JP3997182B2 - Development unit and process cartridge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing unit. as well as Process cartridge The It is related.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a developing means (developing device) mounted on a copying machine or a printer, a longitudinal direction of a developer carrier that is rotatably supported by a developing container and transports the developer to a latent image area on an electrophotographic photosensitive member. There may be a case where seal members are provided at both ends to prevent the toner from flowing out of the developing area. As such a seal member, a magnetic seal member has been proposed that is disposed at both ends of the developing sleeve with a gap from the outer peripheral surface of the developing sleeve (see, for example, Patent Document 1).
[0003]
In addition, toner scraping members for scraping toner that emerges from the gap between the magnetic seal member and the developing sleeve to the inside in the longitudinal direction of the developing sleeve have been proposed (see, for example, Patent Document 2 and Patent Document 3). ).
[0004]
As a method for positioning the magnetic seal member, a configuration is proposed in which the magnetic seal member is abutted against the end face by the urging force generated when the elastic seal member interposed between the sheet metal of the developing blade and the magnetic seal member is compressed. Has been. Furthermore, in order to prevent leakage between the sheet metal of the developing blade and the magnetic seal member, a configuration using an insulating material for the elastic seal member has also been proposed (see, for example, Patent Document 4).
[0005]
However, in these configurations, in order to prevent radiation noise generated when the electrical connection between the magnetic seal member and the developing blade sheet metal is electrically unstable, the gap between the magnetic seal member and the developing blade sheet metal is prevented. It was necessary to insulate.
[0006]
In addition, in the configuration in which the elastic member is compressed between the sheet metal of the developing blade and the magnetic seal to pressurize the magnetic seal, the elastic member requires insulation or the positional relationship between the sheet metal of the developing blade and the magnetic seal Therefore, it is necessary to increase the distance to an insulation distance that does not cause a leak discharge, which is one factor that hinders downsizing of the developing device and the process cartridge.
[0007]
[Patent Document 1]
Japanese Patent No. 3352329
[Patent Document 2]
Japanese Patent No. 3372747
[Patent Document 3]
JP-A-11-143226
[Patent Document 4]
JP 2002-258607 A
[0008]
[Problems to be solved by the invention]
The present invention is a further development of the above prior art.
[0009]
An object of the present invention is to provide a small developing unit and a process cartridge.
[0010]
Another object of the present invention is to provide a scraping member that contributes to miniaturization of the developing unit and the process cartridge.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, in the developing unit according to the present invention,
A developing frame housing a developer having magnetic powder;
A developing roller rotatably supported by the developing frame and carrying and transporting the developer;
A magnetic body provided inside the developing roller;
Conductive material supported by the developing frame Planar A developer regulating member having a support portion and a regulating portion that abuts against the developing roller and regulates the amount of developer on the developing roller;
Provided at both ends in the longitudinal direction of the developing roller with a gap from the surface of the developing roller, When viewed along the perpendicular direction of the planar support portion Said Planar A magnetic seal supported by the developing frame so as not to overlap the support portion, and is abutted against the developing frame Contact end face And said Contact end face A pressure-receiving portion that receives a force for abutting against the developing frame, and a magnetic seal having
When viewed along the perpendicular direction Said to overlap with said pressurized part Planar A scraping member provided on the support portion, the scraping portion moving the developer on the developing roller inward in the longitudinal direction of the developing roller; Contact end face In order to pressurize the portion to be pressed so as to abut against the developing frame Planar An insulative scraping member having a projecting portion projecting toward the developing frame from the support portion;
It is characterized by having.
[0012]
In the process cartridge according to the present invention,
The image forming apparatus main body includes the developing unit and an electrophotographic photosensitive member, and is detachable from the image forming apparatus main body.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent. Further, the materials, shapes, etc. of the members once described in the following description are the same as those in the first description unless otherwise described.
[0015]
(First embodiment)
With reference to FIGS. 1 to 18, a developing unit and a process cartridge according to a first embodiment and an image forming apparatus having these will be described.
