Abstract:
A server device comprising: a communication unit, a storage unit storing device identification information for identifying an image forming apparatus communicable with the server device via the communication unit. Recording material is contained in a cartridge attachable to and detachable from the image forming apparatus. The control unit is configured to perform: (a) receiving residual amount information about residual amount of the recording material; (b) determining whether or not the residual amount of the recording material is equal to or less than a first threshold; (c) determining whether or not the residual amount information is about the cartridge that has been delivered in accordance with an order instruction; and in response to affirmative determination made in (b) and affirmative determination made in (c), transmitting the order instruction to the external device via the communication unit.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from Japanese Patent Application No. 2015-073937 filed Mar. 31, 2015. The entire content of the priority application is incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to a server device for ordering cartridges and a program thereof. 
       BACKGROUND 
       [0003]    An image recording apparatus records an image onto a recording paper by making recording material such as ink adhere on the recording paper. Thus, recording processing of the image recording apparatus involves purchase and management of consumables such as a cartridge filled with the recording material; however, the purchase and management of the consumables are troublesome to a user. Thus, in recent years, some services provide management, delivery, or the like of the cartridge. In such services, a new cartridge is ordered in response to the attachment of a spare cartridge to the image forming apparatus. 
       SUMMARY 
       [0004]    Management of the cartridge can be achieved to some extent in the prior art. However, there may be a case where ink of the cartridge used in the image recording device runs short before arrival of a new cartridge delivered by the service at user&#39;s hand. In such a case, the user may purchase the cartridge at a retailer before arrival of the delivered cartridge and uses the purchased cartridge to perform print processing. The conventional management does not assume such a situation, and thus flexible cartridge management cannot be achieved. An object of the present invention is to achieve more flexible cartridge management. 
         [0005]    It is therefore an object of the disclosure to provide a server device including a communication unit, a storage unit, and a control unit. The communication unit is configured to communicate at least with an external device. The storage unit stores device identification information for identifying an image forming apparatus communicable with the server device via the communication unit. The image forming apparatus is configured to form an image on a recording sheet by using recording material. The recording material is contained in a cartridge attachable to and detachable from the image forming apparatus. The control unit is configured to perform: (a) receiving, via the communication unit, residual amount information about residual amount of the recording material remaining in the cartridge connected to the image forming apparatus identified by the device identification information; (b) determining, based on the residual amount information, whether or not the residual amount of the recording material is equal to or less than a first threshold; (c) determining whether or not the residual amount information is about the cartridge that has been delivered in accordance with an order instruction to deliver a cartridge to a user of the image forming apparatus identified by the device identification information; and (d) in response to affirmative determination made in (b) and affirmative determination made in (c), transmitting the order instruction to the external device via the communication unit. 
         [0006]    According to one aspect, a non-transitory computer readable storage medium stores a set of program instructions installed on and executed by a server device. The server device includes a communication unit, a storage unit, and a control unit. The communication unit is configured to communicate at least with an external device. The storage unit stores device identification information for identifying an image forming apparatus communicable with the server device via the communication unit. The image forming apparatus is configured to form an image on a recording sheet by using recording material. The recording material is contained in a cartridge attachable to and detachable from the image forming apparatus. The program instructions includes: (a1) receiving, via the communication unit, residual amount information about residual amount of the recording material remaining in the cartridge connected to the image forming apparatus identified by the device identification information; (b1) determining, based on the residual amount information, whether or not the residual amount of the recording material is equal to or less than a first threshold; (c1) determining whether or not the residual amount information is about the cartridge that has been delivered in accordance with an order instruction to deliver a cartridge to a user of the image forming apparatus identified by the device identification information; and (d1) in response to affirmative determination made in (b1) and affirmative determination made in (c1), transmitting the order instruction to the external device via the communication unit. 
         [0007]    According to another aspect, an automatic cartridge ordering system includes an image forming apparatus, and a server device. The image forming apparatus is configured to form an image on a recording sheet by using recording material. The recording material is contained in at least one cartridge attachable to and detachable from the image forming apparatus. The server device includes a communication unit configured to communicate at least with the image forming apparatus and an external device, a storage unit storing device identification information for identifying the image forming apparatus connected to the communication unit, and a control unit. The control unit is configured to perform: (a2) receiving, via the communication unit, residual amount information about residual amount of the recording material remaining in the cartridge connected to the image forming apparatus identified by the device identification information; (b2) determining, based on the residual amount information, whether or not the residual amount of the recording material is equal to or less than a first threshold; (c2) determining whether or not the residual amount information is about the cartridge that has been delivered in accordance with an order instruction to deliver a cartridge to a user of the image forming apparatus identified by the device identification information; and (d2) in response to affirmative determination made in (b2) and affirmative determination made in (c2), transmitting the order instruction to the external device via the communication unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The particular features and advantages of the disclosure will become apparent from the following description taken in connection with the accompanying drawings, in which: 
           [0009]      FIG. 1  is a block diagram of a communication system according to a first embodiment; 
           [0010]      FIG. 2  is a schematic diagram of a management table stored in a data storage area of an information management server according to the first embodiment; 
           [0011]      FIG. 3  is a schematic diagram of a management table stored in a delivery management server according to the first embodiment; 
           [0012]      FIG. 4  is a sequence diagram indicating operation of the communication system according to the first embodiment; 
           [0013]      FIG. 5  is a sequence diagram indicating operation of the communication system according to the first embodiment; 
           [0014]      FIG. 6  is a workflow of the information management server according to the first embodiment; 
           [0015]      FIG. 7  is a workflow of the information management server according to the first embodiment; 
           [0016]      FIGS. 8A and 8B  are a schematic diagram of a management table stored in a data storage area of an information management server according to a second embodiment; 
           [0017]      FIG. 9  is a sequence diagram indicating operation of a communication system according to the second embodiment; 
           [0018]      FIG. 10  is a sequence diagram indicating operation of the communication system according to the second embodiment; 
           [0019]      FIG. 11  is a workflow of the information management server according to the second embodiment; and 
           [0020]      FIG. 12  is a workflow of the information management server according to the second embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    A Communication system according to a first embodiment will be described while referring to the accompanying drawings wherein like parts and components are designated by the same reference numerals to avoid duplicating description. 
