JP4055528B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a charging device that charges an image carrier such as a photosensitive member or an intermediate transfer member using a contact charging member such as a charging roll, and in particular, has a function of removing foreign matter adhering to the surface of the contact charging member. The present invention relates to a charging device provided.
[0002]
[Prior art]
In general, in an image forming apparatus such as a printer or a copying machine using an electrophotographic method, in order to form an electrostatic latent image on an image carrier such as a photosensitive drum, the image carrier is charged in advance to a predetermined potential. A charging device is used. In addition, in an image forming apparatus using an intermediate transfer member such as an intermediate transfer belt, a charging device that charges the intermediate transfer member is used to primarily transfer the toner image formed on the image carrier to the intermediate transfer member. It is done.
[0003]
In recent years, various contact-type charging devices using a charging roll have been proposed and put into practical use as this type of charging device. In a contact-type charging device using a charging roll, an elastic charging roll is rotatably arranged on the surface of the image carrier, and a bias voltage is applied to the charging roll to perform charging in the vicinity of the contact portion. Exists. Such contact-type charging devices are less likely to generate discharge products such as ozone and nitrogen oxides compared to non-contact type charging devices such as corotrons that use corona discharge, and the charging device itself is downsized. There is an advantage that you can. On the other hand, since the charging roll is placed in contact with the image carrier, the residual toner adhering to the image carrier, external additive components contained in the toner, dust, paper dust and other foreign matters are transferred to and adhered to the charging roll. It becomes easy. For this reason, there has been a problem that abnormal discharge or unstable discharge is generated in accordance with the change in the charging performance of the portion where the foreign matter adheres, and image quality defects such as fog are likely to occur.
[0004]
In order to solve such a problem, a technique has been proposed in which a cleaning brush is brought into contact with the surface of the charging roll to remove foreign matter adhering to the charging roll. However, when this method is adopted, this time, the removed foreign matter adheres to the cleaning brush and accumulates, so that the cleaning ability of the charging roll is lowered, and the foreign matter attached to the charging roll is insufficiently removed. The problem may recur. Accordingly, it has been proposed to arrange a cleaning brush so as to be rotatable, and to attach a hitting member that contacts the rotating cleaning brush and knocks off foreign matter adhering to the cleaning brush (see Patent Document 1).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-199606 (page 4, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, as in the invention described in Patent Document 1, in order to dispose the cleaning brush in a rotatable manner, it is necessary to provide a cleaning brush rotation drive mechanism, which increases costs and increases the size of the apparatus. There was a technical problem that caused complications.
Further, since the hitting member always comes into contact with the cleaning brush, when the rotation of the cleaning brush is stopped, there is a technical problem that the brush in a portion that comes into contact with the hitting member is deformed and the cleaning performance is deteriorated. It was seen.
The present invention has been made in order to solve the above technical problems, and the object of the present invention is to provide a simple configuration with a long-term performance of removing foreign substances adhering to a contact charging member such as a charging roll. It is to maintain.
Another object of the present invention is to suppress the deformation of the cleaning brush.
[0007]
[Means for Solving the Problems]
For this purpose, in the present invention, a cleaning brush for cleaning the contact charging member is disposed so as to be able to contact with and separate from the contact charging member, and in conjunction with the movement of the cleaning brush away from the contact charging member. By providing a brush cleaning member that cleans the cleaning brush, it is possible to achieve a long-term performance of removing foreign substances adhering to the contact charging member with a simple configuration.
Further, in the present invention, the brush cleaning member that cleans the cleaning brush is disposed so as to be in contact with and away from the cleaning brush, thereby suppressing the deformation of the cleaning brush.
[0008]
That is, the charging device of the present invention includes a contact charging member that is rotatably contacted to the image carrier and charges the image carrier, and a cleaning brush that is disposed so as to be able to contact and separate from the contact charging member. The brush cleaning member that moves away from the cleaning brush in conjunction with the contact operation of bringing the cleaning brush into contact with the contact charging member and contacts the cleaning brush in conjunction with the separation operation of separating the cleaning brush from the contact charging member And so on. In this charging device, the brush cleaning member may be a linear member disposed along the longitudinal direction of the cleaning brush.
[0009]
And a support member for swingably supporting the cleaning brush, and a swing support member for supporting the brush cleaning member and swinging in conjunction with swinging of the support member. it can.
Furthermore, it may further include a slide support member that supports the brush cleaning member and slides in conjunction with the contact and separation operation of the cleaning brush with respect to the contact charging member.
[0010]
From another point of view, the charging device of the present invention is disposed so as to be rotatable in contact with the image carrier, and a contact charging member that charges the image carrier and a contact charging member that can freely contact and separate from the contact charging member. The cleaning brush, the support member that swingably supports the cleaning brush, and the contact charging member that moves away from the support member in conjunction with the contact operation of contacting the cleaning brush with the contact charging member. And a contact / separation member that contacts the support member in conjunction with the separation operation of separating the cleaning brush from the contact member.
The charging device may further include a slide support member that supports the contact / separation member and slides in conjunction with the contact / separation operation of the cleaning brush with respect to the contact charging member.
[0011]
The image forming apparatus of the present invention includes an image carrier that is rotatably arranged, a contact charging member that is rotatably contacted with the image carrier, and charges the image carrier, and a contact charging member. A cleaning brush that is detachably attached to the cleaning brush, and a cleaning brush that is detachable from the cleaning brush in conjunction with an abutting operation that abuts the cleaning brush against the contact charging member. A brush cleaning member that contacts the cleaning brush in conjunction with a separation operation for separating the cleaning brush from the contact charging member, a shutter member that opens and closes an optical path for exposing the image carrier charged by the contact charging member, It has a link mechanism that interlocks the contact / separation operation of the cleaning brush with the contact charging member and the opening / closing operation of the shutter member.
In this image forming apparatus, the link mechanism closes the shutter member when the cleaning brush is brought into contact with the contact charging member, and opens the shutter member when the cleaning brush is separated from the contact charging member. can do.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.
—Embodiment 1—
FIG. 1 is a diagram showing an overall configuration of an image forming apparatus according to Embodiment 1, and shows a so-called tandem type digital color printer. An image forming apparatus shown in FIG. 1 includes an image processing system 10 that forms an image corresponding to gradation data of each color, a sheet conveyance system 40 that conveys recording paper (sheet), such as a personal computer or an image reader. An IPS (Image Processing System) 50, which is an image processing system that is connected to a device or the like and performs predetermined image processing on received image data, is provided.
[0013]
The image processing system 10 includes four image forming units 11Y and 11M of yellow (Y), magenta (M), cyan (C), and black (K), which are arranged in parallel at regular intervals in the horizontal direction. , 11C, 11K, a transfer unit 20 for transferring the toner images of the respective colors formed on the photosensitive drums 12 (image carriers) of the image forming units 11Y, 11M, 11C, 11K onto the intermediate transfer belt 21, and image formation A ROS (Raster Output Scanner) 30 that is an optical system unit for irradiating the units 11Y, 11M, 11C, and 11K with laser light is provided. Further, the main body 1 is provided with a fixing device 29 for fixing the image on the recording paper (sheet) secondarily transferred by the transfer unit 20 to the recording paper using heat and pressure. Further, toner cartridges 19Y, 19M, 19C, and 19K are provided for supplying toner of each color to the image forming units 11Y, 11M, 11C, and 11K.
