JP2004317643A - Developing frame, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing frame constituted so that toner is prevented from leaking out of the periphery of a magnetic sealing member and the magnetic sealing member can be easily attached to the developing frame. <P>SOLUTION: As for the developing frame including developer, a developing roller for carrying the developer, a developer control member for controlling the quantity of the developer carried by the developing roller and the sealing member for sealing in the developer at the longitudinal end part of the developing roller, a wall nearly vertical to the longitudinal direction of the developing roller is arranged between a developing chamber and the sealing member, and the wall is provided with a positioning surface in the longitudinal direction of the developing roller of the sealing member. In this case, a rib arranged in the developing frame functions as the wall, and also, magnetic developer is used as the developer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a developing frame, a process cartridge, and an image forming apparatus that prevent a developer from flowing out between both ends of a developing roller and a developing frame.
[0002]
[Prior art]
2. Description of the Related Art An image forming apparatus such as a printer using an electrophotographic technique selectively forms a latent image by selectively exposing a uniformly charged photosensitive drum (electrophotographic photosensitive member), and visualizes the latent image with toner. At the same time, the toner image is transferred to a recording medium to record an image.
[0003]
In such an apparatus, the photosensitive drum, the charging device, the developing device, the cleaning member, and the like are integrated into a cartridge to form a cartridge. A photosensitive drum that can be replenished and replaces a photosensitive drum component that has reached the end of its life and that facilitates maintenance by a user is widely used.
[0004]
In such a developing device of a process cartridge, seal members for preventing the developer from flowing out of the developing area are provided at both ends of the rotating developer carrier.
[0005]
Conventionally, an elastic member such as felt or foamed rubber has been used as a seal member for preventing the developer from flowing out. However, a magnetic seal member having an inner peripheral surface magnetized to multiple poles with NS poles is also used. Is used with the configuration shown in JP-A-11-143225.
[0006]
The magnetic seal member is arranged in a non-contact manner with a certain gap to the developer carrier, and prevents the developer from flowing out by a concentrated magnetic field formed between the magnetic seal member and a magnet in the developer carrier. Has become. Since the magnetic seal member is not in contact with the developer carrier unlike the elastic member such as felt or foam rubber, it is advantageous in that the torque increases and the seal member deteriorates.
[0007]
Recently, a magnetic brush portion of conductive magnetic particles, in which conductive magnetic particles are carried and conveyed to an image carrier by a magnetic particle carrier having a magnet disposed therein, and held magnetically by the magnetic particle carrier. There is a charging device of a magnetic brush type in which a magnetic brush is circulated and conveyed to a contact portion with the image carrier by rotating the magnetic particle carrier by bringing the magnetic brush into contact with the image carrier and charging the surface of the image carrier. Even in a simple device, the magnetic seal member is effective as a means for preventing the outflow of the conductive magnetic particles from both ends of the magnetic particle carrier.
[0008]
[Problems to be solved by the invention]
The present invention is a further development of the above-described conventional example, in which toner leakage from the periphery of the magnetic sealing member is prevented, and the mounting of the magnetic sealing member to the developing frame is facilitated. It is an object to provide an image forming apparatus.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a typical configuration according to the present invention includes a developer, a developing roller that carries the developer, and a developer regulation for regulating an amount of the developer carried by the developing roller. In a developing frame body including a member and a seal member for sealing the developer at a longitudinal end of the developing roller, a developing frame and the seal member are disposed between the developing chamber and the seal member. A wall is provided, and the wall has a positioning surface of the seal member in a longitudinal direction of the developing roller.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0011]
In the following description, the longitudinal direction of the process cartridge refers to a direction that intersects with the direction in which the process cartridge is attached to and detached from the apparatus main body (a direction substantially orthogonal to the axis of the image carrier), and is parallel to the surface of the recording medium. And a direction intersecting (substantially perpendicular to) the conveying direction of the recording medium. The left and right are left or right when the recording medium is viewed from above according to the transport direction of the recording medium. Further, the upper surface of the process cartridge is a surface located above when the process cartridge is mounted on the apparatus main body, and the lower surface is a surface located below.
[0012]
<Embodiment 1>
This will be specifically described with reference to FIGS. FIG. 1 is a schematic diagram illustrating the configuration of an electrophotographic image forming apparatus equipped with a process cartridge, and FIG. 2 is a schematic diagram illustrating the configuration of a process cartridge. Here, as the order of the description, first, the overall configuration of the process cartridge and the electrophotographic image forming apparatus using the same will be described, and then the detailed configuration according to the present invention will be described.
[0013]
(overall structure)
As shown in FIG. 1, an electrophotographic image forming apparatus (laser beam printer, hereinafter referred to as an “image forming apparatus”) A is configured to transmit information light based on image information from an exposure apparatus 1 as an optical unit into a drum shape. An electrostatic latent image is formed on the photosensitive drum 7 by irradiating an electrophotographic photosensitive member (hereinafter, referred to as “photosensitive drum”) 7, and this electrostatic latent image is used as a developer (hereinafter, referred to as “toner”) ) To form a toner image.
