JP2017116648A - Developing device, process cartridge, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply a sufficient amount of developer from a storage chamber to a developing chamber, while increasing the capacity of the storage chamber.SOLUTION: A developing device includes a conveyance member 23 which comes into contact with the inner wall surface of a storage chamber 18a, to be elastically deformed and conveys the developer from the storage chamber 18a to a developing chamber 18b through an opening 18c by using a return force from an elastically deformed state and a conveyance auxiliary member 19 which is provided on a downstream side from a recess 18d in the rotational direction of the conveyance member 23 and projected toward an upstream side in the rotational direction, and assists the conveyance of the developer. The recess 18d is located on the downstream side from the bottom part 18f of the storage chamber 18a and on the upstream side from the opening 18c in the rotational direction of the conveyance member 23. In a process for allowing the conveyance member 23 to pass through the recess 18d, the conveyance member 23 simultaneously comes into contact with the inner wall surface of the storage chamber 18a and the conveyance auxiliary member 19.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a developing device that develops an electrostatic latent image formed on a photosensitive drum, a process cartridge that forms a developer image on the photosensitive drum and is detachable from the apparatus main body, and a developer. The present invention relates to an image forming apparatus that forms an image on a recording medium.

  In an image forming apparatus using an electrophotographic system, a photoreceptor is uniformly charged in order to form a toner image on the photoreceptor. The charged photoconductor is selectively exposed to form an electrostatic image on the photoconductor, and the electrostatic image formed on the photoconductor is developed as a toner image. The toner image formed on the photosensitive member is transferred to a recording material such as paper or a plastic sheet, and then the toner image transferred to the recording material is heated and pressed to fix the toner image on the recording material. . In this way, an image is formed on the recording material.

  Here, conventionally, in an in-line image forming apparatus in which a plurality of photoconductors are arranged in a row in the horizontal direction, the plurality of photoconductors may be arranged below the intermediate transfer belt. When the photosensitive member is disposed below the intermediate transfer belt, the intermediate transfer belt is disposed between the exposure device, the developing device, and the fixing device, so that the exposure device, the developing device, and the fixing device are separated from each other. Can be arranged. For this reason, the developing device, the exposure device, and the like are hardly affected by the heat from the fixing device.

  When the photosensitive member is arranged below the intermediate transfer belt in this way, it is necessary to transport toner as a developer in the developing device toward the photosensitive member against gravity. In general, the developing device stores a developing chamber in which a developing roller for supplying toner to a photosensitive member, a developer supplying roller for supplying toner to the developing roller, and the like, and toner supplied to the developing chamber are accommodated. And a toner storage chamber as a storage chamber. Here, when the plurality of photoconductors are disposed below the intermediate transfer belt, basically, the developing chamber is positioned below the photoconductor and the toner storage chamber is positioned below the developing chamber. In this case, it is necessary to supply toner from the toner storage chamber to the developing chamber against gravity. In the technique disclosed in Patent Document 1, the agitation member to which the flexible sheet is attached rotates, so that the toner is conveyed from the toner storage chamber to the developing chamber disposed above the toner storage chamber.

  Here, as shown in FIG. 8, a process cartridge 7 that transports toner from the toner storage chamber to the developing chamber against gravity is considered. When a plurality of process cartridges 7 are arranged in a line in the horizontal direction in the image forming apparatus, a space H may exist between the adjacent process cartridges 7 as shown in FIG. As shown in FIG. 8B, a virtual technique in which the concave portion 18d is provided in the toner storage chamber 18a and the volume of the toner storage chamber 18a is increased by effectively using the space H can be considered. The recess 18d is formed by protruding the wall surface of the toner storage chamber toward the space H side.

