JP6788358B2 - Process cartridge and image forming equipment - Google Patents

Description

The present invention relates to a process cartridge and an image forming apparatus using the process cartridge.

Here, the process cartridge is a device in which a photoconductor drum, which is an image carrier, and a process means acting on the photoconductor drum are integrally formed into a cartridge and detachably attached to the image forming apparatus main body. is there. For example, a photoconductor drum and at least one of a developing means, a charging means, and a cleaning means as the process means are integrally formed into a cartridge.

The image forming apparatus is an image forming apparatus that forms an image on a recording medium by using an image forming method. Examples of the image forming apparatus include, for example, a copier, a printer (LED printer, laser beam printer, etc.), a facsimile apparatus, a word processor, and the like.

An electrophotographic image forming apparatus for developing an electrostatic latent image formed on an image carrier by a developing means to make it a visible image generally requires replenishment of a developer and maintenance of various process means. In order to facilitate the replenishment and maintenance of the developing agent, a process cartridge in which a photoconductor drum, a developing means, and the like are collectively made into a cartridge and which can be attached to and detached from the image forming apparatus main body has been put into practical use.

As the process cartridge, as described in Patent Document 1, an image carrier unit that holds an image carrier, cleaning means, etc., and a developing unit that holds a developer carrier are bonded by a coupling member. Is generally known. In this process cartridge, the developing unit is rotatably supported by the image carrier unit with the coupling member as the axis of rotation, and the developing unit is rotatably supported by the weight of the developing unit or by urging means such as a spring. Being urged to the side. The developer carrier in the developing unit can come into contact with the image carrier in the image carrier unit with a constant pressing force, and the image forming apparatus can stably form an image.

Further, like the process cartridge described in Patent Document 2, a configuration in which the developing unit is slidably supported in the image carrier unit in the horizontal direction has been proposed. In this configuration, it is not necessary to put the weight of the developer accommodating portion on the image carrier unit.

JP 2012-78793 JP-A-2002-40903

However, in the process cartridge described in Patent Document 1, since a large amount of the developer is stored in the developing unit at the initial stage of use, the weight of the developing agent is large, and therefore the weight of the developing unit is large. Therefore, a predetermined pressing force is obtained by a large moment force together with the urging means. Recently, it has been desired to reduce the cost per print, and as a result, the print life of the process cartridge has been increased, and the storage capacity of the developer in the developing unit has been increasing accordingly.

Further, since a predetermined pressing force must be secured even at the end of durability, the pressing force by the urging means must be a predetermined value or more regardless of the increase in the developer due to the change in the print life. From this point of view, when the capacity of the developer increases as the print life increases, an excessive pressure is applied at the initial stage of use to maintain a predetermined distance between the image carrier and the developer carrier. The spacer member for the purpose was deformed by excessive pressing force, which sometimes caused image distortion.

On the other hand, in the process cartridge described in Patent Document 2, since the developing unit is slidably supported by the image carrier unit in the horizontal direction, the change in the capacitance of the developing agent does not contribute to the above-mentioned pressing force. become. Therefore, the pressing force is applied only by the urging means, and the pressing force is kept constant.

However, in the configuration described in Patent Document 2, the pressing force may not be stable when the contact direction of the developer carrier with the image carrier is different from the slide direction of the developing unit. ..

The present invention has been made in consideration of the above problems, and an object of the present invention is to suppress fluctuations in the pressing force between the developer carrier and the image carrier due to fluctuations in the amount of the developer, and to support the developer on the image carrier. It is an object of the present invention to provide a process cartridge and an image forming apparatus capable of realizing a stable pressing force regardless of the contact direction of the body.

