JP4689750B2 - Electrophotographic image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic image forming apparatus.

  An electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming process. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, etc.), a facsimile apparatus, and the like. The recording medium is an image on which an image is formed by an electrophotographic image forming apparatus, and includes, for example, paper, an OHP sheet, and the like. Here, in the electrophotographic image forming apparatus, a configuration is known in which a drawer member configured to be freely put in and out is provided to the apparatus main body. According to this configuration, the drawer member is pushed into the apparatus main body while the plurality of cartridges are supported by the drawer member. As a result, the cartridges can be mounted together in the apparatus main body. Further, the drawer member is pulled out from the apparatus main body. As a result, the cartridges can be collectively removed from the apparatus main body. In the case of this technique, the cartridge can be replaced while the drawer member is pulled out of the apparatus main body. Therefore, the cartridge replacement work by the user can be improved (see Patent Document 1).

  However, in the above configuration, when the drawer member is pulled out from the apparatus main body, a part of the peripheral surface of the developing roller is exposed from the developing cartridge. Therefore, there is a possibility that the user may inadvertently contact the developing roller or the electrophotographic photosensitive drum when the developing cartridge is replaced. In addition, there is a possibility that the developing roller may inadvertently contact other members.

JP 2003-15378 A

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic image forming apparatus that improves workability when a developing cartridge is replaced. Another object of the present invention is to provide an electrophotographic image forming apparatus capable of preventing a user from inadvertently contacting a developing roller .

That is, in an electrophotographic image forming apparatus that forms an image on a recording medium, an electrophotographic photosensitive drum, a developing roller that develops an electrostatic latent image formed on the electrophotographic photosensitive drum, and the developing roller include the static roller. A developer accommodating portion that accommodates a developer used for developing an electrostatic latent image, a protective position that covers a part of the peripheral surface of the developing roller, and a part of the peripheral surface of the developing roller that is retracted from the protective position and exposed A developing roller shutter that moves between a retracted position and a removably mounted developing cartridge on the main body of the electrophotographic image forming apparatus, and for mounting the developing cartridge on the main body of the apparatus A front position between an inner position located inside the apparatus main body and an outer position located outside the apparatus main body in order to pull out the developing cartridge from the apparatus main body. A cartridge supporting member that moves in a state in which the developing cartridge is detachably supported, and a force receiving portion provided in the developing cartridge, the force for moving the developing roller shutter from the protection position to the retracted position. A force receiving portion to be received, a force applying portion provided in the cartridge support member, a first slope provided in the opening, and a first straight portion extending below the first slope. A force applying portion having a second slope extending downward from the first straight portion, and a second straight portion extending downward from the second slope, and the electrophotographic photosensitive drum, wherein as the developing roller is positioned away for supporting the longitudinal direction of the one end and the other end of said developing cartridge, a support portion provided in the cartridge supporting member, said cartridge support In a state in which wood is located at the outer position, the cartridge the developing cartridge in order to support the supporting member, when caused to enter the developing cartridge downward from above to the cartridge supporting member, the force receiving portion In contact with the first inclined surface of the force applying portion , and when the developing cartridge further enters the cartridge support member, the first linear portion and the second portion of the force applying portion . In the state where the force receiving portion sequentially contacting the slope and the second linear portion receives the force from the force applying portion and moves the developing roller shutter from the protection position to the retracted position , wherein as the cartridge supporting member and the electrophotographic photosensitive drum which is supported on the said developing roller is spaced apart, the length of the developing cartridge A support portion for supporting said one end of the longitudinal direction and the other end side, in a state in which the cartridge supporting member is located at the inner position, by pressing the developer cartridge, the electrons are located away And a pressing member for bringing the photographic photosensitive drum into contact with the developing roller.

As described above, according to the present invention, it is possible to improve the workability when the developing cartridge is replaced. Further, according to the present invention, the user can prevent inadvertent contact with the developing low la.

FIG. 3 is a cross-sectional view of an image forming apparatus according to Reference Example 1. The perspective view which shows the mounting part of the drawer member which concerns on the reference example 1. FIG. Explanatory drawing of the drawer unit which concerns on the reference example 1. FIG. The perspective view of the drawer | drawing-out unit which concerns on the reference example 1. FIG. FIG. 4 is a cross-sectional view of a developing cartridge according to Reference Example 1. 3 is a perspective view of a developing cartridge according to Reference Example 1. FIG. FIG. 9 is a perspective view showing a state when the developing cartridge according to Reference Example 1 is mounted. The perspective view regarding the drawer member which concerns on the reference example 1. FIG. Explanatory drawing of mounting the drawer member according to Reference Example 1 into the apparatus main body. The state explanatory drawing with which the drawer member which concerns on the reference example 1 was mounted | worn in the apparatus main body. FIG. 6 is an explanatory diagram illustrating a state where positioning of the developing cartridge according to Reference Example 1 is completed. Explanatory drawing of the interlocking mechanism of the door which concerns on the reference example 1, and a press member. 1 is a perspective view of a developing cartridge according to Embodiment 1. FIG. FIG. 3 is a perspective view relating to a drawer member according to the first embodiment. FIG. 3 is a diagram illustrating a mechanism when the developing cartridge according to the first embodiment is mounted. FIG. 3 is a diagram illustrating a state in which the positioning of the developing cartridge according to the first embodiment is completed. FIG. 4 is a cross-sectional view of an image forming apparatus according to Reference Example 2 . FIG. 4 is a cross-sectional view of an image forming apparatus according to Reference Example 2 . FIG. 10 is an explanatory diagram of a developing cartridge according to Reference Example 3 . FIG. 10 is a diagram illustrating a mechanism when a developing cartridge according to Reference Example 3 is mounted.

EMBODIMENT OF THE INVENTION With reference to drawings, the form for implementing this invention is demonstrated illustratively based on an Example below. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .
( Reference Example 1)
An electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) according to Reference Example 1 of the present invention will be described with reference to FIGS.

<Overall configuration of image forming apparatus>
The configuration of the image forming apparatus according to Reference Example 1 of the present invention will be described with reference to FIG. FIG. 1A is a cross-sectional view of the image forming apparatus. FIG. 1B is a sectional view showing a state in which the drawer member is pulled out in the image forming apparatus. FIG. 1C is an enlarged view of a part (near the developing cartridge) in FIGS.

The image forming apparatus 100 according to this reference example includes four electrophotographic photosensitive drums 1 (hereinafter referred to as photosensitive drums or drums) that are arranged in a horizontal direction with respect to an installation surface (not shown). Yes. The drum 1 is rotated clockwise (FIG. 1A) by driving means (not shown). Further, in the image forming apparatus 100, as the electrophotographic image forming process means, in addition to the drum 1, the charging member 2, the scanner unit 3, a plurality of developing cartridges 4 (4y, 4m, 4c, 4k), and static An electrotransfer means 5 is provided. The cartridge 4y stores a yellow developer (hereinafter referred to as toner) t in a toner container (developer storage unit) 41a (FIG. 5), and forms a yellow image. The cartridge 4m stores a magenta toner t in a toner container 41b and forms a magenta image. The cartridge 4c contains cyan toner t in a toner container 41c, and forms a cyan image. The cartridge 4k stores black toner t in a toner container 41d, and forms a black image. Each cartridge 4 has the same configuration except that the color of the toner stored therein is different. Each cartridge 4 is mounted at a predetermined location on the drawer member 13. Here, the charging member 2 uniformly charges the surface of the drum 1. The scanner unit 3 irradiates the photosensitive drum 1 with a laser beam based on the image information to form an electrostatic latent image on the surface of the photosensitive drum 1. The cartridge 4 develops the electrostatic latent image formed on the surface of the photosensitive drum 1 using the toner t (FIG. 5). The transfer unit 5 transfers the toner image formed on the photosensitive drum 1 to a sheet material (recording medium) S. Specific examples of the sheet material S include paper, an OHP sheet, and cloth.

  Further, the image forming apparatus 100 is provided with a cleaning member (cleaning blade) 6 that removes residual toner t remaining on the peripheral surface of the photosensitive drum 1 after transfer. The drum 1 is obtained by applying an organic photoconductive layer (OPC photoreceptor) to the outer peripheral surface of an aluminum cylinder. Both ends of the drum 1 are rotatably supported by the drawer member 13 by bearings (not shown). At one end thereof, a gear (not shown) is arranged to receive a rotational force from a motor (not shown). Thereby, the photosensitive drum 1 is rotated by the rotational force transmitted from the motor via the gear. The charging member 2 is a contact charging method. More specifically, the charging member 2 is a conductive roller configured in a roller shape, and this roller is brought into contact with the surface of the photosensitive drum 1. The surface of the photosensitive drum 1 is uniformly charged by applying a charging bias voltage to the roller. Therefore, the charging member 2 is a charging roller. The scanner unit 3 is disposed on the upper side of the photosensitive drum 1. In the unit 3, image light (laser beam) corresponding to the image signal is irradiated from a laser diode (not shown) to expose the surface of the charged photosensitive drum 1. As a result, an electrostatic latent image corresponding to the image signal is formed on the surface of the photosensitive drum 1. Each developing cartridge 4 includes a toner container 41 (41a, 41b, 41c, 41d) that stores toner t. The toner t in the toner container 41 is sent to the toner supply roller 43. Then, the toner is applied to the outer periphery of the developing roller 40 by the toner supply roller 43 and the developing blade 44 pressed against the outer periphery of the developing roller 40, and the toner t is charged.