[0016]
[Description of Entire Image Forming Apparatus]
First, a schematic configuration of an image forming apparatus and a process cartridge that can be attached to and detached from the image forming apparatus will be described with reference to FIGS.
[0017]
Here, the image forming apparatus is an apparatus that forms an image on a recording medium (for example, recording paper, OHP sheet, cloth, etc.) using an electrophotographic image forming process. Examples of the image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.), an electrophotographic facsimile apparatus, an electrophotographic word processor, and the like. In the present embodiment, an electrophotographic laser beam printer will be described as an example of the image forming apparatus.
[0018]
The process cartridge refers to a cartridge in which at least the developing means and the electrophotographic photosensitive member are integrated into a cartridge that can be attached to and detached from the image forming apparatus main body. In addition, at least one of charging means and cleaning means may be provided. Alternatively, the charging unit, the developing unit, the cleaning unit, and the electrophotographic photosensitive member may be integrally formed as a cartridge, and the cartridge may be detachable from the image forming apparatus main body.
[0019]
FIG. 1 is a schematic cross-sectional view of a laser beam printer which is an embodiment of an image forming apparatus including a process cartridge. FIG. 2 is an external perspective view showing how the process cartridge is mounted on the image forming apparatus main body. FIG. 3 is a schematic perspective view of the process cartridge according to the present embodiment. FIG. 4 is a longitudinal sectional view showing a schematic configuration of the process cartridge according to the present embodiment.
[0020]
As shown in FIG. 1, a laser beam printer (hereinafter referred to as “printer”) A is detachably provided with a process cartridge (hereinafter referred to as “cartridge”) B as an image forming unit.
[0021]
Further, as shown in FIG. 4, the cartridge B has a drum-shaped electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 7. The photosensitive drum 7 is charged by a charging roller 8 as charging means. Then, an electrostatic latent image corresponding to the image information is formed on the photosensitive drum 7 by the laser beam light corresponding to the image information irradiated from the optical means 1 having a laser diode, a polygon mirror, a lens, and a reflection mirror. This electrostatic latent image is developed using a developer (toner) stored in the developing unit 19 to form a developer image (toner image).
[0022]
The developer used in the present embodiment will be described by taking a developer made of magnetic toner (hereinafter referred to as “toner”) as magnetic powder as an example. However, the present invention can also be suitably employed when a developer comprising a magnetic carrier that is magnetic powder and a non-magnetic toner is used.
[0023]
The developing frame 13 includes a developing roller 10, a developing blade 12 as a toner amount regulating member for applying a triboelectric charge to the toner on the surface of the developing roller 10 and forming a toner layer having a predetermined thickness, and the developing roller 10 includes a magnet roller 11 that is a magnetic material included in the toner 10 and a developing chamber 13d that stores toner (developer) that is magnetic powder. The developing frame 13 is welded to a storage container 14 that stores toner, and constitutes a developing unit 19.
[0024]
The storage container 14 is provided with an agitating member 15 for agitating the toner and feeding the toner into the developing chamber 13d. The toner in the storage container 14 is sent out to the developing roller 10 that is rotatably supported by the opening 13e of the developing chamber 13d by the rotation of the stirring member 15. The toner further adheres to the surface of the developing roller 10 and is conveyed along with the rotation of the developing roller 10, and a triboelectric charge is applied by the developing blade 12.
[0025]
In addition, a toner layer having a predetermined thickness is formed on the developing roller 10 and conveyed to a developing region where the photosensitive drum 7 and the developing roller 10 face each other. The toner conveyed to the developing area is transferred to the electrostatic latent image on the photosensitive drum 7 to form a toner image. The developing roller 10 is connected to a developing bias circuit (not shown), and normally a developing bias voltage in which a DC voltage is superimposed on an AC voltage is applied.
[0026]
On the other hand, in synchronization with the formation of the toner image, the recording medium 2 set in the cassette 3a is conveyed to the transfer position by the pickup roller 3b, the conveyance roller pairs 3c and 3d, and the registration roller pair 3e. At the transfer position, a transfer roller 4 as transfer means is disposed, and a toner image on the photosensitive drum 7 is transferred to the recording medium 2 by applying a voltage.
