JP2001092334A - Process cartridge and electrophotographic image forming device equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an abrasion of the surface of both end parts of a photoreceptor drum and to improve the durability. SOLUTION: In the process cartridge, a plurality of process means 8a and 10d are arranged around a photosensitive drum 4 by a prescribed distance and they can integrally be attached/detached to/from an image forming device. Distance guarantee members 10j and 8n arranged on both ends of the the plurality of process means are pressed to a photosensitive drum 7 in different positions in the axial direction of the photosensitive drum 7 to guarantee the distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus and a process cartridge detachable from a main body of the apparatus.

Here, an electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming method. And, as an example of the electrophotographic image forming apparatus,
For example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, and the like), a facsimile machine, a word processor, and the like are included.

[0003]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image process, an electrophotographic photosensitive member and a process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is used as a main body of the image forming apparatus. A process cartridge system which can be attached to and detached from is used. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a serviceman, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in image forming apparatuses.

[0004] Such a process cartridge includes a developing unit in which a developing frame incorporating a developing roller and a developing blade, a toner frame accommodating a toner as a developer, a photosensitive drum and a cleaning blade. A cleaning frame in which a cleaning frame incorporating the same is rotatably connected has been awarded.

[0005]

It is difficult to reduce the size of the process cartridge having the cleaning frame.
Therefore, the transfer residual toner is collected by the charging device without the cleaning blade, but the process cartridge can be reduced in size by finally collecting it in the developing device.

Here, a charging device using a magnetic brush has been proposed in recent years, and the use of the charging device has made it possible to achieve the above object.

However, in this case, the charging roller used for charging the magnetic brush must be held at a predetermined interval with high accuracy with respect to the photosensitive drum, like the developing roller. That is, there arises a problem that both the developing roller and the charging roller are accurately held on the photosensitive drum.

The present invention is a process cartridge which is detachable from an electrophotographic image forming apparatus and does not have a cleaning frame. The process cartridge accurately holds a plurality of process means such as a developing roller and a charging roller on a photosensitive drum.
An object of the present invention is to provide a process cartridge having excellent durability.

[0009]

The main aspects of the present invention are as described below with reference to the claims.

According to a first aspect of the present invention, there is provided a process in which a plurality of processing means are disposed around an electrophotographic photosensitive drum at a predetermined distance, and these are detachable from an image forming apparatus main body as an integrated cartridge. In the cartridge, the distance is ensured by contacting the distance assurance members disposed at both ends of each of the plurality of process means with the electrophotographic photosensitive drum. A process cartridge that is disposed at a position that does not overlap with each other in the direction.

According to a seventh aspect of the present invention, there is provided a recording medium in which a plurality of process means are arranged at a predetermined distance around an electrophotographic photosensitive drum, and a process cartridge comprising these as an integrated cartridge is detachable. In the electrophotographic image forming apparatus for forming an image, a, the distance is assured by a distance assurance member disposed at both ends of each of the plurality of process means abutting on the electrophotographic photosensitive drum; The distance assurance member includes: mounting means for removably mounting a process cartridge disposed at a position that does not overlap with each other in the longitudinal direction of the electrophotographic photosensitive drum; and transport means for transporting the recording medium. An electrophotographic image forming apparatus comprising:

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

In the following description, the longitudinal direction refers to a direction crossing the transport direction of the recording medium and parallel to the recording medium. The short direction refers to a direction perpendicular to the long direction. The left and right are the left and right as viewed in the transport direction of the recording medium. Further, “above the developing device” means above the developing device in a mounted state.

FIG. 1 is a diagram showing an image forming apparatus to which the present invention is applied. The image forming apparatus includes an image forming unit 31 that forms a toner image on a photosensitive drum as an image carrier.
Y, 31C, and 31BK, an intermediate transfer belt 4a for transferring the toner image in a single transfer, a secondary transfer roller 40 as a transfer unit for transferring the toner image on the belt 4a to the recording medium 2, and the recording medium 2 to the intermediate transfer belt 4a. And a feeding unit for feeding the recording medium 2 to the transfer unit, a fixing unit, and a paper discharging unit.

Hereinafter, image formation will be described.

