JP2008299030A - Magnetic seal member, developing device and process cartridge - Google Patents

Abstract

Provided is a magnetic seal member that prevents uneven density of toner caused by an excessive contact force between a developing blade and a developing roller, and can obtain a uniform image density.
An overhanging portion 10r22 of a magnetic seal member 10r is provided in a developing chamber 10i to secure a sealing property of a clearance between a seal long end surface 10r8 and a rubber member 10e2 of a developing blade 10e to prevent toner leakage. As a result of the assembly, the protruding portion 10r21 of the magnetic seal member 10r is positioned in the developing chamber 10i, the protruding portion 10r25 bites into the rubber member 10e2 of the developing blade 10e, and the magnetic seal member 10r receives an elastic reaction force from the rubber member 10e. Then, the circumscribed surface 10r4 is pressed against the mounting arc portion 10f14 to position the first developing frame body 10f1 and the second developing frame body 10f2. The opposing surface of the overhanging portion 10r22 and the rubber member 10e2 of the developing blade 10e are not in contact with each other, and the contact pressing force with the developing roller 10d does not increase even at the end portion, and a uniform image density can be ensured in the longitudinal direction.
[Selection] Figure 6

Description

  The present invention relates to a developing device and a process cartridge installed in an electrophotographic image forming apparatus, and more particularly to a magnetic seal member that is mounted on the developing device and a process cartridge to prevent developer leakage. Here, the electrophotographic image forming apparatus is an apparatus for forming an image on a recording medium using an electrophotographic image forming system, and an electrophotographic copier, an electrophotographic printer such as a laser printer or an LED printer, a factory device, a word processor, And multifunctional multifunction devices are included. The process cartridge refers to a cartridge in which at least the developing means and the electrophotographic photosensitive member are integrated into a cartridge and can be attached to and detached from the main body of the electrophotographic image forming apparatus. Hereinafter, such an electrophotographic image forming apparatus is simply referred to as an “image forming apparatus”.

  In an image forming apparatus using an electrophotographic image forming process, a process cartridge in which an electrophotographic photosensitive member and a process unit acting on the electrophotographic photosensitive member are integrally formed into a cartridge can be attached to and detached from the image forming apparatus main body. The method is adopted. According to the process cartridge system, the maintenance of the apparatus can be performed by the user himself / herself without relying on a service person, so that the operability can be remarkably improved, and the use of the image forming apparatus is increasing.

  On the other hand, a developing device provided in a process cartridge is equipped with a developing roller as a developer carrying member that carries and rotates a developer (hereinafter referred to as “toner”). Seal members are attached to both ends of the developing roller to prevent the toner from leaking out of the developing area.

  Up to now, elastic members such as felt and foamed rubber have been frequently used as the material of the seal member. However, a magnetic seal member having an inner peripheral surface magnetized to N and S poles has come to be used. As for the magnetic seal member, for example, there is a magnetic seal member described in Patent Document 1 previously proposed by the present applicant. In this case, the developer carrying member such as the developing roller is mounted in a non-contact manner with a certain clearance, and the developer leaks due to the concentrated magnetic field formed between the magnet and the magnetic seal member in the developing roller. I try to prevent getting out. Similarly, the present applicant has also proposed a magnetic seal member in Patent Documents 2, 3, 4, 5, etc., but here, the magnetic seal member disclosed in Patent Document 1 is represented as an outline. This will be described with reference to FIGS.

  As shown in FIG. 17, the developing device D includes a developing roller 10d and a developing blade 10e that is a developer regulating means. A rubber member 10e2 as an elastic member is attached to the developing blade 10e so as to be held by the sheet metal portion 10e1 over almost the entire length in the longitudinal direction, and contacts the surface of the developing roller 10d to evenly level the toner. FIG. 18 shows an assembled state of the developing roller 10d and the developing blade 10e. In the developing blade 10e, a magnetic seal member 10r is mounted with a required clearance g2 between the outer peripheral surface of the developing roller 10d at a position where both ends of the sheet metal portion 10e1 overlap from the outside. On the inner peripheral surface of the magnetic seal member 10r facing the outer peripheral surface of the developing roller 10d, a magnetic brush is formed in the clearance g2 by magnetic poles provided in the circumferential direction of the developing roller 10d. By forming the magnetic brush, the toner is prevented from flowing out of the developing area from the end of the developing roller 10d.

  As shown in FIGS. 19A to 19C, the magnetic seal member 10r is brought into contact with both end faces 10r8 and 10r9 in the width direction, and the first developing frame 10f1 shown in FIGS. 21A to 21C. Are inserted between the positioning surfaces 10f15 and 10f16. As a result, both end surfaces 10r8, 10r9 on the magnetic seal member 10r side and the positioning surfaces 10f16, 10f15 on the first developing frame 10f1 face each other, and the magnetic seal member 10r is positioned in the width direction. That is, by inserting the seal end surface into the frame body positioning surface, the circumscribed surface 10r4 contacts the mounting arc portion 10f14, and the contact end surface 10r6 abuts against the mounting end surface 10f25 of the second developing frame 10f2.

  Also, as shown in FIGS. 20A and 20B, a seal member 10s (see FIG. 17) is attached to the contact surface 10r5 of the magnetic seal member 10r by an adhesive means such as a double-sided tape. The seal member 10s prevents the toner from leaking from both ends of the rubber member 10e2 of the developing blade 10e. That is, the seal member 10s is attached to the developing chamber wall 10f31 of the first developing frame 10f1 shown in FIG. 21A, and the developing blade 10e is fixed to the first developing frame 10f1 with a stop screw.

  Further, as shown in FIGS. 19A to 19C and FIGS. 22A and 22B, the urging member 30 is compressed between the sheet metal portion 10e1 of the developing blade 10e and the contact surface 10r5. And is held. By compressing and clamping in this manner, the urging force of the urging member 30 acts on the contact surface 10r5, and the outer contact surface 10r4 and the mounting arc portion 10f14, and the contact end surface 10r6 and the mounting end surface 10f25 are securely in contact with each other. Positioning in the circumferential direction is performed.

JP 2005-242253 A JP 2001-134082 A JP-A-11-143225 JP-A-11-133742 JP 2000-155466 A

  By the way, in the case of a magnetic seal member including the one disclosed in Patent Document 1, the following points are desired to be improved.

