JP2017142380A - Image forming apparatus and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology advantageous for determining, in a shorter time, whether a toner storage container (toner bottle) has been replaced in an image forming apparatus.SOLUTION: An image forming apparatus (MFP), when the possibility arises that a toner bottle has been replaced by a user after determining the absence of toner in a developing unit (YES in S103), executes an operation to supply a toner from the toner bottle to the developing unit (S105). The MFP further determines whether the toner bottle has been replaced on the basis of a change in output frequency of an ON signal from a toner sensor in the developing unit (the number of times N the ON signal is output per unit time) according to the execution of the toner supply operation (S108 to S111).SELECTED DRAWING: Figure 4

Description

  The present invention relates to an electrophotographic image forming apparatus and a control method thereof.

  2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus such as a printer, a copying machine, or a facsimile machine, an electrostatic latent image formed on a photosensitive member is developed using a developer (toner) in a developing unit, thereby generating toner. Form an image. The toner image formed on the photosensitive member is transferred to a recording material such as a sheet, whereby a printed matter is generated. In such an image forming apparatus, the toner consumed in the developing device is supplied to the developing device from a toner bottle that can be replaced by the user.

  In general, an image forming apparatus includes a sensor for detecting toner in a developing device in order to supply a necessary amount of toner from a toner bottle to the developing device. For example, when the image forming apparatus determines that there is no toner in the developing device based on the output of the sensor, the toner bottle or the stirring member in the toner bottle is rotated by a toner bottle motor, thereby supplying the toner from the toner bottle to the developing device. Perform replenishment operation to replenish. Further, the image forming apparatus determines that no toner remains in the toner bottle if the determination result based on the output of the sensor does not change from the absence of toner to the presence of toner even if the toner replenishment operation is continued for a certain period of time. Prompt the user to replace the toner bottle. Thereafter, when the image forming apparatus detects the possibility that the toner bottle has been replaced based on detection of opening / closing of the door or the like, the image forming apparatus performs the toner supply operation again.

  In the above operation example, for example, when the user accidentally opens or closes the door, or accidentally replaces the empty toner bottle, the toner is replenished in the developing device even if the toner replenishment operation is continued for a certain period of time. It will never be done. As a result, the image forming apparatus notifies the user of replacement of the toner bottle again, and the downtime of the image forming apparatus becomes longer due to the time required to perform such notification. With respect to such a problem, Patent Document 1 requires such a determination by determining whether the toner bottle has been replaced based on the rotational speed obtained from the FG signal output from the toner bottle motor. A technique for reducing time is described. Patent Document 2 describes a technique for determining whether a toner bottle has been replaced based on a measurement result of a load (current value) of a toner bottle motor.

JP 2009-288679 A JP2013-97005A

  However, in Patent Document 1, in order to obtain the rotation speed from the FG signal, a port for inputting the FG signal and a motor for outputting the FG signal are required, which may increase the apparatus cost. Further, in Patent Document 2, when the toner bottle motor is replaced with a non-genuine toner bottle (a toner bottle containing toner of a component different from the regular toner contained in the genuine toner bottle), the measurement result of the load on the toner bottle motor is obtained. The result can be different from that of regular toner. In that case, an error may occur in the determination of whether or not the toner bottle has been replaced.

  The present invention has been made in view of the above-described problems, and provides an advantageous technique for determining in a shorter time whether or not a toner container (toner bottle) has been replaced in an image forming apparatus. Objective.

  The present invention can be realized as an image forming apparatus, for example. An image forming apparatus according to an aspect of the present invention includes: a detection unit that detects toner supplied from a toner storage container to a developing device by a toner supply unit; a first determination unit that determines replacement of the toner storage container; The supply state of the toner supplied by the toner supply unit that is detected by the detection unit and changes after the first determination unit determines the replacement of the toner container, and the toner supply unit before the change supplies And a second determination unit that compares the toner supply state to be determined and determines the toner supply state by the toner supply unit after the toner determination unit replacement determination by the first determination unit. And

  According to the present invention, it is possible to provide an advantageous technique for determining in a shorter time whether or not the toner storage container has been replaced.

