JP4463676B2 - Process cartridge, developing cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus employing an electrophotographic method such as a laser printer, a process cartridge mounted on the image forming apparatus, and a developing cartridge constituting the process cartridge.

  2. Description of the Related Art An image forming apparatus employing an electrophotographic method such as a laser printer is known that includes a process cartridge including a photosensitive cartridge and a developing cartridge that is detachably attached to the photosensitive cartridge (Patent Document). 1).

  According to such a process cartridge, since the photosensitive member cartridge and the developing cartridge are separated, even if the developer is used up, as long as the photosensitive member cartridge does not break down, if the developing cartridge alone is replaced with a new one, it will continue to be used. It is possible to reduce the burden on the environment without discarding the photoconductor that can still be used.

JP 2000-267547 A

  In recent years, from the viewpoint of environmental problems, there has been an increasing demand to refill a developing cartridge that has run out of toner again and reuse the cartridge.

  However, some developing cartridges constitute a part of a sheet conveyance path formed inside the process cartridge. In this case, there is a possibility that a part of the developing cartridge is worn by the passage of the sheet. When the developer cartridge thus worn is refilled with toner and reused, the passing paper may be caught in the worn portion or conveyed in an unexpected direction. Problems may arise.

  In view of the above problems, an object of the present invention is to provide a developing cartridge and the like suitable for reuse.

  In order to solve the above problems, a developing cartridge according to the present invention is a developing cartridge used in an image forming apparatus for forming an image on a conveyed sheet material, and a developer containing chamber for containing a developer is formed. A first housing, and a guide member that is arranged in the first housing and guides the sheet material to be conveyed toward the downstream side in the conveyance direction, and the guide member is all in contact with the sheet material. It consists of a separate member from the first housing and is replaceable by being fixed so as to be removable.

  According to this, since all the guide members that are likely to be worn by contact with the paper are constituted by the first casing and separate members and are fixed so as to be removable, the guide members can be replaced by removing them. Can only be replaced with a new one. For this reason, when the developing cartridge is reused, it is possible to suppress the occurrence of a jam or the like caused by the wear of the guide member even if the developing cartridge is reused by replacing only the guide member with a new one.

  In particular, if the guide member is detachably fixed, it is easy to remove it.

  If the guide member is made of a material that is harder than the first housing and has excellent wear resistance, the guide member is less worn and need not be replaced, and the removed guide member need not be discarded. Therefore, the load on the environment can be further reduced.

  In the developing cartridge according to the present invention, the first housing is arranged in communication with the developer accommodating chamber on the downstream side in the sheet conveying direction with respect to the developer accommodating chamber, and is supplied from the developer accommodating chamber. A developing chamber is formed in which a developer carrying body for carrying the developer is arranged, and the guide member is arranged on the developer carrying body side with respect to the developing chamber.

  Normally, the developer carrying member is used in close proximity to the photosensitive member. Therefore, the developer carrying member can be reliably conveyed to the photosensitive member on which the toner image for transferring the toner image to the sheet material is formed as described above. Can be guided to.

  Specifically, the first housing has a wall portion that defines the developing chamber, and the guide member is provided at a position facing the developing chamber on the outer wall of the wall portion. The first housing includes a lower frame in which a developer storage chamber and a development chamber are formed and an upper portion of the developer storage chamber is opened, and an upper frame that is mounted on the opening of the lower frame, and a guide The member is provided on the lower wall portion that is formed on the lower frame in the wall portion and that defines the bottom surface of the developing chamber.

  Since it is constituted in this way, the guide member can be arranged closer to the photoreceptor. Therefore, it is possible to guide the sheet material so that the sheet material can be reliably conveyed to the photoconductor side.

  Moreover, as a guide member, what has the some rib erected by the lower wall part and the film member which covers a some rib can be used.

  By using the film member in this way, it is possible to provide a reusable developing cartridge only by sticking the film member on the developing cartridge that has been sold on the market while leaving the rib shape of the developing cartridge.

  Here, the guide member has a relatively small thickness by extending the shape of the guide member along the conveying direction of the sheet material and decreasing its height as it approaches the developer storage chamber from the developing chamber. It is formed so that its height decreases as it approaches the developer containing chamber side having a relatively large thickness from the developing chamber side. Therefore, when the developing cartridge is mounted on the mounting body with its top surface horizontal, the contact surface of the guide member with the recording medium can be disposed substantially horizontally. As a result, it is possible to guide the recording medium satisfactorily.

  In addition, by adjusting the conductivity of the guide member to be different from the material of the first housing or using a material that is superior to the material of the first housing, the potential of the paper before transfer is adjusted in advance. The transfer operation can be stabilized.

  Further, if the guide member is detachably fixed to the first housing with the adhesive double-sided tape, the guide member can be easily removed when the developing cartridge is reused.

The process cartridge according to the present invention is a process cartridge used in an image forming apparatus for forming an image on a sheet material, and includes a first housing in which a developer storage chamber for storing a developer is formed, A guide member that is arranged in one housing and guides the sheet material to be conveyed toward the downstream side in the conveyance direction, and the first housing of the guide member is located at a portion facing the sheet material conveyance path. A developing cartridge that is constituted by a separate member from the first casing and is detachably fixed over the entire surface, a second casing in which the developing cartridge can be attached and detached, and a second casing that is disposed in the second casing. A photosensitive member on which an electrostatic latent image to be developed by the developer supplied from the developer carrying member is formed; a developer storage chamber facing portion formed in the second housing and disposed to face the developer storage chamber; A guide member of the second housing; Provided at a gap in a position direction, characterized by comprising a photosensitive member cartridge having a bottom wall portion of the sheet feeding inlet is formed to KyuIri the sheet material to the guide member.

  According to this, in the case of reusing a process cartridge in the process cartridge as well as the above developing cartridge, even if only the guide member of the developing cartridge is replaced with a new one, the guide member is worn due to wear. Since it is possible to suppress the occurrence of jam and the like, it is suitable for reuse.

  Further, in the process cartridge, the photosensitive member cartridge includes a transfer unit disposed opposite to the photosensitive member in the second casing, and the transfer unit is fed from the sheet material inlet to the photosensitive member. By passing the sheet material, the developer developed on the photoreceptor is transferred to the sheet material.

  Here, the transferred sheet material is discharged from a sheet material discharge port formed in the second housing.

  By providing such a developing cartridge or process cartridge in the image forming apparatus, it is possible to suppress the occurrence of problems such as paper jam even if the developing cartridge is reused.

  According to the invention of the present application, the portion of the guide member that is likely to be worn by contact with the paper is composed of a separate member from the housing. For example, the guide member can be replaced with a new one, or the guide member can be worn away. It can be made of a material excellent in Therefore, when the developing cartridge is reused, it is possible to suppress the occurrence of a jam or the like caused by wear of the guide member. Therefore, it is possible to provide a developing cartridge or the like suitable for reuse.

  An embodiment in which an image forming apparatus according to the present invention is applied to a laser printer will be described below with reference to the drawings.

[First Embodiment]
(1) Overall Configuration of Laser Printer FIGS. 1 and 2 are cross-sectional side views of a main part showing an embodiment of a laser printer as an image forming apparatus of the present invention. This laser printer 1 includes a feeder unit 4 for feeding a sheet 3 as a recording medium and an image forming unit 5 for forming an image on the fed sheet 3 in a main body casing 2. Yes.

  In the main casing 2, an attachment / detachment opening 6 for attaching / detaching the process cartridge 20 is formed on one side wall, and a front cover 7 for opening / closing the attachment / detachment opening 6 is provided.

  The front cover 7 is rotatably supported by a cover shaft (not shown) inserted through the lower end portion thereof, and can be opened and closed with the cover shaft as a fulcrum.

Further, on the inner surface of the front cover 7, two ribs 351 serving as protrusions for preventing mounting of different models are opposed to each other in the width direction in order to prevent failure due to mounting of the process cartridge 20 used for different models. It arrange | positions and it protrudes toward the inner side of the main body casing 2. As shown in FIG. A concave portion 352 is formed in the process cartridge 20. When the process cartridge 20 is mounted on the main casing 2 and the front cover 7 is closed, the ribs 351 are fitted into the recesses 352 of the process cartridge 20, and the opening / removal opening 6 is opened by the front cover 7 as shown in FIG. Closed. When the front cover 7 is opened (tilted) from this state, as shown in FIG. 2, the ribs 351 are detached from the recesses 352 of the process cartridge 20, and the attachment / detachment openings 6 are opened. The process cartridge 20 can be attached to and detached from the main casing 2 via the portion 6. On the other hand, when a process cartridge used for a model different from the laser printer 1 is attached to the main body casing 2 and the front cover 7 is closed, each rib 351 interferes with the process cartridge and the front cover 7 may be completely closed. Therefore, it is possible to prevent such a process cartridge from being mounted.

