JP2014016485A - Process cartridge - Google Patents

Abstract

To provide a process cartridge capable of ensuring rigidity in a guide while reducing the size.
[Solution]
The developing cartridge 19 includes a developing roller shaft fitting portion 66 that covers the developing roller shaft 67. A first guide rail 95R having a first bearing surface 110R is formed on the right side wall 81R of the drum cartridge 18. When the developing cartridge 19 is mounted on the drum cartridge 18, the developing side contact portion 64 of the developing side electrode 53 is exposed from the right side wall 81R when viewed from the right side, and guides the developing roller shaft fitting portion 66. The first bearing surface 110 </ b> R is arranged close to the first bearing surface 110 </ b> R. The first bearing surface 110R is reinforced by being covered from the right side by the covering portion 97.
[Selection] Figure 5

Description

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

  Conventionally, an electrophotographic printer in which a process cartridge is detachably mounted is known.

  As a process cartridge mounted on such a printer, for example, a developing cartridge having a photosensitive member on which an electrostatic latent image is formed and having a developing roller for supplying developer to the photosensitive member is attached and detached. A guide groove is provided for supporting both ends of the developing roller shaft of the developing roller so as to guide the developing roller to the photosensitive member, and is configured to be detachable from the main body of the image forming apparatus with the developing cartridge mounted. A body cartridge has been proposed (see, for example, Patent Document 1).

JP 2000-250310 A

  In such a developing cartridge, both end portions of the developing roller shaft and an electrode electrically connected to the developing roller shaft for applying a developing bias to the developing roller shaft are both disposed on the outer surface of the developing cartridge. ing.

  In order to connect the electrode of the developing cartridge and the electrode on the main body side, the electrode of the developing cartridge is also exposed from the outer surface of the photosensitive cartridge.

  A guide groove for guiding the developing roller shaft is further formed on the outer surface of the photosensitive member cartridge. The periphery of the guide groove of the photosensitive member cartridge that defines the guide groove is required to be rigid in order to support the developing roller shaft.

  However, in recent years, there is a demand for downsizing process cartridges.

  When the process cartridge is reduced in size, the developing roller shaft and the electrode are arranged close to each other on the outer surface of the developing cartridge. Along with this, on the outer surface of the photosensitive cartridge, the peripheral edge portion of the guide groove and the space for exposing the electrode are arranged close to each other.

  If the space for exposing the electrode is arranged close to each other, it is not possible to ensure a sufficient peripheral area that defines the guide groove. As a result, the rigidity of the photoreceptor cartridge in the guide groove is reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a process cartridge capable of ensuring the rigidity of a guide while reducing the size.

(1) In order to solve the above-described problems, the process cartridge of the present invention carries a photoreceptor cartridge having a photoreceptor configured to carry an electrostatic latent image, and a developer for developing the electrostatic latent image. And a developer cartridge that is configured to rotate and that is configured to rotate and is detachably attached to the photosensitive cartridge.

  The developing cartridge includes a protrusion that extends in a first direction parallel to the rotation axis of the developer carrier.

  The photosensitive cartridge has a first wall that is disposed on one side of the developing cartridge in the first direction and forms a housing portion that houses the developing cartridge.

  The first wall is formed with a first guide configured to guide the protruding portion and a covering portion that covers the first guide from the outside in the first direction.

  The developing cartridge includes a first electrode on an outer surface on one side in the first direction.

  The first electrode is exposed from the first wall when viewed from one side in the first direction toward the other side.

  According to such a structure, the 1st guide comprised so that a protrusion part may be guided is reinforced by the coating | coated part which coat | covers from the outer side of a 1st direction.

  Therefore, even if the space for exposing the electrode is arranged close to the first guide, the rigidity of the first guide can be sufficiently ensured.

As a result, the rigidity of the first guide can be ensured while reducing the size of the process cartridge.
(2) Moreover, the coating | coated part may protrude in one side rather than the 1st wall in the 1st direction.

  According to such a configuration, in the first direction, since the covering portion protrudes to the one side from the first wall, the thickness of the covering portion can be ensured by the amount of protrusion.

Therefore, the first guide can be reinforced more reliably.
(3) Further, the photosensitive cartridge has a second wall disposed on the other side of the developing cartridge in the first direction, and a second guide configured to guide the protrusion on the second wall. The second guide is open toward the other side in the first direction, and the protruding portion passes through the second guide and protrudes to the other side in the first direction from the second wall. It may be.

According to such a configuration, even if the distance between the first wall and the second wall is shortened, the protruding portion can be supported, and the process cartridge can be downsized.
(4) The first guide is formed so as to protrude from the first wall toward the other side in the first direction, and the second guide is formed on the one side from the second wall in the first direction. You may form so that it may protrude toward.

  According to such a structure, the 1st guide and the 2nd guide can ensure large the part which supports a protrusion part, without enlarging to the 1st direction outer side.

As a result, it is possible to more reliably guide the protrusion while reducing the size of the process cartridge.
(5) Further, the protrusion may be a shaft of the developer carrier.

  According to such a structure, a protrusion part can be provided using the axis | shaft of a developing agent carrier.

As a result, by reducing the number of parts, the configuration can be simplified and the cost can be reduced.
(6) Further, the image forming apparatus of the present invention includes a process cartridge and a housing configured to be detachably mounted on the process cartridge.

  The housing includes a second electrode that is electrically connected to the first electrode.

  The attachment / detachment locus of the protrusion when the process cartridge is attached / detached to / from the housing overlaps the second electrode when projected in the first direction.

  If the attachment / detachment locus of the protrusion when the process cartridge is attached / detached to / from the housing overlaps with the second electrode, the protrusion and the second electrode may slide to damage the second electrode.

  However, according to such a configuration, even if the projecting portion moves so as to overlap the second electrode, the projecting portion is covered with the covering portion, and the second electrode is not slid with the covering portion but with the covering portion. Move.

Therefore, damage to the second electrode can be prevented.
(7) Further, the protrusion may be disposed on the downstream side of the first electrode in the direction in which the process cartridge is mounted on the housing.

  In this case, the attachment / detachment locus of the protrusion when the process cartridge is attached to / detached from the housing always overlaps with the second electrode.

  However, according to such a configuration, even if the protruding portion moves along the attachment / detachment locus, the protruding portion is covered with the covering portion, and the second electrode slides with the covering portion instead of the protruding portion. .

  Therefore, damage to the second electrode can be prevented.

  According to the present invention, it is possible to ensure rigidity in the guide while reducing the size of the process cartridge.

