JP5590978B2 - Developing device, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus that forms an image on a recording material using an electrophotographic method, and more particularly to a developing device and a process cartridge that are applied to the image forming apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive drum and a process means acting on the electrophotographic photosensitive drum are integrally formed as a cartridge, and the cartridge is detachable from the apparatus main body The method is adopted. According to this process cartridge system, maintenance of the apparatus can be performed by the user himself without relying on a service person. Therefore, operability can be remarkably improved. For this reason, this process cartridge system is widely used in electrophotographic image forming apparatuses.

In the developing device in such an image forming apparatus, a developing chamber and a developer storage chamber are provided. A developer supply device is provided for supplying the developer from the developer storage chamber to the development chamber through the opening. This developer supply device is a plastic supply member attached to a rotating shaft in the developer accommodating chamber, and the developer is caused to fly by an elastic restoring force by rotation of the supply member and release of its own elastic deformation. There is a configuration that conveys the toner to the developing chamber (see, for example, Patent Document 1).
Further, there is Patent Document 2 as a document disclosing related conventional examples.

JP 2008-170951 A JP 2008-33215 A

However, in a conventional image forming apparatus having a developer supply device using a plastic member, the plastic member may be plastically deformed by the action of transportation environment, storage environment, use environment, or external force. When the plastic member is plastically deformed, the developer cannot be caused to fly by the elastic restoring force due to the release of the elastic deformation, and there is a concern that the developer transport amount may change.
SUMMARY An advantage of some aspects of the invention is that it supplies a constant amount of developer more stably from a developer storage chamber to a development chamber to obtain a higher quality image. .

In order to achieve the above object, the present invention provides:
A developer storage chamber for storing the developer;
A developing chamber in which a developing roller for developing the electrostatic latent image is rotatably arranged, and a developer is supplied from the developer containing chamber;
A developer supply member rotatably provided in the developer storage chamber and capable of supplying the developer in the developer storage chamber to the development chamber by rotating;
A developing device in which the developer is supplied from the developer storage chamber to the development chamber by being blown off by the developer supply member;
An elastic member that rotates the developer supply member such that the developer in the developer storage chamber is blown toward the development chamber by the developer supply member ;
The developer supply member further has a function of stirring the developer in the developer accommodating chamber by transmitting a rotational driving force from a drive source,
In a state in which the rotational driving force from the drive source is not transmitted to the developer supply member, the developer is blown by rotating the developer supply member by the elastic member, and the developer storage chamber is transferred to the development chamber. developer is characterized Rukoto supplied.

  According to the present invention, it is possible to supply a constant amount of developer more stably from the developer accommodating chamber to the developing chamber and obtain a higher quality image.

Schematic side view of the front side in the longitudinal direction of the developing unit in Embodiment 1. FIG. 3 is a schematic cross-sectional view for explaining the overall configuration of the image forming apparatus according to the first embodiment. FIG. 2 is a schematic cross-sectional view of a process cartridge containing toner according to the first exemplary embodiment. 1 is a schematic perspective view of a process cartridge according to Embodiment 1. FIG. 1 is a schematic perspective view of a developing unit of Embodiment 1. FIG. Schematic cross-sectional view for explaining the configuration of the conveying member in the first embodiment FIG. 3 is an exploded perspective view illustrating a driving configuration of the developing unit in Embodiment 1. FIG. 6 is a diagram illustrating the rotation direction of each gear of the developing unit in Embodiment 1. Schematic perspective view showing the front side in the longitudinal direction of the developing unit in Embodiment 1 FIG. 3 is a side view illustrating a driving configuration of the developing device according to the first embodiment. Schematic cross-sectional view for explaining the configuration of the conveying member in the first embodiment FIG. 6 is a schematic diagram illustrating a driving configuration of a conveying member in the developing unit according to the second embodiment.

DETAILED DESCRIPTION Exemplary embodiments for carrying out the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the scope to the following embodiments.
In this embodiment, the image forming apparatus forms an image on a recording material using an electrophotographic image forming system. Examples of the image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, etc.), a facsimile apparatus, a word processor, and the like. The process cartridge has at least developing means (developing device) that acts on a photosensitive drum as an image carrier, and is configured to be detachable from the image forming apparatus main body. The process cartridge is configured such that at least the developing unit of the photosensitive drum and the process unit acting on the photosensitive drum is integrally formed into a cartridge, and the cartridge is configured to be detachable from the image forming apparatus main body. Good. As other process means of the developing means, a charging means and a cleaning means can be exemplified.

