JP2008129115A - Waste toner conveying device, imaging device, 4-unit tandem type imaging device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent caking of toner with saved energy by moving only a waste toner conveying device with an arbitrary timing after the stop of a machine, namely, an image forming apparatus such as a copying machine. <P>SOLUTION: Waste toner discharged from photoreceptor cleaning devices 18 is conveyed to a waste toner tank 18b by a waste toner pipe 18a. During the job of the image forming apparatus, the waste toner is constantly moved. When the job ends and the machine stops, the conveyance of the waste toner also stops, and a cooling fan in the machine also stops. At this time, a toner, especially a polymerization toner is highly likely to cake. To avoid this, the toner remaining in the waste toner pipe 18a is moved after an elapse of a certain period of time. Then, after an arbitrary time has elapsed from the end of the job, a waste toner conveyance screw is driven. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a waste toner conveying device provided for a cleaning device of an image forming device in an image forming apparatus such as a copying machine, a facsimile machine, and a printer.

  In the cleaning of each unit provided in the image forming apparatus using the image forming system using the polymerized toner manufactured by the polymerization method, in addition to the difficulty in cleaning due to the shape (circularity) of the toner, waste toner due to the poor fluidity Clogging is a problem. In particular, it has been found that when heat is applied to the waste toner remaining in the waste toner conveyance path, it becomes easy to solidify after a lapse of time.

  As a result, a lump is formed in the waste toner path, leading to a machine failure. Various patent documents disclose an invention for solving this problem.

JP 2005-156721 A JP 10-1111631 A Japanese Patent Laid-Open No. 11-024524 JP 2002-006711 A

  Accordingly, an object of the present invention is to provide means for solving the above-described conventional problems by preventing the solidification of the toner by moving only the waste toner conveying device at an arbitrary timing after the machine stops.

  According to a first aspect of the present invention, there is provided a waste toner conveying apparatus for each color using an apparatus for forming an electrostatic latent image for each color on a photoconductor, and a polymerized toner produced by polymerizing the electrostatic latent image. A two-component developing device for forming a toner image, a transfer device for transferring an image formed on the photosensitive member to an intermediate image carrier, and a toner image formed on the intermediate image carrier is conveyed from a paper feeding device. A paper transfer device that forms an image on the transfer paper by applying arbitrary bi-ice to the transfer paper by applying it from the transfer device, and fixes the toner image on the transfer paper further downstream in the transport direction of the transfer paper In a waste toner transporting device for transporting waste toner, which is used in an image forming apparatus having a fixing device, it is optional after a job end to transport waste toner discharged from a cleaning device of each unit in the image forming device. time of Characterized in that it operates on.

  According to the second aspect of the present invention, in the waste toner conveying apparatus according to the first aspect, the determination of the execution of the driving after the job end is made with reference to the temperature obtained from the means for detecting the in-machine temperature of the image forming apparatus. It is characterized by performing.

  According to a third aspect of the present invention, in the waste toner conveying apparatus according to the first aspect, the execution determination of the drive after the job end is performed with reference to the number of copies of the image forming apparatus.

  According to a fourth aspect of the present invention, in the waste toner conveying apparatus of the first aspect, the execution determination of the drive after the job end is performed with reference to a job time of the image forming apparatus.

  According to the fifth aspect of the present invention, in the waste toner conveying device according to any one of the first to fourth aspects, when the operating drive motor is not occupied, the rotation direction of the drive motor can be arbitrarily selected. It is characterized by doing so.

  According to the sixth aspect of the present invention, in the waste toner conveying device according to any one of the first to fifth aspects, the waste toner conveying speed can be arbitrarily set.

  According to a seventh aspect of the present invention, in the waste toner conveying apparatus according to the sixth aspect, the waste toner conveyance speed is made faster than the speed during the job.

  According to the eighth aspect of the present invention, in the waste toner conveying apparatus according to the sixth aspect, the waste toner conveyance speed is made slower than the speed during the job.

  According to a ninth aspect of the present invention, in the waste toner conveying apparatus according to the sixth aspect, the conveyance of waste toner after completion of the job is performed separately for each unit in the image forming apparatus.

  An image forming apparatus according to claim 10 includes the waste toner conveying device according to any one of claims 1 to 9.

  A quadruple tandem type image forming apparatus according to claim 11 includes the waste toner conveying device according to any one of claims 1 to 9.

  An image forming apparatus according to a twelfth aspect includes the waste toner conveying apparatus according to any one of the first to ninth aspects.

  An image forming apparatus according to the thirteenth aspect includes the quadruple tandem type image forming apparatus according to the eleventh aspect.

