JP2011044807A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that stores communication log while maintaining energy-saving state in the image forming apparatus connectable to a network. <P>SOLUTION: The image forming apparatus connectable to the network and which enters energy-saving state, has a main control part which totally controls the image forming apparatus, and a sub control part which processes network communication. The sub control part makes an inquiry about the current time to a time server which manages the current time on the network to acquire the current time, and stores the acquired current time and the content of the network communication in a sub side memory under management as log information when the main control part is in energy-saving state and the network communication is performed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus connectable to a network.

  An image forming apparatus that can be connected to a network performs a network communication process (for example, part of a network response) by a sub CPU (energy saving CPU) that consumes less power than a main CPU (Central Processing Unit). Some maintain the energy saving state (power saving state) of the main CPU. As described above, it is important to maintain an energy saving state in the image forming apparatus. In addition, as an invention aiming at maintaining an energy saving state, there are those disclosed in Patent Documents 1 and 2, for example.

  In the image forming apparatus as described above, as a security measure, a communication log (log information) is stored in the image forming apparatus when network communication is executed (for example, when communication fails).

  The communication log requires time when network communication is executed. Therefore, in the image forming apparatus, in order to save the communication log when the main CPU is in the energy saving state, the sub CPU needs to know the time when the network communication is executed (for example, the time when the communication fails). Time management is usually performed by the main CPU. Therefore, the sub CPU makes an inquiry about the time to the main CPU. The main CPU that has received this inquiry returns from the energy saving state, and the energy saving state is interrupted. Therefore, for example, when the number of opportunities to save communication logs increases, for example, when communication failures occur frequently, the main CPU returns from the energy-saving state each time, and thus there arises a problem that a sufficient period of the main CPU in the energy-saving state cannot be secured.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image forming apparatus capable of storing a communication log while ensuring an energy saving period in an image forming apparatus connectable to a network. .

  In order to achieve such an object, the image forming apparatus of the present invention can be connected to a network, and in an image forming apparatus that can be shifted to an energy saving state, the image forming apparatus performs network communication with a main control unit that controls the entire image forming apparatus. A sub-control unit for processing, and when the main control unit is in an energy-saving state and network communication is performed, the sub-control unit is currently connected to a time server that manages the current time on the network. The present invention is characterized in that the current time is acquired by inquiring the time, and the acquired current time and the contents of the network communication are stored as log information in the sub-side memory under management.

  Further, in the image forming apparatus of the present invention, the sub control unit is in an energy saving state when the storage area of the sub-side memory runs out, or even if the storage area of the sub-side memory is empty. When the period exceeds a predetermined period, the main control unit returns from the energy saving state, and when the main control unit returns from the energy saving state, the main control unit receives log information from the sub control unit and stores it in the nonvolatile storage means. It is characterized by storing.

  Further, in the image forming apparatus of the present invention, the sub control unit inquires the time server of the current time for the timer under management when the main control unit is in the energy saving state and network communication is performed. When the current time is acquired from the time server, the calculation is performed based on the acquired current time and the time counted by the timer, and the calculated time is stored as log information. To do.

  In the image forming apparatus of the present invention, the sub-control unit is connected to the time server when the power source of the image forming apparatus is turned on instead of when the main control unit is in the energy saving state and network communication is performed. If the current time is inquired, the current time is obtained, and the timer is managed based on the obtained current time. Instead, the present time is obtained from the timer.

  In the image forming apparatus of the present invention, the sub control unit causes the timer to manage the current time based on the current time acquired from the time server, and then causes the time server to set the current time at a predetermined interval. The current time is reacquired by making an inquiry, and the current time being managed by the timer is corrected based on the reacquired time.

  The image forming apparatus according to the present invention further includes network monitoring means for monitoring whether or not network communication is being executed in the image forming apparatus, and the sub-control unit performs network communication as a result of monitoring by the network monitoring means. When not executing, the main control unit is returned from the energy saving state, the log information stored in the sub-side memory is transmitted to the main control unit, and when the main control unit returns from the energy saving state, the sub control unit logs. Information is received and stored in a non-volatile storage means.

