JP2002258611A - Rotary type developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the rotary type developing device of a trickle system in which a developer in a developing unit is maintained in a just proper quantity over the long-term. SOLUTION: The rotary type developing device of a trickle system is provided with a first discharge part 12. The first discharge part 12 is equipped with a first discharge port 10 opened at the upper part of the development housing 5 of a developing unit 2 in a development position Pd, and a first shutter member 11 which is turnably supported between a closing position where the member 11 abuts on the upper part inside surface of the development housing 5 to close the first discharge port 10 and an opening position where the member 11 separates from the upper part inside surface of the development housing 5 to open the first discharge port 10, opens the first discharge port 10 by an action of gravity in the development position Pd, and stores a surplus developer, meanwhile, closes by the action of gravity the first discharge port 10 in a standby position Pa after development, and discharges the stored surplus developer. The developing device is further provided with a second discharge part 15 which has the same structure as the first discharge part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used for forming a multicolor image in an image forming apparatus such as an electrophotographic copying machine or a printer, and more particularly, to a two-component developer comprising a toner and a carrier. The present invention relates to an improvement of a rotary developing device having a plurality of developing devices used in a rotary holder.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine or a printer, an electrostatic latent image on a latent image carrier such as a photosensitive drum is visualized by a developing device. In a developing device of this type using a two-component developer composed of a toner and a carrier, the toner is consumed by the developing operation, but the carrier remains in the developing device without being consumed. Therefore, the carrier stirred together with the toner in the developing device deteriorates as the stirring frequency increases.

Therefore, in order to suppress the deterioration of the developer,
A so-called trickle developing method has already been adopted. This trickle developing system replenishes the toner consumed by the developing operation, replenishes new carrier into the developing device, discharges excess developer in the developing device due to the replenishment, and removes such developer. By successively repeating the supply and discharge operations, the deteriorated developer in the developing device is replaced with newly supplied toner and carrier, and the developing characteristics of the developer in the developing device are kept constant. As a result, it is possible to maintain the charging performance of the developer and suppress a decrease in the image quality of the formed image.

On the other hand, in recent years, color copying machines and printers have been developed. In an image forming apparatus such as a copying machine or a printer, as one method for obtaining a color image, a plurality of color toner images are sequentially formed on a latent image carrier, and the plurality of color toner images are recorded on a recording medium such as paper. There is known a method of sequentially or collectively superimposing them on top. In such a color image forming apparatus, for example, a plurality of developing devices for each color component are mounted on a rotary holder, and necessary developing devices are arranged to face the latent image carrier by rotating the rotary holder. A device using a rotary developing device (a so-called rotary system) has already been proposed and put to practical use.

The present applicant has already proposed a rotary developing device employing a so-called trickle system (see, for example, JP-A-11-295983). For example, as shown in FIG. 39, the rotary developing device includes yellow (Y), magenta (M),
Developing devices 502Y, 502M, 502C and 502K accommodating the respective developers of cyan (C) and black (K) are mounted, and each developing device is driven by driving the rotary holder 501 by a holder driving device (not shown). 502Y, 5
02M, 502C, and 502K are selectively disposed at a developing position Pd facing the latent image carrier 500 to perform development.
After the development, it is moved to a post-developing standby position Pa above the development position Pd. Each of the developing units 502Y to 502K is, for example, a black developing unit 5Y.
For example, a developing housing 503 having an opening at a portion facing the latent image carrier 500 is provided, and a developing roll 504 is provided at a position facing the opening of the developing housing 503. A pair of agitating / conveying augers 505 and 506 are provided in a developing housing 503 adjacent to the developing roll 504, and a layer thickness regulating member 507 is provided on the developing roll 504 in front of a developing site.

The black developing unit 502K is provided with a supply pipe 508 for supplying a developer composed of black toner and a carrier through a supply port (not shown) provided in the developing housing 503. Further, a discharge port 509 for discharging surplus developer and a discharge port 509 are provided above the stirring and conveying auger 506 of the developing housing 503.
A discharge unit 511 including a shutter 510 that opens and closes the shutter 510 is provided. Here, the shutter 510 rotates between a closed position where the shutter 510 contacts the inner surface of the upper portion of the developing housing 503 to close the outlet 509 and an open position where the shutter 510 is separated from the inner surface of the upper portion of the developing housing 503 and opens the outlet 509. In the developing position Pd, the discharge port 509 is opened by the action of gravity to store the surplus developer, while at the post-developing standby position Pd, the discharge port 509 is closed by the action of gravity. In addition, the stored excess developer is discharged.

On the other hand, the rotary shaft 50 of the rotary holder 501
1a have communication ports 512Y, 512M, 5 at approximately 90 ° intervals.
12C and 512K are opened, and these are connected to the outlets 509 of the developing units 502Y to 502K. A passage extending in the axial direction is formed inside the rotation shaft 501a of the rotation holder 501, and a fixed collection tube 513 substantially matching the inner diameter of the passage is accommodated along the passage. A collection auger 514 extending in the axial direction is provided inside the fixed collection pipe 513, and one collection port for one communication port 512 located on the upper side of the rotating shaft 501a is provided above the collection auger 514. A mouth 515 is formed.

In the rotary developing device, for example, when a black toner image is continuously developed, a black developing device 502K is arranged at a developing position Pd, and the agitating and conveying augers 505 and 506 are driven to develop the developing housing 503.
The developer inside the latent image carrier 500 is agitated and transported, and the developing roller 504 is also driven to develop the electrostatic latent image on the latent image carrier 500 with toner. Then, as the toner is consumed by the developing operation, new toner and carrier are supplied from the supply pipe 508, the amount of the developer in the developing housing 503 increases, and the bulkiness (upper surface position) of the developer is reduced. To rise. At this time, the shutter 510 of the discharge unit 511 is in the open position, and a part of the developer circulated and conveyed by the stirring and conveying augers 505 and 506 is stored on the upper surface of the shutter 510. When the development by the black developing device 502K is completed, the black developing device 502K moves to the post-developing standby position Pa, and at this time, the shutter 510 moves from the open position to the closed position. At this time, the developing position Pd
The developer (excess developer) stored on the shutter 510 is discharged out of the developing housing 503 with the closing of the shutter 510, and the discharged excess developer passes through the communication port 512K and the recovery port 515. Then, it is guided to the fixed collection tube 513, and then discharged to the outside of the developing device by the collection auger 514.

By doing so, the deterioration of the developer in each of the mounted developing devices 502Y, 502M, 502C, and 502K is suppressed, and the amount thereof is also maintained in an appropriate range.
Further, by providing the shutter 510, unnecessary discharge of the developer can be suppressed, and the configuration is simplified because the shutter 510 is automatically opened and closed by gravity.
It has such advantages.

[0010]

However, for example, when a continuous developing operation is performed using one developing device (a black developing device 502K for a monochrome image), for example, when a monochrome image is continuously formed, the developing Housing 503
While new developer is supplied one after another, the developer storage capacity of the shutter 510 is limited, so that the amount of developer in the black developing device 502K becomes excessive and further excessive. The developer that has been pushed up the shutter 510 to the closing position causes a situation in which excessive developer cannot be discharged, so that the drive system of the agitating and conveying augers 505 and 506 is overloaded,
In addition, there has been a technical problem in that the toner charge is reduced due to insufficient stirring, and the resulting development failure (image quality reduction) occurs.

In order to solve such a technical problem, the applicant of the present invention has proposed in the above-mentioned rotary developing device that the black developing device 50 is provided at predetermined time intervals when a monochrome image is continuously formed.
A technique is proposed in which the 2K developing operation is stopped, the black developing device 502K is moved to the post-developing standby position Pa to discharge the excess developer, and then moved to the developing position Pa again to restart the developing operation. (Japanese Patent Laid-Open No. 200
0-122414).

Further, the present applicant has proposed a black developing device 502.
A technique was also proposed in which the size of the discharge unit 511, that is, the discharge port 509 and the shutter 510 provided in the K, was set to be larger than those of other colors so as to increase the amount of developer that can be stored. Open 2000-3218
No. 58).

However, in the former case, there is a technical problem that extra time is required and the image forming efficiency is liable to be reduced because a mode must be provided for temporarily suspending image formation and discharging excess developer. Was seen.

Further, in the latter case, although it is possible to increase the developer storage capacity of the shutter 510, the excess developer is
It is not possible to completely avoid a situation in which 0 is pushed up to the closed position, and there remains a problem that the developer cannot be discharged eventually.

On the other hand, Japanese Patent Application Laid-Open No. 2000-321858 discloses a case in which a slit portion communicating with the discharge port 509 is provided in the vicinity of the discharge port 509 to prevent the shutter 510 from being pushed up to the closed position by excessive developer. Also, there is described a technique in which excess developer can be discharged through the slit portion. However, there is a technical problem that the amount of developer that can be discharged only by the slit portion is limited, and it is not possible to cope with a large amount of excess developer.

Also, in the above-mentioned rotary developing device, in consideration of the fact that a monochrome image is frequently formed, the black developing device 5 is located near the developing position Pd during non-image formation.
02K is made to wait. Then, when forming a full-color image, it is known that development is performed in the order of yellow (Y) → magenta (M) → cyan (C) → black (K) in order to obtain high image quality. Then
In this type, when a full-color image is formed, the black developing device 502K is skipped and the yellow developing device 5K is skipped.
Although the development starts from 02Y, there is a problem that the developer in the black developing device 502K jumps out through the outlet 509 at that time. This developer
Since the developer is not a surplus developer, the developer is unnecessarily discharged, which leads to poor development due to a shortage of the developer and poor image quality due to the shortage of the developer, and an increase in the amount of wastefully consumed developer. There was a technical problem of getting lost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problems, and is intended to solve the above-mentioned technical problem. A developing device is provided.

