JP2008164748A - Developing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing unit capable of reducing contamination in the inside of a machine with toner sticking or scattering after supplied. <P>SOLUTION: Each developing unit 13 having a developing roller 15 is filled with image formation toner. One or more developing units 13 are accommodated in the main body 3 of a rotary developing device. A cleaning brush 20 is disposed so as to come into contact with the main body 3 of the rotary developing device. Toner to be supplied to each developing unit 13 is stored in a supply toner storage container 5. The supply toner is supplied to each developing unit 13 from a toner supply member 26 that can be brought into contact with or separated from the main body 3 of the rotary developing device. The cleaning brush 20 is disposed in contact with the surface of the toner supply member 26. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention stores a developing device filled with toner for image formation and provided with a developing roller, a rotary developing device main body containing at least one of the developing devices, and a replenishing toner for replenishing the developing device. The present invention relates to a developing unit including the replenishing toner container and a toner replenishing member that can be moved toward and away from the rotary developing device main body to replenish the replenishing toner to the developing unit.

  Conventionally, a developing unit used in an image forming apparatus is filled with a certain amount of toner in the developing unit for easy maintenance, and is replaced when the toner runs out.

  However, the developing unit is relatively expensive and cannot be frequently replaced from an economical point of view. To perform a certain amount of image forming processing, the volume of toner filled in the developing unit must be increased. Did not get.

  In view of this, an image forming apparatus employing a rotary developing system (rotating type developing device) in order to reduce the size of the developing unit is known (see Patent Document 1).

  The developing unit used in the image forming apparatus adopting this rotary developing system divides the inside of a cylindrical developing drum into four (in the case of color image formation), and each of the divided chambers has yellow (Y) and magenta ( M), cyan (C), and black (K) toners are filled.

  Then, the developing drum is rotated as necessary (according to the toner color to be used), and a developing sleeve provided for each chamber is brought into contact with the surface of the photosensitive drum to supply toner to the photosensitive drum.

Further, when the amount of toner filled in each chamber decreases, the supply toner filled in the toner replenishing cartridge is replenished in each chamber with the tip of the extendable nozzle facing each chamber.
JP-A-10-1981149

  However, in the developing unit configured as described above, the tip of the nozzle faces each chamber in order to replenish the toner for replenishment, so that the surface of the developing drum near the replenishing port that the tip of the nozzle faces faces. There is a problem that the toner for replenishment adheres or scatters to the periphery, and when the developing drum rotates, the adhered / scattered toner adheres to the photosensitive drum and causes contamination in the apparatus and unevenness of the original document. It was.

  Accordingly, an object of the present invention is to provide a developing unit that can suppress the occurrence of in-machine contamination due to adhesion or scattering of replenishing toner after toner replenishment in consideration of the above circumstances.

The developing unit of the present invention includes a developing unit filled with image forming toner and provided with a developing roller, a rotating developing device main body containing one or more developing devices, and a contact with the rotating developing device main body. And a possible cleaning body.
The developing unit of the present invention includes a replenishing toner container that contains replenishing toner to be replenished to the developing unit, and a rotary developing device main body for replenishing the replenishing toner to the developing unit. And a toner replenishing member capable of approaching and separating, wherein the cleaning body contacts the surface of the toner replenishing member.

  At this time, it is preferable that the cleaning body is disposed so as to be able to approach and separate from the rotary developing device main body.

  Further, it is preferable that the cleaning body is housed in a cleaning case, and the toner attached to the rotary developing device and removed by the cleaning body can be collected in the cleaning case.

  Further, the cleaning body approaches the rotary developing device main body immediately before the replenishment position is reached by rotating the rotary developing device main body after separating the toner supply member from the developing device, and It is preferable to move away from the main body of the rotating developer when the replenishment position passes.

  In addition, the present invention can be an image forming apparatus that employs a developing unit having one of the above-described configurations.

  The developing unit of the present invention can suppress the occurrence of in-machine contamination due to adhesion and scattering of the replenishing toner after toner replenishment.

  Next, a developing unit according to an embodiment of the present invention is applied to a color printer as an image forming apparatus and will be described with reference to the drawings.

  FIG. 1 is an explanatory view of an image forming apparatus including a developing unit according to an embodiment of the present invention. FIG. 2 is an external perspective view of a developing unit used in the developing unit according to an embodiment of the present invention. 3 is an enlarged view of a main part of the developing unit according to the embodiment of the present invention.

