Patent Publication Number: US-9411290-B2

Title: Image forming apparatus configured to set an initial value of an amount of recording material remaining in a containing unit, associated control method, and storage medium

Description:
BACKGROUND 
     1. Field 
     Aspects of the present invention generally relate to an image forming apparatus, a control method, and a storage medium. 
     2. Description of the Related Art 
     Image forming apparatuses form an image on a sheet using a recording material such as toner. In general, the recording material is contained in a containing unit such as a cartridge. Some image forming apparatuses detect the amount of recording material remaining in the containing unit, and display a value acquired by the detection on a display unit such as a user interface (UI). 
     Conventionally, a sensor has been provided, and a value detected by the sensor has been directly displayed as the amount of remaining recording material. In many cases, there has been adopted a sensor capable of demonstrating high detection accuracy only when the remaining amount is smaller than a certain level, in view of factors such as cost. In such cases, the sensor discretely detects, for example, 100%, 20%, and 0% as the amount of remaining recording material. Accordingly, the display unit also discretely displays, for example, 100%, 20%, and 0% as the amount of remaining recording material. 
     In contrast, Japanese Patent Application Laid-Open No. 2006-343621 discusses a technique for displaying on a display unit the amount of remaining recording material in continuous percentages while adopting a sensor that discretely detects a remaining amount. For example, when image formation is performed, a predicted value of a toner remaining amount is calculated based on a dot count value of raster data. The calculated predicted value is then displayed as a current value of the toner remaining amount. When a sensor value of the toner remaining amount is acquired from the sensor, the current value is updated with the acquired sensor value. 
     When a toner cartridge is replaced, it is necessary to initialize the current value of the toner remaining amount. Therefore, a toner remaining amount value stored in a memory tag of the toner cartridge is adopted as an initial value of the toner remaining amount. 
     However, when the toner remaining amount value is not stored in the memory tag of the toner cartridge, the current value of the toner remaining amount cannot be appropriately initialized. Therefore, the toner remaining amount cannot be appropriately displayed at least until the sensor detects the toner remaining amount. 
     SUMMARY 
     Aspects of the present invention are generally directed to an image forming apparatus capable of appropriately initializing a current value of a toner remaining amount even if a toner remaining amount value is not stored in a memory tag of a toner cartridge when the toner cartridge is mounted. 
     According to an aspect of the present invention, an image forming apparatus performing image formation using a recording material stored in a containing unit includes an acquisition unit configured to acquire information from the containing unit when the containing unit is mounted to the image forming apparatus, the information indicating a number of pages for which image formation is executable using the recording material stored in the containing unit from a state in which the containing unit is new, a calculation unit configured to calculate, based on the information, an amount of the recording material remaining in the containing unit if a new containing unit is mounted to the image forming apparatus, and a setting unit configured to set a value representing the amount calculated by the calculation unit as an initial value of an amount of the recording material remaining in the containing unit. 
     Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a configuration of an image forming apparatus. 
         FIG. 2  is a block diagram illustrating a configuration of a controller. 
         FIG. 3  is a block diagram illustrating a configuration of a print engine. 
         FIG. 4  is a flowchart (a first half) illustrating control for detecting a toner remaining amount. 
         FIGS. 5A and 5B  are flowcharts (a second half) illustrating the control for detecting the toner remaining amount. 
         FIG. 6  is a diagram illustrating a data configuration of a memory tag. 
         FIG. 7  is a flowchart illustrating details of processing for initializing a current value of the toner remaining amount. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1  is a block diagram illustrating a configuration of an image forming apparatus according to a first exemplary embodiment. 
     A data processing apparatus  101  (e.g., a personal computer (PC)) generates image data, and transmits the generated image data to an image forming apparatus  102 . 
     The image forming apparatus  102  (e.g., a laser beam printer) receives the image data from the data processing apparatus  101 , and forms an image on a sheet based on the received image data. The image forming apparatus  102  may be a multi-function peripheral having functions such as a scanner function and a fax function. 