[0018]

That is, according to a first aspect of the present invention, as shown in FIGS. 1A to 1C, a plurality of developing devices 2 (for example, 2a to 2d) are mounted on a rotary holder 1. Mounted,
By rotating the rotary holder 1 intermittently, each developing unit 2 is selectively arranged at the developing position Pd facing the latent image carrier 3, and each color component latent image on the latent image carrier 3 is corresponded. The developing unit 2 develops the toner, and the developing position Pd
Is a rotary developing device that moves to an upper post-developing standby position Pa after development, wherein each of the developing devices 2 contains a two-component developer composed of toner and carrier and partially A developing housing 5 having a developing opening 4 formed therein; a developer carrying member 6 disposed to face the developing opening 4 for carrying and transporting the two-component developer; A stirring and conveying member 7 (for example, 7 a, 7 a)
b), a developer replenishing section 8 for replenishing toner and carrier into the developing housing 5, and a developer discharging section 9 for discharging excess developer in the developing housing 5. The developer discharge section 9 is provided at the developing position P
d, a first outlet 10 opened above the developing housing 5 of the developing device 2, a closed position where the first outlet 10 is closed by contacting the inner surface of the upper part of the developing housing 5, and an inner surface of the upper part of the developing housing 5. The developing position Pd is rotatably supported between the opening position and the opening position where the first discharge port 10 is opened. At the developing position Pd, the first discharge port 10 is opened by the action of gravity to release the surplus developer. A first discharge unit 12 including a first shutter member 11 that closes the first discharge port 10 by the action of gravity and discharges the stored excess developer at the post-development standby position Pa while storing the developer;
The developing housing 5 of the developing device 2 at the developing position Pd
A second outlet 13 opened at an upper portion of the developing housing 5, a closed position where the second outlet 13 is brought into contact with the inner surface of the developing housing 5 to close the second outlet 13, and the second outlet 13 is separated from the inner surface of the developing housing 5. The developing position Pd is rotatably supported between an open position and the developing position Pd, where the second discharge port 13 is opened by the action of gravity to store the surplus developer, while the post-developing standby position. Pa has a second discharge portion 15 having a second shutter member 14 for closing the second discharge port 13 by the action of gravity and discharging the stored excess developer to the outside of the developing housing 5. And FIG. 1C is a cross-sectional view taken along the line IC-IC of FIG.

In such technical means, the developer discharge section 9 in the first embodiment of the present invention has two discharge sections, that is, a first discharge section 12 and a second discharge section 15. Here, the first discharge unit 12 includes a first discharge port 10 and a first shutter member 11, while the second discharge unit 15 includes a second discharge port 13 and a second shutter member 1.
4 Here, from the viewpoint of simplification of the configuration, each of the discharge ports 10, 13 and each of the shutter members 1
It is preferable that each of the components 1 and 14 is the same.

Further, the first discharge section 12 and the second discharge section 15
The disposition position may be appropriately selected as long as it is above the developing housing 5, but from the viewpoint of facilitating the accumulation of the surplus developer in the first shutter member 11 and the second shutter member 14. In this case, it is preferable that both are located above the stirring and conveying member 7 at the developing position Pd.

FIG. 2A shows a second embodiment of the present invention.
As shown in (c), a plurality of developing devices 2 are
(For example, 2 a to 2 d), and the developing device 2 is selectively disposed at a developing position Pd facing the latent image carrier 3 by intermittently rotating the rotary holder 1. A developing device 2 located at the developing position Pd and moving to an upper post-developing standby position Pa after the development, while developing the latent image of each color component on the developing device 2 with a corresponding developing device 2; A developing housing 5 containing a two-component developer composed of a toner and a carrier and having a developing opening 4 formed in a part thereof; a developing housing 5 disposed facing the developing opening 4; A developer carrier 6 that carries and transports the two-component developer; and a stirring and transporting member 7 (for example, 7a, 7b) that agitates and transports the two-component developer in the developing housing 5 and supplies the two to the developer carrier 6. And toner and toner in the developing housing 5. A developer replenishing section 8 for replenishing the carrier, and a developer discharging section 9 for discharging the surplus developer in the developing housing 5, wherein the developer discharging section 9 is provided at the developing position Pd. A main outlet 16 opened at the upper part of the developing housing 5 of the container 2 and the main outlet 1 contacting the inner surface of the upper part of the developing housing 5.
The main discharge port 16 is rotatably supported between a closed position where the main discharge port 6 is closed and an open position where the main discharge port 16 is opened apart from the inner surface of the upper part of the developing housing 5. A shutter for closing the main discharge port 16 by the action of gravity at the post-developing standby position Pa and opening the outlet 16 to store the surplus developer and discharging the stored surplus developer to the outside of the developing housing 5. A main discharge portion 18 having a member 17; a sub-discharge port 19 provided above the developing housing 5 of the developing device 2 at the developing position Pd and below the main discharge port 16; It is characterized by having a sub-discharge unit 21 provided with an outlet 19 and a bypass path 20 for connecting and connecting the main discharge port 16. FIG. 2C shows the IIC-I of FIG. 2B.
FIG. 3 is an IC cross-sectional view.

In such technical means, the developer discharge section 9 in the second embodiment of the present invention has two discharge sections, namely a main discharge section 18 and a sub discharge section 21. Here, the main discharge portion 18 is composed of the main discharge port 16 and the shutter member 17, which is described in the first discharge portion 12 or the second discharge portion 1 in the first embodiment of the present invention.
5 may be appropriately selected from those similar to 5. Also,
The sub-discharge unit 21 includes the sub-discharge port 19 and the bypass path 20.
It must be above the developing housing 5 of the developing device 2 at the developing position Pd and below the main discharge port 16.

Further, a third embodiment of the present invention is shown in FIG.
As shown in (c), a plurality of developing devices 2 are
(For example, 2 a to 2 d), and the developing device 2 is selectively disposed at a developing position Pd facing the latent image carrier 3 by intermittently rotating the rotary holder 1. A developing device 2 located at the developing position Pd and moving to an upper post-developing standby position Pa after the development, while developing the latent image of each color component on the developing device 2 with a corresponding developing device 2; A developing housing 5 containing a two-component developer composed of a toner and a carrier and having a developing opening 4 formed in a part thereof; a developing housing 5 disposed facing the developing opening 4; A developer carrier 6 that carries and transports the two-component developer; and a stirring and transporting member 7 (for example, 7a, 7b) that agitates and transports the two-component developer in the developing housing 5 and supplies the two to the developer carrier 6. And toner and toner in the developing housing 5. A developer supply unit 8 for replenishing Yaria, said to and a developer discharging section 9 for discharging the surplus developer in the developing housing 5, the developer discharging section 9,
The developing housing 5 of the developing device 2 at the developing position Pd
The main discharge port 16 opened at the upper part of the developing housing 5, a closed position where the main discharge port 16 contacts the inner surface of the developing housing 5 to close the main discharging port 16, and the main discharging port 16 is opened apart from the inner surface of the developing housing 5. At the developing position Pd, the main discharge port 16 is opened by the action of gravity to store the excess developer, while the post-development standby position Pa causes gravity. A shutter member 17 for closing the main discharge port 16 by the action and discharging the stored excess developer to the outside of the developing housing 5, and an auxiliary discharge opening provided above the developing housing 5 of the developing device 2 at the developing position Pd. An outlet 22 and an auxiliary driving means 23 for driving the stirring and conveying member 7 of the developing device 2 at the post-developing standby position Pa. FIG. 3C is a sectional view taken along the line IIIC-IIIC in FIG.

In such a technical means, the developer discharge section 9 in the third embodiment of the present invention includes the main discharge port 16,
It has a shutter member 17 and an auxiliary outlet 22. Here, the main outlet 16 and the shutter member 17 may be appropriately selected from those similar to those in the second embodiment of the present invention. On the other hand, the disposition position of the auxiliary discharge port 22 is different from that of the sub discharge port 19 in the second embodiment of the present invention. It does not need to be lower than this, and may be set as appropriate.

The auxiliary driving means 23 drives the stirring and conveying member 7 of the developing device 2 at the developing position Pd if it drives the stirring and conveying member 7 of the developing device 2 at the post-developing standby position Pa. It may be used also as a driving unit for performing the operation, or may be provided independently.

Still further, a fourth embodiment of the present invention is shown in FIG.
As shown in (a) to (c), a plurality of developing devices 2 (for example, 2a to 2d) are mounted on a rotating holder 1, and the rotating holder 1 is intermittently rotated to face the latent image carrier 3. Each developing device 2 is selectively disposed at a developing position Pd to be developed, and each color component latent image on the latent image carrier 3 is toner-developed by the corresponding developing device 2 and the developing device 2 at the developing position Pd
Is a rotary developing device that moves to an upper post-developing standby position Pa after the development, wherein each of the developing devices 2 contains a two-component developer composed of toner and carrier and partially has a developing opening 4. The developing housing 5 is provided with a developing member, the developer carrier 6 is disposed facing the developing opening 4 and carries and carries the two-component developer, and the two-component developer in the developing housing 5 is stirred. A stirring and conveying member 7 (for example, 7a, 7b) for conveying and supplying the developer to the developer carrier 6, a developer replenishing unit 8 for replenishing toner and carrier into the developing housing 5, and a surplus in the developing housing 5 A developer outlet 9 for discharging the developer, wherein the developer outlet 9 is provided with a main outlet 16 opened above the developing housing 5 of the developing device 2 at the developing position Pd; 5 Upper inner surface The main discharge port 16 is rotatably supported between a closed position in which the main discharge port 16 is closed by contact and an open position in which the main discharge port 16 is opened apart from the inner surface of the upper portion of the developing housing 5. The main discharge port 16 is opened by the action of gravity to store the surplus developer, while at the post-developing standby position Pa, the main discharge port 16 is closed by the action of gravity to develop the stored surplus developer. Shutter member 17 for discharging outside housing 5
And an auxiliary discharge port 22 opened above the developing housing 5 of the developing device 2 at the developing position Pd, and further moves to the post-developing standby position Pa without performing development at the developing position Pd. The developing device 2 is temporarily stopped at the developing position Pd, and idle driving means 24 for idle driving the stirring and conveying member 7 of the developing device 2 at the developing position Pd is provided. FIG. 4 (c) is the same as FIG.
It is IVC-IVC sectional drawing of (b).

In such a technical means, the developer discharge section 9 in the fourth embodiment of the present invention includes the main discharge port 16,
It has a shutter member 17 and an auxiliary outlet 22. Here, the main outlet 16, the shutter member 17, and the auxiliary outlet 22 may be appropriately selected from those similar to those of the third embodiment of the present invention.

