JP2018045049A - Developer holding body, developing device, support member, driving member, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a situation where transmission of a rotational driving force to a developer holding member is stopped, compared with a case where a developer holding body does not include a configuration to assist a driving member.SOLUTION: A developer holding body 61 comprises: a developer holding member 65 that has a cylindrical shape, rotates with an axis of the cylinder as the rotation center, and holds a developer on its surface; a driving assistant member 68 that has a ring shape, is provided to press an inner peripheral surface of the developer holding member at one end in the axial direction of the developer holding member 65, while matching the axis of the developer holding member with the center of the ring, and transmits a rotational driving force to the developer holding member; and a driving member 67 that is provided on the same end as is the driving assistant member 68 with respect to the developer holding member 65, supports the developer holding member 65, and drives to rotate the driving assistance member 68 with the axis of the developer holding member 65 and the center of the driving assistant member 68 as the rotation center.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a developer holder, a developing device, a support member, a driving member, and an image forming apparatus.

  In Patent Document 1, a flange member made of a metal such as aluminum or stainless steel is fixed to the left end portion of the developing roller by a method such as press-fitting or caulking, and from the left end portion to the outside along the longitudinal direction of the developing roller. It has a shaft part as a protruding flange, and a roller gear is fixed to the shaft part by a method such as a key or a set screw, so that the developing roller has a driving force from the drum gear assembled to the photosensitive drum to the roller gear. It is reported that the developing roller is rotationally driven at a predetermined rotational speed.

JP 2000-315011 A

The developer holding member is provided with a developer holding member that is rotatably arranged, and a drive member that transmits a rotational driving force to the developer holding member by supporting and rotating the developer holding member. There is.
Here, when the adhesive is not applied to the contact portion of the driving member with respect to the developer holding member and the driving member is not configured to assist, the driving member may idle relative to the developer holding member, When the external force acts on the member and the driving member is displaced and disengaged from the developer holding member, the rotational driving force may not be transmitted to the developer holding member.
An object of the present invention is to prevent the rotational driving force from being transmitted to the developer holding member as compared with the case where the driving member is not assisted.

The invention described in claim 1 has a cylindrical shape, a developer holding member that rotates about the axis of the cylinder and holds the developer on the surface, and has a ring shape, and the developer Provided in a state in which the shaft of the developer holding member and the center of the ring coincide with each other on one end side in the axial direction of the holding member and press the inner peripheral surface of the developer holding member. A driving auxiliary member for transmitting a driving force to the developer holding member; and an end portion on the same side as the driving auxiliary member with respect to the developer holding member, supporting the developer holding member, and developing the developing member. And a drive member that rotationally drives the drive auxiliary member about the axis of the agent holding member and the center of the drive auxiliary member.
According to a second aspect of the present invention, the drive member has a cylindrical shape, the axis of the cylinder is aligned with the axis of the developer holding member, and the inner surface of the developer holding member is 2. The device according to claim 1, wherein the inner peripheral surface is fitted while being pressed and a part of the inner peripheral surface is inserted inside the drive assisting member and rotates together with the drive assisting member about the axis of the cylinder. It is a developing agent holding body of description.
The invention according to claim 3 is provided inside the developer holding member and protrudes along the axial direction of the developer holding member, and the driving member is located outside the developer holding member in the axial direction. The developer holding member according to claim 1, further comprising a support member that supports the inside of the developer holding member.
According to a fourth aspect of the present invention, the drive assisting member has a recessed portion that is recessed on the inner peripheral surface, and the drive member has a protruding portion that protrudes outward in the radial direction. 4. The developer holding member according to claim 1, wherein the developer holder is inserted into the inside of the driving assisting member and rotates in a state in which the protruding portion is inserted into the hollow portion. 5.
According to a fifth aspect of the present invention, the drive assisting member is made of a material that is less likely to be deformed when fitted to the inner peripheral surface of the developer holding member than the drive member. 5. The developer holding member according to any one of items 4 to 4.
A sixth aspect of the present invention is the developer holder according to any one of the first to fifth aspects, wherein the drive assisting member is made of metal.
According to a seventh aspect of the invention, the drive member is made of a material that is more easily deformed when fitted to the inner peripheral surface of the developer holding member than the developer holding member. The developer holding member according to any one of 1 to 6.
The invention according to claim 8 is the developer holder according to any one of claims 1 to 7, wherein the driving member is made of a resin material.
According to a ninth aspect of the present invention, in the drive assisting member, the driving member holds the developer in the axial direction of the developer holding member where the portion pressing the inner peripheral surface of the developer holding member is in the axial direction. The developer holding member according to claim 1, wherein the developer holding member is provided on an inner side than a portion where the inner peripheral surface of the member is pressed.
According to a tenth aspect of the present invention, in the drive member, the location where the inner peripheral surface of the developer holding member is pressed is in the axial direction of the developer holding member, and the drive auxiliary member holds the developer. The developer holding body according to any one of claims 1 to 8, wherein the developer holding body is provided inside the developer holding member with respect to a portion where the inner peripheral surface of the member is pressed.
The invention according to claim 11 has a cylindrical shape, a developer holding member that rotates around the axis of the cylinder and holds the developer on the surface, and a cylindrical shape, and the cylinder The axis of the developer holding member is made to coincide with the axis of the developer holding member, the inner holding surface is pressed against the inner peripheral surface of the developer holding member, and the shaft is rotated about the axis of the cylinder. And a drive member that rotationally drives the developer holding member, and is provided inside the developer holding member and protrudes along the axial direction of the developer holding member, and is more than the developer holding member in the axial direction. And a supporting member that supports the inside of the driving member on the outside.
The invention described in claim 12 has a cylindrical shape, a developer holding member that rotates about the axis of the cylinder and holds the developer on the surface, and has a ring shape, and the developer Provided in a state in which the shaft of the developer holding member and the center of the ring coincide with each other on one end side in the axial direction of the holding member and press the inner peripheral surface of the developer holding member. A driving auxiliary member for transmitting a driving force to the developer holding member; and an end portion on the same side as the driving auxiliary member with respect to the developer holding member, supporting the developer holding member, and developing the developing member. A drive member that rotationally drives the drive auxiliary member with the shaft of the agent holding member and the center of the drive auxiliary member as a rotation center; and a cylindrical shape that rotates about the axis of the cylinder as the rotation center; A developer conveying member for conveying the developer to the holding member; A developing apparatus comprising a.
The invention according to claim 13 has a cylindrical shape, is covered by a cylindrical developer holding member, and has an end protruding in the axial direction of the developer holding member, and the protruding end portion Drive that has a cylindrical shape outside the developer holding member in the axial direction, fits on the inner peripheral surface of the developer holding member, and rotates the developer holding member around the axis of the cylinder It is a support member which supports the inside of a member.
The invention according to claim 14 has a cylindrical shape, and the shaft of the cylinder is placed in a state where the inner peripheral surface is pressed against the inner peripheral surface of the developer holding member having a cylindrical shape. The developing member in the axial direction of the developer holding member is fitted with the axis of the developer holding member and protrudes from the inside of the developer holding member along the axial direction of the developer holding member. A driving member that is supported outside the developer holding member and rotates the developer holding member by rotating about the axis of the cylinder.
According to a fifteenth aspect of the present invention, there is provided an image holding member for holding an electrostatic latent image, a cylindrical shape having a cylindrical shape and rotating about the axis of the cylinder to hold a developer on the surface, and the image holding member. A developer holding member disposed opposite to the developer holding member, and a developer carrying member having a cylindrical shape and rotating around the axis of the cylinder to convey the developer to the developer holding member. A developer that develops the electrostatic latent image with the developer; and a driving unit that applies a driving force to rotationally drive the developer holder, the developer holder having a cylindrical shape, A developer holding member that rotates about the axis of the cylinder and holds the developer on the surface; and a developer holding member that has a ring shape and is on one end side in the axial direction of the developer holding member. The shaft of the developer is aligned with the center of the ring, and the inner peripheral surface of the developer holding member is pushed. A driving auxiliary member that transmits a rotational driving force to the developer holding member, and is provided on the same end side as the driving auxiliary member with respect to the developer holding member. The image forming apparatus includes a driving member that supports the member and that rotates the driving auxiliary member around the axis of the developer holding member and the center of the driving auxiliary member.

