JP2017211464A - Developing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent aggregation of developer inside a developer storage part by stirring and conveying the developer inside the developer storage part such that the developer is not pressed against a wall surface.SOLUTION: A developing device 105 comprises: a developer storage part 1 that stores a toner 6; and a stirring member 5d that is provided inside the developer storage part 1 rotatably on a rotation shaft 5c, and includes a stirring surface 20 extending along the rotational direction to stir the toner 6 and having an inclination in a direction to approach an inner wall 200 of the developer storage part 1 in the rotational direction.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a developing device that supplies a developer conveyed from a developer container to an image carrier, and an image forming apparatus such as a copying machine, a printer, or a facsimile that employs an electrophotographic system equipped with the developing device.

  In an image forming apparatus such as a copying machine, a printer, or a facsimile machine, when the developer accumulates locally in the developing device, the degree of deterioration of the developer in the developing device becomes non-uniform, resulting in image defects such as density reduction or fogging. May occur. Therefore, in the image forming apparatus, it is necessary to circulate by stirring and conveying the developer in the developing device so that the developer does not accumulate locally in the developing device.

  Patent Document 1 proposes an image forming apparatus having a mixed stirring structure. Specifically, Patent Document 1 discloses a stirring unit that is arranged in parallel with a rotation axis at a predetermined interval and rotates around the rotation axis, and is arranged along the stirring unit and rotates together with the stirring unit. An image forming apparatus including a blade portion for stirring and conveying powder is proposed. The blade portion includes an outer diameter side flat surface portion having a function of extruding powder in the outer diameter direction.

  The powder that collides with the outer diameter side flat surface portion is rebounded by the outer diameter side flat surface portion, and is pushed out of the rotation region with the rotation of the mixing and stirring structure. As a result, according to the image forming apparatus of Patent Document 1, a toner circulation region can be formed in a region larger than the outside of the rotation region of the mixing and stirring structure, and the developer can be prevented from accumulating locally.

JP 2012-032617 A

  However, in Patent Document 1, there is a problem that the developer pushed out of the rotation region is pushed in the wall surface direction and is pressed against the wall surface to be aggregated.

  An object of the present invention is to provide a developing device and an image forming apparatus capable of preventing aggregation of the developer in the developer accommodating portion by stirring and transporting the developer in the developer accommodating portion without pressing against the wall surface. Is to provide.

  A developing device according to the present invention is a developing device that supplies a developer conveyed from a developer container to an image carrier, and includes a developer container that contains the developer, and an inside of the developer container. A stirring member that is rotatably provided about a rotation axis and includes a stirring surface that extends along the rotation direction and stirs the developer, and the stirring surface contains the developer in the rotation direction. It has the inclination of the direction which approaches the inner wall of a part, It is characterized by the above-mentioned.

  An image forming apparatus according to the present invention includes an image carrier on which an electrostatic latent image is formed, and the developing device that supplies a developer to the electrostatic latent image.

  According to the present invention, agglomeration of the developer in the developer accommodating portion can be prevented by stirring and transporting the developer in the developer accommodating portion without being pressed against the wall surface.

1 is a cross-sectional view of an image forming apparatus according to Embodiment 1 of the present invention. It is sectional drawing of the developing device which concerns on Embodiment 1 of this invention. It is a top view of the stirring chamber stirring conveyance member which concerns on Embodiment 1 of this invention. It is a front view of the stirring chamber stirring conveyance member which concerns on Embodiment 1 of this invention. It is an expanded sectional view of the principal part of the developing device concerning Embodiment 1 of the present invention. It is a comparison figure with the past of the aggregation degree of the developer in the developer accommodating part which concerns on Embodiment 1 of this invention. It is a top view of the stirring chamber stirring conveyance member which concerns on Embodiment 2 of this invention. It is a front view of the stirring chamber stirring conveyance member which concerns on Embodiment 2 of this invention. It is an expanded sectional view of the principal part of the developing device which concerns on Embodiment 2 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
<Configuration of image forming apparatus>
The configuration of the image forming apparatus A according to Embodiment 1 of the present invention will be described with reference to FIG. Here, the image forming apparatus A exemplifies a copying machine, a printer, a facsimile, or the like adopting an electrophotographic system.

  The image forming apparatus A includes a charging high-voltage power supply 101, a charging roller 102, an image carrier 103, an exposure unit 104, a developing device 105, a transfer roller 108, a cleaning blade 109, and a collected toner storage space 110. And a fixing unit 112.

