JPH07168433A - Developing device - Google Patents

Abstract

PURPOSE:To prevent foreign matter or a toner agglomerate from being carried into a developing unit again, even if the foreign matter enters the developing unit or the toner agglomerate is formed in the developing unit. CONSTITUTION:A filter 52 blocking the passage of the material of a prescribed grain size or above, that is, the material larger than the grain size of conventional normal toner as a concrete example is provided on a toner circulating path between first/second toner carrying screws 26 and 27 in each toner hopper 5, the foreign matter and the toner agglomerate are separated from the toner by the filter 52 and prevented from being carried to the developing unit, again. Moreover, an opening 53 communicated with the outside, so as to be opened/ closed by a shutter 54 is formed on the side nearer to the second toner carrying screw 27 than the filter 52 of each toner hopper 5, to discharge the foreign matter and the toner agglomerate outside a machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device applied to an image forming apparatus such as a copying machine, a facsimile or a printer, and more specifically to an opening provided at a portion facing a latent image carrier and the opening. A developing device having a developer carrying member arranged so that a part of the developing device is exposed, and a developer for supplying the developing device to the developing device. A developer storage portion, a supply transport member that transports and supplies the developer in the developer storage portion to the developing device, and a surplus developer that has not contributed to development is transported to the developer storage portion and collected. The present invention relates to a developing device having a collecting and transporting member.

[0002]

2. Description of the Related Art Conventionally, a latent image carrier is exposed with a color-separated light image, each formed latent image is developed with a toner having a complementary color of the color-separated light, and a plurality of obtained toner images are formed on the same transfer paper. Full-color image forming apparatus such as a full-color copying machine that superimposes and transfers the images on the latent image carrier, and the latent images are separately exposed to the images to be reproduced in different colors, and the formed latent images are developed in different colors. 2. Description of the Related Art A multicolor image forming apparatus or the like is known in which a plurality of toner images obtained by developing with a developing agent are superposed and transferred onto the same transfer paper. These image forming apparatuses require a plurality of developing devices for developing a plurality of colors. However, if each developing device is separately configured and installed in parallel around the latent image carrier, the size of the device increases. There was a drawback that it would end up.

Therefore, conventionally, a rotary member is provided so as to be close to the latent image bearing member, and a plurality of developing devices are supported at predetermined positions by the rotary member so that each developing device is supported by the latent image bearing member. A rotary developing device has been developed in which a latent image on a latent image carrier is developed with toner of each color by sequentially rotating and conveying the toners to opposite developing positions.

Here, in such a rotary developing device, a hollow toner supply member having an opening for discharging toner is provided so as to extend in the longitudinal direction inside each developing device, and each developing device is developed. Contains toner to be replenished in the container,
A replenishment toner accommodating portion provided separately from each developing device and the toner supply member are connected by a flexible cylinder, and a flexibility such as a screw provided in the replenishment toner accommodating portion and the cylinder is provided. It is known that the toner is conveyed from the replenishment toner storage portion to the corresponding developing device by the above conveying member (for example, see Japanese Patent Laid-Open No. 60-233668).

Further, a hopper portion is constituted so that the toner is accommodated in each developing device, and a predetermined amount of toner is retained by the rotating operation of the developing device in the vicinity of the developer carrier in each developing device. Those provided are also known (for example, Shokai Sho 6
3-153258).

[0006]

However, the above-mentioned Japanese Unexamined Patent Application Publication No.
As described in Japanese Patent Application Laid-Open No. 0-233668, a replenishment toner accommodating portion provided separately from each developing device is connected to each developing device by a flexible cylindrical body, and is conveyed from the replenishment toner accommodating portion by a conveying member. In the rotary type developing device configured to convey the toner to the developing device, a driving means for driving the conveying member that conveys the toner from the replenishment toner storage portion to the developing device is required, which makes the device complicated and high. There is a drawback that the cost is high, and the toner that is transported from the replenishment toner storage portion to the developing device is always subjected to mechanical force by the transport member, so that it is deteriorated early.

Further, as shown in Japanese Utility Model Laid-Open No. 63-153258, the toner is accommodated in each developing device, and the developing is carried out in the vicinity of the developer carrying member in each developing device. In a rotary developing device having a hopper portion in which a predetermined amount of toner is retained by the rotating operation of the device, if a large amount of toner is stored in each developing device in advance,
There is a drawback that the entire developing device becomes large.
Further, when the amount of toner in the axial direction of the developer carrier becomes non-uniform due to the use of the developing device, the amount of toner cannot be made uniform only by the rotation operation, and there is sufficient toner in the hopper. However, there is a drawback that uneven density may occur in the image.

