JP2004125930A - Development unit and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing unit in which a developer can be stably sealed and an image forming apparatus provided with the unit. <P>SOLUTION: A developing unit is constituted of a plurality of frame bodies, and provided with an end part sealing member 373 is installed in one frame body 369 and seals the space between the end part of a developing roll and the frame body 369, a sheet member 356 provided to the other frame body 370 and seals the space between the developing roll and the other frame body 370, a filler 378 injected to an overlapping range between a melt lump 377 of a melt rib 371 protruding from a joint part of one frame body 369 and the other frame body 370 and the end part sealing meber 373 and the sheet member 356 and sealing by being brought into contact with one frame body 369, the other frame body 370, the end part sealing member 373, the sheet member 356 and the protruding melt lump 377 is provided. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a developing unit containing powder such as toner and an image forming apparatus including the same.
[0002]
Here, the image forming apparatus forms an image on a recording medium using an electrophotographic image forming method. For example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, or the like), an electrophotographic facsimile machine, a word processor, and the like are included.
[0003]
The developing unit is a unit of developing means for developing an electrostatic latent image formed on an electrophotographic photosensitive member and members attached thereto.
[0004]
[Prior art]
2. Description of the Related Art Conventionally, the following configuration is known as an image forming apparatus for forming a multicolor image on a recording medium by an electrophotographic method. That is, a plurality of developing units accommodating developers of different colors are arranged on a rotating mechanism with respect to an electrophotographic photosensitive drum, and a developing unit accommodating a developer of a predetermined color is opposed to the photosensitive drum. The image is developed and the developer image is transferred to a recording medium. Further, by performing these development and transfer operations for each color, a multicolor image is obtained on a recording medium.
[0005]
There is a cartridge configuration in which the developing unit can be attached to and detached from the image forming apparatus main body so as to reduce a user's maintenance work.
[0006]
The developing unit has a mechanism for coating the developing roller, which is a developing unit, with the developer, and stores the developer therein, so that a gap is formed between members so that the developer does not leak out of the developing unit. Is provided with a seal member. The conventional seal configuration is as follows.
[0007]
(1) The gap between both ends of the gap between the developing roller and the developing container is sealed with a member made of a raised material such as felt in order to improve the rubbing condition with the rotating developing roller ( End seal). Further, a proposal has been made to apply a small amount of lubricating oil to the surface layer (for example, see Patent Document 1).
[0008]
(2) Sealing the gap between the developing roller and the developing container by contacting the PET sheet member attached to the developing container with the developing roller to the gap on the lower surface of the developing roller (anti-blowing sheet) (For example, refer to Patent Document 1).
[0009]
(3) Filler is injected into the end face of the end seal in the gap between the end seal and the developing container at the portion where the end seal and the blowout prevention sheet overlap, and the filler is filled into the end seal. It seals by making it contact an end surface and a blowing prevention sheet.
[0010]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-56560
[Problems to be solved by the invention]
However, the above-described multi-color image forming apparatus includes a developing device having at least four developing units containing developers of Y (yellow), M (magenta), C (cyan), K (black) and each color. It must be accommodated in the image forming apparatus. Therefore, in order to reduce the size and cost of the image forming apparatus, it is necessary to reduce the size of the developing device.
[0012]
One of the effective means for reducing the size of the developing device is to reduce the number of frames forming the developing container.
[0013]
Generally used as a means for joining frames, ultrasonic welding is applied to this portion in a state where the welding rib provided on one frame is in contact with the other frame, and frictional heat is applied. This is a means for melting the welding ribs and joining the frames together (ultrasonic welding).
[0014]
For this joining, a space for the welded portion, that is, a space for bringing the ultrasonic welding horn into contact with the frame, and a space for receiving the frame near the ultrasonic welding horn are required. Therefore, when the number of frames constituting the developing container increases, the space required for ultrasonic welding increases. Therefore, in order to reduce the size of the developing device, it is effective to reduce the number of frames constituting the developing container.
[0015]
Conventionally, the following two means have been used to construct such a developing container.
[0016]
(1) As a conventional means for forming a developing container with two frames, a frame for attaching an end seal and a frame for attaching a blowing prevention sheet are divided, and the two are joined to form a developing container. Means to do.
