JP2002328530A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the torque rise of a developer draw-up means and the deterioration of developer by preventing the developer from entering the bearing part of the developer draw-up means. SOLUTION: This developing device is equipped with a developer supply means 146 for supplying the developer to a photoreceptor drum 28, a 1st stirring means 68 for stirring and carrying the developer, a 2nd stirring means 70 provided below the 1st stirring means 68, and the developer draw-up means 82 for drawing up the developer from the 2nd stirring means 70 to the 1st stirring means 68. In the device, a rotating body 83 having a magnet 85 is disposed on the outside of a housing 144 (side wall 134) as the developer draw-up means 82. By rotating the rotating body 83 so that the magnet 85 is rotated and moved from the 2nd stirring means 70 to the 1st stirring means 68, the developer in the housing 144 is drawn up from the 2nd stirring means 70 to the 1st stirring means 68 by the magnetic force of the magnet 85 at such a time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for supplying a developer to a surface of a photoreceptor drum on which an electrostatic latent image is formed to perform development, and an image forming apparatus having the same.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, a developing device using a two-component developer composed of a toner and a carrier to develop an electrostatic latent image formed on a photosensitive drum. However, the developing device using the two-component developer mixes the toner and the carrier and frictionally mixes the toner and the carrier in order to start the charging of the replenishment toner and make the toner concentration distribution in the developing device uniform. A developer agitating means for charging and transporting the developer in a required direction is provided.

As such a developing device, for example, there is a developing device described in JP-A-10-142942. The developing device includes a first stirring and conveying means for stirring and conveying the developer in a first direction, and a first stirring and conveying means provided below the first stirring means and receiving the developer from the first stirring and conveying means.
Second stirring and conveying means for stirring and conveying in a direction opposite to the direction of, a developer supply means for supplying the developer supplied from the second stirring and conveying means to the photoconductor, and conveyance by the second stirring and conveying means. And a developer pumping means (feeding means) for pumping the developer to the first stirring means by magnetic force.

[0004]

However, according to the above-described developing device, the developer pumping means transfers the developer to the second device.
When the developer is conveyed from the stirring and conveying means to the first stirring means, the developer and the developer pumping means come into direct contact with each other and pump the developer to the first stirring means. May enter. When the developer enters the bearing portion of the developer pumping means, there arises a problem that the torque for rotationally driving the developer pumping means increases and the developer deteriorates.

Further, in the above-mentioned developing device, since the developer pumping means consisting of a roller rotating body is arranged beside the first stirring means and the second stirring means, the first stirring means and the second stirring means are disposed. There is a problem that a large space is required in a direction orthogonal to the rotation axis direction (longitudinal direction) of the stirring means 2, and the size of the developing device is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. When the developer is conveyed from the second stirring and conveying means to the first stirring means by the developer pumping means, the developer is removed. A first object is to eliminate the intrusion of the developer into the bearing portion of the pumping means, thereby eliminating the increase in the torque of the developer pumping means and the deterioration of the developer. Further, the first stirring means and the second stirring means A second object of the present invention is to reduce the size of the means in a direction orthogonal to the rotation axis direction (longitudinal direction).

[0007]

According to a first aspect of the present invention, there is provided a developer supply unit for supplying a developer to a photoreceptor, and a developing unit provided near the developer supply unit. A first stirring means for stirring and transporting the developer, and receiving the developer at a downstream end of the developer in the transport direction of the developer provided below the first stirring means, stirring and transporting the developer. A developing device comprising: a second stirring means for supplying the developer to the developer supply means; and a developer pumping means for receiving the developer at a downstream end portion of the developer in the conveying direction of the developer and supplying the developer to the first stirring means. In the apparatus, the developer pumping means is provided outside a developing device housing in which the first stirring device and the second stirring device are housed, and the developer is magnetically passed through the second stirring device through a wall of the developing device housing. Before Those which induce the first agitating means.

According to this structure, the developer pumping means applies a magnetic force to the developer in the housing from the outside of the housing of the developing device in which the first stirring means and the second stirring means are housed, so that the developer is not separated from the developer. Since the developer is guided from the second stirring means to the first stirring means in the contact state, the developer is prevented from entering the bearing portion of the developer pumping means when the developer is pumped.

