JP2010044265A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that can prevent stopping of printing and exchanging a toner cartridge even when the residual amount of toner is sufficient due to a detection error of a toner residual amount detection mechanism. <P>SOLUTION: The image forming apparatus has: a storage element for storing the amount of developer in a developer container in integration process number of dots; a counting section for counting the printing process number of dots for the printing data which is received from the same apparatus; the developer container for containing the developer; an agitating member that is rotatably provided inside the developer container; a sensor member for measuring a rotational cycle of the agitating member; and a control section for controlling the storage element, the sensor member and the counting section under a given condition. The control section detects that the amount of the developer is a fixed value or less by the sensor member, and when the amount of the developer becomes a threshold value or less based on the integration process number of dots and the printing process number of dots, information is given that prompts the exchange of the developer container. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is used in an image forming apparatus that develops an electrostatic latent image formed on a latent image carrier on the basis of image data input from a host device or the like, visualizes it, prints it on a recording medium, and outputs it. The present invention relates to replacement control of a toner cartridge that is a developer container.

  Conventionally, in image forming apparatuses such as printers, copiers, facsimile machines, and electrophotographic color recording apparatuses, the surface of a latent image carrier uniformly charged by a charging member is exposed by an exposure source to form an electrostatic latent image. The toner image is formed by developing the electrostatic latent image with a developing member supplied with toner as a developer from the toner supply member, and then the toner image is transferred to a recording medium and fixed.

  Here, a toner cartridge is attached to the developing unit in the image forming apparatus, and toner is supplied to the developing unit. In addition, since the image quality cannot be maintained when the toner remaining amount in the toner holding space inside the developing unit falls below a certain value, stirring that measures the remaining amount of toner while stirring the toner provided in the developing unit. There is an image forming apparatus that detects the remaining amount of toner based on the rotation cycle of a member (see, for example, Patent Document 1).

JP 2006-23537 A

  However, the above-described configuration largely depends on the powder characteristics of the toner, and even if the remaining amount of toner stored in the apparatus is the same, for example, the toner may be removed due to variations in toner fluidity. Since the rotation period of the stirring member that measures the remaining amount of toner while stirring is changed, there is a problem that an error in detecting the remaining amount of toner becomes large.

  Accordingly, in view of the above technical problem, the present invention solves the problem that printing is stopped due to a detection error of the toner remaining amount detection mechanism even though the remaining amount of toner in the apparatus is sufficient, and the toner An object of the present invention is to provide an image forming apparatus capable of preventing the toner cartridge from being replaced while the toner is remaining in the cartridge.

  In order to solve the above-described problems, an image forming apparatus according to the present invention includes a storage element that stores the amount of developer stored in a developer storage unit as the number of accumulated processing dots, and printing of print data received from a host device. A measuring unit that measures the number of processed dots, a developer containing unit that contains the developer supplied from the developer containing unit, a stirring member that is rotatably provided inside the developer containing unit, and A sensor member that measures a rotation period of the stirring member; and a control unit that controls the storage element, the sensor member, and the measurement unit under a predetermined condition, and the control unit is configured to control the developer by the sensor member. When it is detected that the developer inside the container is below a certain value, the developer stored in the developer container based on the number of accumulated processing dots and the number of printing processing dots is below a threshold value. in front And performing a notification to urge the replacement of the developer storage device.

  According to the image forming apparatus of the present invention, in addition to the toner amount detection mechanism composed of hardware components, the dot filling amount based on the toner filling amount is provided as a criterion for determining the replacement timing of the toner cartridge, so that the toner can be printed. It is possible to prevent the problem of excessive or insufficient deficiency.

  Hereinafter, a preferred embodiment of the image forming apparatus of the present invention will be described with reference to the drawings. The image forming apparatus of the present invention is not limited to the following description, and can be appropriately changed without departing from the gist of the present invention.

[First Embodiment]
First, the image forming apparatus 1 of the present embodiment will be described. FIG. 1 shows a configuration diagram of the image forming apparatus 1. The image forming apparatus 1 prints an image on the recording medium 3 based on the image information.

  The image forming apparatus 1 takes out the recording medium 3 from the paper feed cassette 11 and conveys the recording medium 3 to a transfer roller 31 provided in the transfer unit 30, based on image information received from the upper apparatus 100. The developing unit 20 that forms a toner image, the transfer unit 30 that transfers the toner image formed by the developing unit 20 to the recording medium 3, and the toner image transferred to the recording medium 3 by the transfer unit 30 is melted and pressurized to be fixed. And a discharge unit 50 that discharges the recording medium 3 discharged from the fixing unit 40 to the stacker 55. In the image forming apparatus 1, a control board 60 that performs control and the like related to the replacement of the toner cartridge 24 is provided. The sheet conveyance path 2 is a substantially S-shaped path through which the recording medium 3 is conveyed in the paper feeding unit 10, the developing unit 20, the transfer unit 30, the fixing unit 40, and the discharge unit 50. Hereinafter, the respective components disposed in the paper conveyance path 2 will be specifically described with reference to FIGS. 1 and 2.

  The paper supply unit 10 takes out the recording medium 3 from the paper supply cassette 11 and conveys the recording medium 3 to a transfer roller 31 provided in the transfer unit 30. The paper feed unit 10 includes a hopping roller 12, a pressure roller 13, and a registration roller 14. Hereinafter, each component constituting the sheet feeding unit 10 will be described in detail. The recording medium 3 is a recording paper of a predetermined size for developing monochrome or color image information, and is generally made of paper such as recycled paper, glossy paper, and high-quality paper, or an OHP film. The paper feed cassette 11 stores a plurality of recording media 3 in a stacked manner, and supplies the recording media 3 into the image forming apparatus 1 when printing is started. The paper feed cassette 11 is configured to be detachable from the image forming apparatus 1. Further, the hopping roller 12 rotates in a state of being pressed against the recording medium 3 stacked and accommodated in the paper feeding cassette 11 to thereby remove the recording medium 3 taken out from the paper feeding cassette 11 one by one, which will be described later. 13 and the registration roller 14. The pressure roller 13 and the registration roller 14 are arranged to face each other so as to sandwich the conveyed recording medium 3, and by rotating the pressure roller 13 pressed by the registration roller 14, the pressure roller 13 and the registration roller 14 are inclined. The recording medium 3 is conveyed to a transfer roller 31 provided in a transfer unit 30 (to be described later) while performing takeoff or the like.

