JP2019008237A - Image formation apparatus - Google Patents

Abstract

To prevent the damage on a toner conveyance member due to forgetting to remove a sealing member.SOLUTION: A system controller 200 of an image formation apparatus 1 controls the drive current flowing in a coil of a stepping motor 300 so that the deviation between the command phase indicating the target phase of a rotor of the stepping motor 300 driving a conveyance unit of a developing unit and the rotation phase of the rotor becomes small. The system controller 200 determines that removal of seal member 405 of the developing unit 400 is forgotten, stops the stepping motor 300 (S104) and performs error notification (S105) when the q-axis current iq obtained by performing dq conversion of the drive current flowing in the coil of the stepping motor 300 detected by current detection units 312, 313 by a coordinate conversion unit 231 is larger than a prescribed value (Yes in S102) in the initialization operation of the developing unit 400.SELECTED DRAWING: Figure 7

Description

  The present invention relates to control of an image forming apparatus having a cartridge type developer that is detachable from the image forming apparatus.

  An electrophotographic image forming apparatus forms an electrostatic latent image on a photoconductor as an image carrier by charging and exposure, and develops the electrostatic latent image using toner as a developer to form a toner image. Then, the toner image is transferred to a recording medium to form an image on the recording medium. Some of these image forming apparatuses adopt a cartridge system in order to cope with replacement of components having different lifetimes or supply of consumables such as toner. For example, a developing cartridge in which a toner container for containing toner and a developing roller are integrated, and a process cartridge in which a photosensitive member, a charging unit, a cleaning unit, and the like are also integrated are known.

  In such a cartridge, in order to prevent toner leakage during transportation or replacement, the opening of a toner container that contains toner is sealed with a seal member or the like. The sealing member is generally opened by the user when a new cartridge is mounted on the image forming apparatus. That is, since the seal member is manually opened, the cartridge may be mounted on the image forming apparatus while the seal member is forgotten to be opened.

  When the toner in the toner container is transported by the cartridge mounted without the seal member being peeled off, the toner transport member (screw or the like) tries to transport the blocked toner downstream in the transport direction. Therefore, an excessive force is applied to the toner conveying member, and the toner conveying member may be damaged.

  Patent Document 1 proposes a configuration in which a winding member that peels and winds the seal member in the cartridge is provided, and the seal member is automatically wound when the cartridge is mounted using a drive source.

Japanese Patent Laying-Open No. 2015-161896

  However, according to the conventional technique, it is necessary to newly provide a winding member in the cartridge in order to peel off the sealing member (sealing member) and wind it once when the cartridge is mounted. In addition, it is necessary to secure a driving force for peeling off the sealing member attached with a force that does not peel off during transportation by adding a motor or improving specifications. Therefore, the cost of the image forming apparatus has been increased.

  The present invention has been made to solve the above problems. An object of the present invention is to provide a mechanism capable of preventing damage to a toner conveying member due to forgetting to remove a sealing member.

  An image forming apparatus according to the present invention includes a storage unit that stores a developer and a transport unit that transports the developer stored in the storage unit in the direction of the opening of the storage unit. An image forming apparatus in which a developing unit having a sealing member to be sealed is attached in a detachable manner, a motor that drives a conveying unit of the developing unit, and rotation of a rotor of the motor Phase determining means for determining the phase, and controlling the drive current flowing in the motor winding so that the deviation between the command phase representing the target phase of the rotor and the rotational phase determined by the phase determining means is small. Control means for detecting the drive current flowing in the winding, and the control means, when the value related to the drive current detected by the detection means is greater than a predetermined value, the motor To stop And butterflies.

  According to the present invention, the control means stops the motor when the value relating to the drive current detected by the detection means is larger than the predetermined value. As a result, it is possible to prevent the conveyance unit from being damaged due to forgetting to remove the sealing member.