[0014]
Then, in synchronization with the formation of the toner image, the recording medium (recording sheet, OHP sheet, cloth, etc.) 2 is separated and fed one by one from the cassette 3a by the pickup roller 3b and the pressing member 3c pressed against the same, and is conveyed. The toner image formed on the photosensitive drum 7 of the process cartridge B along the guide 3f1 is transferred to the recording medium 2 by applying a voltage to the transfer roller 4 as a transfer unit, and the recording medium 2 is transferred along the transport guide 3f2. The sheet is conveyed to the fixing unit 5.
[0015]
The fixing means 5 is composed of a fixing rotator 5d which includes a driving roller 5a and a heater 5b and is formed of a tubular sheet rotatably supported by a support 5c, and applies heat and pressure to the recording medium 2 passing therethrough. The applied voltage fixes the transferred toner image. The recording medium 2 is conveyed by a discharge roller 3d, and is discharged to a discharge section 6 through a reverse conveyance path.
[0016]
In the present embodiment, the conveyance means 3 is constituted by the pickup roller 3b, the pressure contact member 3c, the discharge roller 3d, and the like.
[0017]
(Process cartridge)
On the other hand, the process cartridge B includes an electrophotographic photosensitive member and at least one process means. Here, as the process means, for example, a charging means for charging an electrophotographic photosensitive member, a developing means for developing an electrostatic latent image formed on the electrophotographic photosensitive member, and a cleaning means for cleaning toner remaining on the electrophotographic photosensitive member There are cleaning means and the like.
[0018]
As shown in FIG. 2, the process cartridge B according to the present embodiment rotates a photosensitive drum 7 which is an electrophotographic photosensitive member having a photosensitive layer, and applies a voltage to a charging roller 8 which is a charging means to apply the photosensitive drum. The surface of the body drum 7 is uniformly charged, and the charged photosensitive drum 7 is exposed to information light (light image) based on the image information from the exposure device 1 through the exposure opening 9b. An electrostatic latent image is formed on the surface of the developing device 7, and the electrostatic latent image is developed by a developing unit 10 as a developing device.
[0019]
(Developer)
Next, the developing device D incorporated in the process cartridge B will be described with reference to FIGS.
[0020]
The developing device D includes components for supplying power to the first developing frame 10f1, the second developing frame 10f2, the end member 10g, and the developing roller 10d as a developer carrier, which form the toner storage unit 10a. A developing roller 10d as a developer carrier, a developing blade 10e as a developer regulating member for regulating the layer thickness of the developer on the developing roller 10d, and a device for preventing toner from leaking from both ends of the developing roller 10d. It is made of a magnetic material sealing member 10r or the like (see FIG. 3).
[0021]
In the developing device D, the toner in the toner storage unit 10a is sent out by a rotatable sending member 10b which is a toner sending unit. The developing roller 10d, which is a developing rotator (developer carrying member) containing the fixed magnet 10c, is rotated, and the toner layer provided with triboelectric charge by the developing blade 10e, which is a developer regulating member, is rotated by the developing roller 10d. The toner image is formed on the surface, and the toner is transferred to the photosensitive drum 7 in accordance with the electrostatic latent image, thereby forming a toner image and visualizing the toner image.
[0022]
The first developing frame 10f1 is rotatably supported with respect to the cleaning frame 11d so that the developing roller 10d of the developing device D can face the photosensitive drum 7 in parallel at a predetermined interval. A gap holding member 10m (see FIG. 3) for holding a gap between the roller 10d and the photosensitive drum 7 is disposed at both ends of the developing roller 10d.
[0023]
As shown in FIG. 3, there are holder members (hereinafter, referred to as "end members") 10g on both side surfaces of the first developing frame 10f1, and coupling holes for rotatably hanging the cleaning device described below. It has an arm portion 10g7 on which 10g8 is formed.
[0024]
The toner storage section 10a and the developing chamber 10i are formed by combining a first developing frame 10f1 and a second developing frame 10f2. That is, the developing frame of the present embodiment includes the first developing frame 10f1 and the second developing frame 10f2.
[0025]
As shown in FIG. 4, the first developing frame 10f1 includes a stirring shaft 10b1 for supplying toner and a sheet member 10b2 fixed to the stirring shaft 10b1, and regulates drive transmission and the length of the stirring shaft 10b1. The transport gear 10b3 is coupled to the stirring shaft 10b1 together with a seal member 10b4 for preventing toner from flowing out of the first developing frame 10f1.
[0026]
The first developing frame 10f1 is provided with a toner passage opening 10k through which the toner stored in the toner storage unit 10a passes when supplied to the developing roller 10d.
[0027]
Further, as shown in FIG. 4, the toner seal member 27 is heat-fixed to the seal mounting portion 10h along four edges of the toner passage opening 10k. At one end of the first developing frame 10f1 in the longitudinal direction, as shown in FIG. 3, a toner filling port 10u for filling the toner into the toner storage section 10a is provided. Sealed.
[0028]
The developing device D sends out the toner stored in the toner storage portion 10a by a feed member 10b, forms a toner layer on a developing roller 10d by the magnetic force of a fixed magnet 10c, and supplies the toner layer. The latent image formed in No. 7 is developed with toner to be a visible image. The toner image is transferred to the recording medium 2 by applying a voltage having a polarity opposite to that of the toner image to the transfer roller 4.