FIG. 1 is a central sectional view of a printer as an example of an image forming apparatus. 2A is a perspective view of the developing cartridge shown in FIG. 1 as viewed from the upper right side, and FIG. 2B is a right side view of the developing cartridge shown in FIG. 3A is a perspective view seen from the upper left side of the developing cartridge shown in FIG. 1, and FIG. 3B is a left side view of the developing cartridge shown in FIG. 4 is an exploded perspective view seen from the rear right side of the power supply unit of the developing cartridge shown in FIG. FIG. 5A is a perspective view seen from the upper left side of the drum cartridge shown in FIG. 1, and FIG. 5B is an enlarged view of the covering portion shown in FIG. 6A and 6B are explanatory views for explaining the mounting of the developing cartridge to the drum cartridge. FIG. 6A shows a state in which the developing cartridge is guided by the first guide curved surface of the power supply unit shown in FIG. (B) shows a state in which the developing cartridge is guided by the second guide curved surface of the drive unit shown in FIG. FIG. 7A is a right side view of the process cartridge shown in FIG. 1, and FIG. 7B is a left side view of the process cartridge shown in FIG. FIG. 8 is an explanatory diagram for explaining the mounting of the process cartridge to the main body casing.

1. Overall Configuration of Printer As shown in FIG. 1, a printer 1 as an example of an image forming apparatus includes a main body casing 2 as an example of a casing.

  In addition, the printer 1 includes a paper feed 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 direction when placed in the horizontal direction is used as a reference, and specifically, the arrow direction shown in each drawing is used as a reference.
(1) Main Body Casing The main body casing 2 is formed in a substantially box shape having 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.

  In addition, the main 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.

The paper feed cover 8 is swingably (moved) 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 of the paper supply cover 8 as a fulcrum.
(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 placing portion 9 is communicated with the outside of the main body 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, 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 body casing 2 and is mounted on the main body 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 photosensitive cartridge configured to be detachable from the main body casing 2, and a developing cartridge 19 configured to be detachable from the drum cartridge 18.

  The drum cartridge 18 includes a photosensitive drum 20 as an example of a photosensitive member, a transfer roller 21, and a scorotron charger 22.

  The photosensitive drum 20 is formed in a cylindrical shape that is long in the left-right direction. The photosensitive drum 20 includes a photosensitive drum shaft 86 and a drum 87 that is supported by the photosensitive drum shaft 86 and has a photosensitive layer formed on the surface thereof. The rear portion of 18 is rotatably provided.

  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.

  Specifically, the transfer roller 21 is disposed on the rear side of the photosensitive drum 20 so that the axial center thereof is positioned slightly below the axial center 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, an imaginary line segment (not shown) connecting the axis center of the transfer roller 21 and the axis center of the photosensitive drum 20 and an imaginary straight line (not shown) extending horizontally along the front-rear direction are formed. The acute angle formed 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 to face the front upper side of the photosensitive drum 20 with a space therebetween.

  Specifically, the scorotron charger 22 is disposed with a space in the circumferential direction of the photosensitive drum 20 with respect to the transfer roller 21, and is an imaginary link between the axial center of the photosensitive drum 20 and the axial center of the transfer roller 21. And an imaginary line segment (not shown) connecting the axial center of the photosensitive drum 20 and the charging wire 23 (described later) is about 120 °. Has been placed.

  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 a space therebetween.

  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 rear lower side.

  The developing cartridge 19 is disposed on the front lower side of the photosensitive drum 20 and includes a developing frame 25.

  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 upper surface of the lower wall.

  The supply roller groove 30 has a substantially semicircular shape along the peripheral surface of the 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 extend rearward and upward continuously from the rear end portion of the supply roller groove 30.

  The lower film sticking 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 attachment surface 32 is disposed to face the lower portion of the photosensitive drum 20 with a space in the vertical direction, and overlaps the axial center of the photosensitive drum 20 when projected in the vertical direction. Is arranged.

  The developing chamber 27 is provided with a supply roller 33, a developing roller 34 as an example of a developer carrying member, a layer thickness regulating blade 35, and a lower film 36.

  The supply roller 33 includes a supply roller shaft 57 and a sponge roller 58 that covers the supply roller shaft 57, and a rear portion of the developing chamber 27 so that a lower portion thereof is disposed in the supply roller groove 30. It is provided rotatably. Thus, 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).

  The developing roller 34 includes a developing roller shaft 67 as an example of a shaft of a developer carrying member, and a rubber roller 68 that covers the developing roller shaft 67, and a peripheral surface at a lower portion thereof and the developing roller facing surface 31 are connected to each other. The rear side of the developing chamber 27 is rotatably provided so as to face each other with a space therebetween.

  That is, the developing roller 34 is configured to rotate with the center of the developing roller shaft 67 extending in the left-right direction as the rotation axis.

  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 rear upper side of the supply roller 33 and on the front lower side of the photosensitive drum 20. The axial center of the supply roller 33, the axial center of the developing roller 34, and the axial center of the photosensitive drum 20 are located on substantially the same straight line along the radial direction of the photosensitive drum 20.

  Further, the developing roller 34 is arranged with a space in the circumferential direction of the photosensitive drum 20 with respect to the scorotron charger 22, and a virtual line segment (which connects the axial center of the photosensitive drum 20 and the charging wire 23 ( (Not shown) and an imaginary line segment (not shown) connecting the axis center of the photosensitive drum 20 and the axis center of the developing roller 34 are arranged so that an angle of about 120 ° is formed. . 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.

  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 above 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, and exposes the peripheral surface of the photosensitive drum 20.

  Specifically, the laser beam L is emitted rearward from the scanner unit 16 and exposes 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 point where the photosensitive drum 20 and the transfer roller 21 are in contact with the axial center of the photosensitive drum 20. Is set to

  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 that guides the attachment / detachment of the process cartridge 15 is provided on the inner surface of the main casing 2 corresponding to 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 above 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 surface of the developing roller 34 as a thin layer having a constant thickness.

  On the other hand, the surface of the photosensitive drum 20 is uniformly charged by the scorotron charger 22 and then exposed by the scanner unit 16. Thereby, an electrostatic latent image based on the image data is formed on the peripheral surface of the photosensitive drum 20. The toner carried on the developing roller 34 is supplied to the electrostatic latent image on the circumferential surface of the photosensitive drum 20, whereby a toner image (developer image) is carried (developed) on the circumferential surface of the photosensitive drum 20. Is done.

  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 fed one by one by the rotation of the sheet feeding roller 12. After that, 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 fed sheet by sheet at a predetermined timing (photosensitive drum 20 (described later) and transfer roller 21 ( (To be described later).

  Then, the paper 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 passing 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 body casing 2 by the paper discharge roller 40.

