JP2023073361A - Image forming apparatus and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the configuration of a mechanism that separates an image carrier and a developer carrier in a process cartridge from each other.

SOLUTION: An image forming apparatus comprises: an attachment part to which process cartridges P are removably attached; and engaging members 61 that can engage with force receiving parts provided on second units 4 of the process cartridges P. The engaging members 61 are each movable to three different positions: a first position for engaging with the force receiving part 44b of the second unit 4 to maintain the second unit 4 at a separation position; a second position for permitting the second unit 4 from moving from the separation position to a contact position during image formation; and a third position for, when the process cartridge P is attached to the attachment part, being pressed by the process cartridge P to retreat, thereby permitting the process cartridge P to be attached.

SELECTED DRAWING: Figure 15

COPYRIGHT: (C)2023,JPO&INPIT

Description

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

Here, the image forming apparatus forms an image on a recording medium. Examples of image forming apparatuses include electrophotographic copiers and electrophotographic printers (laser beam printers, LED printers, etc.).

A recording medium is one on which an image is formed using an electrophotographic image forming process. Examples include recording paper, OHP sheets, labels, and the like.

A process cartridge is a cartridge that integrally includes an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member, and is detachable from the main body of the image forming apparatus.

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic forming process, an electrophotographic photoreceptor (hereinafter referred to as a photoreceptor drum) and process means acting on the photoreceptor drum are integrated into a cartridge. A process cartridge system is adopted in which the cartridge is detachable from the main body of the image forming apparatus.

According to this process cartridge system, the maintenance of the image forming apparatus can be performed by the user himself/herself without relying on service personnel, so that the maintainability can be improved remarkably. Therefore, the process cartridge system is widely used in image forming apparatuses.

A conventional process cartridge includes a photoreceptor drum unit having a cleaning frame for holding the photoreceptor drum, a developing unit having a developing roller and a developing blade as means for developing a latent image on the photoreceptor drum, and toner as a developer. consists of

2. Description of the Related Art There is known an image forming apparatus called an in-line system in which a plurality of process cartridges are arranged. This in-line image forming apparatus has a process cartridge having a photosensitive drum and a developing unit for each color of yellow, magenta, cyan, and black, and superimposes images of each color to form a full-color image.

When forming an image, the developing roller is urged toward the photosensitive drum with a predetermined pressure. In the contact development method in which the developing roller is in contact with the photosensitive drum for development, the developing roller is in contact with the surface of the photosensitive drum with a predetermined pressure.

For example, when a developing roller having an elastic layer is used and the elastic layer is brought into contact with the surface of the photosensitive drum and the developing roller is not used for a long period of time, the elastic layer of the developing roller may be deformed. This may cause image unevenness during development.

As another example, regardless of the presence or absence of the elastic layer, if the developing roller is in contact with the photosensitive drum during non-image formation, the developer carried by the developing roller will unnecessarily adhere to the photosensitive drum. There is As another example, if the photoreceptor drum and the developing roller are in contact with each other and are rotating at times other than during development, the contact between the photoreceptor drum and the developing roller may occur due to rubbing between the photoreceptor drum and the developing roller. , deterioration of the developer may be accelerated.

In view of this, Japanese Patent Laid-Open No. 2002-100001 discloses a configuration in which a mechanism is provided in the apparatus main body of an image forming apparatus to separate the photosensitive drum and the developing roller by acting on the process cartridge when image formation is not performed. This image forming apparatus has a structure in which the process cartridge is mounted on a drawer member movably provided in the apparatus main body, and the process cartridge is mounted inside the image forming apparatus together with the drawer member. When the drawer member is moved to attach or detach the process cartridge to/from the main body of the apparatus, the separating mechanism is retracted from the moving path of the process cartridge so as not to interfere with the process cartridge.

JP 2007-213024 A

The present invention is a further development of the prior art described above. SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive and compact image forming apparatus and process cartridge by simplifying the configuration of a mechanism for separating an image carrier and a developer carrier of a process cartridge.

Another object of the present invention is to provide an image forming apparatus in which, when the process cartridge is mounted in the apparatus main body of the image forming apparatus, an engaging member on the side of the apparatus main body which engages with the process cartridge is retracted so that the process cartridge can be securely mounted. . Another object of the present invention is to provide a detachable process cartridge for this image forming apparatus.

The configuration of the invention according to the present application is
a process cartridge,
a photoreceptor drum;
a first frame supporting the photoreceptor drum so that the photoreceptor drum is rotatable about its rotational axis;
a developing roller;
supporting the developing roller so that the developing roller is rotatable about its rotational axis; and attaching the developing roller to the photosensitive drum so that the latent image on the photosensitive drum can be developed by the developing roller. a second frame that can swing about a swing axis with respect to the first frame between a first position of contact and a second position of separating the developing roller from the photosensitive drum; ,
a projection configured to receive a force from outside the process cartridge for moving the second frame from the first position to the second position;
(i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotation axis of the roller, (I) the projection is positioned below the photosensitive drum, and (II) the photosensitive drum is positioned below the photosensitive drum. When viewed along the axis of the body drum, the projection is a process cartridge provided so as to pass through a vertical line drawn from the swing shaft.

Also, another configuration of the present application is:
A process cartridge,
a photoreceptor drum;
a first frame supporting the photoreceptor drum so that the photoreceptor drum is rotatable about its rotational axis;
a developing roller;
supporting the developing roller so that the developing roller is rotatable about its rotational axis; and attaching the developing roller to the photosensitive drum so that the latent image on the photosensitive drum can be developed by the developing roller. a second frame that can swing about a swing axis with respect to the first frame between a first position of contact and a second position of separating the developing roller from the photosensitive drum; ,
a force receiving portion that receives a force from outside the process cartridge for moving the second frame from the first position to the second position;
(i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotational axis of the photoreceptor drum is When the process cartridge is oriented so as to be positioned below the rotation axis of the developing roller, (I) the force receiving portion is positioned below the photosensitive drum, and ( II) In the process cartridge, when viewed along the axis of the photosensitive drum, the force receiving portion is provided so as to pass through a vertical line drawn from the swing shaft.
Also, another configuration of the present application is:
A process cartridge,
a photoreceptor drum;
a first frame supporting the photoreceptor drum so that the photoreceptor drum is rotatable about its rotational axis;
a developing roller;
supporting the developing roller so that the developing roller is rotatable about its rotational axis; and attaching the developing roller to the photosensitive drum so that the latent image on the photosensitive drum can be developed by the developing roller. a second frame that can swing about a swing axis with respect to the first frame between a first position of contact and a second position of separating the developing roller from the photosensitive drum; ,
a projection configured to receive a force from outside the process cartridge for moving the second frame from the first position to the second position;
(i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the axis of rotation of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotation axis of the roller, (I) the projection is positioned below the photosensitive drum, and (II) the photosensitive drum is positioned below the photosensitive drum. When viewed along the axis of the body drum, when a parallel line parallel to the force receiving surface of the protrusion is drawn to pass through the swing shaft, the protrusion is provided to pass through the parallel line. It is a process cartridge with

Also, another configuration of the present application is:
a process cartridge,
a photoreceptor drum;
a first frame supporting the photoreceptor drum so that the photoreceptor drum is rotatable about its rotational axis;
a developing roller;
supporting the developing roller so that the developing roller is rotatable about its rotational axis; and attaching the developing roller to the photosensitive drum so that the latent image on the photosensitive drum can be developed by the developing roller. a second frame that can swing about a swing axis with respect to the first frame between a first position of contact and a second position of separating the developing roller from the photosensitive drum; ,
a force receiving portion configured to receive a force from outside the process cartridge for moving the second frame from the first position to the second position;
(i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotational axis of the photoreceptor drum is When the process cartridge is oriented so as to be positioned below the rotation axis of the developing roller, (I) the force receiving portion is positioned below the photosensitive drum, and ( II) When viewed along the axis of the photoreceptor drum, when a parallel line parallel to the surface of the force receiving portion that receives the force is drawn through the swing shaft, the force receiving portion It is a process cartridge provided so as to pass through parallel lines.

As described above, according to the present invention, it is possible to simplify the configuration of the mechanism for separating the image carrier and the developer carrier of the process cartridge.

Further, when the process cartridge is mounted in the apparatus main body of the image forming apparatus, the engaging member of the apparatus main body that engages with the process cartridge can be retracted, so that the process cartridge can be securely mounted in the apparatus main body.

1 is a perspective view of an image forming apparatus according to Embodiment 1; FIG. 1 is a cross-sectional view of an image forming apparatus according to Embodiment 1; FIG. 1 is a cross-sectional view of an image forming apparatus according to Embodiment 1; FIG. 1 is a cross-sectional view of an image forming apparatus according to Embodiment 1; FIG. 1 is a cross-sectional view of an image forming apparatus according to Embodiment 1; FIG. (a) is a perspective view showing a state in which the opening/closing door is closed. (b) It is a perspective view showing a state in which the opening/closing door is open. (c) is a perspective view showing a state in which the cartridge tray is pulled out; (a) It is sectional drawing which shows the state which the opening-and-closing door closed. (b) is a cross-sectional view showing a state in which the opening/closing door is opened. 1 is a perspective view of a process cartridge according to Embodiment 1. FIG. (a) is a perspective view showing a process cartridge mounted. (b) is a perspective view showing a state in which the developing unit is in a contact position; (c) is a perspective view showing a state in which the developing unit is at the separated position; 1 is a cross-sectional view of a process cartridge according to Embodiment 1; FIG. 1 is a perspective view of a process cartridge according to Embodiment 1. FIG. 1 is a perspective view of a process cartridge according to Embodiment 1. FIG. 1 is a perspective view of a process cartridge according to Embodiment 1. FIG. (a) A diagram showing a moving member 62 and a spacing member 61; (b) a diagram showing the spacing member 61; (c) The figure which shows the moving member 62. FIG. (a) is a cross-sectional view showing a state where the process cartridge is mounted; (b) is a cross-sectional view showing a state in which the developing unit is in a contact position; (c) is a cross-sectional view showing a state in which the developing unit is at the separated position; 4 is a cross-sectional view showing the relationship between the process cartridge and the spacing mechanism according to the first embodiment; FIG. (a) is a cross-sectional view showing a state where the process cartridge is mounted; (b) is a cross-sectional view showing a state in which the developing unit is in a contact position; (c) is a cross-sectional view showing a state in which the developing unit is at the separated position; FIG. 11 is an enlarged view of a moving member and a spacing member according to Embodiment 2; FIG. 11 is an enlarged view of a moving member and a spacing member according to Embodiment 2; FIG. 11 is a cross-sectional view showing the relationship between the process cartridge and the spacing mechanism according to the third embodiment; FIG. 11 is a cross-sectional view of a process cartridge according to Example 3; FIG. 11 is a cross-sectional view of a process cartridge according to Example 3; FIG. 11 is a cross-sectional view showing the relationship between the process cartridge and the spacing mechanism according to the third embodiment; FIG. 11 is a cross-sectional view of a spacing mechanism according to Example 3; (a) is a cross-sectional view showing a state where the process cartridge is mounted; (b) is a cross-sectional view showing a state in which the developing unit is in a contact position; (c) is a cross-sectional view showing a state in which the developing unit is at the separated position; FIG. 12 is a cross-sectional view showing the relationship between the process cartridge and the spacing mechanism according to the fourth embodiment; FIG. 11 is a cross-sectional view of a spacing mechanism according to Example 4; FIG. 12 is a cross-sectional view showing the relationship between the process cartridge and the spacing mechanism according to the fourth embodiment; FIG. 11 is a cross-sectional view of a spacing mechanism according to Example 4; FIG. 11 is a cross-sectional view showing a process cartridge according to Example 4; FIG. 11 is a perspective view of a process cartridge according to Example 5; FIG. 12 is a cross-sectional view showing the relationship between the process cartridge and the spacing mechanism according to Embodiment 5; FIG. 11 is a diagram showing the configuration of a spacing mechanism according to Example 6; FIG. 11 is a diagram showing the configuration of a spacing mechanism according to Example 6; FIG. 11 is a diagram showing the configuration of a spacing mechanism according to Example 6;