As shown in the figure, a paper cassette 3a for stacking and storing a plurality of recording media (for example, recording paper, OHP sheets, cloth, etc.) 2 is detachably mounted on the image forming apparatus. Paper feed cassette 3a by pickup roller 3b
Is separated one by one by a pair of retard rollers 3c, and is conveyed to a pair of registration rollers 3g by conveyance rollers 3d and 3f.

When the recording medium 2 is conveyed, the registration roller pair 3g stops rotating, and the recording medium 2 is corrected for skew by hitting the nip.

Process cartridge B including image carrier
In the case of the four-drum full-color system, four colors of yellow, magenta, cyan, and black are arranged in parallel in Y, BM, BC, and BB as shown in the figure. Each of the process cartridges BY, BM, BC, and BB is provided with an optical scanning system 1Y, 1M, 1C, and 1BK. After a toner image is formed on a photosensitive drum for each color by an image signal, transfer is performed. The toners of the respective colors are superimposedly transferred onto the intermediate transfer belt 4a running in the direction of the arrow by the rollers 4 (4Y, 4M, 4C, 4BK).

Thereafter, the recording medium 2 is sent to the secondary transfer roller 40 at a predetermined timing, and the toner image on the intermediate transfer belt 4a is transferred onto the recording medium 2, and the fixing device 5
Is discharged by the discharge roller pairs 3h and 3i, and is stacked on the tray 6 on the apparatus main body 14.

The image forming units 31Y, 31M, 31C,
31BK is a process cartridge BY, BM, BC, BB except for the optical scanning systems 1Y, 1M, 1C, 1BK.
Is composed. Since the configuration of the process cartridge is the same, the process cartridge BY will be described.

As shown in FIG. 2, the process cartridge B
Y is a device in which a charging unit, an exposure unit, a developing unit, and a transfer opening are provided around the photosensitive drum 7. In this embodiment, a two-component developer having a magnetic carrier powder is used.
Therefore, the photosensitive drum 7 used in the embodiment of the present invention
As the organic photoreceptor, a commonly used organic photoreceptor can be used. Desirably, an organic photoreceptor having a surface layer having a material having a resistance of 10 ² to 10 ¹⁴ Ω · cm or an amorphous When a silicon photoreceptor or the like is used, charge injection charging can be realized, which is effective in preventing ozone generation and reducing power consumption. Further, the chargeability can be improved.

Therefore, in the present embodiment, a photosensitive drum 7 having a negatively charged organic photosensitive member provided on a drum base made of aluminum is used.

The charging means is a magnetic brush charger 8 using a magnetic carrier. The charger 8 has a fixed magnet 8b disposed inside a hollow cylindrical charging roller 8a rotatably supported. After the transfer, the toner remaining on the photosensitive drum 7 is taken into the charger 8 which rotates in the direction of the arrow shown in the figure.

The charging roller 8a rotates in the same direction as the photosensitive drum 7, and its peripheral surface moves in a direction opposite to the moving direction of the peripheral surface of the photosensitive drum 7. The photoconductor drum 7 and the charging roller 8a are not contacted with a gap of about 0.2 to 1.0 mm, and are set so that the magnetic carrier can be charged in contact with the photoconductor drum 7. .

In the present embodiment, a developing method in which a two-component developer is brought into contact with the developing means (two-component non-contact development) is employed.

FIG. 2 shows the developing means 10 for two-component magnetic brush development used in the present embodiment. The developing sleeve 10d has a hollow cylindrical shape and is rotatably supported. A fixed magnet 10c is provided in the developing sleeve 10d.

The developing sleeve 10d rotates in the same direction as the photosensitive drum 7, and the peripheral surface moves in a direction opposite to the moving direction of the peripheral surface of the photosensitive drum 7. The photoconductor drum 7 and the developing sleeve 10d are not in contact with each other and have a gap of about 0.2 to 1.0 mm, and are set so that the developer can be developed while being in contact with the photoconductor drum 7. .

The toner mixed with the carrier is supplied by stirring screws 10g and 10h in a casing partitioned by a longitudinal partition wall 10f excluding both ends. The toner supplied from a toner supply container (not shown) is
g is dropped to one end side and is agitated while being sent in one direction in the longitudinal direction, passes through the portion without the partition wall 10f on the other end side, moves to one end side with the stirring screw 10h, and then moves to the partition wall 10f on one end side. The mixture is stirred and circulated while being fed by the stirring screw 10h through the portion without.

