JP4348633B2 - Process cartridge, drum cartridge and developer cartridge - Google Patents

Description

  The present invention relates to a process cartridge, a drum cartridge, and a developing cartridge provided in an image forming apparatus such as a laser printer.

2. Description of the Related Art Conventionally, there has been known a process cartridge including a drum cartridge having a photosensitive drum and a developing cartridge having a developing roller and detachable from the drum cartridge. In this type of process cartridge, the photosensitive drum is made to face the developing roller as the developing cartridge is attached to the drum cartridge (see, for example, Patent Document 1).
JP 200531214 A

However, in the above-described process cartridge, the surface of the photosensitive drum is exposed from the drum cartridge when the developing cartridge is not attached to the drum cartridge. In that case, the surface of the photosensitive drum is damaged due to interference with other members, and there is a problem that the image is deteriorated due to the photosensitive drum having the damaged surface.
SUMMARY OF THE INVENTION The object of the present invention is to prevent the surface of the photosensitive drum from being exposed from the drum cartridge with a simple structure when the developing cartridge is not attached to the drum cartridge, and to cause the image drum to be damaged. It is an object of the present invention to provide a drum cartridge, a developing cartridge attached to the drum cartridge, and a process cartridge including the drum cartridge and the developing cartridge.

To achieve the above object, an invention according to claim 1, and a drum cartridge having a photosensitive drum, having a current image roller, a process cartridge and a developer cartridge detachably mountable to the drum cartridge The drum cartridge communicates with the drum housing portion in a facing direction in which the photosensitive drum and the developing roller face each other when the developing cartridge is attached to the drum cartridge, when the developing cartridge is mounted on the drum cartridge. A rotation axis of the photosensitive drum and one end side in an orthogonal direction orthogonal to the facing direction are opened, and a cartridge storage portion for storing the developing cartridge detachably from the one end side; and the drum storage portion and the cartridge storage portion Against the other end side in the orthogonal direction. The developer cartridge is attached to and detached from the drum cartridge between a housing having a passage for allowing a recording medium to pass from the cartridge housing portion to the drum housing portion, and between the drum housing portion and the cartridge housing portion. A shutter member that can be opened and closed so as to cover the photosensitive drum. The developing cartridge has a working portion that acts on the shutter member, and the shutter member is housed in the cartridge of the housing. A rotating part supported rotatably on the side of the part, and extending from the rotating part in a direction orthogonal to the direction in which the rotating shaft of the rotating part extends, and the developing cartridge is mounted on the drum cartridge An actuated part that sometimes comes into contact with the actuating part and receives pressure from the developing cartridge, and a pivot shaft of the pivot part extend. An arm part extending from the rotating part in a direction perpendicular to the direction and different from the actuated part, and connected to the actuated part by the arm part, and the developing cartridge is connected to the drum cartridge When the surface of the photosensitive drum in a non-attached state covers a facing portion that can face the developing roller, and the developer cartridge is attached to the drum cartridge, the actuated portion receives pressure from the developer cartridge. A cover portion that opens to a side opposite to the mounting direction of the developing cartridge with respect to the drum cartridge along a surface of the one end side of the developing cartridge in the orthogonal direction, and exposes the facing portion to the developing roller. It is characterized by having .

According to such a configuration, the shutter member is opened and closed in conjunction with the mounting of the developing cartridge. Accordingly, the shutter member can expose the photosensitive drum and the surface thereof can be opposed to the developing roller at the same time as the developing cartridge is mounted on the drum cartridge. On the other hand, at the same time as the developing cartridge is detached from the drum cartridge, the shutter member covers the surface of the photosensitive drum and can be prevented from being damaged due to interference with other members. Therefore, it is possible to improve the operability as compared with the case where the opening and closing of the shutter member is not interlocked with the mounting of the developing cartridge, and the photosensitive drum is fixed by the shutter member when the developing cartridge is not attached to the drum cartridge. The surface can be protected .

Also, an invention according to claim 2, in the invention described in claim 1, wherein the drum cartridge includes a cartridge accommodating portion for accommodating the developer cartridge, the cartridge accommodating section, the axial direction of the photosensitive drum A drum side wall disposed at an end of the drum is provided, and the actuated portion is disposed on the inner side in the axial direction with respect to the drum side wall.

  According to such a configuration, when the developing cartridge is accommodated in the cartridge accommodating portion by disposing the acting portion of the shutter member on the inner side of the photosensitive drum in the axial direction of the drum side wall in the cartridge accommodating portion, The portion can reliably receive the pressure from the developing cartridge. Therefore, the shutter member can be reliably rotated and the photosensitive drum can be opened.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the drum cartridge includes a cartridge housing portion that houses the developing cartridge, and the cartridge housing portion is a shaft of the photosensitive drum. A drum side wall disposed at an end in a direction, and the drum side wall is provided with a guide portion that guides the shaft of the developing roller toward the photosensitive drum when the developing cartridge is attached to the drum cartridge. The shutter member is provided at a position that does not obstruct the guide of the shaft of the developing roller by the guide portion.

According to such a configuration, since the shutter member is provided at a position that does not obstruct the guide of the shaft of the developing roller by the guide portion, smooth operation of opening / closing the shutter member and attaching / detaching the developing cartridge to / from the drum cartridge can be performed. Can be secured.
According to a fourth aspect of the present invention, in the third aspect of the present invention, the arm portion is disposed outwardly in the axial direction of the developing roller with respect to the shaft of the developing roller guided by the guide portion. It is characterized by comprising an interference avoidance unit.

According to such a configuration, the arm portion is disposed at a position where the arm portion is most likely to interfere with the shaft of the developing roller guided by the guide portion. An interference avoidance unit is provided outward in the axial direction. Therefore, the interference avoiding portion reliably avoids the interference between the arm portion and the shaft of the developing roller, and further smooth operation of opening / closing the shutter member and attaching / detaching the developing cartridge to / from the drum cartridge can be ensured .

Also, the invention according to claim 5, in the invention of any one of claims 1 to 4, wherein the shutter member, said surface facing the photosensitive drum, and a cover portion covering the surface of the An arm unit that supports the cover unit; a shaft unit that rotatably supports the arm unit; and an urging unit that urges the arm unit so that the cover unit covers the photosensitive drum. It is characterized by being.

According to such a configuration, the arm portion is urged by the urging means so that the cover portion covers the photosensitive drum. Therefore, the shutter member can reliably cover the photosensitive drum when the developing cartridge is not attached to the drum cartridge .

