JP2006071951A - Image forming device and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which can detect an abnormal loading of the cartridge in the main part of the device, and efficiently and correctly adjust the amount of the developer in the cartridge, and to provide its control method. <P>SOLUTION: This device has a means of applying bias, a sensor for sensing the amount of the developer in the developer container, a developer amount sensing means for detecting the developer amount in the container by detecting the voltage matching the capacitance between the biased means and the sensor, and a controller for deciding that the cartridge is loaded in state that is unstable in the main part of the device, when the voltage sensed by the developer amount sensor is not within the range set, in advance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an image forming apparatus using an electrophotographic system or an electrostatic recording system, and more particularly to a cartridge such as a process cartridge or a developing device (“developing cartridge”). The present invention relates to an image forming apparatus that can be detachably attached to the main body of the image forming apparatus and includes a developer amount detecting means for detecting the remaining amount of developer in the cartridge, and a control method thereof.

  Conventionally, in an image forming apparatus having a detachable cartridge containing a developer, the amount of developer in the cartridge is detected in order to replace the cartridge at an appropriate timing according to consumption of the contained developer. Means are provided.

  For example, in an image forming apparatus, a developer carrier that carries a developer is provided as a developing unit in a developer accommodating portion of a cartridge or a portion connectable to the developer accommodating portion of a cartridge. The carrier is a member to which a developing bias is applied to move the developer carried during the developing operation to the surface of the image carrier. In the developer container, the carrier is electrostatically opposed to the developer carrier. There is a means for detecting the amount of developer by providing a conductive member for forming a capacitance and detecting a capacitance detection value corresponding to the capacitance of the conductive member.

  Further, Patent Document 1 sequentially detects the amount of developer by measuring a capacitance between sheet metal electrodes to which a bias is applied with a conductive member provided in a cartridge developer container. A method is disclosed.

  However, it has been found that the developer amount detecting means for detecting using the electrostatic capacity has a problem that it is difficult to accurately detect the developer amount when there is an abnormality in the mounting of the cartridge.

  For example, during the image forming operation (printing operation), the posture of the cartridge with respect to the apparatus main body becomes unstable, and the contact point of the bias becomes unstable, so that contact noise may occur in the supplied bias.

  When contact noise occurs, a bias applied to an application member that is a sheet metal electrode, that is, a conductive member, and a conductive member that is paired with the application member, as described in Patent Document 1. In the configuration in which the developer amount is detected by an induced voltage detected according to the capacitance formed between a detection member as a certain capacity component member, contact noise affects the induced voltage, and the induced voltage is It was confirmed that a capacitance value that deviated from the assumed capacity far from the theoretical value of the induced voltage according to the developer amount, which fluctuated greatly, was detected from the capacitance and bias. . In that case, the detected value of the developer amount largely fluctuates, and in some cases, the user may be notified of the wrong developer amount.

As the cartridge, a process cartridge in which an image bearing member such as an electrophotographic photosensitive member bearing an image on the surface and an image forming unit such as a developing unit acting on the cartridge are integrated, and a developer can be accommodated. A developing cartridge or the like in which the developer container is detachable from the image forming apparatus can be considered.
JP 2000-250380 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of detecting an abnormality related to the state of insertion of a cartridge into an image forming apparatus main body and efficiently and accurately controlling the amount of developer in the cartridge, and a control method therefor.

The above object is achieved by the image forming apparatus and the control method thereof according to the present invention. In summary, the first aspect of the present invention is an image forming apparatus in which a cartridge having a developer containing portion for containing a developer for developing an electrostatic latent image formed on an image carrier is detachably provided. ,
An application member to which a bias is applied and a detection member for detecting the amount of developer in the developer accommodating portion are provided, and a voltage corresponding to a capacitance generated between the application member and the detection member is detected. A developer amount detecting means for detecting the developer amount in the developer containing portion based on the detected voltage;
A controller that determines that the state in which the cartridge is inserted into the main body of the image forming apparatus is unstable when the voltage detected by the developer amount detection unit is outside a preset range.
An image forming apparatus is provided.

According to a second aspect of the present invention, there is provided a developer cartridge having a developer accommodating portion for accommodating a developer for developing an electrostatic latent image formed on an image carrier, wherein the developer in the developer accommodating portion is removable. A developer amount detecting means for detecting the amount, the developer amount detecting means comprising an application member to which a bias is applied, and a detection member for detecting the developer amount in the developer accommodating portion, In the control method of the image forming apparatus for detecting a voltage corresponding to the capacitance generated between the application member and the detection member, and detecting the amount of developer in the developer accommodating portion based on the detected voltage.
When the pre-processing before starting the image forming operation is executed, if the voltage detected by the developer amount detecting means is outside the preset range, the state in which the cartridge is inserted into the image forming apparatus main body is unstable. A process of determining that there is,
A step of outputting the determination information that the insertion state of the cartridge is unstable to the outside;
A step of starting an image forming operation after the instability of the inserted state of the cartridge is released,
An image forming apparatus control method is provided.

According to a third aspect of the present invention, there is provided a developer cartridge having a developer containing portion for containing a developer for developing an electrostatic latent image formed on the image carrier, wherein the developer in the developer containing portion is removable. A developer amount detecting means for detecting the amount, the developer amount detecting means comprising an application member to which a bias is applied, and a detection member for detecting the developer amount in the developer accommodating portion, In a control method of an image forming apparatus that detects a voltage corresponding to an electrostatic capacitance generated between an application member and the detection member, and detects a developer amount in the developer storage portion based on the detected voltage.
Determining that the state in which the cartridge is inserted into the main body of the image forming apparatus is unstable when the voltage detected by the developer amount detecting means is outside a preset range during the image forming operation; ,
A step of stopping the image forming operation and outputting the determination information that the inserted state of the cartridge is unstable to the outside.
An image forming apparatus control method is provided.