[0029]
The configuration of the toner seal at the longitudinal end of the developing roller 10d will be described later.
[0030]
(Cleaning device)
Next, the configuration of the cleaning device C will be described in detail with reference to FIGS. 2 and 5 to 7.
[0031]
The toner image developed by the developing means as described above is transferred to the recording medium 2 at the transfer section. After the transfer, the toner remaining on the photosensitive drum 7 is scraped off by the cleaning blade 11a, and is scooped and removed by the squeeze sheet 11b. The residual toner on the photosensitive drum 7 is removed and stored by the cleaning unit 11 collected in the toner storage unit 11c.
[0032]
The cleaning unit 11 is a unit that removes and stores the toner remaining on the photoconductor drum 7 after the transfer from the photoconductor. A first sealing member 11e for preventing toner leakage from the both ends of the rubber on both sides of the cleaning blade 11a from the removed toner accommodating section 11c as the accommodating means; A second seal member 11h for preventing toner leakage behind the cleaning blade is fixed to a predetermined position of the cleaning frame 11d with a double-sided tape or the like.
[0033]
Next, a cleaning blade is fixed to a predetermined position of the cleaning frame 11d with a screw, and the cleaning blade 11a is used to prevent toner leakage from both ends of the rubber of the cleaning blade 11a and to wipe off adhered matter such as toner on the photosensitive drum 7. A third seal member 11f as a reference and a scooping sheet 11b as a scooping member are fixed to the cleaning frame 11d by a double-sided tape 11g or the like.
[0034]
The cleaning device C supplies power to the above-described cleaning unit 11, the photosensitive drum 7, the drum shutter 12, and the charging roller 8 from the image forming apparatus main body A, and further supplies power to the charging roller 8 from the electrode 8c. , A roller bearing 8b serving as a bearing, and the other bearing 8a.
[0035]
The electrode 8c is fitted in the cleaning frame 11d, the roller bearing 8b and the other bearing 8a are incorporated in the cleaning frame, and the shaft of the charging roller 8 is fitted in the bearings 8a and 8b.
[0036]
The process cartridge B described in the present embodiment includes a cleaning device C that rotatably supports the photosensitive drum 7 and a developing device D that develops a visible image on the photosensitive drum 7.
[0037]
A predetermined pressure is applied between the developing device D and the cleaning device C in order to maintain an interval.
[0038]
The photoconductive drum 7 is connected on one side to a triangular coupling portion 70 for driving transmission, a developing gear 10, a gear for transmitting power to the transfer roller 4, and a drum gear 71 integrally formed with a ground contact, and the other is provided with a bearing. Flange 85 is connected. The photosensitive drum 7 has a bearing 18c connected to the triangular coupling portion 70 side by a screw, and the other is press-fitted into the cleaning frame 11d and supported so that the positioning pin 18d fits in the positioning portion 18b.
[0039]
In the process cartridge B of the present embodiment, as shown in FIG. 2, a drum shutter 12 that can integrally cover a transfer opening 9a and an exposure opening 9b of the photosensitive drum 7 facing the transfer roller 4 has a cleaning frame. It is rotatably provided on the body 11d.
[0040]
(Drum shutter)
Here, the configuration of the drum shutter 12 will be briefly described.
[0041]
The drum shutter 12 has a drum protection portion 12a that can cover the transfer opening 9a where the photosensitive drum 7 contacts the transfer roller 4. A rotary shaft 12b (see FIG. 2) for rotatably supporting the cleaning frame 11d in the vicinity of the charging roller 8 includes a sliding portion 12b1 that slides on the cleaning frame 11d at both ends of the rotary shaft 12b. A connecting portion 12b3 for connecting the sliding portion 12b1 is provided.
[0042]
The drum shutter 12 has two connecting portions 12c provided at both left and right portions connecting the both ends of the drum protecting portion 12a and the outside of the rotating shaft 12b. There is a rib 12e disposed outside the rotary shaft 12b1 and provided on the right connecting portion 12c and extending outward in the longitudinal direction of the drum shutter 12 (see FIG. 7). The rib 12e is a shutter on the image forming apparatus main body side. The drum shutter 12 is held on the guide surface, and the posture in which the drum shutter 12 is open is maintained.
[0043]
An urging force is applied to the drum shutter 12 in a direction in which the drum shutter 12 covers the photosensitive drum 7 by a spring force of a shutter spring 12d. As a result, when the process cartridge B is taken out of the apparatus main body, the drum shutter 12 maintains the closed state covering the transfer opening 9a of the photosensitive drum 7 in the state shown in FIGS.
[0044]
On the other hand, in a state in which the image forming operation is possible in the apparatus main body, the drum shutter is opened and closed by the drum shutter opening / closing means on the image forming apparatus main body side to expose the transfer opening 9a as shown in FIGS. The transfer roller 4 takes a posture that can be brought into contact.
