JP2015132649A - Developing apparatus, process cartridge, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing apparatus configured to prevent developer from entering a space between a developer carrier and a seal member arranged in sliding contact with a rotation axial end of the developer carrier even when a plurality of recesses are formed on an outer peripheral surface of the developer carrier, and to provide a process cartridge and an image forming apparatus.SOLUTION: In a seal pasting section formed to face a rotation axial end of a developing roller 51 (developer carrier), a seal member 72 with brush bristles 74 formed of multiple kinds of bristles 74a, 74b having different lengths is pasted. Specific long bristles 74a are implanted so as to tilt to a rotation axial center, from the downstream in a rotation direction of the developing roller 51 toward the upstream in the rotation direction.

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof, a developing device installed therein, and a process cartridge.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, a plurality of recesses are substantially formed on a core metal (rotating shaft) as a developing device for developing a latent image formed on a photosensitive drum (image carrier). It is known that a developing roller (developer carrier) provided with an iris-shaped roller portion is opposed to a photosensitive drum to perform a developing process (see, for example, Patent Documents 1 to 3). ).

  Specifically, in Patent Documents 1 to 3 and the like, the developing roller has a roller portion in which a plurality of concave portions (groove portions) are formed in a substantially iris shape on a core metal (rotating shaft portion). Further, a toner supply roller (developer supply member) and a regulation blade (developer regulation member) made of a rubber material are installed so as to be in pressure contact with the outer peripheral surface of the development roller. The toner (developer) accommodated in the developing device is supplied onto the developing roller by the toner supply roller, and the toner carried on the developing roller is thinned to an appropriate amount by the regulating blade. Further, in the region facing the photosensitive drum, the toner thinned on the developing roller is supplied to the latent image on the photosensitive drum, and the developing process is performed.

Further, in the developing device configured as described above, in order to prevent the leakage of toner from both end portions in the rotation axis direction of the developing roller, the wall surface (seal sticking portion) is opposed to both end portions in the rotation axis direction of the developing roller. ) Is formed as a part of the casing (developing case), and a seal member made of a felt material or the like is stuck on the wall surface so as to bite into the developing roller.
In particular, Patent Document 1 includes a non-groove forming portion in which a concave portion is not formed at a part of both ends in the rotation axis direction of the developing roller, and a seal member (side seal) is formed with a groove forming portion and a non-groove forming portion The technique of installing so that it may straddle is disclosed.

  In the conventional developing device, the developer (toner) gradually enters the recesses at both ends in the rotation axis direction of the developer carrying member (developing roller) in which the seal member has engulfed, and the developer that has entered further develops. In some cases, the developer leaks to the outside of the printer, or the developer that has entered solidifies (fixes) due to friction with the seal member and damages the seal member.

  The present invention has been made to solve the above-described problems. Even when a plurality of recesses are formed on the outer peripheral surface of the developer carrier, the developer carrier is provided at the end in the rotation axis direction. It is an object of the present invention to provide a developing device, a process cartridge, and an image forming apparatus in which a developer is difficult to enter between a seal member installed so as to be in sliding contact with a developer carrier.

  The developing device according to claim 1 of the present invention is a developing device for developing a latent image formed on an image carrier and forming a toner image while containing a developer therein, A developer carrying member that faces or contacts the image carrier and rotates in a predetermined direction and has a plurality of recesses formed on an outer peripheral surface thereof, and a part of the developing case, the developer carrying A seal sticking portion formed so as to be opposed to an end portion in the rotation axis direction of the body, and brush hairs which are attached to the seal sticking portion and slidably contact the end portion in the rotation axis direction of the developer carrier. And the brush bristles of the seal member are formed such that, among the plurality of bristles constituting the brush bristles, the bristles or / and the rigidity are larger than the other bristles. Special hairs, the special hairs facing the developer It is from the downstream side in the rotational direction that is implanted as toward the upstream side in the rotation direction fall on the side of the rotation axis direction central portion.

  According to the present invention, even when a plurality of recesses are formed on the outer peripheral surface of the developer carrier, the seal member installed so as to be in sliding contact with the rotation axis direction end of the developer carrier, and the developer carrier It is possible to provide a developing device, a process cartridge, and an image forming apparatus in which the developer hardly enters between the body and the image forming apparatus.

1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. 2 is a cross-sectional view illustrating an image forming unit in the image forming apparatus. FIG. It is the schematic which shows the drive means which drives a developing roller, and the biasing means which biases a developing roller toward a photosensitive drum. FIG. 2 is a schematic cross-sectional view showing a part of the developing device in the axial direction facing a photosensitive drum. It is an expanded sectional view showing the neighborhood of the contact position of a development roller and a doctor blade in the peripheral direction. FIG. 10 is a perspective view showing the developing case with the developing roller removed. (A) Schematic which shows the relationship between the recessed part of a developing roller, and a sealing member, (B) The schematic which shows the bristle of a sealing member. FIG. 3 is a schematic cross-sectional view showing a vicinity of a contact position between a developing roller and a seal member in an enlarged manner in the circumferential direction. FIG. 7 is a schematic cross-sectional view showing a vicinity of a contact position between a developing roller and a seal member as a comparative example, enlarged in the circumferential direction. FIG. 9 is a schematic cross-sectional view showing a vicinity of a contact position between a developing roller and a seal member as a modified example 1 in an enlarged manner in the circumferential direction. FIG. 4A is a schematic diagram showing a relationship between a concave portion of the developing roller and a seal member, and FIG. 5B is a schematic diagram showing brush bristles of the seal member, as modified example 2;

Embodiment.
Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

First, the configuration and operation of the entire image forming apparatus will be described with reference to FIGS.
As shown in FIG. 1, an intermediate transfer belt device 15 is installed in the center of the image forming apparatus main body 100. Further, process cartridges 6Y, 6M, 6C, 6K corresponding to the respective colors (yellow, magenta, cyan, black) are arranged in parallel so as to face the intermediate transfer belt 8 (intermediate transfer member) of the intermediate transfer belt device 15. Yes.

  Referring to FIG. 2, a process cartridge 6Y corresponding to yellow includes a photosensitive drum 1Y as an image carrier, a charging device 4Y (charging unit) disposed around the photosensitive drum 1Y, and a developing device 5Y ( The developing unit), the cleaning device 2Y (cleaning unit), the charge eliminating unit (not shown), and the like are configured to be detachable (replaceable) from the image forming apparatus main body 100 as one unit. Then, an image forming process (charging process, exposure process, developing process, transfer process, cleaning process) is performed on the photosensitive drum 1Y, and a yellow image is formed on the photosensitive drum 1Y. That is, the process cartridge 6Y constitutes an image forming unit together with the primary transfer roller 9Y (primary transfer device) and the like.