According to a fourth aspect of the present invention, there is provided a cartridge having a developer accommodating portion for accommodating a developer for developing the electrostatic latent image formed on the image carrier, and the developer amount in the developer accommodating portion is removable. A developer amount detecting means for detecting the developer amount, the developer amount detecting means comprising: an application member to which a bias is applied; and a detection member for detecting the developer amount in the developer accommodating portion; In a method for controlling an image forming apparatus, wherein a voltage corresponding to a capacitance generated between a member and the detection member is detected, and a developer amount in the developer accommodating portion is detected based on the detected voltage.
Determining that the state in which the cartridge is inserted into the main body of the image forming apparatus is unstable when the voltage detected by the developer amount detecting means is outside a preset range during the image forming operation; ,
The image forming operation continues, the developer amount detection value in the cartridge by the developer amount detecting means when the cartridge insertion state is determined to be unstable is invalidated, and the cartridge insertion state is unstable. A step of storing determination information as being history information,
A step of outputting, to the outside, the history information indicating that the insertion state of the cartridge is unstable when post-processing is performed after completion of the image forming operation.
An image forming apparatus control method is provided.

  According to the image forming apparatus and the control method of the present invention, the posture of the cartridge in the image forming apparatus can be corrected, the amount of developer in the cartridge can be efficiently and accurately maintained, and good image formation can be maintained.

  Hereinafter, an image forming apparatus and a control method thereof according to the present invention will be described in more detail with reference to the drawings. However, the relative arrangement of components, the display screen, and the like described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified.

Example 1
FIG. 2 shows a schematic cross section of an embodiment of the image forming apparatus according to the present invention. The image forming apparatus 100 according to the present exemplary embodiment is a laser beam printer that receives image information from an external host device such as a personal computer that is communicably connected to the apparatus body, and outputs the image information as an image visualized by an electrophotographic method. is there. In the image forming apparatus 100 according to the present exemplary embodiment, consumables such as an electrophotographic photosensitive member, a developing unit, and a developer can be attached to and detached from the apparatus main body A as a process cartridge B.

  An image forming operation in the image forming apparatus 100 will be described. The image forming apparatus 100 includes a drum-type electrophotographic photosensitive member that is an image carrier, that is, a photosensitive drum 1. The photosensitive drum 1 is formed by forming a photosensitive material such as OPC or amorphous Si on a cylindrical substrate such as aluminum or nickel, and is driven by a driving means 22 in a predetermined direction in the direction indicated by an arrow a (clockwise) in the figure. Driven at speed.

  Around the photosensitive drum 1, there is provided charging means 2 for uniformly charging the peripheral surface of the rotating photosensitive drum 1 to a predetermined polarity and potential. In this embodiment, a contact charging device (charging roller) 2 that performs a charging process by contacting the peripheral surface of the photosensitive drum 1 is used as a charging unit.

  In order to form an electrostatic latent image on the uniformly charged surface of the charging roller 2 of the photosensitive drum 1, a laser beam scanner 3 is provided as image information exposure means. The laser beam scanner 3 includes a semiconductor laser (not shown), a polygon mirror, an F-θ lens, and the like. The laser beam scanner 3 emits a laser beam L that is ON / OFF controlled in accordance with image information sent from a host device (not shown) that is communicably connected to the apparatus main body A, and is exposed to light. The uniformly charged surface of the drum 1 is scanned and exposed to form an electrostatic latent image.

  Further, a developing device 4 having a developing means is disposed around the photosensitive drum 1, and the developing device 4 develops the electrostatic latent image formed on the photosensitive drum 1 as a toner image. As a developing method, a well-known jumping developing method, two-component developing method, or the like can be used, and it is often used in a combination of image exposure and reversal development. In this embodiment, a negatively charged insulating magnetic one-component developer (toner) is used to apply toner by reversal development to a portion of the negatively charged photosensitive drum 1 where the negative potential is attenuated by exposure. Supply.

  A transfer roller 5 as a transfer unit is provided on the downstream side of the developing device 4 in the rotation direction a of the photosensitive drum 1. In this embodiment, the transfer roller 5 is a rotary-shaped contact charging member having an elastic layer, and is brought into pressure contact with the photosensitive drum 1 to form a transfer nip portion N. The transfer roller 5 is rotationally driven by the driving means 23 in the direction indicated by the arrow b (counterclockwise) in the drawing at a predetermined peripheral speed. The toner image formed on the photosensitive drum 1 is sequentially electrostatically transferred to the recording material P (transfer material) supplied from the recording material supply unit 8 to the transfer nip N.

  The recording material supply unit 8 includes a recording material storage unit such as a recording material cassette 9 and a manual feed tray 11, separation rollers 10 and 12 for separately supplying (feeding) recording materials P one by one, a registration roller 13, and a pre-transfer guide 16. Etc. The recording material P supplied from the recording material storage portions 9 and 11 waits at the pre-feed sensor 14 and then passes through the registration roller 13, the registration sensor 15, and the pre-transfer guide 16, and the transfer nip portion N (image forming portion). Paper is fed to

  The recording material P is supplied to the transfer nip portion N in synchronization with the toner image formed on the surface of the photosensitive drum 1 by the registration sensor 15. The paper feed rollers 10 and 12 are provided to solve the problem of erroneously feeding a plurality of recording materials P when the recording materials P are supplied.

  The recording material P that has received the transfer of the toner image at the transfer nip portion N and has passed through the transfer nip portion N is separated from the surface of the photosensitive drum 1 and is conveyed to the fixing device 7 through the sheet path 17. The fixing device 7 of the present embodiment is a film heating type fixing device configured by a pair of pressure rollers of a heating film unit 7a and a pressure roller 7b. The recording material P holding the toner image is nipped and conveyed by the fixing nip T which is a pressure contact portion between the heating film unit 7a and the pressure roller 7b, and is heated and pressed. As a result, the toner image is fixed on the recording material P and becomes a permanent image.

  The recording material P on which the toner image has been fixed is discharged out of the apparatus by the paper discharge roller 18 face up to the lower tray 19 or face down to the upper tray 20.

  On the other hand, the surface of the photosensitive drum 1 after the toner image is transferred to the recording material P is cleaned by removing the transfer residual toner by the cleaning device 6 and is repeatedly used for image formation. The cleaning device 6 of this embodiment is a blade cleaning device as a cleaning unit, and includes a cleaning blade 6a and a waste toner container 6b that stores residual toner removed from the photosensitive drum 1 by the cleaning blade 6a. Yes.