  In order to prevent the toner from flowing out from the end portion of the rubber member 10e2 of the developing blade 10e, the elastic seal member 10s is brought into contact with the end portion in the longitudinal direction of the rubber member 10e2, and the clearance d1 is closed and filled. Therefore, the pressing force with which the rubber member 10e2 of the developing blade 10e abuts against the developing roller 10d becomes higher than the other portions, which causes toner adhesion unevenness (spots) on the developing roller 10d, and the density of the image. May appear as uneven or foggy. In order to reduce the pressing force to the developing roller 10d, an elastic seal member 10s having a small elastic reaction force is used, or a variation in the amount of biting between the elastic seal member 10s and the rubber member 10e2 is reduced, and the end portion Ingenuity has been made to minimize the increase in pressing force in the case.

  Therefore, the object of the present invention is a further development of the prior art, and prevents unevenness in the toner density caused by excessive contact force between the developing blade and the developing roller, thereby obtaining a uniform image density. An object of the present invention is to provide a magnetic seal member.

  Another object of the present invention is to provide a developing device and a process cartridge to which such a magnetic seal member is attached.

  To achieve the above object, a representative magnetic seal member of the present invention includes a developing frame, a developer carrying member that carries the developer and is attached to the developing frame, and regulates the amount of the developer. A magnetic material sealing member for preventing leakage of the developer from between the developer frame and the developer carrier in a developing device comprising: A seal member main body having an inner peripheral surface facing the outer peripheral surface of the body, and an opposing surface that protrudes from the seal member main body to the inside in the longitudinal direction of the developer carrying member and faces the developer chamber, and faces the developer regulating means And an overhanging portion having the above.

  According to the magnetic seal member of the present invention, the sealability between the developing frame and the developer carrying member (developing roller) is ensured to prevent the developer from leaking out of the developing region. In addition, a protruding portion is provided on the seal member main body of the magnetic seal member so as to protrude inward in the longitudinal direction of the developer carrying member and face the developing chamber. The overhanging portion prevents the developer regulating means [the rubber member (elastic member) of the developing blade) from coming into contact with the developer carrying member with an excessive force, thereby preventing the occurrence of uneven developer density. Thereby, a uniform image can be obtained.

  Hereinafter, preferred embodiments of a magnetic seal member, a developing device, and a process cartridge according to the present invention, and preferred embodiments of an image forming apparatus including these devices will be described with reference to the drawings. In addition, in order to clarify the difference with patent document 1, the description which attaches | subjects the same code | symbol to what is common to the member shown by FIGS. Is given a new code.

  First, the term “longitudinal direction”, which is a term used in the following description and refers to a process cartridge and related members, refers to a direction (image carrier) perpendicular to a direction in which the process cartridge can be attached to and detached from the image forming apparatus main body. Axis direction). That is, it is also a direction orthogonal to the sheet conveying direction for conveying a recording medium such as plain paper, recording sheet, OHP sheet, etc. (hereinafter referred to as “sheet”). The “left and right” of the process cartridge means the left side and the right side of the sheet as viewed from above along the sheet conveyance direction. In addition, the “upper surface” of the process cartridge refers to a surface located above in a state where the process cartridge is mounted on the main body of the image forming apparatus, and the lower surface refers to a surface located below.

(Image forming device)
FIG. 1 shows a laser beam printer as a specific example of the image forming apparatus A. In this laser beam printer, for example, information light based on image information is irradiated from an exposure device 1 of an optical means to a photosensitive drum 7 which is an electrophotographic photosensitive member, and this photosensitive drum 7 is used as an image bearing member and is statically applied to the drum surface. An electrostatic latent image is formed and carried. The electrostatic latent image is developed using a magnetic developer (toner) to form a toner image on the photosensitive drum 7.

  In synchronization with the formation of the toner image, the sheets 2 are separated and fed one by one from the cassette 3a by the pickup roller 3b and the pressure contact member 3c that is in pressure contact therewith. The sheet 2 is guided and conveyed by the conveyance guide 3f1, and is sent to the photosensitive drum 7 provided as an image carrier in the process cartridge B. The conveying means 3 includes the pickup roller 3b, the press contact member 3c, the discharge roller 3d, and the like. In the photosensitive drum 7, the toner image on the drum is transferred to the sheet 2 by applying a bias voltage to the transfer roller 4 that is a transfer unit. The sheet 2 on which the toner image has been transferred is guided by the conveyance guide 3 f 2 and sent to the fixing unit 5.

  The fixing unit 5 includes a driving roller 5a and a fixing rotating body 5d formed of a cylindrical sheet that includes a heater 5b and is rotatably supported by a support 5c. Pressure is applied to fix the transferred toner image. After fixing, the sheet 2 is discharged to the discharge unit 6 by the discharge roller 3d.

(Process cartridge)
Next, as shown in FIG. 2 as a single unit, the process cartridge B of the present embodiment includes the photosensitive drum 7 and developing means for developing at least the electrostatic latent image formed on the photosensitive drum 7. Configured.

-Photosensitive drum-
The photosensitive drum 7 having a photosensitive layer is rotatably supported. By applying a charging bias voltage to the charging roller 8 constituting the charging means, the surface of the photosensitive drum 7 is uniformly charged. Information light (light image) based on image information from the exposure device 1 is exposed to the charged photosensitive drum 7 through the exposure opening 9 b, and an electrostatic latent image is formed on the surface of the photosensitive drum 7. The electrostatic latent image is developed using the developing means 10 in the next developing device D.

-Developer-
2 and 3, the developing device D incorporated in the process cartridge B includes a first developing frame 10f1, a second developing frame 10f2, and an end member 10g that form a toner storage portion 10a. Further, the developing device D has a developing roller 10d as a developer carrying member as one of the main parts of the developing means 10, and includes parts for supplying power to the developing roller 10d. Further, the developing device D has a developing blade 10e that is a developer regulating member that regulates the toner layer thickness on the developing roller 10d, and further prevents the toner from leaking from both ends of the developing roller 10d. It has a sealing member 10r and the like. The developing blade 10e is attached with a rubber member (elastic member) 10e2 with a length almost in the entire length in the longitudinal direction.

  In the developing device D, the toner accommodated in the toner accommodating portion 10a is sent out by rotating the feeding member 10b serving as toner feeding means. Further, the developing roller 10d of the developer carrying member, which is also a developing rotating member incorporating the fixed magnet 10c, is rotatably supported. A toner layer imparted with triboelectric charge by a developing blade 10e as a developer regulating member is formed on the surface of the developing roller 10d, and the toner is transferred to the photosensitive drum 7 in accordance with the electrostatic latent image, whereby a toner image is obtained. To form a visible image.

  The first developing frame member 10f1 is pivotally supported by the cleaning frame member 11d in a state where the developing roller 10d is opposed to the drum peripheral surface of the photosensitive drum 7 with a predetermined clearance with the rotation axis parallel. Has been. In addition, spacers 10m for holding a clearance with the photosensitive drum 7 are attached to both ends of the developing roller 10d.