  However, in such a virtual technique, when the toner is conveyed by the stirring member 23, as shown in FIG. 9, when the leading end of the stirring sheet 23b passes through the recess 18d, the leading end of the stirring sheet 23b is stored in the toner. There is a case where it does not contact the wall surface of the chamber 18a. Such a state occurs when the distance from the wall surface of the toner storage chamber 18a to the rotating shaft of the stirring member 23 is larger than the length of the stirring sheet 23b. At this time, a gap N is generated between the stirring sheet 23b and the recess 18d. As a result, the toner placed on the stirring sheet 23b falls by its own weight from the gap N, and the amount of toner conveyed from the toner storage chamber 18a to the developing chamber 18b by the stirring sheet 23b may be reduced.

JP 2011-039554 A JP 2004-361463 A

  An object of the present invention is to supply a sufficient amount of developer from the storage chamber to the development chamber while increasing the volume of the storage chamber.

In order to achieve the above object, the developing device according to the present invention comprises:
A developer carrying member carrying the developer;
A developing chamber having the developer carrier;
A storage chamber having an opening and a recess, located below the developing chamber, and storing a developer;
A conveying member that conveys the developer from the accommodating chamber to the developing chamber via the opening by using a force that is elastically deformed by contacting the inner wall surface of the accommodating chamber and restoring from the elastically deformed state; ,
A conveyance auxiliary member that is provided on the downstream side of the concave portion in the rotation direction of the conveyance member, protrudes to the upstream side in the rotation direction, and assists the conveyance of the developer,
In the rotation direction of the transport member, the recess is located downstream from the bottom of the storage chamber and is located upstream from the opening.
In the process in which the transport member passes through the recess, the transport member contacts the inner wall surface of the storage chamber and the transport auxiliary member at the same time.

In order to achieve the above object, the process cartridge according to the present invention comprises:
The developing device;
An image carrier,
It is detachable from the image forming apparatus.

In order to achieve the above object, an image forming apparatus according to the present invention includes:
Having at least one of the developing device or the process cartridge;
An image is formed on a recording medium using a developer.

  The present invention can supply a sufficient amount of developer from the storage chamber to the development chamber while increasing the volume of the storage chamber.

Schematic sectional view of a process cartridge according to an embodiment Schematic sectional view of an image forming apparatus according to an embodiment The figure which shows a mode that a process cartridge is inserted in the apparatus main body of an image forming apparatus. Schematic sectional view of a conventional process cartridge FIG. 4 is a diagram illustrating a state in which toner in a toner storage chamber is conventionally transported to a developing chamber The figure which shows a mode that the toner in a toner storage chamber is conveyed to a developing chamber in an Example. Schematic sectional view of a process cartridge according to an embodiment Schematic sectional view of the process cartridge in the reference example Schematic sectional view of the process cartridge in the reference example Figure specifically explaining the recess The figure which shows the state where the crevice is covered concretely The figure explaining the rotation area | region of the stirring member extended Cross-sectional perspective view of a process cartridge according to an embodiment

(Example)
Embodiments of the present invention are illustrated below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments should be appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions. This is not intended to limit the scope to the following embodiments.

<Electrophotographic image forming apparatus>
First, the overall configuration of an electrophotographic image forming apparatus (image forming apparatus) according to an embodiment will be described with reference to FIGS. FIG. 2 is a schematic cross-sectional view of the image forming apparatus 100 according to the embodiment. FIG. 3 is a diagram illustrating a state in which the process cartridge 7 </ b> Y is inserted into the apparatus main body of the image forming apparatus 100.

  The image forming apparatus 100 includes first to fourth image forming units SY, SM, SC, and SK for forming yellow (Y), magenta (M), cyan (C), and black (K) images, respectively. Have. In the present embodiment, the configurations and operations of the first to fourth image forming units SY to SK are substantially the same except that the colors of the formed images are different. Therefore, in the following, when there is no need for distinction, the subscripts Y, M, C, and K will be omitted, and the description will be made comprehensively.