  In the following, in the laser printer 1 and the process cartridge 20, the side on which the front cover 7 is provided (upstream side in the mounting direction of the process cartridge 20) is referred to as “front side”, and the opposite side (downstream side in the mounting direction of the process cartridge 20). ) As “rear side”.

  The feeder unit 4 includes a paper feed tray 9 that is detachably attached to the bottom of the main casing 2, a paper feed roller 10 and a separation pad 11 that are provided above the front end of the paper feed tray 9, and a paper feed roller 10, a pickup roller 12 provided on the rear side of the paper feed roller 10, a pinch roller 13 disposed oppositely on the lower front side of the paper feed roller 10, and a pair of upper and lower registration rollers 14 provided on the upper rear side of the paper feed roller 10. ing.

  Inside the paper feed tray 9, there is provided a paper pressing plate 15 on which the paper 3 can be stacked. The sheet pressing plate 15 is supported at the rear end so as to be swingable, so that the front end can be moved in the vertical direction.

  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 formed in a substantially L-shaped cross section so as to go from the front side to the lower side of the paper pressing plate 15, and its upper end is attached to a lever shaft 18 provided at the front end of the paper feed tray 9. The rear end portion is in contact with the front end portion of the lower surface of the paper pressing plate 15. Accordingly, when a clockwise rotational driving force in the drawing is input to the lever shaft 18, the lever 17 rotates about the lever shaft 18, and the rear end portion of the lever 17 lifts the front end portion of the paper pressing plate 15.

  When the front end of the sheet pressing plate 15 is lifted, the uppermost sheet 3 on the sheet pressing plate 15 is pressed by the pickup roller 12, and the sheet feeding roller 10, the separation pad 11, and the like are rotated by the rotation of the pickup roller 12. The conveyance is started in between.

  On the other hand, when the paper feed tray 9 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 in a state along the bottom surface of the paper feed tray 9. In this state, the sheets 3 can be stacked on the sheet pressing plate 15.

  When the sheet 3 sent out between the sheet feeding roller 10 and the separation pad 11 by the pickup roller 12 is sandwiched between the sheet feeding roller 10 and the separation pad 11 by the rotation of the sheet feeding roller 10. Each sheet is reliably fed and fed. The fed paper 3 passes between the paper feed roller 10 and the pinch roller 13 and is conveyed to the registration roller 14.

The registration roller 14 is composed of a pair of upper and lower rollers. After the sheet 3 is registered, the transfer position (between the photosensitive drum 92 and the transfer roller 94 between the photosensitive drum 92 and the photosensitive drum 92) of the image forming unit 5 is registered. The upper toner image is conveyed to a position where the toner image is transferred to the paper 3.

  The image forming unit 5 includes a scanner unit 19, a process cartridge 20, a fixing unit 21, and the like.

  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, a reflecting mirror 26, and the like. The laser beam based on the image data emitted from the laser light source is deflected by the polygon mirror 22 as shown by the broken line, passes through the fθ lens 23, and then the optical path is turned back by the reflecting mirror 24, and further passes through the lens 25. After that, the optical path is further bent downward by the reflecting mirror 26, so that the surface of the photosensitive drum 92 of the process cartridge 20 is irradiated.

  The process cartridge 20 is detachably attached to the main casing 2 below the scanner unit 19 (see FIG. 2). The process cartridge 20 includes a drum cartridge 27 (see FIG. 9) and a developing cartridge 28 (see FIG. 3) that is detachably attached to the drum cartridge 27.

  When the process cartridge 20 is mounted on the main casing 2, the process cartridge 20 is connected to the drum drive gear 191 (both see FIG. 11) connected to the left end of the drum main body 124 in the axial direction and exposed from the gear opening 196. The drum gear, which is provided in the main body casing 2 and receives a rotational driving force from a motor (not shown), is engaged, and the rotational driving force from the motor is input to the drum driving gear 191 so that the photosensitive drum 92 is rotated.

  In the process cartridge 20 thus mounted in the main casing 2, as shown in FIG. 1, first, the toner accommodated in the toner accommodating chamber 30 of the developing cartridge 28 is agitated by the agitator 46 to release the toner. It is discharged from the outlet 58 toward the developing chamber 36.

  The toner discharged from the toner discharge port 58 to the developing chamber 36 is supplied to the developing roller 32 by the rotation of the supplying roller 31, and at this time, the gap between the supplying roller 31 and the developing roller 32 to which the developing bias is applied. Is positively triboelectrically charged.

  The toner supplied to the surface of the developing roller 32 enters between the pressure contact portion 67 (see FIG. 3) of the layer thickness regulating blade 33 and the developing roller 32 as the developing roller 32 rotates, and has a constant thickness. Is carried on the surface of the developing roller 32 as a thin layer.

  On the other hand, the scorotron charger 93 (see FIG. 1) generates corona discharge by applying a grid voltage and a discharge voltage to uniformly positively charge the surface of the photosensitive drum 92. The surface of the photosensitive drum 92 is uniformly positively charged by the scorotron charger 93 as the photosensitive drum 92 rotates, and then exposed by high-speed scanning of the laser beam from the scanner unit 19 to form on the paper 3. An electrostatic latent image corresponding to the image to be formed is formed.

  When the photosensitive drum 92 is further rotated, the toner held on the surface of the developing roller 32 and positively charged toner is brought into contact with the photosensitive drum 92 by the rotation of the developing roller 32. The electrostatic latent image formed on the surface, that is, the surface of the photosensitive drum 92 that is uniformly positively charged, is supplied to an exposed portion exposed to a laser beam and having a lowered potential. As a result, the electrostatic latent image on the photosensitive drum 92 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 92.

  Here, the sheet 3 passes through the paper inlet 332 and is conveyed between the photosensitive drum 92 and the transfer roller 94 while being guided by the film member 331a constituting the sheet conveying path.

  Thereafter, when the photosensitive drum 92 further rotates and faces the transfer roller 94, the toner image carried on the surface of the photosensitive drum 92 is transferred from the sheet 3 conveyed by the registration roller 14 to the photosensitive drum 92 and the transfer roller 94. The sheet is transferred to the sheet 3 by the transfer bias applied to the transfer roller 94 while passing through the transfer position between the two. The sheet 3 to which the toner image is transferred is conveyed to the fixing unit 21 on the downstream side in the sheet conveying direction.

  Here, when the photosensitive drum 92 further rotates and faces the cleaning brush 95, paper dust from the paper 3 adhering to the surface of the photosensitive drum 92 after the transfer is sucked by the cleaning bias applied to the cleaning brush 95. Entangled with a brush. The transfer residual toner remaining on the surface of the photosensitive drum 92 after the transfer is collected by the developing roller 32.

  The fixing unit 21 is provided on the rear side of the process cartridge 20, and includes a fixing frame 182, and a heating roller 183 and a pressure roller 184 in the fixing frame 182.

  The heating roller 183 includes a metal base tube and a halogen lamp provided in the metal base tube, and is rotationally driven by input of a driving force from a motor (not shown).

  The pressure roller 184 is disposed opposite the heating roller 183 so as to press the heating roller 183. The pressure roller 184 includes a metal roller shaft and a roller made of a rubber material that covers the periphery of the roller shaft, and is driven in accordance with the rotational drive of the heating roller 183.

  In the fixing unit 21, the toner transferred onto the paper 3 at the transfer position is thermally fixed while the paper 3 passes between the heating roller 183 and the pressure roller 184. The sheet 3 on which the toner is fixed is conveyed to a sheet discharge path 185 extending in the vertical direction toward the upper surface of the main casing 2. The sheet 3 conveyed to the sheet discharge path 185 is discharged onto a sheet discharge tray 187 formed on the upper surface of the main body casing 2 by a sheet discharge roller 186 provided on the upper side.

(2) Configuration of Process Cartridge FIG. 3 is a side sectional view of the process cartridge 20.