In this way, the sheet S is fed from the sheet placing portion 9, passes between the photosensitive drum 20 and the transfer roller 21 (nip point), 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. Details of Developing Cartridge Next, the developing cartridge 19 will be described in detail.

  In the description of the developing cartridge 19, when referring to the direction, the direction when the developing cartridge 19 is arranged horizontally is used as a reference, and specifically, the direction of the arrow shown in each drawing is used as a reference. That is, the up / down / front / rear direction with respect to the printer 1 is slightly different from the up / down / front / rear direction with respect to the developing cartridge 19, and the developing cartridge 19 1 is attached.

Further, when referring to directions in the drum cartridge 18 and the process cartridge 15 described below, the above is also followed.
(1) Development Frame As shown in FIGS. 2A and 3A, the development frame 25 is a substantially box in which an opening extending in the left-right direction is formed on the rear side so that the development roller 34 is exposed. A pair of left and right side walls 42 formed in a shape and having a substantially rectangular shape in side view, a lower wall 43 laid between the lower ends of the pair of left and right side walls 42, and a pair of left and right side walls 42 and a lower wall 43 And a front wall 44 provided between the front ends.

  The lower wall 43 is formed along the supply roller groove 30, the developing roller facing surface 31, and the lower film attaching surface 32 in the rear portion, and the cross-sectional view along the rotation locus of the agitator 29 is omitted in the front portion. It is formed in an arc shape.

  On the outer side surface of the front end portion of the lower wall 43, a pair of left and right leg portions 45 that protrude downward are provided at positions that divide the lower wall 43 into approximately three equal parts in the left-right direction.

  The front end surface of the leg 45 is formed substantially flush with the outer surface of the front wall 44, and its lower end surface (grounding surface) extends below the lower end portion of the outer peripheral surface of the front side portion of the lower wall 43. ing.

  On the outer surface of the lower wall 43 between the pair of left and right leg portions 45, a plurality of thin rib-shaped anti-slip 46 extending in the left-right direction is provided.

The front wall 44 is formed so as to continuously extend upward from the front end portion of the lower wall 43, and a pair of left and right grip portions 47 projecting frontward and upward are formed at the left and right ends thereof.
(2) Right side wall As shown in FIGS. 2A and 2B, a power supply unit 50 is provided on the outer surface of the right side wall 42 (hereinafter, referred to as the right side wall 42 </ b> R).

  As shown in FIG. 4, the power supply unit 50 includes a supply electrode 51, a bearing member 52, and a development electrode 53.

  The supply electrode 51 is formed from a conductive resin material in a substantially bowl shape extending in a direction connecting the front upper side and the rear lower side. The supply electrode 51 is integrally provided with a supply side contact portion 54, a connecting portion 55, and a supply roller shaft insertion portion 56.

  The supply side contact portion 54 is disposed at the front upper end of the supply electrode 51. The supply-side contact portion 54 is formed in a rectangular tube shape that extends in the left-right direction and has a substantially rectangular shape in side view with the right end portion closed.

  On the lower side of the supply side contact portion 54, a second guide electrode surface 105 that is inclined from the right side surface to the left side as it goes downward is defined.

  The connecting portion 55 is formed in a substantially crank-shaped bent flat plate shape extending continuously from the left end edge of the supply side contact portion 54 to the rear lower side.

  The supply roller shaft insertion portion 56 is provided continuously to the rear lower end portion of the connecting portion 55 and is formed in a substantially cylindrical shape extending in the left-right direction.

  The bearing member 52 is formed from an insulating resin material in a substantially rectangular flat plate shape as viewed from the side in the direction connecting the front upper side and the rear lower side. The bearing member 52 is integrally provided with an insulating part 59, a fixed part 60, and a bearing part 61.

  The insulating part 59 is disposed at the front upper end of the bearing member 52. The insulating portion 59 is formed in a rectangular tube shape that extends in the left-right direction and is substantially L-shaped in side view with the right end portion closed.

  The rear end portion of the insulating portion 59 is partitioned from a first guide curved surface 78R having a substantially arc shape that is curved downward from the upper side surface toward the rear side.

  The fixed portion 60 is formed in a substantially flat plate shape extending continuously from the left end edge of the insulating portion 59 to the lower rear side.

  The bearing portion 61 is continuously provided on the rear lower side of the fixed portion 60 and is formed in a flat plate shape having a substantially rectangular shape in a side view. The bearing portion 61 is formed with a developing roller shaft insertion hole 62 and a supply roller shaft covering portion 63.

  The developing electrode 53 is formed from a conductive resin material in a substantially rectangular flat plate shape in a side view in the longitudinal direction in a direction connecting the front upper side and the rear lower side. The developing electrode 53 is integrally provided with a developing side contact portion 64 as an example of a first electrode, a fixed portion 65, and a developing roller shaft fitting portion 66.

  The development side contact portion 64 is disposed at the front upper end of the development electrode 53. The development side contact part 64 is formed in a substantially rectangular tube shape in side view extending in the left-right direction and closed at the right end.

  The fixed portion 65 continuously extends from the lower end portion of the development side contact portion 64 to the rear lower side, and is formed in a substantially block shape having a length in the left-right direction equivalent to the development side contact portion 64.

  A first guide electrode surface 104 that inclines to the left side toward the rear side is defined at the rear lower end portion of the right side surface of the fixed portion 65.

  The developing roller shaft fitting portion 66 is formed in a substantially flat plate shape extending continuously from the left end portion of the fixed portion 65 to the rear side, and includes a developing roller shaft covering portion 69 as an example of a protruding portion.

  The developing roller shaft covering portion 69 is formed in a substantially cylindrical shape that protrudes from the substantially center in the front-rear direction to the right side so as to penetrate the developing roller shaft fitting portion 66.

  The supply electrode 51 is supported on the right side wall 42 </ b> R of the developing frame 25 so that the supply roller shaft insertion portion 56 is fitted on the supply roller shaft 57.

  Thereby, the supply electrode 51 is electrically connected to the supply roller shaft 57.

  The bearing member 52 is supported by the right side wall 42R of the developing frame 25 so as to cover the supply roller shaft insertion portion 56 and the connecting portion 55 of the supply electrode 51 from the right side.

  A developing roller shaft 67 is rotatably inserted into the developing roller shaft insertion hole 62 of the bearing portion 61.

  Further, a supply roller shaft 57 is rotatably fitted to the supply roller shaft covering portion 63 of the bearing portion 61.

  As a result, the bearing member 52 rotatably supports the supply roller shaft 57 and the developing roller shaft 67 with respect to the developing cartridge 19 and is positioned with respect to the developing frame 25.

  The insulating portion 59 is disposed opposite to the supply side contact portion 54 of the supply electrode 51 with a space therebetween.