According to the first aspect of the present invention, it is possible to prevent the rotational driving force from being transmitted to the developer holding member as compared with the case where the driving member is not assisted.
According to the second aspect of the present invention, it is not necessary to separately provide the driving member with a configuration for transmitting the rotational driving force to the developer holding member.
According to the third aspect of the present invention, the driving member is less likely to be detached from the developer holding member as compared with the case where the supporting member supports the driving member inside the developer holding member in the axial direction of the developer holding member. Can do.
According to the fourth aspect of the present invention, the rotational driving force is not transmitted to the auxiliary driving member as compared with the case where the rotational driving force is transmitted by rotating the driving member while pressing the inner peripheral surface of the auxiliary driving member. Can be suppressed.
According to the fifth aspect of the present invention, the driving assistance for the developer holding member is made as compared with the case where the driving assistance member is made of a material that is more easily deformed than the driving member when the driving assistance member is fitted to the developer holding member. The idling of the member can be made difficult to occur.
According to the sixth aspect of the present invention, it is possible to make it difficult for the driving assisting member to rotate freely with respect to the developer holding member as compared with the case where the driving assisting member is made of a resin material.
According to the invention of claim 7, when the driving member is made of a material that is harder to be deformed than the developer holding member when the driving member is fitted to the developer holding member, driving assistance for the developer holding member is achieved. The idling of the member can be made difficult to occur.
According to the eighth aspect of the present invention, it is possible to make it difficult for the drive assisting member to rotate idly with respect to the developer holding member as compared with the case where the drive member is made of metal.
According to the ninth aspect of the present invention, the drive member presses the inner peripheral surface of the developer holding member in the axial direction of the developer holding member where the driving auxiliary member presses the inner peripheral surface of the developer holding member. Compared with the case where the outer side is provided outside the part, it is possible to make it difficult to cause deformation of the part pressed by the driving auxiliary member of the developer holding member.
According to the tenth aspect of the present invention, the drive auxiliary member presses the inner peripheral surface of the developer holding member in the axial direction of the developer holding member where the driving member presses the inner peripheral surface of the developer holding member. The drive member can be further prevented from coming off from the developer holding member as compared with the case where the drive member is provided outside the location.
According to the eleventh aspect of the present invention, the drive member is less likely to be detached from the developer holding member as compared with the case where the support member supports the drive member inside the developer holding member in the axial direction of the developer holding member. Can do.
According to the twelfth aspect of the present invention, it is possible to prevent the rotational driving force from being transmitted to the developer holding member as compared with the case where the driving member is not assisted.
According to the thirteenth aspect of the present invention, the support that makes the drive member less likely to come off the developer holding member than the case in which the support member supports the drive member inside the developer holding member in the axial direction of the developer holding member. A member can be provided.
According to the fourteenth aspect of the present invention, the drive member is less likely to be detached from the developer holding member as compared with the case where the drive member is supported by the support member inside the developer holding member in the axial direction of the developer holding member. be able to.
According to the fifteenth aspect of the present invention, it is possible to prevent the rotational driving force from being transmitted to the developer holding member as compared with the case where the driving member is not assisted.

1 is a diagram illustrating an example of a configuration of an image forming apparatus to which a first exemplary embodiment is applied. FIG. 3 is a diagram illustrating a configuration of a developing device. FIG. 3 is a diagram illustrating a configuration of a developing roll. It is the figure which showed the structure of the driving force transmission ring. It is the figure which showed the structure of the flange member. It is the figure which showed the structure of the image development roll of 2nd Embodiment. It is the figure which showed the structure of the flange member of 2nd Embodiment. It is the figure which showed the structure of the driving force transmission ring of 2nd Embodiment.

<First Embodiment>
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram showing an image forming apparatus 1 according to the present embodiment.
As an example of an image forming unit arranged in the image forming space 2, the image forming apparatus 1 includes a plurality of image forming units 10 (10Y, 10M) of yellow (Y), magenta (M), cyan (C), and black (K). 10M, 10C, 10K).