The image forming apparatus according to the present invention will be described in more detail below with reference to FIGS. 1 to 35. FIG.

<Example 1>
1 to 5 show a laser beam printer which is an image forming apparatus A of this embodiment. The overall configuration and functions of this laser beam printer will be described. In the following embodiments, as an image forming apparatus A, a full-color image forming apparatus to which four process cartridges can be attached and detached is exemplified.

The number of process cartridges to be mounted on the image forming apparatus is not limited to this. It is appropriately set as needed.

[Overview of Image Forming Apparatus]
FIG. 2 is a sectional view of the overall configuration of the image forming apparatus A of this embodiment. A main body (hereinafter referred to as "apparatus main body") 100 of the image forming apparatus A includes a laser scanner 11, an intermediate transfer belt 13, a fixing film 24, a pressure roller 25, a paper feed tray 19, a paper feed roller 20, and the like. is set up.

Also, four process cartridges P (PY, PM, PC, PK) of a first process cartridge PY, a second process cartridge PM, a third process cartridge PC, and a fourth process cartridge PK are horizontally arranged. ing. Each of the first to fourth process cartridges P (PY, PM, PC, PK) has a similar electrophotographic image forming process mechanism, and uses different developer colors.

Each of the first to fourth process cartridges P (PY, PM, PC, PK) has a developing unit 4 having a developing roller 41 for developing the electrostatic latent image on the photosensitive drum 1 .

The first process cartridge PY accommodates a yellow (Y) developer in the developing unit 4 and forms a yellow developer image on the surface of the photosensitive drum 1 .

The second process cartridge PM accommodates magenta (M) developer in the developing unit 4 and forms a magenta developer image on the surface of the photosensitive drum 1 .

The third process cartridge PC accommodates cyan (C) developer in the developing unit 4 and forms a cyan developer image on the surface of the photosensitive drum 1 .

The fourth process cartridge PK contains a black (K) developer in the developing unit 4 and forms a black developer image on the surface of the photosensitive drum 1 .

Sheets (recording media) S stacked and accommodated in a sheet feed tray 19 are fed by a sheet feed roller 20 rotating clockwise (in the direction of arrow W) in the figure, and fed by a belt drive roller 14 and a secondary transfer roller 18 . It is sent to a contact portion (hereinafter referred to as a “nip portion”).

The photosensitive drum 1 rotates counterclockwise (in the direction of arrow K) in the drawing, and electrostatic latent images are sequentially formed on its outer peripheral surface by laser light L from a laser scanner 11. The latent image is developed by the developing roller 41 to form a toner image (developer image).

The photosensitive drum 1 is an image carrier that carries an image (toner image). The developing roller 41 is a developer carrier that carries a developer (toner) for developing the electrostatic latent image.

A toner image formed on the photosensitive drum 1 is transferred to an intermediate transfer belt 13 as an intermediate transfer member. When forming a color image, each color of yellow, magenta, cyan, and black is developed on the photosensitive drum 1 , and the toner images respectively formed are sequentially transferred to the intermediate transfer belt 13 .

Next, the toner image formed on the intermediate transfer belt 13 is transferred onto the sheet S sent to the nip portion between the belt driving roller 14 and the secondary transfer roller 18 . In this embodiment, the toner image on the photosensitive drum 1 is once transferred to the intermediate transfer belt 13 and then transferred to the paper S, but the toner image may be transferred directly from the photosensitive drum 1 to the paper S. In this case, instead of the intermediate transfer belt 13, a conveying belt (conveying member) for conveying the recording medium (paper S) is provided, and yellow, magenta, cyan, and black colors are applied to the paper S conveyed by the conveying belt. The toner images may be sequentially transferred.

The paper S onto which the toner image has been transferred is sent to the nip portion between the fixing film 24 and the pressure roller 25, where the toner image is fixed to the paper S by being heated and pressurized. The paper S on which the toner image has been fixed is discharged to a paper discharge tray 27 by a paper discharge roller pair 26 .

[Overview of how to replace the process cartridge]
3 to 5 are diagrams for explaining the process cartridge replacement method of this embodiment.

A method for exchanging the process cartridge P of this laser beam printer will be described below.

A member that moves while holding the process cartridges PY, PM, PC, and PK will be referred to as a cartridge tray 28 in the following description. The cartridge tray 28 is a mounting member for mounting the process cartridges PY, PM, PC, and PK. The cartridge tray 28 is supported by a cartridge tray holding member (hereinafter referred to as a "tray holding member") 32 with respect to the apparatus main body 100, and is provided slidably in the horizontal direction (directions of arrows M and N) in FIG. ing.

As shown in FIG. 3, the space inside the apparatus main body 100 serves as a mounting portion for the process cartridge P. As shown in FIG. By being placed on the cartridge tray 28 , the process cartridge P moves toward the mounting portion of the apparatus main body 100 and is mounted on the apparatus main body 100 . Also, the process cartridge P is detachable from the mounting portion of the apparatus main body 100 . A detailed description will be given below.

The opening/closing door 30 is rotatable with respect to the apparatus main body 100, and FIG. 3 shows a state in which the opening/closing door 30 is opened. The opening/closing door 30 is an opening/closing member that opens and closes an opening through which the cartridge tray 28 passes. By opening the opening/closing door 30 in the direction of the arrow D in FIG.

A connecting arm 33 is provided to connect the opening/closing door 30 and the tray holding member 32 . The connecting arm 33 and the tray holding member 32 constitute interlocking means (interlocking mechanism) for moving the cartridge tray 28 in conjunction with the opening/closing operation of the open/close door 30 . That is, when the open/close door 30 is opened from the closed state (see FIG. 2), the connecting arm 33 pulls the tray holding member 32 upward and to the right (in the direction of the arrow Y), thereby moving the cartridge tray 28 upward. Move (see Figure 3). At this time, the photosensitive drum 1 is separated from the intermediate transfer belt 13, and the cartridge tray 28 becomes ready to be pulled out from the main body 100 of the apparatus. That is, the user can draw out the cartridge tray 28 by pulling the handle portion 29 .

At this time, the process cartridge P placed on the cartridge tray 28 is also moved in a direction crossing the axis of the photosensitive drum 1 and pulled out of the apparatus main body 100 .

The interlocking mechanism for moving the cartridge tray 28 in conjunction with the opening/closing operation of the opening/closing door 30 will be further described below.

FIG. 6 is a perspective view of the image forming apparatus. FIG. 6(a) shows a state in which the opening/closing door 30 is closed, and FIG. 6(b) shows a state in which the opening/closing door 30 is opened. FIG. 6C further shows a state in which the cartridge tray 28 is pulled out from the inside of the apparatus main body 100 of the image forming apparatus. 7 is an enlarged view of the opening/closing door 30 and the cartridge tray 28. FIG. FIG. 7(a) shows a state in which the opening/closing door 30 is closed, and FIG. 7(b) shows a state in which the opening/closing door 30 is opened.

As shown in FIG. 7A, a connecting arm 33 is attached to the opening/closing door 30, and a boss 33a provided on the connecting arm 33 engages with a groove 32b provided on the tray holding member 32. As shown in FIG. there is As a result, the opening/closing operation of the opening/closing door 30 and the tray holding member 32 are interlocked. That is, the tray holding member 32 has a boss 32a, and this boss 32a is engaged with a groove 101a provided in the side plate 101 of the apparatus main body 100. As shown in FIG. When the door 30 is opened from the closed state (see FIG. 7(a)), the tray holding member 32 moves along the groove 101a of the side plate 101 in the direction of arrow D1 shown in FIG. 7(b).

Here, since the groove 101a of the side plate 101 has a step, when the tray holding member 32 moves, it not only moves horizontally but also moves upward by a distance L1. Therefore, the cartridge tray 28 held by the tray holding member 32 also moves upward by L1. At this time, if the process cartridge P is mounted on the cartridge tray 28 , the photosensitive drum 1 is separated from the intermediate transfer belt 13 .

In this state, when the user pulls the handle portion 29 shown in FIG. 6(b), the cartridge tray 28 is pulled out of the apparatus main body 100 and moved to the pulled-out position as shown in FIG. 6(c).

FIG. 4 is a cross-sectional view showing a state in which the cartridge tray 28 is pulled out from the inside of the apparatus main body 100 in the direction of arrow C. As shown in FIG. In this state, the upper surfaces of the process cartridges PY, PM, PC, and PK are opened, and the respective process cartridges PY, PM, PC, and PK can be removed upward (in the direction of arrow E) as shown in FIG.