On the other hand, the idle driving means 24 is connected to the developing position P
d, the developing device 2 that moves to the post-developing standby position Pa without performing development is temporarily stopped at the developing position Pd, and the stirring and conveying member 7 of the developing device 2 is moved at the developing position Pd.
It is preferable that the drive unit also drives the agitating / conveying member 7 of the developing device 2 at the developing position Pd during normal development from the viewpoint of simplifying the configuration.

In the rotary developing device according to the first to fourth aspects of the present invention, the number of the developing devices 2 mounted on the rotary holder 1 may be any number as long as it is plural. 1 to 4 show an example in which four developing devices 2 (2a to 2d) are mounted on the rotary holder 1. The post-development standby position Pa is shown in FIGS.
As shown in FIG. 4, the position is not limited to the vertical direction of the developing position Pd, and the position may be appropriately changed depending on the number of the developing devices 2 or the like.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the accompanying drawings. First Embodiment FIG. 5 shows a first embodiment of an electrophotographic copying machine to which a rotary developing device according to the present invention is applied. In the figure, reference numeral 31 denotes a photosensitive drum (latent image carrier) rotating in the direction of an arrow, reference numeral 32 denotes a charger such as a corotron for pre-charging the photosensitive drum 31, and reference numeral 33 denotes an image writing device such as a laser scanning device. The device (ROS) irradiates the surface of the photosensitive drum 31 with a laser beam modulated by a laser drive signal generated for each color component. The ROS 33 operates according to an image output instruction input from a host device (not shown).
S) The digital image input from the image reading device 36 via 35 is written on the photosensitive drum 31 as an electrostatic latent image. Reference numeral 34 denotes a rotary developing device on which developing devices corresponding to the respective colors of Y, M, C, and K are mounted, and develops an electrostatic latent image formed on the photosensitive drum 31 to form a toner image of each color component. Is formed. Reference numeral 37 denotes a drum cleaner for removing residual toner on the photosensitive drum 31, and reference numeral 38 denotes an intermediate transfer belt disposed so as to be in contact with the surface of the photosensitive drum 31, which is stretched over a plurality of rolls. And rotate in the direction of the arrow. Further, a transfer roll 39 is provided at a portion (primary transfer position) of the intermediate transfer belt 38 that faces the photoconductor drum 31. Thus, the toner image on the photosensitive drum 31 is electrostatically attracted to the intermediate transfer belt 38.

Further, at the secondary transfer position of the intermediate transfer belt 38 facing the transport path of the paper P, a secondary transfer device 40 composed of a secondary transfer roll and an opposing roll is disposed. On the other hand, an electrostatic latent image is transferred. Thereafter, the sheet P to which the unfixed image has been transferred is thermally fixed by the fixing device 41.

Next, the paper transport system of the image forming apparatus according to the present embodiment will be described. The paper transport system has a plurality of paper trays 42 to 45 for loading paper P, and a manual feed tray 46 for supplying paper P from outside the apparatus. Also,
On the upper part of each of the paper trays 42 to 45, the stacked paper P
Roll 47 picking up from the top in contact with
A separating mechanism 4 composed of a feed roll and a retard roll for separating sheets P one by one
8, on the downstream side, a take-away roll 49 for temporarily stopping the sheet P and then re-sending the sheet P at a predetermined timing.
have. These takeaway rolls 49 also have a function as transport rolls for simply transporting the paper P when the paper P is supplied from the lower paper trays 43 to 45.

A paper path 50 downstream of the take-away rolls 49 has a registration roll (registration roll) 51 for transporting the paper P to the secondary transfer device 40 at the timing of image formation. After the positioning is stopped by the registration roll 51, the unfixed image is transferred onto the sheet P. Further, on the downstream side, a transport belt 52 is provided, and the paper P is transported to the fixing device 41 by the transport belt 52.

Further, in the present embodiment, when the duplex mode is selected, a sheet return mechanism for reversing the sheet P fixed on one side by the fixing device 41 and returning it to the secondary transfer position is provided. This paper return mechanism is provided with a paper branch path 54 that branches downward with respect to a paper discharge path 53 from the fixing device 41, and a paper reversing path 55 is further extended downward from the paper branch path 54. In addition, a paper return path 56 returning from the paper inversion path 55 to the paper path 50 just before the secondary transfer position is connected. And
A plurality of transport rolls 57 are provided in the sheet branch path 54, the sheet reversing path 55, and the sheet return path 56. In particular, the transport rolls 57 provided in the sheet reversing path 55 rotate forward and backward at appropriate timing. ing. Furthermore,
A switching gate (not shown) for switching the transport path is provided between the sheet discharge path 53 and the sheet branch path 54, and between the sheet branch path 54, the sheet reversing path 55, and the sheet return path 56. In addition, the paper path is appropriately switched according to the selected mode.

Next, the rotary developing device 3 according to this embodiment
4 will be described in detail. FIG. 6 is a cross-sectional view of a main part of the rotary developing device 34 according to the present embodiment, and FIG. 7 is a cross-sectional view of a main part of a different part of the rotary developing device 34 from FIG. In the present embodiment, the rotary holder H includes a pair of rotary plates PL1 and PL2 described later (see FIG. 9) before and after the black developing device GK, the yellow developing device GY, the magenta developing device GM, and the cyan developing device GC are mounted. And a rotation axis GA.

During image formation, each of the developing units GK to GC is moved to a first stop position (developing position) P facing the photosensitive drum 31 with the rotation of the rotary holder H.
1. 90 ° clockwise in the figure from the first stop position P1
Rotated second stop position (standby position after development) P2, 180
The rotation stops sequentially at a third stop position P3 rotated by °° and a fourth stop position P4 rotated at 270 °, and stops. The rotational force is transmitted to the developing rolls R0 of the developing units GK, GY, GM, and GC stopped at the first stop position P1, so that the developing operation can be performed. Further, new developer is supplied to the developing devices GK, GY, GM, GC stopped at the first stop position P1, and the deteriorated developer can be discharged.
The details will be described later.

FIG. 8 is a perspective view showing a support mechanism of the rotary holder H. FIG. 9 is a diagram showing a state in which the developing units GK to GC are mounted on the rotary holder H. FIG. 10 is an enlarged sectional view of a rotary shaft GA provided in the rotary developing device 34 according to the present embodiment. FIG. 10A is a sectional view taken along line XA-XA in FIG. ) Is the aforementioned FIG.
(A) is a sectional view taken along line XB-XB. FIG. 11 is an explanatory view of a drive mechanism for transmitting a rotational force to the rotary developing device 34.

8 to 11, the main body of the image forming apparatus has a front fixed frame F1 and a rear fixed frame F2, and a fixed cylindrical member F1a (described later) is fixed to the front surface of the front fixed frame F1. Have been. The rotary shaft GA of the rotary developing device 34 has a square cylindrical portion GA0 having a square cross section at the axial center, a front cylindrical portion GA1 at the axial front portion, and a rear cylindrical portion GA2 at the axial rear portion. are doing. The front cylindrical portion GA1 and the rear cylindrical portion GA2 are connected to the fixed cylindrical member F1a via bearings BR1 and BR2, respectively.
And is rotatably supported by the rear fixed frame F2.

A front rotation plate PL1 and a rear rotation plate PL2 are fixed to the front end and the rear end of the square tube portion GA0. The rotation axis GA, the front rotation plate PL1
The rear rotating plate PL2 constitutes a rotating holder H that supports and rotates the developing units GK, GY, GM, and GC of the four colors. Also, the rear rotating plate PL2
A ring gear G1 (see FIGS. 8, 9, and 11) is fixed to the rear surface via four studs STD (see FIG. 11). The ring gear G1 meshes with a gear G2 connected to an output shaft of a drive motor M1 (see FIG. 11) supported on the rear fixed frame F2. Therefore, the ring gear G1 rotates when the drive motor M1 rotates, and the rotary holder H rotates with the rotation of the ring gear G1.

A developer discharge passage 101 (see FIG. 10B) having a circular cross section is formed in the rotary shaft GA so as to penetrate in the axial direction. 9 and 10A) are formed. 9 and 10, the square tube portion GA of the rotation shaft GA
In the rear end portion, a discharged developer inflow hole 103 communicating with the developer discharge passage 101 from four side surfaces extending in the axial direction.
(See FIG. 7). A pin insertion hole 104 is provided on each side surface of the square tube portion GA0 (see FIGS. 6 and 9).
Are formed. The pin insertion hole 104 is a hole into which a protruding pin (described later) of each of the developing devices GK, GY, GM, and GC is inserted, and is used for positioning and fixing each of the developing devices GK to GC.

In FIG. 10A, a developer discharge tube 107 is provided in the developer discharge passage 101 of the rotation shaft GA. The rear end of the developer discharge tube 107 is fixed to a rear discharge tube fixing member F2a.
2a is fixed to the rear fixed frame F2. Further, the front end of the developer discharge cylinder 107 is a bearing 10.
The front end of the developer discharge cylinder 107 is axially shorter than the front end of the rotary shaft GA, supported by the developer discharge path 101 of the rotary shaft GA via the shaft 8. FIG. 10 (b)
At the rear end side of the developer discharge cylinder 107, an inflow path connection port 107a is formed at an upper portion, and the inflow path connection port 107a is connected to each of the discharged developer inflows of the square cylindrical portion GA0 of the rotary shaft GA. The position in the axial direction is the same as that of the hole 103 (see FIGS. 7 and 10A). Further, the developer discharge cylinder 10
A discharge outlet 107b is formed at the front end of 7.

In FIG. 10B, a magnet seal 10 is provided on a portion of the outer peripheral surface of the fixedly supported developer discharge cylinder 107 adjacent to the inflow path connection port 107a.
9 is adhered and fixed. A sheet communication port 109a is formed in the magnet seal 109, and is always in communication with the inflow path connection port 107a of the developer discharge cylinder 107. A small gap is provided between the outer peripheral surface of the magnet seal 109 and the inner peripheral surface (developer discharge path 101) of the rotary shaft GA so as not to generate contact friction resistance when the rotary shaft GA rotates. . The magnet seal 109 moves the developer through the gap between the outer peripheral surface of the developer discharge cylinder 107 and the inner peripheral surface of the rotating shaft GA to another discharged developer inflow hole 103 of the rotating shaft GA. This is a member for preventing the operation.