Schematic configuration diagram of the image forming apparatus of the present embodiment Block diagram illustrating the control configuration of the image forming apparatus of the present embodiment Schematic configuration diagram of the motor drive control device of the present embodiment The figure which shows the schematic structure of the motor of a present Example, and the relationship of a dq axis | shaft. FIG. 2 is a diagram illustrating a schematic configuration of a developing device and its periphery according to the present exemplary embodiment. Schematic configuration diagram of the developing device of this embodiment Flowchart for explaining an example of the initialization operation processing of the developing device of this embodiment Timing chart of motor speed command and q-axis current of this embodiment

Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. However, the shape of the component parts described in this embodiment and the relative arrangement thereof should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions, and the scope of the present invention is limited. It is not intended to be limited to the following embodiments.
First, the schematic configuration and operation of an image forming apparatus showing an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a cross-sectional view illustrating a schematic configuration of the image forming apparatus according to the present embodiment.

  The image forming apparatus 1 of this embodiment is an electrophotographic system in which four image forming units for forming toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) are arranged in parallel. A color image forming apparatus. Each image forming unit has the same configuration except that the color of the toner image to be formed is different.

  In each image forming unit, the photosensitive drums 101a to 101d are uniformly charged by the charging rollers 102a to 102d, and are exposed in accordance with the image signals of the respective colors from the laser scanners 103a to 103d, so that electrostatic latent images are formed. It is formed. These electrostatic latent images are developed with toners of yellow, magenta, cyan, and black, respectively, by developing devices 400a to 400d. The developing devices 400a to 400d are of a cartridge type so that the constituent members can be easily exchanged, and are configured to be detachable from the image forming apparatus 1.

  The toner developed on the photosensitive drums 101a to 101d is transferred to the intermediate transfer belt 106 by the primary transfer rollers 105a to 105d, and a full color toner image is formed on the intermediate transfer belt 106. The transfer residual toner on the photosensitive drums 101a to 101d is collected by the drum cleaners 107a to 107d.

  Further, the image forming apparatus 1 includes a plurality of paper feeding units such as paper feeding cassettes 111 and 112 and a manual paper feeding unit 113. When the image forming operation is started, the recording paper S is sent from any of the paper feeding units. Is fed. The recording sheet S is conveyed by the conveyance roller 114 and further conveyed toward the registration roller 116 by the pre-registration roller 115. The recording sheet S that has reached the registration roller 116 is subjected to skew correction and is temporarily stopped from being conveyed. Then, after adjusting the timing so that the toner image on the intermediate transfer belt 106 is transferred to a desired position on the recording paper S, the recording paper S is conveyed to the secondary transfer roller 109 of the secondary transfer unit 118. The toner image is transferred to the recording paper S.

  The toner image transferred to the recording paper S is pressed and heated by the fixing device 110 and fixed on the recording paper S. The recording sheet S that has been fixed is discharged out of the image forming apparatus 1 from the discharge unit 119a or 119b. The transfer residual toner on the intermediate transfer belt 106 that has not been transferred in the secondary transfer unit 118 is collected by the intermediate transfer body cleaner 108.

Next, the relationship between the operation of the system controller 200 that comprehensively controls the image forming apparatus 1 and each part of the image forming apparatus 1 will be described with reference to FIG.
FIG. 2 is a block diagram illustrating a control configuration of the image forming apparatus 1.

  The system controller 200 controls the image forming apparatus 1 in an integrated manner. The system controller 200 mainly plays a role of driving each load in the image forming apparatus 1, collecting and analyzing information of the sensors 250, and exchanging data with the operation unit 203, that is, the user interface. I'm in charge.

  The system controller 200 includes a CPU 200a, a ROM 200b, and a RAM 200c. The CPU 200a executes various sequences related to a predetermined image forming sequence by executing a program stored in the ROM 200b. The ROM 200b stores a threshold value of a q-axis current iq, which will be described later, in advance.

  The RAM 200c functions as a work area for the CPU 200a. The RAM 200c stores rewritable data that needs to be temporarily or permanently stored during the operation of the CPU 200a. For example, various data, image formation command information from the operation unit 203, and the like are stored in the RAM 200c.

  The system controller 200 sends specification setting value data of each unit necessary for the image processing unit 202 to the image processing unit 202. In addition, the system controller 200 receives signals from each unit, for example, a document image density signal, and controls the high-voltage control unit 220 and the image processing unit 202 to perform settings for optimal image formation.

