JP2000075661A - Developing cartridge and electrophotographic image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing cartridge which is easily assembled and has satisfactory rigidity regardless of its enlarged size. SOLUTION: This developing cartridge is provided with openings for shafts (axial body) 20YR1 and 20YR2 of a feeding roller 20YR to penetrate on side faces of a developing frame 201, a round hole 201H on the driving side, and a U groove 201U on the driven side. The feeding roller 20YR is assembled so that the shaft 20YR1 on the drive side is allowed to penetrate through the round hole 201H, and thereafter the shaft 20YR2 on the non-drive side is allowed to fall in the U groove 201U. Then, a plugging member 210 for plugging the U groove 201U is inserted in the U groove 201U.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electrophotographic image forming apparatus and a developing cartridge.

Here, the electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming method. The electrophotographic image forming apparatus includes, for example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, and the like), a facsimile machine, a word processor, and the like.

A developing cartridge is a cartridge in which developing means is integrated into a cartridge, and this cartridge is made detachable from an electrophotographic image forming apparatus main body.

[0004]

2. Description of the Related Art First, an example of a conventional color laser printer will be schematically described with reference to FIG.

[0005] As shown in FIG. 9, this printer transfers a recording medium 102 fed from a feeding device 101 to a transfer drum 1.
The recording medium 102 is conveyed to a transfer unit opposed to the photosensitive drum 104a.
Each color toner image formed by exposure, latent image formation, and development is transferred onto the recording medium 102 to obtain a color image. Then, the recording medium 102 is conveyed to a fixing device 106, where the toner image is fixed on the recording medium 102, and then discharged to a discharge section 108 in the upper portion of the apparatus by a discharge roller 107.

The printer includes a primary charger 104b, a cleaner 104c, a laser scanner unit 110, a rotary developing device 105, and a paper feeding device 101 around a photosensitive drum 104a.
And a transfer drum 103 and the like.

The primary charger 104b has a conductive roller. The conductive roller is brought into contact with the photosensitive drum 4a, and a voltage is applied to the roller.
Is uniformly charged.

The laser scanner section 110 has a laser diode (not shown). When the laser diode receives an image signal, the laser diode generates image light corresponding to the image signal and irradiates the image light to the polygon mirror 110a. The polygon mirror 110a is rotated at a high speed by a scanner motor to reflect image light, and reflects the reflected image light via the imaging lens 110b and the reflection mirror 110c to the image carrier unit 104.
The photosensitive drum 104a is selectively irradiated and exposed from the exposed portion, thereby forming an electrostatic latent image on the photosensitive drum 104a.

The rotary developing device 105 includes developing cartridges 105M, 105C, 105Y, and 105 containing developers of each color, ie, magenta, cyan, yellow, and black.
K. These four color developing cartridges are
The developer cartridge 05e is rotatable, rotates in conjunction with a self-rotating gear disposed on the outer periphery of a gear that revolves around the center of each developing cartridge, and its posture is maintained constant.

In forming an image, for example, a magenta developing cartridge 105M corresponding to a latent image is stopped at a position facing the photosensitive drum 104a, and a developing roller 105b faces the surface of the photosensitive drum 104a at a small interval. Is positioned as follows.

At the time of development, the developing roller 105b receives the application of a bias and the rotational drive, so that the photosensitive drum 104a
The upper latent image is developed to form a toner image.

A supply roller 105a is slidably contacted with the developing roller 105b disposed in each developing cartridge so that the developer not contributing to the development is scraped off so that fresh developer is always supplied. Has become.

On the other hand, a developer container 1 for storing a developer
At 05d, the developer conveying means 105t for supplying the developer to the supply roller 105a is
The developer is conveyed at 05a.

The paper feeding device 101 is a recording medium 10 such as paper.
2 is provided, and the cassette 101a is mounted on the bottom of the apparatus main body 109. At the time of image formation, the sheet feeding roller 101b disposed near the exit of the cassette 101a rotates according to the image forming operation, and separates the recording medium 102 one by one from the sheet feeding cassette 101a toward the transfer drum 103. Send.

