Abstract:
In a conventional image forming apparatus, there is a problem in which setting information cannot be changed in power-saving mode. An image forming apparatus F1 includes an interface unit F12 that transmits and receives signals to and from a PC client even in power-saving mode, an information storage unit F14 that is supplied with power to become responsive when a request for changing a setting state is provided, and an SNMP control unit F11 that controls the information storage unit F14 upon request from the PC client. Therefore, by starting the information storage unit F14, it is possible to change the setting information, such as a specified emulation of the image forming apparatus and user account information recorded on the information storage unit F14 of the image forming apparatus F1. Also, in conventional technology, in order to check whether a setting-information changing function unit of the image forming apparatus is in a startup state, an external terminal device has to repeatedly make an inquiry until a functional unit of changing the setting information of the image forming apparatus becomes in a startup state. This problem is solved by providing a function of replying with a time until startup in response to an inquiry from the external terminal device and a function of reporting a difference in power mode among functional units.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a technology allowing a setting item of an image forming apparatus to be changed even in power-saving mode. 
         [0003]    2. Background Technology 
         [0004]    In order to suppress power consumption, an output apparatus, such as an image forming apparatus, on a network enters power-saving mode in which power supply to a portion that consumes large power, such as a printing unit, is cut off. However, in power-saving mode, no reply can be made to a response from the network to the output apparatus about a setting state. Therefore, in order to check the setting state of the output apparatus, it is required to transmit a packet for making a transition from power-saving mode to normal mode from a terminal device through the network to make a transition from power-saving mode to normal mode, and then check the setting state. 
         [0005]    However, returning to normal mode only for the purpose of checking the setting state poses some problems, such as requiring large power consumption and too long time for mode transition. 
         [0006]    To solve these problems, in a method, a status register independently of the CPU of the output apparatus is provided and, at the time of making an inquiry about the setting state from the terminal device to the output apparatus in power-saving mode through the network, status information stored in the status register is sent back (Japanese Patent Laid-Open Publication No. 2002-99399). 
         [0007]    However, in this method, the amount of information with which the output apparatus can respond is extremely small from several bits to several tens of bits storable in the status register. Moreover, although reading the setting information of the output apparatus (responding to an inquiry) is possible, writing (changing the setting information) is impossible. 
         [0008]    In another method, an image processing apparatus is provided with a first ASIC (Application Specific Integrated Circuit) operating in conjunction with the CPU and a second ASIC that can respond, in conjunction with a network interface, to a signal from a terminal device for requesting a change of power-saving mode of the image processing apparatus, and a startup request signal is transmitted from the terminal device to the second ASIC to start up the first ASIC and the CPU (Japanese Patent Laid-Open Publication No. 2005-94679). 
         [0009]    However, this method is merely a way of starting up the CPU and, a transition to normal mode is still required in order to read and write the setting state of the image processing apparatus. 
         [0010]    Therefore, when the setting information, such as user account information, of the image forming apparatus is desired to be changed on the image forming apparatus, it is required to write the setting information of the image forming apparatus. This operation does not require power supply to a printing unit, which consumes power most in the image forming apparatus, and can be performed in power-saving mode, which however cannot be achieved in the conventional technology. 
       SUMMARY OF THE INVENTION 
       [0011]    An object of the present invention is to allow a setting item of an image forming apparatus to be changed even in power-saving mode. 
         [0012]    In the conventional technology, when the image forming apparatus is in power-saving mode, no setting item can be written. 
         [0013]    In the present invention, a signal control unit that can control power supply to an information storage unit with a signal from an external terminal device is provided. Also, the information storage unit provided in the present invention is started up by the signal control unit even in power-saving mode to enable writing of setting information. 
         [0014]    With the improvement described above, even when the image forming apparatus is in power-saving mode, the information storage unit retaining setting items of the apparatus is started up to enable writing and reading a setting item. 
         [0015]    Another object of the present invention is to allow a time required until the information storage unit becomes in a startup state to be reported to an external terminal device. 
         [0016]    The above object is achieved by providing the signal control unit with a function of reporting a time required until startup in response to an inquiry about a startup time of the information storage unit from the external terminal device. 