     A UI  301  has a display unit displaying various types of information to a user, and an operation unit accepting various operations from the user. On the display unit, a current value of a toner remaining amount, which will be described below, is displayed. The current value of the toner remaining amount may be transmitted to an external apparatus such as the data processing apparatus  101  via an external interface (I/F), and displayed on a display unit of the external apparatus. 
     A controller  302  generates bitmap data based on page-description language (PDL) data, and transmits the generated bitmap data to a print engine  303 . The controller  302  will be described in detail below with reference to  FIG. 2 . 
     Based on the bitmap data received from the controller  302 , the print engine  303  performs image formation on a sheet by using toner in an electrophotographic method. The method of the image formation may be methods other than the electrophotographic method, for example, an inkjet method. In such a case, a recording material in the inkjet method is ink whereas a recording material in the electrophotographic method is toner. 
     The controller  302  and the print engine  303  are provided as separate components, but may be combined into one unit. 
       FIG. 2  is a block diagram illustrating a configuration of the controller  302 . 
     A central processing unit (CPU)  401  controls the image forming apparatus  102  by loading, into a random-access memory (RAM)  403 , a program stored in a read-only memory (ROM)  402 , and executing the program. Further, as described below, the CPU  401  calculates a toner remaining amount, based on a predicted value of a toner consumption amount and a sensor value of a toner remaining amount. The predicted value of the toner consumption amount is converted from a dot count value acquired by a dot count unit  409 . The CPU  401  is notified by the print engine  303  of the sensor value of the toner remaining amount. The CPU  401  then causes the UI  301  to display the calculated toner remaining amount via a panel I/F  405 , or notifies the data processing apparatus  101  of the calculated toner remaining amount via an external I/F  404 . 
     The ROM  402  stores information such as the program to be executed by the CPU  401 . 
     The RAM  403  stores information such as the program loaded from the ROM  402 . The RAM  403  also stores PDL data, intermediate data generated by interpreting the PDL data, bitmap data generated by rendering the intermediate data, and temporary statuses of various types of processing and log information that are necessary for other processing. 
     The external I/F  404  interconnects the data processing apparatus  101  and the controller  302 , and relays data communication, i.e., transmission and reception of data, performed therebetween. 
     The panel I/F  405  interconnects the UI  301  and the controller  302 , and relays data communication, i.e., transmission and reception of data, performed therebetween. 
     An engine I/F  406  interconnects the print engine  303  and the controller  302 , and relays data communication, i.e., transmission and reception of data, performed therebetween. 
     A direct memory access controller (DMAC)  407  performs data access to the RAM  403 , i.e., writing and reading of data into and from the RAM  403 , upon receipt of a command from the CPU  401 . 
     A rendering unit  408  rasterizes the intermediate data into the bitmap data. 
     The dot count unit  409  counts the number of dots consuming the toner in image formation, among dots included in the rasterized bitmap data. Specifically, the dot count unit  409  counts the number of dots corresponding to colors other than white. For example, in a case of monochrome printing, the dot count unit  409  counts the number of dots corresponding to K (black). In a case of color printing, the dot count unit  409  counts the number of dots corresponding to any of Y (yellow), M (magenta), C (cyan), and K (black). The CPU  401  or the rendering unit  408  may count the number of dots. 
     An electrically erasable programmable ROM (EEPROM)  410  stores information such as setting information of the image forming apparatus  102 . 
     A bus  411  interconnects components in the controller  302 . 
       FIG. 3  is a block diagram illustrating a configuration of the print engine  303 . 
     A CPU  501  controls the print engine  303  by loading into a RAM  503  a program stored in a ROM  502 , and executing the program. 
     The ROM  502  stores information such as the program to be executed by the CPU  501 . 
     The RAM  503  stores information such as the program loaded from the ROM  502 . 
