JP4779429B2 - Developer processing apparatus and image forming apparatus - Google Patents

Description

  The present invention is a developer that can be used by being mounted on an image forming apparatus such as an electrophotographic copying machine, a printer (laser printer, LED printer, etc.), a facsimile machine, a word processor, or a composite machine that combines two or more thereof. The present invention relates to a processing apparatus and an image forming apparatus equipped with the developer processing apparatus.

  In an electrophotographic monocolor image forming apparatus, for example, the surface of an image carrier such as a photoconductor is charged to a predetermined potential, and image exposure is performed on the charged area in accordance with the original image to form an electrostatic latent image. Then, the electrostatic latent image is developed with a developing device containing a developer to form a visible toner image, and the visible toner image is transferred to a recording medium such as recording paper and fixed by heating and pressing. The transfer residual toner remaining on the image carrier after the transfer is removed by a cleaning device.

  In a color image forming apparatus, for example, a toner image of each color formed on an image carrier such as a photoconductor is primarily transferred onto an intermediate transfer member such as an intermediate transfer belt, and multiple toners on the intermediate transfer member. The image is secondarily transferred to a recording medium such as recording paper and fixed under heat and pressure. Transfer residual toner or the like remaining on the image carrier after the primary transfer is removed by a cleaning device for the image carrier, and transfer residual toner or the like remaining on the intermediate transfer member after the secondary transfer is removed by a cleaning device for the intermediate transfer member. Removed.

  As described above, in the electrophotographic image forming apparatus, there are a developing device, a cleaning device, and the like as a part that handles the developer. The developing device has a developer container, and for example, a developer roller for supplying and attaching the developer (particularly the toner) to the electrostatic latent image on the image carrier, and the developer on the developer roller. Rotating members such as a developer supply roller for supplying the developer and a stirring member for stirring the developer and supplying the developer to the developer supply roller are rotatably disposed.

  The cleaning device has, for example, a cleaning blade or a cleaning roller that removes the developer from the image carrier or the intermediate transfer member, and transports the developer in the removed container to the waste bottle. Or a rotary member for conveyance (for example, a conveyance screw) for conveyance for reuse.

  Various rotating members in the developing device, the cleaning device, and the like can be rotatably supported by the developer container in various modes. Generally, however, the end of the rotating shaft of the rotating member is attached to the wall of the developer container. By being supported by the provided bearing part, it is rotatably arranged in the container.

  In addition, it prevents the developer made of fine particles in the container from entering the bearing part and fusing to the part to prevent smooth rotation of the rotating member or leaking out of the container and contaminating the surroundings. In order to achieve this, a sealing means for preventing the developer from entering the bearing portion is employed.

  Such sealing means has a sealing lip made of a material such as nitrile rubber (NBR), ethylene-propylene rubber (ternary copolymer) (EPDM), fluorine rubber, silicon rubber, polytetrafluoroethylene (PTFE), or the like. An elastic seal member is often employed.

As a compact example of the seal structure in the case where an elastic seal member having such a lip portion is employed, the sealing means shown in FIG. 8 can be shown. In the example shown in FIG. 8, the end sh ′ of the rotation shaft sh of the rotation member (rotation member having spiral blades in the illustrated example) RM is rotatable to the bearing portion B provided on the wall W of the developer container. The lip portion 401 of the elastic seal member 40 is in contact with the peripheral surface S1 ′ of the small diameter portion on the bearing side of the stepped portion S ′ formed by varying the shaft diameter at the shaft end portion. .
This type of sealing means is also disclosed in, for example, Japanese Patent Application Laid-Open No. 8-190268.

  When such a sealing means is employed, the tip of the lip portion of the elastic seal member is brought into contact with the peripheral surface of the rotating shaft end with a constant contact pressure and contact angle, and the rotating shaft end peripheral surface The developer is devised so that the developer does not leak by increasing the accuracy of the smoothness or suppressing the eccentricity of the rotating shaft.

JP-A-8-190268

  However, for example, when the rotating member is rotated at a high speed for a long period of time, the seal member pressed against the circumferential surface of the rotating shaft end turns up, and a gap is formed between the rotating shaft end and the seal member. There are cases where the bearing part enters and melts or leaks to the outside through the bearing part.