  Further, as shown in FIG. 3 in which the entire developing device D is disassembled, holders 10g having arm portions 10g7 are provided on both side surfaces of the first developing frame 10f1. The arm portion 10g7 has a coupling hole 10g8 for rotatably supporting the cleaning device C described below. Further, the toner storage portion 10a and the developing chamber 10i are formed by coupling a first developing frame 10f1 and a second developing frame 10f2 constituting a developing frame. The first developing frame 10f1 is provided with a toner passage port (not shown) through which the toner stored in the toner storage portion 10a passes when supplied to the developing roller 10d. Further, a toner seal member 27 is heat-fitted and fixed to the seal mounting portion along the four edges of the toner passage opening. Further, as shown in FIG. 3, a toner filling port 10u for filling the toner storage portion 10a with a toner is provided at one end in the longitudinal direction of the first developing frame 10f1, and the cap member 10j is filled with the toner after filling the toner. Sealed.

  Accordingly, the toner in the toner storage portion 10a is sent out by the feeding member 10b, and a toner layer is formed and supplied to the developing roller 10d by the magnetic force of the fixed magnet 10c. As a result, a developing bias voltage is applied, and the electrostatic latent image formed on the photosensitive drum 7 is developed with toner to form a visible image. The visualized toner image is transferred to the sheet 2 by applying a voltage having a polarity opposite to that of the toner image to the transfer roller 4. The configuration of the toner seal at the end in the longitudinal direction of the developing roller 10d will be described later.

-Cleaning device-
Next, the cleaning device C will be described with reference to FIG. The toner image developed by the developing means 10 is transferred to the sheet 2 at the transfer portion, and the toner remaining on the photosensitive drum 7 after the transfer is scraped off and removed by the cleaning blade 11 a of the cleaning means 11. The residual toner scooped up by the scooping sheet 11b is collected in the removed toner storage portion 11c. Further, the cleaning unit 11 includes a first seal member (not shown) that prevents the toner from leaking from the back sides of both ends of the cleaning blade 11a of the removed toner storage portion 11c. In addition, the cleaning unit 11 includes a second seal member 11h that prevents the toner from flowing out to the back side of the cleaning blade 11a. The second seal member 11h is fixed and fixed to a predetermined position of the cleaning frame 11d with a double-sided tape or the like. The cleaning blade 11a is fixed to a predetermined position of the cleaning frame 11d with a fastening screw. Further, the scooping sheet 11b, which is a scooping member, is fastened and fixed to the cleaning frame 11d with a double-sided tape 11g or the like. The cleaning frame body 11 d supports the cleaning unit 11, the photosensitive drum 7, the drum shutter 12, and the charging roller 8.

  The drum shutter 12 is rotatably provided on the cleaning frame 11 d and covers and closes the transfer opening 9 a of the photosensitive drum 7 facing the transfer roller 4. The drum shutter 12 has a drum protection portion 12a that covers a transfer opening 9a for the photosensitive drum 7 to come into contact with the transfer roller 4. The drum shutter 12 is arranged in a direction to cover the photosensitive drum 7 with an urging spring (not shown). The shutter 12 is energized. Accordingly, the drum shutter 12 covers and closes the transfer opening 9a of the photosensitive drum 7 while the process cartridge B is taken out from the image forming apparatus main body. When the process cartridge B is mounted in the image forming apparatus main body and an image forming operation is possible, the image forming apparatus A is rotated by the drum shutter opening / closing means provided on the image forming apparatus A side to expose the transfer opening 9a to expose the photosensitive drum 7. The posture is such that the transfer roller 4 can come into contact.

  As described above, the process cartridge B of the present embodiment includes the photosensitive drum 7, the cleaning frame 11d that rotatably supports the photosensitive drum 7, and the developing frame that houses the developing device D that develops the electrostatic latent image. The body 10f1, 10f2, etc. are provided. Incidentally, a predetermined pressure is applied between the developing frame members 10f1 and 10f2 and the cleaning frame member 11d in order to maintain a gap.

(Magnetic seal member: first embodiment)
Next, with reference to FIG. 4 to FIG. 6, a seal structure that secures a required sealing property in the developing device D and prevents toner leakage with respect to the magnetic seal member that is the gist of the present invention will be described. .

  As shown in FIGS. 4A to 4C, the magnetic seal member 10r of the first embodiment has a magnet 10r1, and is made of a magnetic material on the side surface in the longitudinal direction of the developing roller 10d and in the width direction of the magnet 10r1. A magnetic plate 10r2 is joined. As the magnet 10r1, for example, an injection molded product having a width of 2.5 mm provided with a nylon binder containing Nd—Fe—B magnetic powder can be used. The magnetic plate 10r2 joined to the side surface of the magnet 10r1 is made of an iron material having a thickness of 0.5 mm, and both are joined by injection molding insert molding. The seal member body of the magnetic seal member 10r is provided with a semicircular inner peripheral surface 10r3 that forms a clearance g2 between the developing roller 10d and the inner peripheral side facing the developing roller 10d. . A semicircular arc-shaped circumscribed surface 10r4 in contact with the first developing frame body 10f1 and the second developing frame body 10f2 is formed on the outer peripheral side located opposite to the inner peripheral surface 10r3. The outer peripheral surface has a concave groove 10r23 that avoids the rib of the first developing frame 10f1, and the groove 10r23 is provided with a wall surface 10r12 for positioning the magnetic seal member 10r in the longitudinal direction.

  Further, the magnetic seal member 10r is provided with a contact end surface 10r6 that contacts the second developing frame 10f2 at the lower end position of the seal member body, and is opposite to the contact end surface 10r6 across the inner peripheral surface 10r3. Has an end face 10r19. Further, end faces 10r8 and 10r9 for positioning with the first developing frame body 10f1 are provided on both sides of the seal member body in the width direction (longitudinal direction of the developing roller 10d). The end faces 10r9 on both sides are end faces on the magnetic plate 10r2 side, and the end face 10r8 on one side is the opposite side and the end face on the developing chamber 10i (see FIG. 2) side. From one end surface 10r8, a projecting portion 10r21 is provided so as to project from a portion opposite to the contact end surface 10r6 of the seal member body, facing the developing chamber 10i. The overhanging portion 10r21 is provided with a facing surface 10r22 facing the rubber member 10e2 of the developing blade 10e, and a protruding portion 10r25 and an upper end surface 10r24 are provided extending upward from the facing surface 10r22.