According to a second aspect of the present invention, there is provided a developer supply means for supplying a developer to a photoreceptor, and a first stirring means provided near the developer supply means for stirring and transporting the developer. A second agitator provided below the first agitator and receiving the developer at the downstream end in the developer transport direction by the first agitator, agitating and transporting the developer, and supplying the developer to the developer supply unit; And a developer pumping means for receiving the developer at the downstream end of the developer in the transport direction of the developer by the second stirring means and supplying the developer to the first stirring means. A rotating body,
The magnet is disposed on the side facing the first stirring means and the second stirring means, and has a magnet on a surface facing the first and second stirring means. Is what you do.

According to this configuration, the surface of the disk-shaped rotating body on which the magnet is provided rotates while facing the first and second stirring means, and the magnet is moved by the rotation, so that the developer is moved to the second position. Since the developer is pumped from the stirring means to the first stirring means, a large space is not required around the first stirring means and the second stirring means for disposing the developer pumping means.

[0011] The invention according to claim 3 is based on claim 1.
In the developing device described in the above, the developer pumping means is a disk-shaped rotating body, and is disposed in a substantially central portion in the vertical direction beside the first stirring means and the second stirring means, Having a magnet on a surface facing the first and second stirring means,
It rotates about the center of the surface having the magnet as a rotation axis.

According to this configuration, the developer pumping means rotates the disk-shaped rotating member disposed outside the developing device housing in which the developer is stored, so that the developer is not in contact with the developer, and the developer is not in contact with the developer. In addition to being able to pump the developer, the developer pumping means can be provided without requiring a large space around the first stirring means and the second stirring means, and the size of the apparatus can be reduced to achieve compactness. Can be.

The invention described in claim 4 is the same as the claim 2.
Alternatively, in the developing device according to claim 3, the developer pumping means is arranged so that a rotation axis thereof is orthogonal to a longitudinal direction of the first and second stirring means.

According to this configuration, the developer pumping means can be provided without requiring a large space in the direction orthogonal to the longitudinal direction of the first and second stirring means.

The invention described in claim 5 is the same as the claim 2.
4. The developing device according to claim 3, wherein the developer pumping unit is configured such that a rotation axis thereof is in a same direction as a longitudinal direction of the first and second stirring units, and the first and second developer stirring units are arranged in the same direction. It is arranged near the end of the stirring means in the rotation axis direction.

According to this structure, the first and second stirring means are not greatly increased in the longitudinal direction.
The size of the device in the direction orthogonal to the longitudinal direction of the first and second stirring means can be further reduced.

According to a sixth aspect of the present invention, there is provided a method for developing an electrostatic latent image formed on a photosensitive drum.
An image forming apparatus comprising the developing device according to any one of claims 1 to 5.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a developing device and an image forming apparatus according to one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a color printer as an image forming apparatus according to the present invention.

A schematic configuration of a color printer 1 to which the present invention is applied will be described with reference to FIG. A color printer 1 feeds a sheet member 3 as a transfer body one sheet at a time.
A transport unit 6 for transporting the sheet member 3 sent from the paper supply unit 4, an image forming unit 5 for forming a toner image to be transferred to the sheet member 3, and a toner image formed by the image forming unit 5. A transfer unit 7 for transferring the sheet member 3, a fixing unit 8 for fixing the toner image of the sheet member 3 transferred by the transfer unit 7, and a sheet discharging unit 10 for receiving the sheet member 3 discharged from the fixing unit 8. And an optical unit 11 for forming an electrostatic latent image on the photosensitive drum 28 by a laser beam.

The paper feed unit 4 includes a first paper feed unit 15 that feeds the sheet members 3 stacked on the first paper feed tray 12 to the downstream side one by one with a paper feed roller 13 and a retard roller 14.
And a second paper feed unit 18 that feeds the sheet members 3 from the manual feed tray 16 to the downstream side one by one by a paper feed roller 17.

The transport section 6 includes a transport path 20 for guiding the transport of the sheet member 3 sent from the first paper feed section 15, a transport roller 21 provided in the middle of the transport path 20, and a transport roller 21. A registration roller pair 22 for receiving the sheet member 3 from the printer, temporarily stopping the leading end of the sheet member 3, restricting (correcting) the oblique feeding, and feeding the image to the image forming unit 5 on the downstream side;
The manual feed path 23 communicates with the second paper feed unit 18.

The image forming section 5 includes a first image forming section 24 having black toner, a second image forming section 25 having cyan toner, a third image forming section 26 having magenta toner, and a fourth image forming section having yellow toner. And a unit 27. The first to fourth image forming units 24, 25, 26, and 27 have a cylindrical photosensitive drum 28 and a charging device that applies a charge to the photosensitive drum 28 to uniformly charge the surface of the photosensitive drum 28. 29
A developing device 30 for forming a toner image on the electrostatic latent image on the surface of the photosensitive drum 28, a cleaning device 33 including a fur brush 31 for removing residual toner on the photosensitive drum 28 and a cleaning blade 32; And the developing device 30 is a portion according to the present invention.