FIG. 2 is a cross-sectional view illustrating a configuration of an MFP according to an embodiment. FIG. 3 is a schematic diagram illustrating a configuration of a toner supply unit according to an embodiment. FIG. 2 is a block diagram illustrating a configuration of a control system of the MFP according to an embodiment. 6 is a flowchart (first example) illustrating a procedure of determination processing related to toner bottle replacement in the MFP according to the embodiment; 9 is a flowchart (second example) illustrating a procedure of determination processing related to toner bottle replacement in the MFP according to an embodiment. FIG. 6 is a diagram (first example) illustrating an example of the measurement timing of the number of ON signal outputs from a toner sensor in an MFP according to an embodiment. FIG. 10 is a diagram (second example) illustrating an example of the measurement timing of the number of ON signal outputs from the toner sensor in the MFP according to an embodiment.

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

  The image forming apparatus according to the present embodiment is an apparatus that forms an image on a sheet by an electrophotographic method, such as a printing apparatus (printer), a copier, a multifunction peripheral (MFP), and a facsimile machine. Note that a multifunction peripheral is an apparatus having at least two or more functions among a plurality of types of functions including, for example, a print function, a scan function, a copy function, and a facsimile function. Here, a case where the image forming apparatus is an MFP having a printing function, a scanning function, and a copying function will be described.

<Image forming apparatus (MFP)>
FIG. 1 is a cross-sectional view illustrating a configuration of the MFP 100 according to the present embodiment. The MFP 100 may be an image forming apparatus that forms a multicolor image using a plurality of colors of toner (developer), but an image forming apparatus that forms a single color image using a single color toner will be described. The MFP 100 includes a printer unit 101 that forms an image on a sheet, a reader unit 102 that reads an image of a document, and an ADF unit 103 that transports a document to be read. The sheet may be referred to as recording paper, recording material, recording medium, paper, transfer material, transfer paper, or the like.

  In the printer unit 101, the recording paper P stored in the paper feed cassette 110 is fed to the transport path one by one by the pickup roller 111, the paper feed roller 112 and the retard roller 113. The recording paper P fed from the paper feed cassette 110 is transported along the transport path by the transport roller 114. When the recording paper P reaches the position of the registration roller pair 115, skew correction is performed by the stopped registration roller pair 115. Thereafter, when the registration roller pair 115 starts to rotate, the recording paper P is conveyed to the transfer nip portion between the photosensitive drum 131 and the transfer roller 133.

  In the printer unit 101, the laser scanner unit 120, the photosensitive drum (photosensitive member) 131, the charging roller 132, the transfer roller 133, and the developing device 140 constitute an image forming unit that forms an image on the recording paper P. In the image forming portion, the outer peripheral surface of the rotationally driven photosensitive drum 131 is uniformly charged to a predetermined polarity potential by the action of the charging roller 132. The laser scanner unit 120 exposes the charged photosensitive drum 131 with a light beam (laser light). Specifically, the laser scanner unit 120 outputs laser light L that is modulated according to image information (time-series digital pixel signals), and scans the charged photosensitive drum 131 with the laser light L, thereby performing photosensitivity. An electrostatic latent image is formed on the drum 131. The laser scanner unit 120 uses the laser beam L based on image data (image information) obtained by reading an image of a document by the reader unit 102 or image data received from an external device such as a PC via a network. Is output.

  The developing device 140 includes a developing roller 141 and develops the electrostatic latent image on the photosensitive drum 131 using toner supplied (supplied) from the toner replenishing unit 150 to form a toner image. The toner image formed on the photosensitive drum 131 moves to the transfer nip portion as the photosensitive drum 131 rotates. By applying a transfer bias having a polarity opposite to that of the photosensitive drum 131 to the transfer roller 133, the toner image on the photosensitive drum 131 is transferred to the surface of the recording paper P at the transfer nip portion.

  The recording paper P on which the toner image is transferred in the image forming unit is conveyed into the fixing device 160. The fixing device 160 fixes the toner image on the recording paper P to the recording paper P by applying heat and pressure to the recording paper P by a fixing heater and a pressure roller. The recording paper P on which an image has been formed in this manner is discharged (discharged) to the discharge tray 171 outside the apparatus by the discharge roller 170 after passing through the fixing device 160.

  When double-sided printing is performed on the recording paper P, the recording paper P on which image formation on the first surface has been completed is transported in the reverse direction by the paper discharge roller 170 after passing through the position of the reverse flapper 181 and reversed. It is guided to the reverse conveyance path 180 by the flapper 181. The recording paper P guided to the reverse conveyance path 180 is conveyed again to the position of the registration roller pair 115 by the conveyance rollers 182 and 183. At that time, the recording paper P is in a state in which the first surface and the second surface are reversed as compared with the image formation on the first surface. Thereafter, the recording paper P is discharged to the paper discharge tray 171 after the image formation on the second surface is performed in the same manner as the image formation on the first surface.