Here, the developing step of visualizing the electrostatic latent image formed on the photosensitive drum 7 by the two-component magnetic brush method using the developing device 10 and the circulation system of the developer will be described. First, the developer pumped up by the poles of the magnet 10c with the rotation of the developing sleeve 10d is regulated by a regulating blade 10e arranged perpendicular to the developing sleeve 10d in the process of being conveyed, and is placed on the developing sleeve 10d. A thin layer is formed. When the developer having a thin layer formed thereon is conveyed to the main developing pole, ears are formed by magnetic force. The electrostatic latent image on the photosensitive drum 7 is developed by the spike-shaped developer, and then the developer in the developing sleeve 10d is released by the repulsive magnetic field into the developing container 10
It is returned in a.

A DC voltage and an AC voltage are applied to the developing sleeve 10d from a power source (not shown). Generally, in the two-component developing method, when an AC voltage is applied, the developing efficiency increases,
Although the image has high quality, fogging tends to occur easily. For this reason, usually, the developing sleeve 1
By providing a potential difference between the DC voltage applied to 0d and the surface potential of the photosensitive drum 7, it is possible to prevent toner from adhering to the non-image area during development.

This toner image is then transferred to the intermediate transfer belt 4a by the intermediate transfer device 4. Intermediate transfer device 4
The endless belt 4a is driven by a driving roller 4b and a driven roller 4b.
c and the secondary transfer facing roller 4d, and is rotated in the direction of the arrow in FIG. Further, transfer charging rollers 4Y, 4M, 4C, and 4BK are provided in the transfer belt 4a, and each transfer charging roller is supplied with power from a high-voltage power supply while generating a pressing force from the inside of the belt 4a toward the photosensitive drum 7. By that
The toner image on the photosensitive drum 7 is sequentially transferred to the upper surface of the intermediate transfer belt 4a by performing charging with the opposite polarity to the toner from the back side of the belt 4a.

As the intermediate transfer belt 4a, a belt made of a polyimide resin can be used. The material of the belt 4a is not limited to the polyimide resin,
Dielectrics such as polycarbonate resin, polyethylene terephthalate resin, polyvinylidene fluoride resin, polyethylene naphthalate resin, polyetheretherketone resin, polyethersulfone resin, polyurethane resin and other plastics, and fluorine-based and silicon-based rubbers are suitable. Can be used.

Transfer residual toner remains on the surface of the photosensitive drum 7 after the transfer of the toner image. When the transfer residual toner is passed through the charger as it is, a phenomenon occurs in which the charging potential of only the remaining image portion is reduced, or the previous image portion becomes thin or dark on the next image (hereinafter, referred to as ghost). Would. Even if the transfer residual toner passes under the charged magnetic brush in contact with the photosensitive drum 7, the shape of the previous image remains in most cases. Therefore, it is necessary to take in the transfer residual toner that has reached the charged area into the magnetic brush charger 8 with the rotation of the photosensitive drum 7 and erase the history of the pre-image. At this time, when an AC voltage is applied to the magnetic brush charger 8, the toner is easily taken into the charger 8 due to the vibration effect of the electric field between the photosensitive drum and the charger. Here, the transfer residual toner on the photoreceptor drum 7 often has both positive and negative polarities due to peeling discharge at the time of transfer.
It is desirable that the transfer residual toner be positively charged in consideration of the ease of taking in the toner.

In the present embodiment, the conductive brush 11 is brought into contact with the photosensitive drum 7 between the intermediate transfer device 4 and the magnetic brush charger 8, and a bias having a polarity opposite to the charging bias is applied. The transfer residual toner of the positive polarity passes through the magnetic brush charger 8, and the transfer residual toner of the negative polarity is temporarily captured by the conductive brush 11, and is discharged onto the photosensitive drum 7 again after the charge is removed. Thereby, the transfer residual toner is more easily taken in the direction of the magnetic brush.