Also, the invention according to claim 6, in the invention described in claim 5, the turning locus of the object acting portion over the opening and closing of the shutter member is closed position side of the cover portion with respect to the shaft portion It is characterized by being located in.
According to such a configuration, the rotation trajectory of the operated part over the opening and closing of the shutter member is located on the closed position side of the cover part with respect to the shaft part. For this reason, if the developer cartridge is pressed against the shaft portion only on the closed position side of the cover portion, the cover portion can be opened from the closed position toward the open position.

The invention according to claim 7 is the invention according to claim 6 , wherein the arm portion is provided so as to extend from the shaft portion along a radial direction of the shaft portion, and the arm portion and the covered portion are provided. It is characterized in that the angle formed with the action part is an obtuse angle.
According to such a configuration, the angle formed around the shaft portion between the arm portion and the operated portion is an obtuse angle. Therefore, when the pressure from the developing cartridge is applied to the affected part, the distance between the contact position between the acted part and the developing cartridge and the cover part supported by the arm part is an acute angle. It can take longer than the case. For this reason, the pressure from the developing cartridge is applied to the affected part, and the stroke when the cover part moves from the closed position to the open position becomes large. Therefore, the photosensitive drum can be reliably exposed when the developing cartridge is mounted on the drum cartridge. Further, when the cover part moves from the closed position to the open position, the restoring force for the cover part to return to the closed position is also greater when the angle is an obtuse angle than when the angle is an acute angle. . Therefore, when the developing cartridge is detached from the drum cartridge, the movement of the cover portion from the open position to the closed position can be ensured smoothly and reliably .

Also, an invention according to claim 8, in the invention of any one of claims 1 to 7, wherein the working portion so as to protrude toward the axial outer side of the developing roller from the developing cartridge It is characterized by being provided.
According to such a configuration, the pressing force that rotates the shutter member in the opening direction is more reliably applied to the shutter member by the action portion that is provided so as to protrude outward in the axial direction of the developing roller from the developing cartridge. Can be granted.

According to a ninth aspect of the invention, in the eighth aspect of the invention, the developing cartridge includes a developing side wall disposed at an end portion in the axial direction of the developing roller, and the action portion includes the developing portion. It is characterized by being provided on the side wall.
According to such a configuration, the pressing force for rotating the shutter member in the opening direction can be more reliably applied to the shutter member by the action portion provided on the developing side wall of the developing cartridge .

According to the first aspect of the present invention, the operability can be improved and the surface of the photosensitive drum can be protected by the shutter member when the developing cartridge is not attached to the drum cartridge .

According to the invention described in 請 Motomeko 2, it is possible to reliably rotate the shutter member, it is possible to open the photosensitive drum.

According to the third aspect of the invention, it is possible to ensure a smooth operation of opening / closing the shutter member and attaching / detaching the developing cartridge to / from the drum cartridge.
According to the fourth aspect of the invention, it is possible to ensure further smooth operation of opening / closing the shutter member and attaching / detaching the developing cartridge to / from the drum cartridge .

According to the fifth aspect of the present invention, the shutter member can reliably cover the photosensitive drum when the developing cartridge is not attached to the drum cartridge .
According to the invention described in 請 Motomeko 6, from the developing cartridge, when applying pressing to the actuated portion only at the closed position of the cover portion with respect to the shaft portion, toward the cover portion from the closed position to the open position Can be opened.

According to the seventh aspect of the present invention, when the developing cartridge is detached from the drum cartridge, the movement of the cover portion from the open position to the closed position can be ensured smoothly and reliably .

According to the eighth aspect of the present invention, the pressing force for rotating the shutter member in the opening direction can be more reliably applied to the shutter member.
According to the ninth aspect of the present invention, the pressing force for rotating the shutter member in the opening direction can be more reliably applied to the shutter member .

1. 1 is a side sectional view of an essential part showing a laser printer as an embodiment including a developing cartridge, a drum cartridge, and a process cartridge of the present invention. The laser printer 1 includes a main body casing 2, a feeder unit 4 for feeding a paper 3 as a recording medium housed in the main body casing 2, and an image formed on the fed paper 3. The image forming unit 5 is provided. 2 is a left sectional view of the process cartridge, FIG. 3 is a right perspective view of the process cartridge, and FIG. 5 is a right side view of the developing cartridge. In FIG. 1, a shutter member 80 described later is omitted for convenience. Further, in FIG. 3, a right side wall 97 described later is omitted.

(1) Main Body Casing As shown in FIG. 1, an attachment / detachment port 6 for attaching / detaching the process cartridge 20 is formed on one side wall of the main body casing 2, and a front for opening / closing the attachment / detachment port 6. A cover 7 is provided. The front cover 7 is rotatably supported by a cover shaft (not shown) inserted through the lower end portion thereof. Thus, when the front cover 7 is closed around the cover shaft, the attachment / detachment opening 6 is closed by the front cover 7, and when the front cover 7 is opened with the cover shaft as a fulcrum (tilted), the attachment / detachment opening 6 is opened. The process cartridge 20 can be attached to and detached from the main casing 2 through the attachment / detachment opening 6.

In the following description, in a state where the process cartridge 20 is mounted on the main casing 2, the right side (the side on which the front cover 7 is provided) in FIG. 1 is defined as the front side, and the left side in FIG. Further, the front side in the paper thickness direction in FIG. 1 is the left side, and the back side in the paper thickness direction in FIG. 1 is the right side.
(2) Feeder unit The feeder unit 4 includes a paper feed tray 8 that is detachably attached to the bottom of the main body casing 2 along the front-rear direction, and a separation roller 9 that is provided above the front end of the paper feed tray 8. And a separation pad 10 and a paper feed roller 11 provided on the rear side of the separation roller 9 (upstream side of the separation pad 10 in the conveyance direction of the paper 3). The feeder unit 4 includes a paper dust removing roller 12 provided on the front upper side of the separation roller 9 (downstream side in the transport direction of the paper 3 with respect to the separation roller 9), and a pinch disposed to face the paper dust removing roller 12. And a roller 13.

The paper feed side transport path of the paper 3 is folded back to the rear side in a substantially U shape from the vicinity of the paper dust removing roller 12 and is further downstream in the transport direction and below the process cartridge 20 at the feeder section 4. Is provided with a registration roller 14 composed of a pair of rollers.
Inside the paper feed tray 8 is provided a paper pressing plate 15 on which the paper 3 can be stacked. The sheet pressing plate 15 is supported so as to be swingable at the rear end portion, so that the front end portion is disposed below, the placement position along the bottom plate 16 of the paper feed tray 8 and the front end portion are disposed above. Oscillating between the inclined supply position.

