JP2018173617A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that enables a user to easily and accurately grasp the amount of remaining printing agent stored in a storage box even during power-down.SOLUTION: A process cartridge 3 storing toner is removably attached to a cartridge attachment position set in an apparatus body 2. The process cartridge 3 is provided with a non-volatile display 33 that can maintain display of an image without receiving supply of power. On the non-volatile display 33, the amount of remaining toner stored in the process cartridge 3 is displayed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus such as a printer.

  2. Description of the Related Art Conventionally, some image forming apparatuses are provided with a display for displaying various information on an outer surface of an apparatus main body (housing). The display displays information related to various settings, for example, the number of prints, print quality, print paper (sheet) size, and the like, as well as the remaining amount of consumables consumed during printing.

  As a display mounted on the image forming apparatus, a liquid crystal display is generally used. However, in the liquid crystal display, when the power of the image forming apparatus is turned off, the display disappears. Therefore, by providing a non-volatile display such as electronic paper and displaying the remaining amount of consumables on the non-volatile display, the remaining amount of consumables continues to be displayed even when the image forming apparatus is turned off. Proposals have been made (see, for example, Patent Document 1).

JP 2010-194799 A

  However, in a configuration in which a storage box that stores printing agents (toner, ink), which are consumables, is detachably mounted in the apparatus main body, the storage box is replaced while the image forming apparatus is powered off. Until the power is turned on, the remaining amount of printing agent in the storage box mounted in the apparatus main body after the replacement is unknown.

  In addition, in a configuration in which a small window through which the printing agent can be seen is formed in the storage box, the storage box looks at the storage box taken out from the main body of the apparatus, and the remaining amount of the printing agent in the storage box is accurately determined. Difficult to grasp.

  An object of the present invention is to provide an image forming apparatus in which a user can easily and accurately grasp the remaining amount of printing agent stored in a storage box even when the power is turned off.

  In order to achieve the above object, an image forming apparatus according to the present invention is an image forming apparatus that forms an image on a sheet, and is detachably mounted on the apparatus main body and a mounting position set in the apparatus main body. A storage box for storing a printing agent used for forming the image forming apparatus, a non-volatile display attached to the storage box and capable of maintaining image display without receiving power supply, and a control unit provided in the apparatus main body. The control unit executes display processing for displaying information on the remaining amount of the printing agent stored in the storage box on the nonvolatile display.

  As described above, the storage box for storing the printing agent is detachably mounted at the mounting position set in the apparatus main body. The storage box is provided with a non-volatile display capable of maintaining image display without receiving power. Information on the remaining amount of the printing agent stored in the storage box is displayed on the non-volatile display.

  As a result, even when the image forming apparatus is powered off, information regarding the remaining amount of the printing agent is displayed on the non-volatile display, so that the user can easily and accurately grasp the remaining amount of the printing agent from the display. it can.

  According to the present invention, the user can easily and accurately grasp the remaining amount of the printing material stored in the storage box even when the power is turned off.

1 is a perspective view of a printer according to an embodiment of the present invention, showing a state in which a process cartridge is mounted on an apparatus main body and a front cover is closed. FIG. 2 is a perspective view of the printer, showing a state where the front cover is opened and the process cartridge is detached from the apparatus main body. It is a perspective view of a process cartridge. FIG. 2 is a block diagram illustrating an electrical configuration of a printer. It is a circuit diagram of the connection circuit which connects an IC chip and a graphic chip. It is a flowchart which shows the flow of a display rewriting process. It is a figure which shows the example of a screen of a non-volatile display. It is a flowchart which shows the flow of a main body display process. It is a figure which shows the example of a screen of a volatile display. It is a flowchart which shows the flow of the process at the time of mounting | wearing. It is a flowchart which shows the flow of a process during standby. It is a flowchart which shows the flow of the process during printing. It is a flowchart which shows the flow of a cover open process. It is a flowchart which shows the flow of a power-off process.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Appearance configuration of printer>
A printer 1 (an example of an image forming apparatus) shown in FIGS. 1 and 2 is a monochrome laser printer.

  The printer 1 includes an apparatus main body 2 and a process cartridge 3 (an example of a storage box) that is detachably attached to the apparatus main body 2.