When the process cartridge P is mounted in the apparatus main body 100, the cartridge tray 28 is pulled out, the process cartridge P is placed thereon, and then the cartridge tray 28 is housed inside the apparatus main body 100 in the reverse order. At this time, the process cartridge P placed on the cartridge tray 28 also moves in a direction crossing the axis of the photosensitive drum toward the mounting portion of the apparatus main body 100 .

By closing the opening/closing door 30 after the cartridge tray 28 is accommodated in the apparatus main body 100, the tray holding member 32 is pushed down in the lower left direction (arrow Z direction) in FIG. As a result, the cartridge tray 28 also moves downward, and the photosensitive drum 1 of the process cartridge P contacts the intermediate transfer belt 13 . That is, by closing the opening/closing door 30 , the cartridge tray 28 is mounted at the mounting position inside the apparatus main body 100 . At the same time, the process cartridge P is arranged at a position where the photosensitive drum 1 is brought into contact with the intermediate transfer belt 13 and image formation is possible (see FIG. 2).

In this embodiment, the contact state and the separation state between the photosensitive drum 1 and the intermediate transfer belt 13 are switched in conjunction with the opening and closing of the opening/closing door 30 . However, as described above, instead of the intermediate transfer belt 13, a transport belt for transporting the sheet S may be provided. In this case, it is preferable to switch between the contact state and the separation state between the photosensitive drum 1 and the conveying belt in conjunction with the opening and closing of the opening/closing door 30 .

FIG. 8 is an external perspective view of the process cartridges PY, PM, PC, and PK. As described above, the process cartridges PY, PM, PC, and PK have the same electrophotographic process mechanism, and differ in the color of toner contained therein and the amount of toner to be filled.

The process cartridge P is a laterally long box-shaped assembly whose lateral direction is the axial direction (longitudinal direction) of the photosensitive drum 1 and whose longitudinal direction is the lateral direction. The photosensitive drum 1 is rotatably supported by a driving side cartridge cover member 46 disposed on the right side of the cleaner unit 5 and a non-driving side cartridge cover member 47 disposed on the left side. A drum coupling member 55 (see FIG. 9) as a photosensitive drum drive input portion and a developing coupling member as a drive input portion to the developing roller 41 in the developing unit 4 are provided at the driving side shaft end portion of the process cartridge P. 56 are provided. Details will be described later. A cartridge electrical contact (not shown) is provided on the left side surface. In the above-described process cartridge P, the right side surface provided with the drum coupling member 55 to which the driving force is transmitted from the apparatus main body 100 and the development coupling member 56 (see FIG. 9) is the driving side. is the non-drive side.

FIG. 10 is a cross-sectional view of the process cartridge P cut in a direction perpendicular to the axis of the photosensitive drum 1. As shown in FIG. A driving force from the apparatus main body 100 is transmitted to the drum coupling member 55 of the process cartridge P and the developing coupling member 56 (see FIG. 9). As a result, in FIG. 10, the photosensitive drum 1 rotates counterclockwise (in the direction of arrow K), and the developing roller 41 rotates in the clockwise direction (in the direction of arrow L) at a predetermined speed.

In this embodiment, the process cartridge P is composed of a cleaner unit 5 and a developing unit 4 rotatably connected to the cleaning unit 5 . The cleaner unit 5 is a first unit (photosensitive drum unit) that holds the photosensitive drum 1 , and the developing unit 4 is a second unit that holds the developing roller 41 .

The charger 3 provided in the cleaner unit 5 is a contact charging type charging member that contacts the photosensitive drum 1 and is driven to rotate. The cleaning blade 51 is an elastic rubber blade, and is arranged so that its tip is in contact with the photosensitive drum 1 . The cleaning blade 51 serves to remove toner remaining on the photosensitive drum 1 . The transfer residual toner removed by the cleaning blade 51 is stored in the toner storage section 52 in the cleaner unit 5 .

The developing unit 4 has a developing roller 41 and a developing blade 42 as developing means. The development unit 4 further has a development chamber (developer storage section) 43 that stores toner.

As shown in FIG. 10 , the developing roller 41 is arranged in the developing chamber 43 , and the developing blade 42 is arranged so that the tip thereof contacts the developing roller 41 . The developing blade 42 serves to regulate the toner carried on the peripheral surface of the developing roller 41 into a thin layer.

FIG. 13 shows part of the component configuration of the developing unit 4. As shown in FIG. As shown in the drawing, a bearing member 44 that rotatably supports the development coupling member 56 and the development roller 41 is fixed to one end of the development unit 4 in the longitudinal direction. More specifically, the first bearing portion 44p (cylindrical outer surface) of the bearing member 44 is fitted with the developing coupling member 56, and the second bearing portion 44q (cylindrical inner surface) is fitted with the shaft portion 41a of the developing roller 41. and rotatably support them. A developing roller gear 45 is fitted to the shaft portion 41 a of the developing roller 41 . An outer peripheral surface 56 g of the development coupling member 56 is a gear portion that meshes with the development roller gear 45 . As a result, the driving force input from the apparatus main body 100 is transmitted to the developing roller 41 via the developing coupling member 56 .

A developing cover member 57 is fixed outside the developing unit 4 . The development cover member 57 is configured to cover the development coupling member 56 and the development roller gear 45 . Further, the developing cover member 57 is provided with a cylindrical portion 57b. The development coupling member 56 is exposed from an opening 57d inside the cylindrical portion 57b.

As shown in FIGS. 11 and 12, when the developing unit 4 and the cleaner unit 5 are assembled, the cylindrical portion 57b of the developing cover member 57 is rotatable on the supporting portion 46a of the driving side cartridge cover member 46 at one longitudinal end. Mate. At the other end, a projecting portion 4b projecting from the developing unit 4 is rotatably fitted into the supporting hole portion 47a of the non-driving side cartridge cover member 47. As shown in FIG. Thereby, the developing unit 4 is rotatably supported with respect to the cleaner unit 5 . Here, the rotation center (rotation axis) of the developing unit 4 with respect to the cleaner unit 5 is referred to as the rotation center (rotation axis) X. As shown in FIG. The rotation center X is an axis connecting the center of the support hole portion 46a and the center of the support hole portion 47a.

The developing unit 4 is biased by a pressure spring 53 that is an elastic member, and is configured such that the developing roller 41 abuts on the photosensitive drum 1 with the rotation center X as the center. More specifically, as shown in FIG. 10, the developing unit 4 is pressed in the direction of arrow G by the biasing force of the pressure spring 53, and a moment in the direction of arrow J1 about the rotation center X is generated. It is configured to work. As a result, the developing roller 41 can be brought into contact with the photosensitive drum 1 with a predetermined pressure. Also, the position of the developing unit 4 with respect to the cleaner unit 5 at this time is defined as a contact position.

Further, as shown in FIG. 13, a bearing member 44 is arranged at the end of the developing unit 4 in the axial direction (longitudinal direction) of the developing roller 41, and the bearing member 44 is formed with a projecting portion 44d. As shown in FIG. 13 , the protruding portion 44 d protrudes in a direction intersecting the axis of the developing roller 41 and away from the developing roller 41 . The projecting portion 44d is provided with a force-receiving portion 44b that contacts the separation mechanism 60 provided in the apparatus main body 100 and receives force. The force receiving portion 44b receives a force from the separating mechanism 60 to bring the developing roller 41 and the photosensitive drum 1 into contact with each other and separate them from each other. The structures of the projecting portion 44d, the force receiving portion 44b, and the spacing mechanism 60 will be described in detail below.

[Separation Mechanism of Main Body of Electrophotographic Image Forming Apparatus]
Next, a separating mechanism 60 for separating the developing roller 41 of the developing unit 4 from the photosensitive drum 1 will be described with reference to FIGS. 9, 14 and 15. FIG. FIG. 9 is a perspective view showing the relationship between the process cartridge P and the spacing mechanism 60. As shown in FIG. FIG. 15 is a sectional view showing the relationship between the process cartridge P and the spacing mechanism 60. As shown in FIG. 14A and 14B are partially enlarged views of the spacing mechanism 60. FIG. 14A shows the spacing member 61 assembled with the moving member 62, FIG. c) shows the moving members 62 respectively.

As described above, the developing unit 4 is urged by the pressure spring 53 provided in the process cartridge P and positioned at the contact position where the developing roller 41 contacts the photosensitive drum 1 . However, if the developing roller 41 is in contact with the photosensitive drum 1 for a long period of time, the developing roller 41 may leave a dent mark. is desirable. Therefore, the apparatus main body 100 of this embodiment has a separation mechanism 60 that separates the developing roller 41 from the photosensitive drum 1 .

As shown in FIGS. 9 and 14, the spacing mechanism 60 has a moving member 62 movably provided inside the apparatus main body 100 and a spacing member 61 movably supported by the moving member 62 .

The spacing member 61 is an engaging member that is L-shaped and engages with the process cartridge P. As shown in FIG. That is, the spacing member 61 applies force to the force receiving portion 44b, which is the engaged portion of the process cartridge P, by engaging (contacting) the force receiving portion 44b.

The spacing member 61 is movable with respect to the moving member 62 in the height direction of the apparatus main body 100 (vertical direction in FIG. 15, arrow H1 and H2 directions). That is, as shown in FIG. 14, the spacing member 61 is supported by a support portion (hereinafter referred to as a guide portion) 62a of the moving member 62 so as to slide in the directions of arrows H1 and H2. Specifically, the shaft portion 62p of the moving member 62 is engaged with the hole portion 61p of the engaging member 61 . A locking portion 61q of the spacing member 61 is arranged in the locking hole 62q of the moving member 62. As shown in FIG. The locking portion 61q of the spacing member 61 is engaged with the restricting portion 62b of the moving member 62 so that the spacing member 61 does not drop off from the moving member 62. As shown in FIG.

Further, as shown in FIG. 15, the spacing member 61 is in a position where it can be engaged with the force receiving portion 44b by a biasing spring 63 as an elastic member attached to the moving member 62 (hereinafter referred to as "normal position"). ). That is, the biasing spring 63 functions as a biasing member that biases the spacing member 61 toward the normal position.

