JP2020109507A - Developing device, process cartridge, and image recording device - Google Patents

Abstract

To improve the sealing performance of a developer at an end of a restricting member by a simple configuration.SOLUTION: Provided is a developing device comprising: a developer container for accommodating a developer; a developer carrier for carrying the developer; a magnet member provided inside of the developer carrier and having a magnetic pole part in which a plurality of magnetic poles are arrayed in the direction of rotation of the developer carrier; a seal member provided in the developer container so as to face the developer carried with a space therebetween and having a plurality of magnetic poles for restricting the leakage of the developer from a longitudinal end of the developer carrier to the outside of the developer container; and a restriction member for coming in contact with the developer carrier and restricting the thickness of layer of the developer. In a direction leading from the longitudinal end side toward center side of the developer carrier, an end of the restriction member and an end of the magnetic pole part of the magnet member are arranged in the order stated between one end to the other end of the seal member.SELECTED DRAWING: Figure 1

Description

The present invention relates to a developing device that develops on an image carrier. More specifically, the present invention relates to a non-contact developing device of a one-component developing system that develops on an image carrier in a non-contact manner. Further, a process cartridge using the developing device as a developing means for developing an image carrier such as an electrophotographic photosensitive member or an electrostatic recording dielectric, and a copying machine using the developing device as a developing means for developing the image carrier. The present invention relates to an image forming apparatus such as a printer.

In the electrophotographic image forming apparatus, a magnetic non-contact developing method is widely used as a one-component developing method for developing an electrostatic latent image formed on an electrophotographic photosensitive member as a development target (image bearing member) with a one-component developer. Has been. Here, a magnetic non-contact development type developing device will be described.

In a magnetic non-contact developing type developing device, a developer is carried on a developing sleeve (developer carrying body) containing a magnet. Then, the photoconductor (image bearing member) is opposed to the surface of the developing sleeve with a predetermined minute gap, and the developer is caused to fly from the developing sleeve toward the photoconductor to perform development. The developer in the developing device is conveyed to the developing sleeve by a stirring mechanism or gravity. Further, the magnetic one-component developer is supplied to the developing sleeve by receiving a constant magnetic force by a magnet contained in the developing sleeve.

In the above-mentioned magnetic non-contact developing system, Japanese Patent Application Laid-Open No. 2004-242242 discloses a configuration in which a magnetic seal member is arranged so as to face the longitudinal end of the developing sleeve. This is a method in which the magnetic seal member is arranged so as to have a predetermined gap from the end portion in the longitudinal direction of the developing sleeve, and then the toner (developer) is held on the magnetic seal member by the magnetic force of the magnetic seal member. That is, by holding the toner, which is trying to move to the outside of the developer container through the gap between the developer container and the longitudinal end portion of the developing sleeve, on the magnetic seal member, the toner is prevented from leaking out of the developer container. ing.

Here, in the conventional developing device, the developing blade as a regulating member for regulating the layer thickness of the toner carried on the developing sleeve is arranged so as to contact the developing sleeve. In this conventional developing device, the magnetic seal member described in Patent Document 1 is arranged outside the developing blade in the longitudinal direction. At this time, some gap may be formed between the end surface of the developing blade and the side surface portion of the magnetic seal member. The toner carried on the developing sleeve in this gap is located outside the developing blade, and is not restricted by the developing blade. That is, if a gap is formed between the end face of the developing blade and the side face of the magnetic seal member, the amount of toner (developer amount) carried on the developing sleeve in this gap becomes larger than in other regions. .. Further, the toner located outside the developing blade is not easily charged because it is not rubbed by the developing blade, and the amount of charge is low. Therefore, when toner is carried on the developing sleeve in the area of the gap between the end surface of the developing blade and the magnetic seal member, the toner easily moves to the photoconductor from this area. Such toner may move to a region of the photoconductor on which a toner image should not be formed and cause so-called fog.

Therefore, Patent Document 2 discloses a configuration in which another seal member (hot melt) is newly provided in the gap between the end surface of the developing blade and the magnetic seal member. According to the configuration of Patent Document 2, since the gap between the end surface of the developing blade and the magnetic seal member is newly filled with another seal member (hot melt), the toner is applied to the developing sleeve outside the end portion of the developing blade. It becomes possible not to carry them.

JP, 10-39630, A JP, 2006-208552, A

However, in the configuration of Patent Document 2 described above, since another seal member (hot melt) is newly provided in the gap between the end surface of the developing blade and the magnetic seal member, the configuration is complicated and the cost increases. There is.

Then, the objective of this invention is to improve the sealing performance of the developer in the edge part of a regulation member with a simple structure.

In order to achieve the above object, the present invention provides a developer container for containing a developer, a developer carrier for carrying the developer, and a rotation of the developer carrier provided inside the developer carrier. Is provided in the developer container so as to face a magnetic member having a magnetic pole portion in which a plurality of magnetic poles are arranged in a direction, with respect to the developer carrying member, and the magnetic member in the longitudinal direction of the developer carrying member. A seal member having a plurality of magnetic poles for restricting the leakage of the developer from the end portion to the outside of the developer container, and a restricting member for contacting the developer carrier and restricting the layer thickness of the developer, In a developing device including, in the direction from the end portion side in the longitudinal direction of the developer carrying member toward the center side, between the one end portion and the other end portion of the sealing member, The end portion and the end portion of the magnetic pole portion of the magnet member are arranged in this order.

According to the present invention, at the end portion of the regulation member, it is possible to suppress the developer from being carried by the developer carrying member by the seal member, and the sealing performance of the developer at the end portion of the regulation member can be achieved with a simple structure. Can be improved.

6A to 6D are detailed explanatory diagrams of an end portion of the developing device according to the first embodiment. 3 is a cross-sectional view of the image forming apparatus according to the first exemplary embodiment. FIG. 3 is a sectional view of the process cartridge according to Embodiment 1. FIG. 2 is a perspective view of the developing device according to Embodiment 1. FIG. 3A and 3B are perspective views of the process cartridge according to the first embodiment. FIG. 3 is a perspective view of the developing container unit according to the first exemplary embodiment. (A)-(c) is explanatory drawing of the developing sleeve unit which concerns on Example 1. FIG. (A) (b) is explanatory drawing of the magnet which concerns on Example 1. FIG. (A) (b) is explanatory drawing of the magnetic seal which concerns on Example 1. FIG. (A) and (b) are explanatory views of the developing container unit end portion according to the first embodiment. FIGS. 9A and 9B are explanatory views of an end portion of the developing device according to the second embodiment. (A)-(d) is explanatory drawing of the developing sleeve unit which concerns on Example 3. FIG. FIG. 9 is an explanatory diagram of a developing device according to a third embodiment. FIGS. 7A and 7B are explanatory views of an end portion of the developing device according to the first embodiment.

