JP2021047462A - Process cartridge - Google Patents

Abstract

To simplify a configuration of a mechanism that separates an image carrier and a developer carrier of a process cartridge.SOLUTION: An image forming apparatus includes: attachment parts to and from which each process cartridge P can be attached and detached; and engaging members 61 capable of engaging with force receiving parts provided to a second unit 4 of the process cartridge P. The engaging member 61 can be moved among three different positions of: 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 allowing the second unit 4 to move from the separation position to a contact position during image formation; and a third position for retreating by being pressed by the process cartridge P when the process cartridge P is attached to the attachment part, so as to allow the process cartridge P to be attached to the attachment part.SELECTED DRAWING: Figure 15

Description

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

Here, the image forming apparatus is for forming an image on a recording medium. Examples of the image forming apparatus include an electrophotographic copying machine and an electrophotographic printer (laser beam printer, LED printer, etc.).

The recording medium is one in which an image is formed by using an electrophotographic image forming process. For example, recording paper, transparencies, labels and the like.

Further, the process cartridge is a cartridge in which the electrophotographic photosensitive member and the process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge and can be attached to and detached from the main body of the image forming apparatus.

Conventionally, in an image forming apparatus using an electrophotographic forming process, an electrophotographic photosensitive member (hereinafter referred to as a photoconductor drum) and a process means acting on the photoconductor drum are integrally made into a cartridge. Then, a process cartridge method is adopted in which the cartridge can be attached to and detached from the main body of the image forming apparatus.

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

A conventional process cartridge has a photoconductor drum unit having a cleaning frame for holding a photoconductor drum, a developing roller as a means for developing a latent image on the photoconductor drum, a developing blade, and a developing unit having toner as a developer. It is composed of.

As an image forming apparatus, a so-called in-line method in which a plurality of process cartridges are arranged is known. This in-line image forming apparatus includes a process cartridge having a photoconductor drum and a developing unit for each of the yellow, magenta, cyan, and black colors, and superimposes images of each color to form a full-color image.

When the image is formed, the developing roller is urged toward the photoconductor drum at a predetermined pressure. In the contact development method in which the developing roller is in contact with the photoconductor drum for development, the developing roller is in contact with the surface of the photoconductor drum at 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 photoconductor drum and is not used for a long time, the elastic layer of the developing roller may be deformed. As a result, unevenness of the image may occur during development.

Further, as another example, when the developing roller is in contact with the photoconductor drum during non-image formation regardless of the presence or absence of the elastic layer, the developer carried on the developing roller is unnecessarily adhered to the photoconductor drum. There is. Further, as another example, when the photoconductor drum and the developing roller are in contact with each other and rotate at a time other than during development, the photoconductor drum, the developing roller, and the photofinishing roller due to rubbing between the photoconductor drum and the developing roller. , Deterioration of the developer may be accelerated.

Therefore, Patent Document 1 discloses a configuration in which the main body of the image forming apparatus is provided with a mechanism that acts on the process cartridge to separate the photoconductor drum and the developing roller when the image forming is not performed. This image forming apparatus has a configuration in which a process cartridge is attached to a drawer member movably provided in the main body of the apparatus, and the process cartridge is attached to the inside of the image forming apparatus together with the drawing member. When the pull-out member is moved to attach / detach the process cartridge to / from the apparatus main body, the pull-out member is retracted from the moving path of the process cartridge so that the separating mechanism does not interfere with the process cartridge.

Japanese Unexamined Patent Publication No. 2007-21304

The present invention is a further development of the above-mentioned conventional technique. An object of the present invention is to simplify the configuration of a mechanism for separating an image carrier of a process cartridge and a developer carrier, and to provide an inexpensive and compact image forming apparatus and process cartridge.

Further, when the process cartridge is mounted on the device main body of the image forming apparatus, the engaging member on the device main body side that engages with the process cartridge is retracted to provide an image forming apparatus capable of reliably mounting the process cartridge. .. Another object of the present invention is to provide a detachable process cartridge for this image forming apparatus.

A typical configuration of the invention according to the present application in order to achieve the above object is
In an image forming apparatus that forms an image on a recording medium,
A first unit having an image carrier, a developer carrier, a contact position where the developer carrier is brought into contact with the image carrier, and the developer carrier are separated from the image carrier. A second unit that can be moved to a separated position, and a mounting part that allows the process cartridge to be attached and detached.
An engaging member that can engage with the force receiving portion provided in the second unit,
With
The engaging member is
A first position for maintaining the second unit in the separated position by engaging with the force receiving portion, and
A second position for allowing the second unit to move from the distance position to the contact position during image formation.
When the process cartridge is mounted on the mounting portion, a third position for allowing the process cartridge to be mounted by retracting by being pressed from the process cartridge and
It is characterized in that it can be moved to three different positions.

Further, another configuration of the present invention is
In an image forming apparatus that forms an image on a recording medium,
A first unit having an image carrier, a contact position having a developer carrier and bringing the developer carrier into contact with the image carrier, and a distance separating the developer carrier from the image carrier. A process cartridge with a second unit that can be moved to a position, and
An engaging member that can engage with the force receiving portion provided in the second unit,
With
The engaging member is
A first position for maintaining the second unit in the separated position by engaging with the force receiving portion, and
A second position for allowing the second unit to move from the distance position to the contact position during image formation, and
When the process cartridge is mounted on the main body of the image forming apparatus, it is pressed from the process cartridge and retracted to allow the process cartridge to be mounted.
It is characterized in that it can be moved to three different positions.

Another configuration of the present invention is
In the process cartridge that can be attached to and detached from the main body of the image forming apparatus
The first unit with the image carrier and
A second unit having a developer carrier and movable to a contact position where the developer carrier is brought into contact with the image carrier and a separation position where the developer carrier is separated from the image carrier.
It engages with an engaging member provided on the second unit and provided on the main body of the apparatus, and receives a force from the engaging member for moving the second unit from the contact position to the separation position. With the force receiving part
When the process cartridge is mounted on the apparatus main body, it is provided in the second unit, and by pressing the engaging member, the engaging member is moved to a retracted position that allows the process cartridge to move. Department and
It is characterized by having.

Another configuration of the present invention is
In the process cartridge that can be attached to and detached from the main body of the image forming apparatus
The first unit with the image carrier and
A second unit having a developer carrier and movable to a contact position where the developer carrier is brought into contact with the image carrier and a separation position where the developer carrier is separated from the image carrier.
It engages with an engaging member provided on the second unit and provided on the main body of the apparatus, and receives a force from the engaging member for moving the second unit from the contact position to the separation position. With the force receiving part
With
When the force receiving portion engages with the engaging member, a force for pulling each other is generated between the engaging member and the force receiving portion.

Another configuration of the present invention is
The first unit with the image carrier and
A second unit having a developer carrier, which is a contact position where the developer carrier is brought into contact with the image carrier by rotatably coupling with the first unit, and the developer carrier. A second unit that can be moved to a distance position that separates the image carrier from the image carrier.
A protruding portion provided at the end of the second unit in the axial direction of the developer carrier and protruding in a direction intersecting the axial direction and away from the developer carrier.
With
The protrusion has a recess or an opening and has a recess or an opening.
The recess or the opening is provided with a force receiving portion that receives a force for moving the second unit from the contact position to the separated position.
When viewed along the axial direction of the developer carrier, the force receiving portion faces the side where the developer carrier is located.

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 on the device body of the image forming apparatus, the engaging member on the device body side that engages with the process cartridge can be retracted, and the process cartridge can be reliably mounted on the device body.