A typical configuration according to the present invention for achieving the above object is a process cartridge that can be attached to and detached from the image forming apparatus main body, in which an image carrier unit that rotatably holds the image carrier and a developer carrier are rotated. It has a developing unit that can be held, and the developing unit is movable with respect to the image carrier unit, and the developer carrier and the image carrier are provided so as to be detachable from each other. The image carrier unit has a first support portion and a second support portion, and the developing unit is supported by the first supported portion supported by the first support portion and the second support portion. It has a second supported portion , the first support portion is located closer to the image carrier than the second support portion, and the developer carrier can be brought into contact with and detached from the image carrier. The first supported portion is movably supported in the first direction, which is the direction in which the first supported portion has the longest moving distance with the movement of the developing unit. The second support portion is a second direction that intersects the first direction and has the longest movement distance among the directions in which the second supported portion can move with the movement of the developing unit. The second supported portion is movably supported in the direction, the first support portion and the second support portion receive a force in the gravity direction due to the weight of the developing unit, and the force in the gravity direction is the first support. The second support portion receives a larger force than the portion.

In the present invention, as described above, the developing unit is movably supported by the first support portion and the second support portion with respect to the image carrier unit, and the developer carrier is image-supported by the first support portion. The developing unit was supported in a direction that allows contact and detachment with respect to the body, and the developing unit was supported in a direction intersecting the contact and separation direction by the second support portion. Then, the gravity when supported is configured so that the second support portion receives a larger force than the first support portion. Therefore, fluctuations in the pressing force between the developer carrier and the image carrier due to fluctuations in the amount of the developer are suppressed, and stable pressing force is realized regardless of the contact direction of the developer carrier with the image carrier. can do.

It is a schematic view of the side surface of the drive side which shows the state which the process cartridge is positioned in the image formation apparatus main body of the image forming apparatus which concerns on embodiment to which this invention is applicable. It is sectional drawing of the image forming apparatus which concerns on embodiment to which this invention can apply. It is sectional drawing of the process cartridge which concerns on embodiment to which this invention is applied. It is a perspective view of the image forming apparatus main body which concerns on embodiment to which this invention is applied. It is a perspective view which shows the attachment / detachment of the process cartridge which concerns on embodiment to which this invention is applied to the image forming apparatus main body. It is an exploded perspective view explaining the drive side of the process cartridge which concerns on embodiment to which this invention is applied. It is an exploded perspective view explaining the non-driving side of the process cartridge which concerns on embodiment to which this invention is applied. It is a perspective view of the process cartridge which concerns on embodiment to which this invention is applied. It is a side view of the process cartridge for demonstrating the pressurization structure which concerns on embodiment to which this invention is applicable. It is sectional drawing of the process cartridge for demonstrating the pressurization structure which concerns on embodiment to which this invention is applied. It is a schematic diagram of the non-driving side side surface which shows the state which the process cartridge is positioned in the image forming apparatus main body of the image forming apparatus which concerns on embodiment to which this invention is applicable.

Next, a process cartridge according to an embodiment of the present invention and an image forming apparatus using the same will be described.

<Overall configuration of image forming device>
First, the overall configuration of the image forming apparatus will be described with reference to FIG. The image forming apparatus of FIG. 2 is a laser beam printer using electrophotographic technology in which the process cartridge B is detachably attached to the apparatus main body A. When the process cartridge B is mounted on the apparatus main body A, the exposure apparatus 3 is arranged at a position facing the electrophotographic photosensitive member drum (hereinafter, drum) 62 as an image carrier of the process cartridge B. Further, a sheet tray 4 containing a recording medium (hereinafter, sheet) P to be image-formed is arranged under the process cartridge B.

Further, the apparatus main body A includes a pickup roller 5a, a feeding roller pair 5b, a transport roller pair 5c, a transfer guide 6, a transfer roller 7, a transport guide 8, a fixing device 9, and a discharge along the transport direction D of the sheet P. The roller pair 10, the discharge tray 11, and the like are sequentially arranged. The fixing device 9 is composed of a heating roller 9a and a pressure roller 9b.

When forming an image, the peripheral surface of the drum 62, which rotates by applying a bias to the charging roller 66, is charged, and the exposure device 3 exposes the image according to the image signal to form an electrostatic latent image. It is made into a visible image by developing with toner.

In synchronization with the image formation, the sheet P is fed from the sheet tray 4 by the sheet transport means including the pickup rollers 5a and the like, and the developer image is transferred from the drum 62 to the sheet P by applying a bias to the transfer roller 7 at the transfer unit. Will be done. The sheet P is heated and pressurized in the fixing device 9 to fix the developer image, and then discharged to the discharge tray 11 by the discharge roller pair 10.