Example 1 will be described below.
(Overall configuration of electrophotographic image forming apparatus)
First, an overall configuration of an electrophotographic image forming apparatus (hereinafter, image forming apparatus) 100 according to the present embodiment will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view for explaining the overall configuration of the image forming apparatus 100 of the present embodiment.
As shown in FIG. 2, the image forming apparatus 100 has four process cartridges 7 (7a, 7b, 7c, 7d) that are detachable. Here, the configuration and operation of each process cartridge and transfer means are substantially the same except that the color of the developer (hereinafter referred to as toner) used is different. Accordingly, in the following description, if no distinction is required, the subscripts a, b, c, and d given to the reference numerals in FIG. 2 are omitted to indicate that the elements are provided for any color. The overall explanation is as follows.

Recording material conveying means is provided so that the recording material S stored in the cassette 17 passes through the secondary transfer roller 70 and the fixing unit 74 and is conveyed above the image forming apparatus main body (hereinafter, apparatus main body) 100A. Yes. An intermediate transfer unit 5 is provided above the process cartridge 7. The intermediate transfer unit 5 includes a driving roller 56, a driven roller 57, a primary transfer roller 58 at a position facing the photosensitive drum 1 of each color, and a counter roller 59 at a position facing the secondary transfer roller 70, and a transfer belt. 9 is passed. The transfer belt 9 circulates and moves in the direction of arrow X in FIG. 2 so as to face and be in contact with all the photosensitive drums 1.

  In image formation, the photosensitive drum 1 is selectively exposed from the scanner unit 3, and an electrostatic latent image is formed on the photosensitive drum 1. The electrostatic latent image on the photosensitive drum 1 is developed by the developing action of the developing unit 4 as a developing device. Thereby, each color toner image (developer image) is formed on each photoconductive drum 1. Then, by applying a voltage to the primary transfer roller 58, each color toner image formed on each photosensitive drum 1 is primarily transferred onto the transfer belt 9. On the other hand, the recording material S stored in the cassette 17 is conveyed by the feeding roller 54. In synchronization with this image formation, the registration roller pair 55 conveys the recording material S to the secondary transfer position where the opposing roller 59 and the secondary transfer roller 70 are in contact with each other with the transfer belt 9 interposed therebetween. Here, a transfer bias voltage is applied to the secondary transfer roller 70, whereby each color toner image on the transfer belt 9 is secondarily transferred to the recording material S. As a result, a color image is formed on the recording material S. The recording material S on which the color image is formed is heated and pressurized by the fixing unit 74 to fix the toner image. Thereafter, the recording material S is discharged to the discharge unit 75 by the discharge roller 72.

(Process cartridge)
Next, the process cartridge 7 will be described with reference to FIGS. FIG. 3 is a schematic sectional view of the process cartridge 7 containing toner. The process cartridge 7a containing yellow toner, the process cartridge 7b containing magenta toner, the process cartridge 7c containing cyan toner, and the process cartridge 7d containing black toner have the same configuration. . FIG. 4 is a schematic perspective view showing a state of the process cartridge 7 according to the present embodiment before being attached to the apparatus main body 100A. FIG. 5 is a schematic perspective view of the developing unit 4 of the present embodiment. In the following description, the “longitudinal direction” refers to the rotation axis direction of the developing roller 25 (the recording material width direction orthogonal to the recording material conveyance direction during image formation). Also, regarding the longitudinal end portions of the constituent members of the image forming apparatus 100, the front and back of the drawing in the state shown in FIG. 2 are referred to as “front (front)” and “back”, respectively.
The process cartridge 7 includes a drum unit 26 and a developing unit 4. The drum unit 26 includes the photosensitive drum 1, the charging roller 2, and the cleaning member 6. The developing unit 4 includes a developing roller 25.

  The photosensitive drum 1 is rotatably attached to the cleaning frame 27 of the drum unit 26 via the drum front bearing 10 and the drum back bearing 11 (see FIG. 4). A drum coupling 16 and a flange 85 are provided at the end of the photosensitive drum 1 (see FIG. 4). Here, the drum coupling 16 is a drum coupling member for transmitting a driving rotational force from the apparatus main body 100A to the photosensitive drum 1, and the photosensitive drum 1 is moved to an arrow in FIG. 3 by the transmitted driving rotational force. Rotate in direction A.