It is a perspective view of the image forming apparatus which concerns on Example 1. FIG. It is sectional drawing of the image forming apparatus which concerns on Example 1. FIG. It is sectional drawing of the image forming apparatus which concerns on Example 1. FIG. It is sectional drawing of the image forming apparatus which concerns on Example 1. FIG. It is sectional drawing of the image forming apparatus which concerns on Example 1. FIG. (A) is a perspective view showing a state in which the opening / closing door is closed. (B) It is a perspective view which shows the state which the opening and closing door is open. (C) It is a perspective view which shows the state which pulled out the cartridge tray. (A) It is sectional drawing which shows the state which the opening and closing door is closed. (B) is a cross-sectional view showing a state in which the opening / closing door is opened. It is a perspective view of the process cartridge which concerns on Example 1. FIG. (A) It is a perspective view which shows when the process cartridge is attached. (B) It is a perspective view which shows the state which a developing unit is in a contact position. (C) It is a perspective view which shows the state which the development unit is in a separated position. It is sectional drawing of the process cartridge which concerns on Example 1. FIG. It is a perspective view of the process cartridge which concerns on Example 1. FIG. It is a perspective view of the process cartridge which concerns on Example 1. FIG. It is a perspective view of the process cartridge which concerns on Example 1. FIG. (A) The figure which shows the moving member 62 and the separating member 61. (B) The figure which shows the separation member 61. (C) The figure which shows the moving member 62. (A) It is sectional drawing which shows when the process cartridge is attached. (B) It is sectional drawing which shows the state which the development unit is in a contact position. (C) It is sectional drawing which shows the state which the development unit is in a separated position. It is sectional drawing which shows the relationship between the process cartridge and the separation mechanism which concerns on Example 1. FIG. (A) It is sectional drawing which shows when the process cartridge is attached. (B) It is sectional drawing which shows the state which the development unit is in a contact position. (C) It is sectional drawing which shows the state which the development unit is in a separated position. It is an enlarged view of the moving member and the separating member which concerns on Example 2. FIG. It is an enlarged view of the moving member and the separating member which concerns on Example 2. FIG. It is sectional drawing which shows the relationship between the process cartridge and the separation mechanism which concerns on Example 3. FIG. It is sectional drawing of the process cartridge which concerns on Example 3. FIG. It is sectional drawing of the process cartridge which concerns on Example 3. FIG. It is sectional drawing which shows the relationship between the process cartridge and the separation mechanism which concerns on Example 3. FIG. It is sectional drawing of the separation mechanism which concerns on Example 3. FIG. (A) It is sectional drawing which shows when the process cartridge is attached. (B) It is sectional drawing which shows the state which the development unit is in a contact position. (C) It is sectional drawing which shows the state which the development unit is in a separated position. It is sectional drawing which shows the relationship between the process cartridge and the separation mechanism which concerns on Example 4. FIG. It is sectional drawing of the separation mechanism which concerns on Example 4. FIG. It is sectional drawing which shows the relationship between the process cartridge and the separation mechanism which concerns on Example 4. FIG. It is sectional drawing of the separation mechanism which concerns on Example 4. FIG. It is sectional drawing which shows the process cartridge which concerns on Example 4. FIG. It is a perspective view of the process cartridge which concerns on Example 5. FIG. It is sectional drawing which shows the relationship between the process cartridge and the separation mechanism which concerns on Example 5. FIG. It is a figure which shows the structure of the separation mechanism which concerns on Example 6. It is a figure which shows the structure of the separation mechanism which concerns on Example 6. It is a figure which shows the structure of the separation mechanism which concerns on Example 6.

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

<Example 1>
FIGS. 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 embodiment, as the image forming apparatus A, a full-color image forming apparatus to which four process cartridges can be attached and detached is illustrated.

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

[Outline of image forming device]
FIG. 2 is a cross-sectional view of the overall configuration of the image forming apparatus A of this embodiment. 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 are contained in the main body (hereinafter, referred to as “device main body”) 100 of the image forming apparatus A. is set up.

Further, four process cartridges P (PY, PM, PC, PK) of the first process cartridge PY, the second process cartridge PM, the third process cartridge PC, and the fourth process cartridge PK are arranged in the horizontal direction. ing. Each of the first to fourth process cartridges P (PY, PM, PC, PK) has the same electrophotographic image forming process mechanism, and the colors of the developing agents are different from each other.

Further, each of the first to fourth process cartridges P (PY, PM, PC, PK) has a developing unit 4 provided with a developing roller 41 for developing an electrostatic latent image on the photoconductor drum 1.

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

The second process cartridge PM contains a magenta (M) developer in the developing unit 4, and forms a magenta-colored developer image on the surface of the photoconductor drum 1.

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

The paper (recording medium) S loaded and stored in the paper feed tray 19 is fed by the paper feed roller 20 that rotates in the clockwise direction (arrow W direction) in the drawing, and the belt drive roller 14 and the secondary transfer roller 18 are fed. It is sent to the contact part (hereinafter referred to as "nip part").

The photoconductor drum 1 rotates in the counterclockwise direction (in the direction of arrow K) in the drawing, and an electrostatic latent image is sequentially formed on the outer peripheral surface of the photoconductor drum 1 by the laser beam L from the laser scanner 11, and then the electrostatic image is formed. The latent image is developed by the developing roller 41, and a toner image (developer image) is formed.

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

The toner image formed on the photoconductor drum 1 is transferred to the intermediate transfer belt 13 as the intermediate transfer body. When forming a color image, yellow, magenta, cyan, and black colors are developed on the photoconductor drum 1, and the toner images formed on the respective colors are sequentially transferred to the intermediate transfer belt 13.

Next, the toner image formed on the intermediate transfer belt 13 is transferred to the paper S sent to the nip portion of the belt drive roller 14 and the secondary transfer roller 18. In this embodiment, the toner image of the photoconductor drum 1 is once transferred to the intermediate transfer belt 13 and then transferred to the paper S, but the toner image may be directly transferred to the paper S from the photoconductor drum 1. In this case, instead of the intermediate transfer belt 13, a transport belt (conveyor member) for transporting the recording medium (paper S) is provided, and the paper S conveyed by the transport belt is of each color of yellow, magenta, cyan, and black. The toner images may be transferred in sequence.

The paper S on which the toner image is transferred is sent to the nip portion of the fixing film 24 and the pressure roller 25, where it is heated and pressed to fix the toner image on the paper S. The paper S on which the toner image is fixed is ejected to the output tray 27 by the output roller pair 26.

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

Hereinafter, a method of exchanging the process cartridge P of this laser beam printer will be described.

A member that moves while holding the process cartridges PY, PM, PC, and PK is referred to as a cartridge tray 28 from 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 “tray holding member”) 32 with respect to the apparatus main body 100, and is slidably provided in the lateral direction (arrows M and N directions) of FIG. ing.

As shown in FIG. 3, the space inside the apparatus main body 100 is the mounting portion of the process cartridge P. By placing the process cartridge P on the cartridge tray 28, the process cartridge P moves toward the mounting portion of the device main body 100 and is mounted on the device main body 100. Further, the process cartridge P is removable from the mounting portion of the apparatus main body 100. The details will be described below.

The opening / closing door 30 is rotatably provided with respect to the device 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 / closes an opening through which the cartridge tray 28 passes. By opening the opening / closing door 30 in the direction of arrow D in FIG. 3, the user can access the cartridge tray handle portion (hereinafter, referred to as “handle portion”) 29.

Further, a connecting arm 33 is provided so as to connect the opening / closing door 30 and the tray holding member 32. The connecting arm 33 and the tray holding member 32 form an interlocking means (interlocking mechanism) for moving the cartridge tray 28 in conjunction with the opening / closing operation of the opening / closing door 30. That is, when the opening / closing door 30 is opened from the closed state (see FIG. 2), the connecting arm 33 pulls the tray holding member 32 upward to the right (in the direction of arrow Y) to move the cartridge tray 28 upward. Move (see FIG. 3). At this time, the photoconductor drum 1 is separated from the intermediate transfer belt 13, and the cartridge tray 28 is in a state where it can be pulled out from the apparatus main body 100. That is, the user can pull out the cartridge tray 28 by pulling the handle portion 29.

At this time, the process cartridge P placed on the cartridge tray 28 also moves in the direction intersecting the axis of the photoconductor drum 1 and is pulled out to the outside of the apparatus main body 100.

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

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

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

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

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

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. 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 mounting the process cartridge P on the apparatus main body 100, the cartridge tray 28 is pulled out in the reverse procedure, the process cartridge P is placed on the cartridge tray 28, and then the cartridge tray 28 is stored inside the apparatus main body 100. At this time, the process cartridge P placed on the cartridge tray 28 also moves in the direction intersecting the axis of the photoconductor drum and heads toward the mounting portion of the apparatus main body 100.

Then, by storing the cartridge tray 28 in the apparatus main body 100 and then closing the opening / closing door 30, the tray holding member 32 is pushed down in the lower left direction (arrow Z direction) of FIG. 3 via the connecting arm 33. As a result, the cartridge tray 28 also moves downward, and the photoconductor drum 1 of the process cartridge P comes into contact with 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 photoconductor drum 1 is brought into contact with the intermediate transfer belt 13 and an image can be formed (see FIG. 2).