In view of the above-mentioned drawbacks, the applicant of the present invention has integrally provided a hopper portion for accommodating the toner to be supplied to each developing device, for example, on the end side of each developing device, and supplying toner to this hopper portion. A replenishment toner accommodating portion for accommodating the replenishment toner is attached to the hopper so that the interiors of the hopper and the replenishment toner accommodating portion are communicated with each other. A rotary developing device has been proposed in which the toner is supplied from the developing unit to the developing unit and the excess toner is collected from the developing unit to the hopper unit by a conveying member such as a screw.

In the rotary developing device having this structure, the toner can be replenished from the replenishment toner storage portion to the hopper portion without using any mechanical toner conveying mechanism.
Further, since the toner used in the developing device is stored in the hopper portion and the replenishment toner storing portion and is not directly stored in the developing device, the developing device can be downsized, It is possible to prevent the entire apparatus from increasing in size.

However, as described above, in the developing device constructed so that the toner is supplied from the hopper to the developing unit and the excess toner is collected from the developing unit to the hopper by a conveying member such as a screw, If foreign matter such as paper powder enters the container or if some toner agglomerates to form a large lump, the foreign material and toner agglomerates are temporarily discharged from the developing device to the hopper by the conveying member. However, it is again conveyed to the developing device by the conveying member.

When the above-mentioned foreign matters and toner aggregates are conveyed to the developing device, the toner layer formed on the surface of the developer carrying member is disturbed and, as a result, the image is disturbed. There was a problem.

The present invention has been made in view of the above problems, and an object of the present invention is to supply a developer from a developer accommodating portion to a developing device and from the developing device to the developer accommodating portion. In a developing device configured to collect excess developer by a conveying member, even if foreign matter enters the developing device or a developer aggregate is formed in the developing device, the foreign matter and the developer aggregate Is to be prevented from being conveyed again into the developing device after being once collected in the developer accommodating portion.

[0013]

In order to achieve the above object, the invention of claim 1 is such that an opening is provided at a portion facing a latent image carrier and a part thereof is exposed from the opening. And a developer accommodating portion configured to communicate with the developing device, the developer accommodating portion accommodating a developer to be supplied to the developing device. Development having a supply transport member that transports and supplies the developer in the developer storage unit to the developing device, and a recovery transport member that transports and recovers the excess developer that has not contributed to development to the developer storage unit In the apparatus, a filter is provided in the developer accommodating portion so as to prevent passage of substances having a predetermined particle size or more. According to a second aspect of the invention, in the developing device according to the first aspect,
A plurality of the developing devices are arranged around a rotation shaft, and the plurality of developing devices are rotated about the rotation shaft to displace any developing device to a developing position facing the latent image carrier to perform development. It is characterized by being configured to perform. According to a third aspect of the present invention, in the developing device according to the first or second aspect, the filter is provided on a moving path of the excess developer collected in the developer accommodating portion to the supply transport member. It is what The invention of claim 4 relates to claim 1,
In the second or third developing device, the developer accommodating portion is provided with an opening that is opened and closed by a shutter and communicates with the outside. The invention of claim 5 is
The developing device according to claim 4 is characterized in that the opening is provided closer to the collecting and conveying member than the filter in the developer accommodating portion.

[0014]

According to the first aspect of the invention, the developer in the developer accommodating portion is conveyed and supplied to the developing device by the supplying and conveying member. Further, the excess developer that has not contributed to the development is conveyed from the developing device to the developer accommodating portion by the collecting and conveying member and is collected. Then, the excess developer collected in the developer accommodating portion is again conveyed by the supply conveying member in the longitudinal direction of the developer carrier and is supplied. Here, since a filter is provided in the developer accommodating portion to prevent passage of a substance having a predetermined particle size or more, foreign matter that has entered the developing device and developer aggregates formed in the developing device are excessive. Even if the developer and the developer are collected in the developer accommodating portion, the foreign matter and the developer aggregate can be separated from the developer by using the filter.

