JP7354671B2 - Developing device and image forming device - Google Patents

Description

The present invention relates to a developing device and an image forming apparatus equipped with the same.

In electrophotographic image forming devices such as copying machines and printers, toner is attached to an electrostatic latent image formed on the surface of an image bearing member such as a photoreceptor drum and developed, resulting in toner that is later transferred to paper. Image forming devices are widely used. In a developing device, in order to continuously form a uniform image, a developer containing toner contained in a developing container is conveyed while being stirred inside the developing container.

In the developing device, air is sucked into the developing container from the outside by rotating the developing roller or the stirring member, and the air pressure inside the developing container may increase. This increase in air pressure within the developer container may cause the developer to scatter from the inside of the developer container to the outside. An example of a conventional technique that attempts to eliminate such problems is disclosed in Patent Document 1.

In the developing device of the conventional image forming apparatus disclosed in Patent Document 1, a developing roller is disposed in the upper part of the housing (developing container), and a stirring screw is disposed in the lower part. A communication port is formed in a region of the cover disposed on the upper surface of the housing on the opposite side of the developing roller from the developing region where the developing roller and the photoreceptor drum face each other. The communication port opens upward, communicates the inside and outside of the housing, and is covered with a filter. This makes it possible to prevent toner from leaking while suppressing an increase in air pressure inside the developing device.

JP2017-21280A

A large amount of toner in the developer container floats in a region where the toner is peeled off from the developer roller during the development operation, on the downstream side in the rotational direction of the developer roller in the development area where the developer roller and the photoreceptor drum face each other. The problem with the developing device of the conventional image forming apparatus disclosed in Patent Document 1 is that the communication port is formed near a region where a large amount of toner peeled off from the developing roller floats. This necessitates the use of an expensive, high-performance filter that has high toner sealing performance and high air passage performance.

The present invention has been made in view of the above points, and provides a developing device and an image forming device that have a structure that suppresses cost increase and that can suppress scattering of developer to the outside of a developing container. The purpose is to

In order to solve the above problems, the developing device of the present invention includes a developing container, a developer carrier, and a regulating blade. The developer container accommodates developer containing toner to be supplied to the image carrier. The developer carrier is rotatably supported by the developer container, and supplies toner in the developer container to the image carrier in a development area facing the image carrier. The regulating blade is disposed on the upstream side of the development region in the rotational direction of the developer carrier, and regulates the layer thickness of the developer carried by the developer carrier. Furthermore, the developing device includes an exhaust section and a filtration section. The exhaust section is formed between a side surface of the regulation blade on the upstream side in the rotational direction of the developer carrier and a wall of the developer container that faces the side surface, and is connected to the developer container through an exhaust port that opens at the tip. Exhaust air from inside to outside. The filter section is disposed within the exhaust section adjacent to the exhaust port, and restricts leakage of developer from the exhaust port.

According to the configuration of the present invention, the exhaust portion for suppressing an increase in air pressure within the developer container is formed adjacent to the regulation blade. Further, in the area where the regulating blade regulates the layer thickness of the developer carried by the developer carrier, more developer is fed to the image carrier, and floating toner is reduced. In other words, the exhaust section can be provided in an area where there is less floating toner peeled off from the developer carrier during the development operation, and even an inexpensive filter (filtration section) can effectively control the leakage of developer from the exhaust port. I can do it. Thereby, it is possible to suppress scattering of the developer to the outside of the developer container with a configuration in which increase in cost is suppressed.

1 is a schematic cross-sectional view showing the configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a vertical cross-sectional view of an image forming section of an image forming apparatus according to an embodiment of the present invention. 1 is a horizontal sectional view of a developing device of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a vertical cross-sectional view showing the vicinity of the exhaust section of the developing device according to the first embodiment of the present invention. FIG. 3 is a horizontal cross-sectional view of a developing device according to a second embodiment of the present invention. FIG. 7 is a partial side view showing the vicinity of an exhaust section of a developing device according to a second embodiment of the present invention. FIG. 7 is a partial horizontal sectional view of an exhaust section of a developing device according to a second embodiment of the present invention.

Embodiments of the present invention will be described below based on the drawings. Note that the present invention is not limited to the following content.