  The other three process cartridges 6M, 6C, and 6K (image forming unit) have substantially the same configuration as the process cartridge 6Y (image forming unit) corresponding to yellow except that the color of the toner used is different. Therefore, an image corresponding to each toner color is formed. Hereinafter, description of the other three process cartridges 6M, 6C, and 6K (image forming unit) will be omitted as appropriate, and only the process cartridge 6Y (image forming unit) corresponding to yellow will be described.

Referring to FIG. 2, the photosensitive drum 1Y (image carrier) is driven to rotate clockwise by a motor (not shown). Then, the surface of the photosensitive drum 1Y is uniformly charged at the position of the charging device 4Y (charging roller) (this is a charging process).
Thereafter, the surface of the photosensitive drum 1Y reaches the irradiation position of the exposure light emitted from the exposure unit 7Y (optical writing head), and an electrostatic latent image corresponding to yellow is formed by exposure scanning at this position. (This is an exposure process.)

Thereafter, the surface of the photosensitive drum 1Y reaches a position facing the developing device 5Y (developing device main portion 50), and the electrostatic latent image is developed at this position to form a yellow toner image (development). Process.)
Thereafter, the surface of the photosensitive drum 1Y reaches a position facing the intermediate transfer belt 8 and the primary transfer roller 9Y, and the toner image on the photosensitive drum 1Y is transferred onto the intermediate transfer belt 8 (intermediate transfer body) at this position. (It is a primary transfer process). At this time, a small amount of untransferred toner remains on the photosensitive drum 1Y.

Thereafter, the surface of the photosensitive drum 1Y reaches a position facing the cleaning device 2Y, and untransferred toner remaining on the photosensitive drum 1Y at this position is collected in the cleaning device 2Y by the cleaning blade 2a (cleaning). Process.)
Finally, the surface of the photosensitive drum 1Y reaches a position facing a neutralization unit (not shown), and the residual potential on the photosensitive drum 1 is removed at this position.
Thus, a series of image forming processes performed on the photosensitive drum 1Y is completed.

The image forming process described above is performed in the same manner as the process cartridge 6Y (image forming unit) for yellow in the other process cartridges 6M, 6C, and 6K (image forming unit). That is, exposure light based on image information is emitted from the exposure unit disposed above the image forming unit onto the photosensitive drums of the process cartridges 6M, 6C, and 6K.
Thereafter, the toner images of the respective colors formed on the respective photosensitive drums through the developing process are transferred onto the intermediate transfer belt 8 in an overlapping manner. In this way, a color image is formed on the intermediate transfer belt 8.

  Here, referring to FIG. 1, the intermediate transfer belt device 15 includes an intermediate transfer belt 8, four primary transfer rollers 9Y (see FIG. 2), a driving roller, a driven roller, and the like. The intermediate transfer belt 8 is stretched and supported by a driving roller, a driven roller, and a primary transfer roller, and is endlessly moved in the arrow direction (counterclockwise direction) in FIG. 1 by the rotational driving of the driving roller.

The primary transfer roller 9Y sandwiches the intermediate transfer belt 8 with the photosensitive drum 1Y to form a primary transfer nip. A transfer voltage (transfer bias) opposite to the polarity of the toner is applied to the primary transfer roller 9Y.
The intermediate transfer belt 8 travels in the direction of the arrow and sequentially passes through the primary transfer nip of each primary transfer roller (9Y). In this way, the toner images of the respective colors on the respective photosensitive drums (1Y) are primarily transferred while being superimposed on the intermediate transfer belt 8.

  Thereafter, the intermediate transfer belt 8 onto which the toner images of the respective colors are transferred in an overlapping manner reaches a position facing the secondary transfer roller 19 (secondary transfer device). At this position, the drive roller (secondary transfer counter roller) sandwiches the intermediate transfer belt 8 with the secondary transfer roller 19 to form a secondary transfer nip. The four-color toner images formed on the intermediate transfer belt 8 are transferred onto a recording medium P such as transfer paper conveyed to the position of the secondary transfer nip (secondary transfer step). . At this time, untransferred toner that has not been transferred to the recording medium P remains on the intermediate transfer belt 8.

Thereafter, the intermediate transfer belt 8 reaches the position of the intermediate transfer cleaning device 16 (intermediate transfer cleaning blade). At this position, the untransferred toner on the intermediate transfer belt 8 is mechanically removed by an intermediate transfer cleaning blade (intermediate transfer cleaning device 16) that is in pressure contact with the intermediate transfer belt 8. The intermediate transfer cleaning blade is a substantially plate-like member made of an elastic material such as urethane rubber, and is in contact with the intermediate transfer belt 8 with a predetermined contact pressure and contact angle.
Thus, a series of transfer processes performed on the intermediate transfer belt 8 is completed.

Here, referring to FIG. 1, the recording medium P conveyed to the position of the secondary transfer nip is fed from a sheet feeding unit 26 disposed below the apparatus main body 100 to a sheet feeding roller 27 and a registration roller pair 28. (A pair of timing rollers) or the like.
Specifically, a plurality of recording media P such as transfer paper are stored in the paper supply unit 26 in a stacked manner. When the paper feed roller 27 is driven to rotate counterclockwise in FIG. 1, the uppermost recording medium P is fed toward the rollers of the registration roller pair 28.

  The recording medium P transported to the registration roller pair 28 temporarily stops at the position of the roller nip of the registration roller pair 28 whose rotation drive has been stopped. Then, the registration roller pair 28 is rotationally driven in synchronization with the color image on the intermediate transfer belt 8, and the recording medium P is conveyed toward the secondary transfer nip. In this way, a desired color image is transferred onto the recording medium P.

Thereafter, the recording medium P on which the color image is transferred at the position of the secondary transfer nip is conveyed to the position of the fixing device 20 (fixing nip). At this position, the color image (toner image) transferred to the surface is fixed on the recording medium P by heat and pressure generated by the fixing belt 21 (fixing member) and the pressure roller 22 (pressure member). (This is a fixing process.)
Thereafter, the recording medium P is discharged out of the apparatus by a pair of paper discharge rollers. The recording medium P discharged out of the apparatus by the pair of paper discharge rollers is sequentially stacked on the stack unit (main body cover 110) as an output image.
Thus, a series of image forming processes in the image forming apparatus is completed.