  The developing electrode 53 is supported by the bearing member 52 so that the developing roller shaft covering portion 69 is fitted on the developing roller shaft 67.

  As shown in FIG. 4, the supply electrode 51, the bearing member 52, and the development electrode 53 are fixed to the development frame 25 by a common screw 48.

  Thus, the developing cartridge 19 includes the supply side contact portion 54 and the development side contact portion 64 on the right side surface of the right side wall 42R, and as shown in FIG. 2, between the supply electrode 51 and the development electrode 53, A bearing member 52 is interposed, and the supply electrode 51 and the developing electrode 53 are insulated from each other by the bearing member 52.

  The developing roller shaft 67 is covered with a developing roller shaft covering portion 69, and the developing roller shaft covering portion 69 and the supply side contact portion 54 and the development side contact portion 64 (first electrode) are close to each other. Has been placed.

Further, the developing roller shaft covering portion 69 protrudes rightward so that the rotation axis of the developing roller 34 and the axial direction coincide with each other. The direction parallel to the rotation axis of the developing roller 34 is the first direction.
(3) Left side wall As shown in FIGS. 3A and 3B, a drive unit 70 is provided on the left side surface of the left side wall 42 (hereinafter referred to as the left side wall 42L).

  The drive unit 70 includes a gear train (not shown) and a gear holder 71.

  The gear train includes a plurality of gears for rotationally driving the developing roller 34, the supply roller 33, and the agitator 29.

  Further, the gear train includes a developing side coupling 72 to which driving force is input from the main body side coupling 10 (see the broken line) in the main body casing 2.

  The development side coupling 72 transmits driving force to a plurality of gears.

  The gear holder 71 is formed in a substantially box shape that opens to the right and rear, and is mounted on the left side wall 42L from the left side so as to collectively cover the gear train.

  On the left side surface of the gear holder 71, a coupling exposed cylinder 73, a collar engaging groove 74, and a convex portion 75 are formed.

  The coupling exposing cylinder 73 is formed in a substantially cylindrical shape that penetrates the gear holder 71 so as to expose the developing side coupling 72 and protrudes to the left at a substantially center in the front-rear direction of the left side surface of the gear holder 71. .

  The collar engaging groove 74 is formed on the rear side of the coupling exposure cylinder 73 and is formed in a substantially C shape in side view that is recessed from the rear end edge of the gear holder 71 toward the front lower side.

  The convex portion 75 is the rear upper side of the left side surface of the gear holder 71 and the upper side of the coupling exposed cylinder 73, has a substantially claw shape in a side view, and protrudes leftward.

  A second guide curved surface 78L is defined at the rear end of the convex portion 75 at a position and shape substantially symmetrical to the first guide curved surface 78R of the power supply unit 50.

  That is, the second guide curved surface 78L is divided into a substantially arc shape that is curved downward from the rear end portion of the convex portion 75 continuously toward the rear side.

  A color member 76 as an example of a protruding portion is fitted on the left end portion of the developing roller shaft 67 of the developing roller 34.

  The gear holder 71 is mounted on the left side wall 42L from the left side and developed so that the developing side coupling 72 is inserted into the coupling exposed cylinder 73 and the collar member 76 is inserted into the collar engaging groove 74. It is fixed to the frame 25.

Then, the development side coupling 72 is exposed through the coupling exposure cylinder 73, and the color member 76 is moved to the left from the left side wall 42L of the development cartridge 19 so that the rotation axis of the development roller 34 coincides with the axial direction. Protrudes toward the left from the collar engaging groove 74.
3. Details of Drum Cartridge (1) Drum Frame The drum cartridge 18 includes a drum frame 80 as shown in FIG. The drum frame 80 includes a pair of left and right side walls 81 (a right side (one side) side wall 81 as an example of a first wall and a left side (the other side) side wall 81 as an example of a second wall) and a lower wall. 82, a front wall 83, an upper wall 84, and a rear wall 106.

  The pair of left and right side walls 81 are formed in a substantially L shape in a side view extending in the rear portion and extending forward in the front portion, and are arranged to face each other with a space therebetween.

  A pair of left and right bosses 85 are formed at the front end portions of the outer surfaces of the pair of left and right side walls 81 so as to protrude outward in the left and right direction.

  In addition, a pair of left and right photosensitive drum shaft insertion holes 88 are formed in the rear portion of the pair of left and right side walls 81 at substantially the center in the vertical direction.

  Further, as shown in FIG. 7A, a plurality of recesses 89 are formed in the right side wall 81 (hereinafter referred to as the right side wall 81R) below the photosensitive drum shaft insertion hole 88.

  The concave portion 89 has a circular shape or a long hole shape in a side view, and is arranged in alignment with the photosensitive drum shaft insertion hole 88 in the circumferential direction.

  The size of the recess 89 is about half or less than the size of a main body side development electrode 100 (described later) and a main body side supply electrode 101 (described later) as an example of the second electrode.

  In addition, a chamfer 90 is formed on the rear end surface of the right side wall 81R so as to incline to the left side toward the rear side in the entire vertical direction.

  An angle A formed by the end surface of the chamfer 90 and the right side surface of the right side wall 81R is set to be 50 ° or more and less than 90 ° (see FIG. 5B).

  As shown in FIG. 5A, the lower wall 82 is constructed between the lower ends of the pair of left and right side walls 81.

  The front wall 83 is constructed between a pair of left and right side walls 81 and a front end portion of the lower wall 82, and a grip portion 109 that protrudes forward and upward is formed at the approximate center in the left-right direction.

  The upper wall 84 is constructed between the upper ends of the rear portions of the pair of left and right side walls 81.

  The rear wall 106 is formed so as to bulge rearward from the rear end portion of the pair of left and right side walls 81.

  The rear wall 106 has a substantially U-shaped rear wall 107 (see FIG. 1) and extends forward from both left and right ends of the rear wall 107 and is connected to the front ends of the pair of left and right side walls 81. A pair of left and right rear wall side walls 108 is provided.

  A drum accommodating portion 91 is defined by a rear portion of the pair of left and right side walls 81, an upper wall 84, a lower wall 82 facing the upper wall 84, and a rear wall 106.

  As shown in FIG. 1, the drum accommodating portion 91 supports the photosensitive drum 20, the transfer roller 21, and the scorotron charger 22.

  As shown in FIG. 5A, the photosensitive drum 20 is rotatably supported on the pair of left and right side walls 81 by inserting the photosensitive drum shaft 86 through the pair of left and right photosensitive drum shaft insertion holes 88. ing.

  The photosensitive drum shaft 86 of the photosensitive drum 20 protrudes outward in the left-right direction of the pair of left and right side walls 81.