FIG. 1 is a schematic cross-sectional view showing the configuration of an image forming apparatus 1 according to an embodiment. FIG. 2 is a cross-sectional view showing the vicinity of the image forming section 20 of the image forming apparatus 1. As shown in FIG. An example of the image forming apparatus 1 according to the present embodiment is a tandem color printer that transfers a toner image onto a sheet of paper P using an intermediate transfer belt 31. The image forming apparatus 1 may be, for example, a so-called multifunction peripheral having functions such as printing, scanning (image reading), and facsimile transmission.

As shown in FIGS. 1 and 2, the image forming apparatus 1 includes a paper feed section 3, a paper transport section 4, an exposure section 5, an image forming section 20, a transfer section 30, and a fixing section 6 provided in its main body 2. , a paper ejection section 7 and a control section 8.

The paper feed section 3 stores a plurality of sheets of paper P, and separates and sends out the sheets of paper P one by one during printing. The paper transport unit 4 transports the paper P sent out from the paper feed unit 3 to the secondary transfer unit 33 and the fixing unit 6, and further discharges the fixed paper P from the paper discharge port 4a to the paper discharge unit 7. . When double-sided printing is performed, the paper transport unit 4 distributes the paper P after fixing the first side to the reversal transport unit 4c by the branching unit 4b, and transfers the paper P to the secondary transfer unit 33 and the fixing unit 6 again. transport. The exposure section 5 irradiates the image forming section 20 with laser light that is controlled based on image data.

Image forming section 20 is arranged below intermediate transfer belt 31 . The image forming section 20 includes a yellow image forming section 20Y, a cyan image forming section 20C, a magenta image forming section 20M, and a black image forming section 20B. These four image forming sections 20 have the same basic configuration. Accordingly, in the following description, the identification symbols "Y", "C", "M", and "B" representing each color may be omitted unless there is a need to specifically limit them.

The image forming section 20 includes a photosensitive drum (image carrier) 21 that is rotatably supported in a predetermined direction (clockwise in FIGS. 1 and 2). The image forming section 20 further includes a charging section 22, a developing device 40, and a drum cleaning section 23 around the photosensitive drum 21 along the rotation direction thereof. Note that the primary transfer section 32 is arranged between the developing device 40 and the drum cleaning section 23.

The charging unit 22 charges the surface of the photoreceptor drum 21 to a predetermined potential. Then, an electrostatic latent image of the original image is formed on the surface of the photoreceptor drum 21 by the laser beam irradiated from the exposure section 5 . The developing device 40 applies toner to this electrostatic latent image and develops it, forming a toner image. Each of the four image forming units 20 forms toner images of different colors.

The transfer section 30 includes an intermediate transfer belt 31, primary transfer sections 32Y, 32C, 32M, and 32B, a secondary transfer section 33, and a belt cleaning section 34. Intermediate transfer belt 31 is arranged above the four image forming sections 20 . The intermediate transfer belt 31 is an intermediate transfer member that is rotatably supported in a predetermined direction (counterclockwise in FIG. 1), and to which toner images formed in each of the four image forming units 20 are sequentially superimposed and primarily transferred. . The four image forming units 20 are arranged in a so-called tandem system in which they are lined up in a row from the upstream side to the downstream side in the rotational direction of the intermediate transfer belt 31.

The primary transfer sections 32Y, 32C, 32M, and 32B are arranged above the image forming sections 20Y, 20C, 20M, and 20B of each color with the intermediate transfer belt 31 in between. The secondary transfer section 33 is located upstream of the fixing section 6 of the paper conveyance section 4 in the paper conveyance direction, and is located on the intermediate transfer belt 31 of the transfer section 30 rather than the image forming sections 20Y, 20C, 20M, and 20B of each color. is placed on the downstream side in the rotational direction. The belt cleaning section 34 is arranged upstream in the rotational direction of the intermediate transfer belt 31 from the image forming sections 20Y, 20C, 20M, and 20B of each color.

The toner images are primarily transferred onto the outer circumferential surface of the intermediate transfer belt 31 at the primary transfer portions 32Y, 32C, 32M, and 32B of each color. As the intermediate transfer belt 31 rotates, the toner images of the four image forming units 20 are successively transferred to the intermediate transfer belt 31 in a superimposed manner at a predetermined timing, so that the outer peripheral surface of the intermediate transfer belt 31 is coated with yellow, A color toner image is formed in which toner images of four colors, cyan, magenta, and black, are superimposed. The drum cleaning unit 23 removes toner and the like remaining on the surface of the photoreceptor drum 21 after the primary transfer.