  As shown in FIG. 1, a color printer 1 is connected to a computer or the like (not shown), and transfers and fixes a color image on transfer paper based on image information sent from the computer or the like. In the color printer 1, the right side in FIG. 1 is the front side operated by the operator.

  The color printer (device main body) 1 includes a photosensitive drum 2, a rotary developing device main body 3, a laser unit 4 as an exposure device, a replenishment toner container 5, a toner supply device 6, and an intermediate transfer belt 7. And a secondary transfer roller 8 and a fixing device 9.

[Configuration of Photosensitive Drum 2]
The photosensitive drum 2 has an electrostatic latent image formed on the surface thereof, and is rotatably provided in the center of the apparatus main body. The rotation shaft extends in the width direction from the front side of the apparatus main body. 1 is provided so as to extend in the depth direction with respect to the paper surface of FIG. In addition, a charging roller 10 for uniformly charging the surface of the photosensitive drum 2 is provided above the photosensitive drum 2. Further, a drum cleaning device 11 for cleaning toner and adhering matter remaining on the surface of the photosensitive drum 2 is provided on the side of the photosensitive drum 2.

[Configuration of Rotating Developing Device Body 3]
The rotary developing device main body 3 develops the electrostatic latent image formed on the photosensitive drum 2 with toner of each color, and the rotation center is adjacent to the photosensitive drum 2 and the rotation center of the photosensitive drum 2. It is provided so that it may become the almost same height position. Further, as shown in FIG. 2, the rotary developing device main body 3 includes a rotary frame 12 that divides the inside into four parts, and four developing devices 13 that are supported by the rotary frame 12 corresponding to the four color toners. ing.

  The rotary frame 12 has a cylindrical shape that is rotatable about an axis parallel to the rotation center axis of the photosensitive drum 2, and is rotated by a driving mechanism including a motor and a gear (not shown). The rotary frame 12 has four storage chambers 14 formed by dividing the inside of the rotary developing device main body 3 into four equal parts in the circumferential direction by partitions 12a extending radially from the center of rotation. A developing unit 13 corresponding to four toner colors of yellow, magenta, cyan, and black is disposed in the chamber 14.

  Each developing device 13 has substantially the same configuration, and as shown in FIG. 2, a developing roller 15 and the like that can be disposed to face the photosensitive drum 2 are provided. Further, each developing device 13 is disposed away from the replenishing toner container 5, whereby the space for toner storage in the rotary developing device main body 2 is small, and the developing device 13 is miniaturized. Further, the developing device 13 can be attached to and detached from the rotary developing device main body 3 respectively, and maintenance and replacement of the developing device 13 can be easily performed. Further, in order to replenish the developing device 13 with toner from the replenishing toner container 5 to the inside of the developing device 13, as shown in FIG. 3, on the outer peripheral surface of the toner case 17 constituting the outer shape of the developing device 13. A toner replenishing unit 18 is provided.

  The toner replenishing portion 18 is formed of an elastic material (for example, rubber) in which a toner replenishing opening is formed in a part of the toner case 17 and a slit 18a that normally closes the opening is formed. Yes.

  On the other hand, a cleaning brush 20 of a cleaning unit 19 is provided on the outer periphery of the rotary developing device main body 3 so as to be able to contact and separate.

  As a result, the rotary developing device main body 3, the replenishing toner container 5, the toner supply device 6, and the cleaning unit 19 described above constitute the developing device unit of the present invention.

  The cleaning unit 19 is provided in the cleaning case 21, a cleaning case 21 disposed obliquely upward with respect to the color printer 1, a cleaning brush 20 as a cleaning body partially exposed from the upper end of the cleaning case 21, and the cleaning case 21. A metal roller 22 that comes into contact with the cleaning brush 20, a scraping blade 23 that comes into contact with the surface of the metal roller 22, and a recovery spiral 24 disposed inside the lower end of the cleaning case 21 are provided.

The cleaning brush 20 is rotated by driving of a driving motor (not shown), and scrapes toner and the like adhering to the surface of the rotary developing device main body 3 into the cleaning case 21 by contacting the surface of the rotary developing device main body 3. It is to include. At this time, as the material of the cleaning brush 20, conductive fibers such as rayon, nylon, acrylic and polyester are used, and the resistance of the fiber yarn is preferably in the range of 10 ⁴ to 10 ¹¹ Ωcm.

