JPH08185046A - Developing device - Google Patents

Abstract

PURPOSE: To provide a developing device capable of preventing the soiling of the inside and the outside of an equipment caused by the falling and the scattering of toner from a connected part at the time of attaching and detaching the developing device to an absorbing means as the developing device where the scattering of the toner from a space between the developing device and a photoreceptor is prevented by forming a dust collecting duct at a part of the main body of the developing device and connecting a dust collecting absorbing means to be freely attachable and detachable to the duct. CONSTITUTION: This device is provided with the developing device 1 provided with developing housings 3 and 4 being attachable and detachable to the main body of an image forming device and having an aperture 10 on the side of an surface opposed to the photoreceptor 2, a case arranged at the inside of the developing housing and having developer at the inside and a ventilation path 12 formed between a discharge hole 11 formed on the wall surfaces of the developing housings 3 and 4 on the side other than the side of the surface opposed to the photoreceptor 2 and the aperture, and the absorbing means 5 being freely attachable and detachable to the developing device 1 and provided with a communicative hole 15 communicating with the exhaust hole 11 when it is attached to the developing device 1, and a shutter member 25 capable of opening and closing the exhaust hole 11 is arranged in the vicinity of the exhaust hole on the side of the developing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an image forming apparatus equipped with a developing device using a dry developer, and more particularly in a developing device equipped with detachable suction means for dust collection, when the suction means is attached or detached. The present invention relates to a developing device for preventing the toner from scattering.

[0002]

2. Description of the Related Art In an image forming apparatus utilizing an electrophotographic process such as a copying machine, a printer and a facsimile machine, an electrostatic latent image formed on a photoconductor is developed with toner supplied from a developing device. A visible image is formed on the recording paper by a transfer device, the transferred image is fixed by a fixing device, and then the recording paper is discharged to the outside of the machine. As the developing device, a dust collecting duct is formed in a part of the developing device main body, and a dust collecting suction means is detachably connected to the duct so that the developing device and the photoconductor are separated from each other. It is known to prevent the toner from scattering from the inside. For example, the actual exploitation Sho 63-16846
Japanese Patent Publication No. 4 discloses a structure in which an elastic sheet member is provided at the joint between the duct and the suction means. Further, Japanese Utility Model Laid-Open No. 63-168465 discloses a configuration in which a valve for switching a flow path to a suction unit is arranged when ducts extending from two developing devices are connected to the suction unit. However, in all of these conventional examples, when the developing device is attached or detached at the time of maintenance or the like, the toner accumulated in the duct often drops from the connection part with the suction means and stains the inside and outside of the machine. .

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and a dust collecting duct is formed in a part of a developing device main body, and a dust collecting suction means is detachably attached to the duct. In the developing device in which the connection prevents the toner from scattering between the developing device and the photoconductor, the toner drops from the connecting portion when the developing device is attached to or detached from the suction means. It is an object of the present invention to provide a developing device capable of preventing scattering and soiling inside and outside of a device.

[0004]

To achieve the above object, the present invention according to claim 1 is a developing housing which is detachable from the main body of an image forming apparatus and has an opening on the side facing the photoconductor, and the developing housing. Development including a case that is disposed inside the housing and has a developer inside, and an air passage formed between an exhaust hole formed on a wall surface of the development housing other than a surface facing the photoconductor and the opening. And a suction unit that is detachable from the developing device and has a communication hole that communicates with the exhaust hole when the developing device is attached to the developing device. A shutter member that can open and close the exhaust hole is arranged.

According to a second aspect of the present invention, a plurality of adjoining developing housings, which are independently attachable to and detachable from the image forming apparatus main body and have openings on the side facing the photoconductor, and the developing housings. A case having a developer inside, a ventilation path formed between an exhaust hole formed on a wall surface of the developing housing other than the surface facing the photoconductor and the opening, and the developing housings. A developing device having a ventilation hole formed in each side wall adjacent to each other, and an exhaust hole detachable from the developing device and formed in one developing housing when mounted on the developing device. A suction member having a communication hole communicating therewith, and a shutter member capable of opening and closing the exhaust hole is disposed near the exhaust hole on the developing device side.