Hereinafter, preferred embodiments of the present invention will be illustratively described in detail with reference to the drawings. However, the functions, dimensions, materials, shapes, and their relative arrangements of the components described in the following examples are intended to limit the scope of the present invention to them unless otherwise specified. Not the one.

[Example 1]
Hereinafter, the developing device according to the first embodiment will be described. Here, the developing device (developing means) included in the process cartridge detachable from the image forming apparatus main body of the image forming apparatus will be described as an example.

The overall configuration of the image forming apparatus and the image forming process will be described with reference to FIGS. 2 and 3. FIG. 2 is a cross-sectional view of an image forming apparatus body (hereinafter, referred to as apparatus body A) and a process cartridge (hereinafter, referred to as cartridge B) of the image forming apparatus according to the first embodiment. FIG. 3 is a sectional view of the cartridge B. Here, the apparatus main body A is a portion excluding the cartridge B from the image forming apparatus.

<Overall structure of image forming apparatus>
The image forming apparatus shown in FIG. 2 is a laser beam printer using an electrophotographic technique in which the cartridge B is attachable to and detachable from the apparatus main body A. As shown in FIG. 2, the cartridge B is detachably attached to the apparatus main assembly A in the image forming apparatus. An exposure device 3 (laser scanner unit) for forming a latent image on the electrophotographic photosensitive drum 62 of the cartridge B mounted in the apparatus body A is arranged in the apparatus body A. Further, in the apparatus main body A, below the cartridge B, a sheet tray 4 that stores a recording medium (hereinafter, referred to as a sheet material P) to be an image forming target is arranged.

Further, in the apparatus body A, along the conveyance direction D of the sheet material P, a pickup roller 5a, a feeding roller pair 5b, a transfer guide 6, a transfer roller 7, a conveyance guide 8, a fixing device 9, a discharge roller pair 10, The discharge tray 11 and the like are sequentially arranged. The fixing device 9 is composed of a heating roller 9a and a pressure roller 9b.

<Image forming process>
Next, the outline of the image forming process will be described. Based on the print start signal, an electrophotographic photosensitive drum (hereinafter referred to as drum 62) as an image carrier is rotationally driven in the direction of arrow R at a predetermined peripheral speed (process speed).

The charging roller 66 to which the bias voltage is applied contacts the outer peripheral surface of the drum 62 and charges the outer peripheral surface of the drum 62.

The exposure device 3 outputs a laser beam L according to image information. The laser light L passes through a laser opening 71h provided in the cleaning frame 71 of the cartridge B to scan and expose the outer peripheral surface of the drum 62. As a result, an electrostatic latent image corresponding to the image information is formed on the outer peripheral surface of the drum 62.

On the other hand, as shown in FIG. 3, in the developing unit 20 as the developing device, the toner T as the developer in the toner chamber 29 is agitated and conveyed by the rotation of the conveying member 43, and sent to the toner supply chamber 28. The toner T is carried on the surface of the developing sleeve 32 as a developer carrying member by the magnetic force of the magnet 34 as a magnet member.

The toner T is frictionally charged by the developing elastic member 42b (regulating member) of the developing blade 42, and the layer thickness on the peripheral surface of the developing sleeve 32 is regulated. The toner T on the peripheral surface of the developing sleeve 32 whose layer thickness is regulated is developed on the drum 62 according to the electrostatic latent image formed on the outer peripheral surface of the drum 62, and is visualized as a toner image.

Further, as shown in FIG. 2, the sheet material P stored in the lower part of the apparatus main body A is sent out from the sheet tray 4 by the pickup roller 5a and the feeding roller pair 5b in synchronization with the output timing of the laser light L. Then, the sheet material P is conveyed to the transfer position between the drum 62 and the transfer roller 7 via the transfer guide 6. At this transfer position, the toner image is sequentially transferred from the drum 62 to the sheet material P.

The sheet material P to which the toner image is transferred is separated from the drum 62 and is conveyed to the fixing device 9 along the conveyance guide 8. Then, the sheet material P passes through a nip portion between the heating roller 9a and the pressure roller 9b which form the fixing device 9. At the nip portion between the heating roller 9a and the pressure roller 9b, pressure/heat fixing processing is performed and the toner image is fixed on the sheet material P. The sheet material P that has undergone the toner image fixing process is conveyed to the discharge roller pair 10, and is discharged to the discharge tray 11 by the discharge roller pair 10.

On the other hand, as shown in FIG. 3, the residual toner on the outer peripheral surface of the drum 62 after the transfer is removed by the cleaning member 77, and the drum 62 is used again in the image forming process. The toner removed from the drum 62 is stored in the waste toner chamber 71b of the cleaning unit 60 having a photosensitive drum.

In the above, the charging roller 66, the developing sleeve 32, the transfer roller 7, and the cleaning member 77 are process means that act on the drum 62. The charging roller 66, the developing sleeve 32, the transfer roller 7, and the cleaning member 77 are a charging means, a developing means, a transfer means, and a cleaning means as a process means that act on the drum 62 in this order.

<Structure of entire cartridge>
Next, the overall configuration of the cartridge B will be described with reference to FIGS. 3, 8, 9, and 10. FIG. 3 is a sectional view of the cartridge B. 8, 9, and 10 are perspective views illustrating the configuration of the cartridge B. In the present embodiment, description will be made while omitting screws for connecting the respective parts.

In the following description, the direction of the rotation axis that is the center of rotation of the developing sleeve 32 is the longitudinal direction (arrow Y direction shown in FIG. 1). Further, in the longitudinal direction of the developing sleeve 32 (direction of arrow Y in FIG. 1), the side where the developing sleeve 32 receives the driving force from the apparatus main body A is the driving side, and the opposite side is the non-driving side. Further, in the longitudinal direction of the developing sleeve 32 (direction of arrow Y in FIG. 1), the side toward the center of the developing sleeve 32 (center side) is defined as the inner side in the longitudinal direction (direction of arrow Y1), and the end of the developing sleeve 32 is The facing side (end side) is defined as the outer side in the longitudinal direction (arrow Y2 direction side).