<Toner supply part>
FIG. 2 is a schematic diagram illustrating the configuration of the toner replenishing unit 150 in the MFP 100. A toner bottle (toner storage container) 200 pre-filled with toner is installed in the toner supply unit 150 by the user. The toner supply unit 150 includes a toner bottle 200, a bottle motor 201, a toner conveyance path 210, a screw 212 provided in the toner conveyance path 210, and a screw motor (conveyance path motor) 211. The toner conveyance path 210 is provided between the toner bottle 200 and the developing device 140 and corresponds to a toner hopper (storage unit) that stores toner discharged (supplied) from the toner bottle 200. The toner conveyance path 210 is used for conveying the toner discharged from the toner bottle 200 to the developing device 140. Although not shown in FIG. 2, a motor drive circuit that drives each motor is provided for the bottle motor 201 and the screw motor 211. The CPU 400 controls driving of each motor by controlling each motor driving circuit.

  The rotation axis of the toner bottle 200 is connected to the bottle motor 201 via a drive gear train (not shown), and a rotational driving force can be applied from the bottle motor 201 via the drive gear train. When the bottle motor 201 is driven to rotate, the toner bottle 200 rotates in the direction indicated by the arrow A. As the toner bottle 200 is driven and rotated by the bottle motor 201, the toner is discharged from the inside of the toner bottle 200 and flows into the toner conveyance path 210.

  A screw 212 is provided in the toner conveyance path 210. The rotating shaft of the screw 212 is connected to the screw motor 211 via a drive gear train (not shown), and a rotational driving force is applied from the screw motor 211 via the drive gear train. The screw 212 is driven and rotated by the screw motor 211 to convey the toner flowing from the toner bottle 200 into the toner conveyance path 210 in one direction (from left to right in FIG. 2). The toner conveyed through the toner conveyance path 210 is discharged to the developing device 140 at the end of the toner conveyance path 210. Note that a toner sensor 221 for detecting the presence or absence of toner in the developing device 140 is provided inside the developing device 140.

<MFP control system>
FIG. 3 is a block diagram showing the configuration of the control system of MFP 100 according to the present embodiment. FIG. 3 shows a configuration particularly related to the present embodiment, such as determination processing relating to replacement of the toner bottle 200 described later. The MFP 100 includes a CPU 400, a ROM 401, a RAM 402, and an EEPROM 403 as a control system.

  The ROM 401 stores a control program for controlling the entire MFP 100. The RAM 402 is a volatile storage device (memory) that is used as a work area of the CPU 400 and is used for temporarily storing various data such as image data. CPU 400 controls MFP 100 as a whole by reading a control program stored in ROM 401 into RAM 402 and executing it. The EEPROM 403 is a non-volatile storage device (memory) and is used to hold various data such as the remaining amount of toner in the toner bottle 200.

  The operation unit 410 includes a display unit (liquid crystal display or the like), receives a user operation, transmits operation information indicating the content of the user operation to the CPU 400, and operates an operation screen based on the screen information transmitted from the CPU 400. Is displayed on the display. For example, the CPU 400 can notify the user by displaying on the operation unit 410 a replacement message that prompts the user to replace the toner bottle 200.

  The CPU 400 controls the operation of the toner replenishing unit 150 by controlling the driving of the bottle motor 201 and the screw motor 211. A signal output from the toner sensor 221 of the developing device 140 is input to the CPU 400. The CPU 400 controls the supply (replenishment) of toner from the toner replenishing unit 150 to the developing device 140 based on the signal output from the toner sensor 221.

  The toner sensor 221 is, for example, a magnetic permeability sensor. When toner containing magnetic material is detected, the toner sensor 221 outputs an ON state signal (ON signal), and when no toner is detected, an OFF state signal (OFF signal). Output. As described above, when the toner sensor 221 detects toner, the toner sensor 221 outputs an ON signal as a detection signal indicating that the toner has been detected. The CPU 400 determines (detects) the presence or absence of toner in the developing device 140 based on the output signal from the toner sensor 221.

