JP4884267B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus that forms an image by transferring a developer image onto a recording medium.

Conventionally, in an image forming apparatus such as a printer, a copier, a facsimile machine, or a multifunction machine that forms an image by an electrophotographic method, a waste toner collecting unit is provided in contact with the photoconductor, and the photoconductor is not transferred to the recording medium. There has been proposed a technique for collecting the remaining transfer residual toner by the operation of a photoreceptor (for example, see Patent Document 1).
JP 2002-23448 A

  However, in the conventional image forming apparatus, it is necessary to install a space for collecting the transfer residual toner in the image forming apparatus, which is disadvantageous for downsizing and weight reduction of the image forming apparatus.

  The present invention solves the problems of the conventional image forming apparatus, and moves the transfer residual developer remaining on the image carrier without being transferred to the recording medium to be fixed on the recording medium, It is an object of the present invention to provide an image forming apparatus that can be reduced in size and weight without requiring a space for collecting the transfer residual developer in the image forming apparatus.

Therefore, in the image forming apparatus of the present invention, a plurality of image carriers on which latent images based on print data are formed, a developer is supplied to each of the image carriers, and the latent images are developed and developed. A plurality of developing sections for forming a developer image; a plurality of transfer sections for transferring the developer image to a recording medium; and a plurality of recovering untransferred developers remaining on the image carrier without being transferred. And a fixing unit for fixing the developer image transferred onto the recording medium to the recording medium, and a plurality of the recording mediums according to the proportion of print dots corresponding to each of the image carriers. The transfer residual developer collected by each of the plurality of collection units is moved to each of the sections on the recording medium, and the transfer residual developer on the recording medium is fixed to the recording medium.

  According to the present invention, the image forming apparatus is configured to move and fix the untransferred developer remaining on the image carrier without being transferred to the recording medium onto the recording medium. Thereby, it is not necessary to install a space for collecting the transfer residual developer in the image forming apparatus, and the size and weight can be reduced.

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

  FIG. 1 is a schematic diagram of an image forming apparatus according to a first embodiment of the present invention.

  In the figure, reference numeral 1 denotes an image forming apparatus, for example, an electrophotographic printer, a facsimile machine, a copying machine, a printer, a facsimile machine, and a multifunction machine having the functions of a copying machine. May be. In the present embodiment, the case where the image forming apparatus 1 is a so-called tandem color electrophotographic printer will be described.

  In this case, the image forming apparatus 1 has four colors of yellow (Y), magenta (M), cyan (C), and black (K) arranged in tandem along the conveyance path of the recording paper P as a recording medium. Image forming units 10Y, 10M, 10C, and 10K corresponding to each of the image forming units and a fixing device 12 as a fixing unit are included. The recording paper P is a printing paper, an envelope, an OHP (Over Head Projector) sheet, or the like, but may be of any kind. Then, toners as four types of developer are sequentially superimposed and transferred onto the recording paper P conveyed by the transfer belt 24 which is also a transfer member to which the developer image is transferred, whereby the color image is transferred onto the recording paper P. It is formed and fixed by the fixing device 12.

  The image forming units 10Y, 10M, 10C, and 10K have substantially the same configuration except that the toners used are different. The order of arrangement does not necessarily have to be as shown in the figure, and can be changed as appropriate. In the case of a monochrome image forming apparatus, only one image forming unit 10, for example, a black image forming unit 10K may be provided.

  Since the image forming units 10Y, 10M, 10C, and 10K have the same configuration, the configuration of the image forming unit 10Y using yellow toner will be described as an example here.

  The image forming unit 10Y includes a photoconductor drum 11y as an image carrier using an organic photoconductor on the surface. The photosensitive drum 11y rotates, for example, at an outer diameter of 30 [mm] and a peripheral speed of about 162 [mm / sec]. A charging roller 21y is disposed around the photosensitive drum 11y as a charging unit that charges the photosensitive drum 11y. The charging roller 21y charges the contacted photosensitive drum 11y when a positive voltage or a negative voltage is applied by a predetermined charging device power source 22y.

  An exposure device 23y as an exposure unit for forming an electrostatic latent image is disposed around the photosensitive drum 11y. The exposure device 23y irradiates the surface of the photosensitive drum 11y with light corresponding to the image signal, and forms an electrostatic latent image on the photosensitive drum 11y. As the exposure device 23y, for example, any combination of an LED (Light Emitting Diode) array and a so-called lens array, a combination of a laser and an image forming optical system, and the like can be applied.

  Further, around the photosensitive drum 11y, a developing roller 41y is provided as a developing unit which is a developing unit that develops the electrostatic latent image formed on the photosensitive drum 11y with toner. The developing roller 41y develops an electrostatic latent image formed on the photosensitive drum 11y in contact with the toner by applying a positive voltage or a negative voltage by a predetermined developing device power source 42y, and a developer image. As a result, a toner image is formed. Further, a layer forming blade 52y, which is a toner regulating member that keeps the toner amount on the developing roller 41y constant, is disposed in contact with one end of the developing roller 41y as a layer forming device. Further, as a toner supply device, a toner supply roller 51y that supplies toner to the developing roller 41y is disposed in contact therewith. A positive voltage or a negative voltage is applied to the toner supply roller 51y and the layer forming blade 52y by a predetermined power supply 53y for the toner supply device.

  Further, around the photosensitive drum 11y, a transfer roller 43y serving as a transfer unit that is a transfer unit that transfers the toner image onto the recording paper P that is a recording medium is disposed. The transfer roller 43y is disposed in contact with the back surface of the transfer belt 24 that forms a medium transport path for transporting the loaded recording paper P in the horizontal direction by power according to the rotation of the drive roller 11a and the driven roller 11b. Is done. The transfer roller 43y is applied with a positive voltage or a negative voltage by a predetermined transfer device power supply 44y in a state where the recording paper P placed on the transfer belt 24 is sandwiched between the transfer drum 24 and the transfer roller 43y. A toner image is transferred onto the recording paper P or the transfer belt 24 using a voltage.

  Further, around the photosensitive drum 11y, a cleaning roller 45y serving as a collection unit that is brought into contact with the photosensitive drum 11y is disposed as a cleaning device that is a toner collecting unit. The cleaning roller 45y is composed of a metal shaft and a porous sponge, and a transfer voltage remaining on the photosensitive drum 11y is applied by applying a positive voltage or a negative voltage by a predetermined cleaning device power supply 46y. Collect residual toner. The cleaning roller 45y rotates, for example, with an outer diameter of 11 [mm] and a peripheral speed of about 220 [mm / sec].

  As described above, the image forming unit 10Y develops the electrostatic latent image formed on the photosensitive drum 11y using yellow toner, and the obtained toner image is recorded on the recording paper placed on the transfer belt 24. Transfer on P. Each power source and each motor (not shown) for driving each power source and each roller in the image forming unit 10Y are controlled by a print control unit 60 described later.