The process cartridge 20 shown in FIG. 3 can hold only the developing cartridge 28 and detach the developing cartridge 28 with respect to the drum cartridge 27. The cartridge 27 and the developing cartridge 28 are held together and can be attached to and detached from the main casing 2 (see FIG. 1). (2-1) Configuration of Developing Cartridge FIG. 4 is a side sectional view of the developing cartridge 28, and FIG. 5 is a perspective view of the developing cartridge 28 shown in FIG. 6 is a perspective view of the developing cartridge 28 with the film member 311a removed and seen obliquely from the lower right on the front side. FIG. 7 is a perspective view of the developing cartridge 28 shown in FIG. is there. FIG. 8 is a perspective view of the developing cartridge 28 shown in FIG.

As shown in FIGS. 3 and 4, the developing cartridge 28 includes a supply roller 3 as a process member.
1. A developing-side housing 29 is provided as a first housing that houses a developing roller 32 as a developer carrier, an agitator 46, and a layer thickness regulating blade 33.

  The development side housing 29 is made of, for example, a resin material such as polystyrene, and has a box shape with the rear side opened. The development side housing 29 includes a lower frame 34 and an upper frame 35, and includes a toner storage chamber 30 as a developer storage portion, a development chamber 36, and an upper extension portion 37 as a first extension portion.

  The lower frame 34 connects the left side wall 38 and the right side wall 39 (see FIGS. 5 and 6) opposed to each other with an interval in the width direction, and connects the left side wall 38 and the right side wall 39 and is arranged vertically. The lower wall 40 and the upper wall 41 are integrally provided with an upper front wall 42 (see FIGS. 5 and 6) as a first wall portion provided at the front edge of the upper wall 41.

  The lower wall 40 has a plate shape extending in the front-rear direction and the width direction, is inclined upward from the rear side toward the front side, and includes a rear lower wall portion 43 for defining the developing chamber 36, and a rear lower wall. A front lower wall portion 44 that is continuous with the front end edge of the portion 43 and has a substantially arcuate cross-section along the rotation path of the agitator 46 is integrally provided. The lower wall 40 is provided so as to be sandwiched between the left side wall 38 and the right side wall 39 shown in FIG.

  As shown in FIG. 8, substantially L-shaped stoppers 341 in the rear view are provided at both ends in the width direction at the rear end portion of the rear lower wall portion 43. These stoppers 341 come into contact with the respective bearing support portions 144 (see FIG. 9) provided on the drum cartridge 27 when the developing cartridge 28 is mounted on the drum cartridge 27, and further to the rear of the developing cartridge 28. Restrict movement. The developing cartridge 28 is positioned in the front-rear direction with respect to the drum cartridge 27 by the contact of the stopper 341 with the bearing support portion 144 and the backward pressing by the pressing member 151 (see FIG. 9).

  In the front-rear direction of the developing cartridge 28, that is, in the direction in which the sheet is transported, the developing roller 32 is located on the developing roller 32 side from the center C of the developing-side housing 29 (see FIG. 4), and the developing cartridge 36 is disposed. As shown in FIG. 6, a plurality of ribs 311 and a film member 311a functioning as a guide member for guiding the sheet to the downstream side in the transport direction are provided on the lower surface of the rear lower wall portion 43. The plurality of ribs 311 are arranged in parallel in the width direction at intervals, and the film member 311a is arranged so as to cover each rib 311 as shown in FIGS. Each rib 311 is formed so that its height decreases as it approaches the front side from the rear side. When the developing cartridge 28 is mounted on the main body casing 2 with its top surface horizontal, the film member 311 a is The contact surface of the rib 311 with the sheet 3 is arranged substantially horizontally.

  As shown in FIG. 6, the film member 311 a is a film wider than the sheet 3 made of polyethylene terephthalate, and is bent along the contact surface with the rib 311, that is, along the end 311 b of the rib 311. As shown by the arrows in FIG. 6, the film member 311a is fixed to adhesive portions 311c and 311d provided on the upstream side and the downstream side of the rib 311 in the paper transport direction as shown in FIG. . The surface of the film member 311 a opposite to the adhesive surface has a function of guiding the paper 3.

  As shown in FIGS. 3 and 4, a positioning portion 84 for positioning the developing cartridge 28 with respect to the drum cartridge 27 is formed at the deepest portion of the front lower wall portion 44. The positioning portions 84 are formed in a convex shape downward so that the protrusions 118 (FIG. 9) of the drum cartridge 27 can come into contact with each other, and are spaced apart from each other in the width direction as shown in FIG. Two are provided.

  Further, as shown in FIGS. 3 and 4, a lower partition portion 55 that protrudes upward in a substantially triangular shape is formed along the width direction at the boundary between the rear lower wall portion 43 and the front lower wall portion 44. Is formed.

  As shown in FIG. 5, the upper wall 41 has a flat plate shape that is wider than the facing interval between the left side wall 38 and the right side wall 39, and is extended between the upper end edges of the left side wall 38 and the right side wall 39. As shown in FIGS. 3 and 4, an upper surface opening 49 having a substantially rectangular shape in plan view on which the upper frame 35 is mounted is formed at a position corresponding to the toner storage chamber 30 in the upper wall 41.

  A blade support portion 57 protruding downward is formed along the width direction at the rear end portion of the upper wall 41.

  Further, the front end edge of the lower wall 40 is connected to the front end portion of the upper surface opening 49 in the upper wall 41, and the upper wall 41 is further extended forward in front of the connecting portion, and is in the front-rear direction. And it is set as the upper wall extension part 50 as an upper wall of the 1st extension part extended along the width direction. The upper surface of the upper wall extension 50 is formed into a planar shape (a flat shape that is substantially free of irregularities in appearance).

  As shown in FIGS. 5 and 6, the upper front wall 42 has a plate shape and is formed so as to be bent in a substantially perpendicular direction downward from the front edge of the upper wall extension 50. The upper front wall 42 extends partway in the thickness direction (vertical direction) of the developing-side housing 29, and its front surface is formed in a planar shape (a flat shape that is substantially free of irregularities in appearance).

  Further, at both ends in the width direction of the upper front wall 42, a first wall projecting portion having a substantially elongated rectangular shape in front view that projects further downward and a projecting plate 51 as a connecting portion are connected to the upper front wall 42. It is integrally formed. The front surface of each protruding plate 51 is formed in a planar shape (a flat shape having substantially no unevenness in appearance) and is flush with the front surface of the upper front wall 42. As a result, the upper front wall 42 including the protruding plates 51 is formed as a substantially U-shaped planar shape (a flat shape that is substantially free of irregularities in appearance). In addition, a left side wall extension 52 and a right side wall extension 53 are connected to each protruding plate 51 in the orthogonal direction.

  The left side wall 38 and the right side wall 39 have a plate shape extending in the vertical direction, and an upper wall 41 is installed at the upper edge of the left side wall 38 and the lower wall 40 is sandwiched below the upper wall 41. Are arranged so as to face each other.

  The left side wall 38 and the right side wall 39 have rear end edges extending to the rear end edge of the rear lower wall portion 43 of the lower wall 40 and the rear end edge of the upper wall 41, respectively, It extends to the front wall 42 and is connected to each protruding plate 51. A front lower wall portion 44 is connected to the left side wall 38 and the right side wall 39 in the front-rear direction. The front lower wall portion 44 extends forward from the connection portion, and extends from the connection portion in the front-rear direction to the upper front wall 42. , Respectively, are a left side wall extension 52 and a right side wall extension 53 as a pair of first side walls.

  A gear cover 77 is provided on the left side wall 38 as shown in FIG. Inside the gear cover 77 is provided a gear mechanism portion 45 as drive input means for inputting a mechanical drive force to the developing roller 32, the supply roller 31 and the agitator 46.

Also, a new product detector 301 for detecting whether or not the developing cartridge 28 is new is disposed on the left side wall 38 on the front side of the input gear 68. The new product detector 301 includes a new product detection lever 302 that protrudes outward (left side) in the width direction from a lever projection hole that is formed in the gear cover 77 and has a substantially arc shape when viewed from the side. The new detection lever 302 is positioned at one end (front end) of the lever protruding hole when the developing cartridge 28 is new, and the other one from the end of the lever protruding hole when the developing cartridge 28 is used for the first time. It is designed to be moved to the end. Therefore, the new product detector 301 can detect whether the developing cartridge 28 is a new product or an old product (a product with a use history) based on the position of the new product detection lever 302.