[0017]
(2) As a conventional sealing configuration of this part, a filler is injected into the end face of the end seal to fill a gap between the end seal end face and the blowout prevention sheet, and the filler is filled with the end seal and the blowout prevention sheet. Means for contacting and sealing.
[0018]
However, when the above-mentioned means are combined, there is a problem in how to seal the joint between the filler and the frame.
[0019]
For example, as shown in FIG. 8, a case may be considered in which a filler is not turned around in a gap that has not been joined at the joint surface between the frame bodies, and a gap is formed. In this case, the toner leaks out of the gap in the direction of the arrow shown in FIG.
[0020]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the related art, and an object of the present invention is to provide a developing unit in which a developing container is composed of a small number of frames and a developer can be stably sealed. And an image forming apparatus provided with the same.
[0021]
[Means for Solving the Problems]
In order to achieve the above object, in the developing unit according to the present invention,
A developing roller for developing the latent image formed on the image carrier with a developer,
At least two frames, a developing container joined by melting the welding ribs provided on the frame, and
A developing unit that holds the developing roller and stores the developer therein, wherein the developing unit is provided in one of the two frames, and a gap between an end of the developing roller and the one frame is provided. An end sealing member for sealing
A sheet member provided on the other frame of the two frames, for sealing a gap between the developing roller and the other frame;
A molten mass of the welding rib protruding from a joint between the one frame and the other frame,
Filling that is injected into a region where the end seal member and the sheet member overlap, and contacts and seals the one frame, the other frame, the end seal member, the sheet member, and the protruding molten mass. Agent,
It is characterized by having.
[0022]
According to this configuration, no gap is generated at the joint between the frames, and the filler is injected without directly applying the sealing member or the sheet member to the protruding molten mass of the welding rib, and the space between the members is reduced. Can be sealed.
[0023]
The one frame or the other frame is provided with a hole through which the molten mass protrudes at a position where an end face of the end seal is exposed, and when the filler is injected from the hole. It is suitable.
[0024]
According to this configuration, the region into which the filler is injected is defined, and the filler can be easily and reliably injected into the desired region.
[0025]
In the image forming apparatus according to the present invention,
An image carrier on which a latent image is formed;
The developing unit for developing the latent image with toner,
Transfer means for transferring the developed toner image to a recording medium,
Conveying means for conveying the recording medium,
It is characterized by having.
[0026]
It is preferable that the image forming apparatus further includes a mounting unit that makes the developing unit detachable from the image forming apparatus main body.
[0027]
It can be particularly preferably adopted when a plurality of developing units are mounted and a rotating body is provided for sequentially forming images on the image carrier.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the present invention will be illustratively 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 thereto unless otherwise specified. Absent. The materials, shapes, and the like of the members once described in the following description are the same as those in the first description unless otherwise specified.
[0029]
In the following description, the “front surface of the apparatus” refers to the surface on the upstream side of the conveyance of the recording medium from the transfer process to the fixing process (right side in FIG. 1), and “left and right with respect to the apparatus body” means the front side of the apparatus. Look left or right. Further, the “longitudinal direction” is a direction that is parallel to the surface of the recording medium and intersects (substantially orthogonal) to the transport direction of the recording medium.
[0030]
(Outline of image forming operation of color image forming apparatus)
First, the overall configuration of the color image forming apparatus will be schematically described with reference to FIG. FIG. 1 shows an embodiment of a color electrophotographic image forming apparatus according to the present embodiment, which shows a schematic configuration of a color laser beam printer in which a developing cartridge (developing unit), a drum cartridge, and an intermediate transfer body unit are loaded in an image forming apparatus main body. FIG.
[0031]
As shown in FIG. 1, the color image forming apparatus main body irradiates a light image based on image information from an exposure unit 3 to a developer image (hereinafter referred to as a “toner”) on an image carrier (hereinafter referred to as “photosensitive drum”) 1. An image). Then, the recording medium is conveyed by conveyance means including a pickup roller 18, a conveyance roller pair 19, a registration roller pair 7 and the like in synchronization with the formation of the toner image, and the toner image formed on the photosensitive drum 1 is transferred to the intermediate transfer member 5a. Transcribed.