As shown in FIG. 2, the charging unit C comprises a charging roller 8a, a regulating blade 8c, and a conductive brush 11 integrally formed by a charging frame 13. FIG. 2, FIG.
The charging frame 13 forms a part of the exterior of the process cartridge B as shown in FIG. As shown in FIG. 2, the lower edge 13a of the charging frame 13 is parallel to the photosensitive drum 7 in the longitudinal direction at a distance close to the photosensitive drum 7. From the lower edge 13a, the process cartridge B
It has upper and lower walls 13b that are substantially vertical so as to form an exterior, and has a corner 13c that curves at the upper part. It has a top plate 13d in a direction substantially horizontal from the corner 13c and has a substantially key-shaped cross section. A space below the top plate 13d is a space, and a member mounting portion (not shown) is integrated at both ends in the longitudinal direction. It is molded into.

FIG. 3 is a side view of the charging unit C viewed from the inside. Process cartridge B of charging frame 13
A charging roller bearing 22 and an end cover 23 are screwed together at one end on the front side in the mounting direction (mounting from the front of the apparatus body 14 in the longitudinal direction). A gear unit 24 is fixedly screwed to the other end of the charging frame 13. The output shaft of the gear unit 24 is connected to the charging roller 8a, and the gear unit 24 is driven from outside the process cartridge BY to rotate the charging roller 8a. The driving source of the charging roller 8a is
It is provided in. The metal regulating blade 8c is spaced from the charging roller 8a as shown in FIG. 2, and is fixed to the supporting metal plate 8d by small screws 8j. As shown in FIG. 2, the supporting metal plate 8d has a groove-shaped cross section, is fitted into the dowel 13i of the seat 13g of the back member 25 extending in the longitudinal direction of the charging frame 13, and is inserted through the hole of the supporting metal plate 8d to form the small screw 8k. Is screwed into the seat 13g, whereby the supporting plate 8d is fixed to the charging frame 13.

(Apparatus of Charging Unit) The charging unit C is supported by the developing frame 12 so as to be swingable about a swing center SC shown in FIG. For this reason, as shown in FIG. 3, the swing center S is provided on a gear case 26 of a gear unit 24 fixed to one end of the charging frame 13 on the far side in the longitudinal direction.
A cylindrical shaft portion 26a is provided on C, and a cylindrical hole 23a is provided on the swing center SC in the end cover 23 at the other end in the longitudinal direction.

As shown in FIG. 2, the developing frame 12 accommodates the agitating screws 10g and 10h on both sides of the partition wall 10f, and has a lower portion 12f having a seat 12e for mounting a regulating blade 10e, and a process cartridge BY mounting direction. 12g that forms the exterior part on the left side
End plate portion 12h (back side) as shown at both ends in the longitudinal direction,
12i (front side). One end plate portion 12h has a hole 12j for enabling the cylindrical shaft portion 26a of the charging unit C to be movable via a bearing. The other end plate 1
2i has a hole 12m having the same diameter as the hole 23a of the charging frame 13.
Is provided. Therefore, the end plate 1 of the developing frame 12
With the cylindrical shaft 26a of the charging unit C inserted into the hole 12j of 2h, the cylindrical fitting hole 23a of the charging unit C is inserted.
To the hole 12m of the end plate 12i of the developing frame 12. When the rear cover 17 on the rear side when viewed from the mounting direction of the process cartridge B is aligned with the end of the developing frame 12, a hollow cylindrical shape protruding in the longitudinal direction on the inner side of the rear cover 17 is formed. The outer circumference of the shaft support 17a fits into the hole 12j of the developing frame 12, and the inner circumference fits into the cylindrical shaft 26a of the charging unit C at the same time. Also, a hole 1 provided in the end plate portion 12i of the developing frame 12 is provided.
The support shaft 27 that fits and protrudes at 2 m fits into the hole 23a of the charging unit C. Thus, the charging unit C has the cylindrical shaft portion 26a on one end side rotatably supported by the rear cover 17 and the hole 23a on the other end side in the developing frame 1.
2 to be rotatably supported.

In the upper part of the developing frame 12, the top plate 29 is fixed with its peripheral edge in contact with the end plates 12h and 12i inside the guide portion 12a above the side plate 12g. Here, the end plates 12h and 12i extend to the upper edge of the guide 12a.