  As shown in FIG. 3, the right side wall 39 is provided with a toner supply port 47 as a developer supply port for supplying toner to the toner storage chamber 30. The toner supply port 47 is formed in a circular shape penetrating in the thickness direction of the right side wall 39 at a position corresponding to the toner storage chamber 30 in the right side wall 39. The toner supply port 47 is provided with a cap 48 for preventing toner from leaking from the toner storage chamber 30 through the toner supply port 47. The cap 48 has a circular shape slightly larger than the toner supply port 47 and closes the toner supply port 47.

  Further, as shown in FIGS. 5 and 6, the left lower portion of the left outer surface of the left wall extension 52 and the lower rear portion of the right outer surface of the right wall extension 53 have a cylindrical shape as a working portion and a locked portion. Development-side bosses 79 are provided so as to protrude outward in the width direction.

  Furthermore, both side shaft end portions of the developing roller shaft 64 are provided so as to protrude from the rear end portions of the left side wall 38 and the right side wall 39. A color member 83 as a common conductive member is attached to the left shaft end of the supply roller shaft 62 and the left shaft end of the developing roller 32. The collar member 83 is made of a conductive resin material, covers both the left shaft end portion of the supply roller shaft 62 and the left shaft end portion of the developing roller 32, and is slidably connected thereto. Are electrically connected, and the supply roller 31 and the developing roller 32 are held at the same potential. The portion of the color member 83 that covers the left shaft end of the developing roller 32 functions as a developing roller electrode 76 as a developing electrode that contacts a developing roller contact (not shown) on the main body side.

  As shown in FIG. 5, the upper frame 35 has a substantially rectangular flat plate shape, and as shown in FIG. 3, the upper frame 35 closes the upper surface opening 49 of the lower frame 34 and is provided so as to be attached to the lower frame 34. . A plurality of ribs 54 are arranged in parallel on the lower surface of the upper frame 35 at intervals in the width direction. Further, on the lower surface, an upper partition plate 56 is formed along the width direction so as to face the lower partition portion 55 of the lower wall 40 and project downward. The upper partition plate 56 and the lower partition portion 55 are spaced apart in the vertical direction, and the gap is formed as a toner discharge port 58.

  In the developing-side housing 29, the developing chamber 36 is arranged to communicate with the toner containing chamber 30 downstream of the toner containing chamber 30 in the sheet conveying direction via the toner discharge port 58, and the upper partition plate 56 and the lower side An internal space behind the partition 55 is defined as the developing chamber 36, and an internal space ahead of the upper partition plate 56 and the lower partition 55 is defined as the toner storage chamber 30. The development chamber 36 and the toner storage chamber 30 is formed on the lower frame 34. Further, in the developing side housing 29, the front side wall 50 including the upper wall extension 50, the protruding plate 51, the left side wall extension 52, and the right side wall extension 53 extends from the toner storage chamber 30 to the front side. The formed upper extension 37 is formed to be provided on the lower frame 34.

  Further, as shown in FIGS. 5 and 6, the upper wall extension portion 50 is provided with a development side grip portion 201. The developing side gripping part 201 includes an upper notch part 202 as a first notch part and a developing side handle 203 provided in the upper notch part 202.

The upper notch portion 202 has a front end portion of the upper wall extension portion 50 cut out in a substantially rectangular shape along the width direction in a plan view at the center portion in the width direction of the upper wall extension portion 50. The upper wall extension 50 and the upper front wall 42 are continuously cut out so that the upper end of the wall 42 is cut out in a substantially rectangular shape along the width direction. At both ends in the width direction of the upper notch 202, notch side walls 204 are formed so as to be orthogonal to the upper wall extension 50 and the upper front wall 42.

  The development side handle 203 is provided across the width direction of the upper notch 202 so as to be bridged between both the notch side walls 204. The development side handle 203 has a hook shape, and its cross-sectional shape is formed in a substantially concave shape that is recessed downward (in the thickness direction of the development side housing 29). A front wall portion 205 provided to be connected, a bottom wall portion 206 extending rearward from a lower end edge of the front wall portion 205, and extending upward from a rear end edge of the bottom wall portion 206, And a rear wall portion 207 facing each other in the front-rear direction.

  Further, a finger hooking portion 208 is formed at the center in the width direction of the developing side handle 203 so as to bulge from the front wall portion 205 toward the rear wall portion 207. Specifically, the finger hook portion 208 has a substantially trapezoidal shape in which the cross-sectional shape when cut along a vertical plane extending in the front-rear direction is substantially triangular, and the cross-sectional shape when cut along a horizontal plane is narrower toward the rear side. Is formed so as to have a space.

(2-2) Configuration of the Drum Cartridge FIG. 9 is a perspective view of the drum cartridge 27 shown in FIG. 3 as viewed from the front left (front side) diagonally upward, and FIG. FIG. 11 is a perspective view of the drum cartridge 27 as viewed from the lower left side of the back side (rear side).

  As shown in FIGS. 3 and 9, the drum cartridge 27 includes a drum-side casing 91 as a second casing. The drum cartridge 27 includes a photosensitive drum 92 that is a photosensitive member as a process member, a scorotron charger 93 that is a charging unit, a transfer roller 94 that is a transfer unit, and a cleaning unit. And a cleaning brush 95 as means.

  The drum-side casing 91 is made of, for example, a resin material such as polystyrene. As shown in FIG. 9, the left-side wall 96, the right-side wall 97, the bottom wall 98, and the second wall are opposed to each other with a gap in the width direction. Are integrally formed from the lower front wall 99 and the rear upper wall 100 as a portion, and includes a drum storage portion 102, a developer cartridge storage portion 103 as a developer storage portion facing portion, and a lower extension portion 104 as a second extension portion. It has.

  The left side wall 96 and the right side wall 97 are disposed so that the inner surfaces thereof face each other in the axial direction of the photosensitive drum 92, and the front side wall portion 105 having a substantially bow shape in side view and the front side having a substantially rectangular shape in side view. Side wall part 106 and extended side wall part 107 as a second side wall having a substantially rectangular shape in side view are successively formed from the rear side toward the front side.

  FIG. 12 is a left side view of the drum cartridge 27.

  As shown in FIG. 12, the rear side wall portion 105 of the left side wall 96 includes a first wall 108 that is flush with the front side wall portion 106 in the width direction, and a lower portion of the first wall 108 than the first wall 108. The second wall 109 disposed on the inner side in the width direction, the third wall 110 connecting the first wall 108 and the second wall 109, and the inner side in the width direction above the first wall 108 above the first wall 108 The fourth wall 111 disposed in the first wall 108, the fifth wall 112 connecting the first wall 108 and the fourth wall 111, the second wall 109 and the second wall 109 behind the second wall 109 and below the fourth wall 111. A sixth wall 113 disposed on the inner side in the width direction than the four walls 111 and a seventh wall 114 connecting the second wall 109 and the fourth wall 111 and the sixth wall 113 are integrally provided.

  The first wall 108 is disposed on the outermost side in the width direction, and is formed so as to extend from the front side wall portion 106 to the central portion in the vertical direction of the rear side wall portion 105.

  The second wall 109 has a substantially right triangular shape protruding downward and is formed so as to extend in parallel with the first wall 108 and is disposed at the lower end of the rear side wall 105.

  The third wall 110 connects the lower end edge of the first wall 108 and the upper end edge of the second wall 109, and is formed to extend in a direction orthogonal to the first wall 108 and the second wall 109.

  The transfer electrode opening 142 having a substantially rectangular shape in front view and side view is formed by cutting out the second wall 109 and the third wall 110 into a substantially L-shaped front section. A transfer electrode 137 is provided in the transfer electrode opening 142 so as to protrude outward in the width direction.

  The transfer electrode 137 is made of a conductive resin material. As shown in FIG. 11, the electrode contact portion 252 that protrudes outward in the width direction from the transfer electrode opening 142 and the upper end portion of the electrode contact portion 252 are formed. It is formed in a substantially L-shaped cross section integrally including an escape preventing portion 251 extending outward in the width direction (left side). A contact member (not shown) that contacts the escape prevention portion 251 of the transfer electrode 137 from above is provided on the inner side in the width direction of the left side wall 96, and the contact member is connected to the escape prevention portion 251. The contact prevents the transfer electrode 137 from escaping upward when the transfer electrode 137 contacts the transfer contact (not shown) on the main body side.