  The apparatus main body 2 has a first side surface 11 and a second side surface 12 that are parallel to each other.

  In addition, in order to use in the following description, the direction orthogonal to the first side surface 11 is referred to as “front-rear direction”, and the first side surface 11 side in the front-rear direction is referred to as “front side”. Further, the left and right are defined based on the state of the printer 1 viewed from the front side. In each of FIGS. 1 to 3, the defined direction is indicated by an arrow.

  The first side surface 11 is provided with an opening 13 and a front cover 14 that opens and closes the opening 13. The front cover 14 has a closed position (a position shown in FIG. 1) that closes the opening 13 around an axis extending in the left-right direction, and an open position (the figure shown in FIG. 1) that falls from the closed position to the front side and opens the opening 13. 2 (position shown in FIG. 2).

  In addition, the apparatus main body 2 has an upper surface 15 that extends over the upper ends of the first side surface 11 and the second side surface 12. A recess 16 that is recessed downward is formed on the upper surface 15, and a region in the recess 16 and on the first side surface 11 side of the recess 16 is formed as a paper discharge tray 21.

  A paper feed tray 22 is detachably provided at the bottom of the apparatus body 2. In other words, the paper feed tray 22 is mounted on the bottom of the apparatus main body 2 so that it can be pulled out from the mounting position to the front side. The paper feed tray 22 is configured to be supported in a state where a plurality of sheets such as printing paper are stacked.

  A volatile display 23 is provided on the upper surface 15 of the apparatus body 2. The volatile display 23 is a display that cannot maintain the display of an image without receiving power supply, and includes, for example, a liquid crystal display.

  The process cartridge 3 is detachably mounted at a cartridge mounting position in the apparatus main body 2. In a state where the front cover 14 is opened, the process cartridge 3 can be mounted at the cartridge mounting position through the opening 13, and the process cartridge 3 can be detached from the cartridge mounting position.

  As shown in FIGS. 2 and 3, the process cartridge 3 includes a photosensitive drum 31 and a developing housing 32. The developing case 32 may be formed integrally with a frame that supports the photosensitive drum 31, or may be configured to be coupled to and separated from the frame. In the latter configuration, the developing case 32 may be detachable from the frame through the opening 13 with the frame remaining in the apparatus main body 2. It is an example of a storage box.

  The developing case 32 contains toner (developer). Further, the developing case 32 is provided with a developing roller (not shown), and the toner accommodated in the developing case 32 is supplied to the peripheral surface of the photosensitive drum 31 by the developing roller.

  Printing on the sheet is performed in a state where the process cartridge 3 is mounted at the cartridge mounting position and the front cover 14 is closed. At the time of printing, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 31, and the toner contained in the developing housing 32 is supplied to the peripheral surface of the photosensitive drum 31 by the developing roller. As a result, the electrostatic latent image is developed into a toner image. On the other hand, a sheet is sent out from the sheet feeding tray 22 and conveyed in the apparatus main body 2 toward the sheet discharge tray 21. In the middle of the conveyance, the toner image carried on the photosensitive drum 31 is transferred to the sheet and fixed, whereby printing on the sheet is achieved.

  A non-volatile display 33 is provided on the upper surface of the developing case 32. The non-volatile display 33 is a display such as electronic paper that can maintain image display without receiving power supply. The display area of the non-volatile display 33 has a rectangular outer shape extending in the left-right direction.

  As shown in FIG. 3, a lock recess 35 that is recessed to the right side is formed on the left side surface of the developing case 32. Correspondingly, a lock member 36 is provided in the apparatus main body 2 on the left side of the cartridge mounting position, as shown in FIG. The lock member 36 is displaceable to a lock position that is advanced to the right side from a wall surface 37 that extends in the front-rear direction and the vertical direction on the left side of the cartridge mounting position, and a lock release position that is retracted to the left side from the lock position.

  When the lock member 36 is advanced to the lock position and the lock member 36 is engaged with the lock recess 35 with the process cartridge 3 mounted at the cartridge mounting position, the process cartridge 3 is prohibited from being detached from the cartridge mounting position ( Cartridge lock). When the lock member 36 is retracted from the lock position to the lock release position and the engagement between the lock recess 35 and the lock member 36 is released, the removal of the process cartridge 3 from the cartridge mounting position is permitted.

