WO2014010119A1

WO2014010119A1 - Cartridge

Info

Publication number: WO2014010119A1
Application number: PCT/JP2012/080831
Authority: WO
Inventors: 進佐久間; 啓城森
Original assignee: ブラザー工業株式会社
Priority date: 2012-07-09
Filing date: 2012-11-29
Publication date: 2014-01-16
Also published as: JP2014016487A

Abstract

Provided is a cartridge that can secure an efficient disposition of a photosensitive drum while being able to suppress a size increase of the cartridge. A process cartridge (15) is provided with: a photosensitive drum (20) provided with a drum main body (81) and a drum gear (83); and an electricity supply unit (43) that contacts (acts upon) main body electrodes (133a, 133b) provided to a main body casing (2). A first non-image-forming region (T1) is formed at the peripheral surface of the left end of the drum main body (81), and a second non-image-forming region (T2) is formed at the peripheral surface of the right end of the drum main body (81). Also, the drum gear (83) is provided to the left end of the drum main body (81) in a manner so that a gear section (97) neighbors the left end of the drum main body (81) from the left side, and the electricity supply unit (43) is disposed at the right-front side of the right end of the drum main body (81) in a manner so as to protrude to the right beyond the right end surface of the drum main body (81).

Description

cartridge

The present invention relates to a cartridge mounted on an image forming apparatus employing an electrophotographic system.

Conventionally, an electrophotographic printer in which a cartridge is detachably mounted is known. The cartridge includes a photosensitive drum extending in the left-right direction, a transfer roller, an electrode member, and a gear mechanism.

As such a cartridge, for example, there is a process cartridge including a drum cartridge including a photosensitive drum and a transfer roller, and a developing cartridge that includes a developing roller, a developing roller electrode, and a gear mechanism section and is detachably attached to the drum cartridge. It has been proposed (see, for example, Patent Document 1).

In such a process cartridge, a drum driving gear for receiving a driving force and a transfer roller gear for transmitting the driving force to the transfer roller are provided at the left end portion of the photosensitive drum. Further, the developing roller electrode is provided so as to protrude leftward from the drum driving gear and the transfer roller gear, and the gear mechanism portion is provided so as to face the drum driving gear and the transfer roller gear on the front side. It has been.

In such a process cartridge, when attached to the printer, a bias is applied from the printer to the developing roller via the developing roller electrode, and a driving force is input to the developing roller via the gear mechanism. The

JP 2006-72285 A

However, it is desirable that the photosensitive drum is disposed at a substantially central portion in the left-right direction of the process cartridge.

However, in the process cartridge described in Patent Document 1, the drum driving gear and the transfer roller gear are provided on the left end side of the photosensitive drum, and the developing roller electrode is directed to the left rather than the drum driving gear and the transfer roller gear. It is provided to protrude.

Therefore, it is necessary to secure a space for providing the drum driving gear, the transfer roller gear, and the developing roller electrode in the left part of the process cartridge on the left side of the photosensitive drum, and the part on the right side of the right end of the photosensitive drum. A relatively large space is ensured as compared with the above.

As a result, the photosensitive drum is provided in the process cartridge so as to be packed on the right side, and it is difficult to ensure an efficient arrangement of the photosensitive drum.

On the other hand, if a separate space is provided in a portion on the right side of the right end portion of the photosensitive drum in the process cartridge, the photosensitive drum can be disposed at a substantially central portion in the left-right direction of the process cartridge. There is a problem that.

Therefore, an object of the present invention is to provide a cartridge capable of ensuring an efficient arrangement of the photosensitive drum while suppressing an increase in size of the cartridge.

(1) In order to achieve the above-described object, the cartridge of the present invention includes an element tube that extends in the axial direction and has a photosensitive layer formed on the peripheral surface, and a first end that is one end of the element tube in the axial direction. A tube with respect to a photosensitive drum provided with a gear provided to a part and configured to receive a driving force from the outside, and a second end which is an end opposite to the first end of the tube And an action member configured to act on a member outside the cartridge.

The blank tube includes a first non-image forming region formed on the peripheral surface of the first end, a second non-image forming region formed on the peripheral surface of the second end, and a first non-image forming region. And an image forming area formed between the second non-image forming area.

Further, the action member has a protruding portion that is disposed on the outer side in the axial direction than the second end portion.

In addition, the axial length of the first non-image forming area is longer than the axial length of the second non-image forming area, and the axial length of the gear is shorter than the axial length of the protruding portion. ing.

According to such a configuration, the gear is provided at the first end portion of the raw tube, and the protruding portion of the action member is disposed on the outer side in the axial direction from the second end portion. On the other hand, a space for providing the gear is secured outside in the axial direction, and a space for arranging the protruding portion is secured outside in the axial direction with respect to the second end portion of the base tube.

Therefore, compared with the case where a space is secured outside in the axial direction and a space is secured only on one side in the axial direction of the raw tube with respect to each of both ends in the axial direction of the raw tube, the raw tube is more efficient. Arrangement can be secured.

In addition, on one side (first end side) in the axial direction of the raw tube, a first non-image forming region that is longer than the second non-image forming region and a gear that is shorter than the protruding portion are arranged, A second non-image forming region that is shorter than the first non-image forming region and a long protruding portion that is compared to the gear are disposed on the other axial side (second end side) of the raw tube.

That is, a space for arranging the first non-image forming region and the gear is secured on one side in the axial direction of the cartridge, and the second non-image forming region and the protruding portion are arranged on the other side in the axial direction of the cartridge. Space is reserved.

Therefore, a space is ensured in a well-balanced manner on both sides in the axial direction of the cartridge, and an efficient arrangement of the image forming areas formed between the first non-image forming area and the second non-image forming area can be ensured.

Therefore, according to the cartridge of the present invention, it is possible to secure an efficient arrangement of the base tube of the photosensitive drum, particularly the image forming region, while suppressing an increase in size of the cartridge.
(2) Further, the thickness of the photosensitive layer in a part of the first non-image forming region is formed thinner than the thickness of the photosensitive layer in the image forming region, and the thickness of the photosensitive layer in a part of the second non-image forming region is Further, it may be formed thicker than the photosensitive layer in the image forming region.

According to such a configuration, the axial end portion of the element tube is the first end portion or the first end portion depending on the thickness of each photosensitive layer in a part of the first non-image forming region and a part of the second non-image forming region. It can be easily determined which of the two ends corresponds. Therefore, it is possible to facilitate the assembly operation of the cartridge.
(3) Further, the cartridge may include a first cartridge including a photosensitive drum, and a second cartridge configured to be able to store a developer and to be detachably attached to the first cartridge. .

In this case, the second cartridge is disposed so as to face the raw tube from the outside in the radial direction, and is configured to supply the developer to the image forming region, the first end, and the gear. And a working member that is arranged so as to be opposed to each other from the outside in the radial direction and configured to transmit a driving force from the outside of the second cartridge to the developer carrier.

Further, the action member may be an electrode member configured to be electrically connected to the developer carrying member.

According to such a configuration, since the photosensitive member is provided in the first cartridge and the developer is accommodated in the second cartridge, for example, when the photosensitive member reaches the end of its life, only the first cartridge is replaced. If the remaining amount of developer is less than the predetermined value, only the second cartridge can be replaced.

Therefore, the running cost can be reduced as compared with the case where the developer is accommodated in one cartridge and the photosensitive member is provided.