         [0022]    &lt;Configuration of Communication System&gt; 
         [0023]      FIG. 1  is a block diagram of a communication system  1  exemplified as an embodiment of the present disclosure. The communication system  1  includes a printer  10 , an information management server  50 , and a delivery management server  70 . Printer  10  is an example of an image recording apparatus. Information management server  50  is an example of a server device. The delivery management server  70  is an example of an external device. 
         [0024]    The printer  10  mainly includes a CPU (Central Processing Unit)  12 , a storage unit  14 , a display  16 , an input I/F  18 , a recording unit  20 , a connecting unit  22 , a reading unit  24 , a detection sensor  26 , and a network I/F  28 . These components are capable of communicating with each other via a bus  30 . 
         [0025]    The CPU  12  executes processing in accordance with a control program  32  in the storage unit  14 . The control program  32  is a program for managing a residual amount of ink to be used in the printer  10  and purchasing a cartridge  36  using the information management server  50 . The storage unit  14  is a combination of a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an HDD (Hard Disk Drive) and a buffer of the CPU  12 . Further, the storage unit  14  has a data storage area  34 . The data storage area  34  is an area for storing data required to execute the control program  32 . 
         [0026]    The display  16  displays various screens on the basis of input image data. The display  16  may be, but not limited to, an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence). The input I/F  18  has keys for a user to execute functions of the printer  10 . The input I/F  18  may be, for example, a touch panel integrally formed with the display  16  and receives a user operation for an icon displayed on the display  16 . The input I/F  18  may have a hard key instead of the touch panel. 
         [0027]    The recording unit  20  serves as a print mechanism and has an inkjet head. The CPU  12  inputs a drive signal to the recording unit  20 , causing the inkjet head to eject ink in response to the input drive signal. The connection unit  22  is connected to a cartridge  36  filled with ink to be used in the recording unit  20 . The connection unit  22  can be connected with the plurality of cartridges  36  corresponding to a plurality of ink colors. The cartridge  36  is attached with an IC chip  38  storing a serial ID for identifying the cartridge  36 . The specific information includes two types of information, i.e., a model number of the cartridge  36  and a serial ID as a unique identifier for uniquely identifying the cartridge  36 . That is, there may be two cartridges  36  that have the same model number, i.e. the character strings representing the model number are exactly the same between the two cartridges  36 . On the contrary, any two cartridges  36  never have the same serial ID, even if the two cartridges  36  have the same model number. The specific information of one cartridge  36  is therefore unique among other cartridges  36 . In the embodiment, the model number is different from each color; in other words, the ink color of the cartridge  36  can be designated by identifying the model number. The reading unit  24  reads the serial ID from the IC chip  38  of the cartridge  36  connected to the connection unit  22 . The detection sensor  26  detects a residual amount of ink in the cartridge  36  connected to the connection unit  22 . The serial ID is an example of cartridge identification information or third information. 
         [0028]    The network I/F  28  is capable of communicating with an external device and is connected to Internet  42  via a router, not illustrated. The internet  42  is connected to the information management server  50  and the delivery management server  70 . With this configuration, the printer  10  can perform data communication with the information management server  50  via the network I/F  28 . 
         [0029]    The information management server  50  mainly includes a CPU  52 , a storage unit  54 , and a network I/F  56 . These components are capable of communicating with each other via a bus  58 . The CPU  52  is an example of a control unit and a computer. The network I/F  56  is an example of a communication unit. 
         [0030]    The CPU  52  executes processing based on a control program  60  in the storage unit  54 . The control program  32  is a program for managing a residual amount of ink used in the printer  10  and purchasing the cartridges  36 . Hereinafter, the CPU  52  that executes the control program  60  is also referred to simply by a program name thereof. For example, “control program  60 ” may represent “CPU  52  that executes the control program  60 ”. The storage unit  54  is a combination of a RAM, a ROM, a flash memory, an HDD, and a buffer of the CPU  52 . The storage unit  54  further has a data storage area  62 . The data storage area  62  is an area for storing data required to execute the control program  60  and stores a management table  63  illustrated in  FIG. 5 . The control program  60  is an example of a control program. The data storage area  62  is an example of a storage unit. 
         [0031]    The network I/F  56  communicates with an external device, and is connected to the delivery management server  70  on the Internet  42  and the printer  10  via a router, not illustrated. With this configuration, the information management server  50  can perform data communication with the printer  10  and the delivery management server  70  via the network I/F  56 . The delivery management server  70  stores a management table  71  illustrated in  FIG. 3 . 
         [0032]    &lt;Management of Ink Utilizing Communication System&gt; 
         [0033]    In the communication system  1 , the information management server  50  manages ink consumption (ink is example of recording material). When a residual amount of ink used in the printer  10  becomes equal to or less than a threshold amount, the information management server  50  transmits, to the delivery management server  70 , an order instruction of the cartridge  36  corresponding to this ink. The delivery management server  70  orders the cartridge  36 , and the cartridge  36  will be delivered to the user of the printer  10 . Accordingly, the user can save time with little effort in the management of purchase and the residual amount of ink in the cartridge  36 , and the system  1  can therefore improve user&#39;s convenience. However, there may be a case where the user himself/herself purchases the cartridge  36  at a retailer and connects the purchased cartridge  36  to the connection unit  22  to perform print processing. When the cartridge  36  is ordered in such a case, a plurality of cartridges may be disadvantageously in stock at user&#39;s hand. Thus, preferably, in such a case, the order of the cartridge  36  is avoided. 
         [0034]    More in detail, for example, in response to a reduction in the amount of the ink of the cartridge  36  connected to the connection unit  22 , the information management server  50  transmits an order instruction for instructing the delivery management server  70  to deliver the cartridge  36 . Normally, the user uses the cartridge  36  delivered in accordance with the order; however, for some reasons, the user himself/herself may purchase the cartridge  36  at a retailer and connects the purchased cartridge  36  to the connection unit  22  to perform print processing. In such a case, the ordered cartridge  36  is left as a stock at user&#39;s hand. Then, when ink of the cartridge  36  connected to the connection unit  22 , that is, ink of the cartridge  36  that the user him or herself has purchased at a retailer is reduced, the information management server  50  transmits the order instruction to the delivery management server  70 . In such a case, the ordered cartridge  36  has already been in stock, so that the order of the cartridge  36  is preferably avoided. In view of this, in the communication system  1 , when the cartridge  36  being used in the printer  10  is not the ordered cartridge, the cartridge  36  is not ordered even if a residual amount of ink of the cartridge  36  becomes equal to or less than a threshold amount. 