<Overall configuration of process cartridge>
As shown in FIG. 3, the process cartridge B has an image carrier unit 60 and a developing unit 20.

The image carrier unit 60 includes a drum 62, a charging roller 66, a cleaning member 77, a cleaning frame 71 that supports them, and a lid member 72 that is fixed to the cleaning frame 71 by welding or the like. In the image carrier unit 60, the charging roller 66 and the cleaning member 77 are respectively arranged in contact with each other on the outer peripheral surface of the drum 62.

The developing unit 20 includes a developing roller 32 as a developer carrier, a developing container 23 that supports the developing roller 32, a developing blade 42, and the like. A magnet roller 34 is provided in the developing roller 32. Further, in the developing unit 20, a developing blade 42 for regulating the toner layer on the developing roller 32 is arranged. Spacing members 38 are attached to both ends of the developing roller 32, and when the spacing members 38 and the drum 62 come into contact with each other, the developing roller 32 is held with a minute gap from the drum 62. Further, a blowout prevention sheet 33 for preventing toner from leaking from the developing unit 20 is provided at the edge of the bottom member 22 facing the developing roller 32 so as to come into contact with the developing roller 32. Further, the toner chamber 29 formed by the developing container 23 and the bottom member 22 is provided with a first transport member 43, a second transport member 44, and a third transport member 50. The first transport member 43, the second transport member 44, and the third transport member 50 agitate the toner contained in the toner chamber 29 and transport the toner to the toner supply chamber 28.

<Process cartridge attachment / detachment configuration>
Next, attachment / detachment of the process cartridge B to / from the apparatus main body A will be described with reference to FIGS. 4 and 5. In the following description, in the rotation axis direction of the drum 62, the side on which the drum 62 receives the driving force from the image forming apparatus main body is the driving side, and the opposite side is the non-driving side.

FIG. 4 is a perspective view of the apparatus main body A in which the opening / closing door 13 is opened in order to attach / detach the process cartridge B. FIG. 5 is a perspective view of the apparatus main body A and the process cartridge B in which the opening / closing door 13 is opened for attaching / detaching the process cartridge B.

An opening / closing door 13 is rotatably attached to the apparatus main body A. When the opening / closing door 13 is opened, the process cartridge insertion port 17 is provided in the non-driving side plate 16 provided on the non-driving side of the apparatus main body A. A guide rail 12 for mounting the process cartridge B on the apparatus main body A is provided in the process cartridge insertion port 17, and the process cartridge B is inside the apparatus main body A along the guide rail 12 in the direction of arrow C in FIG. It is attached to. Further, a drive shaft 14 for transmitting the drive is provided in the drive force receiving portion 63a (FIG. 6) provided in the process cartridge B. The drive shaft 14 is driven by a motor (not shown) of the device main body A, whereby the drum 62 coupled with the drive force receiving portion 63a rotates by receiving the driving force from the device main body A. Further, the charging roller 66 and the developing roller 32 are fed from a power feeding unit (not shown) of the apparatus main body A.

<Process cartridge support configuration>
The apparatus main body A is provided with a drive side plate 15 and a non-drive side plate 16 for supporting the process cartridge B. The drive side plate 15 is provided with an elongated hole 15c as a rotation stop portion that restricts the rotation of the drive side first support portion 15a, the drive side second support portion 15b, and the mounted process cartridge B with respect to the apparatus main body. ing. Further, the non-driving side plate 16 is provided with a non-driving side first support portion 16a and a non-driving side second support portion 16b.

Specifically, the support portion 73b (FIG. 6) provided on the drum bearing 73 of the process cartridge B is supported by the drive-side first support portion 15a and the drive-side second support portion 15b, and the drive-side drum side member 69 (FIG. 6) The boss 69f provided in FIG. 6) is supported by the elongated hole 15c. Further, the non-driving side first protrusion 71f (FIG. 7) and the non-driving side second protrusion 71g (FIG. 7) provided in the cleaning frame 71 of the process cartridge B are respectively the non-driving side first support portion 16a. The process cartridge B is supported by the apparatus main body A by being supported by the non-driving side second support portion 16b.