According to a third aspect of the present invention, the shutter member is opened / closed in association with an operation of attaching / detaching the developing device to / from the image forming apparatus main body. In the invention according to claim 4, an elastic member for covering an outer surface of the shutter member exposed to the outside from the exhaust hole when the exhaust member is closed by the shutter member is provided when the shutter member opens the exhaust hole. The shutter member is arranged on the inner wall of the developing housing, which is opposed to the outer surface of the shutter member.

According to a fifth aspect of the present invention, when the shutter member opens the exhaust hole, a storage portion for storing at least a shutter piece of the shutter member is provided separately from the ventilation passage. . According to a sixth aspect of the present invention, the developing housing is provided with a cleaning member for slidingly contacting an outer surface of the shutter member to clean the surface when the shutter member is opened and closed.

[0008]

According to the first and second aspects of the present invention, when the developing device is detached from the image forming apparatus, the exhaust hole is covered by the shutter member, and the toner accumulated inside the developing device is ejected to the outside of the device. It does not fall or scatter, and the inside and outside of the image forming apparatus are not contaminated. In the invention according to the third aspect, it is possible to save the trouble of opening and closing the shutter by manual operation and prevent forgetting to open and close the shutter.

According to the fourth aspect of the invention, when the scattered toner is collected and is conveyed in the ventilation passage, the toner is not accumulated on the shutter member arranged in the ventilation passage.
The toner will not fall out of the device when the shutter is closed. In the invention according to claim 5, since the shutter member is hermetically housed in a portion isolated from the ventilation passage, toner does not adhere to the shutter member, and when the shutter member is closed, the toner does not adhere to the outside of the developing device. It will not scatter. In the invention according to claim 6, the surface is cleaned by a cleaning blade (may be a brush) that is in sliding contact with the outer surface of the shutter piece every time the shutter member is opened and closed, and the adhered toner remains in the developing device. When the shutter member is closed, toner does not fall out of the developing device and scatter.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the embodiments shown in the drawings. FIG. 1 is a sectional view showing a structure of a developing device according to an embodiment of the present invention, and FIG. 2 is a structural explanatory view of a developing housing detached from the developing device. The developing device of this embodiment is an example of the developing device used in the image forming section of a four-color full-color machine. The developing device 1 has one or a plurality of developing housings 3 and 4 (first unit 3 and second unit 4) configured to be attachable to and detachable from an image forming unit centered on the photosensitive drum 2. A suction unit 5 is detachably attached to the developing device 1. Each of the developing housings 3 and 4 having substantially the same structure has a developing roller 6 inside.
a, a paddle 6b, and one or more cases 7 having a developer. Each of the developing housings 3 and 4 has an opening 10 on the side facing the photoconductor 2, and an exhaust hole 11 on the wall surface other than the side facing the photoconductor, and further between the opening 10 and the exhaust hole 11. The ventilation path 12 is formed.

A communication hole 15 which communicates with the exhaust hole 11 of each of the developing housings 3 and 4 is formed on the side wall surface of the developing device of the suction means 5, and a connecting portion between the holes 11 and 15 is sealed by a packing 16 or the like. At the same time, a filter or the like is arranged in this communication portion as required. An exhaust opening 17 is provided on the other side wall of the suction means 5, and a fan 18 and a filter 19 are sequentially arranged in the exhaust opening 17. By rotating the fan 18, the air containing toner between the photoconductor 2 and the developing device is introduced into the suction means 5 through the ventilation passage 12, the exhaust hole 11, and the communication hole 15, and the filter 19 removes toner and the like. After being removed, it is discharged to the outside. Further, the development device is cooled at the same time as the dust collection.