The cartridge B has a cleaning unit 60 as a first unit and a developing unit 20 as a second unit. The process cartridge is an apparatus body of an electrophotographic image forming apparatus in which an electrophotographic photosensitive member and at least one of a charging unit, a developing unit, and a cleaning unit, which act on the electrophotographic photosensitive member, are integrally formed as a cartridge. It can be attached to and detached from. Here, the cartridge B has at least a developing unit 20 as a developing device according to the present embodiment.

<Structure of cleaning unit>
As shown in FIG. 3, the cleaning unit 60 includes a drum 62, a charging roller 66, a cleaning member 77, and a cleaning frame body 71 that supports these members. In the cleaning unit 60, the charging roller 66 and the cleaning member 77 are arranged in contact with the outer peripheral surface of the drum 62, respectively.

The cleaning member 77 has a rubber blade 77a, which is a blade-shaped elastic member formed of rubber as an elastic material, and a support member 77b that supports the rubber blade 77a. The rubber blade 77a is in contact with the drum 62 in the counter direction with respect to the rotating direction of the drum 62 (direction of arrow R). That is, the rubber blade 77a is in contact with the drum 62 so that its tip end faces the upstream side in the rotation direction of the drum 62.

As shown in FIG. 3, the waste toner removed from the surface of the drum 62 by the cleaning member 77 is stored in the waste toner chamber 71 b formed by the cleaning frame 71 and the cleaning member 77.

Further, as shown in FIG. 3, a sheet member 65 for preventing the waste toner from leaking from the cleaning frame 71 is provided at the edge of the cleaning frame 71 so as to contact the drum 62.

The drum 62 receives a driving force from a main body driving motor (not shown) that is a driving source, and is rotationally driven in the arrow R direction in accordance with the image forming operation.

The charging roller 66 is rotatably attached to the cleaning unit 60 via charging roller bearings 67 at both ends in the longitudinal direction of the cleaning frame 71. The charging roller 66 is pressed against the drum 62 by pressing the charging roller bearing 67 toward the drum 62 by the urging member 68. The charging roller 66 rotates following the rotation of the drum 62.

<Structure of developing unit>
The configuration of the developing unit 20 as the developing device according to this embodiment will be described with reference to FIGS. 3 and 4. FIG. 4 is a perspective view illustrating the configuration of the developing unit 20. As shown in FIG. 4, the developing unit 20 includes a developing container unit 30, a developing sleeve unit 31, a first holder unit 26, and a second holder unit 27. The developing sleeve unit 31 is supported via the first holder unit 26 and the second holder unit 27 so that the developing sleeve 32 can rotate with respect to the developing container unit 30.

<Coupling of cleaning unit and developing unit>
A method of connecting the cleaning unit 60 and the developing unit 20 described above will be described with reference to FIG. 5A and 5B are exploded perspective views of the cartridge B. As shown in FIGS. 5A and 5B, in the developing unit 20, the support portion 26 a of the first holder unit 26 and the support portion 27 a of the second holder unit 27 are the first hanging holes of the cleaning unit 60. 71i and the second hanging hole 71j. As a result, the developing unit 20 is connected to the cleaning unit 60. Then, the pressure spring 25, which is a biasing member, is compressed between the cleaning unit 60 and the developing unit 20, and the developing sleeve 32 is biased toward the drum 62. At this time, the spacing members 38 provided at both ends of the developing sleeve 32 come into contact with the drum 62, so that a minute gap is formed between the developing sleeve 32 and the drum 62.

<Structure of developing unit>
Each configuration of the developing unit 20 will be described in more detail with reference to FIGS. 3 and 6 to 9. 6 is an exploded perspective view of the developing container unit 30, FIG. 7 is an explanatory view of the developing sleeve unit, and FIG. 8 is an explanatory view of the magnet 34.

As described above, the developing unit 20 includes the developing container unit 30, the developing sleeve unit 31, the first holder unit 26, and the second holder unit 27.

First, as shown in FIGS. 3 and 6, the developing container unit 30 includes a developing container 23, a bottom member 22, a developing blade 42, and the like.

As shown in FIG. 3, the developing container 23 and the bottom member 22 form a developer container that contains the toner T as a developer. Here, the developing container 23 and the bottom member 22 are integrally connected by means such as welding, and form a toner chamber 29 for storing the toner T as a developer and a toner supply chamber 28. The transport member 43 is rotatably supported inside the developing container 23. A transport gear 50 is provided on the longitudinal drive side of the transport member 43. The transport member 43 rotates when the transport gear 50 (see FIG. 6) receives a driving force to stir the toner in the toner chamber 29 and transport the toner in the toner chamber 29 to the toner supply chamber 28. The developing elastic member 42b as a regulating member contacts the developing sleeve 32, regulates the layer thickness of the toner carried on the developing sleeve 32, and rubs the toner to frictionally charge the toner.

As shown in FIG. 6, the developing blade 42 has a supporting member 42a made of sheet metal and a developing elastic member 42b made of an elastic material such as urethane rubber as a regulating member. The developing blade 42 is fixed to a predetermined position with respect to the developing container 23 with screws 93 at both ends of the supporting member 42a together with a cleaning member 47 described later. Further, a magnetic seal 35 as a seal member is arranged at a position corresponding to both ends of the developing elastic member 42b of the developer container formed by the developing container 23 and the bottom member 22, and an end portion in the longitudinal direction of the developing sleeve. The leakage of toner from the outside to the outside of the developer container is regulated. The details of the magnetic seal 35 will be described later. The seat member 33 is provided on the seat surface portion 22a of the bottom member 22 so as to straddle the magnetic seals 35 at both ends. The seat member 33 is fixed to the seat surface portion 22a with one end 33a protruding from the seat surface portion 22a. Here, the one end 33a of the sheet member 33 is an end portion on the toner supply chamber 28 side in the lateral direction orthogonal to the longitudinal direction (the arrow Y direction shown in FIG. 10) of the sheet member 33.

Next, the developing sleeve unit 31 includes a developing sleeve 32, a magnet 34, a spacing member 38, a conductive bearing member 37, and a developing sleeve gear 39, as shown in FIGS. 7A to 7C. .. The spacing members 38 are provided at both ends of the developing sleeve 32 in the longitudinal direction. The spacing members 38 provided at both ends of the developing sleeve 32 are brought into contact with the drum 62 by the urging force of the pressure spring 25 compressed between the cleaning unit 60 and the developing unit 20, so that the developing sleeve 32 and the drum 62 are separated from each other. Make a small gap between them. The developing sleeve gear 39 is provided at a drive-side end portion of the developing sleeve 32 in the longitudinal direction, and is configured to rotate integrally with the developing sleeve 32 when receiving a driving force. The developing sleeve 32 is a developer carrier that carries the toner supplied from the toner chamber to the toner supply chamber.