  5 and 6 show a structure for attaching the magnetic seal member 10r to the first developing frame 10f1. 5A and 5B, the magnetic seal member 10r is attached in a state where the first developing frame 10f1 and the second developing frame 10f2 are coupled. In order to facilitate understanding of the attachment end surface 10f25, only the second developing frame 10f2 is shown in FIG. 5B, and the first developing frame 10f1 is not shown. 6 (a) and 6 (b), FIG. 6 (a) shows a part of the developing blade 10e cut for convenience of explanation. The outline before cutting is indicated by a two-dot chain line. Further, the developing roller 10d and the holder 10g in the unit state are omitted. FIG. 6B is a diagram showing a state where the rubber member 10e2 of the developing blade 10e is bent toward the developing chamber 10i when the developing roller 10d is attached.

  The magnetic seal member 10r is positioned with respect to the first developing frame 10f1 and the second developing frame 10f2. The positioning surface 10f15 of the first developing frame 10f1, the end surface 10r9 on one side in the width direction of the magnetic seal member 10r, and the wall surface 10r12 of the positioning surface 10f16 on the outer side in the longitudinal direction of the rib 10f39 are inserted so as to face each other. . However, although there is a minute clearance between the positioning surface, the end surface, and the wall surface, relative movement in the width direction of the seal member can be restricted within an allowable range.

  After the insertion, the circumscribed surface 10r4 is brought into contact with the mounting arcuate portion 10f14 of the first developing frame 10f1, and the abutting end surface 10r6 is abutted against the mounting end surface 10f25 of the second developing frame 10f2 to be temporarily stopped. Further, the developing blade 10e is fixed to the first developing frame 10f1 with a screw (see FIG. 3). The projecting portion 10r21 of the magnetic seal member 10r projects to the inside of the developing roller 10d in the longitudinal direction and faces the developing chamber 10i. Then, the protruding portion 10r25 protruding from the overhanging portion 10r21 bites into the rubber member 10e2 of the developing blade 10e.

  Due to the biting into the rubber member 10e2, the magnetic seal member 10r receives a repulsion (elastic reaction force) due to the elastic force from the rubber member 10e and generates a force to rotate in the direction of arrow A in FIG. The surface 10r4 is pressed against the mounting arc portion 10f14. At the same time, the contact end face 10r6 is pressed against the attachment end face 10f25 of the second developing frame 10f2. Since the contact end face 10r6 and the attachment end face 10f25 are set to bite in, the seal member body of the magnetic seal member 10r is surely against the development frame body composed of the first development frame body 10f1 and the second development frame body 10f2. Is positioned.

  Note that the end surface 10r19 is not in contact with the sheet metal portion 10e2 of the developing blade 10e, and has a distance at which no leakage can occur between the sheet metal portion 10e2 and the magnetic seal member 10r (not shown). Further, since the protruding portion 10r25 is set at a position overlapping the sheet metal portion 10e1 of the developing blade 10e, it does not affect the bending of the rubber member 10e2 of the developing blade 10e. Therefore, the pressing force due to the contact with the developing roller 10d at the end of the rubber member 10e2 does not increase more than necessary.

  When the developing roller 10d is attached in this manner, as shown in FIG. 6B, the rubber member 10e2 of the developing blade 10e bends toward the developing chamber 10i, but there is a clearance between the bent rubber member 10e2. The shape of the facing surface 10r22 is set so that d3 can be maintained. The upper end surface 10r24 is provided with a clearance d4 with respect to the ceiling 10f32 on the developing chamber side in consideration of the assembly of the magnetic seal member 10r. In addition, the members do not interfere with each other between the longitudinal end face 10r8 of the magnetic seal member 10r and the rubber member 10e2 in consideration of manufacturing variations of the developing frame 10f1, the magnetic seal member 10r, and the developing blade 10e. A clearance d1 is provided. A clearance g2 is provided between the inner peripheral surface of the magnetic seal member 10r and the outer peripheral surface of the developing roller 10d.

  From the above, the magnetic seal member of the first embodiment has an effect by acting as follows.

  The magnet 10r1 is magnetized with a plurality of N poles and S poles, and magnetic brush spikes are formed in the clearance g2 between the developing roller 10d and the minute clearances between the circumscribed surface 10r4, the positioning surface 10f16, and the recess 10f17. This prevents the toner from leaking from the end of the developing roller 10d. In the case of this embodiment, the clearance g2 is set to 0.1 to 0.7 mm, and the magnetic flux density due to the magnetic force of the magnetic seal member 10r at that time is about 1000 to 2000 Gs on the developing roller 10d. Similarly, spikes of magnetic brushes are formed in the clearances d1, d3, and d4 to prevent toner leakage from each clearance.

  Further, the toner leakage path is blocked by a rib 10f3 having a thin tip that bites into the rubber member 10e2 of the developing blade 10e. Accordingly, the sealing performance is ensured at portions other than the longitudinal end of the rubber member 10e2 of the developing blade 10e to which the magnetic force of the magnetic seal member 10r does not reach, and the toner does not leak from above the developing chamber 10i.

  Further, an overhanging portion 10r22 of the magnetic material sealing member 10r is provided facing the developing chamber 10i. Thereby, the sealing performance of the clearance between the end surface 10r8 on one side in the width direction of the magnetic seal member 10r and the rubber member 10e2 of the developing blade 10e can be ensured, and toner leakage can be prevented.

  Further, since the opposing surface 10r22 and the rubber member 10e2 of the developing blade 10e are arranged in a non-contact manner, the pressing force that contacts the developing roller 10d at the end of the developing blade 10e does not increase excessively and is uniform in the longitudinal direction. A high image density.

  Further, since the protrusion 10r25 bites the rubber member 10e2 of the developing blade 10e to obtain a repulsion due to an elastic force, that is, an elastic reaction force, thereby biasing and positioning the magnetic seal member 10r, FIG. The urging member 30 shown by is unnecessary. At the same time, it is not necessary to provide the urging member contact surface 10r5 shown in FIG. 20, which is a seating surface for attaching the urging member 30. Therefore, since the space where the urging member contact surface 10r5 is reduced and the space where the protruding portion 10r21 is provided are substantially the same, the component unit price of the magnetic seal member 10r does not increase.

  As described above, the conventionally used elastic seal member 10s and the biasing member 30 can be reduced, and the member cost and the assembling cost can be reduced accordingly.