  It should be noted that each of the components forming the image forming unit 10M using magenta toner, the image forming unit 10C using cyan toner, and the image forming unit 10K using black toner is the same as the components forming the image forming unit 10Y. It is shown as m, c, and k appended to the numerical part of the reference numeral. Therefore, in the following, when the respective parts of the image forming units 10Y, 10M, 10C, and 10K are collectively referred to, only the numerical portions of the reference numerals indicating the respective portions are attached as necessary.

  When printing as image formation is started, the recording paper P is conveyed to the image forming unit 10. The recording paper P is fed from a tray 32 or an MPT tray (Mu1ti Purpose Tray) 33. When the recording paper P is fed from the tray 32, a hopping roller 30 controlled by a hopping roller control unit 91 described later is driven, and one recording paper P is taken out and conveyed by the drive roller. Further, when the recording paper P is fed from the MPT tray 33, the MPT hopping roller 31 controlled by the MPT hopping roller control unit 92 described later is driven, and one recording paper P is taken out and conveyed by the drive roller 34. Is done. In either case, thereafter, the leading edge of the recording paper P reaches the first image forming unit 10Y.

  In addition, the image forming apparatus 1 is a cleaning device for the transfer belt 24, a belt cleaning blade 15 that is in contact with the transfer belt 24 around the drive roller 11 b on the upstream side in the medium conveyance direction, and the transfer belt by the belt cleaning blade 15. And a waste toner box 17 for collecting the waste toner 16 scraped from above. The belt cleaning blade 15 is a plate member having elasticity, and is arranged so that the edge portion is in contact with the transfer belt 24, and scrapes off toner remaining on the transfer belt 24 by the operation of the transfer belt 24. is there.

  Further, a fixing device 12 that forms a medium conveyance path is disposed downstream of the transfer belt 24. The fixing device 12 includes two rollers arranged in parallel with each other in the vertical direction, and the toner image on the recording paper P is fixed by heat and pressure applied at a nip portion formed between the rollers to form an image. And the recording paper P is conveyed. In the example shown in the figure, one roller is provided with a heater 12a as a heating means.

  Then, the driving roller 11a and the driven roller 11b are driven to rotate, and the recording paper P is conveyed by the transfer belt 24 in the direction of arrow X in the drawing at a predetermined medium conveying speed. Accordingly, each of the four image forming units 10Y, 10M, 10C, and 10K forms toner images of each color on the photosensitive drums 11y, 11m, 11c, and 11k, and the recording paper P on which the toner images of each color are conveyed. The images are sequentially transferred onto the image and then fixed together by the fixing device 12. Thereby, a color image is formed.

  Next, the configuration of a control device that controls the operation of the image forming apparatus 1 will be described.

  FIG. 2 is a block diagram showing the configuration of the control device of the image forming apparatus according to the first embodiment of the present invention.

  As shown in the figure, the control device includes a print control unit 60 that controls the operation of the entire image forming apparatus 1. The print control unit 60 includes an I / F control unit 61, a memory 62, an operation unit 68 for requesting user approval for toner disposal described later, a tray paper out sensor 69, various other sensors 70, and a display unit 90 is connected.

  The I / F control unit 61 is an interface that transmits and receives print data transferred from a host device (not shown), and supplies the print data transferred from the host device to the print control unit 60.

  The memory 62 includes a reception memory 63 and an image data editing unit 64 allocated to a storage area configured by a RAM (Random Access Memory) and the like, and a ROM (Read Only Memory) 65. The reception memory 63 functions as a work area for the print control unit 60 and temporarily stores data received from the host device. The image data editing unit 64 functions as a work area when editing image data under the control of the print control unit 60. Further, the ROM 65 stores a printing operation control program executed by the printing control unit 60 and also stores a timing determination processing program executed by the printing control unit 60 in order to determine the timing of a toner discarding operation described later. To do.

  In the RAM in the memory 62, a parameter storage unit 66p that temporarily stores a parameter Px that is a count value of a print dot number counter 83px in a data amount counting unit 80, which will be described later, and an execution timing of the toner discarding operation are determined. A threshold value storage unit 67p that stores a threshold value N that is a parameter for performing the operation, a parameter storage unit 66q that temporarily stores a parameter Q that is a count value of the number of rejections by the user of the toner discarding operation, and a toner A threshold value storage unit 67q that temporarily stores a threshold value M, which is an upper limit parameter of the number of times of discard operation refusal, an automatic execution parameter 86 that stores whether or not toner discard is designated to be automatically performed, and a toner discard operation. Tray designation parameter 87, which is a parameter for storing the supply source of recording paper P to be used in the process But it assigned as a storage area.

  Here, the tray for performing the toner discarding operation is designated by supplying unnecessary recording paper P from the MPT tray 33 for the toner disposal and performing the toner discarding operation, or conversely, special paper as the recording paper P. This is to prevent erroneous execution from the MPT tray 33 that is often used for paper feeding. Further, the automatic execution parameter is required because the demand of the image forming apparatus 1 is not required when the image forming apparatus 1 is required to execute automatically, as will be described later. This is to prevent the toner discarding operation from being erroneously performed when there are many or when special paper is used as the recording paper P.

  The operation unit 68 includes a switch that gives an instruction from the operator to the image forming apparatus 1. Information input via the operation unit 68 is supplied to the print control unit 60. Further, the tray paper out sensor 69 not only determines whether or not the recording paper P is in the designated tray when the toner discarding operation is performed, but is also used during normal printing. Various sensors 70 other than the tray paper out sensor 69, such as a temperature sensor that detects the temperature of each part constituting the image forming apparatus 1, a medium conveyance state detection sensor that detects the conveyance state of the recording paper P, and the like. It consists of various sensor groups.

  Information detected by the tray out-of-paper sensor 69 and various sensors 70 is supplied to the print control unit 60. The display unit 90 is controlled by the print control unit 60 to notify the user that the toner needs to be discarded and the recording paper P is out of the tray.

  In addition to the exposure device 23, the print controller 60 includes a charging voltage controller 71, a developing voltage controller 72 as a second voltage controller, and supply voltage control. A transfer voltage control unit 74 as a third voltage control unit, a cleaning control unit 75 as a first voltage control unit, a motor control unit 76, and a fixing control unit 77 are connected.

  The charging voltage control unit 71 controls the charging roller 21 and the charging device power source 22. Specifically, the charging voltage control unit 71 controls the voltage applied to the charging roller 21 by the charging device power source 22 and the driving of the charging roller 21 under the control of the printing control unit 60. Control.

  The developing voltage control unit 72 controls the developing roller 41 and the developing device power source 42. Specifically, the developing voltage control unit 72 controls the voltage applied to the developing roller 41 by the developing device power source 42 and the driving of the developing roller 41 under the control of the printing control unit 60. Control.

  The supply voltage control unit 73 controls the toner supply roller 51, the layer forming blade 52, and the power supply 53 for the toner supply device. Specifically, the supply voltage control unit 73 controls the voltage applied to the supply roller 51 and the layer forming blade 52 by the toner supply device power source 53 under the control of the print control unit 60, and the supply. The driving of the roller 51 and the layer forming blade 52 is controlled.