         [0035]    Specifically, after purchasing the printer  10 , the user makes a contract with a predetermined company for an ink management service using the information management server  50 . Then, the user connects starter cartridges  36  as one set in the package of the printer  10  to the connecting unit  22 , and executes print processing. Further, according to the contract, a serial ID of the printer  10  (hereinafter, also referred to as “printer ID”), which is an object of the contract, is registered in the information management server  50 . The printer ID and a user ID are registered in correlation with each other in the delivery management server  70 . The user ID includes an address and a name of a contractor. The printer ID is an example of device identification information. 
         [0036]    In the printer  10 , when print processing is executed by consuming ink in the cartridge  36  as a starter kit in the package of the printer  10 , communication is established between the printer  10  and the information management server  50  ( FIG. 2 : M 100 ). Then, in the printer  10 , the detection sensor  26  periodically detects the residual amount of ink in each color in the cartridges  36 , which are connected to the connecting unit  22 . Information of the detected residual amount of ink in each color (hereinafter, also referred to as “ink information”) is transmitted from the printer  10  to the information management server  50  (M 102 ). In other words, the ink information includes ink colors and the residual amount of ink in correlation with each ink color. The information of the detected residual amount of ink or the ink information is an example of residual amount information. 
         [0037]    When the detection sensor  26  detects the residual amount of ink, the IC chip  38  of the cartridge  36  connected to the connecting unit  22  is read by the reading unit  24 , and the printer  10  acquires the specific information of the connected cartridge  36 . When the ink information is transmitted to the information management server  50 , the specific information of the connected cartridge  36 , the printer ID, and the ink information of the printer  10  are transmitted to the information management server  50 . The ink information, the specific information of the connected cartridge  36 , and the printer ID that are transmitted to the information management server  50  are also collectively referred to as “printer information”, hereinafter. 
         [0038]    Upon reception of the printer information, the information management server  50  analyzes the printer information. In the analysis of the printer information, the information management server  50  performs a determination using the specific information of the connected cartridge  36  in the printer information and another determination employing the ink information in the printer information. More in detail, the specific information of the connected cartridge  36  and the specific information of the ordered cartridge  36 , which are corresponding to each printer ID, are stored in correlation with each other in the management table  63 , as illustrated in  FIG. 2 . 
         [0039]    When the specific information of the connected cartridge  36  received this time coincides with the specific information of the connected cartridge  36  received previous time, the information management server  50  determines that the cartridge  36  connected to the connecting unit  22  has not been exchanged. Otherwise, when the specific information of the connected cartridge  36  received this time does not coincide with the specific information of the connected cartridge  36  received previous time, the information management server  50  determines that the cartridge  36  has been exchanged and connected to the connecting unit  22 . In the embodiment, the cartridge  36  is in the package of the printer  10  as a starter kit, and connected to the connecting unit  22  of the printer  10 . The specific information of the connected cartridge  36  received this time therefore coincides with the specific information of the connected cartridge  36  received previous time, and the information management server  50  determines that the cartridge  36  has not been exchanged. 
         [0040]    In the analysis of the printer information, the information management server  50  determines whether an order condition of cartridge  36  is satisfied on the basis of the ink information in the printer information (M 104 ). Specifically, the information management server  50  determines whether the residual amount of ink in each color indicated by the ink information is less than or equal to a threshold amount. When the ink residual amount indicated by the ink information is more than a threshold amount, the information management server  50  determines that the order condition is not satisfied, so that the cartridge  36  is not ordered. Otherwise, when the ink residual amount indicated by the ink information is equal to or less than a threshold amount, the information management server  50  determines that the order condition is satisfied. The information management server  50  then transmits, to the delivery management server  70 , the order instruction of the cartridge  36  in the ink color corresponding to the ink information (M 106 ). Incidentally, the order instruction includes the model number of the cartridge  36  in the ink color that is determined to satisfy the order condition, so that the delivery management server  70  can specify the model number of the cartridge  36  that needs to be delivered in the ordering processing. The information management server  50  transmits together with the order instruction, to the delivery management server  70 , the ink information used for the determination and the printer ID received from the printer  10 . Upon reception of the order instruction, the delivery management server  70  performs ordering processing of the cartridge  36  specified by the received model number (M 108 ). 
         [0041]    More in detail, as illustrated in  FIG. 3 , the above-mentioned printer ID and the user ID are stored in the delivery management server  70  in correlation with each other. The delivery management server  70  extracts the user ID registered in correlation with the printer ID received together with the order instruction, and outputs an instruction to a delivery agent to deliver the cartridge  36  to a user identified by the user ID. Then, the delivery agent delivers the cartridge  36  to the user. 
         [0042]    After execution of the ordering processing, the delivery management server  70  transmits, to the information management server  50 , a specific information of the cartridge  36  delivered in accordance with the ordering processing (M 110 ). Here, the specific information of the ordered cartridge  36  is also referred to as “specific information of the ordered cartridge  36 ”. For convenience, the specific information of the ordered cartridge  36  transmitted from the delivery management server  70  to the information management server  50  in M 110  is assumed to be “specific information #A”. Then, upon reception of the specific information of the ordered cartridge  36 , the information management server  50  stores the specific information of the ordered cartridge  36  in the management table  63  (M 111 ). 
         [0043]    When the ink has run short before arrival of the cartridge  36  delivered in accordance with the ordering processing of the delivery management server  70 , the user may purchase the cartridge  36  at a retailer. In such a case, the user usually removes the empty cartridge  36  connected to the connection unit  22 , and connects the cartridge  36  that the user has purchased to the connection unit  22  (M 112 ). 