The color toner image on the outer peripheral surface of the intermediate transfer belt 31 is transferred onto the paper P that is synchronously fed by the paper transport section 4 at a secondary transfer nip formed in the secondary transfer section 33 . The belt cleaning section 34 removes toner and the like remaining on the surface of the intermediate transfer belt 31 after the secondary transfer to clean it.

The fixing unit 6 heats and presses the paper P onto which the toner image has been transferred, thereby fixing the toner image onto the paper P.

The control unit 8 includes a CPU, an image processing unit, a storage unit, and other electronic circuits and electronic components (not shown). The CPU controls the operation of each component provided in the image forming apparatus 1 and performs processing related to the functions of the image forming apparatus 1 based on control programs and data stored in the storage section. The paper feed section 3, paper transport section 4, exposure section 5, image forming section 20, transfer section 30, and fixing section 6 each receive instructions from the control section 8 individually, and print on the paper P in conjunction with each other. The storage unit is configured by a combination of a non-volatile storage device such as a program ROM (Read Only Memory) and a data ROM (not shown) and a volatile storage device such as a RAM (Random Access Memory).

Next, the configuration of the developing device 40 will be explained using FIG. 3 in addition to FIG. 2. FIG. 3 is a horizontal sectional view of the developing device 40. Note that since the basic configuration of the developing devices 40 for each color is the same, description of identification symbols representing each color and description of the constituent elements will be omitted. In addition, in this description, the "axial direction" refers to the axial direction of rotation of the photoconductor drum 21, the first stirring member 45, the second stirring member 46, and the developing roller 47, which extend parallel to each other (in the depth direction of the paper surface in FIG. 3 (left and right horizontal direction).

The developing device 40 is detachable from, for example, the main body 2 of the image forming apparatus 1. As shown in FIGS. 2 and 3, the developing device 40 includes a developing container 41, a partition 42, a first stirring chamber 43, a second stirring chamber 44, a first stirring member 45, a second stirring member 46, and a developing roller 47. , a regulating blade 48 and a developer supply pipe 49.

The developer container 41 accommodates, for example, a two-component developer containing toner and a magnetic carrier as the developer supplied from the developing device 40 to the surface of the photoreceptor drum 21 . The developer container 41 has an elongated shape extending along the axial direction in which the rotation center of the photoreceptor drum 21 extends, and is arranged with its longitudinal direction being horizontal.

The partition portion 42 is provided at a lower portion inside the developer container 41 . The partition portion 42 is provided at a lower portion of the developer container 41 at approximately the center in a direction intersecting the axial direction (horizontal direction in FIG. 2), and extends in the axial direction and the vertical direction. The partition portion 42 partitions the inside of the developer container 41 in a direction intersecting the axial direction.

The first stirring chamber 43 and the second stirring chamber 44 are provided inside the developing container 41. The first stirring chamber 43 and the second stirring chamber 44 are formed by dividing the inside of the developer container 41 by the partition portion 42, and are arranged in parallel with each other. The second agitation chamber 44 is disposed inside the developer container 41 and adjacently below the area where the developing roller 47 is disposed. The first stirring chamber 43 is located inside the developing container 41 in a region farther from the developing roller 47 than the second stirring chamber 44 is. The first stirring chamber 43 receives developer supply via a developer supply pipe 49 shown in FIG.

The partition section 42 includes a first communication section 421 and a second communication section 422. The first communicating portion 421 and the second communicating portion 422 are arranged at both ends of the partition portion 42 in the axial direction. The first communication part 421 and the second communication part 422 penetrate the partition part 42 at both end sides in the longitudinal direction of the first stirring chamber 43 and the second stirring chamber 44, and the first stirring chamber 43 and the second stirring chamber 44 is communicated.

The first stirring member 45 is arranged inside the first stirring chamber 43 . The second stirring member 46 is arranged inside the second stirring chamber 44 . The first stirring member 45 and the second stirring member 46 are rotatably supported by the developer container 41 around an axis extending parallel to the photoreceptor drum 21 . The first agitation member 45 and the second agitation member 46 rotate about their axes to agitate and convey the developer in opposite directions along the axis of rotation, and in a predetermined conveyance direction (see FIG. 3). Circulate in the direction of arrows F1 and F2).