Further, in FIG. 10 (b), in the developer discharge cylinder 107, a discharge rotary shaft 111a and a rotary blade 111b fixed to the outer periphery of the discharge rotary shaft 111a.
Developer transport member (discharge transport auger) 11 having
1 is arranged. The rear end of the discharge rotary shaft 111a of the discharged developer conveying member 111 is rotatably supported by a conveying member rear end support member 112 (see FIGS. 9 and 10A). The end support member 112 is fixed to the rear end of the developer discharge tube 107. The front end of the discharge rotation shaft 111a is rotatably supported by the front end of the rotation shaft GA. The discharge rotating shaft 111a of the discharged developer conveying member 111 extends rearward through the rear end supporting member 112 of the conveying member, and has a gear G3 (see FIGS. 9 and 10 (a)) at the rear end. ) Is fixed, and a gear G4 (FIG. 9) for transmitting torque is attached to the gear G3.
See). The rotating force of a developer discharge motor (not shown) is transmitted to the gear G4. When the developer discharge motor is driven, the gear G3, the gear G4, and the discharge rotary shaft 111a are integrally rotated. You. still,
In the present embodiment, the discharged developer conveying member 111
When the developing units GK to GY are stopped at positions other than the first stop position P1, the rotation is stopped.

8, 9, and 11, the rear rotating plate PL2 has four input gears G5 according to the developing units GK to GC and four input gears G5 which rotate integrally with the input gears G5. Is provided. The input gear G5 is arranged on the rear side of the rear rotation plate PL2, and the four integrated rotation gears G6 are provided on the front side of the rear rotation plate PL2. The input gear G5 is connected to the gear G7 when the corresponding developing device GK to GC moves to the first stop position P1, and separates from the gear G7 when the corresponding developer unit GK moves away from the first stop position P1. The rear end of the rotating shaft of the gear G7 passes through the inside of the ring gear G1 and is rotatably supported by the rear rotating plate PL2 behind the ring gear G1. A gear G8 coaxial with the gear G7 meshes with a gear G9 for rotational driving. The rotating force of a developing device driving motor (not shown) is transmitted to the gear G9. A supply shaft mounting hole 113 (only one is shown in FIG. 8) is provided adjacent to each of the four integrally rotating gears G6 that rotate integrally with the input gear G5. The supply shaft mounting hole 113 is a member that rotatably supports a rear end of a supply rotation shaft 115a described later.

FIG. 12 is a perspective view of a yellow developing unit GY, a magenta developing unit GM, and a cyan developing unit GC.
FIG. 12A shows a state in which the developer supply cylinder 114 has been removed from the developing housing V. FIG.
FIG. 2A is a diagram showing the arrangement of gears provided at the rear end of the developing housing V, and FIG. 12C is a diagram showing a state in which a developer supply cylinder 114 is attached to the developing housing V. FIG. 13 is a sectional view taken along line XIII-XIII in FIG.
14A and 14B are explanatory views of a structure for mounting the developing device on the rotary holder H. FIG. 14A is a front view of the rear rotary plate PL2 of the rotary holder H, and FIG. 14B is FIG. X
FIG. 4 is a sectional view taken along line IVB-XIVB. FIG. 24 is a perspective view of the black developing device GK, which will be described later.

A developer replenishing member Th (FIGS. 9 and 12) for replenishing a new developer into the developing housing V of each of the developing units GY, GM, and GC moved to the first stop position P1.
(C) has a developer replenishing cylinder 114 and a replenishing developer transport member 115 for transporting the replenishing developer in the developer replenishing cylinder 114. The developer supply cylinder 114 has a developer carry-in port 114a opened at the front end thereof and a supply connection port 114b (see FIG. 6) connected to the developing housing V. In FIG. 12C, the replenishment developer conveying member 115 has a replenishment rotary shaft 115a and a rotary blade 115b fixed around the replenishment rotary shaft 115a.

The front end of the supply rotation shaft 115a is connected to an opening (developer carrying port) 11 at the front end of the developer supply cylinder 114.
It extends forward from 4a, and is equipped with a bearing 116 as shown in FIG. Rotary shaft for replenishment 1
The rear end of 15a is rotatably mounted in the supply shaft mounting hole 113 for supply (see FIG. 8). A gear G10 is mounted at the rear end of the replenishing rotary shaft 115a. The rear end of the replenishing rotary shaft 115a is
3, the gear G10 is connected to the gear G6.
(See FIG. 8). The replenishing rotary shaft 11
The bearing 116 at the front end of the fixed cylindrical member F1a
It is mounted in a bearing accommodation hole (not shown) of each rotating cylindrical member described later rotatably supported therein. In this state, the developer is carried in from the developer carrying-in port 114a. Each of the color component developers is supplied to a ring-shaped connecting member L from a developer container (not shown) provided for each color.
k, Ly, Lm, and Lc are fed into the respective entrances 157 (see FIG. 8), and these ring connecting members Lk, Ly, Lm, and Lc are connected.
The developer is supplied to the developer supply cylinder 114 via the.

Since the developing units GY, GM, and GC have exactly the same configuration, the yellow developing unit GY will be described below. 6, 7, 9, and 12, the developing housing V of the yellow developing unit GY is configured by connecting a container main body V1 forming a container lower part and a container cover V2 forming a container upper part. A two-component developer including a negatively charged toner and a positively charged magnetic carrier is contained therein. FIG.
3A, the container body V1 has a pair of front and rear projecting pins V1a, V1a and locking claws V1b, V1
1b (see FIG. 22 (b)), and the pair of projecting pins V1a, V1a are provided in the pin insertion holes 4, 4 of the rotating shaft GA.
(See FIGS. 6 and 9). The protruding pin V
1a and V1a are used for positioning the developing housing V.

In FIGS. 6 and 7, the developing housing V has an opening, and accommodates a developing roll R0, a developing roll accommodating portion 117, a first developer reservoir 118 adjacent to the developing roll accommodating portion 117, and First developer reservoir 118
And a second developer reservoir 119 adjacent to the second developer reservoir 119. A layer thickness regulating member 120 for regulating the layer thickness of the developer on the developing roll R0 is disposed in the developing roll accommodating portion 117. Further, a first stirring and conveying member R1 is disposed in the first developer reservoir 118, and the second developer reservoir 1 is disposed in the first developer reservoir 118.
19, a second stirring and conveying member R2 is disposed. The first and second stirring and conveying members R1 and R2 constitute a stirring and conveying member (R1 + R2). Further, the first developer reservoir 118 and the second developer reservoir 119 constitute a developer stirring / transport area (118 + 119).

As shown in FIG. 13, between the first developer reservoir 118 and the second developer reservoir 119, partition walls 121 are provided at portions other than both ends thereof, and the first developer reservoir 118 is provided. 118 and the second developer reservoir 119 are connected at connection portions E at both ends in the front-rear direction (axial direction).
In FIG. 13, the first stirring / conveying member R1 disposed in the first developer reservoir 118 includes a rotating shaft R1a extending in the conveying direction of the two-component developer, and a rotating shaft fixed to the outer periphery of the rotating shaft R1a. Wing R1b. The second stirring and conveying member R2 disposed in the second developer reservoir 119
Also has a rotating shaft R2a and a rotating blade R2b.
2c and a low conveying section R2d having a low conveying force. The low transport section R2d is provided downstream of a developer discharge port (described later) formed in the container cover V2 in the developer transport direction.

The developing roll R0 shown in FIGS. 6, 7, and 13 is a conventionally known one in which a rotatable sleeve is provided outside a fixedly disposed magnet roll. The developer in the first developer pool 118 is attracted to the surface of the developing roll R0 by the magnetic force of the magnet roll, and is transported to the developing area Q2 (see FIGS. 6 and 7). .

6 to 8, FIG. 9, FIG. 12 (b), FIG.
, The rotation axis (roll axis) R0 of the developing roll R0
A (see FIGS. 12 (b) and 13) both end portions protrude outward from the end wall of the developing housing V, and the rotation shaft R0A
Are mounted with bearings R0B and R0B, and a gear G11 is mounted on the rear end of the rotating shaft R0A. Figure 1
In FIG. 3, both ends of the rotating shafts R1a and R2a of the first stirring and conveying member R1 and the second stirring and conveying member R2 are rotatably supported by end walls of the developing housing V. The end protrudes outward. Gears G12 and G13 are fixed to the rear ends of the shafts R1a and R2a of the first and second stirring and conveying members R1 and R2. FIG.
In (b), the gears G12 and G13 mesh with each other, and the gears G11 and G12 are connected via an intermediate gear G14.

FIG. 15 is an enlarged partial cross-sectional view of the inflow path forming member provided on the upper wall of the container of the developing housing V.
FIG. 16 is a plan sectional view of the inflow path forming member shown in FIG. FIG. 17 is a cross-sectional view of the inflow path forming member shown in FIG. 15, and FIG.
FIG. 17B is a sectional view taken along the line VIIA of FIG.
FIG. 17C is a sectional view taken along the line IB, and FIG.
It is a line sectional view. FIG. 18 is a longitudinal sectional view of the inflow path forming member shown in FIG. 15, and is a sectional view taken along line XVIII-XVIII in FIG.

In FIG. 12, the container cover V2
The roll housing wall V2a forming the developing roll housing portion 117 (see FIGS. 6 and 7) and the second
A container upper wall V2b disposed on the developer reservoir 119; and a container main body V1 extending downward from a right side of the container upper wall V2b.
And a locked side wall V2c abutting on the side wall. When the container cover V2 is attached to the container body V1,
Locking holes V2d (see FIG. 22 (b)) formed in the locked side wall V2c of the container cover V2 have locking claws V1b, V1b (FIG. 22 (b)) formed on the outer surface of the container body V1. reference)
Locked by. In FIG. 7, the second developer reservoir 1 stopped at the first stop position (development position) P1.
At the rear of the 19 container upper wall V2b, a concave forming upper wall 127 bulging upward is provided. In FIGS. 15 and 17,
A lower protruding portion 128 is provided on the right side of the recess forming upper wall 127.
Is provided. A developer outlet 127a is formed at the center of the recess forming upper wall 127, and locking portions 127b, 12
7b (see FIG. 17B) is formed.

