JPH07120105B2 - Developing device in image forming apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a developing device in an image forming apparatus that visualizes an electrostatic latent image formed on a latent image carrier.

2. Description of the Related Art In the developing device of the above-mentioned type used in an image forming apparatus such as a copying machine or a printer, the developer contained in the developer chamber must be discharged outside the developing device as needed. Particularly in a developing device using a two-component developer having a toner and a carrier, the carrier deteriorates over time, and therefore the developer in the developer chamber is discharged for the purpose of replacing the deteriorated developer with a new developer. There is a need to.

In such a case, conventionally, the developing unit of the developing device was detached from the main body of the image forming apparatus, the unit was inverted, and the deteriorated developer was discharged from the opening in the upper part.
Such work is not only complicated, but the developer may be scattered during the discharging work, and the hands and clothes of the worker may be soiled.

It is an object of the present invention to provide a developing device of an image forming apparatus which eliminates the above-mentioned conventional drawbacks and can discharge the developer in the developer chamber to the outside by a simple operation.

Structure In order to achieve the above object, the present invention carries out a two-component developer existing in a developer chamber in a developing device to be discharged to the outside of the developing device and discharging the developer to the outside of the developing device. And a developer carry-in means for carrying in the two-component developer into the developer chamber, the carry-in means and the developer carry-out means communicate with each other outside the developer chamber, and the developer carry-out means outside the developer chamber. It is proposed to provide a constitution in which a flow path switching means is provided for switching between returning the two-component type developer carried to the developer compartment to the developer chamber by the developer carry-in means or discharging the developer as it is outside the development mounting.

Embodiments Embodiments in which the present invention is applied to a developing device of a multicolor copying machine will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a developing unit of a developing device supported by the copying machine main body 2. The developing unit 1 has an appropriate number of
In the illustrated example, three developing devices 3, 3R, 3B are integrally incorporated, and the developer chambers 4, 4R, 4B of the developing devices 3, 3R, 3B are each made of a casing member 5 made of a non-magnetic material such as aluminum. Three partition walls
6,6R, 6B and two end walls 7,8 (second
(See FIGS. 3, 3 and 4).

Each developer chamber 4, 4R, 4B has different color developer 9, 9R, 9B
In this example, each of these developers is black, red, and blue. It is also possible to store cyan, yellow, and magenta toner developers in each developer chamber to form a full-color image, or to store the same color developer in each developer chamber. Can also be configured for selective use. As the developers 9, 9R, 9B, a two-component developer having a carrier and a toner, at least a part of which is a magnetic developer, is used.

Although the first to third developing units 3, 3R and 3B are arranged radially around the rotation center O of the developing unit 1, all of their structures are substantially the same, and therefore, in the following description. The structure of the first developing device 3 is mainly clarified, and with respect to each part of the other developing devices 3R and 3B, the reference numerals assigned to the respective elements of the first developing device 3 are denoted by R and B, and duplicated. The description is omitted. The same applies to the toner supply devices described later that belong to the developing devices 3, 3R and 3B, respectively.

The developing unit 1 is rotatably supported around its rotation center O, and each developing device (more accurately, its developing roller) is rotated to a predetermined developing position to perform a developing operation. The developing device 3 of No. 1 occupies the developing position.

In FIG. 1, the developing roller 10 provided in the first developing device 3 exposes an opening or a part thereof formed by the two partition walls 6 and 6R (see also FIG. 4). The latent image carrier rotatably supported by the copying machine main body 2, in this example, occupies a predetermined developing position with respect to the photosensitive drum 11.
At that time, the developing roller 10 is positioned parallel to the photosensitive drum 11 with a predetermined minute gap. A latent image carrier composed of a photosensitive belt may be used instead of the photosensitive drum.
Depending on the model of the image forming apparatus, a latent image carrier composed of a dielectric belt or a dielectric drum is used.

As can be seen from FIG. 3, both support shafts 12 and 13 of the developing roller 10 are rotatably supported by both end walls 7 and 8 of the developing unit 1 and are located at the inner side of the copying machine main body 2 (see FIGS. 2 and 3). One support shaft 13 (on the left side of the drawing) penetrates the end wall 8 and a developing roller gear 14 is fixed to the tip thereof.