  The developing unit 20 forms a toner image based on the image information received from the host device 100. FIG. 2 shows a configuration diagram of the developing unit 20. The developing unit 20 includes a photosensitive drum 21 that carries an electrostatic latent image based on image information, a charging member 22 that stores charges on the surface of the photosensitive drum 21, and light corresponding to the image information. An LED head 23 provided on the main body of the image forming apparatus 1 that irradiates the surface, a toner cartridge 24 that is a developer container that contains toner as a developer, and a toner supply member 25 that supplies toner to the developing member 26 The developing member 26 that develops the electrostatic latent image on the surface of the photosensitive drum 21 with toner, the developing blade 27 that regulates the thickness of the toner carried on the developing member 26 to be uniform, and the photosensitive drum 21 The cleaning member 28 is configured to remove residual toner. The developing unit 20 is detachably attached to the image forming apparatus 1.

  Further, the developing unit 20 has, as the remaining toner amount detecting mechanism according to the present invention, an agitating member 70 for agitating the toner in the toner holding space 29 that is a developer accommodating portion and detecting the remaining amount, and the agitating member 70. , A bearing 72 connected to the stirring member 70, a sensor 73 for detecting the remaining amount of toner in the toner holding space 29, and a similar method for detecting the remaining amount of toner. The photocoupler 74, a storage element 90 which will be described later with reference to FIGS. 5 and 6 and the like for storing the number of accumulated processing dots, and a constituent member comprising each member connecting the control board 60 and the storage element 90. . Hereinafter, the constituent members constituting the developing unit 20 will be specifically described with reference to FIG. 2 in addition to FIG. 1 for the constituent members that form toner images based on image information. Thereafter, each component constituting the toner remaining amount detecting mechanism according to the present invention will be described in detail with reference to FIGS. 2 to 9 as appropriate in addition to FIG.

  The photosensitive drum 21 in the developing unit 20, which is a constituent member that forms a toner image based on image information, is a latent image carrier on which a developer image is formed, and carries an electrostatic latent image based on the image information. In order to do so, it is possible to store charges on the surface. The photosensitive drum 21 includes a cylindrical portion and is provided so as to be rotatable. The photosensitive drum 21 has a gear (not shown) on one side of the photosensitive drum 21, and is rotationally driven by a rotating gear (not shown) in the image forming apparatus 1 via a rotating gear. In such a photosensitive drum 21, a photosensitive layer made of a photoconductive layer and a charge transport layer is formed on a conductive base layer made of aluminum or the like. Further, the charging member 22 applies a predetermined positive voltage or negative voltage to the surface of the photosensitive drum 21 using a power source (not shown), so that the charge is uniformly stored on the surface of the photosensitive drum 21. Is for. The charging member 22 is provided so as to be rotatable while contacting the surface of the photosensitive drum 21 with a constant pressure. Such a charging member 22 is configured by covering a conductive metal shaft with a semiconductive rubber such as silicone. The LED head 23 is configured to be able to form an electrostatic latent image on the surface of the photosensitive drum 21 by irradiating the surface of the photosensitive drum 21 with light corresponding to image information. It is provided in the main body of the image forming apparatus 1 so as to be positioned above the body drum 21. Such an LED head 23 is composed of a combination of a plurality of LED elements, a lens array, and LED driving elements.

  The toner cartridge 24 in the developing unit 20, which is a component that forms a toner image based on image information, is a developer container that stores toner as a developer, and is mounted above the toner supply member 25. Is done. Further, the toner cartridge 24 is formed of a rectangular portion having, for example, a substantially circular side surface and long in the direction perpendicular to the conveyance direction of the recording medium 3A. The toner cartridge 24 is configured to be detachable so that it can be replaced when the toner is consumed by printing. The toner cartridge 24 has a toner storage space 24D in the toner cartridge 24. After the toner cartridge 24 is mounted on the developing unit 20, when a later-described lever 24 </ b> C provided on the toner cartridge 24 is rotated in a predetermined direction, a shutter (not shown) provided in the toner cartridge 24 is opened. The toner stored in the toner storage space 24 </ b> D passes through the opened shutter and is supplied to the toner holding space 29 that is a developer accommodating portion in the developing unit 20. The toner supply member 25 is provided so as to supply toner to the developing member 26 by contacting the developing member 26 while rotating. The toner supply member 25 is rotationally driven by being driven by a gear disposed on a developing member 26 (described later) via an idle gear (not shown) fixed to the shaft of the toner supply member 25 and driven. . Such a toner supply member 25 is constituted by, for example, covering a conductive metal shaft with rubber added with a foaming agent. Further, the developing member 26 is driven to rotate by being driven by a gear disposed on the photosensitive drum 21 via a gear (not shown) fixed to the shaft of the developing member 26. The developing member 26 conveys the toner to the photosensitive drum 21 while rotating, and develops the electrostatic latent image formed on the surface of the photosensitive drum 21 with the toner.

  The developing member 26 is rotationally driven by being driven by a gear disposed on the photosensitive drum 21 via a gear (not shown) fixed to the shaft of the developing member 26 and driven. Such a developing member 26 is formed of a cylindrical portion, and is configured by covering a conductive metal shaft with a semiconductive urethane rubber material or the like. Further, the developing blade 27 is provided so that a tip portion of the developing blade 27 is in contact with the surface of the developing member 26, and scrapes off the toner exceeding a certain amount while being supplied from the toner supplying member 25 to the surface of the developing member 26. Thus, the thickness of the toner formed on the surface of the developing member 26 is regulated to be always uniform. Such a developing blade 27 is formed of a plate-like elastic member such as stainless steel. The cleaning member 28 is formed of a cylindrical portion made of a rubber material or the like, and removes toner remaining on the photosensitive drum 21 after the toner image formed on the photosensitive drum 21 is transferred to the recording medium 3A. In addition, it is disposed so as to contact the surface of the photosensitive drum 21 while rotating.

  Next, the stirring member 70 in the developing unit 20, the sensor 73, the photocoupler 74, and the like, which are constituent members of the toner remaining amount detection mechanism according to the present invention, will be described with reference to FIGS. To do. FIG. 2 is a configuration diagram of the developing unit 20, and FIG. 3 is a perspective view of the stirring member 70. The stirring member 70 is disposed in a lower portion of the toner holding space 29 provided in the developing unit 20 and at a position adjacent to the toner supply member 25. The agitating member 70 is a toner agitating member for agitating the toner in the toner holding space 29, and is a toner remaining amount detecting member for detecting the remaining amount of toner in the toner holding space 29. Therefore, first, a structure related to toner stirring for stirring the toner in the toner holding space 29 will be described, and then, a structure related to toner remaining amount detection for detecting the remaining amount of toner in the toner holding space 29 will be described. .