[0045]
(Magnetic seal member and developing method in developing device)
Next, a seal configuration for preventing toner leakage in the above-described developing device D will be described with reference to FIGS. FIG. 8 shows a magnetic seal. FIG. 8A shows the positional relationship between the first developing frame 10f1, the second developing frame 10f2, the developing roller 10d, the elastic member 30, and the magnetic seal 10r. FIG. 4B is a perspective view of the magnetic sealing member 10r, and FIG. 4C is an explanatory diagram illustrating a state of generation of a magnetic field in the magnetic sealing member 10r. FIGS. 9A and 9B show the positional relationship between the magnet 10r1 and the magnetic plate 10r2 of the magnetic sealing member. FIG. 9A is an overall view, and FIG.
[0046]
As shown in FIG. 8A, the magnetic sealing member 10r is attached to the first developing frame 10f1 and the second developing frame 10f2, and a gap is formed between the first developing frame 10f1 and the outer peripheral surface of the developing roller 10d. A gap g2 is formed.
[0047]
As shown in FIG. 8B, a magnetic plate 10r2 made of a magnetic material is joined to a side surface in the width direction (longitudinal direction of the developing roller 10d) of the magnet 10r1 of the magnetic seal member 10r. The magnet 10r1, which is a component of the magnetic sealing member 10r, is a 2.5 mm-width injection-molded product provided with a nylon binder containing a magnetic powder of Nd-Fe-B, and is joined to a side surface thereof. The magnetic plate 10r2 is made of an iron material having a thickness of 0.5 mm, and both are joined by insert molding of injection molding.
[0048]
As shown in FIG. 8C, a plurality of NS poles are magnetized on the inner peripheral surface 10r3 of the magnet 10r1 (the surface facing the outer peripheral surface of the developing roller 10d), and a gap g2 with the developing roller 10d is formed. Ears of the magnetic brush are formed to prevent toner from leaking from the end of the developing roller 10d. In the present embodiment, the gap g2 is set to 0.1 to 0.7 mm, and the magnetic flux density due to the magnetic force of the magnetic sealing member 10r at that time is about 1000 to 2000 Gs on the developing roller 6.
[0049]
By the way, the positional relationship between the magnet 10r1 and the magnetic plate 10r2 in the magnetic seal member 10r is such that the magnet 10r1 is disposed on the opening side of the first developing frame 10f1 as shown in FIG. The magnetic plate 10r2 is disposed further outside (at both ends in the longitudinal direction of the developing roller 10d).
[0050]
By arranging the magnet 10r1 on the opening side of the first developing frame 10f1 and the magnetic plate 10r2 outside the opening as described above, the magnetic force lines of the magnetic sealing member 10r are shown in FIG. 9B. As described above, since the magnetic flux is formed between the magnet 10r1 and the magnetic plate 10r2 and enters the magnetic plate 10r2 having a high magnetic permeability, the magnetic force lines extending to the outside of the width of the magnetic seal member 10r are not generated. Therefore, since the toner on the magnetic seal member 10r does not spread outside 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 member 10r is strong. A good sealing property can be obtained in which toner does not leak even when an impact or the like is applied when attaching or detaching to the image forming apparatus main body.
[0051]
Next, a method of attaching the magnetic material sealing member 10r will be described with reference to FIG. 8 and FIGS. 10 is a perspective explanatory view of the magnetic seal member 10r, FIG. 11 is a perspective explanatory view of a mounting portion of the magnetic seal member 10r, and FIG. 12 is a cross-sectional explanatory view showing a method of mounting the magnetic seal member 10r. 13 is an explanatory perspective view illustrating a mounting portion of the magnetic seal member 10r of the first developing frame, and FIG. 14 is a cross-section taken along a plane orthogonal to the longitudinal direction, which describes a frame contact end surface 10r6 of the magnetic seal member 10r. FIG.
[0052]
As shown in FIGS. 8A and 10, the magnetic seal member 10r has a semicircular inner peripheral surface 10r3 that forms a gap g2 between the inner peripheral side (developing roller 10d side) and the developing roller 10d. The outer peripheral side (the first developing frame 10f1 and the second developing frame 10f2 side) opposite to the inner peripheral surface 10r3 is in contact with the first developing frame 10f1 and the second developing frame 10f2. It has a semicircular circumscribed surface 10r4.
[0053]
Also, an elastic member 30 (see FIG. 8 (a)) which is arranged by being compressed between the sheet metal part 10e1 (see FIG. 8 (a)) of the developing blade 10e attached to the first developing frame 10f1 and the magnetic seal member 10 ) Has an elastic member contact surface 10r5 with which it contacts.
[0054]
Further, it has a frame body contact end face 10r6 which is on the opposite side of the inner peripheral face 10r3 as viewed from the elastic member outer contact face 10r4 and which comes into contact with the second developing frame.
[0055]
On the other hand, as shown in FIG. 11A, the first developing frame body 10f1 is provided with a mounting arc portion 10f14 that is in contact with the circumscribed surface 10r4 of the magnetic seal member 10r.
[0056]
As shown in FIG. 11 (b), the second developing frame 10f2 is provided with a mounting arc portion 10f24 that is in contact with the circumscribed surface 10r4 of the magnetic seal member 10r, and the frame contact of the magnetic seal member 10r. A mounting end face 10f25 that is in contact with the contact end face 10r6 is provided. As shown in FIG. 8A, the magnetic sealing member 10r is attached in a state where the first developing frame 10f1 and the second developing frame 10f2 are connected. 11B, only the second developing frame 10f2 is shown and the first developing frame 10f1 is omitted.