As shown in FIG. 2, a spring seat 29 is
a are provided at two locations in the longitudinal direction. This spring seat 2
A compression coil spring 30 held by 9 a is compressed between the top plate 29 and the charging frame 13. With the spring force of the spring 30, the charging unit C is moved around the swing center SC as shown in FIG.
In the clockwise direction.

As shown in FIG. 3, a distance assurance member 8n is rotatably fitted in a journal 8a2 provided around the center of rotation by reducing the diameter of the end of the charging roller 8a. The distance assurance member 8n is pressed against the image area of the photosensitive drum 7 by the spring force of the compression coil spring 30. With such a configuration, a gap is provided between the photosensitive drum 7 and the charging roller 8a, and the transfer residual toner that is going to pass through the opposing portion between the charging roller 8a and the photosensitive drum 7 is formed on the peripheral surface of the charging roller 8a. The direction of movement is opposite to the direction of movement of the peripheral surface of the photosensitive drum 7, and a charging bias is applied to capture the image.

In the above description, the line connecting the swing center SC and the center of the charging roller 8a and the line connecting the charging roller 8a and the center of the photosensitive drum 7 are substantially perpendicular.

As shown in FIG. 2, the developing sleeve 10d is attached to the developing frame 12 so as to be swingable about the SLv pressing center. As shown in FIG. 4, the reduced journal portions 10d1 on both sides of the developing sleeve 10d.
Is fitted with a distance assurance member 10j having a radius larger than the developing sleeve 10d by the developing gap. A swing arm 32 fitted with the journal 10d1 is provided outside the distance assurance member 10j.

FIG. 8 is a cross-sectional view perpendicular to the developing sleeve 10d showing the vicinity of the side surface of the swing arm 32. The root of a swing arm 32 is swingably supported by a support shaft 33 press-fitted in the longitudinal direction with respect to both end plates 12h and 12i of the developing frame 12. The support shaft 3 of the swing arm 32
3, a bearing hole 32a is provided almost directly above, and a stopper portion 32b is provided above the bearing hole 32a. Support shaft 3
The spring seat 37c is provided on a line that is substantially perpendicular to a line connecting the center of pressure SLv, which is the center of 3, and the center of the bearing hole 32a.

Journal portions 10d1 at both ends of the developing sleeve 10d are rotatably supported in the bearing holes 32a of the swing arm 32. A compression coil spring 35 is contracted between the spring seat 32c and the spring seat 12n provided on the end plates 12h and 12i of the developing frame 12. As a result, the developing sleeve 10d is turned around the pressing center SLv toward the photoconductor drum 7 and pressurized, and the distance assurance member 10j is brought into pressure contact with the end of the photoconductor drum 7 outside the image area to perform development. A predetermined gap (0.2 to 1.0 mm) is maintained between the sleeve 10d and the photosensitive drum 7.

The developing sleeve 10d is driven from outside the process cartridge BY. The drive source is provided in the apparatus main body 14.

The process cartridge BY is detachably mounted on the apparatus main body 14. This mounting means is provided with, for example, a pair of guide rails (not shown) in a direction perpendicular to the plane of the paper of FIG. The process cartridge BY is mounted along the guide rail. The process cartridge BY is provided at its upper portion with guide portions 12a and 29b serving as guide strips in the longitudinal direction. Guide portions 12a, 29b along the guide rails
Is guided and the process cartridge BY is accommodated in the apparatus main body 14. Removal of the process cartridge BY from the apparatus main body 14 is the reverse of the above. Thus, the image forming unit BY is established. Other process cartridges BM, B
Similarly to the process cartridge BY, C and BB are removably mounted on the apparatus main body 14.

(Method of Holding SD Gap) The gap between the developing sleeve or the charging roller and the photosensitive drum (hereinafter referred to as S
D gap) is shown in FIGS.
The details will be described with reference to FIGS.

As shown in FIG. 4, at both ends of the developing sleeve 10d, a distance assurance member 10j for maintaining a gap Gd with the photosensitive drum 7 with high precision is rotatably supported.
As the distance assurance member 10j, a cylindrical roller member as shown in FIG. 5 or an abutting member as shown in FIG. However, in this embodiment, as described above, the direction of movement of the peripheral surface of the photosensitive drum and the direction of movement of the peripheral surface of the developing sleeve are opposite to each other, and the sliding portion between the abutting member and the developing sleeve or the photosensitive drum. The latter abutment member was adopted for the purpose of reducing the relative speed and suppressing the occurrence of wear.