  In the case of the magnetic seal member of the first embodiment, the development frame 10f has been described as having two frames, the first development frame 10f1 and the second development frame 10f2. It is not limited to a frame, and a single frame is possible as long as the target effect is obtained. Moreover, although the protrusion part 10r25 was demonstrated with the mountain-shaped elongate shape, it is not this limitation. In view of the elastic force of the rubber member 10e2 of the developing blade 10e and the intrusion amount between the protruding portion 10r25 and the rubber member 10e2, any shape may be used as long as it receives an appropriate repulsive force from the developing blade rubber member 10e2. As shown in FIGS. 16A and 16B, for example, the shape may be a needle-like protrusion 10r27 having a sharp tip or a planar protrusion 10r28 having a flat surface at the tip.

(Magnetic seal member: second embodiment)
Next, 2nd Embodiment of a magnetic body sealing member is described with reference to each figure of FIGS.

  As shown in FIGS. 7A and 7B, in the magnetic seal member 10r of the second embodiment, a magnetic plate 10r2 made of a magnetic material is joined to the side surface in the width direction of the magnet 10r1. The magnetic seal member 10r has a semicircular arc-shaped inner peripheral surface 10r3 that forms a clearance g2 with the developing roller 10d on the inner peripheral side, and a clearance g3 with the developing device frame 5 on the outer peripheral side. A semicircular arc portion 10r14 and a semicircular arc portion 10r15 are formed. Further, a mounting hole (through hole) 10r16 concentric with the semicircular arc part 10r15 is formed in the seal member main body of the magnetic seal member 10r at a portion opposite to the inner peripheral surface 10r3, and development is performed with the through hole as a rotation center. It is rotatably coupled to the frame. The outer peripheral surface has a concave groove 10r23 that avoids the rib of the first developing frame 10f1, and the groove 10r23 is provided with a wall surface 10r12 for positioning the magnetic seal member 10r in the longitudinal direction. Furthermore, an end face 10r19 is provided on the opposite side of the contact end face 10r6 with the contact end face 10r6 in contact with the second developing frame 10f2 and the inner peripheral face 10r3 interposed therebetween.

  Further, end faces 10r8 and 10r9 are provided at both ends in the width direction for positioning with the first developing frame 10f1. One end face 10r9 is the end face on the magnetic plate 10r2 side, and the other end face 10r8 is the opposite face to the developing chamber 10i side shown in FIG. A projecting portion 10r21 projecting from the end surface 10r8 toward the developing chamber 10i is disposed. The projecting portion 10r21 has a facing surface 10r22 facing the developing chamber 10i side of the rubber member 10e2 of the developing blade 10e, an upper end surface 10r24, and a protruding portion 10r25 protruding from the facing surface.

  FIGS. 8-10 shows the attachment state of the magnetic body sealing member 10r by this embodiment. As shown in FIGS. 8A to 8C, the magnetic seal member 10r is attached in a state where the first developing frame 10f1 and the second developing frame 10f2 are coupled. For ease of understanding, the attachment end surface 10f25 is illustrated with only the second developing frame 10f2 in FIG. 8C, and the first developing frame 10f1 is omitted. FIG. 9 shows a method of attaching the holder 10g, FIGS. 10A and 10B show a part of the developing blade 10e cut for convenience of explanation, an outline before cutting is shown by a two-dot chain line, and a unit state The developing roller 10d and the holder 10g are omitted. FIG. 10B is a reproduction of the state where the rubber member 10e2 of the developing blade 10e is bent toward the developing chamber 10i when the developing roller is attached.

  Therefore, the magnetic seal member 10r is positioned with respect to the first developing frame 10f1 and the second developing frame 10f2. The first developing frame 10f1 is inserted so that the positioning surface 10f15 and the longitudinal end surface 10r9 of the magnetic seal member 10r and the positioning surface 10f16 and the wall surface 10r12 on the outer side of the rib 10f39 face each other. Although there is a minute clearance between the positioning surface, the longitudinal end surface, and the wall surface, relative movement in the longitudinal direction can be restricted within an allowable range.

  The positioning surface 10f15 has a through hole 10f40 into which a positioning boss provided on an end member 10g described later is inserted. After the insertion, the semicircular arc portions 10r14 and 10r15 are attached to the mounting arcuate portions 10f14 and 10f18 of the first developing frame 10f1, and the abutting end surface 10r6 is attached to the mounting end surface 10f25 of the second developing frame 10f2. Contact by its own weight. Further, the developing blade 10e is fixed to the first developing frame 10f1 with a screw (see FIG. 3).

  Next, by temporarily positioning the developing roller 10d on the developing frame 10f, the holder 10g shown in FIG. 9 is assembled to the developing frame 10f. The positioning boss 10g10 of the holder 10g is inserted into the through hole 10f40 and is inserted into the mounting hole 10r16 of the magnetic seal member 10r. Since the mounting hole 10r16 and the through hole 10f40 and the positioning boss 10g10 are set to have a fitting relationship, the mounting hole 10r16 is positioned when the assembly of the holder 10g is completed.

  10A and 10B show the fixed state of the magnetic seal member 10r and the configuration of the SLV end. The protruding portion 10r21 of the magnetic seal member 10r is located inside the developing chamber 10i. The magnetic seal member 10r is supported by a positioning boss 10f35 so as to be rotatable around the mounting hole 10r16. By setting the protruding portion 10r25 protruding from the overhanging portion 10r21 to bite into the rubber member 10e2 of the developing blade 10e, the magnetic seal member 10r is repelled by the elastic force from the rubber member 10e. Due to this elastic reaction force, a rotational force is generated in the magnetic seal member 10r in the direction indicated by the arrow A in FIG. When the rotational force is generated, the contact end surface 10r6 is pressed against the mounting end surface 10f25 of the second developing frame 10f2, and the magnetic seal is surely positioned with respect to the developing frames (the first developing frame 10f1 and the second developing frame 10f2). To be made.

  Since the protrusion 10r25 is set at a position overlapping the sheet metal portion 10e1 of the developing blade 10e, it does not affect the bending of the rubber member 10e2 of the developing blade 10e. Therefore, the contact pressure with the developing roller 10d at the end of the developing blade rubber member 10e2 does not increase. Further, the end face 10r19 is not in contact with the sheet metal portion 10e2 of the developing blade 10e, and has a distance at which no leakage can occur between the sheet metal portion 10e2 and the magnetic seal member 10r. (Not shown). Further, as shown in FIG. 10B, when the developing roller 10d is attached, the rubber member 10e2 of the developing blade 10e bends toward the developing chamber 10i side, but the opposing surface so that the clearance d3 from the developing blade rubber member 10e2 can be held. The shape of 10r22 is determined.

