Patent Publication Number: US-10791227-B2

Title: Image forming apparatus that carries out communication with multiple external apparatuses, control method for the image forming apparatus, and storage medium

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an image forming apparatus, a control method for the image forming apparatus, and a storage medium. 
     Description of the Related Art 
     Conventionally, there is known an image forming apparatus which carries out communication with a plurality of external apparatuses such as a mobile terminal, a client PC, and a DHCP server (see, for example, Japanese Laid-Open Patent Publication (Kokai) No. 2013-205982). This image forming apparatus is connected to the mobile terminal by a wireless LAN and also connected to the client PC and the DHCP server by a wired LAN via a LAN cable. When carrying out wireless LAN communication with the mobile terminal, the image forming apparatus itself acts as an access point and automatically issues an IP address for use in wireless LAN communication with the mobile terminal. As a result, the image forming apparatus carries out wireless LAN communication with the mobile terminal using Wi-Fi Direct (registered trademark), Bluetooth (registered trademark), or the like. The image forming apparatus also carries out wired LAN communication with the client PC using an IP address issued by the DHCP server. 
     Each of IP addresses for use in communication between the image forming apparatus and the mobile terminal and communication between the image forming apparatus and the client PC is comprised of a network address and a host address. 
     However, a network address of an IP address for use in wireless LAN communication between the image forming apparatus and the mobile terminal and a network address of an IP address for use in wired LAN communication between the image forming apparatus and the client PC may conflict with each other. As a result, both wireless LAN communication between the image forming apparatus and the mobile terminal and wired LAN communication between the image forming apparatus and the client PC may be possible. In this case, for example, if a communication setting that gives higher priority to wireless LAN communication between the image forming apparatus and the mobile terminal than to wired LAN communication between the image forming apparatus and the client PC is made in advance, wireless LAN communication between the image forming apparatus and the mobile terminal is carried out. Thus, even when a user wishes transmission of data from the image forming apparatus to the client PC, the data is transmitted to the mobile terminal and hence cannot be transmitted to the client PC to which transmission of the data is wished by the user. Namely, when the image forming apparatus carries out LAN communications with a plurality of external apparatuses, a problem arises when a plurality of IP addresses for use in the respective LAN communications conflict with one another because it is impossible to properly carry out the LAN communications with the plurality of external apparatuses. 
     SUMMARY OF THE INVENTION 
     The present invention provides an image forming apparatus which is capable of properly carrying out communication with a plurality of external apparatuses, a control method for the image forming apparatus, and a storage medium. 
     Accordingly, the present invention provides an image forming apparatus comprising a wireless communicator that performs wireless communication with a first external apparatus, a network I/F that connects a printing control apparatus which communicates with a second external apparatus on a network to the image forming apparatus, a memory that stores programs, and a processor that executes the programs to: determine whether a network address of a first IP address used in the wireless communication with the first external apparatus conflicts with a network address of a second IP address used in communication with the second external apparatus, and execute a predetermined process at least in a case where it is determined that the network address of the first IP address conflicts with the network address of the second IP address. 
     According to the present invention, communication is properly carried out with the plurality of external apparatuses. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are conceptual diagrams schematically showing arrangements of image forming systems including an MFP which is an image forming apparatus according to an embodiment of the present invention, in which  FIG. 1A  shows the image forming system including no EFI that is a printing control apparatus, and  FIG. 1B  shows the image forming system including the EFI. 
         FIGS. 2A and 2B  are block diagrams schematically showing internal arrangements of some component elements of the image forming system in  FIGS. 1A and 1B , in which  FIG. 2A  is a block diagram schematically showing an internal arrangement of the MFP in the image forming system in  FIG. 1A , and  FIG. 2B  is a block diagram schematically showing internal arrangements of the MFP and the EFI in the image forming system in  FIG. 1B . 
         FIG. 3  is a flowchart showing the procedure of a startup process which is carried out by a CPU of the MFP in  FIGS. 2A and 2B . 
         FIG. 4  is a flowchart showing the procedure of a notification process which is carried out in step S 308  in  FIG. 3 . 
