JPH08248748A - Developing device - Google Patents

Abstract

PURPOSE: To prevent a faulty image from being formed caused by the deterioration of developer or the flocculated powder thereof by setting a developer stirring member positioned at the most back part with respect to a developer carrier so that the total rotating quantity thereof becomes small in comparison with the other developer stirring member. CONSTITUTION: Gears 18 and 19 are respectively fixed to the rotary shafts 12a and 14a of a small agitator 12 and one large agitator 14. Then, a driving motor 23 is coupled to the rotary shaft 15a of the other large agitator 15. When a photoreceptor drum is rotated in order to form an image, a developing sleeve 9 coupled to the photoreceptor drum through gears 20 to 22, the agitator 12 and the agitator 14 are followingly driven to be rotated. Then, the developer in a housing 8 is successively carried to the surface of the sleeve 9 through the agitator 12. When the counted value of the pixel of image information arrives at a prescribed value, the motor 23 is driven to be rotated extending over prescribed time and the agitator 15 is rotated in order to form the image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used in an image forming apparatus such as an electrophotographic copying machine, a printer or an electronic printing device, which electrostatic latent image is formed on an electrostatic latent image carrier. The present invention relates to a developing device that develops an image using a one-component developer.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus such as the electrophotographic copying machine and the printer, there are the following ones, for example. This image forming apparatus, as shown in FIG.
The photoconductor drum 100 has a diameter set to be relatively small, and the photoconductor drum 100 is rotationally driven at a predetermined speed in a direction of an arrow by a driving unit (not shown). The surface of the photosensitive drum 100 is primarily charged to a predetermined potential by a bias charge roll 101 that contacts the surface of the photosensitive drum 100, and then the surface of the photosensitive drum 100 is imaged by a laser writing device or the like. Image exposure 102 is output according to the information, and an electrostatic latent image according to the image information is formed. Next, the electrostatic latent image formed on the photoconductor drum 100 is developed into a developed image by the developing device 103 using a magnetic one-component developer or the like. It is transferred by the transfer roll 105 onto the transfer paper 104 conveyed from a paper feed cassette (not shown) at a timing. After that, the transfer sheet 104 on which the developed image is transferred is separated from the surface of the photoconductor drum 100 by being discharged by a static eliminator (not shown), and is conveyed to a fixer (not shown). The one or both of the above fix the developed image on the transfer sheet 104 and discharge it to the outside of the apparatus, thus ending the image forming step.

Incidentally, the surface of the photosensitive drum 100 after the transfer process of the developed image is cleaned by the blade 106a of the cleaning device 106 to remove residual toner and the like so as to be ready for the next image forming process.

By the way, in the developing device 103 used in the image forming apparatus as described above, as shown in FIGS. 11 and 12, the developing sleeve 108 arranged in the opening portion of the developing device housing 107 on the side of the photosensitive drum 100. Inside the developing sleeve 108, a magnet roll 109 in which a magnetic pole having a predetermined polarity is magnetized at a predetermined position is provided.
Is fixedly placed. In addition, the developing sleeve 108
On the back side of the developing sleeve 108, the one-component developer 11
A small agitator 111 that supplies 0 is arranged. Further, inside the developing device housing 107, a developer accommodating portion 112 that accommodates the developer 110 is formed so as to occupy most of the developing device housing 107. Are two large agitators 11 for stirring the developer 110 and performing triboelectric charging.
3, 114 are arranged in parallel. Then, the developer 110 stored in the developer storage portion 112 is frictionally charged while being stirred by the two large agitators 113 and 114, and is sequentially conveyed to the front side of the developing device housing 107, and the small agitator 111 is transferred. The developer 110 conveyed to the developing sleeve 108 via the developing sleeve 108 and held on the surface of the developing sleeve 108 has a layer thickness regulating blade 115.
Is regulated to a predetermined layer thickness while being frictionally charged by the photosensitive drum 10 as the developing sleeve 108 rotates.
It is conveyed to the developing position which faces the surface of 0, and a developing process is performed.

