JP6834637B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus suitable for collecting or reusing a waste developer.

Conventionally, some image forming devices have a toner recycling system. As such a recycling system, there is a system that collects unused toner after image formation and returns it to a developing device, detects dust contained in the toner, and discards the toner containing the dust. (See, for example, Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 11-38851 Japanese Unexamined Patent Publication No. 5-289462 Japanese Unexamined Patent Publication No. 2005-3783

However, when the toner is used repeatedly, the toner deteriorates due to scraping of the surface layer of the toner due to stirring, so that the toner is less likely to be charged at the time of image formation, image defects occur, and print quality deteriorates. As an image defect, for example, there is a defect that the toner does not get on the paper due to insufficient charge amount and white points occur in the output image. Further, when the toner is reused, dust such as paper dust is mixed with the toner, so that the toner is less likely to be charged even if the toner returned to the developing device is agitated, which leads to image failure.

If deteriorated toner or toner mixed with dust is returned to the developing device, not all of the returned toner will be used for the next printing, so the returned toner will remain in the developing device little by little. .. Therefore, by repeating printing, the developer containing toner and carriers in the developing apparatus deteriorates, and dust stays in the developing apparatus, so that the chargeability of the developing agent decreases. Therefore, there is a problem that the quality of the printed image is deteriorated.

The present invention has been made to solve the above-mentioned problems, and one of the objects of the present invention is an image capable of suppressing deterioration of image quality by suppressing a decrease in chargeability of a developer. It is to provide a forming apparatus.

In order to achieve the above object, according to one aspect of the invention, the image forming apparatus forms an image carrier on which the image of the developer is carried and the image is transferred to a recording medium, and an image on the image carrier. A developing device that supplies a developing agent for this purpose, a collecting device that recovers the developer remaining on the image carrier after transfer to a recording medium, and a transporting device that transports the developer recovered by the collecting device while stirring. , A measuring device that measures the change in the charge amount of the developer while being stirred by the transport device, a waste container that stores the developer to be discarded, and a developer that is transported by the transport device to the side of the developer or the waste container. It includes a sorting device for sorting and a control device for controlling the sorting device according to a change in the amount of charge measured by the measuring device.

Preferably, the control device controls the sorting device to distribute the developer to the developing device side when a predetermined criterion indicating that the change in the amount of charge measured by the measuring device is properly charged is satisfied. ..

Preferably, the control device controls the sorting device to distribute the developer to the side of the waste container if the change in charge measured by the measuring device does not meet a predetermined criterion indicating that it is properly charged. To do.

More preferably, the control device controls the sorting device so as to prohibit the developer from being distributed to the waste container side when the remaining amount of the developer that can be supplied by the developing device is less than a predetermined amount.

Preferably, the predetermined standard is a standard that the rate of increase in the amount of charge is equal to or higher than the predetermined value.
Preferably, the measuring device includes a plurality of detection units that detect the respective charge amounts at a plurality of positions in the transfer path of the transfer device, and changes the charge amount based on the charge amounts detected by the plurality of detectors. measure. The control device controls the sorting device so as to sort the developer according to the change in the amount of charge measured by the measuring device.

More preferably, the detection unit is an electrostatic sensor.
Also preferably, the measuring device includes a plurality of positions of the transport path including a first position and a second position after the first position. The transport device requires a specific time to transport the developer from the first position to the second position. The control device shakes the developer according to the change from the charge amount at the first position to the charge amount at the second position after a specific time has elapsed from the measurement time of the charge amount at the first position. Control the sorting device to separate.

Preferably, the control device further accepts settings related to image formation by the image forming device, and changes the distribution criteria by the sorting device according to the settings.

More preferably, the control device is placed on the developing device side by the sorting device when the setting for lower image quality of the formed image is accepted than when the setting for higher image quality than the setting is accepted. Loosen the criteria for distributing the developer.

Further, preferably, when the control device receives a setting in which foreign matter is likely to be mixed in the developing agent, the developing device is subjected to a sorting device rather than in the case where a setting in which foreign matter is less likely to be mixed in the developing agent than the setting is accepted. Tighten the criteria for distributing the developer to the side of.