The moving member 62 is located below the process cartridges P (PY, PM, PC, PK) and is movably provided in the apparatus main body 100 . That is, the moving member 62 is provided with a circular cam 64 , and the cam drive shaft 65 is connected to the cam 64 at a position away from the center of the circle forming the cam 64 . The cam 64 receives a driving force from a driving source (not shown) provided in the apparatus main body 100 to rotate around a cam driving shaft 65, and moves the moving member 62 in a substantially horizontal direction (horizontal direction in FIG. 15, arrow M, N direction).

By the rotation of the cam 64 , the moving member 62 moves to a position (hereinafter referred to as “non-image forming position”) where the developing roller 41 and the photosensitive drum 1 are separated from each other, and the developing roller 41 contacts the photosensitive drum 1 . position (hereinafter referred to as "image forming position"). Further, as will be described later, in this embodiment, the spacing member 61 supported by the moving member 62 is characterized in that when the process cartridge P is mounted in the apparatus main assembly 100, it is pushed away by the process cartridge P. and

The behavior of the separating member 61 when the process cartridge P is attached to the apparatus main body 100 and the mechanism by which the separating mechanism 60 separates the developing roller 41 from the photosensitive drum 1 will be described in detail below.

FIG. 16 shows the cartridge tray 28 and the process cartridge P and the separation mechanism 60 when the process cartridge P is mounted in the apparatus main body 100 . As described above, when the opening/closing door 30 is open, the cartridge tray 28 moves upward (in the direction of arrow H2) (in FIG. 3, moves upward to the right, in the direction of arrow Y). At this time, the spacing member 61 and the projecting portion 44d of the bearing member 44 have a gap d. Therefore, even if the cartridge tray 28 and the process cartridge P are moved in the horizontal direction (directions of arrows M and N) in this state, the spacing member 61 and the bearing member 44 do not interfere with each other.

After inserting the cartridge tray 28 and the process cartridge P into the apparatus main body 100, the opening/closing door 30 is closed. As described above, in conjunction with the closing of the opening/closing door 30, the process cartridge P moves leftward and downward (in the direction of the arrow Z in the figure) within the apparatus main body 100, and the photosensitive drum 1 comes into contact with the intermediate transfer belt 13 ( 2 and 3). At this time, the moving member 62 is at the non-image forming position shown in FIGS. in an interfering position.

However, a biasing spring 63 is attached to the spacing member 61 . Therefore, when the spacing member 61 interferes with the process cartridge P and is pressed by the pressing portion 44c of the process cartridge P, the biasing spring 63 is compressed and the spacing member 61 moves in the moving direction of the process cartridge P (arrow H1 direction). move almost parallel to the That is, the spacing member 61 is pushed from the normal position (moved to the withdrawal position) by being pressed by the pressing portion 44c, and allows the process cartridge P to move. As a result, the process cartridge P is mounted at a predetermined position in the main body 100 of the apparatus. The pressing portion 44c is formed on the end surface of the protruding portion 44d that protrudes from the developing unit 4. As shown in FIG.

Next, the force receiving portion 44b of the projecting portion 44d and the spacing member 61 are engaged. For this purpose, the moving member 62 is once moved rightward (in the direction of arrow N) in FIG. 15A to a position (image forming position) where the spacing member 61 and the projecting portion 44d do not interfere. As shown in FIGS. 9B and 15B, when the moving member 62 moves to the image forming position where the spacing member 61 no longer interferes with the projecting portion 44d, the spacing member 61 is extended by the biasing spring 63. Move upward (in the direction of arrow H2). As a result, the spacing member 61 rises to a position (normal position) where it can be engaged with the force receiving portion 44b.

Next, when the moving member 62 moves leftward (arrow M direction) in FIG. 15(b), the spacing member 61 engages with the force receiving portion 44b provided on the projecting portion 44d. Further, when the moving member 62 moves leftward (in the direction of arrow M) and returns to the non-image forming position, the moving member 62 applies force to the force receiving portion 44b via the spacing member 61 . As a result, the moving member 62 moves the developing unit 4 to a position (separated position) where the developing roller 41 is separated from the photosensitive drum 1 with a gap e as shown in FIGS. 9(c) and 15(c). It is in a state where

As shown in FIG. 14, the moving direction of the spacing member 61 with respect to the moving member 62 is determined by the guide portion 62a, and the spacing member 61 can slide only in the directions of arrows H1 and H2. The direction of movement of the spacing member 61 (directions of arrows H1 and H2) intersects the direction of movement of the movement member 62 (directions of arrows M and N). Therefore, when the moving member 62 moves, even if the spacing member 61 receives force in the directions of arrows M and N from the force receiving portion 44b, the spacing member 61 is supported by the guide portion 62a and engages with the force receiving portion 44b. can be maintained. As a result, the moving member 62 can reliably move the developing unit 4 to the separating position where the developing roller 41 and the photosensitive drum 1 are separated from each other. In particular, in this embodiment, the direction of movement of the spacing member 61 (directions of arrows H1 and H2) is substantially perpendicular to the direction of movement of the movement member 62 (directions of arrows M and N).

When the image forming apparatus forms an image, the moving member 62 moves to the image forming position shown in FIG. 15(b). At this time, the developing unit 4 is moved from the separated position to the contact position by the force of the pressure spring 53 (see FIG. 8), and the developing roller 41 is brought into contact with the photosensitive drum 1 (see FIG. 15B). In this state, the developing roller 41 develops the electrostatic latent image formed on the photosensitive drum 1 using developer.

Then, when the image formation is completed, the moving member 62 moves to the non-image forming position, thereby maintaining the developing roller 41 in a state separated from the photosensitive drum 1 until the image forming operation is started (FIG. 15(c)). reference). As a result, deformation of the developing roller 41 due to contact pressure with the photosensitive drum 1 can be suppressed.

[Three positions of the spacing member]
In summary, the spacing member 61 can move between three different positions (the spacing member 61 can assume three different states).

(1) FIG. 15(c) shows a state in which the spacing member 61 is at the operating position (first position). When the spacing member 61 is in the active position with the process cartridge P attached to the apparatus main body 100, the spacing member 61 engages with the force receiving portion 44b. As a result, the separating member 61 acts (applies force) to the developing unit 4 to move the developing unit 4 to the separated position and separate the developing roller 41 from the photosensitive drum 1 .

(2) FIG. 15(b) shows a state in which the spacing member 61 is in the non-operating position (second position). When the spacing member 61 is at the non-operating position with the process cartridge P attached to the apparatus main body 100 , the spacing member 61 allows the developing roller 41 to come into contact with the photosensitive drum 1 . That is, the spacing member 61 does not apply force to the force receiving portion 44b, or reduces the force applied to the force receiving portion 44b so that it does not act on the developing unit 4. FIG. As a result, the developing unit 4 causes the developing roller 41 to approach and contact the photosensitive drum 1 by the force of the pressure spring 53 (see FIG. 10). That is, the developing unit 4 moves to the contact position.

(3) FIG. 15(a) shows a state in which the spacing member 61 is at the retracted position (third position). When the process cartridge P is attached to the apparatus main body 100, the separating member 61 collides with the descending process cartridge P and is pressed to be in a retracted state. That is, the spacing member 61 allows the process cartridge P to be attached to the apparatus main body 100 by moving to the retracted position (third position).

When the spacing member 61 is at the operating position or the non-operating position, the spacing member 61 is at the normal position (non-retracted position) with respect to the moving member 62 .

In other words, the separation member 61 being in the operating position means that the relative position of the separation member 61 with respect to the moving member 62 is the normal position and the moving member 62 is in the non-image forming position. At this time, the spacing member 61 engages with the developing unit 4 (acts on the developing unit 4) and applies force to the developing unit 4 to move the developing unit to the separated position. The developing roller 41 and the photosensitive drum 1 are separated.

Further, the spacing member 61 being at the non-operating position means that the relative position of the spacing member 61 with respect to the moving member 62 is the normal position and the moving member 62 is at the image forming position. At this time, the moving member 62 does not act on the developing unit 4 by separating from the developing unit 4 or reducing the force applied to the developing unit 4 . As a result, the developing unit 4 moves to the contact position, and the developing roller 41 contacts the photosensitive drum 1 .

On the other hand, when the spacing member 61 is at the retracted position, the spacing member 61 is retracted from the normal position, the moving member 62 is at the non-image forming position, and the developing unit 4 is at the contact position.

It is as follows when summarized in the table.

Here, after the image formation is completed, the moving member 62 is arranged at the non-image forming position for separating the developing roller 41 and the photosensitive drum 1 from each other. Therefore, even when the process cartridge P is mounted, the moving member 62 is at the non-image forming position. When the process cartridge P is mounted, the developing unit 4 is in a state in which the developing roller 41 is brought into contact with the photosensitive drum 1 by the biasing force of the pressure spring 53. Therefore, the projecting portion 44d of the developing unit 4 is It interferes with the spacing member 61 (see FIG. 15(a)). However, as described above, the spacing member 61 moves from the normal position (action position: see FIG. 16) to the retracted position (see FIG. 15A) by being pushed by the pressing portion 44c provided on the projecting portion 44d. can do. Therefore, the separation member 61 does not hinder the movement of the process cartridge P, and the process cartridge P is securely attached to the apparatus main assembly 100 .

On the other hand, when the process cartridge P is removed from the image forming apparatus with the spacing member 61 at the retracted position (see FIG. 15A), the spacing member 61 is moved to the normal position (action position: FIG. 15A) by the force of the biasing spring 63. 16). That is, by opening the door 30 (FIG. 30), the process cartridge P is lifted in the H2 direction in FIG. 15(a). Interlocking with the movement of the process cartridge P, the spacing member 61 also moves in the H2 direction.

In summary, in this embodiment, the spacing member 61 engaged with the force receiving portion 44b of the process cartridge P is movably provided on the moving member 62 and is retracted by being pressed by the process cartridge P. FIG. As a result, the mechanism for retracting the spacing member 61 can be simplified, and the configurations of the spacing mechanism 60 and the apparatus main body 100 and the configuration of the process cartridge P can be simplified. Moreover, since the spacing member 61 can be retracted by the distance that the process cartridge P moves, it is not necessary to secure a large retraction space for retracting the spacing member 61 . Thereby, the size of the device main body 100 can be reduced.

Further, the moving member 62 reciprocates between the non-image forming position and the image forming position to move the spacing member 61 from the retracted position (FIG. 15(a)) to the non-operating position (FIG. 15(b)). It is moved to the action position (Fig. 15(c)). The separating member 61 can be engaged with the developing unit 4 to separate the developing roller 41 from the photosensitive drum 1 . Accordingly, deformation of the developing roller 41 can be suppressed. Further, it is possible to prevent the toner adhering to the developing roller 41 from adhering to the photosensitive drum 1 during non-image formation.