Due to the rotation of the first agitation member 45 and the second agitation member 46, the developer passes through the first communication part 421 and the second communication part 422 provided at both ends of the partition part 42 in the axial direction. It circulates between the chamber 43 and the second stirring chamber 44. In the first stirring chamber 43 and the second stirring chamber 44, toner (positively charged toner) supplied from the outside is mixed with a magnetic carrier, stirred, and charged.

The developing roller 47 is arranged inside the developing container 41 and above the second stirring member 46 . The developing roller 47 is rotatably supported by the developing container 41 around an axis extending parallel to the photoreceptor drum 21 . The developing roller 47 includes, for example, a cylindrical developing sleeve that rotates counterclockwise in FIG. 2 and a developing roller side magnetic pole fixed within the developing sleeve (both not shown). A predetermined developing voltage in which an alternating current voltage is superimposed on a direct current voltage is applied to the developing roller 47 . A portion of the surface of the developing roller 47 is exposed from the developing container 41 and faces the photosensitive drum 21 . The developing roller 47 carries the developer in the second stirring chamber 44 and supplies toner to the surface of the photoreceptor drum 21 in a development area facing the photoreceptor drum 21 .

The regulating blade 48 is arranged on the upstream side in the rotational direction of the developing roller 47 in the developing area where the developing roller 47 and the photoreceptor drum 21 face each other. The regulating blade 48 is disposed close to the developing roller 47 with a predetermined distance between its tip and the surface of the developing roller 47. The regulating blade 48 extends over the entire area of the developing roller 47 in the axial direction. The regulating blade 48 regulates the layer thickness of the developer carried by the developing roller 47 that passes through the gap between its tip and the surface of the developing roller 47 .

The developer is stirred and circulated in the first stirring chamber 43 and the second stirring chamber 44 by the first stirring member 45 and the second stirring member 46, is charged, and is carried on the surface of the developing roller 47. The layer thickness of the developer supported on the surface of the developing roller 47 is regulated by a regulating blade 48 . A magnetic brush (not shown) made of toner and magnetic carrier is formed on the surface of the developing roller 47. When a predetermined developing voltage is applied to the developing roller 47, the toner carried on the surface of the developing roller 47 flies onto the surface of the photosensitive drum 21 in the development area due to the potential difference between the surface potential of the photosensitive drum 21 and the developing roller 47. Then, the electrostatic latent image on the surface of the photoreceptor drum 21 is developed.

The developer supply pipe 49 is disposed at one end of the developer container 41 in the axial direction of the developing roller 47 and extends in the vertical direction. The lower end of the developer supply pipe 49 is located outside the first stirring chamber 43 in the axial direction and communicates with the first stirring chamber 43 . Note that the first stirring member 45 extends to the lower part of the developer supply pipe 49. The upper end of the developer supply pipe 49 is connected to a developer transport section (not shown) provided in the main body 2 of the image forming apparatus 1 .

Regarding replenishment of developer to the developing device 40, the image forming apparatus 1 includes a container 51 shown in FIG. 1 and a developer transport section. Both the container 51 and the developer transport section are arranged above the developing device 40. Four containers 51 and four developer transport sections are provided, each corresponding to four colors: yellow, cyan, magenta, and black. The container 51 accommodates developer to be supplied to the developing device 40 and is removable from the developer transport section. The developer contained in the container 51 is supplied to the first stirring chamber 43 of the developer container 41 via the developer transport section and the developer supply pipe 49.

FIG. 4 is a vertical cross-sectional view showing the vicinity of the exhaust section 61 of the developing device 40 of the first embodiment. For example, the developing device 40 of the first embodiment includes an exhaust section 61 and a filter section 62 shown in FIG.

The exhaust portion 61 is formed between a side surface 481 of the regulating blade 48 on the upstream side in the rotational direction of the developing roller 47 and a wall portion 411 of the developer container 41 that faces the side surface 481. The exhaust portion 61 extends over the entire side surface 481 of the regulating blade 48 in the axial direction of the developing roller 47 . The exhaust section 61 approaches and separates from the developing roller 47 along the side surface 481 of the regulating blade 48 in a direction intersecting the axial direction of the developing roller 47, and extends from the inside of the developing container 41 to the outside. extends towards.