  Among the image forming means for performing the image forming operation, the photosensitive drum 1 as the image carrier, the charging roller 2 as the charging means, the developing device 4 having the developing means, and the cleaning device 6 are the frame 24 as the process cartridge B. And is detachably mounted on the apparatus main body A via mounting means 21. In this embodiment, a laser scanner 3 is provided above the process cartridge B in the apparatus main body A with the process cartridge B mounted on the apparatus main body A, and faces the photosensitive drum 1 below. A transfer roller 5 is provided.

  Here, the developing device 4 is provided in the process cartridge B, and the developer 40 is accommodated therein. The image forming apparatus includes a developer amount detection unit that can detect the remaining amount of the developer 40 in the process cartridge B according to consumption. Here, with reference to FIG. 3, the developing device 4 and the developer amount detecting means of the process cartridge B will be described in detail.

  The developing device 4 includes a developer (toner) storage unit 41 for storing a magnetic one-component toner (toner), which is a developer 40, a development unit 42 connected to the toner storage unit 41, and a development drum 42. A developing roller 43 that is a developer carrying member as a developing means provided to be opposed to the developing roller 1 and a developing blade that is in contact with the developing roller 43 and is a developer regulating member that regulates the thickness of the toner layer conveyed by the developing roller 43 44 and a stirring member 45 that stirs the toner in the toner storage unit 41 and feeds the toner into the developing unit 42.

  That is, the toner 40 can be accommodated in the toner accommodating portion 41 and the developing portion 42 as the developing means support, and these constitute a developer accommodating portion. A toner sealing member 47 is adhered between the toner container 41 and the developing section 42 before the process cartridge B is used in the developer accommodating section. The toner sealing member 47 is provided so that the toner does not leak even when a severe impact occurs during transportation of the process cartridge B, for example. The toner sealing member 47 is opened by the user immediately before the process cartridge B is mounted on the apparatus main body A.

  After opening the sealing member 47, the process cartridge B sends the toner 40 contained in the toner container 41 to the developing unit 42 while stirring the toner 40 by the stirring member 45. The developing unit 42 includes a developing roller (developer carrying member) 43 that is a nonmagnetic sleeve having a built-in fixed magnet roll as a magnetic field generating unit as a developing unit, and is in the forward direction with the rotation direction a of the photosensitive drum 1. It is rotatably supported in the c direction (counterclockwise direction). As the developing roller 43 rotates, the toner transported on the developing roller 43 is regulated in layer thickness by the developing blade 44 and given triboelectric charge. The toner 40 conveyed to the portion (developing portion) facing the photosensitive drum 1 by the rotation of the developing roller 43 is caused by an electrostatic latent image formed on the photosensitive drum 1 by a developing bias applied to the developing roller 43 during development. The image is transferred to the photosensitive drum 1 according to the image. In this embodiment, a developing bias in which an AC voltage and a DC voltage are superimposed is applied to the developing roller 43 from a developing bias applying means 32 (FIG. 4) which is a bias applying circuit.

  The image forming apparatus 100 includes a developer amount detection unit that can detect the remaining amount of the developer 40 according to consumption of the developer 40 in the developer container of the developing device 4.

  In the present embodiment, as the developer amount detecting means, the developing unit 42 has a capacitance between the developing roller 43 as an application member to which a bias as a developing bias is applied, that is, the developing roller. A bar-shaped conductive member 46 (capacitance antenna) serving as an electrode, that is, a capacitance component (detection member) is installed so as to constitute a capacitor structure as an electrode together with 43.

  The capacitive antenna 46 is a position where the presence / absence of toner in the developing unit 42 and the toner amount in the vicinity of the developing roller 43 can be detected, and the position where the toner circulation in the developing unit 42 is not hindered, that is, the image. In order not to affect the toner, the toner is not uniformly applied to the developing roller 43.

  Any material may be used for the capacitive antenna 46 as long as it is a conductive member. However, a material that does not adversely affect the toner particles and is resistant to environmental conditions such as humidity is desired. And the location made into the shape which can be electrically supplied from the outside is provided in the at least one side. The connectable portion may be directly connected by a conductive wire or the like, or may be in the form of skewering with a conductive pin-shaped conductive member from the side surface of the process cartridge B. In this embodiment, the capacitive antenna 46 is pierced from the side surface of the process cartridge B so as to be parallel to the developing roller 43, and one side surface of the capacitive antenna 46 is attached to a capacitive antenna receiving portion (not shown) provided inside the opposite side surface. Fix it. The pierced side of the capacitive antenna 46 has such a length as to protrude a little from the side wall of the process cartridge B. This protrusion is connected to an electrical contact provided so as to be exposed on the side surface of the process cartridge B, or is configured integrally with the electrical contact.

  Further, a bias is applied from the outside of the process cartridge B to a developer amount detecting means having a developing roller 43 as an applying member and a capacitive antenna 46 as a detecting member, and the electrostatic capacity is measured to thereby determine the toner amount. measure. Here, as this bias, an alternating current which is a developing bias provided for performing the developing process is applied to the developing roller 43, and a voltage value induced in the capacitive antenna 46 is detected. At that time, the dielectric constant generated between the developing roller 43 and the capacitive antenna 46 varies depending on the amount of developer existing between them, and the voltage value induced in the capacitive antenna 46 also varies. The developer amount is detected from these different voltage values.

  FIG. 4 shows a circuit configuration of the developer amount level detection unit when the process cartridge B is normally attached to the apparatus main body A. Each of the apparatus main body A and the process cartridge B is provided with electrical contacts 33A, 33B, 34A, 34B. When the process cartridge B is mounted in the apparatus main body A, the developing roller 43 provided in the process cartridge B and the apparatus main body A through the electric contact 33A (the apparatus main body A side) and the electric contact 33B (the process cartridge B side). A developing bias applying circuit 32 provided in the inside is electrically connected. Further, through the electrical contact 34A (apparatus main body A side) and the electric contact 34B (process cartridge B side), a capacitive antenna 46 provided in the process cartridge B and a developer amount level detection unit 35 provided in the apparatus main body A, Are electrically connected.

