Patent Publication Number: US-11642893-B2

Title: Image forming apparatus capable of performing processes in accordance with operation mode set therefor

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application No. 2020-025863 filed Feb. 19, 2020. The entire content of the priority application is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to an image forming apparatus, an image forming system, and a method of controlling the image forming apparatus. 
     BACKGROUND 
     In recent years, cartridges for use with image forming apparatuses are provided to users through a subscription service. For example, prior art describes a service that uses a server to manage cartridge usage for subscription in an image forming apparatus. Specifically, the server issues credit the image forming apparatus based on a user&#39;s payment. Upon receiving a print job, the image forming apparatus checks the remaining credit therefor to determine whether printing operation using subscription cartridges can be performed. When determining that printing operation is not allowed based on an amount of the remaining credit, the image forming apparatus requests the user to replace the subscription cartridge with a commercial cartridge or to add credit. 
     SUMMARY 
     The image forming apparatus described in the prior art enters a subscription mode to permit use of the subscription cartridge when credit is issued, even when a commercial cartridge is attached to the image forming apparatus. Consequently, if the image forming apparatus receives a print request while the commercial cartridge is attached thereto, the image forming apparatus would execute the print job using the commercial cartridge without issuing any notification to the user. In such cases, it is difficult in the conventional image forming apparatus to prompt the user to replace the current commercial cartridge with a subscription cartridge at a suitable timing either before or after the image forming apparatus enters the subscription mode. 
     In view of the foregoing, it is an object of the present disclosure to provide a technique for prompting a contracted user at a suitable timing to use a subscription type supply cartridge. 
     In order to attain the above and other object, according to one aspect, the present disclosure provides an image forming apparatus including: a main casing; a supply cartridge; a printing mechanism; a display; and a controller. The supply cartridge is attachable to the main casing. The supply cartridge includes a supply cartridge memory storing therein type information indicative of a type of the supply cartridge which is one of a normal type and a subscription type. The printing mechanism is configured to perform a printing process using the supply cartridge. The controller is configured to perform processes in accordance with an operation mode for the image forming apparatus. The operation mode is configured to be set to one of a pre-contract mode and a formal contract mode. The controller is configured to perform: first determining, based on information inputted into the controller, whether an agreement is made for the image forming apparatus; first setting, when the first determining determines that an agreement is made for the image forming apparatus, the operation mode to the pre-contract mode; second determining which of the normal type and the subscription type the type of the supply cartridge attached to the main casing is; displaying, when the second determining determines that the type of the supply cartridge attached to the main casing is the normal type while the operation mode is set to the pre-contract mode, display information related to the pre-contract mode on the display; and second setting, when the second determining determines that the type of the supply cartridge attached to the main casing is the subscription type while the operation mode is set to the pre-contract mode, the operation mode from the pre-contract mode to the formal contract mode. 
     According to another aspect, the present disclosure provides an image forming system including: an image forming apparatus; and a communication apparatus that can communicate with the image forming apparatus via an Internet. The image forming apparatus includes: a main casing; a supply cartridge; a printing mechanism; a display; a communication interface; and a controller. The supply cartridge is attachable to the main casing. The supply cartridge includes a supply cartridge memory storing therein type information indicative of a type of the supply cartridge which is one of a normal type and a subscription type. The printing mechanism is configured to perform a printing process using the supply cartridge. The communication interface is configured to communicate with the communication apparatus. The controller is configured to perform processes in accordance with an operation mode for the image forming apparatus. The operation mode is configured to be set to one of a pre-contract mode and a formal contract mode. The communication apparatus is configured to perform: transmitting to the controller agreement information indicating that an agreement is made for the image forming apparatus. The controller is configured to perform: setting, based on the agreement information received from the communication apparatus, the operation mode to the pre-contract mode; first determining which of the normal type and the subscription type the type of the supply cartridge attached to the main casing is; displaying, when the first determining determines that the type of the supply cartridge attached to the main casing is the normal type while the operation mode is set to the pre-contract mode, display information related to the pre-contract mode on the display; and setting, when the first determining determines that the type of the supply cartridge attached to the main casing is the subscription type while the operation mode is set to the pre-contract mode, the operation mode from the pre-contract mode to the formal contract mode. 
     According to still another aspect, the present disclosure provides a method of controlling an image forming apparatus configured to form an image using a supply cartridge. The method includes: first determining whether an agreement is made for the image forming apparatus; setting, when the first determining determines that an agreement is made for the image forming apparatus, an operation mode for the image forming apparatus to a pre-contract mode; second determining which of a normal type and a subscription type a type of the supply cartridge attached to the image forming apparatus is; displaying, when the second determining determines that the type of the supply cartridge attached to the image forming apparatus is the normal type while the operation mode is set to the pre-contract mode, display information related to the pre-contract mode on a display; and setting, when the second determining determines that the type of the supply cartridge attached to the image forming apparatus is the subscription type while the operation mode is set to the pre-contract mode, the operation mode for the image forming apparatus from the pre-contract mode to a formal contract mode. 
     According to still another aspect, the present disclosure provides an image forming apparatus including: a main casing; a supply cartridge; a printing mechanism; and a controller. The supply cartridge is attachable to the main casing. The supply cartridge includes a supply cartridge memory storing therein type information indicative of a type of the supply cartridge which is one of a normal type and a subscription type. The printing mechanism is configured to perform a printing process using the supply cartridge. The controller is configured to perform processes based on an operation mode set for the image forming apparatus. The operation mode is configured to be set to one of a normal mode and a contract mode. The controller is configured to perform one of: setting the operation mode from the normal mode to the contract mode based on a command received from a server via a network; and setting the operation mode from the normal mode to the contract mode based on the type information stored in the supply cartridge memory of the supply cartridge attached to the main casing. 