  As described above, the charging roller 2 and the cleaning member 6 are disposed on the circumference of the photosensitive drum 1. Further, the residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 6 falls into the removed toner chamber 27a. Then, the rotational driving force of a main body driving motor (not shown) as a driving source provided in the apparatus main body 100A is transmitted to the drum unit 26, whereby the photosensitive drum 1 is rotationally driven in accordance with the image forming operation. The charging roller 2 is rotatably attached to the cleaning frame 27 via the charging roller bearing 28, and is pressurized toward the photosensitive drum 1 by the urging member 29, and is driven to rotate by the photosensitive drum 1.

The developing unit 4 includes a developing roller 25 that contacts the photosensitive drum 1 and rotates in the direction of arrow B in FIG. 3 and a developing frame 31 as a frame that supports the developing roller 25. The developing roller 25 is rotatably supported by the developing frame 31 via a pre-development bearing 12 and a developing rear bearing 13 that are respectively attached to both sides of the developing frame 31 (see FIG. 5).
Further, on the inner side in the longitudinal direction, a developing roller coupling 33 is attached so as to engage with the developing roller 25 (see FIG. 5). Here, the developing roller coupling 33 is a coupling member for transmitting the driving rotational force from the apparatus main body 100 </ b> A to the developing roller 25. Further, on the circumference of the developing roller 25, a supply roller 34 that contacts the developing roller 25 and rotates in the direction of arrow C in FIG. 3 and a developing blade 35 for regulating the toner layer on the developing roller 25 are arranged, respectively. ing. The developing roller 25, the supply roller 34, and the developing blade 35 are disposed in a developing chamber 31 b provided in the developing frame 31. Further, the toner container 31a, which is provided in the developing frame 31 and serves as a developer storage chamber for storing toner, rotates to convey (supply) the toner to the developing chamber 31b and a function of stirring the stored toner. A conveying member 36 having a function of rotating is provided rotatably. Here, the conveying member 36 corresponds to a developer supply member that can supply the toner in the toner storage portion 31a to the developing chamber 31b by rotating.

  Here, the front shaft member 14 and the back shaft member 15 that are press-fitted into the cleaning frame 27 are engaged with the suspension holes 12 a and 13 a of the pre-development bearing 12 and the development back bearing 13. As a result, the developing unit 4 is supported by the cleaning frame 27 so as to be rotatable about the front shaft member 14 and the back shaft member 15 as rotation axes (see FIG. 3). That is, the developing unit 4 is rotatably attached to the drum unit 26.

  As shown in FIG. 4, the cleaning frame 27 is provided with a drum front bearing 10 and a drum back bearing 11 that rotatably support the photosensitive drum 1. The drum back bearing 11 supports a drum coupling 16 coupled to the photosensitive drum 1. The drum front bearing 10 supports a flange 85 coupled to the photosensitive drum 1.

  Further, as shown in FIG. 5, the developing frame 31 is provided with a pressure spring 38. Further, the other end side of the pressure spring 38 is in contact with the cleaning frame 27 facing the developing frame 31. The pre-development bearing 12 is provided with a tension spring 39. Further, the other end side of the tension spring 39 is attached to the drum front bearing 10 provided on the cleaning frame 27. By these pressure spring 38 and tension spring 39, the holes 12 a and 13 a of the pre-development bearing 12 and the development back bearing 13 serve as the center of rotation, and a pressure is applied so that the developing roller 25 contacts the photosensitive drum 1. Thereby, the developing unit 4 is pressed against the drum unit 26.

Next, a series of operations relating to image formation of the process cartridge 7 will be described (see FIGS. 2 and 3).
The main body drive motor starts to rotate in accordance with the image information, and the driving rotational force is transmitted to the photosensitive drum 1, the developing roller 25, the supply roller 34, and the conveying member 36. Then, a charging bias voltage is applied to the charging roller 2 from the apparatus main body 100A, and the surface of the photosensitive drum 1 is uniformly charged. Then, exposure is performed from the scanner unit 3 according to the image information, and a latent image is formed on the photosensitive drum 1.