The transfer drum 103 wraps the fed recording medium 102 and transfers the toner images of the respective colors sequentially formed on the photosensitive drum 104 a onto the recording medium 102. The recording medium 102 is rotated in the direction of the arrow at the same speed as that described above, and is conveyed toward the image transfer section facing the photosensitive drum 4a.

At a predetermined position on the outer peripheral surface of the transfer drum 103, a gripper 103f for gripping the leading end of the recording medium 102 fed from the paper feeding device 101 is provided. An electrostatic attraction roller 103g is provided so as to be able to freely contact and separate.

The fixing device 106 includes a pressure roller 106a that is driven to rotate, and a fixing roller 106b that presses the roller 106a to apply heat and pressure to the recording medium 102. The recording medium 102 that has been separated from the transfer drum 103 and sent to the fixing device 106 passes through the fixing device 106 by being transported by the pressure roller 106a. The toner image is fixed.

The image forming operation of the printer having the above configuration will be described. First, the feed roller 101b shown in FIG. 9 is driven to rotate, and the recording medium 102 in the sheet cassette 101a is rotated by one.
The sheet is separated and fed to the transfer drum 103. The transfer drum 103 rotates in the direction of the arrow in the figure, grips the leading end of the recording medium 102 fed by the gripper 103f, and operates the recording medium 102 by the action of the suction roller 103g.
Is electrostatically attracted to the peripheral surface.

In synchronization with the rotation of the transfer drum 103, the photosensitive drum 104a is driven to rotate in the direction of the arrow in the figure, the surface of the photosensitive drum 104a is uniformly charged by the primary charger 104b, and the magenta image is scanned by the scanner unit 110. By irradiating light, a latent image of a magenta image is formed on the photosensitive drum 104a. Simultaneously with the formation of the latent image, the magenta developing device 105M is driven to apply a developing bias having substantially the same potential as the charging polarity of the photosensitive drum 104a so that the magenta toner adheres to the latent image formed on the photosensitive drum 104a. The latent image is developed by applying the voltage to form a magenta toner image on the photosensitive drum 104a. Then, a transfer voltage having a polarity opposite to that of the magenta toner is applied to the transfer drum 3, and the photosensitive drum 1
The magenta toner image on 04a is transferred onto the recording medium 102 held on the transfer drum 103.

When the transfer of the magenta toner image is completed as described above, the next developing cartridge 105C, 10C
5Y and 105K rotate and are sequentially positioned at the developing position facing the photosensitive drum 104a, and similarly, latent image formation of cyan, yellow, and black, development, and transfer of the toner image onto the recording medium 102 are sequentially performed. Recording medium 102
A color image in which four color toner images are superimposed is formed.

The recording medium 102 on which the transfer of the four color toner images has been completed is separated from the transfer drum 103 and
6, and after the toner image is fixed by the fixing device 106, the discharge tray 1 on the cover provided at the upper part of the apparatus main body.
At 08, the sheet is discharged by the discharge roller 107, and a series of image forming operations ends here.

Transfer drum 1 from which recording medium 102 is separated
In the case 03, after the toner adhered to the surface is cleaned by the cleaner 103h, the charge removed at the time of transfer is removed by the charge removing roller 103k, and the electrical charge is initialized.

In the above-described electrophotographic image forming apparatus, the supply roller 105a is in sliding contact with the developing roller 105b disposed in each developing cartridge, and scrapes off the toner that has not contributed to the development so that fresh development is always performed. An agent is supplied. The supply roller 105a is included in the frame of the developing cartridge as shown in the figure, and when the supply roller 105a is incorporated in the developing cartridge, a U-groove is provided in the frame of the developing cartridge.

On the other hand, a toner container 10 for storing toner
A toner conveying unit 105t is rotatably disposed at 5d, and is configured to convey and supply the toner to the supply roller 105a.

The developing cartridges 105M, 105
C, 105Y, and 105K are detachably attached to the apparatus main body. When the life of the developing cartridge has expired, the user can easily replace each developing cartridge. Improvements are being made.

