JP4269241B2 - Process cartridge, developing cartridge, and image forming apparatus - Google Patents

Description

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

An electrophotographic image forming apparatus is known that includes, for example, an optical system, a photosensitive drum, and a charging roller, a developing roller, a transfer roller, and a cleaning unit disposed around the photosensitive drum. (For example, refer to Patent Document 1).
The surface of the photosensitive drum is first uniformly charged by a charging roller, and then a laser beam corresponding to image information from the optical system is irradiated to form an electrostatic latent image. Thereafter, the electrostatic latent image is developed by the developing roller to form a toner image, and the toner image is transferred to the recording medium by the transfer roller. The toner remaining on the photosensitive drum after the transfer is removed by a cleaning unit.

Further, in such an image forming apparatus, a process cartridge in which a photosensitive drum and a charging roller, a developing roller, a transfer roller, and a cleaning unit disposed around the photosensitive drum are detachably mounted on the apparatus main body. Is provided.
The process cartridge includes a housing that houses the various members described above, and power is supplied to the various members housed in the process cartridge from a power source provided in the apparatus main body on the side wall of the housing, or A plurality of electrodes for grounding are provided. A plurality of gears for driving the various members described above are provided on the side wall of the housing.
Japanese Patent No. 3359194

  An object of the present invention is to provide a process cartridge and a developing cartridge, and an image forming apparatus including them, which can achieve reliable positioning of electrodes and stable supply of electric power and driving force.

To achieve the above object, according to a first aspect of the present invention, there is provided a process cartridge that is detachably attached to an image forming apparatus, and a developing roller that is provided in the casing and carries a developer. And a developing roller driving gear provided on the shaft of the developing roller for transmitting a driving force to the developing roller, and advancing in the axial direction by an urging force of an urging spring from the outside in the axial direction of the developing roller. A coupling portion into which the coupling member is inserted, and an input gear to which a driving force is input from the coupling member via the coupling portion, and the driving force input from the input gear is driven by the developing roller comprising a driving force transmission member for transmitting relative to the gear, and the developer electrode for electrically connecting the image forming apparatus to said developing roller, wherein the housing is a predetermined distance in the axial direction A first housing having two side walls which are opposed to each other and support the developing roller; and a second housing which allows the first housing to be attached and detached, the driving force transmitting member and the developing electrode Is arranged on one of the side walls, and in the mounting direction of the process cartridge, the developing electrode is provided on the downstream side with respect to the driving force transmitting member, and the developing electrode is arranged in the axial direction in the input gear. It is characterized by protruding outward .

According to such a configuration, since the developing electrode is provided on the downstream side in the mounting direction of the process cartridge with respect to the driving force transmission member on one side wall of the first housing, A stable supply of power and driving force to the process cartridge can be achieved.
The second casing includes two side walls disposed to face each other at a predetermined interval, and the second casing includes a process member including a photoconductor used for an image forming process. A plurality of electrodes for electrically connecting the process member to the process member from the image forming apparatus are provided on one side wall of the second casing, and a mounting direction of the process cartridge among the plurality of electrodes is provided. The most downstream electrode may be arranged on the innermost side in the opposing direction of the two side walls with respect to the other electrodes.

  According to such a configuration, the most downstream electrode is disposed on the innermost side in the opposing direction of the two side walls with respect to the other electrodes. Therefore, when attaching or detaching the process cartridge, the electrode crosses a plurality of contacts provided in correspondence with the other electrodes in the apparatus main body at a predetermined interval. Can be prevented. As a result, it is possible to prevent a contact failure of an electrode that is likely to cause a contact failure and to ensure a reliable electrical connection over a long period of time.

In addition, the process member has an image forming area for forming an image on a recording medium in the facing direction, and the most downstream electrode is outside the image forming area in the facing direction. May be arranged.
According to such a configuration, the most downstream electrode is disposed outside the image forming region in the opposing direction. Therefore, image formation is not hindered by the electrode, and it is possible to prevent electrode contact failure while achieving reliable image formation.

The process member may include a photosensitive member and a cleaning unit for cleaning the photosensitive member, and the most downstream electrode may be a cleaning electrode connected to the cleaning unit.
According to such a configuration, since the most downstream electrode is the cleaning electrode, the optimum arrangement of the cleaning means can be ensured.

  The process member includes a photosensitive member, a charging unit for charging the photosensitive member, a developer carrying member for carrying the developer, and supplying the developer to the photosensitive member, and the developing unit. A transfer means for transferring a developer image carried on the photosensitive member to a recording medium by supplying a developer from a developer carrying member; and a cleaning means for cleaning the photosensitive member; It includes a photoconductor electrode connected to the photoconductor, a charging electrode connected to the charging unit, a transfer electrode connected to the transfer unit, and a cleaning electrode connected to the cleaning unit. Yes.

According to such a configuration, in the process cartridge, since all the electrodes corresponding to the main process members are arranged on one side wall, the configuration can be simplified by concentrating and arranging a plurality of electrodes. it can.
In addition, the most downstream electrode is arranged on the inner side in the facing direction with respect to the driving force transmission member.

According to such a configuration, the most downstream electrode is disposed on the inner side in the opposite direction from the driving force transmission member, so that the electrode is contaminated by grease, dust or shavings generated around the driving input means. Can be prevented.
The first casing is provided with a developer accommodating portion for accommodating a developer, and the developer is supplied to the developer accommodating portion on the other side wall of the first casing. A developer supply port may be provided.

According to such a configuration, since the developer supply port is provided on the other side wall opposite to the one side wall where the development electrode is disposed, the developer supplied to the developer supply port is scattered. The development electrode can be prevented from being contaminated.
Further, a step for arranging these electrodes at different positions in the facing direction may be provided between at least two electrodes on one side wall of the second casing.

According to such a configuration, it is possible to provide a distance between electrodes where leakage is likely to occur due to the step. Therefore, the leak generated between the electrodes can be reduced with a simple configuration without increasing the size of the apparatus.
In addition, the one side wall of the second housing is disposed in parallel to the first wall, the first wall disposed on the outer side, the inner side of the first wall, in the facing direction. A second wall; and a third wall connected to the first wall and the second wall and disposed in a direction orthogonal to the first wall and the second wall, the second wall and the An opening that is continuously open to the third wall is formed, and at least one electrode is inserted from the inside of the housing along the direction perpendicular to the third wall with respect to the opening. Further, it may be provided so as to protrude from the opening in a direction orthogonal to the second wall.

According to such a configuration, the electrode can be provided so as to protrude in the direction orthogonal to the second wall if it is inserted into the opening along the direction orthogonal to the third wall from the inside of the housing. Therefore, simple mounting and reliable placement of the electrodes can be achieved.
Further, the electrode is integrally provided with a protruding portion that protrudes from the opening, and a locking plate that is disposed inside the housing and extends in a direction orthogonal to the protruding direction of the protruding portion, A receiving portion that receives the locking plate and a claw portion that locks the locking plate to restrict rotation of the locking plate around the protruding portion are provided inside the second housing. You may have.

According to such a configuration, the electrode can be easily assembled by receiving the locking plate at the receiving portion and locking the locking plate with the claw portion.
The process member includes a rotating shaft having an end surface in contact with the electrode, and a gear provided on the rotating shaft for inputting a driving force to the rotating shaft, and the one side wall and the The gear may be arranged at a predetermined interval in the axial direction of the rotating shaft, and the one side wall and the electrode may be arranged at a predetermined interval in the axial direction of the rotating shaft.

According to such a configuration, since the gear and the electrode are arranged at a predetermined interval with respect to one side wall, damage due to contact of the gear and the side wall with the electrode can be prevented.
Further, the one side wall of the second casing protrudes from the second wall in the projecting direction of the electrode and extends along the edge on the downstream side in the mounting direction of the process cartridge with respect to the opening. A prevention rib may be provided.

  According to such a configuration, since the contact entry preventing rib is provided along the edge of the opening, the process cartridge is mounted on the image forming apparatus, and the contact provided in the image forming apparatus is applied to the electrode. When contacting, the contact point can be guided well, and the contact point can be prevented from entering the gap between the opening and the electrode. Therefore, reliable connection between the contact and the electrode can be achieved.

  The process member includes a developing roller for carrying the developer and a supply roller for supplying the developer to the developing roller, and one end portion in the axial direction of the developing roller and one end portion in the axial direction of the supply roller. Both of these are rotatably supported and connected to a bearing made of an insulating material, the other axial end of the developing roller and the other axial end of the supply roller, for electrically connecting them. And a conductive member made of a conductive material.

According to such a configuration, even if the bearing that simultaneously supports both the one end of the developing roller in the axial direction and the one end of the supply roller in the axial direction is formed to increase positioning accuracy, the bearing is inexpensively insulated. Can be made of material. Therefore, cost can be reduced while improving positioning accuracy. On the other hand, since the developing roller and the supply roller are connected to each other at the other axial end portion by a conductive member made of a conductive material, they can be held at the same potential.

According to a third aspect of the present invention, it is preferable that the process cartridge includes a holding unit that holds both the driving force transmission member and the developing electrode.
According to such a configuration, since the holding unit holds both the developing electrode and the driving force transmission member, the positioning accuracy of both can be improved. Therefore, stable supply of power and driving force to the process cartridge can be achieved while reducing the number of parts and simplifying the apparatus configuration.

According to a second aspect of the present invention, in the second casing, movement of the side wall of the first casing due to transmission of driving force from the image forming apparatus to the driving force transmitting member is restricted. It is preferable that a regulating member is provided.
According to such a configuration, when the driving force from the image forming apparatus is transmitted to the driving force transmission member, the regulation member can prevent the side wall of the first housing from being driven by the driving force. . Therefore, stable supply of electric power and driving force to the process cartridge can be achieved.

According to a fourth aspect of the present invention, it is preferable that the driving force transmitting member and the developing electrode are provided on the downstream side from the center in the mounting direction of the process cartridge.
According to such a configuration, the driving force transmission member and the developing electrode are provided downstream of the central portion in the mounting direction of the process cartridge on one side wall of the first housing. By doing so, the apparatus can be simplified and miniaturized.

According to a fifth aspect of the present invention, in the developing cartridge that is detachably attached to the image forming apparatus, a first casing, a developing roller that is provided in the first casing and carries a developer, A developing roller driving gear provided on the shaft of the developing roller for transmitting a driving force to the developing roller, and advancing in the axial direction by an urging force of an urging spring from the outside in the axial direction of the developing roller. A coupling portion into which a coupling member is inserted; and an input gear to which a driving force is input from the coupling member via the coupling portion, and the driving force input from the input gear is transmitted to the developing roller driving gear. And a developing electrode for electrically connecting the developing roller to the developing roller from an image forming apparatus, wherein the first casing has a predetermined interval in the axial direction. Paired apart The driving force transmitting member and the developing electrode are arranged on one of the side walls, and the developing electrode is mounted in the mounting direction of the developing cartridge with respect to the image forming apparatus. The developing force is provided on the downstream side with respect to the driving force transmission member, and the developing electrode protrudes outward from the input gear in the axial direction .

According to such a configuration, since the developing electrode is provided on the downstream side in the mounting direction of the developing cartridge with respect to the driving force transmitting member on one side wall of the first housing, A stable supply of electric power and driving force to the developing cartridge can be achieved.
According to a sixth aspect of the present invention, it is preferable that the developing cartridge includes a holding portion that holds both the driving force transmitting member and the developing electrode.

According to such a configuration, since the holding unit holds both the developing electrode and the driving force transmission member, the positioning accuracy of both can be improved. Therefore, stable supply of electric power and driving force to the developing cartridge can be achieved while reducing the number of parts and simplifying the apparatus configuration.
According to a seventh aspect of the present invention, it is preferable that the driving force transmitting member and the developing electrode are provided on the downstream side from the central portion in the mounting direction of the developing cartridge.

According to such a configuration, since the driving force transmitting portion and the electrode are provided on the one side wall on the downstream side from the central portion in the mounting direction of the developing cartridge, the device is arranged by concentrating them. Simplification and miniaturization can be achieved.
An invention according to an eighth aspect is an image forming apparatus, the process cartridge according to any one of the first to fourth aspects, or the one according to any one of the fifth to seventh aspects. A developing cartridge is provided.

Since this image forming apparatus includes a process cartridge or a developing cartridge having electrodes with reduced contact failure and a process cartridge or a developing cartridge that can achieve a stable supply of electric power and driving force, a stable image can be obtained. Formation can be ensured over a long period of time.
According to a ninth aspect of the present invention, the image forming apparatus is provided so as to be able to advance and retreat with respect to the driving force transmitting member, and is advanced in the axial direction by an urging force of an urging spring and inserted into the connecting portion. It is preferable that a coupling member for inputting a driving force to the driving force transmitting member is provided.

According to this structure, when the process cartridge is mounted to the image forming apparatus, the contacts are in contact with advanced to the electrode, is electrically connected, also, the coupling member with the driving force transmitting member Enter the driving force. Therefore, stable supply of electric power and driving force to the process cartridge can be achieved.

According to the first aspect of the present invention, reliable positioning of the electrodes and stable supply of power and driving force to the process cartridge can be achieved.
According to the third aspect of the present invention, stable supply of power and driving force to the process cartridge can be achieved while reducing the number of parts and simplifying the apparatus configuration.

According to the second aspect of the present invention, stable supply of electric power and driving force to the process cartridge can be achieved.
According to the fourth aspect of the present invention, the device can be simplified and downsized.
According to the sixth aspect of the present invention, stable supply of power and driving force to the developing cartridge can be achieved while reducing the number of parts and simplifying the apparatus configuration.

According to the seventh aspect of the invention, the apparatus can be simplified and downsized.
According to the fifth aspect of the present invention, reliable positioning of the electrodes and stable supply of power and driving force to the developing cartridge can be achieved.
According to the eighth aspect of the invention, stable image formation can be ensured over a long period of time.

  According to the ninth aspect of the present invention, stable supply of electric power and driving force to the process cartridge can be achieved.

(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 a process cartridge 20 described later is formed on one side wall, and a front cover 7 for opening / closing the attachment / detachment opening 6 is provided. Yes.
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. The process cartridge 20 has a recess 352 described later. 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 opposite to 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. As a result, 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 rotation of the pickup roller 12 causes the sheet feeding roller 10, the separation pad 11, and The conveyance is started during the period.
On the other hand, when the paper feed tray 9 is detached from the main casing 2, the front end portion of the paper pressing plate 15 moves downward due to its own weight, and 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, and after the sheet 3 is registered, the transfer position of the image forming unit 5 (between a photosensitive drum 92 and a transfer roller 94, which will be described later) The toner image on the drum 92 is conveyed to a position at which the toner image is transferred onto 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 rotationally driven, 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 a 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 a photosensitive drum 92 (to be described later) 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). As shown in FIG. 3, the process cartridge 20 includes a drum cartridge 27 (see FIG. 11) and a developing cartridge 28 (see FIG. 4) that is detachably attached to the drum cartridge 27.
The developing cartridge 28 can be attached to and detached from the main body casing 2 integrally with the drum cartridge 27, and only the developing cartridge 28 is attached to the main body casing 2 with the drum cartridge 27 mounted on the main body casing 2. It can also be attached to and detached from.
(2) Configuration of Developing Cartridge FIG. 4 is a side sectional view of a main part of the developing cartridge of the laser printer shown in FIG.