On the other hand, at both ends of the charging roller 8a, as shown in FIG. 3, distance assurance members 8n for maintaining the gap Gc with the photosensitive drum 7 with high accuracy are rotatably supported. As the distance assurance member 8n, a cylindrical roller member (see FIG. 5) and an abutting member (see FIG. 6) are also suitable for the same reason as described above, but in the present embodiment, an abutting member is employed.

These distance assurance members 10j and 8n are not shown in FIG.
As shown in FIG. 3, the photosensitive drums 7 are arranged at positions that do not overlap in the longitudinal direction. This is because, when the distance assurance members are arranged at positions where the distance assurance members overlap each other, the contact surface 7a of the photosensitive drum 7 is rubbed twice as much as when the distance assurance members 10j and 8n do not overlap. This is because the surface 7a may be worn away.

If a foreign substance such as scattered toner adheres to the contact surface 7a, the chance of the distance assurance member passing over the foreign substance is doubled. This is because image defects are likely to occur.

The following is a summary of the embodiments of the present invention.

First, a plurality of process means are arranged around the photosensitive drum 7 at a predetermined distance, and these are integrated as a cartridge, and are detachably mountable to the image forming apparatus main body 14 as process cartridges BY, BH, and BC. , BB, the distance is assured by the distance assurance members 10j, 8n disposed at both ends of each of the plurality of process means abutting on the photosensitive drum 7, respectively. The process cartridge is disposed at a position where the photosensitive drum 7 does not overlap with each other in the longitudinal direction.

Second, in the first case, the distance assurance member 10 is used.
The process cartridges j and 8n are cylindrical roller members rotatably supported by the process means.

Third, in the first case, the distance assurance member 10
Reference numerals j and 8n denote process cartridges which are rotatably supported by the process means and are abutting members having one end having substantially the same shape as the peripheral surface of the photosensitive drum 7.

Fourth, there is provided a process cartridge in which at least one of the process means is a developing sleeve 10d.

Fifthly, there is provided a process cartridge in which at least one of the process means is a charging roller 8a.

Sixth, in the fourth or fifth embodiment, at least one of the process means is a process cartridge which rotates so that the peripheral surface moves in a counter direction with respect to the moving direction of the peripheral surface of the photosensitive drum 7.

Seventh, in an electrophotographic image forming apparatus provided with a plurality of process means arranged around the photosensitive drum 7 at a predetermined distance and a process cartridge integrally formed as a cartridge, which is detachably provided. The distance is assured by the distance assurance members 10j, 8n disposed at both ends of each of the plurality of process means abutting on the photosensitive drum 7, and furthermore, the distance assurance members 10j, 8n.
Are process cartridges BY, BM, and B disposed at positions that do not overlap with each other in the longitudinal direction of the photosensitive drum 7.
An electrophotographic image forming apparatus including a mounting unit for detachably mounting C and BB, and a conveying unit for conveying the recording medium 2.

[0061]

As described above, in a process cartridge in which a plurality of process means are arranged at a predetermined distance around an electrophotographic photosensitive drum, and these can be detachably mounted on an image forming apparatus main body as an integral cartridge. The distance is assured by a distance assurance member disposed at each end of each of the plurality of process means abutting on the electrophotographic photosensitive drum, and furthermore, the distance assurance member is in the longitudinal direction of the electrophotographic photosensitive drum 7. By adopting a configuration in which the process cartridges are not overlapped with each other, the durability of the process cartridge that can provide high-quality images can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electrophotographic image forming apparatus.

FIG. 2 is a vertical sectional view of a process cartridge.

FIG. 3 is a longitudinal front view of a process cartridge (developing unit).

FIG. 4 is a longitudinal front view of a process cartridge (charging unit).

FIG. 5 is a lateral front view for explaining a distance assurance member (cylindrical roller member).

FIG. 6 is a lateral front view for explaining a distance assurance member (abutting member).

FIG. 7 is a diagram illustrating a photosensitive drum longitudinal abutting portion.