According to a second aspect of the present invention, a plurality of the developing devices are arranged around a rotating shaft, and the developing devices are rotated about the rotating shaft so that any developing device can be used as the latent image carrier. Since the development is carried out by displacing it to the developing position opposite to the above, even if the foreign matter or the developer agglomerate adheres to the surface of the filter, the developer accommodating part is also rotated together with the rotation of the developing device. The foreign matter and the developer aggregate can be separated from the filter surface by the rotation.

In the third aspect of the invention, since the filter is provided on the moving path of the surplus developer recovered in the developer accommodating portion to the supply conveying member, the recovering conveying member accommodates the developer. The excess developer collected in the section is not conveyed to the developing device again unless it passes through the filter and the filter. Therefore, the foreign matter and the developer agglomerate collected in the developer accommodating portion by the collecting and conveying member are reliably separated from the surplus developer by the filter when moving along with the surplus developer in the circulation path.

According to the fourth aspect of the present invention, the developer accommodating portion is provided with an opening which is opened and closed by a shutter and communicates with the outside. Even when accumulated in the developer accommodating portion, the foreign matter and the developer aggregate can be discharged to the outside of the machine through the opening.

According to the fifth aspect of the invention, since the opening is provided closer to the collecting and conveying member than the filter in the developer accommodating portion, the foreign matter and the developer aggregate accumulated in the developer accommodating portion are machined. It is possible to prevent the normal developer from being excessively discarded when discharged to the outside.

[0019]

EXAMPLES An example of the developing device of the present invention will be described below. FIG. 1 is a schematic cross-sectional configuration diagram of a rotary developing device according to the present embodiment applied to an image forming apparatus such as a copying machine, a facsimile, a printer. Note that FIG. 1 shows a state in which a developing unit as one developing unit, for example, a yellow developing unit described later is in the developing position. As shown in FIG. 1, a rotary type (also referred to as a revolver type or a rotary type) developing device (hereinafter referred to as a developing device) 20 is arranged in the vicinity of a drum-shaped photoconductor 30 as a latent image carrier. . The developing device 20 is configured such that a yellow developing device 22Y, a magenta developing device 22M, a cyan developing device 22C, and a black developing device 22K are housed in a casing 21. The developing device 20 is rotatably provided around the central axis of rotation, and the casing 2
For example, it is rotated in the direction indicated by arrow A by a drive mechanism (not shown). By this rotation, the developing devices 22Y, 22M,
Any developing device of 22C and 22K can be moved to a developing position facing the photoconductor 30.

Developing units 22Y, 22M, 22 of this embodiment
C and 22K are developing devices using a non-magnetic one-component developer,
Yellow, magenta, cyan, and black toners are contained, respectively, and the electrostatic latent image is visualized by supplying the toner to the electrostatic latent image formed on the photoconductor 30. The developing devices 22Y, 22M, 22C and 22K have cylindrical developing rollers 23Y, 23M,
23C and 23K are provided, respectively. The developing rollers 23Y, 23M, 23C, and 23K are connected to the developing devices 2
Openings 22 provided in 2Y, 22M, 22C, 22K
It is arranged so that a part of each is exposed to the outside from a.

The developing device 20 having the above-described structure is rotated about the central axis of rotation so that each of the developing devices 22Y, 22M, 22C and 22K is selectively placed at the developing position in synchronization with the color information. The developing units 22Y, 22M, 22C and 22K have the developing rollers 23Y, 23M, 23C and 2 at the developing position.
3K is rotated in the direction of arrow B in the figure to sequentially develop the corresponding electrostatic latent images formed on the photoconductor 30. Then, the developed images are superposed on a transfer sheet (not shown) to form a full-color image.

Hereinafter, each developing device 22Y,
22M, 22C, 22K will be described in detail. Since the respective color developing devices 22Y, 22M, 22C and 22K have the same form and the same operation, in the following description, the yellow developing device 22Y will be described as an example and the other developing devices 22M, 22C,
Description of 22K is omitted. In addition, each developing device 22
About the same corresponding member in Y, 22M, 22C, and 22K, only the alphabetic character at the end of the reference numeral in FIG. 1 is changed and shown. FIG. 2 is a schematic configuration diagram of a developing device that constitutes the developing device 20, that is, a yellow developing device 22Y in this case. In FIG. 2, the developing device 22Y is arranged below the photoconductor 30 when used for development, and supplies yellow toner as a non-magnetic one-component developer to the electrostatic latent image formed on the photoconductor 30.