As shown in FIG. 4, the developing cartridge 28 includes a developing-side housing 29 as a first housing, a supply roller 31 as a process member provided in the developing-side housing 29, and a developing as a developer carrier. A roller 32, an agitator 46, and a layer thickness regulating blade 33 are provided.
The development-side housing 29 is made of, for example, a resin material such as polystyrene, has a box shape with an opening on the rear side (see FIG. 7), and includes a lower frame 34 and an upper frame 35, and stores toner as a developer storage portion. The chamber 30 is provided with a developing chamber 36 and an upper extension 37 as a first extension.

  The lower frame 34 is opposed to the left side wall 38 with an interval in the width direction (a direction orthogonal to both the front-rear direction as the first direction and the up-down direction as the second direction, and so on). (See FIGS. 8 and 9) and the right side wall 39 (see FIG. 10), and the lower wall 40 and the upper wall 41, which are connected between the left side wall 38 and the right side wall 39 and are arranged above and below, and the upper wall 41 And an upper front wall 42 as a first wall portion provided at the front end edge of the front end edge.

  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 described later 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.

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 portion 84 is formed in a convex shape downward so that a later-described protrusion 118 of the drum cartridge 27 can be abutted and positioned, and two positioning portions 84 are provided at intervals in the width direction.
Further, a lower partition 55 that protrudes upward in a substantially triangular shape is formed along the width direction at the boundary between the rear lower wall 43 and the front lower wall 44.

5 is a perspective view of the developing cartridge shown in FIG. 4 as viewed from the front side, and FIG. 6 is a plan view of the developing cartridge shown in FIG.
As shown in FIGS. 5 and 6, the upper wall 41 has a flat plate shape wider than the facing distance 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. . An upper surface opening 49 (see FIG. 4) 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 on the upper wall 41.

A blade support portion 57 protruding downward is formed at the rear end portion of the upper wall 41 along the width direction.
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 front side from the connection portion is further extended forward, along the front-rear direction and the width direction. An upper wall extension 50 is formed as an upper wall of the first extension extending in the direction. The upper surface of the upper wall extension 50 is formed in a planar shape (a flat shape that is substantially free of irregularities in appearance).

The upper front wall 42 has a plate shape and is formed so as to be bent in a substantially right angle 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).
In addition, 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 that is substantially free of irregularities in appearance) and is flush with the front surface of the upper front wall 42. As a result, the upper front wall 42 including each protruding plate 51 is formed as a substantially U-shaped planar shape (a flat shape that is substantially free of irregularities in appearance).

Also, a left side wall extension 52 and a right side wall extension 53, which will be described later, 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 that the inner surfaces of the two face each other. As shown in FIG. 4, 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. However, it extends to the upper 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.

  As shown in FIG. 9, the left side wall 38 is provided with a gear mechanism portion 45 described later. Further, as shown in FIG. 10, 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.

  As shown in FIGS. 4 and 5, the upper frame 35 has a substantially rectangular flat plate shape, is provided so as to close the upper surface opening 49 of the lower frame 34 and 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, an internal space behind the upper partition plate 56 and the lower partition portion 55 is defined as the developing chamber 36, and an internal space ahead of the upper partition plate 56 and the lower partition portion 55 is defined. The toner chamber 30 is defined, and the developing chamber 36 and the toner chamber 30 are formed in 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.

  The toner storage chamber 30 stores positively chargeable non-magnetic one-component toner as a developer. Examples of the toner include polymerizable monomers such as styrene monomers such as styrene, and acrylic monomers such as acrylic acid, alkyl (C1 to C4) acrylate, and alkyl (C1 to C4) methacrylate. Polymerized toner obtained by copolymerization by suspension polymerization or the like is used. Such a polymerized toner has a substantially spherical shape, has extremely good fluidity, and can achieve high-quality image formation.

The toner is mixed with a colorant such as carbon black, wax, and the like, and an external additive such as silica is added to improve fluidity. The average particle size of the toner is about 6 to 10 μm.
Further, in the toner storage chamber 30, a toner detection window 85 for allowing light from a toner empty sensor (not shown) including a photosensor provided in the main body casing 2 to pass through on the left side wall 38 and the right side wall 39. , Provided at opposite positions in the width direction.

  The agitator 46 is provided in the toner storage chamber 30. The agitator 46 is provided at a central portion in a side view in the toner storage chamber 30, and a rotating shaft 59 that is rotatably supported by the left side wall 38 and the right side wall 39, and a stirring member 60 that extends from the rotating shaft 59 in the radial direction. And. Note that the left shaft end portion of the rotation shaft 59 is provided so as to protrude from the left wall 38. The stirring member 60 may be provided with a film that slides on the inner surface of the toner storage chamber 30 at the tip.

The supply roller 31 includes a metal supply roller shaft 62 and a sponge roller 63 made of a conductive foam material that covers the periphery of the supply roller shaft 62. ing. Note that the left shaft end of the supply roller shaft 62 is provided so as to protrude from the left wall 38.
The developing roller 32 is disposed below the rear side in the developing chamber 36, is in pressure contact with the supply roller 31, and is provided so that the rear portion is partially exposed rearward from the developing side housing 29. Yes. The developing roller 32 is covered with a metallic developing roller shaft 64 and a rubber roller 65 made of a conductive rubber material covering the developing roller shaft 64. More specifically, the rubber roller 65 is made of conductive urethane rubber or silicone rubber containing carbon fine particles, and the surface thereof is covered with fluorine-containing urethane rubber or silicone rubber. Note that the end portions of both sides of the developing roller shaft 64 are provided so as to protrude from the left side wall 38 and the right side wall 39.

Further, as shown in FIG. 20, the supply roller 31 and the developing roller 32 are rotatably supported by a common bearing member 82 at the right shaft end portion of the supply roller shaft 62 and the right shaft end portion of the developing roller 32. ing. The bearing member 82 is made of an insulating resin material and is provided on the right wall 39 in a state where both the right shaft end portion of the supply roller shaft 62 and the right shaft end portion of the developing roller 32 are rotatably supported. Yes. On the other hand, 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. A portion of the color member 83 that covers the left shaft end portion of the developing roller 32 functions as a developing roller electrode 76 as a developing electrode with which a developing roller contact 175 described later contacts.

  As shown in FIG. 4, the layer thickness regulating blade 33 is disposed in the developing chamber 36, and is provided with a blade 66 made of a metal leaf spring material and a lower end portion of the blade 66, and made of insulating silicone rubber. And a press-contact portion 67 having a semicircular cross section. In the layer thickness regulating blade 33, the upper end portion of the blade 66 is supported by the blade support portion 57 above the developing roller 32, and the pressing portion 67 is pressed against the surface of the rubber roller 65 of the developing roller 32 by the elastic force of the blade 66. ing.

FIG. 9 is a left side surface of the developing cartridge shown in FIG. 4 and shows a state where the gear cover is removed.
As shown in FIG. 9, the left side wall 38 is provided with a gear mechanism portion 45 as drive input means for inputting mechanical drive force to the developing roller 32, the supply roller 31 and the agitator 46. .

  The gear mechanism portion 45 includes an input gear 68 as a driving force transmission portion disposed in the front-rear direction rear portion of the left side wall 38, an intermediate gear 70 disposed on the front side of the input gear 68 and meshing with the input gear 68, An agitator drive gear 69 that is disposed on the front side of the intermediate gear 70 and meshes with the intermediate gear 70; a developing roller drive gear 71 that is disposed obliquely below the rear side of the input gear 68 and meshes with the input gear 68; A supply roller driving gear 72 is provided below the input gear 68 and meshes with the input gear 68.

  The input gear 68 is formed with a coupling hole 74 at the center thereof for coupling a coupling member 73 (see FIG. 26) as driving force input means described later so as not to be relatively rotatable. The agitator drive gear 69 is provided at the left shaft end portion of the rotation shaft 59 of the agitator 46 so as not to be relatively rotatable. The developing roller drive gear 71 is provided at the end of the left shaft of the developing roller shaft 64 so as not to be relatively rotatable. The supply roller driving gear 72 is provided at the end of the left shaft of the supply roller shaft 62 so as not to be relatively rotatable.

  Further, as shown in FIGS. 5 and 8, the gear mechanism portion 45 is provided with a gear cover 77 as a holding portion. The gear cover 77 has an inner surface on which an input gear 68, an intermediate gear 70, an agitator driving gear 69, a developing roller driving gear 71, and a supply roller driving gear 72 are rotatably held and covered with these gears. It is formed and attached to the left side wall 38. Also, the gear cover 77 holds the gears 77 at the same time as the left shaft end of the developing roller shaft 64 protrudes further outward in the width direction from the gear cover 77. Further, the gear cover 77 is integrally provided with a cover extension portion 86 projecting forward from the front upper portion thereof. The cover extension 86 is disposed outside the left side wall 96 of the drum-side casing 91, which will be described later, with the developing cartridge 28 attached to the drum cartridge 27, and the left-side wall 96 of the drum-side casing 91 is bent. This is prevented (see FIG. 13).

Further, as shown in FIGS. 5 and 6, the upper wall extension 50 is provided with a gripping part 78 and a developing side boss 79 as an actuated part and a locked part.
The gripping part 78 includes a handle 81 provided in an upper notch 80 as a first notch formed at the front end of the upper wall extension 50.
The upper notch 80 has a front end portion of the upper wall extension 50 cut out in a substantially rectangular shape in the width direction in a plan view in the center portion in the width direction of the upper wall extension 50, and the upper front portion in the front view. 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.

The handle 81 is an upper notch 80 and is provided between a notch portion at the front end portion of the upper wall extension 50 and a notch portion at the upper end portion of the upper front wall 42, and more specifically, the upper notch portion. The upper notch 80 is provided across the width of the upper notch 80 so as to be laid between the front edge of the upper wall extension 50 arranged on both sides in the width direction 80 and the upper edge of the upper front wall 42.
As shown in FIG. 3, the handle 81 has a bowl shape, and its cross-sectional shape protrudes downward (in the thickness direction of the developing-side housing 29). More specifically, the handle 81 has a cut-out portion of the upper front wall 42. It is formed in a substantially concave shape that is recessed toward. Further, as shown in FIGS. 5 and 19, the upper surface of the handle 81 is formed flush with the upper surface of the upper wall extension 50 disposed on both sides in the width direction.

The development-side boss 79 has a cylindrical shape and is provided so as to protrude outward in the width direction from the rear lower part of the left outer surface of the left wall extension 52 and the rear lower part of the right outer surface of the right wall extension 53, respectively. ing.
Furthermore, as shown in FIGS. 5 and 6, the process cartridge 20 is mounted on the main casing 2 (see FIG. 1) and the front cover 7 (see FIG. 1) is closed on the upper wall extension 50. Sometimes, a recess 352 for preventing mounting of a different model into which each rib 351 provided on the front cover 7 is fitted is provided.

Each concave portion 352 has an upper wall extension in a plan view at a position where it can be received without interfering with each rib 351 when the front cover 7 is closed (in this embodiment, the left end portion of the upper wall extension portion 50). The upper wall extension 50 and the upper front wall 42 are continuous so that the front end portion of the portion 50 is cut out in a substantially rectangular shape and the upper end portion of the upper front wall 42 is cut out in a substantially rectangular shape in front view. It is formed by cutting out. Thereby, the upper part and the front of the recessed part 352 are open | released.
(3) Configuration of Drum Cartridge FIG. 11 is a principal side sectional view showing the drum cartridge of the process cartridge shown in FIG. 3, and FIG. 12 is a perspective view seen from the front side of the drum cartridge shown in FIG. .

As shown in FIGS. 11 and 12, the drum cartridge 27 includes a drum-side casing 91 as a second casing, and a photosensitive drum 92 that is a photosensitive member as a process member provided in the drum-side casing 91. A scorotron charger 93 as charging means, a transfer roller 94 as transfer means, and a cleaning brush 95 as cleaning means are provided.
The drum-side casing 91 is made of, for example, a resin material such as polystyrene, and the left side wall 96 and the right side wall 97, the bottom wall 98, and the lower front wall serving as the second wall portion are arranged to face each other with a gap in the width direction. 99 and the rear upper wall 100, and is provided with a drum housing portion 102, a developer cartridge housing portion 103 as a developer housing portion facing portion, and a lower extension portion 104 as a second extension portion.

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 described later, and the rear side wall portion 105 having a substantially bow shape in a side view and a substantially rectangular shape in a side view. The front side wall part 106 and the 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.
As shown in FIGS. 14 and 17, the rear side wall portion 105 of the left side wall 96 includes a first wall 108 formed flush with the front side wall portion 106 in the width direction, and a first wall 108 below the first wall 108. The second wall 109 disposed on the inner side in the width direction than the wall 108, the third wall 110 connecting the first wall 108 and the second wall 109, and the first wall 108 above the first wall 108 The fourth wall 111 arranged on the inner side in the width direction, the fifth wall 112 connecting the first wall 108 and the fourth wall 111, the second wall behind the second wall 109 and below the fourth wall 111. 109 and the fourth wall 111 are integrally provided with a sixth wall 113 disposed on the inner side in the width direction, and a second wall 109 and a seventh wall 114 connecting the fourth wall 111 and the sixth wall 113. Yes.

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 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.
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 so as 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 so as 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.
The seventh wall 114 connects the rear end edges 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.

A gear opening 196 for exposing a drum drive gear 191 described later is formed between the third wall 110 and the fifth wall 112 along the facing direction.
18 is a right side view of the process cartridge shown in FIG. 3, and FIG. 22 is a front sectional view of the drum cartridge shown in FIG.
As shown in FIGS. 18 and 22, 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 is formed to be flush with the front side wall portion 106 in the width direction. A first wall 108, a second wall 109 disposed below the first wall 108 in the width direction inside the first wall 108, and a third wall 110 connecting the first wall 108 and the second wall 109. Is integrated.

  Each front side wall portion 106 of the left side wall 96 and the right side wall 97 has a roller shaft guide portion 115 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. 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. .

The roller shaft guide part 115 is formed as an upper end edge of the front side wall part 106, and extends from the middle in the front-rear direction of the front side wall part 106 diagonally downward from the front to the rear, and then extends in a substantially horizontal flat shape. It is formed as follows.
The roller bearing insertion portion 116 is 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.
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 a rear side bottom wall portion 193 that is recessed in a substantially V-shaped cross section and a first flat plate shape. A front bottom wall portion 194 as a two bottom wall and an extended bottom wall portion 195 as a first bottom wall formed in a substantially rectangular flat plate shape are successively formed from the rear side toward the front side.

The lower front wall 99 is formed to bend in a perpendicular direction upward from the front 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 (a flat shape that is substantially free of irregularities in appearance).

  Further, as shown in FIG. 12, the lower front wall 99 is cut out in a substantially rectangular shape in front view from the upper edge at the center in the width direction of the lower front wall 99, as shown in FIG. As shown, a lower notch 119 is formed as a second notch continuous to the upper notch 80. As a result, when the developing cartridge 28 is mounted on the drum cartridge 27, the upper cutout portion 80 and the lower cutout portion 119 form a substantially rectangular opening when viewed from the front.