In this embodiment, the CPU 400 sets the number N of ON signal outputs per unit time from the toner sensor 221 while a stirring member (not shown) for stirring the toner in the developing device 140 is rotating. Based on this, the presence or absence of toner in the developing device 140 is determined. CPU400, if the output count N of the ON signal from the toner sensor 221 is higher than the reference value N _th, it is determined that the toner is present in the developing device 140, the output number N has exceeded the reference value N _th If not, it is determined that there is no toner in the developing device 140.

  When the CPU 400 detects that there is no toner in the developing device 140 based on the output signal from the toner sensor 221, the toner replenishing operation (supplying) for replenishing (supplying) toner from the toner bottle 200 to the developing device 140. Operation). Specifically, the CPU 400 replenishes toner from the toner bottle 200 to the toner conveyance path 210 by driving the bottle motor 201 to rotate the toner bottle 200. Further, the CPU 400 drives the screw motor 211 to rotate the screw 212 so that the toner is transported in the toner transport path 210 and the toner is supplied from the toner transport path 210 to the developing device 140.

  Even if such a toner replenishment operation is performed for a certain period of time, if it cannot be detected that there is toner in the developing device 140 based on the output signal from the toner sensor 221, there is no toner in the toner bottle 200 (that is, There is a high possibility that the toner bottle 200 is empty. In this case, the CPU 400 determines that the toner bottle 200 is empty, and displays a message prompting the user to replace the toner bottle 200 on the operation unit 410.

  Further, the CPU 400 monitors whether or not the toner bottle 200 has been replaced by monitoring a change in the state of the MFP 100. For example, when the CPU 400 opens / closes a door provided in the MFP 100, restarts the power supply of the MFP 100 (OFF / ON), or returns from the sleep state, there is a possibility that the toner bottle 200 has been replaced. Is detected. When the CPU 400 determines that the toner bottle 200 is empty, the CPU 400 starts monitoring the possibility that the toner bottle 200 has been replaced. When detecting that there is a possibility that the toner bottle 200 has been replaced, the CPU 400 performs determination processing regarding replacement of the toner bottle 200 as described below, thereby determining whether the toner bottle 200 has actually been replaced. Determine whether. The CPU 400 controls the execution of the toner supply operation and the image forming operation according to the determination result.

<Toner bottle replacement determination process>
Next, determination processing regarding replacement of the toner bottle 200 in the MFP 100 will be described. In this embodiment, as will be described below, it is determined whether or not the toner bottle 200 has been replaced based on a change in the output frequency of the ON signal from the toner sensor 221 in the developing device 140. The determination process can be performed in a shorter time. Note that the determination of whether or not the toner bottle 200 has been replaced means determination of whether or not the toner bottle 200 installed in the MFP 100 has been replaced with a toner bottle containing toner. That is, when the toner bottle 200 is replaced with an empty toner bottle, it is determined that the toner bottle 200 is not replaced.

  As described above, when the CPU 400 determines that there is no toner in the developing device 140 using the toner sensor 221, the CPU 400 executes the following processing. After determining that there is no toner in the developing device 140, the CPU 400 performs a toner replenishing operation (supply operation) from the toner bottle 200 to the developing device 140 when there is a possibility that the user has replaced the toner bottle 200. Run. Further, the CPU 400 determines whether or not the toner bottle 200 has been replaced based on a change in the output frequency of the ON signal from the toner sensor 221 according to the execution of the toner supply operation. In this embodiment, the ON signal output frequency corresponds to the number N of ON signal outputs per predetermined unit time, and is an example of toner detection frequency.

  Here, a case where it is determined that the toner bottle 200 is empty and there is no toner in the developing device 140 will be described. In this case, when the output frequency of the ON signal from the toner sensor 221 increases with the execution of the toner supply operation, the toner is supplied from the toner bottle 200 to the developing device 140. That is, the toner bottle 200 contains toner, and the empty toner bottle is replaced with a toner bottle containing toner. Therefore, the CPU 400 may determine that the toner bottle 200 has been replaced in this case.

  On the other hand, if the output frequency of the ON signal from the toner sensor 221 does not increase (change) with the execution of the toner supply operation, the toner is not supplied from the toner bottle 200 to the developing device 140. That is, the toner bottle 200 contains no toner, and the empty toner bottle is not replaced with a toner bottle containing toner. Therefore, the CPU 400 may determine that the toner bottle 200 has not been replaced in this case.