  In the image forming apparatus of the present invention, when the main control unit is returned from the energy-saving state, the sub control unit notifies the main control unit of the current time acquired from the time server. Based on the current time notified from the control unit, the time being managed is corrected with a real-time clock under management.

  According to the present invention, in an image forming apparatus connectable to a network, it is possible to provide an image forming apparatus capable of storing a communication log while ensuring a period of energy saving.

1 is a block diagram illustrating a configuration example of an image forming apparatus according to a first embodiment of the present invention. FIG. 6 is a flowchart illustrating an operation example of the image forming apparatus according to the first exemplary embodiment of the present invention. It is a block diagram which shows the structural example of the image forming apparatus which concerns on the 2nd-4th embodiment of this invention. FIG. 6 is a flowchart illustrating an operation example of an image forming apparatus according to a second embodiment of the present invention. FIG. 10 is a flowchart illustrating an operation example of an image forming apparatus according to a third exemplary embodiment of the present invention. FIG. 10 is a flowchart illustrating an operation example of an image forming apparatus according to a fourth exemplary embodiment of the present invention. It is a block diagram which shows the structural example of the image forming apparatus which concerns on the 5th Embodiment of this invention. FIG. 10 is a flowchart illustrating an operation example of an image forming apparatus according to a fifth exemplary embodiment of the present invention. FIG. 10 is a flowchart illustrating an operation example of an image forming apparatus according to a sixth embodiment of the present invention. It is a figure which shows an example of the log information preserve | saved at the image forming apparatus which concerns on the 1st-6th embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
First, the purpose of this embodiment will be described by taking as an example an image forming apparatus capable of shifting to a network connection and an energy saving state (energy saving mode). The image forming apparatus is an example in which a network communication process (for example, part of a network response) is performed by a sub CPU that consumes less power than the main CPU in order to maintain the energy saving state of the main CPU. In addition, the sub CPU has an IPsec engine that can encrypt data on the network as an example.

  In such an image forming apparatus, when encryption communication (an example of network communication) by Ipsec fails during the energy saving state of the main CPU, for example, the failure time together with the failed content is stored as log information (communication log). To be stored in a non-volatile storage device. Therefore, the sub CPU needs to wake up the main CPU that manages the current time, inquire about the current time, and acquire the time when the encryption communication failed.

  However, since the time is acquired after the main CPU returns, an error corresponding to the time from return to acquisition occurs in the time acquired by the sub CPU. In addition, since the main CPU needs to return from the energy saving state, if the encryption communication frequently fails, the main CPU will return from the energy saving state each time, and it is difficult to maintain the energy saving state. Become. That is, when the log information is stored in the image forming apparatus, it is not possible to ensure a sufficient energy saving period of the main CPU.

  Therefore, in this embodiment, even if encryption communication fails in the image forming apparatus, encryption communication fails while ensuring a sufficient period of the main CPU in the energy saving state without returning the main CPU from the energy saving state. The purpose is to be able to save the log information including the specified time.

  The image forming apparatus of the present embodiment will be described with reference to FIGS. 1, 2, and 10. FIG. 1 is a block diagram illustrating a configuration example of the image forming apparatus according to the present exemplary embodiment. FIG. 2 is a flowchart showing an operation example of the image forming apparatus of the present embodiment. FIG. 10 is a diagram illustrating an example of log information stored in the image forming apparatus of the present embodiment.

  As shown in FIG. 1, an image forming apparatus 1 according to the present embodiment is connected to a PC (Personal Computer) 2 and a time server 3 via a network such as a LAN (Local Area Network). The time server 3 is a server that manages the current time. When the time server 3 receives a time inquiry via the LAN, the time server 3 transmits data indicating the current time to the inquiry source.