  The system controller 200 obtains information such as a copy magnification and a density setting value set by the user from the operation unit 203. Further, the system controller 200 provides data for notifying the operation unit 203 of the state of the image forming apparatus 1, for example, the number of image formations, whether or not an image is being formed, occurrence of a jam, and the location thereof. Is sent out. In addition, various settings for tab sheets and exchanges for displaying warnings for tab sheets are performed between the system controller 200 and the operation unit 203.

  The image forming apparatus 1 includes one or a plurality of motors, a DC load such as a clutch / solenoid, and sensors such as a photo interrupter and a micro switch. In the image forming apparatus 1, the recording paper S is conveyed and each unit is driven by appropriately driving a motor and each DC load, and the operation is monitored by various sensors 250. Based on the signals from the various sensors 250, the system controller 200 controls each motor by the motor control unit 230 and at the same time operates the clutch / solenoid by the DC load control unit 240 to smoothly advance the image forming operation. Yes. Further, the system controller 200 sends various high-voltage control signals to the high-voltage control unit 220, so that the primary charger, auxiliary charger, transfer charger, and developer in the various chargers constituting the high-voltage unit 221. An appropriate high pressure is applied to the developing roller.

  The halogen heaters inside the fixing roller and the pressure roller of the fixing device 110 are turned on / off by the AC driver 260 and the energization amount is controlled. The fixing roller is provided with a thermistor 211 as a temperature detector for measuring the surface temperature of the fixing roller. The thermistor 211 outputs an analog signal (voltage value) representing the resistance value of the thermistor that changes according to the temperature change of the fixing roller to the AD converter 210. The AD converter 210 converts the analog signal from the thermistor 211 into a digital value and outputs a digital value as detected temperature data of the fixing roller to the system controller 200. The system controller 200 controls the AC driver 260 based on a digital value as detected temperature data.

  As described above, the operation sequence in the image forming apparatus 1 is controlled by the system controller 200. In this series of control sequences, the motor that is the drive source of each unit is driven and controlled by the configuration of the motor drive control device 2 shown in FIG.

Hereinafter, the configuration and operation of the motor drive control device 2 of the present invention will be described with reference to FIGS.
FIG. 3 is a diagram illustrating a schematic configuration of the motor drive control device 2.
FIG. 4 is a schematic diagram for explaining a schematic configuration of the stepping motor 300, which is simplified for explaining the operation principle.
As shown in FIG. 4, the stepping motor 300 includes a rotor (rotor) 302 attached to an output shaft (shaft) (not shown) and four stators (stator) arranged to face the rotor 302. ) 301a, 301b, 301c, 301d.

  As shown in FIG. 3, the phase command value (θ_ref) to the motor drive control device 2 is a command phase that represents the target phase of the rotor 302 that is output from the CPU 200a. The motor control unit 230 performs position control with vector control based on the phase command value (θ_ref).

The basic configuration of the motor drive control device 2 is inverter control using coordinate transformation used in a brushless DC motor, an AC servo motor, or the like. In the inverter control, as shown in FIG. 4, a stationary coordinate system (α-β coordinate system) representing normal current vectors flowing in the A phase and B phase of the stepping motor 300 is used, and a rotating coordinate system based on the rotational phase θ of the rotor 302 Convert to (dq coordinate system). That is, the stationary coordinate system (α-β coordinate system) in which the A phase direction of the stepping motor 300 is the α axis and the B phase direction is the β axis, and the magnetic pole direction of the rotor 302 is advanced 90 degrees from the d axis and the d axis. The direction is converted into a rotating coordinate system (dq coordinate system) defined as the q axis.
Inverter control is roughly composed of two control loops of current controllers 234 and 235 and a position controller 232.

First, the control loop of the position controller 232 will be described.
The position controller 232 includes a proportional compensator and an integral compensator. The position controller 232 is a current command iq_ref so that a deviation between the rotation phase θ of the rotor 302 of the stepping motor 300 detected by the position detector 314 such as an encoder and the phase command value θ_ref from the CPU 200a becomes small. Output id_ref. That is, the motor drive control device 2 determines the stepping motor so that the deviation between the command phase (θ_ref) indicating the target phase of the rotor and the rotation phase (θ) detected (phase determination) by the position detector 314 becomes small. Control the drive current flowing through 300 windings. Here, the current commands iq_ref and id_ref are current command values after being converted from the stationary coordinate system (α-β coordinate system) to the rotating coordinate system (dq coordinate system). The rotational phase θ may be determined based on an induced voltage induced in the motor winding.
When the current flowing through the stepping motor 300 in the stationary coordinate system (α-β coordinate system) is represented by equation (1), the current value in the rotating coordinate system (dq coordinate system) is represented by equation (2).

