JP3696780B2 - Image forming apparatus and image carrier unit mounted thereon - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus including an image carrier, a charging roller, and a roller cleaning unit that cleans an outer peripheral surface of the charging roller, and an image carrier unit attached thereto.
[0002]
[Prior art]
For example, copying machines, printers, facsimiles, and the like, which are electrophotographic image forming apparatuses, include a charging device that charges the surface of a photoconductor that is an image carrier.
In the charging device, a charging roller in which an elastic member formed into a conductive roller shape is integrally formed on a metal core is brought into contact with the surface of the photoreceptor, and the core of the charging roller and the photoreceptor are contacted. There is a contact-type charging device in which a voltage is applied between them to charge the photoreceptor.
[0003]
In such a contact-type charging device, the roller-like elastic member of the charging roller rotates while contacting the surface of the photoconductor, so that the transfer residual toner remaining on the surface of the photoconductor particularly after the image transfer is transferred to the charging roller. It is easy to transfer to the elastic member.
Further, by winding and fixing, for example, a tape-shaped gap management member around both ends of the elastic member of the charging roller, the portion of the effective charging area of the elastic member is not spaced with a predetermined gap with respect to the surface of the photoreceptor. Even in a charging device (see, for example, Japanese Patent Laid-Open No. 4-360167) that is in contact, toner, dust, and the like floating in the image forming apparatus adhere to the elastic member, so that There were times when it became dirty.
[0004]
Therefore, in a charging device using such a charging roller, a roller cleaning member made of a sponge or the like is slidably contacted with the outer peripheral surface of the elastic member of the charging roller, and thereby toner or the like adhering to the outer peripheral surface of the elastic member. Some have roller cleaning means for cleaning dirt.
[0005]
And, if the roller cleaning member is always in the same position in the axial direction of the charging roller, if the roller cleaning member is formed of sponge or the like, it causes clogging and the cleaning performance deteriorates. The roller cleaning member is swung in the axial direction of the charging roller by a roller cleaning member swinging mechanism.
[0006]
[Problems to be solved by the invention]
However, the conventional roller cleaning member swinging mechanism, as shown in FIG. 10, for example, is a guide (not shown) that can swing the bracket 102 holding the roller cleaning member 101 in the direction of arrow E, which is the axial direction of the charging roller 100. A guide pin 104 that rotatably supports the roller 103 is fixed to the lower surface of one end of the bracket 102.
[0007]
The roller 103 is pressed against the cam 105 by a spring 106, and the roller 105 is rotated in the arrow E direction by rotating the cam 105 in the arrow K direction, so that the roller cleaning member 101 is swung together with the bracket 102. Therefore, there is a problem that the number of parts increases and the cost becomes expensive.
In addition, there is a problem that the number of assembling steps increases as the number of parts increases.
[0008]
The present invention has been made in view of the above problems, and an object thereof is to reduce the cost of a mechanism that swings a roller cleaning member that cleans the surface of the charging roller in the axial direction of the charging roller.
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides an image carrier, a charging roller that is disposed opposite to the image carrier and charges the image carrier, and a roller cleaning member that slides on the outer peripheral surface of the charging roller. An image forming apparatus including a roller cleaning unit having a roller cleaning member swinging mechanism for cleaning in contact with the roller cleaning member in the axial direction of the charging roller is configured as follows.
[0010]
That is, the roller cleaning member swinging mechanism of the image forming apparatus holds the roller cleaning member and bends one end portion into a substantially L shape and protrudes outward to a portion bent into the substantially L shape. A sheet metal bracket having a reinforcing bead that also serves as a cam contact portion formed as described above, and a cam that is rotated by a cam rotating means by contacting a portion of the reinforcing bead protruding in the swinging direction of the roller cleaning member. And an urging member for urging the bracket so that the protruding portion of the reinforcing bead is pressed against the cam.
[0011]
It is effective that the cross-sectional shape of the reinforcing bead is an arc shape.
An image carrier unit mounted on any one of the image forming apparatuses, wherein the charging roller, the roller cleaning unit, and the image carrier are configured as an integrated unit in the main body of the image forming apparatus. There is also provided an image carrier unit that is detachable.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view showing a configuration in the vicinity of a charging device of an image forming apparatus according to an embodiment of the present invention, and FIG. 2 shows an end portion of a bracket for holding a roller cleaning member provided in the image forming apparatus. FIG. 3 is an overall configuration diagram showing a small printer as an example of the image forming apparatus.