  Then, a developing bias is applied to the developing roller 40 from the apparatus main body (hereinafter referred to as the main body 100a). As a result, the toner t adheres to the latent image formed on the drum 1 to form a toner image. That is, the developing roller 40 develops the electrostatic latent image formed on the drum 1 using the toner t. The developing roller 40 is disposed so as to face the drum 1. The developing cartridge 4 is replaced with the developing cartridge 4 when the toner t is consumed and the lifetime is reached (so-called cartridge system).

As shown in FIG. 1, the image forming apparatus 100 is provided with a transfer belt 11 that circulates and moves so as to face and contact all the photosensitive drums 1. Then, the sheet material S is conveyed to the transfer position by the belt 11, and the toner image formed on the surface of the drum 1 is transferred to the sheet material S. Inside the belt 11, a transfer roller 12 is provided at a position facing each drum 1. A positive charge is applied from these transfer rollers 12 to the sheet material S via the belt 11. As a result, the toner image on the photosensitive drum 1 is transferred to the sheet material S.

  Further, the apparatus 100 includes a feeding unit 16 that feeds the sheet material S to the image forming unit. The feeding unit 16 is provided with a cassette 17 for storing a plurality of sheet materials S. At the time of image formation, the feeding roller 18 rotates according to the image forming operation. Thereby, the sheet material S in the cassette 17 is fed one by one. Then, in synchronization with the rotation of the belt 11 and the toner image, the sheet material S is sent to the belt 11 by the registration roller pair 19. Further, the apparatus 100 is provided with a fixing unit 20 that fixes the toner images of a plurality of colors transferred to the sheet material S. The fixing unit 20 includes a rotating heating roller 21b and a pressure roller 21a that is in pressure contact therewith. That is, the sheet material S to which the toner image on the drum 1 is transferred is conveyed while being sandwiched between the rollers 21b and 21a, and at that time, heat and pressure are applied. As a result, the toner image is fixed on the surface of the sheet material S.

  The image forming process is briefly summarized as follows. When the image forming operation is started, the drum 1 rotates. A charging member (charging roller) 2 applies a uniform charge to the surface of the drum 1. The unit 3 exposes the surface of the charged drum 1 according to the image signal, and forms an electrostatic latent image on the surface of the drum 1. Then, the electrostatic latent image is developed by the developing roller 40. On the other hand, the toner images formed on the surface of each drum 1 are sequentially transferred to the sheet material S fed by the feeding unit 16 and conveyed by the belt 11. Transfer of the toner image is performed by an electric field formed between each drum 1 and the transfer roller 12. The sheet material S on which the four-color toner images are transferred is sent to the fixing unit 20 to fix the color image. Then, the sheet material S that has passed through the fixing unit 20 is discharged from the discharge unit 24 to the outside of the apparatus by the discharge roller pair 23.

<Drawer member>
The drawer member (cartridge support member) 13 will be described. The drawer member 13 is removably attached to the cartridge 4. The drawer member 13 has a storage position (inner position I) for storing the cartridge 4 in the main body 100a with respect to the apparatus main body 100a, and a pull-out position (outer position O) for pulling out the cartridge 4 to the outside of the apparatus main body. It is possible to move between. That is, the drawer member 13 supports the cartridge 4 and moves between an inner position I located inside the main body 100a and an outer position O located outside the main body 100a. The movement of the drawer member 13 is performed by the user. Here, FIG.
FIGS. 17A, 17B, and 18 show a state in which the drawer member 13 is located at the inner position I. FIG. 1B, FIG. 8B, FIG. 14B, and FIG. 17A show a state in which the drawer member 13 is located at the outer position O. FIG. FIGS. 1A, 17B, and 18 show a state in which the drawer member 13 is positioned at the inner position I and the drum 1 is in contact with the belt 11. FIG. This position is an image forming position. Here, in the present reference example , the “main body 100a” refers to at least the drawer member 13 and the members (parts) configured to be fixed to or removable from the drawer member 13 among various members (parts) constituting the apparatus 100. Means something other than

As shown in FIG. 1B, the drawer member 13 moves linearly in the horizontal direction (arrow D1, D2 direction) with respect to the installation surface (not shown) of the main body 100a. An arrow D1 is a direction in which the user pushes the drawer member 13 from the outer position O to the inner position I. An arrow D2 is a direction in which the user pulls the drawer member 13 from the inner position I to the outer position O. Then, with the drawer member 13 positioned at the outer position O, the user replaces (detaches) the cartridge 4 with respect to the drawer member 13. Then, with the drawer member 13 positioned at the outer position O (drawer position), the user moves the cartridge 4 substantially in the direction of gravity (the direction of arrow C in FIG. Attach to. The cartridge 4 mounted in this way is arranged so that its longitudinal direction (axial direction of the developing roller 40) is in a direction perpendicular to the moving direction of the drawer member 13. The four developing cartridges 4 are arranged side by side in the moving direction of the drawer member 13. When the cartridge 4 is taken out from the drawer member 13, the user lifts the cartridge 4 from the drawer member 13 (the direction opposite to the arrow C direction).

  The cartridge 4 moves into the apparatus main body 100 a together with the drawer member 13 in a state where it is mounted (supported) on the drawer member 13. The user closes the door 10 with the drawer member 13 positioned at the inner position I. As a result, the drawer member 13 is lowered and all the cartridges 4 are mounted at predetermined positions (image forming positions where image formation is possible) in the main body 100a. At the image forming position, the drum 1 is in contact with the belt 11.

As described above, according to the apparatus 100, the four cartridges 4 can be mounted together in the apparatus main body. In addition, the four cartridges 4 can be pulled out to the outside of the apparatus main body. Therefore, the workability at the time of exchanging the cartridge is superior to that in which the cartridge is individually mounted in the apparatus main body. In this reference example , the drum 1, the charging member (charging roller) 2, and the cleaning member 6 are attached to the drawer member 13. However, the photosensitive drum 1, the charging member 2, and the cleaning member 6 may be integrated into a cartridge to form a process cartridge. In the case of a process cartridge, the process cartridge may be detachable from the drawer member 13. Then, the process cartridge is detachably mounted on the main body 100a by the movement of the drawer member 13.

<Drawer member mounting part>
The configuration of the mounting portion G of the drawer member 13 provided in the main body 100a will be described with reference to FIGS. FIGS. 2A and 2B are perspective views showing a mounting portion G of the drawer member according to Reference Example 1. FIG. In the figure, the scanner unit 3 and the like are omitted from the members (parts) constituting the main body 100a so that the configuration of the mounting portion G can be easily understood. FIGS. 2A and 2B are perspective views as seen from different directions.

  A pair of guide members 14 (14R, 14L) are provided on the inner wall surfaces 100b1, 100b2 of the main body frame 100b so as to face each other. The movement direction of the drawer member 13 is regulated by the guide member 14. That is, the drawer member 13 moves along the guide member 14. The guide member 14 is a rail-shaped member having a U-shaped cross section that guides guided portions 13a, 13b, 13c, and 13d (see FIGS. 4A and 4B) of the drawer member 13. The guide member 14 is provided in a substantially horizontal direction from the vicinity of the entrance of the main body 100a (near the door 10) to the back side. Thereby, the guide member 14 can guide the drawer member 13 from the outer position O to the inner position I. In addition, pressing members 65 and 66 for pressing and positioning the cartridge 4 at a predetermined position are provided above the guide member 14. These pressing members 65, 66 move downward in conjunction with the operation of closing the door (opening / closing member) 10. Accordingly, the pressing members 65 and 66 press the cartridge 4 to a main body side positioning portion (not shown) provided in the main body 100a. That is, the cartridge 3 is positioned at the aforementioned image forming position in the main body by the pressing members 65 and 66. The door (opening / closing member) 10 closes the opening 100c so as to be openable. The opening 100c is through which the drawer member 13 passes when the drawer member 13 moves between the inner position I and the outer position O.

As shown in FIG. 2A, shutter guides 25 and 64 are provided below the guide member 14R. The guide 25 is a member for moving (opening and closing) the drum shutter 29 that covers the top of the drum 1 in a state where the drawer member 13 is positioned at the outer position O (FIG. 3). The guide 64 is a member for moving (opening / closing) the developing roller shutter 42 covering the portion where the developing roller 40 is exposed from the frame 4s of the cartridge 4 in a state where the drawer member 13 is located at the outer position O. (FIGS. 5 and 6). The guides 25 and 64 extend in a substantially horizontal direction from the vicinity of the entrance of the main body 100a to the back side. As shown in FIG. 2B, below the guide member 14L, coupling members (main body side coupling members) 26 are arranged horizontally at substantially equal intervals so as to correspond to the cartridges 4, respectively. Has been. The coupling member 26 transmits a rotational force for rotating the developing roller 40 from the main body 100 a to the cartridge 4. The rotational force is also transmitted to the toner supply roller 43 so that the roller 43 also rotates. The coupling member 26 is retracted into the main body frame 100b when the door 10 is opened (FIG. 2B). The coupling member 26 enters the cartridge 4 side in conjunction with the operation of closing the door 10. The coupling member 26 engages with the cartridge side coupling member 45. Further, below the coupling member 26, a drum drive gear (main body side gear) 27 for transmitting a rotational force for rotating the drum 1 from the main body 100a to the drum 1 is provided. The gears 27 are arranged in the horizontal direction at substantially equal intervals. The gear 27 and the coupling member 26 are provided on the same main body frame 100b side, and are rotated by a rotational force from a drive source (not shown) provided in the main body 100a.

<Drawer member>
The drawer member 13 will be described with reference to FIGS. FIG. 3A is a cross-sectional view of the drawer unit U1 according to the first reference example . FIGS. 3B and 3C are perspective views of a portion where the photosensitive drum 1 is provided. 4A and 4B are perspective views of the drawer unit U1. 4A and 4B are perspective views as seen from different directions.