FIG. 8 is a side view showing pressure applied to a photosensitive drum of a developing roller.

[Explanation of symbols]

B (BY, BM, BC, BB) process cartridge C charging unit D developing unit SC swing center SLv pressing center 1Y, 1M, 1C, 1BK scanning optical system 2 recording medium 3a paper feed Cassette 3b ... Pickup roller 3c
... Retard roller pair 3d, 3f ... Transport roller 3g ... Registration roller pair 3
h, 3i: discharge roller pair 4: intermediate transfer device 4a: intermediate transfer belt 4b: drive roller 4c: driven roller 4d: secondary transfer opposed roller 4Y, 4C, 4M, 4BK: transfer charging roller 5: fixing device 6: tray 7 Photosensitive drum 7a Contact surface of distance assurance member 8 Magnetic brush charger 8a Charging roller 8a2 Journal 8b Magnet 8c Regulator blade
8d: support metal plate 8j: small screw 8k: small screw 8n: charging roller distance assurance member (butting member) 10: developing means (apparatus) 10a: developing container 10c
Magnet 10d Developing sleeve 10d1 Journal part 10e Regulatory blade 10f Partition wall 10
g, 10h: stirring screw 10j: developing sleeve distance guarantee member (butting member) 11: conductive brush 12: developing frame 12a: guide portion 12e ... seat portion 12f: lower portion 12g ... side plate 12h ... end plate portion 12
i: end plate 12j: hole 12m: hole 12n: spring seat 13: charging frame 13a: lower edge 13b: upper and lower walls
13c: corner portion 13d: top plate portion 13e: member mounting portion
13f Member mounting portion 13g Seat portion 13i Tabbing 14 Device main body 17 Rear cover 17a Hollow cylindrical shaft support portion 22 Charging roller bearing 23 End cover 23a Hole 24 Gear unit 25 Back member 26 Gear case 26a: cylindrical shaft portion 27: support shaft 29: top plate 31: image forming unit 31Y, 31M, 31C, 31BK
... Image forming unit 32 ... Swing arm 32a ... Shaft changing hole 32b ... Stopper unit 32c ... Spring seat 35 ... Compression coil spring 40 ... Secondary transfer roller

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazunari Murayama 3- 30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Nobuharu Hoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Non-corporation (72) Inventor Naofumi Horikawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F-term (reference) 2H071 BA04 BA13 BA16 BA29 DA06 DA15

Claims (7)

[Claims] 1. A process cartridge in which a plurality of process means are arranged at a predetermined distance around an electrophotographic photosensitive drum and are detachable from an image forming apparatus main body as an integral cartridge. Distance assurance members provided at both ends of each of the plurality of process means are assured by contacting the electrophotographic photosensitive drum, and the distance assurance members do not overlap with each other in the longitudinal direction of the electrophotographic photosensitive drum. A process cartridge disposed at a position. 2. The process cartridge according to claim 1, wherein said distance assurance member is a cylindrical roller member rotatably supported by said process means. 3. The device according to claim 1, wherein the distance assurance member is a rotatable member rotatably supported by the process means, and has one end having substantially the same shape as the peripheral surface of the electrophotographic photosensitive drum. 2. The process cartridge according to 1. 4. The process cartridge according to claim 1, wherein at least one of said process means is a developer carrier. 5. The process cartridge according to claim 1, wherein at least one of said process means is a charging roller. 6. At least one of said process means comprises:
The process cartridge according to claim 4, wherein the process cartridge rotates so that the peripheral surface moves in a counter direction with respect to a moving direction of the peripheral surface of the electrophotographic photosensitive drum. 7. An electrophotographic apparatus in which a plurality of process means are arranged at a predetermined distance around an electrophotographic photosensitive drum, and a process cartridge in which these are formed as an integral cartridge is detachable and forms an image on a recording medium. In the image forming apparatus, a, the distance is ensured by a distance assurance member disposed at both ends of each of the plurality of process means abutting on the electrophotographic photosensitive drum, and further, the distance assurance member is the electrophotography. An electronic device comprising: mounting means for removably mounting a process cartridge disposed at a position where they do not overlap with each other in the longitudinal direction of the photosensitive drum; and transport means for transporting the recording medium. Photographic image forming device.