JPH07281513A - Contact electrifier, process cartridge and image-forming device - Google Patents

Abstract

PURPOSE:To prevent unsatisfactory electrification by removing foreign matters accumulating below an electrifying film. CONSTITUTION:An electrification nip N is formed by holding the fixed end 21b of the electrifying film 21 by means of a rotary holding member 22 and by bringing its electrifying surface 21a at its free end 21c into contact with the surface of a photosensitive drum 1. Residual toner is accumulated below the electrifying surface 21a after escaping a cleaner 6. The electrifying surface 21a of the electrifying film 21 is rotated and driven via the holding member 22 in the direction shown by the arrow R22. Foreign matters are wiped off by sliding the electrifying surface 21a against a cleaning member 25 made of sponge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact charging device, a process cartridge and an image forming apparatus mounted on an image forming apparatus such as an electrophotographic copying machine and a laser beam printer.

[0002]

2. Description of the Related Art Conventionally, a charging device mounted on an image forming apparatus such as an electrophotographic copying machine is in a non-contact state depending on whether the charging member is in non-contact or in contact with the surface (charged surface) of a body to be charged. They are roughly classified into a charging device and a contact charging device. The advantage of the latter contact charging device is that the charging voltage is lower than the corona charger that represents the former non-contact charging device.
It is mentioned that the amount of generated ozone is small, therefore a device for removing ozone is unnecessary and the configuration can be simplified, and maintenance-free is easy to realize.

As the charging member of the contact charging device, a charging roller having a roller shape, a charging blade having a plate shape, a charging film having a film shape, and the like are known. Of these, in addition to the general advantages of the contact charging device, the charging film has a lower contact pressure than the charging roller and the charging blade, and is less likely to damage the body to be charged, and has a simple structure. It has advantages such as

FIG. 9 shows a schematic structure of an image forming apparatus which charges by a charging film. This image forming apparatus is
The photosensitive drum 1 is provided as a member to be charged, which is rotationally driven in the direction of arrow R1 at a predetermined process speed. The surface of the photosensitive drum 1 is uniformly charged by the contact charging device 2, and subsequently, an electrostatic latent image is formed by irradiation of laser light according to image information of the exposure means 3. Toner is attached to the electrostatic latent image by the developing roller of the next developing device 4 to form a toner image. The toner image formed on the photosensitive drum 1 is transferred by the transfer roller of the transfer device 5 onto the transfer material P which is supplied at a predetermined timing by a paper supply unit (not shown). The transfer material P after the toner image transfer is
The toner image on the surface is fixed by a fixing device (not shown), and the image formation is completed. On the other hand, after the toner image is transferred, the residual toner remaining on the surface of the photosensitive drum 1 without being transferred to the transfer material P is removed by the cleaner 6, and is subjected to the next image forming process starting from charging.

The contact charging device 2 described above holds a rectangular flexible charging member (hereinafter referred to as "charging film" 21) long in the generatrix direction of the photosensitive drum 1 and one end of the charging film 21 as a fixed end. The charged surface 21 on the other free end side
A holding member 22 that a is brought into contact with the surface of the photosensitive drum 1 to form the charging nip portion N, and a charging voltage obtained by superposing the vibration voltage V _AC and the DC voltage V _{DC on} the charging film 21 via the holding member 22. And a power supply 23 for applying The vibration voltage V _AC is equal to the charging start voltage 2 of the photosensitive drum 1.
The peak-to-peak voltage V _PP is more than double. Such a charging voltage is applied to the charging film 21 that is in contact with the surface of the photosensitive drum 1, and the entire surface of the photosensitive drum 1 is uniformly charged by the rotation of the photosensitive drum 1 in the direction of arrow R1.

[0006]

However, when the above-mentioned charging film 21 is used as the charging member, foreign matter such as residual toner and paper dust (hereinafter simply referred to as "foreign matter") is accumulated on the charged surface, resulting in poor charging. There was a problem that occurs.