     According to still another aspect, the present disclosure provides a method of controlling an image forming apparatus configured to form an image using a supply cartridge. The method includes: performing one of: setting an operation mode for the image forming apparatus from a normal mode to a contract mode based on a command received from a server via a network; and setting the operation mode for the image forming apparatus from the normal mode to the contract mode based on type information indicative of a type of the supply cartridge which is one of a normal type or a subscription type. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The particular features and advantages of the embodiment(s) as well as other objects will become apparent from the following description taken in connection with the accompanying drawings, in which: 
         FIG.  1    is a diagram illustrating an image forming system according to one embodiment of the present disclosure; 
         FIG.  2    is a diagram schematically illustrating a configuration of an image forming apparatus according to the embodiment; 
         FIG.  3    is a diagram illustrating electrical connection between a controller and other components in the image forming apparatus according to the embodiment; 
         FIG.  4    is a sequence diagram illustrating a process executed in the image forming system according to the embodiment; 
         FIG.  5    is a table illustrating an example of management information in a contract management server in the image forming system according to the embodiment; 
         FIG.  6    is a flowchart illustrating steps in a process executed by the controller when the image forming apparatus according to the embodiment is in its normal mode; 
         FIG.  7    is a flowchart illustrating steps in a process executed by the controller when the image forming apparatus according to the embodiment is in its pre-contract mode; 
         FIG.  8    is a flowchart illustrating steps in a process executed by the controller when the image forming apparatus according to the embodiment is in its formal contract mode; 
         FIG.  9    is a sequence diagram illustrating another process executed in the image forming system according to the embodiment; and 
         FIG.  10    is a flowchart illustrating steps in another process executed by the controller when the image forming apparatus according to the embodiment is in the pre-contract mode. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, one embodiment of the present disclosure will be described while referring to the accompanying drawings. Note that parts and components described in the embodiment are merely an example, and the parts and components according to the embodiment should not be considered to limit the present disclosure. In the drawings, for facilitate understanding, dimensions and the number of each part may be simplified as necessary. 
     1. Embodiment 
       FIG.  1    is a diagram illustrating an image forming system  100  according to the embodiment. The image forming system  100  includes a plurality of image forming apparatuses  1 , a contract management server  7  as an example of a communication apparatus, and a plurality of registration apparatuses  8 . The image forming apparatus  1  and the contract management server  7  are connected to each other via an Internet so as to communicate each other. As illustrated in  FIG.  1   , the contract management server  7  can communicate with a plurality of image forming apparatuses  1  via the Internet. Also, the contract management server  7  and the registration apparatuses  8  are connected to each other via the Internet so that the contract management server  7  and the registration apparatuses  8  can communicate with each other. 
     In the image forming system  100 , a user of each image forming apparatus  1  enters an agreement with a supplier of supply cartridges. The supply cartridges are parts used in printing processes on the image forming apparatus  1  and include replaceable parts and consumable cartridges. The replaceable parts are parts that should be occasionally replaced due to wear or degradation through use. The replaceable parts are, for example, a drum cartridge  20  and a transfer unit  40  (a transfer belt  41 ) described later. The consumable cartridges are parts that supply materials consumed during printing processes, such as a toner cartridge  30  described later. The concept of a supplier includes a manufacturer or a vendor of supply cartridges, for example. In the following description, the toner cartridge  30  is used as an example of the supply cartridges. 
     In the agreement, printing fees that the user have to pay for using the supply cartridges are set, for example. Specifically, fees may be set based on the number of pages printed; an amount of toner used in each color; which of monochromatic printing or color printing is performed; printing resolution; or a size of printing papers. To calculate fees, a flat-rate system or a measured-rate system may be employed. 
     In a flat-rate system, the user pays a fixed rate so that the user is permitted to print a preset number of pages over a prescribed time period (one month, for example). In a measured-rate system, the user pays fees based on a printing amount. Alternatively, the user may pay a flat rate up to a preset printing amount but, when exceeding the preset printing amount, be required to pay a surcharge that corresponds to the excessive amount. 
     The contract management server  7  is a device that performs information management related to the contracted user, management of charge and payment, and management regarding the provision of services to the contracted user. Services provided to contracted user include a service for shipping toner cartridges  30  to the user. The contract management server  7  includes a controller  71 , a storage unit  73 , and a network interface  75 . Note that the term “interface” is abbreviated as “I/F” in the drawings. The controller  71  is electrically connected to the storage unit  73  and the network interface  75  by bus lines. 
     The controller  71  includes a CPU  711  and a memory  713 . The memory  713  is a storage medium from which information is readable and to which information is writable. An ROM or an EEPROM can be employed as the memory  713 . The memory  713  stores therein a program  715 . The controller  71  executes various processes by operating the CPU  711  in accordance with the program  715 . The storage unit  73  is a hard disk drive or other storage device and configured to store therein management information  731 . The management information  731  includes information related to contracted users, information related to image forming apparatuses  1  registered by contracted users, and payment information (information on credit cards, bank accounts, etc. (refer to  FIG.  5   ). 
     Each registration apparatus  8  is an information terminal used for registering various information into the contract management server  7 . Specifically, each registration apparatus  8  may be a portable device such as a smartphone or tablet computer owned by a user wishing to enter an agreement with the supplier, a computer connected to the image forming apparatus  1  via a cable, or an information terminal operated by the supplier or the like. 
     Each registration apparatus  8  includes a controller  81  and a network interface  83 . The controller  81  is connected to the network interface  83  via bus lines or the like. The controller  81  includes a CPU  811  and a memory  813 . The memory  813  is a storage medium from which information is readable and to which information writable, such as a flash ROM or an EEPROM. The memory  813  stores therein a program  815 . The controller  81  is configured to execute various processes by operating the CPU  811  in accordance with the program  815 . The program  815  includes application software for instructing the controller  81  to execute processes to exchange various information with the contract management server  7 . 
     &lt;Configuration of Image Forming Apparatuses&gt; 
       FIG.  2    is a schematic diagram illustrating a configuration of the image forming apparatus  1  according to the embodiment.  FIG.  3    is a diagram illustrating electrical connection between a controller  51  and other components in the image forming apparatus  1 . 
       FIG.  2    illustrates the image forming apparatus  1  that includes a main casing  10 , a cover  11 , four drum cartridges  20 , four toner cartridges  30 , four light source units (not illustrated), the transfer unit  40 , the controller  51 , and a display  55 . 