         [0044]    The printer  10  periodically detects the ink residual amount and reads the specific information of the connected cartridge  36 , and periodically transmits the printer information to the information management server  50  (M 114 ). The information management server  50  then analyzes the received printer information. As described above, if the cartridge  36  connected to the connection unit  22  has been exchanged in the printer  10 , the information management server  50  determines that the specific information of the connected cartridge  36  received this time does not coincide with that received previous time. In such a case, a field for the specific information of the connected cartridge  36  in the management table  63  is overwritten by the specific information received this time (M 116 ). For convenience, the specific information of the connected cartridge  36  stored in M 116  is assumed to be “specific information #1”. That is, the specific information of the cartridge  36  that is connected to the connection unit  22  in M 112  is “specific information #1”. 
         [0045]    Further, the information management server  50  analyzes the printer information received in M 114  to determine whether the order condition is satisfied for each ink color, based on the ink information in the printer information. When determining that the order condition is satisfied (M 118 ), the information management server  50  determines whether the specific information of the ordered cartridge  36  stored in the management table  63  coincides with the specific information of the connected cartridge  36  that satisfies the order condition. More specifically, the information management server  50  determines whether the specific information of the ordered cartridge  36  delivered in accordance with the ordering processing in M 108  coincides with the specific information of the connected cartridge  36  that is connected to the connection unit  22  in M 112 . Incidentally, the determination is performed in the same ink color. That is, the determination is performed between the specific information of the connected cartridge  36  and the specific information of the ordered cartridge  36  in the same ink color as the connected cartridge  36 . 
         [0046]    In this explanation, the specific information of the ordered cartridge  36  stored in the management table  63  is “specific information #A”, and the specific information of the connected cartridge  36  is “specific information #1.” Accordingly, the information management server  50  determines that the specific information of the ordered cartridge  36  is different from the specific information of the connected cartridge  36  (M 120 ). That is, the information management server  50  determines that the ink information received together with the “specific information #1” in the printer information received in M 114  is different from the ink information including “specific information #A” (i.e. the ink information of the cartridge  36  delivered in accordance with the ordering processing). Accordingly, it is estimated that the connection unit  22  is connected with the cartridge  36  (specific information #1), which is different from the cartridge  36  (specific information #A) delivered in accordance with the ordering processing. It is also estimated that the cartridge  36  delivered in accordance with the ordering processing is in stock at user&#39;s hand. The information management server  50  does not transmit the order instruction even when determining that the order condition is satisfied (M 122 ), on the basis of the ink information. 
         [0047]    For example, when ink is empty in the printer  10 , the cartridge  36  is dispatched in accordance with the ordering processing of the delivery management server  70 . If the shipped cartridge  36  is delivered to the user, the user usually removes the empty cartridge  36  connected to the connection unit  22  and then connects the delivered cartridge  36  to the connection unit  22  (see  FIG. 5 : M 130 ). 
         [0048]    The printer  10  periodically detects the ink residual amount and reads the specific information of the connected cartridge  36 . The printer  10  also periodically transmits the printer information to the information management server  50  (M 132 ). The information management server  50  analyzes the received printer information. As described above, if the cartridge  36  connected to the connection unit  22  has been exchanged in the printer  10 , the information management server  50  determines that the specific information of the connected cartridge  36  received this time does not coincide with that received previous time. In such a case, the specific information of the connected cartridge  36  received this time is overwritten and stored in the management table  63  as illustrated in  FIG. 2  (M 134 ). In M 130 , the cartridge  36  delivered in accordance with the ordering processing (that is, the cartridge  36  with “specific information #A”) is connected to the connection unit  22 , so that the specific information of the connected cartridge  36  stored in M 134  is “specific information #A”. 
         [0049]    In the analysis of the printer information received in M 130 , the information management server  50  determines for each ink color whether the order condition is satisfied, on the basis of the ink information in the printer information. When determining that the order condition is satisfied (M 136 ), the information management server  50  then determines whether the specific information in the management table  63  is in coincidence between the ordered cartridge  36  and the connected cartridge  36  that satisfies the order condition. In detail, the information management server  50  determines whether the specific information of the ordered cartridge  36  delivered to the user in accordance with the ordering processing in M 108  coincides with the specific information of the cartridge  36  connected to the connection unit  22  in M 130 . Here, the determination is performed in the same ink color. That is, the determination is performed between the specific information of the connected cartridge  36  and the specific information of the ordered cartridge  36  in the same ink color as the connected cartridge  36 . 
         [0050]    In this description, the specific information of the ordered cartridge  36  in the management table  63  is “specific information #A”, and the specific information of the connected cartridge  36  is “specific information #A.” Therefore, the information management server  50  determines that the specific information of the ordered cartridge  36  coincides with the specific information of the connected cartridge  36  (M 138 ). Since the connection unit  22  is connected with the cartridge  36  (“specific information #A”) delivered to the user in accordance with the ordering processing, the cartridge  36  is out of stock at the user. Thus, in response to the determination that the order condition is satisfied on the basis of the ink information, the information management server  50  transmits the order instruction to the delivery management server  70  (M 140 ). 
         [0051]    Upon reception of the order instruction, the delivery management server  70  executes the cartridge  36  ordering processing (M 142 ). The delivery management server  70  then transmits, to the information management server  50 , the specific information of the ordered cartridge  36  shipped in accordance with the ordering processing (M 144 ). Here, it is assumed here that the specific information of the ordered cartridge  36  transmitted at this time is “specific information #B”. Upon reception of the specific information of the ordered cartridge  36 , the information management server  50  overwrites the received specific information of the ordered cartridge  36  in the management table  63  (M 146 ). As a result, the specific information of the ordered cartridge  36  “specific information #B” is used in the subsequent determination. 
         [0052]    As described above, in the communication system  1 , the cartridge  36  is ordered, when the information management server  50  determines that the specific information coincides between the ordered cartridge  36  and the connected cartridge  36  and that the order condition is satisfied. Otherwise, the cartridge  36  is not ordered in the state where the specific information of the ordered cartridge  36  differs from that of the connected cartridge  36 , even when the information management server  50  determines that the order condition is satisfied. This can prevent excess stock at user&#39;s hand. Further, as described above, the printer  10  can connect with the cartridges  36  respectively containing each of different ink colors. Thus, the above described management of the ink cartridge  36  can be executed for each color. 