In order to solve this problem, an attempt may be made to secure the sealing performance by increasing the pressure contact force of the seal member to the rotating shaft. However, if this is done, the contact resistance between the rotating shaft and the seal member increases, and the rotation torque increases accordingly. Will be needed.
Today, the toner particle size tends to become smaller as the image quality improvement is requested, and it is becoming increasingly difficult to prevent toner leakage.

  In view of this, the present invention provides a container for containing a developer, and a rotation shaft disposed in the container so that the rotation shaft end is rotatably supported by a bearing portion provided on the container wall. At least one developer processing rotating member, and an elastic seal member for contacting at least one rotating shaft end portion of the rotating member to prevent the developer from entering the bearing portion. In comparison with this type of conventional developer processing apparatus, the developer can be more reliably prevented from entering the bearing portion, and the rotating member can be smoothly rotated by that amount. It is another object of the present invention to provide a developer processing apparatus that can prevent the external leakage of the developer from the bearing portion.

  The present invention also includes a container for storing a developer, and a rotation shaft disposed in the container, the rotation shaft end being rotatably supported by a bearing portion provided on the container wall. At least one developer processing rotating member, and an elastic seal member for contacting at least one rotating shaft end portion of the rotating member to prevent the developer from entering the bearing portion. An image forming apparatus equipped with a developer processing device of a type including the developer processing device, which more reliably prevents the developer from entering the bearing portion than a conventional developer processing device of the same type. Accordingly, the rotating member can be smoothly rotated, and external leakage of the developer from the bearing portion can be more reliably suppressed, and thus a good image can be formed smoothly and accordingly. Dirty due to leakage And to provide an image forming apparatus capable of suppressing.

In order to solve the above problems, the present invention provides:
A container for storing the developer, and at least one disposed in the container so that the end of the rotation shaft is rotatably supported by a bearing portion provided on the container wall. Developer processing rotating member, and a developer processing apparatus including an elastic seal member that contacts at least one rotating shaft end portion of the rotating member to prevent the developer from entering the bearing portion And at least one of the rotating members with which the seal member comes into contact with the end of the rotating shaft has a shaft diameter on the side farther from the bearing than the bearing at the end of the rotating shaft. The elastic sealing member has a large diameter from the peripheral surface of the small-diameter side part forming the step part and the small-diameter side part. Contact both rising surfaces rising to the side Providing developer processing apparatus employing an elastic sealing member having-up unit.
In order to solve the above-described problems, the present invention provides an image forming apparatus equipped with such a developer processing apparatus.

The description of the above-mentioned problem and the “developer processing apparatus” referred to here refers to an apparatus that handles the developer, such as a developing apparatus or a part thereof, a cleaning apparatus or a part thereof.
The “rotating member” is, for example, a developing device, a developing roller, a developer supplying roller for supplying the developer to the developing roller, an agitation rotating member for stirring the developer, and the like, for example, a cleaning device. A cleaning roller, a developer conveying screw for conveying the collected developer, and the like.

  According to the developer processing apparatus of the present invention, the developer processing device is disposed in the developer storage container, and the rotation shaft end portion is rotatably supported by the bearing portion provided on the container wall so as to be rotatable in the container. The at least one rotating member for processing a developer has a shaft diameter at a portion closer to the inner side of the container than the bearing portion at the end portion of the rotating shaft, and the shaft diameter is large on the side farther than the bearing portion and small on the near side. A lip portion of an elastic seal member on both the peripheral surface of the small diameter side portion forming the step portion and the rising surface rising from the small diameter side portion to the large diameter side portion. In other words, the seal by the lip portion is doubled.

  Accordingly, a container for storing the developer, and at least the rotation shaft disposed in the container by being rotatably supported by a bearing portion provided on the container wall, the rotation shaft end portion being disposed in the container. One type of rotating member for processing a developer and a seal member for contacting at least one rotating shaft end portion of the rotating member to prevent the developer from entering the bearing portion. Compared with the developer processing apparatus, the developer can be more reliably prevented from entering the bearing portion, and the rotating member can be smoothly rotated by that amount, and the developer leaks from the bearing portion. Can be suppressed more reliably.

  Further, in the image forming apparatus according to the present invention equipped with such a developer processing device, the developer processing device can more reliably intrude the developer into the bearing portion than the conventional developer processing device of the same type. The rotation member can be smoothly rotated by that amount, and the external leakage of the developer from the bearing portion can be more reliably suppressed, and as a result, a good image can be formed smoothly. Contamination inside the device due to developer leakage can be suppressed.