  The metal roller 22 is applied with a charge having a polarity opposite to that of the toner, and has a function of separating the toner scraped (attached) by the cleaning brush 20 from the cleaning brush 20 according to the polarity.

  The scraping blade 23 is made of an elastic body such as rubber and has a function of scraping off toner or the like adhering to the surface of the metal roller 22.

  The collection spiral 24 collects the toner and the like scraped by the scraping blade 23, and conveys the toner and the like in the depth direction of the paper surface, that is, from one side surface of the color printer 1 to the other side surface. The toner is collected in an abbreviated toner collection box. The toner collection box uses a known toner collection box that collects toner adhering to the intermediate transfer belt 7 and the like. The wall of the cleaning case 21 located on the back side of the color printer 1, the toner collection box, and the like. Are connected by a bellows-like hose or the like, the toner conveyed to the other side surface of the color printer 1 by the recovery spiral 24 can be recovered. For example, the toner collection box may be detachably provided on the side surface of the cleaning case 21 or the like.

[Configuration of laser unit]
The laser unit 4 scans and exposes the photosensitive drum 2 based on image information sent from an external computer or the like, and is disposed above the photosensitive drum 2. The laser unit 4 is provided with known configurations such as a laser light source, a polygon mirror, and a polygon mirror driving motor (not shown). Further, a reflection mirror 25 is provided in front of the laser beam path of the laser unit 4, and the laser light emitted from the laser unit 4 is bent by the reflection mirror 25 and irradiated onto the surface of the photosensitive drum 2. It has become so.

[Configuration of Replenishment Toner Container 5]
The replenishment toner container 5 accommodates toner for replenishment to each developing device 13 of the rotary developing device main body 3 and is detachably installed in the color printer 1 so as to be replaceable. Further, the replenishment toner container 5 has four housing parts that contain replenishment toners of each color of yellow, magenta, cyan, and black from one side surface of the color printer 1 toward the other side surface independently. Is arranged. Further, the replenishment toner container 5 can be taken out (drawn out) as a whole from the front side of the color printer 1, and the container for each color can be independently replaced.

[Configuration of Toner Supply Device 6]
The toner supply device 6 is for supplying the toner of each color stored in the replenishment toner container 5 to the corresponding developing unit 13. The laser unit 4 and the replenishment toner are provided above the photosensitive drum 2. It is arranged in the space between the containers 5. The toner supply device 6 includes four toner supply members 26 (only one is shown in FIG. 1) that can move in the vertical direction, and a tip supply portion 26a of the toner supply member 26 enters the developing device 13 from the slit 18a. By facing it, the replenishment toner can be replenished into the developing device 13.

[Configuration of Intermediate Transfer Belt 7]
The intermediate transfer belt 7 is one to which the toner images of each color formed on the photosensitive drum 2 are sequentially transferred, and is disposed below the photosensitive drum 2 and the replenishment toner container 5. The intermediate transfer belt 7 is stretched between a driving roller 27 and driven rollers 28 and 29 which are arranged apart from each other. Further, the portion of the intermediate transfer belt 7 that faces the photosensitive drum 2 is configured to contact the photosensitive drum 2 by the primary transfer roller 30. In this embodiment, the driven roller 28 has a function of a tension roller for maintaining the tension state of the intermediate transfer belt 7.
The drive roller 27 is located almost directly below the contact portion between the photosensitive drum 2 and the rotary developing device main body 3, and the center thereof is located further below the lowermost end of the rotary developing device main body 3. And it drives by the drive part containing the motor and gear which are not shown in figure.

  The driven roller 28 is disposed close to the bottom of the replenishment toner container 5 on the front side of the color printer 1, and the height position thereof is substantially the same as that of the photosensitive drum 2.

  The primary transfer roller 30 is provided below the photosensitive drum 2, whereby a predetermined range of the transfer belt 7 is in contact with the photosensitive drum 2.

  A belt cleaning device main body 31 for cleaning the transfer belt 7 is provided on the back side of the color printer 1 of the driving roller 27 and below the rotary developing device main body 3.