The magnet 34 is a magnet member provided inside the developing sleeve 32. The magnet 34 is composed of a plastic magnet including a permanent magnet such as ferrite, and a plurality of magnetic poles (here, each of the N pole and the S pole is two poles) are arranged in the circumferential direction of the thick shaft portion 34c as the magnetic pole portion ( See FIG. 8B). In addition to the thick shaft portion 34c, the magnet 34 has a driving side end portion 34a on one side in the longitudinal direction which is the driving side, and a non-driving side end portion 34b on the other side in the longitudinal direction which is the non-driving side. .. In the magnet 34, the thick shaft portion 34c, which is a magnetic pole portion in which a plurality of magnetic poles are arranged, has a larger diameter than the driving side end portions 34a and the non-driving side end portions 34b on both sides in the longitudinal direction. In addition, the thick shaft portion 34c, the driving side end portion 34a, and the non-driving side end portion 34b that configure the magnet 34 are integrally molded with a plastic magnet. Then, a magnetizing operation for applying magnetism to the thick shaft portion 34c of the integrally molded magnet 34 is performed, and as shown in FIG. 8B, a plurality of magnetic pole portions 34s1, 34n1, 34s2, 34n2 are arranged. Is formed.

The magnet 34 is provided inside the developing sleeve 32, and the driving side end 34a and the non-driving side end 34b are provided so as to leave a gap 32d between the outer peripheral surface of the thick shaft portion 34c and the inner peripheral surface of the developing sleeve 32. Is supported. The magnet 34 is rotatably supported at the drive-side end 34 a thereof by the internal support surface 32 c of the developing sleeve 32. In the conductive bearing member 37, the support portion 37a is inserted into the inner peripheral surface 32a of the developing sleeve 32 and rotatably supports the developing sleeve 32, while the second support portion 37b fixes the non-driving side end portion 34b of the magnet 34. I support you. Here, the second support portion 37b and the non-driving side end portion 34b of the magnet 34 are provided with a D-cut shape 34b1 (see FIG. 8A) so that the conductive bearing member 37 and the magnet 34 do not rotate with respect to each other. ing. Further, a contact portion (not shown) contacts a power feeding portion (not shown) of the apparatus main body A to form a power feeding path from the apparatus main body A to the developing sleeve 32.

As shown in FIG. 4, the developing sleeve unit 31 is coupled to the developing container unit 30 by the first holder unit 26 and the second holder unit 27. Here, the support portion 26b of the first holder unit 26 rotatably supports the support portion 39a (see FIG. 7A) of the developing sleeve gear 39, and the second holder unit 27 rotates the conductive bearing member 37 with respect to each other. I support not to. As a result, the developing sleeve 32 is rotatably supported while the magnet 34 is not rotated with respect to the developing container unit 30. Here, as shown in FIG. 8B, the magnet 34 is arranged such that three poles of each magnetic pole are on the toner supply chamber 28 side and the remaining one pole faces the drum 62. In this embodiment, the magnetic pole 34s1 is provided on the drum 62, the magnetic pole 34n1 is provided on the developing elastic member 42b, and the magnetic pole 34n2 is provided on the sheet member 33. The magnetic pole 34s2 is provided on the opposite side of the magnetic pole 34s1 and between the magnetic poles 34n1 and 34n2. Each magnetic pole of the magnet 34 functions as follows. The magnetic pole 34s1 facing the drum 63 holds the toner so that the toner does not fly to the drum side more than necessary. Among the magnetic poles facing the toner supply chamber 28 side (magnetic seal side), the magnetic pole 34s2 holds the toner conveyed to the toner supply chamber 28 by the conveying member on the surface of the developing sleeve 32. By facing the developing elastic member 42b, the magnetic pole 34n1 makes it easier to regulate the toner held on the surface of the developing sleeve 32. By facing the sheet member 33, the magnetic pole 34n2 further prevents the toner from blowing out from the toner supply chamber 28.

<Structure of magnetic seal>
Next, the magnetic seals provided on both ends of the developing elastic member 42b will be described in detail with reference to FIGS. 1, 9, 10, and 14. The magnetic seal is configured such that the driving side and the non-driving side are symmetrical with respect to the center in the longitudinal direction, and therefore the magnetic seal on the driving side will be described as an example. 9A and 9B are explanatory views of the magnetic seal 35 on the drive side. FIGS. 10B and 10B are explanatory views of the developing unit 20 in the vicinity of the drive-side end portion 42b1 of the developing elastic member 42b.

As shown in FIGS. 9(a) and 9(b), the magnetic seal 35 as a seal member includes a magnet portion 35a having a permanent magnet such as ferrite or neodymium and a soft magnetic material such as iron, aluminum or SUS. It is composed of a certain non-magnet portion 35b. The inner surface 35c of the magnet portion 35a is provided so as to face the outer peripheral surface of the developing sleeve with a gap 35i (see FIG. 1C) therebetween, and to extend along the outer peripheral surface of the developing sleeve in the rotating direction of the developing sleeve. ing. A plurality of N poles and S poles, which are magnetic poles, are arranged at constant intervals on the inner surface 35c and the outer surface 35d of the magnet portion 35a, and magnetic force lines 35j are generated on the inner surface 35c and the outer surface 35d. .. On the other hand, the non-magnet portion 35b is provided in contact with one side surface of the magnet portion 35a, and prevents the magnetic force lines 35j from leaking to the outside of the non-magnet portion 35b. Here, the one side surface of the magnet portion 35a provided with the non-magnet portion 35b is a side surface of the magnet portion 35a on the end side in the longitudinal direction of the developing sleeve. Further, a cutout portion 35e is provided on the inner surface 35c of the magnet portion 35a on the side opposite to the non-magnet portion 35b. The cutout portion 35e is cut out in a direction that is farther from the outer peripheral surface of the developing sleeve than the inner surface 35c in a direction orthogonal to the rotation axis of the developing sleeve (direction parallel to the arrow Y direction).