  Such an elastic seal member is, for example, directly or indirectly through another member, a container (for example, a seal member holding recess formed in a container wall provided with the bearing portion) or a seal member holding formed in the bearing portion. It can be held in a recess or the like.

In the development processing apparatus according to the present invention, in order to more reliably prevent the developer from entering the bearing portion , the developer is directed toward the lip portion of the seal member at the large-diameter side portion forming the stepped portion. A protruding cylindrical portion is provided, and a free end of the cylindrical portion is brought into contact with the lip portion.

The developer handled by the developer processing apparatus according to the present invention may be a so-called one-component developer mainly composed of toner or a so-called two-component developer mainly composed of toner and carrier. Therefore, when the developer processing apparatus according to the present invention is a developing apparatus, it may be a one-component developing apparatus using a one-component developer or a two-component developing apparatus using a two-component developer.
Further, the image forming apparatus according to the present invention may be any of a copying machine, a printer, a facsimile machine, a multifunction machine combining these two or more, and may be a monocolor image forming apparatus or a color image forming apparatus. .

  As described above, according to the present invention, the container for storing the developer, and the rotation shaft end portion which is disposed in the container and rotatably supported by the bearing portion provided on the container wall. At least one developer processing rotating member disposed in a rotatable manner, and at least one rotating shaft end portion of the rotating member to contact the end of the rotating shaft to prevent the developer from entering the bearing portion. Compared with this type of conventional developer processing apparatus, the developer processing apparatus of the type including an elastic seal member can more reliably prevent the intrusion of the developer into the bearing portion, and the rotation of the developer processing apparatus. It is possible to provide a developer processing apparatus capable of smoothly rotating a member and more reliably suppressing external leakage of the developer from the bearing portion.

  Further, according to the present invention, a container for containing the developer, and the rotation shaft end portion disposed in the container and rotatably supported by the bearing portion provided on the container wall can be rotated in the container. At least one rotating member for processing the developer disposed, and an elastic seal member for contacting at least one rotating shaft end portion of the rotating member to prevent the developer from entering the bearing portion; An image forming apparatus equipped with a developer processing device of a type including the developer processing device, which more reliably intrudes the developer into the bearing portion than the conventional developer processing device of the same type. The rotation member can be smoothly rotated by that amount, and the external leakage of the developer from the bearing portion can be more reliably suppressed, and as a result, a good image can be smoothly formed and developed. For agent leakage Contaminate it is possible to provide an image forming apparatus capable of suppressing that.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an example of an image forming apparatus provided with a developing device D1, which is an example of a developing processing device as an example of a developing agent processing device according to the present invention.
This image forming apparatus has a photosensitive drum PC that is driven to rotate counterclockwise in the figure as an electrostatic latent image carrier. Around this photosensitive drum PC, a charging device CH, a developing device D1, a transfer roller TR, a cleaning device CL, and an eraser IR are arranged in this order. Above the photosensitive drum PC, there is provided an image exposure apparatus IE that performs image exposure corresponding to a document image on the photosensitive drum PC.

  According to this image forming apparatus, the surface of the photosensitive drum PC that is rotationally driven is uniformly charged by the charging device CH, and image exposure is performed on the charged area from the image exposure device IE, whereby the surface of the photosensitive drum PC is exposed. An electrostatic latent image is formed. This electrostatic latent image is developed by the developing device D1 and becomes a visible toner image.

On the other hand, a recording medium RS is supplied from a recording medium (transfer paper or the like) supply unit (not shown) in synchronism with the electrostatic latent image on the photosensitive drum PC, and on the photosensitive drum PC, the recording medium RS is supplied. The toner image is transferred by the transfer roller TR to which a transfer voltage is applied. The transferred toner image is fixed on the recording medium RS by a fixing device (not shown).
After the transfer, the developer remaining on the photosensitive drum PC is cleaned by the cleaning device CL, and the residual charge is erased by the eraser IR.

  The cleaning device CL has a cleaning blade BL in contact with the surface of the photosensitive member 1, and a container CL ′ for collecting the transfer residual developer removed from the photosensitive member thereby, and the developer collected in the container CL ′. It has a developer conveying screw (screw conveyor) SC for carrying it out. The screw SC is rotatably supported at a shaft end portion thereof by a bearing portion (not shown) provided on the container CL ′ wall.