[0027]
The recording medium 2 that has received the transfer of the toner image is conveyed to the fixing unit 5 through the conveyance guide 3f. The fixing unit 5 includes a driving roller 5c and a fixing roller 5b including a heater 5a. The fixing unit 5 applies heat and pressure to the passing recording medium 2 to fix the toner image on the recording medium 2.
[0028]
Thereafter, the recording medium 2 is conveyed by the discharge roller pairs 3 g and 3 h and discharged to the discharge tray 6. The discharge tray 6 is provided on the upper surface of the printer A. The pickup roller 3b, the conveyance roller pairs 3c and 3d, the registration roller pair 3e, the conveyance guide 3f, the discharge roller pairs 3g and 3h, etc. constitute the conveyance means 3.
[0029]
Further, the toner on the photosensitive drum 7 remaining without being transferred to the recording medium 2 is removed by the cleaning unit 17, and the photosensitive drum 7 is subjected to the next image forming process. The cleaning unit 17 includes an elastic blade 17 a that is provided in contact with the photosensitive drum 7 and scrapes off residual toner on the photosensitive drum 7, and a waste toner chamber 17 b that stores the scraped toner.
[0030]
The cartridge B that is detachably mounted on the printer A configured as described above will be further described in detail.
[0031]
As shown in FIGS. 3 and 4, the cartridge B includes a photosensitive drum unit 20 formed by attaching the photosensitive drum 7, the cleaning unit 17, the charging roller 8, and the like to the drum frame 18, the developing unit 19 described above, Are coupled with each other in a rotatable manner.
[0032]
Further, as shown in FIG. 2, the cartridge B is detachably mounted on a cartridge mounting means (not shown) provided on the printer A main body side by opening the opening / closing door 9 of the printer A main body. .
[0033]
[Development unit and magnetic seal configuration]
Next, the developing unit will be described in detail with reference to FIGS. FIG. 5 is an external perspective view of the developing unit according to the present embodiment, and FIG. 6 is a longitudinal sectional view of the developing frame constituting the developing unit.
[0034]
As shown in FIG. 5, the developing unit 19 is a unit in which the storage container 14 and the developing frame 13 are integrally coupled. The developing frame 13 includes a developing roller 10, a sheet metal portion 12a, and an elastic portion 12b, and a toner layer on the developing roller 10. Thickness A developing blade 12 that regulates toner, a magnetic seal 10r for preventing toner leakage from both ends of the developing roller 10, and a scraper 51.
[0035]
As shown in FIG. 6, the magnetic seal 10 r is attached to the developing frame 13, and a gap g <b> 2 is formed between the magnetic seal 10 r and the outer peripheral surface of the developing roller 10.
[0036]
Further, as shown in FIGS. 9A, 9B and 10, a magnetic plate 10r2 made of a magnetic material is provided on the side surface in the width direction (longitudinal direction of the developing roller 10) of the magnet 10r1 constituting the magnetic seal 10r. It is joined. The magnet 10r1 is an injection molded product having a width of 3.4 mm provided with a nylon binder containing Nd—Fe—B magnetic powder. The magnetic plate 10r2 bonded to the side surface is made of an iron material having a thickness of 0.6 mm. And both are joined by insert molding of injection molding.
[0037]
A plurality of N poles and S poles are formed in the circumferential direction on the inner peripheral surface 10r3 of the magnet 10r1 (the surface facing the outer peripheral surface of the developing roller 10). Therefore, a magnetic brush head is formed in the gap g2 by the magnetic field between the magnet roller 11 and the magnet 10r1 built in the developing roller 10, and toner leakage from the end of the developing roller 10 is prevented. In the present embodiment, the gap g2 is set to 0.1 mm to 0.7 mm, and the magnetic flux density of the magnetic seal 10r at that time is about 100 to 200 mT on the developing roller 10.