         FIG. 5  is a flowchart showing the procedure of a changed-address notification process in which an EFI/PC IP address set in the EFI in the image forming system after completion of the startup process in  FIG. 3  is changed, and the MFP is notified of the changed EFI/PC IP address. 
         FIG. 6  is a flowchart showing the procedure of a receiving process in which the MFP receives the changed EFI/PC IP address, a notification of which was provided in step S 503  in  FIG. 5 . 
         FIG. 7  is a view useful in explaining a setting screen used to set the timing for changing an IP address for the MFP in  FIGS. 1A and 1B . 
         FIG. 8  is a flowchart showing the procedure of a communication establishing process which is carried out when a mobile terminal side IP address is to be changed after completion of the startup process in  FIG. 3 . 
         FIGS. 9A and 9B  are views useful in explaining an access point setting screen and a warning indication displayed on an operation display unit in  FIGS. 1A and 1B . 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereafter, an embodiment of the present invention will be described in detail with reference to the drawings. 
       FIGS. 1A and 1B  are conceptual diagrams schematically showing arrangements of image forming systems including an MFP  101  which is an image forming apparatus according to an embodiment of the present invention, in which  FIG. 1A  shows an image forming system  100  including no EFI (registered trademark)  102  which is a printing control apparatus, and  FIG. 1B  shows an image forming system  150  including the EFI  102 . 
     The image forming system  100  in  FIG. 1A  has an MFP  101 , a client PC  103  (first external apparatus), a mobile terminal  104  (second external apparatus), and a server  111 . The MFP  101 , the client PC  103 , and the server  111  are connected to one another by a wired LAN  105 . The server  111  issues an IP address for use in wired LAN communication, and the MFP  101  carries out wired LAN communication using this IP address. The MFP  101  is connected to the mobile terminal  104  by a wireless LAN using, for example, a Wi-Fi Direct or Bluetooth without involving a relay device which acts as an access point. In the present embodiment, the MFP  101  acts as an access point and automatically issues an IP address for use in wireless LAN communication with the mobile terminal  104  to carry out wireless LAN communication. 
     The image forming system  150  in  FIG. 1B  has the MFP  101 , the EFI  102  (third external apparatus), the client PC  103 , the mobile terminal  104 , and the server  111 . The EFI  102  is placed between the MFP  101  and the client PC  103 , and the MFP  101  is connected to the EFI  102  via an image video cable  109  and a control cable  110 . The EFI  102 , the client PC  103 , and the server  111  are connected to one another via the wired LAN  105 . It should be noted that as with the image forming system  100 , the MFP  101  is connected to the mobile terminal  104  by a wireless LAN. 
     The MFP  101  has a scanner  106 , an operation display unit  107 , and a sheet discharging unit  108 . The scanner  106  reads an original to generate image data. The generated image data is transmitted to, for example, the client PC  103 . The operation display unit  107  receives instructions from a user and displays, for example, status information on the MFP  101 . The operation display unit  107  also displays an access point setting screen  900  and produces a warning indication  910  (requesting unit) as will be described later. Recording sheets with images printed thereon are discharged onto the sheet discharging unit  108 . The EFI  102  works in cooperation with the MFP  101  to perform various types of image processing on image data. The client PC  103  carries out wired LAN communications and sends print jobs to, for example, the MFP  101 . The mobile terminal  104  carries out wireless LAN communications and sends print jobs to the MFP  101 . The server  111  issues IP addresses, which are for use in wired LAN communications, to the MFP  101 , the EFI  102 , and the client PC  103 . 
     It should be noted that in the present embodiment, the MFP  101  is connected only to the EFI  102  but may be connected to the LAN  105  as well as the EFI  102 . 
       FIGS. 2A and 2B  are block diagrams schematically showing internal arrangements of some component elements of the image forming systems  100  and  150  in  FIGS. 1A and 1B , in which  FIG. 2A  is a block diagram schematically showing an internal arrangement of the MFP  101  in the image forming system  100  in  FIG. 1A , and  FIG. 2B  is a block diagram schematically showing internal arrangements of the MFP  101  and the EFI  102  in the image forming system  150  in  FIG. 1B . 