  The transfer voltage controller 74 controls the transfer roller 43 and the transfer device power supply 44. Specifically, the transfer voltage control unit 74 controls the transfer voltage applied to the transfer roller 43 by the transfer device power supply 44 under the control of the print control unit 60, and the driving of the transfer roller 43. To control.

  The cleaning control unit 75 controls the cleaning roller 45 and the cleaning device power supply 46. Specifically, the cleaning voltage control unit 75 controls the voltage applied to the cleaning roller 45 by the cleaning device power supply 46 and the driving of the cleaning roller 45 under the control of the print control unit 60. Control.

  The hopping roller control unit 91 controls driving of the hopping roller 30 under the control of the print control unit 60.

  The MPT hopping roller control unit 92 controls driving of the MPT hopping roller 31 under the control of the print control unit 60.

  Note that the shutter control unit 93 and the stirring (stirring) blade control unit 94 control the driving of the shutter 101 and the stirring blade 102 described in the second embodiment.

  Further, as described in the third embodiment, the dot calculation unit 105 adds the print dot numbers of the image forming units 10Y, 10M, 10C, and 10K, and adds the image forming units 10Y, 10M, 10C, and The ratio of the number of printed dots of 10K is calculated.

  The motor control unit 76 controls the driving of each of the motors 78 that drive the drive roller 34 and other rollers of the image forming apparatus 1 under the control of the print control unit 60.

  The fixing control unit 77 controls the temperature of the fixing device 12 and the speed at which the recording paper P is conveyed under the control of the print control unit 60.

  Further, a data amount counting unit 80 is connected to the print control unit 60. The data amount counting unit 80 is a printing dot number counter 83 px (x = y, m, c, and k) that counts the number of printing dots performed by the image forming units 10Y, 10M, 10C, and 10K on the recording paper P. And a reject count counter 83q that counts the number of times the user rejects the toner discard operation and the toner discard is suspended. The print dot number counter 83 px counts the number of print dots under the control of the print control unit 60.

  Specifically, the data amount counting unit 80 performs predetermined toner (for example, new image forming units 10Y, 10M, 10C) under the control of the print control unit 60 in order to execute a toner processing operation described later. And 10K are mounted on the image forming apparatus 1, and when the toner discarding operation is completed), the printing dot number counter 83px (83py, 83pm, 83pc and 83pk, respectively) is initialized to zero value, and the printing is performed. Data indicating the number of print dots of each of the image forming units 10Y, 10M, 10C, and 10K is input from the control unit 60 to the print dot number counter 83px. The count value indicating the number of print dots counted by the print dot number counter 83px (83py, 83pm, 83pc and 83pk, respectively) in the data amount counting unit 80 is read by the print control unit 60, and as described above, the parameter Px (x = y, m, c, and k) is cumulatively added and stored in the parameter storage unit 66p configured in the memory 62. A refusal counter 83q that counts the number of toner discard operation refusals counts the number of times that the toner discard operation has been temporarily suspended by the user.

  Further, the data amount counting unit 80 controls the printing control unit 60 to discard toner when a predetermined timing (for example, when new image forming units 10Y, 10M, 10C, and 10K are mounted on the image forming apparatus 1). When the operation is completed, the rejection number counter 83q is initialized to zero, and data indicating the toner discard operation rejection number is input from the print control unit 60 to the rejection number counter 83q. The count value indicating the number of toner disposal operation rejections counted by the rejection number counter 83q in the data amount counting unit 80 is read by the print control unit 60, and as described above, the parameter Q is configured in the memory 62 as the parameter Q. Accumulated and stored in the storage unit 66q.

  2 other than the data amount counting unit 80, the parameter storage unit 66q, and the threshold storage units 67p and 67q have the same functions as those in a general electrophotographic recording type image forming apparatus. Have.

  Next, the operation of the image forming apparatus 1 having the above configuration will be described.

  FIG. 3 is a timing chart showing the operation of the image forming unit of the image forming apparatus according to the first embodiment of the present invention, and FIG. 4 is a toner discard of the image forming unit of the image forming apparatus according to the first embodiment of the present invention. It is a figure which shows the timing which starts. In FIG. 3, (a) is the on / off timing of the motor that drives the photosensitive drum, (b) is the voltage change applied to the charging roller, and (c) is the on / off timing of the exposure apparatus. Timing, (d) voltage change applied to the cleaning roller, (e) voltage change applied to the developing roller, and (f) voltage applied to the toner supply roller and the layer forming blade. (G) is a voltage change applied to the transfer roller, (h) is an on / off timing of the hopping roller and the MPT hopping roller, (i) is an on / off timing of the heater, and (j) is an on / off timing. A voltage change applied to the charging roller in the image forming unit downstream in the medium conveying direction, (k) is applied to the transfer roller in the image forming unit downstream in the medium conveying direction. It shows the voltage change.

  First, the image forming apparatus 1 starts a printing operation when a print command is input to the print control unit 60 from the host device at time 0 shown in FIG.

  When the printing operation is started, the print control unit 60 checks the tray designation parameter 87 in the memory 62. When the tray 32 is designated, the hopping roller control unit 91 drives the hopping roller 30 and takes out one sheet of recording paper P. When the MPT tray 33 is designated, the MPT hopping roller control unit 92 drives the MPT hopping roller 31 and takes out one sheet of recording paper P.

  Subsequently, the motor controller 76 powers on the motors 78 of the drive roller 34, the photosensitive drum ly, the charging roller 21y, the transfer belt 24, the cleaning roller 45y, the fixing device 12, the developing roller 41y, and the toner supply roller 51y. Each of them is driven to rotate in the direction of the arrow shown in FIG.

  At the same time, the printing control unit 60 applies a DC charging voltage of, for example, -1200 [V] from the charging device power source 22y to the charging roller 21y, and the surface of the photosensitive drum lly is applied, for example. , Uniformly charged at a surface potential of −600 [V].

  Further, the print control unit 60 applies a DC voltage of, for example, +4000 [V] having a polarity opposite to the charging voltage from the transfer device power supply 44y to the transfer roller 43y.

  Further, the printing control unit 60 applies a DC voltage of, for example, −200 [V] having the same polarity as the charging voltage from the developing device power source 42y to the developing roller 41y.

  Further, the print control unit 60 applies a DC voltage of, for example, −300 [V] having the same polarity as the charging voltage to the toner supply roller 51y and the layer forming blade 52y from the toner supply device power source 53y.

  Further, the printing control unit 60 applies a DC voltage having a polarity opposite to the charging voltage, for example, +400 [V] from the cleaning device power supply 46y to the cleaning roller 45y.