A characteristic configuration of the present invention is that the shutter member 25 is pivotally supported at a position on the exhaust hole 11 side of the developing housings 3 and 4 so as to be rotatable about a shaft 26. The point is that the shutter piece 27 opens and closes the exhaust hole 11 and the communication hole 15. Further, the shutter member 25 is constructed so as to be constantly urged in a direction of closing the exhaust hole 11 by urging means such as a torsion spring 30. Reference numeral 31 is a torsion spring 30.
Is a stopper projection protruding from the inner wall of the developing housing for fixing one end of the stopper. When the developing housing is mounted on the image forming apparatus as shown in FIG. 1, the shutter member 25 is forcibly moved in the opening direction against the spring 30 by the interlocking opening / closing mechanism described later. When the shutter member 25 is forcibly moved to the open position, an elastic seal member 35 such as a sponge is arranged on the inner wall of the developing housing facing the outer surface 27a of the shutter piece 27 and is in close contact with the outer surface 27a. , The shutter member is shown in Figure 1.
In the open state as described above, the toner does not adhere to the shutter piece, and therefore the toner does not drop when the exhaust hole is closed by the shutter member.

As shown in FIG. 2, when the developing housing is detached from the main body of the apparatus, the shutter member 25 is moved in the closing direction by the urging force of the spring 30, and the shutter 37 is attached to the stopper 37 provided at the peripheral portion of the exhaust hole 11. Stop at the abutting position. The stopper 37 is also provided with packing as required.

Instead of disposing the elastic seal member on the inner wall of the developing housing, the elastic seal may be integrated with the outer surface of the shutter piece.

FIG. 3 is a perspective view showing an example of the shutter member and the interlocking opening / closing mechanism, and shows an example of the developing housing 3 of FIG. The shutter member 25 includes the shutter piece 27, a fan-shaped connecting piece 40 bent from both ends in the longitudinal direction of the shutter piece 27, a shaft 26 integrated at the end of the connecting piece 40, and a shaft 26. The developing-side coupling piece 41 fixed to the extension end. When the developing housing is attached to the image forming apparatus main body in the direction of the arrow, the apparatus main body side coupling piece 42 is fixed at a position facing the developing side coupling piece 41. The inclined projections 4 extending in the circumferential direction are provided on the opposing surfaces of the coupling pieces 41, 42, respectively.
1a and 42a are provided, and when the developing housing is attached to the image forming apparatus, the inclined projections 41a and 42a contact each other, and when the attachment is completed, the inclined surface of the fixed inclined projection 42a is located on the developing device side. The inclined projection 41a is forcibly rotated in a predetermined direction (counterclockwise direction = exhaust hole opening direction). As a result, the shutter member 25 moves to the open position shown in FIG. 1 against the spring 30, and this state is maintained.

According to this embodiment, it is possible to save the trouble of opening and closing the shutter each time the developing device is attached and detached, and prevent forgetting to open and close the shutter.

FIG. 4 is an explanatory view of a main part configuration of another embodiment of the present invention, which is characterized in that an accommodating portion 45 for accommodating the shutter piece 27 of the shutter member held in the opened state is provided on the inner wall of the developing housing. Target. The storage portion 45 is in a state of being isolated from the ventilation passage 12 except for the entrance and exit of the shutter piece 27, and an elastic sheet 46 is arranged at the entrance and exit so that the entrance and exit can be opened and closed. By thus storing the shutter member when the shutter member is in the open position and isolating it from the ventilation path, it is possible to prevent the toner from adhering to the shutter member when the shutter is opened and dropping the toner when the shutter member is closed.

FIG. 5 is an explanatory view of the essential parts of another embodiment of the present invention. When the shutter member 25 is rotated in the direction for opening and closing the exhaust hole 11 by the operation of the interlocking opening / closing mechanism, The configuration is characterized in that the cleaning blade 50 is fixed to an appropriate place of the developing housing so as to come into sliding contact with the outer surface of the shutter piece 27. As the cleaning blade 50, for example, one made of polyurethane, which is the same material as the cleaning blade for the surface of the photoconductor, is used. By rubbing the surface 27a of the shutter piece with the free end of the cleaning blade whose one end is fixed to the developing housing,
Since the toner does not adhere to the surface, it is possible to prevent the toner from falling outside and contaminating the periphery when the shutter member is closed.

Next, FIG. 6 and FIG. 7 are views showing the overall construction of a developing device of another embodiment of the present invention and an operation explanatory view.
In the embodiment shown in FIG. 1, one suction means is arranged to communicate with a plurality of developing housings. In this embodiment, the plurality of developing housings are in communication with each other, while the suction means is connected to only one developing housing. By doing
The toner in each developing housing is sucked and cooled.