An impeller 16 having a large number of blades 15 is provided inside the developer chamber 4.
The impeller 16 is integrally fixed to a feed screw shaft 17 which is provided inside the boss portion 32 of the impeller 16 and is parallel to the developing roller 10.
It is driven to rotate counterclockwise in FIG. 1 by the rotation of 17. As a result, the developer in the developer chamber 4, that is, the toner and the carrier are supplied to the developing roller 10 while being stirred, and the toner is frictionally charged to a predetermined polarity by the stirring of the toner and the carrier. A screw 18 is formed on the feeding screw shaft 17 over substantially the entire length thereof.

One end of the feeding screw shaft 17, that is, the left end of FIG. 2 corresponding to the back side of the copying machine main body 2 rotatably penetrates the end wall 8 of the developing unit 1 and is located at the most distal end thereof. The feed gear 19 is fixed, and the feed screw shaft 17 is rotationally driven together with the impeller 16 via the gear 19. The other end of the feed screw shaft 17, that is, the front end of the copying machine main body 2 passes through the supply pipe 20 fixed to the hole of the developing unit end wall 7 and is rotatably supported by the pipe 20. ing.

Inside the developing roller 10, a magnet 21 having a magnetic pole composed of an S pole and an N pole is fixedly arranged in the casing member 5 of the developing unit 1 as shown by S and N in FIG. As a result, when the developing roller 10 is rotationally driven in the counterclockwise direction in FIG. 1 via the above-described developing roller gear 14, the magnetic developer 9 supplied to the developing roller 10 is generated by the magnetic force of the magnet 21. It is carried on the surface and conveyed counterclockwise. The conveyed developer is scraped by a doctor blade 22 fixed to the casing member 5, and a predetermined amount of the developer that has passed through the blade 22 is sent to the photosensitive drum 11 with its layer thickness regulated.

On the other hand, the photosensitive drum 11 is rotationally driven in the clockwise direction in FIG. 1, and an electrostatic latent image corresponding to the image of the original document (not shown) is also formed on the surface thereof by the charging / exposure means (not shown). It When this latent image reaches the opposing developing area D between the photoconductor drum 11 and the developing roller 10, the charged toner in the developer also conveyed to this area D is electrostatically transferred to the electrostatic latent image to form the latent image. Is visualized. The visible image is transferred onto a transfer paper (not shown) by a transfer device (not shown), and the transferred visible image is fixed by a fixing device (not shown). The developer that has passed through the developing area D is returned to the inside of the developer chamber 4 again, mixed with other developers in this chamber, and used again.

The developer scraped off by the doctor blade 22 is guided by the guide member 23 in the direction indicated by the arrow B, and is conveyed to the delivery screw shaft 24 parallel to the delivery screw shaft 17, a part of which is described below. Screw shaft
24 is transported to the outside of the developer room, and other developer is
Guide member 23 as indicated by arrow C in FIGS. 3, 3 and 3a
It flows upward, flows down to the impeller 16 located at the bottom of the developer chamber 4, and is agitated.

As can be seen from FIGS. 1 to 3a, the guide member 23 has a gutter-shaped portion 25 that covers substantially the lower half of the feed screw shaft 24, and each end of the guide member 23 has an end wall 7 of the developing unit 1. ,
It is fixed to 8 respectively. Sending screw shaft 24
One end portion (the left end portion in FIG. 2) is rotatably supported by the end wall 8 on the back side, penetrates this end wall 8 and drives the feed-out screw shaft 24 to the most distal end thereof. The feeding gear 26 for fixing is fixed. In addition, the feed screw shaft 24
The other end portion (the right end portion in FIG. 2) of the pipe 27 penetrates through the inside of the discharge pipe 27 fitted and fixed in the hole of the end wall 7 on the front side.
It is rotatably supported by. Sending screw shaft 24
A screw 28 is also formed, and this screw 28 may be formed over the entire length of the screw shaft 24, but in the example shown in the figure, the shaft portion fitted to the discharge pipe 27 and the inside of the developer chamber The screw 28 is formed only on a part of the shaft portion.

As shown in FIG. 3a, both flange portions 29 of the guide member 23
A large number of guide fins 30 straddling the delivery screw shaft 24 are fixed to the guide fins 30, and these guide fins 30 extend obliquely as shown in FIG. 3a. For this reason, as described above, the developer scraped off by the doctor blade 22 and flowing on the guide member 23 is guided by the guide fins 30 in the direction of arrow C, that is, from the direction orthogonal to the axial direction of the developing roller 10 by α (first Three
(Fig. And Fig. 3a) are guided in the inclined direction C and fall to the bottom of the developer chamber 4 as described above. In this way, the developer flows on the guide member 23 while being displaced in the direction perpendicular to the paper surface of FIG. 1, so that the carrier and the toner are effectively stirred.