  Further, on the rear side of the transfer electrode opening 142, a contact entry prevention rib 209 that protrudes outward in the width direction from the second wall 109 and extends up and down along the rear edge of the transfer electrode opening 142 is provided. .

  As shown in FIG. 12, the fourth wall 111 has a substantially rectangular shape in plan view extending in the front-rear direction, is formed to extend in parallel with the first wall 108, and is disposed at the upper end of the rear side wall 105. . The fourth wall 111 is disposed between the first wall 108 and the second wall 109 in the width direction. On the fourth wall 111, a wire electrode 131 is disposed at the front end, and a grid electrode 132 is disposed at the rear end.

  The fifth wall 112 connects the upper end edge of the first wall 108 and the lower end edge of the fourth wall 111, and is formed to extend in a direction orthogonal to the first wall 108 and the fourth wall 111.

  The sixth wall 113 has a substantially rhombus shape in plan view and is formed to extend in parallel with the first wall 108, and is disposed at the rear end portion of the rear side wall portion 105 on the innermost side in the width direction. A cleaning electrode 148 is disposed at the rear end of the sixth wall 113.

  The seventh wall 114 connects the rear end edge of the second wall 109 and the fourth wall 111 and the front end edge of the sixth wall 113, and connects the second wall 109, the fourth wall 111, and the sixth wall 113. It is formed so as to extend in the orthogonal direction.

  Further, as shown in FIG. 9, a left holding portion 210 that holds the upper end portion of the protruding wall 117 of the left side wall 96 is formed on the front side of the fifth wall 112. The left sandwiching portion 210 extends outward in the width direction from the lower front corner of the fourth wall 111 and faces the upper end surface of the projecting wall 117 from above, and has a substantially triangular opposing plate 211 and a lower surface of the opposing plate 211. The left sandwiching plate 212 and the right sandwiching plate 213 are respectively provided integrally with the left sandwiching plate 212 and the right sandwiching plate 213.

  A gear opening 196 for exposing the drum drive gear 191 is formed between the third wall 110 and the fifth wall 112 along the facing direction.

  Further, the left shaft end portion of the drum shaft 125 made of a conductive metal protrudes from the first wall 108, and the left shaft end portion serves as a photoconductor electrode that contacts a ground contact (not shown) on the main body side. Functions as a ground electrode 127.

  FIG. 13 is a right side view of the drum cartridge 27. As shown in FIG. 13, the rear side wall portion 105 of the right side wall 97 is formed in the same manner as the rear side wall portion 105 of the left side wall 96, and the first wall 108 formed flush with the front side wall portion 106 in the width direction. And the second wall 109 disposed below the first wall 108 in the widthwise direction below the first wall 108 and the third wall 110 connecting the first wall 108 and the second wall 109 together. In preparation.

  Each of the front side wall portions 106 of the left side wall 96 and the right side wall 97 has a roller shaft for guiding the shaft end portion of the developing roller shaft 64 when the developing cartridge 28 is attached and detached, as shown in FIGS. A guide portion 115 and a roller bearing insertion portion 116 as a restricting member that 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 64 guided by the roller shaft guide portion 115. I have.

  The roller shaft guide portion 115 is formed as an upper end edge of the front side wall portion 106, and extends obliquely downward from the middle of the front side wall portion 106 in the front-rear direction, and then extends in a substantially horizontal flat shape. It is formed as follows.

  The roller bearing insertion portion 116 is continuous with the rear side of the roller shaft guide portion 115, and protrudes upward from the rear end portion of the roller shaft guide portion 115. The roller bearing insertion portion 116 is substantially rectangular in a side view from the front end edge of the protrusion wall 117. It is formed by cutting out into a shape, and the lower end edge thereof is continuous with the rear end edge of the roller shaft guide portion 115.

  The extended side wall portions 107 of the left side wall 96 and the right side wall 97 are continuously formed flush with the front side wall portions 106 of the left side wall 96 and the right side wall 97 in the width direction.

  As shown in FIG. 9, the bottom wall 98 is provided so as to connect the lower end edges of the left side wall 96 and the right side wall 97 in the front-rear direction, and as shown in FIG. 3 and FIG. The rear bottom wall portion 193, the front bottom wall portion 194 as a second bottom wall formed in a substantially flat plate shape, and the first bottom wall formed in a substantially rectangular flat plate shape with a central portion in the width direction cut away. The extended bottom wall portion 195 is continuously formed from the rear side toward the front side.

  As shown in FIG. 11, the rear bottom wall 193 has a substantially rectangular discharge port in a rear view for discharging the sheet 3 (see FIG. 1) that passes between the photosensitive drum 92 and the transfer roller 94. 222 is formed. The paper discharge port 222 is formed to be slightly wider than the width of the paper 3 so that, for example, A4 size paper 3 can pass through.

  In addition, a brush support plate 223 extending forward from the upper end edge of the paper discharge port 222 is integrally formed on the rear bottom wall portion 193 in the width direction. As shown in FIG. 3, a brush support portion 123 for supporting the cleaning brush 95 is provided at the front end portion of the brush support plate 223 across the width direction. In addition, a plurality (four in this embodiment) of contact prevention ribs 224 are provided on the lower surface of the brush support plate 223 so as to extend along the conveyance direction (front-rear direction) of the paper 3 at intervals in the width direction. It is formed as follows. Furthermore, a contact prevention part 225 having a substantially triangular shape in the rear view and the bottom view is formed at both ends of the lower surface of the brush support plate 223.

  In addition, a substantially rectangular film member 226 is disposed at the center of the lower surface of the brush support plate 223. This film member 226 is formed using a resin material such as polyethylene terephthalate and has a width that is slightly wider than the axial length of the pickup roller 12, and slightly from the front edge of the brush support plate 223 to the front (photosensitive drum 92 side). It is arranged to protrude.

  The film member 226 is adhered to the center of the lower surface of the brush support plate 223 with an adhesive double-sided tape, and the adhesive double-sided tape is provided up to the front edge of the film member 226 (an edge disposed close to the photosensitive drum 92). It has been. That is, the adhesive double-sided tape is also disposed on the portion of the film member 226 that protrudes from the front edge of the brush support plate 223.

  Also, in the vicinity of the boundary between the rear bottom wall portion 193 and the front bottom wall portion 194 in the bottom wall 98, as shown in FIG. 3, the bottom wall 98 is inclined downward toward the front side so as to leave a gap with the film member 311a. An inclined plate portion 331 is formed.

  A step is formed between the inclined plate portion 331 and the front bottom wall portion 194, and a paper insertion port 332 for introducing the paper 3 into the drum cartridge 27 is formed at the step portion. Is in communication with the outside.

  Furthermore, at the rear end of the inclined plate portion 331, as shown in FIG. 9, the front end of the paper 3 entering from the paper entrance 332 is located on the left and right sides sandwiching a region having a predetermined width in the center in the width direction. A paper guide film 333 is attached so as to guide it so as to abut on the peripheral surface of 92. By providing the sheet guide film 333, the sheet 3 entering the drum cartridge 27 from the sheet insertion port 332 advances along the sheet guide film 333, and the leading end thereof abuts on the peripheral surface of the photosensitive drum 92. . The leading edge of the sheet 3 is guided between the photosensitive drum 92 and the transfer roller 94 by the rotation of the photosensitive drum 92. As described above, after the sheet 3 comes into contact with the photosensitive drum 92 and is guided between the photosensitive drum 92 and the transfer roller 94, leakage between the sheet 3 and the photosensitive drum 92 can be prevented. .

  The lower front wall 99 is formed to bend in a perpendicular direction upward from the front end edge of the extended bottom wall portion 195. The lower front wall 99 has a substantially rectangular flat plate shape, and is formed continuously so that both end portions in the width direction are bent in a direction perpendicular to the left side wall 96 and the right side wall 97. The lower front wall 99 faces the upper front wall 42 in the vertical direction in a state where the developing cartridge 28 is mounted on the drum cartridge 27, and the front surface of the lower front wall 99 is the upper side as shown in FIG. It is formed in a planar shape that is flush with the front surface of the front wall 42 (in terms of appearance, a flat shape that is substantially free of irregularities).

  Further, on the lower front wall 99, as shown in FIG. 9, each protruding plate 51 that protrudes from the upper front wall 42 at both outer sides in the width direction than the lower notch 235 and in the vicinity of both ends. The receiving part 120 for accepting is formed.