In the exhaust section 61, an exhaust port 611 opens at a lower end portion that is a tip spaced apart from the developing roller 47. The exhaust section 61 exhausts air from the inside of the developer container 41 to the outside through an exhaust port 611 that opens at the tip. The air flowing through the exhaust section 61 enters the exhaust section 61 along the arrow Ra1 shown in FIG. 4, is discharged from the exhaust port 611, and is sent to the outside of the developing device 40 along the arrow Ra2. It will be done.

The filter section 62 is arranged within the exhaust section 61 adjacent to the exhaust port 611 . The filter section 62 is arranged on the upstream side of the exhaust port 611 with respect to the air flow direction within the exhaust section 61 . The filter section 62 allows only air to flow and restricts the passage of developer. That is, the filter section 62 restricts leakage of developer from the exhaust port 611.

According to the above configuration, the exhaust portion 61 for suppressing an increase in air pressure within the developer container 41 is formed adjacent to the regulation blade 48 . Further, in the area where the regulating blade 48 regulates the layer thickness of the developer carried by the developing roller 47, more developer is fed to the photoreceptor drum 21, and floating toner is less. That is, the exhaust section 61 can be provided in an area where there is less floating toner peeled off from the developing roller 47 during the developing operation, and even an inexpensive filter (filtration section) can effectively restrict leakage of developer from the exhaust port 611. be able to. Thereby, it is possible to suppress scattering of the developer to the outside of the developer container 41 with a configuration in which increase in cost is suppressed.

The filter section 62 includes a filter member 621 that covers the exhaust port 611. The filter member 621 is made of, for example, urethane, and is filled throughout the exhaust section 61 in a direction intersecting the air flow direction. According to this configuration, it is possible to effectively suppress cost increases.

It is more preferable that the filter member 621 has an open cell structure. According to this configuration, air circulation performance can be improved.

FIG. 5 is a horizontal sectional view of the developing device 40 of the second embodiment. The basic configuration of this second embodiment is the same as the first embodiment described above, so common components will be given the same symbols and names as before, and their explanation will be omitted. Therefore, the description of the configuration other than the characteristic parts may be omitted.

The developing device 40 of the second embodiment includes an exhaust section 71 shown in FIG. The exhaust portion 71 is formed at one end of the developing roller 47 in the axial direction of rotation. Specifically, the exhaust portion 71 is formed at the upstream end in the developer transport direction F2 by the second stirring member 46, which extends in parallel and close to the developing roller 47.

FIG. 6 is a partial side view showing the vicinity of the exhaust section 71 of the developing device 40 of the second embodiment. FIG. 7 is a partial horizontal sectional view of the exhaust section 71 of the developing device 40 of the second embodiment. Note that FIG. 6 is a schematic appearance of the side surface of the developing device 40 seen from the direction indicated by the arrow VI shown in FIG. 5 (the direction intersecting the axial direction of the developing roller 47). The figure shows the state in which the two-dot chain line) has been removed. Further, FIG. 7 is a partial horizontal sectional view of the exhaust section 71 shown in FIG. 6 taken from above along the line VII-VII.

The exhaust section 71 has an exhaust pipe 711 shown in FIGS. 6 and 7. The exhaust pipe 711 is formed so as to face a portion of the developing roller 47 in the axial direction of rotation. Specifically, the exhaust pipe 711 is formed at the upstream end in the developer conveyance direction F2 (see FIG. 5) by the second stirring member 46, facing a part of the developing roller 47 in the axial direction. .

The exhaust pipe 711 extends from the inside of the developer container 41 to the outside (from the top to the bottom in FIG. 6). Specifically, the exhaust pipe 711 extends from an inlet 7111 provided on the inside of the developer container 41 to an exhaust port 7112 provided on the outside of the developer container 41 . Note that the exhaust port 7112 includes two exhaust ports 7112A and 7112B. That is, the exhaust pipe 711 has an exhaust port 7112 opened at the tip thereof that is on the outside of the developer container 41 .

As shown in FIG. 6, the exhaust pipe 711 of this embodiment has a T-shape when viewed from a direction intersecting the axial direction of the developing roller 47, for example. The exhaust pipe 711 of this embodiment has one inlet 7111 and two exhaust ports 7112A and 7112B. One exhaust port 7112A faces the inflow port 7111 along the direction intersecting the axial direction of the developing roller 47. The other exhaust port 7112B is located at the end of an air flow path that extends straight from the inlet port 7111 to one exhaust port 7112A and branches at a right angle in the middle, extending along the axial direction of the developing roller 47. Note that the shape of the exhaust pipe 711 is not limited to the T-shape, but may be other shapes such as a linear shape.