The developing sleeve 108 of the developing device 103.
Is a gear 1 fixed at its end, as shown in FIG.
Reference numeral 16 meshes with a gear (not shown) fixed to the shaft of the photoconductor drum 100, and the photoconductor drum 100 is driven to rotate by being driven to rotate by a drive motor (not shown). Also, the small agitator 1
Gears 117 and 118 and 119 are fixed to the shafts of the large agitator 113 and 114, respectively, and the gear 1 is fixed to the shafts of the large agitators 113 and 114.
The gear 18 and the gear 119 mesh with an idler gear 120 that is rotatably supported by the developing device housing 107. In addition, the shaft of the large agitator 113 is
A gear 121 having a diameter larger than that of the gear 118 is integrally fixed, and the gear 121 is used as the developing device housing 1.
The gear 117 of the small agitator 111 is meshed with the smallest idler gear 122 rotatably supported by the gear 07, and the gear 117 of the small agitator 111 is meshed with the idler gear 123 integrally fixed to the idler gear 122.
The large diameter idler gear 124 integrally fixed to the idler gears 122 and 123 is meshed with a gear fixed to a shaft (not shown) of the photosensitive drum 100, and the photosensitive drum 100 is driven to rotate. Thus, the small agitator 111, the large agitator 113, and the large agitator 114 are driven to rotate and agitate and convey the developer 110.

[0006]

However, the above-mentioned prior art has the following problems. That is, in the developing device 103 configured as described above, the large agitators 113 and 114 in the developer accommodating portion 112 are connected to the photosensitive drum 100 via the plurality of gears 118 to 124.
The large agitators 113, 114 are connected to a gear (not shown) fixed to the shaft of (1) and are always driven to rotate at a predetermined rotation speed when the photosensitive drum 100 rotates. Therefore, the developer 110 stored on the rear side of the developer storage portion 112 is mechanically stirred by the large agitators 113 and 114 for a long period until the developer 110 is conveyed to the developing sleeve 108 and actually contributes to the development. However, there is a problem in that the developer 110 itself is deteriorated due to various stresses. In addition, the developer containing portion 112
The developer 110 accommodated on the rear side of the developing unit 108 agglomerates due to mechanical stress into agglomerated powder, and when the agglomerated powder moves between the developing sleeve 108 and the layer thickness regulating blade 115, the development on the developing sleeve 108 is performed. There has been a problem that streaks and the like are generated in the developer layer, which causes defective formation of the developer layer and causes image defects.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The object of the present invention is to eliminate image defects due to deterioration of the developer and generation of aggregated powder of the developer. It is an object of the present invention to provide a developing device capable of preventing the occurrence of the occurrence.

[0008]

A developing device according to a first aspect of the present invention stores a one-component developer in a developer containing portion in the developing device main body, and at the opening of the developing device main body. A developing device in which a developer carrying member is disposed so as to face the electrostatic latent image carrying member, and a plurality of developer stirring members are provided inside the developing device main body. Among them, at least the developer stirring member located at the rearmost position with respect to the developer carrying member is set so that the total rotation amount is relatively smaller than that of the other developer stirring members.

Further, in the developing device according to the second aspect of the present invention, among the plurality of developer agitating members, at least the developer agitating member located at the rearmost position with respect to the developer carrying member is rotated. The control is performed according to the count amount of the image information developed by the developing device.

Further, according to a third aspect of the present invention, in a developing device, a one-component developer is contained in a developer accommodating portion in the developing device body, and an electrostatic latent image is formed in an opening of the developing device body. The developer carrying body is arranged so as to face the carrying body,
In a developing device in which a plurality of developer agitating members are arranged inside the developing device main body, a residual amount detecting means for detecting a residual amount of the developer is provided near the developer agitating member on the side of the developer carrier. When the remaining amount detecting means detects that the developer is empty, at least the developer stirring member located at the rearmost position with respect to the developer carrying member among the plurality of developer stirring members is rotationally driven. It is configured to include a drive control unit that operates.