  A lever 17 for lifting the front end portion of the paper pressing plate 15 upward is provided at the front end portion of the paper feed tray 9. The lever 17 is supported at a position below the front end portion of the paper pressing plate 15 so that the rear end portion is swingably supported by the lever shaft 18, and the front end portion of the lever 17 is lying on the bottom plate 16 of the paper feed tray 8. The portion can swing between the inclined posture in which the sheet pressing plate 15 is lifted. When a rotational driving force is input to the lever shaft 18, the lever 17 rotates with the lever shaft 18 as a fulcrum, the front end of the lever 17 lifts the front end of the paper pressing plate 15, and the paper pressing plate 15 is fed to the supply position. Move to.

When the paper pressing plate 15 is positioned at the supply position, the paper 3 on the paper pressing plate 15 is pressed by the paper feeding roller 11, and the rotation of the paper feeding roller 11 causes the separation between the separation roller 9 and the separation pad 10. Paper feeding is started toward the separation position.
When the paper feed tray 8 is detached from the main casing 2, the front end of the paper pressing plate 15 moves downward due to its own weight, and the paper pressing plate 15 is positioned at the loading position. When the paper pressing plate 15 is positioned at the mounting position, the paper 3 can be stacked on the paper pressing plate 15.

  The sheet 3 sent out toward the separation position by the sheet feeding roller 11 is rolled and fed one by one when it is sandwiched between the separation roller 9 and the separation pad 10 by the rotation of the separation roller 9. Is done. The fed paper 3 passes between the paper dust removing roller 12 and the pinch roller 13, and after the paper dust is removed there, the paper 3 is folded back along the U-shaped paper feeding side conveying path, and the registration roller It is transported toward 14.

The registration roller 14 conveys the sheet 3 to the transfer position between the photosensitive drum 28 and the transfer roller 31 and to transfer the toner image on the photosensitive drum 28 to the sheet 3 after registration.
(3) Image Forming Unit The image forming unit 5 includes a scanner unit 19, a process cartridge 20, and a fixing unit 21.

(A) Scanner Unit The scanner unit 19 is provided in the upper part of the main casing 2 and includes a laser light source (not shown), a polygon mirror 22 that is driven to rotate, an fθ lens 23, a reflecting mirror 24, a lens 25, and a reflecting mirror 26. Yes. The laser beam based on the image data emitted from the laser light source is deflected by the polygon mirror 22 as shown by a chain line, passes through the fθ lens 23, then the optical path is turned back by the reflecting mirror 24, and further passes through the lens 25. After that, the light path is further bent downward by the reflecting mirror 26, so that the surface of the photosensitive drum 28 of the process cartridge 20 is irradiated.

(B) Process Cartridge The process cartridge 20 is provided below the scanner unit 19 in the main casing 2 and is detachably attached to the main casing 2.
The process cartridge 20 includes a drum cartridge 27 and a developing cartridge 30 that is detachably attached to the drum cartridge 27.

(B-1) Drum Cartridge The drum cartridge 27 includes a drum-side casing 76 and a photosensitive drum 28, a scorotron charger 29, a transfer roller 31, and a cleaning member 32 provided in the drum-side casing 76. ing.
A sheet passage port 67 is formed in the bottom wall 98 (see FIG. 2), which will be described later, of the drum-side housing 76 in front of the transfer position between the photosensitive drum 28 and the transfer roller 31. In addition, a sheet conveyance port 69 is formed on the rear wall 100 (to be described later) of the drum-side housing 76 behind the transfer position. Further, a passage path 68 for transporting the paper 3 via the transfer position is formed between the paper passage port 67 and the paper transport port 69.

  The photosensitive drum 28 has a cylindrical shape, and a drum body 33 formed by a positively chargeable photosensitive layer whose outermost layer is made of polycarbonate or the like, and an axial center of the drum body 33 along the axial direction of the drum body 33. And a metal drum shaft 34 that extends. Both end portions in the axial direction of the drum shaft 34 are supported between a left side wall 96 and a right side wall 97 (see FIG. 4), which will be described later, of the drum side housing 76, and the drum body 33 is rotatably supported by the drum shaft 34. As a result, the photosensitive drum 28 is provided in the drum-side housing 76 so as to be rotatable about the drum shaft 34. Further, the photosensitive drum 28 is rotationally driven by inputting a driving force from a motor (not shown).

  The scorotron charger 29 is supported above a photosensitive drum 28 by a ceiling wall 101 (see FIG. 2), which will be described later, of the drum-side housing 76, and is spaced apart from the photosensitive drum 28 so as not to contact the photosensitive drum 28. Opposing to the drum 28. The scorotron charger 29 is provided between the discharge wire 35 and the photosensitive drum 28, and is disposed between the discharge wire 35 and the photosensitive drum 28. The charge amount from the discharge wire 35 to the photosensitive drum 28 is provided. And a grid 36 for controlling.

In the scorotron charger 29, a bias voltage is applied to the grid 36 and at the same time, a high voltage is applied to the discharge wire 35 to cause corona discharge of the discharge wire 35, so that the surface of the photosensitive drum 28 is uniformly positive. To charge.
The transfer roller 31 is provided below the photosensitive drum 28 in the drum-side casing 76, is opposed to and contacts the photosensitive drum 28 in the vertical direction, and is disposed so as to form a nip with the photosensitive drum 28. The nip is a transfer position between the photosensitive drum 28 and the transfer roller 31 described above. The transfer roller 31 includes a metal roller shaft that is rotatably supported between a left side wall 96 and a right side wall 97, which will be described later, of the drum side housing 76, and a conductive rubber that covers the roller shaft. And a rubber roller made of a material. A transfer bias is applied to the transfer roller 31 during transfer. The transfer roller 31 is rotationally driven by the input of a driving force from a motor (not shown).

The cleaning member 32 is assembled to a rear wall 100 (to be described later) of the drum-side housing 76, and is disposed on the rear side of the photosensitive drum 28 so as to face and contact the photosensitive drum 28.
As shown in FIG. 2, the drum cartridge 27 is provided with a shutter member 80 for protecting the surface of the photosensitive drum 28 when the developing cartridge 30 is not mounted, which will be described in detail later.

(B-2) Developer Cartridge As shown in FIG. 1, the developer cartridge 30 is detachably attached to the drum-side casing 76. Therefore, the developing cartridge 30 can be attached to and detached from the main body casing 2 by attaching and detaching the process cartridge 20 through the attachment and detachment opening 6 by opening and closing the front cover 7 in a state where the developing cartridge 30 is attached. .

