JP3233466B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, a printer and the like, and more particularly to an image forming apparatus for returning a developer collected by a cleaning device to a developing device for reuse. is there.

[0002]

2. Description of the Related Art For example, in an image forming apparatus using a two-component developer composed of a toner and a carrier, conventionally, in response to a demand for resource saving, the toner is externally supplied to a toner replenisher in the developing apparatus of the image forming apparatus. Since the used toner (hereinafter, referred to as fresh toner) is completely used in the image forming apparatus, the toner collected from the latent image carrier by the cleaning device (hereinafter, referred to as collected toner) is supplied to a toner replenisher attached to a developing device. A toner recovery method of returning the toner has been proposed. As this type of toner recovery method, the recovered toner is directly pressure-fed into fresh toner in a replenisher,
There is known an apparatus in which the recovered toner is diffused into the fresh toner by the pressure feeding force (for example, Japanese Patent Publication No.
-77517). Further, a latent image carrier, a developing device, and a cleaning device are integrally formed as a replaceable unit, and a toner recycling device for returning the toner collected by the cleaning device to the developing device in the image forming device main body is provided. When the unit is incorporated in the image forming apparatus, the toner replenisher and the cleaning device of the developing device are connected to the toner recycle device via the connection portion, and the toner collected by the cleaning device is returned to the toner replenisher. Is also known (for example, see Japanese Utility Model Application Laid-Open No. 63-194368).

[0003]

Here, the recovered toner generally has a property that it is less easily charged than the fresh toner. It is necessary to receive an action for charging such as stirring. However, the above-mentioned
According to the configurations disclosed in JP-A-77517 and JP-A-63-194368, the collected toner is returned to the toner replenisher containing the fresh toner, so that the collected toner passes through the same path as the transport path through which the fresh toner passes. The toner is not affected by friction, agitation, and other charging effects to the same extent as the fresh toner. As a result, according to the configuration disclosed in the above-mentioned publication, there is a problem that the rising of the charge of the collected toner may be insufficient.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide a method in which a developer collected by a cleaning device is sufficiently triboelectrically charged without providing a new stirring mechanism. It is an object of the present invention to provide an image forming apparatus which can obtain a good image without causing background smear or developer scattering.

[0005]

In order to achieve the above object, the invention according to claim 1 provides a latent image carrier on which a latent image is formed on a surface, and a developer carried on the surface, the developer being attached to the latent image. A developing device having a developer carrier to be supplied to the developer carrier, a rotatable developer stirring and conveying member configured to supply the developer to the developer carrier, and a developing device remaining on the surface of the latent image carrier. An image forming apparatus having a cleaning device for recovering the developer, wherein the rotating shaft of the developer stirring and conveying member is configured to be hollow,
A hollow developer passage communicating with the rotating shaft from the cleaning device to transfer the developer collected by the cleaning device; and a developer passage through the developer passage from the cleaning device through the developer passage. A transport means for transporting the developer to the rotating shaft and a discharge port for discharging the developer into the developing device are provided on a peripheral surface of the rotating shaft of the developer stirring and transporting member. . The invention according to claim 2 is characterized in that a plurality of or one continuous discharge ports are provided independently in the axial direction of the rotation shaft. According to a third aspect of the present invention, the transfer means extends to the inside of the rotation axis, or another transfer means is provided in the rotation axis, and the developing means is axially developed in the rotation axis. A flexible member for discharging the developer into the developing device at a portion corresponding to the discharge port of the transporting means within the rotary shaft, the transporting means being configured to transport the developer. Is provided. Further, according to the invention of claim 4, the size of the outlet is
It is characterized in that it is formed to be larger on the downstream side of the rotating shaft in the developer conveying direction.
The invention according to claim 5 is characterized in that a plurality of the outlets are provided in a spiral arrangement. According to a sixth aspect of the present invention, there is provided an image forming apparatus, comprising: a filter member configured to be detachable so as to prevent the developer in the developing device from entering the rotation shaft from the discharge port; Is disposed at a position covering the. The invention according to claim 7 is characterized in that a bias voltage having the same polarity as that of a developer collected by the cleaning device and used for development is applied to the filter member. The invention of claim 8 is
Extending the transport means into the rotation axis, or
Another transporting means is provided in the rotating shaft, and a rotating shaft transporting means for transporting the developer in the axial direction within the rotating shaft is constituted, and the developer in the developing device is rotated by the rotating shaft. An intake port for taking in the inside is provided on a peripheral surface of the rotation shaft on the upstream side in the developer conveyance direction within the rotation shaft with respect to the discharge port. According to a ninth aspect of the present invention, the developer recovered by the cleaning device is transported to the upstream side in the developer transport direction in the rotating shaft.