[0032]
Next, the toner image on the intermediate transfer member 5a is transferred to a recording medium by the second transfer means 11, and the recording medium is conveyed to a fixing device 8 having a pressure roller and a heating roller to fix the transferred toner image. To discharge to the discharge unit 10.
[0033]
The image forming process will be described in more detail.
[0034]
The photosensitive drum 1 rotates in the direction of the arrow in FIG. 1 (counterclockwise) in synchronization with the rotation of the intermediate transfer belt 5a. The charging device 2 uniformly charges the surface of the photosensitive drum 1. The exposure unit 3 irradiates the charged photosensitive drum 1 surface with image light based on image information of each color, for example, image light based on yellow image information, and forms an electrostatic latent image corresponding to a yellow image on the photosensitive drum 1. To form
[0035]
Exposure is performed through the following steps. The exposure means 3 irradiates the photosensitive drum 1 with light based on image information read from an external device or the like, and is generally constituted by a laser diode, a polygon mirror, a scanner motor, an imaging lens, and a reflection mirror.
[0036]
Then, when an image signal is given from an external device or the like, the laser diode emits light in accordance with the image signal and irradiates the polygon mirror with the image light. The polygon mirror is rotated at a high speed by a scanner motor, and the image light reflected by the polygon mirror selectively exposes the surface of the photosensitive drum 1 via an imaging lens and a reflection mirror. Form a latent image.
[0037]
The yellow developing cartridge 4Y is rotated to the developing position in synchronization with the formation of the electrostatic latent image, and a predetermined bias voltage is applied to cause the yellow toner to adhere to the electrostatic latent image for development. Thereafter, by applying a bias voltage having a polarity opposite to that of the toner to the pressing roller (primary transfer roller) 5j of the intermediate transfer belt 5a, the yellow toner image on the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 5a.
[0038]
When the primary transfer of the yellow toner image is completed as described above, the next developing cartridge (4M) of the developing device 4 rotates and is positioned at a position facing the photosensitive drum 1. The steps of forming, developing and primary transferring the electrostatic latent image as described above are sequentially repeated for each of the colors magenta (M), cyan (C), and black (Bk), so that the intermediate transfer belt 5 a Are superimposed with toner images of four colors.
[0039]
During this time, the secondary transfer roller 11 is at a position not in contact with the intermediate transfer belt 5a, and the cleaning charging roller 5f as a cleaning unit is also at a position not in contact with the intermediate transfer belt 5a.
[0040]
After the four color toner images are formed on the intermediate transfer belt 5a, the secondary transfer roller 11 is pressed against the intermediate transfer belt 5a as shown in FIG. Further, in synchronization with the rotation of the intermediate transfer belt 5a, the recording medium that has been waiting at a predetermined position near the registration roller pair 7, which is a feeding unit, is sent out to the nip portion between the intermediate transfer belt 5a and the secondary transfer roller 11. It is.
[0041]
Here, immediately before the registration roller pair 7, a pre-registration sensor 14 that detects the leading end of the recording medium, shuts off the rotational driving force of the registration roller pair 7, and waits the recording medium at a predetermined position is provided. .
[0042]
A bias voltage having a polarity opposite to that of the toner is applied to the secondary transfer roller 11, and the toner image on the intermediate transfer belt 5a is collectively and secondarily transferred to the surface of the conveyed recording medium.
[0043]
The recording medium on which the toner image has been secondarily transferred in this manner is conveyed to the fixing device 8 via the conveyance belt unit 12, where the fixing of the toner images of a plurality of colors is performed.
[0044]
The recording medium on which the toner image has been fixed is conveyed along a paper discharge guide 15 by a pair of discharge rollers 13 and discharged to a discharge section 10 above the color image forming apparatus A by a pair of discharge rollers 9 to complete image formation.
[0045]
On the other hand, the cleaning charging roller 5f is pressed against the intermediate transfer belt 5a after the completion of the secondary transfer, and a predetermined bias voltage is applied to the residual toner remaining on the intermediate transfer belt 5a to remove the residual charges.
[0046]
The removed residual toner is electrostatically re-transferred from the intermediate transfer belt 5a to the photosensitive drum 1 via the primary transfer nip, and the surface of the intermediate transfer belt 5a is cleaned.