  First, a structure related to toner stirring for stirring the toner in the toner holding space 29 will be described. The stirring member 70 is made of a rod-shaped iron-based material and is formed in a U-shape. Such a stirring member 70 is driven to rotate about the rotation center part 70A provided at both ends of the U-shaped shape as a central axis, so that the toner is held by the stirring part 70B provided at the front end of the U-shaped shape. The toner in the space 29 is agitated. Further, gears 71 and bearings 72 are connected to the rotation center portions 70 </ b> A at both ends of the stirring member 70, respectively. The agitating member 70 is driven to rotate by receiving a drive from a gear disposed in the toner supply member 25 via a gear 71 connected to one end of the agitating member 70. The bearing 72 connected to the other end of the stirring member 70 is driven by the rotation of the gear 71.

  Next, a structure related to toner remaining amount detection for detecting the remaining amount of toner in the toner holding space 29 will be described. The gear 71 has a drive transmission surface 71 </ b> A that abuts on the stirring member 27 and is driven to rotate. The drive transmission surface 71 </ b> A is provided with a notch that allows a free fall due to weight in a part of the rotational operation related to the stirring member 70. In addition, a sensor 73 having a substantially bar shape, which is a member for detecting the remaining amount of toner, is disposed below the toner holding space 29 and in the vicinity of the stirring member 70. Such a sensor 73 is provided so as to be rotationally driven within a certain range with the rotation center portion 73A as a central axis, and a response portion 73B having a certain magnetic force, which is one end portion of the sensor 73, and the other end portion of the sensor 73. It has the detection part 73C which is. A photocoupler 74, which is a member related to toner remaining amount detection, is disposed below the sensor 73. Such a photocoupler 74 has a structure in which signal light is emitted from one end and received by a detector disposed at the other end facing the photocoupler 74.

  In the configuration described above, when the stirring member 70 rotates about the rotation center portion 70A as the central axis, the response portion 73B that is one end portion of the sensor 73 is attracted to the stirring portion 70B that is the tip portion of the stirring member 70. Specifically, as the stirring member 70 rotates, when the stirring unit 70B comes close to the response unit 73B of the sensor 73 within a certain range in the rotation path of the stirring unit 70B of the stirring member 70, the sensor 73 rotates. By rotating around the center portion 73 </ b> A, the response portion 73 </ b> B of the sensor 73 is attracted to the stirring portion 70 </ b> B of the stirring member 70. Further, if the distance between the response portion 73B of the sensor 73 and the stirring portion 70B of the stirring member 70 is more than a predetermined interval in the rotation path of the stirring portion 70B of the stirring member 70 with the rotation operation of the stirring member 70, the sensor 73 Rotates around the rotation center portion 73A, so that the response portion 73B returns to its original position due to its own weight. The detection unit 73C, which is the other end of the sensor 73, is separated from the photocoupler 74 while the response unit 73B of the sensor 73 is attracted to the stirring unit 70B of the stirring member 70. The signal light from the photocoupler 74 is not shielded. Similarly, the detection unit 73C, which is the other end of the sensor 73, causes the detection unit 73C to enter the photocoupler 74 while the response unit 73B of the sensor 73 is not attracted to the stirring unit 70B of the stirring member 70. As a result, the signal light from the photocoupler 74 is shielded. The signal light is input to the control board 60 through a wiring (not shown). When the signal light of the photocoupler 74 is not shielded by the detection unit 73C, the signal light is input to the control board 60 as a LOW output time by a wiring (not shown). In the control board 60, when the output of the LOW output time from the photocoupler 74 is continuously detected more than a predetermined number of times within a predetermined time, the toner is recognized as being low, and the control process described later is started. To do.

  Specifically, regarding the structure relating to the toner remaining amount detection for detecting the remaining amount of toner in the toner holding space 29, the case where the remaining amount of toner in the toner holding space 29 is small and the remaining amount of toner in the toner holding space 29. A description will be given for each case when the amount is large. First, a case where the toner remaining amount in the toner holding space 29 is small will be described. The stirring member 70 in the toner holding space 29 is rotated about the rotation center portion 70A as a central axis by being urged by a gear 71 that is rotationally driven at a constant speed in the clockwise direction shown in FIG. However, when the stirring portion 70B of the stirring member 70 is urged from the gear 71 beyond the 0 o'clock angle indicated by the clock, the rotation center portion 70A of the stirring member 70 is detached from the drive transmission surface 71A of the gear 71. As a result, the stirring member 70 freely falls while rotating to the position where the toner is located around the rotation center portion 70A. It should be noted that the response unit 73B of the sensor 73 is attracted to the stirring unit 70B of the stirring member 70 and the detection unit 73C is detached from the photocoupler 74 only in a certain region after the stirring member 70 freely falls while rotating. Thus, the signal light of the photocoupler 74 is not shielded. Accordingly, the smaller the remaining amount of toner in the toner holding space 29, the longer the staying time in the fixed area after the stirring unit 70B of the stirring member 70 is free-falling while rotating, so that the signal light is blocked by the photocoupler 74. The time that will not be extended. Next, a case where the toner remaining amount in the toner holding space 29 is large will be described. As the remaining amount of toner in the toner holding space 29 increases, the time for the stirring unit 70B of the stirring member 70 to fall freely while rotating freely decreases, so that the signal light is blocked by the photocoupler 74. Longer time. As described above, the remaining amount of toner in the toner holding space 29 can be measured by converting the signal light to a LOW output time that is not shielded by the photocoupler 74 and detecting it by the control board 60.

  Next, with respect to the toner cartridge 24 in the developing unit 20 and the storage element 90 provided in the toner cartridge 24, which are constituent members of the toner remaining amount detecting mechanism according to the present invention, FIGS. The description will be given with reference.