[0006]

According to the first aspect of the present invention, the conveying means conveys the developer collected by the cleaning device to the inside of the rotating shaft of the developer stirring and conveying member through the developer flow passage.
The developer conveyed to the inside of the rotation shaft is discharged into the developing device from an outlet formed in the peripheral surface of the rotation shaft of the developer stirring and conveying member, and is reliably subjected to the stirring operation by the developer stirring and conveying member. . According to the second aspect of the present invention, a plurality of or continuous one discharge ports are provided independently in the axial direction of the rotation shaft, and the developer is discharged from the discharge port.
The developer is distributed and discharged in the axial direction of the developer stirring and conveying member. According to the third aspect of the present invention, the developer is transported in the axial direction within the rotating shaft of the developer stirring and transporting member, and the developer is discharged to a portion corresponding to the discharge port into the developing device. The developer is conveyed in the axial direction by the rotating shaft conveying means, and is formed on the peripheral surface of the rotating shaft of the developer stirring and conveying member. The toner is immediately discharged from the discharge port into the developing device. According to the fourth aspect of the present invention, the size of the discharge port is formed so as to be larger at the downstream side of the rotary shaft in the developer transport direction, so that the transported developer amount is relatively large. The developer discharge capacity of the discharge port on the upstream side in the direction becomes lower, and the developer discharge capacity of the discharge port on the downstream side in the transport direction in which the amount of the developer to be transported is relatively small increases. As a result, the discharge amount of the developer at the discharge port on the upstream side and the discharge amount on the downstream side are substantially equal. According to the fifth aspect of the present invention, since a plurality of discharge ports are provided in a spiral arrangement, when the developer stirring / conveying member is rotated, the developer is discharged downward by its own weight so that the developer is discharged particularly well. The discharge port sequentially moves in the axial direction of the rotation axis of the developer stirring and conveying member. Then, the respective discharge ports discharge the developer into the developing device. In the invention according to claim 6, the filter member prevents the developer already in the developing device from entering the rotation shaft from the discharge port. Further, since the filter member is configured to be detachable, when the filter member is clogged with the developer, replacement and cleaning can be easily performed.
According to the seventh aspect of the present invention, since a bias voltage having the same polarity as that of the developer that is collected by the cleaning device and used for development is applied to the filter member, the filter member should be used for development. Foreign substances such as developer and paper powder charged to the opposite polarity to the normal developer are adsorbed without being discharged to the developing device. Further, in the invention according to claim 8, the developer in the developing device is taken into the rotating shaft from the take-in port, and is conveyed to the downstream side in the conveying direction in the turning shaft by the conveying means within the turning shaft. Here, the developer collected by the cleaning device and conveyed into the rotating shaft is mixed and stirred with the developer taken into the rotating shaft from the intake port and conveyed through the rotating shaft, and is discharged from the discharge port. It is discharged into the developing device. According to the ninth aspect of the present invention, since the developer collected by the cleaning device is transported to the upstream side in the developer conveying direction in the rotation shaft, the developer is taken into the rotation shaft from the intake port. The collected developer and the developer collected by the cleaning device are mixed and stirred for a relatively long time to the discharge port.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electrophotographic copying machine (hereinafter referred to as a copying machine) as an image forming apparatus will be described. FIG. 1 is a schematic configuration diagram around a photosensitive drum as a latent image carrier of a copying machine according to the present embodiment. The photosensitive drum 10 as a latent image carrier is driven to rotate clockwise as indicated by an arrow a. The surface of the photoconductor drum 10 is first charged by a uniformly charging charger 11. Thereafter, a light source (not shown) scans the document placed on the platen glass, and the reflected light from the document is radiated to the surface of the photosensitive drum 10 by an optical system such as a mirror or a lens to form an electrostatic latent image. It is formed. This electrostatic latent image is stored in the developing device 1
By 2, for example, a toner of a two-component developer composed of a toner and a carrier is supplied to form a toner image.
This toner image is transferred by a transfer charger 13 onto a transfer sheet fed from the direction of arrow b by a sheet feeding device (not shown) and sent to the surface of the photosensitive drum 10. The transfer paper to which the toner image has been transferred is separated from the surface of the photosensitive drum 10 by the separation charger 14, and is conveyed to a fixing device (not shown) where the toner image is fixed and discharged outside the machine as copy paper. On the other hand, the residual toner is removed by the cleaning device 15 from the surface of the photosensitive drum 10 after the transfer of the toner image, and the surface is prepared for the next image formation.