The transfer section 7 is disposed at a position facing an endless transfer belt 37 made of a fluororesin material, a driving roller 38 and a tension roller 40 for driving the transfer belt 37, and each photosensitive drum 28. Transfer roller 4
1a, 41b, 41c, and 41d, and has a function of transferring the sheet member 3 downstream as well as a function of transferring an image to the sheet member 3. The transfer belt 37 is held between the transfer rollers 41a, 41b, 41c, 41d and the respective photosensitive drums 28. Transfer belt 37
Guide rollers 42 and 43 are provided at appropriate positions on the inner peripheral side. When forming only a black-and-white image, the transfer unit 7 uses only the black transfer roller 41a and transfers the other transfer rollers 41b, 41c for magenta, cyan, and yellow.
41d is separated from the photosensitive drum 28.

The fixing section 8 is pressed against the heating roller 44 having a built-in heater, the fixing roller 45, a metal endless belt 46 wound around the heating roller 44 and the fixing roller 45, and the fixing roller 45. Pressure roller 4
7 are provided. And an oil application roller 48 for applying silicon oil to the outer surface of the endless belt 46;
An oil supply roller 50 that supplies oil to the oil application roller 48 and a cleaning roller 51 that cleans the surface of the oil supply roller 50 are provided.

The paper discharge section 10 receives the sheet member 3 discharged from the fixing section 8 and discharges the sheet member 3 with the image forming surface up, and a first paper discharge section 52 (shown by phantom lines in FIG. 1). Part 8
The sheet member 3 discharged from the printer is guided to an upper portion of the apparatus main body 36 by a discharge path 53, and has a second paper discharge portion 54 that is discharged with the image forming surface down. The first paper discharge unit 52 is stored in the apparatus main body 36 when not in use.

The optical unit 11 includes a polygon mirror 5
5, lenses 56 and 57 and a mirror 58 are provided corresponding to each of the photosensitive drums 28, and direct laser light from the slits 61 formed in the optical unit support plate 60 toward each of the photosensitive drums 28. Irradiation.

In the color printer 1 having the above configuration, when the sheet member 3 is sent out from the first sheet supply unit 15 or the second sheet supply unit 18, the sheet member 3 is transported by the transport unit 6 to the first image forming unit 24. Is transferred between the photosensitive drum 28 and the transfer belt 37. The sheet member 3 is provided with a transfer roller 41 corresponding to the photosensitive drum 28 of each color.
a, 41 b, 41 c, 41 d
Black, cyan, magenta, and yellow photosensitive drums 28
, The toner images are sequentially transferred to the sheet member 3. The sheet member 3 on which the toner images of the respective colors are superimposed and the transfer of the color image has been completed is fed between the fixing roller 45 and the pressure roller 47 of the fixing unit 8, where the color image is fixed. After the fixing, the sheet member 3 is discharged to the first paper discharge unit 52 or the second paper discharge unit 54.

Next, the developing device 30 will be described. 2 is a view showing the internal mechanism of the developing device according to the present invention, FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG.
It is sectional drawing.

The housing 144 (developing device housing) of the developing device 30 is formed of a synthetic resin material or the like, and
32 and a first side wall 134 extending upward from the bottom wall 132
2, a front wall 138 at the left end in FIG. 2, a rear wall 140 and an upper wall 142 at the right end in FIG.

The developing device 30 is provided with a developer supply means 146. The developer supply means 146 extends in the direction of the rotation axis of the photosensitive drum 28 and extends over substantially the entire development area. The developer supply means 146 includes a cylindrical developing sleeve 148 made of a non-magnetic material such as aluminum, and a magnet material 15 disposed inside the developing sleeve 148.
0. As shown in FIG.
Reference numeral 48 is rotatably connected to a drive system described later. A rotating shaft 151 to which the developing sleeve 148 is fixed projects through the rear wall 140, and an input gear 152 is attached to a protruding end of the rotating shaft 151. Input gear 1
A driving force from a driving source (not shown) is transmitted to 52 via an output gear 154 and an idle gear 156. And
The developer 100 is attracted to the surface of the developing sleeve 148 by the magnetic force of the magnet material 150 and rotates in the direction indicated by the arrow R1 in FIG. 3 to move the developer 100 on the surface of the sleeve 148 to the photosensitive drum 28 side. You.