Further, the developer that has flowed from the doctor blade 2 to the screw 28 portion of the screw shaft 24 is fed by the feed gear 26.
By the screw 28 of the feed screw shaft 24 which is rotationally driven via the sheet, it is conveyed rightward in FIG. 2, that is, toward the front side of the copying machine main body while being guided by the gutter-shaped portion 25 and the discharge pipe 27, and is developed. It is discharged to the outside of the unit end wall 7.

As shown in FIG. 2, the discharge pipe 27 and the above-mentioned supply pipe 20 are connected via a connecting pipe 31 which will be described in detail later. Therefore, the developer conveyed in the discharge pipe 27 as described above is indicated by an arrow E. As shown in the left side of FIG. 2, while flowing through the connecting pipe 31 into the supply pipe 20, and then being guided in the boss portion 32 of the impeller 16 by the screw 18 of the feed screw shaft 17 which is rotationally driven by the feed gear 19. That is, it is conveyed toward the inner side of the copying machine body 2. The developer sent to the back side is impeller
The toner is discharged into the developer chamber 4 through the opening at the back end of 16 and the exit hole 33 formed in the vicinity thereof. In this way, the developer taken out from the front side region (the right end region in FIG. 2) of the developer chamber 4 by the delivery screw shaft 24 is transferred to the back side region of the developer chamber 4 by the delivery screw shaft 17 ( It is conveyed to the left end region in FIG. 2) and mixed with another developer in the developer chamber 4. For this reason, the toner and the carrier in the developer are effectively stirred, and it is possible to prevent the deterioration of the image quality of the visible image due to insufficient stirring. Also, the feed screw shaft
It sends out 17 and rotates at a higher speed than the screw shaft 24,
It is advantageous to prevent the inconvenience of the developer clogging the discharge pipe 27, the supply pipe 20, and the boss portion 32 of the impeller 16.

By the way, in a two-component developer, when it is used for a long period of time, the carrier in the developer deteriorates. Therefore, when the carrier deteriorates, it is necessary to replace the developer entirely.
In this embodiment, the replacement work is configured as follows so that the replacement work can be performed easily.

As shown in FIG. 2, FIG. 5 and FIG. 5a, FIG. 6, the discharge pipe 27 is fitted and fixed with the first cylindrical portion 35 of the connecting member 34, and the supply pipe 20
A movable cylinder 37 of the flow path switching member 36 is rotatably fitted in the movable cylinder 37 in the direction of arrow F, and the second member of the connecting member 34 is provided outside the movable cylinder 37.
The cylindrical portion 38 of is fixedly fitted to the supply pipe 20. The above-mentioned connecting pipe 31 is integrally fixed to both cylindrical portions 35 and 38 of the connecting member 34. A discharge pipe 39 projecting in the radial direction is integrally attached to the movable cylinder 37, and this cylindrical portion 38 is arranged so that the discharge pipe 39 does not interfere with the second cylindrical portion 38 when the movable cylinder 37 rotates in the arrow F direction. A notch 40 is formed in the.

The discharge pipe 27 and the supply pipe 20 communicate with each other through a hole 41 formed in the discharge pipe 27, a connecting pipe 31, a hole 42 of the movable cylinder 37, and a hole 43 formed in the supply pipe 20 as shown in FIG. Through these, the developer in the discharge pipe 27 is guided to the supply pipe 20 as described above (arrow E). During a normal developing operation, the discharge pipe 39 occupies the position shown by the solid line in FIG. 6, and at this time, the discharge pipe 39 is blocked by the pipe wall of the discharge pipe 27. The developer discharged from the developer chamber 4 to the outside of the developing device 3 by the discharge pipe 27 is supplied to the supply pipe.
After being introduced into the developer chamber 20, the entire amount thereof is returned to the developer chamber 4 through the supply pipe 20.