[0047]
The residual toner remaining on the secondary transfer retransferred to the photosensitive drum 1 is removed and collected by the cleaning blade 6 for the photosensitive drum 1.
[0048]
The collected residual toner follows a conveyance path, which will be described later, as waste toner, and is collected and accumulated in the waste toner box 16.
[0049]
(Configuration of developing cartridge)
The developing device 4 visualizes the electrostatic latent image on the photosensitive drum 1, and in the present embodiment, the four developing cartridges 4Y capable of developing each color of yellow, magenta, cyan, and black , 4M, 4C, and 4Bk.
[0050]
In this embodiment, the developing cartridge which is a cartridge type developing unit detachable from the image forming apparatus will be described in detail. However, the present invention is not limited to this configuration. However, the present invention can be suitably applied.
[0051]
As shown in FIG. 1, the developing cartridges 4Y, 4M, 4C, and 4Bk are detachably held by mounting means formed on a rotary unit 301 that rotates about an axis. While being held by the rotary unit 301, the rotary unit 301 is rotated around an axis, a predetermined developing cartridge is stopped at a position facing the photosensitive drum 1, and a developing roller 305 described later is positioned so as to contact the photosensitive drum 1. After that, a visible image is formed corresponding to the electrostatic latent image on the photosensitive drum 1.
[0052]
At the time of color image formation, the rotary unit 301 makes one rotation for each rotation of the intermediate transfer belt 5a, and the developing process is performed in the order of the yellow developing cartridge 4Y, the magenta developing cartridge 4M, the cyan developing cartridge 4C, and then the black developing cartridge 4Bk. .
[0053]
FIG. 2 is a schematic vertical cross-sectional view of the developing cartridge 4Y (4M, 4C, and 4Bk have the same schematic configuration and will not be described), and FIG. 3 is a perspective view thereof.
[0054]
As shown in FIG. 2, the developing cartridge 4 </ b> Y sends the toner in the developing container 302 constituting the developing frame to the toner supplying roller 304 by the toner stirring member 303, and rotates the toner supplying roller 304 rotating clockwise in FIG. The developing blade 332 pressed against the outer periphery of the roller 305 applies a thin layer of toner to the outer periphery of the developing roller 305 rotating in the clockwise direction in the drawing, and applies electric charge to the toner (friction charging).
[0055]
Then, by applying a developing bias to the developing roller 305 facing the photosensitive drum 1 on which the latent image is formed, toner development is performed on the photosensitive drum 1 according to the latent image. For the magenta developing cartridge 4M, the cyan developing cartridge 4C, and the black developing cartridge 4Bk, toner development is performed by the same mechanism as described above.
[0056]
Further, each developing roller 305 of each developing cartridge is connected to a high-voltage power supply and a driving device (not shown) for developing each color provided in the printer main body when each developing cartridge is rotated to the developing position. Each time, a voltage is selectively applied sequentially and the driving device is connected.
[0057]
FIG. 3 is an external view of the developing cartridge 4Y (4M, 4C, 4Bk). A drive input gear 306 of the developing cartridge 4Y receives a drive input from a gear (not shown) of the image forming apparatus, and drives the above-described developing roller 305, toner supply roller 304, and toner stirring member 303.
[0058]
FIG. 4 is an exploded perspective view of the drive gear train. As shown in FIG. 4, the drive input gear 306 of the developing roller is a stepped gear, one of which is a gear unit 307 that receives a drive input from a gear of the image forming apparatus, a developing roller gear 309, and a toner supply roller gear 310. It comprises a gear unit 308 for transmitting the drive. Then, the drive is transmitted from the developing roller gear 309 to the idler gear 311 and the idler gear 312 of the step gear, and the drive is transmitted to the toner stirring gear 313 for stirring the toner in the developing container 302.
[0059]
(Conventional developing cartridge seal configuration)
FIG. 5 shows a schematic longitudinal sectional view of a conventional developing cartridge. The developing container is composed of three frames (360, 361, 362), and the ultrasonic welding portion 363 of each frame is shown in the figure. Finally, the frame 362 is joined with the frame 360 and the frame 361 joined.