Each image forming unit 10 includes a photosensitive drum 11 as an example of an image carrier and a charging roll 12 that charges the photosensitive drum 11. Further, the image forming unit 10 exposes the surface of the photosensitive drum 11 charged by the charging roll 12 to form an electrostatic latent image, and the static image formed on the photosensitive drum 11 by the exposing device 13. And a developing device 14 as an example of a developing device that develops the electrostatic latent image. Further, the image forming unit 10 includes a cleaning device 15 that removes waste toner on the photosensitive drum 11.
Each image forming unit 10 is a so-called cartridge. However, when forming the cartridge, for example, only the developing device 14 may have a separate structure, and a structure different from the cartridge of the photosensitive drum 11 may be used.

  The image forming apparatus 1 also includes an intermediate transfer belt 16 onto which the color toner images formed on the photosensitive drums 11 of the image forming units 10 are transferred, and the color toner images formed on the image forming units 10. And a primary transfer roll 17 that sequentially transfers (primary transfer) to the intermediate transfer belt 16. Further, the image forming apparatus 1 includes a secondary transfer roll 30 that collectively transfers (secondary transfer) a toner image formed on the intermediate transfer belt 16 in a superimposed manner onto a sheet P that is a recording material (recording paper). Further, a fixing unit 40 for fixing the secondly transferred toner image on the paper P is provided. Further, the image forming apparatus 1 includes a toner cartridge 20 that supplies toner to the developing device 14 of each image forming unit 10. In addition, the image forming apparatus 1 includes a control unit 50 that controls the entire image forming apparatus 1.

The photosensitive drum 11 as an example of the image carrier is formed by forming an organic photosensitive layer on the surface of a thin cylindrical drum made of metal.
The charging roll 12 charges the photosensitive drum 11 to a predetermined potential.
The developing device 14 transfers toner from the developer layer on the developing device 14 to the latent image forming region on the photosensitive drum 11 in the developing region closest to the photosensitive drum 11. Thereby, the electrostatic latent image is developed and visualized as a toner image. The configuration of the developing device 14 will be described in detail later.

  The image forming apparatus 1 executes a series of image forming processes under operation control by the control unit 50. That is, image data acquired from a PC, a scanner, or the like is subjected to image processing by an image processing unit (not shown) and sent to the exposure unit 13 as image data of each color. Each image forming unit 10 receives exposure by the exposure device 13 and is developed by the developing device 14 to form a toner image on the photosensitive drum 11. Each color toner image formed on the photosensitive drum 11 of each image forming unit 10 is sequentially electrostatically transferred (primary transfer) onto the intermediate transfer belt 16 by the primary transfer roll 17, and the superimposed toner on which the respective color toner T is superimposed. An image is formed. The superimposed toner image on the intermediate transfer belt 16 is conveyed to a secondary transfer region where the secondary transfer roll 30 is disposed as the intermediate transfer belt 16 moves. On the other hand, the paper P is fed in accordance with the transport timing of the superimposed toner image and transported to the secondary transfer area. The superimposed toner image on the intermediate transfer belt 16 is collectively electrostatically transferred (secondary transfer) onto the conveyed paper P by the transfer electric field formed by the secondary transfer roll 30 in the secondary transfer portion. Is done. The paper P on which the superimposed toner image has been electrostatically transferred is conveyed to the fixing unit 40 and fixed on the paper P by the fixing unit 40. The paper P after fixing is conveyed to a paper stacking unit provided in the discharge unit of the image forming apparatus 1.

FIG. 2 is a diagram showing the configuration of the developing device 14.
The developing device 14 has an opening H (development opening) facing the photosensitive drum 11 and includes, for example, a two-component developer (for example, a negatively charged toner and a positively charged carrier). A developing housing 60 in which a housing (not shown) is accommodated. In this embodiment, the case where a two-component developer is used as a developer will be described as an example. However, a one-component developer that includes toner and does not include a carrier may be used as the developer.
Further, the developing device 14 is disposed at a position facing the opening H of the developing housing 60, and is arranged to rotate so as to face the photosensitive drum 11, and develops an electrostatic latent image to form a toner image. The developing roller 61 which is an example of the developer holding body is provided.

  Further, the developing device 14 is disposed in the developing housing 60 at the lower back side of the developing roll 61 as viewed from the photosensitive drum 11 and substantially parallel to the axial direction of the photosensitive drum 11. A pair of screw augers 62 and 63 for conveying the agent are provided. In the following description, the screw auger 62 on the side farther from the developing roll 61 is called the first screw auger 62, and the screw auger 63 on the side closer to the developing roll 61 is called the second screw auger 63. Further, the developing device 14 includes a trimmer 64 that is disposed below the developing roll 61 with a predetermined distance from the developing roll 61 and regulates the developer layer thickness on the developing roll 61. The first screw auger 62 and the second screw auger 63 are examples of a developer conveying member.

  The developing housing 60 is formed with a supply port (not shown) through which a new developer supplied from the toner cartridge 20 is supplied and a discharge port (not shown) through which excess developer is discharged. Yes. In addition, the developing housing 60 is provided with a partition wall 60a that partitions the first screw auger 62 and the second screw auger 63 from each other and connects them at both ends. The first screw auger 62 and the second screw auger 63 are both configured by attaching spiral blades around a rotating shaft extending in the direction perpendicular to the paper surface.

  The developing roll 61 is rotationally driven in the direction of arrow A in the figure, and rotates in the same direction as the photosensitive drum 11 and in the counterclockwise direction in the figure at the developing position facing the photosensitive drum 11. It is like that. A function of developing the electrostatic latent image formed on the surface of the photosensitive drum 11 by adsorbing the developer stirred and conveyed by the second screw auger 63 and then moving the developer to the photosensitive drum 11. Have The configuration of the developing roll 61 will be described in detail later.

  The second screw auger 63 rotates so as to stir and convey the developer in the developing housing 60 in one direction. The first screw auger 62 rotates so as to stir and convey the developer in the developing housing 60 in the reverse direction. As a result, the developer in the developing housing 60 is circulated and conveyed in the developing housing 60 while being stirred by the first screw auger 62 and the second screw auger 63.