Further, the developing roller 41 and the photosensitive drum 1 do not rub against each other during non-image formation. Therefore, deterioration of the photosensitive drum 1, the developing roller 41, or the toner carried by the developing roller 41 can be suppressed. Therefore, the process cartridge P can be used for a long period of time.

The spacing mechanism 60 in the above embodiment has the four spacing members 61 arranged on the same moving member 62, and corresponds to the arrangement of the four process cartridges P in the horizontal direction (directions of arrows M and N in FIG. 15). It is placed in the position where In this case, by moving the moving member 62, the plurality of developing rollers 41 and the photosensitive drums 1 can all be separated simultaneously.

However, the spacing mechanism 60 is not limited to this. For example, a spacing mechanism 60 (spacing member 61 and moving member 62) corresponding only to the black process cartridge PK is provided. Separately, a spacing mechanism 60 (spacing member 61 and moving member 62) corresponding to process cartridges (PY, PM, PC) other than black is provided. Such an image forming apparatus may be used. In this case, when the image forming apparatus forms a monochrome image, some of the developing rollers 41 and the photosensitive drums are separated from the photosensitive drums 1 only for the process cartridges other than black (PY, PM, PC). Only the drum 1 can be separated. Such a configuration will be described in detail in a sixth embodiment.

Further, the image forming apparatus of this embodiment is a color image forming apparatus, has a plurality (four) of process cartridges, and has the separating member 61 corresponding to the number of the process cartridges, but the configuration is limited to this. not. The spacing mechanism may be applied to a monochrome image forming apparatus in which only one process cartridge is mounted (in this case, only one spacing member 61 is required).

<Example 2>
This embodiment shows a modification of the spacing member (engagement member) provided in the spacing mechanism. In other words, it shows a configuration in which the spacing member 71 is retracted by rotationally moving with respect to the moving member 72 . In addition, in the present embodiment, the description of the configuration different from that of the first embodiment will be focused, and the description of the configuration that is the same as that of the first embodiment will be omitted.

As shown in FIG. 17, the spacing member 71 is rotatably supported around a support portion 74 provided on the moving member 72 . Further, the spacing member 71 is biased by a biasing spring 73 to a position where it can be engaged with the force receiving portion 44b. Also in this embodiment, the spacing member 71 can move to three different positions (operating position, non-operating position, and retracted position).

FIG. 17A shows a state in which the process cartridges P (PY, PM, PC, PK) are attached to the apparatus main body 100. FIG. At this time, the moving member 72 is at the non-image forming position, and the separating member 71 supported by the moving member 72 is at a position where it interferes with the process cartridge P. FIG. The spacing member 71 interferes with the projecting portion 44d of the process cartridge P and is pressed downward (in the direction of arrow H1). As a result, the spacing member 71 rotates counterclockwise (in the direction of arrow V1) around the support portion 74 in FIG. That is, the spacing member 71 moves to the retracted position.

In order to engage the force receiving portion 44b and the spacing member 71 from the state shown in FIG. direction (arrow N direction). As shown in FIG. 17(b), when the spacing member 71 moves to a position where it does not interfere with the projecting portion 44d, it rotates clockwise (in the direction of arrow V2) around the support portion 74 by the force of the biasing spring 73. It moves to a normal position (non-acting position) where it can be engaged with the force receiving portion 44b.

Next, when the moving member 72 is moved leftward (in the direction of arrow M) from the image forming position shown in FIG. 17B, the separating member 71 and the force receiving portion 44b are engaged. When the moving member 72 is further moved leftward (in the direction of arrow M) in this state, the moving member 72 reaches the non-image forming position, and the spacing member 71 creates a gap e between the developing roller 41 and the photosensitive drum 1. Developing unit 4 is moved to a position (separation position) where it is separated by pressing. Then, the developing roller 41 is kept separated from the photosensitive drum 1 from the end of the image forming operation to the restart of the image forming operation (see FIG. 17(c)). FIG. 17(c) shows a state in which the spacing member 71 has moved to the operating position.

Here, as shown in FIG. 18, the moving member 72 has a rotation regulating portion 72b that stops (regulates) the rotation of the spacing member 71 while it is held at the normal position (operating position). Therefore, when the moving member 72 moves leftward (in the direction of arrow M) shown in FIG. add force. As a result, the spacing member 71 moves the developing unit 4 to the spacing position and maintains this state.

In summary, the spacing member 71 receives force from the retracted position (see FIG. 17A) and the moving member 72 reciprocates between the image forming position and the non-image forming position. It engages with portion 44b. Then, the developing unit 4 is moved to the separated position (see FIG. 17(c)).

In this embodiment, by rotatably providing the spacing member to the moving member, rattling when the spacing member moves is suppressed compared to the case where the spacing member moves linearly (see FIG. 15), and the movement of the spacing member is minimized. can be stabilized. More specifically, when the spacing member 61 is linearly moved as shown in the first embodiment, the spacing member 61 and the guide 62a are fitted (see FIG. 14). The dimension of the hole portion 61p of the spacing member 61 and the dimension of the insertion portion 62p of the guide 62a are varied. If this dimensional variation is large, as shown in FIG. 19, the spacing member 61 may be tilted with respect to the guide 62a, and the movement of the spacing member 61 relative to the guide 62a in the directions of arrows H1 and H2 may become unstable. In this embodiment, by rotatably providing the spacing member 71 to the moving member 72, the movement of the spacing member 71 can be stabilized.

On the other hand, moving the spacing member linearly like the spacing member 61 (see FIG. 14) of the first embodiment can reduce the area required for moving the spacing member rather than rotating it. As a result, the size of the spacing mechanism can be reduced, and the size of the image forming apparatus can be reduced. The above-described instability of operation caused by the inclination of the spacing member 61 with respect to the guide 62a can be suppressed by strictly controlling each dimension.

Therefore, it is preferable to appropriately select the movement structure of the spacing members (61, 71) according to the functions required of the image forming apparatus 100 and the spacing mechanisms (60, 70).

<Example 3>
This embodiment shows a modification of the shape of the spacing member 61 provided in the spacing mechanism 60, the projecting portion 44d, and the force receiving portion 44b. In addition, in the present embodiment, the description of the configuration different from that of the first embodiment will be focused, and the description of the configuration that is the same as that of the first embodiment will be omitted.

In this embodiment, as shown in FIG. 20, the protruding portion 44d is formed with a protruding portion 44a and a recessed portion 44g in order to reliably engage the spacing member 61 with the force receiving portion 44b. A force receiving portion 44b is formed in a concave portion 44g provided in the projecting portion 44d. Although the details will be described later, the engagement between the force receiving portion 44b and the spacing member 61 is reliably maintained by inclining the force receiving portion 44b and the contact portion 61b at a predetermined angle.

Prior to the description of the above operation, first, the shape and arrangement of the force receiving portion 44b of the projecting portion 44d and the contact portion 61b of the spacing member 61 in this embodiment will be described in detail. As shown in FIG. 21, when the developing roller 41 and the photosensitive drum 1 are in contact with each other, the force receiving portion 44b of the projecting portion 44d moves in the orthogonal direction perpendicular to the moving direction of the moving member 62 (directions of arrows M and N). is inclined at an angle θ1 with respect to

FIG. 22 shows a state in which the developing unit 4 is rotated clockwise (in the direction of arrow J2) about the rotation center X by an angle θ0 from the state shown in FIG. Here, the angle θ0 is the rotation angle of the developing unit 4. As shown in FIG. In FIG. 22, the developing roller 41 and the photosensitive drum 1 are separated from each other with a gap e. Further, the force receiving portion 44b of the protruding portion 44d is inclined at an angle θ2 with respect to the orthogonal direction orthogonal to the moving direction of the moving member 62 (directions of arrows M and N).

At this time, the angles θ0, θ1, and θ2 have the following relationship.

θ1=θ0+θ2
In addition, the protruding portion 44d protrudes downward (in the direction of the arrow H1). That is, the protruding portion 44d protrudes in a direction intersecting the axis 41x of the developing roller 41 and away from the developing roller 41 and the rotation center X. As shown in FIG. When the process cartridge P is viewed along the axis 41x of the developing roller 41 (when the process cartridge P is viewed on a plane orthogonal to the axis 41x), the force receiving portion 44b of the projecting portion 44d is It faces toward the center (axis 41x). In other words, in FIG. 21 (a plane perpendicular to the axis 41x of the developing roller 41), when a straight line (tangent line) Q that contacts the force receiving portion 44b and extends along the force receiving portion 44b is drawn, The force receiving portion 44b and the center (axis 41x) of the developing roller 41 are on opposite sides.

Note that this does not mean that the force receiving portion 44b is limited to the configuration in which the developing roller 41 directly faces the force receiving portion 44b, as shown in FIG. may be In other words, when the force receiving portion 44b is viewed along the axis 41x of the developing roller 41 (when the force receiving portion 44b is viewed on a plane orthogonal to the axis 41x), the force receiving portion 44b is located at the position where the developing roller 41 is. It means facing the side you want.

Also, it is not intended to limit the shape of the force receiving portion 44b to a plane. As long as at least the area (surface) that contacts the spacing member 61 faces the side where the developing roller 41 is positioned, the force receiving portion 44b may have another shape such as a curved surface.

More specifically, in FIG. 21, the straight line Q extending along the force receiving portion 44b of the projecting portion 44d does not pass through the axis 41x of the developing roller 41, starting from the force receiving portion 44b. Further, the axis 41x of the developing roller 41 is arranged on the side of the projecting portion 44d facing the force receiving portion 44b (in FIG. 21, the arrow R side of the straight line Q).

Further, the force receiving portion 44b of the protruding portion 44d faces the rotation center X direction of the developing unit 4. As shown in FIG. More specifically, the straight line Q does not pass through the rotation center X of the developing unit 4 in FIG. Further, the rotation center X of the developing unit 4 is arranged on the side of the projecting portion 44d facing the force receiving portion 44b (in FIG. 21, the arrow R side of the straight line Q). That is, in FIG. 21, the force receiving portion 44b and the rotation center X are positioned on the opposite side of the straight line Q. As shown in FIG. Further, the force receiving portion 44b and the photosensitive drum 1 are located on the opposite side of the tangent line Q. As shown in FIG.