[0060]
FIG. 6 shows a conventional seal configuration of an overlapping portion between the blowout prevention sheet 356 and the end seal 373. A filler 378 is injected beside the end seal 373 at the overlapping portion of the end seal 373 and the blowout prevention sheet 356. The filler 378 comes into contact with the end seal 373, the blowout prevention sheet 356, and the developing container 302, and fills and seals a gap in this portion.
[0061]
(Development cartridge seal configuration)
FIG. 9 is a perspective view of a first frame and a second frame constituting the developing unit according to the present embodiment. As shown in FIG. 9, the developing container 302 of the present invention includes two frames, a first frame 369 and a second frame 370, and the two are joined by ultrasonic welding. The ultrasonic welding rib 371 is shown in the figure.
[0062]
FIG. 10 shows a state where each seal member is attached to the developing container 302.
[0063]
The developing blade lower seal 372 is a foamed elastic member that seals a gap between the developing container 302 and the developing blade 332, and is attached to the first frame 369.
[0064]
The end seal 373 is a member made of a raised material that seals a gap between the developing roller 302 and the developing roller 305 at both ends of the developing container 302, and is attached to the first frame 369.
[0065]
The blowout prevention sheet 356 is a PET flexible sheet member having a thickness of about 50 μm that seals a gap between the developing container 302 and the lower portion of the developing roller 305, and is attached to the second frame 370.
[0066]
Regarding the gap between the respective seal members, in the case of the developing blade lower seal 372 and the end seal 373, the developing blade lower seal 372, which is a foamed elastic member, is brought into contact with and penetrates the end seal 373, thereby crushing the gap therebetween. Seal without gaps.
[0067]
Further, the gap between the end seal 373, the blowout prevention sheet 356, and the developing container 302 is sealed by filling a filler in this portion. The configuration of this part will be described below.
[0068]
11 is a cross-sectional view of the developing container according to the present embodiment from the side, and FIGS. 12 to 14 are enlarged views of the overlapped portion of the end seal 373 and the blowout prevention sheet 356 viewed from the direction A shown in FIG. It is a top view.
[0069]
Before attaching the end seal 373, there is a hole 375 of the second frame 370 near the overlap portion (see FIG. 12). The end seal 373 is attached to the first frame 369 with the end face of the end seal 373 aligned with this portion. Since the end seal 373 has a shape with a chamfered corner, the hole 375 of the second frame body is open without being closed even when the end seal 373 is stuck (see FIG. 13).
[0070]
Then, the blowing prevention sheet 356 is attached to a predetermined seating surface 358 of the second frame 370. The blowout prevention sheet 356 is attached to the second frame 370 with a double-sided tape (not shown) (see FIG. 14).
[0071]
16 and 18 are cross-sectional views showing the relationship between the welded portion of the first frame 369 and the second frame 370 and the hole 375. Here, FIG. 16 is a cross-sectional view taken along a line BB of FIG. 15 or FIG. 17, and FIG. 18 is an enlarged view of a portion C of FIG. After the first frame member 369 and the second frame member 370 are welded, a molten mass 377 of the ultrasonic welding rib 371 protrudes from the hole 375 of the second frame member (see FIG. 18).
[0072]
In this state, the filler 378 is filled in the hole 375 of the second frame. As the filler 378, a quick-drying silicone adhesive sealant, an ultraviolet curable bond, or the like is used.
[0073]
When the filler 378 is injected into the hole 375, the filler 378 is applied to the first frame 369, the second frame 370, the end face of the end seal 373, the blowout prevention sheet 356, and the molten mass 377 of the welding rib. Contact and seal the gap in this area. In particular, by bringing the filler 378 into contact with the molten mass 377 of the welding rib, the gap formed between the first frame 369 and the second frame 370 can be effectively filled.
[0074]
FIG. 19 is a view in which the developing blade 332 is attached to the developing container 302, and FIG. 20 is a bearing member 379 which supports the developing roller 305 and the toner supply roller 304 by placing the developing roller 305 on the developing container 302 from the state of FIG. FIG. 4 is a diagram showing a state in which a is attached.
[0075]
【The invention's effect】
As described above, according to the present invention, the developing container is composed of a small number of frames, that is, the frame for attaching the end seal and the frame for attaching the blowing prevention sheet are divided, and the two are joined together. In the developing unit having the configured developing container, it is possible to provide a seal configuration that can easily and reliably seal the developer.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an image forming apparatus according to an embodiment.