  Each receiving part 120 is formed so as to bulge from the upper end edge of the lower front wall 99 downward in a substantially elongated rectangular shape when viewed from the front. As a result, when the developing cartridge 28 is mounted on the drum cartridge 27, each protruding plate 51 is received by each receiving portion 120 as shown in FIG.

  As shown in FIG. 3, the rear upper wall 100 has a plate shape that is slightly inclined downward from the front to the rear, and the upper edge of each rear side wall portion 105 of the left side wall 96 and the right side wall 97 is arranged at the front and rear. It is provided so that it may connect over a direction. The rear upper wall 100 has a rear end edge connected to a rear end edge of the rear bottom wall portion 193 of the bottom wall 98 in the width direction.

  Further, a laser incident window 121 having a substantially rectangular shape in plan view extending in the width direction is opened at the front portion of the rear upper wall 100. The rear upper wall 100 is formed with a charging support portion 122 for supporting the scorotron charger 93 obliquely above the rear portion.

  Further, as shown in FIG. 9, the rear upper wall 100 is integrally formed with a right clamping portion 214 that clamps the upper end portion of the protruding wall 117 of the right side wall 97. The right holding portion 214 slightly protrudes outward in the width direction from the right front end corner portion of the rear upper wall 100, extends forward, and faces the upper end surface of the protruding wall 117 from above. And a left sandwiching plate 216 and a right sandwiching plate 217 that are respectively suspended from the lower surface of the opposing plate 215 and opposed in the width direction with the protruding wall 117 interposed therebetween.

  In the drum-side casing 91, as shown in FIGS. 3 and 9, the rear side wall portions 105 of the left side wall 96 and the right side wall 97, the rear upper wall 100, and the rear upper wall 100 are opposed to each other in the vertical direction. The drum housing portion 102 is defined by the rear bottom wall portion 193 of the bottom wall 98 to be formed. Accordingly, the drum housing portion 102 is formed as a space where the front is opened at the rear portion of the drum-side housing 91.

  Each front side wall portion 106 of the left side wall 96 and the right side wall 97 and the front side bottom wall portion 194 of the bottom wall 98 that continues to the front side wall portion 106 in the width direction form a developing cartridge housing portion 103. Thus, the developing cartridge housing part 103 is formed as a space where the upper part is opened and the rear part communicates with the drum housing part 102 in the middle part in the front-rear direction of the drum-side casing 91.

  Further, the extended side wall portion 107 of the left side wall 96 and the right side wall 97, the extended bottom wall portion 195 of the bottom wall 98 continuous in the width direction with each extended side wall portion 107, and the lower front wall 99, the lower side extended portion. 104 is defined.

  The lower extension 104 is provided with a drum-side grip 234. The drum-side grip 234 includes a lower notch 235 and a drum-side handle 236 as a lifting portion provided in the lower notch 235.

  The lower notch 235 has a front end portion of the extended bottom wall portion 195 cut out in a substantially rectangular shape along the width direction in a plan view in the center portion in the width direction of the lower extension portion 104, and is The extended bottom wall 195 and the lower front wall 99 are continuously cut out so that the upper end of the side front wall 99 is cut out in a substantially rectangular shape along the width direction. The lower notch 235 is formed to be slightly narrower than the upper notch 202 formed in the upper wall extension 50.

  The drum-side handle 236 is slightly inclined to the front side from the rear end edge of the lower notch 235 and the side support 237 as a pair of left and right support parts extending substantially vertically upward from both edges in the width direction of the lower notch 235. Then, the rear support part 238 extending upward and the top support part 239 having a substantially rectangular shape in plan view provided between the side support part 237 and the upper end of the rear support part 238 are integrally provided.

  As shown in FIG. 10, a rectangular opening 240 is formed in the rear support portion 238. As a result, the lower extension 104 extends rearward from the developing cartridge housing 103 at the rear of the drum housing 91, and communicates with the developing cartridge housing 103 via the opening 240. 236 is formed as a space having a substantially rectangular opening section as viewed from the front.

  Further, a step 261 is formed on the top surface portion 239 so that the substantially half portion on the rear side is relatively high and the substantially half portion on the front side is relatively low.

  Further, as shown in FIG. 14, the drum side handle 236 is fitted into the upper notch 202 with the developing cartridge 28 mounted on the drum cartridge 27, and the top surface portion 239 is minute relative to the developing side handle 203. They are arranged vertically opposite to each other with a certain interval. Further, as shown in FIG. 9, a substantially semicircular cutout 241 is formed in the top surface portion 239 at a portion facing the finger hook portion 208 formed on the developing side handle 203.

  The developing cartridge housing portion 103 is provided with a protruding portion 118 that abuts on each positioning portion 84 of the developing cartridge 28 and a rear rib 162 as a second guide portion for guiding the paper 3.

  As shown in FIG. 9, two projections 118 are provided in the middle of the front bottom wall 194 in the front-rear direction and spaced apart from each other in the width direction. Each projecting portion 118 is disposed to face each positioning portion 84 of the developing cartridge 28 attached to the drum cartridge 27 and is formed so as to protrude upward in a semicircular shape in cross section.

  As shown in FIG. 10, the rear rib 162 protrudes downward from the back surface (bottom surface) of the front bottom wall portion 194, and is disposed at the rear portion thereof at intervals from each other in the width direction and extends in the front-rear direction. The plurality of first rear ribs 163 and the first rear ribs 163 are disposed on the front side, and are spaced apart from each other in the width direction (intervals wider than the first rear ribs 163). And a plurality of second rear ribs 164 extending in the direction.

  Further, as shown in FIG. 9, the developer cartridge housing 103 has toner empty sensors (FIG. 9) at positions on the left side wall 96 and the right side wall 97 that face the toner detection windows 85 of the development cartridge 28 in the width direction. A toner passage window 101 for passing light (not shown) is provided.

  Further, as shown in FIG. 9, the lower extension portion 104 includes a pressing portion 149 for pressing the developing roller 32 of the developing cartridge 28 attached to the developing cartridge housing portion 103 toward the photosensitive drum 92, and developing. A lock lever 153 as a lock means for locking the mounting state of the developing cartridge 28 mounted in the cartridge housing portion 103 to the drum cartridge 27, and a drum side as a positioning portion for positioning the drum cartridge 27 with respect to the main body casing 2 And a boss 150.

  Further, as shown in FIG. 10, the lower extension portion 104 includes an upper registration roller 14 for conveying the paper 3 toward the photosensitive drum 92 and a first guide portion for guiding the paper 3. A plurality of front ribs 165 are provided.

  The upper registration roller 14 is rotatably provided along the width direction on the front side of the second rear rib 164 on the lower surface (back surface) of the extended bottom wall portion 195 of the bottom wall 98. The upper registration roller 14 is disposed so as to face the lower registration roller 14 in the vertical direction with the drum cartridge 27 mounted on the main casing 2 (see FIG. 1).

Each front rib 165 is a front surface of the upper registration roller 14 on the lower surface of the extended bottom wall portion 195 of the bottom wall 98 and is opposed to the lower notch portion 119 cut out from the lower front wall 99 (that is, , The central portion in the width direction). The front rib 165 is formed of a resin material harder than the developing side housing 29 and the drum side housing 91, such as polyacetal resin, and is formed separately from the drum side housing 91, and is in contact with the paper 3. When worn out, it can be replaced. More specifically, the plurality of front ribs 165 are arranged so as to extend in the front-rear direction and spaced apart from each other in the width direction (interval wider than the second rear rib 164), and extend in the width direction. They are integrated by being connected by a book connecting member 227 and attached to the lower surface of the extended bottom wall portion 195.

  Thus, the upper registration roller 14 is disposed between the front rib 165 and the rear rib 162 in the front-rear direction.

(2-3) Process Cartridge FIG. 14 is a perspective view of the process cartridge 20 as viewed from the upper left side of the process cartridge 20 and FIG. 15 is a perspective view of the process cartridge 20 as viewed from the lower left side of the front side of the process cartridge 20.

  In a state where the developing cartridge 28 is mounted on the drum cartridge 27, as shown in FIG. 14, the toner storage chamber 30 of the developing cartridge 28 and the developing cartridge storage portion 103 of the drum cartridge 27 are arranged to face each other in the vertical direction.