Further, on the lower front wall 99, as shown in FIG. 12, each projecting plate 51 projecting from the upper front wall 42 at both outer sides in the width direction than the lower notch 119 and in the vicinity of both ends. The receiving part 120 for accepting is formed.
Each receiving portion 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 in a front view. 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. 11, the rear upper wall 100 has a plate shape that is slightly inclined downward from the front to the rear, and the upper end edges of the rear side wall portions 105 of the left side wall 96 and the right side wall 97 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. Further, the rear upper wall 100 has a charging support portion 122 for supporting the scorotron charger 93 obliquely upward at the rear portion thereof, and a brush support portion 123 for supporting the cleaning brush 95 on the inner side of the rear portion thereof. Are integrally formed.

  And in this drum side housing | casing 91, as shown to FIG. 11 and FIG. 12, each rear side wall part 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 an up-down 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 closed space where the front is opened at the rear portion of the drum-side housing 91.

  Further, the developing cartridge housing portion 103 is formed by the front side wall portions 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 is continuous with the front side wall portions 106 in the width direction. . Thus, the developing cartridge housing portion 103 is formed as a space where the upper part is opened in the middle of the drum-side casing 91 in the front-rear direction, the front communicates with the lower extension 104, and the rear communicates with the drum housing 102. Has been.

  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. As a result, the lower extension 104 is formed as a space that extends rearward from the developing cartridge housing 103 at the rear of the drum-side casing 91 and is open at the upper side to communicate with the developing cartridge housing 103. ing.

  As shown in FIG. 11, the photosensitive drum 92 is disposed in the drum housing portion 102. The photosensitive drum 92 has a cylindrical shape and the outermost layer is formed of a positively chargeable photosensitive layer made of polycarbonate or the like, and an axial center of the drum main body 124 extends along the longitudinal direction of the drum main body 124. And a metal drum shaft 125 extending in the direction. The drum shaft 125 is non-rotatably supported by the left side wall 96 and the right side wall 97 of the drum side housing 91 as shown in FIG. A rotation support member 190 is fitted into both end portions in the axial direction of the drum body 124 so as not to be relatively rotatable. Each rotation support member 190 is supported around the drum shaft 125 so as to be relatively rotatable. Thereby, the drum main body 124 is rotatably supported with respect to the drum shaft 125.

Note that the left shaft end portion of the drum shaft 125 is provided so as to protrude from the first wall 108 of the left wall 96, and the contact surface of a ground contact portion 171 described later contacts the end surface of the left shaft end portion. A ground electrode 127 (see FIGS. 14 and 17) is used as a photoconductor electrode.
A drum drive gear 191 that is rotatably supported around the drum shaft 125 is coupled to the left end of the drum body 124 so as not to be relatively rotatable. The drum drive gear 191 is disposed so as to be exposed from the gear opening 196 (see FIG. 14). A compression spring 192 is disposed around the drum shaft 125 at the right end of the drum body 124 between the right wall 97 and the right rotation support member 190. As a result, frictional resistance in the width direction is generated in the drum drive gear 191 to ensure the rotational drive stability of the drum body 124.

As shown in FIG. 11, the scorotron charger 93 is disposed in the drum housing portion 102 and is supported by the charging support portion 122 obliquely above the rear side of the photosensitive drum 92 so as not to contact the photosensitive drum 92. Are opposed to each other with a gap therebetween. The scorotron charger 93 includes a wire 128, a grid 129, and a wire cleaner 130.
The wire 128 is stretched between the left side wall 96 and the right side wall 97 in the charging support portion 122. Further, a wire electrode 131 made of sheet metal is attached to the left end portion of the wire 128, and the wire electrode 131 is formed in the vertical direction on the front end portion of the fourth wall 111 of the left side wall 96 in the charging support portion 122. It is fixed so as to be exposed to the outside in the width direction from between the formed slits (see FIGS. 14 and 17).

  The grid 129 is disposed so as to surround the lower portion of the wire 128 along the width direction, and is laid between the left side wall 96 and the right side wall 97. A grid electrode 132 made of sheet metal is attached to the left end portion of the grid 129, and the grid electrode 132 is connected to the rear end portion of the fourth wall 111 of the left side wall 96 from the lower front side in the charging support portion 122. It is fixed so as to be exposed to the outside in the width direction from between slits formed in a direction inclined obliquely upward on the rear side (see FIGS. 14 and 17).

The wire cleaner 130 is supported by the charging support portion 122 so as to be slidable in the width direction in a state where the wire 128 is sandwiched. The wire 128 is cleaned by sliding the wire cleaner 130 along the width direction.
The transfer roller 94 is disposed in the drum housing portion 102 and is disposed below the photosensitive drum 92. The transfer roller 94 is covered with a metal transfer roller shaft 133 and a rubber roller 134 made of an ion conductive rubber material covering the periphery of the transfer roller shaft 133.

  As shown in FIG. 23A, the transfer roller drive gear 135 is provided at the end of the left shaft of the transfer roller shaft 133 so as not to rotate relative to the transfer roller shaft 133. On the inner side in the axial direction with respect to the gear 135, a bearing member 136 is provided adjacent to the transfer roller driving gear 135 so as to be rotatable relative to the transfer roller shaft 133. The bearing member 136 is supported by a bearing support portion 144 made of a rib provided on the bottom wall 98 in a state where the axial direction and the front-rear direction are positioned. Thus, the left shaft end portion of the transfer roller shaft 133 is rotatably supported by the bearing member 136 supported by the bearing support portion 144 of the bottom wall 98.

Note that the right shaft end portion of the transfer roller shaft 133 is also rotatably supported by the bearing member 136 supported by the bearing support portion 144 of the bottom wall 98 in a state where the axial direction and the front-rear direction are positioned ( (See FIG. 22).
Further, the transfer electrode 137 supported by the transfer electrode support portion 138 provided in the drum-side housing 91 is in contact with the end surface of the left-side shaft end portion of the transfer roller shaft 133. Thus, the axial direction of the transfer roller shaft 133 is positioned by the right bearing member 136 and the left transfer electrode 137.

The transfer electrode 137 is made of a conductive resin material, and has a substantially rectangular plate-shaped locking plate 139 and a direction orthogonal to the direction in which the locking plate 139 extends from the center of one surface of the locking plate 139. And an electrode abutting portion 141 bulging in an arc shape in the direction opposite to the protruding direction of the protruding portion 140 from the center of the other surface.
The transfer electrode support portion 138 includes a second wall 109 and a third wall 110 of the left side wall 96 that are continuously cut out to have a substantially L-shaped cross section. The transfer electrode has a substantially rectangular shape in front view and side view. An opening 142 (see FIG. 15) is formed, and the transfer electrode support portion 138 is a transfer electrode as a receiving portion provided inside the drum-side housing 91 so as to surround the transfer electrode opening 142. A receiving portion 143 is provided.

The transfer electrode receiving portion 143 is formed with two locking ribs 145 that are opposed to each other in the front-rear direction across the transfer electrode opening 142. A hook-like claw portion 147 is formed at the upper end portion of each locking rib 145.
The transfer electrode 137 is assembled and supported on the transfer electrode support 138 as follows. That is, as shown in FIG. 23B, first, the locking plate 139 is disposed on the transfer electrode receiving portion 143, and the protruding portion 140 is placed on the drum side housing 91 with respect to the transfer electrode opening 142. The protrusion 140 is inserted from the inside along the direction orthogonal to the third wall 110, and the protrusion 140 is protruded from the transfer electrode opening 142 in the width direction orthogonal to the second wall 109. Next, of the both ends of the locking plate 139 arranged in the front-rear direction, one end is locked to the claw portion 147 of the one locking rib 145. Thereafter, as shown in FIG. 23C, the locking plate 139 is rotated around the protruding portion 140, and the other end is locked to the claw portion 147 of the other locking rib 145.

As a result, the protrusion 140 of the transfer electrode 137 protrudes outward in the width direction from the transfer electrode opening 142, and the locking plate 139 locks the protrusion 140 by the locking ribs 145. In a state where the rotation around the center is restricted, the transfer electrode is received by the transfer electrode receiving portion 143 and supported by the transfer electrode support portion 138.
As shown in FIG. 23A, the end surface of the left shaft end of the transfer roller shaft 33 is slidably brought into contact with the electrode contact portion 141 of the transfer electrode 137 supported in this manner. ing. In this state, the transfer roller drive gear 135 is disposed at a distance from the second wall 109 in the axial direction (width direction). In addition, the transfer electrode 137 is also arranged at a distance from the second wall 109 in the axial direction (width direction).

  As shown in FIG. 11, the cleaning brush 95 is disposed in the drum housing portion 102, and is supported by the brush support portion 123 on the rear side of the photosensitive drum 92. The cleaning brush 95 has a large number of brush hairs planted on a substantially rectangular elongated support plate extending in the width direction. The cleaning brush 95 is arranged to face the photosensitive drum 92 in the front-rear direction so that the brush hair contacts the surface of the photosensitive drum 92 along the width direction while being supported by the brush support portion 123. A cleaning electrode 148 made of sheet metal is attached to the left end of the support plate of the cleaning brush 95. The cleaning electrode 148 is fixed in the brush support portion 123 so as to be exposed outward in the width direction from between the slits formed in the vertical direction at the rear end portion of the sixth wall 113 of the left side wall 96 (see FIG. 14 and FIG. 17).

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. 12, two protrusions 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 protrusion 118 is arranged to face each positioning portion 84 of the developing cartridge 28 mounted on the drum cartridge 27 and is formed so as to protrude upward in a semicircular cross section.

  As shown in FIG. 15, 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.

In addition, as shown in FIG. 12, the developer cartridge housing portion 103 has a toner empty sensor (see FIG. 12) at positions facing the toner detection windows 85 of the developer cartridge 28 in the width direction on the left side wall 96 and the right side wall 97. A toner passage window 101 for passing light (not shown) is provided.
Further, as shown in FIG. 12, the lower extension portion 104 includes a pressing portion 149 for pressing the developing roller 32 of the developing cartridge 28 mounted in the developing cartridge housing portion 103 against the photosensitive drum 92, and developing. A lock lever 153 as a locking means for locking the mounting state of the developing cartridge 28 mounted on the cartridge housing portion 103 with respect 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.

The pressing portions 149 are provided at both ends in the width direction of the lower extension portion 104, respectively.
FIG. 21 is a process diagram showing a state in which the developing cartridge is mounted on the drum cartridge in the process cartridge shown in FIG. In FIG. 21, the cover extension 86 is omitted.
As shown in FIG. 21, each pressing portion 149 includes a pressing member 151 that removably contacts the developing side boss 79 and attaches the pressing member 151 to the developing side boss 79 when the developing cartridge 28 is attached to and detached from the drum cartridge 27. And a compression spring 152 as urging means for urging the urging member.

  The pressing member 151 is made of a thick plate having a substantially triangular shape when viewed from the side. A rear end surface of the pressing member 151 is inclined downward from the front to the rear, and fixed to bend from the lower end of the guide surface 154 to the front. The surface 155 is formed continuously. A mounting portion 156 extends downward from the rear portion of the lower end surface of the pressing member 151. A lower end portion of the attaching portion 156 of the pressing member 151 is supported by a fixed shaft 157 protruding inward in the width direction from the extended side wall portion 107 of the left side wall 96 and the right side wall 97 so as to be swingable.

One end of the compression spring 152 is fixed to the front end portion of the extended bottom wall portion 195, and the other end is locked to the front portion of the lower end surface of the pressing member 151. Therefore, the pressing member 151 is always held in a state where the mounting portion 156 is inclined obliquely rearward from the lower end portion supported by the fixed shaft 157 by the urging force of the compression spring 152 as shown in FIG. Has been.
The lock lever 153 is provided at the left end in the width direction of the lower extension 104 and adjacent to the pressing member 151 on the outer side in the width direction. The lock lever 153 is a thick plate that is substantially V-shaped when viewed from the side, and an operation plate 158 as an operation unit that is flattened in the width direction is provided at one end. At the other end, an abutment piece 161 is formed as a locking portion protruding inward in the width direction. A flexible piece 159 having elasticity extending diagonally forward and downward is extended to the other end. A support shaft 160 that protrudes inward in the width direction from the extended side wall portion 107 of the left side wall 96 and is disposed obliquely forward and upward with respect to the fixed shaft 157 is inserted into the V-shaped bent portion.

  Thus, the lock lever 153 is rotatably supported by the support shaft 160. Further, the lower end portion of the flexible piece 159 is engaged with a rib (not shown) of the drum-side housing 91. Therefore, the lock lever 153 always has the upper surface of the operation plate 158 substantially the same as the upper surface of the upper wall extension 50 of the developing cartridge 28 attached to the developing cartridge housing portion 103 by the elastic force of the flexible piece 159. (See FIGS. 13 and 19).

As shown in FIGS. 12 and 17, the drum-side boss 150 has a cylindrical shape and extends from the outer surface of the front end portion and the lower end portion of each extended side wall portion 107 in the extended side wall portions 107 of the left side wall 96 and the right side wall 97. It is provided so as to protrude outward both in the width direction.
Further, as shown in FIG. 15, 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. The front rib 165 is 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 back surface (bottom surface) of the extended bottom wall portion 195 of the bottom wall 98. The upper registration roller 14 is arranged to face the lower registration roller 14 in the vertical direction in a state where the drum cartridge 27 is mounted on the main casing 2 (see FIG. 1).
The front rib 165 is a front surface of the upper registration roller 14 on the back surface (bottom surface) of the extended bottom wall portion 195 of the bottom wall 98 and is opposed to the lower cutout portion 119 cut out from the lower front wall 99. (That is, it is provided over the entire width direction including 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 portion of the extended bottom wall portion 195 that faces the lower notch 119 is formed in a substantially rectangular flat plate shape, and the front rib 165 has a width direction on the back surface (bottom surface) of the facing portion. Are spaced apart from each other (interval wider than the second rear rib 164), and a plurality are formed to extend in the front-rear direction.

Thus, the upper registration roller 14 is disposed between the front rib 165 and the rear rib 162 in the front-rear direction.
In the process cartridge 20, the developing cartridge 28 is mounted in the developing cartridge housing portion 103 of the drum cartridge 27 as follows.
That is, as shown in FIGS. 17 and 18, the developing cartridge 28 is firstly provided with color members 83 provided at both ends of the developing roller shaft 64 projecting outward in the width direction of the developing side housing 29. And the bearing member 82 are guided along each roller shaft guide portion 115 of the drum-side housing 91 of the drum cartridge 27, and then the collar member 83 and the bearing member 82 provided at both ends of the developing roller shaft 64 are guided. The roller bearing insertion portions 116 are brought into contact with the rear end edges of the roller bearing insertion portions 116 and received by the roller bearing insertion portions 116. At the same time, the developing boss 79 of the upper extension 37 of the developing cartridge 28 is engaged with the pressing portion 149 of the lower extension 104 of the drum cartridge 27.