  Subsequently, the print control unit 60 drives the exposure device 23y to irradiate the surface of the photoconductive drum ly with light corresponding to the image signal, so that the portion of the photoconductive drum ly charged with static electricity is statically charged. An electrostatic latent image is formed. At this time, the voltage of the portion where the electrostatic latent image is formed drops to about 0 [V] when irradiated with light. The surface of the photosensitive drum lly on which the electrostatic latent image has been written contacts with the developing roller 41y by continuously rotating in the direction of the arrow R shown in FIG.

  Here, since the toner on the developing roller 41y is charged with the same polarity as the charging voltage, the charged toner is caused by an electrostatic effect when the photosensitive drum lyy contacts the developing roller 41y. It adheres to the electrostatic latent image and develops.

  As described above, the surface of the photosensitive drum lyy after the development is in contact with the transfer belt 24. The transfer belt 24 comes into contact with the photosensitive drum ly at a predetermined pressure and is driven in the direction of the arrow X.

  Here, since the transfer belt 24 is charged by applying a voltage having a reverse polarity to the charging voltage by the transfer roller 43y, the toner image on the photosensitive drum lly is transferred onto the recording paper P.

  In this way, the recording paper P on which the toner image has been transferred is conveyed to the image forming unit 10M provided in the next stage in accordance with the driving of the transfer belt 24. The image forming apparatus 1 performs such a process also in the other image forming units 10M, 10C, and 10K on the downstream side in the medium conveyance direction, and discharges the recording paper P as printed matter after the fixing by the fixing device 12 is completed.

  After the fixing by the fixing device 12, the toner remaining on the transfer belt 24 when the recording paper P is printed is continuously conveyed in the direction of the arrow X and is arranged around the drive roller llb on the upstream side in the medium conveying direction. It is scraped in contact with the belt cleaning blade 15 provided.

Thereby, the printing operation in the image forming apparatus 1 is completed. Note that the timing at which the printing operation ends is time t _f in FIG.

In this way, after the printing operation is finished by finishing the scraping of the residual toner by the belt cleaning blade 15, the image forming apparatus 1 controls the transfer residual toner at time t ₀ according to the control of the print control unit 60. Move to the discard operation. Specifically, the image forming units 10Y, 10M, 10C, and 10K of the image forming apparatus 1 perform the transfer residual toner discharging operation. At time t ₀ , when the transfer residual toner is discarded, the recording paper P is fed. The transfer to the transfer residual toner discarding operation may be performed at any timing as long as the residual toner scraping by the belt cleaning blade 15 is completed.

  First, the transfer residual toner discharging operation will be described.

  As shown in FIG. 4, the toner is discarded by dividing the recording paper P into four equal parts in the sub-scanning direction, and discarding the toner on the recording paper P in the order of black, cyan, magenta, and yellow from the leading edge. . In this case, as shown in FIG. 4, the transfer starts when each photosensitive drum 11 comes to a quartering point of the recording paper P. The reason for shifting the position on the recording paper P is to avoid a fixing failure due to an increase in the toner layer thickness.

  Since the operation of discharging the transfer residual toner in the image forming units 10Y, 10M, 10C, and 10K is the same except that the timing is shifted, only the operation in the image forming unit 10Y will be described.

Assuming that the transfer residual toner on the photosensitive drum lly is completely removed at time t _f in Figure 3, under the control of the print control section 60, at time t _0, as described above, the recording paper from the specified tray P is taken out by the hopping roller 30 or the MPT hopping roller 31 and conveyed onto the transfer belt 24 by the drive roller 34.

Then, according to the position on the recording paper P as described above, at time t _1, the cleaning roller 45y from the cleaning device for a power supply 46y, the charging voltage of the same polarity, for example, a DC voltage of -1200 V] Apply. Note that time t ₁ is the time when the transfer start position P ₁ reaches a predetermined point α on the medium transport path, which will be described later.

  Here, the surface potential of the photosensitive drum lly after the transfer process is about 0 [V] due to discharge. The untransferred toner accumulated on the cleaning roller 45y and charged with the same polarity as the charging voltage moves to the surface of the photosensitive drum 11y by Coulomb force. Then, the surface of the photosensitive drum lly is charged to, for example, −600 [V] having the same polarity as the charging voltage by the cleaning roller 45y. At this time, a voltage having the same polarity as the charging voltage and larger than the charging potential on the photosensitive drum lly is applied to the cleaning roller 45y.

  Then, the photosensitive drum lly carrying the transfer residual toner further rotates and comes into contact with the charging roller 21y. Here, a voltage having the same polarity as the transfer residual toner is applied to the charging roller 21y by the power supply 22y for the charging device, the surface potential of the photosensitive drum lly has the same polarity as the charging voltage, and Since the charging voltage is lower than the charging voltage of the charging roller 21y, the transfer residual toner passes through the charging roller 21y while being held on the surface of the photosensitive drum ly by the Coulomb force. At this time, a voltage having the same polarity as the charging voltage and higher than the charging potential on the photosensitive drum lly is applied to the charging roller 21y.

Further, by the photosensitive drum lly rotates, at time t _2, the transfer residual toner on the photosensitive drum lly passing through the charging roller 21y (rotational direction of the distal end portion of the photosensitive drum 11y) and the developing roller 41y Contact. In the time t _2, the a charging voltage of the same polarity, and so as to have the same voltage as the surface of the photosensitive drum lly, applied to the developing roller 41y from the developing device power source 42y.

  For example, the transfer residual toner on the photosensitive drum 11y is charged to the surface potential of −600 [V] by the cleaning roller 45y, and therefore the same voltage of −600 [V] is applied to the developing roller 41y. Apply. The surface potential of the transfer residual toner on the photosensitive drum 11y is a combination of the surface potential of the photosensitive drum 11y and the potential of the entire toner layer of the transfer residual toner, and the surface potential of the surface of the photosensitive drum 11y itself. The potential is about 0 [V]. In the present embodiment, the same voltage is applied, but a negative value larger than −600 [V], for example, −1000 [V] may be applied.

  As a result, the developing roller 41y has the same polarity as the charging voltage and has the same voltage as the surface potential of the photosensitive drum 11y or a voltage having a large absolute value. The toner passes on while being held on the surface of the photoconductive drum lyy, and the toner on the developing roller 41y is not developed on the photoconductive drum lyly, and only the transfer residual toner is held on the photoconductive drum lyly. Passes the developing roller 41y.

Further, the photosensitive drum lly carrying the transfer residual toner further contacts with the recording paper P as shown in FIG. Time t _t in FIG. 3 is a time at which the leading end portion of the transfer residual toner on the photosensitive drum 11y reaches the contact portion between the transfer roller 43y. At this time, the distal end portion of the transfer residual toner on the photosensitive drum 11y and the transfer start position P ₁ is in contact, the transfer residual toner is started to be transferred onto the recording sheet P. Here, the transfer device power supply 44y applies a voltage of, for example, +4000 [V] opposite to the transfer residual toner to the transfer roller 43y. The recording paper P on the transfer belt 24 is moved from the surface of the drum lly.