     The main casing  10  has a rectangular box shape. The four drum cartridges  20 , the four toner cartridges  30 , the transfer unit  40 , and the controller  51  are accommodated in the main casing  10 . The four drum cartridges  20  and the four toner cartridges  30  are attached to the main casing  10  and can replaced with new drum cartridges  20  and new toner cartridges  30 , respectively. The display  55  is positioned at an outer surface of the main casing  10 . The main casing  10  includes a frame for retaining the drum cartridge  20 . 
     The cover  11  is pivotally movable about a rotational shaft  11   a  extending in a first direction. Specifically, the cover  11  is pivotally movable between an open position (a position indicated by solid lines in  FIG.  2   ) and a closed position (a position indicated by two-dot chain lines). Note that the first direction is a direction in which a rotation axis (a drum axis) of a photosensitive drum  21  extends. A sensor  12  is electrically connected to the controller  51  and positioned at the main casing  10 . The sensor  12  is configured to detect movement (open and close) of the cover  11 , and to transmit to the controller  51  a signal indicating that movement of the cover  11  is detected. 
     The drum cartridge  20  includes one photosensitive drum  21 . The photosensitive drum  21  is a hollow cylindrical member extending in the first direction, and rotatable about a drum axis extending in the first direction. As illustrated in  FIG.  2   , each of the drum cartridges  20  further includes a drum memory  22 . The drum memory  22  is flash ROM or EEPROM, for example. The drum memory  22  stores therein information related to the drum cartridge  20  to which the drum memory  22  is attached. 
     The drum cartridge  20  also includes a frame to which one toner cartridge  30  is attachable and from which the toner cartridge  30  is detachable. The drum cartridge  20  to which the toner cartridge  30  is attached is attached to the main casing  10 . 
     The toner cartridge  30  includes a developing roller  31 , a toner memory  32  as an example of a supply cartridge memory, and a casing  33 . The developing roller  31  is a cylindrically shaped member that extends in the first direction. The developing roller  31  is rotatable about a developing shaft extending in the first direction. The toner memory  32  is a storage medium to which information is writable and from which information is readable, such as a flash ROM or an EEPROM. The toner memory  32  stores therein information related to the toner cartridge  30  to which the toner memory  32  is attached. The casings  33  of the four toner cartridges  30  accommodate therein toner of colors different from one another (cyan, magenta, yellow, and black, for example). 
     In a state where the cover  11  is in the open position, the drum cartridge  20  to which the toner cartridge  30  is attached is attached to the main casing  10 , as illustrated in  FIG.  2   . Specifically, the drum cartridge  20  to which the toner cartridge  30  is attached is inserted through an opening in the main casing  10  and attached to a cartridge retaining portion of the main casing  10 . 
     The four light source units are attached to an inner surface of the main casing  10 . When the drum cartridge  20  to which the toner cartridge  30  is attached is attached to the main casing  10  and the cover  11  is moved to the closed position, the light source units face the surfaces of the corresponding photosensitive drums  21 . The light source units can irradiate outer circumferential surfaces of the corresponding photosensitive drums  21  with light. Light sources in the light source units may be lasers or light-emitting diodes (LEDs). 
     The transfer unit  40  includes the transfer belt  41 , a driving roller  43 , a driven roller  45 , and four transfer rollers  47 . The transfer belt  41  is an endless belt that has an annular shape. Each of the photosensitive drums  21  has an outer circumferential surface that can contact an outer peripheral surface of the transfer belt  41 . The transfer belt  41  is looped over the driving roller  43  and the driven roller  45 . The controller  51  controls the driving roller  43  to be driven to circularly move the transfer belt  41 . The driven roller  45  rotates in accordance with the transfer belt  41  that moves by driving of the driving roller  43 . 
     The four transfer rollers  47  are positioned in a space formed inside the annular transfer belt  41 . Each of the transfer rollers  47  is a cylindrical shaped member and extends in the first direction. Each of the transfer roller  47  is rotatable about a rotational axis extending in the first direction. An outer circumferential surface of each of the transfer roller  47  is configured of a conductive rubber, for example. A transfer bias is applied to each of the transfer rollers  47 . 
     The transfer rollers  47  are positioned below the corresponding photosensitive drums  21 . The transfer belt  41  is interposed between the photosensitive drums  21  and the transfer rollers  47 . When a transfer bias is applied to the outer circumferential surface of each of the transfer rollers  47 , toners carried on the outer circumferential surfaces of the corresponding photosensitive drums  21  are transferred onto the transfer belt  41 , and then the toners transferred onto the transfer belt  41  are further transferred onto a printing paper by transfer mechanism (not illustrated), whereby an image is formed onto the printing paper. 
     When a printing process is performed in the image forming apparatus  1 , the entire outer circumferential surface of the photosensitive drum  21  in the drum cartridge  20  is uniformly charged. The corresponding light source unit irradiates the outer circumferential surface of the photosensitive drum  21  with laser light or LED light based on an image to be printed. 
     Next, the developing roller  31  deposits toner onto the outer circumferential surface of the corresponding photosensitive drum  21  that was exposed to light. The transfer unit  40  transfers toner carried on the photosensitive drum  21  onto the printing paper. After toner is transferred onto the printing paper, the printing paper passes through a fixing unit (not illustrated), whereby the toner is thermally fixed to the printing paper. The drum cartridge  20  and the transfer unit  40  is an example of a printing mechanism that performs a printing process using the toner cartridges  30 . 
     As illustrated in  FIG.  3   , the image forming apparatus  1  also includes the controller  51 , an operating unit  53 , the display  55 , and a network interface  57  as an example of a communication interface. The controller  51  includes a CPU  511 , and a device memory  513 . The device memory  513  stores therein a program  515 . The controller  51  is configured to execute various processes by operating the CPU  511  in accordance with the program  515 . Note that the controller  51  may include a dedicated circuit such as an ASIC (application specific integrated circuit). 
     The controller  51  sets an operation mode for the image forming apparatus  1  to one of: a normal mode; a pre-contract mode; and a formal contract mode, and performs processes in accordance with the selected operation mode. As will be described later, the operation mode of the image forming apparatus  1  is set to one of the pre-contract mode and the normal mode based on a setting command received from the contract management server  7 . Process details corresponding to each of the normal mode, the pre-contract mode, and the formal contract mode are specified in the program  515 . 