<Combined configuration of image carrier unit and developing unit>
Next, the coupling configuration of the image carrier unit 60 and the developing unit 20 of the process cartridge described above will be described.

As shown in FIGS. 6 and 7, the image carrier unit 60 is provided with a drum bearing 73 and a drum shaft 78 for rotationally supporting the drum 62. The drum 62 is rotatably supported by inserting the drum flange 63 provided on the drive side into the hole portion 73a of the drum bearing 73. The non-driving side has a configuration in which the drum shaft 78 is press-fitted into the hole 71c provided in the cleaning frame 71 to rotatably support the hole (not shown) of the non-driving drum flange 64. Further, the drive-side drum flange 63 is provided with a flange gear portion 63b for transmitting the drive to the developing roller gear 39 provided on the driving side of the developing roller 32.

A drive-side drum side member 69 for supporting the developing unit 20 and a non-drive-side drum side member 70 are provided on both ends of the cleaning frame 71. The drive-side drum side member 69 has a long hole portion 69d and a positioning hole 69c with respect to the boss 71a provided on the drive side of the cleaning frame body 71 and the support portion 73b of the drum bearing 73 attached to the cleaning frame body 71. By inserting it, it is fixed to the cleaning frame 71. The non-driving side drum side member 70 has a long hole portion 70d and a positioning hole with respect to the outer diameter portion 71e of the cylindrical boss into which the boss 71d provided on the non-driving side of the cleaning frame body 71 and the drum shaft 78 are inserted. By inserting 70c, it is fixed to the cleaning frame 71.

On the other hand, the developing unit 20 includes a bottom member 22, a developing container 23, a driving side developing side member 26, a non-driving side developing side member 27, a developing blade 42, a developing roller 32 and the like. Further, the developing roller 32 is rotatably attached to the developing container 23 by bearing members 37 provided at both ends.

The process cartridge B is formed by supporting the developing unit 20 with the image carrier unit 60 so as to be slidable by the driving side drum side member 69 and the non-driving side drum side member 70.

Specifically, a driving side developing side member 26 and a non-driving side developing side member 27 are arranged at both ends in the longitudinal direction of the developing unit 20. The drive-side developed side member 26 is formed with a developed first supported portion 26a as a first supported portion and a developed second supported portion 26b as a second supported portion. Further, the non-driving side developed side member 27 is formed with a developed third supported portion 27a as a first supported portion and a developed fourth supported portion 27b as a second supported portion.

The supported portion is supported by a support portion provided on the image carrier unit. Specifically, the developed first supported portion 26a engages with the first elongated hole 69a as the first supported portion provided in the drive-side drum side member 69 constituting the image carrier unit, and the developing second The supported portion 26b engages with the second elongated hole 69b as the second supporting portion. Further, the developed third supported portion 27a engages with the third elongated hole 70a as the first supported portion provided in the non-driving side drum side member 70 constituting the image carrier unit, and the developed fourth supported portion 27a is supported. The portion 27b engages with the fourth slotted hole 70b as the second support portion.

The developing unit 20 is supported by the image carrier unit 60 via the driving side drum side member 69 and the non-driving side drum side member 70.

Further, the first hole portion 46Ra of the drive side urging member 46R as the pressing means is hung on the boss 69e of the drive side drum side member 69, and the second hole portion 46Rb is hung on the boss 26c of the drive side development side member 26. ing.

Further, the first hole portion 46F of the non-drive side urging member 46F as the pressing means is hung on the boss 70e of the non-drive side drum side member 70, and the second hole portion 46Fb is the boss 27c of the non-drive side development side member 27. Is hung on.

In the present embodiment, the driving side urging member 46R and the non-driving side urging member 46F are formed of a tension spring, and the developing unit 20 is urged to the image carrier unit 60 by the urging force of the spring to develop. The roller 32 is securely pressed in the direction of the drum 62. Then, the developing roller 32 is held from the drum 62 at a predetermined interval by the spacing members 38 attached to both ends of the developing roller 32.