The control device controls the sorting device so as to prohibit the sorting of the developer toward the waste container until the end of the replacement cycle of the developing device.

According to the present invention, it is possible to provide an image forming apparatus capable of suppressing deterioration of print quality by suppressing a decrease in chargeability of a developer.

It is a block diagram which shows the outline of the structure of the image forming apparatus in embodiment of this invention. It is a block diagram which shows the outline of the structure of the image forming apparatus in this embodiment. FIG. 1 is a first diagram showing an outline of a configuration for reuse (recycling) of toner. It is a 2nd figure which shows the outline of the structure for reuse (recycling) of toner. It is a figure which shows the cross section of the recycling pipe of the part where the waste box shutter is provided. It is a figure which shows the path of the toner to be reused. It is a block diagram which shows a part of the structure of a printer part. It is a flowchart which shows the flow of the toner recycling process executed in the printer part. It is a figure which shows an example of the change of the charge amount at a predetermined position of a recycling pipe. It is a figure which shows an example of the change of the charge amount from the upstream position to the downstream position of a recycling pipe.

Embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.

FIG. 1 is a block diagram showing an outline of a configuration of an image forming apparatus MFP according to an embodiment of the present invention. With reference to FIG. 1, the image forming apparatus MFP is used to operate a control unit 110 for controlling the entire image forming apparatus MFP, a storage unit 120 for storing predetermined information, and an image forming apparatus MFP. Operation unit 130, a display unit 140 for displaying predetermined information of the image forming apparatus MFP, a communication unit 160 for communicating with an external device via a private network 900, and a scanner for reading a predetermined image. A unit 1 and a printer unit 3 for printing a predetermined image are included.

The storage unit 120 includes a RAM (Random Access Memory) used as a work area required for the control unit 110 to execute a program, and a ROM (Read Only Memory) for storing the program to be executed by the control unit 110. And include. Further, in the RAM, a program and data for executing a predetermined process are read from the operation unit 130, the communication unit 160, or the scanner unit 1 and stored. Further, a hard disk drive or a memory card may be used as an auxiliary storage device for assisting the storage area of the RAM.

The operation unit 130 includes a plurality of operation buttons for causing the image forming apparatus MFP to execute a predetermined function, and a touch panel configured on the display of the display unit 140. The operation signal indicating the operation content input to the image forming apparatus MFP by operating the operation button and the touch panel of the operation unit 130 is passed to the control unit 110.

The display unit 140 includes a liquid crystal display device (hereinafter referred to as "LCD" (Liquid Crystal Display)) in which a touch panel is configured on the display. The LCD of the display unit 140 is an image received from the control unit 110 and displays an image showing the state of the image forming apparatus MFP and the operation buttons of the touch panel. The display unit 140 may include another FPD (Flat Panel Display) such as an EL (Electro-Luminescence) display, a plasma display, and an SED (Surface-conduction Electron-emitter Display) instead of the LCD.

The communication unit 160 transmits / receives data to / from an external device via a private network 900 using a predetermined protocol. The communication unit 160 transmits the data received from the control unit 110 to the outside, and transfers the data received from the outside to the control unit 110.

The scanner unit 1 optically reads visual information on the surface of the paper or other object, converts the scanned image into image data, and passes the image data to the control unit 110.

The printer unit 3 converts the image data received from the control unit 110 into an image, and prints the image on printing paper.

The control unit 110 includes an MPU (Micro Processing Unit) and an auxiliary circuit thereof. The control unit 110 controls the storage unit 120, the operation unit 130, the display unit 140, the communication unit 160, the scanner unit 1 and the printer unit 3, and executes a predetermined process according to the programs and data stored in the storage unit 120. , The data input from the operation unit 130, the communication unit 160 or the scanner unit 1 is processed, and the processed data is stored in the storage unit 120, displayed on the display unit 140, or output from the communication unit 160. , The printer unit 3 prints.

The copy function, printer function, scanner function, facsimile function and communication function of the image forming apparatus MFP are the control unit 110, the storage unit 120, the operation unit 130, the display unit 140, the communication unit 160, the scanner unit 1 and the printer unit 3, respectively. This is realized by the cooperation of each part of the image forming apparatus MFP of.