  The image forming apparatus 1 includes an RTC (Real Time Clock) 11, a HDD (Hard Disk Drive) 12, a main CPU (main control unit) 13, a main CPU memory 14, a communication buffer 15, a sub CPU (sub control unit) 16, A network I / F (InterFace) 17 and a sub CPU memory 18 are provided. The RTC 11 is an example of time management means (function for managing the current time). The HDD 12 is an example of a nonvolatile storage unit (a function for storing various information). The main CPU 13 and the main CPU memory 14 are examples of image forming apparatus control means (functions for controlling the entire image forming apparatus). The main CPU memory (main memory) 14 is managed by the main CPU 13. The communication buffer 15, the sub CPU 16, the network I / F 17, and the sub CPU memory 18 are network processing means (functions for performing network communication processing). The sub CPU memory (sub memory) 18 is managed by the sub CPU 16.

  The details of the flow shown in FIG. 2 will be described below.

  The main CPU 13 and the main CPU memory 14 are shifted to the energy saving state and turned off (step S1).

  The network I / F 17 receives the encrypted packet from, for example, the PC 2 (Step S2).

  The network I / F 17 decrypts the encrypted packet (step S3).

  If the encrypted packet is successfully decrypted (step S3 / NO), the sub CPU 16 analyzes the contents of the packet (step S4).

  The sub CPU 16 determines whether or not the packet can be responded to itself (step S5).

  As a result of the determination, if the sub CPU 16 cannot respond (step S5 / NO), the sub CPU 16 turns on the main CPU 13 and the main CPU memory 14 to return from the energy saving state, and passes the packet to the main CPU 13. . Thereafter, the main CPU 13 generates a response packet and responds (step S6).

  On the other hand, if the result of determination is that the sub CPU 16 can respond (step S5 / YES), the sub CPU 16 generates a response packet and responds (step S7).

  If the decryption of the encrypted packet fails in step S3 (step S3 / YES), the sub CPU 16 inquires the time server 3 about the current time and acquires the current time from the time server 3 (step S8). ). This time is the time when packet decryption fails (time when encryption communication fails). At this time, the sub CPU 16 receives from the network I / F 17 contents related to packet decryption failure (information indicating connection request source, encryption algorithm, authentication algorithm, communication failure occurrence timing, etc.). The contents relating to the packet decoding failure are stored as log information together with the time when the packet decoding failed.

  Next, the sub CPU 16 determines whether or not there is an area in the sub CPU memory 18 for storing log information (the time at which packet decryption failed and the contents relating to packet decryption failure) (step S9).

  As a result of the determination, if there is no space in the sub CPU memory 18 (step S9 / NO), the sub CPU 16 turns on the main CPU 13 to return from the energy saving state (step S12).

  When the main CPU 13 returns from the energy saving state, the sub CPU 16 transmits log information that could not be stored in the sub CPU memory 18 to the main CPU 13 via the communication buffer 15. When receiving the log information, the main CPU 13 stores it in the HDD 12 (step S13).

  On the other hand, if the result of determination is that the sub CPU memory 18 is empty (step S9 / YES), the sub CPU 16 determines in advance the elapsed time after the transition to the energy saving state (the period during which the main CPU 13 is in the energy saving state). It is determined whether or not a predetermined time (for example, one day) has been exceeded (step S10). The reason for making such a determination is that if the log information is stored in the sub CPU memory 18 for a long time, the log information may disappear due to the occurrence of a power failure such as a power failure. This is because it is necessary to move and save the log information.

  As a result of the determination, if the predetermined time has not elapsed since the transition to the energy saving state (step S10 / NO), the sub CPU 16 stores the log information in the sub CPU memory 18 (step S11). An example of the log information stored at this time is shown in FIG. The “occurrence time” shown in FIG. 10 is a time at which encryption communication has failed (a time acquired from the time server 3).

  On the other hand, as a result of the determination, when a predetermined time has passed since the transition to the energy saving state (step S10 / YES), the sub CPU 16 turns on the main CPU 13 and the main CPU memory 14 from the energy saving state. Return (step S12).