The developing cartridge 30 includes a housing 62 and a supply roller 37, a developing roller 38, and a layer thickness regulating blade 39 provided in the housing 62.
The housing 62 has a box shape with the rear side opened, and a partition plate 40 is provided in the middle of the front-rear direction so as to partition the inside of the housing 60. The front side of the housing 62 partitioned by the partition plate 40 is partitioned as a toner storage chamber 41 in which toner is stored. Further, the rear side of the housing 62 partitioned by the partition plate 40 is partitioned as a developing chamber 42 in which the supply roller 37, the developing roller 38, and the layer thickness regulating blade 39 are provided.

An opening 46 is formed in the partition plate 40, and the toner container 41 and the developing chamber 42 communicate with each other through the opening 46.
In the toner storage chamber 41, positively charged nonmagnetic one-component toner is stored as a developer. In the toner, a polymerizable monomer, for example, a styrene monomer such as styrene, an acrylic monomer such as acrylic acid, alkyl (C1 to C4) acrylate, alkyl (C1 to C4) methacrylate, A polymerized toner obtained by copolymerization by suspension polymerization or the like is used. This polymerized toner has a substantially spherical shape, has extremely good fluidity, and can achieve high-quality image formation.

Such a toner is blended with a colorant such as carbon black, wax, and the like, and an external additive such as silica is added to improve fluidity. The average particle size of the toner is about 6 to 10 μm.
An agitator rotating shaft 43 is provided in the center of the toner storage chamber 41. The agitator rotating shaft 43 is rotatably supported by both developing side walls 44 arranged to face each other with a gap in the width direction of the housing 62 (the direction orthogonal to the front-rear direction and the vertical direction, hereinafter the same). The agitator rotating shaft 43 is provided with an agitator 45. The agitator 45 is rotated when a driving force from a motor (not shown) is input to the agitator rotating shaft 43.

  Note that a toner detection window 47 for detecting the remaining amount of toner stored in the toner storage chamber 41 is provided on both development side walls 44 of the housing 62 at a position corresponding to the toner storage chamber 41. ing. Each of the toner detection windows 47 is disposed so as to face the toner storage chamber 41 in the width direction. The main body casing 2 is provided with a toner empty sensor (not shown) including a light emitting element and a light receiving element. The light emitting element (not shown) is provided outside one toner detection window 47, and the other is used for toner detection. A light receiving element (not shown) is disposed outside the window 47, is emitted from the light emitting element, is incident on the toner storage chamber 41 through one toner detection window 47, and the other toner is transferred from the toner storage chamber 41. The detection light emitted through the detection window 47 is detected by a light receiving element, whereby the toner empty sensor determines the remaining amount of toner according to the frequency of detection of the detection light. When the amount of toner stored in the toner storage chamber 41 becomes small, a toner empty warning is displayed on an operation panel (not shown) or the like by the determination of the toner empty sensor.

  The supply roller 37 is disposed on the rear side of the opening 46. The supply roller 37 includes a metal supply roller shaft 48 and a sponge roller 49 made of a conductive foam material that covers the supply roller shaft 48. The supply roller shaft 48 is rotatably supported at both ends in the axial direction at positions corresponding to the developing chambers 42 on both developing side walls 44 of the housing 62. The supply roller 37 is rotationally driven when a driving force from a motor (not shown) is input to the supply roller shaft 48.

  The developing roller 38 is disposed on the rear side of the supply roller 37 in contact with the supply roller 37 so as to be compressed. The developing roller 38 includes a metal developing roller shaft 50 and a rubber roller 51 made of a conductive rubber material that covers the developing roller shaft 50. The developing roller shaft 50 is rotatably supported at both ends in the axial direction at positions corresponding to the developing chambers 42 on both developing side walls 44 of the housing 62. The rubber roller 51 is made of conductive urethane rubber or silicone rubber containing carbon fine particles, and the surface thereof is coated with a urethane rubber or silicone rubber coating layer containing fluorine. The developing roller 38 is rotationally driven when a driving force from a motor (not shown) is input to the developing roller shaft 50. A developing bias is applied to the developing roller 38 during development.

  The layer thickness regulating blade 39 includes a pressing portion 52 having a semicircular cross section made of insulating silicone rubber provided at a free end portion of a blade body made of a metal leaf spring material. In the layer thickness regulating blade 39, the base end portion of the blade body is supported by the casing 62 above the developing roller 38, so that the pressing portion 52 is pressed onto the developing roller 38 by the elastic force of the blade body. .

  As shown in FIGS. 3 and 5, the outer surface of the developing side wall 44 on the right side of the housing 62 of the developing cartridge 30 has an action portion protruding outward in the width direction (axial direction of the developing roller shaft 50). The contact protrusion 65 is formed. The contact protrusion 65 is formed as a protrusion along the vertical direction behind the toner detection window 47. The abutment protrusion 65 abuts on a swinging protrusion 85 as an actuated portion of a shutter member 80 provided in the drum cartridge 27 described later when the developing cartridge 30 is mounted on the drum cartridge 27. This will be explained in detail later.

(B-3) Development Transfer Operation As shown in FIG. 1, when a driving force from a motor (not shown) is input to the agitator rotation shaft 43, the agitator rotation shaft 43 is rotated clockwise, and the agitator 45 moves the toner storage chamber 41 in the circumferential direction around the agitator rotating shaft 43. Then, the toner in the toner storage chamber 41 is stirred by the agitator 45 and discharged from the opening 46 toward the developing chamber 42.

  The toner discharged from the opening 46 is supplied to the developing roller 38 by the rotation of the supply roller 37, and at this time, the toner is triboelectrically charged between the supply roller 37 and the developing roller 38. The toner supplied onto the developing roller 38 enters between the pressing portion 52 of the layer thickness regulating blade 39 and the rubber roller 51 of the developing roller 38 as the developing roller 38 rotates, and forms a thin layer with a constant thickness. It is carried on the developing roller 38.

As the photosensitive drum 28 rotates, the surface of the photosensitive drum 28 is first uniformly charged to a positive polarity by the scorotron charger 29 and then exposed by high-speed scanning of the laser beam from the scanner unit 19. An electrostatic latent image corresponding to the image to be formed on the paper 3 is formed.
Next, when the developing roller 38 rotates, the toner carried on the developing roller 38 and charged with positive polarity is formed on the surface of the photosensitive drum 28 when it comes into contact with the photosensitive drum 28. The electrostatic latent image, that is, the surface of the photosensitive drum 28 that is uniformly charged to the positive polarity, is supplied to the exposed portion exposed to a laser beam and having a lowered potential. As a result, the electrostatic latent image on the photosensitive drum 28 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 28.

  Thereafter, the toner image carried on the surface of the photosensitive drum 28 is conveyed by the registration roller 14, enters the drum-side housing 76 through the paper passage port 67, and the paper 3 passing through the passage path 68 is transferred to the photosensitive drum 28. And a transfer bias applied to the transfer roller 31 while passing through a transfer position between the transfer roller 31 and the transfer roller 31. The sheet 3 onto which the toner image has been transferred is discharged out of the drum-side casing 76 from the sheet conveyance port 69 and is conveyed to the fixing unit 21.

