JP2001075457A - Process cartridge and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process cartridge capable of appropriately bringing a pair of carrying rollers into press contact with each other at all times, even in the case one of the pair is arranged on the process cartridge side and the other is arranged on the image forming device main body side. SOLUTION: The upper resist roller 12a is arranged in the process cartridge 2 so as to be made movable in a vertical direction, the lower resist roller 12b is arranged on the printer main body side. The upper resist roller 12a is arranged so as to project outward from the side face of the process cartridge, and a guide means 55 for guiding the upper resist roller 12a is arranged on the printer main body side. When finishing the operation of loading the process cartridge 2 to the printer main body, the upper resist roller 12a is positioned by using a spring 45 so that a prescribed pressurizing force may be applied on the lower resist roller 12b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of a process cartridge provided with a transfer roller for a transfer medium and an image forming apparatus provided with a transfer roller paired with the transfer roller.

[0002]

2. Description of the Related Art In an image forming apparatus for forming a visible image by supplying a developer to an electrostatic latent image formed on a photoreceptor and transferring the visible image to a transfer medium, maintenance is facilitated. For this reason, a method in which the developing process portion is configured as a cartridge that is detachable from the image forming apparatus may be used. Such a cartridge is generally called a process cartridge.

When using a process cartridge,
Various devices have been devised to facilitate attachment and detachment to and from the image forming apparatus main body. For example, in an image forming apparatus, a pair of transport rollers for transporting a transfer medium to a transfer unit is provided, and one of the pair of transport rollers is held by a process cartridge and the other is transported. May be provided on the image forming apparatus main body side in some cases.

[0004]

However, the problem with this arrangement is how to properly press the pair of paper transport rollers when the process cartridge is mounted on the main body of the image forming apparatus. That's what it means.

That is, when the position, angle, pressing force, and the like of the pair of transport rollers change when the process cartridge is replaced, the transfer medium cannot be transported properly.

Therefore, conventionally, in order to maintain good transferability of the transfer medium, the pair of transfer rollers must be provided on the image forming apparatus main body side, for example, when the process cartridge is moved in a substantially horizontal direction. Was hindered.

As another problem, in the configuration in which the pair of transport rollers is provided on the image forming apparatus main body side, paper dust easily accumulates around the pressure contact portion of the transport roller, and when the amount increases, the paper powder passes through the pressure contact portion. However, there was a possibility that the development was adversely affected.

However, in an apparatus employing a method in which the process cartridge is mounted from above the image forming apparatus, it is very difficult to maintain the paper dust around the pressure contact portion of the pair of transport rollers.

In view of the above, the present invention solves such a problem and provides one of a pair of transport rollers on the process cartridge side and the other on the image forming apparatus main body side while maintaining good transportability of the transfer medium. It is an object of the present invention to provide a process cartridge and an image forming apparatus that can perform the above processes.

[0010]

According to a first aspect of the present invention, there is provided a process cartridge, comprising: a photosensitive member on which an electrostatic latent image is formed; And a transfer unit for transferring the visible image to a transfer medium, the process cartridge being detachably provided to the image forming apparatus, the process cartridge being provided on the image forming apparatus side. A cartridge-side transport roller that forms a transport roller pair that transports the transfer medium together with the image-forming-apparatus-side transport roller by being pressed against the image-forming-apparatus-side transport roller; The process cartridge is movably attached to the image forming apparatus in a non-attached state.

According to the first aspect of the present invention, when the process cartridge is not mounted in the image forming apparatus, the transport roller on the cartridge side is movable, and the transport roller on the image forming apparatus side is movable. Not positioned with respect to rollers. Therefore, even when the process roller is replaced with a new process cartridge, the transport roller on the cartridge side moves following the positioning means provided on the image forming apparatus side, and the positioning state is determined only by the positioning conditions of the positioning means. Is done. Therefore, even if the process cartridge is replaced, the relationship such as the pressing force between the transport roller on the cartridge side and the transport roller on the image forming apparatus side is always kept constant, so that the transfer medium is always stable. Transport will be performed.

According to a second aspect of the present invention, there is provided a process cartridge comprising:
In order to solve the problem, in the process cartridge according to claim 1, a rotation axis of the cartridge-side transport roller or the cartridge-side transport roller is formed to be longer than a width of the process cartridge in a width direction,
The process cartridge is mounted so as to protrude from a side surface portion of the process cartridge.

According to a second aspect of the present invention, the cartridge-side transport roller or the rotating shaft of the cartridge-side transport roller is formed to be longer than the width of the process cartridge in the width direction. Since it is mounted so as to protrude from the portion, the means for positioning the cartridge-side transfer roller or the rotation axis of the cartridge-side transfer roller can be provided outside the side surface of the process cartridge. . As a result, the image forming apparatus includes the cartridge-side transport roller or the rotating shaft of the cartridge-side transport roller at a position further outside the side surface of the process cartridge so as to be along the substantially horizontal movement direction of the process cartridge. And the process cartridge can be easily moved in a substantially horizontal direction.

According to a third aspect of the present invention, there is provided a process cartridge comprising:
In order to solve the above-mentioned problem, in the process cartridge according to claim 1 or 2, the cartridge-side transport roller is a metal shaft.

Since the cartridge-side transport roller attached to the process cartridge according to the third aspect is a metal shaft, it has a simple structure while maintaining sufficient rigidity.
Set the cartridge side transport roller longer than the width of the transfer medium
It can be attached to a process cartridge.

According to a fourth aspect of the present invention, there is provided a process cartridge comprising:
In order to solve the above problem, in the process cartridge according to any one of claims 1 to 3, bearings are provided at both ends of the cartridge-side transport roller, and the bearings are provided in the process cartridge. Characterized in that it is movably mounted on the.

According to the fourth aspect of the present invention, since the positioning means on the image forming apparatus acts on the bearings provided at both ends of the transport roller on the cartridge side, the positioning means operates on the cartridge side. Accurate positioning is performed without hindering the rotation of the transport roller.

According to a fifth aspect of the present invention, there is provided a process cartridge comprising:
In order to solve the above-mentioned problem, in the process cartridge according to any one of claims 1 to 4, the process cartridge has an opening for passing the transfer medium near a mounting position of the cartridge-side transport roller. It is characterized by being provided.

According to the fifth aspect of the present invention, since the process cartridge is provided with an opening through which the transfer medium passes in the vicinity of the mounting position of the cartridge-side transport roller, the cartridge-side transport is provided. The transfer medium that is satisfactorily conveyed by the rollers and the image forming apparatus-side conveyance rollers is immediately conveyed to the opening, and the transfer medium is stably conveyed as a whole process cartridge.