An opening 22a is formed in the upper part of the casing 28Y of the yellow developing device 22Y at the developing position. A developing roller 23Y is provided in the opening 22a so as to face the photoconductor 30 at a predetermined peripheral speed ratio with the photoconductor 30 and at the portion facing the photoconductor 30.
It is arranged so as to rotate in the same direction as the zero movement direction.

Below the developing roller 23Y, a supply roller 24Y made of an elastic material such as foamed polyurethane as a toner supply member slides on the developing roller 23Y, and
The developing roller 23Y has a predetermined peripheral speed ratio with respect to the developing roller 23Y at the sliding portion 220Y with the developing roller 23Y.
It is provided so as to rotate in the same direction as the rotation direction of Y.

A blade 25Y made of an elastic material such as urethane rubber is provided near the free end of the developing roller 23Y in the rotational direction downstream of the position where the supply roller 24Y is disposed and near the opening 22a. Are provided so as to contact the developing roller 23Y.

On the left side of the rubbing portion 220Y in the drawing, a screw-shaped first toner conveying member (hereinafter, referred to as a supply conveying member for conveying toner from the front side to the rear side of the drawing).
A first toner carrying screw (26Y), and a screw-shaped second toner carrying member (hereinafter, referred to as a first toner carrying screw) as a collecting and carrying member for carrying the toner from the back side of the paper toward the front side below the supply roller 24Y. A two-toner conveying screw) 27Y is provided. The details of the first toner carrying screw 26Y and the second toner carrying screw 27Y will be described later.

As shown in FIGS. 2B and 3, a toner hopper 5Y as a developer accommodating portion is provided at the longitudinal end of the yellow developing device 22Y. Here, the toner conveying screw 26Y is the toner hopper 5Y.
To the other end of the yellow developing device 22Y in the longitudinal direction, the developing roller 23Y and the supplying roller 24Y are arranged in parallel with each other, and the toner is conveyed from the toner hopper 5Y to the other end of the yellow developing device 22Y. It is interlocked with the roller 23Y and the supply roller 24Y, and is rotated at a predetermined peripheral speed ratio. Further, the casing 28Y is shown in FIG.
As shown in (a), a part thereof is formed so as to contact the supply roller 24Y, and the developing roller 23Y, the supply roller 24Y, and the casing 28Y form a toner carrying space 221Y surrounding the toner carrying member 26Y. .

Then, the first toner carrying screw 26Y
Rotates in a predetermined direction to convey the toner from the toner hopper 5Y into the toner conveying space 221Y, and supplies the toner onto the supply roller 24Y. Supply roller 24
The toner supplied onto Y is supplied to the surface of the developing roller 23Y while being charged by being rubbed by the supply roller 24Y and the developing roller 23Y in the rubbing portion 220Y, and is carried on the surface of the developing roller 23Y. The toner carried on the surface of the developing roller 23Y is uniformly distributed by the blade 25Y, and
The electrostatic latent image formed on the surface of the photoconductor 30 in a thin toner layer having a predetermined thickness is developed by contact or non-contact development.

By the way, the toner not used in the developing step is conveyed to the end portion of the developing device opposite to the toner hopper 5Y by the first toner conveying screw 27Y.
As shown in FIG. 2B, a toner circulating portion 222Y is provided outside the axially effective diameter portion of the developing roller 23Y and the supply roller 24Y at the end of the developing device opposite to the toner hopper 5Y.
Is provided. The toner carried by the first toner carrying screw 26Y to the toner circulating portion 222Y falls under the yellow developing device 22Y due to gravity.

In the lower part of the yellow developing device 22Y, the second
The toner transport screw 27Y is the developing roller 23Y,
Supply roller 24Y and first toner transport screw 26Y
Is arranged in parallel with the first toner carrying screw 26.
The toner is rotated so as to convey the toner in the direction opposite to Y, and the toner not used in the above-described developing process is transferred to the toner hopper 5Y.
Transport to. First toner carrying screw 26Y and second toner
By appropriately setting the carry amount of the toner carrying screw 27Y, the toner can be supplied onto the supply roller 24Y without performing the toner amount detection in the yellow developing device 22Y and the complicated supply amount control, and the layout flexibility is increased. It is possible to provide a small-sized developing device that is large and has a small cross-sectional occupancy ratio to the photoconductor.