In FIG. 3, above the developer supply means 146,
A developer stripping unit 160 is provided to make the supply amount of the developer 100 to the photosensitive drum 28 constant. The developer stripping means 160 includes a cutting blade 62 and a holding portion 64 for holding the cutting blade 62. The holding section 64 is fixedly supported by a partition 66 for accommodating a first stirring means 68 described later. The lower edge of the ear cutting blade 62 of the developer peeling means 160 is disposed over substantially the entire area of the developing sleeve 148 in the rotation axis direction. The developer 10 separated by the blade 62 and separated from the peripheral surface of the developing sleeve 148
0 is a second stirring means 70 and a first stirring means 68 described later.
Is stirred and mixed for use in the next development.

The first stirring means 68 extends in the direction of the rotation axis of the photosensitive drum 28, and a spiral blade 74 is attached around the rotation axis 72. This spiral blade 7
By the rotation of 4, the developer 100 is stirred and transported.
The rotation shaft 72 protrudes outward from the front wall 138,
A gear 75 is attached to one end of the gear 7.
5 is transmitted.

The second stirring means 70 also extends in the direction of the rotation axis of the photosensitive drum 28, and a spiral blade 78 is attached around the rotation shaft 76.
The developer 100 is agitated and conveyed by the rotation of 8. Although not shown in FIG. 2, a gear that meshes with a gear 75 of the first stirring means 68 is provided at one end of the rotation shaft of the second stirring means 70, and
8 is driven by the same drive source (not shown).

As the developer 100 is stirred and transported by the first stirring means 68 and the second stirring means 70, the toner and the carrier are mixed and charged by friction.

Further, as shown in FIG.
A developer scooping means 82 is disposed on the side of the first and second stirring means 70 and substantially at the center in the vertical direction of the first stirring means 68 and the second stirring means 70. The developer pumping means 82 receives the developer 100 at the downstream end in the transport direction of the developer 100 by the second stirring means 70 and moves the developer 100 to the first stirring means 68. The developer pumping means 82 is provided outside the housing 144 in which the first stirring means 68 and the second stirring means 70 are housed, and has a disk-shaped rotating body 83 which is rotatable. A plurality of magnets 85 are provided on a surface 83a of the rotating body 83 facing the first stirring means 68 and the second stirring means 70,
The surface 83a rotates around the rotation shaft 86. The rotation shaft 86 has a side wall 134 and an outer wall 136.
It is pivotally supported. The developer pumping means 82 rotates the magnet 85 by the rotation of the rotator 83, and applies a magnetic force to the developer 100 in the housing 144 through the side wall 134, and the developer 100 is removed from the second stirring means 70 by the magnetic force. One stirring means 68 is guided.

The driving mechanism of the developer pumping means 82 will be described. FIG. 5 is a horizontal sectional view of the developing device 30 showing a drive mechanism portion of the developer pumping means 82. The rotating body 83 of the developer pumping means 82 is rotated by the driving force of the driving source of the first stirring means 68. An outer peripheral portion of the rotating body 83 is a bevel gear 83b, and a driving force is transmitted from a gear 80 provided on a rotating shaft of the first stirring means 68 via a separate gear 87 meshing with the bevel gear 83b. The bevel gear 87 meshes with the bevel gear 83b of the rotating body 83.
a and the spur gear 8 meshing with the gear 80 of the first stirring means 68
7b. The gear 87 is arranged outside the housing 144, and its rotation shaft 89 is supported by the front wall 138. Further, the rotating body 83 of the developer pumping means 82
Is disposed near the opening 112a of the wall 112 that separates the first stirring means 68 and the second stirring means 70 in the developing device 30, and the vertical direction of the first stirring means 68 and the second stirring means 70 as described above. It is arranged at a substantially central position.

Next, the operation of the developer pumping means 82 and the guidance of the developer 100 by the developer pumping means 82 will be described. 6 is a sectional view taken along line AA of FIG. 5, and FIG. 7 is a sectional view taken along line BB of FIG. As described above, the rotating body 83 rotates in the direction of the arrow in FIG. 7 with the rotation of the first stirring means 68 by the gear 87. Due to the rotation of the rotating body 83, the magnet 85 provided on the surface 83a facing the first stirring means 68 and the second stirring means 70 rotates so as to move from the second stirring means 70 to the first stirring means 68. Therefore, the developer 100 in the housing 144 is moved from the second stirring unit 70 to the first
It is guided to the stirring means 68. That is, the housing 14
6, the developer 100 flows in the direction of the arrow in FIG. 6 with the movement of the magnet 85 of the rotating body 83, passes through the opening 112a, and is pumped from the second stirring means 70 to the first stirring means 68.