  By this conversion, the alternating currents iα and iβ and the current command values iq_ref and id_ref flowing in the A phase and the B phase are expressed by direct current. Here, the d-axis current is a component capable of controlling the amount of magnetic flux and does not contribute to torque. On the other hand, the q-axis current is a component (torque current component) that dominates the torque generated by the stepping motor 300, and is a value proportional to the load torque. Therefore, the magnitude of the motor load torque can be monitored by monitoring the value of the q-axis current iq. The q-axis current iq is input from the motor drive control device 2 to the system controller 200 and monitored by the system controller 200 (FIG. 5 described later).

Next, the control loop of the current controllers 234 and 235 will be described.
The current flowing in each phase of the motor is detected by current detectors 312 and 313, and converted to a state (iα, iβ) that can be taken into a programming device such as a CPU or FPGA by an A / D converter 315. Then, the coordinate conversion unit 231 performs dq conversion of the above equation (2) to obtain the q-axis current iq and the d-axis current id. Deviations between the obtained q-axis current iq and d-axis current id and the current command values iq_ref and id_ref output from the position controller 232 described above are input to the current controllers 234 and 235. In normal vector control, the d-axis current is controlled so that the id component that does not contribute to torque becomes zero. The current controllers 234 and 235 are composed of a proportional compensator and an integral compensator like the position controller 232. The amount of current deviation input to the current controllers 234 and 235 is amplified by the current controllers 234 and 235 and then input to the coordinate conversion unit 236 as drive voltages vd and vq. In the coordinate conversion unit 236, vq and vd are inversely converted into driving voltages vα and vβ in the stationary coordinate system. This inverse transformation is calculated by the following equation (3).

The drive voltages vα and vβ converted by the coordinate conversion unit 236 are input to the PWM inverter 311 to drive a full bridge circuit that drives each phase winding, and currents iα corresponding to the drive voltages vα and vβ, iβ is controlled to flow in the winding.
As described above, in the motor drive control device 2, the drive currents iα and iβ detected by the current detectors 312 and 313 are converted into the d-axis current id and the q-axis current iq, and based on the converted currents id and iq. The driving of the stepping motor 300 is controlled.

  By constructing such a feedback system, in vector control, the minimum necessary drive current corresponding to the load is always applied to the motor, and a surplus current (torque margin) for avoiding step-out is required. Power saving and low noise can be achieved compared to open control drive.

  Next, the configuration and operation of the developing device 400 will be described with reference to FIGS. Hereinafter, when the description common to the developing devices 400a, 400b, 400c, and 400d is performed, a, b, c, and d are omitted and referred to as “developing device 400”.

  5 and 6 are diagrams for explaining a schematic configuration of the developing device 400 and its periphery. 5 corresponds to a view of the developing device 400 viewed from the side, and FIG. 6 corresponds to a view of the developing device 400 viewed from above. 5 and 6, the shaded portion indicates the developer D.

  The developing device 400 is a cartridge type that is detachable from the image forming apparatus 1 and can be easily replaced. The developing device 400 includes a conveying screw 401, a conveying screw 402, a developing sleeve 403, a first chamber 406, a second chamber 407, a partition wall 404, and a communication port 408. Further, the developing device 400 includes a seal member (sealing member) 405 in the initial state. When the developing device 400 is attached to the image forming apparatus 1, the photosensitive drum 101 (not shown in FIGS. 5 and 6) is present at a position facing the developing sleeve 403 (right direction in FIGS. 5 and 6). To do.