  A clearance d4 is provided between the upper end surface 10r24 and the ceiling 10f32 of the developing chamber in consideration of the assembly of the magnetic seal member 10r. Further, a clearance d1 is provided between the longitudinal end surface 10r8 of the magnetic seal member 10r and the rubber member 10e2 of the developing blade 10e. The clearance d1 is set so that the developing frame 10f1, the magnetic seal member 10r, and the developing blade 10e do not interfere with each other due to manufacturing variations. A clearance g2 is also provided between the inner peripheral surface of the magnetic seal member 10r and the outer peripheral surface of the developing roller 10d, and the clearance g3 is maintained between the outer peripheral side and the developing device frame 5.

  On the other hand, the magnet 10r1 is magnetized with a plurality of NS poles, and a magnetic brush head is formed in the clearance g2 with the developing roller 10d to prevent toner leakage from the end of the developing roller 10d. In this embodiment, the clearance g2 is set to 0.1 to 0.7 mm, and the magnetic flux density by the magnetic force of the magnetic seal member 10r at that time is about 1000 to 2000 Gs on the developing roller 10d.

  From the above, the magnetic seal member of the first embodiment has an effect by acting as follows.

  Magnetic brush spikes are also formed in the clearances d1, d3, d4, and g3, and toner leakage from each clearance can be prevented. Further, the toner leakage path is blocked by a rib 10f3 having a thin tip that bites into the rubber member 10e2 of the developing blade 10e. Therefore, the toner does not leak from above the developing chamber 10i other than the longitudinal end portion of the developing blade rubber member 10e2 to which the magnetic seal member 10r does not receive the magnetic force.

  Further, by providing the protruding portion 10r22 of the magnetic seal member 10r in the developing chamber 10i, it is possible to prevent the toner from leaking from the clearance between the long end surface 10r8 of the magnetic seal member 10r and the developing blade rubber member 10e2. Further, since the facing surface 10r22 and the rubber member 10e2 of the developing blade 10e are arranged in a non-contact manner, the force that the end of the developing blade 10e abuts against the developing roller 10d does not increase more than necessary, and the longitudinal A uniform image density can be secured in the direction.

  As described above, the conventionally used elastic seal member 10s and the biasing member 30 can be reduced, and the member cost and the assembly cost can be reduced accordingly, so that a low-cost and high-quality one can be provided.

  Also in the magnetic seal member of the second embodiment, the structure in which the developing frame 10f is composed of two frames, the first developing frame 10f1 and the second developing frame 10f2, has been described. However, the present invention is not limited to this, and a single frame can be used as long as the target effect can be obtained. Moreover, although the protrusion part 10r25 was demonstrated with the mountain-shaped elongate shape, it is not this limitation. In view of the elasticity of the rubber member 10e2 of the developing blade 10e and the intrusion amount between the protruding portion 10r25 and the rubber member 10e2, any shape may be used as long as it receives an appropriate repulsive force from the developing blade rubber member 10e2. As shown in FIGS. 16A and 16B, for example, the shape may be a needle-like protrusion 10r27 having a sharp tip or a planar protrusion 10r28 having a flat surface at the tip.

(Magnetic seal member: third embodiment)
Next, a third embodiment of the magnetic seal member will be described with reference to FIGS.

  As shown in FIG. 11, a magnetic plate 10r2 made of a magnetic material is joined to the side surface in the width direction of the magnet 10r1 of the magnetic seal member 10r. From the longitudinal end surface 10r8, an overhanging portion 10r21 projecting toward the developing chamber 10i is disposed. The projecting portion 10r21 has a facing surface 10r22 facing the developing chamber 10i side of the rubber member 10e2 of the developing blade 10e, an upper end surface 10r24, and a protruding portion 10r25 protruding from the facing surface.

  The outer peripheral surface has a groove portion 10r23 that engages with a rib described later of the first developing frame 10f1, and the groove portion 10r23 is provided with a wall surface 10r12 for longitudinal positioning of the magnetic seal member 10r. The magnetic seal member 10r has a semicircular inner peripheral surface 10r3 that forms a clearance g2 between the magnetic seal member 10r and the developing roller 10d on the inner peripheral side (developing roller 10d side). Furthermore, an end face 10r19 is provided on the opposite side of the contact end face 10r6 with the contact end face 10r6 in contact with the second developing frame 10f2 and the inner peripheral face 10r3 interposed therebetween.

  An elastic lining 177 made of an elastic material such as rubber is applied to the outer peripheral side (back surface) located on the opposite side to the inner peripheral surface 10r3. The range of the elastic lining 177 is substantially equal to the width of the magnetic seal member 10r except for the overhanging portion 10r21 and the groove 10r23, and the upper end surface 177g of the elastic lining 177 is substantially the same as the end surface 10r19 of the magnetic seal member 171. In the same plane. The lower end includes a lower end surface 177f that is substantially flush with the frame body contact surface 10r6 of the magnetic seal member 10r and a lower end wrap portion 177h that wraps around the frame body contact end surface 10r9. The elastic lining 177 is attached to the back surface of the magnetic seal member 10r with a double-sided tape. The elastic lining 177 prevents the toner from leaking to the outside from between the magnetic seal member 10r and the developing frame 10f.

  Further, it has longitudinal end faces 10r8, 10r9 for positioning with the first developing frame 10f1. The longitudinal end face 10r9 is an end face on the magnetic plate 10r2 side, and the longitudinal end face 10r8 is the opposite side to the developing chamber 10i side shown in FIG.

  FIG. 12 and the subsequent drawings up to FIG. 15 show the attachment state of the magnetic seal member 10r. As shown in FIG. 12A, the magnetic seal member 10r is attached in a state where the first developing frame 10f1 and the second developing frame 10f2 are coupled. In order to understand the attachment end face 10f25, only the second developing frame 10f2 is shown in FIG. 12B, and the first developing frame 10f1 is omitted. 13 and 14 show the attachment of the magnetic seal member to the developing device frame. FIGS. 15A and 15B are diagrams illustrating the configuration of the end portion of the developing roller after the developing blade is attached. As shown in FIG. 15A, for convenience of explanation, a part of the developing blade 10e is cut, and the outline before the cutting is shown by a two-dot chain line. Further, the developing roller 10d and the end member 10g in the unit state are omitted. FIG. 15B is a diagram illustrating a state where the developing blade rubber member 10e2 is bent toward the developing chamber 10i when the developing roller is attached.