When replacing the developer, the movable unit 37 and the discharge pipe are kept with the developing unit 1 set in a predetermined position in the copying machine main body 2.
The flow path switching member 36 consisting of 39 is rotated to the position shown by the chain line in FIG. At this time, the hole 43a formed in the supply pipe 20 and the discharge pipe 39 coincide with each other. Therefore, in this state, if the developer is sent from the discharge pipe 27 to the supply pipe 20 as described above, this developer is indicated by a chain line in FIG. The entire amount flows out through the discharge pipe 39 as shown by the arrow. The operator receives the developer flowing out from the outlet of the discharge pipe 39 in a container (not shown). In this way, the two-component developer to be discarded in the developer chamber 4 can be discharged. The supply of new developer can be performed by using the toner supply device described later, and the developer can be easily replaced. After the developer is discharged, the flow path switching member 36 may be returned to the position shown by the solid line in FIG. 6, and the developer is discharged to the outside of the developing device by rotating the flow path switching member 36, or the developer is discharged. It is possible to select whether to return to the developer chamber 4. Therefore, when necessary, the two-component developer to be discarded can be discharged to the outside of the developing device. In this way, with the developing unit 1 set in the copying machine main body 2,
By rotating the flow path switching member 36, the old developer can be easily taken out, and it is not necessary to remove the developing unit from the copying machine main body and invert it to replace the developer as in the conventional case.

In the embodiment described above, the delivery screw shaft 24,
The trough-shaped portion 25, the discharge pipe 27, and the connecting pipe 31 remove the two-component developer 9 in the developer chamber 4 in the developing device 3 to be discarded from the developing device 3.
A developer discharging means for discharging the discharged toner to the outside of the developing device is constituted.

Further, the developing device of this example has, in addition to the above-described developer unloading means, a developer carrying-in means for carrying in the two-component developer into the developer chamber 4, and in the illustrated example, the feeding screw shaft 17 The supply pipe 20 and the boss portion 32 of the impeller 16 constitute such developer loading means. The developer carry-in means and the developer discharge means described above communicate with each other outside the developer chamber, and the two-component developer 9 carried outside the developer chamber 4 by the developer carry-out means is carried into the developer carry-in means. By means of the flow path switching means constituted by the flow path switching member 36, it is possible to switch whether to return to the developer chamber 4 or to discharge directly to the outside of the developing device. Thus, in this example, the flow path switching member 36 constitutes the flow path switching means.

As described above, in this example, when the developer should not be discarded, the two-component developer is circulated by the developer carry-out means and the developer carry-in means, which can be efficiently stirred and mixed, and the developer can be efficiently mixed. When it should be discarded, it can be quickly discharged out of the developing device. That is, the structure for stirring the developer and the structure for discharging and carrying in the developer are made common. Further, the illustrated developer unloading means and flow path switching means are merely examples, and it goes without saying that an appropriate configuration capable of carrying powder and switching the carrying path may be adopted. is there.

In the developing device shown in the drawing, as shown in FIG. 9, the developing unit 1 has a pin 78 projecting on the rotation center O of the end wall 8 on the far side thereof as shown in FIG. It is rotatably supported in the hole 80 of the back side plate 79 of the machine body via a bearing 81, and the end wall 7 on the front side is a unit carrier 62.
It is rotatably supported by a support arm 70 on the front side (see FIG. 4), and is configured to bring desired developing devices 3, 3R, 3B to the developing position. In addition, the unit carrier 62
Is supported by the copying machine main body 2 via a slider 61,
The developing unit 1 can be taken out by pulling out the carrier 62 as shown in FIG.

As can be seen from FIG. 9, the motor 88 provided with the unit carrier 62 in the state where the developing unit 1 is set in the main body of the copying machine.
Similarly, the unit 1 is rotated around its center through the gear 89 also supported by the unit 63 and the gear 90 provided on the unit 1 to bring the desired developing units 3, 3R, 3B to the developing position. A developing operation can be performed.

By the way, the toner in the developer moves to the photoconductor drum 11 along with the developing operation, and the toner is sequentially consumed. Therefore, it is necessary to replenish the toner to the developer chamber 4. A configuration for achieving this object will be described below.

As shown in FIGS. 2, 4, and 5, the developing unit 1
A support plate 46 is fixed to the front end wall 7 of the device via a suitable number of support studs 45, and the above-mentioned supply pipe 20 extends through the support plate 46. In the front end region of the supply pipe 20,
Cylindrical holding member forming one element of the toner supply device 44
The portion of the hole 48 that is inserted into the hole 48 and faces the inside of the holding member is open, and the opening 49 and the notch opening 50 formed in the supply pipe 20 coincide with each other. For this reason, the feed screw shaft 17 located inside the supply pipe 20 has these openings 4
It is exposed inside the support member 47 through 9,50.