Further, since the second cartridge includes the developer carrier, the drive member, and the electrode member, the driving force can be transmitted to the developer carrier via the drive member during the image forming operation. In addition, a bias can be applied to the developer carrier via the electrode member.

Further, since the driving member is disposed so as to face the first end portion and the gear from the outside in the radial direction, the first end portion (first non-image forming region) and a space for arranging the gear are provided. A drive member can be arrange | positioned and the space can be utilized effectively.

For this reason, the developer carrying member can reliably supply the developer to the image forming area during the image forming operation, while suppressing an increase in size of the cartridge.

Accordingly, the running cost can be reduced, and the developer can be reliably supplied to the image forming area, and the enlargement of the cartridge can be suppressed.
(4) Further, in a state where the second cartridge is mounted on the first cartridge, the axial center portion of the image forming area and the axial center portion of the developer carrying member are arranged along the radial direction. May be.

According to such a configuration, since the central portion in the axial direction of the image forming region and the central portion in the axial direction of the developer carrier are arranged along the radial direction, the efficiency of the developer carrier is increased. It is possible to more reliably supply the developer to the image forming area while ensuring a proper arrangement.

According to the present invention, it is possible to ensure efficient arrangement of the photosensitive drum, particularly the image forming area, while suppressing an increase in size of the cartridge.

FIG. 1 is a central sectional view showing an embodiment of a printer. FIG. 2 is a perspective view of the process cartridge shown in FIG. 1 as viewed from the upper left side. FIG. 3 is an exploded perspective view of the drum cartridge shown in FIG. 2 as viewed from the upper left side. FIG. 4 is a plan view of the process cartridge (with the cover frame removed) shown in FIG. FIG. 5A is a left side view of the process cartridge shown in FIG. 2, and FIG. 5B is a right side view of the process cartridge shown in FIG. FIG. 6 is a cross-sectional view of the process cartridge shown in FIG.

1. Printer As shown in FIG. 1, the printer 1 includes a main body casing 2 having a substantially box shape.

In addition, the printer 1 includes a paper feeding unit 3 for feeding the paper S and an image forming unit 4 for forming an image on the fed paper S in the main body casing 2.

In addition, when referring to the direction with respect to the printer 1, the state of being placed in the horizontal direction is used as a reference, and specifically, the direction of an arrow in the drawing is used as a reference.
(1) Main Body Casing The main body casing 2 is formed with a cartridge opening 5 for attaching / detaching a process cartridge 15 (described later) and a paper opening 6 for introducing the paper S.

The cartridge opening 5 is formed through the upper end of the main casing 2 in the vertical direction.

The paper opening 6 is formed to penetrate in the front-rear direction at the lower end of the front end of the main casing 2.

Further, the main body casing 2 is provided with a top cover 7 at its upper end and a paper feed cover 8 at its front end.

The top cover 7 is swingably (moved) between a closed position for closing the cartridge opening 5 and an open position for opening the cartridge opening 5 with the rear end as a fulcrum (shown in FIG. 1). (See the two-dot chain line).

The paper feed cover 8 is provided so as to be swingable (movable) between a first position where the paper opening 6 is closed and a second position where the paper opening 6 is opened with the lower end portion as a fulcrum (see FIG. 1).
(2) Paper Feed Unit The paper feed unit 3 includes a paper placement unit 9 provided at the bottom of the main casing 2.

The paper stacking portion 9 is communicated with the outside of the main casing 2 through the paper opening 6.

The sheet S is stacked on the upper surface of the sheet feed cover 8 while the sheet feed cover 8 is disposed at the second position, and the rear part is loaded on the sheet via the sheet opening 6. Stacked in the placement unit 9.

The paper feeding unit 3 includes a pickup roller 11 disposed on the upper side of the rear end portion of the paper placing unit 9, a paper feeding roller 12 disposed on the rear side of the pickup roller 11, and a rear lower side of the paper feeding roller 12. The sheet feeding pad 13 is disposed opposite to the sheet feeding side, and the sheet feeding path 14 extends continuously upward from the rear end portion of the sheet feeding pad 13.
(3) Image Forming Unit The image forming unit 4 includes a process cartridge 15 as an example of a cartridge, a scanner unit 16, and a fixing unit 17.
(3-1) Process Cartridge The process cartridge 15 is configured to be detachable from the main casing 2 and is mounted on the main casing 2 above the rear portion of the paper feed unit 3.

The process cartridge 15 includes a drum cartridge 18 as an example of a first cartridge and a developing cartridge 19 as an example of a second cartridge.

The drum cartridge 18 is configured to be detachable from the main casing 2, and includes a photosensitive drum 20, a transfer roller 21, and a scorotron charger 22.

The photosensitive drum 20 is formed in a substantially cylindrical shape extending in the left-right direction (axial direction), and is provided in the rear portion of the drum cartridge 18. The photosensitive drum 20 can be rotated about its center axis A1 (rotation axis) as a rotation center.

The transfer roller 21 is formed in a substantially cylindrical shape extending in the left-right direction, and is pressed against the photosensitive drum 20 from the rear side. Further, the transfer roller 21 can rotate around its central axis.

Specifically, the transfer roller 21 is disposed on the rear side of the photosensitive drum 20 so that the central axis thereof is positioned slightly below the central axis A1 of the photosensitive drum 20. The lower end edge of the transfer roller 21 is disposed above the lower end edge of the photosensitive drum 20. Specifically, a virtual line segment (not shown) connecting the central axis of the transfer roller 21 and the central axis A1 of the photosensitive drum 20, and a virtual straight line (not shown) extending horizontally along the front-rear direction. The acute angle formed by is about 3 °. Therefore, the pressure (transfer pressure) at which the transfer roller 21 is pressed against the photosensitive drum 20 is not affected by the weight of the transfer roller 21.

The scorotron charger 22 is disposed opposite to the front upper side of the photosensitive drum 20 with an interval.

Specifically, the scorotron charger 22 is disposed at a distance from the transfer roller 21 in the circumferential direction of the photosensitive drum 20, and connects the central axis A 1 of the photosensitive drum 20 and the central axis of the transfer roller 21. An angle formed by a virtual line segment (not shown) and a virtual line segment (not shown) connecting the central axis A1 of the photosensitive drum 20 and the charging wire 23 (described later) is about 120 °. Are arranged as follows.

The scorotron charger 22 includes a charging wire 23 and a grid 24.

The charging wire 23 is stretched so as to extend in the left-right direction, and is opposed to the front upper side of the photosensitive drum 20 with an interval.

The grid 24 is formed in a substantially U shape in a side view opened toward the front upper side, and is provided so as to surround the charging wire 23 from the lower rear side.

The developing cartridge 19 is detachably attached to the drum cartridge 18 and is disposed on the lower front side of the photosensitive drum 20.

Further, the developing cartridge 19 includes a substantially box-shaped developing frame 25, and in the developing frame 25, a toner storage chamber 26 and a developing chamber 27 are formed side by side. The toner storage chamber 26 and the developing chamber 27 are formed to have substantially the same volume, and communicate with each other through a communication port 28.

The toner storage chamber 26 stores toner (developer), and an agitator 29 is provided at a substantially central portion in the front-rear and vertical directions. That is, the agitator 29 is disposed below the photosensitive drum 20.

In the developing chamber 27, a supply roller groove 30, a developing roller facing surface 31, and a lower film attaching surface 32 are formed on the inner surface (upper surface) of the lower wall.

The supply roller groove 30 has a substantially semicircular shape along the peripheral surface of a supply roller 33 (described later), and is formed so as to be recessed downward in the rearward direction.