The wall portion 411 of the developer container 41 facing the exhaust pipe 711 has a recess 4111, as shown in FIG. The recessed portion 4111 is recessed in the wall portion 411 in a direction away from the regulating blade 48 . The recess 4111 is configured in a T-shape along the shape of the exhaust pipe 711. That is, the exhaust pipe 711 has an air circulation space that includes the space between the side surface 481 of the regulating blade 48 and the wall portion 411 of the developer container 41 as well as the interior space of the recess 4111 .

The developing device 40 further includes a filtering section 72. The filter section 72 is arranged in the exhaust pipe 711 adjacent to the exhaust port 7112. The filter section 72 is arranged on the upstream side of each of the two exhaust ports 7112 with respect to the air flow direction within the exhaust pipe 711. That is, the filter section 72 is configured to have a T-shape when viewed from a direction intersecting the axial direction of the developing roller 47, for example. The filtering section 72 has a filter member 721 that covers each of the two exhaust ports 7112, allows only air to flow, and restricts the passage of developer. That is, the filter section 72 restricts leakage of developer from each of the two exhaust ports 7112.

Note that a region other than the exhaust pipe 711 between the side surface 481 of the regulating blade 48 and the wall portion 411 of the developer container 41 is filled with a sealing material 73.

According to the configuration of the second embodiment, the exhaust section 71 for suppressing an increase in the air pressure inside the developer container 41 can be formed with an even smaller configuration. Therefore, it is possible to create a condition in which the developer is difficult to enter the exhaust section 71. Thereby, the effect of restricting leakage of developer from the exhaust port 7112 can be enhanced.

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and various modifications can be made without departing from the gist of the invention.

For example, in the above embodiment, the image forming apparatus 1 is a so-called tandem type color printing image forming apparatus that sequentially forms images of multiple colors, but the image forming apparatus 1 is not limited to such a model. Instead, it may be an image forming apparatus for color printing or an image forming apparatus for monochrome printing that is not a tandem type.

INDUSTRIAL APPLICABILITY The present invention can be used in a developing device and an image forming device.

1 Image forming device 20 Image forming section 21 Photosensitive drum (image carrier)
40 Developing device 41 Developing container 46 Second stirring member 47 Developing roller (developer carrier)
48 Regulation blade 61, 71 Exhaust section 62, 72 Filter section 411 Wall section 481 Side surface 611 Exhaust port 621 Filter member 711 Exhaust pipe 721 Filter member 7112 Exhaust port

Claims (6)

a developer container containing a developer containing toner to be supplied to the image carrier;
a developer carrier that is rotatably supported by the developer container and supplies the toner in the developer container to the image carrier in a development area facing the image carrier;
a regulating blade that is disposed in the development region upstream in the rotational direction of the developer carrier and regulates the layer thickness of the developer carried by the developer carrier;
Equipped with
The regulation blade is formed between a side surface of the regulation blade on the upstream side in the rotational direction of the developer carrier and a wall of the developer container that faces the side surface, and is opened at the tip of the developer container. an exhaust section that exhausts air from the inside to the outside;
a filtration section that is disposed in the exhaust section adjacent to the exhaust port and restricts leakage of the developer from the exhaust port;
Equipped with
The air inflow port of the exhaust section is adjacent to a region where the regulation blade and the developer carrier face each other to regulate the layer thickness of the developer, and faces the developer carrier. developing device. The exhaust section is an exhaust pipe that is formed to face a part of the developer carrier in the axial direction of rotation, extends from the inside of the developer container toward the outside, and has the exhaust port open at its tip. The developing device according to claim 1, characterized in that it has: an agitating member that extends parallel to and close to the developer carrier, is rotatably supported inside the developer container, and transports the developer while agitating it along the axial direction;
3. The developing device according to claim 2, wherein the exhaust pipe is formed at an upstream end in a direction in which the developer is conveyed by the stirring member. 4. The developing device according to claim 1, wherein the filtering section includes a filter member disposed within the exhaust section. 5. The developing device according to claim 4, wherein the filter member has an open cell structure. An image forming apparatus comprising the developing device according to claim 1 .

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