  FIG. 3 is a cross-sectional view of the developing roll 61 as viewed from the III direction in FIG. 2, and the developing roll 61 on one end side in the axial direction of the developing roll 61 (the back side in FIG. 2). FIG. FIG. 4 is a view showing the configuration of the driving force transmission ring 68 provided in the developing roll 61. FIG. 5 is a view showing the configuration of the flange member 67 provided in the developing roll 61.

As shown in FIG. 3, the developing roll 61 includes a developing sleeve 65 as an example of a developer holding member that is rotatably disposed.
The developing roll 61 includes a flange member 67 as an example of a driving member that transmits a driving force to the developing sleeve 65. The flange member 67 is rotatably provided to the developing roll 61 and is provided on one end side in the axial direction of the developing roll 61.

Further, the developing roll 61 includes a driving force transmission ring 68 as an example of a driving auxiliary member that transmits the driving force received from the flange member 67 to the developing sleeve 65. The driving force transmission ring 68 has a ring shape. The driving force transmission ring 68 is rotatably provided and is provided inside the developing sleeve 65.
Furthermore, the developing roll 61 includes a magnet shaft 66 in which a plurality of magnetic poles are arranged. The magnet shaft 66 is fixedly provided inside the developing sleeve 65.

The developing sleeve 65 has a thin cylindrical shape and is made of, for example, a metal material such as aluminum. The developing sleeve 65 has a developer layer formed on the surface thereof.
As shown in FIG. 4, the driving force transmission ring 68 has a ring shape, and is formed of a metal material such as aluminum, for example.

The driving force transmission ring 68 includes a first driving force transmitted portion 681 that is provided on the inner side in the radial direction and receives the driving force from the flange member 67. Further, the driving force transmission ring 68 is provided on the inner side in the radial direction and is provided to face the first driving force transmitted portion 681, and receives the driving force from the flange member 67. 682.
The first driving force transmitted portion 681 has a first recess 681 a as an example of a recessed portion that is recessed outward in the radial direction of the driving force transmitting ring 68.
The second driving force transmitted portion 682 includes a second concave portion 682 a as an example of a concave portion that is recessed outward in the radial direction of the driving force transmission ring 68.

  The flange member 67 shown in FIG. 5 has a cylindrical shape, and is formed of a resin material that is more easily deformed when the developing roll 61 rotates than the developing sleeve 65 and the driving force transmission ring 68. The flange member 67 has a circular shape and a press-fitting portion 671 that is press-fitted into the developing sleeve 65. The flange member 67 includes a first outer edge portion 672 that is provided at one end portion in the axial direction of the press-fit portion 671 and extends outward from the outer peripheral surface of the press-fit portion 671 in the radial direction.

  In addition, the flange member 67 protrudes from the press-fit portion 671 toward the other end side in the axial direction (the side opposite to the side where the first outer edge portion 672 is provided in the axial direction of the press-fit portion 671). A flange ridge 673 is provided. Further, the flange member 67 includes a driving force transmission portion 674 that is provided on the first flange raised portion 673 and transmits a driving force to the driving force transmission ring 68.

  Further, the flange member 67 has one end side in the axial direction from the press-fit portion 671 (the side on which the first outer edge portion 672 is provided in the axial direction of the press-fit portion 671 and the side on which the first protrusion is provided). Is provided with a second flange raised portion 676 that is raised toward the opposite side. Further, the flange member 67 includes a third flange raised portion 677 that protrudes from the second flange raised portion 676 toward one end side in the axial direction of the flange member 67.

The first outer edge portion 672 is provided over the entire circumference of the outer peripheral surface of the press-fit portion 671.
The driving force transmission portion 674 includes a first convex portion 674a as an example of a protruding portion that protrudes outward from the first flange raised portion 673 in the radial direction of the first flange raised portion 673.
The driving force transmission portion 674 includes a second convex portion 674b as an example of a projecting portion that projects from the first flange raised portion 673 toward the outside in the radial direction of the first flange raised portion 673. The second convex portion 674b is provided to face the first convex portion 674a with the first flange raised portion 673 interposed therebetween.

  The first flange raised portion 673 is configured such that the radius of the outer peripheral surface is smaller than the radius of the inner peripheral surface of the driving force transmission ring 68. Therefore, the first flange raised portion 673 can enter the inside of the driving force transmission ring 68 (see FIG. 4). When the first flange raised portion 673 enters the inside of the driving force transmission ring 68, the first convex portion 674a enters the first concave portion 681a in the first driving force transmitted portion 681. Further, the second convex portion 674 b enters the second concave portion 682 a in the second driving force transmitted portion 682.

  As shown in FIG. 3, the second flange raised portion 676 has a radius of the inner peripheral surface between the side close to the first outer edge portion 672 and the side close to the third flange raised portion 677 in the axial direction of the flange member 67. Is different. Specifically, the radius of the inner peripheral surface of the second flange raised portion 676 on the side close to the first outer edge 672 is equal to the third flange raised portion of the second flange raised portion 676. It is configured to be larger than the radius of the inner peripheral surface in the portion near 677. Here, the larger radius is defined as a first inner peripheral surface 676a. The smaller radius is defined as a second inner peripheral surface 676b.

A drive motor M as an example of a drive unit is connected to the third flange raised portion 677. The flange member 67 receives a rotational driving force from the drive motor M and rotates in the direction of arrow B in the figure (clockwise direction in the figure).
A sliding roll (not shown) that slides with respect to the photosensitive drum 11 is connected to the outer peripheral surface of the third flange raised portion 677. The developing roll 61 rotates while the sliding roll is pressed against the photosensitive drum 11, so that the development by the developing device 14 is performed while the distance between the developing roll 61 and the photosensitive drum 11 is kept constant. Is done.