FIG. 2 is a configuration diagram showing an outline of the configuration of the image forming apparatus MFP in this embodiment. With reference to FIG. 2, the image forming apparatus MFP includes a double-sided document automatic feeding apparatus RADF and an image forming apparatus main body A. The double-sided document automatic feeder RADF is located above the image forming apparatus main body A and can be opened and closed. The originals on the original paper feed tray a are conveyed by the paper feed roller b, the separation roller c, the resist roller d, and the transfer drum e, and are discharged.

The image forming apparatus main body A includes a scanner unit 1, a control device 2, a printer unit 3, an image forming unit 4, a cassette feeding unit 5, a conveying unit 6, a fixing device 7, a paper ejection unit 8, and a retransmitting unit 9. Including.

The optical system of the scanner unit 1 includes an exposure unit 14 including a light source and a first mirror, a V mirror unit 15 including a second mirror and a third mirror, a lens 16, and a CCD image sensor 17. The document reading by the double-sided document automatic feed device RADF is performed at a position where the exposure unit 14 is stopped at an initial position below the slit exposure glass 13. Reading the original on the platen glass 11 is performed while moving the exposure unit 14 and the V mirror unit 15. The scanner unit 1 performs image processing on the image information of the scanned original image and transmits it as image data to the control device 2.

The control device 2 includes a control unit 110, a storage unit 120, and a communication unit 160 shown in FIG. The control device 2 stores the image data from the scanner unit 1 in the storage unit 120.

In the image forming unit 4, the charger 22 adds an electric charge to the photoconductor drum 21 which is an image carrier. A semiconductor laser (not shown) included in the printer unit 3 forms an electrostatic latent image on the photoconductor drum 21 by irradiation with laser light based on image data stored in the storage unit 120 of the control device 2. The developing device 23 supplies the toner contained in the two-component developer to the electrostatic latent image of the photoconductor drum 21 to visualize the toner image. In the present embodiment, the case where a two-component developer containing toner and a carrier is used is shown, but a one-component developer containing toner but not a carrier may be used. The transfer device 29A transfers the toner image of the photoconductor drum 21 onto the paper P, which is a transfer material conveyed from the cassette paper feed unit 5. The separator 29B separates the paper P from the photoconductor drum 21. The cleaning device 26 removes the transfer residual toner from the photoconductor drum 21. The transport unit 6 transports the paper P on which the toner image is transferred. The fixing device 7 fixes the toner image. The paper ejection unit 8 ejects the paper P to the paper ejection tray 81 outside the apparatus. The toner replenishing device 24 replenishes the developing device 23 with toner via the toner intermediate replenishing unit 25.

In the case of double-sided copying, the paper P on which the image is formed on the first surface is sent to the re-conveying unit 9 by the transport path switching plate 82, and after the image is formed on the second surface again in the image forming unit 4, the paper is discharged. It is discharged to the output tray 81 outside the apparatus by the unit 8. In the case of reverse paper ejection, the paper P branched from the normal paper ejection passage by the transport path switching plate 82 is switched back at the inverted paper ejection unit 83 and turned upside down, and then ejected outside the device by the paper ejection unit 8. It is discharged to the paper tray 81.

3 and 4, respectively, are first and second views showing an outline of a configuration for toner reuse (recycling). With reference to FIGS. 3 and 4, the cleaning device 26 includes a guide roller 26A and a cleaning blade 26B. The recycling device 27 includes a recycled toner replenishment tank 271, screws 272, 273, a recycling pipe 274, a waste box shutter 275, a shutter drive solenoid 276, a waste pipe 277, and a waste box 278.

The guide roller 26A and the cleaning blade 26B are provided on the downstream side of the transfer device 29A and the separator 29B in the rotation direction of the photoconductor drum 21. The cleaning blade 26B scrapes off the toner (recycled toner) remaining on the photoconductor drum 21. The guide roller 26A guides the scraped toner to the recycled toner replenishment tank 271.

The recycled toner supply tank 271 temporarily stores the recycled toner. The screw 272 conveys the recycled toner stored in the recycled toner supply tank 271 to the opening g of the recycling pipe 274. The screw 273 conveys the toner inside the recycling pipe 274 and returns it to the developing device 23. The toner returned to the developing device 23 is reused together with the toner in the developing device 23. The screws 272 and 273 are rotated by a drive mechanism (not shown).