According to a sixth aspect of the present invention, there is provided an image forming apparatus comprising the process cartridge according to any one of the first to fifth aspects, wherein the process cartridge is detachably mounted. It is characterized in that a positioning means for the transport roller is provided on both side surfaces.

According to the image forming apparatus of the present invention, the process cartridge according to any one of the first to fifth aspects is detachably provided and the positioning means for the transport roller is provided on both side surfaces of the cartridge. When the process cartridge is in a non-mounting state with respect to the image forming apparatus, the cartridge-side conveying roller moves between the direction of pressing the image forming apparatus-side conveying roller provided on the image forming apparatus side and the opposite direction. It is possible to move in both directions,
It is not positioned with respect to the image forming apparatus-side transport roller. Therefore, even when the cartridge is replaced with a new process cartridge, the transport roller on the cartridge side moves following the positioning means provided on the image forming apparatus side, and
The positioning state is determined only by the positioning conditions of the positioning means. Therefore, even if the process cartridge is replaced, the relationship such as the pressing force between the transport roller on the cartridge side and the transport roller on the image forming apparatus side is always kept constant, so that the transfer medium is always stable. Transport will be performed. Further, since the positioning means of the transport roller is provided on both sides of the cartridge, it does not hinder the movement of the process cartridge in the substantially horizontal direction.

According to a seventh aspect of the present invention, there is provided an image forming apparatus according to the sixth aspect, further comprising a guide member for the cartridge-side transport roller, wherein the positioning means comprises It is characterized by including a groove continuous from the member.

According to the image forming apparatus of the present invention, the conveying roller on the cartridge side of the process cartridge is moved in the substantially horizontal direction of the process cartridge by the positioning means including the groove connected to the guide member provided in the image forming apparatus. Positioning is performed along with the movement. Therefore, the movement of the process cartridge in the substantially horizontal direction is not hindered.

According to an eighth aspect of the present invention, there is provided an image forming apparatus according to the sixth or seventh aspect, wherein the process cartridge according to any one of the first to fifth aspects is replaced with the image forming apparatus. Characterized in that it is provided so that it can be taken out or mounted from the front part.

According to the image forming apparatus of the eighth aspect, the process cartridge according to any one of the first to fifth aspects can be taken out or mounted from the front portion of the image forming apparatus. Since the means does not hinder the movement of the process cartridge in the substantially horizontal direction, it is easy to remove or attach the process cartridge from the front of the image forming apparatus.

The process cartridge according to claim 9 is
In order to solve the above problem, a frictional charging member longer than a longitudinal length of the cartridge-side transport roller is provided on the cartridge-side transport roller so as to make a circumferential surface of the cartridge-side transport roller uniform. The process cartridge according to claim 1, wherein the process cartridge is attached so as to cover the same.

According to a ninth aspect of the present invention, the cartridge-side transport roller is provided with a triboelectric charge by a triboelectric charging member. The triboelectric charging member has a length in the longitudinal direction longer than the transport roller on the cartridge side, and is attached in contact so as to uniformly cover the circumferential surface of the transport roller on the cartridge side. . Therefore, the triboelectric charge is reliably applied to the cartridge-side transport roller movably mounted as described above. Then, as a result of the cartridge-side transport roller being satisfactorily applied with triboelectric charges, paper dust adhering to the transfer medium transported to the transport roller position is transferred from the transfer medium side to the cartridge-side transport roller side. Transfer securely. Then, the paper powder transferred to the cartridge-side transport roller is
At a contact portion between the cartridge-side transport roller and the triboelectric charging member, the cartridge-side transport roller is removed from the cartridge-side transport roller and housed in a process cartridge. Therefore,
Paper dust is not conveyed to the developing section. Also,
Even if the paper dust removed as described above accumulates,
Since the process of replacing the process cartridge leads to the operation of discarding the accumulated paper dust as it is, maintenance of the paper dust in the transport roller unit is not required.

According to a tenth aspect of the present invention, there is provided a process cartridge according to the ninth aspect, wherein the surface of the transport roller on the cartridge side is coated with a resin.

According to the process cartridge of the present invention, since the surface of the transport roller on the cartridge side is coated with a resin, the frictional charging member is satisfactorily frictionally charged by the frictionally charging member, thereby reliably removing paper dust.

According to an eleventh aspect of the present invention, there is provided a process cartridge according to the tenth aspect, wherein the resin coating on the surface of the transport roller on the cartridge side is a Teflon coating. .

According to the process cartridge of the present invention, the resin coating on the surface of the cartridge-side transport roller is a Teflon coating, so that the frictional charging member satisfactorily triboelectrically charges and reliably removes paper dust.

According to a twelfth aspect of the present invention, there is provided a process cartridge according to any one of the ninth to eleventh aspects, wherein the frictional charging member is formed of a foamed elastic material. It is characterized by being.

According to the twelfth aspect of the invention, since the frictional charging member is made of a foamed elastic material, the resin-coated cartridge-side transport roller is frictionally charged satisfactorily. Such good paper dust removal is performed.

According to a thirteenth aspect of the present invention, there is provided a process cartridge according to the twelfth aspect, wherein the foamed elastic body forming the frictional charging member is an ether-based foamed elastic body. It is characterized by the following.

According to a thirteenth aspect of the present invention, the foamed elastic body forming the frictional charging member is an ether-based foamed elastic body. In addition, it exhibits good separability with respect to the paper dust removed at the contact portion with the cartridge-side transport roller, and the paper dust is not aggregated.

According to a fourteenth aspect of the present invention, there is provided a process cartridge according to the twelfth aspect, wherein the foamed elastic body forming the frictional charging member is an ester-based foamed elastic body. ,
A scraping member is attached to the cartridge-side transport roller in contact therewith.

According to the process cartridge of the present invention, since the foamed elastic body forming the frictional charging member is an ester-based foamed elastic body, the cartridge-side transport roller is charged favorably as described above. The paper dust removed at the contact portion with the cartridge-side transport roller is slightly easily aggregated. However, since a scraping member is attached to the cartridge-side transport roller in contact with the cartridge-side transport roller, the paper dust that tends to aggregate is reliably removed from the cartridge-side transport roller.

According to a fifteenth aspect of the present invention, there is provided a process cartridge according to any one of the ninth to fourteenth aspects, wherein paper dust is contained in the process cartridge near the cartridge-side transport roller. A housing portion is formed.