Next, the image forming unit in the image forming apparatus will be described in detail with reference to FIG.
As shown in FIG. 2, the process cartridge 6Y includes a photosensitive drum 1Y (image carrier), a charging device 4Y (charging roller), a developing device 5Y, a cleaning device 2Y, and the like.
A photoconductive drum 1Y as an image carrier is a negatively charged organic photoconductor, and is a motor (not shown, a main body side drive gear 90 described later with reference to FIG. 3) installed on the apparatus main body 100 side. 2 is a motor different from the drive motor on which the motor is installed) and is driven to rotate clockwise in FIG.

The charging roller 4Y (charging device) is an elastic roller in which a medium-resistance urethane foam layer in which a urethane resin, carbon black as conductive particles, a sulfurizing agent, a foaming agent, and the like are prescribed is formed on a core metal. The material of the middle resistance layer of the charging roller 4Y is urethane, ethylene-propylene-diene polyethylene (EPDM), butadiene acrylonitrile rubber (NBR), silicone rubber, isoprene rubber, etc. It is also possible to use a rubber material in which a conductive material such as the above is dispersed or a foamed material of these materials. In this embodiment, the charging roller 4Y is configured to contact the photosensitive drum 1Y. However, the charging roller 4Y may be configured not to contact the photosensitive drum 1Y.
The cleaning device 2Y is provided with a cleaning blade 2a that is in sliding contact with the photosensitive drum 1Y, and mechanically removes and collects untransferred toner on the photosensitive drum 1Y. The cleaning blade 2a is a substantially plate-like member formed of an elastic material such as urethane rubber, and is in contact with the photosensitive drum 1Y with a predetermined contact pressure and contact angle.

  The developing device 5Y is arranged such that a developing roller 51 as a developer carrying member is opposed to the photosensitive drum 1Y with a small gap therebetween, and between the members 1Y and 51 (opposing position). A development area is formed. In the developing device 5Y, toner (nonmagnetic or magnetic one-component developer) as a developer is accommodated. The developing device 5Y develops the electrostatic latent image formed on the photosensitive drum 1Y (forms a toner image).

Hereinafter, the developing device 5Y will be described in detail with reference to FIGS.
Referring to FIG. 2, developing device 5Y in the present embodiment is a non-contact one-component developing type developing device, and mainly develops an electrostatic latent image formed on photosensitive drum 1Y. The main part 50 and a toner container 60 as a developer container in which toner (one-component developer) to be supplied to the developing device main part 50 is accommodated.
The developing device 5Y is detachably (replaceable) with respect to the apparatus main body 100 together with the other image forming members 1Y, 2Y, 4Y as a process cartridge 6Y, but with respect to the developing device main part 50 (process cartridge 6Y). Thus, the toner container 60 can be replaced separately. That is, the toner container 60 is detachably (replaceable) at an upper position with respect to the developing device main part 50 (process cartridge 6Y) mounted on the apparatus main body 100. Then, the main body cover 110 (see FIG. 1) is opened and closed around a hinge (not shown) to separate the toner container 60 from the developing device main part 50 and replace only the toner container 60, or the toner container. For example, the developing device main part 50 (process cartridge 6Y) in which 60 is mounted is replaced.
The toner container 60 is replaced at a timing when the toner stored in the toner container 60 runs out, and the developing device main unit 50 (process cartridge 6Y) is replaced by its constituent parts (for example, the developing roller 51, the photosensitive drum 1Y, etc.). Is performed at the timing when the toner reaches the end of its life and the internal toner runs out. Therefore, the toner container 60 may be replaced independently, but the developing device main unit 50 (process cartridge 6Y) is replaced together with the toner container 60 (with the toner container 60 mounted). It will be.

  The developing device main unit 50 includes a developing roller 51 as a developer carrying member, a supply roller 53 as a developer supply member, a doctor blade 52 as a developer regulating member, transport screws 54 and 55 as a plurality of transport members, A partition member 56 that separates the first conveyance path B1 by the first conveyance screw 54 and the second conveyance path B2 by the second conveyance screw 55, a main-side supply port 57 for supplying toner from the toner container 60, and the like. ing.

The developing roller 51 (developer carrier) faces the photosensitive drum 1Y and supplies toner (developer) to the electrostatic latent image formed on the photosensitive drum 1Y. The developing roller 51 includes a rotating shaft portion (core metal) formed of a conductive metal material such as stainless steel and a roller portion 51a (roller main portion) made of an iron-based material or an aluminum-based material. Can be used. Specifically, in the present embodiment, the rotating shaft portions in which the flanges are integrally formed are respectively provided at both ends in the axial direction of the cylindrical roller portion 51a having a conductive surface layer formed on the surface thereof. The developing roller 51 is formed by press-fitting and bonding (this configuration is also defined as a roller portion formed on the rotating shaft portion). In the present embodiment, a plurality of concave portions 51a1 are formed on the surface (outer peripheral surface) of the roller portion 51a of the developing roller 51. Details thereof will be described later with reference to FIG.
The supply roller 53 (developer supply member) is disposed below the two conveying screws 54 and 55, and slidably contacts the development roller 51 to supply toner to the development roller 51. The supply roller 53 has a conductive polyurethane foam layer (having an electrical resistance value of about 10 ³ to 10 ¹⁴ Ω) laminated on a mandrel. The supply roller 53 also has a function of removing from the developing roller 51 toner on the developing roller 51 that has not been subjected to the developing process in the developing area with the photosensitive drum 1Y.
The doctor blade 52 (developer regulating member) is disposed so that the tip thereof contacts the outer peripheral surface of the developing roller 51 at a predetermined angle with a pressure of about 10 to 100 N / m. The amount of developer developed. As the doctor blade 52, a thin plate member made of a metal material such as stainless steel can be used.

  Here, a predetermined voltage is applied to the developing roller 51, the supply roller 53, and the doctor blade 52 from a power supply unit (not shown), and the movement of toner on the developing roller 51 described later is promoted. In the present embodiment, an alternating voltage (AC frequency is about 500 to 1000 Hz, peak so that the toner reciprocates between the developing roller 51 and the photosensitive drum 1Y in the developing region with respect to the developing roller 51. A rectangular wave having a two-peak voltage of about 500 to 3000 V and an application time duty of about 30 to 70% is applied.