In this reference example , the drum 1, the charging member 2, and the cleaning member 6 are fixed to the drawer member 13, and the drawer unit U1 is configured by these. Specifically, the unit U1 includes a drawer member 13, a photosensitive drum 1, a charging member 2, a cleaning container 30, a cleaning member 6, a shutter 29, support portions 31 and 32, and urging members 33 and 34. The drum 1 and the charging member 2 are rotatably provided in the unit U1. Therefore, the “fixed installation” means that the configuration is not intended to be removed by the user from the unit U1. Guided portions 13 (13a, 13b, 13c, 13d) guided by the guide members 14R, 14L of the main body 100a are provided at the four corners of the drawer member 13. The guided portions 13a and 13c are guided by the guide member 14R, and the guided portions 13b and 13d are guided by the guide member 14L. The guided portions 13a and 13b protrude outward from the side walls 13 (13r and 13s) in the direction intersecting with the drawing direction D2 on the upstream side in the drawing direction D2. The guided portions 13a and 13b protrude upstream in the pulling direction D2. As a result, the guided portions 13a and 13b are prevented from tilting downward in a state in which the drawer member 13 is located at the outer position O. The guided portions 13c and 13d protrude outward from the side walls 13 (13r and 13s) in a direction that is downstream of the pulling direction D2 and intersects the pulling direction D2. The guided portions 13c and 13d are cylindrical. Further, a handle portion 28 for the user to operate the drawer unit U1 is provided at one end on the downstream side in the drawer direction D2 of the drawer member 13. Further, as shown in FIG. 4A, an opening 13 e into which the coupling member 26 enters is provided on one side wall 13 s of the drawer member 13. The coupling member 26 enters the opening 13e in conjunction with the operation of closing the door 10. The coupling member 26 that has entered from the opening 13e is engaged with a cartridge side coupling member 45 (see FIG. 6A) of the cartridge 4. As a result, a rotational force is transmitted from the drive source (not shown) provided in the main body 100 a to the developing cartridge 4 through the coupling member 26 and the coupling member 45.

<Drum shutter>
In particular, the drum shutter 29 will be described with reference to FIGS. A shutter 29 for protecting the surface of the drum 1 is provided above the drum 1. The shutter 29 is pivotally supported by a cleaning container 30 fixed to the drawer member 13, and is configured to be rotatable within a certain range. The container 30 also supports the photosensitive drum 1. Further, in the state where the drawer member 13 is pulled out to the outer position O, the shutter 29 is in a position that covers a portion that becomes a contact surface where the photosensitive drum 1 contacts the developing roller 40, that is, a protection position P1 (shown in FIG. 3). is there. The protection position P1 is a portion located above the horizontal plane L that passes through the center (axis line) O of each drum 1. The shutter 29 covers at least the portion of the photosensitive drum 1 in the longitudinal direction.

A force receiving portion 29 a that receives a force from the shutter guide 25 is provided at one end in the longitudinal direction of the shutter 29. The force receiving portion 29a passes through an opening 13f provided in the drawer member 13 and protrudes outward (see FIG. 4). When the pull-out member 13 moves from the outer position O toward the inner position I, the guide 25 as a force applying portion hits the force receiving portion 29a and pushes in the force receiving portion 29a. That is, the force receiving portion 29a moves from one end 13f1 to the other end 13f2 of the arcuate opening 13f against the elastic force of the torsion coil spring (elastic member) 29b. As a result, the shutter 29 rotates. As a result, the shutter 29 is exposed from a protected position P1 shown in FIGS. 3A and 3B to an exposed position P2 (FIG. c) to the position shown in FIG. The shutter 29 is always urged toward the protection position P1 by the elastic force of the torsion coil spring (elastic member) 29b. Thus, when the drawer member 13 is at the outer position O, the shutter 29 is always at the protection position P1 (FIGS. 3A and 3B). One end of the spring 29 b is attached to the shutter 29, and the other end is attached to the drawer member 13. The elastic member is not limited to a torsion coil spring, and may be, for example, a tension spring, a compression coil spring, a leaf spring, or the like. In this reference example , the spring 29b and the force receiving portion 29a are provided on one end side and the other end side in the longitudinal direction of the drum 1, respectively. Here, the longitudinal direction of the drum 1 is a direction orthogonal to the moving direction (arrow D1, D2 directions) in which the drawer member 13 moves. Thereby, each mechanism can be arranged efficiently.

As described above, the surface of the drum 1 is protected by the shutter 29 when the drawer member 13 is pulled out of the main body 100 a. Therefore, it is possible to prevent any member or fallen object from colliding with the upper surface of the drum 1 when the cartridge 4 is attached or detached. Further, it is possible to prevent the user from inadvertently touching the surface of the photosensitive drum 1. In this reference example , an example using the shutter member 42 that covers the surface of the developing roller 40 will be described. However, the shutter member 42 is not necessarily provided in order to exhibit the above-described effects.

In the drawer member 13, a mounting portion 13h for mounting the cartridge 4 is provided at a position facing each drum 1 (see FIG. 4A). On both sides of the mounting portion 13h, guide portions 13i, 13j, 13k, and 13l for guiding the cartridge 4 into the drawer member 13 are provided. Each guide part 13i, 13j, 13k, 13l is comprised by the vertically long groove | channel. Positioning portions 13i1 and 13j1 for positioning the cartridge 4 are provided below the guide portions 13i and 13j. An opening 13e is provided near the lower end of the guide portion 13j. Further, inside the guide portions 13k and 13l, support portions 31 and 32 are provided that hold the cartridge 4 at a position separated from the drum 1 in a state where the drawer member 13 is pulled out. In addition, compression coil springs (elastic members) 33 and 34 that urge the support portions 31 and 32 are provided inside the guide portions 13k and 13l. Further, an opening 13g into which a force receiving portion 42a provided in the shutter 42 enters is provided on the side of the guide portion 13k (see FIG. 4B). The shutter 42 will be described below.

<Shutter for developing cartridge and developing roller>
Next, the cartridge 4 configured to be removable with respect to the drawer member 13 will be described with reference to FIGS. 5 to 6A, 6B, and 6C. FIG. 5 is a cross-sectional view of the cartridge 4. 6A and 6B are perspective views of the cartridge 4. FIGS. 6A and 6B are perspective views as seen from different directions. FIG. 6C is a partially enlarged view of FIG.

  The cartridge 4 includes a developing roller 40, a toner supply roller 43, a developing blade 44, a toner storage container 41, and a shutter 42. The blade 44 is in pressure contact with the peripheral surface of the developing roller 40 and regulates the amount of toner t attached to the peripheral surface of the roller 40. The cartridge 4 is detachably attached to the drawer member 13 by the user, and is detachably attached to the main body 100a. The toner t in the container 41 is sent to the roller 43. The roller 43 and the blade 44 cause the toner t to adhere to the peripheral surface of the developing roller 40, and charge is applied to the toner t. Then, a developing bias is applied from the main body 100a to the developing roller 40. As a result, the toner t adheres to the latent image formed on the drum 1 to form a toner image. That is, the latent image is developed by the developing roller 40. Here, when the toner t in the container 41 is consumed, the user replaces the cartridge 4. As a result, image formation can be performed again.

  As shown in FIG. 6A, a coupling member 45 that receives a rotational force from the coupling member 26 is rotatably supported at one longitudinal end portion of the cartridge 4. The coupling member 45 is engaged with the coupling member 26 and receives a rotational force. The rotational force is transmitted to the developing roller 40 and the roller 43 through a gear (not shown). As a result, the rollers 40 and 43 rotate in a predetermined direction. The outer periphery of the coupling member 45 is covered with a cylindrical rib. The rib portion is a guided portion 46 that is guided by a guide portion 13 j provided on the drawer member 13. The guided portion 46 is provided on a side cover 4 s 1 provided at one end of the container 41. The guided portion 46 also has a function as a positioned portion for positioning the cartridge 4 in the positioning portion 13j1 (see FIG. 4B) provided in the drawer member 13.

  Further, as shown in FIG. 6B, a guided portion 47 is provided on the opposite side in the longitudinal direction of the cartridge 4 and is guided by a guide portion 13 i provided on the drawer member 13. The guided portion 47 is provided on the side cover 4 s 2 provided at the other end of the container 41. The longitudinal direction of the cartridge 4 is the same as the longitudinal direction (axial direction) of the developing roller 40. Both of the guided portions 46 and 47 protrude outward in the longitudinal direction from the side ends (side covers 4s1 and 4s2) of the frame 4s of the cartridge 4. The guided portions 46 and 47 have a guide function when the cartridge 4 is attached to and removed from the drawer member 13 and a function of positioning the developing cartridge 4 within the drawer member 13.

As shown in FIGS. 6A and 6B, protruding protrusions 48 a and 48 b are provided on the upper sides of both sides of the cartridge 4. The upper side is a position above the side end (side cover 4s) in a state where the cartridge 4 is mounted on the drawer member 13 (main body 100a). The protrusion (guided portion) 48 a is guided by the guide portion 13 k when the cartridge 4 is attached to and detached from the drawer member 13. Further, the protrusion (guided portion) 48 b is guided by the guide portion 13 l when the cartridge 4 is attached to or detached from the drawer member 13. The protrusions 48a and 48b are supported by the support portions 31 and 32 (see FIGS. 4A and 4B) in order to support the cartridge 4 (developing roller 40) at a position separated from the photosensitive drum 1. It also has a function as a supported part. That is, the protrusion 48 a is supported by the support portion 31 so that the developing roller 40 and the photosensitive drum 1 are separated from each other. Similarly, the protrusion 48 b is supported by the support portion 32. The protrusions 48a and 48b also have a function as a pressed portion that is pressed by the main body when the cartridge 4 is positioned at a predetermined position of the main body 100a. That is, the protrusion 48a is pressed by the pressing member 65 (FIG. 2A). The protrusion 48b is pressed by the pressing member 66 (FIG. 2B).