     The formal contract mode is an operation mode in which the controller  51  executes processes in accordance with an agreement made for the image forming apparatus  1 . Specifically, while the image forming apparatus  1  is in the formal contract mode, the controller  51  executes a process to transmit the number of printed pages to the contract management server  7 . In this way, the contract management server  7  can manage the number of pages printed in the image forming apparatus  1 . The pre-contract mode is an operation mode in which the controller  51  executes a process for setting the operation mode to the formal contract mode. 
     The operating unit  53  is configured of buttons that receives user&#39;s operations. The display  55  displays thereon images representing various information. Note that the display  55  may also be configured as a touchscreen that functions as the operating unit  53 . 
     When the four drum cartridges  20  and the four toner cartridges  30  are attached to the main casing  10 , the four drum memories  22  and the four toner memories  32  are electrically connected to the controller  51 , as illustrated in  FIG.  3   . Accordingly, the controller  51  can communicate with the drum memories  22  and the toner memories  32 . 
     The drum memory  22  stores therein a drum ID, drum life information, drum type information, drum history information, an on-order flag, and threshold information. The drum ID is identification information for identifying an individual drum cartridge  20 , and specifically, is a serial number. The drum life information includes the accumulated number of rotations of the photosensitive drum  21 , and the accumulated number of pages printed using the photosensitive drum  21 , for example. 
     The accumulated number of rotations of the photosensitive drum  21  is calculated by incrementing or decrementing the number of rotations for the drum cartridge  20  identified by the drum ID each time the drum cartridge  20  is used for a print job. The accumulated number of pages printed using the photosensitive drum  21  is calculated by incrementing or decrementing the number of printed pages for the drum cartridge  20  identified by the drum ID each time the drum cartridge  20  is used for a print job. 
     Incidentally, the drum memory  22  may further store therein compatible models for the drum cartridge  20 , specification of the drum cartridge  20 , information indicating whether or not the drum cartridge  20  is a new product, information indicating whether or not the drum cartridge  20  is a genuine product, error history, and the like. 
     As illustrated in  FIG.  3   , the toner memory  32  stores therein a toner ID, toner life information, and toner type information. The toner ID is identification information for identifying an individual toner cartridge  30 , and specifically, a serial number. The toner life information is information indicating a remaining life of the toner cartridge  30 , and is at least one of an accumulated number of rotations of the developing roller  31 , an accumulated number of pages printed using the developing roller  31 , and an accumulated number of dots. 
     The accumulated number of rotations of the developing roller  31  is calculated by incrementing or decrementing the number of rotations for the toner cartridge  30  identified by the toner ID each time a print job is performed using the toner cartridge  30 . The accumulated number of pages printed using the developing roller  31  is calculated by incrementing or decrementing the number of printed pages for the toner cartridge  30  identified by the toner ID each time a print job is performed with the toner cartridge  30 . 
     The accumulated number of dots formed using the developing roller  31  is calculated by incrementing or decrementing the number of dots for the toner cartridge  30  identified by the toner ID each time a print job is performed using the toner cartridge  30 . Note that the accumulated number of dots corresponds a usage amount of the toner used in a print job. Accordingly, a residual amount of toner in the toner cartridge  30  can be calculated by using a total amount of toner that was accommodated in the casing  33  when the toner cartridge  30  was a new product and the accumulated number of dots. 
     The toner type information indicates a type of the toner cartridge  30 , and specifically is one of: a subscription type and a normal type. Hereinafter, a toner cartridge  30  whose type indicated by the toner type information is “subscription type” will be referred to as a “subscription toner cartridge  30 ”, and a toner cartridge  30  whose type indicated by the toner type information is “normal type” will be referred to as a “normal toner cartridge  30 ”. As described later, the toner type information is used for controlling usage of the toner cartridge  30  in the image forming apparatus  1 . 
     The toner memory  32  may also store therein compatible models for the toner cartridge  30 , specification of the toner cartridge  30 , information indicating whether or not the toner cartridge  30  is a new product, information indicating whether or not the toner cartridge  30  is a genuine product, and the like. 
     The controller  51  permits the normal toner cartridge  30  to be used irrespective of the operation mode set for the image forming apparatus  1 . That is, when the image forming apparatus  1  uses the normal toner cartridge  30 , the controller  51  can execute a printing process regardless the fact that the operation mode for the image forming apparatus  1  is set to the normal mode, the pre-contract mode, or the formal contract mode. On the other hand, the controller  51  prohibits a printing process with the subscription toner cartridge  30  when the operation mode is set to the normal mode, but allows a printing process with the subscription toner cartridge  30  when the operation mode is set to the pre-contract mode or the formal contract mode. 
     Note that the controller  51  need not entirely prohibit usage of subscription toner cartridge  30  when the operation mode is set to the normal mode, and may permit usage of the subscription toner cartridge  30  under certain conditions. For example, the controller  51  may display a screen on the display  55  prompting replacement of the toner cartridge  30  or may display a warning screen on the display  55  warning that usage of the subscription toner cartridge  30  is a breach of contract. 
     The device memory  513  is configured to store therein drum information and toner information. The drum information represents each drum cartridge  20  attached to the main casing  10  and specifically includes the drum ID, the drum life information, the drum type information, the drum history information, the on-order flag, and the threshold information. The toner information is information related to each toner cartridge  30  attached to the main casing  10  and specifically includes the toner ID, the toner type information, and the toner life information. 
     The controller  51  stores various information read from each drum memory  22  in the device memory  513  as the drum information. The controller  51  also stores various information read from each toner memory  32  in the device memory  513  as the toner information. The controller  51  also updates this drum information and toner information as needed. The controller  51  also updates the various information stored in each drum memory  22  and each toner memory  32  based on the updated drum information and toner information. 
     &lt;Operations in the Image Forming System&gt; 
     Next, operations performed on the image forming system  100  will be described.  FIG.  4    is a diagram illustrating a process executed in the image forming system  100  according to the present embodiment.  FIG.  5    is a table illustrating an example of the management information  731 .  FIG.  6    is a flowchart illustrating steps in a process executed by the controller  51  when the operation mode is set to the normal mode.  FIG.  7    is a flowchart illustrating steps in a process executed by the controller  51  when the operation mode is set to the pre-contract mode.  FIG.  8    is a flowchart illustrating steps in a process executed by the controller  51  when the operation mode is set to the formal contract mode. 