  The charging high-voltage power supply 101 applies a predetermined voltage to the charging roller 102.

  The charging roller 102 is discharged when a voltage is applied from the charging high-voltage power supply 101, and charges the image carrier 103 to a predetermined potential.

  The image carrier 103 is charged by the discharge of the charging roller 102. The image carrier 103 is exposed by the exposure unit 104 to form an electrostatic latent image.

  The exposure unit 104 exposes a predetermined area on the image carrier 103 and forms an electrostatic latent image on the image carrier 103 by reducing the potential of the predetermined area.

  The developing device 105 includes a developing roller 2. The developing device 105 charges the charged toner uniformly placed on the developing roller 2 by the action of the electric field generated by the difference between the lowered potential of a predetermined area of the image carrier 103 and the potential applied to the developing roller 2. Is supplied to the electrostatic latent image formed on the image carrier 103.

  The transfer roller 108 transfers the toner adhering to the image carrier 103 to a recording material such as a recording sheet conveyed to a predetermined transfer area along the pre-transfer guide 107.

  The cleaning blade 109 scrapes off the toner remaining on the image carrier 103 without being transferred from the image carrier 103 to the recording material, and drops it in the collected toner storage space 110.

  The collected toner storage space 110 collects the toner scraped off by the cleaning blade 109.

  The fixing unit 112 heats the unfixed toner transferred to the recording material conveyed along the fixing nip entrance guide 111 to fix the recording material, and discharges the recording material on which the toner is fixed.

<Configuration of developing device>
The configuration of the developing device 105 according to Embodiment 1 of the present invention will be described with reference to FIG.

  The developing device 105 includes a developer container 1, a developing roller 2, a developer regulating member 3, a developing chamber stirring member 4, a stirring chamber stirring and conveying member 5, a developer detecting member 7, and a toner bottle 10. And a bottle stirring and conveying member 11.

  The developer accommodating portion 1 is a container that accommodates the developer, and is divided into a stirring chamber 1 a and a developing chamber 1 b by a partition wall 8.

  The developing roller 2 is provided in the developer container 1. The developing roller 2 includes a magnet for attracting and transporting the toner 6 as a developer. The developing roller 2 attracts and transports the toner 6 in the developing chamber 1 b of the developer container 1 to the image carrier 103.

  The developer regulating member 3 charges the toner 6 and contacts the developing roller 2 to regulate the thickness of the toner 6 on the surface of the developing roller 2.

  The developing chamber stirring member 4 is rotatably arranged in the developing chamber 1b. The developing chamber agitating member 4 agitates the toner 6 in the developing chamber 1 b by rotating and conveys it to the developing roller 2.

  The stirring chamber stirring and conveying member 5 is rotatably disposed in the stirring chamber 1a. The agitating chamber agitating and conveying member 5 rotates to agitate the toner 6 in the agitating chamber 1a and convey it to the developing chamber 1b. The details of the configuration of the stirring chamber stirring and conveying member 5 will be described later.

  The developer detection member 7 outputs a voltage corresponding to the magnetic permeability of the magnetic material contained in the toner 6 in the detectable region as a detection result of the remaining amount of toner 6 in the developer storage unit 1. Here, the developer detection member 7 is exemplified by a magnetic permeability sensor.

  The toner bottle 10 as a developer container is a toner cartridge configured to be detachable from the developer container 1. The toner bottle 10 is filled with toner 6 of magnetic one component. The toner bottle 10 includes a toner supply port 12 for supplying the filled toner 6 to the developer storage unit 1. The toner bottle 10 is provided in the developer container 1 so that the toner replenishing port 12 is horizontal with the developer container 1.

  The bottle stirring and conveying member 11 is provided inside the toner bottle 10. The bottle agitating / conveying member 11 includes a rotating shaft 11b provided at the center position of the cylindrical toner bottle 10 and a sheet member 11c. The bottle agitation transport member 11 rotates around the rotation shaft 11b to supply the toner 6 in the toner bottle 10 from the toner supply port 12 to the agitation chamber 1a.

<Configuration of stirring chamber stirring and conveying member>
The configuration of the stirring chamber stirring and conveying member 5 according to the first embodiment of the present invention will be described with reference to FIGS.