At time t ₃ , the transfer residual toner from the cleaning roller 45y to the photosensitive drum 11y is completed. In order to move the cleaning roller 45y from the cleaning roller 45y to the photosensitive drum 11y, this embodiment requires time for one cleaning roller 45y. However, since the cleaning roller 45y only needs to move from the cleaning roller 45y to the photosensitive drum 11y, for example, You may rotate more than one round. However, in order to move the transfer residual toner adhering to the outer periphery of the cleaning roller 45y to the photosensitive drum 11y, it is preferable that the toner is at least the circumference of the cleaning roller 45y1.

At time t _3, the transfer residual toner on the cleaning roller 45y ends are released onto the photosensitive drum 11y, the cleaning device for a power supply 46y with respect to the cleaning roller 45y, the charging voltage and opposite polarity, e.g., + 400 [ V] is applied.

  In this way, by applying a voltage having a polarity opposite to the charging voltage to the cleaning roller 45y again, it is possible to collect the transfer residual toner that has been transferred without being transferred in the transfer process.

At time t ₄ , the collection of the transfer residual toner is completed, and the toner disposal of the image forming unit 10Y is completed. Time t ₄ is the time when the trailing edge of the untransferred toner on the photosensitive drum 11y reaches the contact portion with the developing roller 41y.

Time t ₅ is the time when the trailing end of the transfer residual toner on the photosensitive drum 11y reaches the contact portion with the transfer roller 43y, and the transfer residual toner moved to the photosensitive drum 11y onto the recording paper P. The transfer is complete.

Incidentally, after time t ₅ also image forming section 10M, 10C and 10K of the charging roller 21m, a voltage of -1200 V to 21c and 21k, the transfer roller 43m, the voltage of +4000 V to 43c and 43k It is preferable to apply.

Time t ₆ is the time when the transfer of the transfer residual toner onto the recording paper P in the image forming unit on the most downstream side in the medium conveyance direction, that is, the image forming unit 10K is completed. At this time, a voltage of -1200 [V] is applied to the charging rollers 21m, 21c and 21k of the image forming units 10M, 10C and 10K, and a voltage of +4000 [V] applied to the transfer rollers 43m, 43c and 43k is turned off. It becomes.

Furthermore, time t ₇ is the time when the trailing edge of the recording paper P on which the transfer residual toner has been transferred passes through the fixing device 12. At this time, the energization to the heater 12a of the fixing device 12 is turned off.

Furthermore, time t ₈ is the time when the trailing edge of the recording paper P to which the transfer residual toner has been transferred is discharged out of the image forming apparatus 1. Here, the disposal of the transfer residual toner is completed.

It should be noted that, if the toner waste is carried out between the printing operation and the printing operation, the printing operation at the time t ₈ or later is started will continue.

  Next, the relationship between the toner discarding operation and the position of the recording paper P will be described in more detail.

  FIG. 5 is a diagram showing the relationship between the toner discarding operation of the image forming unit of the image forming apparatus and the position of the recording paper P in the first embodiment of the present invention.

The leading edge of the recording paper P as shown in FIG. 4 is the leading edge of the transfer position to which the toner image formed by the image forming unit 10Y is transferred (transfer start position P ₁ which is the transfer residual developer movement start position). . In this embodiment, the transfer start position P ₁ is the leading edge of the recording paper P. However, the present invention is not limited to this, and it is a blank at a predetermined distance (for example, 5 mm) from the leading edge of the recording paper P. A transfer start position P ₁ can also be set by providing a portion.

Then, as shown in FIG. 5, a writing sensor 81 as a medium detecting unit is provided, the writing sensor 81 detects the leading edge of the recording paper P, and the transfer start position P ₁ is a predetermined point on the medium conveyance path. Until it reaches α, for example, it is counted by a timer or the like, and the applied voltage to the cleaning roller 45y is changed from +400 [V] to −1200 [V] as time t ₁ when the transfer start position P ₁ becomes a predetermined point α on the medium conveyance path. Switch to].

Further, the distance from the contact portion between the cleaning roller 45y of the photosensitive drum 11y to the contact portion between the transfer roller 43y and L _1.

In the present embodiment, when the peripheral speed of the photosensitive drum 11y and the conveyance speed of the recording paper P, that is, the conveyance speed of the transfer belt 24 and the conveyance speed of the drive roller 34 are equal, the photosensitive drum 11y and the transfer roller. If a point that is a predetermined distance L ₂ from the contact portion with 43 y to the upstream side in the medium conveyance direction is α, the point α is a point where L ₁ = L ₂ .

In the present embodiment, since the peripheral speed as the conveying speed of the recording paper P of the photosensitive drum 11y is equal, if it is L ₁ = L _2, there is a speed difference in each corresponding to L ₁ The distance of L ₂ to be changed can be changed as appropriate.

At this time, L ₂ is separated from the contact portion between the photosensitive drum 11 y and the transfer roller 43 y to the upstream side in the medium conveying direction by a distance on the recording paper P that contacts the distance L ₁ by the rotation of the photosensitive drum 11 y. Distance. For example, when the circumferential speed of the photosensitive drum 11y> the conveyance speed of the recording paper P, L ₁ > L ₂ may be satisfied.

  Then, the transfer residual toner deposited on the cleaning roller 45y is discharged to the photosensitive drum 11y.

  The transfer residual toner thus moved onto the recording paper P is conveyed together with the recording paper P in the direction of the arrow X in FIG. 1, and contacts the image forming units 10M, 10C, and 10K on the downstream side in the medium conveyance direction. To do.

  Here, a voltage of +4000 [V] having a polarity opposite to the charging voltage is applied to the transfer rollers 43m, 43c and 43k by the transfer device power sources 44m, 44c and 44k, and the charging device power sources 22m, 22c and For example, a voltage of −1200 [V] is applied to the charging rollers 21m, 21c and 21k by 22k, and the surface potential of the photosensitive drum 11y is charged to about −600 [V]. The transfer residual toner charged to the same polarity as the charging voltage passes through the image forming units 10M, 10C, and 10K without being reversely transferred to the photosensitive drum by the Coulomb force, and reaches the fixing unit 12 at the most downstream side in the medium conveyance direction. Moving.

  The transfer residual toner in the image forming units 10M, 10C, and 10K is also discharged from the cleaning rollers 45m, 45c, and 45k through the same process, moved to the recording paper P, and conveyed to the fixing unit 12.

In addition, in the image forming units 10M, 10C, and 10K on the downstream side of the image forming unit 10Y, the transfer residual toner discharged by the image forming unit 10Y does not adhere to the photosensitive drums 11m, 11c, and 11k (referred to as reverse transfer). applied at time t _1, the image forming section 10M, 10C and 10K of the charging roller 21m, and 21c and 21k, a voltage of -1200 V, the transfer roller 43m, the 43c and 43k a voltage of +4000 V! It is preferable to do.