The developing device 12 includes a developing device 121 and a toner replenishing device 122. The toner supplied to the developing device 121 side is stored in the toner replenishing device 122. In the developing unit 121, a developing roller 16 as a developer carrier is provided at an opening facing the surface of the photosensitive drum 10.
A paddle wheel 17 as a developer agitating / conveying member for supplying a developer comprising a toner and a carrier to the surface of the developing roller 16 while mixing and agitating the developer along a bottom in the developing device casing; Replenisher 12
A spheroid plate 18 for mixing and agitating the toner supplied from 2 with the developer in the developing device 121 and supplying the developer to the paddle wheel 17 is provided.

Further, the cleaning device 15 is provided with a cleaning blade 151 for pressing the leading edge portion against the surface of the photosensitive drum 10 to remove residual toner on the surface of the photosensitive drum 10.
Forms a toner storage portion 152 that stores the removed residual toner.

The developing device 121 and the cleaning device 1
5 is connected by a pipe 19 as a developer passage for returning the toner removed by the cleaning device 15 to the developing device 121.

FIG. 2 shows a pipe 19 and a paddle wheel 17.
It is sectional drawing of a periphery. Here, the paddle wheel 17 includes a hollow cylindrical member 171 as a rotatable rotating shaft that supports both ends of the paddle wheel 17 via bearings 20 on both side walls 121a and 121b of the developing device 121, and the hollow cylindrical member 171. Member 17
1 and a plurality of fins 172 for stirring and transporting the developer. On the inner peripheral surface of the hollow cylindrical member 171, for example, a mesh member 21 as a sheet-like filter member formed of a conductive member such as a metal and having a plurality of fine holes formed in a mesh pattern is detachable. Attached to. The size of each mesh portion of the mesh member 21 is, for example, larger than the particle size of the toner and smaller than the particle size of the carrier in the present embodiment. In addition, the hollow cylindrical member 17
One end 171a of the developing device 121 is open, and the opening protrudes from the side wall 121a of the developing device 121 to the outside. The end portion 171a is a hollow cylindrical portion 2 protruding inside the developing device of the support member 25 attached to the side wall 121a with a screw 25a.
5b is supported via a bearing 26. This bearing 26
Thus, the paddle wheel 17 can be smoothly rotated. Further, the support member 25 also includes a hollow cylindrical portion 25c protruding outside the developing device, and one end of the pipe 19 is connected to the hollow cylindrical portion 25c.