<Electrical configuration of printer>
As illustrated in FIG. 4, the printer 1 includes an ASIC (Application Specific Integrated Circuit) 41, a ROM 42, and a RAM 43 (an example of a storage unit).

  The ASIC 41 includes a CPU 44 (an example of a control unit). The CPU 44 controls each unit by executing a program stored in the ROM 42 based on a signal input to the ASIC 41 and the like. When the control (program) is executed by the CPU 44, the RAM 43 is used as a work area. The RAM 43 may include a nonvolatile memory such as NVRAM (Non Volatile RAM).

  In addition to the ROM 42 and the RAM 43, the ASIC 41 is connected with a volatile display 23, operation keys 45, a cover sensor 46, a solenoid 47, and the like.

  For example, the operation key 45 is disposed on the upper surface 15 of the apparatus main body 2 and includes a power key for switching the power of the printer 1 on and off, a start key for instructing printing start, and the like.

  The operation key 45 may be a touch key provided integrally with the volatile display 23. That is, the volatile display 23 and the operation key 45 may be a touch panel having both a display function by the volatile display 23 and an input function by the operation key 45.

  The cover sensor 46 outputs an off signal when the front cover 14 is located at the closed position, and outputs an on signal when the front cover 14 is located at the open position.

  The solenoid 47 is a drive source that displaces the lock member 36 between the lock position and the lock release position.

  Further, an IC chip 51 is connected to the ASIC 41. On the other hand, the process cartridge 3 (developing housing 32) is provided with a graphic chip 52 for controlling the display of the nonvolatile display 33. The IC chip 51 and the graphic chip 52 are communicably connected, whereby the CPU 44 can control the display of the nonvolatile display 33 via the IC chip 51 and the graphic chip 52.

<Connection circuit>
In the state where the process cartridge 3 is mounted at the cartridge mounting position in the apparatus main body 2, as shown in FIG. 5, there is a connection circuit 61 between the IC chip 51 and the graphic chip 52 so that they can communicate with each other. Composed. The connection circuit 61 is divided into a main body side circuit 62 provided on the apparatus main body 2 and a cartridge side circuit 63 provided on the process cartridge 3 side.

  The IC chip 51 includes a Vcc pin 71, an IN / OUT pin 72, a GND pin 73, and an IN pin 74. Corresponding to this, the main body side circuit 62 includes four terminals 75, 76, 77 and 78. The Vcc pin 71 and the terminal 75 (an example of the second terminal) are connected by the first wiring 81, and the IN / OUT pin 72 and the terminal 76 (an example of the first terminal) are connected by the second wiring 82, and the GND pin 73 and a terminal 77 (an example of a third terminal) are connected by a third wiring 83, and the IN pin 74 and the terminal 78 are connected by a fourth wiring 84. The second wiring 82 and the third wiring 83 are connected via the first resistor 85.

  The graphic chip 52 has a Vcc pin 91, an IN pin 92, a GND pin 93, and an OUT pin 94. Correspondingly, the cartridge side circuit 63 includes four terminals 95, 96, 97, 98. The Vcc pin 91 and the terminal 95 (an example of the fifth terminal) are connected by the fifth wiring 101, the IN pin 92 and the terminal 96 (an example of the fourth terminal) are connected by the sixth wiring 102, and the GND pin 93 and The terminal 97 (an example of the sixth terminal) is connected by the seventh wiring 103, and the OUT pin 94 and the terminal 98 are connected by the eighth wiring 104. The fifth wiring 101 and the sixth wiring 102 are connected via the second resistor 105.

  For example, as shown in FIG. 2, the terminals 95 to 98 of the cartridge side circuit 63 are arranged in a line in the front-rear direction on the right side surface of the developing housing 32. On the other hand, in the apparatus main body 2, the terminals 75 to 78 of the main body side circuit 62 are arranged in a form corresponding to the arrangement form of the terminals 95 to 98 of the cartridge side circuit 63, that is, arranged in a line in the front-rear direction. The terminals 75 to 78 of the main body side circuit 62 are elastically biased toward the left side.