[0026]

In recent years, as the needs of users have diversified, electrophotographic image forming apparatuses have been increased in size to accommodate larger recording media (for example, paper) than conventional ones. There is a need. However, in the developing cartridge having the above configuration, as described in the section of "Prior Art", in order to incorporate the supply roller 105a into the inside of the developing cartridge frame, the wall surfaces at both longitudinal ends of the developing cartridge frame are formed. In many cases, a U-groove opening is provided. For this reason, when the size of the apparatus is increased, the rigidity of the developing cartridge becomes insufficient, and there is a problem that the frame is deformed by the driving force when the developing roller and the like are rotationally driven, which adversely affects the image.

Therefore, it is conceivable to maintain the rigidity of the frame by making the above-mentioned opening a round hole, but this method makes it difficult to incorporate the supply roller into the developing cartridge.

On the other hand, the U-groove portion is a seat surface for attaching a flexible seal member for preventing the developer from leaking from the gap between the developing roller and the frame portion of the developing cartridge. A member for filling the groove is required, and in order to reduce the size of the device, a part of the hole filling member generally serves also as a seating surface for attaching the flexible seal member.

However, when the filling member is a rigid body,
It is very difficult to eliminate the gap between the frame and the U-groove without deforming the frame, and there is a problem that the developer leaks out from the gap to the outside.

Further, there is a problem that a minute step is easily formed at a boundary portion between the filling member and the frame of the developing cartridge, and the developer leaks from a gap between the flexible sealing member and the minute step.

Accordingly, a main object of the present invention is to provide a developing cartridge which can easily assemble and maintain sufficient rigidity even when the size is increased, and an electrophotographic image forming apparatus having the developing cartridge. is there.

Another object of the present invention is to provide a developing cartridge capable of preventing the developer from leaking without causing deformation of the frame of the developing cartridge and an electrophotographic image forming apparatus having the developing cartridge. .

[0033]

The above object is achieved by an electrophotographic image forming apparatus and a developing cartridge according to the present invention. In summary, the present invention provides a developer carrier that rotates at one end receiving a drive from a drive source, a developer supply member that rotates at one end and receives the drive and supplies developer to the developer carrier. A developing frame supporting the developer carrying member and the developer supply member, and a bearing member attached to the development frame and rotatably supporting a shaft of the developer supply member; In a developing cartridge detachably mounted in a photographic image forming apparatus, the developing frame body is formed on both wall surfaces in the longitudinal direction, has two openings through which the shaft body passes, and the shape of the opening is A drive transmission side receiving driving is a round hole, and a non-drive transmission side is a U-shaped groove.

According to another aspect of the present invention, a developer carrier that rotates at one end receiving a drive from a drive source, and supplies the developer to the developer carrier by rotating while receiving the drive at one end. A developer supply member, a developer frame supporting the developer carrier and the developer supply member, and a bearing member attached to the development frame and rotatably supporting a shaft of the developer supply member. In the electrophotographic image forming apparatus in which a developing cartridge having a developing cartridge is detachably mounted, the developing frame is formed on both side walls in a longitudinal direction thereof, and has two openings through which the shaft body passes. An electrophotographic image forming apparatus is provided, wherein the drive transmission side receiving the drive is a round hole, and the non-drive transmission side is a U-shaped groove. Provided.

In the above invention, a flexible end peripheral surface sealing member for sealing a gap between the developing frame and a peripheral surface of the developer carrier at both ends of the developer carrier,
Forming a seating surface for attaching the flexible seal member to the groove, and having a hole filling member that penetrates the shaft body;
The filling member is an elastic member. The filling member has at least one rib-shaped portion on its outer periphery. A sealing member that seals a gap between the shaft member and the filling member; wherein the sealing member seals a gap between a boundary between the filling member and the developing frame and a gap between the end peripheral surface sealing member. It is preferable to also serve as a member to be used. The filling material has a rubber hardness (JIS K-6301 type A) of 30.
It is preferably from 100 to 100.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electrophotographic image forming apparatus and a developing cartridge according to the present invention will be described in more detail with reference to the drawings.