[0057]
When assembling the magnetic seal member 10r to a developing frame composed of the first developing frame 10f1 and the second developing frame 10f2, first, as shown in FIG. 12A, the mounting arc of the first developing frame 10f1 is mounted. The magnetic body seal member 10r is brought into contact with the portion 10f14 until the circumscribed surface 10r4 comes into contact with the portion 10f14, and rotates in the direction indicated by the arrow A in the figure.
[0058]
Then, as shown in FIGS. 12A and 12B, when the frame seal end surface 10r6 of the magnetic seal member 10r rotates until it abuts against the mounting end surface 10f25 of the second developing frame 10f2, the magnetic seal member 10r is rotated. It is determined at a predetermined position.
[0059]
Note that a gap s1 is provided to prevent the back surface 10r7 of the elastic member contact surface 10r5 from abutting on the first developing / developing frame 10f1. The gap s1 has a value capable of absorbing a shape error in manufacturing the first developing frame 10f1, the second developing frame 10f1, and the magnetic seal member 10r.
[0060]
Also, the longitudinal end surfaces 10r8, 10r9 (see FIG. 8B) of the magnetic seal member 10r are inserted between the positioning surfaces 10f15, 10f16 (see FIGS. 11A and 13) of the first developing frame 10f1. By doing so, the positioning of the magnetic seal member 10r in the longitudinal direction is performed.
[0061]
Further, a non-contact surface 10f20 (see FIG. 11A) of the first developing frame 10f1 that does not contact the magnetic seal member 10r with a gap s1 between the back surface 10r7 of the elastic member contact surface 10r5 is provided. Have been.
[0062]
Next, a configuration for preventing toner leakage will be described with reference to FIGS.
[0063]
As shown in FIG. 22B, toner enters the gap s1 between the non-contact surface 10f20 of the first developing frame 10f1 and the magnetic sealing member 10r from the developing chamber 10i in the direction of the arrow xx1 in the drawing, and the gap s1 In order to prevent the toner from leaking out of the process cartridge through the developing cartridge, the first developing frame 10f1 has a shape that blocks the gap s1 and the developing chamber 10i, as shown in FIG. There is provided a rib 10f4 formed of a positioning surface 10f16 that defines the position of the magnetic seal member 10r in the direction.
[0064]
The rib 10f4 has a contact portion 10f17 (see FIGS. 20B and 23) other than the magnetic seal member 10r and the positioning surface 10f16, and is formed at a height that does not interfere with the elastic member 30 and the developing blade 10e. Is appropriately designed.
[0065]
By the rib 10f4, the toner does not enter the gap s1 between the non-contact surface 10f20 of the first developing frame 10f1 and the magnetic seal member 10r from the developing chamber 10i, and it is possible to reliably prevent toner leakage. is there.
[0066]
Further, since the rib 10f4 increases the contact area between the positioning surface 10f16 (see FIG. 13) of the first developing frame and the magnetic sealing member 10r, the magnetic sealing member 10r is moved from the first developing frame 10f1 to the first developing frame 10f1. The assembly to the developing frame composed of the two developing frames 10f2 is facilitated, and the assemblability of the process cartridge is improved.
[0067]
Therefore, in the present embodiment, it is possible to provide a developing frame body that can reliably prevent the magnetic particles from flowing out from the gaps of the magnetic seal member with a simple configuration and can easily assemble the magnetic seal member.
[0068]
Next, the elastic member 30 is disposed on the elastic member contact surface 10r5 of the magnetic seal member 10r. The elastic member 30 is attached to the elastic member contact surface 10r5 using an adhesive means such as a double-sided tape.
[0069]
Next, the developing blade 10e is fixed to the first developing frame 10f1 using fixing means such as screws. The thickness of the elastic member 30 is set to be large in advance by the compression allowance so as to generate an elastic force on the magnetic material contact surface 10r5 in a state where the elastic member 30 is compressed and held between the sheet metal portion 10e1 of the developing blade 10e and the elastic member contact surface 10r5. .
[0070]
Due to the elastic force generated by the elastic member 30, a rotational force is generated in the magnetic seal member 10r in the direction indicated by the arrow A in FIG. The outer peripheral surface 10r4 of the frame contact end face 10r6, which is a rotation stopper in the direction of arrow A, does not separate from the mounting arc 10f14 of the first developing frame 10f1 and the mounting arc 10f24 of the second developing frame 10f2 due to the rotational force. It is set to bite without permission.
[0071]
This will be described in more detail with reference to FIGS.
[0072]
The rotation center when rotating the magnetic seal member 10r in the direction of arrow A is P1. This center P1 coincides with the center of the arc of the circumscribed surface 10r4. On the other hand, a line extending from the frame contact end face 10r6 is denoted by L1, and two areas separated by L1 are denoted by A1 and A2. The area A1 is on the magnetic sealing member 10r side, and the area A2 is on the mounting end face 10f25 side.
[0073]
By setting the center P1 on the area A2 side, the rotational force acts on the side that presses the magnetic seal member 10r against the circumscribed surface 10r4, so that the circumscribed surface 10r4 of the magnetic seal member 10r is in contact with the first developing frame 10f1. It does not separate from the mounting arc 10f14 and the mounting arc 10f24 of the second developing frame 10f2. Therefore, the distance g1 between the developing roller 10d and the magnetic sealing member 10r is fixed.