According to the determination process described above, after the toner supply operation is started, the toner bottle 200 is replaced before it becomes possible to determine the presence or absence of toner in the developing device 140 based on the output signal from the toner sensor 221. It can be determined whether or not it has been done. Specifically, when at least the time required for the toner to move from the toner bottle 200 to the developing device 140 has elapsed, a change in the amount of toner in the developing device 140 can be detected using the toner sensor 221, and as a result. The above-described determination can be executed. This time is supplied from the start of the supply of toner from the toner bottle 200 containing toner, the toner amount output count N of the ON signal from the toner sensor 221 to reach at least the reference value N _th developing unit 140 It is shorter than the time required for Therefore, according to this embodiment even before the output count N of the ON signal from the toner sensor 221 reaches the reference value N _th, since toner bottle 200 is possible to determine whether or not a replacement, more Such a determination process can be performed in a short time.

<Specific example of determination processing>
Next, a specific example of the determination process relating to the replacement of the toner bottle 200 will be described with reference to FIGS. 4 and 6, the first time T _b after a predetermined time [Delta] T ₁ from the toner supply operation is started has elapsed, the output frequency of the ON signal, the toner supply operation starts before the second at time T _a, the output frequency of the oN signal, based on a result of comparison, an example in which the determination (first example). 5 and 7, the output frequency of the ON signal at the first time point T _b after the same elapsed [Delta] T ₁ from the toner supply operation is started, the [Delta] T ₂ before the predetermined time [Delta] T ₁ has elapsed elapsed based on the result of comparison between the output frequency of the oN signal in the second time point T _a, an example in which the determination (second example). In any example, ΔT ₁ is set as a time longer than the time required for the toner to move from the toner bottle 200 to the developing device 140 by the toner replenishment operation. Further, the ON signal output frequency N per unit time is used as the ON signal output frequency from the toner sensor 221, and the reference value N _th = 50 is used in FIGS.

(First example)
FIGS. 4 and 6 are a flowchart illustrating a procedure of determination processing related to replacement of the toner bottle 200 in the first example, and an example of measurement timing of the number N of output of the ON signal from the toner sensor 221, respectively. 4 is realized in the MFP 100 under the control of the CPU 400 when the CPU 400 reads out and executes the control program from the ROM 401.

  When the CPU 400 detects that there is no toner in the developing device 140, the CPU 400 starts executing the procedure shown in FIG. In S101, the CPU 400 determines the presence / absence of toner in the toner bottle 200. If the CPU 400 determines that there is no toner, the process proceeds to S102. Here, if the CPU 400 cannot detect the presence of toner in the developing device 140 using the toner sensor 221 even after a toner replenishing operation from the toner bottle 200 to the developing device 140 for a certain period of time, the CPU 400 It is determined that there is no toner. Further, the CPU 400 stops the toner supply operation.

In S <b> 102, the CPU 400 displays a message prompting the user to replace the toner bottle 200 on the operation unit 410 and monitors whether or not the toner bottle 200 has been replaced (that is, determines whether the toner bottle 200 has been replaced). ). Next, in S103, the CPU 400 determines whether or not there is a possibility that the toner bottle 200 has been replaced. If there is no possibility, the processing in S102 and S103 is continued. Meanwhile, CPU 400, when detecting that occurred may have been replaced (at time T ₁₎ the toner bottle 200, the process advances to S104.

After replacing the determination in S103, in S104, CPU 400 obtains a measured value N _a measure the output number N of the ON signal from the toner sensor 221 (at time T _a). Acquired measured value N _a is stored in EEPROM403. Next, in S105, CPU 400 starts the toner supply operation to the developing device 140 from (at time T ₂₎ the toner bottle 200. Thereafter, in S106, CPU 400 determines whether the time [Delta] T ₁ from time T ₂ has elapsed, the time [Delta] T ₁ has elapsed at time T _b, the process proceeds to S107. In S107, CPU 400 obtains a measured value N _b again measure the output number N of the ON signal from the toner sensor 221 (at time T _b). The acquired measurement value N _b is stored in the EEPROM 403.

In S108, CPU 400 compares the measured value N _a and N _b, if N _b is higher than the N _a proceeds to (N _b> N _a), processing S109, the toner bottle 200 is replaced with judge. After that, in S110, the CPU 400 continues the toner supply operation, ends the display of the replacement message on the operation unit 410, and ends the series of processes. In this case, the MFP 100 can form an image on a sheet using toner supplied from the toner bottle 200 to the developing device 140 by a toner supply operation.