In this way, the developing roller 32 is brought into contact with the photosensitive drum 92 in a state where the developing cartridge 28 is mounted in the developing cartridge housing portion 103 in this way.
More specifically, first, the developing cartridge 28 is disposed above the developing cartridge housing portion 103 of the drum cartridge 27 (see FIG. 21A), and the color members 83 provided at both ends of the developing roller shaft 64 are provided. Further, while guiding the bearing member 82 along each roller shaft guide portion 115, the front end portion of the developing cartridge 28 is lowered, and the developing-side boss 79 is guided by the pressing member 151 as shown in FIG. The surface 154 is moved downward while being rubbed. Then, the pressing member 151 is gradually swung forward with the fixed shaft 157 as a fulcrum against the urging force of the compression spring 152.

  When the collar member 83 and the bearing member 82 provided at both ends of the developing roller shaft 64 are received by the roller bearing insertion portions 116 and the developing roller 32 comes into contact with the photosensitive drum 92, as shown in FIG. The development-side boss 79 reaches the boundary between the guide surface 154 and the fixed surface 155, the development-side boss 79 comes into contact with the contact piece 161 of the lock lever 153, and the lock lever 153 has the elastic force of the flexible piece 159. Against this, the support shaft 160 is rotated as a fulcrum, and the operation plate 158 is swung downward.

  Thereafter, when the front end portion of the developing cartridge 28 is further lowered, the developing side boss 79 passes between the pressing member 151 and the contact piece 161 of the lock lever 153, and as shown in FIG. The side boss 79 is in contact with the fixed surface 155 of the pressing member 151 and is disposed below the contact piece 161 of the lock lever 153. In this state, the pressing member 151 is swung rearward with the fixed shaft 157 as a fulcrum by the urging force of the compression spring 152, so that the fixing surface 155 presses the developing-side boss 79 rearward, thereby developing cartridge. 28 is pressed rearward, and the developing roller 32 is pressed against the photosensitive drum 92.

  Further, since the development side boss 79 is disposed below the contact piece 161 of the lock lever 153, the contact piece 161 is locked to the development side boss 79 from above, and the development side boss 79 is released upward. Can be locked. Further, the lock lever 153 is rotated about the support shaft 160 by the elastic force of the flexible piece 159, and the operation plate 158 is swung upward. As described above, the upper surface of the operation plate 158 is the developer cartridge. The developing cartridge 28 mounted in the accommodating portion 103 is disposed so as to be substantially flush with the upper surface of the upper wall extension 50 of the developing cartridge 28.

  When the developing cartridge 28 is detached from the developing cartridge housing portion 103, the lock lever 153 pushes the support shaft 160 when the operation plate 158 of the lock lever 153 is pushed down against the elastic force of the flexible piece 159. Since the abutment piece 161 rotated as a fulcrum and disposed above the development-side boss 79 swings backward to be unlocked, the development-side boss 79 is connected to the abutment piece 161 of the lock lever 153. The pressing member 151 can be separated upward from the pressing member 151 while pressing the pressing member 151 forward against the urging force of the compression spring 152. Therefore, while raising the front end portion of the developing cartridge 28 upward, the collar member 83 and the bearing member 82 provided at both ends of the developing roller shaft 64 are separated from the roller bearing insertion portions 116, and the roller shaft guide portions 115. , The developing cartridge 28 can be easily detached from the developing cartridge housing portion 103.

Further, when the developing cartridge 28 is attached to the drum cartridge 27, each protrusion 118 of the drum cartridge 27 is positioned in contact with each positioning portion 84 of the developing cartridge 28, and the developing cartridge 28 is positioned with respect to the drum cartridge 27. Positioned and fixed.
In this way, the developing cartridge 28 is mounted on the drum cartridge 27, and the process cartridge 20 is configured.

  In the mounted state as described above, as shown in FIG. 16, the toner storage chamber 30 of the developing cartridge 28 and the developing cartridge storage portion 103 of the drum cartridge 27 are opposed to each other in the vertical direction. Further, the upper extension 37 of the developing cartridge 28 and the lower extension 104 of the drum cartridge 27 are arranged to face 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.

Further, the gear mechanism portion 45 of the developing cartridge 28 and the lock lever 153 are both arranged on the left side in the width direction and arranged so as to overlap in the front-rear direction.
In this process cartridge 20, as shown in FIG. 17, a cleaning electrode 148, a grid electrode 132, a wire electrode 131, and a transfer electrode 137 are provided on the left side wall 96 of the drum side casing 91, and the left side wall thereof. A ground electrode 127 is provided so as to protrude from 96. A developing roller electrode 76 is provided on the left side wall 38 of the developing side housing 29 so as to protrude from the left side wall 96 of the drum side housing 91. That is, all the electrodes (the cleaning electrode 148, the grid electrode 132, the wire electrode 131, the ground electrode 127, the transfer electrode 137, and the developing roller electrode 76) are arranged on the left side in the width direction.

  Further, the gear mechanism portion 45 is also provided on the left side wall 38 of the developing side housing 29 and is arranged on the left side in the same width direction as these electrodes. More specifically, all these electrodes and the gear mechanism portion 45 are on the left side in the width direction, and on the rear side of the center portion in the front-rear direction of the process cartridge 20 (indicated by a point C in FIG. 17). Further, all the electrodes are arranged on the rear side with respect to the input gear 68.

  In addition, among all the electrodes, the cleaning electrode 148 arranged on the rearmost side is provided on the sixth wall 113 arranged on the innermost side in the width direction, so that the grid provided on the fourth wall 111 is provided. The electrode 132, the wire electrode 131, the transfer electrode 137 provided on the second wall 109, and the ground electrode 127 and the developing roller electrode 76 protruding from the first wall 108 are disposed on the innermost side in the width direction. The

  Further, as shown in FIG. 14, the cleaning electrode 148 is disposed inside the gear mechanism portion 45 in the width direction. Further, as shown in FIG. 14, the cleaning electrode 148 transfers a toner image to the sheet 3 passing between the photosensitive drum 92 and the transfer roller 94 in the process cartridge 20 as will be described later. It is arranged on the outer side in the width direction than the image forming area X for forming an image.

  Further, in this process cartridge 20, as shown in FIG. 14, the ground electrode 127 and the developing roller electrode 76 projecting from the first wall 108 and the wire electrode 131 and the grid electrode 132 provided on the fourth wall 111 are interposed. Is provided with a step defined by the fifth wall 112. In addition, a step is defined by the third wall 110 between the ground electrode 127 and the developing roller electrode 76 protruding from the first wall 108 and the transfer electrode 137 provided on the second wall 109. The seventh wall is disposed between the wire electrode 131 and the grid electrode 132 provided on the fourth wall 111, the transfer electrode 137 provided on the second wall 109, and the cleaning electrode 148 provided on the sixth wall 113. Steps defined by 114 are provided. As a result, the cleaning electrode 148, the transfer electrode 137, the wire electrode 131 and the grid electrode 132, the ground electrode 127 and the developing roller electrode 76 are sequentially arranged on the outside in the width direction, and are thus arranged at different positions. Is done.

  The process cartridge 20 is mounted on the main casing 2 as shown in FIG. When the process cartridge 20 is mounted on the main casing 2, the drum side boss 150 of the drum cartridge 27 is engaged with a positioning member 166 provided on the main casing 2 as shown in FIG. The process cartridge 20 is positioned with respect to the main body casing 2.

  Further, as shown in FIG. 24, the main body casing 2 is provided with a left frame 167 disposed to face the left side of the process cartridge 20 mounted on the main body casing 2. The left frame 167 is provided with a cleaning contact portion 168, a grid contact portion 169, a wire contact portion 170, a ground contact portion 171, a transfer contact portion 172, and a developing roller contact portion 173. These contact portions are connected to a power source (high voltage power source) (not shown) provided in the main body casing 2.

The cleaning contact portion 168 is connected to a contact disposed through the wiring so as to contact the cleaning electrode 148 of the process cartridge 20 mounted on the main casing 2. The cleaning electrode 148 is connected to the cleaning electrode 148 from the power source. Apply cleaning bias. The cleaning bias is set to about 400V.
The grid contact portion 169 is connected via a wiring to a contact disposed so as to contact the grid electrode 132 of the process cartridge 20 mounted on the main casing 2, and the grid electrode 132 receives power from the power source. Apply grid voltage. The grid voltage is set to about 900V.

A contact arranged to contact the wire electrode 131 of the process cartridge 20 attached to the main body casing 2 is connected to the wire contact portion 170 via wiring, and the wire electrode 131 is connected to the wire electrode 131 from the power source. Apply discharge voltage. The discharge voltage is set to about 7000V.
A contact disposed so as to contact the ground electrode 127 of the process cartridge 20 mounted on the main casing 2 is connected to the ground contact portion 171 through a wiring, and the ground electrode 127 is grounded. .

  A contact arranged to contact the transfer electrode 137 of the process cartridge 20 mounted on the main body casing 2 is connected to the transfer contact portion 172 via a wiring, and the transfer electrode 137 is connected to the transfer electrode 137 from the power source. Apply transfer bias. The transfer bias is set to a maximum of about −6500 V as a forward transfer bias and about 1600 V as a reverse transfer bias.

A developing roller contact 175, which will be described later, is connected to the developing roller contact portion 173 through wiring, and a developing bias from a power source is applied to the developing roller electrode 76. The development bias is set to about 400V.
The left frame 167 includes a coupling member 73 movably connected to the connection hole 74 of the input gear 68, a swing arm 174 for moving the coupling member 73 back and forth, and a swing arm 174. A developing roller contact 175 is provided as a restricting means that is provided and contacts the developing roller electrode 76 so as to freely advance and retract.

As shown in FIG. 25, the swing arm 174 is integrally provided with an arm portion 176 extending along the front-rear direction and a cam portion 177 provided at the rear end portion of the arm portion 176.
A long hole extending in the vertical direction through which the coupling member 73 is inserted is formed in the cam portion 177, and the upper end portion of the long hole is formed thick in the width direction as shown in FIG. A retracting portion 178 is provided. Further, an advancing portion 179 that is formed thin in the width direction is provided around the lower end portion of the long hole.

The swing arm 174 has a front end portion rotatably supported by the left frame 167 in a state where the coupling member 73 is inserted into the long hole at the rear end portion. The swing arm 174 is provided by the link mechanism 180 so that the rear end swings in the vertical direction in conjunction with the opening and closing of the front cover 7.
The coupling member 73 is disposed to face the connection hole 74 of the input gear 68 of the process cartridge 20 mounted on the main casing 2 in the width direction. A rotational driving force from a motor (not shown) provided in the main body casing 2 is input to the coupling member 73. Further, the coupling member 73 is always biased toward the inner side in the width direction, that is, toward the connecting hole 74 by a biasing spring 181 (see FIG. 24).

The developing roller contact 175 is connected to a power source (not shown) provided in the main casing 2 so as to protrude rearward at the lower end portion of the cam portion 177 of the swing arm 174 as shown in FIG. Is provided.
Then, when the front cover 7 is opened when the process cartridge 20 is attached to or detached from the main casing 2, the swing arm 174 is interlocked with the opening of the front cover 7 as shown in FIG. As shown in FIG. 26 (a), the rear end portion is lowered with fulcrum as a fulcrum, and the retracting portion 178 engages with the coupling member 73. Then, the coupling member 73 retracts from the connection hole 74 of the input gear 68 against the biasing force of the biasing spring 181. Further, in this state, as shown in FIG. 25A, the developing roller contact 175 is retracted from the developing roller electrode 76 and is separated from the developing roller electrode 76 with a gap therebetween.

  Further, when the front cover 7 is closed after the process cartridge 20 is mounted on the main casing 2, the swing arm 174 is interlocked with the closing of the front cover 7 as shown in FIG. As shown in FIG. 26 (b), the advancing portion 179 engages with the coupling member 73. Then, the coupling member 73 advances into the connection hole 74 of the input gear 68 by the biasing force of the biasing spring 181 and is coupled so as not to be relatively rotatable. As a result, the rotational driving force from the coupling member 73 is transmitted to the input gear 68. Then, a driving force is transmitted from the input gear 68 to the agitator driving gear 69 via the intermediate gear 70, and the agitator 46 is rotated. Further, the driving force is transmitted from the input gear 68 to the developing roller driving gear 71, and the developing roller 32 is rotated. Further, the driving force is transmitted from the input gear 68 to the supply roller drive gear 72, and the supply roller 31 is rotated.

In this state, as shown in FIG. 25B, the developing roller contact 175 advances with respect to the developing roller electrode 76 and contacts the developing roller electrode 76 so as to overlap in the width direction. As a result, a developing bias from the power source is applied from the developing roller contact 175 to the developing roller electrode 76.
When the process cartridge 20 is mounted in the main casing 2, the process cartridge 20 is connected to the left end of the drum main body 124 in the axial direction and is exposed to the drum driving gear 191 exposed from the gear opening 196. A drum gear provided to which a rotational driving force from a motor (not shown) is input meshes, and the rotational driving force from the motor is input to the drum driving gear 191 to rotate the photosensitive drum 92.

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 of the layer thickness regulating blade 33 and the developing roller 32 as the developing roller 32 rotates, and develops as a thin layer having a constant thickness. It is carried on the surface of the roller 32.
On the other hand, the scorotron charger 93 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.

  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 on which the toner image is transferred is conveyed to the fixing unit 21 described below.

  Then, 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 by 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 according to the rotational driving 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 casing 2 by a sheet discharge roller 186 provided on the upper side.
(4) Process Cartridge In this process cartridge 20, as shown in FIG. 17, all electrodes (cleaning electrode 148, grid electrode 132, wire electrode 131, ground electrode 127, transfer electrode 137, and developing roller electrode 76) However, since the electrodes are arranged on the left side in the width direction, the configuration can be simplified by concentrating the electrodes.

  Further, as shown in FIG. 14, the cleaning electrode 148 arranged on the rearmost side among all the electrodes is the other electrodes (grid electrode 132, wire electrode 131, ground electrode 127, transfer electrode 137, and development). It is disposed on the innermost side in the width direction with respect to the roller electrode 76). Therefore, when the process cartridge 20 is attached or detached, the cleaning electrode 148 is a contact (grid contact portion 169, wire contact portion 170, ground contact) provided on the left frame 167 of the main body casing 2 corresponding to the other electrodes. Since each contact of the portion 171 and the transfer contact portion 172 and the developing roller contact 175) are crossed at a predetermined interval in the width direction, it can be prevented from being rubbed and worn with such a contact. As a result, it is possible to prevent a contact failure of an electrode that is likely to cause a contact failure and to ensure a reliable electrical connection over a long period of time.

Further, since the cleaning electrode 148 disposed on the rearmost side is disposed on the outer side in the width direction with respect to the image forming region X, the cleaning electrode 148 does not hinder the image formation on the paper 3 and can be reliably performed. Contact failure of the cleaning electrode 148 can be prevented while achieving a good image formation.
If the cleaning electrode 148 is disposed on the rearmost side, the cleaning brush 95 is located on the rear side of the photosensitive drum 92 (that is, downstream of the position where the photosensitive drum 92 and the transfer roller 94 face each other in the rotational direction of the photosensitive drum 92). Side). Therefore, the optimal arrangement of the cleaning brush 95 can be ensured.