     A toner remaining amount sensor  504  measures the amount of toner remaining in a cartridge  509 . Examples of a method for detecting the toner remaining amount employed in the toner remaining amount sensor  504  include a permeability detecting method, a magnetic method, a piezoelectric vibration method, and a transmitted light method. When the toner remaining amount reaches a predetermined value such as 20% and 0%, the toner remaining amount sensor  504  detects the value as the sensor value. More specifically, as the sensor value, the toner remaining amount sensor  504  detects “100%” when the toner remaining amount is in a range of 100% to 21%, “20%” when the toner remaining amount is in a range of 20% to 1%, and “0%” when the toner remaining amount is 0%. The toner remaining amount sensor  504  may be provided inside the cartridge  509 . 
     A drive control unit  505  drives various motors that are necessary for an image forming unit  508  to perform image formation. 
     A status change detection unit  506  detects a status change such as a jam and cover opening in the image forming apparatus  102 . The status change detection unit  506  further detects replacement of the cartridge  509 . The status change may be detected by the CPU  501 . 
     A controller I/F  507  interconnects the controller  302  and the print engine  303 , and relays data communication, i.e., transmission and reception of data, performed therebetween. 
     The image forming unit  508  performs image formation on a sheet by using the toner in the electrophotographic method, based on the bitmap data received from the controller  302 . 
     The cartridge  509  is a process cartridge mountable to the image forming apparatus  102 , as a containing unit containing the toner. The cartridge  509  stores the toner to be used when the image forming unit  508  performs image formation. Further, the cartridge  509  includes a nonvolatile storage medium that stores cartridge information therein. Examples of the cartridge information include information indicating whether the cartridge  509  is new, color information indicating the color of the cartridge  509 , and toner remaining amount information indicating the amount of the toner currently remaining in the cartridge  509 . Although the cartridge  509  is connected to a bus  510 , the cartridge  509  may be connected to the CPU  501  via a dedicated line. 
     The bus  510  interconnects components in the print engine  303 . 
       FIGS. 4, 5A, and 5B  illustrate flowcharts indicating control for detecting the toner remaining amount. 
     In each of  FIGS. 4, 5A, and 5B , the flowchart on the left indicates the control performed by the CPU  401  in the controller  302 . This control is implemented when the CPU  401  loads a control program stored in the ROM  402  into the RAM  403  to execute the control program. On the other hand, the flowchart on the right indicates the control performed by the CPU  501  in the print engine  303 . This control is implemented when the CPU  501  loads a control program stored in the ROM  502  into the RAM  503  to execute the control program. 
     First, in step S 201 , the CPU  501  determines whether the cartridge  509  has been replaced. This determination is made by detecting that the cartridge  509  has been newly mounted to the image forming apparatus  102 . The mounted cartridge  509  is recognized when the status change detection unit  506  detects that the cartridge  509  has been mounted and notifies the CPU  501  of the detection. The mounted cartridge  509  may be detected by detecting opening/closing of a cover provided for replacing the cartridge  509 . Alternatively, the mounted cartridge  509  may be detected via a button or a switch whose ON/OFF state changes in hardware in response to a component being mounted or removed. When the CPU  501  determines that the cartridge  509  has been replaced (YES in step S 201 ), the CPU  501  proceeds to step S 202 . When the CPU  501  determines that the cartridge  509  has not been replaced (NO in step S 201 ), the CPU  501  stays on standby. 
     Then, in step S 202 , the CPU  501  transmits a cartridge replacement notification indicating that the cartridge  509  has been replaced to the controller  302  via the controller I/F  507 . 
     Next, in step S 101 , the CPU  401  determines whether the cartridge replacement notification has been received from the print engine  303  via the engine I/F  406 . When the CPU  401  determines that the cartridge replacement notification has been received (YES in step S 101 ), the CPU  401  proceeds to step S 102 . When the CPU  401  determines that the cartridge replacement notification has not been received (NO in step S 101 ), the CPU  401  stays on standby. 
     Then, in step S 102 , the CPU  401  transmits a cartridge information request for requesting cartridge information of the cartridge  509  to the print engine  303  via the engine I/F  406 . 