[0074]
Sealing members 10s (see FIG. 3) for preventing toner leakage at both ends of the developing blade 10e are attached to the first developing frame 10f1 and the second developing frame 10f2.
[0075]
Further, as shown in FIG. 3, the developing blade 10e is fixed to the first developing frame 10f1 with screws together with a scraping member 10t for scraping toner at both ends of the sheet metal portion 10e1 at the end of the developing roller 10d. At this time, the rib 10f3 of the first developing frame 10f1 whose tip is thinned is set to a size that always intrudes into the developing blade rubber portion 10e2.
[0076]
Alternatively, a double-sided tape (not shown) may be arranged on the developing blade rubber portion 10e2, and the dimensions may be set such that the ribs 10f3 necessarily cut into the adhesive layer of the double-sided tape.
[0077]
Since the rib 10f3 of the first developing frame body 10f1 whose tip is thinned is set to a size that always digs into the developing blade rubber part 10e2, as shown in FIG. 22B, the developing blade rubber part 10e2 and the first developing A gap s11 is formed between the frame and the frame 10f1. The toner flows into the gap s11 from the developing chamber 10i, and the flowing toner advances in the directions of the arrows x1, x2, and x3 shown in FIG.
[0078]
The toner traveling in the direction of the arrow x1 in the figure is securely sealed by the rib 10f3 of the first developing frame 10f1 and the developing blade rubber portion 10e2, so that there is no possibility that the toner leaks outside the process cartridge.
[0079]
As for the toner that advances in the direction of the arrow x2 in the drawing, the longitudinal position is located at a position in contact with the developing blade rubber portion 10e2, is provided continuously with the rib 10f3, and has a wall 10f50 having substantially the same height as the rib 10f3. With this configuration, the flow of toner in the x2 direction can be prevented by the rib 10f5 of the first developing frame 10f1 and the developing blade rubber portion 10e2.
[0080]
Further, for the toner traveling in the x3 direction, the flow of the toner in the x3 direction can be prevented by forming a wall 10f51 provided continuously with the rib 10f3 and having substantially the same height as the rib 10f3.
[0081]
The wall thickness of the wall 10f50 and the wall 10f51 is appropriately set, and is configured as a rib of the first developing frame 10f1.
[0082]
In the case where the rib 10f3 bites into the double-sided tape, if the wall 10f50 and the wall 10f51 are set to a height that bites into the developing blade rubber portion 10e2 or the double-sided tape, toner leakage can be similarly prevented.
[0083]
Therefore, in the present embodiment, it is possible to reliably prevent toner leakage from the gap s11 between the developing blade rubber portion 10e2 and the first developing frame 10f1 with a simple configuration.
[0084]
(Combination of developing device and cleaning device)
The connection between the developing device D and the cleaning device C is performed as follows, as shown in FIG.
[0085]
An arm 10g7 projects from the two end members 10g toward the cleaning frame 11d, and a longitudinal coupling hole 10g8 provided at the tip of the arm 10g7 and a coupling (not shown) provided in the cleaning frame 11d. The cleaning frame 11d and the end member 10g can be rotatably connected to each other by the pins 60 fitted into the holes.
[0086]
A compression coil spring 10g8a whose inner diameter fits into the spring stopper of one end member 10g is contracted between the cleaning frame 11d and a tension spring 10g9b is hooked on the cleaning frame 11d and the end member 10g. Then, the gap holding members 10m on both sides of the developing roller 10d are pressed against the photosensitive drum 7, and the developing roller 10d and the photosensitive drum 7 are held with a predetermined gap, thereby completing the process cartridge B.
[0087]
When the user purchases and uses the process cartridge B, the user holds the toner seal end 27a of FIG. 16 and pulls out the toner cartridge to open the toner passage opening 10k of the first developing frame 10f1, thereby opening the toner container 10a. The toner can be sent to the developing chamber 10i, and preparation for insertion into the image forming apparatus main body A is completed.
[0088]
(Removal and attachment of process cartridge B to image forming apparatus main body)
In order to mount the process cartridge B assembled as described above in the image forming apparatus main body, as shown in FIGS. 17A and 17B, an arc portion 18c1 provided on one side surface of the process cartridge and The rotation stopping portion 18c2 is arranged along a guide member Ga (see FIG. 18) as mounting means provided on the apparatus main body, and a positioning section 18b and a projection 18e provided on the other side surface are provided as guides as mounting means provided on the apparatus main body. It is mounted by inserting along the member Gb (see FIG. 19). When the process cartridge B is mounted on the image forming apparatus main body, the triangular coupling unit 70 is fitted with the drive transmitting unit 90 (see FIG. 18) of the apparatus main body, and the drive can be transmitted to the cartridge.
[0089]
In the first and second embodiments, an example in which a developer is used as an example of magnetic particles has been described. However, as described in the conventional example, a magnetic brush charging type charging device using conductive magnetic particles is used. Alternatively, the present invention can be applied to a magnetic sealing member as a means for preventing the outflow of conductive magnetic particles from both ends of the magnetic particle carrier. That is, the same effects as those described in the first and second embodiments can be obtained.