The transfer residual toner remaining on the photosensitive drum 28 after the transfer is collected by the developing roller 38. Further, the paper dust from the paper 3 adhering to the photosensitive drum 28 after the transfer is collected by the cleaning brush 32.
(C) Fixing Unit The fixing unit 21 is provided on the rear side of the process cartridge 20, and includes a fixing frame 53, and a heating roller 54 and a pressure roller 55 in the fixing frame 53.

The heating roller 54 includes a metal tube whose surface is coated with a fluororesin, and a halogen lamp for heating inserted in the metal tube. The heating roller 54 is rotationally driven by inputting a driving force from a motor (not shown).
The pressure roller 55 is disposed below the heating roller 54 so as to press the heating roller 54. The pressure roller 55 includes a metal roller shaft and a rubber roller made of a rubber material that covers the roller shaft. The pressure roller 55 is driven according to the rotational drive of the heating roller 54.

In the fixing unit 21, the toner image transferred onto the paper 3 at the transfer position is thermally fixed while the paper 3 passes between the heating roller 54 and the pressure roller 55. The sheet 3 on which the toner image is fixed is conveyed toward a sheet discharge tray 56 formed on the upper surface of the main casing 2.
The paper discharge side conveyance path of the sheet 3 from the fixing unit 21 to the paper discharge tray 56 is folded back from the fixing unit 21 to the front side in a substantially U shape. In the discharge side transfer path, a transfer roller 57 is provided in the middle, and a discharge roller 58 is provided at the downstream end.

The sheet 3 heat-fixed in the fixing unit 21 is conveyed to the sheet discharge side conveyance path, conveyed to the sheet discharge roller 58 by the conveyance roller 57, and then discharged onto the sheet discharge tray 56 by the sheet discharge roller 58. The
2. 4. Configuration relating to attachment / detachment of developer cartridge to / from drum cartridge (a) Configuration of drum cartridge FIG. 4 is a top view of the process cartridge, and FIG. 6 is a diagram showing a state (drum cartridge) in which the developer cartridge is detached in FIG. It is. FIG. 7 is a right side view showing the state in which the developing cartridge is detached in FIG. 3 (a view showing a state in which the shutter is closed). FIG. 8 is a right side view of FIG. 3 (a view showing a state in which the shutter is opened), and FIG. 9 is a left side view of the process cartridge (a state in which the shutter is opened). 7 and 8 also omit the right side wall 97.

As shown in FIGS. 6 and 9, the drum-side casing 76 is integrally formed from a left side wall 96 and a right side wall 97 as drum side walls, a bottom wall 98, a front wall 99, a rear wall 100, and a top wall 101. ing.
The left side wall 96 and the right side wall 97 are opposed to each other with a space therebetween in the width direction (the axial direction of the photosensitive drum 28). The left side wall 96 and the right side wall 97 are substantially L-shaped in a side view, and are respectively forward from a rear side wall portion 105 having a substantially bow shape in a side view and a lower half portion of a front end edge of the rear side wall portion 105. A front side wall portion 106 having a substantially rectangular shape in side view and continuously extending toward the side is integrally provided.

The bottom wall 98 is continuously extended over the rear side wall part 105 and the front side wall part 106 between the lower end edges of the left side wall 96 and the right side wall 97. Note that the paper passage port 67 described above is formed in the center portion of the bottom wall 98 in the front-rear direction.
The front wall 99 is constructed between the front end edges of the front side wall portions 106 of the left side wall 96 and the right side wall 97. The front wall 99 is provided with a handle 70 for operating attachment / detachment of the process cartridge 20.

The rear wall 100 is constructed between the rear end edges of the left side wall 96 and the rear side wall portion 105 of the right side wall 97. Note that the above-described sheet conveyance port 69 is formed at the center in the vertical direction of the rear wall 100 (see FIG. 2).
The top wall 101 is installed between the upper end edges of the left side wall 96 and the rear side wall portion 105 of the right side wall 97.

  The drum-side housing 76 is partitioned by the rear side wall portions 105 of the left side wall 96 and the right side wall 97, the bottom wall 98 continuous with the rear side wall portions 105, the top wall 101, and the rear wall 100. This portion is a drum housing portion 102 that houses the photosensitive drum 28, scorotron charger 29, transfer roller 31, and cleaning member 32. The drum housing portion 102 is formed in a box shape whose front side is opened so that an exposure port 63 is formed on the front side (see FIG. 7).

  Further, the front wall portions 106 of the left side wall 96 and the right side wall 97, the bottom wall 98 continuous with the front side wall portions 106, and the portion partitioned by the front wall 99 detachably accommodate the developing cartridge 30. The developing cartridge housing portion 103 is a cartridge housing portion. The developing cartridge housing portion 103 is formed in a bottomed frame shape whose upper side is opened (see FIG. 7).

The drum housing portion 102 and the developing cartridge housing portion 103 communicate with each other through the exposure port 63 (see FIG. 7).
Each front side wall portion 106 of the left side wall 96 and the right side wall 97 is formed with a roller shaft guide portion 115 as a guide portion for guiding the shaft end portion of the developing roller shaft 50 when the developing cartridge 30 is attached and detached. Further, each rear side wall portion 105 is provided with a roller bearing insertion portion 116 which is provided continuously to the rear end of the roller shaft guide portion 115 and receives the shaft end portion of the developing roller shaft 50 guided by the roller shaft guide portion 115. Is formed.

The roller shaft guide part 115 is formed as an upper end edge of the front side wall part 106, and extends from the middle in the front-rear direction of the front side wall part 106 diagonally downward from the front to the rear, and then extends in a substantially horizontal flat shape. It is formed as follows.
The roller bearing insertion portion 116 is formed so as to be continuously cut from the rear end of the roller shaft guide portion 115 so that each rear side wall portion 105 is cut out in a substantially U-shape when viewed from the side.

Further, support holes 58 penetrating in the thickness direction are provided at the upper end portions of the front side wall portions 106 of the left side wall 96 and the right side wall 97 so as to face each other. The shutter member 80 is rotatably supported.
As described above, the shutter member 80 is provided to protect the surface of the photosensitive drum 28 in the drum cartridge 27 from which the developing cartridge 30 has been detached. The shutter member 80 covers the surface of the photosensitive drum 28 and the cover portion 82. A shaft portion 81 for supporting the drum-side housing 76 and an arm portion 83 that continues between the cover portion 82 and the shaft portion 81 are integrally provided.