[Overall Description of Image Forming Apparatus] First, the overall configuration of a color image forming apparatus will be schematically described with reference to FIG. FIG. 1 shows a color laser printer which is an embodiment of a color image forming apparatus.

As shown in FIG. 1, the color laser printer includes an electrophotographic photosensitive member (photosensitive drum) 15 rotating at a constant speed, a fixed black developing cartridge 21B, and a rotatable color developing cartridge of three colors. Yellow developing cartridge 20Y, magenta developing cartridge 20
M, a cyan developing cartridge 20C), and a recording medium that holds a multi-transferred color image developed by the image forming unit and fed from a transfer material feeding unit. An intermediate transfer body 9 for further transferring to the transfer material 2 is provided. The transfer material 2 on which the color image has been transferred from the intermediate transfer body 9 is transported to the fixing unit 25 to be fixed on the transfer material 2, and is discharged to discharge units 37 on the upper surface of the apparatus by discharge rollers 34, 35 and 36.

The three-color rotary developing cartridge and the fixed-type black developing cartridge are configured to be individually detachable from the printer main body.

Next, the configuration of each section of the image forming apparatus will be described in detail sequentially.

[Photosensitive Drum Unit] The photosensitive drum unit 13 includes an image carrier (hereinafter, referred to as a “photosensitive drum”) 1
5 and a container 14 of the cleaning device also serving as a holder for the photosensitive drum 15 are integrally formed. And
The drum unit 13 is detachably supported by the printer main body, and is configured so that the unit can be easily replaced according to the life of the photosensitive drum 15.

The photosensitive drum 15 according to this embodiment has a diameter of 6 mm.
An organic photoconductor layer is coated on the outside of a 2 mm aluminum cylinder, and the container 1 of the cleaning device is formed as described above.
4 rotatably supported.

A cleaner blade 16 and a primary charging means 17 are arranged on the periphery of the photosensitive drum 15, and a driving force of a drive motor (not shown) is transmitted to one end of the photosensitive drum 15 so that the photosensitive drum 15 is imaged. It is designed to rotate counterclockwise in the figure according to the forming operation.

[Charging Means] The primary charging means 17 is a conductive roller using a contact charging method. The conductive roller is brought into contact with the photosensitive drum 15, and a voltage is applied to the conductive roller 17. 15 to uniformly charge the surface.

[Exposure Means] Exposure to the photosensitive drum 15 is performed from the scanner unit 30. That is, when an image signal is given to the laser diode, the laser diode irradiates an image corresponding to the image signal to the polygon mirror 31.

The polygon mirror 31 is a scanner motor 3
1a, the image light rotated at high speed and reflected by the polygon mirror 31 selectively exposes the surface of the photosensitive drum 15 rotating at a constant speed via the imaging lens 32 and the reflecting mirror 33, and as a result, An electrostatic latent image is formed on the image.

[Developing Means] The developing means includes three developing cartridges 20Y, which enable development of each color of yellow, magenta, cyan, and black as described above in order to visualize the electrostatic latent image. 20M and 20C and one black developing cartridge 21B. When each developing cartridge reaches the end of its life, the user replaces them with new developing cartridges so that a high quality image is always obtained. I have.

The black developing cartridge 21B is a fixed developing cartridge, and a developing roller 21BS is provided at a position facing the photosensitive drum 15 at a minute interval (3
(Approximately 00 μm) to form a visible image on the photosensitive drum 15 using a black developer.

In the black developing cartridge 21B, the developer in the container is fed to the developing roller 21BS, which is a developer carrier, by a feeding mechanism 21BT, and is moved clockwise in the drawing by a coating blade 21BB pressed against the outer periphery of the developing roller 21BS. A thin layer of developer is applied to the outer periphery of the rotating developing roller 21BS, and a charge is applied to the developer (friction charging).

The developing bias is applied to the developing roller 21BS facing the photosensitive drum 15 on which the latent image is formed, so that toner development is performed on the photosensitive drum 15 in accordance with the latent image.