The developing roller facing surface 31 has a substantially arc shape along the circumferential surface of the developing roller 34 (described later), and is formed so as to continuously extend from the rear end portion of the supply roller groove 30 toward the rear upper side. .

The lower film attaching surface 32 is formed so as to continuously extend rearward from the rear end portion of the developing roller facing surface 31. That is, the lower film attaching surface 32 is disposed above the developing roller facing surface 31.

Further, the lower film attaching surface 32 is disposed to face the lower portion of the photosensitive drum 20 with a space in the vertical direction, and overlaps the central axis A1 of the photosensitive drum 20 when projected in the vertical direction. Are arranged as follows.

In the developing chamber 27, a supply roller 33, a developing roller 34 as an example of a developer carrier, a layer thickness regulating blade 35, and a lower film 36 are provided.

The supply roller 33 is formed in a substantially cylindrical shape extending in the left-right direction, and is provided in the front portion of the developing chamber 27 so that the lower portion thereof is disposed in the supply roller groove 30. The supply roller 33 is disposed on the rear side of the toner storage chamber 26, and is disposed at substantially the same height as the toner storage chamber 26 in the vertical direction (slightly above the toner storage chamber 26). Further, the supply roller 33 can rotate around its center axis as a rotation center.

The developing roller 34 is formed in a substantially cylindrical shape extending in the left-right direction, and is provided in the rear portion of the developing chamber 27 so that the circumferential surface in the lower portion thereof and the developing roller facing surface 31 face each other with a space therebetween. It has been. The length of the developing roller 34 in the left-right direction is longer than the length of the supply roller 33 in the left-right direction.

The developing roller 34 is provided so as to come into contact with the supply roller 33 from the upper rear side, and its upper and rear portions are exposed from the developing chamber 27, and contact the photosensitive drum 20 from the lower front side. Yes. That is, the developing roller 34 is disposed on the upper rear side of the supply roller 33 and is disposed on the lower front side of the photosensitive drum 20 and below the central axis A1 of the photosensitive drum 20. The central axis of the supply roller 33, the central axis of the developing roller 34, and the central axis A1 of the photosensitive drum 20 are positioned on substantially the same straight line along the radial direction of the photosensitive drum 20.

Further, the developing roller 34 is arranged with a gap in the circumferential direction of the photosensitive drum 20 with respect to the scorotron charger 22, and a virtual line segment connecting the central axis A 1 of the photosensitive drum 20 and the charging wire 23. (Not shown) and an imaginary line segment (not shown) connecting the central axis A1 of the photosensitive drum 20 and the central axis of the developing roller 34 are arranged so that the angle of the angle is about 120 °. ing. That is, the developing roller 34, the scorotron charger 22, and the transfer roller 21 are arranged at substantially equal intervals in the circumferential direction of the photosensitive drum 20. Further, the developing roller 34 can rotate around its center axis.

The upper end portion of the layer thickness regulating blade 35 is fixed to the rear end portion of the upper wall of the developing chamber 27, and the lower end portion thereof is in contact with the developing roller 34 from the front side.

The rear portion of the lower film 36 is fixed to the lower film attaching surface 32, and the front end thereof is in contact with the peripheral surface of the developing roller 34 on the upper side of the developing roller facing surface 31.
(3-2) Scanner Unit The scanner unit 16 is disposed on the front side of the process cartridge 15 so as to face the photosensitive drum 20 with a space in the front-rear direction.

The scanner unit 16 emits a laser beam L toward the photosensitive drum 20 based on the image data to expose the peripheral surface of the photosensitive drum 20.

Specifically, the laser beam L is emitted backward from the scanner unit 16 to expose the peripheral surface at the front end portion of the photosensitive drum 20. That is, the exposure point at which the photosensitive drum 20 is exposed (the peripheral surface at the front end portion of the photosensitive drum 20) is opposite to the nip portion where the photosensitive drum 20 and the transfer roller 21 are in contact with the central axis A1 of the photosensitive drum 20. Is set to the side.

At this time, the developing cartridge 19 is arranged below the emission locus of the laser beam L, and the scorotron charger 22 is arranged above the emission locus of the laser beam L.

A guide portion 37 for guiding the attachment / detachment of the process cartridge 15 is provided on the inner side surface of the main body casing 2 between the scanner unit 16 and the photosensitive drum 20. When the process cartridge 15 is detached from the main casing 2, the process cartridge 15 is guided by the guide portion 37, so that the developing cartridge 19 attached to the drum cartridge 18 has a lower emission locus of the laser beam L. Pass from the top to the top.

At this time, the various rollers (transfer roller 21, supply roller 33 and developing roller 34) provided in the process cartridge 15 also pass the emission locus of the laser beam L from the lower side to the upper side.
(3-3) Fixing Unit The fixing unit 17 is disposed above the rear portion of the drum cartridge 18. Specifically, the fixing unit 17 includes a heating roller 38 disposed on the upper side of the scorotron charger 22 and a pressure roller 39 pressed against the heating roller 38 from the rear upper side.

That is, the heating roller 38 is disposed in the vicinity of the upper end portion (open end portion) of the grid 24 of the scorotron charger 22.
(4) Image Forming Operation The toner in the toner storage chamber 26 of the developing cartridge 19 is supplied to the supply roller 33 through the communication port 28 by the rotation of the agitator 29, and further supplied to the developing roller 34. Between 33 and the developing roller 34, it is triboelectrically charged to the positive polarity.

The toner supplied to the developing roller 34 is regulated in thickness by the layer thickness regulating blade 35 as the developing roller 34 rotates, and is carried on the peripheral surface of the developing roller 34 as a thin layer having a constant thickness.

On the other hand, the peripheral surface of the photosensitive drum 20 is uniformly charged by the scorotron charger 22 and then exposed by the scanner unit 16. As a result, an electrostatic latent image based on the image data is formed on the peripheral surface of the photosensitive drum 20 (specifically, an image forming region T3 (described later, see FIG. 4) of the drum body 81 (described later)). Then, the toner carried on the developing roller 34 is supplied to the electrostatic latent image on the peripheral surface of the photosensitive drum 20 (specifically, an image forming region T3 (see FIG. 4 described later)). A toner image (developer image) is carried on the peripheral surface (specifically, an image forming region T3 (see FIG. 4 described later)).

The sheets S stacked on the sheet loading unit 9 are sent between the sheet feeding roller 12 and the sheet feeding pad 13 by the rotation of the pickup roller 11 and are turned one by one by the rotation of the sheet feeding roller 12. Thereafter, the paper S that has been squeezed is conveyed to the paper feed path 14 by the rotation of the paper feed roller 12 and is imaged one by one at a predetermined timing (between the photosensitive drum 20 and the transfer roller 21). Paper is fed to

Then, the sheet S is conveyed between the photosensitive drum 20 and the transfer roller 21 from the lower side to the upper side. At this time, the toner image is transferred onto the paper S to form an image.

The sheet S is heated and pressed when it passes between the heating roller 38 and the pressure roller 39. At this time, the image is thermally fixed on the paper S.

Thereafter, the paper S is conveyed toward the paper discharge roller 40, and is discharged onto a paper discharge tray 41 formed on the upper surface of the main casing 2 by the paper discharge roller 40.