FIG. 2 is a schematic longitudinal sectional view of a developing cartridge according to the exemplary embodiment.
FIG. 3 is an overall perspective view of a developing cartridge according to the exemplary embodiment.
FIG. 4 is an exploded perspective view of a gear train of the developing cartridge.
FIG. 5 is a schematic longitudinal sectional view of a conventional developing cartridge.
FIG. 6 is a diagram showing a conventional seal configuration of an overlap portion between a blowout prevention sheet and an end seal.
FIG. 7 is a top view for explaining a gap between unjoined portions in a conventional developing unit.
FIG. 8 is a cross-sectional view illustrating a gap at an unjoined portion in a conventional developing unit.
FIG. 9 is an overall perspective view of a first frame and a second frame constituting the developing unit according to the exemplary embodiment.
FIG. 10 is a perspective view showing a state in which each seal member is attached to the developing unit.
FIG. 11 is a side sectional view of the developing container according to the exemplary embodiment.
FIG. 12 is a diagram showing a seal configuration of an overlap portion of an end seal and a blowing prevention sheet.
FIG. 13 is a diagram illustrating a seal configuration of an overlap portion between an end seal and a blowing prevention sheet.
FIG. 14 is a diagram illustrating a seal configuration of an overlap portion between an end seal and a blowing prevention sheet.
FIG. 15 is a front view of the developing container.
FIG. 16 is a sectional view of an ultrasonic welding portion of the developing container.
FIG. 17 is a view showing a seal configuration of an overlap portion between a blowout prevention sheet and an end seal.
FIG. 18 is an enlarged cross-sectional view of a portion C into which the filler shown in FIG. 16 is injected.
FIG. 19 is a diagram in which a developing blade is attached to a developing container.
FIG. 20 is a diagram illustrating a state where a developing roller and a bearing member are attached to a developing container.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging device 3 Exposure means 4 Developing devices 4Y, 4M, 4C, 4Bk Developing cartridge (developing unit)
5a Intermediate transfer belt (intermediate transfer member)
5f cleaning charging roller 6 cleaning blade 7 registration roller pair 8 fixing device 9 discharge roller pair 10 discharge unit 11 secondary transfer roller (second transfer unit)
12 Conveying belt unit 13 Discharge roller pair 15 Discharge guide 18 Pickup roller 19 Conveyor roller pair 301 Rotary unit 302 Developing container 303 Toner stirring means 304 Toner supply roller 305 Developing roller 332 Developing blade 356 Blow-out prevention sheet 358 Seat surface 360, 361 362 Frame body 363 Ultrasonic welding part 369 First frame body 370 Second frame body 371 Ultrasonic welding rib 372 Developing blade lower seal 373 End seal 375 Hole 377 Melted mass 378 Filler 379 Bearing member A Image forming apparatus

Claims (5)

A developing roller for developing the latent image formed on the image carrier with a developer,
At least two frames, a developing container joined by melting the welding ribs provided on the frame, and
A developing unit that holds the developing roller and stores the developer therein, wherein the developing unit is provided in one of the two frames, and a gap between an end of the developing roller and the one frame is provided. An end sealing member for sealing
A sheet member provided on the other frame of the two frames, for sealing a gap between the developing roller and the other frame;
A molten mass of the welding rib protruding from a joint between the one frame and the other frame,
Filling that is injected into a region where the end seal member and the sheet member overlap, and contacts and seals the one frame, the other frame, the end seal member, the sheet member, and the protruding molten mass. Agent,
A developing unit comprising: The one frame body or the other frame body is provided with a hole through which the molten mass protrudes at a position where an end face of the end seal is exposed, and the filler is injected from the hole. The developing unit according to claim 1, wherein: An image carrier on which a latent image is formed;
The developing unit according to claim 1, wherein the latent image is developed with toner.
Transfer means for transferring the developed toner image to a recording medium,
Conveying means for conveying the recording medium,
An image forming apparatus comprising: The image forming apparatus according to claim 3, further comprising a mounting unit that detachably attaches the developing unit to an image forming apparatus main body. The image forming apparatus according to claim 4, further comprising a rotator configured to mount and rotate the plurality of developing units to sequentially form images on the image carrier.

Images