  When the process cartridge 3 is not mounted at the cartridge mounting position and the main body side circuit 62 and the cartridge side circuit 63 are not connected, the terminal 75 of the main body side circuit 62 is open. The / OUT pin 72 is electrically connected to the GND pin 73 through the first resistor 85. Therefore, when the IN / OUT pin 72 is set to the signal input mode, the potential of the GND pin 73, that is, the ground potential is input to the IN / OUT pin 72.

  When the process cartridge 3 is mounted at the cartridge mounting position, the four terminals 75 to 78 of the main body side circuit 62 are elastically brought into contact with the terminals 95 to 98 of the cartridge side circuit 63, respectively. 63 is electrically connected. In this state, when the IN / OUT pin 72 is set to the signal input mode, a potential obtained by dividing the voltage (potential) of the Vcc pin 71 by the first resistor 85 and the second resistor 105 is input to the IN / OUT pin 72. .

  Therefore, whether or not the process cartridge 3 is mounted at the cartridge mounting position can be determined based on whether or not the potential input to the IN / OUT pin 72 is higher than a predetermined potential.

  Further, in a state where the main body side circuit 62 and the cartridge side circuit 63 are electrically connected, the IN / OUT pin 72 of the IC chip 51 is set to the signal output mode, and the IC chip 51 has the IN / OUT pin 72. A signal for controlling the display of the nonvolatile display 33 can be transmitted to the graphic chip 52 via the second wiring 82, the terminals 76 and 96, the sixth wiring 102, and the IN pin 92 of the graphic chip 52.

  Further, in a state where the main body side circuit 62 and the cartridge side circuit 63 are electrically connected, the IC chip 51 is connected to the OUT pin 94, the eighth wiring 104, the terminals 98 and 78, the fourth wiring 84, and the like from the graphic chip 52. Information such as the cartridge ID (an example of identification information) of the process cartridge 3 can be received via the IN pin 74.

<Display rewriting process>
In a state where the process cartridge 3 is mounted in the apparatus main body 2 at the cartridge mounting position, the CPU 44 executes the display rewriting process shown in FIG. 6 to display the display on the nonvolatile display 33 provided in the process cartridge 3. Can be rewritten.

  In the display rewriting process, the CPU 44 displaces the lock member 36 from the lock release position to the lock position, and prohibits the removal of the process cartridge 3 from the cartridge mounting position (S11: cartridge lock).

  Further, the CPU 44 turns on the remaining amount display flag provided in the RAM 43 (S12).

  Then, the CPU 44 reads the remaining amount of toner stored in the RAM 43 in association with the cartridge ID of the process cartridge 3 being mounted, and displays the read remaining amount of toner on the nonvolatile display 33 of the process cartridge 3, or When the remaining amount of toner is already displayed on the non-volatile display 33, the display is rewritten to the display of the remaining amount of toner read from the RAM 43 (S13).

  The remaining amount of toner is, for example, a percentage in which the full amount of toner accommodated in the process cartridge 3 (developing housing 32) is 100%, and the non-volatile display 33 has a remaining toner amount as shown in FIG. The quantity is displayed numerically.

  The process of associating the cartridge ID with the remaining amount of toner and storing it in the RAM 43 will be described later.

  Thereafter, the CPU 44 displaces the lock member 36 from the lock position to the lock release position, permits the removal of the process cartridge 3 from the cartridge mounting position (S14), and ends the display rewriting process.

<Main unit display processing>
In parallel with the execution of the display rewriting process, the CPU 44 executes the main body display process shown in FIG.

  In the main body display process, the CPU 44 determines whether or not the remaining amount display flag is on (S21).

  When the remaining amount display flag is ON (S21: YES), the CPU 44 displays the remaining amount of toner displayed on the nonvolatile display 33 on the volatile display 23 (S22).

  As shown in FIG. 9, the remaining amount of toner is visually displayed as a bar graph on the volatile display 23, and also displayed as a numerical value.

  Thereafter, the CPU 44 turns off the remaining amount display flag (S23) and ends the main body display process.