The three color developing cartridges 20Y, 20Y
0M and 20C are 6000 pages each (A4, 5% printing)
A considerable amount of developer is contained therein, and each is detachably held by a developing rotary 23 which rotates around a shaft 22.

When an image is formed, each developing cartridge is rotated about a shaft 22 while being held by a developing rotary 23, and a predetermined developing cartridge is
5 and the developing roller is positioned so as to face the photosensitive drum 15 at a small interval (about 300 μm), and then a visible image is formed corresponding to the electrostatic latent image on the photosensitive drum 15. I do.

When a color image is formed, the developing rotary 23 rotates for each rotation of the intermediate transfer member 9, and the developing process is performed in the order of the yellow developing cartridge 20Y, the magenta developing cartridge 20M, the cyan developing cartridge 20C, and then the black developing cartridge 20B. .

For example, FIG. 1 shows a state in which the yellow developing cartridge 20Y is positioned stationary at a position facing the photosensitive drum cartridge 13. further,
As shown in detail in FIG.
0Y is a mechanism for feeding the developer in the developing container 20YH 20YT.
Is supplied to the supply roller 20YR, which is a developer supply member, and the supply roller 20YR rotates clockwise in FIG.
And the blade 2 pressed against the outer periphery of the developing roller 20YS
0YB, the developing roller 2 rotates clockwise in the drawing.
A thin layer of a developer is applied to the outer periphery of OYS, and a charge is applied to the developer (triboelectric charging).

A toner is developed on the photosensitive drum 15 in accordance with the latent image by applying a developing bias to the developing roller 20YS facing the photosensitive drum 15 on which the latent image is formed.

For the magenta developing cartridge 20M and the cyan developing cartridge 20C, toner development is performed by the same mechanism as described above.

Each of the rotary developing cartridges 20Y and 20Y
When each developing cartridge is rotated to the developing position, each developing roller of M and 20C is connected to a high-voltage power supply for developing each color provided in the printer main body and a driving source, and selectively selectively for each color development. , And a drive is transmitted.

[Intermediate Transfer Body] The intermediate transfer body 9 transfers the toner image on the photosensitive drum 15 visualized by each developing cartridge four times (Y, M, C,
The image is rotated in a clockwise direction in the figure in synchronization with the outer peripheral speed of the photosensitive drum 15 in order to receive multiple transfer over each of the four color B images. Further, the intermediate transfer body 9 that has undergone the multiple transfer simultaneously multiplex-transfers the toner images of each color on the intermediate transfer body 9 to the transfer material 2 by sandwiching and transferring the transfer material 2 by a transfer roller 10 to which a voltage is applied. .

The intermediate transfer member 9 according to this embodiment has a diameter of 18
The outer circumference of a 6 mm aluminum cylinder 12 is covered with an elastic layer 11 of medium resistance sponge, medium resistance rubber or the like.
The intermediate transfer body 9 is rotatably supported, and is rotated by being driven by an integrally fixed gear (not shown).

[Cleaning Unit] The cleaning unit is configured to transfer the developer visualized on the photosensitive drum 15 by the developing unit to the intermediate transfer member 9 and then transfer the developer to the photosensitive drum 1.
5 is to clean the remaining developer. The removed developer that has been cleaned is stored in the cleaner container 14. The amount of the removed developer stored in the container 14 does not fill the container 14 earlier than the life of the photosensitive drum 15. Therefore, the container 14 is integrally and simultaneously replaced when the life of the photosensitive drum 15 is replaced.

[Paper Feeding Unit] The paper feeding unit feeds the transfer material 2 to the image forming unit, and includes a cassette 1 containing a plurality of transfer materials 2, feed rollers 3 and 4, and double feed prevention. , A paper feed guide 6, a transport roller 7, and a registration roller 8.

At the time of image formation, the paper feed roller 3 is driven and rotated in accordance with the image forming operation, and the transfer material 2 in the cassette 1 is removed by one.
The sheet is separated and fed one by one, guided by the guide plate 6, and reaches the registration roller 8 via the transport roller 7.