  The shaft portion 81 is inserted in the width direction with respect to the support hole 58 described above so that one end protrudes outward in the width direction from each front side wall portion 106 and the other end protrudes inward in the width direction of each front side wall portion 106. The support hole 58 is rotatably supported. An arm portion 83 is continuous with one end protruding outward in the width direction from each front side wall portion 106. A swing protrusion 85 is formed integrally with the shaft 81 at the other end protruding inward in the width direction from each front side wall 106. The swing protrusion 85 is provided so as to protrude from the shaft portion 81 to the radially outer side of the shaft portion 81.

The arm portion 83 is made of a wire, extends from one end of the shaft portion 81 toward the radially outer side of the shaft portion 81, and is rotatably supported by the shaft portion 81. Further, as shown in FIG. 7, the arm portion 83 is disposed so as to form an obtuse angle with the above-described swinging protrusion 85 and the shaft portion 81 as the center.
Further, as shown in FIG. 9, the arm portion 83 has a rotation range around the shaft portion 81 in a range overlapping with the movement range of the developing roller shaft 50 that moves along the roller shaft guide portion 115. A concave portion 84 is formed as an interference avoiding portion that is recessed outward in the width direction so as not to interfere with the developing roller shaft 50 (see FIGS. 3 and 4). As shown in FIGS. 3 and 4, the concave portion 84 is provided to bend outward in the width direction in the middle of the arm portion 83, and in the width direction, the outer end in the width direction is the shaft end of the developing roller shaft 50. It is arrange | positioned in the width direction outer side rather than the part.

The cover portion 82 is continuous with the other end of the arm portion 83.
As shown in FIG. 8, the cover portion 82 is a thin plate having an arc shape in a side sectional view and extending so as to face the drum body 33 of the photosensitive drum 28 in the axial direction of the drum shaft 34. It is constructed at the end and supported by each arm portion 83.
Further, as shown in FIG. 7, a coil spring 86 as a biasing means is wound around the shaft portion 81 supported by the support hole 58 of the right side wall 97 (not shown). One arm portion extending from the winding portion of the coil spring 86 is locked to the arm portion 83 on the right side wall 97 side, and the other arm portion is a locking portion provided on the inner side in the width direction from the right side wall 97. (Not shown).

  Therefore, the shutter member 80 is always urged rearward and obliquely downward (in the direction of the arrow in FIG. 7) by the coil spring 86 so that the cover portion 82 closes the exposure port 63. In a state where the cover portion 82 covers the exposure opening 63 and covers the surface of the drum body 33 of the photosensitive drum 28 (this state is referred to as “closed position”), the drum storage portion 102 and the developing cartridge storage portion 103 are It is isolated by the cover part 82. In the closed position, the cover portion 82 abuts against the bottom wall 98, so that the downward rotation of the shutter member 80 is restricted against the urging force of the coil spring 86.

When the developing cartridge 30 is not attached to the drum cartridge 27, the shutter 80 is always in the closed position by the urging force of the coil spring 86, and the cover portion 82 is on the bottom wall 98 on the passage path 68. Is shut off.
As shown in FIG. 8, the “open position” relative to the “closed position” means that the cover portion 82 of the shutter member 80 opens the exposure port 63, and the surface of the drum body 33 of the photosensitive drum 28 extends from the exposure port 63. This is an exposed state when the developing cartridge 30 is mounted on the drum cartridge 27, and will be described in detail later.

(B) Attaching / detaching the developing cartridge to / from the drum cartridge In the drum cartridge 27 in the posture shown in FIG. First, both axial end portions (see FIG. 5) of the developing roller shaft 50 protruding outward in the width direction in the developing cartridge 30 are guided from the front to the rear along the roller shaft guide portion 115, and obliquely downward. Then, as shown in FIG. 9, it is guided rearward in a substantially horizontal direction and fitted into the roller bearing insertion portion 116.

As a result, as shown in FIG. 8, the developing cartridge 30 is accommodated in the developing cartridge accommodating portion 103, and the mounting of the developing cartridge 30 to the drum cartridge 27 is completed.
During the mounting, the contact protrusion 65 of the developing cartridge 30 contacts the swing protrusion 85 and the swing protrusion 85 is pressed while the developing roller shaft 50 moves from the front to the rear in the substantially horizontal direction described above. Give. Then, according to the lever principle, the swing projection 85 serves as a power point, the shaft portion 81 serves as a fulcrum, the cover portion 82 and the arm portion 83 serve as action points, and the arm portion 83 resists the biasing force of the coil spring 86. Is turned away from the passage 68 toward the open position diagonally upward (see the arrow in FIG. 8). The shutter member 80 ends its rotation when the mounting of the developing cartridge 30 to the drum cartridge 27 is completed, and the cover portion 82 is disposed at the open position.

In the open position, the cover portion 82 of the shutter member 80 opens the exposure port 63 so that the surface of the drum body 33 of the photosensitive drum 28 is opposed to the developing roller 38. In the open position, the cover portion 82 is disposed along the upper wall 60 of the housing 62 of the developing cartridge 30.
Further, the detachment of the developing cartridge 30 from the drum cartridge 27 is an operation reverse to the mounting described above. That is, as shown in FIG. 8, the developing cartridge 30 is detached from the developing cartridge housing portion 103 from the rear to the front, and the contact protrusion 65 is separated from the swing protrusion 85. Then, the cover part 82 is rotated from the open position to the closed position by the biasing force of the coil spring 86.

Incidentally, the rotation trajectory of the free end portion of the swinging projection 85 corresponding to the rotation of the cover portion 82 between the closed position and the open position is an axis as shown by the range of the chain line arrow in FIG. It is located on the closed position side with respect to the portion 81.
3. As described above, the drum cartridge 27 covers the surface of the photosensitive drum 28 in order to protect the surface of the drum body 33 of the photosensitive drum 28 when the developing cartridge 30 is not mounted. When the developing cartridge 30 is mounted, a shutter member 80 is provided that is opened to oppose the surface of the drum body 33 of the photosensitive drum 28 so as to contact the developing roller 38. Specifically, as shown in FIG. 8, when the developing cartridge 30 is mounted on the drum cartridge 27, the contact protrusion 65 of the developing cartridge 30 contacts the swing protrusion 85 of the shutter member 80. The pressing force from 65 is applied to the swinging protrusion 85, and the cover portion 82 rotates around the shaft portion 81 via the arm portion 83 against the urging force of the coil spring 86, thereby the cover portion 82. Is released. On the other hand, by releasing the developing cartridge 30 from the drum cartridge 27, the above-described pressing is released, and accordingly, the biasing force of the coil spring 86 causes the cover portion 82 to center on the shaft portion 81 via the arm portion 83. Rotates and the cover part 82 is closed.