[0038]
Here, as shown in FIG. 9A, the positional relationship between the magnet 10r1 and the magnetic plate 10r2 is such that the magnet 10r1 is disposed on the opening side of the developing device frame 13 and outside the opening (the developing roller 10). Magnetic plates 10r2 are arranged on both ends in the longitudinal direction.
[0039]
As described above, by arranging the magnet 10r1 on the opening side of the developing frame 13 and the magnetic plate 10r2 on the outside of the opening, the lines of magnetic force generated from the magnet 10r1 are as shown in FIG. 9B. Since the magnetic plate 10r2 having a high magnetic permeability is entered, no magnetic field lines are generated that extend outside the width of the magnetic seal 10r.
[0040]
Accordingly, since the toner on the magnetic seal 10r does not spread outward from the magnetic plate 10r2, it is possible to reliably hold the toner in a range where the magnetic force on the surface of the magnetic seal 10r is strong. As a result, it is possible to obtain a good sealing property that prevents the toner from leaking even when an impact is applied when the user attaches / detaches the cartridge B to / from the printer A body.
[0041]
[Developer scraping member]
Further, the toner is moved inward in the longitudinal direction of the developing roller 10 so that the toner coming out of the gap between the magnetic seal 10 r and the surface of the developing roller 10 does not move to the surface facing the photosensitive drum 7 by the rotation of the developing roller 10. A scraper 51 as a scraping member for scraping is disposed. Here, as shown in FIGS. 5 and 6, the scraper 51 is disposed at positions corresponding to the magnetic seals 10 r at both ends in the longitudinal direction of the developing roller 10.
[0042]
FIG. 8 is an external perspective view of the scraper according to the present embodiment as seen from different directions. As shown in FIGS. 8A and 8B, the scraper 51 includes a positioning hole 51d for fitting with a positioning boss 30 provided in the developing frame 13, a screw hole 51c for fixing with a screw 31, and a development. A scraping portion 51a that contacts the roller 10 and scrapes the toner, and further, a pressurizing portion 51b that pressurizes the magnetic seal 10r on the back surface as shown in FIG. 8B.
[0043]
As a material for the scraper 51, polyacetal (POM), polycarbonate, or the like that is insulative and has sliding properties is used.
[0044]
[Magnetic seal positioning configuration]
Next, a method of attaching the magnetic seal 10r will be described with reference to FIGS. 6, 7, and 10 to 16. FIG. Further, the magnetic seal 10r and the scraper 51 are attached to both end portions of the developing roller 10, but the structure on one side is shown in the description.
[0045]
As shown in FIGS. 6 and 10, the magnetic seal 10 r is located on the inner circumferential side of the inner circumferential surface 10 r 3 having a semicircular arc shape that forms a gap g 2 between the developing roller 10 and the inner circumferential surface 10 r 3. A semicircular arc-shaped circumscribed surface 10r4 in contact with the developing frame 13 on the outer peripheral side, a flat pressed surface 10r5 pressed for positioning on the upper side of the magnetic seal 10r, and a developing frame 13 on the lower tip portion. Abutting end face 10r6 that abuts.
[0046]
On the other hand, as shown in FIGS. 6, 11, and 12, the developing frame 13 is provided with a mounting arc portion 13 a that contacts the outer surface 10 r 4 and a mounting end surface 13 b that contacts the contact end surface 10 r 6.
[0047]
As shown in FIG. 13, when the magnetic seal 10r is assembled to the developing device frame 13, the magnetic seal 10r moves until the circumscribed surface 10r4 of the magnetic seal 10r contacts the mounting arc portion 13a (in the direction of arrow X in the figure). Thereafter, when the magnetic seal 10r is rotated until the abutting end surface 10r6 abuts against the mounting end surface 13b which is the abutting portion, the magnetic seal 10r is determined at a predetermined position as shown in FIG.
[0048]
The longitudinal direction of the magnetic seal 10r is determined by inserting the longitudinal end surface 10r7 (see FIG. 10) of the magnetic seal 10r between the longitudinal positioning surfaces 13c (see FIG. 12) of the developing device frame 13.