  The first chamber 406 and the second chamber 407 are configured to accommodate a two-component developer of non-magnetic toner and a magnetic carrier, and are partitioned by a partition wall 404. At both ends of the partition wall 404, communication ports 408a and 408b for communicating the first chamber 406 and the second chamber 407 are provided. The first chamber 406 functions as a storage unit that stores toner in the initial state of the developing device 400. That is, in the initial state of the developing device 400, the developer D is accommodated only in the first chamber 406, and the communication ports 408 a and 408 b serving as openings of the first chamber 406 are sealed by the seal member 405. This prevents the toner from leaking from the developing device 400 during transportation. The sealing member 405 is a sealing member that can be easily peeled off and removed by the user. When the developing device 400 is mounted on the image forming apparatus 1, the seal member 405 should be peeled off by the user. When the seal member 405 is peeled off, the communication ports 408 a and 408 b are opened, and the toner stored in the first chamber 406 can be conveyed to the second chamber 407.

  Inside the first chamber 406, a conveying screw 401 for conveying the developer D is rotatably mounted, and by rotating this, the developer D in the first chamber 406 is conveyed in the direction of the communication port 408a. The In addition, a conveying screw 402 for conveying the developer D is rotatably mounted inside the second chamber 407, and the developer D in the second chamber 407 is rotated in the direction of the communication port 408b by rotating this. Be transported.

  Therefore, when the developing device 400 is used, when the seal member 405 is peeled off and the communication ports 408a and 408b are opened, the developer D contains the first chamber 406, the communication port 408a, the second chamber 407, and the communication port. It is conveyed in the direction of the arrow in FIG. 6 through the circulation path formed by 408b. The developer D is simultaneously agitated during the conveyance process, and the toner is negatively charged and the carrier is positively charged by the friction between the toner particles and the carrier particles.

  Inside the developing sleeve 403, a magnet that is supported non-rotatingly by arranging a plurality of magnetic poles on the surface is arranged. The developer D is carried on the surface of the developing sleeve 403 by the carrier (magnetic material) in the developer D being restrained by the magnetic flux formed between the magnetic poles of the magnet. A magnetic brush in which the negatively charged toner is electrostatically restrained is formed on the surface of the positively charged carrier. When an oscillating voltage in which an AC voltage is superimposed on a negative DC voltage is applied by a power source (not shown), the toner carried on the magnetic brush is transferred to the electrostatic latent image on the photosensitive drum 101, and the electrostatic latent image Develop.

  The conveying screw 401, the conveying screw 402, and the developing sleeve 403 are connected to the stepping motor 300 through gears (not shown), respectively, and rotate by driving the stepping motor 300. The stepping motor 300 is controlled by the motor drive control device 2 by the method described above.

  As shown in FIG. 5, the motor control unit 230 sends the value of the q-axis current iq calculated by the vector control described above to the system controller 200 (not shown in FIG. 3). The q-axis current iq indicates a value proportional to the load torque of the stepping motor 300. Therefore, the system controller 200 can monitor the magnitude of the load torque of the stepping motor 300 by monitoring the value of the q-axis current iq.

Hereinafter, the operation for determining whether to forget to remove the seal member 405 will be described with reference to FIGS.
The determination of forgetting to remove the seal member 405 is performed during the initialization operation of the developing device 400 after the cartridge type developing device 400 is mounted on the image forming apparatus 1. The initialization operation of the developing device 400 corresponds to the initial operation of the developing device 400 attached to the image forming apparatus 1. For example, even when the user operates the operation unit 203 to instruct the execution of the initialization operation of the developing device 400, the system controller 200 automatically detects that the developing device 400 is installed in the image forming apparatus 1. A configuration in which execution of the initialization operation of the developing device 400 is instructed may be employed.

FIG. 7 is a flowchart for explaining an example of the initialization operation processing of the developing device 400 performed by the system controller 200. The processing of this flowchart is realized by the CPU 200a executing a program stored in the ROM 200b.
FIG. 8 is a timing chart showing the speed command of the stepping motor 300 and the state of the q-axis current iq when the initialization operation processing of the developing device 400 shown in FIG. 7 is performed.

For example, when the user instructs the initialization operation of the developing device 400, the system controller 200 starts the process of FIG.
First, in S101, the system controller 200 starts an initialization operation of the developing device 400. Specifically, the system controller 200 drives the stepping motor 300 to rotate the transport screw 401 and the transport screw 402. As a result, the developer D in the developing device 400 is agitated while being circulated and the charge amount of the toner and carrier is increased to an amount necessary for the development process. Note that it takes about 2 minutes to complete the initialization operation of the developing device 400, for example.