In this case, at time t ₆ the discharge is completed the transfer residual toner of the image forming section 10K of the medium conveyance direction downstream side, the charging roller 21y, and a voltage to be applied 21m, and 21c and 21k, the transfer roller 43y, 43m, 43c And the voltage applied to 43k is set to off.

Similarly, in the image forming units 10M, 10C, and 10K, the transfer start positions P ₂ , P ₃ , and P _{4 that} are the respective transfer residual developer movement start positions reach the point where L ₁ = L _2. Then, the voltage applied to the cleaning rollers 45m, 45c and 45k is switched from +400 [V] to -1200 [V], and the same operation as discharging the transfer residual toner in the image forming unit 10Y may be performed.

  As described above, in the image forming apparatus 1 according to the present embodiment, the transfer residual toner in the image forming units 10Y, 10M, 10C, and 10K can be discharged. Then, the fixing unit 12 performs a fixing operation of the transfer residual toner.

  Next, toner disposal timing will be described.

  FIG. 6 is a flowchart showing the execution timing of the transfer residual toner discarding operation of the image forming apparatus according to the first embodiment of the present invention.

  The image forming apparatus 1 discards the transfer residual toner at a timing as shown in FIG.

  First, the print control unit 60 initializes the parameter Px (x = y, m, c, and k) and the parameter Q stored in the parameter storage unit 66p to zero values. The initialization is performed, for example, after the toner disposal is completed. The parameter Px is a parameter for executing the cleaning operation, and counts the number of print dots of each image forming unit 10 with respect to the recording paper P. The parameter Px is counted by the print dot number counter 83 px in the data amount counting unit 80. The counted values are stored in the parameter storage units 66py, 66pm, 66pc, and 66pk via the print control unit 60. That is, in the image forming apparatus 1, when one page is printed, the print control unit 60 controls each of the image forming units 10Y, 10M, and Py in the parameters Py, Pm, Pc, and Pk stored in the parameter storage unit 66p. The print dot numbers py, pm, pc, and pk of 10C and 10K are added.

  The parameter Q is incremented by “1” every time the user rejects the cleaning operation. Similarly, the count value counted by the rejection number counter 83q in the data amount counting unit 80 indicates the print control unit 60. And stored in the parameter storage unit 66q. The parameter 66q is provided to prevent the waste toner from being punctured due to the continued rejection of toner discard by the user.

  Next, the print control unit 60 determines whether print data for the next page exists, and if it exists, performs a printing operation. In addition, the print control unit 60 compares the parameter Px stored in the parameter storage unit 66p with the predetermined threshold value N stored in the threshold storage unit 67p, respectively, when the print data for the next page does not exist, It is determined whether or not the parameter Px has reached the threshold value N. That is, it is determined whether each image forming unit 10 has printed N dots. For example, when “10000” is set as the threshold value N, it is determined whether or not each image forming unit 10 has printed 10,000 dots.

  Here, when it is determined that any of the parameters Px (Py, Pm, Pc, Pk) has reached the threshold value N, the print control unit 60 determines whether or not an instruction to automatically execute toner disposal is given. To do. That is, it is confirmed whether or not the automatic execution parameter 86 is ON. When the automatic execution parameter 86 is ON, the print control unit 60 determines whether or not there is paper in the tray designated by the tray designation parameter 87 by the tray paper out sensor 69. When the print control unit 60 determines that there is a sheet in the designated tray, toner discarding is executed, and the process ends. If it is determined that there is no paper in the designated tray, the user is notified of the out of paper via the display unit 90, and the determination of whether or not there is paper in the tray designated in the tray designation parameter 87 is repeated.

  Next, when automatic execution of the automatic execution parameter 86 is OFF, the print control unit 60 receives the determination of automatic execution OFF and notifies the display unit 90 that toner disposal is necessary. When the print control unit 60 obtains user approval through the operation unit 68, it is determined whether or not there is a sheet in the tray designated by the tray designation parameter 87, and the same operation is performed thereafter.

  Subsequently, it is determined whether or not the user's approval can be obtained. If the user's approval cannot be obtained, the print control unit 60 adds 1 to the parameter Q that is a count value of the toner discard operation refusal count. Next, it is determined whether the toner discard operation rejection count has reached the threshold value M. If the toner discard operation rejection count has not reached the threshold value M, the print control unit 60 returns to the original state and continues printing. When the toner discard operation rejection count reaches the threshold value M, the print control unit 60 notifies the user that toner discard is necessary. Here, the threshold value M is provided to prevent the waste toner from being punctured due to the toner rejection being continuously rejected by the user.

Next, a flowchart will be described.
Step S1: The parameters Px and Q are initialized to zero values.
Step S2 Print one page.
Step S3: The control of the print control unit 60 adds the print dot number counter px (respectively py, pm, pc, pk) to the parameter Px (respectively Py, Pm, Pc, Pk) stored in the parameter storage unit 66p. To do.
Step S4: It is determined whether there is print data for the next page. If there is print data for the next page, the process returns to step S2. If there is no print data for the next page, the process proceeds to step S5.
Step S5: It is determined whether or not the parameter Px (Py, Pm, Pc, or Pk) has reached the threshold value N. When the parameter Px reaches the threshold value N, the process proceeds to step S6, and when the parameter Px does not reach the threshold value N, the process returns to step S2.
Step S6: It is determined whether or not the automatic execution parameter 86 is ON. If the automatic execution parameter 86 is ON, the process proceeds to step S7. If the automatic execution parameter 86 is not ON, the process proceeds to step S9.
Step S7: It is determined whether or not there is paper in the designated tray. If there is paper in the designated tray, the process proceeds to step S8, and if there is no paper in the designated tray, the process proceeds to step S13.
Step S8: Toner disposal is executed, and the process is terminated.
Step S9: The user is notified that toner disposal is necessary.
Step S10: It is determined whether or not user approval can be obtained. If user approval can be obtained, the process proceeds to step S7. If user approval cannot be obtained, the process proceeds to step S11.
Step S11: 1 is added to the parameter Q, which is a count value of the number of toner discard operation refusals.
Step S12: It is determined whether or not the number of toner disposal operation refusal times has reached the threshold value M. If the toner discard operation rejection count has reached the threshold value M, the process returns to step S9. If the toner discard operation rejection count has not reached the threshold value M, the process returns to step S2.
Step S13: The user is notified that the paper is out.

  As described above, in this embodiment, since the transfer residual toner is fixed on the recording paper P, the user can not only process the waste toner as general waste, but also the developing device 40, the toner cartridge, or the image. There is no need to provide a space or mechanism for collecting waste toner in the forming apparatus 1, and the image forming apparatus 1 and the image forming unit 10 can be reduced in size and weight.

  Next, a second embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol. The description of the same operation and the same effect as those of the first embodiment is also omitted.

  FIG. 7 is a schematic diagram of an image forming apparatus according to the second embodiment of the present invention, and FIG. 8 is a diagram illustrating a configuration of a cleaning blade of the image forming apparatus according to the second embodiment of the present invention. In FIG. 8, (a) is a side view, (b) is a perspective view, and (c) is a perspective view of a stirring blade.