In the image forming apparatus shown in FIG. 9, foreign matters such as residual toner and paper dust after transfer are arranged on the upstream side of the contact charging device 2 in the rotation direction of the photosensitive drum 1 (direction of arrow R1). It is removed by the cleaner 6. However,
There is a foreign substance that has not been removed by the cleaner 6 and has passed through the cleaner 6 and is conveyed to the contact charging device 2. The foreign matter collects in the charging nip portion N of the charging film 21 and gradually accumulates to contaminate the charging surface 21a. When the charging surface 21a is contaminated, discharge for charging is hindered at the contaminated part, and charging failure occurs. Further, under high temperature and high humidity, the accumulated foreign matter absorbs moisture, which may cause vertical stripe-shaped charging failure. In addition, these foreign matters are
In the case of a charging roller, it is rotated, and in the case of a charging blade, it is brought into contact with the surface of the photosensitive drum 1 in a non-contact manner with a minute gap therebetween, so that they are less likely to be accumulated.

Therefore, an object of the present invention is to provide a contact charging device, a process cartridge, and an image forming apparatus which prevent foreign matters from being accumulated in a film-shaped charging member to eliminate charging failure. is there.

[0009]

The present invention has been made in view of the above circumstances, and a flexible film-like charging member is brought into contact with a member to be charged, and a charging voltage is applied to the charging member. In a contact charging device for applying a charge to the charged body, the charging member is movably held, the charging member at the time of charging is arranged at a charging position, and the charging surface of the charging member is the charged body. A holding member that contacts the surface to form a charging nip portion, and a moving range of a portion of the charging surface that corresponds to the charging nip portion when the charging member is moved through the holding member. And a cleaning member.

The charging member may have a fixed end held by the holding member and a free end on which the charging nip portion is formed.

The moving operation of the charging member by the holding member can be performed when the charging member is not charged.

The moving operation can be a rotating operation or a swinging operation.

The cleaning member may have a magnet.

A voltage having a polarity opposite to the charge polarity of the developer may be applied to the cleaning member.

Next, in a process cartridge detachably attached to the main body of the image forming apparatus, the contact charging device described in any one of the above and at least the member to be charged are integrally incorporated into a cartridge container to form a cartridge. It is characterized by

Next, the image forming apparatus mounts the above process cartridge on the main body of the image forming apparatus,
A charged body, a contact charging device for uniformly charging the charged body, and a latent image forming means for forming an electrostatic latent image on the charged body,
And a developing unit for developing the electrostatic latent image.

Another image forming apparatus is the contact charging device described above, a charged body whose surface is charged by the contact charging device, and a latent image forming an electrostatic latent image on the charged body. It is characterized by comprising a forming means and a developing means for developing the electrostatic latent image.

[0018]

According to the above structure, the charging surface of the charging member can be moved by moving the holding member.
Further, since the cleaning member is arranged within the moving range of the charging surface at this time, the charging surface is rubbed against the cleaning member by the movement. Therefore, the foreign matter attached to the charged surface is wiped off by the cleaning member.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. <Embodiment 1> FIG. 1 schematically shows a contact charging device according to the present invention and an image forming apparatus equipped with the contact charging device.

The image forming apparatus shown in FIG. 1 includes an electrophotographic photosensitive member (hereinafter referred to as "photosensitive drum") 1 which is a cylindrical member to be charged. The photosensitive drum 1 includes a grounded aluminum drum base 11, and an organic photoconductor (OPC) as a photosensitive layer 12 formed in layers on the outer peripheral surface of the drum base 11. Photosensitive drum 1
Has an outer diameter of 30 mm as a whole and is rotationally driven in the direction of arrow R1 by a driving means (not shown).

Above the photosensitive drum 1, a contact charging device 2 is provided.
Is provided. The contact charging device 2 includes a flexible film-shaped member (hereinafter referred to as “charging film”) 21 as a charging member. As the material forming the charging film 21, metal foil, conductive plastic,
Resin materials etc. can be used.
A conductive material such as carbon is dispersed to adjust the resistance value to a medium resistance (1
It is configured to be about 0 ⁵ to 10 ¹⁰ Ω · cm).
The charging film 21 is formed in a rectangular shape that is long in the axis 1a direction of the photosensitive drum 1, and the length of its long side is set longer than the charging area of the photosensitive drum 1 in the axis 1a direction. Be present. One of short sides of the charging film 21 is fixed to the holding member 22 as a fixed end 21b, and the charging surface 21a on the other free end 21c side is in contact with the surface of the photosensitive drum 1. This contact is caused by the charging film 2
It is done lightly by the elasticity of 1 itself, and by this abutment,
A charging nip portion N is formed on the charging film 21 with the surface of the photosensitive drum 1. The holding member 22 is rotatably arranged around the shaft 22a, and is rotationally driven by a driving unit (not shown) in the direction of arrow R22 at a predetermined timing, for example, when it is not charged. By this rotation driving, the entire charging film 21 is rotated in the direction of arrow R22. Note that, as shown in FIG. 1, a position where the charging film 21 forms a charging nip portion with the photosensitive drum 1 is a charging position.