Of the plurality of developer agitating members, for example, one developer agitating member is set to have a different rotation state from the other developer agitating members. The rotation states may be set differently.

[0012]

In the developing device according to the first aspect of the present invention, among the plurality of developer agitating members, at least the developer agitating member located rearmost with respect to the developer carrying member is
Since the total rotation amount is set to be relatively small compared to other developer stirring members, the developer carrier that stirs the developer that contributes to the development after the consumption of the developer in the main body of the developing device progresses The total rotation amount of the developer stirring member located at the rearmost position with respect to the body can be relatively reduced, the stress exerted on the developer can be reduced, and the deterioration of the developer and the aggregation of the developer can be achieved. It is possible to prevent image defects due to generation of powder or the like.

Further, in the developing device according to the second aspect of the present invention, among the plurality of developer stirring members, at least the developer stirring member located at the rearmost position with respect to the developer carrying member is rotated. Since the control is performed according to the count amount of the image information to be developed by the developing device, it is located at the rearmost position with respect to at least the developer carrier according to the actual consumption of the developer accompanying the developing process. It is possible to control the rotation of the developer stirring member, and by setting the rotation of the developer stirring member to be small, it is possible to reduce the stress or the like applied to the developer as much as possible. It is possible to more effectively prevent the occurrence of image defects due to the generation of agglomerated powder.

Further, in the developing device according to the third aspect of the present invention, a remaining amount detecting means for detecting the remaining amount of the developer is provided in the vicinity of the developer stirring member on the side of the developer carrier, and the remaining amount. When the detection means detects that the developer is empty, drive control means for rotationally driving at least the rearmost developer stirring member with respect to the developer carrying member among the plurality of developer stirring members. Since it is configured to include, it detects that the developer is actually consumed in the developing process, and controls the rotation of at least the rearmost developer stirring member with respect to the developer carrier. By setting the rotation of the developer stirring member to be small, the stress applied to the developer can be reduced as much as possible, and the image due to deterioration of the developer or generation of agglomerated powder of the developer can be achieved. Defect To the a it can be more effectively prevented.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments.

FIG. 3 shows an embodiment of an image forming apparatus to which the developing device according to the present invention is applied. As shown in FIG. 3, the image forming apparatus includes a photosensitive drum 1 whose diameter is set to be relatively small. The photosensitive drum 1 is driven by a driving unit (not shown) in a predetermined direction along the arrow. It is designed to be rotated at a speed. The surface of the photosensitive drum 1 is primarily charged to a predetermined potential by the bias charge roll 2 that contacts the surface of the photosensitive drum 1, and then the surface of the photosensitive drum 1 is imaged by a laser writing device or the like. Image exposure 3 is output according to the information, and an electrostatic latent image according to the image information is formed. Next, the electrostatic latent image formed on the photoconductor drum 1 is developed into a developed image by the developing device 4 using a magnetic one-component developer, and the developed image is formed at a predetermined timing. Is electrostatically transferred by the transfer roll 6 onto the transfer paper 5 conveyed from a paper feed cassette (not shown). After that, the transfer sheet 5 on which the developed image is transferred is separated from the surface of the photoconductor drum 1 by being discharged by a static eliminator (not shown), and is conveyed to a fixer (not shown). The developed image is fixed on the transfer sheet 5 by one or both of the above and is discharged to the outside of the apparatus, and the image forming process is completed.

The surface of the photosensitive drum 1 which has undergone the development image transfer step is cleaned by a blade 7a of a cleaning device 7 to remove residual toner and the like so as to be ready for the next image forming step.