The two conveying screws 54 and 55 (conveying members) are mounted in the apparatus main body 100 and convey the toner stored in the developing device main part 50 in the axial direction (the direction perpendicular to the paper surface of FIG. 2). To form a circulation path.
The first conveying screw 54 as the first conveying member is disposed at a position (upward position) facing the supply roller 53, and conveys the toner horizontally in the axial direction (longitudinal direction) (FIG. 2). The toner is supplied onto the supply roller 53 while being conveyed from the front side to the back side in the direction perpendicular to the paper surface.

The second conveying screw 55 as the second conveying member is disposed at a position (an upper position) facing the first conveying screw 54 via the partition member 56, and the toner is axially (longitudinal direction). ) Horizontally (conveyance from the back side to the front side in the direction perpendicular to the paper surface of FIG. 2). Then, the second transport screw 55 has a first relay unit disposed on the upstream side of the first transport path B1 for the toner circulated from the downstream side of the first transport path B1 by the first transport screw 54 via the second relay unit. Transport through.
The two conveying screws 54 and 55 are arranged so that the rotation axis is substantially horizontal, like the developing roller 51 and the photosensitive drum 1Y. Moreover, as for the two conveyance screws 54 and 55, as for all, the screw part is helically wound by the axial part.

The conveyance path (first conveyance path B1) by the first conveyance screw 54 and the conveyance path (second conveyance path B2) by the second conveyance screw 55 are separated from each other by a partition member 56 (wall portion).
Although illustration is omitted, the downstream side of the second conveyance path B2 by the second conveyance screw 55 and the upstream side of the first conveyance path B1 by the first conveyance screw 54 communicate with each other via the first relay unit. . The toner that has reached the downstream side of the second transport path B2 by the second transport screw 55 falls by its own weight at the first relay section and reaches the upstream side of the first transport path B1.
Further, the downstream side of the first conveyance path B1 by the first conveyance screw 54 and the upstream side of the second conveyance path B2 by the second conveyance screw 55 are communicated with each other via the second relay unit. Then, the toner that has not been supplied onto the supply roller 53 in the first conveyance path B1 stays in the vicinity of the second relay unit and rises, and is conveyed to the upstream side of the second conveyance path B2 via the second relay unit. (Supplied).
In addition, in order to improve the toner transportability in the second relay unit (the transfer of toner against the direction of gravity from the first transport path B1 to the second transport path B2), the downstream of the first transport screw 54. A paddle-shaped part or a screw part formed in the reverse direction of the screw winding direction can also be provided at the position on the side (the position corresponding to the second relay part).

Referring to FIG. 2, the developing device main portion 50 is formed with a main portion-side supply port 57 communicating with the container-side supply port 63 of the toner container 60 at an upper position. The main portion side supply port 57 is for supplying toner (developer) from the toner container 60 to the developing device main portion 50.
Although not shown, gears are provided on the shaft portions of the developing roller 51, the supply roller 53, the first conveying screw 54, and the second conveying screw 55, and a gear train including an idler gear is formed. ing. Then, a driving force is input to these gear trains from a drive motor (drive means) (not shown), and the developing roller 51, the supply roller 53, the first transport screw 54, and the second transport screw 55 are each in the direction of the arrow in FIG. Is driven to rotate. FIG. 3 shows only a part of the gear train (the gear train extending from the first idler gear 41 to the drive gear 43 installed on the developing roller 51), which will be described later. explain.

Here, the toner container 60 as a developer container includes an agitator 61, a container side conveying screw 62 as a container side conveying member, a container side supply port 63, and the like.
The agitator 61 is formed by attaching a thin plate-like flexible member to the rotating shaft portion. The agitator 61 rotates in the counterclockwise direction of FIG. 2 to thereby store the toner accommodated in the accommodating portion C of the toner container 60. Is transported toward the transport path by the container-side transport screw 62.
The container-side transport screw 62 (container-side transport member) transports the toner contained in the container toward the container-side supply port 63 toward one end in the longitudinal direction while being attached to the apparatus main body 100.
The container-side supply port 63 is formed on one end side in the longitudinal direction in the transport path by the container-side transport screw 62. The toner discharged from the container side replenishing port 63 is replenished to the upstream side of the second transport path B2 of the developing device main portion 50 through its main portion side replenishing port 57 by its own weight fall.

The developing device 5Y configured as described above operates as follows.
First, the toner replenished from the toner container 60 into the second transport path B2 through the replenishing ports 57 and 63 is stirred and mixed by the second transport screw 55 together with the toner circulating in the main part 50 of the developing device. , Supplied to the first transport path B1. A part of the toner transported to the first transport path B1 is supplied to and supported by the supply roller 53 while being transported to the first transport screw 54. The toner carried on the supply roller 53 is frictionally charged at the pressure contact portion (contact position) with the developing roller 51 and then moved and carried on the developing roller 51. Thereafter, the toner carried on the developing roller 51 reaches a position (developing area) facing the photosensitive drum 1Y after being thinned and uniformed at the position where it contacts the doctor blade 52. At this position, the toner is attracted to the latent image formed on the photosensitive drum 1Y by the electric field (developing electric field) formed in the developing region.

Here, the developing roller 51 is provided with a drive gear 43 as a drive transmission member on a rotation shaft portion (a rotation shaft portion on one end side in the axial direction, which is located on the left side in FIG. 4). The rotational driving force by the driving motor (driving means) is input.
Specifically, with reference to FIG. 3, in the developing device 5Y in the process cartridge 6Y, a first idler gear 41 is installed on a support shaft 35 standing on a case (developing case). Further, a second idler gear 44 that meshes with the first idler gear 41 is installed on another support shaft (see FIG. 4) that stands on the developing case 58 (case). The developing case 58 is rotatably supported by a rotating shaft portion of the developing roller 51 via a bearing 71, and a driving gear 43 that meshes with the second idler gear 44 is installed on the rotating shaft portion on one end side in the axial direction. (See FIG. 4). When the process cartridge 6Y is set in the apparatus main body 100, the first idler gear 41 installed on the support shaft 35 of the developing device 5Y is replaced with the main body side drive gear 90 (motor shaft of the drive motor) installed in the apparatus main body 100. ).
With this configuration, rotational driving force is input from the main body side driving gear 90 (driving means) to the driving gear 43 via the first idler gear 41 and the second idler gear 44, and the developing roller 51 is rotationally driven together with the driving gear 43. Will be.