[0049]
Next, an elastic seal member 50 for preventing toner leakage from the back surface of the developing blade 12 is attached to a part of the developing frame with double-sided tape. The longitudinal direction of the elastic seal member 50 is a length that reaches the front surface of the pressed surface 10r5 of the left and right magnetic seals 10r (see FIGS. 7 and 14).
[0050]
Next, as shown in FIG. 15, the developing blade 12 is fixed to the developing frame 13 with screws 31 at both ends of the sheet metal portion 12 a together with the scraper 51.
[0051]
Next, as shown in FIG. 16, the developing roller 10 and the magnet roller 11 are assembled in the developing frame 13, and then the holders 40 a and 40 b are fixed to the developing frame 13 with screws 32 from the left and right, thereby developing unit 19. Is assembled.
[0052]
As shown in FIGS. 6 and 7, when the scraper 51 is assembled to the developing device frame 13, the pressurizing portion 51 b (see FIG. 8) of the scraper 51 compresses the elastic seal member 50. The compressed elastic seal member 50 pressurizes the pressed surface 10r5 of the magnetic seal 10r in the direction of arrow Y shown in FIG. As a result, the contact end surface 10r6 of the magnetic seal 10r is constantly pressed in the direction of the mounting end surface 13b of the developing frame 13, and the gap between the magnetic seal 10r and the developing roller 10 is properly maintained.
[0053]
In this way, by using the elastic seal member 50 that seals between the developing blade 12 and the developing frame 13 to pressurize the magnetic seal 10r, stable pressing can be performed without the need for a new elastic member. This can be done and contributes to cost reduction.
[0054]
Further, by using the scraper 51 to compress the elastic seal member 50, it is possible to provide a developing device and a process cartridge that are easy to assemble and low in cost without increasing the number of parts.
[0055]
Next, the positional relationship among the sheet metal part 12a of the developing blade 12, the pressed surface 10r5 of the magnetic seal 10r, and the pressing part 51b of the scraper 51 in a state where the developing unit 19 is assembled will be described.
[0056]
17 is a partial front view showing the positional relationship between the magnetic seal 10r and the developing blade 12, and FIG. 18 is a partial perspective view showing the positional relationship between the scraper and the developing blade.
[0057]
As shown in FIG. 17, when viewed from the direction in which the scraper 51 (developing blade 12) is attached to the developing frame 13, the sheet metal portion 12a and the magnetic seal 10r are in a positional relationship so as not to overlap. More specifically, the sheet metal part 12a and the magnetic seal 10r are projected so as not to overlap when the sheet metal part 12a and the magnetic seal 10r are projected on a plane whose vertical is the mounting direction shown in FIG. 12a and a magnetic seal 10r are arranged. Further, as shown in FIG. 18, the sheet metal part 12a and the pressurizing part 51b of the scraper 51 are also in a positional relationship such that the sheet metal part 12a and the pressurizing part 51b do not overlap when viewed from the direction in which the scraper 51 is attached. ing. More specifically, when the sheet metal part 12a and the pressurizing part 51b are projected on a plane whose mounting direction is a perpendicular line, the sheet metal part 12a and the pressurizing part 51b are not overlapped with each other. A pressurizing part 51b is arranged.
[0058]
For this reason, since the conductive sheet metal part 12a is not disposed between the pressurizing part 51b and the magnetic seal 10r, it is difficult to leak between the magnetic seal 10r and the sheet metal part 12a, and insulation is provided therebetween. Even if the insulating member is provided, since the required insulating performance may be lower than that of the conventional one, the size of the insulating member and the selection of the material are widened, and the cost can be suppressed.
[0059]
In addition, since the sheet metal part 12a is not sandwiched between the pressed surface 51r5 and the pressing part 51b that faces the pressed surface 10r5, the magnetic seal 10r can be positioned together with the assembly of the scraper 51, which facilitates the assembly. it can.