  When a DC bias on which a predetermined AC bias is superimposed is output from the developing bias applying circuit 32 as a bias applying means, the applied bias is passed through the apparatus body A side first contact 33A and the process cartridge B side first contact 33B. Then, it is applied to the developing roller 43 as an application member in the developing unit 42. Then, a current induced in the capacitive antenna 46 according to the amount of toner between the developing roller 43 and the capacitive antenna 46 serving as a detection member passes through the process cartridge B side second contact 34B and the apparatus main body side second contact 34A. To the developer level detector 35 of the apparatus main body A.

  In the developer amount level detection unit 35, the detection circuit 36 detects the input voltage value, digitally converts it, and sends it to an arithmetic circuit (arithmetic control unit) 38. The arithmetic control unit 38 compares the detection result of the detection circuit 36 with a developer amount (toner amount) detection threshold value table stored in the storage unit 39, thereby using, for example, the remaining amount% or the number of printable sheets. Is converted into information for notifying the developer of the developer amount level. The developer amount detection threshold table is a means for associating a predetermined capacitance measurement value (detection voltage value) with a developer amount level, and may be in the form of an arithmetic expression.

  Then, the arithmetic control unit 38 transmits the developer amount level detection result to the controller unit 52 via the central processing arithmetic unit (CPU) 51 provided in the apparatus main body A. The controller 52 controls operations performed in the apparatus main body A. The controller unit 52 includes cartridge unstable information processing means, and performs appropriate control according to the developer amount level detection result. Specifically, the information is transmitted to notification means such as a display unit (not shown) installed in the apparatus main body A, and the developer amount level is notified to the user via this notification means.

  Alternatively, the controller unit 52 transmits a signal for notifying the developer amount level to an external host device (not shown) that is communicably connected to the apparatus main body A, and displays the display unit and the like of the external host device. The developer level information similar to the above can be notified to the user via the notification means.

  In this embodiment, as the developing bias applied to the developing roller 43, a DC bias of about −400 V is used in which an AC bias having a frequency of about 2 kHz and an amplitude of 1.8 kV is superimposed. Then, with respect to the developer level detection value detected by the capacitive antenna 46, some warning information such as “the developer is a sufficient remaining amount” and “the developer is extremely decreased” It is possible to notify the user. In addition, in developer level detection, by making it possible to correlate slight changes in capacitance with developer amount, it is possible to detect sequential developer level that can detect continuous changes in developer amount. It is.

  In the process cartridge B of the present embodiment, the developing roller 43 and the capacitive antenna 46 are arranged so that the amount of developer in the developing unit 42 can be measured over a wide range, and a developing bias is applied to the developing roller 43 to thereby provide a capacitive antenna. By detecting the current value induced in 46 in the detection circuit 36 and the arithmetic circuit 38, the detection accuracy is improved, so that the developer amount level in the process cartridge B is sequentially detected.

  By the way, the electrostatic capacity between the developing roller 43 and the capacitive antenna 46 when the developing bias is applied is the mechanical tolerance caused by the installation position of the detection sheet metal included in the developer amount level detecting unit 35, the power supply Variations occur due to electrical tolerances caused by the high-voltage circuit such as 32, the detection circuit 36, etc., environmental tolerances caused by the change in the dielectric constant of the developer depending on the installation environment, etc. Variation occurs from the locus 74 shown in FIG. 5 to the locus 75 or from the locus 75 to the locus 74.

  Therefore, with respect to the variation in capacitance shown in FIG. 5, the capacitance can be taken from a locus 74 when the capacitance changes in the largest direction and a locus 75 when the capacitance changes in the smallest direction. A value range 73 is determined, and threshold information and the like for appropriately notifying the detection range and warning information are optimized so that the optimum developer amount level can be detected within the range of values that the capacitance can take. In addition, the maximum value of the electrostatic capacity when a large amount of developer is present is stored inside the image forming apparatus main body so that accurate detection of the developer amount level can be performed even when fluctuation due to tolerance occurs. There is means for storing and calculating the developer amount level from the amount of change from the maximum value of the capacitance.

  However, when the insertion state of the process cartridge B in the apparatus main body is unstable, the capacitance detection range including various tolerance variations is caused by contact noise generated at the contact portion between the apparatus main body A and the process cartridge B. On the other hand, it was found that a capacitance deviating significantly was detected.

  When the insertion state of the process cartridge B is unstable, when the detection is performed out of the detection range of the capacitance including the tolerance, the notification means Although it is notified that the time for replacement of the process cartridge B is near, such as “developer is very low” or almost no developer amount remains, The amount of developer and the state of the process cartridge B may be erroneously reported, such as notifying that the battery is sufficiently usable, such as “sufficient remaining amount”.

  Here, in the image forming apparatus of this embodiment, the detailed setting of the image forming operation (printing) in the image forming apparatus 100 is set as follows, and the developer amount level detection operation at that time is normal and the process The case where contact noise occurs due to the unstable insertion state of the cartridge B will be specifically described in detail.

  1: The sheet passing speed is set to 30 ppm at which 30 sheets can be continuously passed per minute.

  2: The interval between papers during continuous image formation (sheet passing) is set to an interval of about 0.5 seconds, the start-up preparation time from when a print command is received to when printing is started is 10 seconds, and printing is finished and finish processing is performed. Fall time is 5 seconds.

  3: The amount of developer accommodated in the toner container 41 is 550 g when fully loaded. The electrostatic capacity value of the developing roller 43 and the capacitive antenna 46 at that time is 6 pF, and 2 pF when the developing unit 42 is empty. Indicates. In this embodiment, the position of the developer was adjusted from 150 g so as to show the capacitance change. Further, fine adjustments were made to the position and distance of the capacitive antenna 46 so that when the developer amount was 150 g or more, the transition of the decrease in developer showed a linear transition.

  4: In the developer amount level detection circuit configuration shown in FIG. 4, since the developer amount level detection in the apparatus main body A is performed using an induced voltage corresponding to the capacitance, the developer amount level in the apparatus main body A is detected. The detection voltage of detection is 1V when it is 1 pF, and 3V when it is 7 pF. The detection voltage range in the circuit 38 can be detected within the range of 0V to 3.5V, and the circuit constants such as resistance are adjusted.