Here, one end of the pipe 19 connecting the developing device 121 and the cleaning device 15 is connected to the developing device 121 as described above, and the other end is connected to the toner storage portion 152 of the cleaning device 15. It is connected to the. Inside the pipe 19, a screw 27 as a conveying means for conveying the toner removed by the cleaning device 15 to the developing device 121 is rotatably provided. The screw 27 also extends inside the hollow cylindrical member 171 of the paddle wheel 17, and the developing device 121
The front end extends to the vicinity of the side wall 121b of the developing device 121. For example, the screw 27 may be provided with a driving device on the cleaning device 15 side, and may be configured to be rotated by the driving device.

A portion of the screw 27 inside the hollow cylindrical member 171 includes two side walls 121a of the developing device 121,
The flexible member 30 is attached between the portions b.
As shown in FIG. 3A, for example, the flexible member 30 is an elongated member having a plurality of protrusions 301 as attachment portions formed on one side edge 30a. The part 301 is affixed to the screw 27. The other side edge 30b is in contact with the inner peripheral surface of the mesh member 21 in the hollow cylindrical member 171 of the paddle wheel 17, as shown in FIG. Here, a flexible member 40 as shown in FIG. 4 can be used instead of the long flexible member 30. This flexible member 40
4A is a member in which an adhesive portion 401 as an attachment portion is formed at one end as shown in FIG. 4A, for example. As shown in FIG. 27. Then, specifically, as shown in FIG. 4C, the flexible member 40 is located at the position of the screw 27 corresponding to the position of the outlet 28 formed on the peripheral surface of the hollow cylindrical member 171 to be described later. By simply attaching the developer, the developer can be sufficiently discharged from the discharge port 28.

In FIG. 2, the other end 171b of the hollow cylindrical member 171 of the paddle wheel 17 is
21 protrudes outward from the side wall 121b, and a hole is formed in the end face. The end 171b is provided with a conductive member 22 which is in contact with the mesh member 21 inside the hollow cylindrical member 171 and whose end protrudes from the hole to the outside of the hollow cylindrical member 171. The end of the conductive member 22 protruding outside the hollow cylindrical member 171 is
A bias voltage having the same polarity as the polarity of the normal toner used for development is applied, and connected to the electrode 24 attached to the electrode holder 23. A paddle wheel drive gear 29 for transmitting drive from a drive source (not shown) to the paddle wheel 17 and rotating the paddle wheel 17 in a predetermined direction is attached to an end 171b of the hollow cylindrical member 171.

A plurality of openings are formed in the peripheral surface of the hollow cylindrical member 171 of the paddle wheel 17 as shown in FIG. 5, and these are removed by the cleaning device 15 and conveyed to the developing device 121. Developing toner 12
The outlets 28a to 28n for supplying the inside of the nozzle 1 are formed.
The opening area of the outlets 28a to 28n is
The hollow cylindrical member 171 is configured to increase in size in order from the discharge port 28a located on the most upstream side in the toner conveying direction to the discharge port 28n located on the most downstream side. Further, the outlets 28a to 28n are arranged such that their arrangement is on the peripheral surface of the hollow cylindrical member 171 of the paddle wheel 17.
It is formed to be spiral.

In the above configuration, the cleaning device 1
5 removes the toner from the surface of the photoconductor drum 10 by a screw 27 extending into the cleaning device 15.
Thereby, the inside of the pipe 19 is transported toward the developing device 121. When the toner is conveyed through the hollow cylindrical member 171 of the paddle wheel 17, the flexible member 30 causes the mesh member 2 to pass through one of the outlets 28a to 28n.
1 and return to the developing device 121.