  The developing device D1 develops an electrostatic latent image on the photoreceptor 1 using a two-component developer Dp mainly composed of magnetic or nonmagnetic toner and a magnetic carrier. As shown in FIG. 2, the developing device D <b> 1 has a buffer unit 2 connected to the developing unit 1 and a toner replenishing unit 6 connected to the buffer unit. 2 is a cross-sectional view taken along line XX in FIG.

  The developing unit 1 includes a container (developing tank) 100 that stores the developer Dp, and further includes a first screw conveyor 11 disposed in the interior thereof, a developer supply rotating member 12 in front of the first screw conveyor 11, and further in front of the first screw conveyor 11. A non-magnetic developing sleeve 130 having a cylindrical cross section and a head height regulating member 140 facing the developing sleeve are provided. The developing sleeve 130 contains a magnet roll Mg in which magnetic poles are arranged.

  The rotation axes of the screw conveyor 11, the rotating member 12, and the developing sleeve 130 are parallel, and both ends of the rotating shafts are respectively provided by bearings provided on the left and right side walls W11 and W12 (see FIG. 3) of the developer container 100. It is rotatably supported. These are rotationally driven in a direction indicated by an arrow in FIG. For example, as shown in FIG. 3, the screw conveyor 11 is rotatably supported by bearing portions B11 and B12 provided on the left and right side walls W11 and W12 of the container 100 at the end of the shaft 10, It is rotationally driven through a gear G1 provided at a shaft end protruding from the bearing B12 to the outside of the container.

  As shown in FIG. 3, the developer Dp conveyed in the conveyor axial direction by the rotation of the screw conveyor 11 is supplied from each part of the conveyor to the developing sleeve side during the conveyance, and the developer supply rotating member 12 Supplied to the surface. The developer Dp supplied to the surface of the developing sleeve 130 is held in the form of a magnetic brush on the surface of the developing sleeve 130 by interaction with the built-in magnet roll Mg, and the developing Dp faces the photoreceptor 1 as the developing sleeve 130 rotates. The developer amount is regulated by the head height regulating member 140 in the middle thereof.

  As the developer is conveyed by the developing sleeve 130, the toner is frictionally charged by coming into contact with the carrier. The developer Dp in the state of a magnetic brush (developer spike) that has reached the development area slides the electrostatic latent image on the photosensitive drum 1 under a development bias applied to the development sleeve 130 from a bias power supply (not shown). Rub and develop the latent image with toner.

  The buffer unit 2 is provided with a second screw conveyor 21 in parallel with the first screw conveyor 11. As shown in FIG. 3, the conveyor 21 is also rotatably supported by bearings B21, B22 provided on the left and right side walls W21, W22 of the buffer container 200 holding the developer at the end of the shaft 20. It is rotationally driven by a drive unit (not shown) via a gear G2 provided at a shaft end protruding from the one bearing portion B22 to the outside of the container.

A partition wall 3 is provided between the first and second screw conveyors 11 and 21, and the developing unit 1 and the buffer unit 2 are partitioned by the partition wall 3.
As shown in FIG. 3, the partition 3 is formed with a first opening 31 and a second opening 32. The first screw conveyor 11 conveys the developer Dp in the developing unit 1 from the second opening 32 side to the first opening 31 side, and sends the developer Dp from the first opening 31 to the second screw conveyor 21. The second screw conveyor 21 can circulate the developer Dp from the first opening 31 side to the second opening 32 side, and further from the second opening 32 to the developing unit 1 below. The first screw conveyor 11 can use the developer Dp circulating in this way again for development.

  The toner replenishing unit 6 includes a hopper 60 that stores the replenishing toner T, a toner agitation rotating member 61 in the hopper, and a screw conveyor 62 that conveys the replenishing toner to the outlet 601 of the hopper 60. Further, as shown in FIG. 3, a duct 63 for guiding the replenishment toner T to the end of the buffer unit 2 on the second opening 32 side and a screw conveyor 64 provided below the duct are included.

  The rotating member 61 and the screw conveyor 62 are rotatably supported by bearing portions (not shown) provided on the hopper wall of the rotating shaft, and are driven to rotate in a direction indicated by an arrow in FIG. 2 by a driving unit (not shown). Is done.