     In the following description, steps executed in the image forming apparatus  1  are executed by the controller  51  unless otherwise specified. Steps executed in the contract management server  7  are executed by the controller  71  unless otherwise specified. 
     First, the user enters an agreement with the supplier. Specifically, the user operates the registration apparatus  8  to transmit an agreement request  401  to the contract management server  7  (an agreement request transmission process S 100 ). The agreement request  401  may include information about the user wishing to enter the agreement (including the user&#39;s name, address, etc.), information about the agreement such as fees, information about payment, and device information for identifying the image forming apparatus  1  used by the user (device ID). Note that the user need not perform the agreement request transmission process S 100  through the registration apparatus  8 . For example, the user may transmit the agreement request  401  to the contract management server  7  through the image forming apparatus  1 . 
     Upon receiving the agreement request  401 , the contract management server  7  registers information included in the agreement request  401  as the management information  731  (a registration process S 101 ). At this time, the contract management server  7  transmits a pre-contract mode setting command  403  to the image forming apparatus  1  that is the subject of the agreement (a pre-contract mode setting request process S 102 ). The pre-contract mode setting command  403  is a command to the controller  51  provided in the image forming apparatus  1 , ordering the controller  51  to switch the operation mode for the image forming apparatus  1  to the pre-contract mode. The image forming apparatus  1  that is the subject of the agreement, i.e., a destination for the pre-contract mode setting command  403 , is identified based on the agreement request  401 . 
     As illustrated in  FIG.  5   , the management information  731  stored in the storage unit  73  for each user includes device information, payment information, an address, an operation mode, and an accumulated printed page number for billing. The operation mode is a mode set for the image forming apparatus  1  and is either the pre-contract mode or the formal contract mode. The accumulated printed page number for billing is a value obtained by the accumulated number of printed pages received from the image forming apparatus  1 . 
     As illustrated in  FIG.  6   , when the operation mode is set to the normal mode, in S 11  the controller  51  determines whether a pre-contract mode setting command  403  is received (a determination process S 11 ). When the controller  51  determines that a pre-contract mode setting command  403  is not received (S 11 : NO), the controller  51  waits until a pre-contract mode setting command  403  is received. When the controller  51  determines that a pre-contract mode setting command  403  was received (S 11 : YES), in S 12  the controller  51  sets the operation mode to the pre-contract mode (a pre-contract mode setting process S 12 ). 
     Thus, the pre-contract mode setting command  403  is information that the contract management server  7  transmits to the image forming apparatus  1  that is subjected to the agreement. In other words, the pre-contract mode setting command  403  is information specifying that an agreement is made for the image forming apparatus  1 . The determination process S 11  corresponds to a process in which the controller  51  determines whether an agreement is made for the image forming apparatus  1  based on the pre-contract mode setting command  403  received from an external device (the process of first determining). 
     Referring back to  FIG.  4   , after receiving the agreement request  401 , the contract management server  7  also transmits a shipping request  405  to a shipping company, specifically, to a server of the shipping company (a shipping request process S 105 ). The shipping request  405  is information requesting the shipping company to deliver a subscription toner cartridge  30  to the user. The shipping request  405  includes the user&#39;s name and address as the delivery destination. 
     Upon receiving the shipping request  405 , the shipping company ships a new subscription toner cartridge  30  to the user (a shipping process S 106 ). When the user receives the new subscription toner cartridge  30 , the user can attach the new subscription toner cartridge  30  to the image forming apparatus  1  (an attachment process S 107 ). 
     In S 13  of  FIG.  7   , the controller  51  of the image forming apparatus  1  operating in the pre-contract mode determines whether the toner cartridge  30  is replaced (a replacement determination process S 13 ). Specifically, the controller  51  determines that the toner cartridge  30  is replaced when detecting that the power was switched from off to on or when the sensor  12  detects that the cover  11  was moved between the closed position and the open position. 
     The controller  51  may also determine whether a toner cartridge  30  is replaced based on the toner ID of the attached toner cartridge  30 . That is, the controller  51  may compare the toner information stored in the device memory  513  to the toner ID stored in the toner memory  32  of the toner cartridge  30  attached to the main casing  10 . The controller  51  determines that the toner cartridge  30  was replaced when the toner information is different from the toner ID and determines that the toner cartridge  30  was not replaced when the toner information matches the toner ID. 
     When the controller  51  determines that the toner cartridge  30  was not replaced (S 13 : NO), the controller  51  repeats the determination in S 13  until the toner cartridge  30  is replaced. On the other hand, when the controller  51  determines that the toner cartridge  30  was replaced (S 13 : YES) when operating in the pre-contract mode, in S 14  the controller  51  determines the type of the toner cartridge  30  attached to the main casing  10 . That is, the controller  51  determines whether the type of the toner cartridge  30  indicated by the type information is the normal type or the subscription type. 
     When the controller  51  determines that the toner cartridge  30  after replaced is the subscription type (S 14 : YES), in S 15  the controller  51  sets the operation mode from the pre-contract mode to the formal contract mode (a formal contract mode setting process S 15 ). Hence, when the user attaches a subscription toner cartridge  30  in the image forming apparatus  1  in the attachment process of S 107  (see  FIG.  4   ), the controller  51  determines that the attached toner cartridge  30  is a subscription toner cartridge  30  and shifts the operation mode to the formal contract mode. 
     After setting the operation mode to the formal contract mode in S 15 , in S 16  the controller  51  notifies the contract management server  7  that the operation mode is set to the formal contract mode (a notification process S 16 ). Upon receiving this notification, the contract management server  7  records information in the management information  731  indicating that the target image forming apparatus  1  now operates under the formal contract mode (a formal contract registration process S 161 ). Specifically, the contract management server  7  changes the operation mode registered in the management information  731  for the image forming apparatus  1  whose operation mode is the formal contract mode from “pre-contract mode” to “formal contract mode.” 