         [0053]    As described above, when determining in S 104  that the order condition is satisfied, the information management server  50  does not determine whether the specific information of the ordered cartridge  36  coincides with that of the connected cartridge  36 . This is because the order of the cartridge  36  in M 106  is the first order for the printer  10 , and usually the cartridge  36  is therefore out of stock at the user. In the communication system  1 , the cartridge  36  is ordered as long as it is the first order and the order condition is satisfied. To rephrase this, the first order is determined irrespective of whether the specific information of the ordered cartridge  36  coincides with that of the connected cartridge  36 . 
         [0054]    &lt;Control Program&gt; 
         [0055]    The ink management processing and the ordering processing for cartridge  36  described above are performed upon execution of the control program  60  by the CPU  52  in the information management server  50 . Hereinafter, a processing flow for execution of the control program  60  will be described using  FIGS. 6 and 7 . 
         [0056]    As illustrated in  FIG. 6 , when the control program  60  is executed by the CPU  52 , communication is established between the printer  10  and the information management server  50  (S 100 ). Then, the information management server  50  waits for reception of the printer information from the printer  10  (S 102 ). Then, the CPU  52  determines whether the printer information has been received from the printer  10  (S 104 ). When it is determined that the printer information has not been received (NO in S 104 ), the processing flow returns to S 102 . Otherwise, when it is determined that the printer information has been received (YES in S 104 ), the received printer information is analyzed (S 106 ). 
         [0057]    On the basis of the specific information of the connected cartridge  36  in the printer information, the CPU  52  then determines whether the cartridge  36  connected to the connecting unit  22  has been exchanged (S 108 ). When it is determined that the cartridge  36  has been exchanged (YES in S 108 ), the specific information of the connected cartridge  36  in the printer information received in S 104  is stored in the management table  63  (S 110 ). Then, the processing flow returns to S 102 . 
         [0058]    Otherwise, when the information management server  50  determines that the cartridge  36  has not been exchanged (NO in S 108 ), the CPU  52  determines, on the basis of the ink information in the received printer information, whether the ink residual amount for each ink color indicated in the ink information is equal to or less than a threshold amount (S 112 ). When the information management server  50  determines that the ink residual amount indicated in the ink information is more than a threshold amount (NO in S 112 ), the processing flow returns to S 102 . Otherwise, when it is determined that the ink residual amount indicated by the ink information is equal to or less than a threshold amount (i.e. if there exists the cartridge  36  whose residual amount of ink is not more than the threshold value) (YES in S 112 ), the CPU  52  examines presence of an ordering history corresponding to the user of the printer  10  for the same ink color as the cartridge  36 . That is, the CPU  52  determines whether the ordering processing corresponding to the user of the printer  10  for the same color as the cartridge  36  whose residual amount of ink is not more than the threshold value has been made for the first time (S 114 ). 
         [0059]    When the CPU  52  determines that there exists an ordering history corresponding to the user of the printer  10  for the same ink color as the cartridge  36  whose residual amount of ink is not more than the threshold value (YES in S 114 ), that is, when the CPU  52  determines that the ordering processing for the same ink color is not the first time, the CPU  52  determines whether the specific information of the connected cartridge  36  coincides with the specific information of the ordered cartridge  36  (S 116 ). When the information management server  50  determines that the specific information of the connected cartridge  36  do not coincide with that of the ordered cartridge  36  (NO in S 116 ), the processing flow returns to S 102 . Otherwise, when the CPU  52  determines that the specific information of the connected cartridge  36  coincides with that of the ordered cartridge  36  (YES in S 116 ), the order instruction is transmitted to the delivery management server  70  (S 118 ). 
         [0060]    When the CPU  52  determines that the ordering history for the user of the printer  10  is absent (NO in S 114 ), that is, when the information management server  50  determines that it would be the first ordering processing for the user of the printer  10 , S 116  is skipped and the order instruction is transmitted to the delivery management server  70  (S 118 ). When the order instruction is transmitted to the delivery management server  70 , the information management server  50  receives the specific information of the ordered cartridge  36  from the delivery management server  70  (S 120 ) and stores the received specific information of the ordered cartridge  36  in the management table  63  (S 122 ). Then, the processing flow returns to S 102 . 
       Second Embodiment 
       [0061]    In the communication system  1  of the first embodiment, on the basis of the specific information of the ordered cartridge  36  transmitted from the delivery management server  70 , it is determined whether the cartridge  36  connected to the connection unit  22  of the printer  10  is the cartridge  36  delivered in accordance with the ordering processing. On the other hand, in a communication system  1  of a second embodiment, by using another method, it is determined whether the cartridge  36  connected to the connection unit  22  of the printer  10  is the cartridge  36  delivered in accordance with the ordering processing. In the second embodiment, instead of the management table  63 , a management table  64  illustrated in  FIGS. 8A and 8B  is stored in the data storage area  62 . The management table  64  is a table for storing the printer ID, the specific information of the connected cartridge  36 , the specific information of the ordered cartridge  36 , and a stock flag in correlation with each other. 
         [0062]    The following describes, using  FIG. 9 , a case where the order condition is satisfied and where the cartridge  36  connected to the printer  10  is the cartridge  36  delivered in accordance with the ordering processing. In the example of  FIG. 9 , the management table  64  illustrated in  FIG. 8A  is used. Specifically, as in the communication system  1  of the first embodiment as well as the communication system  1  of the second embodiment, communication between the printer  10  and the information management server  50  is established (see  FIG. 9 : M 160 ). Then, in the printer  10 , detection of the residual amount of ink and reading of the specific information of the connected cartridge  36  are periodically performed, and the printer information is periodically transmitted from the printer  10  to the information management server  50  (M 162 ). 
         [0063]    Upon reception of the printer information, the information management server  50  analyzes the received printer information. In the analysis of the printer information, the information management server  50  determines for each ink color, on the basis of the ink information in the printer information, whether the order condition is satisfied (M 164 ). When determining that the order condition is satisfied, the information management server  50  transmits, to the delivery management server  70 , the order instruction of the cartridge  36  for the ink corresponding to the ink information (i.e. the string information corresponding to the model number in the specific information of the connected cartridge  36  whose ink color is determined to satisfy the order condition) (M 166 ). As in the first embodiment, the order instruction includes the printer ID. Thus, upon reception of the order instruction, the delivery management server  70  outputs, to a delivery agent, an instruction to deliver cartridge  36  to a user identified by the user ID in the management table  71  in correlation with the printer ID. 