According to the process cartridge of the present invention, since a paper dust accommodating portion is formed inside the process cartridge near the cartridge-side transport roller, the cartridge-side transport roller and the cartridge-side transport roller are frictionally charged as described above. The paper dust removed at the contact portion with the application member is reliably stored in the paper dust storage portion. Then, by exchanging the process cartridges, the paper dust can be satisfactorily stored by the paper dust storage unit in which the paper dust is not accumulated.

In order to solve the above problem, the image forming apparatus according to the present invention is provided with a take-out roller for taking out the transfer medium from the transfer medium accommodating portion for accommodating the transfer medium, and provided in pressure contact with the take-out roller. An image forming apparatus comprising: a separation member; and the process cartridge according to claim 9 is detachably attached to the image forming apparatus.
It is formed to be longer than the length of the take-out roller in the longitudinal direction, and has a positional relationship of uniformly covering the take-out roller in the longitudinal direction when the process cartridge is mounted.

According to the image forming apparatus of the sixteenth aspect,
The transfer medium accommodated in the transfer medium accommodating portion is taken out by a take-out roller, and is supplied one by one at a pressure contact portion between the take-out roller and the separating member. At this time, the surface of the transfer medium is rubbed by the separating member, and paper dust is generated. As described above, the amount of paper dust generated by the rubbing with the separation member is such that the pressure contact area between the take-out roller and the separation member is the area having the highest pressing force, so that the take-out roller is larger than both sides of the transfer medium. Increases in the area where the contact occurs. However, as described above, the longitudinal length of the cartridge-side transport roller with which the triboelectric charging member comes into contact is formed longer than the longitudinal length of the take-out roller, and the take-out roller is moved one by one in the longitudinal direction. In the same manner. Therefore, the paper dust removal area by the cartridge-side conveyance roller surely covers the area where the take-out roller contacts as described above, and further covers the area on both sides of the transfer medium.
Good paper dust removal will be performed.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment in which the present invention is embodied in a laser beam printer will be described. (First Embodiment) First, a first embodiment of the present invention will be described with reference to FIGS.

(Schematic Configuration of Printer) FIG. 1 is a schematic side sectional view of a printer as an image forming apparatus. As shown in FIG. 1, a process cartridge 2 including a photoreceptor cartridge 3 and a developing cartridge 4 is detachably disposed in a main body housing 1 of the printer at a substantially central portion thereof.

A photosensitive drum 13 having a photosensitive surface, such as an organic photosensitive member, is rotatably disposed in the photosensitive cartridge 3, and a transfer roller 14 as a transfer unit is provided below the photosensitive drum 13. It is provided so as to rotate while pressing. A charger 36 such as a scorotron for charging the photosensitive surface of the photosensitive drum 13 is mounted above the photosensitive drum 13. Furthermore,
On the upper part of the case 30 of the photoreceptor cartridge 3, a light incident portion 31 is provided at a position adjacent to the charger 36.
3 is formed longitudinally along the axial direction.

In the developing cartridge 4, a developing roller 22 as a developing means is rotatably arranged facing the photosensitive drum 13, and the toner as a developer stored in the developing cartridge 4 is supplied to the developing roller 22. As a result, the sheet is transported to a position facing the photosensitive drum 13 and development is performed.

A fixing device 5 having a heating roller 15 and a pressure roller 16 is disposed downstream of the process cartridge 2 in the transport direction of the sheet P. The fixing device 5 fixes the toner transferred to the sheet P to the sheet P by a heating action by the heating roller 15 and a pressing action by the heating roller 15 and the pressing roller 16.

Further, on the upper part of the main body housing 1, there is provided a cover-purpose paper discharge tray 1a made of a synthetic resin for mounting the paper discharged from the fixing device 5, and this paper discharge tray 1a. A laser scanner unit 7 including a laser light emitting unit, a polygon mirror 18, a lens 19, a plurality of reflecting mirrors 20, and the like is attached to a lower surface of the laser light source via a frame.

A paper feed unit 6 is arranged below the process cartridge 2. The paper supply unit 6 includes a paper supply cassette 8 that can be mounted from the front (arrow A) direction below the main body housing 1, a support plate 9 on which paper P as a transfer medium is loaded in the paper supply cassette 8, A paper feed roller 10 for taking out the paper P from the paper cassette 8 and a separation pad 11 for separating the paper P to be taken out one by one are provided.

Further, in the printer of this embodiment,
A pair of registration rollers 12a and 12b is provided downstream of the paper supply unit 6 in the transport direction of the paper P. The registration roller pair 12a, 12b is a roller pair for transporting the paper P supplied from the paper supply unit 6 to the pressure contact portion between the photosensitive drum 13 and the transfer roller 14 at a certain timing. In the present embodiment, the upper registration roller 12a
Is attached to the process cartridge 2, and the lower registration roller 12b is attached to the printer body. In the present embodiment, since the process cartridge 2 is configured to be detachable from the front side of the main body, when both the pair of registration rollers 12a and 12b are attached to the main body side as in a conventional apparatus, FIG. As can be seen from the drawing, when removing the process cartridge 2 from the front side of the main body,
The portion of the case 30 of the process cartridge 2 that covers the transfer roller 14 hits the upper registration roller 12a, making it difficult to remove the process cartridge 2. Therefore, the upper registration roller 12a
Is attached to the process cartridge 2 side,
This facilitates removal of the process cartridge 2 from the front side. The “front part of the image forming apparatus” according to claim 8 is the main body housing 1 according to the present embodiment.
, The process cartridge 2 moves in the main body substantially parallel to the conveyance direction of the paper conveyed by the pair of registration rollers 12a and 12b, and is mounted on the main body.

When the print data is transmitted together with a print command from an external device (not shown), for example, a personal computer, the printer according to the present embodiment as a transfer medium stacked on the support plate 9 of the sheet cassette 8. Paper P
Are separated one by one by a separation pad 11 as the sheet feeding roller 10 of the sheet feeding unit 6 rotates, and then the process cartridge 2 is separated via the pair of registration rollers 12a and 12b.
Is transferred between the photosensitive drum 13 and a transfer roller 14 serving as a transfer unit pressing the lower surface of the photosensitive drum 13.