  In this embodiment, the image forming apparatus 100 has four photosensitive drums 1 (1Y to 1K) as image carriers. The photosensitive drum 1 rotates in the direction of arrow A in FIG. A charging roller 2 and a scanner unit 3 as an exposure device are disposed around the photosensitive drum 1. The charging roller 2 is a charging unit that uniformly charges the surface of the photosensitive drum 1. The scanner unit 3 is an exposure unit that irradiates a laser based on image information to form an electrostatic image (electrostatic latent image) on the photosensitive drum 1. Around the photosensitive drum 1, a developing unit 4 (4Y to 4K) as a developing device and a cleaning blade 6 (6Y to 6K) as a cleaning unit are arranged. In this embodiment, the developing unit 4 is configured to be detachable from the apparatus main body of the image forming apparatus 100 as a process cartridge. However, the present invention is not limited to this, and the developing unit 4 as a developing device may be detachable from the apparatus main body of the image forming apparatus alone.

  Further, an intermediate transfer belt 5 as an intermediate transfer body for transferring a toner image on the photosensitive drum 1 to a recording material 12 as a recording medium is disposed to face the four photosensitive drums 1. In this embodiment, the developing unit 4 as a developing device uses toner T (TY to TK), which is a non-magnetic one-component developer, as the developer. In this embodiment, the developing unit 4 develops the electrostatic latent image on the photosensitive drum 1 by bringing a developing roller 17 as a developer carrying member into contact with the photosensitive drum 1.

  In this embodiment, the photosensitive unit 13 includes a photosensitive drum 1, a charging roller 2, a cleaning blade 6, and a removed developer storage unit that stores transfer residual toner (waste toner) remaining on the photosensitive drum 1. As a waste toner container 14a (14aY to 14aK). Further, in this embodiment, the developing unit 4 and the photosensitive unit 13 as a developing device are integrally formed as a cartridge as the process cartridge 7. The process cartridge 7 can be attached to and detached from the image forming apparatus 100 by a mounting guide (not shown) provided in the image forming apparatus 100 and mounting means such as a positioning member.

  In this embodiment, as shown in FIG. 3, the process cartridge 7 can be attached to and detached from the image forming apparatus 100 in the rotation center axis direction (G direction) of the photosensitive drum 1. In this embodiment, the process cartridges 7 of the respective colors have the same shape, and the toners of yellow (TY), magenta (TM), cyan (TC), and black (TK) are contained in the process cartridges 7 of the respective colors. T (TY, TM, TC, TK) is stored. Here, as shown in FIG. 3, the longitudinal direction of the process cartridge 7 is the same direction as the rotation center axis direction (G direction) of the photosensitive drum 1.

  The intermediate transfer belt 5 is in contact with all the photosensitive drums 1 (1Y to 1K) and rotates in the direction of arrow B in FIG. The intermediate transfer belt 5 is supported by a plurality of support members (a driving roller 26, a secondary transfer counter roller 27, and a driven roller 28). On the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8 (8Y to 8K) as primary transfer means are arranged in parallel so as to face the respective photosensitive drums 1. Further, on the outer peripheral surface side of the intermediate transfer belt 5, a secondary transfer roller 9 as a secondary transfer unit is disposed at a position facing the secondary transfer counter roller 27.

<Image formation process>
When forming an image, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. Next, a laser beam is irradiated from the scanner unit 3 according to the image information, and the surface of the charged photosensitive drum 1 is scanned and exposed to form an electrostatic latent image on the photosensitive drum 1 based on the image information. The The electrostatic latent image formed on the photosensitive drum 1 is developed as a toner image by the developing unit 4 as a developing device. The toner image formed on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5 by the primary transfer roller 8.

  For example, when forming a full-color image, the above-described image forming process is sequentially performed in the first to fourth image forming units SY to SK. Then, the toner images of the respective colors are sequentially superimposed (primary transferred) from the image forming units SY to SK onto the intermediate transfer belt 5. Thereafter, in synchronization with the movement of the intermediate transfer belt 5, the recording material 12 is conveyed to the secondary transfer portion. Then, in a state where the secondary transfer roller 9 is in contact with the intermediate transfer belt 5 through the recording material 12, the four-color toner image on the intermediate transfer belt 5 is transferred onto the recording material 12 by the secondary transfer roller 9. Secondary transfer is performed at once.