Reference numeral 601 in FIG. 6 shows an example of a change in the number N of ON signal outputs from the toner sensor 221 when the toner bottle is replaced with toner. In this example, the measurement value N _b of output times N at time T _b is well above the measured value N _a at time T _a, resulting in the toner bottle 200 is determined to have been exchanged. In this determination, as shown in FIG. 6, it is possible to determine the presence or absence of toner in the developing device 140 based on the time T ₄ when the output count N reaches the reference value N _th (that is, based on the output signal from the toner sensor 221). Can be performed at an earlier point in time.

On the other hand, in S108, if N _b does not exceed N _a (N _b ≦ N _a ), the CPU 400 advances the process to S111 and determines that the toner bottle 200 has not been replaced. Thereafter, in S112, the CPU 400 interrupts the toner supply operation, returns the process to S102, and continues displaying the replacement message on the operation unit 410.

Reference numeral 602 in FIG. 6 indicates that from the toner sensor 221 when there is a possibility that the toner bottle 200 has been replaced by opening / closing the door of the MFP 100 at time T ₁ , but the toner bottle 200 has not been replaced. The example of the change of the output frequency N of the ON signal is shown. In this example, the measurement value N _b of output times N at time T _b is not greater than the measured value N _a at time T _a, resulting in the toner bottle 200 is determined not to be replaced. Even in this case, it can be performed at a time earlier than the time T ₄ (that is, the timing at which the presence or absence of toner in the developing device 140 can be determined based on the output signal from the toner sensor 221).

(Second example)
FIGS. 5 and 7 are a flowchart illustrating a procedure of determination processing related to replacement of the toner bottle 200 in the second example, and an example of measurement timing of the ON signal output count N from the toner sensor 221. The processing of each step shown in FIG. 5 is realized in MFP 100 under the control of CPU 400 by CPU 400 reading and executing a control program from ROM 401.

First, S101 to S103 are the same as in the first example. In S103, CPU 400, when detecting that occurred may have been replaced (at time T ₁₎ the toner bottle 200, the process advances to S201.

In S201, CPU 400 starts the toner supply operation to the developing device 140 from (at time T ₂₎ the toner bottle 200. Thereafter, in S202, CPU 400 determines whether the elapsed time [Delta] T ₂ from the time T _2, the time [Delta] T ₂ has elapsed at time T _a, the process proceeds to S203.

In S203, CPU 400 obtains a measured value N _a measure the output number N of the ON signal from the toner sensor 221 (at time T _a). Acquired measured value N _a is stored in EEPROM403. Thereafter, in S204, CPU 400 determines whether the predetermined time [Delta] T ₁ from time _{T 2} has elapsed, the time [Delta] T ₁ has elapsed at time T _b, the process proceeds to S205. In S205, CPU 400 obtains a measured value N _b again measure the output number N of the ON signal from the toner sensor 221 (at time T _b). The acquired measurement value N _b is stored in the EEPROM 403. Thereafter, the CPU 400 advances the process to S108. S108 to S112 are the same as in the first example.

As shown in FIG. 7, in this example as well, as in the first example, if the measured value N _b is obtained at the time T _b , the developing device 140 based on the output signal from the time T ₄ (that is, the output signal from the toner sensor 221). It is possible to perform the determination at a time earlier than the timing at which it is possible to determine the presence or absence of toner.

In S108, by comparing the difference between the measured value N _a and N _a with a predetermined threshold value, it may determine the change in the output frequency of the ON signal from the toner sensor 221 (output frequency). Specifically, the CPU 400 determines that the toner bottle 200 has not been replaced when the difference between the measured values N _a and N _a is smaller than the threshold value, and determines that the toner bottle 200 is not smaller than the threshold value when the difference is not smaller than the threshold value. May be determined to have been exchanged. Further, as shown in FIGS. 6 and 7, the number N of output times of the ON signal from the toner sensor 221 varies in a short cycle. To reduce the effect of such change on the determination process of S108, for example, determine the moving average of the measured values of output times N as measured value N _a and N _b, it may be used for the determination of S108. Moreover, when performing a moving average, you may weight each measured value as needed.

  In this embodiment, the toner supply state is determined based on the number of times the ON signal is output from the toner sensor 221 (output frequency). However, the toner supply state is determined using a toner sensor whose output value represents the amount of toner. May be.