  Therefore, the shutter member 80 is opened and closed in conjunction with the mounting of the developing cartridge 30 to the drum cartridge 27. As a result, the developing cartridge 30 is mounted on the drum cartridge 27, and at the same time, the shutter member 80 can expose the surface of the drum body 33 of the photosensitive drum 28 and face the developing roller 38 so as to be in contact therewith. On the other hand, at the same time as the developing cartridge 30 is detached from the drum cartridge 27, the shutter member 80 covers the surface of the drum main body 33 of the photosensitive drum 28, and can be prevented from being damaged due to interference with other members. Therefore, the operability can be improved as compared with the case where the opening / closing of the shutter member 80 is not interlocked with the mounting of the developing cartridge 30, and the shutter member is in a state where the developing cartridge 30 is not attached to the drum cartridge 27. 80 can protect the surface of the photosensitive drum 28. The shutter member 80 is configured by a simple mechanism such as the shaft portion 81, the cover portion 82, and the arm portion 83, and the cover portion 82 can be reliably rotated about the shaft portion 81. As a result, it is possible to prevent the surface of the drum body 33 of the photosensitive drum 28 from being damaged, which causes image deterioration, and to obtain a high-quality image.

  In addition, the cover 82 is opened and closed by selectively applying the pressing from the contact protrusion 65 of the developing cartridge 30 or the release of the pressing to the swinging protrusion 85, so that the cover 82 is opened and closed. It is not necessary to provide a special configuration, and the number of parts can be reduced. Further, since the cover portion 82 is rotated, it is possible to secure a distance necessary for the cover portion 82 to cover the surface of the drum body 33 of the photosensitive drum 28 in a space-saving manner compared with a case where the cover portion 82 is moved linearly. .

As shown in FIGS. 7 and 8, the cover portion 82 is opened and closed between the drum housing portion 102 and the developing cartridge housing portion 103 so as to open or close the exposure port 63. The developing cartridge housing portion 103 communicates or is isolated by the cover portion 82 with the exposure port 63 as a boundary.
Therefore, when the developing cartridge 30 is attached to the drum cartridge 27, the cover portion 82 opens the exposure port 63, and the drum accommodating portion 102 and the developing cartridge accommodating portion 103 communicate with each other. The toner can be efficiently conveyed from the developed developing cartridge 30 to the drum accommodating portion 102. Further, when the developing cartridge 30 is not attached to the drum cartridge 27, the arm portion 83 is always urged toward the closed position by the coil spring 86, so that the surface of the drum body 33 of the photosensitive drum 28 is not exposed. By the cover part 82, it can protect reliably.

As shown in FIGS. 6 and 8, the swing protrusion 85 is formed so as to protrude radially outward of the shaft 81 at the other end of the shaft 81 protruding inward in the width direction from the front side wall 106. Has been.
Therefore, when the developing cartridge 30 is accommodated in the developing cartridge accommodating portion 103, the abutting protrusion 65 is reliably brought into contact with the swinging protrusion 85, and the pressing force from the abutting protrusion 65 is reliably transmitted to the shaft portion 81. Can do.

  As shown in FIGS. 4 and 9, in the middle of the arm portion 83, the moving range of the developing roller shaft 50 that moves along the roller shaft guide portion 115 and the roller bearing insertion portion 116 is included in the rotation range. In the overlapping range, a concave portion 84 that is bent outward in the width direction is formed so as not to contact the developing roller shaft 50. In addition, the recess 84 has an outer end portion in the width direction that is disposed more outward in the width direction than the end portion of the developing roller shaft 50 in the width direction. Therefore, when the developing cartridge 30 is mounted on the drum cartridge 27, the development guided by the concave portion 84, that is, the roller shaft guide portion 115 and the roller bearing insertion portion 116, of the arm portion 83 that rotates around the shaft portion 81. Interference between the arm portion 83 disposed at the position where the roller shaft 50 is most likely to interfere with the developing roller shaft 50 moving along the roller shaft guide portion 115 is reliably avoided, and the shutter member 80 is opened and closed. A smooth operation of attaching / detaching the developing cartridge 30 to / from the drum cartridge 27 can be ensured.

Further, as shown in FIG. 8, the cover portion 82 is a thin plate having a circular arc shape in a side sectional view, and extends along the upper wall 60 of the housing 62 of the developing cartridge 30 when the shutter member 80 is in the open position. Be placed.
Therefore, the process cartridge 20 can be downsized at the open position of the shutter member 80.

Further, as shown in FIG. 7, the swing protrusion 85 extends along the radial direction of the shaft portion 81 from the shaft portion 81 that rotatably supports the arm portion 83. The shaft portion 81 is rotatably supported.
Therefore, the pressing force applied from the contact protrusion 65 of the developing cartridge 30 to the swing protrusion 85 can be efficiently transmitted to the arm portion 83 via the shaft portion 81.

Further, as shown in FIG. 8, the arm portion 83 and the swinging protrusion 85 are arranged so as to form an obtuse angle with the shaft portion 81 as the center.
Therefore, when the pressing force from the contact protrusion 65 of the developing cartridge 30 is applied to the swing protrusion 85, the contact position between the swing protrusion 85 and the contact protrusion 65 and the cover supported by the arm portion 83. The shortest distance X with the portion 82 can be made longer than when the angle is an acute angle. Thereby, the pressing force from the contact protrusion 65 is applied to the swing protrusion 85, and the stroke when the cover portion 82 moves from the closed position to the open position is increased. Therefore, when the developing cartridge 30 is mounted on the drum cartridge 27, the photosensitive drum 28 can be reliably exposed. Further, when the cover portion 82 is moved from the closed position to the open position, the restoring force for the cover portion 82 to return to the closed position is also greater when the angle is an obtuse angle than when the angle is an acute angle. growing. Therefore, when the developing cartridge 30 is detached from the drum cartridge 27, the movement of the cover portion 82 from the open position to the closed position can be ensured smoothly and reliably.

If the effect of the weight of the shutter member 80 can be further added to the restoring force described above, the movement of the cover portion 82 from the open position to the closed position can be secured without the coil spring 86.
Further, the rotation trajectory of the free end portion of the swinging projection 85 corresponding to the rotation of the cover portion 82 from the closed position to the open position is shown in the shaft portion 81 as shown by the chain arrow in FIG. On the other hand, it is set to be located on the closed position side.

