit that receives a request packet from an external device;
In the standby mode, a response packet is returned to the request packet received by the first communication unit, and in the power saving mode, energization of at least a part is stopped by the power control unit, A second communication unit that makes it impossible to return a response packet;
With
The first communication unit receives the request packet when the second communication unit receives the request packet while a transition process including a shutdown process from the standby mode to the power saving mode is being performed. When the transition process including the shutdown process by the second communication unit is completed in a state where the packet is held and the request packet is held, a return instruction for returning the power mode to the standby mode is output, After returning to the standby mode, the held request packet is output to the second communication unit,
The power control unit returns the power mode to the standby mode in accordance with a return instruction output by the first communication unit,
The second communication unit returns the response packet to the request packet output by the first communication unit after returning ,
And,
When the second communication unit starts the shutdown process, the second communication unit outputs a switching instruction to switch the communication control mode of the first communication unit to the transition control mode to the first communication unit, and the shutdown process Is completed, the switching instruction to switch the communication control mode of the first communication unit to the normal control mode is output to the first communication unit,
The first communication unit is
When a switching instruction for switching to the transition control mode is output from the second communication unit, when the switching instruction for switching the communication control mode to the transition control mode and switching to the normal control mode is output, Switch the communication control mode to the normal control mode,
In the transition control mode, when the request packet is received, the request packet is retained, and when the request packet is retained when the mode is switched to the normal control mode, the return instruction is output. Communication device. When the first communication unit receives the request packet that can be responded to by the first communication unit while the migration process including the shutdown process is being performed in the second communication unit, It returns a response packet, when receiving the request packet can not respond by the first communication unit, a communication device according to claim 1, characterized in that for holding the request packet. When the first communication unit receives the request packet that can be responded by the first communication unit in the power saving mode, the first communication unit returns the response packet and cannot respond by the first communication unit. When the request packet is received, a return instruction for returning the power mode to the standby mode is output,
The power control unit returns the power mode to the standby mode in accordance with a return instruction output by the first communication unit,
The second communication unit, after returning, the communication apparatus according to claim 1 or 2, characterized in that for returning the response packet to the received request packet in the power saving mode by the first communication unit . The communication device according to any one of claims 1 to 3 ,
A processing unit for performing image processing,
The first communication unit receives the request packet for requesting image processing from the external device;
The image processing apparatus, wherein the processing unit performs image processing according to the request packet.

Images