On the other hand, the surface of the photosensitive drum 13 is uniformly charged by the charger 36, and
A laser beam emitted from an emission hole on the lower surface of the frame that supports the photosensitive drum is radiated from a case in the process cartridge 2, that is, from a light incident portion 31 on an upper side of a case 30 that is a housing of the photosensitive cartridge 3, and rotates. 1
An electrostatic latent image is formed by scanning the upper peripheral surface of No. 3. Further, as described later, a thin layer of toner as a developer is formed on the developing roller 22 of the developing cartridge 4, and the toner is conveyed to a portion facing the electrostatic latent image by rotation of the developing roller 22, The electro-latent image is visualized (visible) by the adhesion of the toner, and is then transferred to the sheet P in the pressure transfer area of the transfer roller 14 and the photosensitive drum 13. The paper P after the transfer is heated by a heating roller 15 in the fixing device 5.
The sheet P, which is fed between the roller and the pressure roller 16 and undergoes the heat fixing operation, is discharged from the discharge path 17 onto the discharge tray 1a also serving as the cover.

When the toner is consumed by the printing operation and the toner needs to be replenished, the used process cartridge 2 is removed from the front of the printer main body, and the old developing cartridge 4 is removed from the process cartridge 2. After the new developing cartridge 4 is mounted, the process cartridge 2 may be inserted again from the front of the printer main body and mounted on the printer main body, and anyone can easily supply toner without soiling the hands.
When the photoconductor drum 13 has deteriorated, the process cartridge 2 is similarly removed, the photoconductor cartridge 3 is replaced with a new one, and the process cartridge 2 is replaced again.
May be attached to the printer body.

However, as in this embodiment, in order to facilitate attachment and detachment of the process cartridge 2 to and from the printer main body, the upper registration roller 12a is attached to the process cartridge 2 side, and the lower registration roller 12a
When b is attached to the printer main body, it is important to keep the position, angle, and pressing force of the upper registration roller 12a and the lower registration roller 12b constant in order to perform stable paper conveyance.

That is, even when the new process cartridge 2 is mounted as described above, it is necessary to keep the position, angle, and pressing force of the upper registration roller 12a and the lower registration roller 12b properly. .

Therefore, in the present embodiment, the pair of registration rollers 12a and 12b and the positioning mechanism are configured as follows.

(Detailed Configuration of Registration Roller Pair and Positioning Mechanism) First, in this embodiment, as shown in FIG. 2, the upper registration roller 12a as a cartridge-side transport roller is provided with a bottom opening 30a of the process cartridge 2. Therefore, it is attached so that its surface is exposed. The mounting method does not use a method of pivotally supporting the casing side wall as in a general roller body. Instead, as shown in FIG. 3, which is an enlarged view of a portion B encircled in FIG. 2, the bearing 70 attached to the upper registration roller 12a is used.
And the case 3 of the process cartridge 2
0 and the supporting portion 30b formed integrally therewith, and the upper registration roller 12a is pressed in the direction indicated by the arrow in FIG. Direction).

FIG. 4A shows the upper registration roller 12a.
As shown in (ii), the shaft is made of a metal such as plated iron or stainless steel, and has a length longer than the width of the paper P. A bearing 7 made of resin is provided at both ends of the upper registration roller 12a.
0 and 71 are attached. The bearing body 70 is shown in FIG.
(A) As shown in FIG. 6 (i) and FIGS. 6 (A) to 6 (F), a cylindrical portion 70b in which an insertion hole 70c for inserting a shaft end of the upper registration roller 12a is formed;
Is a member integrally formed with the supporting portion 70d formed with. 6 (D) is a front view, FIG. 6 (E) is a right side view, FIG. 6 (C) is a left side view, FIG. 6 (A) is a top view, FIG.
6B is a cross-sectional view taken along line CC of FIG. 6C, and FIG. 6F is a cross-sectional view taken along line EE of FIG. 6A.

On the other hand, a bearing 71 is attached to the end of the upper registration roller 12a opposite to the end to which the bearing 70 is attached. The bearing body 71 is shown in FIG.
As shown in (i ii) and FIGS. 7 (A) to 7 (E), the bearing member 70 has substantially the same shape. That is, the cylindrical portion 71b in which the insertion hole 71c for inserting the shaft end of the upper registration roller 12a is formed, and the support portion 71d in which the protrusion 71a is formed are integrally formed. However, the bearing 7
1, a gap 71e is formed in the support 71d as shown in FIG.
Are formed, and the supporting portion 71d is easily bent toward the center as shown by an arrow in FIG. 7D. FIG.
7 (D) is a front view, FIG. 7 (E) is a right side view, FIG. 7 (B) is a left side view, FIG. 7 (A) is a top view, and FIG. 7 (C) is FIG.
It is FF sectional drawing of (A).

The bearing bodies 70 and 71 as described above are connected to each other as shown in FIG.
(A) As shown in (ii), after the upper registration roller 12a is attached to both ends of the upper registration roller 12a, the upper registration roller 12a is attached to the case 30 of the process cartridge 2.
Do the following:

First, as shown in FIG. 8, the bearing 70 is attached to the gap 30e formed between the case side wall 30c of the process cartridge 2 and the case bottom wall 30d covering the end of the upper registration roller 12a. Insert at an angle shown in FIG. 8 and push in the direction of arrow G shown in FIG. Projection 7
At the upper end of the supporting portion 70d just above 0a, a chamfered portion 70f is formed obliquely as shown in FIG.
The chamfered portion 70f smoothly abuts the corner of the case bottom wall 30d to facilitate insertion of the bearing body 70 into the gap 30e. Also, since the projecting portion 70a is formed with an inclined surface as shown in FIGS. 3 and 6, the supporting portion 30b of the case 30 shown in FIG.
Insertion of the bearing body 70 into the gap 30e is facilitated.
FIG. 9 shows a state in which the bearing body 70 is inserted into the gap 30e in this manner.

Next, in order to insert the bearing body 71 into the gap 30e, as shown in FIG. 7 (D), both support portions 71d are bent toward the center as shown by the arrows, whereby the support portions 71d are bent. While narrowing the width of 71d, it is pushed into the gap 30e. As described above, the bending of the support portion 71d causes the bearing 71
Into the gap 30e. Also, as shown in FIG. 7, the projection 71 a of the bearing body 71 is formed with an inclined surface, and the support portion 30 b of the case 30 and the inclined surface come into smooth contact with each other.
e is easy to insert.