Next, the path along which the developer 100 is agitated and conveyed will be described. FIG. 8 is an explanatory view showing the state of transport of the developer. Toner supply port TS of toner supply unit not shown
The toner supplied from O to the first stirring means 68 is conveyed in the direction of arrow C1 in FIG. 8 while being stirred and mixed into the developer 100 by the rotation of the first stirring means 68. In the area A1 at the downstream end portion of the conveyance by the first stirring means 68, the spiral blade 74 of the first stirring means 68 is not provided, and an opening (not shown in FIG. 8) is provided below. Therefore, the developer 100 that has been agitated and mixed falls down from the opening due to its own weight (see the arrow D in FIG. 8), and moves to the second agitating means 70 side. The dropped developer 100 is
The mixture is stirred and mixed by the rotation of the stirring means 70, as indicated by an arrow C2 in FIG.
Are supplied to the photosensitive drum 28 by the developing sleeve 148 of the developer supply means 146 while being conveyed in the direction indicated by. Developer 10 not supplied to photoconductor drum 28
8 is conveyed to the conveyance downstream end, that is, to the area A2 in FIG. 8, and the first force above the second stirring means 70 by the magnetic force from the developer pumping means 82 provided outside the side wall 134 in the area A2. It is pumped to the stirring means 68. Then, the sheet is conveyed again from the first stirring means 68 to the conveyance downstream end area A2 through the second stirring means 70.

As described above, the developer 100 is pumped from the second stirring means 70 to the first stirring means 68 by the magnetic force from the developer pumping means 82 provided outside the housing 144. There is no problem such that the developer 100 enters the bearing portion of the developer pumping means 82 to increase the torque and the developer 100 is deteriorated.

The present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, in the above embodiment, the developer pumping means 82 is configured such that the rotation shaft 86 of the rotating body 83 is orthogonal to the rotation axis direction (longitudinal direction) of the first stirring means 68 and the second stirring means 70. But
The rotating shaft 86 of the rotating body 83 may be configured to be in the same direction as the rotating shafts of the first stirring means 68 and the second stirring means 70. In this case, a spur gear is provided on the outer periphery of the rotating body 83,
At the front wall 138 of the housing 144, the first stirring means 6
A rotatable member 82 is rotatably mounted on the side of the gear 80 of No. 8 and substantially at the center of the first agitating means 68 and the second agitating means 70 in the vertical direction. The gear 80 is engaged with the gear 68. And front wall 1
38, a magnetic force is applied to the developer 100 in the housing 144, and the developer 100 is
The developer 100 is moved from the stirring means 70 side to the first stirring means 68 side.
To move.

In the above embodiment, the developer pumping means 82 is provided outside the side wall 134 and the housing 14
Although the developer 100 is pumped up in a state where the developer 100 is not in contact with the developer 100, the developer pumping means 82 may be provided in the housing 144 so as to be brought into contact with the developer 100 and pumped up.

Further, in the above-described embodiment, the developer pumping means 82 is constituted by the disk-shaped rotating body 83. However, the present invention is not limited to this configuration. As shown in FIG. The developer pumping means 160 may be a roller rotating body 95 having a rotation axis in the same direction as the rotation axes of the means 68 and the second stirring means 70. Also in this case, the roller rotating body 95 is arranged in the area A2 in FIG. A pumping roller 97 made of a magnetic material is fixed to the rotating shaft 96 of the roller rotating body 95 over substantially the entire area in the axial direction. The first stirring means 6 described above is attached to the end of the rotating shaft 96.
A gear (not shown) that meshes with the gear 80 of FIG.
Thereby, it is driven to rotate. The pumping roller 97 is made of, for example, solid columnar iron, and has an N pole, an S pole in the circumferential direction.
The poles are alternately arranged, and a total of four poles and a total of eight poles are magnetized over the entire area in the axial direction. The roller rotator 95 is shown in FIG.
, The developer 100 is moved from the second stirring unit 70 to the first stirring unit 6 by the magnetic force passing through the side wall 134.
8

[0043]

As described above, according to the present invention, when the developer is pumped from the second stirring means to the first stirring means, the developer pumping means does not come into contact with the developer in the housing. The developer does not enter the bearing of the developer pumping means. As a result, it is possible to prevent an increase in torque of the developer pumping means and deterioration of the developer.