[0060]
[Leakage measures for magnetic seal]
The magnetic seal 10r is charged by the voltage supplied to the developing roller 10 and charges are accumulated. Alternatively, the toner is present between the developing roller 10 and the magnetic seal 10r and is charged by friction between the magnetic seal 10r and the charge is accumulated.
[0061]
Therefore, when the magnetic seal 10r and the conductive member (for example, the sheet metal portion 12a of the developing blade 12) are in contact with or separated from each other, the magnetic seal 10r and the conductive member There is a problem that leakage occurs between them and noise is generated. With respect to this problem, in this embodiment, the distance S1 (see FIG. 6) between the sheet metal part 12a of the developing blade 12 and the magnetic seal 10r is set to be equal to or greater than the leak limit distance.
[0062]
Further, since the scraper 51 is an insulating material, the distance S2 (see FIG. 6) between the pressurizing portion 51b and the magnetic seal can be made close without being restricted by the leak limit distance, and the compression amount of the elastic seal member 50 Can be set freely, and selection of materials and shapes of elastic seal members is widened. Accordingly, the cost and size of the developing unit and process cartridge can be reduced.
[0063]
The scraper 51 is made of an insulating material. Therefore, when the elastic member that is sandwiched and compressed between the scraper 51 and the magnetic seal 10r is a small piece that does not contact the sheet metal portion 12a, the elastic member does not need electrical insulation. Accordingly, selection of materials and shapes is widened, and the cost and size of the developing unit and process cartridge can be reduced.
[0064]
(Second Embodiment)
A second embodiment will be described with reference to FIGS. FIG. 19 is an external perspective view of the scraper according to the second embodiment, and FIG. 20 is a partial vertical cross-sectional view of the developing device frame constituting the developing unit according to the second embodiment.
[0065]
As shown in FIGS. 19A and 19B, the scraper 52 includes a positioning hole 52d for fitting with a positioning boss 30 provided in the developing frame 13, a screw hole 52c for fixing with a screw 31, and a development. It has a scraping portion 52a that contacts the roller 10 and scrapes the toner, and further includes a mold spring-shaped elastic portion 52e that pressurizes the magnetic seal 10r as shown in FIG. 19B.
[0066]
Next, a method for pressurizing the magnetic seal 10r will be described. As shown in FIG. 19, the elastic portion 52e is integrally formed at a position facing the pressed surface 10r5 of the magnetic seal 10r of the scraper 52. Then, the elastic portion 52e directly pressurizes the pressed surface 10r5 as shown in FIG. 20, whereby the magnetic seal 10r is positioned with respect to the developing device frame 13.
[0067]
Moreover, an insulating effect can be obtained by making the material of the scraper 52 insulative. Further, even in the configuration without the elastic seal member 50 for sealing the developing blade 12, it is possible to form the elastic portion 52e integrally with the scraper 51, which is an insulating member, and directly pressurize and position the magnetic seal 10r. It becomes. Therefore, since a special elastic member for pressurizing the magnetic seal 10r is not required, the cost can be reduced without increasing the number of parts.
[0068]
Note that the attachment of the scraper 52 according to the present embodiment to the developing unit 19 is substantially the same as that of the first embodiment, and thus description thereof is omitted.
[0069]
The embodiments described above are summarized as follows.
[0070]
(1) a developing frame 13 containing a developer having magnetic powder;
A developing roller 10 rotatably supported by the developing frame 13 and carrying and transporting the developer;
A magnetic body (magnet roller 11) provided inside the developing roller 10;
Magnetic seals 10r provided at both ends in the longitudinal direction of the developing roller 10 with a gap from the surface of the developing roller 10,
An abutting portion (attachment end surface 13b) provided on the developing frame 13 with which the magnetic seal 10r abuts;
An insulating member (scraper 51);
An elastic member (elastic seal member 50) that is sandwiched and compressed between the insulating member (scraper 51) that abuts the magnetic seal 10r against the abutting portion (attachment end surface 13b) and the magnetic seal 10r;
A developing unit 19 comprising:
[0071]
(2) a developing frame 13 containing a developer having magnetic powder;
A developing roller 10 rotatably supported by the developing frame 13 and carrying and transporting the developer;
A magnetic body (magnet roller 11) provided inside the developing roller 10;
Magnetic seals 10r provided at both ends in the longitudinal direction of the developing roller 10 with a gap from the surface of the developing roller 10,
An abutting portion (attachment end surface 13b) provided on the developing frame 13 with which the magnetic seal 10r abuts;
An insulating member (scraper 52) having an elastic portion 52e that pressurizes the magnetic seal 10r;
With
The developing unit 19, wherein the insulating member (scraper 52) abuts the magnetic seal 10r against the abutting portion (attachment end surface 13b) by the elastic portion 52e.