Then, the toner in the toner accommodating portion 31a (in the developer accommodating chamber) is sent to the supply roller 34 through the opening 31c for supplying the toner by the rotation of the conveying member 36 (details will be described later). Then, the supply roller 34 rotates, and toner is supplied to the outer periphery of the rotating developing roller 25. The supplied toner is frictionally charged on the outer periphery of the developing roller 25 by the developing blade 35. Then, a developing bias voltage is applied to the developing roller 25 from the apparatus main body 100A. Thereby, the electrostatic latent image formed on the photosensitive drum 1 is developed. The developing roller 25 is disposed to face the photosensitive drum 1. The developing roller 25 is configured to contact the photosensitive drum 1 during image formation and develop the electrostatic latent image formed on the photosensitive drum 1.

[Toner transport configuration]
Next, the toner conveyance configuration in the developing unit 4 of the process cartridge 7 of this embodiment will be described in detail. FIG. 6 is a diagram for explaining the configuration of the conveying member 36 in the present embodiment, and is a cross-sectional view showing a schematic configuration of the developing unit 4. FIG. 7 is an exploded perspective view for explaining the drive configuration of the developing unit 4 in this embodiment.

  As shown in FIG. 6, the conveying member 36 includes a conveying plate 36a, a conveying sheet 36b, and a rotating shaft 36c. The rotation shaft 36c is disposed over the entire length in the longitudinal direction of the toner containing portion 31a substantially parallel to the rotation axis direction of the developing roller 25. The conveyance plate 36a is a plate-like member provided over substantially the entire longitudinal direction of the rotation shaft 36c. Further, the transport plate 36a is coupled to the rotary shaft 36c at one end in a direction (rotational radius direction) orthogonal to the rotary shaft 36c. Further, the conveyance sheet 36b is coupled to the conveyance plate 36a so that the conveyance sheet 36b has a free length in the rotation radius direction on the other end side in the rotation radius direction of the conveyance plate 36a. The rotating shaft 36c is rotatably supported by the toner containing portion 31a.

  Next, the driving configuration of the conveying member 36 will be described with reference to an exploded perspective view showing the front side in the longitudinal direction of the developing unit 4 in FIG. As described above, the developing roller coupling 33 is provided on the inner side in the longitudinal direction of the developing roller 25 (see FIG. 5). The developing roller coupling 33 transmits the rotational driving force from the main body driving motor to the developing roller 25, whereby the developing roller 25 rotates. Further, a first gear 41 is provided on the front side in the longitudinal direction of the developing roller 25, and the cored bar 25j of the developing roller 25 and the hole 41a of the first gear 41 have a shape in which a part of the arc is a straight line. They are fitted (non-rotating mechanism). That is, when the developing roller 25 is rotated by the rotational driving force applied from the main body driving motor, the first gear 41 is also rotated.

  Further, the second gear 42 is rotatably supported by fitting the hole 42 a and the boss 12 j of the pre-development bearing 12. The hole 43a of the third gear 43 and the cored bar 34j of the supply roller 34 are fitted in a shape in which a part of the arc is a straight line. The hole 44 a of the fourth gear 44 is rotatably supported by fitting with the protrusion 31 j of the developing device frame 31. The fifth gear 45 is configured to be rotatable by being attached to the rotation shaft 36c of the conveying member 36, and the hole 45a provided at the rotation center of the fifth gear 45 and the rotation shaft 36c are respectively arcs. Are partly fitted in a straight line. Here, the fifth gear 45 corresponds to a rotating member.

  The rotational driving force of the first gear 41 is transmitted to the third gear 43 via the second gear 42. The rotational driving force of the first gear 41 is transmitted to the fifth gear 45 via the second gear 42 and the fourth gear 44. That is, the developing roller 25, the supply roller 34, and the conveying member 36 of the process cartridge 7 are configured to be rotatable by the rotational driving force from the main body driving motor.

Next, the rotation direction of each gear (gear) will be described with reference to FIG. FIG. 8 is a schematic view for explaining the rotation direction of each gear of the developing unit 4 in this embodiment.
A rotational driving force is transmitted from the main body drive motor to the developing roller 25 through the developing roller coupling 33, and the developing roller 25 rotates counterclockwise. As a result, the first gear 41 rotates in the arrow H direction, the second gear 42 rotates in the arrow I direction, the third gear 43 rotates in the arrow J direction, the fourth gear 44 rotates in the arrow K direction, and the fifth gear 45 rotates in the arrow L direction. . Therefore, the conveying member 36 rotates in the arrow L direction (see FIG. 6).