     Next, in step S 203 , the CPU  501  determines whether the cartridge information request has been received from the controller  302  via the controller I/F  507 . When the CPU  501  determines that the cartridge information request has been received (YES in step S 203 ), the CPU  501  proceeds to step S 204 . When the CPU  501  determines that the cartridge information request has not been received (NO in step S 203 ), the CPU  501  stays on standby. 
     Then, in step S 204 , the CPU  501  transmits the cartridge information of the cartridge  509 , to the controller  302  via the controller I/F  507 . 
     Next, in step S 103 , the CPU  401  determines whether the cartridge information has been received from the print engine  303  via the engine I/F  406 . When the CPU  401  determines that the cartridge information has been received (YES in step S 103 ), the CPU  401  proceeds to step S 104 . When the CPU  401  determines that the cartridge information has not been received (NO in step S 103 ), the CPU  401  stays on standby. 
     Then, in step S 104 , the CPU  401  initializes the current value of the toner remaining amount based on the cartridge information. Here, the current value of the toner remaining amount is a value recognized by the controller  302  as the toner remaining amount of the cartridge  509 , and displayed to a user via the UI  301 . The current value of the toner remaining amount is held in a memory such as the RAM  403 . This step S 104  will be described in detail below with reference to  FIG. 7 . 
     Then, in step S 105 , the CPU  401  determines whether a job demanding execution of image formation has been input from the data processing apparatus  101  via the external I/F  404 . Here, examples of the job include a PDL print job, a copy job, and a FAX reception print job. When the CPU  401  determines that the job has been input (YES in step S 105 ), the CPU  401  proceeds to step S 106 . When the CPU  401  determines that the job has not been input (NO in step S 105 ), the CPU  401  proceeds to step S 111 . 
     Next, in step S 106 , the CPU  401  executes image processing necessary for the image formation based on the job. Here, the image processing includes processing for generating raster data by controlling the rendering unit  408  to rasterize print data. 
     Then, in step S 107 , the CPU  401  transmits the raster data generated through the image processing to the print engine  303  via the engine I/F  406 . 
     Next, in step S 108 , the CPU  401  acquires from the dot count unit  409  a dot count value measured at the time of the generation of the raster data. The dot count value may be acquired page by page, or may be acquired job by job. 
     Then, in step S 109 , the CPU  401  calculates the predicted value of the toner remaining amount, based on the dot count value acquired in step S 108 . Specifically, at first, the CPU  401  performs the following calculation: (the dot count value [dot] in print execution of this job or page)×(a toner consumption amount per dot [g/dot])=(a toner consumption amount [g] due to this job execution). Here, the toner consumption amount per dot may be stored beforehand in the ROM  402 , or may be included in the cartridge information received in step S 103 . Next, the CPU  401  performs the following calculation: (the current toner remaining amount [g])−(the toner consumption amount [g] due to the execution of this job)=(a new toner remaining amount [g]). Next, the CPU  401  performs the following calculation: (the new toner remaining amount [g])/(a toner remaining amount [g] in a state in which a cartridge is unused)=(a predicted value [%] of the new toner remaining amount). Here, the toner remaining amount in the state in which the cartridge is unused may be stored beforehand in the ROM  402 , or may be included in the cartridge information received in step S 103 . 
     Next, in step S 110 , the CPU  401  updates the current value of the toner remaining amount with the predicted value calculated in step S 109 . 
     Meanwhile, in step S 205 , the CPU  501  determines whether the raster data has been received from the controller  302  via the controller I/F  507 . When the CPU  501  determines that the raster data has been received (YES in step S 205 ), the CPU  501  proceeds to step S 206 . When the CPU  501  determines that the raster data has not been received (NO in step S 205 ), the CPU  501  proceeds to step S 208 . 
     Then, in step S 206 , the CPU  501  controls the image forming unit  508  to perform the image formation based on the raster data. 
     Next, in step S 207 , the CPU  501  acquires the sensor value of the toner remaining amount from the toner remaining amount sensor  504 . The sensor value may be acquired upon completion of the image formation per page, or upon completion of the image formation per job. Alternatively, the sensor value may be acquired each time a predetermined time elapses. 