[0072]
(3) The insulating members (scrapers 51, 52) have a scraping portion (51a, 52a) that moves the developer on the developing roller 10 inward in the longitudinal direction of the developing roller (1). ) Or the developing unit 19 according to (2).
[0073]
(4) having a support portion 12a supported by the developing frame 13 and having a developer regulating member (developing blade 12) for regulating the amount of developer on the developing roller 10;
The insulating members (scrapers 51 and 52) are provided on the opposite side of the pressed surface 10r5 of the magnetic seal 10r across a plane having a perpendicular to the direction in which the support portion 12a is attached to the developing frame 13. The developing unit 19 according to (1), (2) or (3).
[0074]
(5) The support portion 12a is disposed so as not to overlap the magnetic seal 10r when viewed from the direction in which the support portion 12a is attached to the developing frame 13. The developing unit 19 described.
[0075]
(6) The development unit 19 according to any one of (1) to (5) and the electrophotographic photosensitive member (photosensitive drum 1) are provided, and are detachable from the main body of the image forming apparatus (printer A). Process cartridge B characterized by
[0076]
(7) A developing frame 13 that stores a developer having magnetic powder, a developing roller 10 that is rotatably supported by the developing frame 13 and carries and conveys the developer, and the inside of the developing roller 10 A magnetic body (magnet roller 11) provided, a magnetic seal provided at both ends in the longitudinal direction of the developing roller 10 with a gap from the surface of the developing roller 10, and the developing frame 13 are provided. A positioning portion (positioning hole 52d) positioned on the developing unit 19 provided with an abutting portion (attachment end surface 13b) against which the magnetic seal 10r abuts;
A scraping portion 52a for moving the developer on the developing roller 10 inward in the longitudinal direction of the developing roller;
An elastic portion 52e that pressurizes the magnetic seal 10r,
The scraping member 52, wherein the scraping portion 52a and the elastic portion 52e are made of an insulating material.
[0077]
【The invention's effect】
As described above, according to the present invention, a small developing unit and a process cartridge can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of an image forming apparatus according to an embodiment.
FIG. 2 is an external perspective view showing a state in which a process cartridge is attached to the image forming apparatus according to the present embodiment.
FIG. 3 is an external perspective view of a process cartridge according to the present embodiment.
FIG. 4 is a longitudinal sectional view showing a schematic configuration of a process cartridge according to the present embodiment.
FIG. 5 is an external perspective view of a developing unit according to the present embodiment.
FIG. 6 is a partial longitudinal sectional view of a developing device frame constituting the developing unit according to the present embodiment.
FIG. 7 is a longitudinal sectional view of a developing unit according to the present embodiment.
FIG. 8 is an external perspective view of the scraper according to the first embodiment viewed from different directions.
FIG. 9 is a schematic diagram showing a positional relationship between a magnetic seal and a developing roller according to the present embodiment.
FIG. 10 is an external perspective view of a magnetic seal according to the present embodiment.
FIG. 11 is an external perspective view of a developing unit according to the present embodiment.
FIG. 12 is a partial perspective view of a mounting portion of a magnetic seal of the developing unit according to the present embodiment.
FIG. 13 is a partial perspective view showing a state in which the magnetic seal is attached to the magnetic seal attaching portion of the developing unit according to the present embodiment.
FIG. 14 is a partial perspective view showing a state where a magnetic seal and an elastic seal member are attached to the developing unit according to the present embodiment.