  The recording material 12 onto which the toner image has been transferred is conveyed to a fixing device 10 as a fixing unit. The toner image is fixed to the recording material 12 by the fixing device 10 heating and pressurizing the recording material 12. The primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer process is removed by the cleaning blade 6. Further, the secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer step is removed by the intermediate transfer belt cleaning device 11. The removed transfer residual toner (waste toner) is discharged to a waste toner box (not shown) of the image forming apparatus 100. Note that the image forming apparatus 100 can form a single-color or multi-color image using only a desired number of image forming units such as one or two.

<Process cartridge>
Next, the overall configuration of the process cartridge 7 mounted on the image forming apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 4 is a schematic sectional view of a conventional process cartridge 7. The developing unit 4 as a developing device has a developing frame 18 that supports various elements in the developing unit 4. The developing unit 4 is provided with a developing roller 17 as a developer carrying member that contacts the photosensitive drum 1 and rotates in the direction of arrow D (counterclockwise) in FIG. At both ends in the longitudinal direction (rotation center axis direction) of the developing roller 17, the developing roller 17 is supported by the developing frame 18 so as to be rotatable via a bearing.

  The developing unit 4 as a developing device includes a toner storage chamber 18a as a storage chamber, a development chamber 18b in which the developing roller 17 is disposed, and an opening 18c that communicates the toner storage chamber 18a and the development chamber 18b. . In this embodiment, the developing chamber 18b is positioned above the toner storage chamber 18a in a posture in which the image forming apparatus 100 is normally used and the developing unit 4 is mounted on the image forming device 100. Further, in the developing chamber 18b, a toner supply roller 20 as a supply member that contacts the developing roller 17 and rotates in the direction of arrow E in FIG. 4, and a developer regulating member for regulating the toner layer on the developing roller 17 The developing blade 21 is arranged. The toner supply roller 20 supplies toner in the developing chamber 18 b (developing chamber) to the developing roller 17.

  Further, the toner storage chamber 18a is used as a transport member for stirring the toner T stored in the toner storage chamber 18a and transporting the toner from the toner storage chamber 18a to the toner supply roller 20 through the opening 18c. The stirring member 23 is provided. The stirring member 23 includes a rotation shaft 23a parallel to the rotation center axis direction of the developing roller 17, and a stirring sheet 23b as a flexible sheet member that stirs and conveys toner. One end of the stirring sheet 23b is attached to the rotating shaft 23a.

  The photoconductor unit 13 includes a cleaning frame 14 as a frame that supports various elements in the photoconductor unit 13 (see FIG. 1). The photosensitive drum 1 is attached to the cleaning frame 14 via a bearing member so as to be rotatable in the direction of arrow A in FIG. A charging roller bearing 15 (see FIG. 1) is attached to the cleaning frame 14. The charging roller bearing 15 extends along a line passing through the rotation center of the charging roller 2 and the rotation center of the photosensitive drum 1. Here, the charging roller bearing 15 is attached to be movable in the direction of arrow C in FIG. The charging roller 2 is rotatably attached to the charging roller bearing 15. The charging roller bearing 15 is urged toward the photosensitive drum 1 by a charging roller pressure spring 16 (see FIG. 1) as urging means.

  The cleaning blade 6 includes an elastic member 6a for removing transfer residual toner (waste toner) remaining on the surface of the photosensitive drum 1 after the primary transfer, and a support member 6b for supporting the elastic member 6a. ing. The waste toner removed from the surface of the photosensitive drum 1 by the cleaning blade 6 falls in the direction of gravity in the space formed by the cleaning blade 6 and the cleaning frame body 14 and is stored in the waste toner storage portion 14a.