  As shown in FIG. 1, the transfer roller 21 is accommodated in the rear wall 106 and is rotatably supported by a pair of left and right rear wall side walls 108.

  The scorotron charger is supported on the upper wall 84.

  In the scorotron charger 22, as shown in FIG. 7A, the charging wire 23 is electrically connected to the charge side electrode 93, and the grid 24 is electrically connected to the grid side electrode 94.

  The charge side electrode 93 is disposed at the front end at the upper end of the right side surface of the right side wall 81R, protrudes upward from the upper wall 84, and protrudes rightward from the right side wall 81R. It is formed in a shape (see FIG. 5B).

  The grid side electrode 94 is disposed behind the charge side electrode 93 at the upper end portion of the right side surface of the right side wall 81R.

  Further, as shown in FIG. 5A, a cartridge mounting portion 92 as an example of a housing portion is defined by a front portion of the pair of left and right side walls 81, a lower wall 82, and a front wall 83.

The cartridge mounting portion 92 is formed in a substantially bottomed rectangular frame shape that communicates with the drum housing portion 91 and is open at the top.
(2) First guide rail and second guide rail In the right side wall 81R, the upper end portion of the front portion along the front-rear direction and the front end portion of the rear portion along the vertical direction are as shown in FIG. Further, a first guide rail 95R for guiding attachment / detachment of the developing cartridge 19 to / from the drum cartridge 18 is partitioned (formed).

  The first guide rail 95R includes a first inclined surface 96R and a first bearing surface 110R as an example of the first guide.

  The first inclined surface 96R is formed so as to be inclined downward toward the rear side at the upper end portion of the front side portion of the right side wall 81R.

  110 R of 1st bearing surfaces are formed in the substantially C shape of the side view by which the front is open | released above the part connected with the front side part in the rear part of the right side wall 81R, and it is notched toward back.

  The first bearing surface 110R opposes the lower surface 111R continuous with the first inclined surface 96R with a space above the lower surface 111R, with an upper surface 112R parallel to the lower surface 111R, the rear end portion of the lower surface 111R, and the upper surface 112R. A rear surface 113R connecting the rear end portion.

  The lower surface 111R is formed so as to incline upward toward the rear side.

  The upper surface 112R is formed so as to protrude toward the front lower side together with the front end portion of the rear side portion of the right side wall 81R continuous to the upper surface 112R.

  The rear surface 113R is formed to be curved at a connection portion with the rear end portion of the lower surface 111R and a connection portion with the rear end portion of the upper surface 112R.

  The groove width of the first bearing surface 110R (the length between the upper surface 112R and the lower surface 111R) is formed to be substantially the same (slightly longer) as the outer diameter of the developing roller shaft covering portion 69 of the developing cartridge 19. ing.

  In the first guide rail 95R, the first inclined surface 96R and the lower surface 111R of the first bearing surface 110R are formed in a flat plate shape protruding from the upper end surface of the right side wall 81R toward the left side (the other side).

  The right side wall 81R is provided with a covering portion 97 that covers the first bearing surface 110R from the right side.

  As shown in FIG. 7A, the covering portion 97 is formed in a substantially trapezoidal shape in a right side view that becomes narrower as it goes upward.

  The covering portion 97 covers the first bearing surface 110R (the lower surface 111R, the upper surface 112R, and the rear surface 113R) in the upper portion, and covers the right side wall 81R on the lower side of the first bearing surface 110R in the lower portion. .

  As shown in FIG. 5B, the covering portion 97 is formed so as to protrude to the right side (one side) from the right side surface of the right side wall 81R.

  Even if the covering portion 97 receives the developing roller shaft covering portion 69 of the developing cartridge 19 by the length W protruding rightward from the right side surface of the right side wall 81R, the plate thickness of the covering portion 97 can be secured. .

  As shown in FIG. 7A, a chamfer 98 is formed on the front end surface of the covering portion 97 so as to incline to the left side toward the rear side.

  An angle B formed by the end surface of the chamfer 98 and the right side surface of the right side wall 81R is set to be 50 ° or more and less than 90 °.

  On the left side wall 81 (hereinafter referred to as the left side wall 81L), as shown in FIG. 5A, a second guide rail 95L is formed at a position and shape symmetrical to the first guide rail 95R. Yes.

  That is, the second guide rail 95L includes a second inclined surface 96L and a second bearing surface 110L as an example of the second guide.

  The second inclined surface 96L is formed so as to be inclined downward toward the rear side at the upper end portion of the front side portion of the left side wall 81L.

  The second bearing surface 110L is formed in a substantially C shape in a side view in which a front is opened and a rear notch is cut out above a portion connected to a front portion in a rear portion of the left side wall 81L.

  The second bearing surface 110L is opposed to the lower surface 111L continuous with the second inclined surface 96L with a space above the lower surface 111L, with an upper surface 112L parallel to the lower surface 111L, a rear end portion of the lower surface 111L, and the upper surface 112L. And a rear surface 113L that connects the rear end portion.

  The lower surface 111L is formed so as to incline upward toward the rear side.

  The upper surface 112L is formed so as to protrude toward the front lower side together with the front end portion of the rear side portion of the left side wall 81L continuous with the upper surface 112L.

  The rear surface 113L is formed to be curved at a connection portion with the rear end portion of the lower surface 111L and a connection portion with the rear end portion of the upper surface 112L.

  The groove width of the second bearing surface 110L (the length between the upper surface 112L and the lower surface 111L) is formed to be substantially the same length (slightly longer) as the outer diameter of the color member 76 of the developing cartridge 19.

  In the second guide rail 95L, the second inclined surface 96L and the lower surface 111L of the second bearing surface 110L are formed in a flat plate shape protruding from the upper end surface of the left side wall 81L toward the right side (one side).

  In the left side wall 81L, the second bearing surface 110L is not covered with the covering portion 97 and is open toward the left side (the other side).

  In addition, the front end surface of the pair of left and right side walls 81 (portion continuous with the upper wall 84) in the rear portion is partitioned as a pair of left and right third guide rails 99 extending in the vertical direction.

A lower end portion of the third guide rail 99 is formed on the right side wall 81R so as to be continuous with a front end portion of the upper surface 112R of the first bearing surface 110R included in the first guide rail 95R, and on the left side wall 81L, the second guide rail is formed. It is formed so as to be continuous with the front end portion of the upper surface 112L of the second bearing surface 110L included in the 95L.
4). Mounting of Developer Cartridge to Drum Cartridge To mount the developer cartridge 19 on the drum cartridge 18, first, the developer cartridge 19 is lifted as shown in FIG.