FIG. 15 is an exploded perspective view showing a state where a developing blade and a scraper are attached to the developing unit according to the present embodiment.
FIG. 16 is an external perspective view showing a state where the developing roller and the holder are attached to the developing unit according to the present embodiment.
FIG. 17 is a partial front view showing the positional relationship between the magnetic seal and the developing blade according to the present embodiment.
FIG. 18 is a partial perspective view showing a positional relationship between a scraper and a developing blade according to the present embodiment.
FIG. 19 is an external perspective view of a scraper according to a second embodiment.
FIG. 20 is a partial longitudinal sectional view of a developing device frame constituting the developing unit according to the second embodiment.
[Explanation of symbols]
A Image forming device (laser beam printer)
B Process cartridge
1 Optical means
2 recording media
3 Transport means
4 Transfer roller
5 Fixing means
6 Discharge tray
7 Photosensitive drum (electrophotographic photosensitive member)
8 Charging roller (charging means)
9 Opening door
10 Developing roller
10r magnetic seal
10r1 magnet
10r2 magnetic plate
10r3 inner surface
10r4 circumscribed surface
10r5 surface to be pressed
10r6 contact end face
10r7 Long end face
11 Magnet roller
12 Development blade (regulating member)
12a Sheet metal part
12b Elastic part
13 Development frame
13a Mounting arc
13b Mounting end face
13c Long positioning surface
13d Development chamber
13e opening
13d Development chamber
14 Storage container (developer storage container)
15 Stirring member
17 Cleaning means
18 Drum frame
19 Development unit
20 Photosensitive unit
30 Positioning boss
31, 32 screw
50 Elastic seal member
51, 52 Scraper (Scraping member)
51a, 52a scraping part
51b Pressurizing part
51c, 52c Screw hole
51d, 52d Positioning hole
52e Elastic part
A Printer (image forming device)
B Process cartridge

Claims (7)

A developing frame housing a developer having magnetic powder;
A developing roller rotatably supported by the developing frame and carrying and transporting the developer;
A magnetic body provided inside the developing roller;
A developer regulating member having a conductive planar support portion supported by the developing frame, and a regulating portion that abuts the developing roller and regulates the amount of developer on the developing roller;
Provided at both ends in the longitudinal direction of the developing roller with a gap from the surface of the developing roller, so as not to overlap the planar support when viewed along the perpendicular direction of the planar support. A magnetic seal supported by the developing device frame, and a contact end surface that is abutted against the developing device frame, and a pressed portion that receives a force for abutting the contact end surface against the developing device frame A magnetic seal having,
A scraping member provided on the planar support portion so as to overlap with the pressed portion when viewed along the perpendicular direction , wherein the developer on the developing roller is moved in the longitudinal direction of the developing roller. A scraping portion that moves inward, and a protrusion that protrudes toward the developing device frame rather than the planar support portion to pressurize the pressed portion so that the abutting end surface abuts against the developing device frame. An insulating scraping member having a portion;
A developing unit comprising: 2. The developing unit according to claim 1, further comprising an elastic member that is compressed between the projecting portion and the pressed portion so that the abutting end surface abuts the developing frame. 2. The developing unit according to 1.   The developing unit according to claim 2, wherein the elastic member seals between the developer regulating member and the developing frame. The scraping member is attached to the developing frame through the planar support portion, and when viewed along the longitudinal direction of the developing roller, the elastic member has the scraping member and the covered member. The developing unit according to claim 2, wherein the developing unit is provided between the pressing unit and the pressure unit. The developing unit according to claim 1, wherein the protruding portion has a plate shape having elasticity and is in contact with the pressed portion. 6. The pressurized portion is a surface, and the magnetic seal and the planar support portion do not overlap when viewed along the direction of the normal to the surface. 2. The developing unit according to item 1.   7. A process cartridge comprising the developing unit according to claim 1 and an electrophotographic photosensitive member, wherein the process cartridge is detachable from the main body of the image forming apparatus.

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