By the way, the developing device 20 having the above structure
, The developing units 22Y, 22
Toner cartridges 1 as replenishment developer accommodating portions having the same configuration are attached to M, 22C, and 22K. Specifically, each toner cartridge 1 is arranged in the developing device longitudinal direction so as to replenish the toner stored in the toner hoppers 5Y, 5M, 5C, and 5K of the developing devices 22Y, 22M, 22C, and 22K from above. The toner hoppers 5Y, 5M, 5C, and 5K are attached from the direction orthogonal to. Hereinafter, the structure of the toner cartridge 1 will be described in detail.

FIG. 4A is a perspective view of the toner cartridge 1 removed from the toner hopper 5, and FIG. 4B is an exploded perspective view thereof. Each toner cartridge 1 is shown in FIG.
When the toner cartridge 1 is mounted on the toner hopper 5 as described above, the outer shape of the toner cartridge 1 as viewed from the longitudinal direction of the developing device is substantially circular so as to be concentric with the rotation center of the developing device 20. The shape seen from the direction is approximately 1/4
It has a circular shape. Then, as shown in FIG. 4B, each toner cartridge 1 is composed of a toner cartridge main body 2, a connecting member 3, and a cap 4.

The toner cartridge main body 2 is composed of a toner containing portion 2a for containing toner and a cylindrical portion 2b. The toner storage portion 2a includes both end walls 201a and 202a having a substantially quarter circle shape and the both end walls 201a and 202a.
a circumferential wall 203a between a and both end walls 201a,
It is composed of plane walls 204a and 205a between 202a. Here, in the center of the plane wall 204a indicated by a double-headed arrow C in FIG. 4B, both end walls 201a,
A toner intake port 2e having a diameter smaller than the width between 202a is formed. The cylindrical portion 2b is provided so as to project from the edge of the toner intake port 2e. In addition, a protrusion 2c (see FIG. 5) is formed on the inner surface of the free end of the cylindrical portion 2b.
(Refer to FIG. 4), and the cylindrical portion 2 in the state of FIG.
A toner discharge port 2d is formed in the lower part of b.

The connecting member 3 has an inner diameter of the cylindrical portion 2 described above.
It is composed of a cylindrical portion 3a larger than the outer diameter of b, and a toner replenishing path 3b configured to be branched from the cylindrical portion 3a in a direction orthogonal to the longitudinal direction of the cylindrical portion 3a. (Hereafter, margin)

As shown in detail in FIG. 5, the cap 4 has a fitting portion 4a fitted into the cylindrical portion 2b of the toner cartridge body 2 and a protrusion 4b provided on the peripheral surface of the fitting portion 4a. And a flange portion 4c having a diameter larger than that of the fitting portion 4a.

The toner cartridge body 2 having the above structure,
As shown in FIG. 5, in the connecting member 3 and the cap 4, the cylindrical portion 2b of the toner cartridge main body 2 is inserted into the cylindrical portion 3a of the connecting member 3 so that the connecting member 3 rotates with respect to the toner cartridge main body 2. It is assembled as possible. Further, the fitting portion 4a of the cap 4 is fitted into the cylindrical portion 2b of the toner cartridge main body 2, and the projection 4b of the cap 4 engages with the projection 2c on the inner surface of the cylindrical portion 2b. It is detachably attached to the cylindrical portion 2b. The cap 4 regulates the movement of the connecting member 3 in the longitudinal direction of the cylindrical portion 3a by the flange portion 4c. Further, as shown in FIG. 3, when the toner cartridge 1 is mounted on the toner hopper 5, the toner replenishing passage 3b of the connecting member 3 and the toner discharge port 2d of the cylindrical portion 2b face each other and the inside of the toner cartridge 1 is in an open state, and the toner storing portion The toner in 2a can freely flow out from the toner replenishing path 3b, and
When the toner replenishing passage 3b is not in a position facing the toner discharge port 2d, the inside of the toner cartridge 1 is in a hermetically sealed state, and the toner in the toner containing portion 2a cannot flow out from the toner replenishing passage 3b. .

The toner cartridge 1 constructed as described above is attached to the toner hopper 5 by fitting the end portion of the toner replenishing path 3b of the connecting member 3 into a replenishing hole (not shown) provided above the toner hopper 5. ing. A shutter mechanism is provided in the supply hole of the toner hopper 5 to prevent the toner from flowing out by blocking the hole when the toner cartridge 1 is removed.