  If the remaining amount display flag is off (S21: NO), it indicates that the display on the non-volatile display 33 of the process cartridge 3 has not been rewritten, so the CPU 44 does not rewrite the display on the volatile display 23, The display process ends.

<Processing during installation>
In a state where the process cartridge 3 is not mounted at the cartridge mounting position of the apparatus main body 2, the CPU 44 executes the mounting process shown in FIG.

  In the mounting process, the CPU 44 determines whether or not the process cartridge 3 is mounted at the cartridge mounting position (S31). The method for determining whether or not the process cartridge 3 is mounted at the cartridge mounting position is as described above.

  When the CPU 44 determines that the process cartridge 3 is mounted at the cartridge mounting position (S31: YES), it reads the cartridge ID from the graphic chip 52 of the process cartridge 3 (S32).

  Then, the CPU 44 determines whether or not the read cartridge ID is already stored in the RAM 43 (S33).

  When the cartridge ID is not stored in the RAM 43 (S33: NO), that is, when a new process cartridge 3 is mounted at the cartridge mounting position of the apparatus main body 2, the CPU 44 sets the cartridge ID of the process cartridge 3 to the process cartridge. 3 is registered in the RAM 43 in association with the remaining amount of toner (S34). The cartridge ID and the remaining amount of toner are registered in a nonvolatile memory included in the RAM 43, or registered in the RAM 43 (volatile memory) and protected by battery backup.

  Thereafter, the CPU 44 executes a display rewriting process (S35) and ends the mounting process.

  On the other hand, if the cartridge ID is already stored in the RAM 43 from the graphic chip 52 of the process cartridge 3 (S33: YES), the CPU 44 skips step S34, executes the display rewriting process (S35), and is attached. End time processing.

  By executing the mounting process, the remaining amount of toner in the process cartridge 3 is displayed on the nonvolatile display 33 and the volatile display 23 in response to the process cartridge 3 being mounted at the cartridge mounting position of the apparatus main body 2. Can do.

<Waiting processing>
When the process cartridge 3 is mounted at the cartridge mounting position of the apparatus main body 2 and printing is not being performed, the CPU 44 executes the standby processing shown in FIG. 11 at a constant cycle.

  In the standby process, the CPU 44 determines whether or not a specified time has elapsed since the previous execution of the display rewriting process (S41).

  When the specified time has elapsed since the previous execution of the display rewriting process (S41: YES), the CPU 44 executes the display rewriting process again (S42).

  When the display rewriting process is executed again, the CPU 44 resets a timer for measuring an elapsed time from the previous execution of the display rewriting process (S43), and ends the waiting process.

  When the specified time has not elapsed since the previous execution of the display rewriting process (S41: NO), the CPU 44 ends the waiting process without executing the display rewriting process, and the process from the previous execution of the display rewriting process. Continue measuring elapsed time.

  By executing this standby processing, each display on the non-volatile display 33 and the volatile display 23 can be rewritten with new contents at least every time the specified time elapses.

<Processing during printing>
During execution of printing by the printer 1, the CPU 44 executes processing during printing shown in FIG.

  In the printing process, the CPU 44 detects the remaining amount of toner in the process cartridge 3 (S51). For example, the toner remaining amount is detected by counting the number of black pixels printed on the sheet, estimating the toner consumption amount from the count value, and obtaining the remaining amount of the process cartridge 3 from the estimated consumption amount. Alternatively, a toner sensor that emits sensor light from the remaining amount detection window provided in the developing case 32 of the process cartridge 3 into the developing case 32 and detects the remaining amount of toner from the light receiving time of the sensor light is provided. It may be provided.

  Then, the CPU 44 determines whether or not a specified amount of toner has been consumed (S52). The prescribed amount is set to 1% of the full amount of toner accommodated in the process cartridge 3, for example.

  When a specified amount of toner is consumed by printing (S52: YES), the CPU 44 updates the remaining amount of toner stored in the RAM 43 in association with the cartridge ID of the process cartridge 3 (S53).

  Thereafter, the CPU 44 executes a display rewriting process (S54) and ends the printing process.