  A perspective view of the toner cartridge 24 is shown in FIG. Further, FIG. 5 shows a top view of the substrate 92 to which the storage element 90 provided in the toner cartridge 24 is joined, FIG. 6 shows a side view, and FIG. 7 shows a bottom view. Further, FIG. 8 shows a perspective view of the developing unit 20 with the toner cartridge 24 attached / detached, and FIG. 9 shows a perspective view of the back surface of the developing unit 20. A pocket portion 24 </ b> A is integrally formed with the toner cartridge 24 at the end surface in the longitudinal direction of the toner cartridge 24. In the pocket portion 24 </ b> A, a memory element 90 and a substrate 92 having a contact 91 described later that is electrically connected to the memory element 90 are mounted. Similarly, a regulation rib 24 </ b> B is integrally formed with the toner cartridge 24 at the end surface in the longitudinal direction of the toner cartridge 24. The restriction rib 24B engages with a rib 80 formed integrally with the housing of the developing unit 20 when the toner cartridge 24 is mounted on the developing unit 20. Similarly, a lever 24C is disposed at the other end of the toner cartridge 24 where the pocket portion 24A is formed. When the lever 24C is rotated in a predetermined direction after the toner cartridge 24 is mounted on the developing unit 20, a shutter (not shown) disposed in the toner cartridge 24 is opened, and the toner in the toner cartridge 24 is developed. The toner cartridge 24 is supplied to the unit 20 and fixed to the developing unit 20. In this way, by rotating the lever 24C in a predetermined direction with the regulating rib 24B and the rib 80 engaged, the toner cartridge 24 is lifted upward to regulate the toner cartridge 24 from being detached from the developing unit 20. .

  In addition, the memory element 90 is electrically connected to a contact 91 provided on the back side of the substrate 92 through a through hole provided on the substrate 92 after being mounted on the substrate 92. The developing unit 20 is provided with connectors 93 </ b> A and 93 </ b> B corresponding to contacts 91 provided on the substrate 92 mounted on the toner cartridge 24. The connectors 93A and 93B are respectively connected to the contacts 95 shown in FIG. Further, the contact 95 is connected to the control board 60 by a wire (not shown) by a connector 96 shown in FIG. 2 disposed at a position corresponding to the contact 95. The connector 93 provided in the developing unit 20 is connected to the contact 95 via a substrate and a wire (not shown). The structure of the memory element 90 will be described later.

  Next, the transfer unit 30 provided in the image forming apparatus 1 will be described. The transfer unit 30 transfers the toner image formed by the developing unit 20 to the recording medium 3. The transfer unit 30 includes a transfer roller 31. The transfer roller 31 is positioned below the photosensitive drum 21 and is rotatably provided in a state where the recording roller 3 is in contact with the transfer roller 31 and the photosensitive drum 21. The transfer roller 31 is supplied with a bias voltage having a polarity opposite to that of the toner and transfers the toner image formed on the surface of the photosensitive drum 21 to the recording medium 3.

  The fixing unit 40 fixes the toner image transferred to the recording medium 3 by the transfer unit 30 by melting and pressing. The fixing unit 40 includes a fixing roller 41 and a pressure roller 42. Hereinafter, each component constituting the fixing unit 40 will be specifically described. The fixing roller 41 and the pressure roller 42 are disposed to face each other with the recording medium 3 conveyed from the transfer roller 31 interposed therebetween, and fix the toner image transferred to the recording medium 3. Specifically, the fixing roller 41 and the pressure roller 42 have elastic surfaces and are formed from a cylindrical portion, and a heater such as a halogen lamp is disposed inside the cylindrical portion. The fixing roller 41 and the pressure roller 42 melt the toner image adhering to the recording medium 3 only with a weak electrostatic force, and then fix the toner image to the recording medium 3 by the pressure of the pressure roller 42. Let The pressure roller 42 is driven by being biased by the rotation of the fixing roller 41.

  The discharge unit 50 discharges the recording medium 3 discharged from the fixing unit 40 to the stacker 55. The discharge unit 50 includes a transport roller 51, a transport roller 52, a discharge roller 53, a discharge roller 54, and a stacker 55. Hereinafter, each structural member which comprises the discharge part 50 is demonstrated. The conveyance roller 51 and the conveyance roller 52 are arranged to face each other so as to sandwich the recording medium 3 conveyed from the fixing unit 40, and the conveyance roller 52 is rotated by the rotation of the conveyance roller 51, thereby recording. The medium 3 is conveyed to the discharge roller 53 and the discharge roller 54. The discharge roller 53 and the discharge roller 54 are arranged to face each other so as to sandwich the recording medium 3 conveyed from the conveyance roller 51 and the conveyance roller 52, and the discharge roller 54 is driven by the rotation of the discharge roller 53. The recording medium 3 is discharged to the stacker 55 by rotating. The stacker 55 is a storage space for storing and storing the recording medium 3B on which image information is printed.

  Next, control of the image forming apparatus 1 will be described. FIG. 10 is a block diagram showing the configuration of the image forming apparatus 1. Hereinafter, a specific description will be given with reference to FIG.

  The image forming apparatus 1 includes a control unit 110 including a microprocessor, a comparison unit 110A, a determination unit 110B, an input / output port, and the like. Image information is obtained by issuing a command from the control unit 110 to the image forming apparatus 1. Is printed on the recording medium 3 and a series of processes for notifying the replacement timing of the toner cartridge 24 is controlled. The control unit 110 is connected to the I / F unit 111, the display panel 112, the motor 113, the voltage setting unit 114, the counting unit 115 as a measurement unit, the timer 116, the storage element 90, the LED head 23, and the photocoupler 74. Connected to. Hereinafter, each component member mutually connected with the control part 110 is demonstrated concretely. However, the description of each component described above with reference to FIGS. 1 to 10 is omitted.

  110 A of comparison parts provided in the control part 110 compare the count value mentioned later, the LOW output time of the photocoupler 74, and a threshold value. In addition, the determination unit 110B provided in the control unit 110, based on the count value, the LOW output time, the comparison result with the threshold value, and the like, the preparation for the replacement related to the toner cartridge 24, whether or not to stop printing, and the like. Make a decision. Further, regarding control of the image forming apparatus 1, an I / F unit (interface unit) 111 receives print data, a control command, and the like from a host device 100 such as a host computer. The display panel 112 is a display unit (not shown) provided in the image forming apparatus 1, and based on a command from the control unit 110, the printing state, printing conditions, and toner cartridge 24 of the image forming apparatus 1 are displayed. A warning or the like related to the replacement and error is notified to the user of the image forming apparatus 1 by displaying it. In addition, the motor 113 rotates and drives each drive member and each conveyance member in the paper feed unit 10, the developing unit 20, the transfer unit 30, the fixing unit 40, and the discharge unit 50 based on a command from the control unit 110. .