         [0064]    Further, the delivery management server  70  receives a cartridge  36  delivery state from a delivery agent. After the delivery agent has delivered the cartridge  36  to the user, a notification indicating completion of the delivery is transmitted to the delivery management server  70 . As a result, the delivery management server  70  recognizes that the cartridge  36  has been delivered at user&#39;s hand (M 170 ). Then, the delivery management server  70  transmits, to the information management server  50 , information (hereinafter, referred to as “delivery completion information”) indicating that the delivery of the cartridge  36  to the user has been completed (M 172 ). Upon reception of the delivery completion information, the information management server  50  set a stock flag of the management table  64  to an in-stock state, as illustrated in  FIG. 8A . 
         [0065]    The stock flag is a flag indicating whether the cartridge  36  delivered in response to the ordering processing is in stock at the user of the printer  10 . The stock flag can be set to either of an in-stock state or an out-of-stock state. When the stock flag is set to the in-stock state, the cartridge  36  delivered in response of the ordering processing is in stock the user of the printer  10 . Otherwise, when the stock flag is set to the out-of-stock state, the cartridge  36  delivered in accordance with the ordering processing is not in stock the user of the printer  10 . 
         [0066]    When the ink is empty in the printer  10 , the user removes the empty cartridge  36  connected to the connection unit  22  and connects the cartridge  36  delivered in accordance with the ordering processing to the connection unit  22  (M 176 ). The printer  10  periodically detects the residual amount of ink and reads the specific information of the connected cartridge  36 . The printer  10  also periodically transmits the printer information to the information management server  50  (M 178 ). 
         [0067]    Then, upon reception of the printer information, the information management server  50  analyzes the printer information. As described above, in the printer  10 , the cartridge  36  connected to the connection unit  22  has been exchanged, so that the information management server  50  determines, on the basis of the specific information of the connected cartridge  36  in the printer information, the specific information of the connected cartridge  36  received this time does not coincide with the specific information stored in the management table  64 . That is, the information management server  50  recognizes that the cartridge  36  has been exchanged in the printer  10  (M 180 ). The information management server  50  then overwrites the management table  64  with the specific information of the connected cartridge  36  in the received printer information (M 181 ). For convenience, it is assumed that the specific information of the connected cartridge  36  is “specific information #A”. 
         [0068]    As described above, the information management server  50  has received the delivery completion information, and the stock flag is thus set to the in-stock state in M 174 . That is, the cartridge  36  delivered in accordance with the ordering processing following the exchange of the cartridge  36  in the printer  10  is in stock at user&#39;s hand. Thus, it is estimated that the cartridge  36  exchanged and connected this time to the connection unit  22  is the cartridge  36  delivered in accordance with the ordering processing. Then, the information management server  50  stores the “specific information #A” received this time in the data storage area  62  as the specific information of the ordered cartridge  36  (M 182 ). That is, in a case where the stock flag is set in the in-stock state and where exchanging of the cartridge  36  in the printer  10  has been recognized, the specific information of the ordered cartridge  36  received this time is stored in the data storage area  62 . In the data storage area  62 , the specific information of the ordered cartridge  36  as a default value has been previously stored. Upon storage of new specific information of the ordered cartridge  36 , the new specific information of the ordered cartridge  36  is overwritten on the stored specific information of the ordered cartridge  36 . Since the cartridge  36  delivered in accordance with the ordering processing is exchanged and connected to the connection unit  22  of the printer  10 , the cartridge  36  delivered in accordance with the ordering processing is not in stock at user&#39;s hand. Accordingly, the stock flag is set to the out-of-stock state (M 184 ). 
         [0069]    The information management server  50  determines, for each ink color, whether the order condition is satisfied (M 188 ) on the basis of the printer information periodically transmitted from the printer  10  (M 186 ). When determining that there exists the cartridge  36  satisfying the order condition (M 188 ), the information management server  50  determines whether the specific information of the ordered cartridge  36  in the management table  64  coincides with the latest specific information of the connected cartridge  36  (i.e. the specific information of the connected cartridge  36  received in M 186 ). Incidentally, the determination is performed in the same ink color as the cartridge  36  that satisfies the order condition. That is, the determination is performed between the specific information of the connected cartridge  36  that satisfies the order condition and the specific information of the ordered cartridge  36  in the same ink color as the cartridge  36  that satisfies the order condition. In the management table  64 , the specific information of the connected cartridge  36  “specific information #A” transmitted in M 178  is stored as the specific information of the ordered cartridge  36 . Since the cartridge  36  has not been exchanged during a time between the previous transmission of the printer information and the current transmission of the printer information, the specific information of the connected cartridge  36  received in M 186  naturally coincides with that of the connected cartridge  36  transmitted in M 178 , i.e. the specific information of the ordered cartridge  36  “specific information #A” in the data storage area  62  (M 190 ). As a result, it is estimated that the cartridge  36  whose ink amount has been reduced is the cartridge  36  delivered in accordance with the ordering processing. Thus, on the basis of the ink information, the information management server  50  determines that the order condition is satisfied. In response to the determination, the information management server  50  transmits the order instruction to the delivery management server  70  (M 192 ). 
         [0070]    The following describes a case where the order condition is satisfied and where the cartridge  36  connected to the printer  10  is not the cartridge  36  delivered in accordance with the ordering processing. As the example of the embodiment,  FIG. 10  and the management table  64  illustrated in  FIG. 8B  is used. For example, there may be a case where the ink runs short before arrival of the cartridge  36  shipped in accordance with the ordering processing at user&#39;s hand, even when the delivery management server  70  has performed the ordering processing. In this case, the user often purchases at a retailer and connect the cartridge  36  to the connection unit  22  of the printer  10 . That is, as illustrated in  FIG. 10 , it is assumed that the processing of M 200  to M 208  is executed like the processing of M 160  to M 168  in  FIG. 9 . In this case, when the cartridge  36  shipped in accordance with the processing of M 208  has not arrived at user&#39;s hand, the delivery completion information is not transmitted from the delivery management server  70  to the information management server  50 . Accordingly, in the information management server  50 , the stock flag is not set to the in-stock state, but to the out-of-stock state. 