Here, as for the toner conveyed in the hollow cylindrical member 171 of the paddle wheel 17, only the toner remaining without dropping at the discharge port 28 on the upstream side in the conveying direction is conveyed to the downstream side, and the toner discharged on the downstream side is discharged. It falls from the exit 28. Therefore, when each of the outlets 28a to 28n has a uniform opening area large enough to drop a sufficient amount of toner, the outlet of the hollow cylindrical member 171 of the paddle wheel 17 on the upstream side in the toner transport direction is provided. At the outlet 28, a large amount of toner is
1, and the amount of toner conveyed downstream is reduced. Therefore, the amount of toner falling from the outlet 28 located on the downstream side in the toner conveying direction is extremely small as compared with the amount on the upstream side. As a result, the toner amount differs in the axial direction of the paddle wheel 17 in the developing device 121, and the developer concentration in the developing device 121 becomes uneven. However, in the present embodiment, the opening area of the discharge ports 28a to 28n is configured to increase toward the downstream side of the hollow cylindrical member 171 of the paddle wheel 17 in the toner transport direction, so that the amount of toner transported is reduced. The relatively large amount of toner discharged from the discharge port 28 on the upstream side in the transport direction is reduced, and the amount of toner discharged from the downstream discharge port 28 on the downstream side in the transport direction is relatively high. as a result,
The amount of discharged toner at the discharge port 28 on the upstream side in the transport direction and the discharge port 28 on the downstream side can be made substantially equal. Therefore, the toner amount in the axial direction of the paddle wheel 17 in the developing device 121 does not become extremely uneven.

The toner returned into the developing device 121 is mixed and stirred with the developer already in the developing device 121 by the paddle wheel 17 immediately after the toner is returned. Here, when the paddle wheel 17 is rotated to mix and stir the developer including the toner and the carrier, the developer is discharged from the discharge port 2.
8a to 28n may collect around the discharge ports 28a to 28n.
28n is covered from the inside of the hollow cylindrical member 171 by the mesh member 21 having a mesh portion formed to be smaller than the particle size of the developer carrier, so that the carrier is discharged from the outlets 28a to 28n to the hollow cylindrical member 171. It can be prevented from flowing into the inside.

Since a bias voltage having the same polarity as that of the regular toner used for development is applied to the mesh member 21 from the electrode 24 via the conductive member 22,
Foreign matter such as paper powder charged to the opposite polarity to the normal toner and toner having poor charging characteristics charged to the opposite polarity to the normal polarity adhere to the mesh member 21 and become
Only the toner charged to the normal polarity is supplied to the developing device 121.

When the mesh member 21 is used for a long period of time, the mesh portion is clogged with foreign matters such as toner and the above-mentioned paper dust, and the toner removed and conveyed by the cleaning device 15 can be returned to the developing device 121. Disappears. Therefore, in this embodiment, the screw 25a is removed and one end 25b of the support member 25 is connected to the hollow cylindrical member 1.
By removing the mesh member 21 from one end 171a, the replacement or cleaning of the mesh member 21 can be easily performed.

In this embodiment, as shown in FIG. 1, a toner concentration detecting means which can be constituted by, for example, an optical sensor for detecting the toner concentration on the photosensitive drum 10 around the photosensitive drum 10. A screw 30 is configured to be driven to rotate by a detection signal of the toner concentration detecting means 30. For example, a reference pattern is formed on the photosensitive drum 10, and the toner density of the reference pattern is detected by the toner density detection unit 30. When the toner density is lower than a certain reference value, the toner is transferred from the cleaning device 15 to the developing device 121. Is configured to rotate the screw 27 so as to convey. Here, the reference value is set to the developing device 121 of the toner replenishing device 122.
May be the same as or different from the ON / OFF signal for controlling the toner replenishment operation for. Further, the toner density detecting means 30 is not limited to the one arranged around the photosensitive drum 10 as described above, but may be provided in the developing device 121. Further, the image area of the original may be measured, and when the image area reaches a certain reference image area, the screw 27 may be rotated so as to convey the toner from the cleaning device 15 to the developing device 121.