The projecting portion 44 d has a projecting portion 44 a projecting so as to cover the rotation center X and the developing roller 41 . The convex portion 44a protrudes toward the cleaning unit 5 and the photosensitive drum 1, thereby forming a concave portion 44g. The concave portion 44g is a hollow that is recessed in a direction away from the cleaning unit 5 and the photosensitive drum 1. As shown in FIG. Further, the concave portion 44g is a space formed between the force receiving portion 44b and the developing roller 41 (an area closer to the developing roller 41 than the contact portion 44b). The force receiving portion 44b and the spacing member 61 can be engaged with each other by the tip of the spacing member 61 entering this space (the recess 44g).

Further, as shown in FIG. 24, the contact portion 61b of the spacing member 61 is inclined at an angle θ3 with respect to the direction orthogonal to the direction of movement of the moving member 62 (directions of arrows M and N).

FIG. 23 shows the force receiving portion 44b and the separating member 61 in a state where the developing roller 41 and the photosensitive drum 1 are in contact with each other. 20 shows the relationship between the force receiving portion 44b and the separating member 61 when the developing roller 41 and the photosensitive drum 1 are separated from each other.

Here, in this embodiment, as shown in FIG. 20, when the moving member 62 moves in the direction of arrow M, the contact portion 61b of the spacing member 61 receives force F1 from the force receiving portion 44b. This force F1 is a force generated in a direction perpendicular to the contact portion 61b. Here, since the contact portion 61b is inclined by θ3 with respect to the direction perpendicular to the moving direction of the moving member 62 (directions of arrows M and N), the force F1 has a component F1x parallel to the moving direction of the moving member 62. , has a component F1y perpendicular to the direction of movement (directions of arrows M and N). Of these, the component F1y is a force component directed upward (in the direction of the arrow H2) in FIG. In other words, the component F1y is a force component acting in the direction (arrow H2 direction) of the spacing member 61 from the retracted position (see FIG. 15(a)) toward the normal position (operating position: see FIG. 15(c)). . Further, the force receiving portion 44b receives downward force F1y' (a component force in the direction of arrow H1) from the contact portion 61b of the spacing member 61 as a reaction force of the force component F1y.

In other words, in this embodiment, the contact portion 61b of the spacing member 61 is moved in the direction (upward) from the retracted position to the normal position (active position) by the force F1 that the contact portion 61b of the spacing member 61 receives from the force receiving portion 44b of the protrusion 44d. , direction of arrow H2). That is, the contact portion 61b of the spacing member 61 is inclined at an angle θ3 so that the force F1 received by the spacing member 61 from the force receiving portion 44b has a component F1y.

In addition, the force receiving portion 44b of the developing unit 4 is inclined in the same direction as the contact portion 61b so that the force receiving portion 44b of the developing unit 4 reliably contacts the contact portion 61b of the spacing member 61. As shown in FIG. That is, the contact portion 61b and the force receiving portion 44b are inclined from the upstream side in the direction of arrow H1 and the upstream side in the direction of arrow N toward the downstream side in the direction of arrow H1 and the direction of arrow M.

The arrow H1 direction is the direction in which the spacing member 61 moves from the operating position (see FIGS. 15(c) and 16) to the retracted position (FIG. 15(a)). That is, the arrow H1 direction is the direction in which the spacing member 61 retreats. The arrow N direction is the direction in which the spacing member 61 moves from the operating position (see FIG. 15(c)) to the non-operating position (see FIG. 15(b)). That is, the arrow M direction is the direction in which the spacing member 61 moves to bring the developing roller 41 into contact with the photosensitive drum 1 .

By inclining the spacing member 61 and the force receiving portion 44b as described above, when the spacing member 61 and the force receiving portion 44b are engaged (abutted), a force acts in the direction of pulling each other. ing. That is, an upward force (H2 direction) is applied to the spacing member 61, and a downward force (H1 direction) is applied to the force receiving portion 44b. As a result, even if the spacing member 61 is movably provided on the moving member 62, when it engages with the force receiving portion 44b, it is reliably maintained at the normal position (operating position) by the force component F1y. It remains engaged with the receiving portion 44b.

In particular, in this embodiment, the angle between the force receiving portion 44b and the contact portion 61b of the spacing member 61 has the following relationship so that the engagement state between the force receiving portion 44b and the spacing member 61 can be maintained more stably. I have to.

θ1≧θ3 (see FIG. 20) and θ2≧θ3 (see FIG. 23).

This is because the angles (θ1, θ2) formed by the force receiving portion 44b with respect to the vertical direction both when the developing unit 4 is at the separated position and when it is at the contact position. This means that it is larger than the angle θ3 formed by 61b. As a result, regardless of the posture of the developing unit 4, the tip of the force receiving portion 44b is reliably brought into contact with the surface forming the contact portion 61b of the spacing member 61. As shown in FIG. Therefore, the contact state between the force receiving portion 44b and the contact portion 61b of the spacing member 61 is stably maintained.

Rearranging the above formula, we get
θ1≧θ3 and θ2=θ1−θ0≧θ3
i.e.
θ1≧θ3 and θ1−θ3≧θ0
is.

When the developing unit 4 is in the contact position, the angle (θ1-θ3) formed by the contact portion 61b of the spacing member 61 and the force receiving portion 44b of the projecting portion 44d is the rotation angle of the developing unit 4. It means that it is equal to or greater than θ0 (the angle from the contact position to the separation position).

<Example 4>
In this embodiment, a modified example of the shape of the spacing member 71 provided in the spacing mechanism 70 and the projecting portion 44d is shown. In addition, in the present embodiment, the description of the configuration different from that of the second embodiment will be focused, and the description of the same configuration will be omitted.

As shown in FIG. 25, the spacing member 71 is rotatably supported around a support portion 74 provided on the moving member 72 . Further, the spacing member 71 is biased by a biasing spring 73 to a position where it can be engaged with the force receiving portion 44b. Also in this embodiment, the spacing member 71 can move to three different positions (operating position, non-operating position, and retracted position).

FIG. 25A shows a state in which the process cartridges P (PY, PM, PC, PK) are installed in the apparatus main body 100. FIG. At this time, the moving member 72 is at the non-image forming position, and the separating member 71 supported by the moving member 72 is at a position where it interferes with the process cartridge P. FIG. The spacing member 71 interferes with the projecting portion 44d of the process cartridge P and is pressed downward (in the direction of arrow H1). As a result, the spacing member 71 rotates clockwise (in the direction of arrow U1) around the support portion 74 in FIG. That is, the spacing member 71 moves to the retracted position.

In order to engage the force receiving portion 44b of the projecting portion 44d with the spacing member 71 from the state shown in FIG. position), the moving member 72 is moved rightward (in the direction of arrow N). As shown in FIG. 25(b), when the spacing member 71 moves to a position where it does not interfere with the projecting portion 44d, it rotates counterclockwise (in the direction of arrow U2) around the support portion 74 by the force of the biasing spring 73. . Then, the spacing member 71 moves relative to the moving member 72 and rises to a normal position (non-action position) where it can contact and engage with the force receiving portion 44b provided on the projecting portion 44d.

Next, when the moving member 72 is moved leftward (in the direction of arrow M) from the image forming position shown in FIG. When the moving member 72 is further moved leftward (in the direction of arrow M) in this state, the moving member 72 reaches the non-image forming position, and the separating member 71 moves to the position (separating position) where the developing roller 41 and the photosensitive drum 1 are separated from each other. position). Then, the developing roller 41 is kept separated from the photosensitive drum 1 from the end of the image forming operation to the restart of the image forming operation (see FIG. 25(c)). FIG. 25(c) shows the state where the spacing member 71 is located at the operating position.

In summary, the spacing member 71 is deactivated by reciprocating the moving member 72 between the image forming position and the non-image forming position from the retracted position (see FIG. 25A). Move through the position to the working position. The spacing member 71 engages with the force receiving portion 44b to move the developing unit 4 to the spacing position (see FIG. 25(c)).

Further, in this embodiment, as shown in FIG. 26, the protruding portion 44d is formed with a convex portion 44a and a concave portion 44g for reliably engaging the spacing member 71 and the force receiving portion 44b in the same manner as in the third embodiment. be done. In this embodiment, the force receiving portion 44b is formed on the concave portion 44g, and the contact portion 71b of the spacing member 71 abuts thereon.

More specifically, as shown in FIG. 21, when the developing roller 41 and the photosensitive drum 1 are in contact with each other, the force receiving portion 44b of the projecting portion 44d moves in the direction of movement of the moving member 72 (directions of arrows M and N). ) is inclined at an angle θ1 with respect to the orthogonal direction. Further, as shown in FIG. 22, in a state in which the developing roller 41 and the photosensitive drum 1 are separated, the force receiving portion 44b moves in the orthogonal direction orthogonal to the movement direction (arrow M, N direction) of the moving member 72. , is inclined at an angle θ2.

Further, as shown in FIG. 28, the contact portion 71b of the spacing member 71 is inclined at an angle θ3 with respect to the orthogonal direction perpendicular to the moving direction of the moving member 72 (directions of arrows M and N).

FIG. 27 shows the relationship between the force receiving portion 44b and the spacing member 71 when the developing roller 41 and the photosensitive drum 1 are in contact with each other. 26 shows the relationship between the force receiving portion 44b and the separating member 71 when the developing roller 41 and the photosensitive drum 1 are separated from each other.

By setting the relationship between the force receiving portion 44b and the contact portion 71b of the spacing member 71 as follows, a force for maintaining the engagement state between the force receiving portion 44b and the spacing member 71 is generated.

θ1≧θ3 and θ2≧θ3 (see FIGS. 26 and 27).

The force receiving portion 44b is inclined in the same direction as the contact portion 71b. That is, the force receiving portion 44b and the contact portion 71b are inclined from the upstream side in the direction of arrow N and the upstream side in the direction of arrow u1 toward the downstream side in the direction of arrow N and the upstream side in the direction of arrow u1 (FIG. 27). reference). The arrow u1 indicates the direction in which the spacing member 71 retreats (the direction in which the spacing member 71 moves from the normal position (action position: see FIG. 25(c)) toward the retracted position (FIG. 25(a)). be.