  The voltage setting unit 114 connected to the control unit 110 sets a voltage value to be applied to each drive member and each transport member based on a command from the control unit 110. The counting unit 115 is a measuring unit that counts the number of dots to be exposed by the LED head 23 from the printing data received from the host device 100 such as a host computer based on a command from the control unit 110, and then performs control. The unit 110 accumulates the accumulated process dot number D1, the accumulated process dot number D2, and the accumulated process dot number D3, which will be described later, compares the process dot value with each threshold value, and each accumulated process dot number to the storage element 90. Store. Further, the timer 116 controls the timing for controlling each component in the image forming apparatus 1 based on a command from the control unit 110. In addition, the storage element 90 stores the above-described threshold, the accumulated process dot number D1, the accumulated process dot number D2, and the accumulated process dot number D3 based on a command from the control unit 110.

  Next, a printing operation according to the image forming apparatus 1 of the present embodiment will be described. FIG. 11 is a flowchart showing the flow of the printing operation according to the image forming apparatus 1.

  The control unit 110 that has received the print data from the host apparatus 100 such as a host computer starts the sequence related to the printing operation by driving the image generating apparatus 1 and starting printing. Next, when the printing process is performed, the counting unit 115 counts the number of printing process dots to be exposed by the LED head 23 from the printing data received from the higher-level device 100 based on a command from the control unit 110 and then integrates it. Add to the number of processed dots D1. Note that the control substrate 60 provided in the image forming apparatus 1 performs integration processing after the toner cartridge 24 that is read and stored in the storage element 90 when the toner cartridge 24 is attached to the developing unit 20 is attached. The number of dots D1 is stored (S1). Next, the count unit 115 writes the cumulative processing dot number D1 in the storage element 90 mounted on the toner cartridge 24. The accumulated processing dot number D1 is replaced by reading the accumulated processing dot number written in the storage element 90 when the identification information written in the storage element 90 is new, and the identification information is the same as the conventional one. In this case, the number of dots is sequentially accumulated according to the printing process. (S2).

  A command is issued from the control unit 110 to the control board 60 to check the LOW output time detected by the photocoupler 74 provided in the developing unit 20, and if the threshold is 300 msec / pulse or more (Yes), the procedure 5 If it is less than 300 msec / pulse (No), proceed to step 4 (S3). Next, when the procedure proceeds to step 4, the counting unit 115 does not add the accumulated processing dot number D2, ends the sequence, and waits until the next printing is executed (S4). Next, when the procedure proceeds to step 5, the counting unit 115 adds 1 to the cumulative processing dot number D2 and writes the dot number in the storage element 90 (S5). Next, the counting unit 115 checks the cumulative processing dot number D2, and if the cumulative processing dot number D2 is 10 or more (Yes), the process proceeds to step 7, and if the cumulative processing dot number D2 is less than 10 (No). In step S6, the sequence ends and the next printing is executed (S6). Next, when the procedure proceeds to step 7, the counting unit 115 recognizes that the amount of toner stored in the toner holding space 29 is small, and starts counting the cumulative processing dot number D2. Specifically, after counting the number of print processing dots to be exposed by the LED head 23 from the print data received from the host apparatus 100, the number is added to the integrated processing dot number D2 (S7). Next, the count unit 115 compares the cumulative processing dot number D2 with the threshold value T1, and if the cumulative processing dot number D2 is equal to or greater than the threshold value T1 (Yes), the process proceeds to step 10, and the cumulative processing dot number D2 is less than the threshold value T1. In the case of (No), go to step 9. The threshold value T1 is arbitrarily set in advance (S8).

  When the procedure proceeds to step 9, the count unit 115 does not add the accumulated processing dot number D3, ends the sequence, and waits until the next printing is executed. That is, when the cumulative processing dot number D2 is less than the threshold value T1, a message notifying that the toner cartridge 24 is ready for replacement is not displayed, printing continues, and the remaining toner amount based on the LOW output time for the photocoupler 74 By continuing this monitoring, the detection accuracy of the toner remaining amount is improved (S9). Next, when the procedure proceeds to step 10, a message notifying the user of the image forming apparatus 1 of preparation for replacement of the toner cartridge 24 on a display panel 112 such as an LCD (not shown) based on a command from the control unit 110. Display (S10). Next, the count unit 115 starts counting the accumulated processing dot number D3. Specifically, after counting the number of print processing dots to be exposed by the LED head 23 from the printing data received from the host apparatus 100, the number is added to the cumulative processing dot number D3 (S11). Next, the counting unit 115 compares the accumulated processing dot number D3 with a predetermined threshold T2 that is set in advance as the replacement preparation period. If the accumulated processing dot number D3 is equal to or greater than the threshold T2 (Yes), the process proceeds to step 13. If the cumulative processing dot number D3 is less than the threshold value T2 (No), the sequence is terminated and the process waits until the next printing is executed. Note that the threshold value T2 is arbitrarily set in advance (S12).

  The count unit 115 compares the accumulated processing dot number D1 stored in the memory in the control board 60 with the dot filling amount at the time when the predetermined printing process predetermined as the previous period replacement preparation period is completed, and the accumulated processing dot number If D1 is greater than or equal to the dot filling amount (Yes), the process proceeds to step 14, and if the accumulated processing dot number D1 is less than the dot filling amount (No), the sequence is terminated and waits until the next printing is executed. To do. The dot filling amount is defined by the amount of toner filled in the toner cartridge 24 and is the number of dots that can be printed according to the print data. Specifically, as the dot filling amount for the toner cartridge 24 having a specification capable of printing 3000 print patterns defined by ISO, the number of dots for 3000 patterns based on ISO is written. Further, the control substrate 60 provided in the image forming apparatus 1 stores the dot filling amount related to the toner cartridge 24 stored in the storage element 90 that is read when the toner cartridge 24 is mounted on the developing unit 20. (S13). Next, the count unit 115 writes an information flag indicating that the toner is empty in the storage element 90 mounted on the toner cartridge 24 (S14). Next, based on a command from the control unit 110, printing of the image forming apparatus 1 is stopped, and a message prompting the user of the image forming apparatus 1 to replace the toner cartridge 24 on the display panel 112 such as an LCD (not shown). Is displayed, the sequence related to the printing operation is terminated (S15).

  Next, as a specific example of the printing operation according to the image forming apparatus 1 according to the present invention described with reference to FIG. 11, the toner consumption detected by the photocoupler 74 from the estimated value of the toner consumption based on the accumulated processing dot number D1. Printing when it is determined that the estimated value of the amount is large, and when it is determined that the estimated value of the toner consumption detected by the photocoupler 74 is smaller than the estimated value of the toner consumption based on the accumulated processing dot number D1. The toner amount with respect to the time related to the operation will be specifically described.