The magnet shaft 66 has a rod-like shape, and is provided with an end protruding in the axial direction. The magnet shaft 66 has a plurality of magnetic poles arranged therein and is formed of, for example, a resin material.
Further, the magnet shaft 66 includes a main body portion 661 that extends from the central portion in the axial direction of the developing sleeve 65 toward both ends.
In addition, the magnet shaft 66 includes a shaft raised portion 662 that rises from the end of the main body portion 661 along the axial direction.
Further, the magnet shaft 66 includes a support portion 663 that protrudes along the axial direction from the end portion of the shaft protrusion portion 662 and supports the flange member 67. The support portion 663 supports the flange member 67 outside the developing sleeve 65 in the axial direction of the developing roll 61.
The magnet shaft 66 is an example of a support member that supports the flange member 67. The magnet shaft 66 is an example of a protruding member that protrudes along the axial direction.

  The main body 661 is formed with five magnetic poles (a pickup pole, a trimming pole, a developing pole, a transport pole, and a pick-off pole (all not shown)) along the outer peripheral surface thereof. Here, the pickup electrode has a function of adsorbing the developer agitated and conveyed by the second screw auger 63 onto the developing sleeve 65. The trimming pole has a function of forming a developer layer on the outer peripheral surface of the developing sleeve 65. Further, the developing pole has a function of moving the toner from the surface of the developing sleeve 65 to the photosensitive drum 11 and developing the electrostatic latent image formed on the surface of the photosensitive drum 11. Further, the transport pole has a function of transporting the developer as the developing sleeve 65 rotates by maintaining the adsorption of the developer to the surface of the developing sleeve 65. The pickoff pole forms a repulsive magnetic field together with the adjacent pickup pole, and has a function of separating the developer adsorbed on the developing sleeve 65 from the developing sleeve 65.

When the developing roll 61 is assembled, first, the driving force transmission ring 68 is press-fitted into the developing sleeve 65.
The radius of the outer peripheral surface of the driving force transmission ring 68 is configured to be slightly larger than the radius of the inner peripheral surface of the developing sleeve 65. Then, the driving force transmission ring 68 is applied to the inner side of the developing sleeve 65 by applying pressure from one end side in the axial direction of the developing roll 61 (the back side in the drawing in FIG. 2) by a press-fitting jig (not shown). Pushed in. Then, the driving force transmission ring 68 is fixed to one end portion in the axial direction of the developing sleeve 65 by being pushed into the developing sleeve 65 by a predetermined length. At this time, the inner peripheral surface of the developing sleeve 65 is pressed against the outer peripheral surface of the driving force transmission ring 68.

Subsequently, the flange member 67 is press-fitted into the developing sleeve 65.
The press-fit portion 671 is configured such that the radius of the outer peripheral surface is slightly larger than the radius of the inner peripheral surface of the developing sleeve 65. Further, the first outer edge portion 672 is configured such that the radius of the outer peripheral surface is larger than the radius of the inner peripheral surface of the developing sleeve 65. The press-fitting portion 671 of the flange member 67 applies pressure from one end side (the side where the driving force transmission ring 68 is provided) in the axial direction of the developing roll 61 by a press-fitting jig (not shown). Is pushed into the developing sleeve 65. At this time, first, the first flange raised portion 673 enters the inside of the developing sleeve 65, and then the press-fit portion 671 is pushed into the inside of the developing sleeve 65. When the press-fitting portion 671 is pushed into the inside of the developing sleeve 65, the first flange raised portion 673 enters the inside of the driving force transmission ring 68 that has been previously press-fitted into the developing sleeve 65 (see FIGS. 3 and 4). ). Further, as described above, the first convex portion 674a in the driving force transmitting portion 674 enters the first concave portion 681a in the first driving force transmitted portion 681 (see FIGS. 4 and 5). Further, the second convex portion 674 b in the driving force transmitting portion 674 enters the second concave portion 682 a in the second driving force transmitted portion 682.

  When the press-fitting portion 671 is further pushed into the developing sleeve 65, the tip on the one end side in the axial direction of the developing sleeve 65 abuts on the first outer edge portion 672 (see FIG. 3). As a result, a press-fitting point P1 into which the press-fitting portion 671 of the developing sleeve 65 is press-fitted is determined, and the flange member 67 is fixed to one end portion of the developing roll 61 in the axial direction. At this time, the inner peripheral surface of the developing sleeve 65 is pressed against the outer peripheral surface of the press-fit portion 671. Thereby, the flange member 67 is supported by the developing sleeve 65.

  Subsequently, the magnet shaft 66 is inserted into the developing sleeve 65 from the other end side in the axial direction of the developing roll 61, and the position with respect to the developing sleeve 65 is determined. At this time, in the axial direction of the developing roll 61, the position of the driving force transmission ring 68 (position in the axial direction of the developing roll 61) and the position of the first flange raised portion 673 of the flange member 67 (axial direction of the developing roll 61). And the position of the shaft raised portion 662 of the magnet shaft 66 (position in the axial direction of the developing roll 61) are aligned. Note that the outer peripheral surface of the shaft raised portion 662 is not in contact with the inner peripheral surface of the first flange raised portion 673.

  Further, the support portion 663 is positioned inside the second flange raised portion 676 of the flange member 67. Further, the radius of the outer peripheral surface of the support portion 663 is configured to be smaller than the radius of the first inner peripheral surface 676 a of the second flange raised portion 676. The outer peripheral surface of the support portion 663 does not contact the first inner peripheral surface 676a of the second flange raised portion 676. On the other hand, the outer peripheral surface of the support portion 663 is in contact with the second inner peripheral surface 676 b of the second flange raised portion 676 and supports the flange member 67. When the flange member 67 rotates, the second inner peripheral surface 676 b slides with respect to the outer peripheral surface of the magnet shaft 66.

Thus, in the present embodiment, a configuration where the magnet shaft 66 supports the flange member 67 (hereinafter referred to as a support location S) is positioned outside the developing sleeve 65 in the axial direction of the developing roll 61 ( Hereinafter, this is referred to as an outer support structure). In other words, the flange member 67 is supported by the magnet shaft 66 outside the portion supported by the developing sleeve 65 in the axial direction of the developing roll 61.
Accordingly, when an external force is applied to the flange member 67, the flange member 67 is hardly detached from the developing sleeve 65, and the rotation driving force is not transmitted to the developing sleeve 65.