[0014]
The transfer unit 20 includes a drive roll 22 that drives an intermediate transfer belt 21 that is an intermediate transfer member, a tension roll 23 that applies a constant tension to the intermediate transfer belt 21, and a secondary transfer of the superimposed toner images of each color onto a recording sheet. For this purpose, a backup roll 24 and a cleaning device 25 for removing residual toner and the like existing on the intermediate transfer belt 21 are provided. The intermediate transfer belt 21 is wound around the drive roll 22, the tension roll 23, and the backup roll 24 with a constant tension, and is rotated by a dedicated drive motor (not shown) having excellent constant speed. The drive roll 22 is circulated at a predetermined speed in the direction of the arrow. As the intermediate transfer belt 21, for example, a belt whose resistance is adjusted with a belt material (rubber or resin) that does not cause charge-up is used. The cleaning device 25 includes a cleaning brush 25a and a cleaning blade 25b, and removes residual toner, paper dust, and the like from the surface of the intermediate transfer belt 21 after the toner image transfer process is completed, and performs the next image forming process. It is comprised so that it may prepare for.
[0015]
In addition to a semiconductor laser and a modulator (not shown), the ROS 30 includes a polygon mirror 31 that deflects and scans laser light (LB-Y, LB-M, LB-C, and LB-K) emitted from the semiconductor laser. In the example shown in FIG. 1, since the ROS 30 is provided below the image forming units 11Y, 11M, 11C, and 11K, there is a risk of contamination due to dropping of toner or the like. Therefore, the ROS 30 is provided with a rectangular parallelepiped frame 32 for sealing each constituent member, and a glass window 33 through which laser light (LB-Y, LB-M, LB-C, LB-K) passes. Is provided above the frame 32 to enhance the shielding effect together with the scanning exposure.
[0016]
The sheet conveying system 40 is loaded with a recording paper (sheet) on which an image is recorded and fed, a nudger roll 42 that picks up and feeds the recording paper from the paper feeding device 41, and is fed from the nudger roll 42. A feed roll 43 that separates and conveys the recording sheets that have been separated one by one and a conveyance path 44 that conveys the recording sheets separated one by one by the feed roll 43 toward the image transfer unit are provided. Further, a registration roll 45 that conveys the recording paper conveyed through the conveyance path 44 in a timely manner toward the secondary transfer position, and a backup roll 24 that is provided at the secondary transfer position via the intermediate transfer belt 21. And a secondary transfer roll 46 for secondary transfer of the image onto the recording paper. Further, a discharge roll 47 for discharging the recording paper on which the toner image is fixed by the fixing device 29 to the outside of the main body 1 and a discharge tray 48 for stacking the recording paper discharged by the discharge roll 47 are provided. In addition, a double-sided conveyance unit 49 is provided that enables double-sided recording by inverting the recording paper fixed by the fixing device 29.
[0017]
Next, the image forming units 11Y, 11M, 11C, and 11K in the image process system 10 will be described in detail.
FIG. 2 is a diagram for explaining the configuration of the image forming units 11Y, 11M, 11C, and 11K. Here, the yellow (Y) image forming unit 11Y and the magenta (M) image forming unit 11M are shown. Has been. The other image forming units 11C and 11K are configured in substantially the same manner.
[0018]
The image forming units 11Y, 11M, 11C, and 11K include a photosensitive drum 12 as an image carrier for supporting a toner image, a charger 13 for charging the photosensitive drum 12 using a charging roll 13a as a contact charging member, and charging. Development that develops the electrostatic latent image charged on the photosensitive drum 12 on the photosensitive drum 12 by the laser beam (LB-Y, LB-M, LB-C, LB-K) from the ROS 30 by the developing roller 14a. A primary transfer roll 15 provided on the intermediate transfer belt 21 to transfer the toner image developed on the photosensitive drum 12 to the intermediate transfer belt 21; A cleaning device 16 for removing residual toner remaining on the drum 12 is provided. Among these, the details of the charger 13 will be described later.
[0019]
In the present embodiment, the photosensitive drum 12, the charger 13, and the cleaning device 16 of the image forming units 11Y, 11M, 11C, and 11K are integrated into a cartridge so that the main body 1 of the image forming apparatus can remove this. Only the cartridge can be removed, and only the cartridge can be attached to the main body 1. Each of these cartridges is mounted with a nonvolatile memory (not shown). In this nonvolatile memory, for example, when the cartridge is mounted in a predetermined image forming unit 11Y, 11M, 11C, or 11K such as the number of rotations of the photosensitive drum 12, the high voltage application time, the number of prints, etc. Each cartridge usage history information is stored. These cartridges can be used by being replaced between the image forming units 11Y, 11M, 11C, and 11K. Since each of the cartridges is equipped with a non-volatile memory, the cartridge itself can store its own usage history information even when the cartridge is used in different units. As a result, for example, the correct lifetime can be determined for each cartridge.
[0020]
Next, the operation of the image forming apparatus shown in FIG. 1 will be described. A color material reflected light image of a document read by a document reading device (not shown) and color material image data formed by a personal computer (not shown) are, for example, R (red), G (green), and B (blue). Each 8-bit reflectance data is input to the IPS 50. In IPS 50, the input reflectance data is subjected to predetermined image processing such as various image editing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame deletion, color editing, and moving editing. Is done. The image data that has been subjected to image processing is converted into color material gradation data of four colors of yellow (Y), magenta (M), cyan (C), and black (K), and is output to the ROS 30.
[0021]
In the ROS 30, laser light (LB-Y, LB-M, LB-C, LB-K) emitted from a semiconductor laser (not shown) is converted into f-θ in accordance with input color material gradation data. The light is emitted to the polygon mirror 31 through a lens (not shown). In the polygon mirror 31, the incident laser light is modulated in accordance with gradation data of each color, deflected and scanned, and image forming units 11Y, 11M, 11C, and 11K through an imaging lens and a plurality of mirrors (not shown). The photosensitive drum 12 is irradiated. On the photosensitive drums 12 of the image forming units 11Y, 11M, 11C, and 11K, the charged surface is subjected to scanning exposure to form an electrostatic latent image. The formed electrostatic latent image is developed as a toner image of each color of yellow (Y), magenta (M), cyan (C), and black (K) in each of the image forming units 11Y, 11M, 11C, and 11K. Is done.
[0022]
The toner images formed on the photosensitive drums 12 of the image forming units 11Y, 11M, 11C, and 11K are multiplex-transferred onto an intermediate transfer belt 21 that is an intermediate transfer member. At this time, the black image forming unit 11 </ b> K that forms a black toner image is provided on the most downstream side in the moving direction of the intermediate transfer belt 21, and the black toner image is finally transferred to the intermediate transfer belt 21. Is done.
[0023]
On the other hand, in the sheet conveyance system 40, the nudger roll 42 rotates in accordance with the timing of image formation, and recording paper of a predetermined size is supplied from the paper feeding device 41. The recording sheets separated one by one by the feed roll 43 are conveyed to the registration roll 45 through the conveyance path 44 and are temporarily stopped. Thereafter, the registration roll 45 rotates in accordance with the movement timing of the intermediate transfer belt 21 on which the toner image is formed, and the recording paper is conveyed to the secondary transfer position formed by the backup roll 24 and the secondary transfer roll 46. . On the recording sheet conveyed from the lower side to the upper side at the secondary transfer position, the toner images in which the four colors are multiplexed are sequentially transferred in the sub-scanning direction using a pressing force and a predetermined electric field. The recording paper on which the toner images of the respective colors are transferred is subjected to a fixing process by heat and pressure by the fixing device 29 and then discharged by a discharge roll 47 to a discharge tray 48 provided on the upper portion of the main body 1. Instead of being discharged as it is to the discharge tray 48, the conveyance direction can be switched by a switching gate (not shown), and the recording sheet fixed by the fixing device 29 can be reversed by the duplex conveyance unit 49. After the reversed recording sheet is conveyed to the registration roll 45, an image can be formed on both sides of the recording sheet by forming an image on the other unprinted side by the same flow as described above. Become.