In this embodiment, a configuration is shown in which the contact state and the separation state of the photoconductor 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 paper S may be provided. In this case, the contact state and the separation state of the photoconductor drum 1 and the transport belt may be switched 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 the colors of the toners contained therein and the filling amount of the toners are different from each other.

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

FIG. 10 is a cross-sectional view showing a cross section when the process cartridge P is cut in a direction perpendicular to the photoconductor drum 1 axis direction. The driving force from the apparatus main body 100 is driven and 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 photoconductor drum 1 is rotationally driven in the counterclockwise direction (arrow K direction), and the developing roller 41 is rotationally driven in the clockwise direction (arrow L direction) at a predetermined speed.

In this embodiment, the process cartridge P is composed of a cleaner unit 5 and a developing unit 4 rotatably coupled to the cleaning unit 5. The cleaner unit 5 is a first unit (photoreceptor drum unit) that holds the photoconductor 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 comes into contact with the photoconductor drum 1 and rotates in a driven manner. The cleaning blade 51 is an elastic rubber blade, and the tip portion thereof is arranged so as to be in contact with the photoconductor drum 1. The cleaning blade 51 serves to remove the toner remaining on the photoconductor drum 1. The transfer residual toner removed by the cleaning blade 51 is accommodated in the toner accommodating portion 52 in the cleaner unit 5.

The developing unit 4 has a developing roller 41 as a developing means and a developing blade 42. The developing unit 4 further has a developing chamber (developing agent accommodating portion) 43 for accommodating 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 portion thereof is in contact with the developing roller 41. The developing blade 42 serves to regulate the toner supported on the peripheral surface of the developing roller 41 to a thin layer.

FIG. 13 shows a part of the component configuration of the developing unit 4. As shown in the figure, a bearing member 44 that rotatably supports the developing coupling member 56 and the developing roller 41 is fixed to one end side of the developing unit 4 in the longitudinal direction. More specifically, the first bearing portion 44p (outer surface of the cylinder) of the bearing member 44 is fitted with the developing coupling member 56, and the second bearing portion 44q (inner surface of the cylinder) is fitted with the shaft portion 41a of the developing roller 41. It fits and supports each rotatably. Further, the developing roller gear 45 is fitted to the shaft portion 41a of the developing roller 41. The outer peripheral surface 56g of the developing coupling member 56 is a gear portion that meshes with the developing roller gear 45. As a result, the driving force input from the apparatus main body 100 is configured to be transmitted to the developing roller 41 via the developing coupling member 56.

Further, the developing cover member 57 is fixed to the outside of the developing unit 4. The developing cover member 57 is configured to cover the developing coupling member 56 and the developing roller gear 45. Further, the developing cover member 57 is provided with a cylindrical portion 57b. The developing coupling member 56 is exposed from the 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 can be rotated around the support portion 46a of the drive side cartridge cover member 46 on the longitudinal end side. Fit. On the other end side, the protruding portion 4b protruding from the developing unit 4 is rotatably fitted into the support hole portion 47a of the non-driving side cartridge cover member 47. As a result, the developing unit 4 is rotatably supported with respect to the cleaner unit 5. Here, the center of rotation (rotation axis) of the developing unit 4 with respect to the cleaner unit 5 is referred to as the center of rotation (rotation axis) X. 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 urged by a pressure spring 53, which is an elastic member, and is configured such that the developing roller 41 abuts on the photoconductor 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 shown in the figure by the urging force of the pressure spring 53, and the moment in the direction of arrow J1 is centered on the center of rotation X. It is configured to work. As a result, the developing roller 41 can come into contact with the photoconductor drum 1 at a predetermined pressure. Further, the position of the developing unit 4 with respect to the cleaner unit 5 at this time is set as the 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 a protruding portion 44d is formed on the bearing member 44. As shown in FIG. 13, the projecting portion 44d projects in a direction intersecting the axis of the developing roller 41 and in a direction away from the developing roller 41. The protruding portion 44d is provided with a force receiving portion 44b that abuts on the separating mechanism 60 provided in the apparatus main body 100 and receives a force. When the force receiving portion 44b receives a force from the separating mechanism 60, the developing roller 41 and the photoconductor drum 1 are brought into contact with each other and separated from each other. The configurations of the projecting portion 44d, the force receiving portion 44b, and the separating mechanism 60 will be described in detail below.

[Separation mechanism of electrophotographic image forming apparatus main body]
Next, the separation mechanism 60 that separates the developing roller 41 of the developing unit 4 from the photoconductor drum 1 will be described with reference to FIGS. 9, 14, and 15. FIG. 9 is a perspective view showing the relationship between the process cartridge P and the separation mechanism 60. FIG. 15 is a cross-sectional view showing the relationship between the process cartridge P and the separation mechanism 60. 14A and 14B are partially enlarged views of the separation mechanism 60, FIG. 14A shows a state in which the separation member 61 is assembled with respect to the moving member 62, and FIG. 14B shows the separation member 61 and FIG. 14 (b). c) shows each of the moving members 62.

As described above, the developing unit 4 is urged by the pressure spring 53 provided on the process cartridge P, and is located at the contact position where the developing roller 41 is brought into contact with the photoconductor drum 1. However, if the developing roller 41 is in contact with the photoconductor drum 1 for a long time, a dent mark may be formed on the developing roller 41. Therefore, when the image is not formed, the developing roller 41 and the photoconductor drum 1 are separated from each other. Is desirable. Therefore, the apparatus main body 100 of this embodiment has a separation mechanism 60 that separates the developing roller 41 from the photoconductor drum 1.

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

The separating member 61 has an L shape and is an engaging member that engages with the process cartridge P. That is, the separating member 61 applies a force to the force receiving portion 44b by engaging (contacting) with the force receiving portion 44b which is the engaged portion of the process cartridge P.

The separating member 61 can move with respect to the moving member 62 in the height direction of the device main body 100 (vertical direction in FIG. 15, arrows H1 and H2 directions). That is, as shown in FIG. 14, the separation member 61 slides in the directions of arrows H1 and H2 by being supported by the support portion (hereinafter, guide portion) 62a of the moving member 62. Specifically, the hole portion 61p of the engaging member 61 is engaged with the shaft portion 62p of the moving member 62. Further, the locking portion 61q of the separating member 61 is arranged in the locking hole 62q of the moving member 62. By engaging the locking portion 61q of the separating member 61 with the regulating portion 62b of the moving member 62, the separating member 61 does not fall off from the moving member 62.

Further, as shown in FIG. 15, the separating member 61 is at a position where it can be engaged with the force receiving portion 44b by the urging spring 63 as an elastic member attached to the moving member 62 (hereinafter, referred to as a “normal position”). ) Is being urged. That is, the urging spring 63 acts as an urging member that urges the separating member 61 toward the normal position.

The moving member 62 is located below the process cartridge P (PY, PM, PC, PK) and is movably provided on the apparatus main body 100. That is, the moving member 62 is provided with a circular cam 64, and the cam 64 is connected to the cam drive shaft 65 at a position away from the center of the circle forming the cam 64. The cam 64 rotates about the cam drive shaft 65 as a rotation center by receiving a driving force from a drive source (not shown) provided in the apparatus main body 100, and moves the moving member 62 in a substantially horizontal direction (horizontal direction in FIG. 15; Move in the direction of arrows M and N).

Due to the rotation of the cam 64, the moving member 62 comes into contact with the photoconductor drum 1 at a position where the developing roller 41 and the photoconductor drum 1 are separated from each other (hereinafter, referred to as a “non-image forming position”). It moves to a position that allows this (hereinafter referred to as "image formation position"). Further, as will be described later, in the present embodiment, the separating member 61 supported by the moving member 62 is pressed from the process cartridge P and retracted when the process cartridge P is mounted on the apparatus main body 100. It is supposed to be.

Hereinafter, the behavior of the separating member 61 when the process cartridge P is mounted on the apparatus main body 100, and the mechanism in which the developing roller 41 and the photoconductor drum 1 are separated by the separating mechanism 60 will be described in detail step by step.