[0090]
Further, in the present embodiment, the configuration in which the magnetic seal member 10r is attached to the two frames of the first developing frame and the second developing frame has been described. Is not indispensable, and there is no problem even if it is attached to one frame as in the conventional example, and the same effects as those described above can be obtained.
[0091]
<Other embodiments>
In the above-described embodiment, the developing frame has been described. However, the present invention is not limited to this, and can be suitably applied to, for example, a process cartridge or an image forming apparatus using the developing frame.
[0092]
Although the process cartridge described in the above-described embodiment has exemplified the case where a single color image is formed, the process cartridge according to the present invention is provided with a plurality of developing units, and is provided with a plurality of color images (for example, a two-color image, a three-color image or a three-color image). The present invention can also be suitably applied to a cartridge that forms full color or the like.
[0093]
The electrophotographic photoreceptor is not limited to the photoreceptor drum, and includes, for example, the following. First, a photoconductor is used as a photoconductor, and examples of the photoconductor include amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and an organic photoconductor (OPC). Further, as the shape for mounting the photoconductor, for example, a drum-shaped or belt-shaped one is used.For example, in the case of a drum-type photoconductor, a photoconductor is vapor-deposited on a cylinder made of an aluminum alloy or the like. It is the one that has been coated.
[0094]
Also, as the developing method, it is possible to use various developing methods such as a known two-component magnetic brush developing method, a cascade developing method, a touch-down developing method, and a cloud developing method.
[0095]
Also, the configuration of the charging means also uses the so-called contact charging method in the above-described embodiment, but as another configuration, a metal shield such as aluminum is provided around three sides of a conventionally used tongue wire, and the tongue wire is used. It is a matter of course that a positive or negative ion generated by applying a high voltage to the photosensitive drum may be moved to the surface of the photosensitive drum to uniformly charge the surface of the photosensitive drum.
[0096]
The charging unit may be a blade (charging blade), a pad type, a block type, a rod type, a wire type, or the like, in addition to the roller type.
[0097]
Further, as a method of cleaning the toner remaining on the photosensitive drum, a cleaning unit may be configured using a blade, a fur brush, a magnetic brush, or the like.
[0098]
Further, the above-described process cartridge includes, for example, an electrophotographic photosensitive member and at least one of processing means. Therefore, as an aspect of the process cartridge, in addition to the above-described embodiment, for example, an electrophotographic photosensitive member and a developing unit may be integrally formed into a cartridge to be detachably mountable to the apparatus main body. There is a photoreceptor, a developing unit, and a charging unit or a cleaning unit which are combined into a cartridge to be detachable from the apparatus main body.
[0099]
That is, the above-described process cartridge refers to a cartridge in which at least the developing means and the electrophotographic photosensitive member are integrally formed into a cartridge and can be detachably attached to the image forming apparatus main body. The process cartridge can be attached to and detached from the apparatus main body by the user himself. Therefore, the maintenance of the apparatus main body can be performed by the user himself.
[0100]
Further, in the above-described embodiment, a laser beam printer is exemplified as an electrophotographic image forming apparatus. However, the present invention is not limited to this. For example, an electrophotographic printer such as an electrophotographic copying machine, an LED printer, and a facsimile Naturally, it can be used in an electrophotographic image forming apparatus such as a device, a word processor, or a multifunction printer (such as a multifunction printer).
[0101]
【The invention's effect】
As is apparent from the above description, according to the present invention, it is possible to provide a developing frame, a process cartridge, and an image forming apparatus that can prevent toner leakage from a peripheral portion of a seal member with a simple configuration.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating the configuration of an electrophotographic image forming apparatus equipped with a process cartridge.
FIG. 2 is a schematic diagram illustrating the configuration of a process cartridge.
FIG. 3 is an exploded perspective view of the developing device.
FIG. 4 is an exploded perspective view of the developing device.
FIG. 5 is an exploded perspective view of the cleaning device.
FIG. 6 is an explanatory perspective view of a cleaning device.
FIG. 7 is an explanatory perspective view of a cleaning device.
FIG. 8 is an explanatory diagram of a magnetic seal.
FIG. 9 is an explanatory diagram of a positional relationship between a magnet of a magnetic sealing member and a magnetic plate.
FIG. 10 is an explanatory perspective view of a magnetic seal member.
FIG. 11 is an explanatory perspective view of a mounting portion of the magnetic seal member.
FIG. 12 is an explanatory sectional view showing a method of attaching a magnetic substance sealing member.
FIG. 13 is an explanatory perspective view illustrating a magnetic seal member mounting portion of the first developing frame.
FIG. 14 is an explanatory cross-sectional view taken along a plane orthogonal to the longitudinal direction for explaining a frame body contact end face of the magnetic seal member.
FIG. 15 is an explanatory view in which a developing device and a cleaning device are divided.
FIG. 16 is a diagram illustrating a state in which the developing device and the cleaning device are combined.
FIG. 17 is an explanatory side view of the process cartridge.
FIG. 18 is an explanatory diagram of a process cartridge mounting guide of the image forming apparatus main body.