Further, the angle (θ1, θ2) of the force receiving portion 44b is made larger than the angle θ3 of the contact portion 71b of the spacing member 71 both when the developing unit 4 is at the contact position and at the separated position. there is

Rearranging the above formula, we get
θ1≧θ3 and θ1−θ0≧θ3
becomes. This means that
θ1≧θ3 and θ1−θ3≧θ0
is.

This is because when the developing unit 4 is in the contact position, the angle (θ1-θ3) formed by the contact portion 71b of the spacing member 71 and the force receiving portion 44b must be greater than or equal to the rotational angle θ0 of the developing unit. means

Further details are provided below. In this embodiment, as shown in FIG. 26, when the moving member 72 moves in the direction of arrow M, the contact portion 71b of the spacing member 71 receives force F1 from the force receiving portion 44b. This force F1 is a force generated in a direction perpendicular to the contact portion 71b. Further, the force receiving portion 44b receives a force F1' opposite to the force F1 from the contact portion 71b of the spacing member 71. As shown in FIG.

The forces received by the contact portion 71b of the spacing member 71 and the force receiving portion 44b will be described below with reference to the drawings. FIG. 29 shows the force F1 that the spacing mechanism 70 and the contact portion 71b of the spacing member 71 receive. The contact portion 71b is inclined at an angle of θ3 so that the separation member 71 receives the force F1 and receives a rotational moment about the support portion 74 in the direction of the arrow U2. That is, the normal to the contact portion 71b of the spacing member 71 (region F1a in FIG. 29) is positioned below the straight line passing through the center 74a of the support portion 74 and perpendicular to the contact portion 71b. there is Therefore, the spacing member 71 receives a rotational moment in the direction of the arrow U2 due to the force F1. That is, the rotational moment directed toward the force receiving portion 44b of the process cartridge P is received. In other words, it is a component in which the spacing member 71 faces in the direction from the retracted position to the normal position. FIG. 30 shows the force F1' received by the force receiving portion 44b.

The force F1' can be decomposed into a component F1x' parallel to the direction of movement of the moving member 72 (directions of arrows M and N) and a component F1y' perpendicular to the direction of movement (directions of arrows M and N). Of these components, the component F1y' is a component directed downward, in other words, it receives a force directed toward the spacing member 71 .

Further, the force F1 that the contact portion 71b of the spacing member 71 receives from the force receiving portion 44b acts in the direction in which the spacing member 71 moves from the retracted position to the normal position and in the direction in which the spacing member 71 approaches the force receiving portion 44b. . In addition, the contact portion 71b is inclined by θ3 so that such an effect occurs. In addition, the force receiving portion 44b is also inclined in the same direction so that the contact portion 71b and the contact portion 71b can be reliably kept in contact with each other.

Thus, in this embodiment, when the spacing member 71 and the force receiving portion 44b come into contact with each other, a force acts on the spacing member 71 and the force receiving portion 44b in a direction to pull them in each other. As a result, even if the spacing member 71 is provided movably with respect to the moving member 72, when it engages with the force receiving portion 44b, it is reliably positioned at the normal position and engages with the force receiving portion 44b. keep it in good condition.

<Example 5>
In this embodiment, a modified example of the shape of the protruding portion of the process cartridge P is shown. In addition, in this embodiment, the description will focus on the configuration different from the first to fourth embodiments, and the description of the same configuration will be omitted.

As shown in FIG. 31, in this embodiment, the process cartridge P is formed with a projecting portion 44e having a substantially rectangular ring shape. The protruding portion 44e protrudes in a direction intersecting the axial direction of the developing roller 41 and away from the rotation center X of the developing roller 41 and the developing unit, as in the previous embodiment. The projecting portion 44e has an opening 44r and a force receiving portion 44h. FIG. 32 shows a state in which the process cartridge P and the spacing member 71 of the spacing mechanism 70 are engaged. The contact portion 71b of the spacing member 71 passes through the opening 44r of the projecting portion 44e and contacts and engages with the force receiving portion 44h provided in the opening 44r.

In this embodiment, as shown in FIG. 32, when the moving member 72 moves in the direction of arrow M, the contact portion 71b of the spacing member 71 receives force F1 from the force receiving portion 44h. This force F1 is a force generated in a direction perpendicular to the contact portion 71b. Further, the force receiving portion 44h receives a force F1' opposite to the force F1 from the contact portion 71b of the spacing member 71. As shown in FIG. Thereafter, similarly to the fourth embodiment, the spacing member 71 receives a rotational moment directed from the retracted position toward the normal position, and the force receiving portion 44h receives a force directed toward the spacing member 71 .

That is, in this embodiment, the force F1 that the contact portion 71b of the spacing member 71 receives from the force receiving portion 44h of the projecting portion 44e acts in the direction (upward) in which the spacing member 71 moves from the retracted position to the normal position. The contact portion 71b and the contact portion 44h are configured. When the spacing member 71 and the force receiving portion 44h come into contact with each other, a force acts in the direction of pulling them together. As a result, even if the spacing member 71 is movably provided on the moving member 72, when it engages with the force receiving portion 44h, it is reliably positioned at the normal position and engaged with the force receiving portion 44h. keep

Also in this embodiment, the force receiving portion 44h is a surface facing the direction where the center of the developing roller 41 (the rotation axis 41x) and the rotation center X are located. A space is formed between the contact portion h and the developing roller 41 by the opening 44r. By inserting the spacing member 71 into this space (opening 44r), the spacing member 71 and the contact portion 44h are reliably engaged.

In the above description, the contact portion 71b of the spacing member 71 and the force receiving portion 44h are not limited to planar shapes. The contact portion 71b and the force receiving portion 44h may be curved surfaces. Moreover, it may be a minute area such as a ridge line or a point.

<Example 6>
In this embodiment, the configuration of the moving member 72 is changed from the above embodiment. There are two moving members 72 as shown in FIG. Hereinafter, when it is necessary to distinguish between the two moving members 72, they are referred to as a moving member 72R and a moving member 72L, respectively. The spacing members (engagement members) 71 provided on the moving member 72R are particularly referred to as spacing members 71Y, 71M, and 71M, and the spacing member (engagement member) 71 provided on the moving member 72L is particularly referred to as a spacing member 71K. call.

The moving member 72R is a moving member for moving the process cartridge PK containing black toner. On the other hand, the moving member 72L is a moving member for moving the process cartridges PY, PM, and PC containing yellow, magenta, and cyan toners. With a plurality of moving members 72, only the developing units 4 of some of the four process cartridges (black process cartridge PK in this embodiment) can be moved to the contact position. The developing units 4 of the other process cartridges (yellow, magenta, and cyan process cartridges PY, PM, and PC) can be held at the separated position. This will be explained below.

In this embodiment, the image forming apparatus A (see FIG. 2) can switch between a monochrome mode for printing monochrome images (black-and-white images) and a full-color mode for printing full-color images. In the monochrome mode, only the black process cartridge PK is used, so the moving member 72L is not movable, and only the moving member 72R is movable. That is, when the moving member 72R moves rightward in FIG. 33(a), the separating member 71K separates from the force receiving portion 44b. As a result, the developing roller 41 of the black process cartridge PK comes into contact with the photosensitive drum 1 . On the other hand, the moving member 72L does not have to move from the state shown in FIG. 33(a). When forming a monochrome image, the yellow, cyan, and magenta process cartridges PY, PM, and PC may be kept in a state in which the developing roller 41 is separated from the photosensitive drum 1 .

On the other hand, in the full-color mode, both the moving members 72R and 72L move rightward from the state shown in FIG. It is better to let

According to the configuration of this embodiment, the moving member 72R and the moving member 72L can move separately. When printing a monochrome image, the developing roller 41 can be separated from the photosensitive drum 1 in the yellow, magenta, and cyan process cartridges PY, PM, and PC. Deformation of the yellow, magenta, and cyan developing rollers 41 can be reliably suppressed. Also, in the monochrome mode, it is possible to prevent the toner carried by the yellow, magenta, and cyan developing rollers 41 from adhering to the photosensitive drum 1 . Further, in the yellow, magenta, and cyan process cartridges PY, PM, and PC, since the photosensitive drum 1 and the developing roller 41 do not rub against each other, deterioration of the photosensitive drum 1, developing roller 41, and toner can be suppressed.

Incidentally, there is a configuration shown in FIG. 33(b) as a modified example of this embodiment. In FIG. 33B, the spacing member 71 provided on the moving member 72R and the spacing members 71Y, 71M, and 71C provided on the moving member 72L are located at different positions of rotation centers. For example, in the spacing member 71Y (engagement member A), the support portion 74Y, which is the center of rotation, is located to the right of the contact portion 71Yb (the portion that contacts the force receiving portion 44b). On the other hand, the support portion 74K, which is the rotation center of the spacing member 71K (engagement member B), is located to the left of the contact portion 71Kb (the portion that contacts the force receiving portion 44b). Therefore, the width W7b of the spacing mechanism 70 in FIG. 33(b) is shorter than the width W7a of the spacing mechanism 70 in FIG. 33(a). With the configuration shown in FIG. 33(b), the spacing mechanism 70 can be made compact.

In order to shorten the width W7b, among the plurality of spacing members 71 arranged side by side, the spacing member 71Y (engagement member A) and the spacing member 71K (engagement member B) positioned at both ends (right end and left end) It is better to bring the positions of the rotation centers of In the configuration shown in FIG. 33B, the center of rotation of the spacing member 71Y (supporting portion 74Y) and the center of rotation of the spacing member 71K (supporting portion 74K) are located between the contact portions 71Yb and 71Kb. That is, the support portions 74Y and 74K are arranged inside (inside) the region Z sandwiched between the contact portions 71Kb and 71Yb to shorten W7b.

The spacing member 71Y disclosed in FIG. 33(b) will be further described with reference to FIG. FIG. 34 shows a state where the spacing member 71Y is engaged with the process cartridge PY. By engaging (abutting) with the force receiving portion 44b, the spacing member 71Y applies a force to the force receiving portion 44b, and at the same time receives a force F1 from the force receiving portion 44b.

This force F1 generates a moment in the direction of arrow s2 around the support portion 74Y. This moment in the direction of the arrow s2 holds the spacing member 71Y at a position (normal position) where it can be engaged with the force receiving portion 44b. In other words, the spacing member 71b does not retreat in the arrow s1 direction.