FIG. 19 is an explanatory view of a developer outlet 127a formed in the upper wall of the developing housing V container and an inner surface side of the container upper wall V2b adjacent to the developer outlet 127a. Is a view from the arrow XIXA of FIG. 18,
FIG. 19B is a cross-sectional view taken along the line XIXB-XIXB in FIG. FIG. 20 is an explanatory view of a storage section transfer connection member mounted on the developer discharge port 127a and a shutter rotatably supported by the storage section transfer connection member. It is a figure showing a state. FIG. 21 is a view showing a state in which the storage section transfer connection member and the shutter shown in FIG. 20 are attached to the developer discharge port. FIG. 22 is a view showing a state in which the storage portion transfer connection member and the shutter mounted on the developer discharge port are in the developing container. FIG. 22A is a longitudinal sectional view, and FIG. It is XXIIB-XXIIB line sectional drawing of a). FIG. 23 is an explanatory view of the storage section transfer connection member shown in FIG. 20,
FIG. 23 (a) is a plan view of the state of FIG. 20 as viewed from the lower surface, FIG. 23 (b) is a view of arrow XXIIIB of FIG. 23 (a), and FIG. 23 (c) is FIG. arrow XXII in b)
FIG. 23D is a view from the IC, and FIG.
FIG. 3 is a sectional view taken along line ID-XXIIID.

In FIGS. 19 (a) and 20, the upper and lower inner surfaces 127c of the developer outlet 127a are provided with developer transfer grooves 127d, 127d which are recessed upward. The width of each developer transfer groove 127d expands at a position apart from the developer discharge port 127a. 20 to 22, a substantially rectangular storage section transfer connection member 1 is provided below the developer discharge port 127a.
29 are mounted. In FIG. 23, the storage section transfer connection member 129 is a rectangular transfer path forming section 129a.
And a rectangular inner developer discharge port 129b formed at the center of the transfer path forming section 129a.
As shown in FIG. 22A, in the present embodiment, the inner developer outlet 129b is formed larger than the developer outlet 127a. As shown in FIG. 22A, the storage portion transfer connection member 129 is connected to the developer outlet 127.
a in the state of being mounted inside the transfer path forming section 129.
a and a developer transfer groove 127d, 1 formed on the inner surface of the container cover V2 facing the transfer path forming portion 129a.
The storage section transfer connection paths 130, 130 are formed between the storage section transfer connection paths 130, 130. The surplus developer in the developing housing V is filled with the developer outlet 127 through the storage section transfer connection paths 130 and 130.
This is a transfer path that is transferred to the a side.

In FIG. 23C, on both long sides (left and right sides) of the rectangular inner developer discharge port 129b, the upper surface of the transfer path forming section 129a is provided with the locked sections 129c and 129c.
9c is formed. The locked portions 129c, 129
c are elastically engaging portions 127b, 127b on the left and right edges of the developer outlet 127a as shown in FIG.
To be locked. FIG. 23 (a), FIG.
(B) and FIG. 23 (d), the transfer path forming section 12
A pair of front and rear shutter support portions 1 are provided on the left end side of the lower surface of 9a.
29d, 129d are formed, and a shutter locking portion 129e is formed in an intermediate portion between the shutter supporting portions 129d, 129d. 20 and 21, the left end side of the shutter 131 is rotatably supported by the shutter support portions 129d, 129d. On the upper surface of the shutter 131, the surplus developer reservoir 13
1a (see FIG. 20).

The opening position of the shutter 131 which is locked by the shutter locking portion 129e (FIG. 22B,
A first stop position P1 in FIG. 7 and a closing position for closing the inner developer discharge port 129b (second stop position P2 in FIG. 7).
). Excess developer reservoir 13 of shutter 131 rotated to the opening position
In 1a, surplus developer having an increased upper surface height can be stored up to a predetermined storable developer amount. The developer loaded on the surplus developer storage section 131a is charged by the shutter 1
When the inner developer outlet 31 rotates to the closed position,
The developer is discharged from the developer discharge port 127a through the discharge port 29b.

As shown in FIG. 22A, at the upstream end of the storage section transfer connection paths 130, 130, the storage section transfer connection port 1 connected to the developer stirring / transport area (118 + 119).
32 and 132 are formed. In FIG. 22 (a), the storage section transfer connection ports 132, 132 are provided at an inner developer discharge port 129 at a first stop position P1, which is a development position.
b, and is always open. Due to the increase of surplus developer in the developing housing V, the shutter 131 is moved to the inner developer outlet 129b.
When the inner developer discharge port 129b is closed by being pushed up, the increased amount of the developer in the container flows into the storage section transfer connection paths 130, 130 when reaching the storage section transfer connection ports 132, 132. The developer outlet 12
7a, the surplus developer reservoir 1 of the shutter 131
31a and transferred to the excess developer storage section 131a.
The developer is stored up to a predetermined storable amount.

Referring to FIGS. 7, 10, 15 and 18,
On the upper side of the developer outlet 127a, an inflow path forming member 13 having a discharged developer temporary storage space 133 formed inside.
4 are provided. 15, a connection port 134a is provided on the right end side of the inflow path forming member 134, and the connection port 134a rotates when the developing housing V is mounted on the rotary holder H (see FIG. 9). Shaft GA
Discharged developer inflow hole 103 formed in the square cylindrical portion GA0 of FIG.
(See FIG. 7) so as to communicate with the developer discharge cylinder 107 in the rotation shaft GA. The developer discharged from the discharged developer temporary storage space 133 is configured to be recovered to a discharged developer recovery container VT disposed at a front end side through a developer discharge tube 107 in the rotation shaft GA. I have.

In FIG. 15, the inflow path forming member 13
A developer discharge space 133a connected to the developer discharge port 127a and a reverse developer storage space 13 are connected to the discharged developer temporary storage space 133 inside the developer discharge space 133b by a backflow prevention partition wall 134b.
3b. When the developer flows backward from the connection port 134a, the backflow developer flows along the backflow prevention partition wall 134b into the backflow developer storage space 133b.
It flows into the side.

As shown in FIGS. 7, 12, and 13, the developer outlet 127 is provided on the upper surface of the second developer reservoir 119.
A developer supply port 136 is formed on the upstream side in the developer transport direction from a. In this embodiment, the developer supply port 1
The developer supply port 136 and the developer discharge port 127a are formed at positions far apart from each other so that the new developer supplied from 36 is not discharged from the developer discharge port 127a immediately after the supply. In FIG. 12, a supply cylinder support member 137 having a pair of cylinder receiving arc surfaces is provided before and after the developer supply port 136 on the surface of the development housing V. The pair of cylinder receiving arc surfaces of the supply cylinder support member 137 abut on the cylindrical outer surface of the developer supply cylinder 114. Incidentally, the symbols 117 to 137, G11 to G14, R
0, R1, R2, V
Y, GM, and GC are configured.

8 and 14, four bearing mounting grooves 141 are formed in the front rotation plate PL1 and the rear rotation plate PL2. The pair of projecting pins V1a, V1a of the developing housing V are inserted and positioned in the pin insertion holes 104, 104 (see FIGS. 6 and 9) of the rotary shaft GA, and a bearing R at the outer end of the roll shaft ROA.
0B and R0B are mounted in the bearing mounting grooves 141 and clamped by the clampers 142. Clamper 142
Is a member rotatable around a hinge shaft 142a, and a screw (not shown) penetrating through a screw through hole 142b (see FIG. 14B) of the clamper 142 has a screw hole 143a (FIG. b)) and fixed to the clamper fixing member 143.

FIG. 24 is a perspective view of the black developing device GK, and FIG.
FIG. 4B shows the arrangement of gears provided at the rear end of the developing housing V in FIG. 24A, and FIG. It is a figure showing a state. FIG. 25 shows XXV-XXV of FIG.
It is a line sectional view. Here, the basic configuration of the black developing device GK is substantially the same as that of another developing device (for example, a yellow developing device GY). Omitted. However, in the black developing device GK, as shown in FIGS. 24 and 25, two inflow path forming members 134 are provided on the container upper wall V2b of the developing housing V.
134 are formed (see FIGS. 12A and 13).
This is different from the other developing devices GY and the like in point. The insides of these two inflow path forming members 134 are respectively provided with yellow developing units G
The same configuration as the inside of the Y inflow path forming member 134 (FIGS.
2), and a developer outlet 127a, a shutter 131, and the like are provided (see FIGS. 15 to 22). Then, the rotation axis G facing the black developing device GK
Two discharge developer inflow holes 103 (see FIG. 7) are formed on the side surface of the square tube portion GA0 of A.

In this manner, when the developing units GK to GC are mounted on the rotary holder H, the roll shaft R0A
The rear end gear G11 meshes with the integrally rotating gear G6. Therefore, when a rotational force is input to the input gear G5, the gear G6, which rotates integrally with the input gear G5, causes the roll shaft R0A to rotate.
The rotational force is transmitted to the gear G11 at the rear end, and the rotational force is sequentially transmitted from the gear G11 to the gears G14, G12, G13. When the gears G11, G12, G13 rotate, the developing roll R0 and the stirring and conveying member (R1 + R2) rotate. Due to the rotation of the stirring and conveying member (R1 + R2), the developer in the first and second developer reservoirs 118 and 119 circulates while being conveyed in opposite directions. Also, the replenishing rotary shaft 115
a Since the gear G10 at the rear end is also meshed with the integral rotary gear G6, the rotational force is also transmitted to the replenishing rotary shaft 115a.

On the other hand, in FIG.
07b, the collection container communication port 102 (FIG. 9,
(See FIG. 10 (a).) The discharged developer collecting container VT for collecting the developer discharged from the collecting container mounting member 171 and the collecting container lower supporting member 172 provided on the side surface of the fixed cylindrical member F1a. 8 is detachably mounted at the position shown in FIG. The collection container communication port 102 rotates around the rotation axis GA with the rotation of the rotation holder H,
When the collection container communication port 102 faces downward, the rotation axis G
The developer in A is discharged into the discharged developer collection container VT. It should be noted that any method may be used for the configuration and the mounting / removing method of the discharged developer collecting container VT.