Further, the developing roller 51 is urged toward the photosensitive drum 1Y by a compression spring 33 as an urging means so as to come into pressure contact with the photosensitive drum 1Y (image carrier) (in the direction of the white arrow in FIG. 4). Energized.)
Specifically, referring to FIG. 3, the shaft portion of the photosensitive drum 1Y is rotatably supported by the housing 30 of the process cartridge 6Y via a bearing. Further, the developing device 5Y is supported on the housing 30 of the process cartridge 6Y so as to be rotatable about a support shaft 35 (fixed to the housing 30), and the developing device 5Y is supported from the back side. A compression spring 33 that biases toward the photosensitive drum 1Y is installed. Further, as shown in FIG. 4, positioning rollers 70 each having an outer diameter slightly larger than the outer diameter of the roller portion 51 a of the developing roller 51 are provided on the rotating shaft portions (both ends in the rotating shaft direction) of the developing roller 51. It is inserted.
With such a configuration, the developing roller 51 is rotated around the support shaft 35 together with the developing device 5Y by the compression spring 33 (clockwise rotation indicated by a thick arrow in FIG. 3), and the positioning roller 70 is rotated. Is positioned at a position in contact with the photosensitive drum 1Y, and is opposed to the photosensitive drum 1Y with a predetermined gap.
Since the first idler gear 41 described above is installed on the support shaft 35, even if the developing device 5Y rotates about the support shaft 35, the first idler gear 41 and the main body side drive gear 90 are not connected. The meshing does not change, and the drive transmission to the developing roller 51 is maintained.

Here, with reference to FIG. 4, FIG. 5, etc., the developing roller 51 (developer carrier) in the present embodiment has a plurality of recesses 51a1 (grooves) formed on the outer peripheral surface thereof. Specifically, the developing roller 51 includes a rotating shaft portion (in this embodiment, the rotating shaft portion on one end side in the rotating shaft direction and the rotating shaft portion on the other end side in the rotating shaft direction are separate members before assembly. The roller part 51a in which the some recessed part 51a1 was formed is provided on the top. The roller portion 51a is formed by rolling a base portion (a portion to be a convex portion other than the concave portion) to form a concave portion 51a1 (groove portion) formed in a substantially iris shape with respect to the rotation axis direction. is there. That is, the concave portion 51a1 of the developing roller 51 is formed in a substantially iris shape so that spirals in opposite spiral directions intersect with each other over the rotation axis direction. In other words, the recess 51a1 of the developing roller 51 intersects spirals in opposite spiral directions from the end portion in the rotation axis direction (a portion in contact with a seal member 72 described later) to the center portion in the rotation axis direction. Thus, it is formed in a substantially iris shape.
In the present embodiment, the concave portion 51a1 formed in a substantially iris shape is formed by spirally forming two groove portions so that the spiral directions of the roller portion 51a are opposite to each other. The crossing angle of the two spiral grooves is set in the range of about 30 to 120 degrees. Thus, the plurality of recesses 51a1 are regularly formed in the axial direction and the circumferential direction. In the present embodiment, the depth of the concave portion 51a1 is formed to be about 10 μm larger than the particle size (weight average particle diameter) of the toner T, and the axial width of the convex portion with respect to the concave portion is about 40 μm. The pitch in the axial direction between the projections and the projections is about 80 μm.

  Thus, by forming the plurality of concave portions 51a1 regularly arranged on the outer peripheral surface (roller portion 51a) of the developing roller 51, as shown in FIG. 5, the toner T enters the plurality of concave portions 51a1. Thus, the excessive toner TK carried on the developing roller 51 is worn out by the doctor blade 52 (developer regulating member). As a result, the amount of toner on the developing roller 51 thinned by the doctor blade 52 is stabilized, and a favorable developing process can be performed. The arrows shown in FIG. 5 indicate the direction in which the developing roller 51 rotates.

  Further, as shown in FIG. 5, in the present embodiment, the doctor blade 52 is a plate-like member formed of a metal material, and the tip portion thereof is an edge portion of a plurality of concave portions 51a1 (a portion surrounded by a broken line) It is arrange | positioned so that it may contact | abut. With such a configuration, even if the toner adheres to the tip portion of the doctor blade 52 (the contact portion that contacts the developing roller 51), the edges of the plurality of recesses 51a1 are sharp to some extent. The fixed toner is peeled off by the edge of the recess 51a1 (the one recess 51a1 is the downstream edge with respect to the rotation direction of the developing roller 51). For this reason, it is possible to suppress a problem that the toner fixed to the contact portion of the doctor blade 52 increases and a streak-like defect is generated on the image corresponding to the fixed position.

In the present embodiment, the plurality of recesses 51a1 in the roller portion 51a of the developing roller 51 are formed in a substantially iris shape with respect to the rotation axis direction (axial direction), but the form of the plurality of recesses 51a1 is limited to this. The plurality of recesses 51a1 can also be formed in a lattice shape with respect to the axial direction.
Even in such a case, the plurality of concave portions 51a1 are regularly arranged on the outer peripheral surface (roller portion 51a) of the developing roller 51, and the developing roller 51 is thinned by the doctor blade 52. The toner amount can be stabilized.

Hereinafter, the characteristic configuration and operation of the developing device 5Y in the present embodiment will be described in detail.
4, 6, and 7, in the developing device 5 </ b> Y according to the present embodiment, a seal sticking portion 58 a () is provided so as to face the end portion in the rotation axis direction of the developing roller 51 (developer carrier). Wall) is formed. The seal sticking portion 58a is formed as a part of the developing case 58 (casing) in the developing device 5Y (developing device main portion 50). A seal member 72 (end seal) is stuck to the seal sticking portion 58a so as to bite into the end of the developing roller 51 in the rotation axis direction. The seal member 72 is provided with brush bristles 74 (see FIG. 7B) that are in sliding contact with the end of the developing roller 51 in the rotation axis direction.