  Next, the shutter 42 that covers the portion where the developing roller 40 is exposed from the frame 4s of the cartridge 4 will be described in detail. The cartridge 4 is provided with a shutter 42 that rotates with respect to the container 41 within a certain range about the rotation shafts 42b and 42c. The shutter 42 is positioned at the protection position Q1 (FIGS. 5 and 6) when the cartridge 4 is a single unit. The shutter 42 covers the portion 40s where the developing roller 40 is exposed from the frame 4s (container 41). The shutter 42 has a shape extending in the longitudinal direction so as to cover almost the entire region in the longitudinal direction of the developing roller 40 in a state where the shutter 42 is located at the protection position Q1 (position shown in FIG. 5) (FIG. 6A). (See (b)). The portion 40s where the developing roller 40 is exposed from the frame 4s is an area where the developing roller 40 faces the photosensitive drum 1 during development. The state where the cartridge 4 is a single unit is a state where the cartridge 4 is not attached to the drawer member 13. The shutter 42 is movable between a protection position Q1 that covers the exposed portion 40s of the developing roller 40 and a retracted position Q2 that exposes the exposed portion 40s (see FIG. 10B). A torsion coil spring (elastic member) 49 is provided on one end side in the longitudinal direction of the shutter 42. One end of the spring 49 is attached to the shutter 42, and the other end is attached to the side end (side cover 4s2). Accordingly, the shutter 42 is urged in the direction of the protection position Q1 by the elastic force of the spring 49. Therefore, the shutter 42 is normally located at the protection position Q1. The spring 49 is not limited to a torsion coil spring, and an appropriate elastic member such as a tension spring, a compression coil spring, a leaf spring, or rubber can be applied. Further, a force receiving portion 42a that receives a force from the developing roller shutter guide 64 (FIG. 2A) is provided on the one end side of the shutter 42 so as to protrude outward in the longitudinal direction. The guide 64 is provided on the inner wall surface 100b1 provided along the moving direction of the drawer member 13 and on one end side in the direction orthogonal to the moving direction (FIG. 2A). When the drawer member 13 moves toward the inside of the main body 100a, the force receiving portion 42a hits against the guide 64 and is pushed. As a result, the shutter 42 rotates. As a result, the shutter 42 moves from the protection position Q1 (FIG. 5) to the retreat position Q2 (FIG. 10B) that exposes the surface of the developing roller 40.

  Thus, the surface of the developing roller 40 is almost covered with the shutter 42 in the normal state. Therefore, when the user handles the cartridge 4, the surface of the developing roller 40 is not inadvertently touched. Accordingly, it is possible to prevent the toner t from being scattered from the surface of the developing roller 40 and the surface of the developing roller 40 from being damaged. Further, when the cartridge 4 is mounted on the drawer member 13, it is possible to prevent the developing roller 40 from colliding with the drawer member 13 and damaging its surface.

<Mounting of developing cartridge to drawer member>
The mounting of the cartridge 4 to the drawer member 13 will be described with reference to FIGS. FIGS. 7A and 7B are perspective views showing a state where the cartridge 4 is mounted on the drawer member 13. When the cartridge 4 is mounted, the drawer member 13 is pulled out from the main body 100a. However, in FIGS. 7A and 7B, the main body 100a is omitted. 7A and 7B are perspective views as seen from different directions. FIG. 8A is a perspective view showing a state in which all the cartridges 4 are mounted on the drawer member 13. In FIG. 8A, the main body is not shown.

The cartridge 4 is mounted on each mounting portion 13 h provided on the drawer member 13. The user installs the developing cartridge 4 in the direction of arrow C, which is substantially the direction of gravity (the direction from the top to the bottom in the vertical direction) (see FIG. 7). At the time of mounting, first, the guided portions 46 and 47 provided at both ends of the cartridge 4 are mounted so as to fit into the corresponding guide portions 13j and 13i in the drawer member 13, respectively. That is, the user guides the guided portion 46 to the guide portion 13j, the guided portion 47 to the guide portion 13i, the protrusion (guided portion) 48a to the guide portion 13k, and the protrusion (guided portion) 48b. Are aligned with the guide portions 13l. Then, the cartridge 4 is dropped into the drawer member 13. At this time, a force receiving portion 42a provided at one end of the shutter 42 is inserted into the opening 13g. In this way, the cartridge 4 is guided by the guide portions 13j, 13i, 13k, and 13l and mounted in the drawer member 13 (see FIG. 8A). FIG. 1B shows a cross-sectional view at that time. Accordingly, the protrusions 48 a and 48 b are placed on the support portions (separation members) 31 and 32. That is, the protrusion 48a is supported by the support portion 31, and the protrusion 48b is supported by the support portion 32 (FIGS. 7B and 8A). Accordingly, the protrusion 48 a is pushed upward by the elastic force of the spring 33 and the protrusion 48 b is pushed upward by the elastic force of the spring 34. Therefore, in the state in which the drawer member 13 is located at the outer position O, the cartridge 4 has one end in the longitudinal direction pushed up by the elastic force of the spring 33 and the other end pushed up by the elastic force of the spring 34 (FIG. 1). (B) (c)). In this state, the cartridge 4 is in a state where the developing roller 40 is separated from the photosensitive drum 1 (FIG. 2). The shutters 29 and 42 are located between the drum 1 and the developing roller 40. That is, the shutter 29 is positioned at the protection position P1 where the drum 1 is covered and the shutter 42 is positioned at the protection position Q1 where the exposed portion 40s of the developing roller 40 is covered. At this time, the guided portions 46 and 47 provided on the cartridge 4 are not in contact with the main body side positioning portions 13i1 and 13j1 for positioning the cartridge 4 on the main body 100a.

  In this manner, the cartridge 4 (developing roller 40) is maintained in a state of being separated from the photosensitive drum 1 in a state where the cartridge 4 (developing roller 40) is dropped onto the drawer member 13 (a state where the cartridge 4 is mounted on the drawer member 13). Therefore, it is possible to prevent the surface of the photosensitive drum 1 from being damaged by the operation of mounting the cartridge 4 on the drawer member 13. As shown in FIG. 8, the force receiving portion 42a of the shutter 42 is in a state of protruding outward from the drawer member 13 from the opening 13g. Further, the force receiving portion 29 a of the shutter 29 is also in a state of protruding outward from the opening portion 13 f provided in the drawer member 13. The force receiving portions 29 a and 42 a protrude in a direction orthogonal to the moving direction of the drawer member 13 (short direction of the drawer member 13 and longitudinal direction of the cartridge 4).

  As described above, in a state where the cartridge 4 is simply mounted on the drawer member 13 (a state where the cartridge 4 is only placed), the developing roller 40 is at a position separated from the photosensitive drum 1. At this time, the force receiving portions 29 a and 42 a are in a state of protruding to the outside of the drawer member 13.

<Mounting the drawer member into the main body>
The mounting operation of the drawer member 13 in the main body 100a will be described with reference to FIGS. 8 (b) to 10 (b). FIG. 8B is a perspective view showing a state in which the drawer member 13 is pulled out from the main body 100a. FIG. 9A is a perspective view showing a state in the middle of mounting the drawer member 13 in the main body 100a. FIG. 9B is a cross-sectional view showing a state in the middle of mounting the drawer member 13 in the main body 100a. FIG. 9C is a partially enlarged view of FIG. FIG. 10A is a perspective view showing a state in which the drawer member 13 is mounted in the main body 100a. FIG. 10B is a cross-sectional view showing a state in which the drawer member 13 is mounted in the main body 100a. 9 and 10, only the members related to the mounting of the drawer member 13 among the various members on the main body side are shown.

As described above, the drawer member 13 is a guided portion 13 (provided on the drawer member 13).
13a, 13b, 13c, 13d) (FIG. 4) is pushed in the direction of arrow D1 along the guide members 14R, 14L (FIGS. 2A and 2B) provided on the main body 100a. Moreover, it is pulled out in the direction of arrow D2. In response to the operation of pushing the drawer member 13 into the main body 100a, the force receiving portion 42a contacts the inclined surface 64a that is a force applying portion provided on the guide 64 (see FIG. 9). The shutter 42 receives a force from the inclined surface 64a according to the moving operation in which the drawer member 13 enters the main body 100a, and resists the elastic force of the spring 49 (see FIG. 6C) in the direction of the arrow E1 ( It rotates to Fig.9 (a). The shutter 42 rotates until the force receiving portion 42 a reaches the flat surface portion 64 b provided on the guide 64. In the state where the drawer member 13 is located at the inner position I, each force receiving portion 42a is supported by the flat portion 64b. Thus, in a state where the drawer member 13 is located at the inner position I, the shutter 42 is located at the retracted position Q2 (FIG. 11). The same applies to the shutter 29. The shutter 29 comes into contact with the developing roller 40 in the photosensitive drum 1 from the protection position P1 (FIG. 3B) that protects the surface of the photosensitive drum 1 in accordance with the operation of pushing the drawer member 13 into the main body 100a. It rotates to the retracted position P2 (FIG. 11) that exposes the part to be. That is, according to the operation of pushing the drawer member 13 into the main body 100a, the force receiving portion 29a comes into contact with the end surface 25a of the shutter guide 25, and the shutter 29 receives force from the end surface 25a. Then, the shutter 29 rotates in the arrow E2 direction (FIG. 9A). The shutter 29 rotates until the force receiving portion 29 a reaches the flat surface portion 25 b provided in the shutter guide 25. When the drawer member 13 is located at the inner position I, each force receiving portion 29a is supported by the flat portion 25b. Thus, in a state where the drawer member 13 is located at the inner position I, the shutter 29 is located at the retracted position P2 (FIG. 11).