FIG. 9 is a schematic perspective view showing the front side in the longitudinal direction of the developing unit 4 in this embodiment. A projection 45j is provided on the end surface of the fifth gear 45 on the front side in the longitudinal direction at a position eccentric from the rotation center (the rotation shaft 36c). The elastic member 46 (in this embodiment, a tension spring) is engaged so that one end engages with the protrusion 45j provided on the fifth gear 45 and the other end engages with the protrusion 31j provided on the developing device frame 31. ) Is provided. The elastic member 46 is configured to apply a rotational force to the rotary shaft 36c in this way, and can rotate the rotary shaft 36c and the transport member 36.
And the cover member 50 is provided in the longitudinal direction outer side. The cover member 50 is formed on the end surface 41b of the first gear 41, the end surface 42b of the second gear 42, the end surface 43b of the third gear 43, the end surface 44b of the fourth gear 44, the protrusion 45j of the fifth gear 45, and the developing frame 31. It is in contact with the provided protrusion 31j. Thereby, each gear (41, 42, 43, 44, 45) and the elastic member 46 are prevented from coming out to the outside in the longitudinal direction.

FIG. 1 is a schematic side view of the front side in the longitudinal direction of the developing unit 4 in this embodiment. FIG. 10 is a schematic side view for explaining the driving configuration of the developing unit 4 in this embodiment. FIG. 11 is a view for explaining the configuration of the conveying member 36 in the present embodiment, and is a cross-sectional view showing a schematic configuration of the developing unit 4.
Here, a straight line connecting the center of the protrusion 31j and the rotation center of the fifth gear 45 is a straight line k, and a straight line connecting the rotation center of the fifth gear 45 and the center of the protrusion 45j is a straight line j. When the rotation direction of the fifth gear 45 (the direction of the arrow G in FIG. 1) is positive and the angle between the straight line k and the straight line j is θ1, the protrusion 45j is elastic when positioned in the range of 0 ° <θ1 <180 °. A positive moment acts on the fifth gear 45 by the elastic restoring force (elastic force) of the member 46. Further, when it is located in the range of 180 ° <θ1 <360 °, a negative moment acts on the fifth gear 45.

Furthermore, as shown in FIG. 10, a part of the circumference of the fifth gear 45 lacks a tooth shape for receiving the transmission of the rotational driving force from the fourth gear 44. That is, in the present embodiment, the fifth gear 45 is constituted by a chip gear that can transmit the rotational driving force from the main body driving motor. Here, when the projection 45j is positioned so that θ1 = 0 °, the drive transmission portion of the fourth gear 44 and the fifth gear 45 is a point P, and the tooth shape missing range (the missing tooth portion range) is θ2. And The tooth shape for receiving the rotational driving force of the fifth gear 45 is missing in the range of θ2 = 90 ° counterclockwise starting from the point P.
Therefore, when the protrusion 45j is positioned in the range of 0 ° <θ1 <90 °, the chipped portion of the fifth gear 45 faces the fourth gear 44, and the fourth gear 44 rotates and drives the fifth gear 45. Force transmission is not performed. Therefore, in this range, the fifth gear 45 rotates with a positive moment due to the elastic restoring force of the elastic member 46.
And when it is located in the range of 90 ° <θ1 <360 °, the rotational driving force is transmitted from the fourth gear 44 and the fifth gear rotates.

That is, as described above, since the fifth gear 45 and the conveying member 36 are coupled, the conveying member 36 rotates during one rotation by the rotational driving force from the main body driving motor and the elastic restoration of the elastic member 46. It has a phase that rotates (using elastic force) by force. When the conveying member 36 is rotated by the rotational driving force from the main body driving motor, the conveying member 36 performs a function of stirring the toner in the toner accommodating portion 31a, and when the conveying member 36 is rotated by the elastic restoring force of the elastic member 46, the developing is performed. The function of conveying (supplying) the toner to the chamber 31b is exhibited.
In this embodiment, the toner is transported from the toner storage portion 31a to the developing chamber 31b by rotating the transport member 36 by applying a rotational force to the rotating shaft 36c by the elastic restoring force of the elastic member 46, thereby flying the toner. ing. At this time, the rotational driving force from the main body driving motor is not transmitted to the conveying member 36.