FIGS. 4B and 4C show a state in which the bearing bodies 70 and 71 are inserted into the gap 30e of the case 30 by the above-described operation. As shown in FIGS. 4B and 4C, the bearing members 70 and 71 project further outward than the case side wall 30c, and the upper registration rollers 12a.
Is moved to the uppermost position, the bearing body 7
The zero cylindrical portion 70b and the cylindrical portion 71b of the bearing body 71 contact the lower end of the case side wall 30c, and further upward movement is restricted. Further, in a state where the upper registration roller 12a is moved to the lowest position, that is, in a state where the upper registration roller 12a is lowered by its own weight, it is an enlarged view around the bearing body in FIGS. 4C and 4C. As shown in FIGS. 5A to 5D, the bearing 7
The protrusion 70a of the “0” and the protrusion 71a of the bearing 71 abut on the support 30b of the case 30 to restrict the lower registration roller 12a from moving downward.

With the above-described configuration, the upper registration roller 12a can freely move in a downward direction in which the lower registration roller 12b is brought into pressure contact and an upper direction in which the upper registration roller 12a is separated from the lower registration roller 12b. Has become.

On the other hand, the lower registration roller 12b is
As shown in FIG. 3, the shaft 12c is made of a plated metal such as iron or stainless steel, and an elastic layer 12d made of urethane rubber or the like formed on the shaft 12c. Is rotatably supported by the printer body. The shaft 12c is connected to a drive source such as a motor via a gear or the like (not shown), and the timing and speed of the rotation start are controlled by a control unit (not shown).

The upper registration roller 12a is provided so as to be vertically movable as described above. However, a means for positioning the upper registration roller 12a is provided on the printer main body side of the present embodiment. When the printer is mounted on the printer body, the positioning means positions the upper registration roller 12a with respect to the lower registration roller 12b so as to have an appropriate position, angle, and pressing force.

Hereinafter, with reference to FIGS. 10 to 15, an operation of mounting the process cartridge 2 in the printer body and a positioning mechanism of the upper registration roller 12a in this embodiment will be described.

The attachment / detachment operation of the process cartridge 2 is performed in a state where the lid 1b at the right end (front side) of the main body housing 1 is turned downward and widely opened as shown in FIG.
As shown in FIG. 10, a pair of left and right guide means 55 made of resin or the like is fixed to the inner surfaces of the left and right sides of the main body housing 1. The upper guide surface 55a formed so as to incline downward from the rising inclined surface which inclines upward as going from the right end to the back side of the right end thereof after the apex portion 55d.
Is disposed below the upper guide surface 55a, and is inclined downward from the right end of the main body housing 1 toward the back side,
A lower guide surface 55b ending at the lower roller 12b of the pair of registration rollers.

FIG. 10 shows a state in which the process cartridge 2 is placed at the insertion start position into the main housing 1. When the process cartridge 2 is inserted from the state shown in FIG. 10 to the state shown in FIG. , Photosensitive drum 1
The third shaft 13a is located at the upper back side of the upper guide surface 55a.
Push so that it approaches. Then, as shown in FIG. 11, the moving action portion 43 of the urging means 42 attached to the process cartridge 2 comes into contact with the rising inclined surface of the upper guide surface 55a, and the lower ends of the left and right sides of the process cartridge 2 A guide member 56 (only one of which is shown in the figure) protruding laterally is fitted on the lower guide surface 55b, and the process cartridge 2 cannot be dislodged upward with respect to the main body housing 1 and is located along the lower guide surface 55b. Only push-in is possible.

At this time, the upper registration roller 12a
Moves downward by its own weight as shown in FIG. 11, and approaches the lower registration roller 12b while sliding on the lower guide surface 55b.

Thus, the process cartridge 2
Is pushed in, the moving action portion 43 is pushed up by the upper guide surface 55a.
Rotates upward about the rotation support shaft 39a (39 (b)), and as shown in FIG.
Is restricted in the pushing direction at the tip end side of the slide support member 40. Then, the slide support member 40 pivots upwardly to the maximum at the point where the moving action portion 43 is at the vertex 55d of the upper guide surface 55a, and in this position, the operated portion 61 is restrained at the tip end side of the slide support member 40. To maintain the state.

At this time, the upper registration rollers 12a
Is in contact with the lower registration roller 12b, and thereafter moves while contacting the lower registration roller 12b.

The process cartridge 2 is further pushed in,
As shown in FIG. 13, when the shaft 13a of the photosensitive drum 13 is set at a predetermined position in the concave portion 55c on the upper back side of the upper guide surface 55a and the observer releases his / her hand from the process cartridge 2, the state shown in FIG. As described above, due to the weight of the process cartridge 2, the upper registration roller 12 a is attached to the lower registration roller 1
The bearing bodies 70 and 71 placed on the upper side of the upper registration roller 12a and mounted on both ends of the upper registration roller 12a are pressed by the spring 45 as shown in FIG. As a result, the upper registration roller 12a comes into pressure contact with the lower registration roller 12b at an appropriate position, angle, and pressing force.

In the state set as described above,
At the tip end side of the slide support member 40, the affected part 6
You will press 1. Thus, the developing roller 22 can be pressed against the photosensitive drum 13 via the developing cartridge 4 by the urging means 42 and the operated portion 61.

Further, in the state shown in FIG.
As shown in FIG. 5, a support member 35 for vertically supporting the shaft 14 a of the transfer roller 14 is pressed upward by an arm member 34 urged by a spring 33, so that the transfer roller 14 is moved to the photosensitive drum 13. On the other hand, a predetermined pressing force is applied.

As described above, in this embodiment, when the process cartridge 2 is detached from the printer main body, the upper registration roller 12a is not fixed, but is freely movable up and down. Only when the printer is mounted on the printer main body, it is positioned so as to be pressed against the lower resist rest roller 12b at an appropriate position, angle and pressing force. Will be determined by the positioning mechanism of
Even when the process cartridge 2 is replaced, the relationship between the upper registration roller 12a and the lower registration rest roller 12b can always be maintained in an appropriate state. As a result, stable paper transport can always be performed.

The positioning is performed by attaching the upper registration roller 12a formed to be longer than the width of the process cartridge 2 in the width direction.
Bearing body 70 provided so as to protrude outward from the side surface of
71, the positioning mechanism can be provided on both side surfaces of the printer main body. Even if the process cartridge 2 is mounted and demounted from the front side of the printer main body, a member that hinders the mounting and demounting in the mounting path. Need not be provided. As a result, the process cartridge 2
Can be easily attached and detached.