  The belt cleaning device main body 31 is provided at a position facing the driving roller 27 so as to be in sliding contact with the surface of the transfer belt 7 and a cleaning brush disposed above the fur brush 32 so as to be in contact with the fur brush 32. The roller 33, the blade 34 disposed so that the tip thereof is in contact with the surface of the cleaning roller 33, and the collection spiral 35 disposed side by side below the blade 34 are provided.

  In the cleaning device main body 31, the deposit on the intermediate transfer belt 7 is scraped off by the fur brush 32, and the deposit scraped off by the fur brush 32 is collected by the cleaning roller 33. Then, the deposit collected on the cleaning roller 33 side is scraped off from the surface of the cleaning roller 33 by the blade 34 and is collected in a toner collection box (not shown) by the collection spiral 35.

[Configuration of Secondary Transfer Roller 8]
The secondary transfer roller 8 is for transferring the image transferred to the intermediate transfer belt 7 onto the transfer paper that has been conveyed, and is disposed below the drive roller 27 so as to face it. The secondary transfer roller 8 is applied with a bias voltage for image transfer to the transfer paper by a voltage application unit (not shown).

[Configuration of Fixing Device 9]
The fixing device 9 is for fusing and fixing the toner transferred onto the transfer paper, and is disposed on the back side of the color printer 1 below the rotary developing device main body 3. The fixing device 9 includes a heating roller 36 that is heated by heat generated by a heater (not shown), and a pressure roller 37 that is pressed against the heating roller 36, and transfer paper is placed between the rollers 36 and 37. Nipped to convey.

[Configuration of transport route]
On the other hand, at the bottom of the color printer 1, there is provided a paper feed cassette 39 having a placement plate 38 on which transfer paper (not shown) is placed, and storing the transfer paper. Then, the transfer paper stored in the paper feed cassette 39 is taken out from the paper feed unit 40 and transported to a transport path 42 to the discharge port 41, and the image transfer / fixing process described above is performed in the transport process. The The paper feed cassette 39 can be pulled out from the front side of the color printer 1 for replacement or replenishment of transfer paper.

  Further, a manual feed tray 43 that can be tilted is provided on the side surface of the color printer 1, and transfer paper can be set on the manual feed tray 43. The transfer paper set on the manual feed tray 43 is taken out from the manual paper feed unit 44 and joined to the transport path 42, and the image transfer / fixing process described above is performed in the transport process.

  Further, on the upstream side of the secondary transfer roller 8 in the transport path 42, the timing adjustment between the downstream end (leading edge) of the transfer paper taken out from the paper feeding unit 40 or the manual paper feeding unit 44 and the intermediate transfer belt 7 is performed. A pair of registration rollers 45 is provided on the downstream side of the fixing device 9 in the conveyance path 42, and the transfer paper that has been fixed for double-sided printing processing is located upstream of the registration path pair 45 in the conveyance path 42. A reversing path 46 for reversing and conveying is provided. At this time, after the transfer paper for reversing is once transported to the vicinity of the discharge port 41, the rear end of the transfer paper is transported to the downstream side of the transport path 42 from the upstream port of the reversing path 46. It is sent to the reverse path 46 by the reverse of the switchback roller 47.

[Image forming operation]
In the above configuration, when the color printer 1 is turned on, various parameters are initialized, and initial settings such as setting the temperature of the fixing device 9 are executed. When image data is input from a computer or the like connected to the color printer 1 and an instruction to start printing is given, an image forming operation is executed as follows. During the image forming operation, the toner replenishing member 26 is moved to the upper retracted position.

  First, after the photosensitive drum 2 is charged by the charging roller 10, scanning exposure corresponding to image data is performed on the photosensitive drum 2 by the laser unit 4, and an electrostatic latent image is formed on the photosensitive drum 2. Is done.

  Next, the rotary developing device main body 3 is rotated so that the developing device 13 of the corresponding color is opposed to the photosensitive drum 2. In this state, the electrostatic latent image on the photosensitive drum 2 is developed with the corresponding color toner.

  The developed image is transferred to the intermediate transfer belt 7, and a full color image is formed on the intermediate transfer belt 7 by sequentially repeating the above operation for each color. The residual toner remaining on the photosensitive drum 2 is cleaned by the drum cleaning device 11 and discarded in a waste toner container (not shown).

  On the other hand, the transfer paper positioned at the uppermost position of the paper feed cassette 3 taken out by the paper feed unit 40 is subjected to the secondary transfer after being matched with the image forming position on the intermediate transfer belt 7 by the registration roller pair 45. It is conveyed to the roller 8.