[0013]
As shown in FIG. 1, the image forming apparatus includes a photosensitive drum 5 that is an image carrier, a charging roller 14 that is arranged to face the photosensitive drum 5 and charges the photosensitive drum 5, and a charging roller 14 that charges the photosensitive drum 5. A roller cleaning member 49 is slidably brought into contact with the outer peripheral surface of the elastic member 17 formed in a roller shape of the roller 14 and cleaned, and the roller cleaning member 49 is swung in the axial direction of the charging roller 14 (in the direction of arrow E). And a roller cleaning device 60 which is a roller cleaning means having a roller cleaning member swinging mechanism 70 to be moved.
[0014]
A roller cleaning member 49 is held by the roller cleaning member swinging mechanism 70, and one end on the left side in FIG. 1 is bent into a substantially L shape and bent into a substantially L shape in FIG. In addition, as shown in FIG. 1, a sheet metal bracket 71 having a reinforcing bead 72 also serving as a cam contact portion 72a formed by drawing so as to protrude outward, and the roller cleaning member 49 of the reinforcing bead 72 shown in FIG. A cam 75 that is rotated by a motor 74 that is a cam rotating means by contacting a cam contact portion 72a that is a portion protruding in a moving direction (leftward in FIG. 1), and a cam in which a bracket 71 protrudes from a reinforcing bead 72 A coil spring 76, which is a biasing member that biases the contact portion 72a in the direction indicated by the arrow N so as to press against the cam 75, is provided.
[0015]
The roller cleaning member swing mechanism 70 includes a bracket 71, a cam 75, a motor 74, and a coil spring 76. The roller cleaning device 60 includes a roller cleaning member swing mechanism 70 and a roller cleaning member 49 swinged by the roller cleaning member swing mechanism 70.
[0016]
In the charging device of this image forming apparatus, an image is formed through film materials 18 and 18 which are gap management members having a predetermined thickness respectively attached to the outer periphery of both end portions of the elastic member 17 in which the charging roller 14 is formed in a roller shape. The effective charging area Ca, which is in contact with the surface of the photosensitive drum 5 as a carrier and thereby becomes an area between the inner sides of the film materials 18 and 18 on both sides of the elastic member 17, is a gap with respect to the surface of the photosensitive drum 5. In this state, a voltage is applied between the charging roller 14 and the photosensitive drum 5 to charge the photosensitive drum 5.
[0017]
The charging roller 14 is made of, for example, epichlorohydrin rubber on the outer periphery of a metal core 16 formed by, for example, SUM-Ni plating (steel surface is nickel-plated), and has a volume resistivity of 1 × 10 ³ to 1 × 10 ⁸ Ω. An elastic member 17 having conductivity of cm is provided.
[0018]
As the elastic member 17, for example, a rubber having an old JIS-A hardness of about 77 degrees and a rubber test piece hardness of 50 degrees or more is used.
The film materials 18 and 18 on both sides are made of, for example, polyethylene terephthalate (PET) having a thickness of 25 to 125 μm and a width of 8 mm, and one side is used as an adhesive surface, and the adhesive surface side is both ends of the elastic member 17 of the charging roller 14. The part is fixed by sticking.
[0019]
In the charging roller 14, both end portions of the cored bar 16 are pressed against the photosensitive drum 5 by the pressurizing springs 19, 19 through the slide bearings 30, 30 with a predetermined pressure.
The charging roller 14 may make the film materials 18 and 18 at both ends contact the photosensitive drum 5 by its own weight without using the pressure spring 19.
[0020]
A driving gear 40 is fixed to one end on the right side of the metal core 16 in FIG. 1, a driving force from a motor (not shown) is transmitted thereto, and the charging roller 14 is rotated at the same linear speed as the photosensitive drum 5. I try to let them.
As for the application of the voltage to the charging roller 14, for example, DC-700V is applied to the portion of the core metal 16 by constant voltage control, and an AC voltage is applied by constant current control.
[0021]
The charging device having the charging roller 14 shown in FIG. 1 is mounted on a small printer which is an image forming apparatus as shown in FIG. 3, for example.
This small-sized printer is a four-drum full-color electrophotographic small-sized printer, and in the apparatus main body 1, there are four image bearing unit units photoconductor units 2 A, 2 B, 2 C and 2 D in the apparatus main body 1. On the other hand, they are detachably attached.