<Configuration of toner transport>
Next, a configuration for conveying the toner in the toner storage chamber 18a as a storage chamber to the developing chamber 18b will be described with reference to FIGS. FIG. 5 is a diagram illustrating a state in which toner in the toner storage chamber 18a is transported to the developing chamber 18b. Since the stirring sheet 23b contacts the inner wall surface of the toner storage chamber 18a, the stirring member 23 rotates in a state where the stirring sheet 23b is elastically deformed (bent).

  The toner storage chamber 18a has a release position 18e where the inner wall surface of the toner storage chamber 18a is in contact with the stirring sheet 23b when the stirring sheet 23b is restored from the elastically deformed state. The stirring sheet 23b comes into contact with the inner wall surface of the toner storage chamber 18a, and force is applied to the stirring sheet 23b from the inner wall surface of the toner storage chamber 18a, whereby the stirring sheet 23b is elastically deformed. Then, at the timing when the stirring sheet 23b passes through the release position 18e, the toner on the stirring sheet 23b (on the conveying member) jumps up by the force that restores the state where the stirring sheet 23b is elastically deformed, and the toner is passed through the opening 18c. Is conveyed into the developing chamber 18b.

That is, while the toner on the stirring sheet 23b is supported by the inner wall surface of the toner storage chamber 18a and the stirring sheet 23b, the stirring sheet 23b lifts the toner and utilizes the restoring force of the elastically deformed stirring sheet 23b. The toner is conveyed to 18b. In this embodiment, the agitating member 23 can agitate and convey most of the toner accumulated on the bottom 18f of the toner storage chamber 18a. As shown in FIG. 4, the length from the tip (other end) of the stirring sheet 23b that extends straight to the rotating shaft 23a is W0, and the length from the bottom 18f of the toner storage chamber 18a to the rotating shaft 23a is W1. Then, in this embodiment, W0> W1.

  Here, a conventional manner in which the toner in the toner storage chamber 18a is conveyed to the developing chamber 18b will be described with reference to FIG. FIG. 5A is a diagram illustrating a state in which the stirring sheet 23b starts to push the upper side of the toner accumulated on the bottom 18f of the toner storage chamber 18a. Thereafter, as shown in FIG. 5B, the stirring sheet 23b rotates in the direction of arrow F in FIG. 5, and lifts the toner accumulated on the bottom 18f upward.

  Further, as shown in FIG. 5C, the stirring sheet 23b rotates in the direction of arrow F, and the end of the stirring sheet 23b reaches the release position 18e. In this state, the toner is placed on the stirring sheet 23b, and at the timing when the end of the stirring sheet 23b passes the release position 18e, the contact state between the stirring sheet 23b and the release position 18e is released, and the stirring sheet 23b Restore from the elastically deformed state. At this time, the toner is splashed up toward the opening 18c by the restoring force of the stirring sheet 23b.

  Next, as shown in FIG. 5D, the toner is conveyed to the opening 18c with a force that restores the stirring sheet 23b from the elastically deformed state, and the stirring sheet 23b opens in the toner storage chamber 18a as a storage chamber. It collides with the surface on which 18c is provided. The toner on the stirring sheet 23b is pushed into the developing chamber 18b by the impact force at this time. Thereafter, the stirring sheet 23b further rotates in the direction of the arrow F, and again enters the state shown in FIG. Then, as it is, the stirring sheet 23b continues to rotate in the direction of arrow F, and whenever the end of the stirring sheet 23b passes through the release position 18e, the toner on the stirring sheet 23b jumps up, and the toner in the toner storage chamber 18a It is conveyed to the developing chamber 18b through the opening 18c.

<Configuration of concave portion of toner storage chamber>
As shown in FIG. 1, a recess 18d is formed by a wall surface 18d1 and a wall surface 18d2 of a toner storage chamber 18a as a storage chamber. Specifically, the concave portion 18d refers to a space surrounded by the wall surface 18d1, the wall surface 18d2, and the dotted line U in FIG. Here, the wall surface 18d1 is a wall positioned on the downstream side of the recess portion 18d in the rotation direction of the stirring member 23, and the wall surface 18d2 is a wall positioned on the upstream side of the recess portion 18d in the rotation direction of the stirring member 23. Further, in a posture in which the image forming apparatus 100 is normally used, the concave portion 18d is positioned below the release position 18e in the vertical direction. The rotation center axis of the developing roller 17 is located above the release position 18e, and the release position 18e is located above the rotation center axis of the stirring member 23.