FIG. 16 shows the process cartridge P and the separation mechanism 60 when the cartridge tray 28 and the process cartridge P are mounted on the apparatus main body 100. As described above, when the opening / closing door 30 is opened, the cartridge tray 28 moves upward (in the direction of arrow H2) (in FIG. 3, it moves upward in the right direction and in the direction of arrow Y). At this time, the separating member 61 and the protruding 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 (arrows M and N directions) in this state, the separating 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 open / close door 30 is closed. As described above, the process cartridge P moves in the lower left (direction of arrow Z in the figure) in the apparatus main body 100 in conjunction with the closing operation of the opening / closing door 30, and the photoconductor drum 1 comes into contact with the intermediate transfer belt 13 ( (See FIGS. 2 and 3). The reason will be described later, but at this time, the moving member 62 is in the non-image forming position shown in FIGS. 9A and 15A, and the separating member 61 supported by the moving member 62 is the process cartridge P. It is in a position to interfere.

However, an urging spring 63 is attached to the separating member 61. Therefore, when the separating member 61 interferes with the process cartridge P and is pressed from the pressing portion 44c of the process cartridge P, the urging spring 63 compresses the separating member 61 in the moving direction of the process cartridge P (direction of arrow H1). Moves almost parallel to. That is, the separating member 61 is retracted from the normal position (moves to the retracted 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 on the apparatus main body 100. The pressing portion 44c is formed on the end surface of the protruding portion 44d protruding from the developing unit 4.

Next, the force receiving portion 44b of the protruding portion 44d and the separating member 61 are engaged with each other. For this purpose, the moving member 62 is once moved in the right direction (arrow N direction) in FIG. 15A, and the moving member 62 is moved to a position (image forming position) where the separating member 61 and the protruding portion 44d do not interfere with each other. As shown in FIGS. 9 (b) and 15 (b), when the moving member 62 moves to an image forming position where the separating member 61 does not interfere with the protruding portion 44d, the separating member 61 is extended by the urging spring 63. It moves in the upward direction (arrow H2 direction). As a result, the separating member 61 rises to a position (normal position) where it can engage with the force receiving portion 44b.

Next, when the moving member 62 moves in the left direction (arrow M direction) in FIG. 15B, the separating member 61 engages with the force receiving portion 44b provided on the protruding portion 44d. Further, when the moving member 62 moves to the left (direction of arrow M) and returns to the non-image forming position, the moving member 62 applies a force to the force receiving portion 44b via the separating member 61. As a result, the moving member 62 moves the developing unit 4 to a position (separation position) where the developing roller 41 is separated from the photoconductor drum 1 with a gap e as shown in FIGS. 9 (c) and 15 (c). Let it be in the state of being made.

As shown in FIG. 14, the separating member 61 is slidable (sliding) only in the directions of arrows H1 and H2 because the moving direction with respect to the moving member 62 is determined by the guide portion 62a. The moving direction of the separating member 61 (directions of arrows H1 and H2) is a direction intersecting the moving direction of the moving member 62 (directions of arrows M and N). Therefore, when the moving member 62 moves, even if the separating member 61 receives a force from the force receiving portion 44b in the directions M and N of the arrows, the separating member 61 is supported by the guide portion 62a and engages with the force receiving portion 44b. Can be kept in a good condition. As a result, the moving member 62 can reliably move the developing unit 4 to a separating position that separates the developing roller 41 and the photoconductor drum 1. In particular, in this embodiment, the moving direction of the separating member 61 (arrows H1 and H2 directions) is substantially orthogonal to the moving direction of the moving member 62 (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. 15B. At this time, the developing unit 4 moves from the separated position to the contacting position by the force of the pressure spring 53 (see FIG. 8), and brings the developing roller 41 into contact with the photoconductor drum 1 (see FIG. 15B). In this state, the developing roller 41 develops the electrostatic latent image formed on the photoconductor drum 1 with a developer.

Then, when the image formation is completed, the moving member 62 moves to the non-image forming position, so that the developing roller 41 is maintained in a state of being separated from the photoconductor drum 1 until the start of the image forming operation (FIG. 15 (c)). reference). As a result, it is possible to prevent the developing roller 41 from being deformed by the contact pressure with the photoconductor drum 1.

[Three positions of separating members]
Summarizing what has been described above, the separating member 61 can move in three different positions (the separating member 61 can take three different states).

(1) FIG. 15 (c) shows a state in which the separating member 61 is in the working position (first position). When the separating member 61 is in the working position with the process cartridge P mounted on the apparatus main body 100, the separating member 61 engages with the force receiving portion 44b. As a result, the separating member 61 acts on the developing unit 4 (applying force) to move the developing unit 4 to the separating position and separate the developing roller 41 from the photoconductor drum 1.

(2) FIG. 15B shows a state in which the separating member 61 is in the non-acting position (second position). When the separating member 61 is in the non-acting position with the process cartridge P mounted on the apparatus main body 100, the separating member 61 allows the developing roller 41 to come into contact with the photoconductor drum 1. That is, the separating member 61 does not apply a force to the force receiving portion 44b, or reduces the force applied to the force receiving portion 44b so that the separating member 61 does not act on the developing unit 4. As a result, the developing unit 4 brings the developing roller 41 closer to the photoconductor drum 1 by the force of the pressure spring 53 (see FIG. 10) and brings them into contact with each other. That is, the developing unit 4 moves to the contact position.

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

When the separating member 61 is in the working position or the non-acting position, the separating member 61 is in the normal position (position not retracted) with respect to the moving member 62.

That is, the fact that the separating member 61 is in the working position means that the relative position of the separating 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 separating member 61 engages with the developing unit 4 (acts on the developing unit 4) and applies a force to the developing unit 4 to move the developing unit to the separated position. The developing roller 41 and the photoconductor drum 1 are separated from each other.

Further, the fact that the separating member 61 is in the non-acting position means that the relative position of the separating member 61 with respect to the moving member 62 is the normal position, and the moving member 62 is in the image forming position. At this time, the moving member 62 does not act on the developing unit 4 by moving away 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 comes into contact with the photoconductor drum 1.

On the other hand, when the separating member 61 is in the retracted position, the separating member 61 is in the retracted state from the normal position, the moving member 62 is in the non-image forming position, and the developing unit 4 is in the contacting position.

The table is as follows.

Here, after the image formation is completed, the moving member 62 is arranged at a non-image forming position for separating the developing roller 41 and the photoconductor drum 1. Therefore, the moving member 62 is in the non-image forming position even when the process cartridge P is mounted. When the process cartridge P is mounted, the developing unit 4 is in a state where the developing roller 41 is in contact with the photoconductor drum 1 by the urging force of the pressure spring 53. It interferes with the separating member 61 (see FIG. 15A). However, as described above, the separating member 61 is pushed from the pressing portion 44c provided on the protruding portion 44d to move from the normal position (acting position: see FIG. 16) to the retracted position (see FIG. 15A). can do. Therefore, the separating member 61 does not hinder the movement of the process cartridge P, and the process cartridge P is securely mounted on the apparatus main body 100.

On the other hand, when the process cartridge P is removed from the image forming apparatus while the separating member 61 is in the retracted position (see FIG. 15A), the separating member 61 is moved to the normal position (acting position: FIG. 16). That is, by opening the door 30 (FIG. 30), the process cartridge P rises in the H2 direction in FIG. 15 (a). In conjunction with the movement of the process cartridge P, the separating member 61 also moves in the H2 direction.

Summarizing the above, in the present embodiment, the separating member 61 that engages with the force receiving portion 44b of the process cartridge P is provided on the moving member 62 so as to be movable, and is pressed by the process cartridge P to retract. As a result, the mechanism for retracting the separating member 61 can be simplified, the configuration of the separating mechanism 60 and the apparatus main body 100, and the configuration of the process cartridge P can be simplified. Further, since the separating member 61 only needs to be retracted by the distance that the process cartridge P moves, it is not necessary to take a large evacuation space for the separating member 61 to retract. As a result, 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 separating member 61 at the retracted position (FIG. 15 (a)) to the non-acting position (FIG. 15 (b)). It is moved to the action position (FIG. 15 (c)) via the passage. The separating member 61 can be engaged with the developing unit 4 to separate the developing roller 41 from the photoconductor drum 1. This makes it possible to prevent the developing roller 41 from being deformed. Further, it is possible to prevent the toner adhering to the developing roller 41 from adhering to the photoconductor drum 1 during non-image formation.