Also, the surface of the disk-shaped rotating body having the magnet rotates in a state facing the first and second stirring means, and the developer is moved from the second stirring means to the first stirring means by the movement of the magnet accompanying this rotation. With this configuration, a large space is not required around the first stirring means and the second stirring means for disposing the developer pumping means, and the size of the apparatus can be reduced and the device can be made compact. .

Further, if the developer pumping means is arranged so that its rotation axis is orthogonal to the longitudinal direction of the first and second stirring means, it is orthogonal to the longitudinal direction of the first and second stirring means. The developer pumping means can be provided without requiring a large space in the direction.

Further, the developer pumping means is arranged near the longitudinal ends of the first and second stirring means so that the rotation axis thereof is in the same direction as the longitudinal direction of the first and second stirring means. With this configuration, it is possible to reduce the size of the device in the direction orthogonal to the longitudinal direction of the first and second stirring means without increasing the length of the first and second stirring means in the longitudinal direction by a large amount.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a color printer as an image forming apparatus according to the present invention.

FIG. 2 is a diagram showing an internal mechanism of the developing device according to the present invention.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view taken along line BB in FIG. 2;

FIG. 5 is a horizontal sectional view of the developing device showing a driving mechanism of a developer pumping unit.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is a sectional view taken along the line BB of FIG. 5;

FIG. 8 is an explanatory diagram illustrating a state of transport of the developer.

FIG. 9 is a sectional view showing another embodiment of the developing device according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 color printer (image forming apparatus) 28 photoreceptor drum 68 first stirring means 70 second stirring means 82, 160 developer pumping means 83 rotating body 83a surface 85 magnet 86 rotating shaft 95 rotating body 100 developer 134 side wall 144 housing ( (Developing device housing) 146 Developer supply means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H031 AB01 AB09 AC01 AC08 AC30 AD01 AD11 BA05 BA09 BB01 FA01 FA07 2H077 AB02 AB14 AB15 AB18 AC02 AC12 AC16 AD06 AD13 AD23 AE06 BA02 CA02 EA03 GA13

Claims (6)

[Claims] 1. A developer supply means for supplying a developer to a photoreceptor, a first stirring means provided near the developer supply means for stirring and transporting the developer, and a first stirring means provided below the first stirring means. A second stirring unit that receives the developer at the downstream end in the transport direction of the developer by the first stirring unit, agitates and transports the developer, and supplies the developer to the developer supply unit; A developer scooping unit that receives a developer at a downstream end in a developer conveying direction and supplies the developer to the first stirring unit; wherein the developer scooping unit includes the first stirring unit and the second stirring unit.
The developing device is provided outside the developing device housing in which the stirring device is accommodated, and guides the developer from the second stirring device to the first stirring device by magnetic force through a wall of the developing device housing. 2. A developer supply means for supplying a developer to a photoreceptor, a first stirring means provided near the developer supply means for stirring and transporting the developer, and a first stirring means provided below the first stirring means. A second stirring unit that receives the developer at the downstream end in the transport direction of the developer by the first stirring unit, agitates and transports the developer, and supplies the developer to the developer supply unit; A developer pumping means for receiving a developer at a downstream end portion in a developer conveying direction and supplying the developer to the first stirring means, wherein the developer pumping means is a disk-shaped rotating body, It is arranged on the side of the stirring means and the second stirring means, has a magnet on a surface facing the first and second stirring means,
A developing device, wherein the developing device rotates around a substantially central portion of a surface having the magnet as a rotation axis. 3. The developer pumping means is a disk-shaped rotating body, and is disposed at a substantially vertical center side of the first stirring means and the second stirring means. 2. The developing device according to claim 1, wherein the developing device has a magnet on a surface facing the stirring means, and rotates about a substantially central portion of the surface having the magnet as a rotation axis. 4. The developer pumping means according to claim 2, wherein said developer pumping means is arranged such that a rotation axis thereof is orthogonal to a longitudinal direction of said first and second stirring means. Developing device. 5. The end of the first and second stirring means in the direction of the rotation axis, wherein the rotation axis of the developer pumping means is in the same direction as the longitudinal direction of the first and second stirring means. The developing device according to claim 2, wherein the developing device is disposed in the vicinity. 6. An image forming apparatus comprising the developing device according to claim 1 for developing an electrostatic latent image formed on a photosensitive drum.