  Accordingly, as shown in FIGS. 12A and 12B, the magnetic seal member 10r is positioned with respect to the first developing frame 10f1 and the second developing frame 10f2. The first developing frame 10f1 is inserted so that the positioning surface 10f15 and the longitudinal end surface 10r9 of the magnetic seal member 10r, and the positioning surface 10f16 and the wall surface 10r12 on the outer side of the rib 10f39 face each other. Although there is a minute clearance between the positioning surface, the longitudinal end surface, and the wall surface, relative movement in the longitudinal direction can be restricted within an allowable range.

  Further, as shown in FIGS. 13A and 13B, the lining 177 of the magnetic seal member 10r is brought along the mounting arc portion 10f14 and lightly pressed, the lower portion 177a of the elastic lining 177 is compressed. Then, the frame contact end surface 10r6 of the magnetic seal member 10r is compressed on the mounting end surface 10f25, and the lower end turning portion 177h is compressed to press the mounting pressing end surface 10f41. The slope 10r26 of the upper end surface 10r24 of the magnetic seal member 10r is in contact with the developing chamber ceiling 10f32. Further, the end surface 10r19 or the opposing surface 10r22 is pushed in the direction C so that the upper end surface 10r24 of the magnetic seal member 10r is moved in the direction of arrow A. As a result, the upper end surface 10r24 of the magnetic seal member 10r and the ceiling 10f32 on the developing chamber side are engaged with each other, and the state is maintained even when the external force is removed (see FIG. 14).

  Next, the state after the developing blade 10e is attached will be described with reference to FIGS. When the developing frame 10f is attached using screws, the protruding portion 10r25 shown in the direction of the symbol C in FIG. 13B contacts the developing blade rubber member 10e2 and is further pushed in. The elastic lining 177 is compressed to the back side. The reaction force is such that the frame contact surface 10f25 of the first developing frame 10f1 with which the lower end surface 10r6 of the magnetic seal member 10r is in contact with the developing chamber side ceiling 10f32 with which the upper end surface 10r24 is in contact, and the protruding portion 10r25. Is supported by the developing blade rubber member 10e2 in contact therewith.

  Since the protrusion 10r25 is set at a position overlapping the sheet metal portion 10e1 of the developing blade 10e, it does not affect the bending of the developing blade rubber member 10e2. Therefore, the contact pressure with the developing roller 10d at the end of the developing blade rubber member 10e2 does not increase. Further, the end face 10r19 is not in contact with the sheet metal portion 10e2 of the developing blade 10e, and has a distance at which no leakage can occur between the sheet metal portion 10e2 and the magnetic seal member 10r (not shown). Further, as shown in FIG. 15B, when the developing roller 10d is attached, the developing blade rubber member 10e2 bends to the developing chamber 10i side, but the clearance d3 can be held between the developing blade 10e and the rubber member 10e2. The shape of the facing surface 10r22 is determined.

  Further, a clearance d1 is provided between the end surfaces 10r8 on both sides in the width direction of the seal member main body of the magnetic seal member 10r and the rubber member 10e2 of the developing blade 10e. The clearance d1 prevents interference between components in consideration of manufacturing variations of the developing frame 10f1, the magnetic seal member 10r, and the developing blade 10e. A clearance g2 is also provided between the inner peripheral surface of the magnetic seal member 10r and the outer peripheral surface of the developing roller 10d.

  By the way, a plurality of N poles and S poles are magnetized in the magnet 10r1, and a spike of a magnetic brush is formed in the clearance g2 from the developing roller 10d to prevent toner leakage from the end of the developing roller 10d. . In this embodiment, the clearance g2 is set to 0.1 to 0.7 mm, and the magnetic flux density by the magnetic force of the magnetic seal member 10r at that time is about 1000 to 2000 Gs on the developing roller 10d. Similarly, spikes of magnetic brushes are formed in the clearances d1 and d3, so that toner leakage from each clearance can be prevented. Further, the toner leakage path is blocked by a rib 10f3 having a thin tip that bites into the rubber member 10e2 of the developing blade 10e. Accordingly, sealing performance is ensured at portions other than the longitudinal end portion of the rubber member 10e2 of the developing blade 10e to which the magnetic force of the magnetic seal member 10r does not reach, and toner does not leak from above the developing chamber 10i.

  As described above, by providing the protruding portion 10r22 of the magnetic seal member 10r inside the developing chamber 10i, toner leakage from the clearance between the long end surface 10r8 of the magnetic seal member 10r and the developing blade rubber member 10e2 can be prevented. .

  Further, since the opposing surface 10r22 and the rubber member 10e2 of the developing blade 10e are arranged in a non-contact manner, the pressing force due to contact with the developing roller 10d at the end of the developing blade 10e does not increase more than necessary, so A uniform image density can be secured in the direction.

  Since the amount from the linear end surface portion 171b to the refracting portion 171e (see FIG. 26) is equal to or less than the amount of the protruding portion 10r21, the component cost of the magnetic seal member 10r is equal to or less. The conventionally used elastic seal member 10s is not necessary. Conventionally, the magnetic seal member 10r is pressed against the sheet metal portion 10e1 of the developing blade 10e. Therefore, as a countermeasure against leakage, the insulating member is sandwiched or a conductive member is used to keep the developing roller 10d, the sheet metal portion 10e1, and the magnetic seal member 10r at the same potential. In this embodiment, since the magnetic seal member 10r contacts the developing blade rubber member 10e, which is a non-conductive material, no leakage occurs, so that an insulating member and a conductive member are not necessary. Therefore, the parts cost and the assembly cost can be reduced, so that a cheaper and higher quality product can be provided to the user.

  In the third embodiment, the developing frame 10f has been described using an example in which the developing frame 10f is configured by two frames (the first developing frame 10f1 and the second developing frame 10f2). However, it is not necessary to have a plurality of frames, and a configuration including only one frame may be used. Moreover, although the protrusion part 10r25 was demonstrated with the mountain-shaped elongate shape, it is not this limitation. In view of the elastic force of the rubber member 10e2 of the developing blade 10e and the elasticity of the elastic lining 177, the protruding portion 10r25 may be configured to abut against the developing blade rubber member 10e2 and stably abut against it. For example, as shown in FIGS. 16A and 16B, the shape may be a needle-like protrusion 10r27 having a sharp tip or a planar protrusion 10r28 having a flat surface at the tip.