FIG. 5 is a view showing a cross section of a recycling pipe 274 at a portion where the waste box shutter 275 is provided. With reference to FIGS. 4 and 5, the waste box shutter 275 is slid in the x direction along the guide 279 by the shutter drive solenoid 276 to open and close the waste port h. When the waste port h is closed, the toner conveyed by the screw 273 is returned to the developing device 23. On the other hand, when the disposal port h is open, the toner conveyed by the screw 273 is disposed of in the disposal box 278 via the disposal port h and the disposal pipe 277.

At the upstream position of the recycling pipe 274, a transmitting unit 281A and a receiving unit 282A of the charge amount sensor are provided so as to sandwich the recycling pipe 274. Similarly, at the downstream position, a transmission unit 281B and a reception unit 282B of the charge amount sensor are provided so as to sandwich the recycle pipe 274. The transmitting units 281A and 281B and the receiving units 282A and 282B of the charge amount sensor are paired to form a mutual capacitance type electrostatic sensor.

The transmitting units 281A and 281B transmit the pulse wave of the electromagnetic wave, and the receiving units 282A and 282B receive the pulse wave, respectively. When the charged toner inside the recycling pipe 274 passes between the transmitting units 281A and 281B and the receiving units 282A and 282B, the capacitance between them changes, so that the pulse wave received by the receiving units 282A and 282B Changes. The amount of charge of the passed toner is calculated from the amount of change.

By using such a mutual capacitance type electrostatic sensor, the amount of charge can be measured with high accuracy. Further, since such an electrostatic sensor is a non-contact type and has a small size, it can be installed at an arbitrary position, so that the degree of freedom in design is high.

FIG. 6 is a diagram showing a path of the toner to be reused. With reference to FIG. 6, as described above, the developing device 23 is replenished with toner from the toner replenishing device 24 as the amount of toner decreases with printing. At the time of printing, toner is supplied from the developing device 23 to the photoconductor drum 21. The toner remaining on the photoconductor drum 21 after being transferred to the paper P on the photoconductor drum 21 is removed by the cleaning device 26. The removed toner is returned to the developing device 23 by the recycling device 27, or is discarded in the waste box 278.

FIG. 7 is a block diagram showing a part of the configuration of the printer unit 3. With reference to FIG. 7, the printer unit 3 includes a printer unit control unit 181, a shutter drive solenoid 276, a motor drive unit 182, a transmission unit 281A and a reception unit 282A of a charge amount sensor at an upstream position, and a downstream position. It includes a transmitting unit 281B and a receiving unit 282B of the charge amount sensor.

The printer unit control unit 181 drives each unit of the printer unit 3, for example, each motor of the shutter drive solenoid 276 and the printer unit 3 in response to a detection signal from each sensor of the printer unit 3 in accordance with a command from the control unit 110. The motor drive unit 182 is controlled.

The printer unit control unit 181 outputs a control signal for outputting a predetermined pulse wave from the transmission units 281A and 281B of the charge amount sensor. In response to this control signal, the transmitting units 281A and 281B output pulse waves. The receiving units 282A and 282B of the charge amount sensor output a detection signal indicating the detected pulse wave to the printer unit control unit 181. The printer unit control unit 181 calculates the charge amount of the toner passing through each position of the recycle pipe 274 based on the received detection signal.

FIG. 8 is a flowchart showing the flow of the toner recycling process executed by the printer unit 3. With reference to FIG. 8, first, the printer unit control unit 181 determines whether or not a signal indicating an instruction to start the operation of the printer unit 3 has been received from the control unit 110 (step S101). If it is determined that the printer has not been received (NO in step S101), the printer unit control unit 181 repeats the process of step S101.

On the other hand, when it is determined that the signal indicating the instruction to start the operation has been received (YES in step S101), the printer unit control unit 181 has the transmitting unit 281A and the receiving unit 282A of the charge amount sensor at the upstream position of the recycling pipe 274. In addition, the measurement of the charge amount by the transmitting unit 281B and the receiving unit 282B of the charge amount sensor at the downstream position is started (step S102).