The angle formed by the wall surface 18d1 and the wall surface 18d2 is equal to or greater than the angle (rest angle) at which the toner that has entered the recess falls under its own weight. That is, the recess 18d has such a shape that the toner that has entered the recess 18d falls by its own weight onto the bottom 18f of the toner storage chamber 18a as a storage chamber. Specifically, in a posture in which the image forming apparatus 100 is normally used, and in a posture in which the developing unit 4 as a developing device is mounted on the image forming apparatus 100, the toner that has entered the recess 18d is in the toner storage chamber 18a. The bottom part 18f is shaped to fall by its own weight. Further, in the toner storage chamber 18a, the recess 18d is located upstream of the opening 18c and the release position 18e in the rotation direction of the stirring member 23. Further, the concave portion 18d is located downstream of the bottom portion 18f in the rotation direction of the stirring member 23. Further, as shown in FIG. 1, a conveyance regulating surface 18g is provided on the inner wall surface of the toner storage chamber 18a. When the distance from the rotating shaft 23a of the stirring member 23 to the conveyance regulating surface 18g is W2, and the distance from the end portion of the stirring sheet 23b that extends straight to the rotating shaft 23a is W0, in this embodiment, W2 <W0. ing.

<Toner transport in recess>
In the present embodiment, as shown in FIG. 12, a conveyance support member 19 as a conveyance auxiliary member that protrudes into the rotation region X of the stirring member 23 is provided on the downstream side of the recess 18 d in the rotation direction of the stirring member 23. Yes. The conveyance support member 19 has a sheet shape and assists the conveyance of the toner. In this embodiment, the conveyance support member 19 is a flexible sheet member. Further, as shown in FIG. 1, in the process in which the end portion of the stirring sheet 23 b passes through the recess 18 d, the transport support member 19 is arranged so that the stirring sheet 23 b contacts the transport support member 19 and the transport regulation surface 18 g at the same time. Has been placed. The conveyance support member 19 covers a part of the recess 18d. Here, FIG. 11 shows a state in which the recess 18d is completely covered with the covering member V for reference.

  Moreover, in the conveyance support member 19 as a conveyance auxiliary member, the edge part of the part which covers a part of recessed part 18d is the free end 19a. The free end 19a of the transport support member 19 is positioned above the rotation center axis of the stirring sheet 23b in a posture in which the image forming apparatus 100 is normally used. Further, the free end 19a of the transport support member 19 is further away from the developing roller 17 than the position 19b where the transport support member 19 is fixed to the inner wall surface of the toner storage chamber 18a serving as a storage chamber. The transport support member 19 extends in the longitudinal direction of the developing unit 4 as a developing device and has a long side in the longitudinal direction of the developing unit 4. Here, the longitudinal direction of the developing unit 4 is a direction in which the rotating shaft of the stirring member 23 extends and the direction in which the developing roller 17 extends as shown in FIG.

  As a result, the conveyance supporting member 19 as the conveyance auxiliary member prevents the toner on the stirring sheet 23b from dropping from the gap between the rotating stirring sheet 23b and the concave portion 18d. The gap with is closed. The toner on the stirring sheet 23b is supported by the inner wall surface of the toner storage chamber 18a, the stirring sheet 23b, and the conveyance support member 19, so that the gap between the stirring sheet 23b and the recess 18d is closed.

  Here, the manner in which the toner in the toner storage chamber 18a provided with the transport support member 19 is transported will be described with reference to FIG. First, as shown in FIG. 6A, when the stirring member 23 rotates, the stirring sheet 23b starts to push the upper side of the toner accumulated in the toner storage chamber 18a. Next, as shown in FIG. 6B, after the stirring sheet 23b passes through the bottom 18f of the toner storage chamber 18a, the stirring sheet 23b moves the toner upward while the stirring sheet 23b and the conveyance regulating surface 18g are in contact with each other. Lift to.