In this small printer, a transfer belt 3 is stretched between a plurality of rollers so as to be rotatable in a direction indicated by an arrow A at a substantially central position in the apparatus main body 1.
[0022]
Then, the photosensitive unit 2A to the photosensitive drum 5 provided on each of the four photosensitive units 2A, 2B, 2C, and 2D are in contact with the upper surface of the transfer belt 3 in FIG. Each 2D is arranged.
In correspondence with the photoreceptor units 2A to 2D, developing devices 10A to 10D having different toner colors are disposed.
[0023]
A writing unit 6 is disposed above the photosensitive units 2A to 2D, and a duplex unit 7 is disposed below the photosensitive units 2A to 2D.
Further, this small printer is equipped with a reversing unit 8 that inverts and discharges the transfer paper P after image formation or conveys it to the duplex unit 7 on the left side of the apparatus main body 1 in FIG.
[0024]
Between the transfer belt 3 and the reversing unit 8, there is provided a fixing device 9 for fixing the image of the transfer paper onto which the image has been transferred.
A reversal conveyance path 20 is formed on the downstream side of the fixing device 9 in the conveyance direction of the transfer sheet, and the transfer sheet P conveyed there can be discharged onto a discharge tray 26 by a discharge roller pair 25. .
[0025]
Further, in the lower part of the apparatus main body 1, paper feed cassettes 11 and 12 that can store transfer papers P of different sizes are arranged in two upper and lower stages.
Further, a manual feed tray 13 is provided on the right side surface of the apparatus main body 1 so as to be openable and closable in the direction indicated by the arrow B, and the manual feed tray 13 is opened so that manual feeding can be performed therefrom.
[0026]
The photoconductor units 2A to 2D are units having the same configuration, the photoconductor unit 2A forms an image corresponding to yellow, and the photoconductor unit 2B forms an image corresponding to magenta. 2C forms an image corresponding to the cyan color, and the photoreceptor unit 2D forms an image corresponding to the black color. They are arranged at intervals in the transfer paper conveyance direction.
[0027]
As shown in FIG. 4, the photosensitive units 2 </ b> A to 2 </ b> D are photosensitive rollers 14 and OPC drum type charged bodies whose surfaces are charged by the charging roller 14 and an electrostatic latent image is formed by exposure. The body drum 5, the brush roller 15 that constitutes a cleaning device that cleans the surface of the photosensitive drum 5, and the roller cleaning device 60 that functions as the roller cleaning means described above are configured as an integral unit. The apparatus main body 1 shown in FIG.
[0028]
The photosensitive unit may be configured as an integrated unit including the charging roller 14, the photosensitive drum 5, and the roller cleaning device 60 by removing the brush roller 15 from the configuration.
In this embodiment, the photosensitive drum 5 having a diameter of φ30 mm is used.
[0029]
Each of the photosensitive drums 5 of the photosensitive units 2A to 2D rotates in the direction indicated by an arrow C in FIG. 4, and the linear speeds thereof are monochrome speed priority mode, monochrome image quality priority mode, color speed priority mode, and color image quality priority. The mode can be adjusted in three stages of 185 mm / sec, 125 mm / sec, and 62.5 mm / sec depending on several modes such as a thick paper / OHP paper feeding mode.
[0030]
Each of the photosensitive units 2A to 2D includes a cleaning blade 47 that slides the tip of the photosensitive drum 5 on the surface of the photosensitive drum 5 to scrape off transfer residual toner, and the brush roller 15 removes the toner scraped off by the cleaning blade 47. Thus, the waste toner recovered by moving the toner transport auger 48 to the toner transport auger 48 and rotating the toner transport auger 48 is transported to a predetermined waste toner storage unit.
[0031]
Further, in the photoreceptor units 2A to 2D, a roller cleaning member 49 made of, for example, sponge is also brought into contact with the surface of the elastic member 17 of the charging roller 14, and toner, dust, etc. floating in the apparatus are brought to the surface of the elastic member 17. Even when it adheres, it can be cleaned.
[0032]
The photoreceptor units 2A to 2D are provided with a positioning main reference portion 51 as a reference for attaching and detaching the photoconductor units 2A to 2D with respect to the apparatus body 1 (see FIG. 3). When the photoconductor units 2A to 2D are mounted on the apparatus main body 1, the photoconductor units 2A to 2D are attached to the bracket 50 by a predetermined mounting position. So that positioning can be performed reliably.