  The stirring chamber stirring and conveying member 5 includes a rotating shaft 5c, a stirring member 5d, a sheet member 5e, and a sheet member 5f.

  The rotating shaft 5c serves as a rotation center when the stirring chamber stirring and conveying member 5 rotates.

  As shown in FIGS. 3 and 4, the agitating member 5 d is provided inside the developer accommodating portion 1 so as to be rotatable along the inner wall 200 of the developer accommodating portion 1 around the rotation shaft 5 c. A plurality of stirring members 5d are provided along the axial direction of the rotating shaft 5c, and the same number is provided on both sides of the center of the rotating shaft 5c in the axial direction. Each of the plurality of stirring members 5d has the same shape. Here, a case where five stirring members 5d are provided on both sides of the center in the axial direction of the rotating shaft 5c is illustrated. The material of the stirring member 5d is exemplified here by ABS (acrylonitrile / butadiene / styrene copolymer).

  As shown in FIG. 5, the stirring member 5d is provided with a stirring surface 20 that extends along the rotation direction R1 of the stirring member 5d to stir the toner 6 and faces the rotation shaft 5c. The stirring surface 20 has an inclination in a direction approaching the inner wall 200 of the developer accommodating portion 1 in the rotation direction R1 of the stirring member 5d. Among the angles formed with the inner wall 200 of the developer container 1, the stirring surface 20 has an obtuse angle θ on the rotation direction side of the stirring chamber stirring and conveying member 5 formed inside the developer container 1. It is configured. Here, the angle θ formed by the stirring surface 20 and the inner wall 200 is exemplified as 170 °.

  As shown in FIG. 5, the stirring member 5 d includes an outer edge portion 21 that curves in an arc shape along the rotation shaft 5 c when viewed from the axial direction of the rotation shaft 5 c and faces the inner wall 200. In the stirring member 5d, the distance a from the center of the rotation shaft 5c to the outer edge portion 21 on the rotation direction side is longer than the distance b from the center of the rotation shaft 5c to the outer edge portion 21 on the opposite direction side of the rotation direction (a> b). ). The distance a is exemplified here as 25 mm. The distance b is exemplified here as 22 mm.

  The sheet member 5e has a sheet shape, is formed along the axial direction of the rotation shaft 5c, extends from the rotation shaft 5c toward the inner wall 200, and rotates around the rotation shaft 5c. The sheet member 5 e is provided with a conveyance surface 30 for conveying the toner 6. The transport surface 30 includes a plurality of developer transport units 31 and a plurality of developer transport units 32 that transport the toner 6 along the axial direction of the rotation shaft 5c. Here, the material of the sheet member 5e is exemplified by PPS (polyphenylene sulfide).

  The developer transport section 31 that is the first transport section is disposed closer to the rotating shaft 5 c than the developer transport section 32. The developer transport part 31 has a shape that gradually tapers from the base end part 31a to the top part 31b. Each of the plurality of developer transport portions 31 is formed to gradually taper in the same direction (right direction in FIG. 4). Each of the plurality of developer transport portions 31 is formed such that the top portion 31b is located on the same straight line parallel to the rotation shaft 5c. The developer transport unit 31 transports the toner 6 from one end side to the other end side in the axial direction of the rotating shaft 5c.

  The developer transport section 32 as the second transport section has a shape that gradually tapers from the base end portion 32a to the top portion 32b. Each of the plurality of developer transport portions 32 is formed to gradually taper in the same direction (left direction in FIG. 4). Each of the plurality of developer transport portions 32 is formed such that the top portion 32b is located on the same straight line parallel to the rotation shaft 5c. The developer transport section 32 transports the toner 6 from the other end side in the axial direction of the rotating shaft 5c to one end side. The conveyance direction of the toner 6 by the developer conveyance unit 31 and the conveyance direction of the toner 6 by the developer conveyance unit 32 are parallel to the axial direction of the rotating shaft 5c and are opposite to each other.

  The sheet member 5f has a sheet shape, is formed along the axial direction of the rotation shaft 5c, extends from the rotation shaft 5c toward the inner wall 200, and rotates around the rotation shaft 5c. The sheet member 5 f is provided with a conveyance surface 30 for conveying the toner 6. The transport surface 30 includes a plurality of developer transport units 33 and a plurality of developer transport units 34 that transport the toner 6 along the axial direction of the rotation shaft 5c. Here, the material of the sheet member 5f is exemplified by PPS (polyphenylene sulfide).