In this way, the paper S is fed from the paper placement unit 9, passes between the photosensitive drum 20 and the transfer roller 21 (nip portion), and then passes between the heating roller 38 and the pressure roller 39. After that, the paper is transported through a substantially C-shaped transport path in side view so that the paper is discharged onto the paper discharge tray 41. 2. Process Cartridge The process cartridge 15 includes a drum cartridge 18 and a developing cartridge 19 as described above and shown in FIG.
(1) Drum Cartridge The drum cartridge 18 includes a drum frame 51.

In the following description of the drum cartridge 18, when referring to the direction, the side on which the photosensitive drum 20 is disposed is the rear side of the drum cartridge 18, and the side on which the scorotron charger 22 is disposed is the upper side. And That is, the up / down / front / rear direction with respect to the drum cartridge 18 is slightly different from the up / down / front / rear direction with respect to the printer 1, and the drum cartridge 18 has the rear side at the rear upper side of the printer 1 and the front side at the front lower side of the printer 1. It is attached to.
(1-1) Drum Frame As shown in FIG. 3, the drum frame 51 includes a base frame 52 and a cover frame 53.

The base frame 52 is formed in a bottomed frame shape having a substantially rectangular shape in plan view with the upper side open. The base frame 52 includes a pair of left and right base side walls 54, a base lower wall 55, a base rear wall 57, and a base front wall 56.

The pair of base side walls 54 are opposed to each other with an interval in the left-right direction.

Each of the pair of base side walls 54 is formed in a substantially flat plate shape that is long in the front-rear direction. The base side wall 54 is integrally provided with a rear portion 60 constituting the rear half and a front portion 61 constituting the front half thereof.

The rear portion 60 is formed in a substantially rectangular shape in side view extending in the vertical direction.

Further, a drum shaft insertion hole 58 is formed in the rear portion 60. The drum shaft insertion hole 58 is formed in a substantially circular shape in a side view at a substantially central portion in the front-rear direction of the rear portion 60. The inner diameter of the drum shaft insertion hole 58 is substantially the same as the outer diameter of a drum shaft 80 (described later) of the photosensitive drum 20. Note that the drum shaft insertion holes 58 of both the base side walls 54 coincide with each other when projected in the left-right direction.

The front part 61 is formed in a substantially rectangular shape in a side view and extending forward from the lower end part of the front end part of the rear part 60 (see FIG. 5A).

The base lower wall 55 is formed in a substantially flat plate shape that is long in the left-right direction so as to be bridged between the lower ends of the base side walls 54. Note that the rear end portion of the base lower wall 55 is disposed below the photosensitive drum 20 and spaced apart from the photosensitive drum 20 in the vertical direction (see FIG. 1).

The base rear wall 57 is disposed on the rear side of the rear end portion of the base lower wall 55 with a space therebetween, and has a substantially flat plate shape that is long in the left-right direction so as to be laid between the rear end portions of the base side walls 54. Is formed. As shown in FIG. 1, the opening area between the base rear wall 57 and the base lower wall 55 serves as a paper feed opening 74 for allowing the sheet S to pass between the photosensitive drum 20 and the transfer roller 21 to pass therethrough. It is partitioned (see FIG. 1).

Further, as shown in FIG. 3, a transfer roller support 70 is provided on the base rear wall 57. The transfer roller support portion 70 is provided so as to bulge rearward from the base rear wall 57 and is formed in a substantially partial cylindrical shape extending in the left-right direction.

The transfer roller support portion 70 is closed at both ends in the left-right direction and open at the upper and front sides. The left end portion of the transfer roller support portion 70 is disposed on the inner side (right side) in the left-right direction than the left base side wall 54, and the right end portion of the transfer roller support portion 70 is located on the inner side in the left and right direction (left side) with respect to the right base side wall 54. Is arranged.

Further, a drum gear exposure opening 72 is formed in the base rear wall 57.

The drum gear exposure opening 72 is formed in a substantially rectangular shape when viewed from the back, between the left end portion of the transfer roller support portion 70 and the left base side wall 54.

The base front wall 56 is formed in a substantially flat plate shape extending in the left-right direction so as to continuously extend upward from the front end portion of the base lower wall 55 and to be installed between the front end portions of the base side walls 54. Has been.

In the base frame 52, a portion between the rear portions 60 of the base side walls 54 is defined as a drum support portion 101 for supporting the photosensitive drum 20 on the front side of the transfer roller support portion 70.

Further, a portion of the base frame 52 on the front side of the drum support portion 101 (a portion defined by the base lower wall 55, the base front wall 56, and the front side portions 61 of the base side walls 54) is the developing cartridge 19. Is divided as a developing cartridge mounting portion 102 that can be mounted.

The cover frame 53 is disposed above the rear end of the base frame 52. The cover frame 53 is formed in a substantially rectangular tube shape that extends in the left-right direction and is opened at the lower side and the front side. The cover frame 53 includes a pair of left and right cover side walls 91, a cover upper wall 92, and a cover rear wall 93.

The pair of cover side walls 91 are arranged to face each other with a gap in the left-right direction.

The cover side wall 91 is formed in a substantially flat plate shape extending in the vertical direction. A drum shaft insertion hole 94 is formed in the cover side wall 91.

The drum shaft insertion hole 94 is formed in a substantially circular shape in a side view at the lower end portion of the cover side wall 91. The inner diameter of the drum shaft insertion hole 94 is substantially the same as the outer diameter of the drum shaft 80 of the photosensitive drum 20. The drum shaft insertion holes 94 of the cover side walls 91 coincide with each other when projected in the left-right direction.

The cover upper wall 92 is formed in a substantially rectangular tube shape extending in the left-right direction and being opened at the lower side so as to be installed between the upper ends of the cover side walls 91 (see FIG. 1). The above scorotron charger 22 is supported inside the cover upper wall 92 (see FIG. 1).

The cover rear wall 93 has a substantially flat plate shape that is long in the left-right direction so as to continuously extend rearward and downward from the rear end portion of the cover upper wall 92 and to be laid between the rear end portions of the cover side walls 91. Is formed. A paper discharge opening 121 is formed in the cover rear wall 93.

The paper discharge opening 121 is formed in a substantially rectangular shape when viewed from the back, which is long in the left-right direction, at a substantially central portion of the cover rear wall 93 in the vertical direction. The paper discharge opening 121 allows the paper S that has passed between the photosensitive drum 20 and the transfer roller 21 to pass toward the fixing unit 17 during the image forming operation (see FIG. 1).
(2) Photosensitive drum The drum cartridge 18 supports the photosensitive drum 20 and the transfer roller 21 as described above.

The photosensitive drum 20 includes a drum body 81, a drum gear 83, a friction member 82, and a drum shaft 80 as an example of a raw tube.

As shown in FIG. 4, the drum body 81 is made of metal and is formed in a substantially cylindrical shape extending in the left-right direction (axial direction), and the photosensitive surface 84 made of resin so as to cover the peripheral surface. Is formed.

The photosensitive layer 84 provided on the peripheral surface of the drum body 81 is immersed in the photosensitive layer coating solution in a state where the drum body 81 is arranged so that the axial direction thereof is along the vertical direction. It is formed by applying a photosensitive layer coating solution to the substrate and then drying it.

In the photosensitive layer coating step, the drum body 81 is disposed such that the axial direction of the drum body 81 is along the vertical direction, so that the coated photosensitive layer coating solution is moved downward by gravity.