[0024]
Next, an image forming operation in the image forming unit 11Y shown in FIG. 2 will be described in detail. The same applies to the other image forming units 11M, 11C, and 11K.
When the image forming operation is started, the photosensitive drum 12 starts to rotate and is charged to a predetermined potential by the charging roll 13a that contacts the surface of the photosensitive drum 12. Then, the surface of the photosensitive drum 12 charged to a predetermined potential is selectively irradiated with the laser beam LB-Y to form an electrostatic latent image corresponding to the image to be created. Next, toner is selectively transferred from the rotating developing roll 14a to the photosensitive drum 12 corresponding to the formed electrostatic latent image, and a toner image corresponding to the image to be created is formed. Further, the toner image formed on the photosensitive drum 12 is transferred onto the intermediate transfer belt 21 by the primary transfer bias applied to the primary transfer roll 15. The residual toner that is not transferred to the intermediate transfer belt 21 and remains on the photosensitive drum 12 is scraped off by the cleaning blade 16a.
[0025]
Next, the charger 13 will be described in detail.
FIG. 3 is a diagram showing the charger 13. The charger 13 is in contact with the surface of the photosensitive drum 12 (see FIG. 1) to charge the surface of the photosensitive drum 12 to a predetermined potential, and a housing 51 that houses the charging roll 13a. It has. A metal shaft 13b is attached to both ends of the charging roll 13a.
In the present embodiment, the charging roll 13a is constituted by, for example, an outer diameter φ14 and a surface layer in which carbon is dispersed in polyamide on a base layer of styrene rubber. Note that fluorine or nylon may be dispersed in the surface layer. The hardness (Asuka C) is 70 ° or less, the surface roughness Rz is 0.9 or less, the friction coefficient is 0.2 or less, and the capacitance is 1500 to 3000 pF.
[0026]
The housing 51 includes a side wall portion 52 provided on one side surface of the charging roll 13a, a bearing portion 53 provided integrally at both longitudinal ends of the side wall portion 52, and a bottom wall portion covering the lower end surface of the charging roll 13a. A charging roll cleaner 54 is also provided as a support member that also serves as a support member. Note that a bearing 55 that rotatably supports the shaft 13b of the charging roll 13a is attached to the bearing portion 53 so as to be movable in a direction in which it is in contact with and away from the photosensitive drum 12 (see FIG. 1). The bearing 55 is biased in a direction approaching the photosensitive drum 12 by a coil spring 56 attached to the bearing portion 53. A predetermined bias voltage is applied to the charging roll 13a via the coil spring 56 and the shaft 13b. In the present embodiment, a drive mechanism for rotating the charging roll 13a is not particularly provided, and is driven to rotate as the photosensitive drum 12 (see FIG. 1) that contacts the charging roll 13a rotates. Yes.
[0027]
FIG. 4 is an enlarged view of an end portion of the charging roll cleaner 54, and FIG. 5 is a diagram illustrating the entire charging roll cleaner 54. The charging roll cleaner 54 includes a flat plate 57 disposed on the lower side of the charging roll 13 a and a side wall portion 58 erected upward from the end of the flat plate 57. The charging roll cleaner 54 is formed in a substantially mountain shape of the flat plate 57. A cleaning brush 59 (shown only in FIG. 5) is fixed to the upper surface 57a with a double-sided tape or the like. As shown in FIGS. 3 to 5, the charging roll cleaner 54 is attached to a bearing portion 53 of the housing 51 so as to be rotatable about a shaft 60, and a stopper ( The rotation is stopped by engaging the bearing portion 53 (not shown). Further, the charging roll cleaner 54 rotates in the reverse direction by contacting a stopper (not shown) provided at the lower end of the inner surface of the side wall 52 while rotating in the direction opposite to the above-described direction. Is supposed to stop.
[0028]
The cleaning brush 59 provided on the charging roll cleaner 54 has a base fabric portion and a flocked portion formed on the film laminate, and a double-faced tape for attaching to the upper surface 57a of the flat plate 57 is provided at the bottom of the film laminate. It is attached. The base fabric part is nylon, the flocked part is conductive PET beltlon (Kanebo Co., Ltd. product name: Nylon in which PET and carbon are kneaded or polyester is a polymer fiber) and non-conductive 6.6 nylon. The pile density is 250 ± 2.5 kf / inch, PET beltlon is 44T / 12f, and 6.6 nylon is 48T / 14f.
[0029]
6 is a perspective view showing a swing mechanism 62 that swings the charging roll cleaner 54 (see FIG. 3) and a drive mechanism 74 that drives the swing mechanism 62, and FIG. 7 is a side view thereof. Here, a black image forming unit 11K is shown. The swing mechanism 62 is disposed below the charging roll 13a (charger 13), and has a cam 63 that drives the charging roll cleaner 54 in a direction in which the charging roll cleaner 54 comes in contact with and separates from the surface of the charging roll 13a. .
[0030]
FIG. 8 is a perspective view showing the cam 63. The cam 63 includes a shaft portion 64 formed in an elongated rod shape with a substantially circular cross section, a narrow flat plate portion 65 integrally formed along the longitudinal direction on the upper surface of the shaft portion 64, and the flat plate portion. A thin synthetic resin Mylar film (trade name) 66 fixed on the top 65 by adhesion with a double-sided tape, an arm portion 68 provided at an axial end of the shaft portion 64, and a free short side of the arm portion 68 It has a bulging portion 68a that bulges outward. As the mylar film 66, for example, a film having a thickness of 125 μm is used. Note that the elastic deformation amount of the mylar film 66 can be varied by appropriately changing the thickness of the mylar film 66, and the pressing force for bringing the cleaning brush 59 into contact with the surface of the charging roll 13a can be adjusted. is there. Further, the Mylar film 66 tends to be elastically deformed particularly in the central portion in the axial direction when the charging roll cleaner 54 is rotated, and the charging roll cleaner 54 is prevented from being insufficiently rotated. A plurality of ribs 69 are attached to the center of the back surface of the.
[0031]
On the other hand, the drive mechanism 74 includes a motor 75 as a drive source, as shown in FIGS. The gear 76 attached to the drive motor 75 is engaged with a fan-shaped gear 80 provided integrally with the drive arm 79 via two-stage reduction gears 76 and 77. The drive arm 79 swings as the drive motor 75 is rotationally driven by a predetermined amount. The drive arm 79 is formed with a projection 79a (shown only in FIG. 7) that contacts the bulging portion 68a of the cam 63.
[0032]
Further, in the present embodiment, as shown in FIGS. 7 and 9, the charging roll cleaner is disposed so as to be rotatable about the shaft 100a and is rotated in conjunction with the swing of the charging roll cleaner 54. A brush cleaner 100 is provided to remove foreign substances adhering to the 54 cleaning brushes 59.
10 and 11 are diagrams for explaining the brush cleaner 100. The brush cleaner 100 is disposed on the side of the charging roll cleaner 54 in parallel with the axial direction of the charging roll cleaner 54, and has substantially L-shaped arms 102 to which shafts 100a are attached at both ends thereof. 103 (swing support member) is formed. Moreover, the wire 104 as a brush cleaning member (linear member) is attached to the free end side of the long sides 102a and 103a to which the shaft 100a is not attached among these arms 102 and 103. A plate-like member 105 is attached to the shafts 100a of the long sides 102a and 103a, and a predetermined space is formed between the wire 104 and the plate-like member 105. On the other hand, the distal end portions of the short sides 102b and 103b to which the shaft 100a is attached among the arms 102 and 103 are arranged to protrude below the charging roll cleaner 54. Here, the wire 104 may be made of a material that hardly adheres to foreign matters such as toner and external additives, such as a resin such as polyacetal and a metal such as stainless steel.