     The MFP  101  in  FIGS. 2A and 2B  has the scanner  106 , the operation display unit  107 , a controller unit  201 , a network unit  202 , a printer  203 , and a wireless communication unit  204 . 
     The controller unit  201  has a CPU  205  (a determination unit, a first changing unit, a second changing unit, a receiving unit), a memory  206 , a reader I/F  207 , a video I/F  208 , a network I/F  209 , and a printer I/F  210 . The controller unit  201  has an HDD  211 , a startup control unit  212 , and a network I/F  213 . The component elements of the controller unit  201  are connected to one another via a system bus  222 . The scanner  106  and the operation display unit  107  are connected to the reader I/F  207 , the printer  203  is connected to the printer I/F  210 , and the wireless communication unit  204  is connected to the network I/F  213 . 
     When the EFI  102  is not connected to the MFP  101 , the network unit  202  is connected to the network I/F  209 , and the client PC  103  and the sever  111  as well are connected to the network I/F  209  via the LAN  105 . When the EFI  102  is connected to the MFP  101 , a video I/F  217 , to be described later, is connected to the video I/F  208  via the image video cable  109 . Also, when the EFI  102  is connected to the MFP  101 , the network unit  202  is connected to the network I/F  209 , and a network I/F  218 , to be described later, as well is connected to the network I/F  209  via the control cable  110 . 
     When the EFI  102  is not connected to the MFP  101 , the network unit  202  obtains an IP address (first address) (hereafter referred to as an “MFP/PC IP address”), which is for use in wired LAN communication between the MFP  101  and the client PC  103 , from the server  111  and sets the obtained MFP/PC IP address in the MFP  101 . When the EFI  102  is connected to the MFP  101 , the network unit  202  obtains an IP address (third address) (hereafter referred to as an “MFP/EFI IP address”), which is for use in wired LAN communication between the MFP  101  and the EFI  102 , from the server  111  and sets the obtained MFP/EFI IP address in the MFP  101 . 
     As an IP address for use in wired LAN communication between the MFP  101  and the EFI  102 , an MFP/EFI IP address is set in the MFP  101 . However, wired LAN communication between the MFP  101  and the EFI  102  is not performed only by the MFP/EFI IP address. Specifically, in order for wired LAN communication between the MFP  101  and the EFI  102  to be performed, an IP address different from an MFP/EFI IP address and set in the EFI  102  (hereafter referred to as an “EFI/MFP IP address”) is needed. When an MFP/EFI IP address and an EFI/MFP IP address correspond to each other, wired LAN communication between the MFP  101  and the EFI  102  is performed. It should be noted that an EFI/MFP IP address is set in the EFI  102  by an EFI network unit  220 , to be described later. 
     Further, when an MFP/EFI IP address and an MFP/PC IP address are changed, the network unit  202  obtains a new MFP/EFI IP address and a new MFP/PC IP address from the server  111  and sets them in the MFP  101 . 
     The printer  203  prints, for example, image data, which corresponds to an original read by the scanner  106 , and PDL (page-description language) data, which is received from the client PC  103 , on recording sheets. The wireless communication unit  204  issues an IP address (second address) (hereafter referred to as a “mobile terminal side IP address”), which is for use in wireless LAN communication between the MFP  101  and the mobile terminal  104  and sets the issued mobile terminal side IP address in the MFP  101 . Also, when a mobile terminal side IP address is changed, the wireless communication unit  204  issues a new mobile terminal side IP address and sets it in the MFP  101 . 
     The CPU  205  executes programs stored in the memory  206  and the HDD  211  to control the component elements of the MFP  101 . The memory  206  is a work memory for the CPU  205 . The HDD  211  is a large-capacity storage device and stores, for example, image data corresponding to an original read by the scanner  106  and PDL data received from the client PC  103 . The HDD  211  also stores information on an MFP/EFI IP address, an MFP/PC IP address, and a mobile terminal side IP address set in the MFP  101 . The information on each of the IP addresses includes a subnet mask which is a numerical value that discriminates between a network address and a host address constituting an IP address. Further, the HDD  211  stores changing IP addresses for use in changing an MFP/EFI IP address, an MFP/PC IP address, and a mobile terminal side IP address. Changing IP addresses are used to generate a MFP/EFI IP address, an MFP/PC IP address, and a mobile terminal side IP address that have been changed. The startup control unit  212  supplies power to the component elements of the MFP  101  and controls startup of the MFP  101 . 