  At this time, since the developing cartridge 19 has the leg portion 45 extending downward from the lower wall 43, there is a gap between the developing cartridge 19 and the horizontal placement surface, and a finger is put into the gap to easily lift it up. be able to.

  Next, as shown in FIG. 6, the rear end portion of the developing cartridge 19 is inserted into the rear end portion of the cartridge mounting portion 92 of the drum cartridge 18 from above.

  Thereafter, the rear end portion of the developing cartridge 19 is pressed against the front end surface of the rear portion along the upper and lower sides of the pair of left and right side walls 81 of the drum cartridge 18, and the front end of the developing cartridge 19 is used with the rear end portion of the developing cartridge 19 as a fulcrum. Rotate the part to the front lower side.

  Specifically, the rear end portion of the insulating portion 59 of the power supply unit 50 mounted on the right side wall 42R of the developing cartridge 19 is brought into contact with the front end portion of the rear side portion of the right side wall 81R of the drum cartridge 18 so as to develop. The rear end portion of the convex portion 75 of the drive unit 70 mounted on the left side wall 42L of the cartridge 19 is brought into contact with the front end portion of the rear side portion along the upper and lower sides of the left side wall 81L of the drum cartridge 18.

  At this time, the first guide curved surface 78R defined at the rear end portion of the insulating portion 59 and the second guide curved surface 78L defined at the rear end portion of the convex portion 75 constitute the rear of the pair of left and right side walls 81. It abuts from the front on the third guide rail 99 defined on the front end surface of the side portion.

  Then, the developing cartridge 19 is guided by the first guide curved surface 78R and the second guide curved surface 78L, and is rotated counterclockwise as viewed from the right side with the contact portion as a fulcrum.

  When the developing cartridge 19 is further rotated counterclockwise as viewed from the right side, the developing roller shaft covering portion 69 protruding to the right side of the developing cartridge 19 contacts the upper end portion of the front side portion of the right side wall 81R of the drum cartridge 18. The collar member 76 projecting to the left side of the developing cartridge 19 contacts the upper end portion of the front side portion of the left side wall 81L of the drum cartridge 18.

  That is, the developing roller shaft covering portion 69 comes into contact with the first guide rail 95R, and the collar member 76 comes into contact with the second guide rail 95L.

  Thereafter, when the developing cartridge 19 is moved so as to be pushed rearward, the developing roller shaft covering portion 69 is guided to the rear lower side by the first inclined surface 96R of the first guide rail 95R, and the collar member 76 is moved to the second guide. The second inclined surface 96L of the rail 95L guides the rear lower side.

  When the developing cartridge 19 is further moved backward, the developing roller shaft covering portion 69 is guided to the rear upper side by the first bearing surface 110R of the first guide rail 95R, and the collar member 76 is moved to the second guide rail. It is guided to the rear upper side by the second bearing surface 110L of 95L.

  Then, the rubber roller 68 of the developing roller 34 and the drum 87 of the photosensitive drum 20 come into contact with each other, and further movement of the developing cartridge 19 is restricted, and the developing roller shaft covering portion 69 is accommodated in the first bearing surface 110R. Then, the collar member 76 is accommodated in the second bearing surface 110 </ b> L, and the front end portion of the developing cartridge 19 is accommodated in the front end portion of the cartridge mounting portion 92.

  Thus, when the front end portion of the developing cartridge 19 is accommodated in the front end portion of the cartridge mounting portion 92, the mounting of the developing cartridge 19 to the drum cartridge 18 is completed, and the process cartridge 15 is formed as shown in FIG.

  In such a process cartridge 15, as shown in FIG. 7A, when the developing side contact portion 64 (first electrode) is viewed from the right side (one side) to the left side (the other side), It is exposed from the right side wall 81R (first wall).

  On the other hand, the supply roller shaft insertion portion 56 of the supply electrode 51, the bearing portion 61 of the bearing member 52, and the developing roller shaft covering portion 69 of the developing electrode 53 are covered with a covering portion 97.

  In addition, the first bearing surface 110R and the development side contact portion 64 (first electrode) are disposed close to each other.

  In such a process cartridge 15, the developing roller shaft covering portion 69 is covered with the covering portion 97.

  On the other hand, as shown in FIG. 7B, the collar member 76 passes through the second bearing surface 110L and protrudes to the left side (the other side) from the left side wall 81L.

  In order to detach the developing cartridge 19 from the drum cartridge 18, the developing cartridge 19 and the drum cartridge 18 are operated in reverse to the mounting operation described above.

  Specifically, the front end portion of the developing cartridge 19 is rotated to the rear upper side with the rear end portion of the developing cartridge 19 as a fulcrum, and then the developing cartridge 19 is detached from the drum cartridge 18 to the upper side.

As described above, the developing cartridge 19 is detachably attached to the drum cartridge 18.
5. Details of Main Body Casing (1) Main Body Side Development Electrode As shown in phantom lines in FIG. 1, the main body casing 2 includes a main body side development electrode 100 as an example of the second electrode on the inner surface of the right side wall, and the main body side. A supply electrode 101 is provided.

  The main body side development electrode 100 is provided so as to come into contact with the development side contact portion 64 when the process cartridge 15 is completely attached to the main body casing 2, and is provided in the rear portion of the main body casing 2.

  The main body side development electrode 100 is formed in a substantially annular shape in plan view, and is disposed obliquely so that the front side is inclined upward and the rear side is inclined downward.

  The main body side development electrode 100 is supported on the inner side surface of the right side wall of the main body casing 2 via an elastic member (not shown), and is always urged toward the left side. The main body side development electrode 100 is electrically connected to a power source (not shown) in the main body casing 2.

  The main body side supply electrode 101 is provided so as to come into contact with the supply side contact portion 54 when the mounting of the process cartridge 15 to the main body casing 2 is completed. 100 is provided on the front side.

  The main body side supply electrode 101 is formed in a substantially annular shape in plan view, and is disposed obliquely so that the front side is inclined upward and the rear side is inclined downward.

The main body side supply electrode 101 is supported on the inner side surface of the right side wall of the main body casing 2 via an elastic member (not shown), and is always urged toward the left side. The main body side supply electrode 101 is electrically connected to a power source (not shown) in the main body casing 2.
(2) Guide Part of Main Body Casing The guide part 37 of the main body casing 2 includes a first main body side guide 102 and a second main body side guide 103.

  The first main body side guide 102 is located on the pair of left and right inner surfaces of the main body casing 2 from the front-rear direction center of the upper end portion (cartridge opening portion 5) of the main body casing 2 to the substantially vertical center of the rear end portion of the main body casing 2. It is provided to extend.