In the process cartridge 20, the gear mechanism 45 is also arranged on the left side in the same width direction as all the electrodes. Therefore, the device configuration can be further simplified.
Further, the gear mechanism portion 45 and all the electrodes are arranged on the left side in the width direction so as to be concentrated on the rear side of the center portion (indicated by a point C in FIG. 17) of the process cartridge 20 in the front-rear direction. ing. Thereby, simplification and downsizing of the apparatus can be achieved by concentrating and arranging the gear mechanism portion 45 and all the electrodes.

  All the electrodes are arranged on the rear side with respect to the input gear 68 of the gear mechanism 45. Thereby, reliable positioning of all the electrodes and stable supply of power and driving force to the process cartridge 20 can be achieved. Further, if all the electrodes are arranged on the rear side with respect to the input gear 68 of the gear mechanism portion 45, the coupling member 73 that moves forward and backward with respect to the connection hole 74 of the input gear 68 interferes with these electrodes. Can be prevented. Therefore, it is possible to prevent damage due to interference of the coupling member 73 of these electrodes.

Further, the cleaning electrode 148 disposed on the rearmost side is disposed on the inner side in the width direction with respect to the gear mechanism portion 45. Therefore, it is possible to prevent the cleaning electrode 148 from being contaminated by grease, dust, shavings, or the like generated around the gear mechanism 45.
Further, in this process cartridge 20, as shown in FIG. 10, a toner supply port 47 is provided in the right side wall 39 of the developing cartridge 28, and all the electrodes and the gear mechanism portion 45 are arranged on the left side in the width direction. The toner supply port 47 is disposed on the right side in the opposite width direction. Therefore, the electrodes can be prevented from being contaminated by the scattering of the toner supplied to the toner supply port 47.

  Further, in the process cartridge 20, as shown in FIG. 14, a third electrode is disposed between the cleaning electrode 148, the transfer electrode 137, the wire electrode 131 and the grid electrode 132, and the ground electrode 127 and the developing roller electrode 76. A step defined by the wall 110, the fifth wall 112, and the seventh wall 114 is provided. Such a step can provide a distance between these electrodes, so that leakage occurring between these electrodes can be reduced with a simple configuration without increasing the size of the apparatus. In particular, in this process cartridge 20, leakage is likely to occur between the wire electrode 131 and the developing roller electrode 76, but the step defined by the fifth wall 112 is between the wire electrode 131 and the developing roller electrode 76. Is provided. Therefore, this step can reduce the leakage between the wire electrode 131 and the developing roller electrode 76 with a simple configuration.

  Further, the transfer electrode 137 is shown in FIG. 23 (b), and as described above, the locking plate 139 is disposed on the transfer electrode receiving portion 143, and the protruding portion 140 is connected to the transfer electrode opening 142. On the other hand, if it is inserted along the direction orthogonal to the third wall 110 from the inside of the drum-side casing 91, it can be provided so as to protrude in the width direction orthogonal to the second wall 109. Therefore, simple mounting and reliable arrangement of the transfer electrode 137 can be achieved. Further, as shown in FIG. 23 (c), as described above, one end portion is then locked to the claw portion 147 of one locking rib 145, and the locking plate 139 is rotated around the protruding portion 140. When the other end is locked to the claw portion 147 of the other locking rib 145, the locking plate 139 is prevented from rotating around the protrusion 140 by the locking of each locking rib 145. In this state, it is received by the transfer electrode receiving portion 143 and supported by the transfer electrode support portion 138. Therefore, the transfer electrode 137 can be easily assembled.

  When the transfer electrode 137 is assembled, as shown in FIG. 23A, the end surface of the left shaft end portion of the transfer roller shaft 33 is slidable against the electrode contact portion 141 of the transfer electrode 137. In this state, the transfer roller drive gear 135 is disposed at a distance from the second wall 109 in the axial direction (width direction), and the transfer electrode 137 is also disposed in the axial direction (width direction) from the second wall 109. At intervals. As a result, the transfer roller driving gear 135 and the transfer electrode 137 are arranged at a predetermined interval with respect to the second wall 109, so that damage caused by contact of the transfer roller driving gear 135 and the transfer electrode 137 with the second wall 109 is caused. Can be prevented.

  In the developing cartridge 28, as shown in FIG. 20, the right shaft end of the supply roller shaft 62 and the right shaft end of the developing roller 32 are rotatably supported by a bearing member 82 made of a common resin material. ing. A color member 83 made of a common conductive resin material is attached to the left shaft end of the supply roller shaft 62 and the left shaft end of the developing roller 32, and the supply roller 31 and the developing roller 32 are connected to each other. The same potential is maintained.

  Thus, even if the bearing member 82 that supports both the right shaft end portion of the supply roller shaft 62 and the right shaft end portion of the developing roller 32 at the same time is formed large in order to increase positioning accuracy, the bearing member 82 It can be made of an inexpensive insulating material. Therefore, it is possible to reduce the cost while improving the positioning accuracy. On the other hand, the left shaft end portion of the supply roller shaft 62 and the left shaft end portion of the developing roller 32 are connected by the collar member 83 made of a conductive material, so that they can be held at the same potential.

  Further, in the developing cartridge 28, as shown in FIG. 5, the gear cover 77 includes various gears (an input gear 68, an agitator driving gear 69, an intermediate gear 70, a developing roller driving gear 71, and a supply roller driving gear) of the gear mechanism unit 45. 72) and the left shaft end portion of the developing roller shaft 64 (that is, the developing roller electrode 76) are held, so that the positioning accuracy of both can be improved. Therefore, stable supply of electric power and driving force to the developing cartridge 28 can be achieved while reducing the number of parts and simplifying the apparatus configuration.

Further, since the gear cover 77 is also disposed on the left side wall 38 where the various shafts and the left end of the developing roller shaft 64 are disposed, the apparatus configuration can be further simplified.
Further, in the laser printer 1, when the front cover 7 is closed after the process cartridge 20 is mounted, the advancing portion 179 of the swing arm 174 is engaged with the coupling member 73 as shown in FIG. The coupling member 73 advances into the connection hole 74 of the input gear 68 and is connected so as not to be relatively rotatable. At the same time, the developing roller contact 175 advances toward the developing roller electrode 76 and comes into contact with the developing roller electrode 76 so as to overlap in the width direction. Therefore, stable supply of power and driving force to the developing cartridge 28 can be achieved.

  In this state, the developing roller contact 175 is brought into contact with the developing roller electrode 76 so as to overlap in the width direction, and the developing roller electrode 76 is pressed by the developing roller contact 175. When the driving force is transmitted to the developing cartridge 28, the developing roller contact 175 can prevent the left side wall 38 of the developing cartridge 28 from being driven by the driving force. Therefore, stable supply of power and driving force to the developing cartridge 28 can be achieved.

  In particular, in the process cartridge 20, the collar member 83 and the bearing member 82 provided at both ends of the developing roller shaft 64 of the developing cartridge 28 are received in the roller bearing insertion portions 116 of the drum cartridge 27. When a driving force is transmitted from the member 73 to the input gear 68, the drum-side casing is engaged by fitting the collar member 83 and the bearing member 82 provided at both ends of the developing roller shaft 64 of each roller bearing insertion portion 116. By restricting the movement of the developing housing 29 at 91, it is possible to more reliably prevent the left side wall 38 of the developing cartridge 28 from being driven.

The laser printer 1 includes the cleaning electrode 148 with reduced contact failure and the process cartridge 20 that can achieve a stable supply of electric power and driving force. Therefore, stable image formation can be performed over a long period of time. Can be secured.
In the process cartridge 20, as shown in FIG. 21, when the developing cartridge 28 is attached to the drum cartridge 27, the pressing member 151 is extended upward at the pressing portion 149 provided in the lower extending portion 104. The pressing member 151 in contact with the developing side boss 79 provided in the portion 37 is pressed toward the developing side boss 79 by the biasing force of the compression spring 152.

  Accordingly, the developing roller 32 of the developing cartridge 28 is reliably pressed toward the photosensitive drum 92 with a simple configuration, and stable mounting of the developing cartridge 28 to the drum cartridge 27 can be ensured. Further, since the pressing portion 149 is provided in the lower extension portion 104 and the development side boss 79 is provided in the upper extension portion 37, the process cartridge 20 can be formed compactly.

  Further, a development-side boss 79 is provided so as to protrude outward in the width direction from the rear lower part of the left outer surface of the left wall extension 52 and the rear lower part of the right outer surface of the right wall extension 53. Therefore, the development-side boss 79 can be reliably brought into contact with the pressing member 151, so that more reliable pressing of the developing roller 32 of the developing cartridge 28 against the photosensitive drum 92 of the drum cartridge 27 can be ensured.

  In the process cartridge 20, when the developing cartridge 28 is mounted on the drum cartridge 27, the contact piece 161 of the lock lever 153 provided on the lower extension 104 is engaged with the developing boss 79 of the upper extension 37. The development-side boss 79 is locked to be released upward, and the mounting state of the development cartridge 28 to the drum cartridge 27 is locked. Therefore, it is possible to ensure that the developing cartridge 28 is securely attached to the drum cartridge 27.

  On the other hand, when the developing cartridge 28 is detached from the drum cartridge 27, if the operation plate 158 of the lock lever 153 is pushed down, the locking of the contact piece 161 with respect to the developing side boss 79 can be released. Can be easily detached from the drum cartridge 27. Therefore, the mounting state of the developing cartridge 28 with respect to the drum cartridge 27 and the release thereof can be achieved with a simple configuration.

Further, the developing-side boss 79 of the developing cartridge 28 serves as both a pressed portion (operated portion) pressed by the pressing member 151 and a locked portion locked by the contact piece 161, so that the configuration is simplified. In addition, the number of parts can be reduced. In addition, although the number of parts increases, you may provide an actuated part and a to-be-latched part separately.
When the developing cartridge 28 is mounted on the drum cartridge 27, the upper surface of the operation plate 158 of the lock lever 153 of the drum cartridge 27 is positioned on the upper wall extension 50 of the developing cartridge 28 as shown in FIGS. 13 and 19. Accordingly, the front end of the process cartridge 20, that is, the appearance of the upper extension 37 and the lower extension 104 can be made clean.

  When the developing cartridge 28 is mounted on the drum cartridge 27, as shown in FIG. 16, the gear mechanism 45 of the developing cartridge 28 and the lock lever 153 of the drum cartridge 27 are both arranged on the left side in the width direction. Since they are arranged so as to overlap in the front-rear direction, the process cartridge 20 can be compactly formed in the width direction.

  Further, as shown in FIG. 15, the drum cartridge 27 includes a front rib on the back surface (bottom surface) of the extended bottom wall portion 195 of the lower extension portion 104, an upper registration roller 14, and a front side of the upper registration roller 14. 165 is provided. A rear rib 162 is provided on the rear side (bottom surface) of the front bottom wall portion 194 of the developing cartridge housing portion 103 on the rear side of the upper registration roller 14. As a result, the sheet 3 fed from the sheet feeding roller 10 is first guided to the registration roller 14 by the front rib 165 and then conveyed by the registration roller 14, and then to the photosensitive drum 92 by the rear rib 162. Guided towards. Therefore, the process cartridge 20 can be made compact while the sheet 3 fed from the sheet feeding roller 10 can be reliably conveyed toward the photosensitive drum 92 by the front rib 165, the registration roller 14, and the rear rib 162. Can be formed. Further, the bottom wall 98 of the drum cartridge 27 can be reinforced by the front rib 165 and the rear rib 162.

  Further, in the process cartridge 20, when the developing cartridge 28 is attached to the drum cartridge 27, the protrusions 118 of the drum cartridge 27 are positioned in contact with the positioning portions 84 of the developing cartridge 28 as shown in FIG. 3. The As a result, the developing cartridge 28 can be simply positioned with respect to the drum cartridge 27 and fixed securely with a simple configuration. The same effect can be obtained by providing the drum cartridge 27 with the positioning portion 84 and providing the developing cartridge 28 with the protrusion 118.

  Further, when the process cartridge 20 is mounted on the main casing 2 when the process cartridge 20 is mounted on the main casing 2, the process cartridge 20 is provided on the lower extension 104 of the drum cartridge 27 as shown in FIG. 1. The drum-side boss 150 is engaged with a positioning member 166 provided in the main body casing 2, and the process cartridge 20 is positioned with respect to the main body casing 2. Therefore, the process cartridge 20 can be compactly formed while the process cartridge 20 can be reliably positioned with respect to the main casing 2.

  Further, in the developing cartridge 28, as shown in FIG. 5, a handle 81 that protrudes downward is provided as a gripping portion 78 in the upper notch portion 80 formed at the front end portion of the upper extension portion 37. Therefore, as compared with the case where the gripping portion 78 is provided immediately from the toner storage chamber 30, the gripping portion is formed in a portion corresponding to the upper extension portion 37 extending from the toner storage chamber 30 along the front-rear direction. 78 is arranged. As a result, the gripping portion 78 can be easily gripped in the mounted state with respect to the main body casing 2, and the smooth mounting and dismounting operation of the developing cartridge 28 with respect to the main body casing 2 can be ensured while forming the developing cartridge 28 compact.

Further, in the developing cartridge 28, as shown in FIG. 4, the upper extension 37 is provided in the lower frame 34 in which the toner storage chamber 30 and the developing chamber 36 are formed. Grasping can be achieved.
Further, as shown in FIG. 5, the upper front wall 42 of the upper extension 37 is disposed along the vertical direction, and the front surface thereof is formed in a planar shape. It can be refreshed. Therefore, the handle 81 can be easily identified, and a smooth attachment / detachment operation of the developing cartridge 28 with respect to the main casing 2 can be ensured.

Further, the upper wall extension 50 of the upper extension 37 has a planar shape on the upper surface. Therefore, the external appearance of the upper extension 37 can be made even cleaner.
Further, since the handle 81 is provided in the upper notch 80, a hand can be inserted into the upper notch 80 and the handle 81 provided in the upper notch 80 can be gripped. Therefore, the handle 81 can be gripped in the middle of the developing-side casing 29 in the thickness direction (in the middle of the vertical direction), and the developing cartridge 28 can be formed in a compact manner, while the developing cartridge 28 can be smoothly attached to and detached from the main casing 2. Can be secured.

  The upper notch 80 is formed so as to continuously cut out the upper wall extension 50 and the upper front wall 42, and the handle 81 has a notch at the front end of the upper wall extension 50 and the upper front. It is provided between the upper end portion of the wall 42 and the cutout portion. As a result, a hand can be inserted into the cutout portion of the upper front wall 42, the hand can be turned to the cutout portion of the upper wall extension 50, and the handle 81 can be gripped from the rear side toward the front side. Therefore, the gripping of the handle 81 can be achieved while forming the developing cartridge 28 compactly. In addition, since the handle 81 can be gripped from the cutout portion of the upper wall extension 50 and can be easily pulled forward, the smooth attachment / detachment operation of the developing cartridge 28 with respect to the main casing 2 can be ensured.

Further, as shown in FIGS. 5 and 19, the upper surface of the handle 81 is formed flush with the upper surface of the upper wall extension 50 arranged on both sides in the width direction. , You can make it cleaner.
Further, the handle 81 has a hook shape, and its cross-sectional shape is formed in a substantially concave shape that is recessed toward the cutout portion of the upper front wall 42 as shown in FIG. Therefore, reliable gripping of the handle 81 can be achieved.