  The developer transport unit 33 as the second transport unit is disposed closer to the rotating shaft 5 c than the developer transport unit 34. The developer transport part 33 has a shape that gradually tapers from the base end part 33a to the top part 33b. Each of the plurality of developer transport portions 33 is formed to gradually taper in the same direction (left direction in FIG. 4). Each of the plurality of developer transport portions 33 is formed such that the top portion 33b is positioned on the same straight line parallel to the rotation shaft 5c. The developer transport unit 33 transports the toner 6 from the other end side in the axial direction of the rotating shaft 5c to one end side.

  The developer conveying portion 34 as the first conveying portion has a shape that gradually tapers from the base end portion 34a to the top portion 34b. Each of the plurality of developer transport portions 34 is formed so as to gradually taper in the same direction (right direction in FIG. 4). Each of the plurality of developer conveying portions 34 is formed such that the top portion 34b is located on the same straight line parallel to the rotation shaft 5c. The developer transport unit 34 transports the toner 6 from one end side to the other end side in the axial direction of the rotating shaft 5c. The direction of toner 6 transported by the developer transport unit 34 and the direction of toner 6 transported by the developer transport unit 33 are parallel to the axial direction of the rotating shaft 5c and are opposite to each other.

<Operation of developing device>
The operation of the developing device 105 according to Embodiment 1 of the present invention will be described.

  The toner 6 replenished from the toner bottle 10 to the developer accommodating portion 1 is agitated by the agitating chamber agitating and conveying member 5 in the agitating chamber 1a, conveyed, and supplied to the developing chamber 1b. The toner 6 supplied to the developing chamber 1 b is stirred and conveyed by the developing chamber stirring member 4 and supplied to the developing roller 2.

  The toner 6 supplied to the developing roller 2 is transported to a developing region facing the image carrier 103 while the layer thickness of the toner 6 is regulated by the developer regulating member 3 by the rotation of the developing roller 2. At this time, the toner 6 supplied to the developing roller 2 flies from the developing roller 2 to the image carrier 103 when a developing bias in which a DC voltage and an AC voltage are superimposed is applied to the developing roller 2. As a result, the electrostatic latent image on the image carrier 103 is developed as a toner image.

  The developer container 1 is always supplied with the toner 6 from the toner bottle 10 until the toner bottle 10 runs out of toner 6. The image forming apparatus A determines that the toner is “present” when the voltage output from the developer detection member 7 exceeds the reference voltage.

  In this state, the toner 6 is consumed by continuing image formation and is no longer supplied from the toner bottle 10 to the agitation chamber 1a when the toner 6 disappears in the toner bottle 10. When the remaining amount of the toner 6 in the stirring chamber 1a becomes equal to or less than a predetermined amount, the image forming apparatus A determines that the voltage output from the developer detecting member 7 is equal to or lower than the reference voltage and the toner is “None”. The replacement of the toner bottle 10 is notified.

<Operation of stirring chamber stirring and conveying member>
Operation | movement of the stirring chamber stirring conveyance member 5 which concerns on Embodiment 1 of this invention is demonstrated.

  The stirring member 5d rotates from the vicinity of the toner supply port 12 to the vicinity of the toner supply port 12 through the lower portion of the stirring chamber 1a, the vicinity of the developing chamber 1b, and the upper portion of the stirring chamber 1a. Thereby, the stirring member 5d stirs the toner 6 in the stirring chamber 1a from the outer peripheral side toward the rotation shaft 5c in the radial direction in the rotation region of the stirring member 5d.

  Further, as shown in FIG. 5, the stirring chamber agitating and conveying member 5 is rotated by having the agitating member 5 d provided with the agitating surface 20 having an inclination approaching the inner wall 200 of the developer accommodating portion 1 in the rotation direction R <b> 1. Accordingly, the toner 6 stored in the stirring chamber 1a is conveyed in a direction away from the inner wall 200. Thus, the stirring member 5d can prevent the toner 6 from aggregating by not pressing the toner 6 in the stirring chamber 1a against the inner wall 200, and can stir the toner 6 so as to be more uniform. it can.

  Further, by configuring the stirring surface 20 so that the angle θ formed by the stirring surface 20 and the inner wall 200 becomes an obtuse angle, the toner 6 stored in the stirring chamber 1a is caused to rotate as the stirring chamber stirring and conveying member 5 rotates. It conveys in the direction away from the inner wall 200. Thus, the stirring member 5d can prevent the toner 6 from aggregating by not pressing the toner 6 in the stirring chamber 1a against the inner wall 200, and can stir the toner 6 so as to be more uniform. it can.