Therefore, if the pressing force from the contact protrusion 65 against the swing protrusion 85 is applied only on the closed position side of the cover part 82, the cover part 82 can be opened from the closed position toward the open position.
Further, as shown in FIG. 8, when the developing cartridge 30 is mounted on the drum cartridge 27, the shutter member 80 faces the upper front side (see the arrow in FIG. 8) against the urging force of the coil spring 86. Then, it is rotated to the open position so as to be separated from the passage 68.

Therefore, when the shutter member 80 is opened, that is, when the developing cartridge 30 is mounted on the drum cartridge 27, smooth passage of the paper 3 through the passage 68 can be ensured.
Further, since the contact protrusion 65 is provided so as to protrude outward in the width direction from the right developing side wall 44 of the developing cartridge 30, the front side wall of the drum cartridge 27 is mounted when the developing cartridge 30 is mounted on the drum cartridge 27. A pressing force for moving the cover member 82 to the open position can be reliably applied to the swing protrusion 85 provided on the inner side in the width direction of the portion 106.

  In the above embodiment, the shutter member 80 is disposed so as to close the exposure port 63 and protect the surface of the drum body 33 of the photosensitive drum 28 in the closed position. On the other hand, as shown in FIG. 2, since the rear surface of the drum body 33 of the photosensitive drum 28 is always exposed from the paper transport port 69, the paper transport port 69 can be provided with a similar shutter member. The surface of the drum body 33 of the photosensitive drum 28 can be more reliably protected. Note that a shutter member that opens and closes such a sheet conveyance port 69 can be provided alone.

  In the above description, the monochrome laser printer is exemplified, but the present invention is not limited to this. For example, a tandem type color laser printer that directly transfers images from a plurality of color photoreceptors to paper, or In addition, the present invention can be applied to an intermediate transfer type color laser printer in which a toner image for each color is temporarily transferred from each photosensitive member to an intermediate transfer member and then transferred to a sheet at once.

It is principal part side sectional drawing which shows a laser printer. It is a left side sectional view of a process cartridge (a mode in which a shutter is opened). It is a right perspective view of a process cartridge. It is a top view of a process cartridge. It is a right side view of the developing cartridge. FIG. 5 is a view showing a state (drum cartridge) in which the developing cartridge is detached in FIG. 4. FIG. 4 is a right side view showing a state in which the developing cartridge is detached in FIG. 3 (a view showing a state in which the shutter is closed). FIG. 4 is a right side view of FIG. 3 (a view showing a state in which a shutter is opened). It is a left side view of a process cartridge (a mode in which a shutter is opened).

3 sheet 20 process cartridge 27 drum cartridge 28 photosensitive drum 30 developing cartridge 38 developing roller 44 developing side wall 50 developing roller shaft 65 abutting protrusion 68 passage 80 shutter member 81 shaft portion 82 cover portion 83 arm portion 84 recessed portion 85 swinging protrusion 86 Coil spring 96 Left side wall 97 Right side wall 102 Drum housing part 103 Developer cartridge housing part 115 Roller shaft guide part

Claims (9)

A drum cartridge having a photosensitive drum, having a current image roller, a process cartridge and a developer cartridge detachably mountable to the drum cartridge,
The drum cartridge is
The drum accommodating portion that accommodates the photosensitive drum, and communicates with the drum accommodating portion in a facing direction in which the photosensitive drum and the developing roller face each other when the developing cartridge is attached to the drum cartridge, and the photosensitive drum rotates. One end side in an orthogonal direction orthogonal to the shaft and the facing direction is opened, and a cartridge storage portion that detachably mounts the developer cartridge from the one end side, and the drum storage portion and the cartridge storage portion in the orthogonal direction A housing provided on the other end side and having a passage for allowing a recording medium to pass from the cartridge housing portion to the drum housing portion;
A shutter member that is opened and closed so as to cover the photosensitive drum in conjunction with the attachment and detachment of the developing cartridge with respect to the drum cartridge, between the drum housing portion and the cartridge housing portion;
With
The developing cartridge has an action portion that acts on the shutter member,
The shutter member is
A rotating part rotatably supported on the cartridge housing part side of the housing;
The rotating portion extends from the rotating portion in a direction orthogonal to the direction in which the rotating shaft extends, and comes into contact with the action portion when the developing cartridge is attached to the drum cartridge. The affected part,
An arm portion extending from the rotating portion in a direction perpendicular to the direction in which the rotating shaft of the rotating portion extends and different from the operated portion;
The arm portion is connected to the actuated portion, covers a facing portion that can face the developing roller on the surface of the photosensitive drum when the developing cartridge is not attached to the drum cartridge, and the developing cartridge is The mounting direction of the developing cartridge with respect to the drum cartridge along the surface of the one end side of the developing cartridge in the orthogonal direction when the actuated portion is pressed from the developing cartridge by being mounted on the drum cartridge And a cover part that opens to the opposite side and exposes the facing part to the developing roller;
A process cartridge. The drum cartridge includes a cartridge housing portion that houses the developing cartridge,
The cartridge housing portion includes a drum side wall disposed at an axial end of the photosensitive drum,
Wherein the working portion is with respect to the drum side walls, characterized in that it is arranged on the inner side of the axial direction, the process cartridge according to claim 1. The drum cartridge includes a cartridge housing portion that houses the developing cartridge,
The cartridge housing portion includes a drum side wall disposed at an axial end of the photosensitive drum,
The drum side wall is provided with a guide portion that guides the shaft of the developing roller toward the photosensitive drum when the developing cartridge is attached to the drum cartridge.
The shutter member may be provided in a position that does not inhibit the guide axis of the developing roller by the guide portion, the process cartridge according to claim 1 or 2. The arm portion than the axis of the developing roller that is guided by the guide portion, characterized in that it comprises an interference avoiding portion disposed axially outward of said developing roller, according to claim 3 Process cartridge. The shutter member is
A cover portion that faces the surface of the photosensitive drum and covers the surface;
An arm portion for supporting the cover portion;
A shaft portion that rotatably supports the arm portion;
Wherein such cover portion to cover the photosensitive drum, characterized in that it includes a biasing means for biasing said arm portions, the process cartridge according to any one of claims 1 to 4. The process cartridge according to claim 5 , wherein a rotation trajectory of the operated part over opening and closing of the shutter member is located on a closed position side of the cover part with respect to the shaft part. The arm portion is provided from the shaft portion so as to extend along the radial direction of the shaft portion, wherein the said arm portion is an angle between the working portion is an obtuse angle, in claim 6 The described process cartridge. 8. The process cartridge according to claim 1, wherein the action portion is provided so as to protrude from the developing cartridge toward the outside in the axial direction of the developing roller. 9. 9. The process cartridge according to claim 8 , wherein the developing cartridge includes a developing side wall disposed at an end portion in the axial direction of the developing roller, and the action portion is provided on the developing side wall. .

Images