     The EFI  102  in  FIG. 2B  has a CPU  214 , a memory  215 , an HDD  216 , a video I/F  217 , network I/Fs  218  and  219 , and the EFI network unit  220 , and these component elements are connected to one another via a system bus  221 . The client PC  103  and the server  111  are connected to the network I/F  219  via the LAN  105 . 
     The CPU  214  executes programs stored in the memory  215  and the HDD  216  to control the component elements of the EFI  102 . The memory  215  is a work memory for the CPU  214 . The HDD  216  is a large-capacity storage device and stores, for example, image data that has been subjected to various types of processing by the EFI  102 . The HDD  216  also stores information, for example, a subnet mask, on an EFI/MFP IP address and an IP address for use in wired LAN communication between the EFI  102  and the client PC  103  (fourth address) (hereafter referred to as an “EFI/PC IP address”). Further, when an EFI/MFP IP address and an EFI/PC IP address are to be changed, the HDD  216  stores changing IP addresses for use in generating an EFI/MFP IP address and an EFI/PC IP address. 
     The EFI network unit  220  obtains an EFI/MFP IP address and an EFI/PC IP address from the server  111  and sets them in the EFI  102 . Also, when an MFP/EFI IP address set in the MFP  101  is changed, the EFI network unit  220  obtains a new EFI/MFP IP address from the server  111  and sets it in the EFI  102 . This avoids a situation in which wired LAN communication between the MFP  101  and the EFI  102  is not performed. 
     When an EFI/PC IP address is set in the EFI  102 , or when an EFI/PC IP address set in the EFI  102  is changed, the EFI  102  informs the client PC  103  accordingly. 
       FIG. 3  is a flowchart showing the procedure of a startup process which is carried out by the CPU  205  of the MFP  101  in  FIGS. 2A and 2B . The startup process in  FIG. 3  is carried out on the precondition that an MFP/EFI IP address or an MFP/PC IP address and a mobile terminal side IP address are set in the MFP  101 . 
     Referring to  FIG. 3 , first, when the MFP  101  is switched on (step S 301 ), the CPU  205  obtains an MFP/EFI IP address or an MFP/PC IP address set in the MFP  101  (step S 302 ). Next, the CPU  205  obtains a mobile terminal side IP address set in the MFP  101  (step S 303 ) and determines whether or not the EFI  102  is connected to the MFP  101  (step S 304 ). 
     As a result of the determination in the step S 304 , when the EFI  102  is not connected to the MFP  101 , the CPU  205  determines whether or not a network address of the MFP/PC IP address and a network address of the mobile terminal side IP address conflict with each other (step S 305 ). As described above, an IP address is comprised of a network address and a host address. The network address identifies a network space to which the IP address belongs, and the host address identifies a device in the network address. The network address and the host address are discriminated based on a subnet mask. In the step S 305 , by ascertaining whether or not the network address of the MFP/PC IP address and the network address of the mobile terminal side IP address conflict with each other, it is determined whether or not network spaces to which the respective IP addresses belong conflict with each other. As a result of the determination in the step S 305 , when the network address of the MFP/PC IP address and the network address of the mobile terminal side IP address do not conflict with each other, the CPU  205  normally starts the MFP  101  and terminates the present process. On the other hand, when the network address of the MFP/PC IP address and the network address of the mobile terminal side IP address conflict with each other, the CPU  205  changes the mobile terminal side IP address in priority to the MFP/PC IP address (step S 306 ). For example, assume that the MFP/PC IP address is 192.168.1.100, and the mobile terminal side IP address is 192.168.1.200. Here, when a subnet mask of the mobile terminal side IP address is 255.255.255.0, the network address of the mobile terminal side IP address is 192.168.1. Therefore, the network address of the mobile terminal side IP address conflicts with the network address of the MFP/PC IP address. To resolve this conflict, the CPU  205  adds 1 to the end of the network address of the mobile terminal side IP address so that it can be 192.168.2. As a result, the conflict of the network addresses is resolved. After that, the CPU  205  normally starts the MFP  101  and terminates the present process. 