In addition, instead of forming a plurality of independent discharge ports 28a to 28n as the discharge port 28, the hollow cylindrical member 1 is formed so that the opening width increases toward the downstream side.
One opening may be formed over substantially the entire width of the opening 71. Further, based on the opening area of the most upstream discharge port 28a in the transport direction in the hollow cylindrical member 171 of the paddle wheel 17, instead of the next discharge port 28b, the same aperture as the reference discharge port 28a is used. Two outlets having the same area are arranged in the circumferential direction of the hollow cylindrical member 171.
Instead of c, three discharge ports having the same opening area as the reference discharge port 28a are arranged in the circumferential direction of the hollow cylindrical member 171.
The configuration may be such that the number of the hollow cylindrical members 171 is increased toward the downstream side in the toner conveying direction.

Next, another embodiment of the present invention will be described. FIG. 6 is a schematic configuration diagram of the periphery of the photosensitive drum of the copying machine according to the present embodiment, and FIG. 7 is a paddle wheel 17 ′ in the developing device 12.
It is a partial sectional view of the periphery. In the copying machine of the present embodiment, similarly to the above-described embodiment, the developing device 121 and the cleaning device 15 are connected to each other by the pipe 19 as a developer passage for returning the toner removed by the cleaning device 15 to the developing device 121. It is connected. As a result, the toner removed from the surface of the photosensitive drum 10 by the cleaning device 15 is conveyed in the pipe 19 toward the developing device 121 by the screw 27 ′ extending into the cleaning device 15. Then, in the developing device 121, it is conveyed through the hollow cylindrical member 171 ′ of the paddle wheel 17 ′, discharged through the discharge port 28 ′, and returned to the developing device 121. The difference between the copying machine of the present embodiment and the copying machine of the above embodiment is that in the copying machine of the above embodiment, the hollow paddle wheel 1 is provided.
7 is used only for conveying the collected toner from the cleaning device 15, whereas in this embodiment, the developing device 12
1 is also used for transporting the developer for horizontal stirring of the developer.

That is, the developer in the developing device 121 is loaded into the hollow cylindrical member 171 'on the upstream side (the right side in FIG. 7) of the peripheral surface of the hollow cylindrical member 171' of the paddle wheel 17 'in the developer transport direction. An intake port 70 for taking in is formed. Further, on the downstream side (left side in FIG. 7) of the peripheral surface of the hollow cylindrical member 171 ′ in the developer transport direction, a hollow cylindrical member 171 ′ is provided.
An outlet 28 'for discharging the developer conveyed inside 1' is formed. Thereby, the developer taken into the hollow cylindrical member 171 ′ from the intake port 70 is conveyed in the axial direction by the screw 27 ′ extending into the hollow cylindrical member 171 ′, and is discharged from the discharge port 28 ′. , The developer is laterally stirred. Further, in the illustrated example, a spiral 71 is provided spirally at the tip of the fin 172 of the paddle wheel 17 ′ over the entire width of the paddle wheel 17 ′, so that the developer conveyance direction in the hollow cylindrical member 171 ′ is The developer can be transported in the opposite direction. In the illustrated example, the side wall 121 of the developing device 121 is used.
b, a part of the large-diameter portion 72 at the tip of the shaft of the screw 27 ′ rotatably supported by the inner peripheral portion of the hollow cylindrical member 171 ′ is connected to the end 1 of the hollow cylindrical member 171 ′.
A screw drive gear 73 for receiving a drive from a drive source (not shown) and rotating the screw 27 ′ in a predetermined direction is attached to the projecting portion.