  In the above configuration, the developer amount level is detected from the amount of change from the maximum value of the capacitance, and a value indicating the maximum value of the capacitance is stored in the arithmetic circuit 38 in the apparatus main body A.

  In FIG. 6, when the developer amount detection result is normally detected with the above configuration, the induced voltage change detected from the developer weight in the process cartridge B and the electrostatic capacity of the developer amount level detection unit ( FIG. 6A shows the relationship between the change amount (FIG. 6B).

  In this configuration, when the developer amount is reduced from 50 g, “white spots” in which characters and the like are missing due to lack of developer are generated. Therefore, 50 g is used as a guide for replacing the process cartridge B.

  Further, in this embodiment, since the amount of change in induced voltage varies from 150 g, when the amount of change in induced voltage near 150 g in FIG. The ratio is 20%. Similarly, 15% is presented at 0.67 V, and 0% is presented at 1.00 V. At 0%, a warning is given to the user that the process cartridge B will be replaced with a new one.

  Next, the insertion state of the process cartridge B in the apparatus main body A is intentionally made unstable, and the output voltage is checked when noise such as contact noise occurs. Here, the development bias contact is made unstable, and contact noise is generated in the development bias.

  FIG. 7 shows an abnormal development bias (FIG. 7B) when contact noise is generated with respect to a normal development bias (FIG. 7A). Here, the amplitude of the development bias waveform (X portion) in which the contact abnormality used this time is instantaneously decreased.

  When contact noise is generated in the developing bias, as shown in FIG. 8, the abnormal induced voltage detection value 72 has a larger detection range than the normal induced voltage detection value 71 generated in the capacitive antenna 46 in this configuration. You can see that it is deviating.

  When contact noise occurs, the detected component of the induced voltage fluctuates in the direction in which the detected value of the induced voltage increases despite the fact that the amplitude component of the developing bias waveform is small. In the capacitance detection means using the induced voltage in the circuit, the induced voltage generated in the capacitive antenna 46 is determined by the capacitance C, the applied bias amplitude V, and the applied bias frequency f, and includes the contact noise applied this time. The bias is based on the result of the phenomenon that the frequency on the circuit is apparently increased due to the momentary decrease in amplitude.

  Furthermore, if the detected value deviates greatly, the maximum value of the capacitance is fixed at the deviated value, or is fixed at the maximum value within the detection range. Cause a large error.

  Therefore, in this embodiment, the developer amount level is detected during the print preparation operation performed when the power is turned on or when the cartridge B is inserted, that is, during the pre-printing operation operation during the pre-rotation. When a detected capacitance value other than the expected value including various tolerance fluctuations in the detection circuit is detected, the insertion state of the process cartridge B into the apparatus main body A is unstable based on the capacitance value. If the process cartridge B is unstable, the user is informed that the insertion of the process cartridge B is unstable, and is urged to correct the insertion state of the process cartridge B. .

  That is, when the induced voltage detected by the electrostatic capacity detection means as the developer amount detection means is outside the preset range, the state where the cartridge B is inserted into the image forming apparatus main body A is unstable. Judge that there is. In other words, the cartridge B insertion state instability determination information is transmitted to the CPU 51 shown in FIG. In this embodiment, the determination information is processed so as to be output to the outside by an operation panel which is a notification means.

  When the value for detecting that the attitude of the process cartridge B is unstable under the above setting conditions is set for a large fluctuation that exceeds a fluctuation range including a mechanical tolerance and an electrical tolerance, the detection voltage becomes 1. It was suitable to judge that the state outside the range of 0V to 3.0V, that is, the state of 3.0V or higher or the state of 1.0V or lower is an abnormal state.

  When it is determined that the posture of the process cartridge B is unstable, a warning such as “Positive posture” is set to be displayed on an operation panel (not shown) as notification means attached to the apparatus main body A. Therefore, when the process cartridge B was inserted in an unstable manner so as to generate contact noise, “posture failure” was displayed on the operation panel after the print preparation operation was completed. When the process cartridge B was reinserted so that the posture of the process cartridge B became normal inside the apparatus main body A, a printing operation could be performed.

  Based on the above results, refer to FIG. 1 for an example of a sequence until the instability of the insertion posture of the process cartridge B into the apparatus main body A in the image forming apparatus 100 in this embodiment is detected and notified to that effect. Further explanation will be given. The following sequence is executed by the central processing unit (CPU) 51.

  In FIG. 1, the apparatus main body A is turned on and waits in a standby state until a print command is received (step 1).

  During the standby state, the presence or absence of the process cartridge B (CRG) is detected using, for example, a developer amount detection means (step 2). If the process cartridge B is not inserted, the operation panel or the like is used to notify the user. On the other hand, the fact is notified (step 9).

  When insertion of the process cartridge B is confirmed, pre-processing operations for image formation (printing) such as pre-rotation and warm-up operation of the fixing device are performed (step 3).

  Judgment whether a value resulting from the unstable insertion state of the process cartridge B has been detected in the induced voltage induced in the capacitive antenna 46 detected in the detection of the developer amount in the cartridge B during the pre-printing processing operation. (Step 4).

  If it is determined that the posture is unstable, the operation panel or the like informs that the posture of the process cartridge B is unstable and prompts to correct the posture (step 10).

  Further, when informing that the posture is corrected, for example, the notification is continued until it is confirmed that the process cartridge B has been inserted or removed (step 11). After adjusting the insertion state of the process cartridge B, the process returns to step 2 again, and the operation is repeated. If the value resulting from the unstable insertion state of the process cartridge B is not detected in step 4, the process returns to step 5. move on.

  After receiving the print command (step 5), after all the image data has been stored in the image signal storage area inside the apparatus main body A, the printing operation is performed (step 6).

  Analyzes the detection value of the developer amount level detected during the printing operation, stores the maximum capacitance value obtained from the detected value, calculates the developer amount level, and alerts the user If necessary, this is notified on the operation panel or the like (step 7).