  When the main CPU 13 returns from the energy saving state, the sub CPU 16 transmits the log information stored in the sub CPU memory 18 so far to the main CPU 13 via the communication buffer 15. When receiving the log information, the main CPU 13 stores it in the HDD 12 (step S13).

  As described above, according to the present embodiment, it is possible to provide an image forming apparatus that can store a communication log while ensuring a sufficient energy saving period in an image forming apparatus that can be connected to a network. The reason is that the main CPU managing the current time is returned from the energy saving state by using a time server installed on the network as a means for the sub CPU to know the current time while the main CPU is in the energy saving state. Therefore, it is possible to secure a period for maintaining the energy saving state. In addition, by using the time server, it is not necessary to provide an RTC on the network processing means side (sub CPU), so that the network processing means can be configured at a low cost.

  [Second Embodiment]

  In the first embodiment, since there is a vacancy in the time from when the network processing means (network I / F 17) fails to decrypt the packet until the time server 3 is inquired to acquire the current time, the packet decryption is performed. There is a problem in that there is a difference between the failed time and the time acquired from the time server 3 (time to save as log information).

  Therefore, an object of the present embodiment is to increase the accuracy of the time to save as log information.

  With reference to FIGS. 3 and 4, the image forming apparatus according to the present exemplary embodiment will be described. FIG. 3 is a block diagram illustrating a configuration example of the image forming apparatus according to the present exemplary embodiment. FIG. 4 is a flowchart showing an operation example of the image forming apparatus of the present embodiment.

  As shown in FIG. 3, the image forming apparatus 1 of the present embodiment is different from the configuration of the first embodiment (see FIG. 1) in that the network processing unit includes a simple timer 19. The timer 19 is placed under the control of the sub CPU 16 and counts (measures) time to notify the sub CPU 16.

  Details of the flow shown in FIG. 4 will be described below. FIG. 4 shows that while the network processing means inquires the time server 3 for the time, the timer 19 is used to count the elapsed time, and the elapsed time counted by the timer 19 is calculated backward from the time acquired from the time server 3. Then, it is a flow for calculating the time when packet decryption fails (time when encryption communication fails). The flow in FIG. 4 corresponds to the details of step S8 in FIG.

  When the network I / F 17 receives the encrypted packet and fails to decrypt it (step S3 / YES in FIG. 2), the sub CPU 16 starts a timer at the timing of starting the time inquiry to the time server 3, for example. 19 starts counting time (step S21). The timing for starting the time inquiry to the time server 3 is, for example, the timing when packet decryption fails (timing when encryption communication fails).

  The sub CPU 16 makes an inquiry about the current time to the time server 3 by NTP (Network Time Protocol) via the network I / F 17 (step S22).

  When the sub CPU 16 obtains the time from the time server 3 (step S23 / YES), the sub CPU 16 corrects the error by subtracting the time counted by the timer 19 from the time obtained from the time server 3, and saves it as log information. (Time when packet decryption failed, time when encryption communication failed, occurrence time) (step S24).

  As described above, according to the present embodiment, the network processing means starts time measurement using a simple timer at a timing when it is desired to leave the time, inquires the current time from the time server, and obtains the time. An accurate time can be obtained by subtracting the time measured by the simple timer from the time. Therefore, the time stored as log information is a highly accurate value.

[Third Embodiment]
In the second embodiment, the time is acquired from the time server 3 every time when packet decoding fails, so there is a problem that a network load is applied.

  Therefore, in this embodiment, the time of the time server is inquired when the power to the image forming apparatus is turned on, not at the timing when packet decryption fails, and the timer of the network processing means is used to manage the acquired time. The purpose is to manage.

  With reference to FIGS. 3 and 5, the image forming apparatus according to the present exemplary embodiment will be described. FIG. 3 is a block diagram illustrating a configuration example of the image forming apparatus according to the present exemplary embodiment. FIG. 5 is a flowchart showing an operation example of the image forming apparatus of the present embodiment. Since the description of FIG. 3 is the same as that of the second embodiment, the description thereof is omitted here. Details of the flow shown in FIG. 4 will be described below.