The developing device 1 includes one or a plurality of developing housings 3 and 4 (first unit 3 and second unit 4) which are detachably attached to an image forming portion centering on the photosensitive drum 2. The suction unit 5 is detachably attached to the developing device 1. Each of the developing housings 3 and 4 having substantially the same structure has one or a plurality of developing rollers 5, paddles 6 and a case 7 having a developer therein. Each developing housing 3, 4 has an opening 1 on the side facing the photoconductor 2.
0, and an exhaust hole 11 is formed on the wall surface of one of the developing housings 3 other than the side facing the photosensitive member, and an air passage 12 is formed between each of the openings 10 and the exhaust hole 11. . Further, ventilation holes 55 communicating with each other are formed on the opposing wall surfaces of the developing housings 3 and 4, so that the interiors of the developing housings are communicated with each other. In addition,
A packing that enhances airtightness is arranged between both ventilation holes 55.

On the side wall surface of the developing device of the suction means 5, there is formed a communication hole 15 which communicates with an exhaust hole 11 provided only in one of the developing housings 3, and a packing 16 or the like is provided for both holes 11,
The connection part between the 15 is sealed, and a filter or the like is arranged in this communication part if necessary. An exhaust opening 17 is provided on the other side wall of the suction means 5, and a fan 18 and a filter 19 are sequentially arranged in the exhaust opening 17. Fan 1
By rotating 8 the air containing the toner between the photoconductor 2 and the developing device is introduced into the suction means 5 through the ventilation passage 12, the ventilation hole 55, the exhaust hole 11 and the communication hole 15, and the filter 19 is used. The toner and the like are removed and then discharged to the outside. Further, the development device is cooled at the same time as the dust collection.

The characteristic structure of this embodiment is that the shutter member 60 for ventilation holes is rotatably supported about the respective ventilation holes 55 of the developing housings 3 and 4 so as to be rotatable about a shaft 61, thereby allowing ventilation. The point is that each of the ventilation holes 55 is opened and closed by a shutter piece 62 that constitutes the hole shutter member 60. Further, the shutter member 25 is configured so as to be constantly biased in a direction of closing the ventilation hole 55 by a biasing means such as a torsion spring 63. Reference numeral 64 is a stopper projection that is provided to project from the inner wall of the developing housing for fixing one end of the torsion spring 63. When the developing housing is attached to the image forming apparatus as shown in FIG.
The ventilation hole shutter member 60 is forcibly moved in the opening direction against the spring 63 by an interlocking opening / closing mechanism similar to that shown in FIG. When the ventilation hole shutter member 60 is forcibly moved to the open position, an elastic seal member 65 such as sponge is fixed to the outer surface of the shutter piece 62 and is in close contact with the inner wall of the housing. In the open state as shown by 6, the toner does not adhere to the shutter piece, and therefore the toner does not drop when the exhaust hole is closed by the shutter member.

When the developing housing is taken out from the main body of the image forming apparatus, the ventilation hole shutter member 60 closes each ventilation hole 55 as shown in FIG.

With regard to the ventilation hole shutter member 60, all the modifications shown in FIGS. 3, 4 and 5 can be applied as they are.

In the embodiment shown in FIGS. 6 and 7, a shutter member for an exhaust hole for opening and closing the exhaust hole 11 in association with the attachment / detachment operation of the developing housing is further provided. The exhaust hole shutter member 70 is rotatably supported in an opening / closing direction about a shaft 71 as a fulcrum, and is constantly urged in a direction of closing the exhaust hole 11 by a spring 72 such as a torsion spring. The spring 72 has one end locked to a stopper 73 protruding from the housing and the other end locked to an appropriate position of the shutter member 70. This shutter member 70 is continuously installed with a continuous installation piece 75 having a curved shape so as to be positioned along the outer peripheral surface of one case 7 (the case closer to the exhaust hole) when opened as shown in FIG. It has a shutter piece 76 fixed to the tip of the piece 75. As shown in FIG. 7, the shutter piece 76 is formed in a shape capable of closing the exhaust hole 11 when it is moved to the closed position, and has a sponge seal 77 integrated with a packing on the outer surface thereof.