Specifically, a seal sticking portion 58a is formed at the end in the rotation axis direction of the developing roller 51 so as to face a part in the circumferential direction of the developing roller 51, and the seal member 72 is provided along the seal sticking portion 58a. is set up. Referring to FIG. 7B, the seal member 72 is made of nylon, rayon, acrylic, vinylon, a base cloth portion 73 formed in a substantially rectangular shape in a single state that is not installed in the seal attaching portion 58a. The brush bristles 74 made of fibers such as polyester and vinyl chloride are densely planted.
With such a configuration, a problem that toner leaks from the gap between the both end portions of the developing roller 51 and the developing case 58 toward the outside of the developing device 5Y (developing device main portion 50) is reduced.

Here, in this Embodiment, with reference to FIG.7 (B), the brush hair 74 of the sealing member 72 is other hair (non-special hair 74b) in the some hair which comprises the brush hair 74. Compared with, special hair 74a is provided so that the hair foot D1 (length) becomes larger. That is, the brush hairs 74 are configured by non-special hairs 74b (short hairs) having short hair feet D2 and special hairs 74a (long hairs) having long hair feet D1.
Then, the special hair 74a having a long bristles falls to the central side (the right side in FIG. 7B) in the rotational axis direction from the downstream side in the rotational direction of the developing roller 51 facing the upstream side in the rotational direction. So that it is planted. Specifically, the brush bristles 74 are in the direction of the rotation axis from the upstream side in the rotational direction to the downstream side in the rotational direction when viewed from the seal member 72 side in the spiral direction opposite to each other in the roller portion 51a of the developing roller 51. It is planted along the spiral direction of the spiral formed so as to be inclined toward the end side.

7A illustrates the developing roller 51 and the seal member 72 as viewed from the seal member 72 side, and FIG. 7B illustrates the seal member 72 in FIG. 7A. It is the figure which looked at (it is a single-piece | unit state) from the downward direction of FIG. 7 (A). Note that the state of the brush bristles 74 in FIG. 7B is a single state without contacting the developing roller 51.
When the spiral angle of the spiral of the roller portion 51a formed so as to be inclined from the upstream side in the rotational direction to the downstream side in the rotational direction when viewed from the seal member 72 side is θ2, 74 (special hair 74a and non-special hair 74b) is formed such that the inclination angle θ1 (the angle at which the straight line connecting from the root to the hair tip inclines toward the center) is greater than 0 and equal to or less than θ2. Further, the brush bristles 74 (special bristles 74a and non-special bristles 74b) are planted so as to be opposed to the rotation direction of the developing roller 51 (the bristles side is located on the upstream side in the rotation direction from the root side). So that it is planted).

  In addition, it is possible to incline the brush bristles 74 in this manner by optimizing the weaving angle when the bristles 74 are woven into the base cloth portion 73 by a weaving machine in the manufacturing process. Further, in order to provide the special hair 74a and the non-special hair 74b having different hair feet in the brush hair 74, the special hair 74a having a long hair foot is formed on the entire surface of the base cloth portion 73, and then a desired portion is left. It is possible by forming the non-special hair 74b by performing the cutting process, or by interweaving the special hair 74a and the non-special hair 74b separately on the base cloth part 73.

By configuring the brush hair 74 of the seal member 72 in this manner, as shown in FIG. 8, the special hair 74a having a long bristle becomes easy to enter the recess 51a1 (groove) from the tip of the hair. Even if T enters, the toner T is scraped out by the special hair 74a and is prevented from proceeding to the end in the direction of the rotation axis. Further, the non-special hair 74b (other hair) having short hairs fills the gap between the developing roller 51 (particularly the convex portion) and the developing case 58 without interfering with the function of the special hair 74a. . In this way, by providing the bristles 74 with the two bristles 74a and 74b having different hair feet and different functions, the toner T is formed in the recesses 51a1 at both ends in the rotation axis direction of the developing roller 51 in which the seal member 72 has engulfed. Gradually enters the toner T and the toner T that has entered further leaks out of the developing device 5Y, and the toner T that has entered solidifies (adheres) due to friction with the seal member 72 and damages the seal member 72. Thus, it is possible to reliably reduce the malfunction and the like, and to secure a good sealing performance without applying a large frictional resistance between the seal member 72 and the developing roller 51.
Here, the above-described effect is that only the special hair 74a is implanted so as to fall from the downstream side in the rotational direction of the developing roller 51 toward the upstream side in the rotational direction toward the central portion in the rotational axis direction, and the non-special hair 74b. Is exhibited even when it is planted so as to fall in a different direction (or so that it does not fall).
Note that the arrows shown in FIG. 8 indicate the direction in which the developing roller 51 rotates.

  Here, in order to reliably exhibit the above-described effect, in the present embodiment, the tip of the special hair 74a is formed so as to enter the inside of the recess 51a1 of the developing roller 51 and contact the bottom. That is, the special hair 74a is set to have a bristle foot D1 whose hair tip enters the inside of the recess 51a1 and contacts the bottom, and is thick enough to enter the recess 51a1. Further, the non-special hair 74b is set to a hair foot D2 whose hair tip is in contact with the convex portion of the developing roller 51 (a hair foot having a slight amount even if it enters the concave portion 51a1). ing.

In addition, in this embodiment, the special hairs 74a are in contact (interference) with each other in the actual use state (in a state where the special hairs 74 are in sliding contact with the developing roller 51). It is planted at intervals so as not to.
Specifically, referring to FIG. 8, since the interval between adjacent special hairs 74a is set to be approximately the same as the pitch value of adjacent recesses 51a1, a plurality of special hairs are provided in recess 51a1. The trouble that the hair 74a enters and is entangled with each other is less likely to occur.
That is, as shown in FIG. 9, when the distance between the adjacent special hairs 74a is narrow, the special hairs 74a that scrape out the toner T that has entered the recesses 51a1 by the plurality of special hairs 74a entering the recesses 51a1 and being entangled with each other. The function of will not be fully demonstrated.