<Pressurization configuration of the developing roller to the drum>
Next, the pressurizing configuration of the developing roller 32 on the drum 62, which is also a feature of the present embodiment, will be described with reference to FIGS. 1, 8 to 10. Note that FIG. 1 is a schematic view showing a state in which the process cartridge B is positioned on the apparatus main body A when viewed from the drive side, and FIG. 8 is a perspective view of the process cartridge B. Further, FIG. 9 is a process cartridge B in a state where the process cartridge B is positioned on the apparatus main body A, and FIG. 10 is a cross-sectional view of the process cartridge B at this time.

First, the slide configuration of the developing unit 20 will be described. As shown in FIG. 8, the developing unit 20 is supported on the driving side by the driving side drum side member 69 fixed to the image carrier unit 60, and the non-driving side can be slid and moved by the non-driving side drum side member 70. It has a slidable configuration supported by. Therefore, the developed first supported portion 26a and the developed third supported portion 27a supported by the first elongated hole 69a and the third elongated hole 70a can be slidable in the directions of arrows E1a-E1b and E3a-E3b in FIG. It becomes. In other words, the first elongated hole 69a restricts the movement of the developing first supported portion 26a in the direction orthogonal to the direction of the arrows E1a-E1b and the axial direction of the developing roller 3. Similarly, the third elongated hole 70a restricts the movement of the developing third supported portion 27a in the direction orthogonal to the arrow E3a-E3b direction and the axial direction of the developing roller 3. On the other hand, the developed second supported portion 26b and the developed fourth supported portion 27b supported by the second elongated hole 69b and the fourth elongated hole 70b can be slidable in the directions of arrows E2a-E2b and E4a-E4b in FIG. It becomes. In other words, the second slot 69b restricts the movement of the developing second supported portion 26b in the vertical direction, which is the direction orthogonal to the arrow E2a-E2b direction and the axial direction of the developing roller 3. Similarly, the fourth slotted hole 70b restricts the movement of the developing fourth supported portion 27b in the vertical direction, which is a direction orthogonal to the arrow E4a-E4b direction and the axial direction of the developing roller 3.

Here, when the urging force by the driving side urging member 46R and the non-driving side urging member 46F is applied, each support portion slides in the directions of arrows E1a, E2a, E3a, and E4a, and the developing unit 20 carries an image. It will be urged by the body unit 60. At this time, the longitudinal directions of the first slot 69a and the third slot 70a are formed in a direction (first direction) in which the developing roller 32 can be brought into contact with and separated from the drum 62. This makes it possible to stably apply the force F (see FIG. 10) that the developing roller 32 presses against the drum 62 via the spacing member 38. Hereinafter, this force F is referred to as a pressing force.

<Relationship with the center of gravity of the developing unit>
Next, the mechanical relationship related to the above-mentioned pressurization configuration will be described. The drive side and the non-drive side have symmetrical shapes, and the drive side will be mainly described below.

As shown in FIG. 9, the development first supported portion 26a provided in the development unit 20 is arranged in the vicinity of the rotation axis of the development roller 32. On the other hand, the developing second supported portion 26b is arranged near the center of gravity 40 of the developing unit, and the center of gravity 40 of the developing unit is located between the developing first supported portion 26a and the developing second supported portion 26b. ing.

Further, the longitudinal direction of the second elongated hole 69b provided in the drive-side drum side member 69 intersects the longitudinal direction of the first elongated hole 69a (first direction = arrow E1a-E1b direction) (second direction). Direction = arrow E2a-E2b direction). In the present embodiment, in the state where the process cartridge B is positioned on the apparatus main body A (see FIG. 1), the second elongated hole 69b is formed so that the second direction is substantially parallel to the horizontal direction. It is formed. That is, the second elongated hole 69b is an elongated hole having a shape extending in the horizontal direction (arrow E2a direction), and is the inner peripheral surface of the second elongated hole 69b that comes into contact with the developed second supported portion 26b. The contact surface 69bb is a horizontal surface (parallel to the direction of arrow E2a). Then, with respect to the movement of the developing second supported portion 26b in the second slot 69b due to the movement of the developing unit 20, the distance at which the developing second supported portion 26b can move in the horizontal direction (arrow E2a direction). Is longer than the distance that can be moved in the vertical direction. Therefore, the direction in which the development second supported portion 26b can move with the movement of the development unit 20 and the longest movement distance (longitudinal direction of the second elongated hole 69b) is the horizontal direction (arrow E2a direction). is there.