Next, the printer unit control unit 181 determines whether or not the period during which the following processing is not being executed has elapsed a predetermined period (step S103). The following processing does not have to be executed every short control cycle of several milliseconds, but may be executed every predetermined period of about several seconds. If it is determined that the predetermined period has not elapsed (NO in step S103), the printer unit control unit 181 repeats step S103.

On the other hand, when it is determined that the predetermined period has elapsed (YES in step S103), the printer unit control unit 181 determines whether or not the current print mode setting is the high image quality mode (step S104). When it is determined that the image quality mode is in the high image quality mode (YES in step S104), the printer unit control unit 181 determines whether or not the remaining amount of toner is large (step S105).

When it is determined that the remaining amount of toner is large (YES in step S105), the printer unit control unit 181 calculates and stores the respective charge amounts q1 and q2 at the current upstream position and downstream position (step S111). Here, it is assumed that the time required to convey the toner from the upstream position to the downstream position of the recycling pipe 274 is T. From the stored charge amount, the printer unit control unit 181 reads out the charge amount q1b at the upstream position before the time T from the present time and the charge amount q2 at the downstream position at the present time (step S112).

FIG. 9 is a diagram showing an example of a change in the amount of charge at a predetermined position of the recycling pipe 274. With reference to FIG. 9, when the toner passes through a predetermined position of the recycling pipe 274 (for example, the position of the charge amount sensor on the upstream side), the charge amount value sharply increases, and the threshold value for determining that there is normal toner. Exceeds. Further, when a toner having a large amount of dust such as dust passes after that, the value of the charge amount falls below the threshold value qa for determining that the dust has accumulated.

Returning to FIG. 8, the printer unit control unit 181 determines whether or not the charge amount q1b> threshold value qa or the charge amount q2> threshold value qa (step S113). When it is determined that q1b> qa and q2> qa (YES in step S113), the printer unit control unit 181 determines whether or not the charge amount q2-charge amount q1b> predetermined increase amount Δq (step S114). ). In this way, since the change in the charge amount is determined by comparing the charge amount q1b when the same toner passes through the upstream position and the charge amount q2 when the same toner passes through the downstream position, it can be determined more accurately. ..

When it is determined that neither q1b> qa nor q2> qa (NO in step S113), or when it is determined that q2-q1b> Δq is not (NO in step S114), the printer unit control unit 181 Controls the shutter drive solenoid 276 so as to open the waste box shutter 275 at the timing when the toner passes through the waste port h (step S115).

On the other hand, when it is determined that the mode is not the high image quality mode (NO in step S111), the remaining amount of toner is not large (NO in step S111), and q1b, q2> qa (YES in step S113) and q2. When it is determined that −q1b> Δq (YES in step S114), the printer unit control unit 181 controls the shutter drive solenoid 276 so as to close the waste box shutter 275 at the timing when the toner passes through the waste port h (YES). Step S116).

After step S115 and step S116, the printer unit control unit 181 determines whether or not a signal indicating an instruction to end the operation of the printer unit 3 has been received from the control unit 110 (step S117). If it is determined that the printer has not been received (NO in step S117), the printer unit control unit 181 returns the process to be executed to the process in step S103.

On the other hand, when it is determined that the signal indicating the instruction to end the operation has been received (YES in step S117), the printer unit control unit 181 has the transmitting unit 281A and the receiving unit 282A of the charge amount sensor at the upstream position of the recycling pipe 274. In addition, the measurement of the charge amount by the transmitting unit 281B and the receiving unit 282B of the charge amount sensor at the downstream position is completed (step S118). After that, the printer unit control unit 181 returns the process to be executed to the process of step S101.

FIG. 10 is a diagram showing an example of a change in the amount of charge from the upstream position to the downstream position of the recycling pipe 274. With reference to FIG. 10, when the toner is deteriorated, the amount of charge of the toner hardly increases from q1 while the toner is conveyed from the upstream position to the downstream position. As shown in step S114, if the charge amount of the toner rises from the charge amount q1 at the upstream position by more than a predetermined increase amount Δq and reaches the charge amount q2 at the downstream position, the toner cannot be reused. Can be judged not to have deteriorated.