Further, the developing roller 41 and the photoconductor drum 1 do not rub against each other during non-image formation. Therefore, it is possible to prevent the toner carried on the photoconductor drum 1, the developing roller 41, or the developing roller 41 from deteriorating. Therefore, the process cartridge P can be used for a long period of time.

The separation mechanism 60 in the above embodiment corresponds to the arrangement of the four separation members 61 on the same moving member 62 and the arrangement of the four process cartridges P in the horizontal direction (arrows M and N in FIG. 15). It is placed in the position where it was. In this case, by moving the moving member 62, the plurality of developing rollers 41 and the photoconductor drum 1 can all be separated from each other at the same time.

However, the separation mechanism 60 is not limited to this. For example, a separation mechanism 60 (separation member 61 and moving member 62) corresponding only to the black process cartridge PK is provided. Then, a separation mechanism 60 (separation member 61 and moving member 62) corresponding to process cartridges (PY, PM, PC) other than black is separately provided. Such an image forming apparatus may be used. In this case, when the image forming apparatus forms a monochrome image, some developing rollers 41 and the photoconductor are separated from the photoconductor drum 1 by separating the developing roller 41 from the photoconductor drum 1 only for process cartridges (PY, PM, PC) other than black. Only the drum 1 can be separated. Such a configuration will be described in detail in Example 6.

Further, the image forming apparatus of this embodiment is a color image forming apparatus, and includes a plurality of (4) process cartridges, and also has a separating member 61 corresponding to the number of process cartridges, but the configuration is limited to this. not. The separation mechanism may be applied to a monochrome image forming apparatus in which only one process cartridge is mounted (in this case, only one separation member 61 is required).

<Example 2>
In this embodiment, a modified example of the separating member (engaging member) provided in the separating mechanism is shown. That is, the configuration in which the separating member 71 is retracted by rotating with respect to the moving member 72 is shown. In this embodiment, the description of the configuration different from that of the first embodiment will be mainly described, and the description of the same configuration as that of the first embodiment will be omitted.

As shown in FIG. 17, the separating member 71 is rotatably supported around a support portion 74 provided on the moving member 72. Further, the separating member 71 is urged by the urging spring 73 at a position where it can engage with the force receiving portion 44b. Also in this embodiment, the separating member 71 can move to three different positions (acting position, non-acting position, retracting position).

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

From the state shown in FIG. 17A, in order to engage the force receiving portion 44b and the separating member 71, move the moving member 72 to the right until the separating member 71 does not interfere with the protruding portion 44d (image forming position). Move in the direction (arrow N direction). As shown in FIG. 17B, when the separating member 71 moves to a position where it does not interfere with the protruding portion 44d, the separating member 71 rotates clockwise (in the direction of arrow V2) around the supporting portion 74 by the force of the urging spring 73. It moves to a normal position (non-acting position) where it can engage with the force receiving portion 44b.

Next, when the moving member 72 is moved to the left (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 with each other. When the moving member 72 is further moved to the left (arrow M direction) in this state, the moving member 72 is in the non-image forming position, or the separating member 71 has a gap e between the developing roller 41 and the photoconductor drum 1. The developing unit 4 is moved to a position (separation position) at which the development unit 4 is separated. Then, the developing roller 41 is maintained in a state of being separated from the photoconductor drum 1 from the end of the image forming operation to the restarting of the image forming operation (see FIG. 17C). FIG. 17C shows a state in which the separating member 71 has moved to the action position.

Here, as shown in FIG. 18, the moving member 72 has a rotation regulating portion 72b that stops (regulates) the rotation of the separating member 71 while holding it at a normal position (acting position). Therefore, when the moving member 72 moves in the left direction (arrow M direction) shown in FIG. 17B, the separating member 71 moves together with the moving member 72 in a state of being engaged with the force receiving portion 44b, and moves to the force receiving portion 44b. Apply force. As a result, the separating member 71 moves the developing unit 4 to the separating position and maintains this state.

Summarizing the above, the moving member 72 reciprocates from the state where the separating member 71 is located at the retracted position (see FIG. 17A) to the image forming position and the non-image forming position, so that the separating member 71 receives a force. Engage with portion 44b. Then, the developing unit 4 is moved to a separated position (see FIG. 17 (c)).

In this embodiment, by rotatably providing the separating member on the moving member, the rattling when the separating member moves is suppressed as compared with the case where the separating member moves linearly (see FIG. 15), and the operation of the separating member is suppressed. Can be stabilized. More specifically, when the separating member 61 is linearly moved as shown in the first embodiment, the separating member 61 and the guide 62a are in a fitting relationship (see FIG. 14). The size of the hole 61p of the separating member 61 and the size of the insertion portion 62p of the guide 62a vary. When this dimensional variation is large, as shown in FIG. 19, the separating member 61 tilts with respect to the guide 62a, and the movement of the separating member 61 with respect to the guide 62a in the directions H1 and H2 may become unstable. In this embodiment, by providing the separating member 71 on the moving member 72 so as to be rotatable, the operation of the separating member 71 can be stabilized.

On the other hand, when the separating member is linearly moved as in the separating member 61 of the first embodiment (see FIG. 14), the region required for moving the separating member can be made smaller than the rotational movement. As a result, the size of the separation mechanism can be reduced, and the image forming apparatus can be miniaturized. The instability of operation due to the tilting of the separating member 61 with respect to the guide 62a as described above can be suppressed by strictly controlling each dimension.

Therefore, the movement configuration of the separation member (61, 71) may be appropriately selected according to the functions required of the image forming apparatus 100 and the separation mechanism (60, 70).

<Example 3>
In this embodiment, a modified example of the shapes of the separating member 61, the protruding portion 44d, and the force receiving portion 44b provided in the separating mechanism 60 is shown. In this embodiment, the description of the configuration different from that of the first embodiment will be mainly described, and the description of the same configuration as that of the first embodiment will be omitted.

In this embodiment, as shown in FIG. 20, a convex portion 44a and a concave portion 44g are formed in the protruding portion 44d in order to securely engage the separating member 61 with the force receiving portion 44b. A force receiving portion 44b is formed in the recess 44g provided in the protruding portion 44d. Although the details will be described later, the force receiving portion 44b and the contact portion 61b are tilted at a predetermined angle to ensure that the force receiving portion 44b and the separating member 61 are engaged with each other.

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

Further, FIG. 22 shows a state in which the developing unit 4 is rotated clockwise (in the direction of arrow J2) by an angle θ0 about the rotation center X from the state shown in FIG. Here, the angle θ0 is the rotation angle of the developing unit 4. In FIG. 22, the developing roller 41 and the photoconductor 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 (arrows M and N directions) of the moving member 62.

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

The protruding portion 44d protrudes downward (in the direction of arrow H1). That is, the protruding portion 44d protrudes in the direction intersecting the axis 41x of the developing roller 41 and in the direction away from the developing roller 41 and the rotation center X. Further, 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 protruding portion 44d is the force receiving portion 44b of the developing roller 41. It faces the center (axis 41x) direction. In other words, in FIG. 21 (a plane orthogonal to the axis 41x of the developing roller 41), when a straight line (tangent line) Q that is in contact with the force receiving portion 44b and extends along the force receiving portion 44b is drawn, with respect to this straight line Q. The center (axis line 41x) of the force receiving portion 44b and the developing roller 41 is on opposite sides.

Note that this does not mean that the force receiving portion 44b is limited to a configuration in which the force receiving portion 44b directly faces the developing roller 41, and as shown in FIG. 13, the force receiving portion 44b is provided on the outer side in the axial direction of the developing roller 41. You may be. That is, 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 positioned with the developing roller 41. It means that it faces the side to do.

Nor is it intended to limit the shape of the force receiving portion 44b to a flat surface. The force receiving portion 44b may have a different shape such as a curved surface as long as the region (surface) that comes into contact with the separating member 61 faces the side where the developing roller 41 is located.

More specifically, in FIG. 21, the straight line Q extending along the force receiving portion 44b starting from the force receiving portion 44b of the protruding portion 44d does not pass through the axis 41x of the developing roller 41. Further, the axis 41x of the developing roller 41 is arranged on the side of the protruding 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. More specifically, in FIG. 21, the straight line Q does not pass through the rotation center X of the developing unit 4. Further, the rotation center X of the developing unit 4 is arranged on the side of the protruding 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 located on opposite sides of the straight line Q. Furthermore, the force receiving portion 44b and the photoconductor drum 1 are located on opposite sides of the tangent line Q.