  Further, in a state where the developing cartridge 28 is mounted on the drum cartridge 27, the lower front wall 99 of the drum cartridge 27 is the same as the upper front wall 42 of the developing cartridge 28 as shown in FIGS. 13 and 19. The front surfaces of the upper front wall 42 and the lower front wall 99 are disposed flush with each other. Therefore, the appearance of the front end portion of the process cartridge 20 can be made clear.

  In addition, the lower front wall 99 is formed with a lower notch 119 that is continuous with the upper notch 80, whereby, as shown in FIG. 13, the upper notch 80 and the lower notch 119 An opening having a substantially rectangular shape when viewed from the front is formed. Therefore, in the process cartridge 20, the outer cutout 80 and the lower cutout 119 form an opening, and the front end of the upper extension 37 and the front end of the lower extension 104 are made clear. Can do. Further, the handle 81 can be easily gripped by inserting a hand into the opening formed by the upper notch 80 and the lower notch 119. Therefore, it is possible to ensure a smooth attachment / detachment operation of the process cartridge 20 with respect to the main body casing 2.

  Further, in a state where 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. 13. Therefore, smooth and compact mounting of the developing cartridge 28 to the drum cartridge 27 can be ensured. Further, the appearance of the front end portion of the process cartridge 20 can be made clear.

  Further, in the developing cartridge 28, the upper front wall 42 is formed so as to bend in a substantially perpendicular direction downward from the front end edge of the upper wall extension 50, and further from the lower end edge of the upper front wall 42. Continuously, the protruding plate 51 is further protruded downward, whereby the upper front wall 42 including each protruding plate 51 has a substantially U-shaped planar shape (these shapes) as shown in FIG. The front surface is formed flush.

  Therefore, for example, as shown in FIG. 27, when the upper front wall 42 and the front surfaces of the protruding plates 51 are placed on a floor 197 as a placement surface, the developing cartridge 28 is placed on the upper side of the developing roller 32. It can stand on the floor 197 in a state where it is placed on the floor. Therefore, the developing cartridge 28 can be placed upright while preventing the developing roller 32 from being damaged. Further, it is possible to easily assemble components such as a toner seal at the time of assembly.

  That is, when the front surface of the upper front wall 42 is formed in a planar shape, the developing cartridge 28 can be placed upright with the upper front wall 42 as a placement surface. In addition, in the placement of the developing cartridge 28 with the upper front wall 42 as a placement surface, the area of the placement surface is increased by the protruding plates 51 that are flush with the front surface of the upper front wall 42. Can do. Therefore, stable placement of the developing cartridge 28 with the upper front wall 42 as a placement surface can be achieved.

  In addition, since the developing cartridge 28 is provided with a recess 352 for preventing different models from being mounted, it is possible to prevent the developing cartridge 28 from being mounted on a model different from the laser printer 1. In addition, by making the configuration for preventing the mounting of the different models into the concave portion, it is possible to prevent the development cartridge 28 from being enlarged. Furthermore, since the concave portion 352 for preventing mounting of a different model is formed in the upper extension 37, it is possible to prevent a decrease in the volume of the toner storage chamber 30 (the amount of toner stored in the toner storage chamber). It is also suitable for downsizing.

  Further, since the upper end of the recess 352 is opened by cutting out the front end portion of the upper wall extension 50, a rib provided on the front cover 7 when the front cover 7 is closed with the cover shaft as a fulcrum. 351 can be securely fitted into the recess 352 from above. Therefore, the developing cartridge 28 can be securely attached to the laser printer 1.

  In addition, since the upper end portion of the upper front wall 42 is notched, the front of the recess 352 is also opened. Therefore, when the front cover 7 is closed with the cover shaft as a fulcrum, a rib 351 provided on the front cover 7 is provided. Can be securely fitted by the recess 352. Therefore, the developing cartridge 28 can be more reliably attached to the laser printer 1.

Furthermore, since the recess 352 is formed at a position where the rib 351 can enter without interference when the front cover 7 is closed, the rib 351 can be more securely fitted into the recess 352. Therefore, the developing cartridge 28 can be more reliably attached to the laser printer 1.
In the laser printer 1 including such a process cartridge 20, it is possible to ensure a smooth attachment / detachment operation of the developing cartridge 28, the drum cartridge 27, or the process cartridge 20 while reducing the size of the apparatus.
(5) Other Embodiments of Process Cartridge FIG. 28 is a side sectional view showing another embodiment of the process cartridge 20. In the drawings referred to in the following description, portions corresponding to the respective portions described above are given the same reference numerals.

The process cartridge 20 shown in FIG. 28 can hold only the developing cartridge 28 and detach the developing cartridge 28 with respect to the drum cartridge 27. With the developing cartridge 28 mounted on the drum cartridge 27, The drum 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).
(5-1) Configuration of Developer Cartridge FIG. 29 is a perspective view of the developer cartridge 28 shown in FIG. 28 as viewed from the upper front side (front side) diagonally upward, and FIG. It is the perspective view seen from the bottom. FIG. 31 is a perspective view of the developing cartridge 28 shown in FIG.

As shown in FIG. 28, the developing cartridge 28 includes a supply roller 31 as a process member, a developing roller 32 as a developer carrier, an agitator 46, and a layer thickness regulating blade 33 as a first housing that houses a developing side housing. A body 29 is provided.
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 37 as a first extension.

The lower frame 34 connects the left side wall 38 and the right side wall 39 (see FIG. 29 or FIG. 30) 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 FIG. 29 or FIG. 30) 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. 31, stoppers 341 that are substantially L-shaped in 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. 32) 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. 32).

  As shown in FIG. 30, a plurality of ribs 311 for guiding the paper 3 are arranged in parallel on the lower surface of the rear lower wall portion 43 at intervals in the width direction. 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 paper of the rib 311 is formed. The contact surface with 3 is arranged substantially horizontally.

  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 portion 84 is formed in a convex shape downward so that a later-described protrusion 118 of the drum cartridge 27 can contact and be positioned, and as shown in FIG. 30, the positioning portion 84 is spaced apart from each other in the width direction. One is provided.

Further, a lower partition 55 that protrudes upward in a substantially triangular shape is formed along the width direction at the boundary between the rear lower wall 43 and the front lower wall 44.
As shown in FIG. 29, the upper wall 41 has a flat plate shape wider than the facing distance 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 FIG. 28, an upper surface opening 49 having a substantially rectangular shape in plan view on which the upper frame 35 is mounted is formed in the upper wall 41 at a position corresponding to the toner storage chamber 30.

A blade support portion 57 protruding downward is formed at the rear end portion of the upper wall 41 along the width direction.
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 in a planar shape (a flat shape that is substantially free of irregularities in appearance).

The upper front wall 42 has a plate shape as shown in FIGS. 29 and 30 and is formed to be bent in a substantially right angle direction downward from the front end 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).
In addition, 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 that is substantially free of irregularities in appearance) and is flush with the front surface of the upper front wall 42. As a result, the upper front wall 42 including each protruding plate 51 is formed as a substantially U-shaped planar shape (a flat shape that is substantially free of irregularities in appearance). Also, a left side wall extension 52 and a right side wall extension 53, which will be described later, 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. Since the gear cover 77 and the gear mechanism 45 have the same configuration in the case of the developing cartridge 28 shown in FIG. 4 and the case of the developing cartridge shown in FIG. 28, the description of these configurations is omitted here. .

  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. 28, 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 FIG. 29 and FIG. 30, 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, the 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 portion of the developing roller 32 functions as a developing roller electrode 76 as a developing electrode with which a developing roller contact 175 described later contacts.

  The upper frame 35 has a substantially rectangular flat plate shape as shown in FIG. 29, and is provided so as to close the upper surface opening 49 of the lower frame 34 and cover the lower frame 34 as shown in FIG. . 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, an internal space behind the upper partition plate 56 and the lower partition portion 55 is defined as the developing chamber 36, and an internal space ahead of the upper partition plate 56 and the lower partition portion 55 is defined. The toner chamber 30 is defined, and the developing chamber 36 and the toner chamber 30 are formed in 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. 29 and 30, 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 central portion 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. It is formed so as to have a space.
Each configuration of the supply roller 31, the developing roller 32, the agitator 46, and the layer thickness regulating blade 33 and the configuration for supporting and driving them are the case of the developing cartridge 28 shown in FIG. 4 and the case of the developing cartridge 28 shown in FIG. Therefore, the description thereof is omitted here.
(5-2) Configuration of Drum Cartridge FIG. 32 is a perspective view of the drum cartridge 27 shown in FIG. 28 as viewed from the front side (front side) obliquely from the upper left side, and FIG. FIG. 34 is a perspective view of the drum cartridge 27 as seen from diagonally below the back side (rear side).

  As shown in FIGS. 28 and 32, 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 configurations of the photosensitive drum 92, the scorotron charger 93, the transfer roller 94, and the cleaning brush 95, and the configuration for supporting and driving them are the same as those of the drum cartridge 27 shown in FIG. 3 and the drum cartridge 27 shown in FIG. Since it is the same as the case, description thereof will be omitted here.
The drum-side casing 91 is made of, for example, a resin material such as polystyrene. As shown in FIG. 32, the left-side wall 96 and 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 a lower front wall 99 and a 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 arranged so that the inner surfaces thereof face each other in the axial direction of the photosensitive drum 92, and the rear side wall portion 105 having a substantially bow shape in a side view and a front portion having a substantially rectangular shape in a side view. A side wall 106 and an extended side wall 107 as a second side wall having a substantially rectangular shape when viewed from the side are successively formed from the rear side toward the front side.
FIG. 35 is a left side view of the drum cartridge 27.

  As shown in FIG. 35, 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. 34, 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 a transfer contact 272 described later.

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. 35, 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 so as 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 so as 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 edges 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. 32, a left clamping portion 210 that clamps an upper end portion of a protruding wall 117 described later 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 front lower corner of the fourth wall 111 and faces the upper end surface of the protruding 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 projecting wall 117 and facing the width direction with the protruding wall 117 interposed therebetween.

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 is a ground electrode 127 as a photosensitive electrode that contacts a ground contact 276 described later. Function as.

FIG. 36 is a right side view of the drum cartridge 27.
As shown in FIG. 36, 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. The first wall 108 is 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 part 115 is formed as an upper end edge of the front side wall part 106, and extends from the middle in the front-rear direction of the front side wall part 106 diagonally downward from the front to the rear, and then extends in a substantially horizontal flat shape. It is formed as follows.
The roller bearing insertion portion 116 is 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. 32, 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 FIGS. 28 and 32, the bottom wall 98 has a substantially V-shaped cross section. 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. 34, the rear bottom wall 193 has a substantially rectangular discharge port in the rear view for discharging the sheet 3 (see FIG. 1) passing 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. 28, a brush support portion 123 for supporting the cleaning brush 95 is provided at the front end portion of the brush support plate 223 in 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.

Further, in the vicinity of the boundary portion between the rear bottom wall portion 193 and the front bottom wall portion 194, as shown in FIG. 28, an inclined plate portion 331 that is inclined downward toward the front side is formed. A step is formed between the inclined plate portion 331 and the front bottom wall portion 194, and a paper entrance 332 for introducing the paper 3 into the drum cartridge 27 is formed at the step portion. .
Furthermore, as shown in FIG. 32, at the rear end portion of the inclined plate portion 331, 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. As shown in FIG. 36, the lower front wall 99 faces the upper front wall 42 in the vertical direction with the developing cartridge 28 mounted on the drum cartridge 27, and the front surface of the lower front wall 99 is the upper side. It is formed in a planar shape that is flush with the front surface of the front wall 42 (in appearance, a flat shape that is substantially free of irregularities).

Further, as shown in FIG. 32, the lower front wall 99 has projections protruding from the upper front wall 42 at both outer sides in the width direction than the lower notch 235 described later and in the vicinity of both ends. A receiving part 120 for receiving the plate 51 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, the protruding plates 51 are received by the receiving portions 120 as shown in FIG. 37.

As shown in FIG. 28, the rear upper wall 100 has a plate shape that is slightly inclined downward from the front to the rear, and the upper end edges of the rear side wall portions 105 of the left side wall 96 and the right side wall 97 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.

  Furthermore, as shown in FIG. 32, 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 clamping 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 projecting wall 117 from above, and has a substantially rectangular facing plate 215 in plan view. 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.

  And in this drum side housing | casing 91, as shown to FIG. 28 and FIG. 32, each rear side wall part 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 an up-down 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 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 has a pair of left and right side support portions 237 extending substantially vertically upward from both edges in the width direction of the lower notch portion 235, and is inclined slightly upward from the rear end edge of the lower notch portion 235 to the front side. A rear support portion 238 that extends and a top surface portion 239 that is substantially rectangular in a plan view and is laid between the upper ends of the side support portion 237 and the rear support portion 238 are integrally provided.
As shown in FIG. 33, 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.
As shown in FIG. 37, 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. 32, a substantially semicircular cutout 241 is formed on 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. 32, two protrusions 118 are provided at intervals in the width direction in the middle of the front bottom wall portion 194 in the front-rear direction. Each protrusion 118 is arranged to face each positioning portion 84 of the developing cartridge 28 mounted on the drum cartridge 27 and is formed so as to protrude upward in a semicircular cross section.

  As shown in FIG. 33, 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.

As shown in FIG. 32, the developer cartridge housing portion 103 has a toner empty sensor (see FIG. 32) on the left side wall 96 and the right side wall 97 at positions facing the toner detection windows 85 of the developer cartridge 28 in the width direction. A toner passage window 101 for passing light (not shown) is provided.
Further, as shown in FIG. 32, 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 a developing portion. 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. The pressing portion 149 and the drum-side boss 150 have the same configuration in the case of the drum cartridge 27 shown in FIG. 3 and in the case of the drum cartridge 27 shown in FIG. 28. Omitted.

Further, as shown in FIG. 33, 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 arranged to face the lower registration roller 14 in the vertical direction in a state where the drum cartridge 27 is 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.
(5-3) Process Cartridge FIG. 37 is a perspective view of the process cartridge 20 as viewed from the upper left side of the process cartridge 20 and FIG. 38 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. 37, 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. As shown in FIGS. 37 and 38, 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 this process cartridge 20, it is possible to hold only the development side handle 203 by putting the finger on the finger hooking portion 208 of the development side handle 203 through the notch 241, and the development cartridge 28 is attached to the drum cartridge 27. It can be made to attach or detach.
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.
Further, since the contact prevention portions 225 having a substantially triangular shape in the rear view and the bottom view are formed at both end portions of the lower surface of the brush support plate 223, the sheet 3 discharged from the discharge port 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.

Further, in this drum cartridge 27, the contact entry preventing rib 209 is provided along the rear end edge of the transfer electrode opening 142, so that the process cartridge 20 is mounted on the main casing 2 and the transfer contact described below is provided. When the contact 272 contacts the transfer electrode 137, the transfer contact 272 can be guided well, and the transfer contact 272 can be prevented from entering the gap between the transfer electrode opening 142 and the transfer electrode 137. it can. Therefore, a reliable connection between the transfer contact 272 and the transfer electrode 137 can be achieved.
(6) Configuration of Left Frame of Laser Printer FIG. 39 is an inner side view of the left frame 167 of the laser printer 1 to which the process cartridge 20 is mounted.