The first elongated hole 69a is an elongated hole having a shape extending in the direction of the arrow E1a, and is a first contact surface 69aa which is an inner peripheral surface of the first elongated hole 69a that contacts the developed first supported portion 26a. Is a plane parallel to the direction of arrow E1a. Then, with respect to the movement of the development first supported portion 26a in the first slot 69a due to the movement of the developing unit 20, the distance at which the developing first supported portion 26a can move in the direction of arrow E1a is in the direction of arrow E1a. It is longer than the distance that can be moved in the direction orthogonal to the axial direction of the developing roller 3. Therefore, the direction in which the development first supported portion 26a can move with the movement of the development unit 20 and which has the longest movement distance (longitudinal direction of the first elongated hole 69a) is the arrow E1a direction.

In the above configuration, the weight M of the developing unit 20 is applied to the center of gravity 40 of the developing unit. Therefore, the force of the weight M of the developing unit 20 in the gravity direction is applied to the first contact surface 69aa of the first elongated hole 69a with which the developing first supported portion 26a abuts, and the developing second supported portion 26b abuts. It will be applied to the second contact surface 69bb of the second elongated hole 69b.

Here, in a state where the process cartridge B is positioned on the apparatus main body A, the horizontal distance from the center of gravity 40 of the developing unit to the developing first supported portion 26a is L1, and the developing second supported from the center of gravity 40 of the developing unit is L1. Let L2 be the horizontal distance to the portion 26b. At this time, as shown in FIG. 9, a reaction force F1 is applied to the first contact surface 69aa of the first elongated hole 69a that supports the developed first supported portion 26a, and the developed second supported portion 26b is supported. A reaction force F2 is applied to the second contact surface 69bb of the second elongated hole 69b.

In the present embodiment, the center of gravity 40 of the developing unit is located closer to the developing second supported portion 26b than the developing first supported portion 26a, and is formed so as to have a relationship of L1 >> L2. Therefore, the influence of the reaction force F1 on the pressing force F is very small. Further, since F1 << F2, most of the weight M of the developing unit 20 is received by the second contact surface 69bb of the second elongated hole 69b. However, since the second contact surface 69bb is formed in the horizontal direction, the reaction force F2 is applied in the direction perpendicular to the second contact surface 69bb. Therefore, the influence of the reaction force F2 on the pressing force F (see FIG. 10) is also small.

In the present embodiment, as described above, the influence of the reaction forces F1 and F2 generated by the weight M of the developing unit 20 on the pressing force F is very small, and the pressing force F is due to the drive side urging member 46R. The force generated by the urging force F3 becomes dominant. That is, F≈F3 (see FIG. 9), and even if the weight M of the developing unit 20 changes and the reaction forces F1 and F2 change, the influence on the pressing force F can be reduced. It becomes.

Further, as described above, the developing roller 32 is formed in the direction in which the developing roller 32 can be brought into contact with and separated from the drum 62 in the longitudinal direction of the first elongated hole 69a provided in the driving side drum side member 69, so that the developing roller 32 can be brought into contact with the drum 62. It is possible to stably apply the pressing force F pressed against. The third elongated hole 70a provided in the non-driving side developing side member 27 has the same configuration.

Further, by forming the second elongated hole 69b provided in the drive side drum side member 69 in the horizontal direction, the influence of the weight M of the developing unit 20 on the force F of the developing roller 32 pressed against the drum 62 is minimized. Can be suppressed. The fourth elongated hole 70b provided in the non-driving side developing side member 27 has the same configuration.

In the above description, the developing roller 32 has been described as being arranged below the horizontal line passing through the center of the drum 62, but the present invention can also be applied to a configuration in which the developing roller 32 is arranged above the horizontal line.