  Since the secondary transfer roller 8 is in contact with the intermediate transfer belt 7, after the full color image formed on the intermediate transfer belt 7 is transferred to the transfer paper by the transfer bias applied to the secondary transfer roller 8, The image is guided to the fixing device 9, and the image is fixed on the transfer paper by heating and pressing by the fixing device 9.

[Configuration of toner supply operation]
When replenishing toner from the replenishing toner container 5 in response to the use of toner in the developing unit 13 accompanying the image transfer described above, the rotating developing device main body 3 is rotated to replenish the developing unit 13 to be replenished to a predetermined level. After being positioned to the position, the leading end supply portion 26a of the toner replenishing member 26 corresponding to the developing device 13 to be replenished is displaced to a supply position as indicated by the chain line in FIG. 1 while opening the slit 18a. The rotation developing device main body 3 is locked in rotation in this state.

  Next, when the toner replenishing member 26 is displaced to a predetermined supply position, the replenishing toner is replenished into the developing device 13 until the replenishing toner supplied from the replenishing toner container 5 into the toner replenishing member 26 runs out. To do.

  When the replenishment of toner for replenishment in the toner replenishing member 26 is completed, the toner replenishing member 26 moves upward, and when the toner replenishing member 26 comes out of the slit 18a, the slit 18a is closed by an elastic force.

  At this time, since the replenishment toner adhering to the vicinity of the tip supply part 26a and the slit 18a is fine particles, it is unavoidable that the replenishment toner is scattered, and the scattered replenishment toner adheres to the toner replenishment part 18. It is preferable to remove the adhered toner.

Therefore, when the return of the toner replenishing member 26 to the retracted position is completed, the rotary developing device main body 3 is rotated at a low speed, and the tip 18b in the rotation direction of the toner replenishing portion 18 that has supplied the toner is Move until it reaches the lower position (cleaning brush 20).
At this time, it is desirable that the rotary developing device body 3 is rotated counterclockwise in FIG. 2 so that the toner replenishing portion 18 does not face downward from the toner replenishing position to the cleaning position. Therefore, when the rotary developing device main body 3 is rotated in the same clockwise direction as that during toner transfer for cleaning processing, the cleaning unit 19 is preferably disposed at the lower right side with respect to the rotary developing device main body 18. .

  With the rotation control at this time, the cleaning brush 20 provided in the cleaning case 21 is brought into pressure contact with the surface of the rotary developing device main body 3 when the tip 18b of the toner replenishing portion 18 reaches the cleaning brush 20.

  The cleaning brush 20 (or the cleaning case 21) can be pressed and separated from the surface of the rotary developing device main body 3 by a solenoid or the like.

  By this pressure contact / separation control, the cleaning brush 20 is brought into pressure contact with the rear end 18c of the toner supply unit 18 immediately before the rear end 18c of the toner supply unit 18 reaches the cleaning brush 20, and the rotary developing device body 3 is rotated as it is. After removing a small amount of replenishing toner and the like adhering to the surface of the toner replenishing portion 18, the cleaning brush 20 (or the cleaning case 21) is attached at the point where the tip 18 b of the toner replenishing portion 18 reaches the contact position of the cleaning brush 20. The rotary developing device main body 3 is separated.

  For the pressure contact / separation position of the cleaning brush 20 (or the cleaning case 21), it is desirable to employ a stepping motor capable of controlling the rotational position as the rotation motor of the rotary developing device main body 3.

  Therefore, when the cleaning brush 20 is pressed against the toner replenishing portion 18, the pressure contact / separation control angle of the cleaning brush 20 is obtained based on the relative position with respect to the toner replenishing portion 18 to be cleaned immediately before the rotation control.

For example, in the case shown in FIG. 2, the angle formed by the rotation direction center position of the toner replenishing portion 18 and the contact position of the cleaning brush 20 (reference to the rotation center of the rotary developing device main body 3) is set to about 180 degrees.
Accordingly, if the rotation control of the rotation motor of the rotary developing device main body 3 is set to require 400 pulses in units of 90 degrees, 800 (400 × 2) pulses have elapsed since the rotation control start of the rotation motor of the rotary developing device main body 3 was started. Since the rotational direction center of the toner replenishing portion 18 reaches the contact position of the cleaning brush 20, the length of the front end 18b and the rear end 18c of the toner replenishing portion 18 (the total length in the rotational direction) is taken into account. If the cleaning angle with respect to the entire length of the toner replenishing portion 18 is 45 degrees, the cleaning brush 20 is controlled to contact the toner replenishing portion 18 between 700 and 900 pulses.