  As described above, according to the present embodiment, it is possible to determine in a shorter time whether or not the toner bottle 200 has been replaced in the MFP 100. For example, even when the user accidentally opens or closes the door of the MFP 100 or replaces it with an empty toner bottle, it is possible to determine whether or not the toner bottle 200 has actually been replaced earlier. . That is, it is possible to perform such determination processing without having to perform a toner replenishing operation for a long time (by simply waiting for the time required for the toner to move from the toner bottle 200 to the developing device 140). In addition, the determination process according to the present embodiment can be realized without increasing the apparatus cost, and an error is caused in the determination result even when the toner bottle containing toner different from the regular toner is replaced. This is advantageous.

100: MFP (image forming apparatus), 131: photosensitive drum, 140: developing device, 150: toner supply unit, 200: toner bottle, 201: bottle motor, 210: toner transport path (toner hopper), 211: screw motor, 212: Screw, 213, 221: Toner sensor, 400: CPU, 403: EEPROM

Claims (11)

Detecting means for detecting toner supplied from the toner container to the developing device by the toner supplying means;
First determination means for determining replacement of the toner storage container;
The supply state of the toner supplied by the toner supply unit that is detected by the detection unit and changes after the first determination unit determines the replacement of the toner container, and the toner supply unit before the change supplies A second determination unit that compares the toner supply state to be determined and determines the toner supply state by the toner supply unit after the first determination unit determines that the toner container has been replaced;
An image forming apparatus comprising: The second determination means is a first detection that is detected by the detection means and is a toner amount supplied by the toner supply means that changes after the first determination means determines the replacement of the toner container. A determination is made as to whether or not the toner container has been replaced based on a comparison result between a result and a second detection result that is the amount of toner supplied by the toner supply means before the change. Item 2. The image forming apparatus according to Item 1. The second determination unit is a toner that is detected by the detection unit and changes in accordance with the amount of toner supplied by the toner supply unit that changes after the first determination unit determines the replacement of the toner container. Based on a comparison result between a first detection result that is a detection frequency and a second detection result that is a toner detection frequency that changes according to the amount of toner supplied by the toner supply unit before the change, the toner storage The image forming apparatus according to claim 1, wherein it is determined whether or not the container has been replaced. The second determination means determines that the toner container is not replaced when the second detection result does not exceed the first detection result, and the second detection result is The image forming apparatus according to claim 2, wherein when the first detection result is exceeded, it is determined that the toner storage container has been replaced. When the difference between the second detection result and the first detection result is smaller than a threshold value, the second determination unit determines that the toner container is not replaced, and the difference is the threshold value. 4. The image forming apparatus according to claim 2, wherein if it is not smaller, it is determined that the toner container has been replaced. 5. The timing for acquiring the first detection result is after the time required for the toner to move from the toner container to the developing device by the supply operation by the toner supply unit. 6. The image forming apparatus according to any one of items 1 to 5. The image forming apparatus according to claim 3, wherein the toner detection frequency is the number of outputs of a detection signal from the detection unit per unit time. A third determination unit for determining the presence or absence of toner in the developer;
The third determination unit determines that there is toner in the developer when the number of outputs per unit time of the detection signal from the detection unit exceeds a reference value, and the output number The image forming apparatus according to claim 1, wherein if the reference value is not exceeded, it is determined that there is no toner in the developing device. An execution means for executing a supply operation for supplying toner from the toner container to the developer;
The first determination unit is configured to open and close a door provided in the image forming apparatus, restart a power source of the image forming apparatus, or return the image forming apparatus from a sleep state. It was determined that the exchange of
The execution unit executes a supply operation for supplying toner from the toner storage container to the developing device when the first determination unit determines that the toner storage container has been replaced. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The execution unit further interrupts the supply operation when the second determination unit determines that the toner storage container has not been replaced, and determines that the toner storage container has been replaced. The image forming apparatus according to claim 9, wherein the supply operation is continued. A method for controlling an image forming apparatus, wherein a detecting unit that outputs a detection signal when toner is detected is provided in a developing unit, and an image is formed by toner supplied from a toner container to a developing unit by a toner supplying unit,
A first determination step of determining replacement of the toner storage container;
The supply state of the toner supplied by the toner supply unit that changes after the replacement of the toner container is determined in the first determination step, and the toner supply unit before the change is detected by the detection unit. A second determination step of comparing the supply state of the toner to be supplied and determining the supply state of the toner by the toner supply means after the replacement determination of the toner container in the first determination step;
A control method for an image forming apparatus.

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