Further, although the configuration has been described in which the longitudinal direction of the second elongated hole 69b and the fourth elongated hole 70b is formed in the horizontal direction, a range in which the angle formed by the horizontal direction is smaller than that of the first elongated hole 69a and the third elongated hole 70a. The same effect can be obtained with the slope configuration inside. That is, as the developing unit 20 moves, the direction in which the developing first supported portion 26a and the developing third supported portion 27a can move has the longest moving distance (first direction) and the horizontal direction. Let the angle be the first angle. With the movement of the developing unit 20, the angle formed by the direction in which the developing second supported portion 26b and the developing fourth supported portion 27b can move the longest moving distance (second direction) and the horizontal direction is determined. Make a second angle. The same effect can be obtained by satisfying the relationship that the second angle is smaller than the first angle.

Further, in general, when the developing unit 20 is viewed in the axial direction of the developing roller 3 in a state where the process cartridge B is positioned on the apparatus main body A, the position of the center of gravity 40 is the position of the developing unit 20 in the horizontal direction. It is located near the center line CL that divides evenly. Therefore, the positions of the developed second supported portion 26b and the developed fourth supported portion 27b are arranged closer to the center line CL than the developed first supported portion 26a and the developed third supported portion 27a in the horizontal direction. Therefore, the relationship between the distances L1 and L2 can be set to L1 >> L2.

<Relationship with the center of gravity of the image carrier unit>
Next, the relationship between the first support portion and the second support portion and the center of gravity of the image carrier unit will be described with reference to FIGS. 1 and 11. Note that FIG. 11 is a schematic view showing the relationship between the support portion and the center of gravity in a state where the process cartridge B is positioned on the apparatus main body A when viewed from the non-driving side. Here, the drive side will be mainly described, but the same applies to the non-drive side.

As shown in FIG. 1, when viewed from the rotation axis direction of the drum 62, the vertical straight line passing through the support portion 73b as the positioning portion is referred to as S1, and the vertical straight line passing through the boss 69f as the rotation stop portion is referred to as S2 ( S2 is also common to the non-drive side). Then, the area between the straight line S1 and the straight line S2 is defined as the region X, the outside of S1 is defined as the region Y, and the outside of S2 is defined as the region Z.

In the present embodiment, the developed first supported portion 26a as the first supported portion, the developed second supported portion 26b as the second supported portion, and the center of gravity 87 of the image carrier unit are located in the region X. Have been placed.

As a result, the force N1 received by the first elongated hole 69a as the first supported portion from the developed first supported portion 26a and the force received by the second elongated hole 69b as the second supported portion from the developed second supported portion 26b. N2 and the weight Gc of the image carrier unit 60 all give a clockwise moment when the support portion 73b is centered. Further, the forces N1, N2, and Gc give a counterclockwise moment around the boss 69f. Therefore, even if the magnitude of the force of N1, N2, Gc changes, the direction of the moment around the support portion 73b and the boss 69f does not change, and the support portion 73b and the boss 69f are always urged in the same direction. Therefore, the cartridge B is stably supported in the apparatus main body A.

In the present embodiment, the case where all the forces N1, N2, Gc are present in the region X has been described, but even when all the forces N1, N2, Gc are present in the region Y or the region Z, the support portion 73b And the direction of the moment around the boss 69f does not change. Therefore, when the forces N1, N2, and Gc are in the same region, the support portion 73b and the boss 69f are always urged in the same direction, and the cartridge B is stably supported in the apparatus main body A.