  In the above-described embodiment, the electrophotographic photosensitive member is exemplified as a case where a photosensitive drum is used. However, the electrophotographic photosensitive member is not limited to this and includes the following. A photoconductor is used as the photoreceptor, and examples of the photoconductor include amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and organic photoconductor (OPC). For example, a drum-like or belt-like shape is used for mounting the photoconductor. For example, in the case of a drum-type photoconductor, a photoconductor is vapor-deposited or coated on a cylinder such as an aluminum alloy. It is what I did. As a developing method, a developing method such as a known two-component magnetic brush developing method can be used. In addition, the configuration of the charging means uses the so-called contact charging method in the above-described embodiment, but other than the roller type, a blade (charging blade), pad type, block type, rod type, wire type, etc. good. Further, as a method for cleaning the toner remaining on the photosensitive drum, a cleaning unit can be configured using a blade, a fur brush, a magnetic brush, or the like.

  As mentioned above, although several embodiment was demonstrated about this invention, other embodiment, an application example, a modification, and those combinations are also possible within the range which does not deviate from the main point of this invention.

1 is a diagram showing a configuration of an electrophotographic image forming apparatus equipped with a process cartridge. The figure which shows the structure of a process cartridge. The figure which shows the structure of a process cartridge. The figure (a)-(c) is a figure which shows a magnetic body sealing member. (A), (b) is a figure explaining the magnetic body sealing member attachment part of a 1st image development frame. (A), (b) is a figure explaining the structure of the edge part of a developing roller. The figure (a)-(c) is a figure which shows a magnetic body sealing member. (A)-(c) is a figure explaining the magnetic body sealing member attaching part of a 1st image development frame. The figure which shows the attachment method of an edge part member. (A), (b) is a figure which shows the structure of the developing roller edge part. The figure (a)-(c) is a figure which shows a magnetic body sealing member. (A), (b) is a figure explaining the magnetic body sealing member attaching part of a 1st image development frame. FIGS. 4A and 4B are cross-sectional views perpendicular to the developing roller showing the attachment of the magnetic seal member to the developing frame. Sectional drawing of a perpendicular direction to the developing roller which shows attachment to the developing device frame of a magnetic body sealing member. (A), (b) is a figure which shows the structure of the edge part of the developing roller after developing blade attachment. The figure (a), (b) is a figure which shows the modification of a protrusion part. The perspective explanatory view explaining the magnetic body sealing member attachment part of the 1st development frame. The perspective view shown about the structure of a magnetic body sealing member. Magnetic body sealing member explanatory drawing. The perspective explanatory drawing of a magnetic body sealing member. The perspective explanatory drawing of a magnetic body sealing member attachment part. Exploded perspective view of the developing device.

Explanation of symbols

A image forming apparatus B process cartridge C cleaning apparatus D developing apparatus d1, d2, d3 clearance g1, g2, g3 clearance S clearance 1 exposure apparatus 2 recording medium 3 transport means 3a cassette 3b pickup roller 3c pressure contact member 3d discharge roller 3f1 transport guide 3f2 conveyance guide 4 transfer roller 5 fixing means 5a driving roller 5b heater 5c support 5d fixing rotating body 6 discharge unit 7 photosensitive drum 8 charging roller 8a bearing 8b roller bearing 8c electrode 9a transfer opening 9b exposure opening
10 Development means
10a Toner compartment
10b Feed member
10b1 stirring shaft
10b2 sheet material
10b3 transport gear
10b4 seal member
10c fixed magnet
10d Developing roller
10e Development blade
10e1 Sheet metal part
10e2 Development blade rubber member
10e3 support member
10f Development frame
10f2 second development frame
10f3 rib
10f1 first developing frame
10f14 mounting arc
10f15, 10f16 Positioning surface
10f17 ... recess
10f25 mounting end face
10f31 Development chamber wall
10f32 Processing room ceiling
10f35 positioning boss
10f36 Positioning rib
10f40 through hole
10g holder
10g7 arm
10g8 coupling hole
10i development chamber
10m clearance holding member
10r Magnetic seal member
10r1 magnet
10r2 magnetic plate
10r3 inner surface
10r4 circumscribed surface
10r5 biasing member contact surface
10r6 Frame contact end face
10r8, 10r9 Longitudinal end face
10r10 protrusion
10r11 butting surface
10r12 wall
10r13 Long end face
10r14 semicircular arc part
10r15 semicircular arc part
10r16 mounting hole
10r19 end face
10r21 overhang
10r22 facing surface
10r23 groove
10r24 top edge
10r25 protrusion
10r26 slope
10r27 needle-like protrusion
10r28 planar protrusion
10s elastic seal member
10t scraping member
10u Toner filling port
11 Cleaning means
11a Cleaning blade
11b ugly sheet
11c Removal toner storage
11d Cleaning frame
30 Energizing member 112 Developing frame 171 Magnetic seal member 171a Semi-circular arc portion 171b End surface portion 171d Arc surface 171e Refraction portion 171f Lower end surface
171g Top end 171h Front

Claims (6)

A developing frame,
A developer carrier that carries the developer and is attached to the developing frame; and
Developer regulating means for regulating the amount of the developer;
A magnetic seal member for preventing the developer from leaking out between the developing frame and the developer carrier in a developing device comprising:
A seal member body having an inner peripheral surface facing the outer peripheral surface of the developer carrier;
A projecting portion that projects from the seal member main body to the inside of the developer carrying member in the longitudinal direction, faces the developing chamber, and has a facing surface facing the developer regulating means;
A magnetic seal member characterized by comprising: The seal member main body further has an arc-shaped outer surface that contacts the developing device frame on the opposite side of the inner peripheral surface, and contacts the developing device frame at a tip position opposite to the protruding portion. A contact end face that contacts,
The overhanging portion further has a protruding portion that protrudes from the facing surface and abuts against an elastic member provided in the developer regulating means,
When the overhanging portion receives an elastic reaction force from the elastic member via the protruding portion, the seal member main body is positioned in a state where the outer surface and the contact end surface are in contact with the developing device frame. The magnetic seal member according to claim 1.   The seal member main body is rotatably coupled to the developing device frame with a through hole provided at a portion opposite to the inner peripheral surface as a rotation center, and is rotated by an elastic reaction force from the elastic member, and the contact end surface The magnetic material sealing member according to claim 2, wherein the magnetic material sealing member is positioned in a state of being in contact with the developing device frame. An elastic seal member that is attached to the seal member main body and secures a sealing property with the developing device frame;
By bringing the protruding portion of the overhanging portion into contact with the elastic member by the elastic force of the elastic sealing member, and bringing the contact end surface of the seal member main body into contact with the developing frame body,
4. The magnetic seal member according to claim 2, wherein the seal member main body is positioned on the developing device frame.   5. A developing device comprising the magnetic seal member according to claim 1, which develops a latent image formed on an electrophotographic photosensitive member.     A process cartridge comprising: the electrophotographic photosensitive member detachably attached to an image forming apparatus main body; and the developing device according to claim 5.

Images