  In the present embodiment, the image forming apparatus 2 is different from the image forming apparatus 1 according to the first embodiment having a cleaning roller 45 as a transfer residual toner recovery unit, and cleaning as a transfer residual toner recovery unit. It has a blade 100. More specifically, the image forming apparatus 2 includes image forming units 96Y, 96M, 96C, and 96K. As in the first embodiment, the image forming units 96Y, 96M, 96C, and 96K have substantially the same configuration except that the toner used is different. Here, the configuration of the image forming unit 96Y using yellow toner will be described as an example. Further, the description of the same part as the image forming unit 10Y in the first embodiment is omitted.

  As shown in FIGS. 8A and 8B, in the image forming unit 96Y, the cleaning blade 100y is in contact with the photosensitive drum 11y. The cleaning blade 100y is a plate member having elasticity, and is arranged so that the edge portion is in contact with the photosensitive drum 11y, and scrapes off the transfer residual toner by the operation of the photosensitive drum 11y.

  Then, the untransferred toner scraped off is accumulated in a space below the cleaning blade 100y. As shown in FIG. 8B, a window 104y is formed on the bottom surface of the space. A shutter 101y is provided so as to cover the window 104y. The shutter 101y is driven via a drive gear 103y by a shutter opening / closing motor (not shown) controlled by the print control unit 60, and can open and close the window 104y.

  A stirring blade 102y having a structure as shown in FIG. 8C is rotatably disposed in the space for accumulating toner. The stirring blade 102y rotates to stir the transfer residual toner, thereby preventing the transfer residual toner from solidifying and assisting the discharge of the transfer residual toner.

  Note that the configuration of other points of the image forming apparatus 2 is the same as that of the image forming apparatus 1 in the first embodiment, and a description thereof will be omitted.

  Next, the operation of the image forming apparatus 2 in the present embodiment will be described.

Similar to the image forming apparatus 1 in the first embodiment, when the image forming apparatus 2 finishes the printing operation, the image forming apparatus 2 proceeds to a transfer residual toner discarding operation. Therefore, assuming that all the transfer residual toner on the photosensitive drum lly has been removed, the recording paper P is conveyed onto the transfer belt 24 under the control of the print control unit 60. Then, as shown in FIG. 4, the transfer residual toner is moved onto the recording paper P. In accordance with the transfer start position P _1, the drive gear 103y is driven by the shutter control unit 93 to open the window 104y bottom of shutter 101y of the cleaning blade 100y is actuated. At the same time, a stirring blade motor (not shown) is driven by the stirring blade controller 94, and the stirring blade 102 is rotated.

  As a result, the untransferred toner accumulated under the cleaning blade 100y falls on the recording paper P on the transfer belt 24. At this time, since the transfer belt 24 is driven by the motor control unit 76 and the recording paper P is conveyed, the position of the transfer residual toner falling on the recording paper P is shifted, and thus the toner on the recording paper P is transferred. The layer thickness is prevented from becoming too large.

  Further, although no pressure is applied to the transfer residual toner by the photosensitive drum lly, the fixing device 12 heats the transfer residual toner while pressurizing it, and therefore, the toner layer on the recording paper P becomes too thick. Fixing failure is unlikely to occur.

  Note that only when the toner is discarded, the medium transport speed is decreased by the motor control unit 76, the speed of the fixing device 12 is decreased, or the fixing temperature is increased by the fixing control unit 77. Accordingly, a method for improving the fixing property of the transfer residual toner can be performed.

  As described above, in this embodiment, the transfer residual toner is moved directly onto the transfer belt 24 by operating the shutter 101 so that the transfer residual toner is transferred to the developing roller 41 when the transfer residual toner is discarded. Contamination of the surface of the developing roller 41 and unused toner due to contact can be prevented. Similarly, contamination of the surface of the charging roller 21 due to the transfer residual toner coming into contact with the charging roller 21 can be prevented.

  Further, since the developing device power source 42 and the cleaning device power source 46 are not used when the transfer residual toner is discarded, the high voltage power source control can be simplified. Therefore, an independent power source for each image forming unit 96 is not necessary, and the cost of the image forming apparatus 2 can be reduced.

  Next, a third embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st and 2nd embodiment, the description is abbreviate | omitted by providing the same code | symbol. Also, the description of the same operations and effects as those of the first and second embodiments is omitted.

  FIG. 9 is a flowchart showing the execution timing of the transfer residual toner discarding operation of the image forming apparatus according to the third embodiment of the present invention.

  In the present embodiment, as described in the third embodiment, the dot calculation unit 105 adds the number of print dots of each image forming unit 10Y, 10M, 10C, and 10K, and each image forming unit 10Y. The ratio of the number of printed dots of 10M, 10C, and 10K is calculated. The image forming apparatus according to the present embodiment has the same configuration as that of the image forming apparatus 1 according to the first embodiment, and thus the description of the configuration is omitted.

  In the image forming apparatus 1 that forms a color image, it is generally difficult for the image forming units 10Y, 10M, 10C, and 10K to have the same number of print dots. In particular, in the image forming apparatus 1 for forming a color image, in an environment where monochrome printing is performed or a large number of documents are printed, only the black image forming unit 10K is used, and the transfer residual toner increases only for black. Things happen.

  In the first and second embodiments, when the number of printed dots in any of the image forming units 10Y, 10M, 10C, and 10K and 96Y, 96M, 96C, and 96K reaches, for example, 10,000 dots Is set to execute toner disposal. Therefore, for example, if the image forming units 10Y, 10M, 10C, and 10K and 96Y, 96M, 96C, and 96K print 200, 200, 200, and 10000 dots, respectively, the toner disposal timing is reached. The waste toner at this time is 10600 dots. However, in the first and second embodiments, when it is set to discard the toner when it reaches 10000 dots, ideally 40000 dots on one recording sheet P Since the waste toner for printing should be able to be discarded, if the toner is discarded by printing at 10600 dots, the recording paper P is wasted and the frequency of toner disposal is more than necessary. The number of print dots that can be printed on one recording paper P depends on the recording paper P. Here, the size of the recording paper P is large enough to discard waste toner for printing 40,000 dots. It is assumed that this is the case.

  Therefore, in the present embodiment, the toner discard frequency is set by setting the toner discard timing when the total number of print dots of the image forming units 10Y, 10M, 10C, and 10K reaches, for example, 40000 dots. Can be reduced.

  First, the print control unit 60 initializes the parameter Px (x = y, m, c, and k) stored in the parameter storage unit 66p and the parameter Q stored in the parameter storage unit 66q to zero values. Since parameter Q is the same operation as that of the first embodiment, description thereof is omitted. The parameter Px is a parameter for executing the cleaning operation, and is a count of the number of print dots of the image forming units 10Y, 10M, 10C, and 10K with respect to the recording paper P. The parameter Px is the same as that in the first embodiment. The same thing.