  Here, FIG. 9B shows a state in the middle of pushing the drawer member 13 into the main body 100a. At this time, the shutter 42 of the cartridge 4y among the four cartridges 4 is in the retracted position Q2 where the surface of the developing roller 40 is exposed. The shutter 42 of the cartridge 4m is in the middle of moving from the protection position Q1 that covers the surface of the developing roller 40 to the retracted position Q2. The shutters 42 of the cartridges 4c and 4k are at the protection position Q1. The same applies to the shutter 29. In the state where the drawer member 13 is completely mounted inside the main body 100, each shutter 42 of the cartridge 4 is in the retracted position Q2. Each shutter 29 is also in a retracted position P2 where the portion of the photosensitive drum 1 that becomes the contact surface with the developing roller 40 is exposed (see FIG. 11). Therefore, the image forming apparatus 100 can form an image on the sheet material S despite the shutters 29 and 42 being provided. Here, the shutter guide 64 is fixed to the inner side surface 100b1 along the moving direction of the drawer member 13. The guide 64 is provided with recesses 64c, 64d, 64e, 64f at equal intervals (see FIG. 2A). Further, the shutter 42 is provided with a spring (elastic member) 49 that biases the shutter 42 toward the protection position Q1 (see FIG. 6C). Therefore, when the pulling member 13 is mounted in the main body 100a, the force receiving portion 42a is pulled by the pulling force of the spring 49 when each force receiving portion 42a reaches the entrance of the recesses 64c, 64d, 64e, 64f. It partially penetrates into the recesses 64c to 64f. However, inclined surfaces (not shown) are provided on both sides of the inlets of the recesses 64c to 64f. Therefore, each force receiving portion 42a does not enter the recesses 64c to 64f more than necessary, and the movement of the drawer member 13 is not hindered. That is, each force receiving portion 42a can be lifted by the action of the inclined surface provided at each inlet when it reaches the recesses 64c to 64f, and can advance again on the shutter guide 64. Here, the concave portions 64c to 64f are provided so that the force receiving portion 42a does not hinder the movement when the cartridge 4 is moved downward by being pressed by pressing members 65 and 66 described later.

When the shutter 42 receives a force from the inclined surface 64a, the pulling member 13 receives a reaction force in the direction opposite to the mounting direction (arrow D1) by the urging force of the spring 49. However, the timing at which the force receiving portion 42a of each cartridge 4 receives the reaction force by contacting the inclined surface 64a is shifted. Therefore, the pushing force (mounting force) of the drawer member 13 does not become extremely heavy. Therefore, the user can move the drawer member 13 with a light force. In this reference example , when the shutter 29 receives a force from the end face 25a according to the movement of the drawer member 13, a reaction force is applied by the urging force of the spring 29b (FIGS. 3B and 3C). receive. However, in this reference example , since the timing is shifted for each cartridge 4, the pushing force of the drawer member 13 does not increase significantly. In other words, when it comes into contact with the slope 64a and the end surface 25a, it receives a reaction force, but once the shutters 42 and 29 are moved to the retracted positions Q2 and P2, almost no force in the direction opposite to the mounting direction is generated. There is no influence on the pushing force of the drawer member 13. Each cartridge 4 (developing roller 40) is kept away from the drum 1 in the process of mounting the drawer member 13 on the main body 100a. That is, a gap g (FIG. 9C, FIG. 10B) is formed between the cartridge 4 (developing roller 40) and the photosensitive drum 1. Therefore, the shutter 42 rotates without interfering with the drum 1. Similarly, the shutter 29 rotates without interfering with the cartridge 4. That is, according to this reference example , when the drawer member 13 is positioned at the outer position O, the photosensitive drum 1 and the developing roller 40 are positioned so that the shutter 42 can be positioned at the protection position. A gap g is formed. This is because both ends of the cartridge 4 in the longitudinal direction are lifted by the support portions (separating members) 31 and 32 in a state where the drawer member 13 is located at the outer position O. Thereby, a gap g is formed between the drum 1 and the developing roller 40. Further, according to this reference example , the gap g is large enough to position the shutter 29 in addition to the shutter 42. Thus, according to the present reference example , the shutter 29 can also be positioned in the gap g. Further, when the cartridge 4 is attached to the drawer member 13 and when the drawer member 13 is pushed into the main body 100a, the developing roller 40 does not contact the photosensitive drum 1. For this reason, it is possible to prevent the developing roller 40 and the surface of the photosensitive drum 1 from being damaged by vibration or the like accompanying the mounting operation.

<Development cartridge positioning configuration>
A configuration for positioning the cartridge 4 with respect to the main body 100a will be described with reference to FIG. FIG. 11 is a sectional view showing a state where the positioning of the cartridge 4 is completed. In FIG. 11, only the members related to the positioning of the cartridge 4 among the various members on the main body side are shown. In association with the operation of closing the door 10, the cartridge 4 moves from a position where the developing roller 40 is separated from the photosensitive drum 1 (FIG. 10B) to a position where the developing roller 40 contacts the drum 1 (FIG. 1A). ) And FIG. 11). As a result, an image can be formed. At this time, the drum 1 comes into contact with the belt 11.

  Such an interlocking mechanism will be described below. As described above, the main body 100a is provided with the pressing members (contact mechanisms) 65 and 66. The pressing members 65 and 66 move downward with the operation of closing the door (opening / closing member) 10 to elastically press the upper surface 4 r of the cartridge 4. As a result, the cartridge 4 is positioned in the main body 100. The pressing members 65 and 66 are interlocked with the opening / closing operation of the door 10 by connecting means (details will be described later). In a state where the door 10 is opened (FIGS. 2A and 2B), the pressing members 65 and 66 are retracted to a position that does not hinder the movement of the drawer member 13. Therefore, there is no problem in the mounting operation of the drawer member 13. Then, the drawer member 13 is positioned at the inner position I, and the door 10 is closed. Thereby, the pressing members 65 and 66 move the cartridge 4 downward against the elastic force of the springs 32 and 33.

  The connection means between the pressing members 65 and 66 and the door 10 will be described with reference to FIG. FIG. 12A shows a state in which the door 10 is opened, and FIG. 12B shows a state in which the door 10 is closed. In addition, components other than the door 10 and the pressing member 65 and their connecting means are omitted.

  As shown in FIG. 12A, chipped gears 101 (the other end side is not shown) are provided at both ends of the rotation axis J <b> 1 of the door 10. The gear 101 rotates in conjunction with the door 10. The gear 101 transmits drive to the rail unit 106 via the intermediate gear 103 and the transmission gear 104. At one end of the unit 106, a rack portion 106f for engaging with the gear 104 is provided. Therefore, according to the opening / closing operation of the door 10, the gears 103 and 104 rotate in the directions of the arrows, and the unit 106 can be moved in the directions of the arrows S1 and S2. The unit 106 is provided with a biasing member 107 that presses the pressing members 65 and 66, and a biasing piece 108 attached to the tip of the biasing member 107. The urging member 107 and the urging piece 108 are both housed in the recess 106a and are configured to be movable in the vertical direction. A force applying portion 106b for moving the pressing members 65 and 66 from the pressing position (FIG. 12 (b)) to the non-pressing position (FIG. 12 (a)) is provided downstream of the recess 106a in the insertion direction of the drawer member 13. Is provided. Since the mechanisms of the pressing members 65 and 66 are the same, only the mechanism of the pressing member 65 will be described.

  First, the door 10 is closed from the state shown in FIG. The gear 101 moves the unit 106 in the arrow S1 direction via the gears 103 and 104. The pressing member 65 in the non-pressing position (FIG. 12A) has one end 65b abutting against the tapered surface 108a provided on the urging piece 108, and rotates in the direction of the arrow about the rotation axis J2. . The pressing member 65 a provided at the other end of the pressing member 65 elastically presses the upper surface 4 r of the cartridge 4 by the rotation operation, and the cartridge 4 is positioned in the main body 100. The urging member 107 and the urging piece 108 are compressed in the recess 106 a and press the cartridge with an urging force corresponding to the compression amount of the urging member 107. At this time, a predetermined pressing force can be generated by setting the urging force of the urging member 107 higher than the urging force of the springs 33 and 34 provided on the pull-out member. When the predetermined image formation is completed and the door 10 is opened, the gear 101 rotates the gear 103 and the gear 104 in the opposite direction. Unit 106 moves in the direction of arrow S2. And the one end part 65b of a press member contact | abuts to the force provision part 106b which is a taper surface provided in the unit 106, and rotates to the non-pressing position shown to Fig.12 (a) centering on the rotating shaft J2. The one end portion 65 b is accommodated in a recess 106 c provided in the unit 106. The urging member 107 and the urging piece 108 return to their original positions. The cartridge 4 (developing roller 40) from which the pressing members 65 and 66 are released is separated from the photosensitive drum 1 again by the urging force of the springs 33 and 34. As described above, the protrusions 48a and 48b are provided at both ends in the longitudinal direction of the cartridge 4 (FIGS. 6A and 6B). The pressing members 65 and 66 press the upper surface 4r of the cartridge 4 corresponding to the protrusions 48a and 48b downward in the short direction of the cartridge 4 (FIG. 10). Due to this pressing force (elastic force), the protrusions 48 a and 48 b push the support portions 31 and 32 (see FIGS. 6 and 7) downward against the elastic force of the springs (elastic members) 33 and 34. As a result, the guided portions 46 and 47 (FIGS. 7A and 7B) provided at the end of the cartridge 4 move downward along the guide portions 13i and 13j. Then, the guided portions 46 and 47 finally come into contact with the positioning portions 13i1 and 13j1 and stop. In this state, the developing roller 40 contacts the photosensitive drum 1. Then, an image can be formed (FIG. 1A). That is, the pressing members (contact mechanisms) 65 and 66 release the separated state between the surface of the developing roller 40 and the surface of the photosensitive drum 1 by the support portions (separating mechanisms) 31 and 32. And the pressing members 65 and 66 make the surface of both contact. Note that the short direction of the cartridge 4 is a direction orthogonal to the longitudinal direction of the cartridge 4 (a direction orthogonal to the developing roller 40).