  First, the toner amount with respect to time when it is determined that the estimated value of the toner consumption detected by the photocoupler 74 is larger than the estimated value of the toner consumption based on the cumulative processing dot number D1 will be described with reference to FIG. To do. Table 1 shows an explanation of each symbol shown in FIG.

L ₀ is understood to be located between La ₁ and Lb ₁ . Further, when the battle value continues 10 times or more at Lb ₁ , counting of the accumulated processing dot number D2 is started at α ₁ . Lb ₁ ′ is a reference line when the photocoupler 74 detects the toner amount even after the threshold value continues 10 times or more. In the present invention, when Lc ₁ reaches the threshold value Ta ₁ , a message prompting for replacement of the toner cartridge 24 is displayed on the display panel 112 at time t ₁₂ . Further, the Ta ₁ and later, the counted toner consumption estimated value Ld ₁ based on the integration process dot number D3, when the toner amount Tae the integrated processing dot number D1 and accumulation process dot number D3 respectively become equal to or more than the threshold value, Printing is stopped at time t ₁ e. For example, when it is determined that the threshold value Tae is reached at Lb ₁ ′, the toner cartridge at time t ₁₁ earlier than time t _{12 with} respect to time t ₁ e connected to the toner amount Tae at which printing is stopped. A message prompting 24 to prepare for replacement is displayed on the display panel 112. Under the above-described conditions, when the preparation for replacement of the toner cartridge 24 is urged at Lb ₁ ′ when the true toner consumption amount L0 is examined, a message prompting the preparation for replacement of the toner cartridge 24 in a state where the remaining amount of toner is larger is displayed. Since the information is displayed on the display panel 112, the notification time for the user is too early.

  Next, the toner amount with respect to time when it is determined that the estimated value of the toner consumption detected by the photocoupler 74 is smaller than the estimated value of the toner consumption based on the integrated processing dot number D1, with reference to FIG. explain. Table 2 shows an explanation of each symbol shown in FIG.

When the battle value has continued 10 times or more at Lb ₂ , counting of the accumulated processing dot number D 2 is started at α ₂ . Now comparing the Lc ₂ and Lb ₂ ', the true amount of toner consumed _{L 0,} the time to reach Tb ₁ is a threshold value for prompting the replacement of the toner cartridge 24 is almost found the following Lc _2. Further, when Ld ₂ and Lb ₂ ′ are compared with respect to the time when the toner amount Tbe is reached, the time t ₂ e ′ related to Lb ₂ ′ is farther from L ₀ than t ₂ e. Therefore, even if the toner runs out and the toner cartridge 24 needs to be replaced, printing is not stopped, and a message prompting for replacement of the toner cartridge 24 is not displayed on the display panel 112, so that the user is not notified. Also, comparing the t ₂₁ and _{t 22,} t ₂₂ is slower than _{t 21.} Therefore, according to the true toner consumption amount L ₀ , a message prompting for preparation for replacement of the toner cartridge 24 immediately before a problem such as print fading that occurs on the recording medium 3 due to the small amount of toner occurs is displayed on the display panel. As a result, the time necessary for the user to prepare for replacement of the toner cartridge 24 cannot be secured sufficiently.

  As described above, according to the first embodiment, in addition to the toner amount detection mechanism including so-called hard members such as the stirring member 70, the sensor 73, and the photocoupler 74, the dot filling amount based on the toner filling amount is replaced with the toner cartridge 24. Since it is provided as a criterion for determining the timing, there is no problem of excessive or insufficient toner in printing, and printing can be performed for a printable number of sheets or more related to the toner cartridge 24. That is, when toner with high fluidity is used due to manufacturing variations among toner lots, etc., the flow of toner in the developing unit 20 is higher than expected by executing more printing with high printing density. If it does not decrease, or if it is detected that the amount of toner is low due to increased fluidity of the toner due to the usage environment of the image forming apparatus 1 or the like, sufficient toner remains in the developing unit 20. However, it is possible to prevent the user from urging the user to replace the toner cartridge 24 by stopping printing.

  Further, according to the first embodiment, even when the remaining amount of toner is determined based on only the dot filling amount stored in the storage element 90 mounted on the toner cartridge 24 and printing is stopped, the developing unit 20 In the case where the developing unit 20 that consumes a relatively small amount of toner is used due to the variation in print density due to the manufacturing variation of the developing member 26 related to the above, or in the state where a lot of toner remains after the user replenishes the toner. Even when printing is stopped, the problem of excessive or insufficient toner during printing does not occur. Further, the replacement preparation display of the toner cartridge 24 is performed based on the detection time of the toner amount detection mechanism, and may be longer than a predetermined replacement preparation period when the user purchases a new toner cartridge 24, for example. Therefore, since the toner cartridge 24 is not shortened, it can be prevented that a new toner cartridge 24 cannot be prepared and printing cannot be performed.

[Second Embodiment]
Next, an image forming apparatus according to a second embodiment of the present invention will be described. The second embodiment is characterized in that the amount of toner consumption can be adjusted by changing the voltage values applied to the toner supply member 25 and the developing member 26. The configuration related to the image forming apparatus is the same as the configuration of the image forming apparatus 1 described in the first embodiment. Therefore, in the present embodiment, a specific description will be given centering on the configuration different from the first embodiment.

  The image forming apparatus according to the second embodiment will be specifically described while comparing with the image forming apparatus 1 described above in the first embodiment. In the image forming apparatus 1 described above in the first embodiment, particularly when the toner density increases due to manufacturing variations of the developing member 26, that is, when the developing unit 20 that consumes more toner is used, If the amount of toner has actually decreased but the dot filling amount read from the storage element 90 has not been reached, a message indicating that preparation for replacement of the toner cartridge 24 is required is displayed on the display panel 112. However, since printing is not stopped, there is a possibility that the toner in the developing unit 20 is insufficient. Normally, the toner amount detection mechanism is configured to detect the remaining amount of toner with a certain margin amount added to the remaining amount of toner that causes blurred printing, but it consumes more toner than the margin amount. Doing so will cause faint printing. Therefore, in the second embodiment, when the toner amount detection mechanism detects a low amount of toner, the low amount of toner is determined by subsequent printing, and then the dot filling amount is compared in the process of comparing the accumulated dot processing number with the dot filling amount. When the difference between the number of processed dots and the accumulated dot processing number is equal to or greater than a predetermined value set in advance, it is determined that there is a possibility of blurring due to a large amount of toner consumption. 26 is characterized in that adjustment related to toner consumption is performed by changing the setting of the bias value to be applied to.