     When an MFP/PC IP address is changed, the server  111  issues a new MFP/PC IP address and sets this new MFP/PC IP address in the MFP  101 . On the other hand, when a mobile terminal side IP address is changed, the MFP  101  itself issues a new mobile terminal side IP address and sets this new mobile terminal side IP address in the MFP  101 . Specifically, changing of an MFP/PC IP address is not completed only by the MFP  101 , whereas changing of a mobile terminal side IP address is completed only by the MFP  101 , and therefore, the mobile terminal side IP address is changed more easily than the MFP/PC IP address is. Accordingly, in the present embodiment, changing of a mobile terminal side IP address is given higher priority than changing of an MFP/PC IP address in the step S 306  as described above. 
     As a mobile terminal side IP address after it is changed, either a changing IP address stored in advance in the HDD  211  may be used as it is, or an IP address input by the user may be used. 
     As a result of the determination in the step S 304 , when the EFI  102  is connected to the MFP  101 , the CPU  214  of the EFI  102  carries out a notification process ( FIG. 4 ), to be described later, in which it notifies the MFP  101  of an EFI/PC IP address (step S 307 ). The CPU  205  then obtains the EFI/PC IP address (step S 308 ). The CPU  205  determines whether or not at least two network addresses among a network address of the MFP/EFI IP address, the network address of the mobile terminal side IP address, and a network address of the EFI/PC IP address conflict with each other (step S 309 ). 
     As a result of the determination in the step S 309 , when the network addresses are different from one another, the CPU  205  normally starts the MFP  101  and terminates the present process. On the other hand, when at least two of the network addresses conflict with each other, the CPU  205  changes at least one of IP addresses corresponding to the competing network addresses (step S 310 ). It should be noted that each IP address is changed in the same manner as in the step S 306  described above. 
     When a mobile terminal side IP address is changed, the MFP  101  issues a new mobile terminal side IP address and sets this new mobile terminal side IP address in the MFP  101 . On the other hand, when an MFP/EFI IP address is changed, a new MFP/EFI IP address issued by the server  111  is set in the MFP  101 . When the new MFP/EFI IP address is set in the MFP  101 , a new EFI/MFP IP address corresponding to the new MFP/EFI IP address is issued by the server  111 . The new EFI/MFP IP address thus issued is set in the EFI  102 . An EFI/PC IP address is changed in the same manner that an MFP/EFI IP address is changed, and in this case, the EFI  102  needs to have the client PC  103  recognize that the EFI/PC IP address has been changed. 
     Specifically, changing of an MFP/EFI IP address or an EFI/PC IP address is not completed only by the MFP  101 , whereas changing of a mobile terminal side IP address is completed only by the MFP  101 . Thus, changing of a mobile terminal side IP address is easier than changing of an EFI/MFP IP address or an EFI/PC IP address. Also, changing of an MFP/EFI IP address is completed by only the server  111 , the MFP  101 , and the EFI  102 , whereas changing of an EFI/PC IP address needs not only the server  111 , the MFP  101 , and the EFI  102  but also the client PC  103 . Thus, changing of an MFP/EFI IP address easier than changing of an EFI/PC IP address. Accordingly, in the present embodiment, changing of a mobile terminal side IP address is given higher priority than changing of an MFP/EFI IP address and an EFI/PC IP address in the step S 310 . Also, changing of an MFP/EFI IP address is given higher priority than changing of an EFI/PC IP address. 