During the image forming operation, the registration roller 8 performs a non-rotating operation for keeping the transfer material 2 stationary and a rotation operation for conveying the transfer material 2 toward the intermediate transfer member 9 in a predetermined sequence. The position of the image and the transfer material 2 at the time of the transfer step, which is the next step, is aligned.

[Transfer Section] The transfer section is composed of a transfer roller 10 capable of swinging. The transfer roller 10 is formed by winding a metal shaft with a medium-resistance foam elastic material, and is movable up and down in the figure and has driving. .

While the four-color developer image is being formed on the intermediate transfer member 9, that is, while the intermediate transfer member 9 is rotated a plurality of times, the transfer roller 10 is connected with a solid line in FIG. And is separated from the intermediate transfer member 9.

After the formation of the four color toner images on the intermediate transfer member 9, the transfer roller 10 is shown by a thin line in the figure by a cam member (not shown) in accordance with the timing of transferring the color image onto the transfer material 2. At the upper position, it is pressed against the intermediate transfer body 9 via the transfer material 2 with a predetermined pressure. At this time, a bias is applied to the transfer roller 10 at the same time, and the toner image on the intermediate transfer body 9 is transferred to the transfer material 2.

Here, since the intermediate transfer body 9 and the transfer roller 10 are driven respectively, the transfer material 2 sandwiched between the two is subjected to the transfer process and at the same time, at a predetermined speed in the left direction in the figure. And is sent to the fixing unit 25 which performs the next process.

[Fixing Unit] The fixing unit 25 includes a developing unit 20,
The fixing device 26 fixes the toner image formed on the transfer material 2 via the intermediate transfer member 9 to the toner image formed by the fixing member 21. As shown in FIG. And a pressure roller 27 for pressing the transfer material 2 against the fixing roller 26. Each roller 26, 27
Is a hollow roller, which has heaters 28 and 29 inside thereof, and is configured to be driven to rotate and to convey the transfer material 2 at the same time.

That is, the transfer material 2 holding the toner image is transported by the fixing roller 26 and the pressure roller 27,
By applying heat and pressure, the toner is fixed on the transfer material 2.

Next, the means for incorporating the supply roller into the frame of the developing cartridge, which is a feature of the present invention, will be described. In the following description, the yellow developing cartridge 20Y will be described as a representative, but the same applies to the magenta and cyan developing cartridges.

As shown in FIG. 2, the developing cartridge 20Y includes a developing container 20YH for storing a developer, a supply roller 20YR, a developing roller 20YS, and a blade 20Y.
The developing frame supporting B and the like is integrally formed.

The drive from the drive source of the printer main body is transmitted to the developing roller 20YS via one end thereof by appropriate means during development, and is also transmitted to the supply roller 20YR via one end at the same time. Rotated in the direction.

FIG. 3 shows a state in which the supply roller 20YR is incorporated in the developing cartridge 20Y.

On the side surfaces of the developing frame 201, the shafts (shafts) 20YR1 and 20YR of the supply roller 20YR are respectively provided.
2 is provided, specifically, on the drive side, that is, the side that receives drive from the drive source (FIG. 3).
A round hole 201H is provided on the middle right side, and a U groove 201U is provided on the non-driving side (left side in FIG. 3). Supply roller 2
After passing the drive-side shaft 20YR1 through the round hole 201H, the non-drive-side shaft 20YR2 is inserted into the U-groove 201YR.
Drop into U. Next, a filling member 210 for filling the U groove 201U is inserted into the U groove 201U. At this time,
Unless the outer diameter of the supply roller shafts 20YR1 and 20YR2 is smaller than the inner diameter of the round hole 201H or the U groove 201U, the incorporation is impossible.

Subsequently, the developing frame 201 and the supply roller 20
YR, a bearing member 21 for positioning the relationship between the developing roller 20YS and the supply roller 20YR, not shown in FIG.
The supply roller 20YR is rotatably supported by 1, 211.

FIG. 4 shows that the supply roller 20YR is
01 is shown as being assembled.

As shown in FIG. 4, the filling member 210 forms an attachment seat surface 201S of an end peripheral surface sealing member 212 (see FIG. 6) for sealing a gap between the developing roller 20YS and the developing frame 201.