     Then, in step S 208 , the CPU  501  determines whether there is any change between the sensor value acquired this time and a previously acquired sensor value. When the CPU  501  determines that the sensor value has changed (YES in step S 208 ), the CPU  501  proceeds to step S 209 . When the CPU  501  determines that the sensor value has not changed (NO in step S 208 ), the CPU  501  returns to step S 205 . 
     Next, in step S 209 , the CPU  501  transmits a sensor value change notification indicating that the sensor value has changed, to the controller  302  via the controller I/F  507 . 
     Next, in step S 111 , the CPU  401  determines whether the sensor value change notification has been received from the print engine  303  via the engine I/F  406 . When the CPU  401  determines that the sensor value change notification has been received (YES in step S 111 ), the CPU  401  proceeds to step S 112 . When the CPU  401  determines that the sensor value change notification has not been received (NO in step S 111 ), the CPU  401  returns to step S 105 . 
     Then, in step S 112 , the CPU  401  transmits a sensor value request for requesting the sensor value to the print engine  303  via the engine I/F  406 . 
     Next, in step S 210 , the CPU  501  determines whether the sensor value request has been received from the controller  302  via the controller I/F  507 . When the CPU  501  determines that the sensor value request has been received (YES in step S 210 ), the CPU  501  proceeds to step S 211 . When the CPU  501  determines that the sensor value request has not been received (NO in step S 210 ), the CPU  501  stays on standby. 
     Then, in step S 211 , the CPU  501  transmits the sensor value to the controller  302  via the controller I/F  507 . 
     Next, in step S 113 , the CPU  401  determines whether the sensor value has been received from the print engine  303  via the engine I/F  406 . When the CPU  401  determines that the sensor value has been received (YES in step S 113 ), the CPU  401  proceeds to step S 114 . When the CPU  401  determines that the sensor value has not been received (NO in step S 113 ), the CPU  401  stays on standby. 
     Then, in step S 114 , the CPU  401  updates the current value of the toner remaining amount with the sensor value received in step S 113 . 
     Next, in step S 115 , the CPU  401  determines whether the toner remaining amount is zero, with reference to the current value of the toner remaining amount. When the CPU  401  determines that the toner remaining amount is zero (YES in step S 115 ), the CPU  401  completes the processing. When the CPU  401  determines that the toner remaining amount is not zero (NO in step S 115 ), the CPU  401  returns to step S 105 . 
     Meanwhile, in step S 212 , the CPU  501  determines whether the toner remaining amount is zero, with reference to the sensor value of the toner remaining amount. When the CPU  501  determines that the toner remaining amount is zero (YES in step S 212 ), the CPU  501  completes the processing. When the CPU  501  determines that the toner remaining amount is not zero (NO in step S 212 ), the CPU  501  returns to step S 205 . 
       FIG. 6  is a diagram illustrating a data configuration of a memory tag. The memory tag is the nonvolatile storage medium included in the cartridge  509 . 
     An entire data area  600  includes a basic area  610  and a free area  620 . 
     The basic area  610  includes a capacity  611 , a color type (YMCK)  612 , a new flag  613 , a page count  614 , a Low-reached history  615 , and an Out-reached history  616 . These will be referred to as “cartridge information”. 
     The capacity  611  indicates a toner amount that can be stored in the cartridge  509  (i.e., the toner remaining amount when the cartridge  509  is new and full). Specifically, the capacity  611  indicates the number of pages for which image formation is executable from a state in which the cartridge  509  is new. 
     The color type (YMCK)  612  indicates the color of the toner stored in the cartridge  509 . 
     The new flag  613  indicates whether the cartridge  509  is new. 
     The page count  614  indicates the number of pages printed using the cartridge  509  (the number of pages for which image formation has been executed). 
     The Low-reached history  615  indicates whether the toner remaining amount of the cartridge  509  has reached a Low level (20%). The Low level is a value indicating that an amount of recording material remaining is small. This value may be a value other than 20% (e.g., 10% or 15%). 