  Thereafter, as shown in FIG. 6C, a part of the stirring sheet 23 b comes into contact with the conveyance support member 19 as a conveyance auxiliary member. At this time, a part of the leading end side of the stirring sheet 23b also contacts the conveyance regulating surface 18g. That is, the stirring sheet 23b is in contact with the conveyance regulating surface 18g and the conveyance support member 19 simultaneously. Next, as shown in FIG. 6D, the stirring sheet 23b rotates to cause the stirring sheet 23b and the conveyance support member 19 to slide, and then the stirring sheet 23b further rotates to rotate the stirring sheet. 23b leaves | separates from the conveyance control surface 18g.

That is, the state is such that “the stirring sheet 23b contacts only the conveyance regulating surface 18g → the stirring sheet 23b contacts the conveyance regulating surface 18g and the conveyance supporting member 19 simultaneously → the stirring sheet 23b contacts only the conveyance supporting member 19”. It will change. When the end of the stirring sheet 23b passes through the recess 18d, the conveyance support member 19 in which the gap between the recess 18d and the stirring sheet 23b protrudes prevents the toner from dropping from the gap between the recess 18d and the stirring sheet 23b. It is. Therefore, a sufficient amount of toner can be stably conveyed from the stirring sheet 23b to the developing chamber 18b. Then, as shown in FIG. 6E, when the end of the stirring sheet 23b passes through the release position 18e, the stirring sheet 23b is restored from the elastically deformed state, and the toner on the stirring sheet 23b enters the opening 18c. You can jump up.

  Here, when the conveyance supporting member 19 receives a force from the stirring sheet 23b in the direction of arrow P in FIG. There is. Therefore, as shown in FIG. 7B, when the stirring sheet 23b comes into contact with the transport support member 19, it is preferable that the transport support member 19 receives a force from the stir sheet 23b in the direction toward the recess 18d (arrow Q). .

  As described above, by providing the conveyance support member 19 in the vicinity of the concave portion 18d, the stirring sheet 23b is moved between the conveyance regulating surface 18g and the conveyance support member 19 in the process in which the end of the agitation sheet 23b reaches the release position 18e. At least one of them must be in contact with one. Therefore, a stable amount of toner can be supplied from the toner storage chamber 18a serving as a storage chamber to the developing chamber 18b without generating a gap N (see FIG. 9) between the stirring sheet 23b and the recess 18d. .

As described above, in the embodiment, the stirring sheet 23b simultaneously contacts the inner wall surface of the toner storage chamber 18a and the conveyance support member 19 in the process in which the stirring sheet 23b passes through the recess 18d. Thereby, it is possible to prevent the toner on the stirring sheet 23b from dropping from the gap between the stirring sheet 23b and the recess 18d.
In the embodiment, when the agitation sheet 23b contacts the conveyance support member 19, the conveyance support member 19 is applied with force from the agitation sheet 23b in the direction toward the recess 18d. Thereby, it can suppress that the conveyance support member 19 turns up by contacting with the stirring sheet 23b, and can suppress that the toner mounted on the stirring sheet 23b falls.

  In each embodiment, the agitating member 23 agitates the toner in the toner storage chamber 18a and conveys it to the developing chamber 18b. However, it is not necessarily limited to this. For example, the member that transports the toner in the toner storage chamber 18a to the developing chamber 18b may not have the function of stirring the toner in the toner storage chamber 18a.