  Next, in S102, the system controller 200 compares the q-axis current iq of the stepping motor 300 with a threshold value stored in advance in the ROM 200b. As described above, the q-axis current iq is a value proportional to the load torque.

The threshold value satisfies the following (A) and (B).
(A) A value larger than a normal q-axis current iq (for example, a current value corresponding to a torque value of 10 [mNm]) when the seal member 405 is peeled off.
(B) A current value corresponding to a torque value that is smaller by an appropriate margin than a current value corresponding to a torque value (for example, 100 [mNm]) that leads to damage of a component when the seal member 405 is not peeled off. That is, the current value at which the parts are not damaged.
As a value that satisfies (A) and (B) at the same time, for example, there is a current value corresponding to a torque value of 30 [mNm], which can be used as the above-described threshold value. This threshold value is stored in advance in the ROM 200b, for example. The current value corresponding to threshold = torque value 30 [mNm] is merely an example, and the threshold is not limited to this.

In S102, when the system controller 200 determines that the q-axis current iq is less than the threshold (iq <threshold) (No in S102), the system controller 200 proceeds to S103.
In S103, the system controller 200 confirms whether or not the initialization operation of the developing device 400 has been completed. If the system controller 200 determines that the initialization operation has not yet been completed (No in S103), it returns the process to S102. That is, the system controller 200 sets the q-axis current iq and the threshold value at a predetermined cycle (for example, the q-axis current calculation cycle of the motor control unit 230 = 25 [μs]) until the initialization operation of the developing device 400 is completed. And forgetting to remove the seal member 405.

  On the other hand, if the system controller 200 determines in S103 that the initialization operation has been completed (Yes in S103), the system controller 200 ends the initialization operation processing of the developing device 400.

Here, referring to FIG. 8A, when the q-axis current iq does not exceed the threshold value in the initialization operation of the developing device 400, that is, when the removal of the seal member 405 of the developing device 400 is not forgotten, the speed command of the stepping motor 300 is determined. And the state of the q-axis current iq will be described.
FIG. 8A is a timing chart showing a state where the q-axis current iq does not exceed the threshold value during the initialization operation of the developing device 400.

  As shown in FIG. 8A, when the initialization operation of the developing device 400 is started, the system controller 200 issues a speed command to the motor drive control device 2, and the stepping motor 300 operates at a speed according to the speed command. Starts (time t0). The stepping motor 300 accelerates at a predetermined acceleration until time t1, and reaches a steady speed at time t1. Thereafter, until the time t2 when the initialization operation of the developing device 400 is completed, the stepping motor 300 rotates at a steady speed. Between time t2 and time t3 when the initialization operation of the developing device 400 is completed, the stepping motor 300 decelerates at a predetermined deceleration and stops at time t3.

The q-axis current iq is a value corresponding to a certain steady torque during rotation at the steady speed at times t1 to t2. During acceleration from time t0 to t1, acceleration torque is added to the steady torque, and the q-axis current iq is larger than that from time t1 to t2. Further, during deceleration from time t2 to time t3, deceleration torque is added to the steady torque, and the q-axis current iq has a value smaller than that from time t1 to time t2.
In this case, any q-axis current iq from time t0 to t3 is less than the threshold value, and the initialization operation of the developing device 400 is completed without applying excessive torque to the conveying screw A401.

Returning to the flowchart of FIG.
The following is a description of the case where the q-axis current iq is greater than or equal to the threshold value in the initialization operation of the developing device 400, that is, the case where the seal member 405 of the developing device 400 is forgotten to be removed.

  In S102, if the system controller 200 determines that the q-axis current iq is equal to or greater than the threshold (iq ≧ threshold) (Yes in S102), the system controller 200 determines that the seal member 405 has not been peeled off, and proceeds to S104. .

  In S104, the system controller 200 stops the stepping motor 300. As a result, even though the communication port 408a is blocked by the seal member 405, the stepping motor 300 continues to rotate and the conveying screw 401 continues to convey the developer D toward the communication port 408a. Can be prevented. Therefore, the density of the developer D in the vicinity of the communication port 408a is increased, an excessive torque is applied to the conveying screw 401, and the occurrence of a situation in which parts are damaged can be prevented. Note that the stepping motor 300 is stopped by, for example, stopping or disconnecting the motor drive power supply, stopping the drive command, stopping the operation of the PWM inverter, or the like.