Next, the operation of the rotary developing device 34 according to the present embodiment will be described. Here, FIG. 26 shows the developing housing V of the yellow, magenta, and cyan developing units GY, GM, and GC stopped at the first stop position (developing position) P1.
FIG. FIG. 27 shows the developing units GY, GM,
GC developer outlet 127a and inner developer outlet 12
FIG. 9B is a diagram showing a state in which 9b faces downward. FIG. 28 shows that the developer in the developing housing V increases in the developing units GY, GM, and GC for some reason and the shutter 13
1 is pushed up, and the pushed up shutter 13
FIG. 4 is a diagram illustrating a state in which the developer in the developing housing V is discharged from the storage part transfer connection port 132 on the downstream side in the developer conveyance direction in a state in which the inner developer discharge port 129b is closed. FIG. 29 shows that in each of the developing units GY, GM, and GC, the developer in the developing housing V increases for some reason, the shutter 131 is pushed up, and the pushed up shutter 131 closes the inner developer outlet 129b. FIG. 8 is a diagram illustrating a state in which the developer in the developing housing V is discharged from the storage section transfer connection port 132 on the upstream and downstream sides in the developer transport direction in the state.

FIG. 30 shows the first stop position (development position).
Developing housing V of black developing unit GK stopped at P1
FIG. FIG. 31 shows two developer outlets 127a and the inner developer outlet 12 of the black developing device GK.
FIG. 9B is a diagram showing a state in which 9b faces downward. FIG. 32 shows that in the black developing device GK, the developer in the developing housing V increases for some reason, the shutter 131 on the downstream side in the developer transport direction is pushed up, and the pushed shutter 131 on the downstream side in the developer transport direction is pushed up. FIG. 10 is a view showing a state in which the developer in the developing housing V is discharged from the storage section transfer connection port 132 on the downstream side in the developer conveyance direction in a state where the inner developer discharge port 129b is closed. FIG.
In the black developing device GK, the developer in the developing housing V increases for some reason, the shutter 131 on the downstream side in the developer conveying direction is pushed up, and the pushed up shutter 131 closes the inner developer discharge port 129b. In this state, the developer in the developing housing V is discharged from the storage portion transfer connection port 132 on the upstream and downstream sides in the developer transport direction, and at the same time, the shutter 13 on the upstream side in the developer transport direction.
FIG. 7 is a diagram illustrating a state in which developer stays on a first surplus developer storage unit 131a.

6 and 7, a plurality of developing units GK, GY, GM, and GC supported by the rotary holder H are driven by the rotation and stoppage of the rotary holder H to form latent images on the surface of the photosensitive drum 31. A first stop position (development position, developer replenishment position) P1, a second stop position (post-development standby position, a developer discharge position where the developer is discharged from the developer container V) P2, The movement stops sequentially at the third stop position P3 and the fourth stop position P4.

Referring to FIGS. 9 and 11, the developing units GK,
When each of the developing housings V of GY, GM, and GC stops at the first stop position P1 (see FIGS. 6 and 7), the developing roll R0, the first stirring and conveying member R1, the second stirring and conveying member R2, and the replenishing developer. The transport member 115 rotates. Due to the rotation of these members, the following operations (1) to (1) are performed at the first stop position P1.
(3) is performed.

(1) In the developing housing V, the agitating and conveying member (R1 + R2) supplies the developer to the developing roll R0. The developing roll R0 conveys a two-component developer including a toner and a carrier to a developing region Q2 facing the surface of the photosensitive drum 31. At this time, the electrostatic latent image on the surface of the photosensitive drum 31 is developed into a toner image by the toner conveyed. By this developing operation, the developing housing V
The toner inside is consumed.

(2) The new developer (high-concentration developer) in a developer container (not shown) is supplied to each of the ring-shaped connecting members Lk,
It is conveyed to each carry-in port 157 of Ly, Lm, and Lc (refer FIG. 9). Then, the developer is supplied from the cylindrical members Bk, By, Bm, and Bc into the developer supply cylinder 114 through the developer carrying-in port 114a (see FIGS. 12C and 24C) for each color. The supplied developer is supplied to the developing housing V by rotation of a supply developer conveying member 115 in the developer supply cylinder 114.
Developer supply port 136 (FIGS. 9, 12 (c), 24)
(C), and the new developer is supplied from the developer supply port 136 into the developing housing V.

The replenished toner of the two-component developer is consumed by the developing operation. However, the carrier of the replenished two-component developer remains in the developing housing V without being consumed. Exceeds a predetermined amount, and an excess developer is generated. The developer discharging operation for discharging the developer (surplus developer including deteriorated carriers) increased by the replenishment of the developer during the developing operation is performed at the first and second stop positions P1 and P2.

(3) At the first stop position P1, the shutter 131 for opening and closing the inner developer discharge port 129b on the downstream side of the second developer reservoir 119 in the developer transport direction is opened by its own weight (see FIG. 7). ), And the inner developer discharge port 129b is opened. In the black developing device GK, both shutters 131 are open. 7, 13, and 25, a portion of the second developer reservoir 119 above the second developer reservoir 119 is located downstream of a developer outlet 127 a formed in the container upper wall V <b> 2 b. The low-conveying section R2d of the rotary blade R2b of the stirring and conveying member R2 is disposed. The low conveying section R2d having a small diameter of the rotary blade R2b has a lower conveying force of the two-component developer than the normal conveying section R2c, which is another part on the rotating shaft R2a. For this reason, the two-component developer in the second developer reservoir 119 stays in a region where the developer outlet 127a is arranged on the upstream side of the low conveyance section R2d,
As shown by an arrow Td in FIGS. 26 and 30, the developer upper surface in the region where the developer outlet 127a is arranged is locally higher than the other regions. 26 and 30,
When the amount of developer in the container increases and the upper surface of the surplus developer in the container reaches a predetermined height, the surplus developer in the locally raised portion becomes the surplus developer storage portion 131a of the shutter 131. Get on top. In addition, a part of the excess developer in the locally raised portion is discharged from the storage portion transfer connection port 132 via the storage portion transfer connection passage 130 to the opening position of the shutter 131 which is rotated to the opening position. It is transferred to the agent storage 131a.

FIG. 28, FIG. 29, or FIG.
As shown in FIG. 33, the shutter 131 (FIG. 32,
In the case of the black developing device GK shown in FIG. 33, the shutter 131 on the downstream side in the developer transport direction is pushed up by the developer in the developing housing V to close the inner developer outlet 129b. The upper surface of the developer in the developing housing V reaches the storage section transfer connection ports 132, 132 on the downstream side in the developer transport direction, and the developer is developed by rotation of the first and second stirring transport members R1, R2. The developer is pushed into the storage part transfer connection paths 130 by the transfer force of the developer, and is transferred to the surplus developer storage part 131a of the shutter 131 closing the inner developer discharge port 129b.

Next, the developing operation is completed, and in FIG.
The respective developing housings V of the developing units GK, GY, GM, GC move from the first stop position P1 to the second stop position P2;
When stopped, the shutter 131, which has been rotated to the open position at the first stop position P1, is rotated to the closed position by its own weight and the gravity of the developer in the developing housing V, and the inner developer discharge port 129b To close. In the black developing device GK, two shutters 131 are used.
Closes the two inner developer outlets 129b together. At the time of the closing, the developer stored on the surplus developer storing portion 131a at the first stop position P1 is discharged from the developing developer V outside the developing housing V via the inner developer discharging port 129b through the developer discharging port 127a. Agent temporary storage space 1
33 is discharged. The discharged developer temporary storage space 13
The developer discharged to the inside 3 is collected in the discharged developer collecting container VT at the front end side of the developer discharging tube 107 through the inside of the developer discharging tube 107 of the rotating shaft GA.

Here, in the present embodiment, as described above, the developer discharge ports 127 are provided at two places of the black developing device GK.
a and the shutter 131 are provided.
The shutter 131 on the downstream side in the developer transport direction shown in FIG.
The developer inside the developing housing V is pushed up to close the inner developer outlet 129b,
After that, the storage portion transfer connection port 13
In a case where the discharge of the developer by the second shutter 2 cannot be made in time, the other shutters 131 on the upstream side in the developer conveyance direction may be used.
Is in the open position, so that the surplus developer can be continuously stored. Accordingly, since the amount of the stored developer on the surplus developer storage portion 131a of the shutter 131 can be increased, even when a large number of monochrome images (black single-color images) are continuously formed, the black development is performed. Since the period until the amount of the developer in the device GK becomes excessive, that is, the period during which the amount of the developer can be kept within an appropriate range, can be lengthened, the image formation is temporarily stopped, and the rotating holder H is rotated to rotate the surplus. The frequency of execution of the surplus developer discharging mode for discharging the developer can be reduced, and the image forming efficiency can be improved accordingly.

Further, in FIG. 7, the second stop position P
When the second developing units GK, GY, GM, and GC move and stop at the third stop position P3, the inner developer outlet 129b is directed downward, but the inner developer outlet 129b is driven by gravity and the developing housing. The developer in the developing housing V is not discharged from the inner developer discharge port 129b because the shutter 131 is closed by the shutter 131 receiving the pressure of the developer in the V. At the third stop position P3, FIG.
As shown in FIG. 31, since the developer outlet 127a faces downward and the developer is present on the storage section transfer connection ports 132, 132, the storage section transfer connection path is connected to the storage section transfer connection ports 132, 132. The developer in the container flows into 130 and 130. However, in this case, the developer that has passed through the storage section transfer connection paths 130, 130 is
It is stored in the L1 portion of 2b (see FIGS. 27 and 31). Therefore, the developer that has flowed into the storage part transfer connection paths 130, 130 is not immediately discharged from the developer discharge port 127a even after passing through the storage part transfer connection paths 130, 130.

In FIG. 7, the movement to the fourth stop position P4,
The shutters 131 of the stopped developing units GK to GC
Does not open due to the pressure of the developer in the developing container V, and the developer in the developing housing V is not discharged.