[0033]
As shown in FIGS. 7 and 9, the brush cleaner 100 is attached with a spring 101 that urges the brush cleaner 100 in a direction in which the brush cleaner 100 is separated from the charging roll cleaner 54. 10 and 11, a link rod 81 is attached to the drive arm 79, details of which will be described later.
[0034]
Next, operations of the charging roll cleaner 54 and the brush cleaner 100 will be described.
First, an operation of cleaning the charging roll 13a with the cleaning brush 59 will be described with reference to FIGS. In the present embodiment, the cleaning brush 59 is normally separated from the charging roll 13a, and the cleaning brush 59 is brought into contact with the charging roll 13a at an appropriate timing so that the surface of the charging roll 13a is cleaned. It has become.
[0035]
First, the drive arm 74 is swung clockwise (right side) in the figure by the drive mechanism 74. Then, the projection 79a of the drive arm 79 presses the bulging portion 68a of the cam 63, and the cam 63 swings counterclockwise in the drawing. As the cam 63 swings counterclockwise, the mylar film 66 attached to the cam 63 presses the lower surface of the charging roll cleaner 54. Accordingly, the charging roll cleaner 54 swings counterclockwise (upward) in the drawing, and the cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 comes into contact with the charging roll 13a and stops. On the other hand, the brush cleaner 100 in which the short portions 102b and 103b are in contact with the lower surface of the charging roll cleaner 54 is clocked in the figure by the biasing force of the spring 101 as the charging roll cleaner 54 swings counterclockwise in the figure. It swings in the turning direction and stops in a state where the wire 104 is separated from the cleaning brush 59.
[0036]
When the photosensitive drum 12 is rotated in this state, the cleaning brush 59 comes into contact with the charging roll 13a that is driven to rotate by the photosensitive drum 12, and foreign substances (particularly external additives) attached to the charging roll 13a are removed. Will be.
By performing such an operation, foreign matter can be removed from the charging roll 13a, and charging failure of the photosensitive drum 12 caused by foreign matter adhesion to the charging roll 13a can be prevented.
[0037]
Next, the operation of cleaning the cleaning brush 59 with the brush cleaner 100 will be described with reference to FIGS. 9 and 11.
First, the drive arm 79 is swung in the counterclockwise direction (left side) in the figure by the drive mechanism 74. Then, the pressure on the bulging portion 68a of the cam 63 by the projection 79a of the drive arm 79 is released, and accordingly, the cam 63 swings in the clockwise direction in the drawing. As the cam 63 swings in the clockwise direction, the mylar film 66 attached to the cam 63 does not press the lower surface of the charging roll cleaner 54. Along with this, the charging roll cleaner 54 swings in the clockwise direction (downward) in the drawing, and the cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 stops in a state of being separated from the charging roll 13a. On the other hand, the brush cleaner 100 in which the short portions 102b and 103b are in contact with the lower surface of the charging roll cleaner 54 has a spring 101 depending on the weight of the charging roll cleaner 54 as the charging roll cleaner 54 swings counterclockwise in the figure. The wire 104 moves to the shaft 60 side of the charging roll cleaner 54 and stops while swinging counterclockwise in the figure against the urging force.
[0038]
By this operation, the foreign matter adhering to the cleaning brush 59 is knocked down by the wire 104. Since the foreign matter knocked down by the wire 104 is sucked by a suction mechanism (not shown) and is captured by a filter (not shown), it is unlikely that the knocked-out foreign matter adheres to the charging roll 13a again. . In addition, since a space is provided between the wire 104 and the plate-like member 105, the cleaning brush 59 struck by the wire 104 can immediately return to the original state, and the cleaning brush 59 is distorted and deformed. It is hard to happen.
[0039]
By performing such an operation, the foreign matter can be removed from the cleaning brush 59, the foreign matter can be prevented from reattaching to the charging roll 13a, and the life of the cleaning brush 59 can be extended.
In addition, since the cleaning brush 59 is attached to the lower side of the charging roll 13a, foreign matters such as residual toner and dust once removed by the cleaning brush 59 fall in the opposite direction to the charging roll 13a side due to gravity. Thus, it is possible to prevent such foreign matter from transferring again to the charging roll 13a side.
[0040]
Incidentally, the image forming apparatus according to the present embodiment is a so-called quadruple tandem type image forming apparatus, and there are a total of four charging rolls 13 a arranged in contact with the photosensitive drum 12 and the photosensitive drum 12. The above-described drive mechanism 74 may be attached to the charging roll cleaner 54 and the cam 63 provided in each of the charging rolls 13a. However, in the present embodiment, in order to simplify the configuration, FIG. As shown in FIG. 11, by attaching a link rod 81 to the drive arm 79 of the drive mechanism 74, the charging rolls 13a of the image forming units 11Y, 11M, and 11C other than the black image forming unit 11K can be swung simultaneously. It has become.
[0041]
FIG. 12 is a view for explaining the link rod 81 attached over the image forming units 11Y, 11M, 11C, and 11K. In the present embodiment, each of the image forming units 11Y, 11M, 11C, and 11K is disposed so as to be swingable about the shaft 71, and laser light (LB-Y, LB-M, LB-C, A shutter 70 that opens and closes the optical path LB-K) is attached, and these shutters 70 are also swung by the link rod 81 described above. In FIG. 12, a black (K) image forming unit 11K and a cyan (C) image forming unit 11C are shown, but the same applies to the other image forming units 11Y and 11M.
[0042]
FIG. 13 is a perspective view of the link rod 81. In the present embodiment, the link rod 81 is made of a sheet metal formed in a state of being bent into a predetermined shape. The link rod 81 has a horizontal portion 83 having a first cutout portion 82 into which the free end side of the drive arm 79 (see FIG. 12) is inserted, and is inclined obliquely downward from the end portion of the horizontal portion 83. A set of an inclined portion 84 provided, a connecting portion 85 provided horizontally from an end portion of the inclined portion 84, and an operating portion 86 provided obliquely upward from the end portion of the connecting portion 85. These are formed corresponding to the other image forming units 11C, 11M, and 11Y. However, the first cutout portion 82 is formed only in the horizontal portion 83 corresponding to the black image forming unit 11K.
[0043]
Each horizontal portion 83 is formed with a second cutout portion 87 into which a shutter arm 72 (described later) of the shutter 70 of each image forming unit 11Y, 11M, 11C, 11K is inserted. Further, the connecting portion 85 provided at the end of the yellow (Y) image forming unit 11Y is supported by a support portion (not shown) provided in the main body 1 (see FIG. 1) so as to be movable in the horizontal direction. It has become.
[0044]
14 is a perspective view showing the support frame 67 on which the shutter 70 is supported, together with the image forming units 11K and 11C, the drive mechanism 74, the link rod 81, and the like. FIG. 15 is a perspective view showing the support frame 67 alone. FIG. In the present embodiment, the cam 63 is attached to a synthetic resin support frame 67 disposed under the image forming units 11Y, 11M, 11C, and 11K so as to be rotatable around both ends of the shaft portion 64. It has been.