Further, in S105, the system controller 200 displays on the display (not shown) of the operation unit 203 of the image forming apparatus 1 that the developing device 400 (cartridge) is mounted without the seal member 405 being peeled off. To notify the user. As a result, it is possible to notify the user that the developing device 400 (cartridge) is mounted without the seal member 405 being peeled off. At the time of the above notification, the location of the seal member 405 and how to remove it are displayed on the operation unit 203 with text, pictures, animations, etc., and the developing device 400 (cartridge) can be correctly attached to the image forming apparatus 1 again. You may control so that it may prompt.
After the process of S105, the system controller 200 ends the process of this flowchart. In this way, the CPU 200a controls the stepping motor 300 based on the torque current component (q-axis current iq) that generates torque in the rotor 302, which is expressed in the rotating coordinate system with the rotation phase (θ) as a reference. Then, the CPU 200a stops the stepping motor 300 when the value of the detected torque current component (q-axis current iq) of the drive current is larger than a predetermined value (the threshold value), and when smaller than the predetermined value, the stepping motor 300a. Control is performed to continue driving the motor 300.

  Here, referring to FIGS. 8B and 8C, the stepping motor 300 when the q-axis current iq is equal to or larger than the threshold in the initialization operation of the developing device 400, that is, when the seal member 405 of the developing device 400 is forgotten to be peeled off. The speed command and the state of the q-axis current iq will be described.

FIG. 8B is a timing chart showing a state where the q-axis current iq gradually increases in the course of the initialization operation of the developing device 400 and eventually becomes equal to or greater than the threshold value.
FIG. 8C is a timing chart showing a state in which the q-axis current iq becomes equal to or greater than the threshold immediately after the initialization operation of the developing device 400 is started.

First, FIG. 8B will be described. The speed command from time t0 to time t1 and the state of the q-axis current iq are the same as those described with reference to FIG.
The stepping motor 300 continues to rotate at a steady speed from time t1 to time t4 in FIG. During this time, the transport screw 401 continues to transport the developer D toward the communication port 408a even though the communication port 408a is blocked by the seal member 405. Therefore, the density of the developer D in the vicinity of the communication port 408a gradually increases, and the torque necessary for rotating the transport screw A401 increases. As a result, the load torque of the stepping motor 300 increases, and the q-axis current iq that is a value proportional to the load torque increases. Eventually, the q-axis current iq reaches the threshold value at time t4, and the stepping motor 300 is stopped. In the example of FIG. 8B, the stepping motor 300 is stopped by setting the speed command to zero. Then, the system controller 200 notifies the user that the seal member 405 has not been peeled off.

  Next, FIG. 8C will be described. The developer D in the first chamber 406 of the developing device 400 attached to the image forming apparatus 1 may be close to the communication port 408a from the beginning depending on how it is transported. That is, the density of the developer D in the vicinity of the communication port 408a is high from the beginning, and the torque required to rotate the transport screw 401 may be large. In this state, when the driving of the stepping motor 300 is started at time t0, the q-axis current iq reaches the threshold value immediately at time t5, and the stepping motor 300 is stopped. In the example of FIG. 8C as well, the stepping motor 300 is stopped by setting the speed command to zero. Then, the system controller 200 notifies the user that the seal member 405 has not been peeled off. Then, the system controller 200 notifies the user that the seal member 405 has not been peeled off.

  As described above, in the image forming apparatus of this embodiment, the q-axis current iq during the initialization operation of the developing device 400 is monitored, and when the q-axis current iq is larger than a predetermined value, the seal member 405 is peeled off. Therefore, stop control is performed to stop the stepping motor 300. In addition, the user can be notified that the seal member has not been peeled off. Thereby, damage to components, such as conveyance screw A401, can be prevented. These can be realized without adding new parts, that is, without increasing costs.