[Modification example]
(1) In the above-described embodiment, the toner recycling process shown in FIG. 8 includes conditional branching in steps S104, S105, S113, and S114. However, the present invention is not limited to this, and any one or more of these conditional branches may be included.

(2) In the above-described embodiment, the recycling pipe 274 contains almost no carrier. Therefore, when a two-component developer is used, a device for replenishing the carrier may be provided on the upstream side of the recycling pipe 274.

[Summary]
(1) As described above, the image forming apparatus MFP carries the image of the developing agent and transfers the image to the paper P, and the photoconductor drum 21 and the developing agent for forming the image on the photoconductor drum 21. 23, a cleaning device 26 that collects the developer remaining on the photoconductor drum 21 after transfer to the paper P, and a recycling device 27 that conveys the developer recovered by the cleaning device 26 while stirring. , Transmission units 281A, 281B and receivers 282A, 282B of the charge amount sensor that measure the change in the charge amount of the developer while being stirred by the recycling device 27, a waste box 278 for storing the developer to be discarded, and a recycling device. To the change in the amount of charge measured by the waste box shutter 275 that distributes the developer conveyed by 27 to the developing device 23 or the waste box 278, and the transmitters 281A and 281B and the receivers 282A and 282B of the charge sensor. A printer unit control unit 181 that controls the disposal box shutter 275 is provided accordingly.

This makes it possible to distribute the developer to the side of the waste box 278 according to the change in the amount of charge. As a result, deterioration of print quality can be suppressed by suppressing deterioration of the chargeability of the developer.

(2) As shown in steps S114 and S116 of FIG. 8, in the printer unit control unit 181, the change in the charge amount measured by the transmitter units 281A and 281B and the receiver units 282A and 282B of the charge amount sensor is appropriate. When the standard indicating that the printer is charged, the charge amount at the downstream position q2-charge amount q1b at the upstream position> the predetermined increase amount Δq is satisfied, the developer is discarded to be distributed to the developing device 23. The box shutter 275 is controlled to be closed.

As a result, the developer can be returned to the developing apparatus 23 when it is determined that the developing agent satisfies the predetermined criteria and is not deteriorated. As a result, the developer can be reused while maintaining print quality.

(3) As shown in steps S114 and S115 of FIG. 8, in the printer unit control unit 181, the change in the charge amount measured by the transmitter units 281A and 281B and the receiver units 282A and 282B of the charge amount sensor is appropriate. When the standard of charging amount q2-upstream position charging amount q1b> predetermined increase amount Δq, which is a predetermined standard indicating that the printer is charged, is not satisfied, the developer is distributed to the waste box 278 side. The waste box shutter 275 is controlled to be opened.

As a result, when it is determined that the developer does not meet the predetermined criteria and is deteriorated, the developer can be discarded in the waste box 278. As a result, the print quality can be maintained by preventing the deteriorated developer from returning to the developing apparatus 23.

(4) As shown in steps S112 and S116 of FIG. 8, when the remaining amount of the developer that can be supplied by the developing device 23 is less than the predetermined amount, the printer unit control unit 181 is placed on the side of the waste box 278. The waste box shutter 275 is controlled to be closed in order to prohibit the distribution of the developer.

This makes it possible to prevent the developer from being discarded when the remaining amount of the developer is low. As a result, the printable period can be extended without replenishing the developer.

(5) In the above-described embodiment, as shown in step S114 of FIG. 8, the predetermined standard is the standard of the charge amount q2- at the upstream position> the charge amount q1b at the upstream position> the predetermined increase amount Δq. And said. However, the present invention is not limited to this, and other criteria may be used as long as the criteria can determine the deterioration of the developer. For example, the charge amount at the downstream position q2-the charge amount at the upstream position q1b ≧ the predetermined increase amount Δq may be used as a reference.