  As described above, the third flange raised portion 677 of the flange member 67 receives the rotational driving force from the drive motor M. The third flange raised portion 677 is pressed against the photosensitive drum 11 via a sliding roll (not shown). In this way, pressing forces F as various external forces act on the outer peripheral surface of the third flange raised portion 677.

Here, for example, the location where the magnet shaft 66 supports the flange member 67 (hereinafter referred to as a support location S ′) is the driving force transmission ring 68 and the first flange raised portion 673 in the axial direction of the developing roll 61. It is assumed that the positions are aligned.
According to this configuration, when the pressing force F acts on the third flange raised portion 677, the pressing force F tends to concentrate on the press-fit portion 671. Specifically, the pressing force F is distributed to the magnet shaft 66 through the support portion S ′ that is relatively far from the portion where the pressing force F acts on the third flange ridge 677 (hereinafter referred to as the operating portion F1). The pressing force F tends to concentrate on the press-fitting portion 671 that is difficult to perform and that is relatively short from the action location F1.

  When the pressing force F is concentrated on the press-fitting portion 671, the press-fitting portion 671 is likely to be displaced (displacement outward in the axial direction of the developing roll 61), and the press-fitting portion 671 may be detached from the developing sleeve 65. There is a possibility that the rotational driving force is not transmitted.

  On the other hand, according to the developing roller 61 having the outer support configuration as in the present embodiment, when the pressing force F acts on the third flange raised portion 677, the support location that is relatively short from the action location F1. The pressing force F is distributed to the magnet shaft 66 through S. Therefore, it is difficult for the pressing force F to concentrate on the press-fitting portion 671 that is relatively far from the action location F1. In this case, the press-fitting portion 671 is unlikely to be displaced, and as described above, the press-fitting portion 671 is unlikely to be detached from the developing sleeve 65, and the rotation driving force is not transmitted to the developing sleeve 65.

  When the flange member 67 rotates in the direction of arrow B in the figure (clockwise direction in the figure), as shown in FIG. 4, the downstream side wall 674c in the rotation direction of the first convex part 674a becomes the first concave part. The downstream side wall 681b in the rotational direction of 681a is pressed. Further, the downstream side wall 674d in the rotational direction of the second convex portion 674b presses the downstream side wall 682b in the rotational direction of the first concave portion 681a. Thereby, the driving force transmission ring 68 receives the rotational driving force from the flange member 67 and rotates in the direction of arrow B in the figure.

When the driving force transmission ring 68 rotates while pressing the inner peripheral surface of the developing sleeve 65, the developing sleeve 65 receives the rotational driving force from the driving force transmission ring 68 and rotates in the direction of arrow B in the figure (see FIG. 3). . Here, in the present embodiment, the central axes of the cylindrical developing sleeve 65, the ring-shaped driving force transmission ring 68, and the cylindrical flange member 67 are coincident with each other, and the center axis is rotated around the center axis. To do. Since the press-fitting portion 671 presses the inner peripheral surface of the developing sleeve 65, the developing sleeve 65 receives a rotational driving force from the flange member 67 when the flange member 67 rotates.
Thus, in the present embodiment, the flange member 67 gives a rotational driving force to the developing sleeve 65 via the driving force transmission ring 68.

The press-fitting portion 671 of the flange member 67 may be deformed by continuing to be pressed against the inner peripheral surface of the developing sleeve 65. If the press-fitting portion 671 is deformed, the flange member 67 may idle with respect to the developing sleeve 65 when the flange member 67 rotates.
Here, when the developing sleeve 65 is configured to receive the rotational driving force only from the flange member 67, the rotational driving force is not transmitted to the developing sleeve 65 because the flange member 67 rotates idly with respect to the developing sleeve 65.

  In contrast, in the present embodiment, the driving force transmission ring 68 is press-fitted into the developing sleeve 65. The developing sleeve 65 receives a rotational driving force not only from the flange member 67 but also from the driving force transmission ring 68. In addition, the driving force transmission ring 68 is less likely to be rotated around the developing sleeve 65 because the driving force transmission ring 68 is less likely to be deformed when rotating while pressing the developing sleeve 65 than the flange member 67. Accordingly, it is possible to prevent the rotational driving force from being transmitted to the developing sleeve 65.

  In this embodiment, the driving force transmission ring 68 is press-fitted into the developing sleeve 65 before the flange member 67 is press-fitted into the developing sleeve 65. Therefore, the driving force transmission ring 68 is disposed on the inner side in the axial direction of the developing sleeve 65 than the press-fitting portion 671 of the flange member 67. As a result, the portion of the developing sleeve 65 that is pressed by the driving force transmission ring 68 is not easily deformed. As a result, the rotational driving force from the driving force transmission ring 68 is prevented from being transmitted to the developing sleeve 65.

Since the developing sleeve 65 is thin as described above, the developing sleeve 65 is easily deformed by pressing, and is particularly likely to be deformed at the tip portion in the axial direction.
Here, for example, when the driving force transmission ring 68 is arranged at the press-fitting location P1 as the tip portion of the developing sleeve 65 in the axial direction, the press-fitting location P1 is pressed and deformed by the driving force transmission ring 68. (There may spread outward in the radial direction of the developing sleeve 65). If the press-fitting point P1 is deformed, the driving force transmission ring 68 may idle with respect to the developing sleeve 65, and the rotational driving force from the driving force transmission ring 68 may not be transmitted to the developing sleeve 65.

  On the other hand, in the present embodiment, the driving force transmission ring 68 is disposed on the inner side in the axial direction of the developing sleeve 65 from the press-fitting point P1 of the developing sleeve 65. Therefore, the portion of the developing sleeve 65 that is pressed by the driving force transmission ring 68 is not easily deformed. As a result, it is difficult for the driving force transmission ring 68 to rotate idly with respect to the developing sleeve 65, and the rotational driving force from the driving force transmission ring 68 is prevented from being transmitted to the developing sleeve 65.