[0045]
The shutter 70 is also attached to the support frame 67 so as to be rotatable about both ends of the shaft 71. A shutter arm 72 made of a synthetic resin plate-like elastic body is attached to both ends of the shaft 71 of the shutter 70, and the shutter arm 72 is a second notch 87 (see FIG. 13). Furthermore, a film 70 a is attached to the free end side of the shutter 70 along the longitudinal direction. Furthermore, a coil spring 73 that urges the shutter 70 in a direction to close the optical path of the laser beams LB-Y, LB-M, LB-C, and LB-K is attached to the shutter 70. When the film 70a attached to the shutter 70 contacts the housing of the developing device 14 (see FIG. 12), the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K are closed, and maintenance is performed. As well as ensuring the safety of the laser, it is possible to prevent dust such as toner falling from above from adhering to the frame 32 and the window 33 (see FIG. 2) of the ROS 30.
[0046]
Next, the operation of the charging roll cleaner 54 and the brush cleaner 100 in each of the image forming units 11Y, 11M, 11C, and 11K using the link rod 81 will be described.
First, the operation of cleaning the charging rolls 13a of the image forming units 11Y, 11M, 11C, and 11K with the cleaning brush 59 will be described with reference to FIG. This operation is performed during a non-image forming operation by each of the image forming units 11Y, 11M, 11C, and 11K.
[0047]
First, the drive arm 74 is swung clockwise (right side) in the figure by the drive mechanism 74. Then, the protrusion 79a of the drive arm 79 presses the bulging portion 68a of the cam 63 of the black (K) image forming unit 11K. At the same time, the link rod 81 slides to the right in the figure, and the operating portion 86 of the link rod 81 presses the bulging portion 68a of the cam 63 of the cyan (C) image forming unit 11C. Although not shown, the other operating portion 86 of the link rod 81 presses the bulging portions 68a of the magenta (M) and yellow (Y) image forming units 11M and 11Y. As a result, the cams 63 of the image forming units 11Y, 11M, 11C, and 11K swing in the counterclockwise direction in the drawing. As the cam 63 of each of the image forming units 11Y, 11M, 11C, and 11K swings counterclockwise in the figure, the mylar film 66 attached to the cam 63 presses the lower surface of the charging roll cleaner 54. As a result, the charging roll cleaner 54 of each of the image forming units 11Y, 11M, 11C, and 11K swings counterclockwise (upward) in the figure, and the cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 is charged. It stops by contacting the roll 13a.
[0048]
On the other hand, the brush cleaner 100 in which the short portions 102b and 103b are in contact with the lower surface of the charging roll cleaner 54 is clocked in the figure by the biasing force of the spring 101 as the charging roll cleaner 54 swings counterclockwise in the figure. It swings in the turning direction and stops in a state where the wire 104 is separated from the cleaning brush 59.
[0049]
Further, as the link rod 81 slides to the right side in the figure, the position of the second notch portion 87 of the link rod 81 moves to the right side in the figure and is inserted into the second notch portion 87. The shutter arm 72 of the shutter 70 of the image forming units 11Y, 11M, 11C, and 11K is urged toward the right side in the drawing. As a result, the shutter arms 72 of the shutters 70 of the image forming units 11Y, 11M, 11C, and 11K close the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K.
[0050]
In this state, when the photosensitive drums 12 of the image forming units 11Y, 11M, 11C, and 11K are rotated, the cleaning brushes 59 are brought into contact with the charging rolls 13a that are driven to rotate by the photosensitive drums 12, respectively. Foreign matter (particularly toner) adhering to the charging roll 13a is removed.
By performing such an operation during non-image formation, foreign matters can be removed from the charging rolls 13a of the image forming units 11Y, 11M, 11C, and 11K without using a complicated mechanism. A charging failure can be prevented.
[0051]
Next, the standby operation of each of the image forming units 11Y, 11M, 11C, and 11K will be described with reference to FIG. This operation is performed before the image forming operation by each of the image forming units 11Y, 11M, 11C, and 11K is finished and the next image forming operation is started.
[0052]
First, the drive arm 79 is swung in the counterclockwise direction (left side) in the figure by the drive mechanism 74. Then, the pressure on the bulging portion 68a of the cam 63 of the black (K) image forming unit 11K by the protrusion 79a of the drive arm 79 is released. At the same time, the link rod 81 slides to the left in the drawing, and the pressing of the operating portion 86 of the link rod 81 against the bulging portion 68a of the cam 63 of the cyan (C) image forming unit 11C is released. Although not shown, the pressing of the magenta (M) and yellow (Y) image forming units 11M and 11Y on the bulging portion 68a of the cam 63 by the other operating portion 86 of the link rod 81 is also released. As a result, the cams 63 of the image forming units 11Y, 11M, 11C, and 11K swing in the clockwise direction in the drawing. As the cam 63 of each of the image forming units 11Y, 11M, 11C, and 11K swings in the clockwise direction, the mylar film 66 attached to the cam 63 does not press the lower surface of the charging roll cleaner 54. Accordingly, the charging roll cleaner 54 of each of the image forming units 11Y, 11M, 11C, and 11K swings clockwise (downward) in the drawing, and the cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 is charged. Stop in a state of being separated from the roll 13a.
[0053]
On the other hand, the brush cleaner 100 in which the short portions 102b and 103b are in contact with the lower surface of the charging roll cleaner 54 has a spring 101 depending on the weight of the charging roll cleaner 54 as the charging roll cleaner 54 swings counterclockwise in the figure. The wire 104 moves to the shaft 60 side of the charging roll cleaner 54 and stops while swinging counterclockwise in the figure against the urging force. By this operation, the foreign matter adhering to the cleaning brush 59 is knocked down by the wire 104.
[0054]
The foreign matter knocked down by each wire 104 is sucked by a suction mechanism (not shown) and is captured by a filter (not shown), so that the knocked-out foreign matter again adheres to the charging roll 13a. Hateful.
In addition, since a space is provided between the wire 104 and the plate-like member 105, the cleaning brush 59 struck by the wire 104 can immediately return to the original state, and the cleaning brush 59 is distorted and deformed. It is hard to happen.
[0055]
Furthermore, as the link rod 81 slides to the left in the figure, the position of the second notch 87 of the link rod 81 moves to the left in the figure, but the size of the second notch 87 is The shutter arm 72 is not biased by the link rod 81 because it is sufficiently larger than the shutter arm 72 of the shutter 70 of each of the image forming units 11Y, 11M, 11C, and 11K inserted into the second notch 87. It becomes a state. As a result, the shutters 70 of the image forming units 11Y, 11M, 11C, and 11K maintain a state in which the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K are closed.
[0056]
By performing such an operation, the foreign matter can be removed from the cleaning brush 59, the foreign matter can be prevented from reattaching to the charging roll 13a, and the life of the cleaning brush 59 can be extended.
[0057]
Finally, with reference to FIG. 17, the operation of the image forming units 11Y, 11M, 11C, and 11K during image formation will be described.
First, the drive arm 79 is further swung in the counterclockwise direction (left side) in the figure by the drive mechanism 74. Then, the protrusion 79a of the drive arm 79 is separated from the bulging portion 68a of the cam 63 of the black (K) image forming unit 11K. At the same time, the link rod 81 slides further to the left in the drawing, and the operating portion 86 of the link rod 81 is separated from the bulging portion 68a of the cam 63 of the cyan (C) image forming unit 11C. Although not shown, the operating portion 86 of the link rod 81 is separated from the bulging portion 68a of the cam 63 of the magenta (M) and yellow (Y) image forming units 11M and 11Y. However, since the pressing of the image forming units 11Y, 11M, 11C, and 11K on the cam 63 has already been released, the mylar film 66 attached to the cam 63 maintains a state in which the lower surface of the charging roll cleaner 54 is not pressed, The cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 maintains a state where it stops in a state of being separated from the charging roll 13a. Further, the brush cleaner 100 also maintains a stopped state on the shaft 60 side of the charging roll cleaner 54.