     On the other hand, when the controller  51  determines in S 14  of  FIG.  7    that the toner cartridge  30  after replacement is the normal type (S 14 : NO), in S 17  the controller  51  performs a first display process to display on the display  55  display information relating to the pre-contract mode. Specifically, the display information includes a message indicating that a subscription toner cartridge  30  is now shipped. The displayed information also prompts the user to confirm whether to use the normal toner cartridge  30 . By executing the first display process of S 17 , the controller  51  can prompt the user to use a subscription toner cartridge  30  (the subscription toner cartridge  30  shipped from the shipping company, for example). 
     As illustrated in  FIG.  4   , when the user wishes to the image forming apparatus in the formal contract mode to execute a printing process, the user issues a print request  407  to the image forming apparatus  1  (a print request process S 201 ). In S 21  of  FIG.  8   , the controller  51  of the image forming apparatus  1  now set to the formal contract mode determines whether a print request  407  was received. When the controller  51  determines that a print request  407  was not received (S 21 : NO), the controller  51  repeats the determination in S 21  until a print request  407  is received from the user. When the controller  51  determines that a print request  407  was received (S 21 : YES), in S 22  the controller  51  executes a printing process based on the received print request  407 . 
     In S 23  the controller  51  determines whether the printing process of S 22  is completed. When determining in S 23  that the printing process is not yet completed (S 23 : NO), the controller  51  waits until the printing process is completed. However, when the controller  51  determines that the printing process is completed (S 23 : YES), in S 24  the controller  51  executes a life information update process to update toner life information in the toner information stored in the device memory  513  based on the contents of the printing process of S 22 . 
     Note that the controller  51  may perform the life information update process in S 24  after the entire printing process is completed, or may perform the life information update process each time a portion of the printing process is completes, for example, after each page is printed. In the life information update process of S 24 , the controller  51  may also update toner life information in the toner memories  32  corresponding to the updated toner life information in the device memory  513 . Here, toner life information in the toner memories  32  may be updated each time toner life information is updated in the device memory  513  or after toner life information is updated in the device memory  513  a plurality of times. 
     After completing the life information update process of S 24 , in S 25  the controller  51  transmits printing information  409  to the contract management server  7  (a printing information transmission process). The printing information  409  is information representing the contents of the printing process executed in the image forming apparatus  1  in S 22  and may include the device information for the image forming apparatus  1 , the number of pages printed, and toner type information for the toner cartridge  30  used in the printing process. 
     As illustrated in  FIG.  4   , upon receiving the printing information  409 , the contract management server  7  updates the management information  731  based on the printing information  409  (an update process S 241 ). That is, when the toner cartridge  30  used in the printing process of S 22  is the subscription type, the contract management server  7  adds the number of pages printed using the toner cartridge  30  to the “accumulated printed page number for billing” in the management information  731 . 
     However, when the toner cartridge  30  used in the printing process of S 22  is the normal type, the contract management server  7  does not update the management information  731 . In this way, the contract management server  7  manages only pages printed using subscription toner cartridges  30  for billing. 
     The image forming apparatus  1  in the formal contract mode uses the subscription toner cartridge  30  for the printing process in S 22 . Consequently, printed page numbers transmitted to the contract management server  7  from the image forming apparatus  1  in the formal contract mode correspond to the usage amount of the subscription toner cartridge  30 . 
     After completing the printing information transmission process in S 25 , in S 26  the controller  51  determines whether a value of the toner life information stored in the device memory  513  matches a first threshold (a first life determination process S 26 ). The first threshold is a threshold value specifying a state in which the remaining life stored in the toner memory  32  is very low. In other words, the first life determination process of S 26  is performed to determine whether the remaining life of the toner cartridge  30  has become very low. For example, when the toner life information is a residual amount of toner in the casing  33 , the first threshold is a value representing a small residual amount (i.e., a residual amount of toner in the toner cartridge  30  that is nearly empty). 
     When the controller  51  determines that the toner life information matches the first threshold (S 26 : YES), in S 27  the controller  51  executes a life determination information transmission process S 27  to transmit life determination information  411  to the contract management server  7 . The life determination information  411  includes the device information for the image forming apparatus  1  and type information for the toner cartridge  30  whose toner life information matches the first threshold. 
     Upon receiving the life determination information  411 , the contract management server  7  identifies the type of the toner cartridge  30  having low remaining life based on the life determination information  411 . When the contract management server  7  identifies that the toner cartridge  30  is the subscription type, the contract management server  7  transmits a shipping request  413  to the shipping company, i.e., the server of the shipping company (a shipping request transmission process S 271 ). The shipping request  413  is information requesting the shipping company to ship a new subscription toner cartridge  30  to the user. Specifically, the shipping request  413  includes information on the shipping destination (the user&#39;s name and address), and information indicating the type of the subscription toner cartridge  30  to be shipped (model number, etc.). 
     When receiving the shipping request  413 , the shipping company ships a new subscription toner cartridge  30  to the user based on the shipping request  413  (a shipping process S 272 ). Note that the shipping company may also be the supplier (vender or manufacturer, for example) of the toner cartridges  30 . 
     In the image forming system  100  described above, the image forming apparatus  1  can transmit the life determination information  411  to the contract management server  7  in order that the user can receive a new subscription toner cartridge  30 . The life determination information  411  corresponds to order information used to order a new subscription toner cartridge  30 . 
     Note that the first life determination process in S 26  may be executed by the contract management server  7 . In this case, the controller  51  operating under the formal contract mode transmits the toner life information to the contract management server  7 . Upon receiving the toner life information, the contract management server  7  determines whether the toner life information matches the first threshold and transmits the shipping request  413  to the server of the shipping company when determining that the toner life information matches the first threshold. In response, the shipping company ships a new toner cartridge  30  to the user. 
     Returning to  FIG.  8   , when the controller  51  determines in S 26  that the toner cartridge  30  does not match the first threshold (S 26 : NO), in S 28  the controller  51  executes a second life determination process in which the controller  51  determines whether the toner life information exceeds a second threshold. The second threshold is a threshold value indicating that the toner cartridge  30  has to be replaced with a new toner cartridge  30 . Specifically, the second threshold indicates when the toner cartridge  30  has no remaining life. 