In the developing device 4 used in the image forming apparatus as described above, as shown in FIG. 3, the developing sleeve 9 is arranged in the opening of the developing device housing 8 on the side of the photosensitive drum 1.
The developing sleeve 9 is made of a nonmagnetic or weakly magnetic material such as stainless steel or aluminum, and is rotationally driven at a predetermined speed in the arrow direction. Further, inside the developing sleeve 9, a magnet roll 10 having a plurality of magnetic poles magnetized along the circumferential direction is arranged in a fixed state. Further, on the back side of the developing sleeve 9, a small agitator 12 as a developer conveying means for supplying the one-component developer 11 to the developing sleeve 9 is arranged in parallel with the developing sleeve 9. This small agitator 1
As shown in FIG. 1, 2 is composed of a non-magnetic shaft 12b having a diameter of about 2 mm, which is connected to the rotating shaft 12a thereof. Further, as shown in FIG. 3, a developer accommodating portion 13 accommodating the developer 11 is formed inside the developing device housing 8 so as to occupy most of the developing device housing 8. In the developer accommodating portion 13, two large agitators 14 and 15 are arranged in parallel as developer conveying means for conveying the developer 11 to the small agitator 12 while stirring and frictionally charging the developer 11. Has been done. As shown in FIGS. 1 and 4, these large agitators 14 and 15 have elongated flat U-shaped shaft members 14b and 15b made of a non-magnetic material and having a diameter of about 3 mm, which are connected to the rotating shafts 14a and 15a. Is equipped with
Elongated urethane sheets 14d and 15d are attached to the shaft members 14b and 15b via outsert molds 14c and 15c made of synthetic resin.
It is fixed over the entire length of 5b.

As shown in FIG. 3, the developer 11 contained in the developer container 13 is frictionally charged while being stirred by the two large agitators 14 and 15.
The toner is sequentially conveyed to the front side of the developing device housing 8 and then conveyed to the developing sleeve 9 via the small agitator 12. The developer 11 held on the surface of the developing sleeve 9 is formed into a thin layer while being triboelectrically charged by the layer thickness regulating blade 16 made of an elastic material such as urethane rubber or silicon rubber. And is conveyed to a developing position facing the surface of the photosensitive drum 1, and the electrostatic latent image on the photosensitive drum 1 is developed.

By the way, in this embodiment, among the plurality of developer agitating members, at least the developer agitating member located at the rearmost position with respect to the developer carrying member is totally rotated as compared with the other developer agitating members. The amount is set to be relatively small.

That is, in this embodiment, the developing sleeve 9 of the developing device 4 has a gear 17 fixed to the end thereof fixed to the shaft of the photosensitive drum 1, as shown in FIGS. The photoconductor drum 1 is driven to rotate by being engaged with a gear (not shown) and rotationally driven by the drive motor (not shown). In addition, the small agitator 12 and one large agitator 14
Gears 18 and 19 are fixed to the rotary shafts 12a and 14a of the developing device housing 8 of the small agitator 12, respectively.
The gear 19 fixed to the rotating shaft 14a of the large agitator 14 meshes with an idler gear 20 rotatably supported by the idler gear 21 and a small diameter idler gear 21 integrally fixed to the idler gear 20. .
A large diameter idler gear 22 is integrally fixed to the idler gears 20 and 21, and the large diameter idler gear 22 is meshed with a gear (not shown) fixed to the shaft of the photosensitive drum 1. By rotating the photosensitive drum 1 by a drive motor (not shown), the small agitator 12 and the large agitator 14 are
It is configured to be driven to rotate via the idler gears 20, 21 and 22 to stir and convey the developer 11 in the developer accommodating portion 13.

A drive motor 23 such as a DC motor is connected to the rotary shaft 15a of the other large agitator 15, and the drive motor 23 is attached to a side plate 24 fixed to the developing device housing 8. ing. And
The large agitator 15 is driven by the drive motor 23 at a speed equal to or slower than that of the one large agitator 15,
It is adapted to be rotationally driven at a predetermined timing.
The drive motor 23 is rotationally driven according to the pixel count value of the image information developed by the developing device 4.