In the present embodiment, the first convex portion 674a of the driving force transmission portion 674 of the flange member 67 is inserted into the first concave portion 681a of the driving force transmission ring 68, and the second convex portion 674b is the second convex portion 674b. It is inserted into the recess 682a. In this state, when the flange member 67 rotates, the rotational driving force of the flange member 67 is applied to the driving force transmission ring 68.
Here, three or more convex portions are provided at equal intervals in the rotational direction of the flange member 67 as the driving force transmission portion 674, and three or more concave portions are provided as the driving force transmission ring 68 in the rotational direction of the driving force transmission ring 68. It is good also as a structure provided in this at equal intervals.

<Second Embodiment>
FIG. 6 is a diagram showing the configuration of the developing roll 61 in the second embodiment. FIG. 7 is a view showing the configuration of the flange member 67 in the second embodiment. FIG. 8 is a diagram showing the configuration of the driving force transmission ring 68 in the second embodiment. Note that a description of a configuration having the same function as the configuration illustrated in FIG. 3 is omitted.
In the first embodiment, when the developing roll 61 is assembled, first, the driving force transmission ring 68 is press-fitted into the developing sleeve 65, and then the flange member 67 is press-fitted into the developing sleeve 65.
On the other hand, in the second embodiment, when assembling the developing roll 61, as shown in FIG. 6, first, the flange member 67 is press-fitted into the developing sleeve 65, and then the driving force transmission ring 68 is connected to the developing sleeve. 65 is press-fit.

  As shown in FIG. 7, the flange member 67 extends from the outer peripheral surface of the press-fit portion 671 to one end side in the axial direction (the side on which the second flange raised portion 676 is provided in the axial direction of the flange member). The claw portion 678a and the second claw portion 678b are formed. The flange member 67 has a second outer edge portion 679a extending outward in the radial direction from the first claw portion 678a, and a third outer edge portion 679b extending outward in the radial direction from the second claw portion 678b. Is formed. The first claw portion 678a and the second outer edge portion 679a and the second claw portion 678b and the third outer edge portion 679b are provided at positions facing each other with the second flange raised portion 676 interposed therebetween. In addition, the set of the first claw portion 678a and the second outer edge portion 679a and the second claw portion 678b and the third outer edge portion 679b is formed with respect to the first protrusion 674a and the second protrusion 674b. At a position shifted by 90 degrees.

As shown in FIG. 8, the driving force transmission ring 68 has a third recess 683 and a fourth recess 684 that are recessed toward the inside in the radial direction on the outer peripheral portion. The third concave portion 683 and the fourth concave portion 684 are provided at positions facing each other on the outer peripheral portion of the driving force transmission ring 68. Further, the set of the third recess 683 and the fourth recess 684 is formed on the first recess 681a of the first driving force transmitted portion and the second recess 682a of the second driving force transmitted portion 682. It is provided at a position shifted by 90 degrees.
As a result, the first claw of the flange member 67 is inserted into the third recess 683 and the fourth recess 684 of the drive force transmission ring 68 in a state where the drive force transmission ring 68 is assembled to the flange member 67 as described later. The portion 678a and the second claw portion 678b enter and mesh with each other.

  In the second embodiment, when the developing roll 61 is assembled, the flange member 67 is first press-fitted into the developing sleeve 65 as described above. The press-fitting portion 671, the first claw portion 678 a, and the second claw portion 678 b of the flange member 67 are developed from one end side in the axial direction of the developing roll 61 by a press-fitting jig (not shown). It will be pushed inside. When the press-fitting portion 671, the first claw portion 678a, and the second claw portion 678b are pushed into the developing sleeve 65, the tip on the one end side in the axial direction of the developing sleeve 65 is the second outer edge. It abuts against the portion 679a and the third outer edge portion 679b. As a result, as shown in FIG. 6, a press-fitting point P <b> 2 into which the press-fitting portion 671 of the developing sleeve 65 is press-fitted is determined, and the flange member 67 is fixed to one end portion in the axial direction of the developing roll 61.

  Subsequently, the driving force transmission ring 68 is pushed into the developing sleeve 65 by a predetermined length from one end side in the axial direction of the developing roll 61 by a press-fitting jig (not shown). When the driving force transmission ring 68 is pushed into the developing sleeve 65, the second flange raised portion 676 of the flange member 67 enters the inside of the driving force transmission ring 68 (see FIGS. 6 and 8). In addition, the first convex portion 674a enters and meshes with the first concave portion 681a. Further, the second convex portion 674b enters and meshes with the second concave portion 682a.

  In the second embodiment, when the driving force transmission ring 68 is pushed into the developing sleeve 65, the second outer edge portion 679 a of the flange member 67 passes through the third recess 683 of the driving force transmission ring 68. Then, the first claw portion 678a enters the third recess 683. Further, the third outer edge portion 679 b of the flange member 67 passes through the fourth recess 684 of the driving force transmission ring 68, and then the second claw portion 678 b enters the fourth recess 684.

  Accordingly, as shown in FIG. 6, the driving force transmission ring 68 is at one end portion in the axial direction of the developing sleeve 65 and outside the press-fit portion 671 of the flange member 67 in the axial direction of the developing sleeve 65. Fixed.

As described above, the press-fitting point P2 of the press-fitting portion 671 of the flange member 67 in the second embodiment is more inside in the axial direction of the developing sleeve 65 than the press-fitting point P1 of the press-fitting portion 671 in the first embodiment. Located in. Specifically, the press-fitting point P2 in the second embodiment is the press-fit in the first embodiment by the length of the driving force transmission ring 68 (the length of the driving force transmission ring 68 in the axial direction). It is located on the inner side in the axial direction of the developing sleeve 65 from the point P1. In addition, as compared with the first embodiment, in the second embodiment, the press-fitting portion 671 of the flange member 67 enters deeper into the inside of the developing sleeve 65.
Accordingly, when an external force is applied to the third flange raised portion 677 of the flange member 67, the flange member 67 is further less likely to be detached from the developing sleeve 65. As a result, it is further suppressed that the rotational driving force is not transmitted to the developing sleeve 65.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Image forming unit, 11 ... Photosensitive drum, 14 ... Developing device, 61 ... Developing roll, 65 ... Developing sleeve, 66 ... Magnet shaft, 661 ... Main part, 662 ... Shaft protruding part, 663 ... support part, 67 ... flange member, 671 ... press-fitting part, 672 ... first outer edge part, 673 ... first flange raised part, 674 ... driving force transmission part, 674a ... first convex part, 674b ... second Convex portion of 676, second flange raised portion, 677, third flange raised portion, 678a, first claw portion, 678b, second claw portion, 679a, second outer edge portion, 679b, third. 681 ... a driving force transmitting ring, 681 ... first driving force receiving portion, 681a ... first recess, 682 ... second driving force receiving portion, 682a ... second recess, 683 ... first. 3 recesses, 684 ... 4th recess , M ... drive motor