In the above configuration, when the paddle wheel 17 'rotates in a predetermined direction, the developer in the developing device 121 flows from the downstream side in the hollow cylindrical member 171' to the upstream side in the transport direction of the developer by the spiral 71. (In the direction of arrow a). Then, the developer transported to the upstream side (the right side in FIG. 7) in the developer transport direction is taken into the hollow cylindrical member 171 ′ from the intake port 70. On the other hand, the toner conveyed from the cleaning device 15 by the screw 27 ′ is stirred and conveyed (in the direction of arrow b) toward the end 171 b of the hollow cylindrical member 171 ′ by the rotation of the screw 27 ′. Here, the developer taken into the hollow cylindrical member 171 ′ from the intake port 70 and the toner carried from the cleaning device 15 are conveyed in the direction of the end 171b while being mixed and stirred, and are discharged from the discharge port 28 ′. It is discharged into the developing device 121.

Therefore, according to the present embodiment, the collected toner having poor charging characteristics is supplied from the intake port 70 to the hollow cylindrical member 1.
Developer and hollow cylindrical member 17 taken in 71 '
Since the mixture is stirred within 1 ′, the charge is sufficiently started.

[0027]

According to the first aspect of the present invention, the developer conveyed to the inside of the rotation shaft is discharged into the developing device from the discharge port formed in the peripheral surface of the rotation shaft of the developer stirring and conveying member. As a result, the developer is reliably subjected to the stirring action by the developer stirring and conveying member, so that the charge is sufficiently started up as compared with the related art, and a good image without background smear, developer scattering, white spots, etc. can be obtained. There is an effect that can be. According to the second aspect of the present invention, the developer collected by the cleaning device and transported to the inside of the rotating shaft of the developer stirring and conveying member is distributed in the axial direction of the developer stirring and conveying member and discharged into the developing device. Therefore, the developer in the developing device is mixed and stirred to have a substantially uniform concentration, and as a result, there is an effect that a good image free from background smear and uneven density can be obtained. According to the third aspect of the present invention, the developer is transported in the axial direction by the rotating shaft transporting means, and is quickly discharged into the developing device from the discharge port formed on the rotating shaft peripheral surface of the developer stirring and transporting member. Therefore, there is an effect that it does not stay in the rotating shaft for a long time and is not fixed or aggregated. According to the fourth aspect of the present invention, since the amount of discharged developer at the upstream discharge port and the downstream discharge port in the developer conveyance direction are substantially equal, the developer in the developing device is mixed to a substantially uniform concentration. As a result, there is an effect that it is possible to obtain a good image free from background contamination and uneven density. According to the fifth aspect of the present invention, by rotating the developer stirring and conveying member, the position of the discharge port for discharging the developer moves in the axial direction of the rotation axis of the developer stirring and conveying member, Since each outlet discharges the developer into the developing device, the developer is
The developer is distributed in the axial direction of the developer stirring and conveying member without being accumulated in the rotating shaft, and is surely discharged into the developing device. Further, the developer in the developing device is mixed and stirred to a substantially uniform concentration. There is an effect that it is possible to obtain a good image free from dirt and uneven density. According to the sixth aspect of the present invention, the filter member is configured to be detachable and can be easily replaced and cleaned when clogged with the developer. There is an effect that the developer transported to the developing device can be surely discharged into the developing device without being accumulated in the rotating shaft. According to the invention of claim 7,
The filter member adsorbs foreign substances such as developer and paper powder charged to the opposite polarity to the regular developer to be used for development without discharging them to the developing device. Only the developed developer is discharged, and there is an effect that it is possible to obtain a good image free from white spots and background stains. According to the eighth aspect of the present invention, the developer collected by the cleaning device and transported to the inside of the rotating shaft is taken into the rotating shaft from the intake port by the in-rotating-shaft conveying means, and is taken into the rotating shaft. Is mixed and stirred with the developer to be conveyed, and is discharged into the developing device from the discharge port. Therefore, the stirring operation is surely performed, the charge is sufficiently started, the background is stained, the developer is scattered, white spots, etc. There is an effect that it is possible to obtain a good image free from defects. According to the ninth aspect of the present invention, the developer taken into the rotary shaft from the intake port and the developer collected by the cleaning device are mixed and stirred for a relatively long time to the discharge port. The lifting is sufficiently performed, and the agglomerated developer is also pulverized, so that it is possible to obtain a good image free from background smear, developer scattering, white spots and the like.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram around a photosensitive drum as a latent image carrier of a copying machine according to an embodiment.