Inside the holding member 47, a toner tank 51 containing toner, in this case black toner, is detachably fitted from the right side of FIG. The position of the toner tank 51 is also schematically shown by a chain line in FIG. Inside the toner tank 51, there is provided a rotating body 53 for sending out toner, which is fixed to a rotating shaft 52. The rotating shaft 52 is rotatably supported by both end walls of the toner tank 51, and one end portion of the rotating shaft 52 is rotatably supported. A gear 54 located outside the tank 51 is fixed to the. The gear 54 is a drive gear 56 supported by the copying machine main body 2 via an intermediate gear 55 rotatably supported by a supporting plate 46 in a state where the developing unit 1 is mounted on the copying machine main body 2.
The drive gear 56 is meshed with (FIG. 4) and is drivingly connected to a toner replenishing motor (not shown) via an intermediate transmission gear, and the rotating body 53 is rotated inside the toner tank 51 by the operation of the motor. . At the time of this rotation, the tip of the rotating body 53 makes sliding contact with the inner peripheral surface of the cylindrical toner tank 51.

As is apparent from FIGS. 2 and 5, the cylindrical wall of the toner tank 51 is provided with a toner discharge port including a large number of small holes 57 facing the openings 49 and 50 described above. Small hole in the example
57 are arranged in one row, but this is made into multiple rows,
They may be arranged in a staggered manner, and the arrangement state can be appropriately selected.

When a toner replenishment signal for supplying toner to the developer chamber 4 is generated, the above-mentioned toner replenishment motor operates to set the developing unit 1 set at a predetermined position in the copying machine main body.
The rotating body 53 of the toner supply device 44 attached to the roller starts to rotate. As a result, the rotating body 53 rotates around the axis of the rotating shaft 52 while sliding its tip end against the inner peripheral surface of the toner tank, and the toner in the tank 51 is sent out through a large number of small holes 57 and pushed out toward the screw shaft 17. . The sent-out toner is sent inside the boss portion 32 of the impeller 16 by the rotation of the sending-in screw shaft 17, and is replenished to the developer chamber 4 from the opening or the outlet hole 33 on the inner side thereof, and the other developer existing there. Mixed with. As described above, in this embodiment, the toner is replenished by utilizing the developer carry-in means that circulates the developer in the developing device, so that it is not necessary to provide each carry-in means, and the structure can be simplified.

If the toner in the toner tank 51 becomes empty, this tank 51
Is removed from the holding member 47, and a new toner tank containing toner is attached to the holding member 47. At that time, as shown in FIG. 5, a seal 58 is attached to the new toner tank 51 from above the small hole 57, and the small hole 57 is closed.
After removing the seal 58, the tank 51 is attached to the holding member 47.

Further, as shown in FIGS. 7 and 8, the cylindrical holding member 47
An elastic roller 59 made of sponge or foam parallel to the feeding screw shaft 17 is rotatably arranged in the space adjacent to the hole 48 of the toner tank 51, and the small hole 57 of the toner tank 51 is adjacent to the elastic roller 59. And the roller 59 is pressed against the outer peripheral surface of the toner tank 51, and the elastic roller 59
Gear 60 fixed to the spindle of the gear 54 of the rotating body 53 (Fig. 5)
May be engaged with. In this configuration, when the toner is supplied, the elastic roller 59 rotates together with the rotating body 53, and the toner ejected from the small holes 57 is sprayed on the peripheral surface of the elastic roller 59.
The toner that has rebounded on the roller surface is fed into the screw shaft.
Sent to 17. A scraper (not shown) for scraping off the toner attached to the elastic roller 59 is in contact with the elastic roller 59. If the elastic roller 59 that is rotationally driven in this manner is provided in pressure contact with the peripheral surface of the toner tank 51, the sealing property between the roller 59 and the peripheral surface of the tank is maintained, and the toner is scattered to the outside of the holding member 47. It is possible to prevent the toner from adhering to the peripheral surface of the toner tank 51 by the elastic roller 59 and keep the tank clean.