Therefore, in the photosensitive layer coating process, the photosensitive layer 84 formed on the peripheral surface of the end portion of the drum body 81 disposed on the upper side (hereinafter referred to as one end portion in the axial direction) is the axis line of the drum body 81. Compared with the photosensitive layer 84 formed on the peripheral surface of the central portion in the direction, it is formed relatively thin. That is, a thin layer region T6 where the thickness of the photosensitive layer 84 is relatively thin is formed on the peripheral surface of one end portion in the axial direction of the drum body 81.

On the other hand, in the photosensitive layer coating process, the photosensitive layer 84 formed on the peripheral surface of the end portion of the drum body 81 disposed below (hereinafter referred to as the other end portion in the axial direction) is formed on the drum body 81. Compared with the photosensitive layer 84 formed on the peripheral surface of the central portion in the axial direction, it is formed relatively thick. That is, the thick layer region T7 in which the photosensitive layer 84 is relatively thick is formed on the peripheral surface of the other end portion in the axial direction of the drum body 81.

In addition, a holding region T4 that is held by a chuck device (not shown) or the like is formed between the thin layer region T6 and the edge on one side in the axial direction of the drum main body 81 in the photosensitive layer coating process. A margin region T5 is formed between the layer region T7 and the other edge of the drum body 81 in the axial direction on the other side in the photosensitive layer coating process. Note that the photosensitive layer 84 is not formed in each of the holding region T4 and the margin region T5.

As a result, non-image forming regions that are not suitable for image formation are formed on the peripheral surface of the drum body 81 at both axial end portions (one axial end portion and the other axial end portion).

Specifically, on the peripheral surface of the drum main body 81, a first non-image forming region T1 including a thin layer region T6 and a holding region T4 on the peripheral surface of one end portion in the axial direction as an example of the first end portion. Is formed, and a second non-image forming region T2 including a thick layer region T7 and a margin region T5 is formed on the peripheral surface of the other end portion in the axial direction as an example of the second end portion, and the first non-image forming region T1 An image forming region T3 is formed between the second non-image forming region T2.

The drum body 81 is disposed in the drum support portion 101 on the front side of the transfer roller 21 so that the first non-image forming area T1 is on the left side and the second non-image forming area T2 is on the right side. .

The left-right direction length D1 of the first non-image forming region T1 is longer than the left-right direction length D2 of the second non-image forming region T2.

Specifically, the horizontal length of the thin layer region T6 (the horizontal length from the left end edge E1 to the right end edge E2 of the thin layer region T6) is the horizontal length of the thick layer region T7 (the right end of the thick layer region T7). (Length in the left-right direction from the edge E3 to the left end edge E4). The horizontal length of the holding region T4 (the horizontal length from the left end edge E1 of the thin layer region T6 to the left end edge of the drum body 81) is also the horizontal length of the margin region T5 (the right end of the thick layer region T7). (Length in the left-right direction from the edge E3 to the right end edge of the drum main body 81).

Further, the thickness of the photosensitive layer 84 in the thin layer region T6 of the first non-image forming region T1 is formed to be thinner than the thickness of the photosensitive layer 84 in the image forming region T3, and the thick layer region T7 of the second non-image forming region T2. The photosensitive layer 84 is formed to have a thickness greater than that of the photosensitive layer 84 in the image forming region T3.

The drum gear 83 is provided at the left end portion (one end portion in the axial direction) of the drum main body 81 as shown in FIG. The drum gear 83 is integrally provided with a raw tube fitting portion 96, a gear portion 97 as an example of a gear, and a shaft support portion 95.

The raw tube fitting portion 96 is formed in a substantially cylindrical shape extending in the left-right direction, and has an outer diameter that is substantially the same (slightly smaller) as the inner diameter of the drum body 81.

Further, an insertion hole 105 through which the drum shaft 80 is inserted is formed in the center portion in the radial direction of the raw tube fitting portion 96. The insertion hole 105 is formed in a substantially circular shape when viewed from the side, and has an inner diameter that is substantially the same as the outer diameter of the drum shaft 80.

The gear portion 97 is formed in a substantially cylindrical shape that protrudes leftward from the left end face of the raw tube fitting portion 96 so that the central axis of the raw tube fitting portion 96 coincides with the central axis. The gear portion 97 has an outer diameter that is substantially the same as the outer diameter of the blank tube fitting portion 96, and gear teeth are formed on the outer circumferential surface of the gear portion 97 over the entire circumference.

In the internal space of the gear portion 97, the shaft support portion 95 is formed in a substantially cylindrical shape that protrudes leftward from the peripheral end portion of the insertion hole 105 so that the core tube fitting portion 96 and the center axis line coincide with each other. ing.

The outer diameter of the shaft support portion 95 is formed to be smaller than the inner diameter of the gear portion 97, and the inner diameter is formed to be substantially the same diameter (slightly larger diameter) as the outer diameter of the drum shaft 80.

Further, the shaft support portion 95 is formed such that the length in the left-right direction is slightly longer than the length in the left-right direction of the gear portion 97. That is, the left end portion of the shaft support portion 95 protrudes slightly from the left end portion of the gear portion 97.

The drum gear 83 is supported by the drum main body 81 by fitting the blank tube fitting portion 96 into the left end portion of the drum main body 81 so as not to be relatively rotatable.

Thereby, the gear portion 97 is provided so as to face the left end portion of the drum body 81 from the left side (outside in the left-right direction). Further, as shown in FIG. 4, the gear portion 97 is disposed between the rear portion 60 of the left side wall 54 of the base frame 52 and the left end portion of the transfer roller support portion 70. Further, the rear lower end portion of the gear portion 97 is exposed from the lower rear side through the drum gear exposure opening 72 as shown in FIG. The gear portion 97 exposed through the drum gear exposure opening 72 is engaged with a drive gear 130 provided in the main casing 2 in a state where the process cartridge 15 is mounted on the main casing 2 (see FIG. 1). .

As shown in FIG. 6, the friction member 82 is provided at the right end (the other end in the axial direction) of the drum body 81. The friction member 82 includes a raw tube fitting portion 98, a contact member 99, and a spring 100.

The raw tube fitting portion 98 is formed in a substantially cylindrical shape with the left end portion closed. The outer diameter of the raw tube fitting portion 98 is formed to be substantially the same diameter (slightly smaller) as the inner diameter of the drum body 81.

Further, an insertion hole 103 through which the drum shaft 80 is inserted is formed in the central portion in the radial direction of the closed portion of the raw tube fitting portion 98.

The contact member 99 is formed in a substantially cylindrical shape whose right end is closed. The contact member 99 has an outer diameter that is substantially the same diameter (slightly smaller) as the inner diameter of the blank tube fitting portion 98.

Further, an insertion hole 104 through which the drum shaft 80 is inserted is formed in the central portion in the radial direction of the closed portion of the contact member 99.

The contact member 99 is fitted from the right side with respect to the raw tube fitting portion 98 so that the spring 100 is accommodated in the internal space. Thereby, the contact member 99 is always urged | biased by the spring 100 toward right.

The friction member 82 is supported by the drum main body 81 by fitting the raw tube fitting portion 98 into the right end portion of the drum main body 81 so as not to be relatively rotatable.

Thereby, the contact member 99 is disposed between the rear side portion 60 of the base wall 54 on the right side of the base frame 52 and the left end portion (closed portion) of the raw tube fitting portion 98. Therefore, the right end surface of the contact member 99 is always in contact with the left surface of the rear portion 60 of the right base side wall 54 by the biasing force of the spring 100.