[0033]
The developing devices 10A to 10D shown in FIG. 3 are all the same in configuration, and they are all two-component developing type developing devices that differ only in the color of the toner used. The developing device 10A uses yellow toner, the developing device 10B uses magenta toner, the developing device 10C uses cyan toner, and the developing device 10D uses black toner. .
[0034]
The writing unit 6 shown in FIG. 5 is a laser diode (LD) type 1-color color beam and monochrome 2-beam, and is a writing unit of one polygon motor having two 6-sided rotary polygon mirrors 22a and 22b.
The writing unit 6 emits yellow scanning light, magenta scanning light, and cyan scanning light by rotating polygon mirrors 22a and 22b emitted from a laser diode (not shown) serving as a light source and rotated by a polygon motor 21. And the black scanning light is reflected separately on the right and left.
[0035]
The scanning light for yellow and the scanning light for magenta pass through the two-layer fθ lens 23, respectively, and the scanning light for yellow is reflected by the mirror 27, passes through the long WTL 24, and is exposed through the mirrors 28 and 29. Irradiated onto the photosensitive drum 5 of the body unit 2A.
The magenta scanning light is reflected by the mirror 31, passes through the long WTL 32, and is irradiated onto the photosensitive drum 5 of the photosensitive unit 2B via the mirrors 33 and 34.
[0036]
Further, the cyan scanning light and the black scanning light pass through the two-layer fθ lens 35, respectively, and the cyan scanning light is reflected by the mirror 36, passes through the long WTL 37, and passes through the mirrors 38 and 39. Irradiated onto the photosensitive drum 5 of the photosensitive unit 2C.
Further, the scanning light for black is reflected by the mirror 41, passes through the long WTL 42, and is irradiated onto the photosensitive drum 5 of the photosensitive unit 2D via the mirrors 43 and 44.
[0037]
The duplex unit 7 shown in FIG. 3 includes a pair of conveyance guide plates 45a and 45b and a plurality of pairs (four sets in this example) of conveyance rollers 46, and forms a duplex image on both sides of the transfer paper. In the image forming mode, the transfer paper P on which an image is formed on one side and conveyed to the reversing conveyance path 54 of the reversing unit 8 and switched back is received, and the transfer paper P is provided with the photosensitive units 2A to 2D. Re-carry toward the image area.
[0038]
The reversing unit 8 includes a plurality of paired transport rollers and a plurality of paired transport guide plates. As described above, the reversing unit 8 reverses the transfer paper P when double-sided image formation is carried out to the double-sided unit 7. The transfer paper P after image formation is discharged out of the machine in the same orientation, or the paper is reversed outside and turned out of the machine.
Separating sheet feeding units 55 and 56 for separating and feeding the transfer sheets P one by one are provided in the sheet feeding unit in which the sheet feeding cassettes 11 and 12 are provided.
[0039]
This small printer employs a roller curvature separation method using the transfer belt 3, and four transfer brushes 57 are provided inside the transfer belt 3 in correspondence with the four photosensitive drums 5, respectively. .
[0040]
In this small printer, when the image forming operation is started, each photosensitive drum 5 rotates in the clockwise direction in FIG. The surface of each photosensitive drum 5 is uniformly charged by applying a voltage between the photosensitive drum 5 and the charging roller 14 of each charging device.
The charging unit 6 irradiates the charged surface of the photosensitive drum 5 of the photosensitive unit 2A with laser light corresponding to the yellow image.
[0041]
Further, a laser beam corresponding to a cyan image is written on the charging surface of the photosensitive drum 5 of the photosensitive unit 2B by the writing unit 6, and a magenta image is applied to the charging surface of the photosensitive drum 5 of the photosensitive unit 2C. Further, a laser beam corresponding to a black image is irradiated on the charging surface of the photosensitive drum 5 of the photosensitive unit 2D, and a latent image corresponding to each color is formed thereon.
Each latent image reaches the position of the developing devices 10A, 10B, 10C, and 10D by the rotation of the photosensitive drum 5, and is developed there by toners of yellow, magenta, cyan, and black, and then is divided into four colors. Toner image.