Further, since the upper registration roller 12a is a metal shaft, the upper registration roller 12a longer than the paper width can be attached to the process cartridge 2 with a simple configuration while maintaining sufficient rigidity. Therefore, cost can be reduced.

As shown in FIG. 1, the paper guide opening 80 provided in the case 30 of the process cartridge 2 for guiding the paper P to the pressure contact portion between the photosensitive drum 13 and the transfer roller 14 has an upper side. Since the sheet P is provided in the vicinity of the registration roller 12a, the sheet P can be easily transported to the pressure contact portion between the photosensitive drum 13 and the transfer roller 14.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 16, the present embodiment is an example in which a sponge 90 as a frictional charging member is brought into contact with the upper registration roller 12a, and paper dust is removed by the upper registration roller 12a.

The upper registration roller 12a of the present embodiment
Is a PFA (Teflon) coated surface of a metal roller made of plated iron or stainless steel.

The sponge 90 as a triboelectric charging member to be brought into contact with the upper registration roller 12a is formed of an ether-based urethane foam (trade name of Everlite (Bridgestone Co., Ltd.)). As the sponge 90, an ester-based foamed elastic body can also be used.

The position of the sponge 90 is such that it contacts the side of the upper registration roller 12a inside the process cartridge 2. The length of the sponge 90 in the longitudinal direction is, as shown in FIG.
L2 is longer than length L1 of 2a. Further, when the case bottom wall 30d shown in FIG. 17 is viewed from the horizontal direction indicated by the arrow C in FIG. 16, the case bottom wall 30d is provided with a notch so as not to cover the surface of the upper registration roller 12a. I have. FIG. 17 shows the upper registration roller 12a and the sponge 9 from above in FIG.
FIG. Therefore, the upper registration roller 12a
Has a surface exposed over the entire length L1, and a sponge 90 longer than the upper registration roller 12a is attached to this surface so as to come into contact therewith. Therefore, even when the upper registration roller 12a is configured to be movable as described above, the contact with the sponge 90 is always maintained.

A scraping sheet 91 is mounted on the upper registration roller 12a so as to come into contact with the surface of the upper registration roller 12a. This scraping sheet 91 is formed of PET or the like.

Further, after the process cartridge 2 is mounted on the image forming apparatus as shown in FIG. 16, the removed paper dust is placed near the bottom of the process cartridge 2 behind the upper registration roller 12a, ie, behind the sponge 90. A paper dust storage chamber 92 for storing is formed.

With the above configuration, when the upper registration roller 12a rotates in the direction of the arrow shown in FIG. 16, the upper registration roller 12a rubs against the sponge 90, and a triboelectric charge is applied. In the above configuration, the voltage of the upper registration roller 12a due to frictional charging was -4 kV to -5 kV. Although the charging polarity of the paper dust is also negative, the voltage value is much lower than the charging voltage value of the upper registration roller 12a, so that the paper dust is attracted to the upper registration roller 12a by the action of the electric field, and It is collected by rotation of 12a.

Further, when the above-mentioned ether-based urethane foam is used for the sponge 90, the paper dust is easily separated, and the collected paper dust is stored in the paper dust storage chamber 92 without agglomeration. You.

Accordingly, it is possible to reliably prevent paper dust from being mixed into the developing section, and to form a high quality image.

When the above-described paper dust removal processing is continued, the paper dust is accumulated in the paper dust accommodating chamber 92. The paper dust in the storage chamber 92 is also removed at the same time, and maintenance work can be facilitated.

Further, by replacing the process cartridge 2, the upper registration roller 12a and the sponge 90 are also replaced with new ones, so that a good paper dust removing process can always be performed.

As described above, the upper registration roller 12a
Is configured as described in the first embodiment, and is provided on the process cartridge 2 side.
Can be used as paper dust removing means that does not require maintenance.

Further, the upper registration roller 12a is
The sponge 90 is longer than the upper registration roller 12a as shown in FIG.
Since the contact surface a is uniformly covered with the transfer medium, good triboelectric charging is always performed.

Further, even when paper dust adheres to the surface of the upper registration roller 12a, since the scraping sheet 91 is provided as described above, the attached paper dust can be reliably removed. When an ether-based urethane foam is used as the sponge 90 as described above, the paper powder has good separability. Therefore, even when the scraping sheet 91 is not provided, the paper powder is reduced to a practically acceptable level. It is possible to remove it. However, when an ester-based foamed elastic body is used as the sponge 90, the scraping sheet 91 is preferably provided because the paper dust tends to aggregate.

Further, in this embodiment, the length L1 of the upper registration roller 12a is configured to be longer than the length L3 of the paper feed roller 10, as shown in FIG. Therefore, in the pressure contact portion between the paper feed roller 10 and the separation pad 11 shown in FIG. 1, a large amount of paper dust generated in the contact area of the transfer medium with the paper feed roller 10 can be reliably removed by the upper registration roller 12a. .

Since the transfer medium is strongly rubbed at the pressure contact portion between the paper feed roller 10 and the separation pad 11, the transfer medium is supplied more than the area on both sides of the transfer medium (the width of the transfer medium is indicated by L4 in FIG. 18). The area in contact with the paper roller 10 has a larger amount of paper dust. However, the upper registration roller 12a
Can sufficiently cover the contact area of the transfer medium with the feed roller 10 and also contact the areas on both sides of the transfer medium, so that the paper dust can be reliably removed.

The member for coating the upper registration roller 12a can be made of not only Teflon but also, for example, fluorocarbon, polycarbonate, polyurethane, acrylic, epoxy and the like. Further, a rubber containing butyl, polyisoprene, neoprene (registered trademark), or the like may be coated on the conductor.

The present invention has been described based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. Can easily be inferred.

[0098]

According to the first aspect of the present invention, since the transport roller on the cartridge side is movably mounted in a state where the process cartridge is not mounted on the image forming apparatus, even if the process cartridge is replaced. By the positioning means on the image forming apparatus side,
The relationship of the pressing force and the like between the cartridge-side transfer roller and the image forming apparatus-side transfer roller can be always kept constant, and the transfer medium can always be stably transferred.

According to the process cartridge of the present invention, the cartridge-side transport roller or the rotation axis of the cartridge-side transport roller is formed to be longer than the width of the process cartridge in the width direction. Since the cartridge is also protruded and attached, a means for positioning the cartridge-side transfer roller or the rotation shaft of the cartridge-side transfer roller can be provided outside the side surface of the process cartridge. As a result, the image forming apparatus includes the cartridge-side transport roller or the rotating shaft of the cartridge-side transport roller at a position further outside the side surface of the process cartridge so as to be along the substantially horizontal movement direction of the process cartridge. And the process cartridge can be easily moved in a substantially horizontal direction.