The drum body 81 is always urged leftward by the spring 100 via the raw tube fitting portion 98. Therefore, the left end portion of the shaft support portion 95 of the drum gear 83 is always in contact with the right surface of the rear portion 60 of the left base side wall 54.

The drum shaft 80 is made of metal and has a substantially cylindrical shape extending in the left-right direction. The drum shaft 80 is formed longer than the distance between the pair of base side walls 54 in the left-right direction.

The drum shaft 80 is inserted at the left end portion thereof into the insertion hole 105 and the shaft support portion 95 of the raw tube fitting portion 96 so as to be relatively rotatable, and the right end portion thereof is inserted through the raw tube fitting portion 98. The hole 103 and the insertion hole 104 of the contact member 99 are inserted so as to be relatively rotatable. Accordingly, the drum shaft 80 is inserted into the drum main body 81 so as to be along the central axis A1 of the photosensitive drum 20.

Also, each of the end portions of the drum shaft 80 in the left-right direction is inserted into the drum shaft insertion hole 58 of the base frame 52 and the drum shaft insertion hole 94 of the cover frame 53 so as not to be relatively rotatable. Thus, the drum body 81 is supported so as to be relatively rotatable with respect to the drum frame 51 with the center axis A1 as the rotation center.

As shown in FIG. 5A, the photosensitive drum 20 is driven by a driving force from a driving source (not shown) such as a motor provided in the main body casing 2 via the driving gear 130. When transmitted to the section 97, as shown in FIG. 1, the drum gear 83 and the drum main body 81 are integrally rotated in the rotational direction X (clockwise in the left side view) indicated by the arrow.

As shown in FIG. 6, the photosensitive drum 20 rubs between the left end portion of the shaft support portion 95 of the drum gear 83 and the right surface of the rear portion 60 of the left base side wall 54 during rotation driving. The right end surface of the contact member 99 and the left surface of the rear portion 60 of the right base side wall 54 rub against each other, thereby restricting rotational driving due to an unintended external force.
(3) Transfer Roller As shown in FIG. 4, the transfer roller 21 covers the transfer roller shaft 86 so that the metal transfer roller shaft 86 extending in the left-right direction and the left and right ends of the transfer roller shaft 86 are exposed. And a roller body 85.

The roller body 85 is made of a conductive soft resin (for example, rubber), and the length in the left-right direction is substantially the same as the length in the left-right direction of the image forming region T3 of the drum body 81.

The transfer roller 21 is disposed in the transfer roller support portion 70 so that the roller main body 85 is in pressure contact with the image forming region T3 of the drum main body 81 from the rear side.

Further, the transfer roller 21 is provided to be rotatable about the center axis thereof by supporting the left and right end portions of the transfer roller shaft 86 on the left and right end portions of the transfer roller support portion 70. The left end portion of the transfer roller shaft 86 is disposed on the right side (inward in the left-right direction) of the right end portion of the gear portion 97 of the drum gear 83.

As shown in FIG. 1, when the photosensitive drum 20 is driven to rotate, the transfer roller 21 rotates in the rotational direction indicated by the arrow (counterclockwise as viewed from the left side) due to friction between the roller main body 85 and the drum main body 81. It is driven and rotated.
3. As shown in FIG. 2, the developing cartridge 19 includes the developing frame 25 described above, a driving unit 44 as an example of a driving member, and a power supply unit 43 as an example of an action member and an electrode member.
(1) Development Frame The development frame 25 is formed in a substantially box shape extending in the left-right direction. As shown in FIG. 1, a development roller 34 and a supply roller 33 are provided in the development chamber 27.

As shown in FIG. 6, the developing roller 34 includes a metal developing roller shaft 65 extending in the left-right direction, and a rubber roller 66 that covers the developing roller shaft 65 so that the left and right ends of the developing roller shaft 65 are exposed. ing.

The rubber roller 66 is formed such that its length in the left-right direction is longer than the length in the left-right direction of the image forming region T3 of the drum main body 81 and shorter than the length in the left-right direction of the drum main body 81.

The developing roller 34 is disposed at the rear end of the developing frame 25 so that the rubber roller 66 is opposed to the drum body 81 of the photosensitive drum 20 from the front lower side (see FIG. 1).

Further, the developing roller 34 is provided so as to be rotatable about the central axis thereof by supporting the left and right ends of the developing roller shaft 65 at the rear end of the developing frame 25.

The supply roller 33 includes a metal supply roller shaft 63 that extends in the left-right direction and a sponge roller 64 that covers the supply roller shaft 63 so that both left and right ends of the supply roller shaft 63 are exposed.

The supply roller 33 is disposed on the lower front side of the developing roller 34 such that the sponge roller 64 is opposed to the rubber roller 66 of the developing roller 34 from the lower front side (see FIG. 1).

Further, the supply roller 33 is provided to be rotatable about the central axis thereof by supporting the left and right ends of the supply roller shaft 63 by the developing frame 25.
(2) Drive Unit The drive unit 44 is disposed on the left side of the developing frame 25 as shown in FIG.

The drive unit 44 includes a development coupling 118 and a gear cover 119 as shown in FIG.

The development coupling 118 is disposed at a substantially central portion in the front-rear direction of the drive unit 44. As shown in FIG. 2, the development coupling 118 is formed in a substantially cylindrical shape extending in the left-right direction, and is supported on the left surface of the left wall of the development frame 25 so as to be relatively rotatable. A coupling recess 116 is formed on the left end surface of the development coupling 118.

The coupling recess 116 is formed so as to be recessed from the left surface of the developing coupling 118 to the right, and is formed in a substantially elongated hole shape in side view extending in the radial direction of the developing coupling 118.

Note that gear teeth (not shown) are formed on the peripheral surface of the right end portion of the development coupling 118. The developing coupling 118 has gear teeth (not shown) engaged with a gear train (not shown), and is driven to the supply roller 33, the developing roller 34, and the agitator 29 via the gear train (not shown). It is connected so that it can be transmitted.

The gear cover 119 is formed in a substantially box shape whose right side and rear side are opened. The gear cover 119 is fixed to the left wall of the developing frame 25 so as to accommodate the developing coupling 118 and a gear train (not shown).

In addition, a coupling collar 120 is formed on the gear cover 119.

The coupling collar 120 is formed in a substantially cylindrical shape extending from the left side wall of the gear cover 119 toward the left side at a substantially central portion in the front-rear direction of the left side wall of the gear cover 119. The coupling collar 120 communicates with the inner side (right side) of the gear cover 119 at the right end thereof. The left end portion of the developing coupling 118 is inserted into the coupling collar 120 so that the coupling recess 116 is exposed.

The main body coupling 131 provided in the main body casing 2 is fitted into the coupling recess 116 so as to be able to transmit drive during the image forming operation.

Then, a driving force from a driving source (not shown, an example of the outside) such as a motor provided in the main body casing 2 is developed via the main body coupling 131, the developing coupling 118, and a gear train (not shown). It is transmitted to the roller 34, the supply roller 33 and the agitator 29.

Thus, each of the developing roller 34 and the supply roller 33 is rotationally driven in the direction of the arrow shown in FIG. 1 (counterclockwise as viewed from the left side).
(3) Power Supply Unit The power supply unit 43 is disposed on the right side of the developing frame 25 as shown in FIG.

As shown in FIG. 5B, the power supply unit 43 includes a supply electrode 76, an insulating member 77, and a developing electrode 78.