         [0017]    With this, the external terminal device does not have to perform a polling operation of making an inquiry about whether the information storage unit is in startup state. Also, the load on the external terminal device for making an inquiry is suppressed. Furthermore, the load on the network due to exchange of inquiry packets is suppressed. 
         [0000]    Furthermore, still another object of the present invention is to provide a predetermined external terminal with a function of reporting a change in state of each functional unit of the image forming apparatus, for example, the fact that the information storage unit becomes in a startup state. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a block structure diagram of an image forming apparatus according to first and second embodiments; 
           [0019]      FIG. 2  is a flowchart of inquiring about the operation of an information storage unit at an image forming apparatus side according to the first embodiment; 
           [0020]      FIG. 3  is a flowchart of changing setting information in the information storage unit at a PC client side according to the first embodiment; 
           [0021]      FIG. 4  is a flowchart of inquiring about an operation state of the information storage unit at an image forming apparatus side according to the second embodiment; 
           [0022]      FIG. 5  is a flowchart of inquiring about a startup time of the information storage unit at the information forming apparatus side according to the second embodiment; and 
           [0023]      FIG. 6  is a flowchart of changing setting information in an information storage unit at a PC client side according to the second embodiment. 
           [0024]      FIG. 7  is a flowchart of a startup of the information storage unit on the image forming apparatus side according to a third embodiment. 
           [0025]      FIG. 8  is a flowchart of changing setting information with respect to the information storage unit on the PC client side according to the third embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    [Structure] 
         [0027]      FIG. 1  is a block structure diagram of an image forming apparatus according to and image forming system according to embodiments of the present invention. 
         [0028]    As depicted in  FIG. 1 , an image forming apparatus F 1  is connected to a PC (Personal Computer) client device F 2 , which is an external terminal device, through a network F 3 . 
         [0029]    The image forming apparatus F 1  includes an interface unit F 12 , a state managing unit F 13 , an information storage unit F 14 , a SNMP control unit F 11 , which is a signal control unit for power supply control over the information storage unit F 14 , and a printing unit F 17 . 
         [0030]    The interface unit F 12  takes charge of transmitting and receiving signals for communications with the PC client F 2  through the network F 3 . 
         [0031]    The SNMP (Simple Network Management Protocol) control unit F 11  (signal control unit) includes a CPU and its peripheral control interface circuits. 
         [0032]    The SNMP control unit F 11  includes an information-storage-unit state checking unit that transmits and receives a signal to and from each component of the image forming apparatus F 1  in response to an SNMP signal transmitted from the PC client F 2  to check the state of each component of the image forming apparatus F 1 . 
         [0033]    Also, the SNMP control unit F 11  includes an information-storage-unit state reporting unit that reports the state of the information storage unit checked by the information-storage-unit state checking unit to the PC client F 2 , which is a terminal device. 
         [0034]    Also, an information-storage-unit starting-up unit is provided that controls power supply to the information storage unit F 14  of the image forming apparatus F 1  according to an SNMP signal 
         [0035]    The information storage unit (storage device) F 14  includes an NVRAM (Non-Volatile Memory) and a hard disk (magnetic disk). The information storage unit F 14  serves as a storage device of the image forming apparatus F 1 , storing a program for controlling the operation of the image forming apparatus F 1  and retaining image data, as well as storing setting information of the image forming apparatus F 1 . 
         [0036]    The state managing unit (RAM: Random Access Memory) F 13  includes a semiconductor memory. The state managing unit F 13  has a function of copying and retaining setting information recorded on the information storage unit F 14 , such as a setting language of the printing unit F 17  in the image forming apparatus F 1 , a specified emulation, and a panel operation language. 
         [0037]    The printing unit F 17  performs printing. In an image forming apparatus based on an electro photographic process, due to heat fixing of toner, a fixing unit, which is a component in the printing unit, particularly consumes large power. For this reason, at the time of power-saving mode, power supply to the entire printing unit is suspended to suppress power consumption of the image forming apparatus. 
         [0038]    Modes of the image forming apparatus F 1  include a power-saving mode and a normal mode. While the image forming apparatus F 1  is operating in normal mode, power is supplied to all components including the printing unit F 17  to perform printing. 