Further, the predetermined standard may be a standard that the rate of increase in the amount of charge is equal to or greater than the predetermined value. Specifically, when the time required to convey the toner from the upstream position to the downstream position of the recycling pipe 274 is T, (charge amount q2-upstream position charge amount q1b at the downstream position) / T is equal to or greater than a predetermined value. Alternatively, it may be a standard with super. The charge amount q2 at the downstream position / the charge amount q1b at the upstream position may be a reference of a predetermined value or more or more than a predetermined value. (Charging amount q2-upstream position charging amount q2-charging amount q1b at the upstream position) / The charging amount q1b at the upstream position may be a reference of a predetermined value or more or more.

(6) As shown in FIG. 4, the charge amount sensor detects a plurality of charge amounts at a plurality of positions (may be two or more) of the developer transport path of the recycling device 27. It includes the transmitting units 281A and 281B and the receiving units 282A and 282B, and measures the change in the charging amount based on the charging amounts detected by the plurality of transmitting units 281A and 281B and the receiving units 282A and 282B. As shown in FIG. 8, the printer unit control unit 181 controls the waste box shutter 275 so as to distribute the developer according to the change in the measured charge amount. The charge amount sensor is an electrostatic sensor.

As a result, the change in the charge amount can be accurately detected, so that the developer can be accurately distributed.

(7) As shown in FIG. 4, a plurality of positions of the transport path include an upstream position and a downstream position after the upstream position. The recycling device 27 requires a specific time T to convey the developer from the upstream position to the downstream position. As shown in step S112 of FIG. 8, the printer unit control unit 181 transfers the charge amount at the upstream position to the charge amount at the downstream position after a specific time T has elapsed from the measurement time of the charge amount at the upstream position. The waste box shutter 275 is controlled so as to distribute the developer according to the change.

As a result, the toner that has passed through the upstream position passes through the downstream position after a specific time T, but the developer is distributed according to the change in the amount of charge when the same toner passes through the upstream position and the downstream position, respectively. Since the change in the charge amount of the toner can be accurately detected, the developer can be distributed more accurately.

(8) As shown in step S111 of FIG. 8, the printer unit control unit 181 further accepts the setting related to the image formation by the image forming apparatus MFP, and changes the sorting standard by the waste box shutter 275 according to the setting. To do.

This makes it possible to distribute the developer according to the print quality required by the settings related to image formation.

(9) As shown in step S111 of FIG. 8, when the setting to lower the image quality of the formed image is accepted, the printer unit control unit 181 receives the setting to set the image quality to be higher than the setting. More loosely than in the case, the standard for distributing the developer to the developing device 23 side by the waste box shutter 275 is loosened.

As a result, when the quality of the formed image may be low, the developer can be made difficult to dispose of and can be easily reused. As a result, the printable period can be extended without replenishing the developer.

(10) In the above-described embodiment, it is as shown in (9) above. However, the present invention is not limited to this, and other methods may be used as long as the criteria for sorting by the waste box shutter 275 is changed according to the setting regarding image formation by the image forming apparatus MFP. For example, when the printer unit control unit 181 accepts a setting in which foreign matter is likely to be mixed in the developing agent (for example, a setting for high image quality, a setting for double-sided printing, a setting for using poor quality paper such as recycled paper). The criteria for distributing the developer to the developing device 23 by the waste box shutter 275 may be stricter than when a setting in which foreign matter is less likely to be mixed into the developer is accepted than the setting.

As a result, when foreign matter is likely to be mixed in the developer, the developer can be easily discarded and hardly reused. As a result, the print quality can be guaranteed.

(11) The printer unit control unit 181 controls the waste box shutter 275 so as to prohibit the distribution of the developer to the waste box 278 side until the end of the replacement cycle of the developing device 23. May be good.

As a result, until the developer deteriorates and it is time to distribute the developer to the waste box 278, it is not necessary to perform the process shown in FIG. 8 for distributing the developer to the waste box 278. get well. Therefore, the processing load of the printer unit control unit 181 can be reduced until the end of the replacement cycle.