     Specifically, when a network address of an MFP/EFI IP address and a network address of a mobile terminal side IP address conflict with each other, changing of the mobile terminal side IP address is given higher priority than changing of the MFP/EFI IP address. When a network address of an EFI/PC IP address and a network address of a mobile terminal side IP address conflict with each other, changing of the mobile terminal side IP address is given higher priority than changing of the EFI/PC IP address. When a network address of an EFI/PC IP address and a network address of an MFP/EFI IP address conflict with each other, changing of the MFP/EFI IP address is given higher priority than changing of the EFI/PC IP address. When a network address of an MFP/EFI IP address, a network address of a mobile terminal side IP address, and a network address of an EFI/PC IP address conflict with one another, the mobile terminal side IP address is changed first, and the MFP/EFI IP address is changed next. 
     In the next step S 311 , the CPU  205  determines again whether or not at least two network addresses among the network address of the MFP/EFI IP address, the network address of the mobile terminal side IP address, and the network address of the EFI/PC IP address conflict with each other. When the CPU  205  determines in the step S 311  that at least two of the network addresses still conflict with each other, the process returns to the step S 310 . On the other hand, when the network addresses are different, the CPU  205  terminates the present process. 
       FIG. 4  is a flowchart showing the procedure of the notification process which is carried out in the step S 308  in  FIG. 3 . The process in  FIG. 4  is carried out by the CPU  214  of the EFI  102  in  FIG. 2B . 
     Referring to  FIG. 4 , first, when the EFI  102  is switched on (step S 401 ), the CPU  214  determines whether or not an EFI/PC IP address is set in the EFI  102  (step S 402 ). As a result of the determination in the step S 402 , when no EFI/PC IP address is set in the EFI  102 , the CPU  214  terminates the present process. On the other hand, when an EFI/PC IP address is set in the EFI  102 , the CPU  214  determines whether or not the EFI  102  is able to communicate with the MFP  101  (step S 403 ). As a result of the determination in the step S 403 , when the EFI  102  is not able to communicate with the MFP  101 , the CPU  214  terminates the present process. On the other hand, when the EFI  102  is able to communicate with the MFP  101 , the CPU  214  notifies the MFP  101  of the EFI/PC IP address set in the EFI  102  (step S 404 ) and terminates the present process. 
     According to the process in  FIG. 3 , in the image forming system  100  (NO in the step S 304 ), a network address of an MFP/PC IP address and a network address of a mobile terminal side IP address may conflict with each other (YES in the step S 305 ). In this case, the mobile terminal side IP address is changed (step S 306 ). This prevents a network address of an MFP/PC IP address and a network address of a mobile terminal side IP address from conflicting with each other. Also, in the image forming system  150  (YES in the step S 304 ), when at least two network addresses among a network address of an MFP/EFI IP address, a network address of a mobile terminal side IP address, and a network address of an EFI/PC IP address conflict with each other (YES in the step S 309 ), at least one of IP addresses corresponding to the competing network addresses is changed (step S 310 ). This makes the network addresses of the MFP/EFI IP address, the mobile terminal side IP address, and the EFI/PC IP address differ from one other. This avoids a situation in which both a wired LAN communication between the MFP  101  and the client PC  103  and a wireless LAN communication between the MFP  101  and the mobile terminal  104  are possible. Moreover, a situation in which all of a wired LAN communication between the MFP  101  and the EFI  102 , a wired LAN communication between the EFI  102  and the client PC  103 , and a wireless LAN communication between the MFP  101  and the mobile terminal  104  are possible is avoided. As a result, the MFP  101  properly carries out communication with the EFI  102 , the client PC  103 , and the mobile terminal  104 . 
     Moreover, according to the process in  FIG. 3 , when a network address of an MFP/PC IP address and a network address of a mobile terminal side IP address conflict with each other, changing of the mobile terminal side IP address is given higher priority than changing of the MFP/PC IP address. As described above, changing of an MFP/PC IP address is not completed by only the MFP  101 . On the other hand, changing of a mobile terminal side IP address is completed by only the MFP  101 . Therefore, giving higher priority to changing of a mobile terminal side IP address than to changing of a MFP/PC IP address easily makes the MFP/PC IP address and the mobile terminal side IP address differ from each other. 