FIG. 2 is a sectional view around a pipe 19 and a paddle wheel 17.

FIG. 3A is an explanatory view of a flexible member 30.
(B) is sectional drawing of the paddle wheel 17 of FIG.

FIG. 4A is an explanatory view of another flexible member. (B) is an explanatory view of an example of attachment of the flexible member. (C) is an explanatory view of an example of attachment of the screw 27 provided with the flexible member in the hollow cylindrical member 171.

FIG. 5 is an explanatory view of a receiving port 28.

FIG. 6 is a schematic configuration diagram around a photosensitive drum of a copying machine according to another embodiment.

FIG. 7 is a cross-sectional view around a paddle wheel 17 'in a developing device of the copying machine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoconductor drum 12 developing device 15 cleaning device 16 developing roller 17 paddle wheel 19 pipe 27 screw 28 a to 28 n outlet 21 mesh member 22 conductive member 23 electrode holder 24 electrode 29 paddle wheel driving gear 70 intake 71 spiral 72 large diameter portion

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuhisa Sudo 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-51-73444 (JP, A) JP-A Sho 54-121133 (JP, A) Hikaru Hei 3-43662 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 21/10-21/12 G03G 15/08-15 / 08 507

Claims (9)

(57) [Claims] A latent image carrier on which a latent image is formed, a developer carrier for supplying a developer carried on the surface to the latent image, and a developer for the developer carrier. An image forming apparatus comprising: a developing device having a rotatable developer stirring / conveying member for supplying; and a cleaning device for collecting a developer remaining on the surface of the latent image carrier. A hollow developer communication passage which communicates with the rotating shaft from the cleaning device and through which the developer recovered by the cleaning device is transferred; and And a discharge means for discharging the developer into the developing device on a peripheral surface of the rotating shaft of the developer stirring and conveying member. An image forming apparatus, comprising: 2. The image forming apparatus according to claim 1, wherein a plurality of or one continuous discharge port is provided independently in the axial direction of the rotation shaft. 3. The developing device according to claim 1, wherein said conveying means extends into said rotating shaft, or another conveying means is provided in said rotating shaft to convey the developer in said rotating shaft in the axial direction. A flexible member for discharging the developer into the developing device is provided at a portion corresponding to the discharge port of the transporting means in the rotating shaft, which constitutes the rotating shaft transporting means. The image forming apparatus according to claim 1, wherein: 4. The image forming apparatus according to claim 2, wherein the size of the discharge port is larger at a position downstream of the rotary shaft in the developer conveying direction. 5. An image forming apparatus according to claim 1, wherein a plurality of said discharge ports are provided in a spiral arrangement. 6. A detachable filter member for preventing a developer in the developing device from entering the rotary shaft from the discharge port is provided at a position covering at least the discharge port. 2. An arrangement according to claim 1, wherein
Image forming apparatus. 7. An image forming apparatus according to claim 6, wherein a bias voltage having the same polarity as that of a developer collected by said cleaning device and used for development is applied to said filter member. 8. The developing device according to claim 1, wherein said transport means extends into said rotary shaft, or another transport means is provided in said rotary shaft to transport developer in the axial direction within said rotary shaft. The rotating shaft transport means is constituted, and an inlet for taking in the developer in the developing device into the rotating shaft is provided at a position upstream of the discharge port in the developer transport direction within the rotating shaft. The image forming apparatus according to claim 1, wherein the image forming apparatus is provided on a peripheral surface of the rotation shaft. 9. An image forming apparatus according to claim 8, wherein the developer collected by said cleaning device is transported to an upstream side in a direction of transporting the developer within said rotating shaft.