The second main body side guide 103 is provided on the pair of left and right inner surfaces of the main body casing 2 at a distance from the front side of the first main body side guide 102 and has substantially the same inclination as the first main body side guide 102. And a rear portion having a larger downward slope than the first main body side guide 102, and is provided so that the distance from the first main body side guide 102 increases toward the rear.
6). Mounting of Process Cartridge to Main Body Casing In order to mount the process cartridge 15 to the main body casing 2, first, the top cover 7 (see FIG. 1) of the main body casing 2 is disposed at the open position, and the cartridge opening 5 is opened. .

  Next, as shown in FIG. 8, the right and left end portions of the photosensitive drum shaft 86 of the photosensitive drum 20 are fitted to the left and right pair of first main body side guides 102 by holding the holding portion 109 of the process cartridge 15. Then, the process cartridge 15 is inserted into the main casing 2 from the cartridge opening 5.

  Then, when the process cartridge 15 is pushed rearward and downward so that the photosensitive drum shaft 86 is along the first main body side guide 102, the left and right pair of bosses 85 of the drum frame 80 are moved to the left and right pair of second main body side. The guide 103 is fitted.

  Further, when the process cartridge 15 is pushed rearward and downward, the process cartridge 15 moves rearward and downward such that the photosensitive drum shaft 86 is along the first main body side guide 102 and the boss 85 is along the second main body side guide 103. To do.

  As the process cartridge 15 is inserted into the main casing 2, the distance between the first main body side guide 102 and the second main body side guide 103 increases, so that the process cartridge 15 gradually becomes counterclockwise as viewed from the right side. Rotate.

  At this time, the main body side development electrode 100 in the main body casing 2 is brought into contact with the chamfer 90 of the right side wall 81R from the front side.

  Then, the main body-side developing electrode 100 is displaced to the right along the inclination of the chamfer 90 against the urging force, but does not fit into the concave portion of the concave portion 89 of the right side wall 81R, and the right side in the drum housing portion 91. The wall 81R is slid relatively forward.

  Further, when the process cartridge 15 is rotated, the main body side development electrode 100 is brought into contact with the chamfer 98 of the covering portion 97 from the front side.

  Then, the main body side development electrode 100 slides relatively to the front side on the right side surface of the covering portion 97 while being displaced to the right side along the inclination of the chamfer 98 against the biasing force.

  At this time, since the developing roller shaft covering portion 69 is covered by the covering portion 97, the developing roller shaft covering portion 69 passes through the main body side developing electrode 100 from the front upper side to the rear lower side.

  That is, the mounting locus X of the developing roller shaft covering portion 69 overlaps the main body side developing electrode 100 when projected in the direction of the rotation axis of the developing roller 34.

  Further, when the process cartridge 15 is rotated, the main body side development electrode 100 is brought into contact with the first guide electrode surface 104 of the development electrode 53 from the lower rear side, and the main body side supply electrode 101 is in contact with the supply side contact. It abuts on the second guide electrode surface 105 of the portion 54 from below.

  Then, the main body-side developing electrode 100 slides relatively frontward while being displaced to the right along the inclination of the first guide electrode surface 104 against the biasing force, and comes into contact with the developing-side contact portion 64. The At this time, the main body side development electrode 100 slides on the right surface of the head of the screw 48 and comes into contact with the development side contact portion 64.

  Further, the main body side supply electrode 101 slides relatively upward while being displaced to the right along the inclination of the second guide electrode surface 105 against the biasing force, and comes into contact with the supply side contact portion 54. The

  Thereby, the main body side development electrode 100 (second electrode) and the development side contact portion 64 (first electrode) of the development electrode 53 are electrically connected.

  Further, the main body side supply electrode 101 and the supply side contact portion 54 of the supply electrode 51 are electrically connected.

  When the photosensitive drum shaft 86 and the boss 85 reach the deepest portions of the first main body side guide 102 and the second main body side guide 103, the front end portion of the process cartridge 15 is irradiated with the laser beam L as shown in FIG. Arranged below the emission locus, the mounting of the process cartridge 15 to the main casing 2 is completed.

  Thereafter, when the top cover 7 of the main casing 2 is placed in the closed position and the printer 1 is operated, the power from the power source (not shown) in the main casing 2 causes the main body side developing electrode 100 and the developing electrode 53 to move. The toner is sequentially supplied to the developing roller shaft 67 and is supplied to the supply roller shaft 57 via the main body side supply electrode 101 and the supply electrode 51 sequentially.

  In order to remove the process cartridge 15 from the main casing 2, the process cartridge 15 and the main casing 2 are operated in reverse to the mounting operation described above.

  Specifically, after the top cover 7 is disposed at the open position, the process cartridge 15 is pulled out to the front upper side.

  In this way, the process cartridge 15 is configured to be detachably attached to the main casing 2.

  The attachment / detachment locus of the developing roller shaft covering portion 69 when the process cartridge 15 is detached from the main body casing 2 is the same as the locus X of the developing roller shaft covering portion 69 when the process cartridge 15 is attached to the main body casing 2. It is.

That is, the attachment / detachment locus (trajectory X) of the developing roller shaft covering portion 69 when the process cartridge 15 is attached / detached to / from the main body casing 2 is projected on the main body side when projected in the direction of the rotation axis (developing roller shaft 67) of the developing roller 34. It overlaps with the developing electrode 100 (second electrode).
7). Action and Effect (1) In the process cartridge 15, the first bearing surface 110R that guides the developing roller shaft covering portion 69 and the space that exposes the developing side contact portion 64 of the developing electrode 53 are close to each other on the right side wall 81R. Be placed. Therefore, it is not possible to ensure a sufficient area in the right side wall 81R that defines the first bearing surface 110R, and the rigidity of the first bearing surface 110R is reduced.

  However, in the process cartridge 15, the first bearing surface 110R is reinforced by the covering portion 97 that covers from the right side (outside).

  Therefore, the drum cartridge 18 has sufficient rigidity in the first bearing surface 110R even if the space on the right side wall 81R that exposes the developing side contact portion 64 of the developing electrode 53 is disposed close to the first bearing surface 110R. Can be secured.

As a result, it is possible to ensure the rigidity of the first bearing surface 110R while reducing the size of the process cartridge 15.
(2) Further, according to this process cartridge 15, since the covering portion 97 protrudes to the right side from the right side wall 81R, the developing roller shaft covering portion 69 of the developing cartridge 19 is received by the protruding length W. However, the plate thickness of the covering portion 97 can be ensured.

Therefore, the first bearing surface 110R can be reinforced more reliably.
(3) Further, according to the process cartridge 15, the collar member 76 protrudes to the left side through the second bearing surface 110L of the left side wall 81L opened toward the left side (the other side), and the second bearing It is supported in all the left and right directions of the surface 110L.