     Further, according to the process in  FIG. 3 , changing of a mobile terminal side IP address is given higher priority than changing of an MFP/EFI IP address and an EFI/PC IP address. Changing of an MFP/EFI IP address is given higher priority than changing of an EFI/PC IP address. As described above, changing of an MFP/EFI IP address and an EFI/PC IP address is not completed by only the MFP  101 . On the other hand, changing of a mobile terminal side IP address is completed by only the MFP  101 , and changing of an MFP/EFI IP address is completed by only the server  111 , the MFP  101 , and the EFI  102 . Changing of an EFI/PC IP address needs not only the server  111 , the MFP  101 , and the EFI  102  but also the client PC  103 . Thus, changing of a mobile terminal side IP address is easier than changing of an MFP/EFI IP address, and changing of an MFP/EFI IP address is easier than changing of an EFI/PC IP address. Namely, in the process in  FIG. 3 , an address that is easy to change is changed with the highest priority, and this easily makes a mobile terminal side IP address, an MFP/EFI IP address, and an EFI/PC IP address differ from each other. 
       FIG. 5  is a flowchart showing the procedure of a changed-address notification process. In the process in  FIG. 5 , an EFI/PC IP address set in the EFI  102  in the image forming system  150  after completion of the startup process in  FIG. 3  is changed, and the MFP  101  is notified of the changed EFI/PC IP address. The process in  FIG. 5  is carried out by the CPU  214  of the EFI  102 . 
     Referring to  FIG. 5 , first, the CPU  214  detects that an EFI/PC IP address set in the EFI  102  has been changed (step S 501 ) and determines whether or not the EFI  102  is able to communicate with the MFP  101  (step S 502 ). As a result of the determination in the step S 502 , when the EFI  102  is not able to communicate with the MFP  101 , the CPU  214  terminates the present process. On the other hand, when the EFI  102  is able to communicate with the MFP  101 , the CPU  214  sends a notification of the changed EFI/PC IP address to the CPU  205  of the MFP  101  and terminates the present process. 
       FIG. 6  is a flowchart showing the procedure of a receiving process in which the MFP  101  receives the changed EFI/PC IP address the notification of which was sent in the step S 503  in  FIG. 5 . The process in  FIG. 6  is carried out by the CPU  205  of the MFP  101 . 
     Referring to  FIG. 6 , first, the CPU  205  receives the changed EFI/PC IP address from the EFI  102  (step S 601 ). Next, the CPU  205  obtains an MFP/EFI IP address set in the MFP  101  (step S 602 ) and obtains a mobile terminal side IP address set in the MFP  101  (step S 603 ). Then, the CPU  205  determines whether or not a network address of the changed EFI/PC IP address conflicts with a network address of the MFP/EFI IP address or a network address of the mobile terminal side IP address (step S 604 ). 
     As a result of the determination in the step S 604 , when the network address of the changed EFI/PC IP address conflicts with neither the network address of the MFP/EFI IP address nor the network address of the mobile terminal side IP address, the CPU  205  terminates the present process. On the other hand, when the CPU  205  determines that the network address of the changed EFI/PC IP address conflicts with the network address of the MFP/EFI IP address or the network address of the mobile terminal side IP address, the process proceeds to step S 605 . In the step S 605 , the CPU  205  changes the mobile terminal side IP address in priority to the changed EFI/PC IP address with the timing set in advance in the MFP  101  through a setting screen ( FIG. 7 ) (setting unit). After that, the CPU  205  terminates the present process. It should be noted that each IP address is changed in the same manner as in the step S 310  described above. 
     The setting screen  700  has a change-at-once button  701 , a change-at-restart button  702 , and a change-at-non-communication-time button  703 . When the change-at-once button  701  is selected, an MFP/EFI IP address or a mobile terminal side IP address is changed at a predetermined time point. It should be noted that the predetermined time point is, for example, a time point at which it is determined that a network address of a new EFI/PC IP address after it is changed conflicts with a network address of either an MFP/EFI IP address or a mobile terminal side IP address. When the change-at-restart button  702  is selected, an MFP/EFI IP address or a mobile terminal side IP address is changed when the MFP  101  is restarted next, and when the startup process described above is carried out. When the change-at-non-communication-time button  703  is selected, an MFP/EFI IP address or a mobile terminal side IP address is changed when the MFP  101  is communicating with neither the EFI  102  nor the mobile terminal  104 . 