2A and 9A, the guide 64 is provided with recesses 64c to 64f at equal intervals. Further, an escape portion 13g1 is provided in a part of the opening portion 13g. The concave portions 64c to 64f and the escape portion 13g1 are provided so that the force receiving portion 42a does not hinder the movement when the cartridge 4 is moved downward by being pressed by the pressing members 65 and 66. That is, when the cartridge 4 is pressed downward by the pressing members 65 and 66, the force receiving portion 42a moves in the recesses 64c, 64d, 64e, 64f and the escape portion 13g1. Therefore, the movement of the cartridge 4 is not hindered. Further, the shutter 42 does not deviate greatly from the exposure position.

  As described above, when the door 10 is closed, an image can be formed, and an image forming operation by the above-described image forming process can be performed. Incidentally, the transfer belt 11 is retracted by a separating means (not shown) so as not to rub against the photosensitive drum 1 when the drawer member 13 is moved. When the door 10 is closed, the separated state is released, and the photosensitive drum 1 comes into contact with the transfer belt 11.

<Development cartridge removal work>
Next, replacement of the cartridge 4 will be described. The replacement of the cartridge 4 is performed, for example, when the toner is consumed and is lost. When removing the cartridge 4 from the main body 100a, first, the door 10 is opened. Thereby, the pressing to the protrusions 48a and 48b by the pressing members 65 and 66 is released. Thereby, the cartridge 4 moves upward by the elastic force of the springs 33 and 34 (state shown in FIG. 10). Then, the user pulls out the drawer member 13 from the main body 100a in the direction of the arrow D2 (FIG. 1B). In the process of pulling out the drawer member 13, when the force receiving portion 42 a passes the end portion 64 a of the shutter guide 64, the shutter 42 returns to the protection position Q 1 by the elastic force (biasing force) of the spring 49. The same applies to the shutter 29. That is, when the force receiving portion 29a passes the end portion 25a of the shutter guide 25, the shutter 29 returns to the protection position P1 by the elastic force (biasing force) of the spring (elastic member) 29b.

  As described above, when the drawer member 13 is pulled out, all the shutters 42 and 29 return to the protection position (original position). As a result, when the drawer member 13 is positioned at the outer position O, the developing roller 40 and the photosensitive drum 1 are protected. In this state, the user can remove the cartridge 4 from the drawer member 13 by lifting the cartridge 4 upward. At this time, the developing roller 40 and the photosensitive drum 1 are separated by a gap g by the support portions 31 and 32. This is as described above.

<Excellent points of image forming apparatus according to this reference example >
As described above, according to the image forming apparatus 100 according to the present reference example , the plurality of cartridges 4 can be mounted together in the main body 100a by the pull-out member 13, and can be pulled out of the apparatus main body. . The cartridge 4 is provided with a shutter 42 configured to be movable between a protective position Q1 that covers the surface of the developing roller 40 and a retracted position Q2 that exposes the surface of the developing roller 40. The shutter 42 is in the protection position Q1 when the cartridge 4 is a single body and when the drawer member 13 is positioned at the outer position O that is pulled out of the main body 100a. Accordingly, the user does not carelessly touch the surface of the developing roller 40 when the cartridge 4 is attached to or detached from the drawer member 13. Therefore, workability when replacing the cartridge 4 is improved. Further, it is possible to prevent the surface of the developing roller 40 from being damaged when the cartridge 4 is replaced. The shutter 42 is configured to be interlocked with the movement operation of the drawer member 13 in a state where the cartridge 4 is mounted on the drawer member 13. That is, when the drawer member 13 moves from the outer position O to the inner position I, the shutter 42 moves from the protection position Q1 to the retracted position Q2 in conjunction with this movement. Conversely, when the drawer member 13 moves from the inner position I to the outer position O, the shutter 42 moves from the retracted position Q2 to the protected position Q1 in conjunction with this movement. Thus, the opening / closing operation of the shutter 42 can be automatically performed by the user's operation of moving the drawer member 13. Therefore, it is not necessary for the user to open and close the shutter 42 separately. Further, in this reference example , the movement timings of the shutters 42 provided in each of the four cartridges 4 are different. That is, in the process in which the drawer member 13 moves from the outer position O to the inner position I, the shutter 42 is moved in the order of the cartridge 4y, the cartridge 4m, the cartridge 4c, and the cartridge 4k. Therefore, in addition to the force for pushing the drawer member 13, a force for moving the shutter 42 is required, but the mounting workability of the drawer member 13 is not deteriorated. This is because the movement timings of the four shutters 42 are different. In the present reference example , a support portion (contact / separation mechanism) is provided for bringing the drum 1 and the developing roller 40 into contact with or separating from each other with the cartridge 4 mounted (supported) on the drawer member 13. Yes. That is, in the state where the drawer member 13 is pulled out to the outer position O, the drum 1 and the developing roller 40 are separated from each other. Further, according to this reference example , even when the drawer member 13 is in the inner position I, the drum 1 and the developing roller 40 are separated when the door 10 is opened. When the drawer member 13 is mounted inside the main body and the door 10 is closed, the drum 1 and the developing roller 40 come into contact with each other. Accordingly, it is possible to prevent the surface of the drum 1 and the surface of the developing roller 40 from being damaged when the developing cartridge 4 is attached or detached. Further, a gap g can be formed between the shutters 29 and 42 so that the shutters 29 and 42 can move from the retracted positions P2 and Q2 to the protected positions P1 and Q1. That is, the shutters 29 and 42 can be positioned at the retracted positions P2 and Q2. In this reference example , a shutter 29 configured to be movable between the protection position P1 and the retracted position P2 is provided. The shutter 29 is in the protection position P1 when the drawer member 13 is pulled out from the main body 100a. The position covered by the shutter 29 is a portion located above the horizontal plane L passing through the center O of the drum 1 and is a portion that becomes a contact surface with the developing roller 40 on the peripheral surface of the drum 1 (FIG. 3A )). Further, in this reference example , the cartridge 4 is located at the separated position when mounted on the drawer member 13 (supported state). Here, the separation position is a position where the drum 1 and the cartridge 4 are separated (FIGS. 1B, 9C, 9B, 9C, and 10). That is, the photosensitive drum 1 and the developing roller 40 are separated from each other. Further, the cartridge 4 is mounted on the drawer member 13 from the upper side to the lower side in the vertical direction. Therefore, as described above, it is possible to prevent the surface of the drum 1 from being damaged during the mounting operation of the cartridge 4 in conjunction with the mounting of the cartridge 4 with respect to the drawer member 13 in the spaced position. Further, according to the present reference example , even if foreign matter falls toward the surface of the drum 1 during the mounting operation, the shutter 29 can prevent it. In addition, according to this reference example , since it covers the upper side from the horizontal surface L, it is hard to receive the influence of a fallen object.

  It goes without saying that the action of the shutter 29 can be applied even when the shutter 42 covering the surface of the developing roller 40 is not provided. In addition, although it is the area | region of the drum 1 which the shutter 29 has covered, it is not necessary to cover all the parts located above the horizontal surface L which passes along the centerline (axis line) O of the drum 1, and it may also cover partially. The above-mentioned purpose can be achieved. As described above, according to the apparatus 100, the replacement work of the cartridge 4 can be performed very easily. In addition, it is possible to prevent the developing roller 40 from being damaged during the replacement work.

<Others>
In Reference Example 1, the drum 1 and the charging member 2 are rotatably mounted on the drawer member 13, and the cleaning member 6 is mounted. That is, these are attached to the drawer member 13 so that the user cannot remove them . Also, in Reference Example 1, showing the configuration of a case of providing the shutter 29 for protecting the surface of the drum 1.

(Example 1 )
A first embodiment to which the present invention is applied will be described with reference to FIGS. In the reference example 1, the configuration in which the shutter 42 is interlocked with the movement of the drawer member 13 is shown. In this embodiment, the opening and closing of the shutter for protecting the developing roller is interlocked with the operation of attaching and detaching the cartridge to and from the drawer member. Since other configurations and operations are the same as those in Reference Example 1, the same components are appropriately denoted by the same reference numerals, and description thereof is omitted.

FIG. 13 is a perspective view of the developing cartridge according to the first embodiment. FIG. 14A is a perspective view of the drawer member according to the first embodiment. FIG. 14B is a perspective view showing a state in which the developing cartridge is mounted on the drawer member. In FIG. 14B, the main body is shown in a simplified manner. FIG. 15 is a view showing a mechanism when the developing cartridge is mounted on the drawer member. FIG. 16A is a side view showing a state where the positioning of the developing cartridge is completed. FIG. 16B is a cross-sectional view showing a state where the positioning of the developing cartridge is completed. 16A and 16B show only members related to positioning of the developing cartridge among various members on the main body side.

This embodiment is different from the reference example 1 in that a shutter 52 for protecting the surface of the developing roller 40 is interlocked by an operation of attaching and detaching the developing cartridge 50 to and from the drawer member 51.