The above-described embodiment can be regarded as an invention of the image forming apparatus MFP and also as an invention of the recycling apparatus 27.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Scanner unit, 2 Control device, 3 Printer unit, 4 Image forming unit, 5 Cassette feeding unit, 6 Conveying unit, 7 Fixing device, 8 Paper ejection unit, 9 Recycling unit, 11 Document base glass, 13 For slit exposure Glass, 14 exposure unit, 15 mirror unit, 16 lenses, 17 image sensor, 21 photoconductor drum, 22 charger, 23 developer, 24 toner replenisher, 25 toner intermediate replenisher, 26 cleaning device, 26A guide roller, 26B Cleaning blade, 27 Recycling device, 29A transfer device, 29B separator, 81 Paper output tray, 82 Transport path switching plate, 83 Reverse paper output unit, 110 Control unit, 120 Storage unit, 130 Operation unit, 140 Display unit, 160 Communication 181 Printer unit Control unit, 182 Motor drive unit, 271 Recycled toner supply tank, 272, 273 screws, 274 Recycle pipes, 275 Waste box shutters, 276 Shutter drive solenoids, 277 Waste pipes, 278 Waste boxes, 279 guides, 281A , 281B transmitter, 282A, 282B receiver, 900 private network, A image forming device main body, MFP image forming device, P paper, RADF double-sided original automatic feeder, a original paper feed tray, b paper feed roller, c separation roller , D resist roller, e transport drum, g opening, h disposal port.

Claims (12)

An image carrier that carries an image of a developer and transfers the image to a recording medium,
A developing device that supplies a developer to form the image on the image carrier, and
A recovery device that recovers the developer remaining on the image carrier after transfer to the recording medium.
A transport device that transports the developer recovered by the recovery device while stirring, and
A measuring device for measuring a change in the amount of charge of the developer while being agitated by the transport device, and a measuring device.
A waste container for storing the developer to be discarded and
A sorting device that distributes the developer transported by the transport device to the developing device or the waste container side,
An image forming apparatus including a control device that controls the sorting device according to a change in the amount of charge measured by the measuring device. When the control device satisfies a predetermined criterion indicating that the change in the amount of charge measured by the measuring device is properly charged, the control device controls the sorting device so as to distribute the developer to the developing device side. The image forming apparatus according to claim 1. When the control device does not meet a predetermined criterion indicating that the change in the amount of charge measured by the measuring device is properly charged, the control device sets the sorting device so as to distribute the developer to the side of the waste container. The image forming apparatus according to claim 1, which is controlled. The control device controls the distribution device so as to prohibit the distribution of the developer to the side of the waste container when the remaining amount of the developer that can be supplied by the developing device is less than a predetermined amount. The image forming apparatus according to claim 3. The image forming apparatus according to any one of claims 2 to 4, wherein the predetermined standard is a standard that the rate of increase in the amount of charge is equal to or higher than a predetermined value. The measuring device is
A plurality of detection units for detecting the amount of charge at each of a plurality of positions in the transport path of the transport device are included.
The change in the charge amount is measured based on the charge amount detected by each of the plurality of detectors.
The image forming apparatus according to claim 1, wherein the control device controls the distribution device so as to distribute the developer according to a change in the amount of charge measured by the measuring device. The image forming apparatus according to claim 6, wherein the detection unit is an electrostatic sensor. The plurality of positions of the transport path include a first position and a second position after the first position.
The transport device requires a specific time to transport the developer from the first position to the second position.
The control device responds to a change from the charge amount at the first position to the charge amount at the second position after the lapse of the specific time from the measurement time of the charge amount at the first position. The image forming apparatus according to claim 6, wherein the sorting device is controlled so as to sort the developer. The control device further
Accepts settings related to image formation by the image forming device,
The image forming apparatus according to claim 1, wherein the criteria for sorting by the sorting device is changed according to the setting. The control device is
Criteria for distributing the developer to the developing device side by the sorting device than when the setting for lower image quality of the formed image is accepted, than when the setting for higher image quality than the setting is accepted. The image forming apparatus according to claim 9, wherein the image forming apparatus is loosened. The control device is
When a setting that makes it easier for foreign matter to enter the developer is accepted, the developer is placed on the side of the developer by the sorting device than when a setting that makes it harder for foreign matter to enter the developer than the setting is accepted. The image forming apparatus according to claim 9, wherein the sorting criteria are strict. The image according to claim 1, wherein the control device controls the sorting device so as to prohibit sorting the developer toward the waste container until the end of the replacement cycle of the developing device. Forming device.

Images