At this time, as described above, the developing frame 201 on the driving side is connected to the shaft 20YR1 of the supply roller 20YR.
Since the hole through which the toner is passed is the round hole 201H, the developing frame 2
01 is kept rigid. The hole on the non-drive side is U-shaped groove 201
For U, the rigidity is reduced, but when the supply roller 20YR is rotationally driven, the problem that the developing frame 201 is deformed due to the sufficient rigidity on the driving side receiving the force does not occur.

Next, the filling member 210 and the developing frame 201
The sealing means will be described.

In the present embodiment, the filling member 210 uses an elastic member. More specifically, chlorobrene rubber having a rubber hardness of 60 (as defined in JIS K-6301 type A) is used. This is because the sealing member 210 and the filling member 210 are sealed while the deformation of the developing frame member 201 is minimized by using the filling member 210 as an elastic member. According to experiments by the present inventors, the rubber hardness is desirably 30 to 100, and other materials can be selected as long as the material is an elastic member satisfying the rubber hardness.

Referring to FIG. 5, a description will be given of a means for further improving the sealing property between the filling member 210 and the developing frame 201. FIG. 5 is an enlarged front view of the filling member 210 (a).
And a side view (b).

As shown in both figures, a rib 210R is provided on the outer periphery of a portion of the filling member 210 which is in close contact with the developing frame 201. When the filling member 210 is inserted into the developing frame 201, the rib 210R is completely crushed, so that the degree of adhesion with the developing frame 210 is increased. Fill-in-the-blank member 21
If the same amount of crushing as when the rib 210R is provided is used, the developing frame will be deformed. However, by adopting this method, even if the degree of adhesion between the developing frame 201 and the filling member 210 is increased, the developing The frame 201 does not deform.

Further, in this embodiment, the rib 210R
Are provided, but this is because the sealing performance is improved by increasing the number of the contact portions with the ribs, so that even one can function sufficiently. It is also possible to further increase the margin by increasing. In the present embodiment, the shape of the rib is also rounded at the tip, but the same effect can be obtained with a square or triangular shape.

However, there is a part where the sealability is insufficient with the above-described structure alone. That is, the seating surface 201S for attaching the end peripheral surface sealing member 212 (see FIG. 6) for sealing the gap between the developing roller 20YS and the developing frame 201 is provided by the above-described hole filling member 210.
And the developing frame 201, a small step is formed at the boundary between the two on the sticking seat surface 201 </ b> S, and a minute gap is generated here. Although the above-mentioned minute step is a very small step, as described above, it cannot be eliminated unless the bonding seat surface 201S of the end peripheral surface sealing member 212 is formed by a plurality of components.

The shaft 20Y of the supply roller 20YR
A gap is also formed between the outer diameter of R2 and the inner diameter portion of the hole filling member 210. This is because the filling member 210 deforms itself and comes into close contact with the U groove 201U of the developing frame 201 as described above, so that the relationship between the supply roller 20YR and the shaft 20YR2 has a sufficient gap. This is because it is necessary.

Therefore, in the present embodiment, as shown in FIG.
And the outside surface of the end peripheral sealing member 212, the minute step of the pasting seat surface 201S, the peripheral surface of the shaft 20YR2 of the supply roller 20YR and the hole filling member 2
This seals toner leaking from the gap with the inner diameter of No. 10.

This part will be described in more detail. FIG. 7 is a side view showing a state before the bearing member 211 of the developing cartridge 20Y of this embodiment is assembled. As shown in the drawing, the seating surface 201S of the end peripheral surface sealing member 212 for sealing the gap between the developing roller 20YS and the developing frame 201 is formed by the developing frame 201 and the filling member 210. However, as described above, by forming the bonding seat surface 201S of the end peripheral surface sealing member 212 with a plurality of components, a minute step is likely to occur at the boundary between the components.

Therefore, as shown in the enlarged view of FIG. 8, an end peripheral surface sealing member 212 generated due to a minute step (not shown) formed at the boundary between the developing frame 201 and the filling member 210 described above. The sealing member 212, the filling member 210, and the sealing member 213 that covers the boundary portion of the developing frame 201 from the side surface are provided for the toner leaking from the minute gap generated on the attaching seat surface 201S. It seals by doing.