The holding member 22 is connected to a power source 23, and the power source 23 supplies a bias voltage (V _DC + V _AC ) in which an alternating current V _AC is superimposed on a direct current V _DC via the holding member 22. Apply to. As a result, the charging film 21 has a charging surface 2 that comes into contact with or approaches the surface of the photosensitive drum 1.
1a (hereinafter, "charging surface" means a surface on which the charging film 21 is disposed at the charging position shown in FIG. 1 and is actually used for charging when a voltage is applied thereto. That is, the charging nip portion N The portion corresponding to and the vicinity thereof) are rotated in the direction of arrow R1 via the photosensitive drum 1.
The surface is uniformly charged to a predetermined polarity (negative polarity in this embodiment).

A cleaning member 25 is disposed within the rotation range of the charging surface 21a of the charging film 22 when the holding member 22 is rotated in the direction of arrow R22. That is, the charging surface 21a is configured to come into contact with the cleaning member 25 by the rotation of the charging film 21 accompanying the rotation of the holding member 22 (detailed later).

An electrostatic latent image is formed on the surface of the photosensitive drum 1 uniformly charged by the contact charging device 2 by the laser light of the exposing means 3. The laser light emitted corresponding to the image information removes the negative charges in the portion corresponding to the image information and forms an electrostatic latent image on the surface of the photosensitive drum 1.

The electrostatic latent image is developed by the developing device 4. The developing device 4 attaches the negatively charged toner carried and conveyed by the developing roller to the electrostatic latent image at the developing position to visualize the electrostatic latent image as a toner image.

The toner image formed on the photosensitive drum 1 is
The image is transferred onto the transfer material P by the transfer device 5. A transfer material is supplied to the photosensitive drum 1 from a sheet feeding / conveying means (not shown) at a predetermined timing, and the supplied transfer material P is charged with the toner image on the photosensitive drum 1 in the opposite polarity to the toner. Transferred by the transferred transfer device 5.

The toner image on the surface of the recording material P after the transfer of the toner image is fused and fixed by a fixing device (not shown), and the image formation is completed.

On the other hand, the photosensitive drum 1 after the toner image transfer is
Foreign matter such as residual toner and paper dust remaining on the surface without being transferred to the transfer material P is scraped off by the cleaning blade of the cleaner 6, and is supplied to the next image forming process starting from charging.

By the way, foreign matter such as residual toner and paper dust adhered to the surface of the photosensitive drum 1 cannot be completely removed by the cleaner 6, and a part of the foreign matter that has slipped through the cleaner 6 is indicated by an arrow mark on the photosensitive drum 1. The contact charging device 2 is also reached with the rotation in the R1 direction. Then, the foreign matter that has arrived is accumulated and contaminates the charging surface 21 a of the charging film 21. Due to this contamination, charging failure occurs as described above.

Therefore, in the present invention, the above-mentioned foreign matter is removed to prevent charging failure. That is, the contact charging device 2 according to the present invention incorporates a mechanism for removing foreign matter.

As described with reference to FIG. 1, the charging film 21 is fixed to the one fixed end 21b by the holding member 22.
Is held, and the charging surface 21a on the other free end 21c side contacts the surface of the photosensitive drum 1 to form a charging nip portion with the surface of the photosensitive drum 1. Further, the holding member 22 is
The shaft 22a is driven to rotate in the direction of arrow R22 by driving means (not shown) on the image forming apparatus main body side. By this rotation drive, the charging surface 21a also rotates in the direction of arrow R22. The cleaning member 25 described above is arranged within the rotation range of the charging surface 21a at this time. The cleaning member 25 is made of, for example, a sponge-like material such as foaming urethane. Cleaning member 2
5, the rotation of the holding member 22 in the direction of arrow R22
The charging surface 21a is rubbed, and at this time, the foreign matter attached to the charging surface 21a is wiped by the cleaning member 25. The rotation operation of the holding member 22 is performed when it is not necessary to charge the photosensitive drum 1, that is, when the image is not formed. Non-image formation includes, for example, startup of the image forming apparatus, interval between prints, and wait time. The holding member 22 is rotated once or several times at these timings, and is controlled to return to the position shown in FIG. 1 after rotation. The number of rotations of the holding member 22 is
It may be set appropriately according to the state of adhesion of foreign matter.