Further, the protruding portion 44d has a convex portion 44a that projects so as to cover the rotation center X and the developing roller 41. The convex portion 44a projects in a direction approaching the cleaning unit 5 and the photoconductor drum 1 to form a concave portion 44g. The recess 44g is a recess that is recessed in a direction away from the cleaning unit 5 and the photoconductor drum 1. Further, the recess 44g is a space formed between the force receiving portion 44b and the developing roller 41 (a region closer to the developing roller 41 than the contact portion 44b). When the tip of the separating member 61 enters this space (recessed portion 44g), the force receiving portion 44b and the separating member 61 can be engaged with each other.

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

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

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

That is, in this embodiment, the abutting portion 61b of the separating member 61 moves from the retracted position to the normal position (acting position) due to the force F1 received from the force receiving portion 44b of the protruding portion 44d (upward). , The component force (F1y) acting in the direction of arrow H2 is generated. That is, the contact portion 61b of the separating member 61 is inclined at an angle θ3 so that the force F1 received by the separating member 61 from the force receiving portion 44b has the component F1y.

Further, the force receiving portion 44b is inclined in the same direction as the contact portion 61b so that the force receiving portion 44b of the developing unit 4 surely contacts the contact portion 61b of the separating member 61. That is, the contact portion 61b and the force receiving portion 44b are inclined so as to be from the upstream side in the arrow H1 direction and the upstream side in the arrow N direction to the downstream side in the arrow H1 direction and the downstream side in the arrow M direction.

The arrow H1 direction is the direction in which the separating member 61 moves from the action 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 separating member 61 retracts. Further, the arrow N direction is a direction in which the separating member 61 moves from the acting position (see FIG. 15C) to the non-acting position (see FIG. 15B). That is, the arrow M direction is the direction in which the separating member 61 moves in order to bring the developing roller 41 into contact with the photoconductor drum 1.

By inclining the separating member 61 and the force receiving portion 44b as described above, when the separating member 61 and the force receiving portion 44b are engaged (contacted), a force acts in a direction in which they are drawn into each other. ing. That is, a force is applied upward (H2 direction) to the separating member 61, and a force is applied downward (H1 direction) to the force receiving portion 44b, so that the separating member 61 and the force receiving portion 44b are drawn into each other. As a result, even if the separating member 61 is movably provided on the moving member 62, when it engages with the force receiving portion 44b, it is reliably maintained in the normal position (acting position) by the component force F1y, and the force is maintained. The state of being engaged with the receiving portion 44b is maintained.

In particular, in this embodiment, the angle between the force receiving portion 44b and the contact portion 61b of the separating member 61 has the following relationship so that the engaging state between the force receiving portion 44b and the separating 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 portions 44b with respect to the vertical direction are the abutting portions of the separating member 61 in both the case where the developing unit 4 is in the separated position and the case where the developing unit 4 is in the contacted position. It means that it becomes 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 surely brought into contact with the surface of the separating member 61 forming the contact portion 61b. Therefore, the contact state between the force receiving portion 44b and the contact portion 61b of the separating member 61 is stably maintained.

To summarize the above formula,
θ1 ≧ θ3 and θ2 = θ1-θ0 ≧ θ3
That is,
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 61b of the separating member 61 and the force receiving portion 44b of the protruding 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 rotation to the separated position).

<Example 4>
In this embodiment, a modified example of the shapes of the separating member 71 and the protruding portion 44d provided in the separating mechanism 70 is shown. In this embodiment, the description of the configuration different from that of the second embodiment will be mainly described, and the description of the same configuration will be omitted.

As shown in FIG. 25, the separating member 71 is rotatably supported around a support portion 74 provided on the moving member 72. Further, the separating member 71 is urged by the urging spring 73 at a position where it can engage with the force receiving portion 44b. Also in this embodiment, the separating member 71 can move to three different positions (acting position, non-acting position, retracting position).

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

From the state shown in FIG. 25A, in order to engage the force receiving portion 44b of the protruding portion 44d with the separating member 71, the separating member 71 does not interfere with the process cartridge P (protruding portion 44d) (image formation). The moving member 72 is moved to the right (arrow N direction) until the position). As shown in FIG. 25B, when the separating member 71 moves to a position where it does not interfere with the protruding portion 44d, the separating member 71 rotates counterclockwise (in the direction of arrow U2) around the supporting portion 74 by the force of the urging spring 73. .. Then, the separating member 71 moves with respect to the moving member 72, and rises to a normal position (non-acting position) where the force receiving portion 44b provided on the protruding portion 44d can be brought into contact with and engaged with the force receiving portion 44b.

Next, when the moving member 72 is moved to the left (direction of arrow M) from the image forming position shown in FIG. 25 (b), the separating member 71 and the force receiving portion 44b are engaged with each other. When the moving member 72 is further moved to the left (arrow M direction) in this state, the moving member 72 reaches the non-image forming position, and the separating member 71 is at a position where the developing roller 41 and the photoconductor drum 1 are separated (separation). The development unit 4 is moved to the position). Then, the developing roller 41 is maintained in a state of being separated from the photoconductor drum 1 from the end of the image forming operation to the restarting of the image forming operation (see FIG. 25 (c)). FIG. 25C shows a state in which the separating member 71 is located at the action position.

In summary, the moving member 72 reciprocates between the image forming position and the non-image forming position from the state where the separating member 71 is located at the retracted position (see FIG. 25A), so that the separating member 71 does not act. It moves to the action position via the position. Then, the separation member 71 engages with the force receiving portion 44b to move the developing unit 4 to the separation position (see FIG. 25C).

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 separating member 71 and the force receiving portion 44b, as in the third embodiment. Will be done. In this embodiment, the force receiving portion 44b is formed on the concave portion 44g, and the contact portion 71b of the separating member 71 comes into contact with the recessed portion 44g.

More specifically, as shown in FIG. 21, when the developing roller 41 and the photoconductor drum 1 are in contact with each other, the force receiving portion 44b of the protruding portion 44d is in the moving direction of the moving member 72 (arrows M and N directions). ), The angle θ1 is tilted with respect to the orthogonal direction. Further, as shown in FIG. 22, in a state where the developing roller 41 and the photoconductor drum 1 are separated from each other, the force receiving portion 44b is oriented in a direction orthogonal to the moving direction (arrows M and N directions) of the moving member 72. , The angle θ2 is tilted.

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

FIG. 27 shows the relationship between the force receiving portion 44b in a state where the developing roller 41 and the photoconductor drum 1 are in contact with each other, and the separating member 71. Further, FIG. 26 shows the relationship between the force receiving portion 44b in a state where the developing roller 41 and the photoconductor drum 1 are separated from each other, and the separating member 71.

By setting the relationship between the force receiving portion 44b and the contact portion 71b of the separating member 71 to the following relationship, a force for maintaining the engaged state between the force receiving portion 44b and the separating 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 arrow N direction and the upstream side in the arrow u1 direction toward the downstream side in the arrow N direction and the upstream side in the arrow u1 direction (FIG. 27). reference). The arrow u1 is in the direction in which the separating member 71 retracts (the direction in which the separating member 71 moves from the normal position (acting position: see FIG. 25 (c)) toward the retracting position (FIG. 25 (a))). is there.

Further, in both the case where the developing unit 4 is in the contact position and the case where the development unit 4 is in the separation position, the angle (θ1, θ2) of the force receiving portion 44b is made larger than the angle θ3 of the contact portion 71b of the separation member 71. There is.

To summarize the above formula,
θ1 ≧ θ3 and θ1-θ0 ≧ θ3
Will be. This means
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 and the force receiving portion 44b of the separating member 71 is equal to or larger than the rotation angle θ0 of the developing unit. Means.

This will be described in more detail below. As shown in FIG. 26 in this embodiment, when the moving member 72 moves in the direction of the arrow M, the contact portion 71b of the separating member 71 receives the force F1 from the force receiving portion 44b. This force F1 is a force generated in the direction perpendicular to the contact portion 71b. Further, the force receiving portion 44b receives a force F1'in the opposite direction of the force F1 from the contact portion 71b of the separating member 71.