  The screw conveyor 64 extends the rotation shaft 20 of the second screw conveyor 21 in the buffer unit 2 and is provided with a screw on the extension shaft. The screw conveyor 64 conveys replenishment toner to the opposite side of the conveyor 21 and the second screw conveyor. The replenishment toner T collides with and mixes with the circulating developer Dp conveyed at 21.

  Here, the support of the screw conveyor 11 of the developing unit 1 and the screw conveyor 21 of the buffer unit 2 will be further described. As shown in FIG. 4, one side of the rotary shafts 10 and 20 made of metal or the like of the conveyors 11 and 21. A stepped portion S is formed at the end (the left end in FIG. 3). This stepped portion S is on the inner side of the bearing portions B11, B21 provided on the container walls W11, W21, and the side closer to the bearing portion has a small diameter d2 with respect to the shaft diameter d1 on the side farther from the bearing portion. It is formed with. And this small diameter part 101 (201) is rotatably supported by bearing part B11, B21.

What is important here is that each of the annular elastic seal members 4 made of rubber or the like is fitted in the recesses formed in the bearing portions B11 and B21, and the lip portion 41 has its own elasticity and a small diameter shaft. Relative to the rising surface S2 that is slidably pressed against the peripheral surface S1 of the portions 101 and 201 and rises from the small diameter shaft portions 101 and 201 to the large diameter shaft portion (the main body portion of the shafts 10 and 20). In other words, a double seal structure is provided.
Although not shown, the same double seal structure is adopted for the right side container walls W12 and W22 shown in FIG.

With this double seal structure, the developer Dp in the container or the fine particle toner constituting the developer enters the left bearing portions B11 and B21 and the right bearing portions B12 and B22 as shown in FIG. Compared with the conventional seal structure, it is reliably prevented, and the screw conveyors 11 and 21 can be smoothly rotated over a long period of time, and the developer Dp or the toner constituting the developer passes through the bearing portion to the outside. Leakage can be prevented more reliably.
As a result, it is possible to smoothly form a good image as well as to prevent contamination in the image forming apparatus due to developer leakage and possible side effects.

  The elastic seal member that enables such a double seal structure is not limited to the seal member 4 described above. For example, it is possible to employ a seal member 4 'shown in FIG. The sealing member 4 ′ has a lip portion 41 ′ bent and is in contact with the peripheral surface S 1 of the small diameter shaft portions 101 and 201 with a larger area, thereby improving the sealing effect accordingly. Of course, the lip portion 41 'is also slidably pressed against the rising surface S2 rising from the small diameter shaft portions 101, 201 to the large diameter shaft portion (the main body portion of the shafts 10, 20).

In the example of the developer processing apparatus (here, the developing apparatus) according to the present invention, the seal structure shown in FIG. 6 is adopted in order to increase the sealing effect . That is, in the double seal structure shown in FIG. 4, the shaft diameter is set at the end of the large-diameter shaft portion (the main body portion of the shafts 10 and 20) at the ends of the rotary shafts 10 and 20 of the screw conveyors 11 and 21. An intermediate shaft diameter portion 101 ′, 201 ′ that is smaller than the shaft portion main body but larger than the small diameter shaft portions 101, 201 is provided to support the cylindrical member 5 in a cantilevered manner, and its free end is elastic. The slidable contact is made with the lip portion 41 of the seal member 4. According to this, there exists a sealing effect also in the site | part which the member 5 and the lip | rip part 41 mutually contact, and it can be said that a triple seal structure is achieved. This seal structure is also applicable when the elastic seal member 4 ′ shown in FIG. 5 is employed.

  As described above, the double seal structure or triple seal structure with respect to the bearing portion of the rotating shaft related to the screw conveyors 11 and 21 is the other rotating member in the developing device D1, the developer conveying screw SC in the cleaning device CL described above, Furthermore, the present invention can also be applied to a rotating member in an apparatus portion that handles developer.

  FIG. 7 shows another example of the developing device. A developing device D2 shown in FIG. 7 is different from the developing device D1 shown in FIG. 2 in place of the developing sleeve 130, the magnet roll Mg, and the head height regulating member 140, and a developing roller 13 and a blade-like developer regulating member 14 that contacts the developing roller 13. The latent image on the photosensitive drum PC is developed with a developer mainly composed of toner T. The other points are substantially the same as those of the developing device D1, and substantially the same parts and portions as those of the developing device D1 are denoted by the same reference numerals as those of the developing device D1.