With the above-described structure, in the developing device applied to the image forming apparatus according to this embodiment, image defects due to deterioration of the developer and generation of agglomerated powder of the developer occur as follows. It is designed to prevent That is, in the developing device 4, as shown in FIGS. 1 and 2, when the photosensitive drum 1 rotates during image formation, the developing sleeve connected to the photosensitive drum 1 via gears 20, 21, and 22. 9, the small agitator 12 and the large agitator 14 are driven to rotate, and the developer in the developing device housing 8 is sequentially conveyed to the surface of the developing sleeve 9 via the small agitator 12 and is formed on the photosensitive drum 1. The latent image is developed.

At this time, in the developing device 4, as shown in FIGS. 1 and 2, the small agitator 12 and the large agitator 14 are used.
However, while it is driven to rotate by the rotational driving force of the photosensitive drum 1, the large agitator 15 is not rotationally driven because the drive motor 23 is normally stopped.

Then, in the image forming apparatus to which the developing device 4 is applied, the pixel count value of the image information on which the image is formed becomes a predetermined value for forming the image on the transfer paper 5 of about 2000 to 3000 sheets, for example. When it reaches, the CPU controlling the operation of the image forming apparatus detects this, and the drive motor 23 is rotationally driven for a predetermined time during image formation, and the large agitator 15 is rotationally driven. After that, the large agitator 15 rotates the drive motor 23 during image formation to synchronize with the small agitator 12 and the large agitator 14 so that the large agitator 15 rotates at a rotation speed equal to or smaller than the predetermined rotation speed of the large agitator 14. It is designed to be rotationally driven by a number.

As described above, in the above embodiment, of the small agitator 12 and the large agitators 14 and 15, the large agitator 15 located furthest to the rear with respect to the developing sleeve 9 is
The drive motor 23 is normally stopped by stopping it, and when the pixel count value of the image information to be developed by the developing device 4 reaches a predetermined value, the drive motor 23 is driven to drive the large agitator. It is configured to drive 15 for the first time. Therefore, after the consumption of the developer 11 in the developing device housing 8 progresses, the total rotation amount of the large agitator 15 located at the rearmost position with respect to the developing sleeve 9 that agitates the developer 11 that contributes to the development,
It is possible to reduce the amount relatively, and it is possible to reduce the stress or the like applied to the developer 11, and it is possible to prevent image defects due to deterioration of the developer 11 or generation of aggregated powder of the developer 11.

Further, in this embodiment, the small agitator 12 is used.
Also, the large agitator 15 located farthest to the developing sleeve 9 among the large agitators 14 and 15 is configured to be controlled according to the count amount of the image information to be developed by the developing device 4. Depending on the actual consumption of the developer 11 due to the
It is possible to control the rotation of the large agitator 15 located at the rearmost with respect to, and by setting the rotation of the large agitator 15 small, it is possible to reduce the stress or the like applied to the developer 11 as much as possible. It is possible to more effectively prevent the occurrence of image defects due to deterioration of the developer 11 and generation of aggregated powder of the developer 11.

Second Embodiment FIGS. 6 and 7 show a second embodiment of the present invention.
The same parts as those in the above-described embodiment are designated by the same reference numerals, and in the second embodiment, the rotary shaft 1 of the large agitator 15 will be described.
A shaft 30 is fixed to 5a, and the shaft 30 and a gear 31 are connected via a clutch 32. The gear 31 is a large agitator 1 via an idler gear 33.
4 is connected to a gear 19a fixed to the gear 4, and the rotational driving force of the large agitator 14 is transmitted to the large agitator 15 side. Then, by turning the clutch 32 ON / OFF as necessary, the large agitator 1
5 is normally stopped, and the large agitator 15 is rotationally driven at a predetermined timing to remove the large agitator 1.
It is possible to stir and convey the developer 11 to the large agitator 14 side without giving extra stress or the like to the developer 11 in the vicinity of No. 5.

The other structure and operation are the same as those of the above-mentioned embodiment, and the description thereof will be omitted.