  As shown in FIG. 39, the inner surface (the surface facing the process cartridge 20) of the left frame 167 is disposed on the left side surface of the process cartridge 20 when the process cartridge 20 is mounted on the main body casing 2. The wire electrode 131 (see FIG. 35), the transfer electrode 137 (see FIG. 35), the developing roller electrode 76 (see FIG. 37), the grid electrode 132 (see FIG. 35), and the cleaning electrode 148 (see FIG. 35), respectively. A wire contact 271, a transfer contact 272, a developing roller contact 273, a grid contact 274, and a cleaning contact 275 that are disposed at positions and are in contact with the respective electrodes are provided.

The wire contact 271 is formed by bending a wire in a substantially U shape in plan view, and is connected to the wire contact portion 170 (see FIG. 24) via wiring.
The transfer contact 272 is formed by bending a wire in a substantially U shape in plan view, and is disposed below the wire contact 271 in the vertical direction. The transfer contact 272 is connected to the transfer contact portion 172 (see FIG. 24) via wiring.

The developing roller contact 273 is formed by bending a wire in a substantially triangular shape when viewed from the side, and is disposed obliquely below the front side of the wire contact 271 and obliquely above the front side of the transfer contact 272. The developing roller contact 273 is connected to the developing roller contact portion 173 (see FIG. 24) via wiring.
The grid contact 274 is formed by bending a wire in a substantially U shape in a plan view and is disposed obliquely below the rear side of the wire contact 271. The grid contact 274 is connected to the grid contact portion 169 (see FIG. 24) via wiring.

The cleaning contact 275 is formed by bending a wire in a substantially U shape in a plan view, and is disposed obliquely below the rear side of the grid contact 274 and obliquely above the rear side of the transfer contact 272. The cleaning contact 275 is connected to a cleaning contact portion 168 (see FIG. 24) via wiring.
Further, a ground contact 276 with which the ground electrode 127 abuts when the process cartridge 20 is mounted on the main body casing 2 is provided on the inner side surface of the left frame 167. The ground contact 276 is formed by bending the wire in a substantially triangular shape when viewed from the side, and is opposed to the ground electrode 127 disposed on the left side surface of the process cartridge 20, and is a position between the wire contact 271 and the transfer contact 272. Arranged between. The ground contact 276 is connected to the ground contact portion 171 (see FIG. 24) via wiring.

The configurations of the wire contact portion 170, the transfer contact portion 172, the developing roller contact portion 173, the grid contact portion 169, the cleaning contact portion 168, and the ground contact portion 171 and the voltages applied thereto are shown in FIG. 28 and the process cartridge 20 shown in FIG. 28, the description thereof will be omitted here.
A coupling member 73 is disposed on the inner surface of the left frame 167 in the vicinity of the upper portion of the developing roller contact 273 and in front of the wire contact 271 in the horizontal direction.

  Further, on the inner surface of the left frame 167, when the process cartridge 20 is mounted on the main casing 2 behind the transfer contact 272 and the ground contact 276 and below the grid contact 274, the process cartridge 20 ( A drum gear 321 that meshes with a drum drive gear 191 (see FIG. 34 or 35) provided in the drum cartridge 27) is disposed.

  Further, on the inner side surface of the left frame 167, the toner passage formed on the left side wall 96 of the drum-side casing 91 is in front of the developing roller contact 273 and the process cartridge 20 is mounted on the main casing 2. A toner empty sensor 371 for detecting an empty state of toner stored in the developing cartridge 28 (toner storage chamber 30) is disposed at a position facing the window 101 (see FIG. 32) in the width direction. The toner empty sensor 371 includes a pair of a light emitting element and a light receiving element, and one of the light emitting element and the light receiving element is disposed on the left frame 167.

  Further, a registration roller pressing spring 372 for pressing the left shaft end portion of the registration roller 14 held by the process cartridge 20 downward with the process cartridge 20 mounted on the front side of the toner empty sensor 371. Is arranged. The registration roller pressing spring 372 is a torsion spring and is supported by a shaft 373 projecting inward in the width direction from the left frame 167, and one end thereof is directed obliquely upward to the front side along the electrode guide surface 322 described below. The other end portion is provided so as to extend obliquely downward on the front side.

  Also, a new article detection actuator 374 having a substantially V shape in a side view is disposed between the toner empty sensor 371 and the registration roller pressing spring 372 in the front-rear direction and above the toner empty sensor 371 and the registration roller pressing spring 372. Has been. The new article detection actuator 374 is swingably supported by a shaft 375 protruding inward in the width direction from the left frame 167, and a lower end portion is always urged forward by a spring (not shown).

  Furthermore, on the inner side surface of the left frame 167, an electrode guide surface 322 for guiding the ground electrode 127 and the developing roller electrode 76 when the process cartridge 20 is attached to the main body casing 2 and a ground contact 276 are provided. A ground electrode receiving portion 323 that receives the ground electrode 127 in a state where the process cartridge 20 is mounted on the main body casing 2 is formed.

  The electrode guide surface 322 is an inclined surface whose rear side is inclined downward from the upper part of the front end of the left frame 167 toward the ground electrode receiving part 323 (drum gear 321), and the rear end is continuous with the ground electrode receiving part 323. . The electrode guide surface 322 is formed so as to cross the developing roller contact 273 and the ground contact 276 in a side view, and the developing roller contact 273 and the ground contact 276 protrude upward from the electrode guide surface 322. It is provided as follows.

  When the process cartridge 20 is mounted, the ground electrode 127 guided by the electrode guide surface 322 gets over the developing roller contact 273 while pushing the developing roller contact 273 downward, and further pushes the ground contact 276 downward. Overcoming the ground contact 276, it is received by the ground electrode receiving portion 323. When the ground electrode 127 is received in the ground electrode receiving portion 323, the ground electrode 127 is pressed obliquely upward on the rear side by the spring property of the ground contact 276. As a result, the ground electrode 127 is prevented from being detached from the ground electrode receiving portion 323, and the ground contact 276 is reliably brought into contact with the ground electrode 127.

  Further, the developing roller electrode 76 guided by the electrode guide surface 322 gets over the developing roller contact 273 while pushing the developing roller contact 273 downward, and when the mounting of the process cartridge 20 is completed (the earth electrode 127 receives the earth electrode). When the developing roller contact 273 comes into contact with the front side obliquely downward, the developing roller contact 273 is pushed upward and obliquely upward by the spring property of the developing roller contact 273. As described above, the developing roller contact 273 is arranged so as to come into contact with the developing roller electrode 76 from the obliquely lower front side when the process cartridge 20 is mounted. Compared with the configuration arranged so as to abut, the distance between the developing roller contact 273 and the wire contact 271 can be widened, and leakage between the developing roller contact 273 and the wire contact 271 can be prevented.

  Further, when a new developing cartridge 28 (process cartridge 20) is attached, a new article detecting lever 302 (see FIG. 37) of the new article detector 301 provided in the developing cartridge 28 is in the middle of the attaching process. The lower end of the new actuator 374 abuts against the lower end of the 374 and is pressed rearward by the new detection lever 302. As a result, the new article detection actuator 374 rotates counterclockwise in the figure, and based on the rotation of the new actuator 374, it is detected that the developing cartridge 28 is new. On the other hand, the new product detection lever 302 of the new product detector 301 is moved from one end of the lever projection hole to the other end when the development cartridge is used for the first time. The new article detection lever 302 does not contact the new article detection actuator 374, and the new article detection actuator 374 does not rotate. Based on this, it is possible to detect that the mounted developing cartridge 28 is an old product.

  When the process cartridge 20 is mounted, the toner passing window 101 and the toner empty sensor 371 formed on the left side wall 96 of the drum-side casing 91 face each other in the width direction. Further, the lower end portion of the registration roller pressing spring 372 comes into contact with the left shaft end portion of the registration roller 14 held by the process cartridge 20, and the left shaft end portion of the registration roller 34 is directed downward by the registration roller pressing spring 372. Pressed.

Further, a part of the lever driving force transmission gear 277 that is rotatably supported by the left frame 167 is exposed on the inner side surface of the left frame 167 at the front lower end. When the paper feed tray 9 (see FIG. 1) is attached to the main casing 2, an input gear (not shown) provided in the paper feed tray 9 meshes with the lever driving force transmission gear 277. When a driving force is input from the lever driving force transmission gear 277 to the input gear, the lever 17 (see FIG. 1) is rotated by the driving force, and the lever 17 lifts the front end portion of the paper pressing plate 15. At this time, the lever driving force transmission gear 277 applies a force for urging the paper feeding tray 9 in the mounting direction to the input gear, so that the paper feeding tray 9 has a lever driving force transmission gear 277 and a tray lock described later. Due to the cooperation with the piece 283, separation from the main casing 2 is restricted.
(7) Configuration of Right Frame of Laser Printer FIG. 40 is an inner side view of the right frame of the laser printer 1 to which the process cartridge 20 is mounted.

The main casing 2 is provided with a right frame 281 arranged to face the process cartridge 20 mounted on the main casing 2 on the right side.
On the inner side surface of the right frame 281, a shaft guide surface 361 for guiding the right shaft ends of the drum shaft 125 and the developing roller shaft 64 when the process cartridge 20 is attached to the main body casing 2, and the main body casing 2 A drum bearing insertion portion 362 that receives the right shaft end portion 7 of the drum shaft 125 in a state where the process cartridge 20 is mounted is formed.

  The shaft guide surface 361 and the drum bearing receiving portion 362 are formed so as to face the electrode guide surface 322 and the ground electrode receiving portion 323 of the left frame 167 in the width direction of the main body casing 2, respectively. That is, the shaft guide surface 361 is formed as an inclined surface whose rear side is inclined downward from the upper front end of the right frame 281 toward the drum bearing insertion portion 362, and the rear end thereof is continuous with the drum bearing insertion portion 362.

  When the process cartridge 20 is mounted, the ground electrode 127 (the left shaft end portion of the drum shaft 125) and the developing roller electrode 76 (the left shaft end portion of the developing roller shaft 64) are guided to the electrode guide surface 322 of the left frame 167. On the other hand, the right shaft end portions of the drum shaft 125 and the developing roller shaft 64 are guided by the shaft guide surface 361. At the same time as the ground electrode 127 is received by the ground electrode receiving portion 323, the right shaft end portion of the drum shaft 125 is received by the drum bearing receiving portion 362.

  Further, on the inner side surface of the right frame 281, the toner passage formed on the right side wall 97 of the drum-side casing 91 is in front of the developing roller contact 273 and the process cartridge 20 is mounted on the main casing 2. Of the light emitting elements and the light receiving elements constituting the toner empty sensor 371, an element different from the element disposed on the left frame 167 is disposed at a position facing the window 101 (see FIG. 32) in the width direction.

  Further, a registration roller pressing spring 381 for pressing the right shaft end of the registration roller 14 held by the process cartridge 20 downward in a state where the process cartridge 20 is mounted on the front side of the toner empty sensor 371. Is arranged. The registration roller pressing spring 381 is a torsion spring, is supported by a shaft 382 protruding inward in the width direction from the right frame 281, and one end portion of the registration roller pressing spring 381 extends forward and obliquely upward along the shaft guide surface 361. The other end is provided so as to extend obliquely downward on the front side.

  In a state where the process cartridge 20 is mounted, the toner passing window 101 and the toner empty sensor 371 formed on the right side wall 97 of the drum side casing 91 face each other in the width direction. Further, the lower end portion of the registration roller pressing spring 381 comes into contact with the right shaft end portion of the registration roller 14 held in the process cartridge 20, and the right shaft end portion of the registration roller 34 is directed downward by the registration roller pressing spring 381. Pressed.

In addition, a concave portion 282 that is recessed outward in the width direction is formed on the inner side surface of the right frame 281 at the front lower end, and the paper feed tray 9 (see FIG. 1) is detached in the concave portion 282. A tray lock piece 283 is provided as a lock mechanism for preventing the above.
The tray lock piece 283 includes a curved arm 284 that extends in the front-rear direction and is curved so that the tip end faces the outside of the recess 282, and a contact portion 285 provided at the tip of the curved arm 284. A base end portion of the bending arm 284 is swingably attached to a shaft 286 extending in the vertical direction in the recess 282. Further, a spring (not shown) is connected to the bending arm 284, and the spring is always elastically biased in a direction in which the contact portion 285 protrudes out of the recess 282.

  When the paper feed tray 9 is attached to the main casing 2, a lock piece locking portion (not shown) that bulges from the right side surface of the paper feed tray 9 comes into contact with the contact portion 285 of the tray lock piece 283, The lock piece 283 is pressed in a direction in which the contact portion 285 is retracted into the recess 282 against the biasing force of a spring (not shown) as the lock piece engaging portion moves. Then, when the lock piece locking portion gets over the contact portion 285, the tray lock piece 283 is returned to the direction in which the contact portion 285 protrudes from the recess 282 by the biasing force of a spring (not shown), and the contact portion 285 is moved. It is locked from the front side of the lock piece locking portion. Thereby, undesired detachment of the sheet feeding tray 9 from the main body casing 2 can be prevented.

On the inner side surface of the right frame 281, a pressing plate that fits into a ground connection hole (not shown) formed on the right side surface of the paper feed tray 9 when the paper feed tray 9 is attached to the main body casing 2. A ground contact 287 is provided so as to protrude.
Further, the right frame 281 is provided with a fan 288 for dissipating heat from the process cartridge 20 and the fixing unit 21 to the outside of the main casing 2 at the center in the front-rear direction of the upper end portion. The fan 288 is arranged so that the right frame 281 communicates with the inner side in the width direction and the outer side in the width direction.
(8) Other Embodiments of Mechanism for Advancing and Retracting Coupling Member FIG. 41 is a side view showing another embodiment of the coupling member 73, and (a) Shows the advancing state of the coupling member 73, and (b) shows the retracted state of the coupling member 73.

The left frame 167 is provided with a coupling member 73 movably connected to a connection hole 74 (see FIG. 37) of the input gear 68 and an arm 291 for moving the coupling member 73 forward and backward.
The arm 291 is integrally provided with an arm portion 292 extending along the front-rear direction and a cam portion 293 provided at the rear end portion of the arm portion 292.

The cam portion 293 is formed with a long hole extending in the front-rear direction through which the coupling member 73 is inserted, and a retracting portion 294 formed thick in the width direction is provided around the rear end portion of the long hole. It has been. Further, an advancing portion 295 that is formed thin in the width direction is provided around the front end portion of the long hole.
The arm 291 is supported so as to be movable in the front-rear direction along the left frame 167 in a state where the coupling member 73 is inserted through the long hole at the rear end. The arm 291 is provided so as to move in the front-rear direction in conjunction with opening and closing of the front cover 7.

  The coupling member 73 is disposed to face the connection hole 74 of the input gear 68 of the process cartridge 20 mounted on the main casing 2 in the width direction. A rotational driving force from a motor (not shown) provided in the main body casing 2 is input to the coupling member 73. Further, the coupling member 73 is always urged toward the inner side in the width direction, that is, toward the connecting hole 74 by an urging spring (not shown).