[0058]
On the other hand, the brush cleaner 110 in which the short portions 102b and 103b contact the charging roll cleaner 54 also maintains the state where the wire 104 is stopped on the shaft 60 side of the charging roll cleaner 54 because the position of the charging roll cleaner 54 does not change. . However, as described above, since a space is provided between the wire 104 and the plate-like member 105, the wire 104 exists between the cleaning brushes 59, and the cleaning brush 59 becomes addictive and deforms. This situation is unlikely to occur.
[0059]
Further, as the link rod 81 slides to the left in the drawing, the position of the second cutout portion 87 of the link rod 81 further moves to the left in the drawing, and each inserted into the second cutout portion 87. The shutter arm 72 of the shutter 70 of the image forming units 11Y, 11M, 11C, and 11K is now urged toward the left side in the drawing. As a result, the shutters 70 of the image forming units 11Y, 11M, 11C, and 11K open the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K.
[0060]
By opening the shutter 70 in this manner, image formation can be performed.
Further, in this state, since the cleaning brush 59 is separated from the charging roll 13a, the rotation of the charging roll 13a driven by the photosensitive drum 12 is hardly hindered, and the rotation failure of the charging roll 13a during the image forming operation and This can prevent charging failure and image formation failure.
[0061]
-Embodiment 2-
The present embodiment is substantially the same as the first embodiment except that the configuration of the brush cleaner is different. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
18 is a side view showing the black (K) image forming unit 11K, the drive mechanism 74, and the link rod 81 in the present embodiment, and FIG. 19 is a perspective view thereof. In the present embodiment, instead of the swinging brush cleaner 100 used in the first embodiment, a brush cleaner 110 that slides following the slide of the link rod 81 is provided.
[0062]
As shown in FIG. 19, the brush cleaner 110 includes a support member 111 (slide support member) that is fixedly disposed on the link rod 81 and adjacent to the second cutout portion 87, and the support member 111. A rail 112 (slide support member) attached to the outer end of the charging roll cleaner 54 on the opposite side in the axial direction, and a brush having one end fixed to the support member 111 and the other end slidably inserted into the rail 112. And a cleaning rod 113 as a cleaning member (linear member). In particular, in the present embodiment, the arrangement height of the cleaning rod 113 is set to be substantially the same as the height of the cleaning brush 59. Similar brush cleaners 110 are provided for the other image forming units 11Y, 11M, and 11C.
[0063]
Next, the operation of the charging roll cleaner 54 and the brush cleaner 100 in each of the image forming units 11Y, 11M, 11C, and 11K using the link rod 81 will be described.
First, an operation for cleaning the charging rolls 13a of the image forming units 11Y, 11M, 11C, and 11K with the cleaning brush 59 will be described with reference to FIG. This operation is performed during a non-image forming operation by each of the image forming units 11Y, 11M, 11C, and 11K.
[0064]
First, the drive arm 74 is swung clockwise (right side) in the figure by the drive mechanism 74. Then, the protrusion 79a of the drive arm 79 presses the bulging portion 68a of the cam 63 of the black (K) image forming unit 11K. At the same time, the link rod 81 slides to the right side in the drawing, and although not shown, each operation portion 86 of the link rod 81 is cyan (C), magenta (M), and yellow (Y) image forming unit 11C. , 11M and 11Y are pressed. As a result, the cams 63 of the image forming units 11Y, 11M, 11C, and 11K swing in the counterclockwise direction in the drawing. As the cam 63 of each of the image forming units 11Y, 11M, 11C, and 11K swings counterclockwise in the figure, the mylar film 66 attached to the cam 63 presses the lower surface of the charging roll cleaner 54. As a result, the charging roll cleaner 54 of each of the image forming units 11Y, 11M, 11C, and 11K swings counterclockwise (upward) in the figure, and the cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 is charged. It stops by contacting the roll 13a.
[0065]
On the other hand, the brush cleaner 110 slides to the right in the drawing as the link rod 81 slides to the right in the drawing, and stops in a state where the cleaning rod 113 is separated from the cleaning brush 59.
[0066]
Further, as the link rod 81 slides to the right side in the figure, the position of the second notch portion 87 of the link rod 81 moves to the right side in the figure and is inserted into the second notch portion 87. The shutter arm 72 of the shutter 70 of the image forming units 11Y, 11M, 11C, and 11K is urged toward the right side in the drawing. As a result, the shutter arms 72 of the shutters 70 of the image forming units 11Y, 11M, 11C, and 11K close the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K.
[0067]
In this state, when the photosensitive drums 12 of the image forming units 11Y, 11M, 11C, and 11K are rotated, the cleaning brushes 59 are brought into contact with the charging rolls 13a that are driven to rotate by the photosensitive drums 12, respectively. Foreign substances (particularly external additives) adhering to the charging roll 13a are removed.
By performing such an operation at the time of non-image formation, even in this embodiment, foreign substances can be removed from the charging rolls 13a of the image forming units 11Y, 11M, 11C, and 11K without using a complicated mechanism. In addition, it is possible to prevent charging failure of each photosensitive drum 12.
[0068]
Next, the operation of each of the image forming units 11Y, 11M, 11C, and 11K during standby will be described with reference to FIG. This operation is performed before the image forming operation by each of the image forming units 11Y, 11M, 11C, and 11K is finished and the next image forming operation is started.
[0069]
First, the drive arm 79 is swung in the counterclockwise direction (left side) in the figure by the drive mechanism 74. Then, the pressure on the bulging portion 68a of the cam 63 of the black (K) image forming unit 11K by the protrusion 79a of the drive arm 79 is released. At the same time, the link rod 81 slides to the left in the drawing, and although not shown, the cyan (C), magenta (M), and yellow (Y) image forming units 11C by the operating portions 86 of the link rod 81 are shown. , 11M, and 11Y are released from the pressed portions 68a. As a result, the cams 63 of the image forming units 11Y, 11M, 11C, and 11K swing in the clockwise direction in the drawing. As the cam 63 of each of the image forming units 11Y, 11M, 11C, and 11K swings in the clockwise direction, the mylar film 66 attached to the cam 63 does not press the lower surface of the charging roll cleaner 54. Accordingly, the charging roll cleaner 54 of each of the image forming units 11Y, 11M, 11C, and 11K swings clockwise (downward) in the drawing, and the cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 is charged. Stop in a state of being separated from the roll 13a.
[0070]
On the other hand, the brush cleaner 110 slides to the left in the drawing as the link rod 81 slides to the left in the drawing, but stops before the cleaning rod 113 contacts the cleaning brush 59.
[0071]
Furthermore, as the link rod 81 slides to the left in the figure, the position of the second notch 87 of the link rod 81 moves to the left in the figure, but the size of the second notch 87 is The shutter arm 72 is not biased by the link rod 81 because it is sufficiently larger than the shutter arm 72 of the shutter 70 of each of the image forming units 11Y, 11M, 11C, and 11K inserted into the second notch 87. It becomes a state. As a result, the shutters 70 of the image forming units 11Y, 11M, 11C, and 11K maintain a state in which the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K are closed.
[0072]
By performing such an operation, in the present embodiment also, the foreign matter can be removed from the cleaning brush 59, the foreign matter can be prevented from reattaching to the charging roll 13a, and the life of the cleaning brush 59 can be extended. can do.
[0073]
Finally, the operation of the image forming units 11Y, 11M, 11C, and 11K during image formation will be described with reference to FIGS.