     According to the process in  FIG. 6 , a changed EFI/PC IP address is received from the EFI  102  (step S 601 ). Then, a network address of the changed EFI/PC IP address may conflict with a network address of an MFP/EFI IP address or a network address of a mobile terminal side IP address. In this case, the MFP/EFI IP address or the mobile terminal side IP address is changed (step S 605 ). As described above, changing of an EFI/PC IP address is not easier than changing of an MFP/EFI IP address or a mobile terminal side IP address. Thus, after an EFI/PC IP address is changed, an MFP/EFI IP address or a mobile terminal side IP address is changed to prevent an EFI/PC IP address, which takes time and effort to change, from being changed twice. 
       FIG. 8  is a flowchart showing the procedure of a communication establishing process which is carried out when a mobile terminal side IP address is changed after the startup process in  FIG. 3  is completed. The process in  FIG. 8  is carried out by the CPU  205  of the MFP  101 . 
     Referring to  FIG. 8 , first, the CPU  205  detects that a mobile terminal side IP address has been changed (step S 801 ). As the mobile terminal side IP address, for example, a new IP address or the like is input via an access point setting screen  900  ( FIG. 9A ) displayed on the operation display unit  107 . The mobile terminal side IP address is changed by setting the input new IP address or the like as a mobile terminal side IP address in the MFP  101 . The access point setting screen  900  has an IP address input field  901  and a subnet mask input field  902 . A new IP address is entered into the IP address input field  901 , and a subnet mask is entered into the subnet mask input field  902 . 
     Referring to again  FIG. 8 , the CPU  205  obtains an MFP/EFI IP address or an MFP/PC IP address set in the MFP  101  (step S 802 ) and determines whether or not the EFI  102  is connected to the MFP  101  (step S 803 ). As a result of the determination in the step S 803 , when the EFI  102  is not connected to the MFP  101 , the CPU  205  determines whether or not a network address of the changed mobile terminal side IP address and a network address of the MFP/PC IP address conflict with each other (step S 804 ). As a result of the determination in the step S 804 , when the network address of the changed mobile terminal side IP address and the network address of the MFP/PC IP address do not conflict with each other, the CPU  205  terminates the present process. On the other hand, when the network address of the changed mobile terminal side IP address and the network address of the MFP/PC IP address conflict with each other, the CPU  205  produces a warning indication  910  ( FIG. 9B ) on the operation display unit  107  (step S 805 ) and terminates the present process. The warning indication  910  requests entry of a new IP address or the like on the access point setting screen  900  again. 
     As a result of the determination in the step S 803 , when the EFI  102  is connected to the MFP  101 , the CPU  205  obtains an EFI/PC IP address (step S 806 ). The CPU  205  then determines whether or not the network address of the changed mobile terminal side IP address conflicts with the network address of the MFP/PC IP address or a network address of the EFI/PC IP address (step S 807 ). As a result of the determination in the step S 807 , when the network addresses are different, the CPU  205  terminates the present process. On the other hand, when the CPU  205  determines that the network address of the changed mobile terminal side IP address conflicts with the network address of the MFP/PC IP address or the network address of the EFI/PC IP address, the process proceeds to the step S 805 . 
     According to the process in  FIG. 8 , in the image forming system  150  (YES in the step S 803 ), a network address of a changed mobile terminal side IP address conflicts with a network address of an MFP/PC IP address or a network address of an EFI/PC IP address. In this case (YES in the step S 807 ), the warning indication  910  is produced on the operation display unit  107  (step S 805 ). As a result, the user recognizes that proper communication with the EFI  102 , the client PC  103 , or the mobile terminal  104  constituting the image forming system  150  is impossible. 
     Other Embodiments 
     Embodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Applications No. 2015-087664, filed Apr. 22, 2015 and No. 2016-032961, filed Feb. 24, 2016 which are hereby incorporated by reference herein in their entirety.