Hereinafter, the forces received by the contact portion 71b and the force receiving portion 44b of the separating member 71 will be described with reference to the drawings. FIG. 29 shows the force F1 received by the contact portion 71b of the separation mechanism 70 and the separation member 71. The contact portion 71b is inclined at an angle θ3 so that the separating member 71 receives a rotational moment in the arrow U2 direction about the support portion 74 by receiving the force F1. That is, the normal line of the contact portion 71b of the separation member 71 (region F1a in FIG. 29) is configured to be located 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 separating member 71 receives a rotational moment in the direction of arrow U2 due to the force F1. That is, it receives a rotational moment toward the force receiving portion 44b of the process cartridge P. In other words, the separating member 71 is a component that 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 moving direction (arrows M and N directions) of the moving member 72 and a component F1y' perpendicular to the moving direction (arrows M and N directions). Of these, the component F1y'is a downward-facing component, in other words, receives a force toward the separating member 71.

Further, the force F1 received by the contact portion 71b of the separating member 71 from the force receiving portion 44b acts in the direction in which the separating member 71 moves from the retracted position to the normal position and in the direction in which the separating member 71 approaches the force receiving portion 44b. .. Further, the contact portion 71b is tilted by θ3 so that such an action occurs. Further, the force receiving portion 44b is also inclined in the same direction so that the contact portion 71b and the contact portion 71b are surely maintained in contact with each other.

As a result, in this embodiment, when the separating member 71 and the force receiving portion 44b come into contact with each other, a force in a direction of pulling each other acts on the separating member 71 and the force receiving portion 44b. As a result, even if the separating member 71 is movably provided with respect to the moving member 72, when it engages with the force receiving portion 44b, it is surely positioned at the normal position and engages with the force receiving portion 44b. Keep it in a 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 this embodiment, the description of the configuration different from that of the first to fourth embodiments will be mainly described, 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 protruding portion 44e having a ring shape having a substantially rectangular outer 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 above-described embodiment. The protruding 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 separating member 71 of the separating mechanism 70 are engaged with each other. The contact portion 71b of the separating member 71 passes through the opening 44r of the protrusion 44e and abuts and engages with the force receiving portion 44h provided in the opening 44r.

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

That is, in this embodiment, the force F1 received by the contact portion 71b of the separating member 71 from the force receiving portion 44h of the protruding portion 44e acts in the direction (upward) in which the separating member 71 moves from the retracted position to the normal position. The contact portion 71b and the contact portion 44h are configured. When the separating member 71 and the force receiving portion 44h come into contact with each other, a force acts in a direction in which they are drawn into each other. As a result, even if the separating 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.

Further, also in this embodiment, the force receiving portion 44h is a surface facing the direction in which the center (rotation shaft 41x) of the developing roller 41 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. When the separating member 71 enters this space (opening 44r), the separating member 71 and the contact portion 44h are surely engaged with each other.

In the above, the contact portion 71b of the separating member 71 and the force receiving portion 44h are not limited to the planar shape. The contact portion 71b and the force receiving portion 44h may be curved surfaces. Further, it may be a minute region that forms a ridgeline or a point.

<Example 6>
In this embodiment, the configuration of the moving member 72 is changed from the above-described embodiment. As shown in FIG. 33 (a), there are two moving members 72. 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. Further, the separating member (engaging member) 71 provided on the moving member 72R is particularly referred to as a separating member 71Y, 71M, 71M, and the separating member (engaging member) 71 provided on the moving member 72L is particularly referred to as a separating member 71K. Call.

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

In this embodiment, the image forming apparatus A (see FIG. 2) can switch between a monochrome mode for printing a monochrome image (black and white image) and a full color mode for printing a full color image. In the monochrome mode, since only the black process cartridge PK is used, the moving member 72L does not move, and only the moving member 72R needs to be moved. That is, when the moving member 72R moves to the right in FIG. 33A, the separating member 71K is separated from the force receiving portion 44b. As a result, the developing roller 41 of the black process cartridge PK comes into contact with the photoconductor 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 process cartridges PY, PM, and PC of yellow, cyan, and magenta may keep the developing roller 41 away from the photoconductor drum 1.

On the other hand, in the full color mode, both the moving member 72R and the moving member 72L move to the right from the state shown in FIG. 33A, so that the developing roller 41 abuts on the photoconductor drum 1 in all the cartridges P. It is good to let it.

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 photoconductor 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. Further, in the monochrome mode, it is possible to prevent the toner supported on the yellow, magenta, and cyan developing rollers 41 from adhering to the photoconductor drum 1. Further, in the yellow, magenta, and cyan process cartridges PY, PM, and PC, since the photoconductor drum 1 and the developing roller 41 do not rub against each other, deterioration of the photoconductor drum 1, the developing roller 41, and the toner can be suppressed.

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

In order to shorten the width W7b, of the plurality of separating members 71 arranged side by side, the separating members 71Y (engaging member A) and the separating members 71K (engaging member B) located at both ends (right end and left end). It is advisable to bring the position of the center of rotation of. In the configuration shown in FIG. 33 (b), the rotation center of the separation member 71Y (support portion 74Y) and the rotation center of the separation member 71K (support portion 74K) are located between the contact portion 71Yb and the contact portion 71Kb. That is, the support portions 74Y and 74K are arranged inside (inside) the region Z sandwiched between the contact portion 71Kb and the contact portion 71Yb to shorten W7b.

The separating member 71Y disclosed in FIG. 33B will be further described with reference to FIG. 34. FIG. 34 shows a state in which the separating member 71Y engages with the process cartridge PY. The separating member 71Y applies a force to the force receiving portion 44b by engaging (contacting) with the force receiving portion 44b, but at the same time receives the force F1 from the force receiving portion 44b.

This force F1 generates a moment in the direction of arrow s2 centered on the support portion 74Y. Due to the moment in the direction of the arrow s2, the separating member 71Y is held at a position (normal position) where it can engage with the force receiving portion 44b. That is, the separating member 71b is prevented from retracting in the direction of the arrow s1.

In this embodiment, the elastic member (urging spring 73) that urges the separating member 71 is a compression coil spring. However, the structure of the elastic member is not limited to this, and a torsion spring 75 may be used, for example, as shown in FIG. 35. In addition to this embodiment, it is effective to use the torsion spring 75 in a configuration in which the separating member 71 rotates as in the second and fourth embodiments.

1 Photoreceptor drum 4 Development 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 Separation member (engagement member)
62 Moving member 62a Guide part (support part)
71 Separation member (engagement member)
72 Moving member 74 Center of rotation (support part)
100 Device body (image forming device body)
204 Development Cartridge A Image Forming Device P (PY, PM, PC, PK) Process Cartridge

Typical configurations disclosed in this application are:
It ’s a process cartridge,
Photoreceptor drum and
The first frame body that supports the photoconductor drum and the first frame body that supports the photoconductor drum so that the photoconductor drum can rotate about its rotation axis.
With a developing roller
The developing roller is supported on the developing roller so that the developing roller can rotate about its rotation axis, and the developing roller is mounted on the photoconductor drum so that the latent image of the photoconductor drum can be developed by the developing roller. A second frame that can swing about the swing axis with respect to the first frame between the first position to be brought into contact and the second position that separates the developing roller from the photoconductor drum. A second frame having a protrusion provided with a force receiving portion configured to receive a force for moving the second frame from the first position to the second position from the outside of the process cartridge. With the body
(I) The second frame is in the first position, and (ii) the photoconductor drum and the protrusion are located in the lower part of the process cartridge, and the rotation axis of the photoconductor drum is the development. When the process cartridge is oriented so as to be located below the rotation axis of the roller, (I) the force receiving portion is located below the photoconductor drum and (II). When viewed along the axis of the photoconductor drum, the horizontal length of at least a part of the protrusions increases as the distance from the swing axis of the second frame increases in the vertical direction.