In the present embodiment, a stepping motor is used as a motor for driving a load in the developing device 400, but the motor type is not limited to this, and a brushless motor, for example, may be used.
In this embodiment, the change in the load torque is detected based on the q-axis current iq, but this is not restrictive. For example, a change in load torque can be detected based on a deviation between the phase command value θ_ref and the rotational phase θ. This is because as the load torque applied to the rotor increases, the deviation between the phase command value θ_ref and the rotation phase θ also increases. Also, a change in load torque can be detected based on the q-axis current command value iq_ref. This is because the q-axis current command value iq_ref is a value determined based on the deviation between the phase command value θ_ref and the rotational phase θ. That is, the CPU 200a controls the stepping motor 300 to stop when the target value (iq_ref) of the torque current component of the driving current is larger than the predetermined value, and to continue driving the stepping motor 300 when the target value is smaller than the predetermined value. The structure to do may be sufficient.

  Further, in this embodiment, the configuration using vector control has been described as an example. However, any configuration may be used as long as the driving current of the motor changes according to a change in load torque, even if the configuration does not use vector control. . For example, in a configuration in which the motor is moved by position control or speed control, the drive current of the motor changes depending on the load torque. Therefore, it is possible to determine whether or not the seal member has been removed by providing a threshold for the drive current, comparing the threshold with the actual drive current, and monitoring whether the drive current is equal to or greater than the threshold. .

  As described above, it is possible to prevent damage to the toner conveying member due to forgetting to remove the seal member without incurring cost increase due to addition of new parts.

In addition, the structure of the various data mentioned above and its content are not limited to this, You may be comprised with various structures and content according to a use and the objective.
Although one embodiment has been described above, the present invention can take an embodiment as, for example, a system, apparatus, method, program, or storage medium. Specifically, the present invention may be applied to a system composed of a plurality of devices, or may be applied to an apparatus composed of a single device.
Moreover, all the structures which combined said each Example are also contained in this invention.

(Other examples)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in the computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.
Further, the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device.
The present invention is not limited to the above embodiments, and various modifications (including organic combinations of the embodiments) are possible based on the spirit of the present invention, and these are excluded from the scope of the present invention. is not. That is, the present invention includes all the combinations of the above-described embodiments and modifications thereof.

1 Image forming device
2 Motor drive device
200 System controller
230 Motor controller
300 Stepping motor
311 PWM inverter

Claims (6)

A sealing member that seals the opening in an initial state includes an accommodating portion that accommodates the developer and a conveying portion that conveys the developer accommodated in the accommodating portion toward the opening of the accommodating portion. An image forming apparatus that detachably mounts a developing unit attached to a part,
A motor for driving the transport section of the developing device;
Phase determining means for determining the rotational phase of the rotor of the motor;
Control means for controlling the drive current flowing in the winding of the motor so that the deviation between the command phase representing the target phase of the rotor and the rotational phase determined by the phase determination means is small;
Detecting means for detecting a drive current flowing in the winding;
Have
The image forming apparatus according to claim 1, wherein the control unit stops the motor when a value related to the drive current detected by the detection unit is larger than a predetermined value.   The image forming apparatus according to claim 1, wherein the control unit continues driving the motor when a value related to the drive current detected by the detection unit is smaller than the predetermined value. The control means controls the motor based on a torque current component that generates torque in the rotor, expressed in a rotation coordinate system based on the rotation phase determined by the phase determination means,
The control means stops the motor when the value of the torque current component of the drive current detected by the detection means is larger than a first value as the predetermined value, and is detected by the detection means The image forming apparatus according to claim 1, wherein when the value of the torque current component of the driving current is smaller than the first value, the driving of the motor is continued. The control means controls the motor based on a torque current component that generates torque in the rotor, expressed in a rotation coordinate system based on the rotation phase determined by the phase determination means,
The control means stops the motor when the target value of the torque current component of the drive current is larger than the second value as the predetermined value, and the target value of the torque current component of the drive current is The image forming apparatus according to claim 1, wherein the driving of the motor is continued when the value is smaller than the second value.   The control means stops the motor when the deviation between the command phase and the rotational phase determined by the phase determination means is larger than a third value as the predetermined value, and the deviation is the third value. The image forming apparatus according to claim 1, wherein the driving of the motor is continued when the value is smaller than the value.   6. The image forming apparatus according to claim 1, further comprising a notification unit that notifies a user that the sealing member has not been removed when the motor is stopped. The image forming apparatus described in 1.

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