Claims (15)

A developer holding member that has a cylindrical shape and rotates around the axis of the cylinder to hold the developer on the surface;
An inner periphery of the developer holding member having a ring shape, with the shaft of the developer holding member being aligned with the center of the ring on one end side in the axial direction of the developer holding member. A driving auxiliary member that is provided in a state of pressing the surface and transmits a rotational driving force to the developer holding member;
The developer holding member is provided on the same end side as the driving auxiliary member, supports the developer holding member, and rotates about the axis of the developer holding member and the center of the driving auxiliary member. A driving member for rotationally driving the driving auxiliary member,
A developer holding body.   The drive member has a cylindrical shape, aligns the axis of the cylinder with the axis of the developer holding member, and presses the inner peripheral surface against the inner peripheral surface of the developer holding member. 2. The developer holding member according to claim 1, wherein the developer holding member is fitted in a state and partially inserted into the inside of the drive assisting member, and rotates together with the drive assisting member about the axis of the cylinder.   A support member that is provided inside the developer holding member and protrudes along the axial direction of the developer holding member, and supports the inside of the driving member outside the developer holding member in the axial direction; The developer holding body according to claim 1 or 2 provided. The drive assisting member has a recessed portion that is recessed on the inner peripheral surface,
The driving member has a protruding portion that protrudes outward in the radial direction, and a part of the driving member is inserted inside the driving auxiliary member and rotates while the protruding portion is inserted in the recess. The developer holder according to any one of claims 1 to 3.   The developer according to any one of claims 1 to 4, wherein the drive assisting member is made of a material that is less likely to be deformed when fitted to the inner peripheral surface of the developer holding member than the drive member. Holding body.   The developer holding member according to claim 1, wherein the driving auxiliary member is made of metal.   The development according to claim 1, wherein the driving member is made of a material that is more easily deformed when fitted to the inner peripheral surface of the developer holding member than the developer holding member. Agent holder.   The developer holding member according to claim 1, wherein the driving member is made of a resin material.   The driving auxiliary member presses the inner peripheral surface of the developer holding member at a location where the inner peripheral surface of the developer holding member is pressed in the axial direction of the developer holding member. The developer holding member according to claim 1, wherein the developer holding member is provided inside the portion.   The drive auxiliary member presses the inner peripheral surface of the developer holding member at a location where the inner peripheral surface of the developer holding member is pressed in the axial direction of the developer holding member. The developer holding member according to claim 1, wherein the developer holding member is provided inside the developer holding member with respect to the portion. A developer holding member that has a cylindrical shape and rotates around the axis of the cylinder to hold the developer on the surface;
It has a cylindrical shape, the shaft of the cylinder is aligned with the axis of the developer holding member, and is fitted in a state of pressing the inner peripheral surface against the inner peripheral surface of the developer holding member, A drive member for rotating the developer holding member by rotating about the axis of the cylinder,
A support member that is provided inside the developer holding member and projects along the axial direction of the developer holding member, and supports the inside of the drive member outside the developer holding member in the axial direction;
A developer holding body. A developer holding member that has a cylindrical shape and rotates around the axis of the cylinder to hold the developer on the surface;
An inner periphery of the developer holding member having a ring shape, with the shaft of the developer holding member being aligned with the center of the ring on one end side in the axial direction of the developer holding member. A driving auxiliary member that is provided in a state of pressing the surface and transmits a rotational driving force to the developer holding member;
The developer holding member is provided on the same end side as the driving auxiliary member, supports the developer holding member, and rotates about the axis of the developer holding member and the center of the driving auxiliary member. A driving member for rotationally driving the driving auxiliary member,
A developer carrying member having a cylindrical shape, rotating around the axis of the cylinder and carrying the developer to the developer holding member;
A developing device comprising:   It has a cylindrical shape, is covered with a cylindrical developer holding member, and has an end protruding in the axial direction of the developer holding member, and the protruding end from the developer holding member in the axial direction. And a support member that has a cylindrical shape and is fitted on the inner peripheral surface of the developer holding member and supports the inside of a drive member that rotates the developer holding member about the axis of the cylinder. .   A cylindrical shape, and with the inner peripheral surface of the developer holding member having a cylindrical shape pressed against the inner peripheral surface, the axis of the cylinder is aligned with the axis of the developer holding member. And is supported outside the developer holding member in the axial direction of the developer holding member by a protruding member that protrudes from the inside of the developer holding member along the axial direction of the developer holding member. A driving member that rotationally drives the developer holding member by rotating about the axis of the cylinder. An image carrier for holding an electrostatic latent image;
A cylindrical shape having a cylindrical shape and a developer holding body which rotates around the axis of the cylinder and holds the developer on the surface and is disposed opposite to the image holding body. A developer conveying member that rotates about the axis of the developer and conveys the developer to the developer holder, and develops the electrostatic latent image with the developer,
Driving means for applying a driving force for rotationally driving the developer holder;
With
The developer holder is
A developer holding member that has a cylindrical shape and rotates around the axis of the cylinder to hold the developer on the surface;
An inner periphery of the developer holding member having a ring shape, with the shaft of the developer holding member being aligned with the center of the ring on one end side in the axial direction of the developer holding member. A driving auxiliary member that is provided in a state of pressing the surface and transmits a rotational driving force to the developer holding member;
The developer holding member is provided on the same end side as the driving auxiliary member, supports the developer holding member, and rotates about the axis of the developer holding member and the center of the driving auxiliary member. A driving member for rotationally driving the driving auxiliary member,
An image forming apparatus including:

Images