         [0039]    During operation in normal mode, if no print request is present in the image forming apparatus for a predetermined period, the apparatus goes into power-saving mode. 
         [0040]    In power-saving mode, power is supplied to the interface unit F 12 , the SNMP control unit F 1 , and the state managing unit F 13  to cause these units to be in an operating state. However, power supply to the information storage unit F 14  and the printing unit F 17  is cut off, with the state being such that power is suppressed to maximum. 
         [0041]    At the time of transition from the normal mode to the power-saving mode, upon instruction from the SNMP control unit F 11 , the setting information of the image forming apparatus F 1  retained in the information storage unit F 14  is copied to the state managing unit F 13 , and then a transition is made to power-saving mode. 
         [0042]    In power-saving mode, upon inquiry (reading) from the PC client F 2  about the setting information of the image forming apparatus F 1 , the information copied to the state managing unit F 13  is returned. 
         [0043]    When the setting information of the image forming apparatus is required to be changed (written) in power-saving mode, the information storage unit F 14  is started up. 
         [0044]    In a state where the information storage unit F 14  is started up, power is supplied to the information storage unit to allow the setting information of the image forming apparatus F 1  to be changed from the PC client F 2 . For example, new user registration can be performed. Also in this case, power is not supplied to the printing unit F 17 , with the state being such that power is suppressed second most, following the power-saving mode. 
         [0045]    When the information storage unit F 14  is started up and writing of the setting information is completed, power supply to the information storage unit may be immediately cut off. Alternatively, if a request for changing the setting information to the image forming apparatus does not occur within a predetermined time, a setting is possible in which power supply to the information storage unit is cut off after a lapse of a predetermined time. Still alternatively, the startup state may continue as it is. 
         [0046]    The PC client F 2 , which is an external terminal device, includes an information-storage-unit state obtaining unit that obtains the state indicative of whether the information storage unit F 14  of the image forming apparatus F 1  is operable, an information-storage-unit starting-up unit for starting up the information storage unit F 14 , and an image-forming-apparatus setting changing unit that sets setting information of the image forming apparatus F 1  in the information storage unit F 14 . 
         [0047]    [F 1 owcharts] 
         [0048]    Using flowcharts of  FIGS. 2 and 3 , a flow of operation is described. 
         [0049]    To control the operation of the information storage unit F 14  in the image forming apparatus F 1 , an MIB (Management Information Base) is provided for the purpose of reporting the operation state of the information storage unit F 14  and starting up the information storage unit F 14 . By setting a specific value (“wakeup”) in this MIB, the information storage unit F 14  can be started up (can be caused to make a transition to a writable state). 
         [0050]    First,  FIG. 2  shows a flowchart of a program for response with the state of the information storage unit F 14  of the image forming apparatus F 1 . The program executing this flowchart operates within the image forming apparatus F 1 . 
         [0051]    When an inquiry to the information-storage-unit state reporting MIB is provided to the image forming apparatus F 1  (step S 1 ), a network device checks the state of the information storage unit (step S 2 ). 
         [0052]    If the information storage unit F 14  is in operation and in a writable state, a reply with “enable” is provided (step S 3 ). 
         [0053]    If power supply to the information storage unit F 14  is cut off in power-saving mode and immediate writing is not allowed, a reply with “disable” is provided (step S 4 ). 
         [0054]    Next, using the flowchart of  FIG. 3 , the operation of changing the setting of the image forming apparatus F 1  from the PC client F 2  is described. A program for executing this flowchart operates within the PC client F 2 . 
         [0055]    When the application software on the PC client F 2  changes the setting of the image forming apparatus F 1 , the value of the MIB in the information storage unit F 14  is first obtained (step S 11 ). 
         [0056]    It is then determined whether the value indicates “enable” (step S 12 ). If the value indicates “enable”, setting change is immediately performed (step S 13 ). 
         [0057]    If the determination result in step S 12  indicates NO, that is, if the MIB value of the information storage unit indicates “disable”, “wakeup” is set to an information-storage-unit state reporting MIB (step S 14 ). 