According to the process cartridge of the third aspect, since the transport roller on the cartridge side is a metal shaft, it has a simple configuration while maintaining sufficient rigidity, and has a simple structure and a longer length than the width of the transfer medium. The transport roller can be attached to the process cartridge.

According to the fourth aspect of the present invention, since the positioning means on the image forming apparatus acts on the bearings provided at both ends of the transport roller on the cartridge side, the positioning means operates on the cartridge side. Accurate positioning can be performed without hindering the rotation of the transport roller.

According to the fifth aspect of the present invention, since the opening for passing the transfer medium is provided in the vicinity of the mounting position of the cartridge side transport roller, the cartridge side transport roller and the image forming apparatus side are provided. The transfer medium conveyed favorably by the conveying rollers is immediately conveyed to the opening, and the transfer medium can be stably conveyed as the whole process cartridge.

According to the image forming apparatus of the present invention, since the positioning means for the transport roller is provided on both side surfaces of the cartridge, the cartridge-side transport roller and the image forming apparatus can be used even when the process cartridge is replaced with a new one. The relationship between the pressing force and the like with the apparatus-side transport roller can be always kept constant, and the positioning means for the transport roller is provided on both side surfaces of the cartridge, so that the process cartridge is substantially The process cartridge can be easily attached and detached without hindering movement in the horizontal direction.

According to the image forming apparatus of the present invention, since the positioning means is a groove connected to the guide member, it does not hinder the movement of the process cartridge in a substantially horizontal direction, so that the process cartridge can be easily attached and detached. can do.

According to the image forming apparatus of the eighth aspect, the process cartridge of any one of the first to fifth aspects is provided so as to be taken out or mounted from the front portion of the image forming apparatus. In the case where the process cartridge according to any one of (5) and (5) can be taken out or mounted from the front portion of the image forming apparatus, as described above, the positioning means does not hinder the movement of the process cartridge in the substantially horizontal direction. It is possible to easily remove or mount the cartridge from the front portion of the image forming apparatus.

10. The process cartridge according to claim 9, wherein the cartridge-side transport roller is provided with a frictional charging member longer than the longitudinal length of the cartridge-side transport roller in the circumferential direction of the cartridge-side transport roller. Since it was attached in contact so as to cover the surface uniformly,
Paper dust can be reliably removed. In addition, even if the removed paper dust is accumulated, the process of replacing the process cartridge leads to the operation of discarding the accumulated paper dust as it is, so that the maintenance of the paper dust at the transport roller unit can be eliminated.

According to the tenth aspect of the present invention, since the surface of the cartridge-side transport roller is coated with a resin, the frictional charging member can be satisfactorily triboelectrically charged to reliably remove paper dust. it can.

According to the process cartridge of the present invention, the resin coating on the surface of the transport roller on the cartridge side is a Teflon coating, so that the frictional charging member favorably triboelectrically charges and reliably removes paper dust. Can be.

According to the process cartridge of the twelfth aspect, since the frictional charging member is formed of a foamed elastic material, the resin-coated cartridge-side transport roller can be frictionally charged satisfactorily. And excellent good paper dust removal can be performed.

According to a thirteenth aspect of the present invention, the foamed elastic body forming the frictional charging member is an ether-based foamed elastic body. It shows good separability from paper dust removed at the contact portion with the cartridge-side transport roller, and prevents paper dust from agglomerating, thereby enabling good collection of paper dust.

According to the fourteenth aspect of the present invention, since the foamed elastic body forming the frictional charging member is an ester-based foamed elastic body, the cartridge-side transport roller is charged well as described above. The paper dust removed at the contact portion with the cartridge-side transport roller is slightly easily aggregated. However, since a scraping member is attached to the cartridge-side transport roller in contact with the cartridge-side transport roller, the paper dust that tends to aggregate can be reliably removed from the cartridge-side transport roller.

According to the fifteenth aspect of the present invention, since a paper dust accommodating portion is formed inside the process cartridge near the cartridge-side transport roller, the cartridge-side transport roller and the cartridge-side transport roller are frictionally charged as described above. The paper dust removed at the contact portion with the application member is reliably stored in the paper dust storage portion. By exchanging the process cartridge, the paper dust can be satisfactorily stored by the paper dust storage unit in which the paper dust is not accumulated.

According to the image forming apparatus of the sixteenth aspect,
The cartridge-side transport roller is formed so that the length in the longitudinal direction is longer than the length of the take-out roller, and has a positional relationship of uniformly covering the take-out roller in the longitudinal direction when the process cartridge is mounted. As a result, the cartridge-side transport roller can reliably cover the area covered with the paper dust contacted by the take-out roller, and also covers both sides of the transfer medium, so that good paper dust removal is performed. be able to.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a side view illustrating a schematic configuration of a process cartridge in the image forming apparatus of FIG.

FIG. 3 is an enlarged view showing the vicinity of an upper registration roller mounting portion in the process cartridge of FIG. 2;

4A and 4B are diagrams showing an upper registration roller in the process cartridge of FIG. 2, wherein FIG. 4A is a front view of a bearing body, and FIGS. 4A and 4B are upper registration rollers having bearing bodies attached to both ends. (A) (iii) is a front view of the bearing, (B) (i) is a front view showing the position of the bearing relative to the side wall of the process cartridge when the upper registration roller is moved to the upper position, (B) (ii) is a side view showing the position of the upper registration roller with respect to the process cartridge side wall when the upper registration roller is moved to the upper position, and (B) and (iii) move the upper registration roller to the upper position. (C) and (i) are axes relative to the side wall of the process cartridge when the upper registration roller is moved to the lower position. Front view showing the position of the receiver,
(C) and (ii) are side views showing the position of the upper registration roller with respect to the side wall of the process cartridge when the upper registration roller is moved to the lower position, and (C) and (iii) move the upper registration roller to the lower position. FIG. 7 is a front view showing a position of a bearing body with respect to a side wall of a process cartridge in a case where it is set.

5A and 5B are enlarged views of the vicinity of the bearing body with respect to FIG. 4C, wherein FIG. 5A is an enlarged view of FIGS. 4C and 4I and FIG.
(C) (ii) Enlarged view around the bearing body, (C) is FIG. 4 (C)
(Ii) Enlarged view of the periphery of the bearing body, (D) in FIG. 4 (C) (ii)
It is an enlarged view of i).