  When all the operations are normally completed, the end operation is performed, and a standby state is taken until the next print command is received (step 8).

  In the above-described sequence, when displaying that the insertion state of the process cartridge B is unstable on the operation panel or the like, or when displaying that the process cartridge B is not inserted, the central processing unit (CPU) Information 51 indicates that the insertion state of the process cartridge B is unstable, and information indicating that the process cartridge is not inserted is output to the operation panel for display.

  Even if the insertion posture of the process cartridge B is unstable by detecting the insertion state of the process cartridge B into the apparatus main body A according to the induced voltage value obtained from the capacitive antenna 46 in step 4 of the above-described sequence. The user can be notified of this, and the insertion posture of the process cartridge B can be corrected, and the developer amount level can be detected with high accuracy.

  Note that the scope of the present invention is given as an example with respect to the bias value, the bias causing contact noise, and other values as described in the present embodiment, and is not limited thereto. . In the present embodiment, a configuration using the developing roller 43 and the capacitive antenna 46 is adopted as the developer level detection means in the process cartridge B. However, the configuration is limited to this as long as the configuration uses electrostatic capacitance. Instead, the application member and the detection member may be a combination of other conductive members. For example, instead of using the developing roller 43 as the application member, a sheet metal similar to the capacitive antenna 46 generates capacitance. It is good also as a structure which applies this voltage.

  The configurations of the image forming apparatus and the cartridge to which the present invention can be applied are not limited to those described above. For example, in this embodiment, a process cartridge having a photosensitive drum as an image carrier is used. However, any cartridge that can be detachably attached to the image forming apparatus main body and has a developer accommodating portion and an internal developer amount detecting means. For example, it may be a developing cartridge including only a developer accommodating portion provided with a developer amount detecting means which is an application member and a detecting member.

  The image forming apparatus may also be a color image forming apparatus that includes a plurality of cartridges, each containing a different color developer, or may have an intermediate transfer member. The developer is also a negatively chargeable one-component magnetic toner in this embodiment, but may be a non-magnetic toner, a two-component developer, or a positively chargeable toner.

  The same effect is assumed due to contact failure or contact noise generated in the developer amount level detection circuit in addition to contact noise generated in the high-voltage contact portion due to unstable cartridge insertion. Even when an external capacitance is detected, the same effect can be obtained by using the means shown in this embodiment. Also, the bias values presented in the present embodiment and the values described with reference to the drawings are examples for explaining the present invention, and are not limited thereto.

Example 2
Next, another embodiment of the present invention will be described. Since the basic configuration and operation of the image forming apparatus according to the present exemplary embodiment are the same as those of the first exemplary embodiment, elements having the same function and configuration are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the first embodiment, the determination that the process cartridge B is not normally attached to the apparatus main body A is performed using the detection value obtained from the capacitive antenna 46 during the pre-printing processing operation (pre-rotation), and the insertion state is unstable. In the case where it is determined that there is, the embodiment has been described in which the user is informed and the insertion state is corrected so that the developer amount level can be stabilized.

  The insertion state of the process cartridge B in the apparatus main body A can be detected in most cases in the pre-printing process stage (during pre-rotation operation), but as the printing operation continues, depending on the case, during the printing operation (during image formation) ) May be unstable.

  Therefore, in this embodiment, even when paper is passed in the printing operation, the detection range is greatly deviated and an abnormal induced voltage value is detected in the capacitive antenna 46, that is, between the developing roller 43 and the capacitive antenna 46. An example will be described in which contact noise occurs due to the detection of an abnormal capacitance, and the process cartridge B is determined to be in an unstable state.

  Again, if it is determined that the state in which the cartridge B is inserted into the image forming apparatus main body A is unstable, the determination information is transmitted to the controller unit 52 (FIG. 4), and the controller unit 52 detects it. The value is not adopted in the calculation in the developer amount level detection unit 35, and the printing operation is stopped and the user is notified from the operation panel to prompt the user to correct the attitude of the process cartridge B.

  Here, a printing operation was performed with the apparatus settings described in Example 1, a normal developing bias was applied during the pre-rotation, and after printing several sheets, an abnormal developing bias was applied. In this way, from the state where the normal development bias is applied, the printing operation is stopped at the moment when the abnormal development bias is applied, and “Position Poor” is displayed on the operation panel, and the printing operation is stopped.

  That is, when the insertion state of the process cartridge B becomes unstable and an abnormal induced voltage is generated in the capacitive antenna 46, the process cartridge B is output as “posture defect”, so that the posture of the process cartridge B is the main body of the apparatus. A can be reinserted so as to be normal inside A, and a normal printing operation can be obtained again.

  Based on the above results, in the image forming apparatus 100 according to the present exemplary embodiment, an example of a sequence from detection of instability of the insertion posture of the process cartridge B to the apparatus main body A and notification to that effect with reference to FIG. Further explanation will be given. The following sequence is executed by the central processing unit (CPU) 51.

  In FIG. 9, the apparatus main body A waits in a standby state until the power is turned on and a print command is received (step 1).

  In the standby state, the presence / absence of the process cartridge B is detected by the above method (step 2), and if the process cartridge B is not inserted, the user is notified on the operation panel or the like (step 8). When insertion of the process cartridge B is confirmed, a pre-printing processing operation is performed.

  After receiving the print command (step 3), after all the image data has been stored in the image signal storage area inside the apparatus main body A, the printing operation is performed (step 4).

  The detection value of the developer amount level detection obtained during the printing operation is analyzed, and it is determined whether a value resulting from the unstable insertion state of the process cartridge B has been detected (step 5).

  If it is determined that the posture is unstable, the printing operation is stopped (step 9), the operation panel or the like informs that the posture of the process cartridge B is unstable, and prompts the posture to be corrected (step 10). ).

  If it is notified that the posture is corrected, the operation is stopped until the insertion state of the process cartridge B can be confirmed (step 11).

  When it is confirmed that the insertion of the process cartridge B is correct, the same print image is printed again (step 4), and the detection value is analyzed again (step 5).

  When the detected value is within the normal range, the maximum value of the electrostatic capacity obtained from the detected value is stored and the developer amount level is calculated. Notification is made (step 6).