         [0058]    Then, the value of the information-storage-unit state reporting MIB is monitored (obtained at predetermined intervals) (step S 15 ) to check the value (step S 16 ). 
         [0059]    If the value indicates “enable”, the setting is changed (step S 13 ). If the value indicates “disable”, the procedure returns to the stage of obtaining the value of the information-storage-unit state reporting MIB (step S 15 ) to repeat step S 16  for determining the value. 
         [0060]    The process on the PC client F 2  side is thus completed. 
         [0061]    If “wakeup” is set to the information-storage-unit state reporting MIB in step S 14 , the SNMP control unit F 11  of the image forming apparatus F 1  senses that “wakeup” has been set to the value of the information-storage-unit state reporting MIB, and supplies power to the information storage unit F 14  to start up the information storage unit F 14 . 
         [0062]    [Effects of the Present Embodiment] 
         [0063]    The image forming apparatus F 1  and the image forming system formed of image forming apparatus F 1  and the PC client F 2  according to the present embodiment include: the interface unit F 12  that transmits and receives signals to and from the PC client F 2  even in power-saving mode; the information storage unit F 14  that is in a suspended state with power supply being cut off in power-saving mode and is supplied with power to become responsive when writing of setting information of the image forming apparatus F 1  is required; and the SNMP control unit F 11  that controls the state managing unit F 13  and the information storage unit F 14  with an SNMP signal transmitted and received by the interface unit F 12 . Therefore, even when the image forming apparatus F 1  is in power-saving mode, “wakeup” is set to the MIB value of the information storage unit F 14  with an SNMP signal from the PC client F 2 , thereby starting up the information storage unit F 14 . This makes it possible to change the setting information recorded on the information storage unit F 14  of the image forming apparatus F 1 , such as a setting language of the image forming apparatus, a specified emulation, a panel operation language, and user account information. 
         [0064]    Also, at the time of transition from the normal mode to the power-saving mode, the setting information of the image forming apparatus F 1  stored in the information storage unit F 14  is copied to and retained in the state managing unit F 13 . With this, even when the information storage unit F 14  is not started up in power-saving mode, it is possible to respond to reading of the setting information requested from the PC client F 2 . 
       Second Embodiment 
       [0065]    An image forming apparatus and an image forming system according to a second embodiment of the present invention are next described. The structure of the second embodiment is identical to that of the first embodiment shown in  FIG. 1 . 
         [0066]    In the second embodiment, the SNMP control unit F 11 , which is a signal control unit of the image forming apparatus F 1 , includes, in addition to the functional units described in the first embodiment, a startup time reporting unit that reports a startup time required until the information storage unit F 14  becomes in a startup state, in response to a request from the PC client F 2 , which is an external terminal device. 
         [0067]    Also in the second embodiment, the PC client F 2 , which is an external terminal device, includes, in addition to the functional units described in the first embodiment, an information-storage-unit startup time obtaining unit that obtains the startup time required until the information storage unit F 14  of the image forming apparatus F 1  becomes in a startup state. 
         [0068]    Other components are identical to those in the first embodiment, and therefore are not described herein. 
         [0069]    [F 1 owcharts] 
         [0070]    Using flowcharts of  FIGS. 4 ,  5 , and  6 , the flow of operation is described. 
         [0071]    To control the operation of the information storage unit F 14  in the image forming apparatus F 1 , the following MIB are provided. 
         [0072]    As an MIB representing the operation state of the information storage unit F 14 , an information-storage-unit state reporting MIB is provided to reply with an operable state (“enable”), an inoperable state (“disable”), or a state during startup process (“wait”), in response to an operation state check externally provided. 
         [0073]    Also, by setting a specific value “wakeup” to this MIB, the information storage unit F 14  can be started up (can be caused to make a transition to a writable state). 
         [0074]    Furthermore, an information-storage-unit startup time reporting MIB is provided to reply with a time required for startup when the information storage unit F 14  is in a state during startup process (“wait”). During the startup process, a reply with a time T required until startup is provided. 