[0042]
On the other hand, the transfer paper P is fed from the selected paper feed stage of the paper feed cassette 11 or 12 by the separation paper feed unit 55 or 56, and the pair of registration rollers provided immediately before the photosensitive unit 2A. 59, the toner image is conveyed between the photosensitive drum 5 of the photosensitive unit 2A and the transfer belt 3 at an accurate timing coincident with the toner image formed on each photosensitive drum 5.
[0043]
At that time, the transfer paper P is charged to a positive polarity by a paper suction roller 58 disposed in the vicinity of the entrance of the transfer belt 3, and thereby electrostatically attracted to the surface of the transfer belt 3.
Then, while the transfer paper P is attracted to the transfer belt 3 and is conveyed in the same direction by the rotation of the transfer belt 3 in the direction of arrow A, yellow, magenta, cyan, and cyan are transferred to the upper surface in FIG. Each black toner image is sequentially transferred, and when passing through the photoreceptor unit 2D, a full-color toner image of four colors superimposed is formed.
[0044]
The transfer paper P is heated and pressed by the fixing device 9 to melt and fix the toner image, and then passes through the paper discharge system corresponding to the designated mode, and then the paper discharge tray 26 at the upper part of the apparatus main body. Or the paper is fed straight from the fixing device 9 and passes through the reversing unit 8 and is ejected straight.
[0045]
Alternatively, when the double-sided image forming mode is selected, the sheet is sent to the reversing conveyance path 54 in the reversing unit 8 described above, then switched back and conveyed to the double-sided unit 7, and is fed again from there to the photosensitive unit. The image forming unit provided with 2A to 2D is discharged after an image is formed on the back surface.
Thereafter, when two or more image formations are instructed, the above-described image forming process is repeated.
[0046]
By the way, as described with reference to FIGS. 1 and 2, the small printer has a roller cleaning member 49 for cleaning the outer peripheral surface of the elastic member 17 formed in a roller shape of the charging roller 14, and the roller cleaning is performed. The member 49 is configured to swing in the axial direction of the charging roller 14 (the direction indicated by arrow E in FIG. 1) by a roller cleaning member swinging mechanism 70.
[0047]
Accordingly, the outer peripheral surface of the elastic member 17 of the charging roller 14 is contaminated by toner or dust floating in the image forming apparatus, but the dirt can be cleaned by the roller cleaning member 49. Charging performance can be obtained.
[0048]
If the roller cleaning member 49 is always in contact with the charging roller 14 at the same position in the axial direction of the charging roller, the roller cleaning member 49 is clogged and the cleaning performance is deteriorated. In the printer, the roller cleaning member 49 is swung in the axial direction of the charging roller 14 by the roller cleaning member swinging mechanism 70, so that the axial contact position between the roller cleaning member 49 and the charging roller 14 always changes. .
Accordingly, good cleaning properties can be maintained over a long period of time.
[0049]
That is, in this small printer, by driving the motor 74 shown in FIG. 1, the cam 75 formed in a shape in which the cam height changes from H ₁ to H ₂ is rotated during one rotation as shown in FIG. 1, the bracket 71 in which the cam contact portion 72a is pressed against the cam 75 by the urging force of the coil spring 76 and the roller cleaning member 49 together with the roller cleaning member 49 are only strokes of H ₂ -H ₁ (FIG. 6). By swinging, the axial contact position of the roller cleaning member 49 with the charging roller 14 is changed.
[0050]
A roller cleaning member swinging mechanism 70 that swings the roller cleaning member 49 is a part of a reinforcing bead 72 that is formed to reinforce a bent portion of a sheet metal bracket 71 that holds the roller cleaning member 49. 10 is used as a cam contact portion 72a that engages with the cam 75. Therefore, it is necessary to use the roller 103 that is in rolling contact with the cam 105 described in FIG. 10 and the guide pin 104 that rotatably supports the roller 103. Absent.
As a result, the cost can be reduced by the reduction in the number of parts. Further, the number of assembling steps can be reduced as the number of parts is reduced.
[0051]
Note that it is effective that the reinforcing bead 72 formed on the bracket 71 by drawing (pressing) has an arc shape as shown in FIG.
In this way, the cam contact portion 72a formed in the arc shape comes into contact with the cam surface 75a of the cam 75 as shown in FIG. The cam abutting portion 72a moves accurately along the cam surface 75a.