6A and 6B are diagrams showing the bearing body shown in FIGS. 4A and 4I, wherein FIG. 6A is a top view, FIG. 6B is a cross-sectional view taken along line CC of FIG.
(C) is a left side view, (D) is a front view, (E) is a right side view, and (F) is a FF sectional view of (C).

FIGS. 7A and 7B are views showing the bearing body shown in FIGS. 4A and 4C, wherein FIG. 7A is a top view, FIG. 7B is a left side view, and FIG. (D) is a front view, and (E) is a right side view.

FIG. 8 is a view for explaining a method of mounting an upper registration roller to which a bearing body is mounted on a process cartridge (part 1).

FIG. 9 is a view for explaining a method of mounting an upper registration roller to which a bearing body is mounted on a process cartridge (part 2).

FIG. 10 is a view for explaining mounting of a process cartridge on a printer main body (part 1).

FIG. 11 is a diagram for explaining how the process cartridge is mounted on the printer main body (part 2).

FIG. 12 is a view for explaining attachment of a process cartridge to a printer main body (part 3).

FIG. 13 is a view for explaining attachment of the process cartridge to the printer main body (part 4).

FIG. 14 is a diagram illustrating a positioning state of an upper registration roller with respect to a lower registration roller when the process cartridge is mounted on a printer main body.

FIG. 15 is a diagram illustrating a positioning state of a transfer roller with respect to a photosensitive drum when a process cartridge is mounted on a printer main body.

FIG. 16 is a sectional view illustrating a schematic configuration of a process cartridge according to a second embodiment of the present invention.

17 is a view of the upper conveying roller and the triboelectric charging member as a paper dust removing unit in the process cartridge of FIG. 16, as viewed from above in FIG.

FIG. 18 is a view illustrating a relationship among widths of an upper conveying roller, a photosensitive drum, a sheet feeding roller, and a separation pad in the process cartridge of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body housing 2 Process cartridge 12a Upper registration roller 12b Lower registration roller 13 Photoconductor drum 14 Transfer roller 22 Developing roller 30 Case 45 Spring 70, 71 Bearing body 90 Sponge 91 Scraping sheet 92 Paper dust storage chamber

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/00 518 G03G 15/00 518 3F343 (72) Inventor Yasushi Okabe Yashirocho, Mizuho-ku, Nagoya-shi, Aichi, 15 No. 1 Brother Industrial Co., Ltd. F term (reference) 2H071 BA04 BA13 BA15 BA23 BA27 BA29 BA32 DA05 DA15 DA23 DA26 2H072 BA03 CA01 CB05 CB07 CB09 HB07 3F049 AA03 CA01 CA32 DA12 DB02 LA01 LB03 3F101 AB01 AB07 AB03 AB01 A01 LB03 AB01 BA02 BA07 BB02 DA08 EA03 3F343 FA02 FB01 FC17 FC24 GA01 GB01 GC01 GD01 JA18 JD08 KB06 KB17

Claims (16)

[Claims] 1. A photoreceptor on which an electrostatic latent image is formed, developing means for visualizing the electrostatic latent image on the photoreceptor with a developer, and transfer for transferring the visible image to a transfer medium And a process cartridge detachably provided in the image forming apparatus, wherein the process cartridge is conveyed by being pressed against an image forming apparatus side conveying roller provided on the image forming apparatus side. A cartridge-side transport roller that forms a transport roller pair that transports the transfer medium together with a roller, wherein the cartridge-side transport roller is movably attached to the image forming apparatus in a state where the process cartridge is not mounted. A process cartridge characterized by the above-mentioned. 2. The method according to claim 1, wherein the cartridge-side transport roller or a rotating shaft of the cartridge-side transport roller is formed to be longer than a width of the process cartridge in a width direction, and is mounted so as to protrude from a side portion of the process cartridge. The process cartridge according to claim 1, wherein: 3. The process cartridge according to claim 1, wherein the cartridge-side transport roller is a metal shaft. 4. The cartridge according to claim 1, wherein bearings are provided at both ends of the transport roller on the cartridge side, and the bearings are movably attached to the process cartridge. A process cartridge according to any one of the preceding claims. 5. The process cartridge according to claim 1, wherein an opening for passing the transfer medium is provided in the vicinity of a mounting position of the cartridge-side transport roller. The process cartridge as described. 6. An image forming apparatus provided with the process cartridge according to claim 1 in a detachable manner, comprising: positioning means for the cartridge-side transport roller on both side surfaces of the cartridge. An image forming apparatus comprising: 7. The image forming apparatus according to claim 6, further comprising a guide member for the cartridge-side transport roller, wherein the positioning unit includes a groove connected to the guide member. 8. The image forming apparatus according to claim 6, wherein the process cartridge according to any one of claims 1 to 5 is provided so as to be taken out or mounted from a front portion of the image forming apparatus. . 9. The cartridge-side transport roller is provided such that a frictional charging member longer than a longitudinal length of the cartridge-side transport roller uniformly covers a circumferential surface of the cartridge-side transport roller. The process cartridge according to claim 1, wherein the process cartridge is mounted in contact with the process cartridge. 10. The process cartridge according to claim 9, wherein a surface of the cartridge-side transport roller is coated with a resin. 11. The process cartridge according to claim 10, wherein the resin coating on the surface of the cartridge-side transport roller is a Teflon (registered trademark) coating. 12. The process cartridge according to claim 9, wherein the frictional charging member is formed of a foamed elastic body. 13. The process cartridge according to claim 12, wherein the foamed elastic body forming the frictional charging member is an ether-based foamed elastic body. 14. The foamed elastic body forming the frictional charging member is an ester-based foamed elastic body, and a scraping member is attached to the cartridge-side conveying roller in contact therewith. The process cartridge according to claim 12, wherein 15. The process cartridge according to claim 9, wherein a paper dust accommodating portion is formed inside the process cartridge near the cartridge-side transport roller. 16. The image forming apparatus according to claim 9, further comprising a take-out roller for taking out the transfer medium from the transfer medium accommodating portion for containing the transfer medium, and a separating member provided in pressure contact with the take-out roller. An image forming apparatus in which the process cartridge is detachably mounted, wherein a longitudinal length of the cartridge-side transport roller is formed longer than a longitudinal length of the take-out roller, and when the process cartridge is mounted, An image forming apparatus having a positional relationship of uniformly covering the take-out roller in the longitudinal direction.