     The Out-reached history  616  indicates whether the toner remaining amount of the cartridge  509  has reached an Out level (0%). The Out level is a value indicating that an amount of recording material remaining is zero. This value may be a value other than 0% (e.g., in a range of 1% to 3%). 
     The free area  620  includes a toner remaining amount value  621 . New information can be added or a modification of information can be made to the free area  620  freely, according to a request by the CPU  501 . 
     The toner remaining amount value  621  indicates the toner remaining amount [%] of the cartridge  509 . The toner remaining amount may be stored in [g]. 
       FIG. 7  is a flowchart illustrating details of processing for initializing the current value of the toner remaining amount. 
     When the processing illustrated in  FIG. 7  is executed, various types of information (those described above with reference to  FIG. 6 ) of the memory tag included in the cartridge information received in step S 103  are used. 
     First, in step S 301 , the CPU  401  determines whether the memory tag is attached to the cartridge  509 , based on the cartridge information received in step S 103 . Specifically, when the various types of information described above with reference to  FIG. 6  are included in the cartridge information received in step S 103 , the CPU  401  determines that the memory tag is attached to the cartridge  509 . Otherwise the CPU  401  determines that the memory tag is not attached to the cartridge  509 . When the CPU  401  determines that the memory tag is attached to the cartridge  509  (YES in step S 301 ), the CPU  401  proceeds to step S 302 . When the CPU  401  determines that the memory tag is not attached to the cartridge  509  (NO in step S 301 ), the CPU  401  proceeds to step S 308 . 
     Next, in step S 302 , the CPU  401  determines whether the cartridge  509  is new based on the new flag  613 . Specifically, when the new flag  613  included in the cartridge information is ON, the CPU  401  determines that the cartridge  509  is new. On the other hand, when the new flag  613  is OFF, the CPU  401  determines that the cartridge  509  is not new. When the CPU  401  determines that the cartridge  509  is new (YES in step S 302 ), the CPU  401  proceeds to step S 303 . When the CPU  401  determines that the cartridge  509  is not new (NO in step S 302 ), the CPU  401  proceeds to step S 305 . 
     Then, in step S 303 , the CPU  401  calculates a toner remaining amount initial value based on the capacity  611 . Specifically, the CPU  401  calculates the toner remaining amount initial value by using the following expression:
 
 A   i   =C   t   ×P   i ,
 
where A i  denotes the toner remaining amount initial value [μg], C t  denotes the toner consumption amount per page of specific data [μg/sheet] (a predetermined value), and P i  denotes the number of printable pages using the specific data [sheets] (the capacity  611 ). A sign “×” refers to multiplication. P i  and C t  are values that are predetermined assuming a case of printing the specific data (standard data such as ISO data). The toner consumption amount C t  may be defined in a module of a program held in the ROM  402 , or may be held by the memory tag of the cartridge  509  as the cartridge information. The above expression “C t ×P i ” is not limited to this example of calculation. For example, a predetermined value according to the type of the cartridge  509  may be directly defined in a module of a program held in the ROM  402 , or may be directly held by the memory tag of the cartridge  509  as the cartridge information.
 
     Next, in step S 304 , the CPU  401  sets the calculated toner remaining amount initial value as an initial value of the current value of the toner remaining amount. Specifically, the CPU  401  divides the toner remaining amount initial value calculated in each of steps S 303 , S 306 , S 307 , S 309 , and S 310 , by “C t ×P i ” that is the capacity when the cartridge  509  is new. As a result, the value of the toner remaining amount is obtained in “%”. The CPU  401  then sets the obtained value as the initial value of the current value of the toner remaining amount. 