The supply electrode 76 is made of a conductive resin material and is disposed at the front end of the power supply unit 43. The supply electrode 76 is formed in a substantially rectangular shape in a side view, extends in the left-right direction, and is formed in a substantially rectangular tube shape with the right end portion closed (see FIG. 2).

The supply electrode 76 is electrically connected to the supply roller shaft 63 of the supply roller 33 through a connecting portion (not shown).

The insulating member 77 is made of an insulating resin material, and is disposed adjacent to the rear side of the supply electrode 76. The insulating member 77 is formed in a substantially L shape in side view. Specifically, the insulating member 77 includes a front side portion extending in the up-down direction and a rear side portion extending continuously rearward from the upper end portion of the front side portion. The insulating member 77 is formed in a substantially rectangular tube shape extending in the left-right direction and closed at the right end (see FIG. 2). The insulating member 77 is supported on the right surface of the right side wall of the developing frame 25.

The developing electrode 78 is made of a conductive resin material, and is disposed behind the front portion of the insulating member 77 and below the rear portion of the insulating member 77. Further, the developing electrode 78 is formed in a substantially rectangular shape in side view, extends in the left-right direction, and is formed in a substantially rectangular tube shape with the right end portion closed.

The developing electrode 78 is electrically connected to the developing roller shaft 65 of the developing roller 34 via a connecting portion (not shown).

The supply electrode 76, the insulating member 77, and the development electrode 78 have substantially the same length in the left-right direction.

In the state where the process cartridge 15 is mounted on the main casing 2, the right end surfaces of the supply electrode 76 and the developing electrode 78 are the main supply electrode 133 a provided on the main casing 2 and the main assembly side as shown in FIG. The developing electrode 133b (an example of a member outside the cartridge 15) contacts (acts), respectively. Then, the supply electrode 76 and the development electrode 78 are electrically connected to the main body side supply electrode 133a and the main body side development electrode 133b, respectively.

Thus, during the image forming operation, the supply roller shaft 63 (see FIG. 6) of the supply roller 33 is supplied from the power supply (not shown) provided in the main body casing 2 via the main body side supply electrode 133a and the supply electrode 76. Supply bias is applied. Further, a developing bias is applied to the developing roller shaft 65 (see FIG. 6) of the developing roller 34 via the main body side developing electrode 133b and the developing electrode 78.
4). As shown in FIG. 2, the developing cartridge 19 is mounted on the developing cartridge mounting portion 102 of the drum cartridge 18.

In the state where the developing cartridge mounting portion 102 is mounted, the left and right center portion P2 of the rubber roller 66 of the developing roller 34 is different from the left and right center portion P1 of the image forming region T3 of the drum body 81 as shown in FIG. It is arranged on the front side of the central portion P1 in the left-right direction in the image forming region T3 so as to be aligned along the direction.

The drive unit 44 of the developing cartridge 19 is disposed so as to face the left end portion of the drum body 81 (the left portion in the first non-image forming region T1) and the gear portion 97 of the drum gear 83 from the front side. .

The power supply unit 43 of the developing cartridge 19 is disposed on the right front side with respect to the right end portion of the drum body 81, and the right end portion is slightly on the right side (right side of the right surface of the front side portion 61 of the base side wall 54 ( It is arranged on the outside in the left-right direction).

That is, the power supply unit 43 protrudes rightward from the right end surface of the drum main body 81, and a portion disposed on the right side of the right end surface of the drum main body 81 is partitioned as a protruding portion 132.

The horizontal length D5 of the protruding portion 132 is formed to be longer than the horizontal length D4 of the gear portion 97 of the drum gear 83.

The sum of the left and right lengths of the gear portion 97 and the first non-image forming region T1 (the sum of D4 and D1) is the sum of the left and right lengths of the protruding portion 132 and the second non-image forming region T2 ( The sum of D5 and D2).
5. Effect (1) In the process cartridge 15, as shown in FIG. 4, the drum gear 83 is provided at the left end portion (an example of the first end portion) of the drum body 81 of the photosensitive drum 20, and the gear portion 97 of the drum gear 83. Is provided adjacent to the left end portion of the drum body 81 from the left side (outside in the left-right direction).

Further, the power supply unit 43 of the developing cartridge 19 is provided so as to protrude toward the right (axially outer side) from the right end surface (an example of the second end) of the drum body 81 of the photosensitive drum 20. A portion protruding from the right end surface of the drum body 81 in the power supply unit 43 is formed as a protruding portion 132.

That is, the gear portion 97 of the drum gear 83 is provided at the left end portion of the drum main body 81, and the protruding portion 132 of the power supply unit 43 is disposed on the right side of the right end portion of the drum main body 81. Thus, a space for providing the gear portion 97 is secured on the left side (axially outside), and a space for arranging the protruding portion 132 is secured on the right side (axially outside) of the right end portion of the drum body 81. .

For this reason, a space is secured on the outer side in the left-right direction with respect to each of the left and right ends of the drum body 81 of the photosensitive drum 20, and a space is secured only on either side of the drum body 81 in the left-right direction In comparison, an efficient arrangement of the drum body 81 can be ensured.

Further, at the left end portion (one side in the axial direction) of the photosensitive drum 20, the first non-image forming region T 1 that is longer in the left-right direction than the second non-image forming region T 2 and the left and right portions are compared with the protruding portion 132. A gear portion 97 having a short direction length is arranged.

In addition, at the right end portion (the other side in the axial direction) of the photosensitive drum 20, the second non-image forming region T 2 that is shorter in the left-right direction than the first non-image forming region T 1 and the left and right portions compared with the gear portion 97. A protruding portion 132 having a long directional length is arranged.

That is, a space for arranging the first non-image forming region T1 and the gear portion 97 is secured in the left portion of the process cartridge 15, and the second non-image forming region T2 and the protruding portion 132 are disposed in the right portion of the process cartridge 15. Space for placing is secured.

As a result, a space is secured in a balanced manner on each of the left and right sides of the process cartridge 15, and the image forming area T3 formed between the first non-image forming area T1 and the second non-image forming area T2 is efficiently Arrangement can be secured.

Therefore, according to the process cartridge 15, it is possible to ensure an efficient arrangement of the drum body 81 of the photosensitive drum 20, particularly the image forming region T3, while suppressing an increase in the size of the process cartridge 15.
(2) Further, as shown in FIG. 4, the thickness of the photosensitive layer 84 in the thin layer region T6 of the first non-image forming region T1 is thinner than the thickness of the photosensitive layer 84 in the image forming region T3. The thickness of the photosensitive layer 84 in the thick layer region T7 of the non-image forming region T2 is thicker than the thickness of the photosensitive layer 84 in the image forming region T3.

Therefore, depending on the thickness of the photosensitive layer 84 in each of the thin layer region T6 and the thick layer region T7, the non-image forming region formed on the peripheral surface of the end in the left-right direction of the drum body 81 is the first non-image forming region T1 or It is possible to easily determine which of the second non-image forming regions T2 corresponds.

That is, it is possible to easily determine which of the both ends in the axial direction of the drum body 81 should be arranged in the left-right direction in the process cartridge 15.

As a result, the assembly work of the process cartridge 15 can be facilitated.
(3) Further, as shown in FIG. 2, the process cartridge 15 is detachably mounted on the drum cartridge 18 including the photosensitive drum 20, the toner can be stored, and the developing cartridge mounting portion 102 of the drum cartridge 18 can be detached. And a developing cartridge 19.