As shown in FIG. 13, the shutter 52 for protecting the surface of the developing roller 40 has a shape extending in the longitudinal direction so as to cover almost the entire longitudinal region of the developing roller 40. As in the case of Reference Example 1, the shutter 52 is rotatably supported within a certain range. The shutter 52 covers the surface of the developing roller 40 (FIG. 15A) and the developing roller 40. It is configured to be movable between a retreat position R2 (FIG. 15D) that exposes the surface. The shutter 52 is urged toward the protection position by the elastic force of the spring (elastic member) 53, and the shutter 52 is maintained at the protection position R1 unless an external force is applied. Further, a force receiving portion 52 a protrudes outward in the longitudinal direction at one end portion in the longitudinal direction of the shutter 52 (one longitudinal end portion of the developing roller 40). The force receiving portion 52a receives force from slopes (force applying portions) 51b and 51c provided on the drawer member 51, and moves the shutter 52 to the retracted position R2 against the elastic force of the spring 53.

As shown in FIG. 14A, an opening 51 a into which the force receiving portion 52 a is inserted is provided on the side of the drawer member 51. The opening 51a is provided with slopes (force applying portions) 51b and 51c. A linear portion (first straight portion) 51d that extends linearly is provided below the slope (first slope) 51b. Further, a linear portion (second linear portion) 51e that linearly extends is also provided below the inclined surface (second inclined surface) 51c. The cartridge 50 (50y, 50m, 50c, 50k) according to the present embodiment is mounted on each mounting portion 51h provided on the drawer member 51. Also in the case of the present embodiment, the cartridge 50 is mounted by the user in a state where the drawer member 51 is located at the outer position O drawn from the main body 100a. That is, the cartridge 50 is attached to the drawer member 51 from the upper side to the lower side in the substantially vertical direction (the arrow C direction and the gravity direction in FIG. 14B). The cartridge 50 is removed from the drawer member 51 in the opposite direction.

Next, a mechanism when the cartridge 50 is mounted on the drawer member 51 will be described with reference to FIG. The user mounts the cartridge 50 in the direction of arrow C with respect to the drawer member 51. At this time, first, the force receiving portion 52a hits the slope 51b. Further, by moving the cartridge 50 in the arrow C direction, the shutter 52 receives a force from the inclined surface 51b and starts moving in the arrow F1 direction (see FIG. 15A). When the cartridge 50 is further moved downward, the force receiving portion 52a passes through the slope 51b and reaches the straight portion 51d. The shutter 52 is moved downward by the elastic force (biasing force) of the spring (elastic member) 53 while the force receiving portion 52a slides on the side surface of the linear portion 51d (see FIG. 15B). Thereafter, the force receiving portion 52a contacts the slope 51c, and the shutter 52 further moves in the direction of arrow F1 (see FIG. 15C).

Finally, the cartridge 50 is moved until the protrusion 48a hits the support portion 31 provided on the drawer member 51 (see FIG. 15D). Note that the shutter 52 further rotates in the direction of the retracted position R2 while the force receiving portion 52a is moving along the linear portion 51e. Then, the shutter 52 stops at the position shown in FIG. This position is the retracted position R2 of the shutter 52. At this time, the force receiving portion 52 a is in contact with the inclined surface 51 c by the elastic force of the spring 53. In this way, the shutter 52 moves to the retracted position R2 and is maintained in that state. As in Reference Example 1, each developing roller 40 is kept away from the drum 1 when the shutter 52 is operated. Accordingly, the shutter 52 moves (rotates) without interfering with the drum 1. Similarly, the shutter 29 moves (rotates) without interfering with the cartridge 4. The configuration in which the drum 1 and the developing roller 40 are separated from and in contact with each other is the same as that in the first reference example . In the present embodiment, by providing the support portions 31 and 32, when the inclined surface 51b, the inclined surface 51c, the linear portion 51d, and the like are provided, these can be further arranged near the drum 1. Therefore, the height of the drawer member 51 can be reduced. Therefore, if the support portions 31 and 32 are not provided, when the shutter 52 is rotated, it is necessary to rotate the shutter 52 at a location far from the surface of the drum 1. This is to prevent the shutter 52 from interfering with the drum 1. In the case where the support portions 31 and 32 are not provided, it is necessary to dispose portions (the inclined surface 51b, the inclined surface 51c, and the straight portion 51d in this embodiment) that are in contact with the shutter 52 and rotate the shutter 52 at a location far from the drum 1. There is. In such a case, it is necessary to enlarge the drawer member 51. However, according to the present embodiment, since the support portions 31 and 32 are provided, the drawer member 51 does not need to be particularly large. Further, according to this embodiment, the developing roller 40 does not come into contact with the drum 1 during the mounting operation of the drawer member 51. Therefore, it is possible to suppress the development roller 40 and the surface of the drum 1 from being damaged due to vibration associated with the mounting operation. Further, the drawer member 51 is mounted in the main body 100a in a state where all the cartridges 50 are mounted on the drawer member 51. Further, in the process in which the drawer member 51 is mounted in the main body 100a, the shutter 29 moves from the protection position P1 to be protected to the retracted position P2. This configuration is the same as in Reference Example 1.

  In conjunction with the closing operation of the door 10, the pressing members 65 and 66 move downward to press the upper surface of the cartridge 50. As a result, the cartridge 50 moves downward. At this time, the developing roller 40 moves from a position separated from the drum 1 to a position in contact with the drum 1.

  FIGS. 16A and 16B show a state when the developing roller 40 is in contact with the photosensitive drum 1. At this time, the force receiving portions 52a are respectively located in the linear portions 51c, and at this time, the shutter 52 is in the retracted position. FIG. 16B is a cross-sectional view of the drawer unit U2 and the cartridge 50. In this figure, the drum 1 and the developing roller 40 are in contact with each other and an image can be formed. That is, the drum 1 and the belt 11 are in contact with each other.

With the configuration as described above, the same effect as in Reference Example 1 can be obtained in this embodiment. In the present embodiment, the shutter 52 is configured to be interlocked with the attaching / detaching operation of the cartridge 50 with respect to the drawer member 51. That is, in the process of mounting the cartridge 50 on the drawer member 51, the shutter 52 moves from the protection position R1 to the retracted position R2 in conjunction with the mounting operation. On the other hand, in the process of removing the cartridge 50 from the drawer member 51, the shutter 52 moves from the retracted position R2 to the protected position R1 in conjunction with the removing operation. When the cartridge 50 is removed from the drawer member 51, it returns to the original position (protection position R1). This is because the shutter 52 is urged toward the protection position R1 by the elastic force of the spring (elastic member) 53. Thus, according to the present embodiment, the opening / closing operation of the shutter 52 is automatically performed by the attaching / detaching operation with respect to the cartridge 50 drawing member 51. Therefore, it is not necessary for the user to open and close the shutter 52 separately. Thus, also in the present embodiment, the same effect as in the case of the reference example 1 can be obtained. Further, in this embodiment, when the drawer member 51 is moved, a force for moving the shutter 52 is unnecessary. For this reason, in this embodiment, the force required to move the drawer member 51 can be reduced compared to the case of the reference example 1. The developing roller 40 is in a state of being separated from the photosensitive drum 1 with the cartridge 50 mounted on the drawer member 51. Further, the doors 10 are brought into contact with each other in conjunction with the operation of closing the door 10 in a state where the drawer member 51 is positioned at the inner position I. The fact that these contact / separation mechanisms are provided is the same as in Reference Example 1. Therefore, the operational effects relating to this contact / separation mechanism are the same as those in Reference Example 1.

( Reference Example 2 )
A reference example 2 of the present invention will be described with reference to FIGS. In Reference Example 1, the configuration in which the photosensitive drum, the charging member, the cleaning member, and the like are installed (fixed) on the drawer member is shown. In the present reference example , these are provided on the main body 100a side, and a configuration in which only the developing cartridge is mounted on the drawer member is shown. Since other configurations and operations are the same as those in Reference Example 1, the same components are appropriately denoted by the same reference numerals, and description thereof is omitted.

FIG. 17A is a cross-sectional view illustrating a state in which the drawer member is pulled out in the image forming apparatus according to Reference Example 2 . FIG. 17B is a cross-sectional view illustrating a state in which the drawer member is mounted in the main body and the door is opened in the image forming apparatus according to Reference Example 2 . FIG. 18 is a cross-sectional view of an image forming apparatus according to Reference Example 2 .

This reference example is different from the reference example 1 in that a photosensitive drum 81, a charging member (charging roller) 82, and a cleaning member (cleaning blade) 83 are provided in the main body 100a. Accordingly, only the developing cartridge 84 (84y, 84m, 84c, 84k) is mounted on the drawer member 80.