  When the specified amount of toner is not consumed (S52: NO), the CPU 44 ends the printing process without executing the update of the remaining amount of toner stored in the RAM 43 and the display rewriting process, and then printing. A new process is executed.

  When the prescribed amount of toner is consumed by executing the printing process, the remaining amount of toner stored in the RAM 43 is updated, and each display on the nonvolatile display 33 and the volatile display 23 is rewritten with new contents. Can do.

<Cover open processing>
In a state where the process cartridge 3 is mounted at the cartridge mounting position of the apparatus main body 2, the CPU 44 executes the cover open process shown in FIG.

  In the cover open process, the CPU 44 determines whether or not the front cover 14 (see FIG. 1) has been displaced from the closed position to the open position (cover open) (S61).

  The displacement of the front cover 14 from the closed position to the open position can be detected from the output signal of the cover sensor 46. That is, the CPU 44 detects that the front cover 14 has been displaced from the closed position to the open position in response to the output signal of the cover sensor 46 being switched from the off signal to the on signal.

  When the front cover 14 is displaced from the closed position to the open position (S61: YES), the CPU 44 executes a display rewriting process (S62) and ends the cover open process.

  When the front cover 14 is not displaced from the closed position to the open position (S62: NO), the CPU 44 ends the cover open process without executing the display rewriting process, and then newly executes the cover open process.

  By executing the cover opening process, each display on the non-volatile display 33 and the volatile display 23 can be rewritten with new contents in accordance with the opening of the front cover 14.

<Power off process>
Further, in a state where the process cartridge 3 is mounted at the cartridge mounting position of the apparatus main body 2, the CPU 44 executes the power-off process shown in FIG. 14 at a constant cycle.

  In the power-off process, the CPU 44 determines whether or not the printer 1 is turned off by pressing the power key included in the operation key 45 (S71).

  When the power is turned off (S71: YES), the CPU 44 executes a display rewriting process (S72) and ends the power off process.

  When the power is not turned off (S71: NO), the CPU 44 determines whether or not the power cord extending from the apparatus main body 2 is pulled out from the outlet of the external power source (for example, commercial AC power source) (S73).

  When the power cord is pulled out from the outlet (S73: YES), the CPU 44 executes a display rewriting process (S72) and ends the power off process.

  When both the power-off by pressing the power key and the removal of the power cord from the outlet are not performed (S73: NO), the CPU 44 ends the power-off process without executing the display rewriting process.

  By executing the power-off process, each display on the non-volatile display 33 and the volatile display 23 can be rewritten with new contents in response to turning off the power by pressing the power key or pulling out the power cord from the outlet.

<Effect>
As described above, the process cartridge 3 containing the toner is detachably mounted at the cartridge mounting position set in the apparatus main body 2. The process cartridge 3 is provided with a non-volatile display 33 capable of maintaining image display without supplying power. The non-volatile display 33 displays the remaining amount of toner stored in the process cartridge 3.

  Thereby, even when the printer 1 is powered off, the remaining amount of toner is displayed on the non-volatile display 33, so that the user can easily and accurately grasp the remaining amount of toner from the display.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, the storage box is not limited to the process cartridge 3 and the developing housing 32, and may be a toner box. The toner box is a cartridge that accommodates toner and replenishes toner to a developing device including a developing roller. The toner box may be configured to be directly detachable from the apparatus main body 2 or may be configured to be detachably mounted to the process cartridge 3.

  Although a monochrome laser printer has been taken up as an example of the image forming apparatus, the present invention can also be applied to a color laser printer, and is not limited to a laser printer, and forms an image on a sheet by an inkjet method. An inkjet printer may be used. When the present invention is applied to an ink jet printer, an ink cartridge containing ink is an example of a storage box.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

DESCRIPTION OF SYMBOLS 1: Printer 2: Apparatus main body 3: Process cartridge 13: Opening part 14: Front cover 23: Volatile display 33: Non-volatile display 36: Lock member 43: RAM
44: CPU
51: IC chip 52: Graphic chip 62: Main body side circuit 63: Cartridge side circuit 75, 76, 77, 95, 96, 97: Terminal 85: First resistor 105: Second resistor