Therefore, even if the distance between the right side wall 81R and the left side wall 81L is shortened, the collar member 76 can be supported and the process cartridge 15 can be downsized.
(4) Further, according to the process cartridge 15, the first guide rail 95R is located on the left side (the other side) from the upper end surface of the right side wall 81R on the first inclined surface 96R and the lower surface 111R of the first bearing surface 110R. It is formed in a flat plate shape that protrudes toward it.

  The second guide rail 95L is formed in a flat plate shape that protrudes from the upper end surface of the left side wall 81L toward the right side (one side) on the lower surface 111L of the second inclined surface 96L and the second bearing surface 110L. .

  Therefore, the first guide rail 95R and the second guide rail 95L can secure a large portion for supporting the developing roller shaft covering portion 69 and the color member 76 without increasing the size outward in the left-right direction.

As a result, it is possible to more reliably guide the developing roller shaft covering portion 69 and the color member 76 while reducing the size of the process cartridge 15.
(5) Further, in the printer 1, when the process cartridge 15 is mounted on the main casing 2, the covering portion 97 that covers the developing roller shaft covering portion 69 is located before the developing side contact portion 64 (first electrode). The main body side developing electrode 100 (second electrode) comes into contact. That is, in the mounting direction, the developing roller shaft covering portion 69 is disposed downstream of the developing side contact portion 64 (first electrode).

  Therefore, the attachment / detachment locus X of the developing roller shaft covering portion 69 when the process cartridge 15 is attached / detached to / from the main body casing 2 always overlaps with the main body side developing electrode 100 when projected in the direction of the rotation axis of the developing roller 34. When the process cartridge 15 is attached to and detached from the main casing 2, if the attachment / detachment locus X of the developing roller shaft covering portion 69 overlaps with the main body side developing electrode 100, the developing roller shaft covering portion 69 and the main body side developing electrode 100 slide. There is a risk that the main body side developing electrode 100 may be damaged.

  However, according to this printer 1, even if the developing roller shaft covering portion 69 moves so as to overlap the main body side developing electrode 100, the developing roller shaft covering portion 69 is covered with the covering portion 97, and the main body side developing electrode 100 slides with the covering portion 97 instead of the developing roller shaft covering portion 69.

Therefore, damage to the main body side development electrode 100 can be prevented.
8). In the above-described embodiment, the right end portion of the developing roller shaft 67 is covered with the developing roller shaft covering portion 69, and the left end portion of the developing roller shaft 67 is covered with the color member 76.

  However, both end portions of the developing roller shaft 67 are directly guided by the first guide rail 95R and the second guide rail 95L without providing the developing roller shaft covering portion 69 and the color member 76 at both ends of the developing roller shaft 67. You may let them.

  Further, a protruding portion such as a boss is separately provided outward in the left-right direction from the right side wall 81R and the left side wall 81L, not the both end portions of the developing roller shaft 67, the developing roller shaft covering portion 69 and the collar member 76 provided thereon. You may make it protrude and guide the protrusion part to the 1st guide rail 95R and the 2nd guide rail 95L.

  The process cartridge 15 described above is an embodiment of the process cartridge of the present invention. The printer 1 described above is an embodiment of the image forming apparatus of the present invention. The present invention is limited to the above-described embodiment. Not.

  The image forming apparatus of the present invention can be configured as a color printer in addition to a 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 members and a recording medium conveying member, a plurality of photosensitive members, an intermediate transfer member, and a transfer member. An intermediate transfer type tandem color printer can also be configured.

  Further, the developing cartridge 19 can be configured such that a toner cartridge in which toner is accommodated is detachably attached to a housing having a developer carrier.

  Further, instead of the above-described photosensitive drum 20, for example, a photosensitive member such as a photosensitive belt can be applied.

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

  Further, instead of the supply roller 33 described above, 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, in place of the transfer roller 21 described above, for example, a contact type transfer member such as a transfer belt, a transfer brush, or a transfer blade, or a non-contact type transfer member such as a corotron type can be applied. .

  Further, in place of the above scorotron charger 22, for example, a non-contact charger such as a corotron charger or a charger provided with a sawtooth discharge member, or a contact charger such as a charging roller, for example. Etc. can be applied.

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

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

DESCRIPTION OF SYMBOLS 1 Printer 2 Main body casing 15 Process cartridge 18 Drum cartridge 19 Developing cartridge 20 Photosensitive drum 34 Developing roller 64 Developing side contact part 69 Developing roller shaft covering part 67 Developing roller shaft 76 Color member 81R Right side wall 81L Left side wall 92 Developing cartridge mounting part 100 Main body side development electrode 110R First bearing surface 110L Second bearing surface X Trajectory

Claims (7)

A photoreceptor cartridge having a photoreceptor configured to carry an electrostatic latent image;
A developer carrying member configured to carry a developer that develops the electrostatic latent image and configured to rotate; and a developer cartridge that is detachably attached to the photoreceptor cartridge,
The developer cartridge includes a protrusion extending in a first direction parallel to a rotation axis of the developer carrier,
The photosensitive cartridge has a first wall that is disposed on one side of the developing cartridge in the first direction and forms a housing portion that houses the developing cartridge;
The first wall is formed with a first guide configured to guide the protruding portion, and a covering portion that covers the first guide from the outside in the first direction,
The developing cartridge includes a first electrode on an outer surface on one side in the first direction,
The process cartridge according to claim 1, wherein the first electrode is exposed from the first wall when viewed from one side to the other side in the first direction.   2. The process cartridge according to claim 1, wherein the covering portion protrudes to one side of the first wall in the first direction. The photosensitive cartridge has a second wall disposed on the other side of the developing cartridge in the first direction;
A second guide configured to guide the protrusion is formed on the second wall,
The second guide is open toward the other side in the first direction,
3. The process cartridge according to claim 1, wherein the protruding portion passes through the second guide and protrudes to the other side in the first direction from the second wall. 4. The first guide is formed so as to protrude from the first wall toward the other side in the first direction,
The process cartridge according to claim 3, wherein the second guide is formed so as to protrude from the second wall toward the one side in the first direction.   The process cartridge according to claim 1, wherein the protrusion is a shaft of the developer carrying member. The process cartridge according to any one of claims 1 to 5,
A housing configured to detachably mount the process cartridge;
The housing includes a second electrode electrically connected to the first electrode,
The image forming apparatus according to claim 1, wherein an attaching / detaching locus of the protruding portion when the process cartridge is attached / detached to / from the housing overlaps the second electrode when projected in the first direction.   The image forming apparatus according to claim 6, wherein the protrusion is disposed downstream of the first electrode in a direction in which the process cartridge is attached to the housing.

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