  According to the present invention, since only the waste toner conveying device is moved at an arbitrary timing after the machine of the image forming apparatus such as a copying machine is stopped, solidification of the toner can be prevented with energy saving.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  FIG. 1 is a schematic cross-sectional view of an example of an image forming apparatus that is an object of the present invention. FIG. 1 is a schematic diagram of a copier configured by a combination of a quadruple tandem type photosensitive unit and an intermediate transfer belt 10 (hereinafter referred to as this section). In FIG. In the figure, 100 is a copying apparatus main body, 200 is a paper feed table on which it is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) further mounted thereon.

  The copying apparatus main body 100 is provided with an endless belt-like intermediate transfer belt 10 in the center. In the intermediate transfer belt 10, for example, a base layer made of a material that is difficult to stretch, such as a canvas, is formed on a fluororesin having a small elongation or a rubber material having a large elongation as a base layer, and an elastic layer is provided thereon. The elastic layer is formed of, for example, fluorine-based rubber or acrylonitrile-butadiene copolymer rubber. The surface of the elastic layer is coated with, for example, a fluororesin and a smooth coat layer. Then, as shown in FIG. 1, it is wound around three support rollers 14, 15, 16 and can be rotated and conveyed in the clockwise direction in the figure.

  In the illustrated example, an intermediate transfer member cleaning device that removes residual toner remaining on the intermediate transfer belt 10 after image transfer on the left side of the second support roller 15 in the figure among the three support rollers 14, 15, 16. 17 is provided. On the intermediate transfer belt 10 stretched between the first support roller 14 and the second support roller 15, four image forming units of black, yellow, magenta, and cyan are unitized along the conveyance direction. The tandem image forming device 20 is configured by arranging the process cartridge units (hereinafter referred to as PCUs) 19 in parallel. An exposure device 21 is further provided on the upper side of the tandem image forming device 20 as shown in FIG.

  On the other hand, a secondary transfer device 22 is provided on the opposite side of the intermediate transfer belt 10 from the tandem image forming device 20. In the illustrated example, the secondary transfer device 22 is configured by a secondary transfer belt 24, which is an endless belt, being stretched between two rollers 23, and pressed against the third support roller 16 via the intermediate transfer belt 10. And the image on the intermediate transfer belt 10 is transferred to a sheet. A fixing device 25 for fixing the transfer image on the sheet is provided on the left side of the secondary transfer device 22 in the drawing. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.

  The secondary transfer device 22 also has a sheet transport function for transporting the image-transferred sheet to the fixing device 25. Of course, it is difficult to provide the sheet conveying function together, but a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22.

  In the illustrated example, a sheet reversing device 28 for reversing the sheet to record images on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20.

  When making a copy using this copying machine, set the document on the document table 30 of the automatic document feeder 400 or open the automatic document feeder 400 and set the document on the contact glass 32 of the scanner 300. Then, the automatic document feeder 400 is closed to hold the document. When a start switch (not shown) is pressed, when a document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. The scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. Then, the first traveling body 33 emits light from the light source, and the reflected light from the document surface is further reflected toward the second traveling body 34, reflected by the mirror of the second traveling body 34, and passed through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  Further, when a start switch (not shown) is pressed, one of the support rollers 14, 15, 16 is also rotated by a drive motor (not shown), and the other two support rollers are driven to rotate, and the intermediate transfer belt 10 is moved. Rotate and convey. At the same time, the individual photoconductors 40 are rotated by the individual PCUs 19 to form black, yellow, magenta, and cyan monochrome images on the respective photoconductors 40. Then, along with the conveyance of the intermediate transfer belt 10, the monochrome images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

  On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selected and rotated, and the sheet is fed from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller The sheet is separated one by one at 45 and put into the sheet feeding path 46, conveyed by the conveying roller 47, guided to the sheet feeding path 48 in the copying machine main body 100, abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.

  Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is recorded on the sheet.

  The sheet after the image transfer is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the path is switched by the switching claw 55. The sheet is discharged by the discharge roller 56 and stacked on the sheet discharge tray 57. Alternatively, the path is switched by the switching claw 55 to enter the sheet reversing device 28, where it is reversed and guided again to the transfer position, and the image is also recorded on the back surface. After that, the paper is discharged onto the paper discharge tray 57 by the discharge roller 56.

  On the other hand, the intermediate transfer belt 10 after the image transfer is removed by the intermediate transfer body cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after the image transfer, so that the tandem image forming device 20 can prepare for another image formation.