Also in this reference example , the cartridge 84 is mounted on the drawer member 80 in a state where the drawer member 80 is located at the outer position O. At this time, the shutter 85 provided in the cartridge 84 is in the protection position Q1 as in the case of the reference example 1 (FIG. 17A). With the cartridge 84 attached to the drawer member 80, the drawer member 80 is pushed into the main body 100a (in the direction of arrow D1 in FIG. 17A). When the drawer member 80 is moved in the pushing direction, the shutter 85 is interlocked with the movement operation of the drawer member 80. That is, the developing roller shutter guide 87 is provided on the main body 100a, and the shutter 85 moves from the protection position Q1 (FIG. 17A) to the retracted position Q2 (FIG. 17B) as the drawer member 80 moves. Move to the position shown in. This configuration is the same as the configuration of Reference Example 1. The shutter 85 corresponds to the shutter 42, and the shutter guide 87 corresponds to the shutter guide 64. In this reference example , the drum 81, the charging member 82, and the cleaning member 83 are provided below the drawing member 80 and the passage region of the cartridge 84 attached to the drawing member 80 (FIGS. 17A and 17B). ). Therefore, these members do not hinder the movement of the drawer member 80. Then, after the drawer member 80 is mounted in the main body 100a, when the door 10 is closed, the drawer member 80 is moved downward by the connecting means (not shown) (the drawer member 80 is located at the position shown in FIG. 17B). To descend). As a result, the developing roller 86 provided in the cartridge 84 comes into contact with the drum 81, and an image forming operation is possible (see FIG. 18). The drum 81 is in contact with the belt 11. The cartridge 84 is provided with a shutter 85 configured to be movable between a protection position Q1 and a retracted position Q2. The shutter 85 is in the protection position Q1 when the cartridge 84 is in a single state and when the cartridge 84 is simply mounted on the drawer member 80 drawn out of the main body 100a. Accordingly, it is possible to prevent the user from inadvertently coming into contact with the surface of the developing roller 86 during the operation of attaching / detaching the cartridge 84 to / from the drawer member 80. Further, the surface of the developing roller 86 can be prevented from being damaged when the cartridge 84 is replaced. Also in this reference example , the opening and closing of the shutter 85 is configured to be interlocked with the moving operation of the drawer member 80 in a state where the cartridge 84 is mounted on the drawer member 80. This is the same as in Reference Example 1. Accordingly, the opening / closing operation of the shutter 85 can be automatically performed by the movement operation of the drawer member 80. Therefore, it is not necessary for the user to open and close the shutter 85 separately. Further, in this reference example , in a state where the drawer member 80 is pulled out of the main body 100a, and a state where the drawer member 80 is mounted inside the main body 100a and the door 10 is open, the photosensitive member is exposed. The body drum 81 and the developing roller 86 are separated from each other. When the drawer member 80 is mounted inside the main body 100a and the door 10 is closed, the drum 81 and the developing roller 86 come into contact with each other. Therefore, when the cartridge 84 is attached to and detached from the drawer member 80, the surface of the drum 81 and the surface of the developing roller 86 can be suppressed from being damaged. In this reference example , as in the case of the reference example 1, the configuration in the case where the shutter 85 moves in conjunction with the movement of the drawer member 80 is shown. However, in the configuration in which the photosensitive drum 81 is provided on the main body 100a side, as shown in the first embodiment, the opening / closing of the shutter for protecting the surface of the developing roller is interlocked with the operation of attaching / detaching the cartridge to / from the drawer member. It is also possible to adopt a configuration that does this.

( Reference Example 3 )
Reference Example 3 of the present invention will be described with reference to FIGS. 19 (a) and 19 (b) and FIGS. 20 (a), 20 (b), and 20 (c). In the reference example 1, the configuration in which the opening and closing of the drum shutter is interlocked with the movement of the drawer member has been described. In this reference example , a description will be given of a configuration in which opening and closing of the drum shutter is interlocked with an operation of attaching and detaching the developing cartridge to and from the drawer member.

A developing cartridge 94 of this reference example is shown in FIG. This reference example is different from the reference example 1 in that one end of the cartridge 94 has a protrusion (force applying portion) 97 that receives a force for opening the drum shutter 96 from the main body 100a.

  The protrusion 97 protrudes toward the downstream side in the mounting direction (the direction from the top to the bottom in the vertical direction, the direction of arrow C in FIG. 19B) in which the cartridge 94 is mounted on the drawer member 51. The protrusion 97 is one end in the longitudinal direction of the cartridge 94 (longitudinal direction of the developing roller), and is disposed further outside the shutter 52 in the longitudinal direction. The protrusion 97 is fixed to the side cover 94s1.

FIG. 19B is a view showing a state before the cartridge 94 is mounted on the drawer member 51. In the present reference example , an engaging portion (force receiving portion) 96 a is provided at a position corresponding to the protrusion 97 of the cartridge 94 to be mounted at the longitudinal end portion of the shutter 96. The engaging portion 96 a is provided integrally with the shutter 96. Accordingly, the shutter 96 and the engaging portion 96a are interlocked. That is, when the engaging portion 96a is rotated around the drum 1, the shutter 96 is also rotated. Note that the engaging portion 96a may be a separate body from the shutter 96 as long as both are interlocked.

A state in which the shutter 96 is interlocked with the mounting operation of the cartridge 94 will be described with reference to FIG. In the state shown in FIG. 19, at least a portion of the surface of the drum 1 that is located above the horizontal plane L passing through the center (axis) of the drum 1 is covered (FIG. 19B). Therefore, it is possible to prevent any member or fallen object from colliding with the upper side of the drum 1 when the cartridge 94 is attached or detached. Therefore, the surface of the drum 1 can be prevented from being damaged.
Further, it is possible to prevent the user from inadvertently touching the surface of the photosensitive drum 1.

When the cartridge 94 is further lowered from the state shown in FIG. 19B, the protrusion 97 starts to contact the engaging portion 96a (FIG. 20A). Further, when the cartridge 94 is lowered, the shutter 96 starts to move (rotate) from the protection position P1 toward the retracted position P2 in conjunction with the movement (rotation) of the engaging portion 96a. As a result, a part of the photosensitive drum 1 is exposed and can be brought into contact with the surface of the developing roller 40 (FIG. 20B). That is, according to this reference example , the shutter 96 does not move carelessly when the cartridge 94 is not attached. Therefore, the surface of the photosensitive drum 1 can be protected. Thereafter, the drawer member 51 is pushed into the main body 100a. Then, the door 10 is closed. In conjunction with the operation of closing the door 10, the pressing members 65 and 66 press the upper surface of the cartridge 94 downward. As a result, the cartridge 94 supported by the springs 33 and 34 is lowered (moved downward). As a result, the developing roller 40 moves from a position away from the drum 1 to a position in contact with the drum 1 (FIG. 20C). The configuration for separating the developing roller 40 from the drum 1 and the configuration for bringing them into contact with each other are the same as those in the first reference example .

In this reference example , the shutter 52 is provided on the surface of the developing roller 4. For example, the opening and closing of the shutter 52 may be the same as in the first embodiment. That is, the shutter 52 may be moved from the protection position Q1 to the retracted position Q2 in conjunction with the operation of mounting the cartridge 94 on the drawer member 51. Further, as shown in Reference Example 1, the movement of the shutter 52 may be interlocked with the operation of the drawer member 51 moving from the outer position O to the inner position I. Alternatively, the shutter 52 may be omitted only for the purpose of protecting the upper surface of the photosensitive drum 1.

According to this reference example , the above-described effects similar to those of the above-described reference examples and Example 1 can be obtained. Further, according to the present reference example , as in the first reference example , a contact / separation mechanism (contact mechanism and separation mechanism) for bringing the drum 1 and the developing roller 40 into contact with each other or separating them from each other is provided. Accordingly, it is possible to prevent the surface of the drum 1 and the surface of the developing roller 40 from being damaged when the cartridge 94 is attached or detached. Further, a gap g can be formed between the shutter 52 and the drum shutter 96 so that the shutter 52 and the drum shutter 96 can be moved from the positions covering the respective surfaces to the exposed positions.

  1,81 Electrophotographic photosensitive drum (photosensitive drum, drum), 4, 50, 84, 94 Developer cartridge, 10 Door (opening / closing member), 13, 51, 80 Drawer member (cartridge support member), 25, 64 Shutter Guide, 29, 96 Drum shutter, 40 Developing roller, 42, 52, 85 Shutter, 97 Protrusion, 100 Electrophotographic image forming apparatus (image forming apparatus)

Claims (2)

In an electrophotographic image forming apparatus for forming an image on a recording medium,
An electrophotographic photosensitive drum;
A developing roller for developing the electrostatic latent image formed on the electrophotographic photosensitive drum; a developer containing portion for containing the developer used by the developing roller for developing the electrostatic latent image; and a periphery of the developing roller. An electrophotographic image forming apparatus, comprising: a protective position that covers a part of the surface; and a developing roller shutter that moves between the protective position and a retracted position that retracts from the protective position and exposes a part of the peripheral surface of the developing roller. A developing cartridge that is detachably mounted on the apparatus main body of the apparatus;
In order to mount the developing cartridge on the apparatus main body, an inner position located inside the apparatus main body and an outer position located outside the apparatus main body in order to pull out the developing cartridge from the apparatus main body. A cartridge support member that moves in a state in which the developer cartridge is detachably supported, and
A force receiving portion provided in the developing cartridge, the force receiving portion receiving a force for moving the developing roller shutter from the protection position to the retracted position;
A force applying portion provided in the cartridge support member, the first inclined surface provided in the opening, the first straight portion extending below the first inclined surface, and the first straight line A force applying portion having a second slope extending downward from the portion and a second linear portion extending downward from the second slope ;
Said to lie electrophotographic photosensitive drum and the developing roller moves away, the supports and the longitudinal direction of the one end and the other end of the developing cartridge, a said cartridge supporting portion provided on the support member When the cartridge support member is moved from the upper side to the lower side in order to cause the cartridge support member to support the developer cartridge with the cartridge support member positioned at the outer position, The first linear portion of the force applying portion as the force receiving portion comes into contact with the first inclined surface of the force applying portion and the developing cartridge further enters the cartridge support member. , said second inclined surface, and the force receiving portion successively in contact with the second straight portion are subjected to the force from said force applying portion, said current The roller shutter in the state of being moved to the retracted position from said protected position, said as cartridge supporting member and the electrophotographic photosensitive drum which is supported on the said developing roller is spaced apart, the said developing cartridge a support portion for supporting said one end side in the longitudinal direction and the other end side,
With the cartridge support member positioned at the inner position, the pressing member that presses the developing cartridge to bring the electrophotographic photosensitive drum positioned away from the developing roller into contact with each other, and
An electrophotographic image forming apparatus comprising:   The electrophotographic image forming apparatus according to claim 1, wherein the developing cartridge includes an elastic member that urges the developing roller shutter toward the protection position.

Images