4 ... developing unit, 17 ... developing roller, 18a ... toner storage chamber, 18b ... developing chamber,
18c ... opening, 18d ... concave, 18f ... bottom, 19 ... conveyance support member, 23 ... stirring member

Claims (15)

A developer carrying member carrying the developer;
A developing chamber having the developer carrier;
A storage chamber having an opening and a recess, located below the developing chamber, and storing a developer;
A conveying member that conveys the developer from the accommodating chamber to the developing chamber via the opening by using a force that is elastically deformed by contacting the inner wall surface of the accommodating chamber and restoring from the elastically deformed state; ,
A conveyance auxiliary member that is provided on the downstream side of the concave portion in the rotation direction of the conveyance member, protrudes to the upstream side in the rotation direction, and assists the conveyance of the developer,
In the rotation direction of the transport member, the recess is located downstream from the bottom of the storage chamber and is located upstream from the opening.
The developing device, wherein the transport member simultaneously contacts the inner wall surface of the storage chamber and the transport auxiliary member in a process in which the transport member passes through the recess.   The developer is supported on the inner wall surface of the storage chamber, the transport member, and the transport auxiliary member, so that a gap between the transport member and the recess is closed. Item 2. The developing device according to Item 1. The transport member includes a rotation shaft and a sheet member that rotates about the rotation shaft,
When the sheet member comes into contact with the inner wall surface of the storage chamber and the sheet member is deformed, a restoring force for conveying the developer to the developing chamber is given to the conveying member,
One end of the sheet member is attached to the rotating shaft,
The contact state between the other end of the sheet member and the inner wall surface of the storage chamber is released, and the force applied to the transport member from the inner wall surface is released, so that the restoring force applied to the transport member is The developing device according to claim 1, wherein a developer is conveyed to the developing chamber.   The concave portion is located below a release position where the other end and the inner wall surface are in contact with each other when the contact state between the other end and the inner wall surface is released. The developing device according to claim 3.   5. The developing device according to claim 1, wherein the conveyance auxiliary member has a sheet shape and covers a part of the concave portion. In the sheet-like conveyance auxiliary member, an end portion of a portion covering a part of the concave portion is a free end,
The developing device according to claim 5, wherein the free end of the conveyance auxiliary member is located above a rotation center axis of the conveyance member. In the sheet-like conveyance auxiliary member, an end portion of a portion covering a part of the concave portion is a free end,
The developing device according to claim 5, wherein the free end of the conveyance auxiliary member is farther from the developer carrying member than a position where the conveyance auxiliary member is fixed to an inner wall surface of the storage chamber. .   The developing device according to claim 1, wherein the conveyance auxiliary member is in a sheet shape and extends in a longitudinal direction of the developing device. The developing device according to claim 1, further comprising a supply member that supplies the developer in the developing chamber to the developer carrying member. The transport member includes a rotation shaft and a sheet member that rotates about the rotation shaft,
When the sheet member comes into contact with the inner wall surface of the storage chamber and the sheet member is deformed, a restoring force for conveying the developer to the developing chamber is given to the conveying member,
One end of the sheet member is attached to the rotating shaft,
The contact state between the other end of the sheet member and the inner wall surface of the storage chamber is released, and the force applied to the transport member from the inner wall surface is released, so that the restoring force applied to the transport member is Developer is conveyed to the development chamber,
In the vertical direction,
The rotation center axis of the developer carrying member is above a release position where the other end and the inner wall surface are in contact with each other at a timing when the contact state between the other end and the inner wall surface is released. Located
The developing device according to claim 1, wherein the release position is located above a rotation center axis of the transport member.   The developing device according to claim 1, wherein the conveyance assisting member has flexibility.   The force from the said conveyance member is given to the said conveyance auxiliary member in the direction which goes to the said recessed part when the said conveyance member contacts the said conveyance auxiliary member, The any one of Claim 1 to 11 characterized by the above-mentioned. The developing device according to 1.   13. The developing device according to claim 1, wherein the concave portion is shaped such that the developer that has entered the concave portion falls by its own weight onto the bottom of the storage chamber. . A developing device according to any one of claims 1 to 13,
An image carrier,
A process cartridge which is detachable from an image forming apparatus. It has at least one of the development device according to any one of claims 1 to 13, or the process cartridge according to claim 14,
An image forming apparatus, wherein an image is formed on a recording medium using a developer.

Images