  When all the operations are normally completed, the end operation is performed and a standby state is taken until the next print command is received (step 7).

  In the above-described sequence, when displaying that the insertion state of the process cartridge B is unstable or displaying that the process cartridge B is not inserted on the operation panel or the like, the central processing unit (CPU) Information 51 indicates that the insertion state of the process cartridge B is unstable, and information indicating that the process cartridge B has not been inserted is output to the operation panel for display.

  Even if printing is performed by detecting the insertion state of the process cartridge B into the apparatus main body A in accordance with the induced voltage and capacitance value obtained from the capacitive antenna 46 in step 5 which is the time of image formation in the above sequence. Even if the insertion posture of the process cartridge B becomes unstable during operation, it is possible to notify the user and correct the insertion posture of the process cartridge B, and printing is performed while the insertion state of the process cartridge B is unstable. The operation is not continued and the developer amount level can be detected with high accuracy.

  In this embodiment, the same effects as those of the first embodiment can be achieved. Further, in the sequence of FIG. 9, if the process of detecting the developer amount at the time of the previous rotation is added as in the first embodiment, and the insertion state of the process cartridge B can be confirmed both at the time of the previous rotation and during the image forming operation, More preferred.

Example 3
Next, another embodiment of the present invention will be described. Since the basic configuration and operation of the image forming apparatus of the present embodiment are the same as those of the first and second embodiments, elements having the same functions and configurations are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the first embodiment, the determination that the process cartridge B is not normally attached to the apparatus main body A is performed using the detection value obtained from the capacitive antenna 46 during the pre-printing processing operation (pre-rotation), and the insertion state is not satisfactory. The embodiment has been described in which the developer amount level can be stabilized by notifying the user of the fact that it is determined to be stable and correcting the insertion state.

  Further, in the second embodiment, when it is determined that the process cartridge B is not normally attached to the apparatus main body A during the printing operation (at the time of image formation), the fact is transmitted to the controller unit 52 and the developer amount level is determined. An embodiment in which the detection value is not adopted for calculation, the user is informed, and the printing operation is interrupted to correct the insertion state of the process cartridge B, thereby making it possible to stabilize the developer amount level. Explained.

  By the way, even if contact noise occurs due to the unstable insertion state of the process cartridge B and affects the developer amount level detection, there is almost no influence on the output print image.

  Therefore, in this embodiment, when it is determined that the insertion state of the process cartridge B is unstable, the controller unit 52 stops only the developer amount level detection operation, and continues the print command stored in the apparatus main body A. In addition, the history of determining that the insertion state is unstable is stored, and after the image forming operation by the print command is completed, that is, when post-processing is executed (for example, to make the surface potential of the photosensitive drum uniform) In the post-rotation operation), the user is notified of that.

  In other words, in this embodiment, the history of the determination that the insertion state of the process cartridge B is unstable is stored in the arithmetic circuit 38 (FIG. 4) of the developer amount level detection unit in the apparatus main body A. Set to do.

  Here, in the image forming apparatus 100 according to the present embodiment, a sequence from when the state in which the insertion posture of the process cartridge B to the apparatus main body A is unstable is detected and notified to that effect is further described with reference to FIG. explain. The following sequence is executed by the central processing unit (CPU) 51.

  In FIG. 10, the apparatus body A is turned on and is in a standby state until the control mechanism receives a print command (step 1).

  In the standby state, the presence or absence of the process cartridge B is detected (step 2), and if the process cartridge (CRG) B is not inserted, the user is notified of this through the operation panel or the like (step 10). When the insertion of the process cartridge B is confirmed, a pre-printing processing operation is performed.

  After receiving the print command (step 3), after all the image data has been stored in the image signal storage area inside the apparatus main body A, the printing operation is performed (step 4).

  The detection value of the toner amount detection obtained during the printing operation is analyzed, and it is determined whether the electrostatic capacitance value resulting from the unstable insertion state of the process cartridge B has been detected (step 5).

  If it is determined that the posture is unstable, a history of detecting that the insertion posture is unstable is stored (step 11).

  The printing operation is continued until the printing of the image information stored in the apparatus main body A is completed.

  Then, a post-processing operation (post-rotation operation) when all the printing of the image information based on the print command is completed is performed (step 6), and at that time, the presence or absence of a contact failure history is confirmed (step 7), If there is a history, it is notified to the user (step 12).

  Thereafter, when the insertion posture of the process cartridge B is corrected (inserted / removed) (step 13), the history is deleted (step 14).

  In addition, when a detection value determined to have an unstable insertion posture is used for the calculation of the developer amount level, accurate detection of the developer level cannot be performed, and thus the detection value is not used for the calculation. Also, once it is determined that the insertion state is unstable, the detected value is unstable until the insertion state of the process cartridge B is corrected. Until the posture of the process cartridge B is corrected (inserted / removed) from the detection value, all the detection values obtained by the developer amount level detection are not used for the calculation of the developer amount.

  That is, when it is determined that the insertion state of the cartridge B is unstable, the developer amount detection value in the cartridge B at the time of determination is invalidated.

  In step 5, when the developer level detection value is obtained in a normal state, the developer amount is calculated from the detected value of the developer level detection, and a warning is required for the user. To that effect (step 8).

  When all the operations are completed normally, the operation is terminated and a standby state is taken until the next print command is received (step 9).

  In the above-described sequence, when displaying that the insertion state of the process cartridge B is unstable on the operation panel or the like, or when displaying that the process cartridge B is not inserted, the central processing unit (CPU) Information 51 indicates that the insertion state of the process cartridge B is unstable, and information indicating that the process cartridge B has not been inserted is output to the operation panel for display.

  In step 5 of the above-described sequence, the insertion state of the process cartridge B into the apparatus main body A is detected according to the induced voltage value and capacitance value obtained from the capacitive antenna 46, and the insertion posture of the process cartridge B is unstable. In step 11, the fact that the insertion state of the process cartridge B is unstable is stored in step 11, the printing operation is continued as long as the printing command remains in the apparatus main body A, and all the printing commands are completed. Later, in step 12, the user is informed that the posture of the process cartridge B is unstable, and the developer amount detection value in the cartridge B is invalidated when the insertion of the cartridge B is unstable. As a result, the posture of the cartridge B can be corrected after the image forming operation is completed, and it is not necessary to stop the image forming operation. , The improvement of the performance of the print output, it is possible to perform highly accurate developer amount level detection.