  Furthermore, since the stirring member 5d has a configuration in which a> b, as illustrated in FIG. 2, the rotation locus (S1) on the rotation direction R1 side of the stirring chamber stirring and conveying member 5 is Outside the rotation locus (S2) on the opposite side of the rotation direction R1. That is, the rotation locus S1 is further away from the rotation shaft 5c than the rotation locus S2. Accordingly, the agitating chamber agitating and conveying member 5 conveys the toner 6 in the agitating chamber 1a so as to scoop up with the rotation in the rotation direction R1, and agitates the toner 6 from the outside to the inside of the rotation radius. Thus, the stirring member 5d can prevent the toner 6 from aggregating by not pressing the toner 6 in the stirring chamber 1a against the inner wall 200, and can stir the toner 6 so as to be more uniform. it can.

  The sheet member 5e and the sheet member 5f agitate and convey the toner 6 stored in the agitating chamber 1a as the agitating chamber agitating and conveying member 5 rotates. Thus, the stirring chamber agitating and conveying member 5 stirs and conveys the toner 6 by the sheet member 5e and the sheet member 5f in addition to the agitating member 5d, thereby preventing the toner 6 from staying in the agitating chamber 1a and uniformly. The toner 6 can be stirred so that

  Further, the developer transport unit 31 and the developer transport unit 32 provided on the sheet member 5e form respective toner transport paths on the transport surface 30 as the stirring chamber agitating and transporting member 5 rotates, and the toner 6 is supplied. Transport in opposite directions. The toner 6 conveyed from the one end side to the other end side in the axial direction of the rotating shaft 5c along the conveying surface 30 by the developer conveying portion 31 is transferred to the axis of the rotating shaft 5c along the conveying surface 30 by the developer conveying portion 32. It circulates by being conveyed from the other end side in the direction to the one end side. This prevents the toner 6 from staying in the stirring chamber 1a and allows the toner 6 to be stirred so as to be more uniform.

  Further, the developer transport unit 33 and the developer transport unit 34 provided on the sheet member 5f form respective toner transport paths on the transport surface 30 in accordance with the rotation of the stirring chamber stirring transport member 5, and the toner 6 is supplied. Transport in opposite directions. The toner 6 conveyed from the other end side in the axial direction of the rotating shaft 5c along the conveying surface 30 by the developer conveying unit 33 to the one end side is transferred to the axis of the rotating shaft 5c along the conveying surface 30 by the developer conveying unit 34. It circulates by being conveyed from one end side in the direction to the other end side. This prevents the toner 6 from staying in the stirring chamber 1a and allows the toner 6 to be stirred so as to be more uniform.

  In FIG. 6, 200 g of toner 6 is filled in the developer container 1, the rotation speed of the stirring chamber stirring and conveying member 5 is set to 100.57 rpm, and the idle rotation for 12 hours without consuming the toner 6 is N2 and N2. It shows the result of carrying out twice and measuring the degree of aggregation.

  From FIG. 6, it was confirmed that the present embodiment provided with the stirring member 5d has an effect of preventing the aggregation of the toner 6 compared to the conventional case where the stirring chamber stirring and conveying member 5 is not provided with the stirring member 5d. . In the above-described embodiment, the configuration in which the stirring chamber stirring and conveying member 5 is rotatably disposed in the developer accommodating portion 1 has been described. However, the same effect can be obtained in a configuration in which the stirring chamber is transported by stirring horizontally. it can.

  As described above, according to the present embodiment, by providing the stirring surface 20 having an inclination in the direction of approaching the inner wall 200 of the developer containing portion 1 in the rotation direction of the stirring member 5d, the inside of the developer containing portion 1 is provided. Since the toner 6 is agitated and conveyed without being pressed against the inner wall 200, the aggregation of the toner 6 in the developer accommodating portion 1 can be prevented.

(Embodiment 2)
The image forming apparatus according to Embodiment 2 of the present invention has the same configuration as that shown in FIG. Further, the configuration of the developing device excluding the stirring chamber stirring and conveying member according to the present embodiment is the same as that shown in FIG.