First, the drive arm 79 is further swung in the counterclockwise direction (left side) in the figure by the drive mechanism 74. Then, the protrusion 79a of the drive arm 79 is separated from the bulging portion 68a of the cam 63 of the black (K) image forming unit 11K. At the same time, the link rod 81 slides further to the left in the figure, and although not shown, each operating portion 86 of the link rod 81 is an image forming unit of cyan (C), magenta (M), and yellow (Y). It is separated from each bulging part 68a of 11C, 11M, and 11Y. However, since the pressing of the image forming units 11Y, 11M, 11C, and 11K on the cam 63 has already been released, the mylar film 66 attached to the cam 63 maintains a state in which the lower surface of the charging roll cleaner 54 is not pressed, The cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 maintains a state where it stops in a state of being separated from the charging roll 13a.
[0074]
On the other hand, the brush cleaner 110 slides to the left in the drawing as the link rod 81 slides further to the left in the drawing, and the cleaning rod 113 strikes the hair tip of the cleaning brush 59 toward the shaft 60 side of the charging roll cleaner 54. And stop. By this operation, the foreign matter adhering to the cleaning brush 59 is struck down by the cleaning rod 113.
[0075]
Note that the foreign matter knocked down by the cleaning rod 113 is sucked by a suction mechanism (not shown) and is captured by a filter (not shown), so that the knocked-out foreign matter again adheres to the charging roll 13a. Hateful. In addition, since a space is provided below the cleaning rod 113, the cleaning brush 59 hit by the cleaning rod 113 can immediately return to the original state, and the cleaning brush 59 becomes addictive and deforms. Is less likely to occur.
[0076]
Further, as the link rod 81 slides to the left in the figure, the position of the second notch 87 of the link rod 81 is now moved to the left in the figure and is inserted into the second notch 87. The shutter arm 72 of the shutter 70 of each of the image forming units 11Y, 11M, 11C, and 11K is now urged toward the left side in the drawing. As a result, the shutters 70 of the image forming units 11Y, 11M, 11C, and 11K open the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K.
[0077]
By opening the shutter 70 in this manner, image formation can be performed.
Further, in this state, since the cleaning brush 59 is separated from the charging roll 13a, the rotation of the charging roll 13a driven by the photosensitive drum 12 is hardly hindered, and the rotation failure of the charging roll 13a during the image forming operation and This can prevent charging failure and image formation failure.
In particular, unlike the first embodiment, in the present embodiment, the cleaning rod 113 is separated from the cleaning brush 59 during standby, so that the deformation of the cleaning brush 59 can be further suppressed. .
[0078]
-Third embodiment-
This embodiment is substantially the same as the second embodiment, but the height of the cleaning rod 113 of the brush cleaner 110 is different. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 23 is a side view showing the black (K) image forming unit 11K, the drive mechanism 74, and the link rod 81 in the present embodiment. This brush cleaner 110 has exactly the same configuration as that described in the second embodiment, but the arrangement height of the cleaning rod 113 is lower than the height of the cleaning brush 59 and the height of the charging roll cleaner 54 is high. Is different in that it is set to be approximately the same. Similar brush cleaners 110 are provided for the other image forming units 11Y, 11M, and 11C.
[0079]
Next, the operation of the charging roll cleaner 54 and the brush cleaner 110 in each of the image forming units 11Y, 11M, 11C, and 11K using the link rod 81 will be described.
First, the operation of cleaning the charging rolls 13a of the image forming units 11Y, 11M, 11C, and 11K with the cleaning brush 59 will be described with reference to FIG. This operation is performed during a non-image forming operation by each of the image forming units 11Y, 11M, 11C, and 11K.
[0080]
First, the drive arm 74 is swung clockwise (right side) in the figure by the drive mechanism 74. Then, the protrusion 79a of the drive arm 79 presses the bulging portion 68a of the cam 63 of the black (K) image forming unit 11K. At the same time, the link rod 81 slides to the right side in the drawing, and although not shown, each operation portion 86 of the link rod 81 is cyan (C), magenta (M), and yellow (Y) image forming unit 11C. , 11M and 11Y are pressed. As a result, the cams 63 of the image forming units 11Y, 11M, 11C, and 11K swing in the counterclockwise direction in the drawing. As the cam 63 of each of the image forming units 11Y, 11M, 11C, and 11K swings counterclockwise in the figure, the mylar film 66 attached to the cam 63 presses the lower surface of the charging roll cleaner 54. As a result, the charging roll cleaner 54 of each of the image forming units 11Y, 11M, 11C, and 11K swings counterclockwise (upward) in the figure, and the cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 is charged. It stops by contacting the roll 13a. On the other hand, the brush cleaner 110 slides to the right in the drawing as the link rod 81 slides to the right in the drawing, and stops in a state where the cleaning rod 113 is separated from the cleaning brush 59.
[0081]
Further, as the link rod 81 slides to the right side in the figure, the position of the second notch portion 87 of the link rod 81 moves to the right side in the figure and is inserted into the second notch portion 87. The shutter arm 72 of the shutter 70 (shutter member) of the image forming units 11Y, 11M, 11C, and 11K is urged toward the right side in the drawing. As a result, the shutter arms 72 of the shutters 70 of the image forming units 11Y, 11M, 11C, and 11K close the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K.
[0082]
In this state, when the photosensitive drums 12 of the image forming units 11Y, 11M, 11C, and 11K are rotated, the cleaning brushes 59 are brought into contact with the charging rolls 13a that are driven to rotate by the photosensitive drums 12, respectively. Foreign substances (particularly external additives) adhering to the charging roll 13a are removed.
By performing such an operation at the time of non-image formation, even in this embodiment, foreign substances can be removed from the charging rolls 13a of the image forming units 11Y, 11M, 11C, and 11K without using a complicated mechanism. In addition, it is possible to prevent charging failure of each photosensitive drum 12.
[0083]
Next, the operation during standby of the image forming units 11Y, 11M, 11C, and 11K will be described with reference to FIG. This operation is performed before the image forming operation by each of the image forming units 11Y, 11M, 11C, and 11K is finished and the next image forming operation is started.
[0084]
First, the drive arm 79 is swung in the counterclockwise direction (left side) in the figure by the drive mechanism 74. Then, the pressure on the bulging portion 68a of the cam 63 of the black (K) image forming unit 11K by the protrusion 79a of the drive arm 79 is released. At the same time, the link rod 81 slides to the left in the drawing, and although not shown, the cyan (C), magenta (M), and yellow (Y) image forming units 11C by the operating portions 86 of the link rod 81 are shown. , 11M, and 11Y are released from the pressed portions 68a. As a result, the cams 63 of the image forming units 11Y, 11M, 11C, and 11K swing in the clockwise direction in the drawing. As the cam 63 of each of the image forming units 11Y, 11M, 11C, and 11K swings in the clockwise direction, the mylar film 66 attached to the cam 63 does not press the lower surface of the charging roll cleaner 54. Accordingly, the charging roll cleaner 54 of each of the image forming units 11Y, 11M, 11C, and 11K swings clockwise (downward) in the drawing, and the cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 is charged. Stop in a state of being separated from the roll 13a.
[0085]
On the other hand, the brush cleaner 110 slides in the same direction as the link rod 81 slides to the left in the figure, but stops before the cleaning rod 113 contacts the charging roll cleaner 54.
[0086]
Furthermore, as the link rod 81 slides to the left in the figure, the position of the second notch 87 of the link rod 81 moves to the left in the figure, but the size of the second notch 87 is The shutter arm 72 is not biased by the link rod 81 because it is sufficiently larger than the shutter arm 72 of the shutter 70 of each of the image forming units 11Y, 11M, 11C, and 11K inserted into the second notch 87. It becomes a state. As a result, the shutters 70 of the image forming units 11Y, 11M, 11C, and 11K maintain a state in which the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K are closed.