As shown in FIGS. 10A and 10B, the magnetic seal 35 is arranged so that the outer surface 35d contacts the supporting portion 23c formed by the developing container 23 and the bottom member 22. The magnetic seal 35 is installed on the support portion 23c such that the magnet portion 35a is inside in the longitudinal direction (arrow Y1 direction side) and the non-magnet portion 35b is outside in the longitudinal direction (arrow Y2 direction side). As shown in FIG. 10B, the developing blade 42 is provided so that the drive-side end portion 42b1 of the developing elastic member 42b overlaps the magnetic seal 35 in the longitudinal direction (arrow Y direction). At this time, the end surface 35e1 of the cutout portion 35e of the magnetic seal 35 is located on the outer side in the longitudinal direction (arrow Y2 direction side) with respect to the drive side end portion 42b1 of the developing elastic member 42b. A cleaning member 47 is further provided near the driving side end portion 42b1 of the developing elastic member 42b. The cleaning member 47 includes a scraping portion 47a that scrapes the toner by coming into contact with the developing sleeve. The scraping portion 47a of the cleaning member 47 is composed of an elastically deforming portion 47b and a folded portion 47c. As shown in FIG. 10B, the cleaning member 47 has a long end so that the tip 47b1 of the elastically deformable portion 47b becomes longer from the inner side in the longitudinal direction to the outer side (arrow Y2 direction side) (see FIG. 14, L2>L1). It is formed so as to be inclined with respect to the direction (arrow Y direction). As shown in FIG. 10B, the scraping portion 47a is provided so as to straddle the outer side surface 35p of the magnetic seal 35 in the longitudinal direction (arrow Y direction). Further, the scraping portion 47a is arranged such that the inner end 47a1 thereof has a slight gap 47d from the driving side end portion 42b1 of the developing elastic member 42b. That is, as shown in FIG. 10B, in the longitudinal direction (direction of arrow Y), the inner end 47a1 as the inner end surface of the cleaning member 47 and the drive side end portion 42b1 as the outer end surface of the developing elastic member 42b are separated. They are opposed to each other with a gap 47d. Therefore, in the direction from the outer side in the longitudinal direction toward the inner side (arrow Y1 direction side), between the outer side surface 35p of the magnetic seal 35 and the inner side surface 35k of the magnetic seal 35, the inner end (center side end portion) of the scraping portion 47a is formed. ) 47a1 and the drive-side end 42b1 of the developing elastic member 42b. Further, as shown in FIG. 10B, the seat member 33 is attached to the seat surface portion 22a of the bottom member 22 so that the end portion 33b in the longitudinal direction overlaps the magnet portion 35a. In this configuration, the supporting portion 23c is formed by the developing container 23 and the bottom member 22, but the supporting portion 23c may be formed by one frame.

<Toner Sealing Structure at End of Developing Elastic Member>
Next, the toner sealing structure at both ends of the developing elastic member 42b will be described in detail with reference to FIGS. 1(a) to 1(d). FIG. 1 is an explanatory diagram of the developing unit 20, and is a diagram showing a state in which the developing sleeve unit 31 is assembled to the developing container unit 30. For the sake of explanation, the developing sleeve unit 31 is not shown in FIGS. 1A and 1B. Further, FIG. 1C is a cross-sectional view taken along the plane A of FIG. FIG. 1D is a perspective view of an essential part showing a contact state of the cleaning member with respect to the developing sleeve. In the following description, since the toner sealing structure is the same at both ends of the developing elastic member 42b, only the structure of the driving side end will be described.

When the developing sleeve unit 31 is assembled to the developing container unit 30, the developing elastic member 42b is elastically deformed by coming into contact with the developing sleeve 32 as shown in FIG. 1C, and the notch of the magnetic seal 35 is formed. It is accommodated in the part 35e.

At this time, as shown in FIG. 1B, the notch portion 35e is formed so that a minute gap 35f is formed in the longitudinal direction (arrow Y direction) with respect to the driving side end portion 42b1 of the developing elastic member 42b. ing. Further, as shown in FIG. 1C, the cutout portion 35e is formed so as to have a minute gap 35h in the circumferential direction (the arrow X direction) of the developing sleeve 32 with respect to the developing elastic member 42b. Further, as shown in FIG. 1C, the notch portion 35e is orthogonal to the developing elastic member 42b in the longitudinal direction (arrow Y direction) and in the circumferential direction of the developing sleeve 32 (arrow X direction) (arrow Z). A minute gap 35g is formed in the (direction). At this time, as shown in FIG. 1C, the inner surface 35c of the magnetic seal 35 is provided with a minute gap 35i with respect to the surface of the developing sleeve 32. As an example, when the gap 35f is set to 0.5 mm, the gap 35g and the gap 35h are set to 0.3 mm, and the gap 35i is set to 0.6 mm, suitable sealing performance by the magnetic seal 35 is obtained. In this way, the developing elastic member 42b is accommodated in the magnetic seal 35 in a non-contact manner when accommodated in the cutout portion 35e of the magnetic seal 35.

Further, the scraping portion 47a of the cleaning member 47 is also elastically deformed by coming into contact with the developing sleeve 32. Then, since the tip 47b1 of the elastically deformable portion 47b is inclined with respect to the longitudinal direction (arrow Y direction) (see FIG. 10B), the contact portion 47e of the scraping portion 47a with respect to the developing sleeve 32 is the developing sleeve. It is inclined with respect to the rotation axis C of 32. More specifically, the contact portion 47e of the scraping portion 47a is directed from the outer side in the longitudinal direction of the developing sleeve 32 toward the inner side (arrow Y1 direction side) as it goes to the downstream side in the rotation direction (arrow S direction) of the developing sleeve 32. Further, the developing sleeve 32 is inclined from the rotation axis C. That is, in the contact portion 47e of the scraping portion 47a, the contact portion 47e2 on the inner side in the longitudinal direction contacts the downstream side in the rotating direction (arrow S direction) of the developing sleeve 32, compared to the contact portion 47e1 on the outer side in the longitudinal direction. It is inclined with respect to the rotation axis C of the developing sleeve 32 so as to be in contact with each other.

The magnet 34 is arranged inside the developing sleeve 32 with a gap 32d from the developing sleeve 32 (see FIG. 7C). The drive-side end portion 34c1 of the thick shaft portion 34c of the magnet 34 is, as shown in FIG. It is placed between 35k.

That is, as shown in FIG. 1B, in the direction from the end portion side in the longitudinal direction of the developing sleeve 32 toward the center side, the end portion of the developing elastic member 42b and the end portion of the magnet are above the magnetic seal. It is arranged like. Between the outer surface 35p, which is one end of the magnetic seal 35, and the inner side surface 35k, which is the other end, between the drive side end 42b1 of the developing elastic member 42b and the thick shaft portion 34c (magnetic pole portion) of the magnet 34. The drive-side end portion 34c1 is arranged in this order.