     In other words, the second life determination process of S 28  is performed to determine whether the toner cartridge  30  must be replaced based on the toner life information. For example, when the toner life information specifies the residual amount of toner in the casing  33 , the second threshold may be a value representing that the residual amount of toner is zero, i.e., a value indicating that the casing  33  is empty. 
     When the image forming apparatus  1  determines that the toner life information exceeds the second threshold (S 28 : YES), in S 29  the controller  51  displays on the display  55  display information that includes a message indicating that the toner cartridge  30  must be replaced (a first replacement display process). Upon seeing the message displayed on the display  55  in the process of S 29 , the user can attach a new subscription toner cartridge  30 , which was delivered to the user, to the main casing  10  (an attachment process S 291 ). When the controller  51  determines that the toner life information does not exceed the second threshold (S 28 : NO), the controller  51  ends the process of  FIG.  8   . 
     Next, a process performed on the image forming system  100  when the image forming apparatus  1  in the pre-contract mode performs a printing process will be described with reference to  FIGS.  9  and  10   .  FIG.  9    is a diagram illustrating steps in the process executed in the image forming system  100 .  FIG.  10    is a flowchart illustrating steps in the process executed by the controller  51  when the image forming apparatus  1  is in the pre-contract mode. 
     As illustrated in  FIG.  9   , a user wishing to execute a printing process on the image forming apparatus  1  in the pre-contract mode issues a print request  407  to the image forming apparatus  1  (a print request process S 401 ). In S 41  of  FIG.  10   , the controller  51  of the image forming apparatus  1  in the pre-contract mode determines whether a print request  407  is received (a reception determination process). 
     When the controller  51  determines that a print request  407  is not received (S 41 : NO), the controller  51  waits until a print request  407  is inputted. On the other hand, when the controller  51  determines that a print request  407  was received (S 41 : YES), in S 42  the controller  51  executes a second display process in which the controller  51  displays on the display  55  display information related to the pre-contract mode. The display information may include a message indicating that the image forming apparatus  1  is in the pre-contract mode. The display information may also include a message indicating that a new subscription toner cartridge  30  is now shipped. 
     The controller  51  continues to operate under the pre-contract mode as long as the normal toner cartridge  30  is attached to the main casing  10 . When using the normal toner cartridge  30 , the user can gain no benefits described in the agreement entered with the supplier. Thus, by executing the second display process in S 42 , the controller  51  prompts the user to attach a subscription toner cartridge  30 . By using the subscription toner cartridge  30 , the user can then receive the benefits of the agreement. 
     After completing the second display process of S 42 , in S 43  the controller  51  executes a printing process based on the received print request  407 . In S 44  the controller  51  determines whether the printing process of S 43  is completed (a print complete determination process S 44 ). When the controller  51  determines that the printing process of S 43  is not yet completed (S 44 : NO), the controller  51  repeats the determination in S 44  until the printing process is completed. When the controller  51  determines that the printing process in S 43  ended (S 44 : YES), in S 45  the controller  51  executes a life information update process to update life information described in S 24  of  FIG.  8   . That is, the controller  51  updates the toner life information in the toner information stored in the device memory  513  based on contents of the printing process in S 43 . 
     After updating the life information in the life information update process of S 45 , in S 46  the controller  51  executes a printing information transmission process to transmit printing information  409  described in the printing information transmission process of S 25  in  FIG.  4    to the contract management server  7 . 
     As illustrated in  FIG.  9   , upon receiving the printing information  409 , the contract management server  7  updates the management information  731  based on the printing information  409  (an update process S 451 ). The printing information  409  transmitted to the contract management server  7  indicates the number of pages printed using the normal toner cartridge  30 . Here, the contract management server  7  does not add the number of printed pages specified by the printing information  409  to the “accumulated printed page number for billing”. Consequently, all pages printed using the normal toner cartridge  30  are excluded from the management information  731  and only pages printed using the subscription toner cartridge  30  are subjected to billing. 
     Note that the controller  51  need not execute the printing information transmission process of S 46  while the image forming apparatus  1  is in the pre-contract mode. In other words, the printing information transmission process of S 46  may be omitted so that the controller  51  does not transmit the page numbers printed using the normal toner cartridge  30  to the contract management server  7 . In this way, the contract management server  7  need only manage printed page numbers transmitted from the controller  51  in the process of S 25  (see  FIGS.  4  and  8   ) while the image forming apparatus  1  is in the formal contract mode. 
     After completing the printing information transmission process of S 46  illustrated in  FIG.  10   , in S 47  the controller  51  executes a first life determination process identical to that of S 26  in  FIG.  8    to determine whether the toner life information matches the first threshold. When the controller  51  determines that the toner life information matches the first threshold (S 47 : YES), the controller  51  executes a determination information notification process in S 48 . 
     Specifically, in S 48  the controller  51  transmits life determination information  411  (see  FIG.  9   ) to the contract management server  7 . The life determination information  411  includes type information for the toner cartridge  30  whose toner life information was determined to match the first threshold. In this case, the type of the toner cartridge  30  indicated by the type information is the normal type. 
     Upon receiving the life determination information  411 , the contract management server  7  determines that the type of the toner cartridge  30  whose life information matches the first threshold is the normal type based on the life determination information  411 . Accordingly, the contract management server  7  does not execute the shipping request transmission process of S 271  (see  FIG.  4   ). Hence, a new subscription toner cartridge  30  is not transmitted to the user in this case. Note that the determination information notification process of S 48  may be omitted when the controller  51  operates under the pre-contract mode. 
     On the other hand, when the controller  51  determines that the toner life information does not match the first threshold (S 47 : NO), in S 49  the controller  51  executes a second life determination process described in S 28  of  FIG.  8   . That is, the controller  51  determines whether the toner life information saved in the device memory  513  exceeds the second threshold. 
     When the controller  51  determines that the toner life information does not exceed the second threshold (S 49 : NO), the controller  51  ends the process of  FIG.  10   . On the other hand, when the controller  51  determines in S 49  that the toner life information exceeds the second threshold (S 49 : YES), in S 50  the controller  51  determines whether the image forming apparatus  1  can communicate with the contract management server  7 . That is, the controller  51  performs a test to determine whether a response can be received from the contract management server  7  after transmitting prescribed information to the contract management server  7 . When a response is received from the contract management server  7 , the controller  51  determines that the controller  51  can communicate with the contract management server  7 . When a response is not received, the controller  51  determines that the controller  51  cannot communicate with the contract management server  7 . 