  According to the developing device D 1, the toner T supplied to the developing roller 13 is made a toner thin layer having a predetermined thickness by the regulating member 14 and is frictionally charged by contact with the regulating member 14. The thus-charged thin layer toner T shifts to an electrostatic latent image on the photoreceptor PC under the development bias applied to the development roller 13 in the development region, and develops the latent image.

Also in the developing device D2, the above-described double seal structure or triple seal structure is adopted for one or more of the rotating members such as the screw conveyors 11 and 21, and the rotation of the rotating members is made smooth. It is possible to prevent toner from leaking out of the developing device better than before.

  Although the image forming apparatus described above is a monocolor image forming apparatus, the present invention can also be applied to a color image forming apparatus.

  The present invention achieves smooth rotation of a rotating member in a developer processing apparatus such as a developing apparatus in an image forming apparatus and prevents developer leakage from the developer processing apparatus, thereby forming a good image smoothly. In addition, it can be used to suppress contamination in the image forming apparatus due to developer leakage.

1 is a diagram illustrating a schematic configuration of an example of an image forming apparatus . FIG. 2 is a cross-sectional view of an example of a developing device in the image forming apparatus of FIG. 1. FIG. 3 is a diagram illustrating a developer circulation state and the like in the developing device illustrated in FIG. 2. It is a figure which shows the example of a developer seal structure with respect to the bearing part of the screw conveyor in the developing device shown in FIG. It is a figure which shows the other example of a developer seal structure. It is a figure which shows the further another example of a developer seal | sticker structure. It is sectional drawing of the other example of the image development apparatus. It is a figure which shows the conventional developer seal structure with respect to the bearing part of the rotation member in a developer processing apparatus.

Explanation of symbols

PC Photosensitive drum CH Charging device TR Transfer roller CL Cleaning device CL ′ Developer recovery container BL Cleaning blade SC Developer transport screw IR Eraser IE Image exposure device RS Recording medium D1 Developing device 1 Developing unit 100 Developing container (Developing tank)
W11, W12 Container walls B11, B12 Bearing portion 11 First screw conveyor 10 Rotating shaft G1 of conveyor 11 Small shaft portion 101 'of rotating shaft 10 End portion of rotating shaft 10 Intermediate shaft diameter portion S Step portion S1 of shaft 10 end portion Small diameter shaft Peripheral surface S2 rising surface 12 of stepped portion 12 developer supplying rotating member 130 developing sleeve 140 head height regulating member Mg magnet roll 2 buffer unit 21 second screw conveyor 10 rotating shaft G2 of conveyor 21 gear 201 small diameter of rotating shaft 20 end portion Shaft portion 201 ′ Intermediate shaft diameter portion 3 Partition 31 First opening portion 32 Second opening portion 4, 4 ′ Ring elastic seal member 41, 41 ′ Lip portion 5 Cylindrical member 6 Toner replenishing portion 60 Hopper 601 Hopper outlet 61 Toner stirring Rotating member 62 Screw conveyor 63 Duct 64 Screw conveyor Dp below duct 63 Two-component developer T Toner D2 developing unit 13 developing roller 14 developer regulating member

Claims (2)

A container for storing the developer, and at least one disposed in the container so that the end of the rotation shaft is rotatably supported by a bearing portion provided on the container wall. Developer processing rotating member, and a developer processing apparatus including an elastic seal member that contacts at least one rotating shaft end portion of the rotating member to prevent the developer from entering the bearing portion And at least one of the rotating members with which the seal member comes into contact with the end of the rotating shaft has a shaft diameter on the side farther from the bearing than the bearing at the end of the rotating shaft. The elastic sealing member has a large diameter from the peripheral surface of the small-diameter side part forming the step part and the small-diameter side part. Contact both rising surfaces rising to the side Tsu and an elastic sealing member is employed having up portion, the cylindrical portion is provided which projects toward the lip portion of the elastic seal member to said larger diameter portion which forms the stepped portion, the cylindrical-shaped portion A developer processing apparatus, wherein a free end of the toner is in contact with the lip portion . An image forming apparatus equipped with the developer processing apparatus according to claim 1.