         [0075]    First, a flowchart of a program for responding with the state of the information storage unit F 14  in the image forming apparatus F 1  is depicted in  FIG. 4 . A program executing this flowchart operates within the image forming apparatus F 1 . 
         [0076]    When an inquiry to the information-storage-unit state reporting MIB is provided to the image forming apparatus F 1  (step S 31 ), the image forming apparatus F 1  checks the state to see whether the information storage unit is operable (step S 32 ). 
         [0077]    If the information storage unit F 14  is in operation and in a writable state, a reply with “enable” is provided (step S 33 ). 
         [0078]    If the information storage unit F 14  is not in an operable state in step S 32 , the operation goes to S 34 . In S 34 , it is checked whether the information storage unit F 14  is in a startup process. 
         [0079]    If the information storage unit F 14  is in a startup process, a reply with “wait” as a value of the information-storage-unit state reporting MIB is provided (step S 35 ). 
         [0080]    If power supply to the information storage unit F 14  is cut off in power-saving mode and not in a startup process and immediate writing is not allowed, a reply with “disable” is provided (step S 36 ). 
         [0081]    A series of processes regarding a reply of the information-storage-unit state reporting MIB is thus completed. 
         [0082]    Next, with reference to the flowchart of  FIG. 5 , a flow of operation when a reply with an information-storage-unit startup time is provided is described. A program executing this flowchart operates within the image forming apparatus F 1 . 
         [0083]    When an inquiry to the information-storage-unit startup time checking MIB is provided to the image forming apparatus F 1  (step S 41 ), the image forming apparatus checks the state to see whether the information storage unit is in a startup process (step S 42 ). 
         [0084]    If the information storage unit F 14  is in a startup process, the operation goes to S 43 . If the information storage unit F 14  is not in a startup process, the operation goes to S 44 . 
         [0085]    If the information storage unit F 14  is in a startup process, the time required for startup is checked and a reply is provided with the time T being set to the information-storage-unit startup time reporting MIB (step S 43 ). 
         [0086]    If the information storage unit F 14  is not in a startup process, a reply s provided with the value of the information-storage-unit startup time reporting MIB being set as 0 (step S 44 ). 
         [0087]    A series of processes regarding a reply of the information-storage-unit startup time reporting MIB is thus completed. 
         [0088]    Next, with reference to the flowchart  FIG. 6 , the operation when the setting of the image forming apparatus F 1  is changed from the PC client F 2  is described. A program executing this flowchart operates within the PC client F 2 . 
         [0089]    When application software on the PC client F 2  changes the setting of the image forming apparatus F 1 , the value of the MIB in the information storage unit F 14  is first obtained (step S 51 ). 
         [0090]    It is then determined whether the value indicates “enable” (step S 52 ). If the value indicates “enable”, setting change is immediately performed (step S 53 ). 
         [0091]    If the determination result in step S 52  indicates NO, it is determined whether the MIB value indicates “wait” (step S 54 ). If the value indicates “wait”, the operation goes to S 56 . Otherwise, the operation goes to S 55 . 
         [0092]    If the value of the MIB indicates “wait”, the MIB value T indicating the information-storage-unit startup time is obtained (step S 56 ). 
         [0093]    Next, in S 57 , the operation waits for the obtained time T seconds until the information storage unit starts up. 
         [0094]    Then, in step S 53 , setting change is performed. 
         [0095]    If the MIB value in step S 54  does not indicate “wait”, that is, if the MIB value of the information storage unit indicates “disable”, “wakeup” is set to the information-storage-unit state reporting MIB to start up the information storage unit (step S 55 ). Thereafter, the operation goes to S 56 , S 57 , and then S 53  in a manner similar to that when the value of the information-storage-unit state reporting MIB indicates “wait”. 
         [0096]    The process on the PC client F 2  side is thus completed. 
         [0097]    If “wakeup” is set to the information-storage-unit state reporting MIB in step S 55 , the SNMP control unit F 1  of the image forming apparatus F 1  senses that “wakeup” has been set to the value of the information-storage-unit state reporting MIB, and supplies power to the information storage unit F 14  to start up the information storage unit F 14 . 