Since the shaft 71 is connected with the interlocking opening / closing mechanism having the same structure as that shown in FIG.
The shutter member 70 is forcibly opened to the position shown in FIG. 6 when it is attached to the main body of the apparatus, and the exhaust hole is closed as shown in FIG. 7 when the attachment is released.

Further, in order to prevent the toner from adhering to and depositing on the sponge seal 77 when the shutter member is in the open state as shown in FIG. 6, the covering cover 80 has one end 8 thereof.
1 is rotatably supported by a housing 3 and is elastically biased in a counterclockwise direction by a spring (not shown). Further, the cover cover 80 is set to have a length so as to continue to engage with the shutter member even when the shutter member closes the exhaust hole 11 as shown in FIG. 7. Therefore, even when the shutter member 70 shifts from the open state shown in FIG. 6 to the closed state shown in FIG. 7, the shutter member 70 is in contact with the outer surface of the shutter member at at least one location, so that the shutter member is not covered. When it returns to the open position in FIG. 6, it is possible to cover the outer surface of the shutter member.

When the suction means 5 is driven in the mounted state shown in FIG. 6 in the above structure, the toner located in the gap between the developing housings 3 and 4 and the photoconductor is sucked through the ventilation passage 12 and the ventilation hole 55. It is sucked to the means 5 side. Further, since the shutter member 70 closes the exhaust hole 11 when the developing housings 3 and 4 are detached from the image forming apparatus, the toner accumulated in the housing or the like does not drop outside the housing and scatter to pollute the outside. . Similarly, the ventilation hole 55 that connects the housings 3 and 4 is also closed by the ventilation hole shutter member 60, so that the toner is prevented from falling from there. Also, the shutter member 70 in the open position
Since the outer surface of the is covered with the cover 80 to prevent the toner from adhering, it is possible to prevent the toner from scattering to the outside when the toner is moved to the closed position.

In any of the above-described embodiments, the shutter member which opens and closes in conjunction with the operation of attaching and detaching the developing housing to the main body of the image forming apparatus is provided on the developing housing side, but the suction means is attached and detached from the developing housing. A shutter member and an interlocking opening / closing mechanism for preventing the toner from scattering at that time may be provided on the suction means side.

[0030]

As described above, according to the first aspect of the invention, the exhaust hole is formed on the wall surface of the developing housing other than the side facing the photosensitive member, and the exhaust hole and the opening on the photosensitive member side are formed. A developing device having an air passage formed between the developing device and a suction means that is detachable from the developing device and has a communication hole that communicates with the exhaust hole when attached to the developing device. Since a shutter member capable of opening and closing the exhaust hole is arranged near the exhaust hole on the developing device side, the exhaust hole is covered by the shutter member when the developing device is detached from the image forming apparatus. The accumulated toner does not fall outside the apparatus and scatter, and the inside and outside of the image forming apparatus are not contaminated.

According to a second aspect of the present invention, ventilation holes are formed in adjacent side walls of the plurality of developing housings, respectively, and the developing housing is detachable from the developing device and mounted on the developing device. A suction means having a communication hole communicating with an exhaust hole formed in one developing housing is provided, and a shutter member capable of opening and closing the exhaust hole and the ventilation hole is provided near the exhaust hole and the ventilation hole on the developing device side. I placed it, so
When the developing device is detached from the image forming apparatus, the exhaust hole and the ventilation hole are covered by the shutter member, so that the toner accumulated inside the developing device is prevented from dropping and scattering outside the image forming apparatus. It will not become dirty.

According to the third aspect of the present invention, the shutter member is opened / closed by the interlocking opening / closing mechanism in conjunction with the operation of attaching / detaching the developing device to / from the main body of the image forming apparatus. You can prevent forgetting to open and close the shutter.

According to a fourth aspect of the present invention, when the shutter member closes the exhaust hole, an elastic member that covers the outer surface of the shutter member exposed from the exhaust hole to the outside, and the shutter member opens the exhaust hole. Then, the shutter member was placed on the inner wall of the developing housing facing the outer surface thereof. Therefore, when the scattered toner is collected and conveyed in the ventilation passage, the toner does not accumulate on the shutter member arranged in the ventilation passage, and the toner falls out of the apparatus when the shutter is closed. Will disappear.