  Next, a printing operation according to the image forming apparatus of this embodiment will be described. FIG. 14 is a flowchart showing the flow of the printing operation according to the image forming apparatus.

  The control unit 110 that has received the print data from the host apparatus 100 such as a host computer starts the sequence related to the printing operation by driving the image generating apparatus 1 and starting printing. Note that the procedures 21 to 32 related to the printing operation of the image forming apparatus in the second embodiment are the procedures 1 to procedures related to the printing operation of the image forming apparatus 1 in the first embodiment described above with reference to FIG. 12 is the same. Next, when the procedure proceeds from the procedure 32 to the procedure 33, the counting unit 115 compares a value obtained by subtracting the accumulated processing dot number D1 from the dot filling amount with a predetermined threshold A described later, and performs the accumulation processing from the dot filling amount. If the value obtained by subtracting the number of dots D1 is equal to or smaller than the threshold A (Yes), the process proceeds to step 36, and if the value exceeds the threshold A (No), the process proceeds to step 34 (S33). Next, when proceeding to step 34, the counting unit 115 compares the accumulated processing dot number D2 with a predetermined threshold T3, and when the accumulated processing dot number D2 is equal to or larger than the threshold T3 (Yes), the counting unit 115 proceeds to step 38. If it is less than the threshold T3 (No), the process proceeds to step 35 (S34).

  When the procedure proceeds to step 35, the bias values applied to the toner supply member 25 and the developing member 26 are changed, and the subsequent printing is continued. SB is a bias value applied to the toner supply member 25 during printing, and DB is a bias value applied to the developing member 26 during printing. When normal printing is executed, SB = −500V and DB = −300V, but SB = −400V and DB = −250V are changed. Normally, the toner carried on the developing member 26 becomes more latent as the difference between the surface potential of about −30V to −50V charged to the photosensitive drum 21 where the latent image is written and DB is larger. Since it becomes easy to move to the photosensitive drum 21 on which an image is written, the amount of toner adhering to the photosensitive drum 21 increases. Further, the larger the difference between DB and SB, the easier it is for the toner to move from the toner supply member 25 to the developing member 26, so the amount of toner adhering to the developing member 26 increases. That is, by changing the setting so that the above-described bias value difference is reduced, the amount of toner carried and developed on the photosensitive drum 21 is reduced, so that toner consumption is suppressed. Note that how much the toner consumption changes due to the bias value setting change is determined by the characteristics of each member constituting the developing unit 20 including the toner, and thus the change value of each setting described above is an example ( S35).

  When the process proceeds from step 33 to step 36, the counting unit 115 compares the accumulated processing dot number D2 with a preset threshold value T4, and when the accumulated process dot number D2 is equal to or less than the threshold value T4 (Yes), the process proceeds to step 37. If the threshold value T4 is exceeded (No), the sequence is terminated and the process waits until the next printing is executed (S36). Note that the procedures 37 to 39 related to the printing operation of the image forming apparatus in the second embodiment are the procedures 13 to 33 related to the printing operation of the image forming apparatus 1 in the first embodiment described above with reference to FIG. The same as 15.

  Of the sequence described above, a part specific to the second embodiment will be described using a specific example. Assuming that the toner consumption assumed during the printing process predetermined as a replacement preparation period for the toner cartridge 24 is 5 g, the amount of toner remaining in the developing unit 20 when it is detected that the toner amount is small is detected. The difference between the assumed toner remaining amount and the print blur limit remaining toner amount when printing is stopped after subtracting the amount of toner consumed during preparation for replacement, that is, the so-called margin toner amount is 10 g. In this case, assuming that the estimated number of processing dots for 10 g consumption is, for example, if the difference between the dot filling amount and the number of accumulated processing dots is a dot difference corresponding to 9 g, printing is continued without changing the bias setting. As a result, the amount of toner that exceeds the margin toner amount by about 4 g or a little over is consumed, and printing is stopped for toner replacement. In this case, since the printing blur has not yet reached the limit toner remaining amount, the printing blur does not occur. If the difference is equal to or greater than 10 g, the bias value applied to the toner supply member 25 or the developing member 26 is changed to continue printing while suppressing the toner consumption. However, if the cumulative processing dot number D2, ie, the so-called low toner amount, exceeds 15g, which is the sum of the replacement preparation 5g and the margin 10g, print blurring occurs. Since it is determined that the possibility is high, an empty flag is written in the storage element 90, and a print stop process is performed. Even when the difference between the dot filling amount and the accumulated processing dot number D1 is less than the equivalent of 10 g, if the accumulated processing dot number D2 exceeds the sum 15 g of the replacement preparation 5 g and the margin 10 g, the print may be blurred. Since it is determined that the possibility of the occurrence is high, an empty flag is written in the storage element 90 and a print stop process is performed.

  As described above, according to the second embodiment, the toner amount detection mechanism detects a low amount of toner, the low amount of toner is determined by subsequent printing, and then the dot filling is performed in the process of comparing the accumulated dot processing number with the dot filling amount. When the difference between the amount and the accumulated dot processing number is equal to or greater than a predetermined value set in advance, it is determined that there is a possibility of blurring due to a large amount of toner consumption. By changing the setting of the bias value applied to the member 26, adjustment relating to toner consumption is performed. Therefore, it is possible to prevent the printing from being stopped even though the toner remains in the developing unit 20, and to prevent the user from prompting the user to replace the toner cartridge 24, and the toner in the developing unit 20 can be prevented. It is possible to prevent the occurrence of fading due to the lack of printing.