  In this embodiment, the same effects as those of the first and second embodiments can be achieved.

It is a flowchart which shows an example of the image formation operation | movement which performed the control method which concerns on this invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. It is a schematic block diagram which shows an example of the cartridge which concerns on this invention. FIG. 3 is a block diagram illustrating an example of an in-cartridge developer amount detection unit and a control mechanism thereof according to the present invention. 6 is a graph showing the relationship between the electrostatic capacity detected by the developer amount detecting means and the developer amount in the cartridge. 7 is a graph showing the relationship between the developer weight in the cartridge and the detection amount detected by the developer amount detection means (FIG. 6A) and the relationship between the detected voltage change amount (FIG. 6B). FIG. 8 is a waveform diagram of a developing bias in a normal state (FIG. 7A) and a state where contact noise is generated (FIG. 7B). 6 is a graph showing a comparison of developer amount detection voltage values in a normal state and in a state where contact noise occurs. It is a flowchart which shows the other example of the image formation operation | movement which performed the control method which concerns on this invention. It is a flowchart which shows the other example of the image formation operation | movement which performed the control method which concerns on this invention.

Explanation of symbols

1 Photosensitive drum (image carrier)
4 Developing Device 32 Developing Bias Applying Unit 33A, 33B, 34A, 34B Electrical Contact 35 Developer Amount Level Detection Unit 41 Toner Storage Unit (Developer Storage Unit)
42 Development unit (developer storage unit)
43 Development roller (developer carrier, application member)
46 Capacitive antenna (detection member)
51 Central processing unit CPU
52 Controller A A Image forming apparatus body B Process cartridge (cartridge)

Claims (8)

An image forming apparatus in which a cartridge having a developer containing portion for containing a developer for developing an electrostatic latent image formed on an image carrier is detachably provided.
An application member to which a bias is applied and a detection member for detecting the amount of developer in the developer accommodating portion are provided, and a voltage corresponding to a capacitance generated between the application member and the detection member is detected. A developer amount detecting means for detecting the developer amount in the developer containing portion based on the detected voltage;
A controller that determines that the state in which the cartridge is inserted into the main body of the image forming apparatus is unstable when the voltage detected by the developer amount detection unit is outside a preset range.
An image forming apparatus. When the controller unit determines that the insertion state of the cartridge is unstable, the controller unit includes means for outputting the determination information to the outside.
The image forming apparatus according to claim 1. If the controller determines that the cartridge is in an unstable insertion state, invalidates the developer amount detection value in the cartridge by the developer amount detection means at the time of the determination;
The image forming apparatus according to claim 2. The cartridge has a developer carrier that carries the developer in the developer container and conveys the developer to the electrostatic latent image on the surface of the image carrier.
The developer carrying member also serves as the application member, and the bias is applied to the developer carrying member in order to move the developer carried on the developer carrying member onto the image carrying member. Bias,
The image forming apparatus according to claim 1, 2 or 3.   5. The image formation according to claim 1, wherein the cartridge is a process cartridge including at least the image carrier and a developing unit that develops the electrostatic latent image. apparatus. An amount of developer for detecting the amount of developer in the developer accommodating portion, the cartridge having a developer accommodating portion for accommodating a developer for developing the electrostatic latent image formed on the image carrier, which is detachable. The developer amount detecting means includes an application member to which a bias is applied, and a detection member for detecting the developer amount in the developer accommodating portion, and the application member and the detection member In the control method of the image forming apparatus for detecting a voltage corresponding to the electrostatic capacity generated between and detecting the amount of developer in the developer containing portion based on the detected voltage,
If the voltage detected by the developer amount detecting means is outside a preset range when pre-processing before the image forming operation is started, the state where the cartridge is inserted into the image forming apparatus main body is unstable. A process of determining that there is,
A step of outputting the determination information that the insertion state of the cartridge is unstable, to the outside;
A step of starting an image forming operation after the instability of the inserted state of the cartridge is released,
A control method for an image forming apparatus. An amount of developer for detecting the amount of developer in the developer accommodating portion, the cartridge having a developer accommodating portion for accommodating a developer for developing the electrostatic latent image formed on the image carrier, which is detachable. The developer amount detecting means includes an application member to which a bias is applied, and a detection member for detecting the developer amount in the developer accommodating portion, and the application member and the detection member In the control method of the image forming apparatus for detecting a voltage corresponding to the electrostatic capacity generated between and detecting the amount of developer in the developer containing portion based on the detected voltage,
Determining that the state in which the cartridge is inserted into the main body of the image forming apparatus is unstable when the voltage detected by the developer amount detecting means is outside a preset range during the image forming operation; ,
A step of stopping the image forming operation and outputting the determination information that the inserted state of the cartridge is unstable to the outside.
A control method for an image forming apparatus. An amount of developer for detecting the amount of developer in the developer accommodating portion, the cartridge having a developer accommodating portion for accommodating a developer for developing the electrostatic latent image formed on the image carrier, which is detachable. The developer amount detecting means includes an application member to which a bias is applied, and a detection member for detecting the developer amount in the developer accommodating portion, and the application member and the detection member In the control method of the image forming apparatus for detecting a voltage corresponding to the electrostatic capacity generated between and detecting the amount of developer in the developer containing portion based on the detected voltage,
A step of determining that the state in which the cartridge is inserted into the main body of the image forming apparatus is unstable when the voltage detected by the developer amount detecting means is outside a preset range during the image forming operation; ,
The image forming operation continues, invalidates the developer amount detection value in the cartridge by the developer amount detection means when it is determined that the cartridge insertion state is unstable, and the cartridge insertion state is unstable. A step of storing determination information as being history information,
A step of outputting to the outside the history information that the cartridge insertion state is unstable when post-processing is performed after completion of the image forming operation.
A control method for an image forming apparatus.

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