  Here, the registration roller 49 is generally used while being grounded, but it is also possible to apply a bias in order to remove paper dust from the sheet. For example, a bias is applied using a conductive rubber roller. The conductive rubber roller is, for example, a conductive NBR rubber having a diameter of 18 mm and a surface of 1 mm thickness. The electric resistance is the volume resistance of the rubber material, for example, about 109 Ωcm, and the applied voltage is -800 V (applying a voltage of about −200 V to the toner transfer side (front side). In general, the intermediate transfer method makes it difficult for paper dust to move to the photoconductor, so there is little need to consider paper dust transfer, and it may be grounded. However, in order to charge the sheet more uniformly, an AC voltage having a DC offset component may be used.

  The paper surface after passing through the registration roller 49 to which a bias is applied in this way is slightly charged on the negative side. Accordingly, in the transfer from the intermediate transfer belt 10 to the sheet, the transfer conditions may change and the transfer conditions may be changed as compared with the case where no voltage is applied to the registration roller 49.

  In the tandem-type image forming apparatus 20 described above, each PCU 19 includes a charging device, a developing device, a primary transfer device 62, a photoconductor cleaning device 18, and a static elimination device, specifically around a drum-shaped photoconductor 40. Etc.

  Then, the remaining toner is cleaned from the surface of the photoreceptor 40 by the photoreceptor cleaning device 18 of each PCU, and the cleaned toner is sent to the waste toner transport path as waste toner.

  FIG. 2 shows a waste toner conveyance path. Waste toner discharged from the photoconductor cleaning device 18 is sent to a waste toner tank 18b by a waste toner transport screw (not shown) installed in the waste toner pipe 18a (the transport direction is indicated by an arrow in the figure). Show). During the job for image formation by the image forming apparatus, the waste toner conveying screw is also driven to rotate, so that the waste toner always moves. Therefore, the waste toner in the waste toner pipe 18a is not solidified.

  However, when the job is completed and the machine is stopped, not only the waste toner conveying screw is stopped, but also the in-machine cooling fan (not shown) is stopped. As a result, the temperature inside the aircraft rises for a while. At this time, if the toner is easily solidified with respect to the temperature, it may solidify after a certain period of time. In particular, polymerized toners that have recently been used tend to have a strong tendency.

  For this reason, it is important to move (move) the toner remaining in the waste toner pipe 18a after a certain period of time. However, it takes time to completely discharge the toner in the waste toner conveyance path. It becomes negative in terms of Therefore, this is solved by driving the waste toner conveying screw after an arbitrary time has elapsed from the job end. That is, the object here is not to completely discharge the waste toner in the waste toner conveyance path, but to make a lump by moving the waste toner.

  The flow of the operation is shown in FIG. After the job start (step 1) and job end (step 2), the machine is stopped (step 3) and a timer (or a counter may be used) is started (step 4). If the job does not start during that time (step 4) 5), for example, after a predetermined time T has elapsed (step 6: t> T: or t ≦ T may be satisfied), the drive of the waste toner conveying screw is turned on (step 7). If a job is entered before the arbitrarily determined drive time T has elapsed, the timer or counter is reset.

  As shown in FIG. 4, after the job end (step 2) and machine operation stop (step 3), the temperature inside the machine is monitored (step 3a), and the timer is activated only when the temperature rises above a certain temperature. The waste toner conveying screw can be driven after a certain arbitrary time has elapsed. When this method is used, the machine is not operated more than necessary. In-machine temperature can be dealt with by selecting and using one or more temperature detection sensors usually installed in the machine.

  As a result of experiments conducted by the present inventor, it has been confirmed that, in a certain type of toner, when the in-machine temperature exceeds about 50 ° C., a phenomenon that leads to solidification of the toner as time passes. Since the solidification has been confirmed about 12 hours after the machine is stopped, the setting of the timer is effective for 3 to 6 hours.

  The above control can also be implemented by using the number of copies or using the job time instead of temperature detection. In general, the waste toner conveying screw is driven from a motor. However, providing the motor exclusively for the screw not only increases the cost but also increases the size of the machine.

  Therefore, as shown in the simplified diagram of FIG. 5, the problem can be solved by using two one-way clutches CL1 and CL2 and using the forward rotation (CW) and the reverse rotation (CCW) of the drive motor M.

  In addition, regarding the driving of the conveyance device after the job in each of the above-described embodiments, it is possible to deal with the user more widely by making the driving speed variable. For example, a user who has a large number of copies per day has a large amount of waste toner that is discharged. Therefore, it is possible to provide more margin for solidification of the waste toner by increasing the transport speed than usual (machine failure). The margin is increased. On the other hand, for a user with a small copy volume, it is possible to reduce the occurrence of sound by lowering the transport speed.