Embodiment 2 This embodiment is substantially the same as Embodiment 1, except that the configuration of the black developing unit GK is partially different.
Note that among the components of the image forming apparatus according to the present embodiment, the same components as those of the image forming apparatus according to the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the detailed description thereof will be given here. Description is omitted. FIG. 34 is a longitudinal sectional view of the developing housing V of the black developing device GK stopped at the first stop position (developing position) P1. Unlike the first embodiment, the black developing device GK according to the present embodiment is provided with one developer outlet 127a and one shutter 131, and is provided with a sub-discharge unit 2 adjacent to the developer discharge space 133a.
00 is provided.

The sub-discharge unit 200 includes a first sub-discharge port 201 and a second sub-discharge port opened below the developer discharge port 127a on the inner surface of the container cover V2 of the black developing device GK at the developing position. It has an outlet 202 and a bypass path 204 that is connected through a communication port 203 to a developer discharge space 133a that communicates with the sub discharge ports 201 and 202 and the developer discharge port 127a. The first sub-discharge port 201 is provided on the lower side (the second stirring and conveying member R2 side) between the first sub-discharge port 201 and the second sub-discharge port 202. Elastic seal films 205 and 206 having one end fixed are provided on the bypass passage 204 side of the first sub-discharge port 201 and the second sub-discharge port 202. A discharge control port 207 is provided between the second sub discharge port 202 and the communication port 203 in the bypass path 204, and an elastic seal film 208 having one end fixed to the discharge control port 207 is also provided in the discharge control port 207.

In the black developing device GK according to the present embodiment, since the main discharge portion including the developer discharge port 127a and the shutter 131 and the sub discharge portion 200 are provided, for example, as shown in FIG. When the amount of the developer in the developing housing V increases, the surplus developer is stored on the shutter 131, and the pressure of the developer causes the elastic seal film 205 provided in the first secondary discharge port 201 to be elastically deformed. Excess developer flows into the bypass path 204. Further, the amount of the developer further increases, and for example, the release shutter 131 shown in FIG. 35 is pushed up by the developer in the developing housing V to close the inner developer discharge port 129b. In the case where the discharge of the developer due to the increase cannot be made in time, the elastic sealing film 205 provided in the first sub-discharge port 201 is provided.
In addition, the elastic seal film 206 provided in the second sub-discharge port 202 is also elastically deformed, and the
Since the surplus developer flows into the space 4, the surplus developer can be continuously stored. The surplus developer in the bypass path 204 is pushed out by elastically deforming the elastic seal film 208 when the amount reaches a predetermined amount, and is discharged through the communication port 203. Further, when the amount of the developer in the developing housing V decreases, the elastic sealing films 205 and 206 elastically deform and return to the original state, that is, the position where the first sub-discharge port 201 and the second sub-discharge port 202 are closed. The surplus developer once flowing into the bypass path 204 does not return to the inside of the developing housing V.

Accordingly, since a surplus developer can be stored in the auxiliary discharge portion 200 in addition to the surplus developer storage portion 131a of the shutter 131, a large number of monochrome images (black monochromatic images) are continuously formed. In such a case, the period until the amount of the developer in the black developing device GK becomes excessive, that is, the period in which the amount of the developer can be kept in an appropriate range can be lengthened. Thus, the frequency of execution of the surplus developer discharging mode in which the rotation holder H is rotated to discharge the surplus developer can be reduced, and the image forming efficiency can be improved accordingly.

Embodiment 3 The basic structure of the rotary developing device 34 according to this embodiment is as follows.
Although substantially the same as that of the first embodiment, each of the developing devices GK to GY mounted on the rotary holder H has the configuration shown in FIG. As shown in FIG. 37, a gear G7 'is disposed at a position corresponding to the second stop position P2, whereby the input gear G5 moves the corresponding developing units GK to GC to the first stop position (developing position). ) When it is moved from P1 to a second stop position (standby position after development) P2, it is connected to the gear G7 ',
When separated from the second stop position P2, the gear G7 'is released.

In this embodiment, only when the black developing device GK reaches the second stop position P2, the gear G7 'is driven to drive the first stirring and conveying member R1, R2 of the black developing device GK. Second stirring and conveying member R2 (see FIGS. 6 and 7)
To rotate. Then, pressure is applied to the developer in the developing housing V of the developing device GK at the second stop position P2,
As a result, a part of the developer is forcibly transported from the storage section transfer connection port 132 to the storage section transfer connection path 130. In the present embodiment, the surplus developer in the black developing device GK is forcibly discharged at the second stop position P2. In addition, the amount of the developer in the black developing device GK can be reduced until it falls within an appropriate range.

Embodiment 4 FIG. 38 shows a standby state (home position) of the rotary developing device 34 according to Embodiment 4 during a non-development operation. The basic configuration of the rotary developing device 34 according to the present embodiment is substantially the same as that of the first embodiment, but all of the developing devices GK to GC mounted on the rotary holder H are shown in FIG.
2 has the configuration shown in FIG. In the present embodiment, in the standby state at the time of the non-development operation, the black developing device GK is moved to the first standby position PS closest to the first stop position (development position) P1.
Are located in one. Further, as a result, when viewed from the yellow developing unit GY, the magenta developing unit GM, the cyan developing unit GC, and the black developing unit, respectively, 90 °, 180 °, 27 °
They are arranged at the second standby positions PS2, PS3, PS4 shifted by 0 °.

In this rotary developing device 34, when forming a monochrome image (monochrome black image), first, the rotary holder H is rotated by 45 ° to move the black developing device GK at the first standby position PS1 to the first stop position P1. (Fig. 6,
(See FIG. 7). Then, after the development is performed at the first stop position P1, the rotary holder H is further rotated by 45 °, and the excess developer of the black developing device GK is discharged at the second stop position (standby position after development) P2. . Thereafter, the rotation holder H is further rotated to move the black developing device GK to the first standby position P.
Return to S1, and end the development process.

On the other hand, in the rotary developing device 34,
When forming a full-color image (Y, M, C, K color images)
Also in this case, first, the rotary holder H is rotated by 45 °
The black developing device GK at the standby position PS1 is moved to the first stop position P1. Then, the stirring and conveying members R1 and R2 are driven at the first stop position P1 to stir the internal developer. At this time, the developing operation itself (application of the developing bias) is not performed. Then, after the stirring is performed at the first stop position P1, the rotary holder H is further rotated by 45 °, and the excess developer of the black developing device GK is discharged at the second stop position (standby position after development) P2. At the same time, the yellow developing unit GY is moved to the first stop position P1 to perform development. Thereafter, the magenta developing device GM, the cyan developing device GC, and the black developing device GK are sequentially moved to the first stop position P1 to perform development. And the black developer GK
(First stop position P1) and discharge of surplus developer (second stop position P2), the black developing device G
K is returned to the first standby position PS1, and the developing process is terminated.

In the present embodiment, even during the formation of a full-color image, the black developing device GK is once stopped at the first stop position (developing position) P1, and the developer is stirred.
Since the developer is leveled, wasteful discharge of the developer when stopping at the second stop position P2 can be suppressed.

[0090]

As described above, according to the first and second aspects of the present invention, since the storage capacity of the surplus developer in the developing device is increased, the developer in the developing device is reduced. It can be maintained at an appropriate amount without excess or deficiency for a long time.

According to the second aspect of the present invention, the surplus developer in the developing device is forcibly discharged.
The amount of the developer in the developing device can be maintained at an appropriate amount without excess or shortage over a long period of time.

Further, according to the fourth aspect of the present invention, since the bias of the developer in the developing device is reduced, the amount of the developer in the developing device can be maintained at an appropriate amount for an extended period of time. Can be.

[Brief description of the drawings]

FIGS. 1A to 1C are explanatory views showing an outline of a rotary developing device according to a first embodiment of the present invention.

FIGS. 2A to 2C are explanatory views showing an outline of a rotary developing device according to a second embodiment of the present invention.

FIGS. 3A to 3C are explanatory views showing an outline of a rotary developing device according to a third embodiment of the present invention.

FIGS. 4A to 4C are explanatory views showing an outline of a rotary developing device according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of Embodiment 1 of the image forming apparatus to which the rotary developing device according to the present invention is applied.

FIG. 6 is a cross-sectional view of the rotary developing device according to the first embodiment.

7 is a cross-sectional view of another part of the rotary developing device of FIG.

FIG. 8 is a perspective view showing a mounted state of the rotary holder on the apparatus main body.

FIG. 9 is an explanatory diagram showing a state where each developing device is mounted on a rotary holder.

10A is a sectional view taken along line XA-XA of FIG. 9, and FIG. 10B is a sectional view taken along line XB-XB of FIG. 10A.

FIG. 11 is an explanatory diagram of a rotational force transmitting member provided on a rotary holder.

FIGS. 12A and 12B are perspective views of yellow, magenta, and cyan developing units according to the first embodiment, where FIG. 12A is a perspective view illustrating a state in which a developer supply cylinder is removed from a developing housing, and FIG. FIG. 8A is a view showing the arrangement of gears provided at the rear end of the developing housing, and FIG. 8C is a perspective view showing a state in which a developer supply cylinder is attached to the developing housing.

FIG. 13 is a sectional view taken along line XIII-XIII in FIG. 7;

14A and 14B are explanatory views of a mounting structure of a developing device to a developing housing, wherein FIG. 14A is a front view of a rear rotating plate of the developing housing, and FIG. 14B is a sectional view taken along line XIVB-XIVB of FIG. .

FIG. 15 is an enlarged partial cross-sectional view of an inflow path forming member provided on a container upper wall of the developing housing.

16 is a plan sectional view of the inflow path forming member shown in FIG. 11;

17 is a cross-sectional view of the inflow path forming member shown in FIG. 11, (a) is a cross-sectional view taken along line XVIIA-XVIIAA in FIG. 16,
(B) is a sectional view taken along the line XVIIB-XVIIB in FIG. 16, and (c) is a sectional view taken along the line XVIIC-XVIIC in FIG.

18 is a longitudinal sectional view of the inflow path forming member shown in FIG. 11, and is a sectional view taken along line XVIII-XVIII in FIG.