In addition, the sealing member 72 in this Embodiment formed the special hair 74a so that a hair foot may become long compared with other hair (non-special hair 74b) in the some hair which comprises the brush hair 74. FIG.
On the other hand, referring to FIG. 10, the special hair so that the rigidity (hardness of the hair) is larger than the other hair (non-special hair 74 b) among the plurality of hairs constituting the brush hair 74. 74a can also be formed. In such a case, the difference in stiffness in the hair can be formed by changing the thickness of the fibers constituting the hair as shown in FIG. 10, or by changing the material of the fibers constituting the hair. can do. An example of the latter is the case where the special hair 74a is formed of PET fiber and the non-special hair 74b is formed of nylon fiber.
Even in such a case, at least the special hair 74a having high rigidity is planted so as to fall from the downstream side in the rotational direction of the developing roller 51 facing the downstream side toward the upstream side in the rotational axis direction. By doing so, the same effect as that of the present embodiment can be obtained. That is, the special hair 74a having high rigidity is likely to enter the recess 51a1 (groove) from the tip of the hair, so that even if the toner T enters the recess 51a1, the toner T is scraped out by the special hair 74a and the direction of the rotation axis. Proceeding to the end side is prevented. Further, the non-special hair 74b (other hair) having low rigidity is difficult to enter the concave portion 51a1, and the gap between the developing roller 51 (particularly, the convex portion) and the developing case 58 without interfering with the function of the special hair 74a described above. Will be filled. As described above, by providing the bristles 74 with the two bristles 74a and 74b having different rigidity and different functions, the toner T is placed in the recesses 51a1 at both ends in the rotation axis direction of the developing roller 51 that the seal member 72 bites into. The toner T gradually enters and the toner T that has entered further leaks to the outside of the developing device 5Y, or the toner T that has entered solidifies (adheres) due to friction with the seal member 72 and damages the seal member 72. Thus, it is possible to reliably reduce problems and the like, and to ensure good sealing performance without applying a large frictional resistance between the seal member 72 and the developing roller 51.
In the present embodiment, the special hair 74a is formed such that the hair foot and the rigidity are larger than the other hair (non-special hair 74b) among the plurality of hairs constituting the brush hair 74. You can also. Even in such a case, the same effect as that of the present embodiment can be obtained.

Further, in the present embodiment, the concave portion 51a1 of the developing roller 51 is formed in a substantially iris shape so that spirals in opposite spiral directions intersect each other over almost the entire region in the rotation axis direction.
On the other hand, referring to FIG. 11A, the recess 51a1 of the developing roller 51 (developer carrying member) is the seal member at the end portion in the rotation axis direction (the portion where the seal member 72 contacts). In the range of the rotation axis direction excluding the rotation axis direction end portion, it is formed in a spiral shape so as to be inclined toward the rotation axis direction end portion side from the rotation direction upstream side to the rotation direction downstream side as seen from the side of 72. It can also be formed in a substantially iris shape so that spirals in opposite spiral directions cross each other. That is, as shown in FIG. 11 (A), the roller portion 51a of the developing roller 51 has a spiral shape portion 51a12 (a portion in which a spiral is formed in one direction) at both ends contacting the seal member 72. The other part is the iris-shaped part 51a11 (the part in which intersecting spirals are formed as in the case shown in FIGS. 4 and 7).
And when the roller part 51a is formed in that way, it is preferable to plant the bristle 74 along the spiral direction of the recessed part (spiral shape part 51a12) in a rotating shaft direction end part. Specifically, in the example of FIGS. 11A and 11B, the seal member 72 is formed so as to incline toward the end in the rotational axis direction from the upstream side in the rotational direction toward the downstream side in the rotational direction when viewed from the seal member 72 side. When the spiral angle of the spiral of the spiral-shaped portion 51a12 is θ2, the inclination angle θ1 of the brush hair 74 (special hair 74a and non-special hair 74b) (a straight line connecting from the root to the hair tip is inclined toward the central portion). Is an angle greater than 0 and less than or equal to θ2. Further, the brush bristles 74 (special bristles 74 a and non-special bristles 74 b) are implanted so as to be inclined against the rotation direction of the developing roller 51.
With this configuration, since there are no recesses (grooves) intersecting the bristles direction of the bristles 74 when viewed from the seal member 72 side, the toner that is conveyed against the bristles 74 is removed. As T decreases, damage caused to the brush bristles 74 due to sliding contact with the developing roller 51 can be weakened, and the function of the seal member 72 in the present embodiment described above can be more easily exhibited.
11 is a view corresponding to FIG. 7, and FIG. 11A shows the developing roller 51 and the seal member 72 as viewed from the seal member 72 side, FIG. 11B is a view of the seal member 72 in FIG. 11A as viewed from below in FIG.
Further, as shown in FIG. 11A, in order to form the iris-shaped portion 51a11 and the spiral-shaped portion 51a12 on the developing roller 51, a first rolling process in which a predetermined direction is a spiral direction is formed on the base portion of the roller portion. The second rolling process is performed from the one end side end to the front of the other end side end, and the second rolling process in which the direction intersecting the predetermined direction with the base of the roller portion is a spiral direction is performed from the other end side end to the one end side end. This can be achieved by applying it to the front (by shifting the range in which the spiral is formed).

  As described above, in the present embodiment, the hair stick (or / and rigidity) is attached to the seal sticking portion 58a formed so as to face the end portion in the rotation axis direction of the developing roller 51 (developer carrier). A stick member 72 having brush hairs 74 made of a plurality of types of hairs 74a and 74b having different hairs is affixed, and special hairs 74a having large bristle feet (or / and rigidity) are downstream in the rotation direction of the developing roller 51. It is planted so as to fall from the side toward the center in the rotational axis direction toward the upstream side in the rotational direction. Thus, even when a plurality of recesses 51 a 1 are formed on the outer peripheral surface of the developing roller 51, the seal member 72 installed so as to be in sliding contact with the rotation shaft direction end of the developing roller 51, and the developing roller 51 It is possible to make it difficult for the toner T (developer) to enter between them.

In the present embodiment, the photosensitive drum 1Y (image carrier), the developing device 5Y (developing device main part 50), the charging device 4Y, and the cleaning device 2Y are integrated as a process cartridge 6Y. The present invention was applied to cases where However, the application of the present invention is not limited to this, and all or a part of these apparatuses 1Y, 2Y, 3Y, and 5Y are each configured as a unit that is detachably attached to the image forming apparatus main body 100. Of course, the present invention can be applied even if it is. In such a case, the same effect as in the present embodiment can be obtained.
In the present application, “process cartridge” means a charging device (charging unit) for charging an image carrier, a developing device (developing unit) for developing a latent image formed on the image carrier, and an image carrier. It is defined as a unit in which at least one of the cleaning devices (cleaning unit) for cleaning the top and the image carrier are integrated and installed detachably with respect to the image forming apparatus main body.