Claims (15)

An image forming apparatus for forming an image on a sheet,
The device body;
A storage box that is detachably mounted at a mounting position set in the apparatus main body and stores a printing agent used for image formation;
A non-volatile display attached to the housing box and capable of maintaining image display without receiving power;
A control unit provided in the apparatus main body,
The said control part is an image forming apparatus which performs the display process which displays the information regarding the residual amount of the printing agent accommodated in the said storage box on the said non-volatile display. The image forming apparatus according to claim 1,
A lock member that displaces between a lock position that prohibits removal of the storage box from the mounting position and a lock release position that permits release of the storage box from the mounting position;
The said control part is an image forming apparatus which positions the said lock member in the said lock position during rewriting of the display of the said non-volatile display by the said display process. The image forming apparatus according to claim 1, wherein:
The said control part is an image forming apparatus which performs the said display process according to the use condition of the printing agent accommodated in the said storage box, and rewrites the display content of the said non-volatile display. The image forming apparatus according to claim 3, wherein
The printing agent is toner;
The control unit executes the display process each time the remaining amount of toner stored in the storage box decreases by 1% with respect to the maximum amount of toner stored in the storage box, and the nonvolatile display An image forming apparatus that rewrites the display content. The image forming apparatus according to any one of claims 1 to 4,
A cover that is attached to the apparatus main body and that opens and closes an opening through which the storage box passes when attached to and detached from the mounting position;
The image forming apparatus, wherein the control unit executes the display process in response to the opening of the cover. An image forming apparatus according to any one of claims 1 to 5,
The image forming apparatus, wherein the control unit executes the display process in response to power supply to the control unit being cut off. The image forming apparatus according to any one of claims 1 to 6,
A power cord extending from the apparatus body and connected to an external power source;
The image forming apparatus, wherein the control unit executes the display process in response to the power cord being disconnected from the external power source. An image forming apparatus according to any one of claims 1 to 7,
The control unit is configured to execute the display process again in response to a lapse of a predetermined time from the execution of the display process. The image forming apparatus according to claim 8, wherein
The control unit executes the display process in response to the storage box being mounted at the mounting position, and thereafter, in response to a lapse of a certain time from execution of the display process, the display An image forming apparatus that executes processing again. An image forming apparatus according to any one of claims 1 to 9,
An image forming apparatus, further comprising: an IC chip attached to the storage box and connected to be communicable with the control unit in a state where the storage box is mounted at the mounting position. The image forming apparatus according to claim 10, wherein
A storage unit provided in the apparatus main body;
The IC chip stores identification information of the storage box,
The controller is
Reading the identification information of the storage box from the IC chip by communication with the IC chip,
An image forming apparatus that associates identification information read from the IC chip with a remaining amount of printing agent stored in the storage box and stores the information in the storage unit. The image forming apparatus according to claim 10, wherein
A first terminal provided in the apparatus body, a first terminal, a second terminal to which a constant voltage is applied, a third terminal connected to the ground, and a first resistor interposed between the first terminal and the third terminal A main body side circuit including:
A fourth terminal, a fifth terminal, and a sixth terminal that are provided in the storage box and are connected to the first terminal, the second terminal, and the third terminal, respectively, in a state where the storage box is mounted at the mounting position. The image forming apparatus further includes a cartridge side circuit including a second resistor interposed between the fourth terminal and the fifth terminal. An image forming apparatus according to any one of claims 1 to 12,
A volatile display that is provided in the apparatus main body and cannot maintain image display without power supply;
The said control part is an image forming apparatus which performs the main body display process which displays the information regarding the residual amount of the printing agent accommodated in the said storage box on the said volatile display. The image forming apparatus according to claim 13,
The control unit executes the main body display process in synchronization with the display process, and causes the volatile display to display information on the remaining amount displayed on the nonvolatile display in the display process in the main body display process. , Image forming apparatus. The image forming apparatus according to claim 13 or 14,
On the non-volatile display, the remaining amount of the printing agent stored in the storage box is displayed numerically,
The volatile display is an image forming apparatus in which the remaining amount of the printing agent stored in the storage box is displayed as a numerical value and a bar graph.

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