Next, the foreign matter removing operation will be briefly described with reference to FIGS. In addition, FIG.
(B), (c), and (d) illustrate the case where the rotation angle of the holding member 22 is 0 °, 90 °, 180 °, and 270 °, respectively.

When the rotation angle is 0 ° in (a), that is, when the charging film 21 is arranged at the charging position, the charging film 21 is in contact with the surface of the photosensitive drum 1, so that the charging nip portion is formed. On the charging surface 21 on the upstream side of N, the foreign matter Y that has passed through the cleaner 6 is attached and gradually accumulated. As described above, the foreign matter Y causes a charging failure such as vertical stripes especially under high temperature and high humidity.

As shown in (b), the holding member 22 has approximately 90
When rotated, the charging film 21 starts to contact the cleaning member 25 due to its elasticity, and when the charging film 21 further rotates, the foreign matter Y adhering to the charging surface 21a rubs against the cleaning member 25. Is
As shown in (c), when rotated by 180 °, the foreign matter Y is completely wiped from the charging film 21. Since the charging film 21 is made of a flexible film having appropriate elasticity, the charging film 21 is rotated by the holding member 22 in the direction of arrow R22, as shown in FIG.
As in (b) and (c), the vicinity of the charging surface 21a can be evenly rubbed against the cleaning member 25 while flexing flexibly, so that the foreign matter Y can be effectively wiped off.

When the holding member 22 is further rotated after the foreign matter Y is wiped off, the charging film 21 is separated from the cleaning member 25 and passes through the state rotated by 270 ° in (d), as shown in (a). Return to the initial charging position. As a result, the photosensitive drum 1 can be charged again.

The operation of returning to (a) through (a) to (d) is performed once or several times in the non-image forming apparatus to remove the foreign matter Y on the charging surface 21a. It is possible to prevent charging failure due to the foreign matter Y.

Next, referring to FIG. 3, the charging film 21
The positional relationship between the cleaning member 25 and the cleaning member 25 will be described. As shown in the figure, by rotating the holding member 22 by 90 °,
Consider the case where the fixed end 21b of the charging film 21 is arranged above and the free end 21a side is horizontally extended to the left in the figure. In this state, if the distance between the fixed end 21b of the charging film 21 and the charging surface 21a (in the figure, the portion of the charging surface 21 corresponding to the charging nip portion N is shown) is D, the fixing is performed. If the distance d between the end 21b and the side surface 25a of the cleaning member 25 on the holding member 22 side is set to ⅔ or less of the above-mentioned distance D, the cleaning member 25 ensures that the charged surface 21a to which foreign matter is easily attached is attached. By rubbing, foreign matter can be satisfactorily removed.
Further, when the distance d is set to D / 2 or less, the cleaning performance of the cleaning member 25 is further improved.

As described above, the contact charging in which the flexible film-like charging film 21 is brought into contact with the surface of the photosensitive drum 1 and a charging voltage is applied to the charging film 21 to charge the photosensitive drum 1 In the apparatus 2, the charging film 21 is rotated by the holding member 22, and the cleaning member 25 is arranged within the rotation range of the charging surface 21a at the time of this rotation, so that the cleaning member 25 slides the charging surface 21a of the charging film 21. Since it can be rubbed, the foreign material adhering to the charging surface 21a can be effectively removed by the cleaning member 25. Therefore, it is possible to prevent the charging failure due to the adhesion of the foreign matter to the charging surface 21a of the charging film 21. <Second Embodiment> FIG. 4 shows a second embodiment of the present invention. The present embodiment is an embodiment effective when the toner used for developing the electrostatic latent image formed on the photosensitive drum 1 is a magnetic toner, and the cleaning member 2 of the above-described Embodiment 1 is used.
A magnet 26 is provided in the reference numeral 5.