With the above configuration, good toner sealing performance can be obtained at the drive-side end portion 42b1 of the developing elastic member 42b. First, in the gap 35i between the magnetic seal 35 and the developing sleeve 32, a magnetic field is generated between the magnetic force line 35j generated on the inner surface 35c of the magnetic seal 35 and the magnet 34. These magnetic fields can prevent the toner T from leaking from the gap 35i. Next, in the gaps 35f, 35g, and 35h between the developing elastic member 42b and the magnetic seal 35, a magnetic field is generated between the magnetic force line 35n generated in the cutout portion 35e and the magnet 34. These magnetic fields can prevent the toner T from leaking from the gaps 35f, 35g, and 35h. As a result, the amount of toner leaking to the outside of the developing elastic member 42b in the longitudinal direction can be reduced, and the toner sealing performance can be improved.

Further, on the outer side in the longitudinal direction of the developing elastic member 42b, the scraping portion 47a of the cleaning member 47 is located inside the longitudinal direction of the developing sleeve 32 (indicated by the arrow) with respect to the toner T attached to the developing sleeve 32. Scratch back toward (Y1 direction side). At this time, the drive-side end 34c1 of the thick shaft portion 34c of the magnet 34 is located inside the developing elastic member 42b in the longitudinal direction (arrow Y1 direction side), so that the magnetic field generated by the magnet 34 is outside the developing elastic member 42b in the longitudinal direction. Is getting weaker. Then, the magnetic force that attracts the toner T to the developing sleeve 32 decreases. The toner T is rotated along with the developing sleeve 32 by a frictional force generated according to the force attracted to the developing sleeve 32. Therefore, when the magnetic field of the magnet 34 decreases, the toner T is less likely to follow the developing sleeve 32, so that the amount of the toner T reaching the scraping portion 47a can be suppressed. As a result, the scraping portion 47a can maintain good scraping performance. Further, the amount of toner leaking from the gap 47d between the inner end 47a1 of the scraping portion 47a and the developing elastic member 42b can be suppressed, so that a phenomenon such as so-called fogging can be suppressed.

In addition, as shown in FIG. 14, between the outer side surface 35p of the magnetic seal 35 and the inner side surface 35k of the magnetic seal 35 in the direction from the outer side in the longitudinal direction toward the inner side (arrow Y1 direction side), the scraping portion 47a is formed. The inner end (center-side end) 47a1 and the drive-side end 42b1 of the developing elastic member 42b are arranged in this order. For this reason, when the developing sleeve 32 rotates, the toner T entrained in the developing sleeve 32 in the region F1 where the developing sleeve 32 and the developing elastic member 42b contact in the longitudinal direction (arrow Y direction) does not contact the cleaning member 47. .. Further, the toner T entrained in the developing sleeve 32 in the region F2 where the developing sleeve 32 and the scraping portion 47a contact each other in the longitudinal direction (arrow Y direction) does not contact the developing elastic member 42b. In addition, the inner end 47a1 of the scraping portion 47a and the drive-side end portion 42b1 as the outer end surface of the developing elastic member 42b face each other with a gap 47d therebetween. Therefore, the toner T scraped back to the inner end 47a1 of the scraping portion 47a by the cleaning member 47 does not come into contact with the developing elastic member 42b. That is, there is no region where the toner T that follows the developing sleeve 32 comes into contact with both the developing elastic member 42b and the cleaning member 47. Therefore, since the toner T does not rub against both the developing elastic member 42b and the cleaning member 47, the toner deterioration due to the rubbing can be suppressed. Here, the deterioration of the toner refers to deformation or cracking of the toner. The deteriorated toner is more likely to aggregate than the non-deteriorated toner, and as a result, the toner may remain attached on the developing sleeve 32. In such a state, the toner adhered on the developing sleeve 32 is repeatedly rubbed by the developing blade 42 and the cleaning member 47, and finally fixed on the developing sleeve 32. If the toner can be fixed on the developing sleeve 32, the toner will not be properly regulated, and the image will be adversely affected. However, according to this configuration, the inner end 47a1 of the scraping portion 47a and the drive-side end portion 42b1 of the developing elastic member 42b are arranged in this order between the outer side surface 35p of the magnetic seal 35 and the inner side surface 35k of the magnetic seal 35. It As a result, the toner on the developing sleeve 32 is not rubbed by both the developing blade 42 and the cleaning member 47, so that the toner deterioration due to the rubbing can be suppressed and the toner adhesion on the developing sleeve 32 can be reduced. Further, since the cleaning member 47 also cleans the developing sleeve 32, the toner sealing performance at the end portion in the longitudinal direction of the developing blade 42 is maintained in a good state.

As described above, according to the present embodiment, the toner is prevented from leaking from the end portion in the longitudinal direction of the developing blade without adding a component (a new seal member different from the magnetic seal) unlike the conventional case. It is possible to improve the toner sealing performance. As a result, it is possible to suppress image defects with a simple configuration without adding any parts as in the conventional case. Further, it is possible to reduce the use ratio of expensive materials such as neodymium used for the magnetic seal 35, and to provide a less expensive developing device. Furthermore, toner adhesion can be reduced.

[Example 2]
Next, the developing device according to the second embodiment will be described. In the present embodiment, parts different from the above-described embodiments will be described in detail. Unless otherwise specified, the materials, shapes, etc. are the same as those in the above-described embodiments. The same numbers are given to such parts, and detailed description thereof is omitted.

The present embodiment is different from the above-described first embodiment in the arrangement configuration of the cleaning member. Hereinafter, the cleaning member, which is a feature of this embodiment, will be described with reference to FIGS. 11(a) and 11(b). 11A and 11B are explanatory diagrams of the developing device 120 according to the second embodiment.

As shown in FIGS. 11A and 11B, the cleaning member 47 according to the present embodiment has the scraping portion 47a and the like as in the first embodiment described above, and is provided in the developing container 23 together with the developing blade 42. It is fixed. In the cleaning member 47 according to this embodiment, the inner end 47a1 on the inner side in the longitudinal direction of the scraping portion 47a (on the side of the arrow Y1 direction) drives the drive-side end portion 42b1 of the developing elastic member 42b and the thick shaft portion 34c of the magnet 34. It is located on the inner side in the longitudinal direction with respect to the side end portion 34c1. On the other hand, the outer end 47a2 of the scraping portion 47a on the outer side in the longitudinal direction (on the side of the arrow Y2 direction) is located on the outer side in the longitudinal direction with respect to the outer side surface 35p of the magnetic seal 35. When the developing sleeve 32 is assembled to the developing container unit 30 (see FIG. 4), the cleaning member 47 has the contact portion 47e inclined with respect to the rotation axis C of the developing sleeve 32 as in the first embodiment described above. Contact the sleeve 32.