  Further, as a point to consider the pressure contact control of the cleaning brush 20, there is a pressure contact response time of the cleaning brush 20.

  For example, if the pressure contact response time is 100 ms and the motor rotation speed of the rotary developing device body 3 is 500 Hz, 200 (100 × 2) pulses are required for the pressure contact response, and rotation control of the rotation motor of the rotary developing device body 3 is performed. If the cleaning brush 20 is pressed when 500 (700 ms-200 ms) pulses have elapsed from the start, the rear end 18c of the toner replenishing portion 18 comes into contact.

  Also, with regard to the separation control of the cleaning brush 20, the arrival position (time) of the tip 18b of the toner replenishing portion 18 up to the contact position of the cleaning brush 20 and the control timing time can be calculated by the same calculation method as described above. There is no need to provide position detection sensors for the front end 18b and the rear end 18c of the toner replenishing portion 18. Thereafter, the rotary developing device main body 3 is moved at a normal high-speed forward rotation to the image formation start color position for the next transfer paper, and the toner replenishment operation is completed.

  As described above, according to the developing unit of the present invention, when toner is replenished to the rotary developing device main body 3 from the outside, the tip supply portion 26a of the toner replenishing member 26 is moved to the developing device 13 (toner replenishment) after the replenishment conveyance is completed. Since a small amount of toner for replenishment or the like may adhere to the upper portion of the toner replenishing portion 18 when the toner is removed from the toner replenishing portion 18), the cleaning toner 19 removes the adhering toner to perform subsequent rotation development. The rotation centrifugal force accompanying the normal rotation control of the apparatus main body 3 can suppress the scattering of the replenishing toner and the in-machine contamination due to the scattering.

  In the above embodiment, the developing unit according to the present invention is applied to the color printer 1. However, for example, an image forming unit such as a monochrome printer, a copying machine, or a multifunction machine equipped with these functions is used. Of course, it can be applied to the entire apparatus.

FIG. 2 is an explanatory diagram of an image forming apparatus including a developing unit according to an embodiment of the present invention. FIG. 2 is an external perspective view of a developing device used in the developing device unit according to the embodiment of the present invention. FIG. 4 is an enlarged view of a main part of a developing unit according to an embodiment of the present invention.

Explanation of symbols

1. Color printer (device main unit)
DESCRIPTION OF SYMBOLS 3 ... Rotating developing device 5 ... Replenishment toner container 6 ... Toner supply device 12 ... Rotating frame 12a ... Partition 13 ... Developing device 14 ... Storage chamber 15 ... Developing roller 17 ... Toner case 18 ... Toner replenishing part 18a ... Slit 18b ... Front end 18c Rear end 19 Cleaning unit 20 Cleaning brush (cleaning body)
21 ... Cleaning case 22 ... Metal roller 23 ... Scraping blade 24 ... Recovery spiral 26 ... Toner supply member

Claims (6)

  A developing device filled with toner for image formation and provided with a developing roller, a rotating developing device main body containing at least one developing device, and a cleaning body capable of contacting the rotating developing device main body A developing unit characterized by comprising: A replenishing toner container that contains replenishing toner to be replenished to the developing unit; and a toner replenishing member that can move toward and away from the rotary developing device main body to replenish the replenishing toner to the developing unit. ,
The developer unit according to claim 1, wherein the cleaning body contacts a surface of the toner supply member.   The developing unit according to claim 1, wherein the cleaning body is disposed so as to be close to and away from the main body of the rotary developing device.   The cleaning body is built in a cleaning case, and the toner attached to the rotary developing device and removed by the cleaning body can be collected in the cleaning case. 4. The developing unit according to any one of 3 above.   The cleaning body approaches the revolving developer main body immediately before the replenishment position is reached by rotating the rotary developing device main body after separating the toner replenishing member from the developing device and replenishing the main body. The developer unit according to claim 3, wherein the developer unit is separated from the rotary developer body when the position passes.   An image forming apparatus comprising the developing unit according to claim 1.

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