By thus providing the magnet 26 in the cleaning member 25, it becomes possible to more effectively remove the magnetic residual toner, which is the main part of the foreign matter Y contaminating the charging surface 21a, with the help of magnetic force. Further, there is an effect of preventing the residual toner once removed from the charging film 21 from scattering away from the cleaning member 25. <Third Embodiment> FIG. 5 shows a third embodiment of the present invention. In this embodiment, the cleaning member 25 of the first embodiment is used.
In addition, a voltage for promoting cleaning is applied. The voltage that promotes cleaning here is
This is a voltage having a polarity opposite to the charge polarity of the toner used for development. Specifically, in this embodiment, since toner having a negative charge polarity is used, during the cleaning operation (holding member 2
2), a DC voltage of +1 kV is applied to the cleaning member 25 by the power supply 27.

By applying such a voltage to the cleaning member 25, the negative polarity toner adhering to the charging film 21 could be effectively cleaned.

Further, the voltage applied to the cleaning member 25 is effective even if an AC voltage of 1 to several kV is superposed on the above DC voltage. Further, it is obvious that the cleaning member 25 may be set to a constant potential (eg, grounded) and a voltage having the same polarity as the charging polarity of the toner may be applied to the cleaning film 25 on the charging film 21 side. <Fourth Embodiment> FIGS. 6 and 7 show a fourth embodiment of the present invention.
In the embodiment of FIG. 6, the holding member 2 of the cleaning member 25 is used.
The edge portion 25b is formed on the side facing the surface 2, and the charging surface 21a of the charging film 21 is rubbed by the edge portion 25b. According to this, the charged surface 21a
It has the effect of removing foreign matter adhering to the. Further, in the embodiment of FIG. 7, the cleaning member 25 is provided with the uneven portion 25c at the portion facing the holding member 22, so that the charging surface 21a of the charging film 21 can be inspected several times. It is possible to effectively remove foreign matter.

The member indicated by 13 in FIGS. 6 and 7 is
It is a receiving member for preventing foreign matter removed from the charging surface 21a from spilling from the cleaning member 25 and dropping onto the photosensitive drum 1 again. <Fifth Embodiment> FIG. 8 is an example in which the contact charging device 2 according to the present invention is applied to a process cartridge C.

The process cartridge C includes a cartridge container 70, a photosensitive drum 1, and the contact charging device 2 described above.
The developing device 4 and the cleaner 6 are integrally incorporated. The above-mentioned photosensitive drum 1 is rotatably supported by the cartridge container 70 in the direction of arrow R1, and the contact charging device 2 has the charging film 21, the holding member 22, and the cleaning member 25 as described above, and the developing device 4
Has a toner container 41 for accommodating toner, a developing roller 42 for adhering toner to the electrostatic latent image on the photosensitive drum 1, a doctor blade 43 for regulating the layer thickness of the toner on the developing roller 42, and the cleaner 6 Is a waste toner container 6
1. It has a cleaning blade 62. As the process cartridge C according to the present invention, at least the charged body such as the photosensitive drum 1 and the above-mentioned contact charging device 2 for charging the charged body, that is, a mechanism for removing foreign matter attached to the charging film 21 are provided. Any device having the contact charging device 2 is sufficient.

The process cartridge C having the above structure is
Since the charging film 21 is provided as the charging member, the overall configuration is simple and inexpensive, and since the cleaning member 25 for removing the foreign matter adhering to the charging film 21 is provided, the foreign matter can clean the charged surface. It is possible to prevent defective charging due to contamination.

Further, in the image forming apparatus in which the process cartridge C having the above-described structure is detachably mounted on the main body of the image forming apparatus, there is no charging failure, so that the image failure due to the charging failure can be effectively prevented.

The contact charging device 2 according to the present invention is not limited to the case where it is mounted on the apparatus main body through the process cartridge C having the above-mentioned structure, but is a type which is directly mounted on the apparatus main body without using the process cartridge C. Even when it is mounted on the image forming apparatus, it is possible to effectively prevent charging failure due to charging failure with a simple configuration.