In the present embodiment, the first conveying path B1 and the second conveying path B2 are formed in the developing device main portion 50 of the developing device 5Y to circulate the toner in the longitudinal direction. The structure of the main part 50 is not limited to this. For example, an agitation chamber in which an agitation paddle for agitating the toner in the vertical direction (for example, a flexible member made of Mylar or the like is radially formed on the rotating shaft) is installed in the developing device main part 50. Can also be provided. Further, the toner container 60 is provided with an agitating member for agitating and conveying the toner in the vertical direction instead of the container side conveying screw 62, and the container side replenishing port 63 and the main part side replenishing port 57 are arranged in the axial direction (longitudinal direction). It can also be configured to be provided at a plurality of locations.
Also, in the case where a process cartridge is installed below the intermediate transfer belt, the doctor blade 52 comes into contact with the developing roller 51 at a lower position and moves from the contact position to the upper developing area. Naturally, the present invention can also be applied to the developing device 5Y configured to rotate the developing roller.
In these cases, the same effects as in the present embodiment can be obtained.

In this embodiment, the image forming apparatus 100 is provided with the non-contact one-component developing type developing device 5Y configured such that the developing roller 51 is opposed to the photosensitive drum 1Y with a gap. The present invention was applied. On the other hand, the present invention is also applied to an image forming apparatus in which a developing device of a one-component developing system in which a developing roller is opposed (abutted) to a photosensitive drum without a gap is provided. Can be applied.
Further, in the present embodiment, the distal end portion of the doctor blade 52 made of a metal material is configured to contact the recess 51a1, but the abdomen of the doctor blade 52 can also be configured to contact the recess 51a1. In addition, the doctor blade 52 can be formed of a resin material.
In the present embodiment, the present invention is applied to the developing device 5Y in which a one-component developer made only of toner is accommodated as a developer. On the other hand, a developer carrying member (developing roller) having a plurality of concave portions formed on the outer peripheral surface is used even in a developing device in which a two-component developer composed of toner and carrier is accommodated as a developer. Of course, the present invention can be applied to any device.
Further, in the present embodiment, the present invention is applied to the color image forming apparatus 100 in which the toner image is transferred to the intermediate transfer belt 8 by a plurality of image forming units. In contrast, the present invention can naturally be applied to a monochrome image forming apparatus in which a toner image is transferred to a recording medium by one image forming unit.
In such cases, the same effects as in the present embodiment can be obtained.

Further, in the present embodiment, the bristles 74 in the seal member 72 are divided into special hairs 74a having large hair feet (or / and rigidity) and non-special hairs 74b having small hair feet (or / and rigidity), The hairs are composed of two types of hairs 74a and 74b having different hair feet (or / and rigidity). On the other hand, the bristles 74 in the seal member 72 include special hairs 74a having large bristle feet (or / and rigidity) and two or more types of non-special hairs 74b having small bristle feet (or / and rigidity). It can also be composed of three or more types of hair having different hair feet (or / and rigidity). In other words, a plurality of types of non-special hairs 74b having small hair feet (or / and rigidity) can be provided.
In such a case, the same effect as in the present embodiment can be obtained.
In the present application, “a special hair formed so as to have higher hair or / and rigidity than the other hair among the plurality of hairs constituting the brush hair” It is not necessary to be rigid, and within the scope of the technical idea of the present invention, it is defined to include those having some hairy feet and / or stiffness variations.

  It should be noted that the present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be modified as appropriate within the scope of the technical idea of the present invention, other than suggested in the present embodiment. is there. In addition, the number, position, shape, and the like of the constituent members are not limited to the present embodiment, and the number, position, shape, and the like suitable for implementing the present invention can be achieved.

1Y photosensitive drum (image carrier),
5Y developing device,
6Y, 6M, 6C, 6K process cartridge,
7Y exposure part (writing part),
51 Developing roller (developer carrier)
51a roller section,
51a1 recess (groove),
51a11 iris shape part, 51a12 spiral shape part,
52 Doctor blade (developer regulating member),
53 Supply roller (developer supply member),
58 Development case,
58a seal sticking part,
72 sealing members,
73 base fabric part,
74 brush hair,
74a special hair, 74b non-special hair (other hair),
100 Image forming apparatus (image forming apparatus main body),
T Toner.

JP 2013-76978 A JP 2008-292594 A JP 2009-122642 A

Claims (7)

A developing device that houses a developer and forms a toner image by developing a latent image formed on an image carrier;
A developer carrying body that faces or contacts the image carrying body and rotates in a predetermined direction, and has a plurality of recesses formed on the outer peripheral surface thereof;
A part of the developing case, a seal sticking part formed to face the end of the developer carrying member in the rotation axis direction; and
A seal member in which brush bristles are attached to the seal sticking portion and slidably contacted with an end portion in the rotation axis direction of the developer carrier;
With
The brush bristles of the seal member include special hairs that are formed such that the hairs or / and the rigidity thereof are larger than the other bristles among the plurality of bristles constituting the bristles,
The developing device according to claim 1, wherein the special bristles are planted so as to fall from the downstream side in the rotation direction of the developer carrying member facing thereto toward the upstream side in the rotation axis direction.   2. The developing device according to claim 1, wherein the special hair is formed so that a tip of the special hair enters the inside of the concave portion of the developer carrying member and contacts the bottom. 3.   The developing device according to claim 1, wherein the special hairs are planted at intervals so that the special hairs do not come into contact with each other in an actual use state. The concave portion of the developer carrying member is formed in a substantially iris shape so that spirals in opposite spiral directions intersect with each other over the rotation axis direction.
The brush bristles are formed so as to incline toward the end in the rotational axis direction from the upstream side in the rotational direction to the downstream side in the rotational direction when viewed from the seal member side among the spirals in the spiral directions opposite to each other. 4. The developing device according to claim 1, wherein the developing device is planted along a spiral direction of the spiral. The concave portion of the developer carrying member is
At the end in the rotational axis direction contacting the seal member, it is formed in a spiral shape so as to incline from the upstream side in the rotational direction to the downstream side in the rotational direction when viewed from the side of the seal member,
In the range of the rotation axis direction excluding the rotation axis direction end, it is formed in a substantially iris shape so that the spirals in the spiral direction opposite to each other intersect each other,
The developing device according to claim 1, wherein the brush bristles are planted along a spiral direction of the concave portion at the end portion in the rotation axis direction. A process cartridge that is detachably attached to the image forming apparatus main body,
A process cartridge comprising the developing device according to claim 1.   An image forming apparatus comprising the developing device according to claim 1.

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