FIG. 19 is an explanatory diagram of a process cartridge mounting guide of the image forming apparatus main body.
FIG. 20 is an explanatory sectional view of the vicinity of a magnetic seal member of the first developing frame.
FIG. 21 is an explanatory perspective sectional view of the vicinity of a magnetic seal member of the first developing frame.
FIG. 22 is an explanatory perspective view of the vicinity of a magnetic seal member of the first developing frame.
FIG. 23 is an explanatory sectional view of the vicinity of a magnetic seal member of the first developing frame.
[Explanation of symbols]
A Image forming device
B process cartridge
C Cleaning device
D developing device
P1 center of rotation
g2 gap
s1, s11 gap
1 Exposure equipment
2 Recording media
3 transport means
3a cassette
3b Pickup roller
3c crimping member
3d discharge roller
3f1 transport guide
3f2 transport guide
4 Transfer roller
5 Fixing means
5a drive roller
5b heater
5c support
5d fixing rotating body
6 discharge section
7 Photoconductor drum
8 Charging roller
8a bearing
8b roller bearing
8c electrode
9a Transfer opening
9b Exposure aperture
10 Developing means
10a Toner storage section
10b Feeding member
10b1 Stirring shaft
10b2 sheet member
10b3 Transport gear
10b4 Seal member
10c Fixed magnet
10d developing roller
10e developing blade
10e1 sheet metal part
10e2 Developing blade rubber
10f1 First developing frame
10f14 mounting arc
10f15, 10f16 Positioning surface
10f17 contact point
10f2 Second developing frame
10f20 non-contact surface
10f24 mounting arc
10f25 mounting end face
10f3,10f4,10f5 rib
10f50, 10f51 wall
10g end member
10g7 arm
10g8 coupling hole
10g9a Compression coil spring
10g9b Extension spring
10h Seal mounting part
10i development room
10j Cap member after toner filling
10k toner passage opening
10m gap holding member
10r Magnetic seal member
10r1 magnet
10r10 protrusion
10r11 butting surface
10r2 magnetic plate
10r3 inner surface
10r4 circumscribed surface
10r5 elastic member contact surface
10r6 Frame body contact end face
10r7 back side
10r8, 10r9 Long end face
10s seal member
10t scraping member
10u toner filling port
11 Cleaning means
11a Cleaning blade
11b Squishy sheet
11c Removal toner storage section
11d cleaning frame
11e, 11f, 11h Seal member
11g double-sided tape
12 Drum shutter
12a Drum protection unit
12b Rotary axis
12b1 Sliding part
12b3 Connecting part
12c connecting part
12d shutter spring
12e rib
18b Positioning unit
18c bearing
18c1 arc
18c2 Rotation stop
18d positioning pin
18e protrusion
27 Toner seal member
27a Toner seal end
30 elastic members
60 pins
70 Triangular coupling
71 Drum gear
85 flange
90 Drive transmission unit

Claims (15)

A developer, a developing roller for carrying the developer, a developer regulating member for regulating the amount of the developer carried on the developing roller, and sealing the developer at a longitudinal end of the developing roller. In the developing frame body including the sealing member to be stopped,
A developing frame provided between the developing chamber and the seal member, the wall substantially perpendicular to the longitudinal direction of the developing roller, and the wall has a positioning surface of the seal member in the longitudinal direction of the developing roller. . The developing frame according to claim 1, wherein the wall is a rib provided on the developing frame. The developing frame according to claim 1, wherein the developer is a magnetic developer. The developing frame according to any one of claims 1 to 3, wherein the wall has a contact portion with the seal member other than the positioning surface. The developing frame according to claim 1, wherein the seal member is a magnetic seal member. A developer, a developing roller for carrying the developer, a developer regulating member for regulating the amount of the developer carried on the developing roller, and sealing the developer at a longitudinal end of the developing roller. In a process cartridge including
A process cartridge, wherein a wall substantially perpendicular to the longitudinal direction of the developing roller is provided between the developing chamber and the seal member, and the wall has a positioning surface of the seal member in the longitudinal direction of the developing roller. 7. The process cartridge according to claim 6, wherein the wall is a rib provided on a developing frame. The process cartridge according to claim 6, wherein the developer is a magnetic developer. 9. The process cartridge according to claim 6, wherein the wall has a contact portion with the seal member other than the positioning surface. 10. 10. The process cartridge according to claim 6, wherein the seal member is a magnetic seal member. A developer, a developing roller for carrying the developer, a developer regulating member for regulating the amount of the developer carried on the developing roller, and sealing the developer at a longitudinal end of the developing roller. A sealing member to stop, and an image forming apparatus including
An image forming apparatus, wherein a wall substantially perpendicular to a longitudinal direction of a developing roller is provided between a developing chamber and the seal member, and the wall has a positioning surface of the seal member in a longitudinal direction of the developing roller. . The image forming apparatus according to claim 11, wherein the wall is a rib provided on a developing frame. The image forming apparatus according to claim 11, wherein the developer is a magnetic developer. 14. The image forming apparatus according to claim 11, wherein the wall has a contact portion with the seal member other than the positioning surface. 15. The current image forming apparatus according to claim 11, wherein the seal member is a magnetic seal member.

Images