  When the image forming apparatus is powered on, the software initialization of the sub CPU 16 starts. During the initialization, the sub CPU 16 inquires the time server 3 about the current time (step S31).

  The sub CPU 16 waits until the time is acquired from the time server 3 (step S32 / NO).

  When the sub CPU 16 acquires the current time from the time server 3 (step S32 / YES), the sub CPU 16 notifies the timer 19 of the acquired time, and causes the timer 19 to perform time management from that time (step S33). Therefore, the sub CPU 16 of this embodiment needs to employ a multitask real-time OS.

  Thereafter, when it becomes necessary to acquire the current time, such as when saving log information, the sub CPU 16 acquires the current time from the timer 19 that is managing the current time (step S34).

  As described above, according to the present embodiment, the network processing unit obtains the current time from the time server when the power of the image forming apparatus is turned on, and then manages the time using the timer as a starting point. By performing the above, the time can be easily acquired from the timer. Therefore, the sub CPU can acquire the current time without imposing a load on the network.

[Fourth Embodiment]
In the third embodiment, since the time is acquired from the time server only when the power of the image forming apparatus is turned on, any image forming apparatus whose power is cut off every day may be used. If the image forming apparatus is still in the state, the timer for performing time management is a simple type, so that there is a problem that the time is likely to be greatly shifted.

  Therefore, the present embodiment aims to prevent the time managed by the timer from changing significantly even if the image forming apparatus is used in a situation where the power is not frequently turned ON / OFF in the third embodiment. And

  With reference to FIGS. 3 and 6, the image forming apparatus according to the present exemplary embodiment will be described. FIG. 3 is a block diagram illustrating a configuration example of the image forming apparatus according to the present exemplary embodiment. FIG. 6 is a flowchart showing an operation example of the image forming apparatus of the present embodiment. Since the description of FIG. 3 is the same as that of the second embodiment, the description thereof is omitted here. Details of the flow shown in FIG. 6 will be described below.

  Steps S41 to S43 are the same as Steps S31 to S33 in FIG. 3 described above, and a description thereof is omitted here.

  The sub CPU 16 waits until a predetermined time (for example, 10 hours) elapses (step S44 / NO).

  When the predetermined time has elapsed (step S44 / YES), the sub CPU 16 inquires the time server 3 again about the current time in order to correct the time managed by the timer 19 (step S45).

  The sub CPU 16 reacquires the current time from the time server 3, notifies the timer 19 of the current time, and causes the timer 19 to perform time management starting from the time (step S46). As a result, the time being managed by the timer 19 is corrected. After step S46, it is desirable to return to the determination in step S44 and periodically correct the time.

  As described above, according to the present embodiment, the network processing unit not only acquires the time from the time server when the power of the image forming apparatus is turned on, but then again from the time server at regular intervals. By acquiring the time, the current time under management is corrected. This makes it possible to correct a time lag that occurs with the passage of time.

[Fifth Embodiment]
In the first embodiment, when a large amount of data is transmitted to the HDD at a time when the log information is stored in the HDD (non-volatile storage means), there is a problem that reception processing from the network cannot be performed during that time.

  Therefore, an object of the present embodiment is to monitor the network and transmit log information to the HDD when the network is free.

  The image forming apparatus of the present embodiment will be described with reference to FIGS. FIG. 7 is a block diagram illustrating a configuration example of the image forming apparatus according to the present exemplary embodiment. FIG. 8 is a flowchart showing an operation example of the image forming apparatus of the present embodiment.

  As shown in FIG. 7, the image forming apparatus 1 of the present embodiment is different from the configuration of the first embodiment (see FIG. 1) in that the network processing unit includes a network monitoring unit 20. The network monitoring unit 20 monitors the network I / F 17 to check whether network communication (for example, packet reception) is being executed. The result of the check is notified to the sub CPU 16.

  Details of the flow shown in FIG. 8 will be described below.

  When the network I / F 17 receives an encrypted packet from, for example, the PC 2 and fails to decrypt the packet, the sub CPU 16 analyzes the contents of the packet (step S51).