  Next, when printing one page, the print control unit 60 prints the number of print dots py of each of the image forming units 10Y, 10M, 10C, and 10K in the parameters Py, Pm, Pc, and Pk stored in the parameter storage unit 66p. , Pm, pc and pk are added.

  Subsequently, the print control unit 60 determines whether there is print data for the next page. If there is print data for the next page, the print operation is performed as in the first embodiment. . If there is no print data for the next page, unlike the first embodiment, the print control unit 60 uses the parameters Px (x = y, m, c and k) stored in the parameter storage unit 66p. ) Is added by the dot calculation unit 105. The added value is compared with a predetermined threshold value 4N stored in the threshold value storage unit 67p, and it is determined whether or not the total of the parameters Px has reached the threshold value 4N. That is, each image forming unit 10 determines whether or not a total of 4N dots have been printed. For example, when “40000” is set as the threshold value 4N, it is determined whether or not the image forming apparatus 1 has printed a total of 40000 dots. If it has not reached 40,000 dots, printing is continued. If it has reached 40,000 dots, the same operation as in the first embodiment is performed to discard the toner.

  In this embodiment, the method of using the recording paper P for toner disposal is different from that in the first embodiment.

  That is, the dot calculation unit 105 calculates the ratio of print dots of the image forming units 10Y, 10M, 10C, and 10K. For example, the print dot ratio of the image forming unit 10K is Pk / (Py + Pm + Pc + Pk). Specifically, if the number of printing tods in the image forming units 10Y, 10M, 10C, and 10K is 5000, 5000, 5000, and 25000, respectively, and the total is 40000 dots, the image forming units 10Y, 10M, The ratio of 10C and 10K print dots is 1/8, 1/8, 1/8, and 5/8.

Then, according to the control of the print control unit 60, as in the case of the first and second embodiments, 1/8, 1/8, 1/8, and 5/8 from the leading edge of the recording paper P are set. The toner is discarded from the position where the transfer start positions P _{1 to} P ₄ that are the transfer residual developer movement start positions are divided.

Next, a flowchart will be described.
Step S21: The parameter Px is initialized to zero.
Step S22 One page is printed.
Step S23: The print control unit 60 controls the parameter Px (Py, Pm, Pc, Pk) stored in the parameter storage unit 66p by adding the print dot number counter px (py, pm, pc, pk). To do.
Step S24: It is determined whether there is print data for the next page. If there is print data for the next page, the process returns to step S22. If there is no print data for the next page, the process proceeds to step S25.
Step S25: It is determined whether or not the sum (Py + Pm + Pc + Pk) of the parameters Px has reached the threshold value 4N. If the total of the parameters Px has reached the threshold value 4N, the process proceeds to step S26, and if the total of the parameters Px has not reached the threshold value 4N, the process returns to step S22.
Step S26: It is determined whether or not the automatic execution parameter 86 is ON. If the automatic execution parameter 86 is ON, the process proceeds to step S27. If the automatic execution parameter 86 is not ON, the process proceeds to step S29.
Step S27: It is determined whether or not there is paper in the designated tray. If there is paper in the designated tray, the process proceeds to step S28, and if there is no paper in the designated tray, the process proceeds to step S33.
Step S28: Toner disposal is executed, and the process is terminated.
Step S29 The user is notified that the toner needs to be discarded.
Step S30: It is determined whether or not user approval can be obtained. If user approval can be obtained, the process proceeds to step S27. If user approval cannot be obtained, the process proceeds to step S31.
Step S31: 1 is added to the parameter Q, which is a count value of the number of toner disposal operation refusals.
Step S32: It is determined whether or not the toner discard operation rejection count has reached the threshold value M. If the toner discard operation rejection count has reached the threshold value M, the process returns to step S29. If the toner discard operation rejection count has not reached the threshold value M, the process returns to step S22.
Step S33 Notify the user that the paper is out.

  Thus, in the present embodiment, the recording paper P used for toner disposal can be used efficiently, and the frequency of toner disposal can be reduced.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

1 is a schematic diagram of an image forming apparatus according to a first embodiment of the present invention. 1 is a block diagram illustrating a configuration of a control device of an image forming apparatus according to a first embodiment of the present invention. 3 is a timing chart illustrating an operation of the image forming unit of the image forming apparatus according to the first exemplary embodiment of the present invention. FIG. 6 is a diagram illustrating timing for starting toner disposal in the image forming unit of the image forming apparatus according to the first embodiment of the present invention. 6 is a diagram illustrating a relationship between a toner discarding operation of the image forming unit of the image forming apparatus and the position of the recording paper P in the first embodiment of the present invention. FIG. 6 is a flowchart illustrating execution timing of a transfer residual toner discarding operation of the image forming apparatus according to the first exemplary embodiment of the present invention. It is the schematic of the image forming apparatus in the 2nd Embodiment of this invention. FIG. 6 is a diagram illustrating a configuration of a cleaning blade of an image forming apparatus according to a second embodiment of the present invention. 12 is a flowchart illustrating execution timing of a transfer residual toner discarding operation of an image forming apparatus according to a third embodiment of the present invention.

Explanation of symbols

1, 2 Image forming devices 11y, 11m, 11c, 11k Photosensitive drum 12 Fixing devices 41y, 41m, 41c, 41k Developing rollers 43y, 43m, 43c, 43k Transfer rollers 45y, 45m, 45c, 45k Cleaning rollers 100y, 100m, 100c, 100k Cleaning blade P Recording paper

Claims (5)

(A) a plurality of image carriers on which latent images based on print data are formed;
(B) supplying a developer to each of the image carriers, and developing a latent image to form a developer image;
(C) a plurality of transfer portions that transfer the developer image to a recording medium;
(D) a plurality of recovery portions for recovering a transfer residual developer that remains on each of the image carriers without being transferred;
(E) a fixing unit that fixes the developer image transferred onto the recording medium to the recording medium;
(F) The recording medium is divided into a plurality of sections according to the ratio of printing dots corresponding to each of the image carriers, and the residual transfer developer collected by each of a plurality of collecting units is placed on the recording medium. An image forming apparatus, wherein the image forming apparatus is moved to each of the sections to fix a transfer residual developer on the recording medium to the recording medium. The image forming apparatus according to claim 1, wherein the transfer residual developer recovered by the recovery unit moves from the recovery unit onto an image carrier, is transferred by the transfer unit, and moves onto a recording medium. The image forming apparatus according to claim 1, wherein the transfer residual developer collected by the collection unit falls from the collection unit and moves onto a recording medium. The fixing unit includes two rollers arranged in parallel with each other in the vertical direction, and the recording residual developer on the recording medium is recorded on the recording medium by heat and pressure applied in a nip formed between the two rollers. The image forming apparatus according to claim 1, wherein the image forming apparatus is fixed to a medium. The image forming apparatus according to claim 1, wherein the transfer residual developer collected by the collection unit can be switched between automatic execution and manual execution from the collection unit to the recording medium.

Images