  Further, regarding the drive, in the image forming apparatus of the type as in the illustrated embodiment, when each unit is performed simultaneously, there is a possibility that the sound becomes loud. Therefore, the driving of each unit may be performed with a time difference, and the present invention may be implemented while suppressing the generation of sound.

  That is, in the waste toner conveying device of the present invention, since only the waste toner conveying device is moved at an arbitrary timing after the machine is stopped, the solidification of the toner can be prevented with energy saving. Further, since the waste toner conveying device is moved after detecting the temperature inside the apparatus, further energy saving can be achieved. Further, if the drive source, for example, the motor is shared instead of being dedicated, the cost can be further reduced and the machine can be downsized. Furthermore, if the number of images formed such as copying is determined and executed, the operation can be avoided when the operation is unnecessary, and further energy saving can be achieved. Moreover, if the speed of the apparatus is arbitrarily set, the best setting can be achieved with energy saving by adjusting to the necessary conditions.

  It should be noted that the waste toner conveying device of the present invention can suppress the generation of noise if independent operation is possible as in the above-described embodiments.

1 is a schematic cross-sectional view of an example of an image forming apparatus that is an object of the present invention. Perspective view showing waste toner conveyance path Flow chart of operation of embodiment 1 Flow chart of operation of embodiment 2 Flow chart of operation of embodiment 3

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Copying apparatus main body 200 Paper feed table 300 Scanner 400 Automatic document feeder (ADF)
DESCRIPTION OF SYMBOLS 10 Intermediate transfer belt 14, 15, 16 Support roller 17 Intermediate transfer body cleaning device 18 Photoconductor cleaning device 18a Waste toner pipe 18b Waste toner tank 19 Process cartridge unit (PCU)
DESCRIPTION OF SYMBOLS 20 Tandem image forming device 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging Lens 36 Reading sensor 40 Photoconductor 42 Paper feed roller 43 Paper bank 44 Paper feed cassette 45 Separation roller 46 Paper feed path 47 Transport roller 48 Paper feed path 49 Registration roller 50 Paper feed roller 51 Manual tray 52 Separation roller 53 Manual paper feed path 55 Switching claw 56 Discharge roller 57 Discharge tray 62 Primary transfer device CL1, CL2 One-way clutch M Drive motor

Claims (13)

An apparatus for forming an electrostatic latent image for each color on a photoconductor, a two-component developing device for converting the electrostatic latent image into a toner image for each color using a polymerized toner produced by a polymerization method, and the photoconductor A transfer device that transfers the image formed on the intermediate image carrier, and a toner image formed on the intermediate image carrier to which arbitrary bi-ice is applied from the transfer device to the transfer paper conveyed from the paper feeder. Waste toner used in an image forming apparatus comprising: a paper transfer device that forms an image on the transfer paper by transferring the toner image on the transfer paper; and a fixing device that fixes the toner image on the transfer paper further downstream in the transport direction of the transfer paper A waste toner transport device for transporting waste toner, wherein the waste toner transport device operates after an arbitrary time after a job end in order to transport waste toner discharged from a cleaning device of each unit in the image forming apparatus. . 2. The waste toner transport apparatus according to claim 1, wherein the determination of execution of driving after the job end is made with reference to a temperature obtained from a means for detecting an in-machine temperature of the image forming apparatus. apparatus. 2. The waste toner conveying apparatus according to claim 1, wherein the determination of whether to drive after the job end is made with reference to the number of copies of the image forming apparatus. 2. The waste toner conveying apparatus according to claim 1, wherein the determination of execution of driving after the job end is made with reference to a job time of the image forming apparatus. 5. The waste toner conveying device according to claim 1, wherein a rotation direction of the driving motor can be arbitrarily selected when the driving motor for operating the waste toner conveying device is not occupied. Toner transport device. 6. The waste toner transport apparatus according to claim 1, wherein a waste toner transport speed can be arbitrarily set.   7. The waste toner transport apparatus according to claim 6, wherein the waste toner transport speed is higher than the speed during the job.   7. The waste toner transport apparatus according to claim 6, wherein the transport speed of the waste toner is slower than the speed during the job.   7. The waste toner transport apparatus according to claim 6, wherein the drive of transporting the waste toner after completion of the job is performed separately for each unit in the image forming apparatus.   An image forming apparatus comprising the waste toner conveying device according to claim 1.   A quadruple tandem type image forming apparatus comprising the waste toner conveying device according to any one of claims 1 to 9.   An image forming apparatus comprising the waste toner conveying device according to claim 1. An image forming apparatus comprising the quadruple tandem type image forming device according to claim 11.