Next, the replenishment of toner from the toner cartridge 1 to the toner hopper 5 will be described. The toner cartridge 1 installed in the toner hopper 5 is the developing device 2
It rotates with the rotation of 0. Here, for example, in the developing device 20, the yellow developing device 22Y is in the developing position, and then the yellow developing device 22Y is in the non-developing position after the state shown in FIG. 6A and the states shown in FIGS. 6B and 6C. Figure 6
When rotated to the state shown in (d), the yellow developing device 22
The toner accommodated in the toner accommodating portion 2a of the toner cartridge 1 mounted in the Y toner hopper 5Y moves in the toner accommodating portion 2a due to gravity, and as shown in FIG. It collects in the portion 2b and in the vicinity of the toner hopper 5Y. When the developing device 20 is further rotated from this state to return to the state shown in FIG. 6A in which the yellow developing device 22Y is at the developing position, the cylindrical portion 2b is formed.
The toner accumulated inside falls into the toner hopper 5Y. According to this configuration, the toner can be transported to the toner hopper 5 and replenished without providing any toner transport member in the toner cartridge 1.

By the way, as described above, the supply of the toner from the toner hopper 5 to the developing device 22 and the collection of the excess toner from the developing device 22 to the toner hopper 5 are carried out by the first toner carrying screw 26 and the second toner carrying screw 27, respectively.
If foreign matter such as paper dust enters the developing device 22 or if some toner aggregates to form a large lump, the foreign matter and the toner aggregates will be the first
Even if the toner transport screw 26 and the second toner transport screw 27 once discharge the toner from the developing device 22 to the toner hopper 5, the toner is again transported to the developing device 22 by the first toner transport screw 26. And
When such foreign matters and toner aggregates are conveyed to the developing device 22, the toner layer formed on the surface of the developing roller 23 is disturbed, and as a result, the image is disturbed.

Therefore, in the developing device 20 according to the present embodiment, the foreign matter and the toner agglomerate conveyed from the developing device 22 to the toner hopper 5 by the second toner conveying screw 27 are conveyed again to the developing device 22. In order to prevent the above, in each of the toner hoppers 5Y, 5M, 5C and 5K divided by the partition wall 51 as shown in FIG. 7, a substance having a predetermined particle size or more, specifically, a normal normal toner particle size is used. Filters 52Y, 52M, which block the passage of larger substances,
52C and 52K are provided. Specifically, each of the filters 52Y, 52M, 52C, 52K includes a first toner carrying screw 26Y, 26M, 26C, 26K and a second toner carrying screw 27Y, 27M, 27C in each toner hopper 5Y, 5M, 5C, 5K. , 27K on the moving path of the toner.

That is, according to this structure, of the collected and conveyed from the developing device 22Y to the toner hopper 5Y, for example, only those which have passed through the filter 52Y are again developed.
It will be supplied and conveyed to 2Y. Here, since the foreign matter that has entered the developing device 22Y and the toner aggregate formed in the developing device 22Y are larger than the normal normal toner, they cannot pass through the filter 52Y and are separated from the toner. It Therefore, even if the foreign matter or the toner aggregate is collected and conveyed to the toner hopper 5Y, the foreign matter or the toner aggregate is not conveyed to the developing device 22Y again.

By the way, as described above, the toner hopper 5Y
When the filter 52Y is provided inside, there is a possibility that the passage of the toner may be hindered by the above-mentioned use of the developing device 22Y with the passage of time so that the above-mentioned foreign matter or toner aggregates may adhere to the surface of the filter 52Y. However, in the rotary type developing device 20 according to the present embodiment, the toner hopper 5Y also rotates together with the rotation of the developing device 22Y about the rotation center axis.
By this rotation, the foreign matter and the toner aggregate can be separated from the filter surface, and the toner can be prevented from passing through the filter 52Y by the foreign matter and the toner aggregate. Then, by this, the filter 52Y
The sorting performance of can be maintained well.

Further, in the developing device 20 according to the present embodiment, as shown in FIGS.
M, 5C, 5K filters 52Y, 52M, 52C, 5
The second toner transport screw 27Y, 27M,
The shutters 54Y, 27C, 27K are connected to the outside and communicate with the outside.
Opening 5 that can be opened and closed by 54M, 54C, 54K
3Y, 53M, 53C, 53K are formed.