     On the other hand, when the CPU  401  determines that the cartridge  509  is not new (NO in step S 302 ), in step S 305 , the CPU  401  determines whether the toner remaining amount value  621  is stored in the memory tag. Specifically, when the toner remaining amount value  621  is included in the cartridge information received in step S 103 , the CPU  401  determines that the toner remaining amount value  621  is stored in the memory tag. Otherwise the CPU  401  determines that the toner remaining amount value  621  is not stored in the memory tag. When the CPU  401  determines that the toner remaining amount value  621  is stored in the memory tag (YES in step S 305 ), the CPU  401  proceeds to step S 307 . When the CPU  401  determines that the toner remaining amount value  621  is not stored in the memory tag (NO in step S 305 ), the CPU  401  proceeds to step S 306 . 
     Next, in step S 306 , the CPU  401  calculates a toner remaining amount initial value based on the page count  614 . Specifically, the CPU  401  calculates the toner remaining amount initial value by using the following expression:
 
 A   i   =C   t   ×P   i   −C   t   ×P   n ,
 
where A i  denotes the toner remaining amount initial value [μg], C t  denotes the toner consumption amount per page of the specific data [μg/sheet] (a predetermined value), P i  denotes the number of printable pages using the specific data [sheets] (the capacity  611 ), and P n  denotes the number of print pages [sheets] (the page count  614 ). A sign “−” refers to subtraction. The expression used in step S 306  may be used in step S 303 . This is because, when the cartridge  509  is new, “P n ” is 0 and therefore “C t ×P n ” is also 0, so that the expression in step S 306  is equivalent to the expression in step S 303 . In the flowchart, this case is equivalent to a case in which steps S 302  and S 303  are removed and the CPU  401  directly proceeds to step S 305  when the CPU  401  determines that the memory tag is attached to the cartridge  509  (YES in step S 301 ).
 
     On the other hand, when the CPU  401  determines that the toner remaining amount value  621  is stored in the memory tag (YES in step S 305 ), in step S 307 , the CPU  401  determines that the toner remaining amount value  621  is the toner remaining amount initial value. 
     When the CPU  401  determines that the memory tag is not attached to the cartridge  509  (NO in step S 301 ), in step S 308 , the CPU  401  acquires the sensor value of the toner remaining amount, and determines whether the acquired sensor value is an indefinite value. Specifically, at first, the CPU  401  acquires the sensor value of the toner remaining amount by executing processing similar to the processing in steps S 112  and S 113  in  FIG. 5B . When the acquired sensor value falls outside a range of 0% to 100% or acquisition of the sensor value has failed, the CPU  401  determines that the sensor value is an indefinite value. Otherwise the CPU  401  determines that the sensor value is not an indefinite value. When the CPU  401  determines that the sensor value is an indefinite value (YES in step S 308 ), the CPU  401  proceeds to step S 309 . When the CPU  401  determines that the sensor value is not an indefinite value (NO in step S 308 ), the CPU  401  proceeds to step S 310 . 
     Then, in step S 309 , the CPU  401  determines that a predetermined alternative value according to the ability of the toner remaining amount sensor  504  is the toner remaining amount initial value. A value expressed by “(an upper limit allowing remaining amount measurement by 1%)+1” (%) is used as the predetermined alternative value. Alternatively, when the Low level (e.g., 20%) indicating that a toner remaining amount is small is provided, and the remaining mount measurement by 1% cannot be performed for a value greater than a Low notification value, a value expressed by “(the Low notification value)+1” (%) may be used as the predetermined alternative value. 
     On the other hand, when the CPU  401  determines that the sensor value is not an indefinite value (NO in step S 308 ), in step S 310 , the CPU  401  determines that the sensor value acquired in step S 308  is the toner remaining amount initial value. 
     According to the present exemplary embodiment, the toner remaining amount can be appropriately set even if the toner remaining amount value is not stored in the memory tag of the cartridge when the cartridge is newly mounted. 
     Additional embodiments can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions recorded on a storage medium (e.g., computer-readable storage medium) to perform the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more of a central processing unit (CPU), micro processing unit (MPU), or other circuitry, and may include a network of separate computers or separate computer processors. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. 
     While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that these exemplary embodiments are not seen to be limiting. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2013-179997 filed Aug. 30, 2013, which is hereby incorporated by reference herein in its entirety.