19A and 19B are explanatory views of a developer outlet formed on the container upper wall and an inner surface side of the container upper wall adjacent to the developer outlet, and FIG. 19A is a diagram viewed from the arrow XIXA in FIG. ,
FIG. 20B is a sectional view taken along line XIXB-XIXB in FIG.

FIG. 20 is an explanatory view of a storage portion transfer connection member mounted on the developer discharge port and a shutter rotatably supported by the storage portion transfer connection member, showing a state before the developer discharge port is mounted. FIG.

FIG. 21 is an explanatory view of a storage section transfer connection member mounted on a developer discharge port and a shutter rotatably supported by the storage section transfer connection member. It is a figure showing the state where it was attached.

22A and 22B are diagrams showing a state in which the storage section transfer connection member and the shutter mounted on the developer discharge port and the shutter are in the developing housing, wherein FIG. 22A is a longitudinal sectional view, and FIG.
It is the XXIIB-XXIIB line sectional view of (a).

23A and 23B are explanatory views of the storage section transfer connection member, wherein FIG. 23A is a plan view as viewed from a lower surface in the state of FIG. 20, and FIG. FIG. 23 (c) is a view as seen from the arrow XXIIIC in FIG. 23 (b), and FIG. 23 (d) is a sectional view taken along the line XXIIID-XXIIID in FIG. 19 (c).

24A and 24B are perspective views of the black developing device according to the first embodiment, where FIG. 24A is a perspective view showing a state in which a developer supply cylinder is removed from a developing housing, and FIG. FIG. 3C is a perspective view showing a state in which a developer supply cylinder is attached to the developing housing.

FIG. 25 is a sectional view taken along line XXV-XXV of FIG. 7;

FIG. 26 shows yellow, magenta, and
FIG. 4 is a vertical sectional view of a developing housing container of the cyan developing device.

FIG. 27 is a diagram illustrating a state in which a developer outlet and an inner developer outlet of the yellow, magenta, and cyan developing units face downward.

FIG. 28 is a first operation diagram for explaining the developer discharging operation in the yellow, magenta, and cyan developing devices.

FIG. 29 is a second operation diagram for explaining the developer discharging operation in the yellow, magenta, and cyan developing devices.

FIG. 30 is a longitudinal sectional view of the developing housing container of the black developing device stopped at the developing position.

FIG. 31 is a diagram illustrating a state in which a developer discharge port and an inner developer discharge port of a black developing device face downward.

FIG. 32 is a first operation diagram illustrating a developer discharging operation in the black developing device.

FIG. 33 is a second operation diagram for explaining the developer discharging operation in the black developing device.

FIG. 34 is a longitudinal sectional view of a developing housing container of a black developing device stopped at a developing position in the rotary developing device according to the second embodiment.

FIG. 35 is a first operation diagram illustrating a developer discharging operation in the black developing device.

FIG. 36 is a second operation diagram for explaining the developer discharging operation in the black developing device.

FIG. 37 is an explanatory diagram showing a state where each developing device is mounted on the rotary holder according to the third embodiment.

FIG. 38 is an explanatory diagram showing a standby state of the rotary developing device during a non-developing operation in the fourth embodiment.

FIG. 39 is an explanatory diagram showing an outline of a conventional rotary developing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating holder, 2 ... Developer, 3 ... Latent image carrier, 4 ... Developing opening, 5 ... Development housing, 6 ... Developer carrier, 7
... stirring and conveying member, 8 ... developer supply section, 9 ... developer discharge section, 10 ... first discharge port, 11 ... first shutter member, 1
2 First discharge unit, 13 Second discharge port, 14 Second shutter member, 15 Second discharge unit, 16 Main discharge port, 17
Shutter member, 18 main discharge section, 19 sub discharge port, 2
0: bypass path, 21: sub-discharge unit, 22: auxiliary discharge port, 23: auxiliary drive means, 24: idle drive means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mutsumi Kikuchi 2274 Hongo, Ebina-shi, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Ryuji Hattori 2274 Hongo, Ebina-shi, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Hirohisa Kono 2274 Hongo, Ebina-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Shino Yokoyama 2274 Hongo, Ebina-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd. AB18 AC02 AC16 AD06 AD13 BA02 BA08 CA19 EA03 GA13

Claims (4)

[Claims] A plurality of developing units mounted on a rotary holder, and each of the developing units is selectively disposed at a developing position facing a latent image carrier by intermittently rotating the rotary holder; A rotary developing device that develops each color component latent image on the carrier with a corresponding developing device and that the developing device at the developing position moves to an upper post-developing standby position after development; A developing housing in which a two-component developer composed of a toner and a carrier is accommodated and a developing opening is partially formed, and a developing housing which is disposed facing the developing opening and carries the two-component developer. A developer carrier to be conveyed; a stirring and conveying member for stirring and conveying the two-component developer in the developing housing to supply the developer carrier to the developer carrier; and a developer replenishing unit for replenishing toner and carrier in the developing housing. And the current A developer discharge portion for discharging surplus developer in the housing, wherein the developer discharge portion is provided at a first discharge port opened above a developing housing of a developing device at the developing position; The first discharge port is rotatably supported between a closed position in which the first discharge port is closed by contacting the inner surface of the developing housing and an open position in which the first discharge port is separated from the inner surface of the developing housing and opened. At the developing position, the first discharge port is opened by the action of gravity to store the surplus developer, while at the post-developing standby position, the first discharge port is closed by the action of gravity to store the surplus developer. A first discharge portion having a first shutter member for discharging the developer, a second discharge port opened at an upper portion of the developing housing of the developing device at the developing position, and abutting on an inner surface of the upper portion of the developing housing. The second discharge port is rotatably supported between a closed position that closes the second discharge port and an open position that is separated from the upper inner surface of the developing housing and that opens the second discharge port. The second discharge port is opened to store the surplus developer, while the standby position after development closes the second discharge port by the action of gravity and discharges the stored surplus developer out of the developing housing. And a second discharge section having a second shutter member. 2. A method according to claim 1, further comprising the step of: mounting a plurality of developing devices on a rotating holder; and intermittently rotating the rotating holder to selectively dispose each developing device at a developing position facing the latent image carrier. A rotary developing device that develops each color component latent image on the carrier with a corresponding developing device and that the developing device at the developing position moves to an upper post-developing standby position after development; A developing housing in which a two-component developer composed of a toner and a carrier is accommodated and a developing opening is partially formed, and a developing housing which is disposed facing the developing opening and carries the two-component developer. A developer carrier to be conveyed; a stirring and conveying member for stirring and conveying the two-component developer in the developing housing to supply the developer carrier to the developer carrier; and a developer replenishing unit for replenishing toner and carrier in the developing housing. And the current A developer discharging portion for discharging surplus developer in the housing, wherein the developer discharging portion is provided with a main discharge opening opened above a developing housing of a developing device at the developing position; The developing device is rotatably supported between a closed position in which the main discharge port is closed by contacting the inner surface of the housing and an open position in which the main discharge port is opened apart from the upper surface of the developing housing. While the main discharge port is opened by the action of gravity to store the surplus developer, the main discharge port is closed by the action of gravity at the standby position after development, and the stored surplus developer is moved out of the developing housing. A main discharge section having a shutter member for discharging, and a sub discharge port opened above the developing housing of the developing device at the developing position and below the main discharge port. Secondary outlet and the rotary type developing apparatus, comprising a sub-discharge section that includes a bypass path connecting communicating the main exhaust port. 3. A plurality of developing devices are mounted on a rotating holder, and each developing device is selectively disposed at a developing position facing the latent image carrier by intermittently rotating the rotating holder, thereby forming the latent image. A rotary developing device in which each of the color component latent images on the carrier is subjected to toner development by a corresponding developing device, and the developing device at the developing position is moved to an upper post-developing standby position after the development, and A developing housing housing a two-component developer composed of a toner and a carrier and partially opening a developing opening; and a developing housing disposed facing the developing opening and carrying the two-component developer. A developer carrier to be conveyed; a stirring and conveying member for stirring and conveying the two-component developer in the developing housing to supply the developer carrier to the developer carrier; and a developer replenishing unit for replenishing toner and carrier in the developing housing. And the current A developer discharge portion for discharging surplus developer in the housing, wherein the developer discharge portion is provided with a main discharge opening opened above a developing housing of the developing device at the developing position; And is rotatably supported between a closed position where the main discharge port is closed by contacting the main discharge port and an open position where the main discharge port is opened apart from the inner surface of the developing housing. A shutter for opening the main discharge port to store the surplus developer, and closing the main discharge port by the action of gravity at the standby position after development and discharging the stored surplus developer to the outside of the developing housing. A member, and an auxiliary discharge port opened above the developing housing of the developing device in the developing position, and further drives a stirring and conveying member of the developing device in the post-developing standby position. Rotary developing apparatus is characterized in that is equipped with an auxiliary driving means that. 4. A plurality of developing devices are mounted on a rotating holder, and each developing device is selectively arranged at a developing position opposed to the latent image carrier by intermittently rotating the rotating holder, and the latent image is provided. A rotary developing device in which each of the color component latent images on the carrier is subjected to toner development by a corresponding developing device, and the developing device at the developing position is moved to an upper post-developing standby position after the development, and A developing housing in which a two-component developer composed of a toner and a carrier is accommodated and a developing opening is partially formed, and a developing housing which is disposed facing the developing opening and carries the two-component developer. A developer carrier to be conveyed; a stirring and conveying member for stirring and conveying the two-component developer in the developing housing to supply the developer carrier to the developer carrier; and a developer replenishing unit for replenishing the developing housing with toner and carrier. And the current A developer discharge portion for discharging surplus developer in the housing, wherein the developer discharge portion is provided with a main discharge opening opened above a developing housing of the developing device at the developing position; And is rotatably supported between a closed position where the main discharge port is closed by contacting the main discharge port and an open position where the main discharge port is opened apart from the inner surface of the developing housing. A shutter for opening the main discharge port to store the surplus developer, and closing the main discharge port by the action of gravity at the standby position after development and discharging the stored surplus developer to the outside of the developing housing. A member, and an auxiliary discharge port opened above the developing housing of the developing device at the developing position. The developing device for moving temporarily stopped in the developing position,
The rotary developing device further includes idle driving means for idle driving the stirring and conveying member of the developing device at the developing position.