Third Embodiment FIG. 8 shows a third embodiment of the present invention. In the third embodiment, the same parts as those in the above-mentioned embodiment are designated by the same reference numerals. A developer remaining amount detector 40 is fixed to a device main body (not shown) via a fixing member 41 so as to be adjacent to the outside of the large agitator 14 side. Then, the large agitator 1 of the developer accommodating portion 13
By detecting the remaining amount of the developer 11 in the vicinity of 4 by the developer remaining amount detector 40, the operation of the drive motor 23 or the clutch 32 fixed to the large agitator 15 is controlled according to the detection result. , Developer 11
Of the developer 11 on the side of the large agitator 15 is agitated and conveyed to the side of the large agitator 14 without causing image quality defects due to insufficient supply in the vicinity of the developing sleeve 9 and without giving extra stress to the developer 11. Is possible.

The other structure and operation are the same as those of the above-mentioned embodiment, and the description thereof will be omitted.

Fourth Embodiment In the fourth embodiment, the number of copies on which an image is formed by the image forming apparatus is cumulatively counted, the consumption amount of the developer 11 is calculated using the cumulative number of copies, and the developer 11 is used. By controlling the operation of the drive motor 23 or the clutch 32 fixed to the large agitator 15 based on the consumption amount of the developer 11, the developer 11 is prevented from causing an image quality defect due to insufficient supply of the developer 11 near the developing sleeve 9. It is possible to stir and convey the developer 11 on the large agitator 15 side to the large agitator 14 side without giving extra stress to the large agitator 15 side.

The other structure and operation are the same as those of the above-mentioned embodiment, and the description thereof will be omitted.

Fifth Embodiment FIG. 9 shows a fifth embodiment of the present invention. The same parts as those of the above embodiment are designated by the same reference numerals. On the other hand, although the large agitator 15 located on the rearmost side is always driven to rotate during image formation similarly to the large agitator 14, the large agitator 15 located on the rearmost side with respect to the developing sleeve 9 is.
Is set so that the rotation speed is significantly slower than that of the large agitator 14 (for example, the rotation speed ratio is about 1/2).
The rotating shafts 12a and 14a of the small agitator 12 and the one large agitator 14 have gears 18 and 19 respectively.
Are fixed, and these gears 18 and 19 mesh with an idler gear 20 rotatably supported by the developing device housing 8 and
An idler gear 50 having a large diameter is integrally fixed to the. The idler gear 50 is meshed with a gear 51 to which a driving force is transmitted from the shaft of the photoconductor drum 1. The small drum agitator 12 and the large agitator 14 are driven by the photoconductor drum 1 being rotationally driven by a drive motor (not shown). Is configured to be driven to rotate via the idler gears 50 and 51 to stir and convey the developer 11 in the developer accommodating portion 13.

The rotating shaft 14 of the large agitator 14
An idler gear 52 having a relatively small diameter is integrally fixed to the gear 19 fixed to a. The idler gear 52 is provided with idler gears 53 and 54 that are rotatably supported by the developing device housing 8. , Large agitator 1
5 meshes with a gear 55 fixed to the rotating shaft 15a. Then, the large agitator 15 is, for example, for the rotational speed of the large agitator 14 of 10.00 rpm,
It is designed to be rotationally driven at a rotation speed of about 5.05 rpm.

Therefore, in this embodiment, a large agitator located at the rearmost position with respect to the developing sleeve 9 is used without using a drive motor, a clutch, a detecting means for detecting the pixel count, the number of copies, the remaining amount of the developer and the like. 15
It is possible to reduce the total number of rotations of the toner and reduce the stress and the like applied to the developer 11 at a low cost as much as possible, and the image defect occurs due to the deterioration of the developer 11 and the generation of aggregated powder of the developer 11. It is possible to more effectively prevent this.

The other structure and operation are the same as those of the above-mentioned embodiment, and the description thereof will be omitted.

[0038]

According to the present invention, which has the above-described structure and operation, the developing device according to the first aspect of the present invention includes at least a developer carrying member among a plurality of developer stirring members. The developer stirring member located at the rearmost position is set so that the total amount of rotation is relatively smaller than other developer stirring members. The total rotation amount of the developer stirring member located at the rearmost position with respect to the developer carrying member that stirs the developer that contributes to the development can be relatively reduced, and the stress or the like given to the developer can be reduced. Therefore, it is possible to prevent image defects due to deterioration of the developer and generation of aggregated powder of the developer.

Further, in the developing device according to the second aspect of the present invention, among the plurality of developer agitating members, at least the developer agitating member located at the rearmost position with respect to the developer carrying member is rotated. Since the control is performed according to the count amount of the image information to be developed by the developing device, the developing device positioned at the rearmost position at least with respect to the developer carrying member is determined according to the actual consumption of the developer accompanying the developing process. It is possible to control the rotation of the developer stirring member, and by setting the rotation of the developer stirring member to be small, it is possible to reduce the stress and the like applied to the developer as much as possible, and to prevent deterioration of the developer and development of the developer. It is possible to more effectively prevent the occurrence of image defects due to the generation of aggregated powder.

Further, in the developing device according to the third aspect of the present invention, a remaining amount detecting means for detecting the remaining amount of the developer is provided near the developer stirring member on the side of the developer carrying member, and the remaining amount is detected. When the means detects that the developer is empty, a drive control means for rotationally driving at least the rearmost developer stirring member with respect to the developer carrying member among the plurality of developer stirring members is provided. Because it is configured to prepare,
It is possible to detect that the developer is actually consumed in the developing process and control the rotation of at least the rearmost developer stirring member with respect to the developer carrying member. By setting the number of rotations to a small value, it is possible to reduce the stress applied to the developer as much as possible, and it is more effective to cause image defects due to deterioration of the developer or generation of aggregated powder of the developer. It can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram showing an embodiment of a developing device according to the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a configuration diagram showing an embodiment of an image forming apparatus to which the developing device according to the present invention is applied.

FIG. 4 is a side view showing a large agitator.

FIG. 5 is a partially cutaway plan view showing a large agitator.

FIG. 6 is a cross-sectional configuration diagram showing a developing device according to Embodiment 2 of the present invention.

FIG. 7 is a side view of the same.

FIG. 8 is a configuration diagram showing an image forming apparatus to which a developing device according to a third embodiment of the present invention is applied.

FIG. 9 is a side view of a developing device according to a fifth embodiment of the present invention.

FIG. 10 is a configuration diagram showing an image forming apparatus to which a conventional developing device is applied.

FIG. 11 is a cross-sectional configuration diagram showing a conventional developing device.

FIG. 12 is a side view of the same.

[Explanation of symbols]

4 developing device, 8 developing device housing, 9 developing sleeve, 11 developer, 12 small agitator, 14, 15
Large agitator, 18-22 gear, 23 drive motor.

Claims (3)

[Claims] 1. A one-component developer is accommodated in a developer accommodating portion in a developing device main body, and a developer carrying member is disposed in an opening of the developing device main body so as to face the electrostatic latent image carrying member. In the developing device in which a plurality of developer stirring members are arranged inside the developing device main body, among the plurality of developer stirring members, the developer located at the rearmost position with respect to at least the developer carrier. A developing device, wherein the stirring member is set so that the total rotation amount is relatively smaller than that of other developer stirring members. 2. The rotation of at least the rearmost developer agitating member of the plurality of developer agitating members with respect to the developer carrying member is rotated according to the count amount of image information developed by the developing device. The developing device according to claim 1, wherein the developing device is controlled. 3. A one-component developer is accommodated in a developer accommodating portion in the developing device main body, and a developer carrying member is arranged in an opening of the developing device main body so as to face the electrostatic latent image carrying member. In the developing device having a plurality of developer agitating members arranged inside the developing device main body, a residual amount detecting means for detecting the residual amount of the developer near the developer agitating member on the developer carrier side. When the remaining amount detecting means detects that the developer is empty, at least the developer stirring member located at the rearmost position with respect to the developer carrying member among the plurality of developer stirring members is provided. A developing device comprising drive control means for rotationally driving.