  In the first embodiment and the second embodiment described above, the image forming apparatus is described as an electrophotographic monochrome printer. However, the image forming apparatus according to the present embodiment may be a color printer, an inkjet printer, a dot printer, or the like. You may provide in a matrix printer, a copier, a facsimile machine, an MFP apparatus, etc. In the present invention, the toner cartridge 24 can be attached to and detached from the developing unit 20. However, the toner cartridge 24 may be integrated into the developing unit 20. When the image forming apparatus according to the present invention is configured as a color printer, four developing units 20K, 20Y that develop image information corresponding to four colors of black, yellow, magenta, and cyan are provided. Although 20M and 20C are disposed in the image forming apparatus, three developing units 20Y, 20M, and 20C corresponding to three colors excluding black may be disposed in the image forming apparatus. Similarly, two developing units 20K that respectively develop image information corresponding to the black color may be provided in the image forming apparatus. As described above, the number of the developing units 20, the combination of the colors of the developing units 20, the arrangement position, and the like are not limited, and can be appropriately changed without departing from the gist of the present invention. When a plurality of developing units 20 are provided in the image forming apparatus, a transfer belt for conveying the recording medium 3 is provided below the developing unit 20. In the present invention, the image forming apparatus that performs contact communication such as an EEPROM has been described. However, the present invention can also be applied to an image forming apparatus that performs non-contact communication such as RFID.

1 is a configuration diagram illustrating an image forming apparatus according to a first exemplary embodiment of the present invention. FIG. 2 is a configuration diagram illustrating a developing unit provided in the image forming apparatus according to the first exemplary embodiment of the present invention. It is a perspective view which shows the stirring member provided in the image development unit of the 1st Embodiment of this invention. 1 is a perspective view illustrating a toner cartridge according to a first embodiment of the present invention. FIG. 3 is a top view illustrating a substrate to which a storage element provided in the toner cartridge according to the first exemplary embodiment of the present invention is bonded. 3 is a side view showing a substrate to which a storage element provided in the toner cartridge according to the first exemplary embodiment of the present invention is bonded. FIG. FIG. 3 is a bottom view illustrating a substrate on which a storage element provided in the toner cartridge according to the first exemplary embodiment of the present invention is bonded. FIG. 3 is a perspective view illustrating a state in which a toner cartridge is attached to and detached from the developing unit according to the first embodiment of the present invention. It is a perspective view which shows the back surface of the developing unit of the 1st Embodiment of this invention. FIG. 3 is a block diagram illustrating control of the image forming apparatus according to the first exemplary embodiment of the present invention. 3 is a flowchart illustrating a flow of a printing operation according to the image forming apparatus of the first exemplary embodiment of the present invention. The amount of toner with respect to time when the estimated value of toner consumption detected by the photocoupler is larger than the estimated value of toner consumption by the integrated processing dot number D1 in the printing operation according to the image forming apparatus of the first embodiment of the present invention. It is a schematic diagram which shows. The amount of toner with respect to time when the estimated value of toner consumption detected by the photocoupler is smaller than the estimated value of toner consumption by the integrated processing dot number D1 in the printing operation according to the image forming apparatus of the first embodiment of the present invention. It is a schematic diagram which shows. 6 is a flowchart illustrating a flow of a printing operation according to an image forming apparatus of a second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Paper conveyance path 3, 3A, 3B Recording medium 10 Paper feed part 11 Paper feed cassette 12 Hopping roller 13 Pressure roller 14 Registration roller 20, 20K, 20Y, 20M, 20C Development unit 21 Photosensitive drum 22 Charging member 23 LED head 24 toner cartridge 24A pocket portion 24B regulating rib 24C lever 24D toner storage space 25 toner supply member 26 developing member 27 developing blade 28 cleaning member 29 toner holding space 30 transfer portion 31 transfer roller 40 fixing portion 41 fixing roller 42 pressure Roller 50 Discharge unit 51 Conveying roller 52 Conveying roller 53 Discharging roller 54 Discharging roller 55 Stacker 60 Control board 70 Stirring member 70A Rotating center portion 70B Stirring unit 71 Gear 71A Drive transmission surface 72 Bearing 73 Sensor 73A Rotating Core 73B Response unit 73C Detection unit 74 Photocoupler 80 Rib 90 Storage element 91 Contact 92 Substrate 93 Connector 94 Substrate 95 Contact 96 Connector 100 Host device 110 Control unit 110A Comparison unit 110B Judgment unit 111 I / F unit 112 Display panel 113 Motor 114 Voltage setting unit 115 Counting unit 116 Timer

Claims (7)

A storage element for storing the amount of developer stored in the developer storage unit as the number of accumulated processing dots;
A measurement unit that measures the number of print processing dots of print data received from the host device;
A developer container for storing the developer supplied from the developer container;
A stirring member rotatably provided inside the developer containing portion;
A sensor member for measuring the rotation period of the stirring member;
A control unit that controls the storage element, the sensor member, and the measurement unit under a certain condition;
When the control unit detects that the developer in the developer storage unit is below a certain value by the sensor member, the control unit stores the developer in the developer storage unit based on the accumulated processing dot number and the printing processing dot number. An image forming apparatus, wherein when the stored developer becomes equal to or less than a threshold value, a notification is made to prompt replacement of the developer storage device.   When the control unit detects that the developer in the developer storage unit is below a certain value by the sensor member, the control unit stores the developer in the developer storage unit based on the accumulated processing dot number and the printing processing dot number. The image forming apparatus according to claim 1, wherein when the stored developer becomes equal to or less than a threshold value, the printing operation of the developer storage device is notified.   When the control unit detects that the developer in the developer storage unit is below a certain value by the sensor member, the control unit stores the developer in the developer storage unit based on the accumulated processing dot number and the printing processing dot number. The image forming apparatus according to claim 1, wherein when the stored developer becomes a threshold value or less, the printing operation of the developer storage device is stopped.   When the control unit detects by the sensor member that the developer inside the developer containing unit is a predetermined value or less, the initial integrated processing dot number, the integrated processing dot number, and the printing processing dot number The image forming apparatus according to claim 1, wherein a printing operation is controlled on the basis of the image forming apparatus. A latent image carrier on which a developer image is formed;
A developing member for developing an electrostatic latent image on the latent image carrier with a developer;
A developer supply member for supplying the developer to the developer member;
A voltage setting unit for supplying a voltage to the developing member and the developer supply member;
When the control unit detects that the developer in the developer storage unit is below a certain value by the sensor member, the control unit stores the developer in the developer storage unit based on the accumulated processing dot number and the printing processing dot number. 5. The image forming apparatus according to claim 1, wherein a voltage value applied to the developing member is changed when the stored developer becomes a threshold value or less. 6.   When the control unit detects that the developer in the developer storage unit is below a certain value by the sensor member, the control unit stores the developer in the developer storage unit based on the accumulated processing dot number and the printing processing dot number. The image forming apparatus according to claim 5, wherein a voltage value applied to the developer supply member is changed when the stored developer becomes a threshold value or less.   The image forming apparatus according to claim 1, wherein the storage element is provided in the developer container.