  The sub CPU 16 determines whether or not the packet can be responded to itself (step S52).

  As a result of the determination, if the sub CPU 16 can respond (step S52 / YES), the sub CPU 16 generates a response packet and responds (step S53).

  As a result of the determination, if the sub CPU 16 cannot respond (step S52 / NO), the sub CPU 16 turns on the main CPU 13 and the main CPU memory 14 to return from the energy saving state (step S54).

  Here, the network monitoring means 20 checks whether a packet is being received from the network (step S55).

  If the packet is being received as a result of the check (step S55 / YES), the sub CPU 16 gives priority to passing the packet to the main CPU 13 first. Thereafter, the main CPU 13 generates a response packet and responds (step S56).

  If the packet is not being received as a result of the check (step S55 / NO), the sub CPU 16 stores a part of the log information stored in the sub CPU memory 18 (for example, the log information structure shown in FIG. Are transmitted to the main CPU 13 via the communication buffer 15. The main CPU 13 transmits the received log information to the HDD 12 and stores it.

  Here, the sub CPU 16 determines whether or not all the log information stored in the sub CPU memory 18 has been transmitted (step S58).

  As a result of the determination, when transmission of all log information is completed (step S58 / YES), the sub CPU 16 shifts to an idle state (step S59).

  As a result of the determination, if transmission of all log information has not been completed (step S58 / NO), that is, if untransmitted log information remains in the sub CPU memory 18, the network monitoring means 20 again It is checked whether or not reception of a packet has been started (step S55). The subsequent steps are the same as above. That is, when a plurality of log information is stored in the sub CPU memory 18, the network monitoring unit 20 does not start receiving a packet from the network every time transmission of one log information is completed. To check. As a result of confirmation, if a packet is received from the network, transmission of a plurality of log information is interrupted, and packet reception is performed with priority.

  As described above, according to this embodiment, when log information temporarily stored on the network processing means side is sent to the nonvolatile storage means on the main CPU side (image forming apparatus control means side), log information Instead of sending everything at once, log information is sent when the network is free while monitoring the network availability. Thereby, the reception process from the network is not interrupted.

  In the present embodiment, the network monitoring unit 20 is added to the configuration of the first embodiment (see FIG. 1), but the configurations of the second to fourth embodiments (see FIG. 3). You may comprise so that it may add to.

[Sixth Embodiment]
In the first embodiment, in the RTC on the main CPU side, a large error occurs in the time under management as time elapses.

  Therefore, an object of the present embodiment is to correct the RTC on the main CPU side using the time acquired from the time server on the network.

  With reference to FIG. 1 and FIG. 9, the image forming apparatus of the present embodiment will be described. FIG. 1 is a block diagram illustrating a configuration example of the image forming apparatus according to the present exemplary embodiment. FIG. 9 is a flowchart showing an operation example of the image forming apparatus of the present embodiment. Since the description of FIG. 1 is the same as that of the first embodiment, the description thereof is omitted here. Details of the flow shown in FIG. 9 will be described below.

  When the predetermined return condition is satisfied, the sub CPU 16 returns the main CPU 13 and the main CP memory 14 from the energy saving state (step S61).

  The sub CPU 16 transmits time information indicating the time acquired in advance from the time server 3 to the main CPU 13 via the communication buffer 15 (step S62).

  The main CPU corrects the time of the RTC 11 using the received time, and matches the time managed on the sub CPU side (step S63).

  As described above, according to this embodiment, the RTC on the main CPU side is corrected using the accurate current time acquired from the time server on the sub CPU side. This makes it possible to correct RTC errors that occur over time.

  In the present embodiment, the RTC time correction on the main CPU side is added to the configuration of the first embodiment (see FIG. 1), but the configuration of the second to fourth embodiments (FIG. 3). You may make it add in reference).

  As mentioned above, although each embodiment of this invention was described, it is not limited to said each embodiment, A various deformation | transformation is possible in the range which does not deviate from the summary.