As described above, in the embodiment, the contact charging device 2
The charging film 21 and the holding member 2 are provided as long as the foreign matter attached to the vicinity of the charging surface 21a of the charging film 21 can be effectively removed by rubbing against the cleaning member 25.
2. The shapes and positions of the cleaning member 25 and the like are not limited to those described above. For example, the holding member 22 may swing rather than rotate. That is, when it is not possible to secure a sufficient space for rotating the charging film 21 due to design restrictions or the like, for example, after moving the charging film 21 in a clockwise direction to remove foreign matter by rubbing, Alternatively, the charging film 21 may be returned in the counterclockwise direction, that is, a so-called swinging operation may be performed to restore the charging time. Further, when attaching the charging film 21 to the holding member 22, both ends may be fixed ends without providing the charging film 21 with the free ends 21c, and the charging film 21 may be configured in a loop shape as a whole. In this case, the central portion of the loop may be brought into contact with the surface of the photosensitive drum 1 to form the charging surface 21a. With this configuration, the photosensitive drum 1
The contact with the surface can be performed more stably.

[0048]

As described above, according to the present invention,
A flexible film-shaped charging member is brought into contact with the member to be charged,
In a contact charging device that performs a charging process by applying a charging voltage to this charging member, the charging surface of the charging member is moved through a holding member, so that the charging surface is rubbed against the cleaning member and attached to the charging surface. The foreign matter can be wiped off, and charging failure due to the foreign matter adhering to the charged surface can be prevented.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a configuration around a contact charging device and a photosensitive drum according to a first exemplary embodiment.

2 (a), (b), (c), and (d) are the first embodiment.
FIG. 6 is a diagram showing a foreign material removing operation by the cleaning member of FIG.

FIG. 3 is a diagram showing the relationship between the length of the charging film and the arrangement position of the cleaning member in the first embodiment.

FIG. 4 is a vertical cross-sectional view showing the configuration of a contact charging device according to a second embodiment.

FIG. 5 is a vertical cross-sectional view showing the configuration of a contact charging device according to a third embodiment.

FIG. 6 is a vertical sectional view showing the configuration of a contact charging device according to a third embodiment.

FIG. 7 is a vertical cross-sectional view showing the configuration of another contact charging device according to the fourth embodiment.

FIG. 8 is a vertical cross-sectional view showing the configuration of a process cartridge of Example 5.

FIG. 9 is a vertical cross-sectional view showing a configuration around a conventional contact charging device and a photosensitive drum.

[Explanation of symbols]

 1 Charged Member (Photosensitive Drum) 2 Contact Charging Device 3 Exposure Means 4 Developing Device 5 Transfer Device 6 Cleaner 11 Drum Base 12 Photosensitive Layer 21 Charging Member (Charging Film) 21a Charging Surface 21b Fixed End 21c Free End 22 Holding Member 23 Power Supply 25 Cleaning Member 26 Magnet C Process Cartridge N Charging Nip P Transfer Material Y Foreign Material

Claims (10)

[Claims] 1. A contact charging device for charging a flexible film-shaped charging member to an object to be charged and applying a charging voltage to the charging member to move the object to be charged. And a holding member that holds the charging member at a charging position during charging, forms a charging nip portion by bringing the charging surface of the charging member into contact with the surface of the member to be charged, and the holding member. A contact charging device, comprising: a cleaning member within a moving range of a portion corresponding to the charging nip portion on the charging surface when the charging member is moved via the charging member. 2. The contact charging device according to claim 1, wherein the charging member has a fixed end held by the holding member and a free end on which the charging nip portion is formed. 3. The contact charging device according to claim 1, wherein the moving operation of the charging member by the holding member is performed when the charging member is not charged. 4. The contact charging device according to claim 1, wherein the moving operation is a rotating operation. 5. The contact charging device according to claim 1, wherein the moving operation is a swinging operation. 6. The contact charging device according to claim 1, wherein the cleaning member has a magnet. 7. The contact charging device according to claim 1, wherein a voltage having a polarity opposite to the charging polarity of the developer is applied to the cleaning member. 8. A process cartridge detachably mountable to an image forming apparatus main body, wherein the contact charging device according to claim 1 and at least an object to be charged are integrally formed in a cartridge container. A process cartridge characterized by being incorporated into a cartridge. 9. By mounting the process cartridge according to claim 8 on an image forming apparatus main body,
A contact charging device for uniformly charging the charged body, a latent image forming means for forming an electrostatic latent image on the charged body, and a developing means for developing the electrostatic latent image. Image forming apparatus. 10. The contact charging device according to claim 1, a charged body whose surface is charged by the contact charging device, and a latent image forming an electrostatic latent image on the charged body. An image forming apparatus comprising: an image forming unit; and a developing unit for developing an electrostatic latent image.