Drive gear provided on the body side of the copying machine for driving the rotating body 53
56 (FIG. 4) is rotatably supported by a lever 56a which is swingably supported by a side plate 83 of the main body via a pivot pin 56c, and the lever 56a is a toner replenishing solenoid 56b (or other driving means). ) Is rotated. That is, when the solenoid 56b is urged by the toner replenishment signal, the upper end of the lever 56a is pulled by the solenoid 56b, and the drive gear supported by the lever 56a engages with the intermediate gear 55 (FIG. 5). When the solenoid 56b is deenergized, the lever 56a is rotated clockwise by the action of a spring (not shown), and the drive gear 56 is separated from the intermediate gear 55. As described above, only when the toner replenishment signal is generated, the solenoid is energized, the drive gear 56 engages with the intermediate gear 55, the rotating body 53 is rotated, and the toner is replenished. After the rotating body 53 is rotated for a predetermined time to replenish the toner, when the toner replenishment is stopped, the drive gear 56 is separated from the intermediate gear 55 and the rotation of the rotating body 53 is stopped. As is known per se, the toner replenishment signal may be generated by a toner concentration detecting means (not shown) when the toner concentration has dropped to a predetermined value, or the toner consumption amount and the developing amount may be reduced. roller
Utilizing the fact that the number of rotations of 10 is substantially proportional, the next toner replenishment signal may be generated when the developing roller 10 rotates a predetermined number of times after toner replenishment.

The toner supply devices 44R and 44B, which are exactly the same as the toner supply device for the first developing device 3, also belong to the developer chambers 4R and 4B of the developing devices 3, 3R and 3B shown in FIGS. 2 and 3, respectively. Toner is supplied to the developer chambers 4R and 4B from the second and third toner tanks 51R and 51B.

The present invention can be widely applied to a non-rotating developing device, a developing device of an image forming apparatus other than a copying machine, and the like.

Effect According to the present invention, the developer carrying-out means carries out the two-component developer existing in the developer chamber in the developing device to be discarded to the outside of the developing device when necessary, and discharges it to the outside of the developing device. It is possible to allow the worker to easily discharge the developer to the outside of the developing device without soiling his / her hands with the developer.
Moreover, the developer carry-in means and the developer carry-out means are communicated with each other outside the developer chamber, and the two-component developer carried outside the developer chamber by the developer discharge means is returned to the developer chamber by the developer carry-in means, Since it is possible to switch whether it is discharged to the outside of the developing device as it is, when the developer should not be discarded, the two-component developer is circulated by the developer carry-out means and the developer carry-in means, and this is efficiently agitated and mixed. In addition, when the developer is to be discarded, it can be quickly discharged out of the developing device.

[Brief description of drawings]

1 is a vertical cross-sectional view of the developing device when the developing unit is set in the main body of the copying machine, and FIG. 2 is II-II of FIG.
FIG. 3 is a cross-sectional view taken along the line of the toner supply device, taken along line II′-II ′, FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1, and FIG. 3a is a guide member. FIG. 4 is a perspective view showing the state of the guide fins, FIG. 4 is a perspective view showing a state in which the storage stand is pulled out from the copying machine main body, and the developing unit is removed from the storage stand. FIG. 5 Toner supply provided on the front side of the developing unit. FIG. 5a is a perspective view of the device, FIG. 5a is a perspective view of the device for switching the flow path of the developer, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5a, and FIG. 7 is a portion showing another example of the toner supply device. FIG. 8 is a perspective view of FIG. 7 with the supply pipe inserted.
FIG. 9 is a cross-sectional view taken along the line VIII-VIII, and FIG. 9 is a perspective view of the storage stand and the elements related thereto when the developing unit is removed, as viewed from the back side. 3,3R, 3B ... Developer, 4,4R, 4B ... Developer chamber 9,9R, 9B ... Developer

Claims (1)

[Claims] 1. A developer carrying-out means for carrying out a two-component developer existing in a developer chamber in the developing device to be discarded to the outside of the developing device and discharging the developer to the outside of the developing device, and to a developer chamber. A developer carry-in means for carrying in a two-component developer, the carry-in means and the developer carry-out means communicate with each other outside the developer chamber,
It is characterized in that a two-component type developer carried to the outside of the developer chamber by the developer carry-out means is provided with a flow path switching means for switching between returning to the developer chamber by the developer carry-in means or discharging the developer as it is to the outside of the developing device. And a developing device in the image forming apparatus.