Next, the state of the conveyance member 36 when the protrusion 45j is positioned in the range of 180 ° <θ1 <360 ° will be described with reference to FIG. That is, the fifth gear 45 is rotated by the rotational driving force of the fourth gear 44, and the conveying member 36 is thereby rotated. The conveyance sheet 36b is in contact with the guide portion 31d of the toner storage portion 31a. Here, the guide portion is an inner wall of the toner storage portion 31 a from the point q to the point r in the rotation direction of the transport member 36. By rotating the conveyance sheet 36b in contact with the guide portion 31d, the conveyance member 36 conveys the toner while stirring the toner on the downstream side of the rotation.
Furthermore, the state of the conveying member 36 when the projection 45j is positioned so that θ1 = 0 ° is shown in FIG. At this time, the transport plate 36a is positioned so as to be substantially horizontal. That is, starting from this substantially horizontal position, the conveying member 36 rotates toward the opening 31c at a speed higher than the rotational speed by the rotational driving force from the main body driving motor by the elastic restoring force of the elastic member 46. . Thereby, the toner carried by the conveying member 36 can be caused to fly toward the opening 31c by the elastic restoring force of the elastic member 46. As described above, the toner stored in the toner storage portion 31a can be conveyed to the developing chamber 31b through the opening 31c by using the elastic restoring force of the elastic member 46.

Since the toner conveying force when the toner accommodated in the toner accommodating portion 31a is conveyed to the developing chamber 31b is based on the elastic restoring force of the elastic member 46, the toner amount in the toner accommodating portion 31a is increased by the configuration of this embodiment. Regardless, the toner can always be supplied to the developing chamber 31b more stably.
Further, in the configuration in which the sheet is used as the conveying member 36 and the toner is conveyed by its restoring force, the toner conveying amount changes when the process cartridge 7 (developing unit 4) is stored for a long time with the sheet bent. May end up. This is because the sheet stored in a bent state is plastically deformed and the restoring force used for toner conveyance is reduced.
However, in this embodiment, the toner is transported by rotating the transport member 36 by the elastic restoring force of the elastic member 46. Therefore, it is not necessary to use a plastic member such as a conventional sheet, and a member having no elastic restoring force (elastic restoring property) such as metal or resin can be applied as the conveying member 36. Accordingly, it is possible to prevent the toner conveyance amount from changing due to the deformation of the conveyance member 36 due to the transport environment, storage environment, use environment, and external force.

Further, since the rotation speed of the conveying member 36 during toner conveyance depends on the elastic restoring force of the elastic member 46, the rotation speed of the rotational driving force input from the image forming apparatus 100 changes in accordance with the process speed. However, the toner conveying force does not change.
Conventionally, in an image forming apparatus having a plurality of process speeds in order to support a plurality of media types, the rotational speed of a supply device (corresponding to the transport member 36) also changes with a change in drive input due to a difference in process speed. . As a result, the toner conveyance amount also changes. Therefore, in Patent Document 2, in order to stabilize the toner conveyance amount, there are a plurality of gears as drive transmission members that transmit the drive input from the image forming apparatus to the supply device, and the reduction ratio can be varied according to the process speed. I have to. With such a configuration, the rotation speed of the supply device is kept constant regardless of the process speed. However, in such a configuration, a configuration in which the reduction ratio is variable according to the process speed is required, and there is a concern that the size and cost of the apparatus may be increased.
In the configuration of the present embodiment, a fixed amount of toner is always transported more stably without providing a configuration that makes the reduction ratio variable according to the process speed, that is, without increasing the size and cost of the apparatus. can do.

As described above, according to the present exemplary embodiment, the elastic member 46 capable of rotating the conveying member 36 in the same direction as the rotation direction when the toner is conveyed from the toner containing portion 31a to the developing chamber 31b is provided. The elastic member 46 is configured to bear a part of the rotation of the conveying member 36. When the conveying member 36 conveys the toner from the toner containing portion 31a to the developing chamber 31b, the conveying member 36 is rotated by the elastic force of the elastic member 46 to blow the toner. At this time, the rotation from the main body driving motor is performed. The driving force is not transmitted to the conveying member 36.
Thereby, it is possible to prevent the toner conveyance amount from changing due to the transport environment, the storage environment, the use environment, and the action of external force. Even when the image forming apparatus has a plurality of process speeds, a constant amount of toner can be transported more stably and constantly without increasing the size of the apparatus and increasing the cost.
Therefore, toner conveyance by the conveyance member 36 can be further stabilized.