According to the invention of claim 5, when the shutter member opens the exhaust hole, a housing portion for housing at least a shutter piece of the shutter member is provided separately from the ventilation passage. Therefore, since the shutter member is hermetically housed in a portion isolated from the ventilation passage, toner does not adhere to the shutter member and toner does not scatter to the outside of the developing device when the shutter member is closed. .

According to the sixth aspect of the invention, the developing housing is provided with a cleaning member for slidingly contacting the outer surface of the shutter member to clean the surface when the shutter member is opened and closed. Therefore, each time the shutter member is opened and closed, the surface thereof is cleaned by the cleaning blade (or a brush) that is in sliding contact with the outer surface of the shutter piece, and the attached toner remains in the developing device. Therefore, the shutter member is closed. Sometimes toner falls outside the developing device,
There is no scattering.

[Brief description of drawings]

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

FIG. 2 is a structural explanatory view of a developing housing detached from a developing device.

FIG. 3 is a perspective view showing an example of a shutter member and an interlocking opening / closing mechanism.

FIG. 4 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 5 is an explanatory view of a main part configuration of another embodiment of the present invention.

FIG. 6 is a diagram showing an overall configuration of a developing device according to another embodiment of the present invention.

FIG. 7 is an explanatory view showing a state where the developing housing of FIG. 6 is removed from the developing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 developing device, 2 photosensitive drums, 3, 4 developing housing (first unit 3, second unit 4), 5 suction means, 10 openings, 11 exhaust holes, 12 ventilation paths, 15
Communication hole, 16 packing, 17 exhaust opening, 18 fan, 19 filter, 25 shutter member, 26
Shaft, 27 Shutter piece, 27a outer surface, 30 Torsion spring, 31 Stopper, 40 Connecting piece, 41 Development side coupling piece, 42 Machine body side coupling piece, 41a, 42a Inclined protrusion, 45 Storage section, 46
Elastic sheet, 50 cleaning blade,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroyuki Mukai 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Satoshi Hatori 1-3-6 Nakamagome, Ota-ku, Tokyo Stocks Company Ricoh

Claims (6)

[Claims] 1. A developing housing that is detachable from the main body of the image forming apparatus and has an opening on the side facing the photoconductor, a case that is disposed inside the developing housing and has a developer inside, and the developing unit. A developing device having an exhaust hole formed in a wall surface of the housing other than the side facing the photoconductor and an air passage formed between the opening, and a developing device detachable from the developing device. A suction member having a communication hole that communicates with the exhaust hole when mounted on the developing device, and a shutter member capable of opening and closing the exhaust hole is disposed near the exhaust hole on the developing device side. Developing device. 2. A plurality of adjoining developing housings, each of which is independently attachable to and detachable from the main body of the image forming apparatus and has an opening on the side facing the photoconductor, and an interior disposed inside each of the developing housings. A case having a developer, an air passage formed between the above-mentioned opening and an exhaust hole formed in a wall surface of the developing housing other than the surface facing the photoconductor, and adjacent side walls of the developing housings. And a communication hole which is detachable from the development device and which communicates with an exhaust hole formed in one development housing when attached to the development device. A developing device, comprising: a suction unit provided, and a shutter member capable of opening and closing the exhaust hole is disposed in the vicinity of the exhaust hole on the developing device side. 3. The developing device according to claim 1, wherein the shutter member is opened / closed in association with an operation of attaching / detaching the developing device to / from the image forming apparatus main body. 4. An elastic member, which covers the outer surface of the shutter member exposed from the exhaust hole when the exhaust member is closed by the shutter member, is provided with an elastic member for covering the outer surface of the shutter member when the shutter member opens the exhaust hole. 4. The developing device according to claim 1, wherein the developing device is arranged on the inner wall of the developing housing, the outer surface of which faces the developing housing. 5. The storage part for storing at least a shutter piece of the shutter member is provided separately from the ventilation passage when the shutter member opens the exhaust hole. 3. The developing device according to 3 or 4. 6. The developing housing is provided with a cleaning member for slidingly contacting an outer surface of the shutter member to clean the surface when the shutter member is opened and closed. The developing device according to 3, 4, or 5.