The developing cartridge 19 includes a developing roller 34 (see FIG. 1), a drive unit 44, and a power supply unit 43. As shown in FIG. 1, the developing roller 34 is in contact with the drum main body 81 from the front lower side (the outer side in the radial direction of the drum main body 81), and supplies toner to the image forming region T3.

Therefore, for example, when the photosensitive drum 20 reaches the end of its life, only the drum cartridge 18 can be replaced, and when the remaining amount of the developer becomes less than a predetermined value, only the developing cartridge 19 can be replaced.

As a result, the toner can be stored in one process cartridge 15 and the running cost can be reduced as compared with the case where the photosensitive drum 20 is provided.

The driving unit 44 is configured to transmit a driving force from a driving source (not shown) such as a motor provided in the main casing 2 to the developing roller 34 (see FIG. 2). The power supply unit 43 is configured to be electrically connected to the developing roller shaft 65 (see FIG. 6) of the developing roller 34.

Therefore, during the image forming operation, a driving force can be transmitted to the developing roller 34 via the driving unit 44, and a bias can be applied to the developing roller 34 via the power supply unit 43.

Further, as shown in FIG. 4, the drive unit 44 has a left end portion of the drum body 81 (left side portion of the first non-image forming region T 1) and a gear when the developing cartridge 19 is mounted on the developing cartridge mounting portion 102. It arrange | positions with respect to each of the part 97 so that it may oppose from the front side (radial direction outer side of the drum main body 81).

Therefore, the drive unit 44 can be arranged in a space for arranging the first non-image forming region T1 and the gear portion 97, and the space can be used effectively.

As a result, the developing roller 34 can reliably supply the toner to the image forming region T3 during the image forming operation, and the process cartridge 15 can be prevented from being enlarged.

Therefore, the running cost can be reduced, and the enlargement of the process cartridge 15 can be suppressed while the toner can be reliably supplied to the image forming region T3. (4) Also, as shown in FIG. 4, in the state where the developing cartridge 19 is mounted on the developing cartridge mounting portion 102 of the drum cartridge 18, the center portion P1 in the left-right direction of the image forming region T3 (the center in the axial direction of the drum main body 81). Portion) and a central portion P2 in the left-right direction of the rubber roller 66 of the developing roller 34 (a central portion in the axial direction of the drum main body 81) are arranged along the front-rear direction (the radial direction of the drum main body 81).

Therefore, it is possible to more reliably supply the toner to the image forming region T3 while ensuring an efficient arrangement of the developing roller 34 (rubber roller 66).
6). Modification The above-described process cartridge 15 is an embodiment of the present invention, and the present invention is not limited to the above-described embodiment.

The printer 1 as an example of the image forming apparatus to which the process cartridge 15 is mounted can be configured as a color printer in addition to the above-described monochrome printer.

When the image forming apparatus is configured as a color printer, the image forming apparatus includes a direct tandem type color printer including a plurality of photosensitive drums and a recording medium conveying member, a plurality of photosensitive drums, an intermediate transfer member, and a transfer member. It can be configured as an intermediate transfer type tandem color printer.

Further, the process cartridge 15 may be configured as an integral type integrally including the drum cartridge 18 and the developing cartridge 19 in addition to the separation type in which the drum cartridge 18 and the developing cartridge 19 are separated as described above.

Further, the developing cartridge 19 can be configured such that a toner cartridge that contains toner is detachably attached to a housing having the developing roller 34.

Further, instead of the developing roller 34 described above, for example, a developer carrier such as a developing sleeve, a developing belt, or a brush-like roller can be applied.

Further, instead of the above-described supply roller 33, for example, a supply member such as a supply sleeve, a supply belt, or a brush-like roller can be applied.

Further, instead of the agitator 29 described above, for example, a conveying member such as an auger screw or a conveying belt can be applied.

Further, instead of the transfer roller 21 described above, for example, a contact type transfer member such as a transfer belt, a transfer brush, a transfer blade, or a film type transfer device, or a non-contact type transfer member such as a corotron type is used. It can also be applied.

Further, instead of the above scorotron charger 22, for example, a non-contact charger such as a corotron charger, a sawtooth discharge member, or a contact charger such as a charging roller may be applied. it can.

Further, instead of the scanner unit 16 described above, an exposure member such as an LED unit can be applied.

The power supply unit 43 described above is an example of an action member. As the action member, in addition to the power supply unit 43, a pressure boss, a bearing member, a toner filling port, a lid member for the toner filling port, and a toner remaining amount are detected. A window for doing this is also included.

Furthermore, the image forming apparatus can also be configured as a multi-function machine equipped with an image reading unit and the like.

Also by these, the same effect as the above-described embodiment can be obtained.

Note that the above-described embodiments and modifications can be combined as appropriate.

15 process cartridge 18 drum cartridge 19 developing cartridge 20 photosensitive drum 34 developing roller 43 feeding unit 44 driving unit 81 drum body 84 photosensitive layer 97 gear portion 132 protruding portion 133a body side supply electrode 133b body side development electrode A1 central axis A1
T1 First non-image forming region T2 Second non-image forming region T3 Image forming region P1 Horizontal center portion P2 of image forming region Horizontal center portion of rubber roller

Claims

An element tube (81) extending in the direction of the axis (A1) and having a photosensitive layer (84) formed on the peripheral surface thereof, and a first end that is one end in the axis direction of the element tube (81); A photosensitive drum (20) comprising a gear (97) configured to receive an external driving force;
With respect to the second end which is the end opposite to the first end in the element pipe (81), the element pipe (81) is arranged on the outside in the radial direction, and is attached to a member outside the cartridge (15). An action member (43) configured to act;
The raw tube (81)
A first non-image forming region (T1) formed on the peripheral surface of the first end;
A second non-image forming region (T2) formed on the peripheral surface of the second end,
An image forming area (T3) formed between the first non-image forming area (T1) and the second non-image forming area (T2);
The action member (43)
A protruding portion (132) disposed on the outer side in the axial direction than the second end,
The axial length (D1) of the first non-image forming region (T1) is formed longer than the axial length (D2) of the second non-image forming region (T2),
The cartridge (15), wherein the axial length (D4) of the gear (97) is shorter than the axial length (D5) of the protruding portion (132).
A thickness of the photosensitive layer (84) in a part (T6) of the first non-image forming region (T1) is formed thinner than a thickness of the photosensitive layer (84) in the image forming region (T3),
The thickness of the photosensitive layer (84) in a part (T7) of the second non-image forming region (T2) is thicker than the thickness of the photosensitive layer (84) in the image forming region (T3). The cartridge (15) according to claim 1, characterized in that:
A first cartridge (18) comprising the photosensitive drum (20);
A second cartridge (19) configured to be able to contain a developer and to be detachably attached to the first cartridge (18);
With
The second cartridge (19)
A developer carrier (34) arranged to face the element tube (81) from the outside in the radial direction and configured to supply a developer to the image forming region (T3);
The first end and the gear (97) are arranged so as to face each other from the outside in the radial direction, and the driving force from the outside of the second cartridge (19) is applied to the developer carrier (34). A drive member (44) configured to transmit;
The action member (43),
The action member (43)
The cartridge (15) according to claim 1 or 2, wherein the cartridge (15) is an electrode member configured to be electrically connected to the developer carrier (34).
In a state where the second cartridge (19) is mounted on the first cartridge (18), the central portion (P1) in the axial direction of the image forming region (T3) and the developer carrying member (34). The cartridge (15) according to claim 3, characterized in that the central part (P2) in the axial direction is arranged along the radial direction.