  For example, the operation in the above-described embodiment can be executed by hardware, software, or a combined configuration of both.

  When executing processing by software, a program in which a processing sequence is recorded may be installed and executed in a memory in a computer incorporated in dedicated hardware. Or you may install and run a program in the general purpose computer which can perform various processes.

  For example, the program can be recorded in advance on a hard disk or a ROM (Read Only Memory) as a recording medium. Alternatively, the program is temporarily or permanently stored on a removable recording medium such as a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto optical) disc, a DVD (Digital Versatile Disc), a magnetic disc, or a semiconductor memory. It can be stored (recorded). Such a removable recording medium can be provided as so-called package software.

  The program may be wirelessly transferred from the download site to the computer in addition to being installed on the computer from the removable recording medium as described above. Or you may wire-transfer to a computer via networks, such as LAN (Local Area Network) and the internet. The computer can receive the transferred program and install it on a recording medium such as a built-in hard disk.

  In addition to being executed in time series in accordance with the processing operations described in the above embodiment, the processing capability of the apparatus that executes the processing, or a configuration to execute in parallel or individually as necessary Is also possible.

  The present invention can be applied to devices / apparatuses, systems, methods, programs, and the like that enable log storage during network connection and transition to an energy saving state.

1 Image forming apparatus 2 PC
3 Time server 11 RTC
12 HDD
13 Main CPU
14 Main CPU memory 15 Communication buffer 16 Sub CPU
17 Network I / F
18 Sub CPU memory 19 Timer 20 Network monitoring means

JP 2008-270918 A JP 2008-305209 A

Claims (7)

In an image forming apparatus that can be connected to a network and can shift to an energy saving state,
A main control unit for controlling the entire image forming apparatus;
A sub-control unit for processing network communication,
The sub-control unit
When the main control unit is in an energy saving state and network communication is performed, the current time is obtained by inquiring the current time with respect to a time server managing the current time on the network,
An image forming apparatus, wherein the acquired current time and the contents of the network communication are stored as log information in a sub-side memory under management. The sub-control unit
When the storage area of the sub-side memory runs out, or even when the storage area of the sub-side memory is empty, the period in which the main control unit is in the energy saving state exceeds a predetermined period. The main control unit is restored from the energy saving state,
The main control unit
2. The image forming apparatus according to claim 1, wherein when the energy saving state is restored, the log information is received from the sub-control unit and stored in a nonvolatile storage unit. The sub-control unit
When the main control unit is in an energy saving state and network communication is performed, the timer under management causes the time server to count the time during the current time inquiry,
2. When the current time is acquired from the time server, calculation is performed based on the acquired current time and the time counted by the timer, and the calculated time is stored as the log information. Or the image forming apparatus according to 2; The sub-control unit
When the main control unit is in an energy saving state and the image forming apparatus is turned on instead of when network communication is performed, the current time is inquired to the time server to determine the current time. Acquired,
Based on the acquired current time, let the timer manage the current time,
4. The image forming apparatus according to claim 3, wherein when the current time needs to be acquired thereafter, the current time is acquired from the timer instead of the time server. The sub-control unit
Based on the current time acquired from the time server, after allowing the timer to manage the current time, query the time server at a predetermined interval to obtain the current time again,
The image forming apparatus according to claim 4, wherein the current time being managed by the timer is corrected based on the reacquired time. Network monitoring means for monitoring whether network communication is being executed in the image forming apparatus;
The sub-control unit
As a result of monitoring by the network monitoring means, when network communication is not being executed, the main control unit is returned from the energy saving state, and log information stored in the sub-side memory is transmitted to the main control unit,
The main control unit
6. The image forming apparatus according to claim 1, wherein the log information is received from the sub-control unit and stored in a nonvolatile storage unit when the energy saving state is restored. The sub-control unit
When the main control unit is returned from the energy saving state, the main control unit is notified of the current time acquired from the time server,
The main control unit
The image forming apparatus according to claim 1, wherein the time being managed is corrected by a real-time clock under management based on the current time notified from the sub-control unit.

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