Here, in this embodiment, during one rotation, the toner is rotated by the rotational driving force from the main body driving motor, and the toner is stirred and the elastic restoring force of the elastic member 46 is rotated. The transport member 36 having the transport function has been described. However, the developer supply member is not limited to this, and may be any member having a function of flying toner and transporting it to the developing chamber 31b. For this purpose, for example, the developer supplying member is rotated by the elastic restoring force of the elastic member 46 without rotating once like the conveying member 36, and then developed to a position where the elastic restoring force of the elastic member 46 is exerted. The agent supply member may be reversed. That is, the developer supply member may be reciprocated within a preset angle range.
Further, in this embodiment, in order to provide a state in which the rotational driving force from the main body drive motor is not transmitted to the conveying member 36, the fifth gear 45 attached to the rotating shaft 36c of the conveying member 36 is constituted by a chipped gear. However, it is not limited to this. One of the gears constituting a transmission path for transmitting the rotational driving force from the main body driving motor to the gear attached to the rotation shaft 36c of the conveying member 36 is a chipped gear, and the rotational driving force from the main body driving motor is A state in which the state is not transmitted to the conveying member 36 may be provided.
Further, in the present embodiment, the case where the developing chamber 31b is provided above the toner accommodating portion 31a and the toner in the toner accommodating portion 31a is conveyed to the developing chamber 31b against gravity is described. However, the present invention is not limited to such a configuration, and can be suitably applied as long as toner is supplied from the developer storage chamber to the developing chamber by being blown off by the developer supply member.

Next, Example 2 will be described with reference to FIG. FIG. 12 is a schematic diagram showing a driving configuration of the conveying member 36 in the developing unit 4 of the present embodiment. Since the basic configuration of the apparatus of the present embodiment is the same as that of the first embodiment described above, the description of the overlapping parts is omitted. Members having the same functions as those in the first embodiment are denoted by the same reference numerals.
In the first embodiment, in a range in which the tooth shape of the fifth gear 45 is partially missing, the rotational driving force from the apparatus main body 100A is not transmitted to the transport member 36, and the transport member 36 is elastically restored by the elastic member 46. The configuration that rotates by force has been described.
On the other hand, in this embodiment, by providing a one-way clutch (single rotation joint) between the fifth gear 47 and the rotating shaft 36c, the rotational driving force from the apparatus main body 100A is not transmitted to the conveying member 36. The conveying member 36 is rotated by the elastic restoring force of the elastic member 46. Here, the fifth gear 47 of the present embodiment corresponds to the fifth gear 45 of the first embodiment in that it has a function capable of transmitting the rotational driving force from the main body drive motor to the rotating shaft 36c. In the present embodiment, the fifth gear 47 corresponds to a driving force transmission member.

In the present embodiment, as shown in FIG. 12, the fifth gear 47 is connected to the rotary shaft 36 c via the one-way clutch 49. The rotating shaft 36c and the inner peripheral portion (bearing portion) of the one-way clutch 49 are fitted in a shape in which a part of the arc is a straight line.
Here, when the fifth gear 47 rotates in the direction of arrow M relative to the rotation shaft 36c, the one-way clutch 49 transmits the rotation driving force to the rotation shaft 36c. On the other hand, when the fifth gear rotates in the direction of arrow N relative to the rotation shaft 36c, the one-way clutch 49 rotates idly with respect to the rotation shaft 36c, and the rotational driving force is applied from the fifth gear 47 to the rotation shaft 36c. Is not transmitted. In other words, when the fifth gear 47 rotates in the arrow M direction, the rotational force of the fifth gear 47 is transmitted to the rotating shaft 36c, and when the rotating shaft 36c rotates in the arrow M direction, the rotating shaft 36c. Is configured to rotate without being restricted by the fifth gear 47.
That is, the one-way clutch 49 does not rotate the fifth gear 47 in the direction of the arrow M relative to the rotation shaft 36c, but rotates the rotation shaft 36c in the direction of the arrow M relative to the fifth gear 47. Is an acceptable mechanism. Here, the arrow M direction is the rotation direction of the rotation shaft 36c when the conveying member 36 conveys the toner.

  Further, an elastic force transmitting member 48 as a rotating member is attached to the rotating shaft 36c on the outer side in the longitudinal direction of the fifth gear 47. The hole portion 48a of the elastic force transmitting member 48 and the rotating shaft 36c are engaged with each other so that a part of the arc is a straight line. Further, the end face of the elastic force transmission member 48 is provided with a projection 48j at a position eccentric from the center of rotation. As in the first embodiment, the elastic member 46 is provided so that one end engages with the protrusion 48j and the other end engages with the protrusion 31j provided on the developing device frame 31.