         [0098]    [Effects of the Second Embodiment] 
         [0099]    The image forming apparatus F 1  and the image forming system formed of the image forming apparatus F 1  and the PC client F 2  according to the second embodiment include: the interface unit F 12  that transmits and receives signals to and from the PC client F 2  even in power-saving mode; the information storage unit F 14  that is in a suspended state with power supply being cut off in power-saving mode and is supplied with power to become responsive when writing of setting information of the image forming apparatus F 1  is required; and the SNMP control unit F 1  that controls the state managing unit F 13  and the information storage unit F 14  with an SNMP signal transmitted and received by the interface unit F 12 . Therefore, even when the image forming apparatus F 1  is in power-saving mode, “wakeup” is set to the MIB value of the information storage unit F 14  with an SNMP signal from the PC client F 1 , thereby starting up the information storage unit F 14 . This makes it possible to change the setting information recorded on the information storage unit F 14  of the image forming apparatus F 1 , such as a setting language of the image forming apparatus, a specified emulation, a panel operation language, and user account information. 
         [0100]    Also, the image forming apparatus can reply with a time required until the information storage unit F 14  during a startup process enters a startup state. Therefore, an operation of checking through polling by an external terminal device whether the information storage unit F 14  is in a startup state is not required. This makes it possible to simplify the process of the application software on the external terminal device. Furthermore, the number of times of obtaining MIB from the image processing apparatus is reduced, thereby making it possible to reduce the load on the network. 
         [0101]    Still further, at the time of transition from the normal mode to the power-saving mode, the setting information of the image forming apparatus F 1  stored in the information storage unit F 14  is copied to and retained in the state managing unit F 13 . With this, even when the information storage unit F 14  is not started up in power-saving mode, it is possible to respond to reading of the setting information requested from the PC client F 2 . 
       Third Embodiment 
       [0102]    An image forming apparatus and an image forming system according to a third embodiment of the present invention are next described. The structure of the third embodiment is identical to that of the first and second embodiments shown in  FIG. 1 . 
         [0103]    In the third embodiment, the SNMP control unit F 11 , which is a signal control unit of the image forming apparatus F 1 , further includes, in addition to the functional units as described in the first and second embodiments, a functional unit (a state change reporting unit) that reports the predetermined PC client F 2  when the state of any of the functional units of the image forming apparatus F 1  is changed (TRAP transmission). Examples of the change in state of any of the functional units include a change in a power supply mode state of the image forming apparatus, a change in an operable state of the signal control unit, and a change in a printable state of the printing unit. 
         [0104]    In the third embodiment, the PC client F 2 , which is an external terminal device, further includes, in addition to the functional units as described in the first and second embodiments, a state change receiving unit that receives a report from the state change reporting unit of the image forming apparatus F 1 . 
         [0105]    Other than that, the third embodiment is identical to the first embodiment, and therefore further description is omitted. 
         [0106]    [F 1 owcharts] 
         [0107]    Using flowcharts of  FIGS. 4 ,  7 , and  8 , a flow of operation is described. 
         [0108]    To control the operation of the information storage unit F 14  in the image forming apparatus F 1 , an MIB (Management Information Base) is used for the purpose of reporting the operation state of the information storage unit F 14  and starting up the information storage unit F 14 . By setting a specific value (“wakeup”) in this MIB, the information storage unit F 14  can be started up (can be caused to make a transition to a writable state). 
         [0109]    Since the flowchart of a series of processes regarding replying to the information-storage-unit state reporting MIB by the information storage unit F 14  of the image forming apparatus F 1  is identical to that in the description of  FIG. 4  according to the second embodiment, and therefore is not described herein. 
         [0110]      FIG. 7  shows a flowchart of a program for receiving a startup request for the information storage unit F 14  from the PC client F 2  and then reporting the PC client F 2  that startup has been completed. The program executing this flowchart operates within the image forming apparatus F 1 . 
         [0111]    When the image forming apparatus F 1  receives a request for startup of the information storage unit F 14  from the PC client F 2  (“wakeup” is set to the information-storage-unit state reporting MIB) (step S 61 ), the image forming apparatus F 1  starts the startup of the information storage unit F 14  (step S 62 ). 