  Here, as shown in FIG. 15, in order to introduce the paper 3 into the process cartridge 20, a paper inlet 332 is formed between the inclined plate portion 331 and the front bottom wall portion 194 of the drum cartridge 27. A film member 311a is affixed to the developing cartridge 28 facing the inclined plate portion 331, and the surface of the developing cartridge 28 guides the paper 3 entering from the paper inlet 332 to be conveyed to the downstream side of the photosensitive drum 92. .

  As described above, when the film member 311a which is a part of the developing cartridge 28 constitutes a part of the sheet conveyance path of the photosensitive cartridge, the film member may be worn due to friction with the sheet 3. Here, when there is no toner in the developing cartridge 28 and the toner is refilled with the toner to be reused, the film member 311a may be further worn due to the passage of the paper 3, and the surface may be uneven. In this case, the paper 3 may be caught by the unevenness of the film member 311a, causing jamming or being conveyed in an unexpected direction.

  However, since the film member 311a is formed of a member different from the lower frame 34, the film member 311a can be replaced when the toner is fully filled. As a result, it is possible to suppress the occurrence of catching of the sheet 3 when the developing cartridge 28 is reused.

  Further, since the film member 311a is disposed closer to the developing roller 32 than the center of the developing-side housing 29, and the tip of the film member 311a extends closer to the photosensitive drum 92 side, the paper entering from the paper-insertion port 332 is provided. 3 can be reliably guided to the photosensitive drum 92 side, and since there is no seam from the paper entrance to the photosensitive drum 92 side, the sheet can be smoothly conveyed.

  Furthermore, by making the material of the film member 311a different from the material of the lower frame 34, the potential at the time of transfer of the paper 3 can be adjusted in advance. Specifically, by using a conductive film having better electrical conductivity than the lower frame 34 made of resin and having self-discharge characteristics, when the paper before transfer has a high resistance value and is charged, It can be neutralized. As described above, since the potential of the sheet 3 before transfer can be adjusted in advance, the transfer operation can be stabilized. On the other hand, when a film having lower conductivity and higher charging property than the lower frame 34 is used, the potential of the sheet can be adjusted in advance before transfer to the sheet having a low resistance value before transfer.

Further, since the film member 311a is separated from the lower frame 34, the material can be reused if it is made of a material harder than the developing side housing 29 such as polyacetal resin and having excellent wear resistance. The occurrence of catching and the like can be further suppressed before. Furthermore, since the wear resistance is excellent, the developing cartridge 28 can be reused as it is without replacing the film member 311a.

  Further, as shown in FIGS. 14 and 15, the upper extension 37 of the developing cartridge 28 and the lower extension 104 of the drum cartridge 27 are opposed to each other in the vertical direction. More specifically, the upper wall extension part 50 of the upper extension part 37 and the extension bottom wall part 195 of the lower extension part 104 are arranged to face each other with an interval in the vertical direction.

  Then, the protruding plates 51 protruding from the upper front wall 42 of the developing cartridge 28 are received by the receiving portions 120 formed on the lower front wall 99 of the drum cartridge 27.

  Further, the drum side handle 236 of the drum cartridge 27 is fitted into the upper notch 202 formed in the upper extension 37 of the developing cartridge 28, and the top surface portion 239 of the drum side handle 236 is connected to the upper wall extension 50. The developing side handle 203 provided in the upper and lower sides is arranged so as to be opposed to each other with a minute interval. Then, the notch portion 241 formed on the top surface portion 239 faces the finger hook portion 208 formed on the developing side handle 203. Therefore, in a state where the developing cartridge 28 is mounted on the drum cartridge 27, the developing side handle 203 and the drum side are formed at portions other than the finger hooking portion 208 of the developing side handle 203 and the notch portion 241 of the drum side handle 236 facing this. The handle 236 can be gripped together, and the drum cartridge 27 and the developing cartridge 28 can be reliably attached to and detached from the main body casing 2 (see FIG. 1). In other words, when the drum cartridge 27 and the developing cartridge 28 are integrally attached to the main body casing 2, the developing cartridge 28 is detached from the drum cartridge 27, or the drum cartridge 27 and the developing cartridge 28 are removed from the main body casing 2. It is possible to prevent only the developing cartridge 28 from being erroneously removed when the two are integrally removed.

  In addition, since the top surface portion 239 of the drum side handle 236 is opposed to the development side handle 203 provided on the upper wall extension 50 of the developing cartridge 28, the top surface portion 239 and the development side handle can be easily arranged. 203 can be gripped together. Therefore, the integral attachment and detachment of the drum cartridge 27 and the developing cartridge 28 with respect to the main body casing 2 can be achieved more reliably.

  Further, the space surrounded by the pair of side support portions 237 and the top surface portion 239 is communicated with the developing cartridge housing portion 103 through the opening 240 formed in the rear support portion 238. When gripping the side handle 203 together, the finger is developed from the space surrounded by the pair of side support portions 237 and the top surface portion 239 through the opening 240 to the developing cartridge housing portion 103. The cartridge 28 can be inserted to a position where it abuts against the front lower wall portion 44 of the cartridge 28. Therefore, it is possible to further easily hold the top surface portion 239 and the development side handle 203. As a result, the integral attachment / detachment of the drum cartridge 27 and the developing cartridge 28 with respect to the main body casing 2 can be achieved more reliably.

  Furthermore, the top surface portion 239 is formed with a step 261 so that the substantially half portion on the rear side is relatively high and the substantially half portion on the front side is relatively low. When gripping the side handle 203 together, a finger can be put on the step 261. Therefore, the top surface portion 239 and the developing side handle 203 can be more easily gripped, and the integral attachment / detachment of the drum cartridge 27 and the developing cartridge 28 with respect to the main body casing 2 can be achieved more reliably. .

Further, in the process cartridge 20, the development side handle 20 is provided via the notch 241.
Only the developing side handle 203 can be gripped by placing a finger on the third finger hooking portion 208, and the developing cartridge 28 can be attached to and detached from the drum cartridge 27.

  Further, in the drum cartridge 27, a left holding portion 210 and a right holding portion 214 are formed, and the left holding portion 210 and the right holding portion 214 hold the protruding walls 117 of the left side wall 96 and the right side wall 97, respectively. . Therefore, the left side wall 96 and the right side wall 97 can be prevented from being inclined or bent in the width direction. As a result, the rigidity of the drum cartridge 27 can be increased, and the drum cartridge 27 (process cartridge 20) can be securely attached to the main body casing 2.

  Further, a plurality of front ribs 165 integrated by being connected by a plurality of connecting members 227 are formed on the lower surface of the extended bottom wall portion 195 of the bottom wall 98 of the drum cartridge 27 as a pair of side support portions. It arrange | positions so that it may span over the lower end of 237. Therefore, the strength (rigidity) of the pair of side support portions 237 (drum side handle 236) can be increased while the sheet 3 can be reliably guided toward the photosensitive drum 92.

  Further, since the contact prevention rib 224 is provided on the lower surface of the brush support plate 223 extending forward from the upper end edge of the paper discharge port 222, the toner image transferred to the paper 3 contacts the lower surface of the brush support plate 223. It is possible to prevent the lower surface of the brush support plate 223 from being stained with toner and the quality of the toner image transferred to the paper 3 from being deteriorated.

  In addition, contact prevention portions 225 having a substantially triangular shape in the rear view and the bottom view are formed at both ends of the lower surface of the brush support plate 223, so that the sheet 3 discharged from the discharge outlet 222 has both ends in the width direction. The sheet is discharged while contacting the contact prevention unit 225. Therefore, the central portion in the width direction of the paper 3 can be prevented from being lifted to the brush support plate 223 side, and the toner image transferred to the paper 3 can be prevented from coming into contact with the brush support plate 223 and the contact prevention rib 224. be able to. As a result, it is possible to reliably prevent the lower surface of the brush support plate 223 from being stained with toner and the quality of the toner image transferred to the paper 3 from being deteriorated.

  In addition, a substantially rectangular film member 226 is disposed at the center of the lower surface of the brush support plate 223, and the film member 226 slightly protrudes forward (photosensitive drum 92 side) from the front edge of the brush support plate 223. Therefore, the paper dust scraped from the surface of the photosensitive drum 92 by the cleaning brush 95 can be received by the film member 226. And since the adhesive double-sided tape is arrange | positioned also in the part protruded from the front-end edge of the brush support plate 223 of the film member 226, the received paper dust can be made to adhere to the adhesive surface of an adhesive double-sided tape, and paper dust Can be prevented from falling off from above the film member 226.