Therefore, as described in the first embodiment, when the protrusion 48j is positioned so that 0 ° <θ1 <180 °, a moment in the rotation direction of the transport member 36 acts on the rotation shaft 36c. Further, in this case, the elastic member 46 is configured to rotate the rotating shaft 36c at a higher speed than when the rotating shaft 36c is rotated by the rotational driving force transmitted by the fifth gear 47. That is, the fifth gear 47 is relatively rotated in the direction of the arrow N with respect to the rotation shaft 36c, and the one-way clutch 49 rotates idly with respect to the rotation shaft 36c.
Therefore, the rotational driving force is not transmitted from the fifth gear 47 to the rotating shaft 36 c by the one-way clutch 49, and the conveying member 36 is rotated by the elastic restoring force of the elastic member 46. Other configurations are the same as those of the first embodiment.

As described above, in this embodiment, the fifth gear 47 and the rotary shaft 36c are engaged with each other, and the fifth gear 47 and the rotary shaft 36c are engaged with each other in the relative rotation in one direction. The shaft 36c is configured to rotate. In the relative rotation in the other direction, the fifth gear 47 and the rotation shaft 36c do not engage with each other, and the fifth gear 47 idles with respect to the rotation shaft 36c. Even in such a configuration, the same effect as in the first embodiment can be obtained.
In the first embodiment described above, one end of the elastic member 46 is engaged with the protrusion 45j provided on the end surface of the fifth gear 45, but it is attached to the rotary shaft 36c as in the present embodiment. One end of the elastic member 46 may be engaged with the end surface of the rotating member.

  4 developing unit; 25 developing roller; 31a toner accommodating portion; 31b developing chamber; 36 transport member; 46 elastic member

Claims (6)

A developer storage chamber for storing the developer;
A developing chamber in which a developing roller for developing the electrostatic latent image is rotatably arranged, and a developer is supplied from the developer containing chamber;
A developer supply member rotatably provided in the developer storage chamber and capable of supplying the developer in the developer storage chamber to the development chamber by rotating;
A developing device in which the developer is supplied from the developer storage chamber to the development chamber by being blown off by the developer supply member;
An elastic member that rotates the developer supply member such that the developer in the developer storage chamber is blown toward the development chamber by the developer supply member ;
The developer supply member further has a function of stirring the developer in the developer accommodating chamber by transmitting a rotational driving force from a drive source,
In a state in which the rotational driving force from the drive source is not transmitted to the developer supply member, the developer is blown by rotating the developer supply member by the elastic member, and the developer storage chamber is transferred to the development chamber. a developing device developing agent, characterized in Rukoto supplied. A frame that supports the developing roller, the frame including the developer storage chamber and the developing chamber;
The elastic member has one end attached to a position eccentric to the rotation shaft on the end surface of the rotation member attached to the rotation shaft of the developer supply member, and the other end attached to the frame. The developing device according to claim 1 , wherein the developer supplying member is configured to be rotated. The rotating member is constituted by a chipped gear that can transmit a rotational driving force from the driving source,
The elastic gear is in a state where the chipped portion of the chipped gear is opposed to a gear capable of transmitting the rotational driving force from the driving source to the chipped gear, and the rotational driving force is not transmitted from the gear to the chipped gear. The developing device according to claim 2 , wherein the developer is blown by rotating the developer supply member by a member, and the developer is supplied from the developer containing chamber to the developing chamber. A driving force transmitting member capable of transmitting a rotational driving force from the driving source to the developer supply member is attached to the rotating shaft via a one-way clutch;
When the driving force transmission member rotates in the rotation direction of the rotation shaft when the developer supply member supplies the developer, the rotation force of the driving force transmission member is transmitted to the rotation shaft, and the rotation When the rotating shaft rotates in a direction, the rotating shaft is configured to rotate without being restricted by the driving force transmission member,
The elastic member rotates the developer supply member at a higher speed than when rotating by the rotational driving force of the driving source transmitted by the driving force transmitting member, and the developer is blown off from the developer storage chamber. The developing device according to claim 2 , wherein a developer is supplied to the developing chamber. At least a developing device according to any one of claims 1 to 4, the process cartridge characterized in that it is detachably attached to the image forming apparatus main body. An image bearing member, an image forming apparatus characterized by comprising a developing device according to any one of claims 1 to 4 for developing acting on the image bearing member.

Images