         [0112]    Also, the address of the PC client F 2  transmitting the startup request is stored in the state managing unit (RAM) F 13  (step S 63 ). 
         [0113]    Then, when the startup of the information storage unit F 14  is completed (step S 64 ), TRAP transmission is performed so as to report the completion of startup to the stored address of the PC client F 2  (step S 65 : the state change reporting unit). 
         [0114]    The process on the image forming apparatus F 1  side is thus completed. 
         [0115]    Next, the operation of changing the setting of the image forming apparatus F 1  from the PC client F 2  is described by using the flowchart of  FIG. 8 . A program executing this flowchart operates within the PC client F 2 . 
         [0116]    When application software on the PC client F 2  changes the setting of the image forming apparatus F 1 , the value of the information-storage-unit state reporting MIB of the information storage unit F 14  is first obtained (step S 71 ). 
         [0117]    It is determined whether the value indicates “enable” (step S 72 ). If the value indicates “enable”, the setting is instantly changed (step S 73 ). 
         [0118]    If the determination result in step S 22  is NO, “wakeup” is set to an information-storage-unit state reporting MIB (step S 74 ). 
         [0119]    Then, when an information-storage-unit startup complete TRAP is received from the image forming apparatus F 1  (step S 75 ), the setting is changed (step S 73 ). 
         [0120]    The process on the PC client F 2  side is thus completed. 
         [0121]    If “wakeup” is set to the information-storage-unit state reporting MIB in step S 74 , the SNMP control unit F 11  of the image forming apparatus F 1  senses that “wakeup” has been set to the value of the information-storage-unit state reporting MIB, and supplies power to the information storage unit F 14  to start up the information storage unit F 14 . 
         [0122]    [Effects of the Third Embodiment] 
         [0123]    The image forming apparatus F 1  and the image forming system formed of the image forming apparatus F 1  and the PC client F 2 : the interface unit F 12  that transmits and receives signals to and from the PC client F 2  even in power-saving mode; the information storage unit F 14  that is in a suspended state with power supply being cut off in power-saving mode and is supplied with power to become responsive when writing of setting information of the image forming apparatus F 1  is required; and the SNMP control unit F 11  that controls the state managing unit F 13  and the information storage unit F 14  with an SNMP signal transmitted and received by the interface unit F 12 . Therefore, even when the image forming apparatus F 1  is in power-saving mode, “wakeup” is set to the MIB value of the information storage unit F 14  with an SNMP signal from the PC client F 2 , thereby starting up the information storage unit F 14 . This makes it possible to change the setting information recorded on the information storage unit F 14  of the image forming apparatus F 1 , such as a setting language of the image forming apparatus, a specified emulation, a panel operation language, and user account information. 
         [0124]    Also, when the process of starting up the image storage unit F 14  is completed, the completion of the startup process can be reported to the PC client F 2 . Therefore, an operation of checking through polling by an external terminal device whether the information storage unit F 14  is in a startup state is not required. This makes it possible to simplify the process of the application software on the external terminal device. Furthermore, the number of times of obtaining MIB from the image processing apparatus is reduced, thereby making it possible to reduce the load on the network. 
         [0125]    Still further, at the time of transition from the normal mode to the power-saving mode, the setting information of the image forming apparatus F 1  stored in the information storage unit F 14  is copied to and retained in the state managing unit F 13 . With this, even when the information storage unit F 14  is not started up in power-saving mode, it is possible to respond to reading of the setting information requested from the PC client F 2 . 
         [0126]    [Others] 
         [0127]    In the flowcharts, reporting when the startup of the information storage unit is completed is described. Also, reporting can be made when the information storage unit enters a sleep state, when the power mode of the image forming apparatus is changed, or when the printable state of the printing unit is changed. 
         [0128]    Also, when reporting the state change of a functional unit to the external terminal device, the image forming apparatus may report as such to a predetermined external terminal device specified in advance, or may broadcast as such within a network. 
         [0129]    To broadcast the state change within a network, not the PC client setting “wakeup” makes a response as shown in  FIG. 8 , but the external terminal device including a state change receiving unit that receives the broadcast may make a response. What is claimed is: