JPH11119529A - Developer carrying screw, developing device and cleaning device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer carrying screw capable of carrying only developer existing in the vicinity of the developer carrying screw without moving the developer to another developer carrying screw in the midst of carrying the developer. SOLUTION: A supply screw 14 which axially rotates to carry the developer in an axial direction is provided with a centripetal member 5 applying inward pressure to the developer. Since the inward pressure is applied to the developer when the screw 14 is rotated, the developer existing in the vicinity of the screw 14 is carried while it is rolled inside the screw 14, whereby only the developer existing in the vicinity of the screw 14 is carried without moving the developer to another screw in the midst of carrying the developer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer conveying screw for conveying a developer by a developing device and a cleaning device of an electrophotographic image forming apparatus such as a copying machine and a printer, and to use the developer conveying screw. The present invention relates to a developing device and a cleaning device. More specifically,
The present invention relates to a developer conveying screw capable of preventing movement of a developer during conveyance between the developer conveying screws. Further, the present invention relates to a developing device which can prevent the movement of the developer between adjacent developer conveying screws by using such a developer conveying screw, and can perform good stirring and circulation of the developer. Further, the present invention relates to a cleaning device capable of suppressing the generation of toner smoke by using such a developer conveying screw.

[0002]

2. Description of the Related Art As an example of a conventional developer conveying screw, there is one used in a developing device described in Japanese Patent Application Laid-Open No. Hei 5-333691. In this developing device, two upper and lower augers (developer conveying screws) 82, 8
Numerals 5 are screws having the same shape, and as shown in FIG. 10, they are arranged in parallel so that their transport directions are opposite to each other with a partition wall 84 interposed therebetween. Then, when these rotate, a conveying force for the developer is generated, so that the developer is circulated as indicated by an arrow. Then, in the circulation of the developer, the developer is supplied to a developer carrier (developing roller) 87 provided adjacent to the auger 82, and the electrostatic latent image on the photoconductor is developed through the developer. Is done. In this developing device, the upper auger 82 is responsible for supplying the developer to the developer carrier 87, and the lower auger 85 is responsible for collecting the excess developer from the developer carrier 87. Here, the partition wall 84 is provided to prevent movement of the developer from being transported from the upper auger 82 to the lower auger 85 during the circulation of the developer. This is because if the developer is moved between the augers during the transportation of the developer, the developer that is not sufficiently stirred is supplied to the developer carrier 87.

[0003] Such an auger is also used in a cleaning device for removing a developer remaining on an image carrier after transfer.

[0004]

However, in the conventional augers 82 and 85 described above, only the developer in the vicinity of each auger can be transported without being moved to another auger 85 or 82 during the transportation. Did not. Therefore, the developing device using the augers 82 and 85 has the following problems. That is, since the partition wall 84 is provided, the delivery of the developer between the auger 82 and the auger 85 at both ends is also prevented,
There is a possibility that the developer may stay at the transfer portion of the developer. When such stagnation of the developer occurs,
The developer is not circulated well, and the augers 82, 85
In some cases, the developer being conveyed is biased. When this bias of the developer occurs in the auger 82,
There has been a problem that the developer is not uniformly supplied from the auger 82 to the developer carrying member 87, and the image quality is deteriorated due to unevenness and fog.

[0005] The cleaning device using such an auger has the following problems. That is, when the conventional auger rotates, the developer mainly generates pressure in the axial direction, but also partially generates outward pressure. Therefore, the developer in the cleaning device is discharged outward while being transported in the axial direction,
There is a problem that toner fumes are generated.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-described problem, and conveys only the developer in the vicinity without moving the developer to another developer conveyance screw during conveyance. It is an object of the present invention to provide a developer conveying screw which can be used. The present invention also provides
It is an object of the present invention to provide a developing device that can stir and circulate the developer while preventing the developer from moving during the conveyance between the developer conveying screws. Still another object of the present invention is to provide a cleaning device capable of preventing the generation of toner smoke.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a developer conveying screw of the present invention is a developer conveying screw which conveys a developer in an axial direction by rotating around a shaft. And centrifugal means for applying an inward pressure to the developer.

[0008] This developer conveying screw has centripetal means for applying an inward pressure to the developer by rotating around the axis. Therefore, when the developer conveying screw rotates, it faces inward with respect to the developer. Pressure is given. Then, due to the inward pressure, the developer in the vicinity of the developer transport screw is transported while being wound inside the screw. For this reason, only the developer in the vicinity can be transported without moving the developer to another developer transport screw during the transport. Further, in the portion where the developer is delivered, the developer of the other developer transport screw is sucked by the inward pressure generated by the rotation of the developer transport screw. For this reason, delivery can be performed smoothly without causing the developer to stay.

In the present invention, as the centripetal means for applying an inward pressure to the developer by rotation of the developer conveying screw, for example, a blade member whose front side moves by rotation to the developer conveying screw is provided. There are things. Here, as an example of the shape embodying the “blade member whose direction of movement by rotation is directed to the front side”, a smooth and continuous smooth outward from the rotation center of the developer conveying screw as shown in FIG. There are shapes curved so as to draw a curve.

According to another aspect of the present invention, there is provided a developer conveying screw for conveying a developer in an axial direction by rotating about a shaft, and applying an outward pressure to the developer. A centrifugal means is provided.

[0011] This developer transport screw has centrifugal means for applying an outward pressure to the developer by rotating around the axis. Therefore, when the developer transport screw rotates, the developer transport screw is directed outward with respect to the developer. Pressure is given. Here, even in the conventional developer conveying screw, an outward pressure is applied to the developer by the rotation thereof,
The pressure is much lower than the pressure generated by the developer conveying screw of the present invention. The large outward pressure prevents movement of the developer from another adjacent developer transport screw, and the developer transport screw transports only the developer nearby. For this reason, only the developer in the vicinity can be transported without moving the developer to another developer transport screw during the transport. In the portion where the developer is transferred, the developer is moved to another developer transport screw by a large outward pressure generated by the rotation of the developer transport screw. For this reason, delivery can be performed smoothly without causing the developer to stay.

The centrifugal means for applying an outward pressure to the developer by the rotation of the developer conveying screw includes, for example, providing a blade member having a front surface directed outward by rotation to the developer conveying screw. There is. Here, as an example of the shape embodying the “blade member whose front surface in the direction of movement by rotation faces outward”, a continuous shape from the rotation center of the developer transport screw toward the outside as shown in FIG. There are shapes that are curved so as to draw a smooth curve.

Further, a developing device according to the present invention, which has been made to solve the above problems, has a developing roller and a plurality of developer conveying screws which rotate around an axis to convey the developer in an axial direction. In the developing device, a portion of one of the developer conveying screws, which receives the developer from another developer conveying screw, is provided with a centering means for applying an inward pressure to the developer.

In this developing device, a portion of the developer transfer screw where the developer is transferred from another developer transfer screw has centripetal means for applying an inward pressure to the developer. Is generated, an inward pressure is generated at the corresponding portion of the developer conveying screw. Therefore, in this portion, the developer in the other developer conveying screw is sucked, and the developer is smoothly delivered without the stagnation of the developer. For this reason,
Since the stirring and circulation of the developer are performed well, the bias of the developer does not occur. As a result, deterioration in image quality due to unevenness and fogging is also prevented.

According to another aspect of the present invention, there is provided a developing device comprising:
In a developing device having a developing roller and a plurality of developer conveying screws that convey the developer in the axial direction by rotating about an axis, the developer is transferred to another developer conveying screw in one of the developer conveying screws. The transfer portion is provided with centrifugal means for applying an outward pressure to the developer.

This developing device has a centrifugal means for applying an outward pressure to the developer at a portion of the developer conveying screw for transferring the developer to another developer conveying screw. An outward pressure is generated at the corresponding portion of the developer conveying screw to be transferred. Therefore, in this portion, the developer is discharged to another developer conveying screw, and the developer is smoothly delivered without stagnation of the developer. Therefore, the developer is well stirred and circulated, so that the bias of the developer does not occur. As a result, deterioration in image quality due to unevenness and fogging is also prevented.

Further, according to another aspect of the present invention, there is provided a developing device having a developing roller and a plurality of developer conveying screws which rotate around an axis to convey the developer in an axial direction. 1 of the agent transport screw
And a centrifugal means for applying an inward pressure to the developer or a centrifugal means for applying an outward pressure to the developer at a portion where supply or recovery of the developer is performed between the developing roller and the developing roller. Features.

In this developing device, a portion of the developer conveying screw where the developer is supplied and collected between the developing roller and the developing roller is provided with a centripetal means for applying an inward pressure to the developer or an outwardly-directed means for applying the developer to the developer. Since the centrifugal means for applying pressure is provided, an inward pressure or an outward pressure is generated by rotation of the developer conveying screw in a region of the developer conveying screw facing the developing roller. Therefore, as described above, due to the inward pressure, the developer in the vicinity of the developer transport screw is transported while being entangled inside the screw, and the outward pressure causes the developer from another developer transport screw adjacent thereto. Since the movement of the developer is prevented, the developer transport screw transports only the developer near the developer transport screw. For this reason, it is possible to convey only the developer in the vicinity without moving the developer to another developer conveying screw during the conveyance without providing a partition. This prevents the developer that is not sufficiently agitated from being supplied to the developing roller, thereby preventing deterioration in image quality due to unevenness and fogging.

A cleaning device according to the present invention, which has been made to solve the above problems, has a cleaning member for recovering the developer remaining on the image carrier after transfer, and a developer for storing the recovered developer. In a cleaning device having a storage tank and a developer transport screw that transports the developer collected by the cleaning member to the developer storage tank, a centrifugal force that applies an inward pressure to the developer to the developer transport screw Means are provided.

In this cleaning device, since the developer collected by the cleaning member is provided with a centrifugal means for applying an inward pressure to the developer, the developer conveying screw for conveying the developer to the developer storage tank is provided. When the transport screw rotates, an inward pressure is applied to the developer. Then, due to the inward pressure, the developer in the vicinity of the developer transport screw is transported while being wound inside the screw. Thus, it is possible to prevent the generation of the toner plume in the cleaning device.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a developer conveying screw according to the present invention. This embodiment is a developing device and a cleaning device using the developer conveying screw of the present invention.

First, a first embodiment will be described. As shown in FIG. 1, a developing device 1 according to the present embodiment has a supply container 14 for storing a developer and a supply screw 14 and a collection screw 16 provided in parallel with each other. Each of these two screws has a rotatable shaft with a large number of screw blades arranged obliquely. However, the directions of inclination of the respective screw blades are opposite to each other.
Further, as shown in FIG. 3, the supply screw 14 is provided with a centering member 5 for applying an inward pressure to the developer. As shown in FIG. 4, the centripetal member 5 is a blade member that is curved so that the front surface in the direction a, which moves by rotation, faces outward from the axis, and faces inward. As shown in FIG. 5, the collection screw 16 is provided with a centrifugal member 6 for applying an outward pressure to the developer. The centrifugal member 6 is shown in FIG.
As shown in FIG. 4, the blade member is curved so that the front surface in the direction b that moves by rotation from the axis to the outside faces outward.

The shafts of the supply screw 14 and the recovery screw 16 are connected to each other by a gear train 28 outside the developer container 10. Further, the collecting screw 16
Is provided with a motor 30 which is controlled from the main body side of the image forming apparatus. In the gear train 28, the gear 26 of the recovery screw 16 and the gear 24 of the supply screw 14 have the same number of teeth. An intermediate gear 25 is provided between the gear 26 and the gear 24. Thus, when the motor 30 is rotated, the supply screw 14 and the recovery screw 16 rotate at the same speed in the same direction. Further, a toner supply port 40 is provided on the upstream side (the right side in FIG. 1) of the supply screw 14,
From here, toner is supplied into the developer storage tank 10.

These two screws are arranged in the vertical direction as shown in the side sectional view of FIG. 2, and the supply screw 14 is located at the upper stage and the recovery screw 16 is located at the lower stage. In addition, the supply screw 14
A developing roller 18 is provided at a height position between the developing roller 18 and the collecting screw 16 with a part thereof protruding from the developer storage tank 10. The developing roller 18 is located close to the photosensitive drum 90 of the image forming apparatus, and
The toner is applied to the 0 electrostatic latent image and developed.

The operation of the developing device 1 will be described. When the motor 30 is rotated under the control of the image forming apparatus main body, the collection screw 16 coaxial with the motor 30 is rotated. The rotation is also transmitted to the supply screw 14 via the gear train 28, and the supply screw 14 also rotates in the same direction as the recovery screw 16 at a constant speed. By the rotation of the supply screw 14 and the recovery screw 16, a conveying force for the developer in the developer storage tank 10 is generated. However, as described above, the directions of inclination of the screw blades of the supply screw 14 and the recovery screw 16 are opposite, so that the direction of transport of the developer is also upside down. In FIG. 1, the paper is conveyed leftward by the supply screw 14 in the upper stage, and conveyed rightward by the recovery screw 16 in the lower stage. The developer transported by the supply screw 14 and reaching the left end portion falls and moves to the lower recovery screw 16. The developer conveyed by the collection screw 16 and reaching the right end portion overflows upward and moves to the supply screw 14. Thus, the developer circulates counterclockwise in the developer storage tank 10.

Then, with the circulation of the developer, a part of the developer of the upper supply screw 14 is supplied to the developing roller 18. As a result, the developing roller 18 moves the photosensitive drum 9
Thus, development for applying toner to the 0 electrostatic latent image becomes possible. Excess developer on the developing roller 18 is collected by the lower collecting screw 16.

In the circulation of the developer, the supply screw 14 is provided with the centrifugal member 5, so that the rotation of the screw generates an inward pressure on the developer. Due to this inward pressure, the supply screw 14 conveys the developer in the vicinity thereof while winding it inward. On the other hand, since the centrifugal member 6 is provided on the collection screw 16, the outward rotation of the developer is generated by the rotation of the screw. With this outward pressure,
The movement of the developer from the supply screw 14 is prevented, and the recovery screw 16 conveys only the developer in the vicinity thereof. Therefore, the supply screw 14 and the recovery screw 16
And the developer in the middle of the conveyance does not move. For this reason, between the time when the toner is supplied from the toner supply port 40 and the time when the toner is supplied to the developing roller 18, the developer is sufficiently stirred and the developer in which the toner is uniformly dispersed is supplied to the developing roller 18. Further, since the developer recovered by the recovery screw 16 does not move to the supply screw 14, it is not supplied to the developing roller 18 as it is.

Further, in the pumping section 9, the developer conveyed by the collecting screw 16 and reaching the right end is pushed upward by the outward pressure generated by the rotation of the collecting screw 16. Then, the developer pushed upward is sucked by the inward pressure generated by the rotation of the supply screw 14. Therefore, the developer is smoothly delivered without the stagnation of the developer.

As described above in detail, in the present embodiment, the developing device which supplies and recovers the developer to and from the developing roller 18 while circulating the developer by the supply screw 14 and the recovery screw 16 arranged vertically. 1
In the above, the supply screw 14 is provided with the centrifugal member 5 that generates an inward pressure by its rotation, and the recovery screw 16 is provided with the centrifugal member 6 that generates the outward pressure by its rotation. The developer in the vicinity is conveyed while being wound inside, and the collection screw 16 prevents the movement of the developer from the supply screw 14 and conveys only the developer in the vicinity. Therefore, the supply screw 14 and the recovery screw 16
And the developer in the middle of the conveyance does not move. This makes it possible to prevent the developer from moving from the supply screw 14 to the recovery screw 16 without providing a partition between the supply screw 14 and the recovery screw 16.
Further, after the toner supplied from the toner supply port 40 is sufficiently stirred, the developer is supplied to the developing roller 18, while the developer collected by the collecting screw 16 is not supplied to the developing roller 18 as it is.

Further, in the pumping portion 9, the developer is smoothly delivered without the stagnation of the developer. Therefore, the developer is well stirred and circulated, so that the bias of the developer does not occur. Therefore, it is possible to prevent a decrease in image quality due to unevenness and fog.

The present embodiment is merely an example, and does not limit the present invention. Therefore, of course, the present invention provides various improvements without departing from the gist thereof.
Deformation is possible. For example, in the present embodiment, the supply screw 14 provided with the centrifugal member 5 and the recovery screw 16 provided with the centrifugal member 6 are both used, but the same effect is obtained by using only one of the screws. be able to. Further, it goes without saying that the present invention can be applied not only to the case where the developer conveying screw is arranged vertically, but also to a developing device or the like arranged side by side.

Further, in a region where the supply and recovery of the developer to and from the developing roller 18 by the supply screw 14 and the recovery screw 16 are performed, the developer is prevented from moving between the supply screw 14 and the recovery screw 16. When a partition is provided, the centrifugal member 6 is provided for the supply screw 14 and the centrifugal member 6 is provided for the recovery screw 16 only in the pumping portion 9 where the developer is pumped from the recovery screw 16 to the supply screw 14. You can also. In this case, even if there is a partition wall between the supply screw 14 and the recovery screw 16, the developer is smoothly transferred, so that the bias of the developer does not occur.

Next, a second embodiment will be described. As shown in FIG. 7, the developing device 2 according to the present embodiment has a supply screw 46, a recovery screw 42, and a stirring screw 44 provided in parallel with each other. These three are arranged in the vertical direction. That is, the stirring screw 44 is located at the top, the recovery screw 42 is located at the bottom, and the supply screw 46 is located at the middle. Further, the centrifugal member 5 is provided at the pumping portion 9 of the stirring screw 44, and the centrifugal member 6 is provided at the pumping portion 9 of the recovery screw 42. Each screw receives rotational drive from a motor outside the tank and is controlled from the main body side of the image forming apparatus, as in the above-described embodiments. The direction of transport of the developer by each screw is determined by the supply screw 46 and the recovery screw 4.
2 is rightward in the figure, and the stirring screw 44 is leftward in the figure.

In the developing device 2, in the pumping section 9 where the developer is pumped, the developer transported by the collection screw 42 and the supply screw 46 to the right end is rotated by the collection screw 42 located at the lowermost stage. While being pushed upward by the outward pressure generated by the agitating screw 44 located at the uppermost stage.
It is sucked by the inward pressure generated by the rotation of. As a result, the developer is smoothly transferred, and the developer is well stirred and circulated, so that the bias of the developer does not occur.

As described above, according to the present embodiment, the centrifugal member 6 is provided at the pumping portion 9 of the collecting screw 42 and the centrifugal member 5 is provided at the pumping portion 9 of the stirring screw 44, so that the collecting screw 42 is generated. And the inward pressure generated by the agitating screw 44, the developer conveyed by the supply screw 46 and the recovery screw 42 and reaching the right end may stay. It moves to the stirring screw 44 smoothly without any change. Thereby, the developer is well stirred and circulated, so that the bias of the developer does not occur, so that the deterioration of the image quality due to unevenness and fog is prevented.

The embodiments described above are merely examples, and do not limit the present invention. Therefore, naturally, the present invention can be variously modified and modified without departing from the gist thereof. For example, in the present embodiment, the centrifugal member 6 and the centripetal member 5 are provided in the pumping portion 9 of the collection screw 42 and the stirring screw 44, respectively. However, only the centrifugal member 6 is provided in the pumping portion 9 of the collection screw 42. Alternatively, only the centrifugal member 5 may be provided on the pumping portion 9 of the stirring screw 44.

Next, a third embodiment will be described. As shown in FIG. 8, the developing device 3 according to the present embodiment has the same basic configuration as the developing device 2 according to the second embodiment, and includes a supply screw 46, a collection screw 42, and a stirring screw. 44 are provided in parallel with each other. The supply screw 46 is the same as the recovery screw 16 in the first embodiment shown in FIG. Further, the stirring screw 44 is the same as the supply screw 14 in the first embodiment shown in FIG. Further, the collecting screw 42 is provided with the first screw shown in FIG.
In this embodiment, the direction of the inclination of the screw blades of the supply screw 14 is reversed. And
These three are arranged in the vertical direction. That is, the stirring screw 44 is located at the top, the recovery screw 42 is located at the bottom, and the supply screw 46 is located at the middle. Each screw receives rotational drive from a motor outside the tank and is controlled from the main body side of the image forming apparatus, as in the above-described embodiments. In addition, the feeding direction of the developer by each screw is such that the supply screw 46 and the recovery screw 42 are rightward in the figure, and the stirring screw 44 is leftward in the figure.

In the developing device 3, the supply screw 46
Generates an outward pressure, and the stirring screw 44 and the collection screw 42 generate an inward pressure. As in the case of the first embodiment, the developer is transferred between the screws during the conveyance. Will not move. Therefore, after the toner is supplied at the toner supply port 40, the developing roller 1
In the meantime, the developer is sufficiently stirred. Further, since the developer collected by the collecting screw 42 does not move to the supply screw 46, the developing roller 18
Not supplied as is.

As described above, according to the present embodiment, the supply screw 46 is provided with the centripetal member 5 for generating an inward pressure by its rotation, and the stirring screw 44 and the recovery screw 42 are provided with the outward pressure by their rotation. Since the centrifugal member 6 that generates the developer is provided, the developer near the supply screw 46 is conveyed while being rolled inward,
In the stirring screw 44 and the recovery screw 42, the movement of the developer from the supply screw 46 is prevented, and only the developer in the vicinity thereof is transported. Therefore, the developer that is being conveyed does not move between the screws. This makes it possible to prevent the developer from being moved between the screws in the course of transport without providing a partition between the screws. Further, after the toner supplied from the toner supply port 40 is sufficiently stirred, the developer is supplied to the developing roller 18, while the developer recovered by the recovery screw 42 is not supplied to the developing roller 18 as it is. Therefore, it is possible to prevent a decrease in image quality due to unevenness and fog.

The present embodiment is merely an example, and does not limit the present invention. Therefore, of course, the present invention provides various improvements without departing from the gist thereof.
Deformation is possible. For example, it is possible to combine the third embodiment and the second embodiment. By doing so, the stirring and circulation of the developer are performed better.

Next, a fourth embodiment will be described. As shown in FIG. 9, the cleaning device 4 according to the present embodiment includes a cleaning blade 31 that collects the developer remaining on the photosensitive drum 90 after the transfer, and a storage tank that stores the collected developer. And a conveying screw 32 for conveying. The cleaning blade 31 is a rubber blade that is pressed against the photosensitive drum 90 to remove the developer remaining on the photosensitive drum 90 by mechanical force. The transport screw 32 is the same as the supply screw 14 in the first embodiment shown in FIG. The transport screw 32 receives a rotational drive from a motor, and the motor is controlled from the main body side of the image forming apparatus, as in the above-described embodiments.

In the cleaning device 4, the developer remaining on the photosensitive drum 90 after the transfer is removed by the cleaning blade 31, captured by the transport screw 32, and transported to the storage tank. In transporting this developer,
Since the conveying screw 32 is provided with the centrifugal member 5 for applying an inward pressure to the developer, the conveying screw 32
When is rotated, an inward pressure is applied to the developer. The developer is conveyed while being wound inside the conveying screw 32 by the inward pressure.

As described above, according to the present embodiment, since the conveying screw 32 is provided with the centripetal member 5 for generating an inward pressure by its rotation, the cleaning blade 31 is provided.
Is transported while being wound inside by the transport screw 32. Accordingly, it is possible to prevent the generation of the toner plume in the cleaning device 4. Note that the present embodiment is merely an example and does not limit the present invention in any way. Therefore, naturally, the present invention can be variously modified and modified without departing from the gist thereof.

[0044]

As described above, according to the developer conveying screw of the present invention, the centrifugal means for applying an inward pressure to the developer by rotating around the axis, or applying an outward pressure to the developer. Since the centrifugal means is provided, only the developer in the vicinity of the developer conveying screw can be conveyed.

Further, according to the developing device of the present invention, by applying the developer conveying screw to a portion where the developer is transferred, the developer can be smoothly transferred, and the developer can be stirred and cooled. A developing device with good circulation is realized. Further, by applying the developer conveying screw to a portion where the developer is supplied or collected between the developing roller and the developing roller, movement of the developer during conveyance from another adjacent developer conveying screw is prevented, and Even if a partition is not provided between the developer conveying screws, a developing device in which the developer does not move during the conveyance between the developer conveying screws is realized. In these developing devices, deterioration in image quality due to unevenness and fogging is prevented.

According to the cleaning device of the present invention,
By applying such a developer conveying screw, a cleaning device that suppresses the generation of toner smoke is realized.

[Brief description of the drawings]

FIG. 1 is a plan cross-sectional view illustrating a configuration of a developing device according to a first embodiment.

FIG. 2 is a side sectional view of the developing device in FIG. 1;

FIG. 3 illustrates a shape of a supply screw in a developing device according to a first embodiment, a shape of a stirring screw in a developing device according to a third embodiment, and conveyance in a cleaning device according to a fourth embodiment. It is a figure which shows the shape of a screw.

FIG. 4 is a sectional side view of the screw shown in FIG. 3;

FIG. 5 is a diagram illustrating a shape of a recovery screw in a developing device according to a second embodiment and a shape of a supply screw in the developing device according to a third embodiment.

FIG. 6 is a side sectional view of the screw shown in FIG. 5;

FIG. 7 is a plan cross-sectional view illustrating a configuration of a developing device according to a second embodiment.

FIG. 8 is a plan cross-sectional view illustrating a configuration of a developing device according to a third embodiment.

FIG. 9 is a cross-sectional view illustrating a configuration of a cleaning device according to a fourth embodiment.

FIG. 10 is a diagram illustrating a configuration of a conventional developing device.

[Explanation of symbols]

 1, 2, 3 Developing device 4 Cleaning device 5 Centrifugal member 6 Centrifugal member 9 Pumping portion 14, 46 Supply screw 16, 42 Recovery screw 18 Developing roller 31 Cleaning blade 32 Transport screw 40 Toner replenishing section 44 Stirring screw 90 Photoconductor drum

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukihiko Okuno 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Co., Ltd. Osaka International Building Minolta Co., Ltd.

Claims (8)

[Claims] 1. A developer conveying screw which conveys a developer in an axial direction by rotating about an axis, comprising a centering means for applying an inward pressure to the developer. Transfer screw. 2. The developer conveying screw according to claim 1, wherein the centering means is a blade member having a front surface facing inward by rotation and facing inward. 3. A developer conveying screw for conveying a developer in an axial direction by rotating about an axis, comprising a centrifugal means for applying an outward pressure to the developer. screw. 4. The developer conveying screw according to claim 3, wherein the centrifugal means is a blade member having a front surface facing outward by rotation and facing outward. 5. A developing device comprising: a developing roller; and a plurality of developer conveying screws that convey a developer in an axial direction by rotating around an axis, wherein the other developer in one of the developer conveying screws is provided. A developing device comprising: a centrifugal means for applying an inward pressure to a developer at a portion where the developer is transferred from a transport screw. 6. A developing device comprising: a developing roller; and a plurality of developer conveying screws for conveying a developer in an axial direction by rotating about an axis, wherein the other developer in one of the developer conveying screws is provided. A developing device comprising: a centrifugal unit that applies an outward pressure to the developer at a portion where the developer is transferred to the transport screw. 7. A developing apparatus comprising: a developing roller; and a plurality of developer conveying screws that convey the developer in an axial direction by rotating about an axis, wherein the developing roller in one of the developer conveying screws is provided. In the part where the supply or collection of the developer is performed between
A developing device comprising: a centrifugal means for applying an inward pressure to the developer; or a centrifugal means for applying an outward pressure to the developer. 8. A cleaning member for collecting the developer remaining on the image carrier after the transfer, a developer storage tank for storing the collected developer, and a developer for collecting the developer collected by the cleaning member. A cleaning device comprising: a developer conveying screw for conveying to a storage tank; and a centrifugal means for applying an inward pressure to the developer to the developer conveying screw.