  When the front cover 7 is opened when the process cartridge 20 is attached to or detached from the main casing 2, the arm 291 moves forward in conjunction with the opening of the front cover 7, as shown in FIG. 41 (b). The retracting portion 294 engages with the coupling member 73. Then, the coupling member 73 retreats from the connection hole 74 of the input gear 68 against the urging force of the urging spring.

Further, when the front cover 7 is closed after the process cartridge 20 is attached to the main casing 2, the arm 291 moves backward in conjunction with the closing of the front cover 7, as shown in FIG. The advancing portion 295 engages with the coupling member 73. Then, the coupling member 73 advances into the connection hole 74 of the input gear 68 by the urging force of the urging spring and is coupled so as not to be relatively rotatable. As a result, the driving force from the coupling member 73 is transmitted to the input gear 68, and the supply roller 31, the developing roller 32, and the agitator 46 are rotated by the driving force transmitted to the input gear 68.
(9) Dimensional relation of each part of process cartridge FIGS. 42 to 47 are a plan view, a rear view, a front view, a left side view, a bottom view, and a sectional view showing dimensions of each part of the drum cartridge 27 shown in FIG. is there. 42 corresponds to the diagram when the drum cartridge 27 is viewed from above in FIG. 32, and FIG. 43 corresponds to the diagram when the drum cartridge 27 is viewed from the back side in FIG. 33 corresponds to the diagram when the drum cartridge 27 is viewed from the front side in FIG. 33, FIG. 45 corresponds to FIG. 35, and FIG. 46 is when the drum cartridge 27 is viewed from the back side in FIG. 47 corresponds to the drawing in which the developing cartridge 28 is removed from FIG.

  The specific dimensional relationship of each part of the drum cartridge 27 shown in FIG. 28 is as shown in FIGS. 42 to 47 and Table 1, Table 2, Table 3, and Table 4 below. 42 to 47, reference numerals are not assigned to the respective parts, but in order to clarify the correspondence between the respective parts shown in FIG. 42 to FIG. 47 and the corresponding parts shown in FIG. In Tables 1 to 4, the reference numerals assigned to the members in the drawings corresponding to the drawings in FIGS. 42 to 47 are used.

The units of numerical values shown in Tables 1 to 4 above are millimeters (mm) except for angles.
Note that the dimension is defined with the drum shaft 125 (ground electrode 127) as a reference position in this way, when the position of the drum shaft 125 in the main body casing 2 deviates from the normal position. This is because poor contact with H.276 may occur.

  48 to 52 are a plan view, a rear view, a left side view, a bottom view, and a cross-sectional view showing the dimensions of each part of the developing cartridge shown in FIG. 48 corresponds to the view when the developing cartridge 28 is viewed from above in FIG. 29, and FIG. 49 corresponds to the view when the developing cartridge 28 is viewed from the back side in FIG. 29 corresponds to a view when the developing cartridge 28 is viewed from the left side in FIG. 29, FIG. 51 corresponds to a view when the developing cartridge 28 is viewed from the back side in FIG. 30, and FIG. 28 corresponds to a view in which the drum cartridge 27 is removed.

  The specific dimensional relationship of each part of the developing cartridge 28 shown in FIG. 28 is as shown in FIGS. 48 to 52 and Table 5, Table 6, Table 7 and Table 8 below. 48 to 52, reference numerals are not assigned to the respective parts, but in order to clarify the correspondence between the respective parts shown in FIG. 48 to FIG. In Tables 5 to 8, the reference numerals assigned to the members in the drawings corresponding to the drawings in FIGS. 48 to 52 are used.

The units of the numerical values shown in Tables 5 to 8 are millimeters (mm) excluding the angle.
Note that the dimensions are defined with the input gear 68 as a reference position in this way, because the coupling member 73 and the input gear 68 are coupled when the position of the input gear 68 in the main body casing 2 deviates from the normal position. This is because there is a possibility of causing a defect.

  As is clear from this dimensional relationship, the thickness (T20 + T23) at the position of the developing chamber 36 of the developing side housing 29 (the position where the developing chamber 36 is formed in the developing side housing 29) is the position of the toner containing chamber 30. It is formed to be smaller than the thickness (T21 + T22) at (the position where the toner storage chamber 30 is formed in the development side housing 29). Since the developing cartridge 28 is mounted on the main casing 2 such that the side on which the developing chamber 36 is provided is disposed on the inner side of the main casing 2, the position of the developing chamber 36 in the developing casing 29 is determined. Is formed smaller than the thickness at the position of the toner storage chamber 30, so that the developing cartridge 28 can be smoothly attached to and detached from the main casing 2.

Further, the thickness at the position of the toner storage chamber 30 is defined based on the positioning portion 84. Therefore, the positioning portion 84 can be prevented from interfering when the developing cartridge 28 is attached to and detached from the main casing 2. As a result, smoother attachment / detachment of the developing cartridge 28 can be achieved.
Furthermore, the thickness of the development side housing 29 at the position of the developing chamber 36 is defined with reference to the rib 311 disposed on the lower surface of the rear lower wall portion 43 of the development side housing 29. Therefore, the rib 311 can be prevented from interfering when the developing cartridge 28 is attached to and detached from the main casing 2. As a result, smoother attachment / detachment of the developing cartridge 28 can be achieved.

  In addition, the height of the rib 311 decreases from the developing chamber 36 side (rear side) having a relatively small thickness toward the toner containing chamber 30 side having a relatively large thickness, and the developing cartridge 28 is moved to its side. When the top surface is horizontal and attached to the main body casing 2, the contact surface of the rib 311 with the paper 3 is formed to be substantially horizontal. Therefore, the paper 3 can be guided well.

  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. FIG. 2 is a side sectional view of a main part of a process cartridge of the laser printer shown in FIG. 1. FIG. 2 is a side sectional view of a main part of a developing cartridge of the laser printer shown in FIG. FIG. 5 is a perspective view of the developing cartridge shown in FIG. 4 as viewed from the front side. FIG. 5 is a plan view of the developing cartridge shown in FIG. 4. It is the perspective view seen from the back side of the developing cartridge shown in FIG. FIG. 5 is a left side surface of the developing cartridge shown in FIG. 4 and shows a state where a gear cover is attached. FIG. 5 is a left side view of the developing cartridge shown in FIG. 4 and shows a state where the gear cover is removed. 5 is a right side surface of the developing cartridge shown in FIG. FIG. 4 is a side cross-sectional view showing a main part of a drum cartridge of the process cartridge shown in FIG. 3. It is the perspective view seen from the front side of the drum cartridge shown in FIG. FIG. 4 is a perspective view seen from the front side of the process cartridge shown in FIG. 3. FIG. 4 is a perspective view of the process cartridge shown in FIG. 3 viewed from the back side. FIG. 4 is a perspective view seen from the bottom side of the process cartridge shown in FIG. 3. FIG. 4 is a plan view of the process cartridge shown in FIG. 3. FIG. 4 is a left side view of the process cartridge shown in FIG. 3. FIG. 4 is a right side view of the process cartridge shown in FIG. 3. FIG. 4 is a front view of the process cartridge shown in FIG. 3. It is the top view which looked at the developing roller and supply roller shown in FIG. FIG. 4 is a process diagram showing a state in which the developing cartridge is mounted on the drum cartridge in the process cartridge shown in FIG. 3, wherein (a) shows a state where the developing-side boss is located above the pressing member, and (b) shows The state where the development-side boss is in contact with the guide surface of the pressing member, (c) is the state where the development-side boss is in contact with the boundary between the guide surface and the fixed surface of the pressing member, and (d) is the development side. The state in which the boss is in contact with the fixed surface of the pressing member is shown. FIG. 12 is a front sectional view of the drum cartridge shown in FIG. 11. FIG. 11 is a left end portion of the transfer roller of the drum cartridge shown in FIG. 11, (a) is a cross-sectional view, (b) is a perspective view in the middle of assembly of the transfer electrode, and (c) is assembly of the transfer electrode. The perspective view of the completion state is shown respectively. FIG. 2 is a plan view of the main part of the laser printer shown in FIG. 1 in a state where a process cartridge is mounted. FIG. 5 is a side view for explaining the advancing / retreating operation of the coupling member when the process cartridge is mounted, where (a) shows the retracted state of the coupling member, and (b) shows the advanced state of the coupling member. Show. FIG. 4 is a front view of a main part for explaining the forward / backward movement of the coupling member when the process cartridge is mounted, where (a) shows the retracted state of the coupling member, and (b) shows the advancement of the coupling member. Indicates the state. FIG. 5 is a side cross-sectional view of a main part showing a state where the developing cartridge shown in FIG. 4 is placed so as to stand on the floor. It is a sectional side view which shows other embodiment (The aspect by which the drum side handle was provided in the drum cartridge) of the process cartridge. FIG. 29 is a perspective view of the development cartridge shown in FIG. FIG. 29 is a perspective view of the developing cartridge shown in FIG. 28 as viewed obliquely from the lower right on the front side. FIG. 29 is a perspective view of the developing cartridge shown in FIG. 28 as viewed obliquely from the upper left side on the back side. FIG. 29 is a perspective view of the drum cartridge shown in FIG. 28 as viewed from diagonally above and to the left on the front side. It is the perspective view which looked at the drum cartridge shown in FIG. 28 from the front side diagonally downward. It is the perspective view which looked at the drum cartridge shown in FIG. 28 from the back side left diagonally downward. FIG. 29 is a left side view of the drum cartridge shown in FIG. 28. FIG. 29 is a right side view of the drum cartridge shown in FIG. 28. FIG. 29 is a perspective view of the process cartridge shown in FIG. FIG. 29 is a perspective view of the process cartridge shown in FIG. 28 as viewed from diagonally downward on the front side. FIG. 2 is an inner side view of a left frame of the laser printer shown in FIG. 1. FIG. 2 is an inner side view of a right frame of the laser printer shown in FIG. 1. It is a side view which shows other embodiment of a coupling member, Comprising: (a) shows the advancing state of a coupling member, (b) shows the retracted state of a coupling member. It is a top view which shows the dimension of each part of the drum cartridge shown in FIG. It is a rear view which shows the dimension of each part of the drum cartridge shown in FIG. It is a front view which shows the dimension of each part of the drum cartridge shown in FIG. It is a left view which shows the dimension of each part of the drum cartridge shown in FIG. FIG. 29 is a bottom view showing dimensions of each part of the drum cartridge shown in FIG. 28. It is sectional drawing which shows the dimension of each part of the drum cartridge shown in FIG. 28 (sectional drawing when cut | disconnected by the AA cutting line shown in FIG. 42). FIG. 29 is a plan view showing dimensions of each part of the developing cartridge shown in FIG. 28. FIG. 29 is a rear view showing dimensions of each part of the developing cartridge shown in FIG. 28. FIG. 29 is a left side view showing dimensions of each part of the developing cartridge shown in FIG. 28. FIG. 29 is a bottom view showing dimensions of each part of the developing cartridge shown in FIG. 28. FIG. 49 is a cross-sectional view showing the dimensions of each part of the developing cartridge shown in FIG. 28 (cross-sectional view taken along the line BB shown in FIG. 48).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser printer 3 Paper 20 Process cartridge 29 Development side housing 30 Toner storage chamber 31 Supply roller 32 Development roller 33 Layer thickness control blade 38 Left side wall 39 Right side wall 45 Gear mechanism part 46 Agitator 47 Toner supply port 68 Input gear 76 Development roller Electrode 77 Gear cover 82 Bearing member 83 Color member 91 Drum side housing 92 Photosensitive drum 93 Scorotron charger 94 Transfer roller 95 Cleaning brush 96 Left side wall 97 Right side wall 108 First wall 109 Second wall 110 Third wall 112 Fifth wall 114 7th wall 127 Ground electrode 131 Wire electrode 132 Grid electrode 133 Transfer roller shaft 135 Transfer roller drive gear 137 Transfer electrode 139 Locking plate 140 Protruding portion 142 Transfer electrode opening portion 143 Transfer electrode receiving portion 147 Claw portion 14 8 Cleaning electrode 175 Development roller contact 209 Contact entry prevention rib

Claims (9)

In a process cartridge that is detachably attached to an image forming apparatus,
A housing,
A developing roller provided in the housing and carrying a developer;
A developing roller driving gear provided on the shaft of the developing roller, for transmitting a driving force to the developing roller;
A coupling portion that is inserted in the axial direction by an urging force of an urging spring from the outside of the developing roller in the axial direction; and a driving force is generated from the coupling member via the coupling portion. A driving force transmitting member that includes an input gear that is input, and that transmits the driving force input from the input gear to the developing roller driving gear;
A developing electrode for making an electrical connection from the image forming apparatus to the developing roller,
The housing is disposed opposite to the axial direction at a predetermined interval, and includes a first housing having two side walls that support the developing roller, and a second housing that is detachable from the first housing. With
The driving force transmitting member and the developing electrode are disposed on one of the side walls, and the developing electrode is provided on the downstream side with respect to the driving force transmitting member in the mounting direction of the process cartridge .
The process cartridge, wherein the developing electrode protrudes outward from the input gear in the axial direction .   2. The process cartridge according to claim 1, wherein the second housing is provided with a restricting member for restricting movement of the side wall due to input of a driving force from the image forming apparatus to the input gear.   The process cartridge according to claim 1, further comprising a holding portion that holds both the driving force transmission member and the developing electrode.   4. The process cartridge according to claim 1, wherein the driving force transmission member and the developing electrode are provided on a downstream side of a center portion in a mounting direction of the process cartridge. 5. In the developing cartridge that is detachably mounted on the image forming apparatus,
A first housing;
A developing roller provided in the first housing and carrying a developer;
A developing roller driving gear provided on the shaft of the developing roller, for transmitting a driving force to the developing roller;
A coupling portion that is inserted in the axial direction by an urging force of an urging spring from the outside of the developing roller in the axial direction; and a driving force is generated from the coupling member via the coupling portion. A driving force transmitting member that includes an input gear that is input, and that transmits the driving force input from the input gear to the developing roller driving gear;
A developing electrode for making an electrical connection from the image forming apparatus to the developing roller,
The first housing includes two side walls that are opposed to each other at a predetermined interval in the axial direction and support the developing roller.
The driving force transmission member and the development electrode is disposed on one of the side walls, in the mounting direction of the developing cartridge relative to the image forming apparatus is provided on the downstream side with respect to the developing electrode is a driving force transmitting member ,
The developing cartridge, wherein the developing electrode protrudes outward from the input gear in the axial direction .   The developing cartridge according to claim 5, further comprising a holding portion that holds both the driving force transmitting member and the developing electrode.   8. The developing cartridge according to claim 5, wherein the driving force transmitting member and the developing electrode are provided on a downstream side of a central portion in a mounting direction of the developing cartridge. 9.   An image forming apparatus comprising the process cartridge according to any one of claims 1 to 4 or the developing cartridge according to any one of claims 5 to 7. Provided to be able to advance and retreat with respect to the driving force transmission member, advance in the axial direction by the urging force of an urging spring, inserted into the connecting portion, and for inputting the driving force to the driving force transmission member The image forming apparatus according to claim 8, comprising a coupling member .

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