     When the controller  51  determines that communication with the contract management server  7  is possible (S 50 : YES), in S 51  the controller  51  displays display information on the display  55  that includes a message prompting the user to replace the current toner cartridge  30  with a subscription toner cartridge  30  (a second replacement display process). On the other hand, when the controller  51  determines that communication with the contract management server  7  is not possible (S 50 : NO), in S 52  the controller  51  displays on the display  55  display information including a message prompting the user to replace the current toner cartridge  30  with a new normal toner cartridge  30  (a third replacement display process). 
     As illustrated in  FIG.  9   , when the user views the message displayed in S 51  and replaces the current toner cartridge  30  with a subscription toner cartridge  30  (an attachment process S 107 ), the controller  51  operating under the pre-contract mode then executes S 13 -S 15  described in  FIG.  7   . That is, in S 13  the controller  51  determines whether the toner cartridge  30  was replaced, in S 14  determines whether the type of toner cartridge  30  is the subscription type, and in S 15  performs a process to change the operation mode to the formal contract mode. 
     Thus, as long as the image forming apparatus  1  can communicate with the contract management server  7 , the contract management server  7  can manage the number of pages printed on the image forming apparatus  1  after the toner cartridge  30  is replaced with a subscription toner cartridge  30 . On the other hand, when the image forming apparatus  1  cannot communicate with the contract management server  7 , the contract management server  7  cannot manage numbers of pages printed using the subscription toner cartridge  30 . Thus, the user is prompted to replace the empty toner cartridge  30  with a normal toner cartridge  30  so that the supplier can avoid loss incurred through the use of a subscription toner cartridge  30 . 
     Note that the controller  51  may transmit toner information to the contract management server  7  as the printing information  409  whether the image forming apparatus  1  is in the pre-contract mode or the formal contract mode. The contract management server  7  may identify the accumulated printed page numbers from the toner life information for the subscription toner cartridge  30  included in the toner information and may record the identified accumulated printed page numbers in the management information  731 . Accordingly, the contract management server  7  can still manage numbers of pages printed using the subscription toner cartridge  30 . 
     The contract management server  7  may also identify the usage amount of the subscription toner cartridge  30  based on toner information received from the controller  51  as the printing information  409  and may record the identified usage amount in the management information  731 . By managing the usage amount for the subscription toner cartridge  30  attached to the contracted image forming apparatus  1 , the contract management server  7  can charge the user based on the usage amount. 
     When the contract management server  7  identifies the usage amount of the toner cartridge  30  received from the controller  51  operating under the pre-contract mode, the contract management server  7  may not record the identified usage amount of the toner cartridge  30  in the management information  731 . Accordingly, the usage amount of the normal toner cartridge  30  used in the image forming apparatus  1  in the pre-contract mode are excluded from the management information  731 , thereby excluding usage amount of the normal toner cartridges  30  from the subject of billing. 
     When toner information transmitted from the controller  51  operating under the formal contract mode represents that the type of the toner cartridge  30  is the normal type, the contract management server  7  also excludes the usage amount for the normal toner cartridge  30  from the management information  731 . Accordingly, the contract management server  7  can exclude the usage amount for the normal toner cartridge  30  from the subject of billing. 
     2. Modifications 
     While the description has been made in detail with reference to the embodiment, it would be apparent to those skilled in the art that the present disclosure is not limited to the above-described embodiment and many modifications and variations may be made thereto. 
     The contract management server  7  is an example of a communication apparatus, but the communication apparatus is not limited to the contract management server  7  described in the embodiment. The communication apparatus may be a personal computer, a smartphone, a tablet computer, or other information terminal. The controller  51  of the image forming apparatus  1  may transmit order information (specifically, the life determination information  411 ) to the information terminal. In this case, the information terminal may transmit the order information to the contract management server  7 . Further, e-mail may be used to perform data communications among apparatuses. 
     Although the image forming apparatus  1  is configured as a color printer in the embodiment and includes toner cartridges  30  for a plurality of colors, the image forming apparatus  1  may instead be a monochromatic printer. In this case, the image forming apparatus  1  includes a drum cartridge having a single photosensitive drum  21  that corresponds to a single toner cartridge  30 . 
     The drum cartridge  20  may also be configured so that a plurality of toner cartridges  30  are attachable to a single drum cartridge  20 . In this case, the single drum cartridge  20  includes a plurality of photosensitive drums  21  provided in one-on-one correspondence with the plurality of toner cartridges  30 . 
     The image forming apparatus  1  may also be configured as a printer based on an inkjet recording method. In this inkjet printer, the supply cartridges are ink cartridges including casings that can accommodate ink therein. Alternatively, the supply cartridge may be a tape cassette that supplies tape as a printing material, or a fixing liquid cartridge that stores therein fixing liquid for fixing ink to a printing material. 
     In S 12  of the above-described embodiment, the controller  51  of the image forming apparatus  1  changes the operation mode from the normal mode to the pre-contract mode when the controller  51  receives a pre-contract mode setting command  403  from the contract management server  7 . As an alternative, the controller  51  of the image forming apparatus  1  may execute one of: (A) a process to set the operation mode from the normal mode to the formal contract mode upon receiving a contract setting command from the contract management server  7  in S 12 , and (B) a process to change the operation mode from the normal mode to the formal contract mode in S 15  when determining that a newly attached toner cartridge  30  is a subscription toner cartridge  30  (S 14 : YES). In other words, the controller  51  of the image forming apparatus  1  may switch the operation mode from the normal mode to the formal contract mode when one of the conditions (A) and (B) is satisfied. In this case, the contract management server  7  is an example of a server, and the formal contract mode is an example of a contract mode. 
     While the description has been made in detail with reference to the present disclosure, the description is merely an example in all aspects and the present disclosure is not limited thereto. It would be apparent to those skilled in the art that many modifications and variations may be made therein without departing from the scope of the disclosure. Further, parts and components appearing in the embodiment and modifications may be suitably combined together and omitted as long as any conflicting structure is avoided.