A ... Device body B ... Process cartridge 14 ... Drive shaft 15 ... Drive side plate 15a ... Drive side first support 15b ... Drive side second support 15c ... Long hole 16 ... Non-drive side plate 16a ... Non-drive side first support 16b ... Non-driving side second support part 20 ... Development unit 26 ... Drive side development side member 26a ... Development first supported part 26b ... Development second supported part 26c ... Boss 27 ... Non-drive side development side member 27a ... Development 3rd supported part 27b ... Development 4th supported part 27c ... Boss 37 ... Bearing member 38 ... Spacing member 46F ... Non-driving side urging member 46R ... Drive side urging member 60 ... Image carrier unit 62 ... Drum 69 ... Drive side drum side member 69a ... 1st slot 69b ... 2nd slot 69c ... Positioning hole 69d ... Slot 70 ... Non-drive side drum side member 70a ... 3rd slot 70b ... 4th slot 70c ... Positioning Hole 70d ... Long hole 78 ... Drum shaft

Claims (8)

In the process cartridge that can be attached to and detached from the image forming apparatus body
An image carrier unit that rotatably holds the image carrier and
A developing unit that rotatably holds the developer carrier and
Have,
The developing unit is movable with respect to the image carrier unit, and the developer carrier and the image carrier are provided so as to be in contact with each other.
The image carrier unit has a first support portion and a second support portion, and has a first support portion and a second support portion.
The developing unit has a first supported portion supported by the first supported portion and a second supported portion supported by the second supported portion.
The first support portion is located closer to the developer carrier than the second support portion, and the developer carrier can be brought into contact with and detached from the image carrier to move the developing unit. Along with this, the first supported portion is movably supported in the first direction, which is the direction in which the first supported portion has the longest moving distance.
The second support portion is a second direction that intersects with the first direction and has the longest movement distance among the directions in which the second supported portion can move with the movement of the developing unit. The second supported portion is movably supported in the direction,
The first support portion and the second support portion receive a force in the gravity direction due to the weight of the developing unit, and the force in the gravity direction receives a larger force on the second support portion than the first support portion. Characterized process cartridge. The process cartridge according to claim 1, wherein the center of gravity of the developing unit is located closer to the second supported portion than to the first supported portion. In the process cartridge that can be attached to and detached from the image forming apparatus body
An image carrier unit that rotatably holds the image carrier and
A developing unit that rotatably holds the developer carrier and
Have,
The developing unit is movable with respect to the image carrier unit, and the developer carrier and the image carrier are provided so as to be in contact with each other.
The image carrier unit includes a first support portion, a second support portion, a positioning portion that is positioned when the process cartridge is mounted on the image forming apparatus main body, and the process cartridge with respect to the image forming apparatus main body. It has a rotation stopper that regulates rotation.
The developing unit has a first supported portion supported by the first supported portion and a second supported portion supported by the second supported portion.
The first support portion is located closer to the developer carrier than the second support portion, and the developer carrier can be brought into contact with and detached from the image carrier to move the developing unit. Along with this, the first supported portion is movably supported in the first direction, which is the direction in which the first supported portion has the longest moving distance.
The second support portion is a second direction that intersects with the first direction and has the longest movement distance among the directions in which the second supported portion can move with the movement of the developing unit. The second supported portion is movably supported in the direction,
When viewed from the direction of the rotation axis of the image carrier,
The center of gravity of the developing unit is arranged between the first supported portion and the second supported portion, and
A vertical straight line passing through the positioning portion is S1,
Let S2 be a vertical straight line passing through the rotation stopper.
Area X, between the straight line S1 and the straight line S2
Area Y outside the straight line S1
When the region Z is outside the straight line S2,
The process cartridge is characterized in that the first supported portion and the second supported portion are arranged in the same region of the regions X, Y, and Z as the region where the center of gravity of the image carrier unit is located. .. Claim 1 is characterized in that the second supported portion is arranged at a position closer to the center line that bisects the developing unit in the second direction than the first supported portion. The process cartridge according to any one of claims 3 . The process cartridge according to any one of claims 1 to 4 , wherein the angle formed by the second direction with the horizontal direction is smaller than that of the first direction. The process cartridge according to claim 5, wherein the second direction is a substantially horizontal direction. The process cartridge according to any one of claims 1 to 6 , further comprising a pressing means for urging the developer carrier toward the image carrier. In an image forming apparatus in which a process cartridge is attached to the main body of the apparatus to form a developing agent image, and the developing agent image is transferred to a recording medium at a transfer unit.
An image forming apparatus comprising the process cartridge according to any one of claims 1 to 7 .

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