According to this structure, the foreign matters and the toner aggregates are removed from the toner hopper 5 as the developing device 22Y is used.
Even when accumulated in Y, the foreign matter and the toner aggregate can be discharged out of the machine through the opening 53Y. Thereby, the sorting performance of the filter can be favorably maintained.

Further, since the opening 53Y is provided closer to the second toner carrying screw 27Y than the filter 52Y in the toner hopper 5Y, when the foreign matter or the toner aggregate is discharged outside the machine, the normal toner is discharged. Can be prevented from being discarded excessively.

[0046]

According to the invention of claim 1, foreign matters and developer aggregates can be separated from the developer by using the filter provided in the developer containing portion.
It is possible to prevent the foreign matter and the developer aggregate from being conveyed again to the developing device.

According to the second aspect of the present invention, since the foreign matter and the developer aggregate can be separated from the filter surface by the rotation of the developer accommodating portion, the foreign matter and the developer aggregate cannot pass through the filter. Can be prevented from being blocked. Thereby, the sorting performance of the filter can be favorably maintained.

According to the third aspect of the present invention, the filter is provided on the moving path of the excess developer collected in the developer accommodating portion to the supply conveying member, so that the foreign matter and the developer are removed. It is possible to reliably separate the agglomerates from the surplus developer and prevent the foreign matters and the developer agglomerates from being conveyed to the developing device again.

According to the invention of claim 4, even when the foreign matter or the developer aggregate is accumulated in the developer accommodating portion, the foreign matter or the developer aggregate can be discharged to the outside of the machine through the opening. It is possible to prevent the passage of the developer through the filter from being blocked by the accumulated foreign matters and developer aggregates. Thereby, the sorting performance of the filter can be favorably maintained.

According to the fifth aspect of the present invention, the opening is provided closer to the collecting and conveying member side than the filter in the developer accommodating portion, so that the foreign matters and the developer aggregate accumulated in the developer accommodating portion. It is possible to prevent the normal developer from being excessively discarded when the toner is discharged from the machine.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional configuration diagram of a rotary developing device according to an embodiment.

FIG. 2A is a schematic cross-sectional configuration diagram of a developing device that constitutes the rotary developing device. FIG. 3B is an overall configuration diagram of the developing device.

FIG. 3 is a perspective view showing a schematic configuration of the developing device.

FIG. 4A is a perspective view of the toner cartridge removed from the toner hopper. FIG. 3B is an exploded perspective view of the toner cartridge.

FIG. 5 is a schematic cross-sectional configuration diagram of a toner channel of the toner cartridge.

6A to 6D are explanatory views of a toner replenishing operation from the toner cartridge to the toner hopper.

FIG. 7 is a schematic configuration diagram of a toner hopper.

[Explanation of symbols]

 1 Toner Cartridge 5 Toner Hopper 23 Developing Roller 24 Supply Roller 26 First Toner Conveying Screw 27 Second Toner Conveying Screw 52 Filter 53 Opening 54 Shutter

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Noriyuki Kimura 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company Ricoh Co., Ltd. (72) Katsuhiro Aoki 1-3-3 Nakamagome, Ota-ku, Tokyo Shares Inside Ricoh Company (72) Inventor Chiyako Hatsuyama 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd.

Claims (5)

[Claims] 1. A developing device having an opening provided at a portion facing a latent image carrier and a developer carrying member arranged so that a part thereof is exposed from the opening, and the developing device. And a supply-conveying member configured to communicate with the inside of the developing device and containing a developer to be supplied to the developing device, and a supply-conveying member that conveys and supplies the developer in the developer-accommodating part to the developing device. And a recovery / conveyance member that conveys and recovers the excess developer that has not contributed to the development to the developer accommodating portion, wherein a substance having a predetermined particle size or more is not passed through the developer accommodating portion. A developing device having a filter. 2. A plurality of the developing devices are arranged around a rotating shaft,
2. A structure in which the plurality of developing devices are rotated about the rotation axis to displace any developing device to a developing position facing the latent image carrier to perform development. Development device. 3. The developing device according to claim 1, wherein the filter is provided on a moving path of the excess developer collected in the developer accommodating portion to the supply conveying member. 4. The developing device according to claim 1, wherein the developer accommodating portion is provided with an opening which is opened and closed by a shutter and communicates with the outside. 5. The developing device according to claim 4, wherein the opening is provided closer to the collecting and conveying member than the filter in the developer accommodating portion.