In this embodiment, the elastic member (biasing spring 73) that biases the spacing member 71 is a compression coil spring. However, the configuration of the elastic member is not limited to this, and for example, a torsion spring 75 may be used as shown in FIG. In addition to this embodiment, it is effective to use the torsion spring 75 in the configuration in which the separation member 71 rotates as in the second and fourth embodiments.

1 photoreceptor drum 4 developing unit (second unit)
5 cleaning unit (first unit)
13 intermediate transfer belt (intermediate transfer body)
28 cartridge tray (mounting member)
30 open/close door (open/close member)
41 developing roller 61 spacing member (engaging member)
62 moving member 62a guide portion (support portion)
71 spacing member (engagement member)
72 moving member 74 center of rotation (supporting part)
100 apparatus main body (image forming apparatus main body)
204 Developing cartridge A Image forming apparatus P (PY, PM, PC, PK) Process cartridge

Claims (26)

a process cartridge,
a photoreceptor drum;
a first frame supporting the photoreceptor drum so that the photoreceptor drum is rotatable about its rotational axis;
a developing roller;
supporting the developing roller so that the developing roller is rotatable about its rotational axis; and attaching the developing roller to the photosensitive drum so that the latent image on the photosensitive drum can be developed by the developing roller. a second frame that can swing about a swing axis with respect to the first frame between a first position of contact and a second position of separating the developing roller from the photosensitive drum; ,
a projection configured to receive a force from outside the process cartridge for moving the second frame from the first position to the second position;
(i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotation axis of the roller, (I) the projection is positioned below the photosensitive drum, and (II) the photosensitive drum is positioned below the photosensitive drum. A process cartridge according to claim 1, wherein said protrusions are provided so as to pass through a vertical line drawn from said swing shaft when viewed along the axis of the body drum. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is oriented so as to be positioned below the rotation axis of the roller,
2. A process cartridge according to claim 1, wherein said protrusion is constructed so as not to move in said vertical direction with respect to said second frame when a force is applied in said vertical direction. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotational axis of the roller, the horizontal length of the bottom of the projection when viewed along the rotational axis of the photosensitive drum is equal to the projection. 3. A process cartridge according to claim 1, wherein the horizontal length of said protrusion at a position different from the bottom of said process cartridge is substantially the same. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotation axis of the roller, the surface of the protrusion that receives the force is substantially vertical when viewed along the rotation axis of the photosensitive drum. A process cartridge according to any one of claims 1 to 3. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotational axis of the roller, the horizontal length of the bottom of the projection when viewed along the rotational axis of the photosensitive drum is equal to the projection. 3. A process cartridge according to claim 1 or 2, wherein the horizontal length of said projections at a position different from the bottom of the cartridge is longer than that of said projections. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotation axis of the roller, the projection is recessed in a direction away from the photosensitive drum as viewed along the axis of the photosensitive drum. 6. A process cartridge according to any one of claims 1, 2 or 5, characterized by comprising: 7. A process cartridge according to any one of claims 1, 2, 5 and 6, wherein said recess is provided in one member. The second frame includes a container for containing toner, and (i) the second frame is located at the first position, and (ii) the rotational axis of the photoreceptor drum is aligned with the developing roller. When the process cartridge is oriented so that the photoreceptor drum and the protrusion are positioned below the process cartridge, the protrusion is located below the bottom of the container. 8. A process cartridge according to any one of claims 1 to 7, wherein the lower side of the process cartridge. The second frame includes a bearing attached to the container and provided with an opening for receiving the shaft of the developing roller,
9. A process cartridge according to claim 8, wherein said projection is provided on said bearing. a process cartridge,
a photoreceptor drum;
a first frame supporting the photoreceptor drum so that the photoreceptor drum is rotatable about its rotational axis;
a developing roller;
supporting the developing roller so that the developing roller is rotatable about its rotational axis; and attaching the developing roller to the photosensitive drum so that the latent image on the photosensitive drum can be developed by the developing roller. a second frame that can swing about a swing axis with respect to the first frame between a first position of contact and a second position of separating the developing roller from the photosensitive drum; ,
a force receiving portion that receives a force from outside the process cartridge for moving the second frame from the first position to the second position;
(i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotation axis of the photoreceptor drum is When the process cartridge is oriented so as to be positioned below the rotation axis of the developing roller, (I) the force receiving portion is positioned below the photosensitive drum, and ( II) A process cartridge in which, when viewed along the axis of the photosensitive drum, the force receiving portion is provided so as to pass through a vertical line drawn from the swing shaft. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotational axis of the photoreceptor drum is When the process cartridge is oriented so as to be positioned below the rotation axis of the developing roller,
11. A process cartridge according to claim 10, wherein said force receiving portion is constructed so as not to move in the vertical direction with respect to said second frame when force is applied in the vertical direction. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotational axis of the photoreceptor drum is The horizontal length of the bottom portion of the force receiving portion viewed along the rotation axis of the photosensitive drum when the process cartridge is positioned below the rotation axis of the developing roller 12. A process cartridge according to claim 10, wherein the horizontal length of the force receiving portion at a position different from the bottom portion of the force receiving portion is substantially the same. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotation axis of the photoreceptor drum is When the process cartridge is oriented so as to be positioned below the rotation axis of the developing roller, the surface of the force receiving portion that receives the force when viewed along the rotation axis of the photosensitive drum is: 13. A process cartridge according to any one of claims 10 to 12, which is substantially vertical. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotation axis of the photoreceptor drum is The horizontal length of the bottom portion of the force receiving portion viewed along the rotation axis of the photosensitive drum when the process cartridge is positioned below the rotation axis of the developing roller 12. A process cartridge according to claim 10, wherein is longer than the horizontal length of the force receiving portion at a position different from the bottom portion of the force receiving portion. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotational axis of the photoreceptor drum is When the process cartridge is oriented so as to be positioned below the rotation axis of the developing roller, the force receiving portion moves away from the photosensitive drum as viewed along the axis of the photosensitive drum. 15. A process cartridge according to any one of Claims 10, 11 and 14, characterized by having a concave recess. 16. A process cartridge according to any one of claims 10, 11, 14 and 15, wherein said recess is provided in one member. The second frame includes a container for containing toner, and (i) the second frame is located at the first position, and (ii) the rotational axis of the photoreceptor drum is aligned with the developing roller. When the process cartridge is oriented so that the photoreceptor drum and the force receiving portion are positioned below the process cartridge, the force receiving portion is located below the rotation axis of the container. 17. A process cartridge according to any one of claims 10 to 16, located below the bottom of the process cartridge. The second frame includes a bearing attached to the container and provided with an opening for receiving the shaft of the developing roller,
18. A process cartridge according to claim 17, wherein said force receiving portion is provided on said bearing. a process cartridge,
a photoreceptor drum;
a first frame supporting the photoreceptor drum so that the photoreceptor drum is rotatable about its rotational axis;
a developing roller;
supporting the developing roller so that the developing roller is rotatable about its rotational axis; and attaching the developing roller to the photosensitive drum so that the latent image on the photosensitive drum can be developed by the developing roller. a second frame that can swing about a swing axis with respect to the first frame between a first position of contact and a second position of separating the developing roller from the photosensitive drum; ,
a projection configured to receive a force from outside the process cartridge for moving the second frame from the first position to the second position;
(i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotation axis of the roller, (I) the projection is positioned below the photosensitive drum, and (II) the photosensitive drum is positioned below the photosensitive drum. When viewed along the axis of the body drum, when a parallel line parallel to the force-receiving surface of the protrusion is drawn through the swing shaft, the protrusion is provided so as to pass through the parallel line. process cartridge. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is oriented so as to be positioned below the rotation axis of the roller,
20. A process cartridge according to claim 19, wherein said projection is configured so as not to move in said vertical direction with respect to said second frame when a force is applied in said vertical direction. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotational axis of the roller, the horizontal length of the bottom of the projection when viewed along the rotational axis of the photosensitive drum is equal to the projection. 21. A process cartridge according to claim 19 or 20, wherein the horizontal length of said projection at a position different from the bottom of said cartridge is substantially the same. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the projection are located below the process cartridge, and the rotation axis of the photoreceptor drum is aligned with the developing device. When the process cartridge is positioned below the rotation axis of the roller, the surface of the protrusion that receives the force is substantially vertical when viewed along the rotation axis of the photosensitive drum. A process cartridge according to any one of claims 19 to 21. a process cartridge,
a photoreceptor drum;
a first frame supporting the photoreceptor drum so that the photoreceptor drum is rotatable about its rotational axis;
a developing roller;
supporting the developing roller so that the developing roller is rotatable about its rotational axis; and attaching the developing roller to the photosensitive drum so that the latent image on the photosensitive drum can be developed by the developing roller. a second frame that can swing about a swing axis with respect to the first frame between a first position of contact and a second position of separating the developing roller from the photosensitive drum; ,
a force receiving portion configured to receive a force from outside the process cartridge for moving the second frame from the first position to the second position;
(i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotational axis of the photoreceptor drum is When the process cartridge is oriented so as to be positioned below the rotation axis of the developing roller, (I) the force receiving portion is positioned below the photosensitive drum, and ( II) When viewed along the axis of the photoreceptor drum, when a parallel line parallel to the surface of the force receiving portion that receives the force is drawn through the swing shaft, the force receiving portion A process cartridge that runs parallel lines. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotational axis of the photoreceptor drum is When the process cartridge is oriented so as to be positioned below the rotation axis of the developing roller,
24. A process cartridge according to claim 23, wherein said force receiving portion is configured so as not to move in the vertical direction with respect to said second frame when force is applied in the vertical direction. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotational axis of the photoreceptor drum is The horizontal length of the bottom portion of the force receiving portion viewed along the rotation axis of the photosensitive drum when the process cartridge is positioned below the rotation axis of the developing roller 25. A process cartridge according to claim 23 or 24, wherein is substantially the same as the horizontal length of said force receiving portion at a position different from the bottom portion of said force receiving portion. (i) the second frame is at the first position; and (ii) the photoreceptor drum and the force receiving portion are located below the process cartridge, and the rotational axis of the photoreceptor drum is When the process cartridge is oriented so as to be positioned below the rotation axis of the developing roller, the surface of the force receiving portion that receives the force when viewed along the rotation axis of the photosensitive drum is: 26. A process cartridge according to any one of claims 23 to 25, which is substantially vertical.

Images