[Second Embodiment]
Next, a second embodiment in which the image forming apparatus according to the present invention is applied to a laser printer will be described. In the first embodiment, the rib 311 and the film member 311a are used as the guide member that constitutes a part of the sheet transport path in the developing cartridge 28. In the second embodiment, the film member is used. Instead of 311a, a guide member 311e in which a film member and a rib are integrated is used. Note that the laser printer according to the present embodiment is different only in the guide member 311e and the rib 311 of the developing cartridge 28b. Therefore, the portions corresponding to the above-described portions are denoted by the same reference numerals and the other configurations are described. Description is omitted.

  FIG. 16 is a perspective view of the developing cartridge 28b as viewed obliquely from the lower front right side.

  As shown in the figure, a pair of ribs 311 are arranged on the lower surface of the rear lower wall portion 43 with a space exceeding the paper passage width in the width direction.

  On the rear lower wall 43 between the ribs 311, a guide member 311 e having the same cross-sectional shape as the rib 311 and wider than the conveyed paper is indicated by the arrow 3 in the drawing. The adhesive parts 311f and 311g provided on the upstream side and the downstream side in the transport direction are fixed with an adhesive double-sided tape.

  FIG. 17 is a side sectional view of the process cartridge 20b.

  As shown in the figure, the guide member 311e is formed such that its height decreases as it approaches the front side from the rear side, and the developing cartridge 28 is mounted on the main body casing 2 with its top surface horizontal. Sometimes, the contact surface of the guide member 311e with the paper is arranged substantially horizontally. The guide member 311e can guide the paper 3 entering from the paper inlet 332 to the photosensitive drum 92 side.

  As described above, the guide member 311e can be exchanged similarly to the first embodiment by providing the guide member 311e having a shape in which the rib and the film are integrated instead of the film member. Therefore, the same effects as those of the first embodiment can be obtained.

  Further, as in the first embodiment, the material of the guide member is made of conductive plastic or the like having a higher conductivity than the lower frame 34 made of resin, so that the potential of the paper before transfer is adjusted in advance. The operation can also be stabilized. Since the guide member 311e is separated from the lower frame 34, if the material is made of a material having higher wear resistance than the lower frame 34, the occurrence of catching or the like can be further suppressed.

(Modification)
In each of the embodiments described above, the surfaces of the film member 311a and the guide member 311e are smooth. However, in order to reduce the contact area with the paper, a plurality of protrusions are provided on the surface, a satin finish is applied, and ribs are provided. It may be provided. Further, a mirror finish may be applied to reduce friction.

  Further, in each of the above embodiments, the film member 311a and the guide member 311e are formed wider than the width of the paper, but there is a particular problem if the portion that contacts the paper becomes a film member even if it is narrower than the paper width. Does not occur. Further, if a plurality of papers having a width smaller than the paper width are arranged in parallel, the wear of the ribs 311 can be further prevented. In the second embodiment, the ribs 311 are provided at both ends in the width direction. However, the same effects as those of the present invention can be obtained even if they are not provided.

  Further, after the film member 311a of the first embodiment is attached to the surface of the guide member 311e in the second embodiment, it is attached to the rear lower wall portion 43 in the second embodiment. Alternatively, the film member 311a may be fixed to the rear lower wall portion 43 according to the second embodiment with a double-sided adhesive tape at the bonding portions 311f and 311g without using the rib 311.

  Here, the shape of the film member 311a is preferably the same as the shape of the rib 311. However, as shown in FIG. 18, the flat film member 311h is simply directed outwardly between the adhesive portions 311f and 311g. You may bend and fix so that it may swell to shape.

  Further, in each of the above embodiments, the film member 311a and the guide member 311e are attached using an adhesive double-sided tape so that the film member 311a and the guide member 311e can be detached, but a pair protruding opposite to the ribs 311 at both ends as shown in FIG. The claw 311j may be provided, and the film member 311a and the guide member 311e may be sandwiched between the claw 311j and the claw 311j from the width direction. In this case, as shown in the enlarged view seen from the rear side in FIG. 19, the claw 311j can support the guide member from below and be fixed so as to be removable from the rear side. Moreover, you may fix by screwing.

  In each of the above embodiments, the process cartridge in which the developing cartridge is mounted on the photosensitive cartridge has been described. However, the present invention can also be applied to a process cartridge in which each cartridge is integrated.

  In each of the above embodiments, conductive plastic is used as the material for the film member 311a and the guide member 311e. However, a highly conductive metal foil or the like may be grounded.

  In addition, it cannot be overemphasized that each component in each said embodiment can be implemented combining them as needed.

FIG. 3 is a side cross-sectional view showing a main part of an embodiment of a laser printer as an image forming apparatus of the present invention, showing a state where a front cover is closed. It is principal part sectional drawing of the laser printer shown in FIG. 1, Comprising: The state which opened the front cover is shown. It is a sectional side view of a process cartridge. FIG. 3 is a side sectional view of a main part of the developing cartridge. FIG. 3 is a perspective view of the developing cartridge as viewed from the upper left obliquely upper side. FIG. 7 is a perspective view of the developing cartridge as viewed from the lower right side on the front side. FIG. 7 is a perspective view of the developing cartridge as viewed from the lower right side on the front side. FIG. 7 is a perspective view of the developing cartridge as viewed from the upper left side obliquely upward. It is the perspective view seen from the front side left diagonal upper direction of the drum cartridge. It is the perspective view which looked at the drum cartridge from the front side diagonally downward. It is the perspective view which looked at the drum cartridge from the back side slanting lower part. It is a left view of a drum cartridge. It is a right view of a drum cartridge. It is the perspective view seen from the front left diagonal upper part of the process cartridge. FIG. 4 is a perspective view of the process cartridge as viewed from the lower left side on the front side. FIG. 6 is a perspective view of a developing cartridge according to a second embodiment viewed from the upper left side of the front side. It is sectional drawing of the process cartridge which concerns on 2nd Embodiment. FIG. 11 is a perspective view of a developing cartridge according to a modification as viewed from the front right and obliquely downward. FIG. 11 is a perspective view of a developing cartridge according to a modification as viewed from the front right and obliquely downward.

DESCRIPTION OF SYMBOLS 1 Laser printer 3 Paper 14 Registration roller 20, 20b Process cartridge 27 Drum cartridge 28, 28b Developing cartridge 29 Developing side housing 30 Toner storage chamber 32 Developing roller 34 Lower frame 35 Upper frame 36 Developing chamber 42 Upper front wall 43 Rear lower Wall portion 44 Front lower wall portion 47 Toner supply port 48 Cap 50 Upper wall extension portion 54 Rib 91 Drum side housing 92 Photosensitive drum 102 Drum housing portion 103 Developer cartridge housing portion 311 Rib 311a Film member 311b Rib end portions 311c and 311d Adhesion Portion 311e Guide member 311f, 311g Bonding portion 332 Paper entry port

Claims (4)

A process cartridge used in an image forming apparatus for forming an image on a sheet material,
A first housing in which a developer containing chamber for containing a developer is formed; and a guide member arranged in the first housing for guiding the sheet material to be conveyed toward the downstream side in the conveying direction. And the first housing of the guide member is composed of a member separate from the first housing over the entire surface of the portion facing the sheet material conveyance path, and can be replaced by being detachably fixed. A cartridge,
A second housing in which the developing cartridge is detachable; a photoconductor that is disposed in the second housing and forms an electrostatic latent image developed by a developer supplied from the developer carrier; A developer housing chamber facing portion that is formed in the second housing and is disposed to face the developer housing chamber; and a position facing the guide member of the second housing with a gap therebetween, A photosensitive member cartridge having a bottom wall portion formed with a sheet material inlet for feeding to the guide member side;
A process cartridge comprising: The photoconductor cartridge includes transfer means arranged to face the photoconductor in the second casing,
The transfer means transfers the developer developed on the photosensitive member to the sheet material by passing the sheet material supplied from the sheet material inlet through the photosensitive member. 2. The process cartridge according to 1 . 3. The process cartridge according to claim 2 , wherein a sheet material discharge port for discharging the transferred sheet material is formed in the second casing. An image forming apparatus comprising: a process cartridge according to claim 1.

Images