When the developing sleeve 32 rotates in the configuration of the present exemplary embodiment, the toner T that wraps around the developing sleeve 32 on the outer side in the longitudinal direction of the developing elastic member 42b (on the side of arrow Y2) is moved by the cleaning member 47 to the inner end of the scraping portion 47a. It is scraped back to 47a1. Then, the magnetic pole 34s1 (see FIG. 8B) of the magnet 34 acts on the toner scraped back to the inner end 47a1 of the scraping portion 47a. For this reason, it is possible to further suppress the movement of the toner that accompanies the developing sleeve 32 to the drum on the outer side in the longitudinal direction of the developing elastic member 42b, and it is possible to further suppress the phenomenon of so-called fogging as compared with the first embodiment. ..

As described above, according to the configuration of the present embodiment, by providing the inner end 47a1 of the cleaning member 47 inside the end 34c1 of the thick shaft portion 34c, it is possible to obtain a better toner sealing performance.

[Example 3]
Next, the developing device according to the third embodiment will be described. In the present embodiment, parts different from the above-described embodiments will be described in detail. Unless otherwise specified, the materials, shapes, etc. are the same as those in the above-described embodiments. The same numbers are given to such parts, and detailed description thereof is omitted.

The present embodiment is different from the above-described first embodiment in the configuration of the developing sleeve unit and the configuration in which the developing sleeve unit is supported in the developing device. The features of this embodiment will be described with reference to FIGS. 12(a) to 12(d) and FIG. 12A to 12D are explanatory views of the developing sleeve unit 31 in the third embodiment. FIG. 13 is an explanatory diagram of the developing unit 20.

As shown in FIGS. 12A to 12D, the developing sleeve unit 31 includes a developing sleeve 32, a magnet 34, a spacing member 38, a conductive bearing member 37, a drive side bearing 140, and a cap member 141. Unlike the first embodiment described above, the developing sleeve gear 139 that receives a driving force from the apparatus main body side is supported in the first holder unit 26 (see FIG. 13).

The cap member 141 among the above-mentioned members constituting the developing sleeve unit 31 has a passive claw 141a that is a receiving portion that is provided on one end side in the longitudinal direction of the developing sleeve 32 and receives a driving force. The drive-side bearing 140 is a first bearing member that rotatably supports one end of the developing sleeve 32 in the longitudinal direction. The conductive bearing member 37 is a second bearing member that rotatably supports the other end of the developing sleeve 32 in the longitudinal direction.

Similar to the first embodiment, the magnet 34 is arranged inside the developing sleeve 32, and the driving side end 34 a is rotatably supported by the inner supporting surface 32 c of the developing sleeve 32. In the conductive bearing member 37, the support portion 37a is inserted into the inner peripheral surface 32a of the developing sleeve 32 and rotatably supports the developing sleeve 32, while the second support portion 37b fixes the non-driving side end portion 34b of the magnet 34. I support you. Here, the second support portion 37b and the non-driving side end portion 34b of the magnet 34 are provided with a D-cut shape 34b1 (see FIG. 8A) so that the conductive bearing member 37 and the magnet 34 do not rotate with respect to each other. ing.

On the other hand, on the drive side of the developing sleeve 32, the cap member 141 is fitted to the drive side supported portion 32e. The cap member 141 is rotated integrally with the developing sleeve 132 by fitting the two-sided hole portion 141b into the two-sided driving-side supported portion 32e which is the same as the hole portion 141b. There is. The shaft portion 141 c of the cap member 141 is rotatably supported by the support portion 140 a of the drive side bearing 140. Further, a passive claw 141a is provided on the driving side end of the cap member 141, and is configured to receive a driving force from the developing sleeve gear 139 supported in the first holder unit 26 (see FIG. 13).

Subsequently, a configuration in which the developing sleeve unit 31 is supported in the developing unit 20 will be described with reference to FIG.

As shown in FIG. 13, on the driving side of the developing sleeve unit 31, the first boss 26c and the second boss 26d of the first holder unit 26 form the supported holes 140b and 140c of the driving side bearing 140 of the developing sleeve unit 31. Supports through. Then, the first boss 26c and the second boss 26d are inserted into the first hole 30a and the second hole 30b of the developing container unit 30, respectively. As a result, the developing container unit 30, the driving side bearing 140, and the first holder unit 26 are integrally connected. Further, the developing sleeve gear 139 is rotatably supported by fitting the inner diameter portion 139a with the support portion 26b of the first holder unit 26. The developing sleeve gear 139 is provided with a driving pawl 139b, which engages with the passive pawl 41a when the developing sleeve unit 31 is assembled, and the drive can be transmitted from the developing sleeve gear 139 to the developing sleeve unit 131. ing.

As described above, according to this embodiment, both sides of the developing sleeve unit 31 in the longitudinal direction are supported by the drive side bearing 140 which is the first bearing member and the conductive bearing member 37 which is the second bearing member. Further, the developing sleeve unit 31 is connected to the developing container unit 130 by the driving side bearing 140. Further, the drive side bearing 140 rotatably supports the developing sleeve 32 between the spacing member 38 and the passive pawl 41a in the longitudinal direction of the developing sleeve 32. For this reason, in this embodiment, the distance h2 from the support portion that rotatably supports the driving side of the developing sleeve 32 to the spacing member 38 in the longitudinal direction of the developing sleeve 32 is the distance h1 shown in FIG. 7C. Can be shortened compared to.

In this embodiment, the support portion that rotatably supports the drive side of the developing sleeve 32 is the drive side bearing 140, and the distance h2 is the distance from the drive side spacing member 38 to the drive side bearing 140. On the other hand, in the above-described embodiment, as shown in FIG. 7C, the supporting portion that rotatably supports the driving side of the developing sleeve 32 is the first holder unit that supports the supporting portion 39a of the developing sleeve gear 39. Is. The distance h1 is the distance from the spacing member 38 on the drive side to the support portion 39a supported by the first holder unit.

As described above, in this embodiment, in the longitudinal direction of the developing sleeve 32, the distance h2 from the supporting portion that rotatably supports the driving side of the developing sleeve 32 to the spacing member 38 is shown in FIG. 7C. It can be made shorter than the distance h1. As a result, when the spacing member 38 is brought into contact with the drum 62 by the urging force of the pressure spring 25 that is the urging member, the deflection of the developing sleeve can be further suppressed as compared with the first embodiment. As a result, the relative position between the developing sleeve 32 and the magnetic seal 35 (the gap 35i shown in FIG. 1C) can be determined with higher accuracy, and the toner sealing performance of the magnetic seal 35 can be further improved. it can.