[0087]
By performing such an operation, in the present embodiment also, the foreign matter can be removed from the cleaning brush 59, the foreign matter can be prevented from reattaching to the charging roll 13a, and the life of the cleaning brush 59 can be extended. can do.
[0088]
Finally, the operation of the image forming units 11Y, 11M, 11C, and 11K during image formation will be described with reference to FIG.
First, the drive arm 79 is further swung in the counterclockwise direction (left side) in the figure by the drive mechanism 74. Then, the protrusion 79a of the drive arm 79 is separated from the bulging portion 68a of the cam 63 of the black (K) image forming unit 11K. At the same time, the link rod 81 slides further to the left in the figure, and although not shown, each operating portion 86 of the link rod 81 is an image forming unit of cyan (C), magenta (M), and yellow (Y). It is separated from each bulging part 68a of 11C, 11M, and 11Y. However, since the pressing of the image forming units 11Y, 11M, 11C, and 11K on the cam 63 has already been released, the mylar film 66 attached to the cam 63 maintains a state in which the lower surface of the charging roll cleaner 54 is not pressed, The cleaning brush 59 attached to the upper surface of the charging roll cleaner 54 maintains a state where it stops in a state of being separated from the charging roll 13a.
[0089]
On the other hand, the brush cleaner 110 slides in the same direction as the link rod 81 slides to the left in the figure, and the cleaning rod 113 collides with the charging roll cleaner 54 and stops. As a result, the cleaning brush 59 vibrates, and the foreign matter attached to the cleaning brush 59 is shaken off. Therefore, in the present embodiment, the cleaning rod 113 functions as a contact / separation member.
Note that the foreign matter that has been shaken off is sucked by a suction mechanism (not shown) and is captured by a filter (not shown), so that it is unlikely that the knocked-out foreign matter adheres to the charging roll 13a again.
[0090]
Further, as the link rod 81 slides to the left side in the figure, the position of the second notch portion 87 of the link rod 81 moves to the left side in the figure and is inserted into the second notch portion 87. The shutter arm 72 of the shutter 70 of each of the image forming units 11Y, 11M, 11C, and 11K is now urged toward the left side in the drawing. As a result, the shutters 70 of the image forming units 11Y, 11M, 11C, and 11K open the optical paths of the laser beams LB-Y, LB-M, LB-C, and LB-K.
[0091]
By opening the shutter 70 in this manner, image formation can be performed.
Further, in this state, since the cleaning brush 59 is separated from the charging roll 13a, the rotation of the charging roll 13a driven by the photosensitive drum 12 is hardly hindered, and the rotation failure of the charging roll 13a during the image forming operation and This can prevent charging failure and image formation failure.
[0092]
In particular, unlike the first and second embodiments, in this embodiment, the charging roller cleaner 54 to which the cleaning brush 59 is attached is impacted without causing direct contact with the cleaning brush 59, thereby generating foreign matter. Since it is shaken off, the deformation of the cleaning brush 59 can be further suppressed.
[0093]
【The invention's effect】
As described above, according to the present invention, it is possible to maintain the performance of removing foreign substances adhering to a charging member such as a charging roll over a long period of time with a simple configuration.
Further, according to the present invention, the deformation of the cleaning brush can be suppressed.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an overall configuration of an image forming apparatus to which the exemplary embodiment is applied.
FIG. 2 is a diagram for explaining a configuration of an image forming unit.
FIG. 3 is a perspective view showing a charger.
FIG. 4 is an enlarged view of an end portion of a cleaner attached to a charger.
FIG. 5 is a diagram illustrating an entire cleaner attached to a charger.
FIG. 6 is a perspective view showing a swing mechanism and a drive mechanism.
FIG. 7 is a side view showing a swing mechanism and a drive mechanism, and is a view showing a cleaning state of a charging roll by a cleaning brush.
FIG. 8 is a perspective view showing a cam.
FIG. 9 is a side view showing a swing mechanism and a drive mechanism, and a view showing a cleaning state of the cleaning brush by a brush cleaner.
FIG. 10 is a perspective view showing a brush cleaner in a non-cleaning state.
FIG. 11 is a perspective view showing a brush cleaner in a cleaning state.
FIG. 12 is a diagram illustrating a cleaning state of the charging roll by a cleaning brush in each image forming unit.
FIG. 13 is a perspective view of a link rod.
FIG. 14 is a perspective view showing a frame to which an image forming unit, a drive mechanism, and a link rod are attached.
FIG. 15 is a perspective view showing a single frame.
FIG. 16 is a diagram illustrating a standby state in each image forming unit.
FIG. 17 is a diagram illustrating a shutter open state in each image forming unit.
FIG. 18 is a diagram illustrating a cleaning state of a charging roll by a cleaning brush in each image forming unit according to the second embodiment.
FIG. 19 is a perspective view showing the brush cleaner in the non-cleaning state of the second embodiment.
FIG. 20 is a diagram illustrating a standby state in each image forming unit according to the second embodiment.
FIG. 21 is a diagram illustrating a shutter open state in each image forming unit according to the second embodiment.
FIG. 22 is a perspective view showing the brush cleaner in the cleaning state according to the second embodiment.
FIG. 23 is a diagram illustrating a cleaning state of the charging roll by the cleaning brush in each image forming unit according to the third embodiment.
FIG. 24 is a diagram illustrating a standby state in each image forming unit according to the third embodiment.
FIG. 25 is a diagram illustrating a shutter open state in each image forming unit according to the third embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main body, 10 ... Image process system, 11Y, 11M, 11C, 11K ... Image forming unit, 12 ... Photosensitive drum, 13 ... Charger, 13a ... Charge roll, 14 ... Developer, 15 ... Primary transfer roll, 16 DESCRIPTION OF SYMBOLS ... Cleaning device, 20 ... Transfer unit, 21 ... Intermediate transfer belt, 40 ... Sheet conveyance system, 50 ... IPS (Image Processing System), 54 ... Charging roll cleaner, 59 ... Cleaning brush, 62 ... Swing mechanism, 63 ... Cam , 66 ... Mylar film, 70 ... Shutter, 72 ... Shutter arm, 74 ... Drive mechanism, 79 ... Drive arm, 81 ... Link rod, 82 ... First cutout part, 83 ... Horizontal part, 84 ... Inclined part, 85: Connecting portion, 86: Actuating portion, 87: Second notch, 100 ... Brush cleaner, 101 ... Spring, 102, 103 ... Arm, 104 ... Wire, 10 ... brush cleaner, 111 ... support member, 112 ... rails, 113 ... cleaning rod

Claims (2)

An image carrier disposed rotatably;
A contact charging member that is rotatably contacted with the image carrier and charges the image carrier;
A cleaning brush disposed so as to be able to contact with and separate from the contact charging member;
The cleaning brush is disposed so as to be able to come into contact with and separate from the cleaning brush, and is separated from the cleaning brush in conjunction with a contact operation of bringing the cleaning brush into contact with the contact charging member. A brush cleaning member that comes into contact with the cleaning brush in conjunction with a separating operation for separating
A shutter member that opens and closes an optical path for exposing the image carrier charged by the contact charging member;
An image forming apparatus comprising: a link mechanism that interlocks a contact operation of the cleaning brush with the contact charging member and an opening / closing operation of the shutter member. The link mechanism is
Claim 1, characterized in that the said shutter member is closed when abutted against the cleaning brush on the contact charging member, to open the shutter member when moved away the cleaning brush from the contact charging member The image forming apparatus described.

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