<Configuration of stirring chamber stirring and conveying member>
The configuration of the stirring chamber stirring and conveying member 15 according to the second embodiment of the present invention will be described with reference to FIGS.

  8 and 9, the same reference numerals are given to portions having the same configurations as those in FIGS. 3 to 5, and description thereof is omitted.

  The stirring chamber stirring and conveying member 15 includes a rotating shaft 5c, a sheet member 5e, a sheet member 5f, and a stirring member 15d.

  The stirring member 15d is provided with a protrusion 22 that protrudes from the tip of the stirring chamber stirring and conveying member 5 in the rotation direction. A surface 22a that intersects with the rotation direction of the stirring chamber stirring and conveying member 5 provided at the tip of the protruding portion 22 in the rotating direction of the stirring chamber stirring and conveying member 5 is configured not to be orthogonal to the rotating direction of the stirring chamber stirring and conveying member 5. Yes. As a result, the protrusion 22 can invade the toner 6 stored in the stirring chamber 5a without causing stress and stir the toner 6 as the stirring chamber stirring and conveying member 5 rotates. In addition, since the structure except the above in the stirring chamber stirring conveyance member 15 is the same structure as the structure of the stirring chamber stirring conveyance member 5, the description is abbreviate | omitted.

  The operation of the agitating chamber agitating and conveying member 15 is the same as that of the agitating chamber agitating and conveying member 5 of the first embodiment, and a description thereof will be omitted.

  In the first embodiment and the second embodiment, the stirring member 5d is configured to be supported by the support shaft on the rotating shaft 5c. However, the present invention is not limited to this, and is supported at both ends of the rotating shaft, for example. It goes without saying that the same effect can be obtained with the configuration.

  In the first and second embodiments, the stirring member 5d is configured to satisfy a> b. However, the stirring member may be configured to satisfy a = b.

A image forming apparatus 1 developer accommodating portion 1a stirring chamber 1b developing chamber 2 developing roller 3 developer regulating member 4 developing chamber stirring member 5 stirring chamber stirring conveying member 5c rotating shaft 5d stirring member 5e sheet member 6 toner 7 developer detecting member 8 Bulkhead 10 Toner bottle 11 Bottle stirring and conveying member 11b Rotating shaft 11c Sheet member 12 Toner replenishing port 15 Stirring chamber stirring and conveying member 15d Stirring member 20 Stirring surface 21 Outer edge portion 22 Projection portion 22a Surface 30 Conveying surface 31 Developer conveying portion 32 Developer Agent conveying unit 101 High-voltage power supply for charging 102 Charging roller 103 Photosensitive drum 104 Exposure unit 105 Developing device 107 Pre-transfer guide 108 Transfer roller 109 Cleaning blade 110 Collected toner storage space 111 Fixing nip inlet guide 112 Fixing unit 200 Inner wall

Claims (6)

A developing device for supplying a developer conveyed from a developer container to an image carrier,
A developer accommodating portion for accommodating the developer;
An agitation member including an agitation surface provided in the developer accommodating portion so as to be rotatable about a rotation axis and extending along the rotation direction to agitate the developer;
Have
The stirring surface is
A developing device having an inclination in a direction approaching an inner wall of the developer accommodating portion in the rotation direction. The stirring member is
A protrusion projecting in the rotational direction;
The protrusion is
A surface intersecting with the rotation direction provided at a tip of the rotation direction is not orthogonal to the rotation direction;
The developing device according to claim 1. The stirring member is
An outer edge portion that curves in an arc shape along the rotation axis when viewed from the axial direction of the rotation shaft and faces the inner wall, and a distance from the center of the rotation shaft to the outer edge portion on the rotation direction side is Longer than the distance from the center of the rotation axis to the outer edge on the opposite side of the rotation direction,
3. The developing device according to claim 1, wherein A sheet-like sheet member extending from the rotating shaft toward the inner wall and rotating around the rotating shaft;
The developing device according to any one of claims 1 to 3, wherein the developing device is any one of the above. The sheet member is
A plurality of first conveying units provided along the axial direction of the rotating shaft, and conveying the developer from one end side to the other end side in the axial direction;
A plurality of second conveying sections provided along the axial direction, for conveying the developer from the other end side to the one end side;
The developing device according to claim 4, further comprising: An image carrier on which an electrostatic latent image is formed;
The developing device according to any one of claims 1 to 5, wherein a developer is supplied to the electrostatic latent image.
An image forming apparatus comprising:

Images