Further, the longitudinal cross-sectional shape of the reinforcing bead 72 may be V-shaped and the tip thereof is R-shaped.
[0052]
On the other hand, when a shape having a flat surface portion 72b such as a reinforcing bead 72 'having a vertical cross-sectional shape in FIG. 9 is used, the flat surface portion 72b also serving as the cam contact portion is a portion of the cam surface 75a as shown in the figure. Since the flat surface portion 72b cannot abut against the skirt portion, the stroke at which the roller cleaning member 49 actually swings is the above-described stroke H ₂ -H ₁ (FIG. 6)).
[0053]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
According to the image forming apparatus of claims 1 and 2 and the image carrier unit of claim 3, the reinforcing bead provided to reinforce the bent portion of the sheet metal bracket for holding the roller cleaning member is associated with the cam. Since it is also configured to serve as a cam contact portion to be combined, it is not necessary to provide a roller for rolling contact with the cam or a guide pin for rotatably supporting the roller in the mechanism for swinging the roller cleaning member. The number of parts can be reduced and the cost can be reduced. Further, the number of assembling steps can be reduced as the number of parts is reduced.
[0054]
According to the image forming apparatus of the second aspect, since the cross-sectional shape of the reinforcing bead is an arc shape, the cam contact portion of the reinforcing bead makes point contact with the cam, so that the roller cleaning swung by the cam is performed. The bracket holding the member moves accurately along the cam surface of the cam.
[Brief description of the drawings]
FIG. 1 is a front view showing a configuration in the vicinity of a charging device of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view showing one end portion of a bracket for holding a roller cleaning member provided in the image forming apparatus.
FIG. 3 is an overall configuration diagram showing a small printer as an example of the image forming apparatus.
FIG. 4 is a configuration diagram illustrating an example of a photoconductor unit that is an image carrier unit provided in the image forming apparatus.
5 is a configuration diagram showing a writing unit provided in the image forming apparatus of FIG. 3. FIG.
FIG. 6 is a perspective view showing a cam that is a component of a roller cleaning member swinging mechanism provided in the image forming apparatus.
FIG. 7 is a longitudinal sectional view showing a reinforcing bead having an arcuate longitudinal section formed on a bracket for holding a roller cleaning member.
FIG. 8 is a cross-sectional view for explaining a state where the cam contact portion is in point contact with the cam surface in the case of the arc-shaped cam contact portion shown in FIG. 7;
FIG. 9 is a cross-sectional view for explaining a state in which the cam contact portion does not contact the skirt portion of the cam surface when the longitudinal cross-sectional shape is a reinforcing bead having a flat portion.
FIG. 10 is a schematic view showing a configuration in the vicinity of a cam of a mechanism for swinging a conventional roller cleaning member.
[Explanation of symbols]
2A to 2D: photoconductor unit (image carrier unit)
5: Photosensitive drum (image carrier) 14: Charging roller 49: Roller cleaning member 60: Roller cleaning device (roller cleaning means)
70: Roller cleaning member swing mechanism 71: Bracket 72: Reinforcement bead 72a: Cam contact part 74: Motor (cam rotating means) 75: Cam 76: Coil spring (biasing means)

Claims (3)

An image carrier, a charging roller disposed opposite to the image carrier to charge the image carrier, and cleaning by bringing a roller cleaning member into sliding contact with the outer peripheral surface of the charging roller and cleaning the roller cleaning member An image forming apparatus comprising: a roller cleaning unit having a roller cleaning member swinging mechanism swinging in the axial direction of the charging roller;
The roller cleaning member swing mechanism holds the roller cleaning member and bends one end into a substantially L shape so that the cam contact is formed so as to protrude outward from the bent portion. A bracket made of sheet metal having a reinforcing bead that also serves as a portion, a cam that is in contact with a portion of the reinforcing bead protruding in the swinging direction of the roller cleaning member, and rotated by a cam rotating means; An image forming apparatus, comprising: a biasing member that biases the protruding portion of the cam to press against the cam. The image forming apparatus according to claim 1, wherein a cross-sectional shape of the reinforcing bead is an arc shape. The image forming apparatus main body mounted on the image forming apparatus according to claim 1 or 2, wherein the charging roller, the roller cleaning means, and the image supporting body are configured as an integral unit. An image carrier unit characterized in that it can be attached to and detached from the image carrier unit.

Images