Claims (27)

In an image forming apparatus that forms an image on a recording medium,
A first unit having an image carrier, a developer carrier, a contact position where the developer carrier is brought into contact with the image carrier, and the developer carrier are separated from the image carrier. A second unit that can be moved to a separated position, and a mounting part that allows the process cartridge to be attached and detached.
An engaging member that can engage with the force receiving portion provided in the second unit,
With
The engaging member is
A first position for maintaining the second unit in the separated position by engaging with the force receiving portion, and
A second position for allowing the second unit to move from the distance position to the contact position during image formation.
When the process cartridge is mounted on the mounting portion, a third position for allowing the process cartridge to be mounted by retracting by being pressed from the process cartridge and
An image forming apparatus characterized in that it can be moved to three different positions. The claim that the force received by the engaging member engaging with the force receiving portion has a component that acts in the direction in which the engaging member moves from the third position to the first position. The image forming apparatus according to 1. A claim that the contact portion of the engaging member that comes into contact with the force receiving portion is inclined with respect to a direction orthogonal to the direction in which the engaging member moves from the first position to the second position. Item 2. The image forming apparatus according to Item 1 or 2. The contact portion of the engaging member that comes into contact with the force receiving portion is on the upstream side in the direction in which the engaging member moves from the first position to the second position, and from the first position to the third position. It is characterized in that it inclines from the upstream side in the moving direction toward the downstream side in the direction of moving from the first position to the second position and toward the downstream side in the direction of moving from the first position to the third position. The image forming apparatus according to claim 3. The image forming apparatus further
A moving member having a support portion that movably supports the engaging member in the first position and the third position, and moving the engaging member to the first position and the second position. The image forming apparatus according to any one of claims 1 to 4, wherein the image forming apparatus is provided. When the engaging member is located at the third position, the moving member reciprocates, so that the engaging member moves to the first position via the second position and the force receiving portion. The image forming apparatus according to claim 5, wherein the image forming apparatus is engaged with. The image forming apparatus according to claim 5 or 6, wherein the moving member has an elastic member that urges the engaging member from the third position toward the first position. The image forming apparatus according to any one of claims 5 to 7, wherein the support portion rotatably supports the engaging member. A plurality of the process cartridges can be mounted on the mounting portion.
The image forming apparatus includes a plurality of the engaging members so as to correspond to the number of the process cartridges.
When two engaging members arranged at both ends of the plurality of engaging members are the engaging member A and the engaging member B,
The contact portion of the engaging member A and the contact portion of the engaging member B that come into contact with the corresponding force receiving portion are
The image forming apparatus according to claim 8, wherein the image forming apparatus is arranged inside a region sandwiched between the rotation center of the engaging member A and the rotation center of the engaging member B. The image forming apparatus according to any one of claims 5 to 7, wherein the support portion slidably supports the engaging member in a direction intersecting the moving direction of the moving member. A plurality of the process cartridges can be mounted on the mounting portion.
The image forming apparatus
A plurality of the engaging members are provided so as to correspond to the number of the process cartridges.
It is provided with a plurality of the moving members.
A claim characterized in that it is possible to move the second unit of some of the process cartridges among the plurality of process cartridges to the contact position and hold the second unit of the other process cartridges in the separated position. Item 6. The image forming apparatus according to any one of Items 5 to 10. The image forming apparatus is further a mounting member for mounting the process cartridge, and has a mounting position mounted inside the image forming apparatus and a pulling out position pulled out to the outside of the image forming apparatus. The image forming apparatus according to any one of claims 1 to 11, further comprising a mountable member. The image forming apparatus further
An intermediate transfer body on which a developer image formed on the image carrier is transferred, or a transport member for transporting a recording medium, and a transport member.
An opening / closing member that opens / closes an opening that the above-mentioned placing member passes through when moving from the mounting position to the drawer position.
An interlocking mechanism that moves the above-mentioned placement member in conjunction with the opening / closing operation of the opening / closing member,
With
The interlocking mechanism brings the image carrier of the process cartridge into contact with the intermediate transfer body or the transport member when the opening / closing member closes in a state where the process cartridge is placed on the above-mentioned placing member. When the opening / closing member opens, the image carrier is separated from the intermediate transfer body or the transport member.
The image forming apparatus according to claim 12, wherein the engaging member is pressed from the process cartridge and moves to the third position when the opening / closing member is closed. In an image forming apparatus that forms an image on a recording medium,
A first unit having an image carrier, a contact position having a developer carrier and bringing the developer carrier into contact with the image carrier, and a distance separating the developer carrier from the image carrier. A process cartridge with a second unit that can be moved to a position, and
An engaging member that can engage with the force receiving portion provided in the second unit,
With
The engaging member is
A first position for maintaining the second unit in the separated position by engaging with the force receiving portion, and
A second position for allowing the second unit to move from the distance position to the contact position during image formation, and
When the process cartridge is mounted on the main body of the image forming apparatus, it is pressed from the process cartridge and retracted to allow the process cartridge to be mounted.
An image forming apparatus characterized in that it can be moved to three different positions. The image forming apparatus according to claim 14, wherein when the engaging member and the force receiving portion engage with each other, a force for pulling each other is generated between the engaging member and the force receiving portion. The contact portion of the engaging member that comes into contact with the force receiving portion and the force receiving portion have the same orientation with respect to the direction orthogonal to the direction in which the engaging member moves from the first position to the second position. The image forming apparatus according to claim 14 or 15, wherein the image forming apparatus is inclined to. The contact portion of the engaging member that comes into contact with the force receiving portion and the force receiving portion are on the upstream side in the direction in which the engaging member moves from the first position to the second position and at the first position. From the upstream side in the direction of moving from the first position to the downstream side in the direction of moving from the first position to the second position and toward the downstream side in the direction of moving from the first position to the third position. 16. The image forming apparatus according to claim 16. The second unit has a recess or an opening, the force receiving portion is provided in the recess or the opening, and the tip of the engaging member has entered the recess or the opening. The process cartridge according to any one of claims 14 to 17, wherein the engaging member engages with the force receiving portion. In the process cartridge that can be attached to and detached from the main body of the image forming apparatus
The first unit with the image carrier and
A second unit having a developer carrier and movable to a contact position where the developer carrier is brought into contact with the image carrier and a separation position where the developer carrier is separated from the image carrier.
It engages with an engaging member provided on the second unit and provided on the main body of the apparatus, and receives a force from the engaging member for moving the second unit from the contact position to the separation position. With the force receiving part
When the process cartridge provided in the second unit is mounted on the apparatus main body, the engaging member is pressed to move the engaging member to a retracted position that allows the process cartridge to move. Pressing part and
A process cartridge characterized by being equipped with. The process cartridge has a protrusion that protrudes in a direction that intersects the axis of the developer carrier and in a direction away from the developer carrier.
The process cartridge according to claim 19, wherein the pressing portion and the force receiving portion are provided on the protruding portion. The process cartridge according to claim 19 or 20, wherein when the force receiving portion engages with the engaging member, a force for pulling each other is generated between the engaging member and the force receiving portion. The force receiving portion is from the upstream side in the direction in which the engaging member retracts and from the upstream side in the moving direction of the force receiving portion when the second unit moves from the separated position to the contact position. It is characterized in that the engaging member is inclined toward the downstream side in the retracting direction and toward the downstream side in the moving direction of the force receiving portion when the second unit moves from the separated position to the contacting position. The process cartridge according to any one of claims 19 to 21. The process cartridge according to any one of claims 19 to 22, wherein the second unit has a recess or an opening, and the force receiving portion is formed in the recess or the opening. In the process cartridge that can be attached to and detached from the main body of the image forming apparatus
The first unit with the image carrier and
A second unit having a developer carrier and movable to a contact position where the developer carrier is brought into contact with the image carrier and a separation position where the developer carrier is separated from the image carrier.
It engages with an engaging member provided on the second unit and provided on the main body of the apparatus, and receives a force from the engaging member for moving the second unit from the contact position to the separation position. With the force receiving part
With
A process cartridge characterized in that when the force receiving portion engages with the engaging member, a force for pulling each other is generated between the engaging member and the force receiving portion. The first unit with the image carrier and
A second unit having a developer carrier, which is a contact position where the developer carrier is brought into contact with the image carrier by rotatably coupling with the first unit, and the developer carrier. A second unit that can be moved to a distance position that separates the image carrier from the image carrier.
A protruding portion provided at the end of the second unit in the axial direction of the developer carrier and protruding in a direction intersecting the axial direction and away from the developer carrier.
With
The protrusion has a recess or an opening and has a recess or an opening.
The recess or the opening is provided with a force receiving portion that receives a force for moving the second unit from the contact position to the separated position.
A process cartridge characterized in that the force receiving portion faces the side where the developer carrier is located when viewed along the axial direction of the developer carrier. The process cartridge according to claim 25, wherein the protruding portion has the recessed portion, and the recessed portion is recessed in a direction away from the first unit. The process cartridge according to claim 26, wherein the protruding portion has a ring shape to form the opening.

Images