[Other Examples]
In the above-described embodiment, the process cartridge having the developing unit and the cleaning unit as the developing device is illustrated, but the present invention is not limited to this. The present invention can be applied to a developing cartridge having a developing sleeve and an apparatus main body in which the developing cartridge is detachable, and the same effect can be obtained.

Further, in the above-described embodiment, the configuration in which one removable cartridge is used in the main body of the image forming apparatus is illustrated, but the number of the cartridges used is not limited and may be appropriately set as necessary. ..

Further, in the above-described embodiment, the configuration in which the process cartridge including the photosensitive drum and the developing device is attachable to and detachable from the main body of the image forming apparatus is illustrated, but the invention is not limited to this. For example, it may be an image forming apparatus in which the respective constituent members such as a photosensitive drum and a developing device are incorporated, or an image forming apparatus in which the respective constituent members are detachable. The same effect can be obtained even when applied to the developing device in these image forming apparatuses.

Further, in the above-described embodiment, the printer is exemplified as the image forming apparatus, but the present invention is not limited to this. For example, the image forming apparatus may be another image forming apparatus such as a copying machine or a facsimile machine, or another image forming apparatus such as a multi-function machine that combines these functions. Alternatively, it may be an image forming apparatus that uses a sheet material carrier and sequentially transfers the toner images of the respective colors onto the sheet material carried by the sheet material carrier. Alternatively, it is an image forming apparatus that uses an intermediate transfer member, sequentially transfers the toner images of the respective colors onto the intermediate transfer member, and transfers the toner images carried on the intermediate transfer member to a sheet material all at once. Is also good. The same effect can be obtained by applying the present invention to the developing device in these image forming apparatuses.

A: Image forming apparatus body (apparatus body)
B... Process cartridge (cartridge)
T... Toner (developer)
20... Developing unit 22... Bottom member 23... Developing container 28... Toner supply chamber 23... Toner chamber 32... Developing sleeve (developer carrying member)
33... Sheet member 34... Magnet 35... Magnetic seal (seal member)
37... Bearing member 42... Developing blade (regulating member)
47... Cleaning member 62... Drum (electrophotographic photosensitive drum)

Claims (11)

A developer container containing the developer,
A developer carrying member carrying a developer,
A magnet member which is provided inside the developer carrier and has a magnetic pole portion in which a plurality of magnetic poles are arranged in the rotation direction of the developer carrier;
The developer container is provided so as to face the developer carrier at a distance, and regulates leakage of the developer from the longitudinal end of the developer carrier to the outside of the developer container. A seal member having a plurality of magnetic poles for
A regulating member for regulating the layer thickness of the developer by contacting the developer carrying member,
A developing device comprising:
In the direction from the end portion side in the longitudinal direction of the developer carrying member toward the center side, between the one end portion and the other end portion of the seal member, the end portion of the regulating member and the magnetic pole in the magnet member. A developing device, characterized in that the ends of the parts are arranged in that order. The seal member is, in a direction orthogonal to the rotation axis of the developer carrier, in a direction farther from the outer peripheral surface of the developer carrier than the inner surface provided along the outer peripheral surface of the developer carrier. The developing device according to claim 1, further comprising a notch portion which is notched and accommodates the regulating member in a non-contact manner. The seal member is
A magnet portion in which the plurality of magnetic poles are arranged along the outer peripheral surface of the developer carrier,
A non-magnet portion provided on a side surface of the magnet portion on the end side in the longitudinal direction of the developer carrier,
The developing device according to claim 2, wherein the cutout portion is provided on a side of the magnet portion opposite to the non-magnet portion in a longitudinal direction of the developer carrying member. The developing device further includes a cleaning member that comes into contact with an end portion in the longitudinal direction of the developer carrying member and scrapes the developer back from the end portion side in the longitudinal direction to the center side.
4. An end face on the inside of the cleaning member and an end face on the outside of the regulation member face each other with a gap in the longitudinal direction of the developer carrying member. The developing device according to 1. In the cleaning member, the contact portion in contact with the developer carrier is closer to the center in the longitudinal direction than to the end portion in the longitudinal direction of the developer carrier, and the rotation direction of the developer carrier. 5. The developing device according to claim 4, wherein the developing device is inclined with respect to the rotation axis of the developer carrying member so as to come into contact with the downstream side of the developing device. The developing device according to claim 4, wherein an inner end of the cleaning member is located inside an end of a magnetic pole portion of the magnet member in a longitudinal direction of the developer carrying member. The magnetic pole part in which the plurality of magnetic poles are arranged in the magnet member is a thick shaft part having a larger diameter than the ends on both sides in the longitudinal direction. The developing device according to 1. An interval holding member provided on the developer carrying member, abutting against the image carrying member by the urging force of the urging member, and forming a gap between the developer carrying member and the image carrying member,
A receiving portion which is provided on one end side in the longitudinal direction of the developer carrier and receives a driving force;
A first bearing member that is connected to the developer container and rotatably supports one end portion in the longitudinal direction of the developer carrier;
A second bearing member that rotatably supports the other end portion in the longitudinal direction of the developer carrier,
Equipped with
8. The first bearing member rotatably supports the developer carrier between the spacing member and the receiving portion in the longitudinal direction of the developer carrier. The developing device according to any one of 1. A process cartridge having an image carrier and a process unit acting on the image carrier, the process cartridge being detachable from an image forming apparatus,
A process cartridge comprising the developing device according to claim 1 as the process means. An image forming apparatus for forming an image on a sheet material, comprising: an image bearing member; and a process unit acting on the image bearing member,
An image forming apparatus comprising the developing device according to claim 1 as the process unit. A developer container containing the developer,
A developer carrying member carrying a developer,
The developer container is provided so as to face the developer carrier at a distance, and regulates leakage of the developer from the longitudinal end of the developer carrier to the outside of the developer container. A seal member having a plurality of magnetic poles for
A regulating member for regulating the layer thickness of the developer by contacting the developer carrying member,
A cleaning member that comes into contact with the longitudinal end of the developer carrier and scrapes the developer back from the longitudinal end toward the center.
A developing device comprising:
In the direction from the end portion side in the longitudinal direction of the developer carrying member toward the center side, between the one end portion and the other end portion of the seal member, the center side end portion of the cleaning member, the regulation member And an end portion of the developing device are arranged in this order.

Images