         [0071]    When the ink runs short before the cartridge  36  shipped in accordance with the ordering processing of the delivery management server  70  has not been delivered at user&#39;s hand, the user removes the cartridge  36  connected to the connection unit  22  and connects the cartridge  36 , which the user purchased at a retailer, to the connection unit  22  (M 210 ). For convenience, the specific information of the cartridge  36  that the user has purchased is assumed to be “specific information #1”. The information management server  50  analyzes the printer information (M 212 ) periodically transmitted from the printer  10 . As described above, when the cartridge  36  connected to the connection unit  22  has been exchanged in the printer  10 , the information management server  50  determines that the specific information received this time does not coincide with the specific information received previous time. Specifically, the determination is made on the basis of the specific information of the connected cartridge  36  “specific information #1” in the printer information. Accordingly, the information management server  50  recognizes that the cartridge  36  has been exchanged in the printer  10  (M 214 ), and then updates the specific information of the connected cartridge  36  of the management table  64 , in which the specific information of the connected cartridge  36  is changed to “specific information #1” received in M 212  (M 213 ). 
         [0072]    At this time, as described above, the information management server  50  has not received the delivery completion information, so that the stock flag is set to the out-of-stock state. That is, at timing when the cartridge  36  is exchanged in the printer  10 , the cartridge  36  shipped in accordance with the ordering processing is not in stock at the user of the printer  10 . Accordingly, it is estimated that the cartridge  36  newly connected to the connection unit  22  of the printer  10  following the cartridge exchange is not the cartridge  36  delivered in accordance with the ordering processing. Thus, the information management server  50  does not store the specific information received this time in the data storage area  62  as the specific information of the ordered cartridge  36  (M 216 ). That is, a specific information different from the specific information transmitted in M 212  is stored in the data storage area  62 . In other words, the specific information of the cartridge  36  connected to the connection unit  22  in M 210  is not stored as the specific information of the ordered cartridge  36 . Accordingly, if the cartridge  36  has not been delivered to the user in accordance with the ordering processing, no specific information of the ordered cartridge  36  is stored in the management table  64 . 
         [0073]    The information management server  50  determines, for each ink color on the basis of the printer information (M 218 ) periodically transmitted from the printer  10 , whether the order condition is satisfied. When determining that there exists the cartridge  36  satisfying the order condition (M 220 ), the information management server  50  determines whether the specific information of the ordered cartridge  36  in the data storage area  62  coincides with the latest specific information of the connected cartridge  36 , i.e. specific information of the connected cartridge  36  received in M 218 . Incidentally, the determination is performed in the same ink color of the cartridge  36  satisfying the order condition. That is, the determination is performed between the specific information of the connected cartridge  36  that satisfies the order condition and the specific information of the ordered cartridge  36  in the same ink color as the cartridge  36  that satisfies the order condition. Here, the specific information of the ordered cartridge  36  is not stored in the management table  64 . The cartridge  36  has not been exchanged from the previous transmission until the current transmission of the printer information, and the specific information of the connected cartridge  36  received in M 218  therefore coincides with the “specific information #1” transmitted in M 212 . Accordingly, the specific information of the ordered cartridge  36  in the management table  64  is different from the specific information of the connected cartridge  36  received this time (M 222 ). Thus, it is estimated that the cartridge  36  whose ink amount has been reduced is not the cartridge  36  delivered in accordance with the ordering processing. Thus, even when the information management server  50  determines that the order condition is satisfied on the basis of the ink information, the information management server  50  does not transmit the order instruction (M 224 ). 
         [0074]    As described above, when receiving the delivery completion information, the information management server  50  sets the stock flag to the in-stock state. If the stock flag is set to the in-stock state and the information management server  50  determines that the cartridge  36  has been exchanged in the printer  10 , the specific information of the connected cartridge  36  received after the exchange of the cartridge  36  is stored in the management table  64  as the specific information of the ordered cartridge  36 . When the specific information of the ordered cartridge  36  in the management table  64  coincides with the specific information of the connected cartridge  36  received from the printer  10 , the information management server  50  determines that cartridge  36  delivered in accordance with the ordering processing is connected to the connection unit  22  of the printer  10 . As a result, the information management server  50  can adequately determine whether the cartridge  36  connected to the connection unit  22  of the printer  10  is the cartridge  36  delivered in accordance with the ordering processing, without acquiring the specific information of the ordered cartridge  36  from the delivery management server  70 . As a result, the same effects as those in the communication system  1  of the first embodiment can be obtained in the communication system  1  of the second embodiment. 
         [0075]    As described above, when determining in M 164  or M 204  that the order condition is satisfied, the information management server  50  does not determine whether the cartridge  36  connected to the connection unit  22  of the printer  10  is the cartridge  36  delivered in accordance with the ordering processing. This is because the order of the cartridge  36  made in M 166  or M 206  is the first order of the cartridge  36  to be used in the printer  10 , and normally the cartridge  36  is not in stock at the user of the printer  10 . Thus, as in the communication system  1  of the first embodiment as well as the second embodiment, the cartridge  36  is ordered upon the first order of the cartridge when the order condition is satisfied. That is, this processing is irrespective of whether the cartridge  36  connected to the connection unit  22  is the cartridge  36  delivered in accordance with the ordering processing. 
         [0076]    The processing in the information management server  50  of the second embodiment is performed upon execution of the control program  60  by the CPU  52  of the information management server  50 . Hereinafter, a processing flow upon execution of the control program  60  will be described using  FIGS. 11 and 12 . 
         [0077]    As illustrated in  FIG. 11 , when the control program  60  is executed by the CPU  52  of the information management server  50  according to the second embodiment, communication is established between the printer  10  and the information management server  50  (S 200 ). Then, the information management server  50  waits for reception of information from the printer  10  or the delivery management server  70  (S 202 ). Then, the CPU  52  determines whether the printer information has been received from the printer  10  (S 204 ). 
         [0078]    When determining that the printer information has not been received (NO in S 204 ), the CPU  52  determines whether the delivery completion information has been received from the delivery management server  70  (S 206 ). When the CPU  52  determines that the delivery completion information has been received (YES in S 206 ), the stock flag is set to the in-stock state (S 208 ). Then the processing flow returns to S 202 . Otherwise, when the CPU  52  determines that the delivery completion information has not been received (NO in S 206 ), the processing of S 208  is skipped, and the processing flow returns to S 202 . 
         [0079]    When determining in S 204  that the printer information has been received (YES in S 204 ), the CPU  52  analyzes the received printer information (S 210 ). Then, the CPU  52  determines, based on the specific information of the connected cartridge  36  included in the printer information, that the cartridge  36  connected to the connection unit  22  of the printer  10  has been exchanged (S 212 ). When determining that the cartridge  36  has been exchanged (YES in S 212 ), the CPU  52  determines whether the stock flag is set to the in-stock state (S 214 ). 
         [0080]    When the CPU  52  determines that the stock flag is not set to the in-stock state (NO in S 214 ), the processing flow returns to S 202 . Otherwise, when the CPU  52  determines that the stock flag is set to the in-stock state (YES in S 214 ), the specific information included in the printer information received in S 204  is stored in the data storage area  62  as the specific information of the ordered cartridge  36  (S 216 ). Then, the stock flag is changed to the out-of-stock state (S 218 ). The processing flow then returns to S 202 . 
         [0081]    When determining that the cartridge  36  has not been exchanged (NO in S 212 ), the CPU  52  determines, based on the ink information included in the received printer information, whether the order condition is satisfied. That is, the CPU  52  determines whether the residual amount of ink in each color indicated by the ink information is equal to or less than a threshold amount (S 220 ). When the CPU  52  determines that the residual amount of ink in each color indicated by the ink information is more than a threshold amount (NO in S 220 ), the processing flow returns to S 202 . Otherwise, when the CPU  52  determines that the residual amount of ink indicated in the ink information is equal to or less than a threshold amount (i.e. when there exists the cartridge  36  whose residual amount of ink is not more than the threshold value) (YES in S 202 ), the CPU  52  examines existence of the ordering history corresponding to the user of the printer  10  for the ink color of the cartridge  36  whose residual amount of ink is not more than the threshold value. That is, the CPU  52  determines whether it is the first ordering processing for the user of the printer  10  (S 222 ). 
         [0082]    When the CPU  52  determines that the ordering history for the user of the printer  10  exists (YES in S 222 ), the CPU  52  determines whether the latest specific information received in S 204  coincides with the specific information of the ordered cartridge  36  in the data storage area  62  (S 224 ). When the CPU  52  determines that the latest specific information of the connected cartridge  36  and the specific information of the ordered cartridge  36  do not coincide with each other (NO in S 224 ), the processing flow returns to S 202 . Otherwise, when the information management server  50  determines that the latest specific information of the connected cartridge  36  coincides with the specific information of the ordered cartridge  36  (YES in S 224 ), the order instruction is transmitted to the delivery management server  70  (S 226 ). Then, the processing flow returns to S 202 . 
         [0083]    When the CPU  52  determines that the cartridge  36  ordering history for the user of the printer  10  is absent (NO in S 222 ), S 224  is skipped, and the order instruction is transmitted to the delivery management server  70  (S 226 ). Then, the processing flow returns to S 202 . 
         [0084]    While the description has been made in detail with reference to specific embodiments thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the above described embodiments. 
         [0085]    Specifically, in the above embodiments, the information management server  50  and the delivery management server  70  are provided as separated servers; however, they may be integrated into a single server. In this case, the integrated server issues an order of the cartridge  36  to a delivery agent and acquires the specific information of the ordered cartridge  36  and delivery completion information by itself. 
         [0086]    In the above description, the printer  10  periodically transmits the ink information to the information management server  50 ; alternatively, the printer  10  may transmits the ink information at a predetermined timing. For example, the ink information may be transmitted to the information management server  50  at timing when the residual amount of ink of the cartridge  36  is reduced to a predetermined amount. Further, in the above description, the printer  10  detects the residual amount of ink by means of the detection sensor  26 ; alternatively, the printer  10  may detect the residual amount by a calculation. Specifically, the printer  10  calculates the ink amount consumed in the print processing on the basis of image data and print settings, and then subtracts the calculated amount of ink from the current residual amount of ink. Further, in the above description, the recording unit  20  is an inkjet type; alternatively, the recording unit  20  may be an electrophotographic type. In this case, the cartridge  36  is filled with toner, in place of the ink. 
         [0087]    Further, in the above description, the printer  10  is a color printer; alternatively, the printer  10  may be a monochrome printer. In this case, only a single cartridge  36  can be connected to the connecting unit  22 . 
         [0088]    Further, in the above description, the information management server  50  and the printer  10  directly exchange data such as the printer information; alternatively, they may indirectly exchange the data via a PC. Specifically, data exchange can be performed between the printer  10  connected to the PC by a USB cable, a LAN, or a wireless LAN and the information management server  50  via the PC. 
         [0089]    Further, in the above description, the information management server  50  transmits, to the delivery management server  70 , the printer ID together with the order instruction of the cartridge  36 , and the delivery management server  70  specifies the user ID based on the printer ID; alternatively, the information management server  50  may transmit information different from the printer ID, and the delivery management server  70  may specify the user ID based on the information. 
         [0090]    Further, in the above description, determination of whether the cartridge  36  has been exchanged is based on the specific information in the printer information. Alternatively, the determination may be based on the ink information in the printer information. Specifically, when the residual amount of ink indicated by the ink information received in N-th round is more than the residual amount of ink indicated by the ink information received in (N−1)th round, it can be determined that exchange of the cartridge  36  has been made. 
         [0091]    Further, in the above description, the information management server  50  is constituted of a single web server; alternatively, it may be constituted of a plurality of web servers. 
         [0092]    Further, in the above description, the CPU  52  or the like executes processing of  FIGS. 6, 7, 11, and 12 ; alternatively, these processing may be executed by the CPU  52 , an ASIC, or another logic integrated circuit or may be executed by cooperation of the CPU  52 , ASIC, or another logic integrated circuit. 
         [0093]    While the description has been made in detail with reference to specific embodiments thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the above described embodiments.