At this time, as shown in FIG. 6, the seal member 213 is formed by the bearing member 211 which is a positioning member of the supply roller 20YR, and the seal member 213 is formed by the developing frame 201, the filling member 210, and the peripheral surface of the end portion. Seal member 2
By pressing against the side surface of the twelfth, a sufficient sealing performance can be obtained.

Further, the inner diameter of the seal member 213 is adjusted so that the seal member 213 functions as a seal member for sealing the gap between the shaft 20YR2 of the supply roller 20YR and the inner diameter hole of the filling member 210.
It is configured to be press-fitted to the outer diameter of YR2.

In the description of the present embodiment, the developing cartridge 20Y has been described as an example, but the same applies to the developing cartridges 20M and 20C.

[0092]

As is clear from the above description, according to the electrophotographic image forming apparatus and the developing cartridge of the present invention, the developing frame is formed on both side walls in the longitudinal direction, and the shaft penetrates through the developing frame. It has two openings, and the shape of the openings is such that the drive transmitting side receiving the drive is a round hole and the non-drive transmitting side is a U-groove, so that the assembling work is easy and sufficient rigidity can be achieved even if the size is increased A flexible end peripheral surface sealing member for sealing a gap between the developing frame and the peripheral surface of the developer carrier at both ends of the developer carrier; and the U-groove. A seating surface for attaching the end peripheral surface sealing member to the end portion, and a filling member through which the shaft body passes. The filling member is an elastic member, so that the developing frame is deformed. Without leakage of developer

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of an electrophotographic image forming apparatus according to the present invention.

FIG. 2 is a sectional view showing one embodiment of a developing cartridge according to the present invention.

FIG. 3 is an explanatory diagram illustrating a state in which a supply roller and a filling member are incorporated into a developing cartridge.

FIG. 4 is an explanatory diagram illustrating a state after a supply roller and a filling member are incorporated into a developing cartridge.

FIG. 5 is a front view (a) and a side view (b) showing one embodiment of the filling member according to the present invention.

FIG. 6 is an enlarged perspective view of a main part showing how a seal member is attached to a developing cartridge.

FIG. 7 is a side view illustrating a state before a bearing member is assembled to the developing cartridge.

FIG. 8 is an enlarged side view showing a state where a seal member is attached to the developing cartridge.

FIG. 9 is a configuration diagram illustrating an example of a conventional electrophotographic image forming apparatus.

[Explanation of symbols]

 Reference Signs List 15 photosensitive drum (electrophotographic photosensitive member) 20C, 20M, 20Y developing cartridge 20YR supply roller 20YR1, 20YR2 shaft (shaft) 201 developing frame 201H round hole 201U U-groove 210 hole filling member 211 bearing member 212 end peripheral surface sealing member 213 Seal member

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H071 BA03 BA14 BA27 BA35 BA36 DA08 2H077 AA02 AA35 AC04 AD06 AD13 BA08 CA12 FA21 GA13

Claims (10)

[Claims] A developer carrying member that receives a drive from a drive source at one end and rotates; a developer supply member that receives the drive at one end and rotates to supply a developer to the developer carrying member; An electrophotographic image forming apparatus including: a developer frame supporting the developer carrier and the developer supply member; and a bearing member attached to the developer frame and rotatably supporting a shaft of the developer supply member. In the developing cartridge detachably mounted to the apparatus, the developing frame is formed on both side walls in the longitudinal direction, has two openings through which the shaft body passes, and the shape of the opening receives the driving. A developing cartridge wherein the drive transmission side is a round hole and the non-drive transmission side is a U-groove. 2. A flexible end peripheral surface sealing member for sealing a gap between the developing frame and the peripheral surface of the developer carrier at both ends of the developer carrier, The developing cartridge according to claim 1, further comprising: a filling member that forms a seat surface for attaching the end peripheral surface sealing member and penetrates the shaft body, wherein the filling member is an elastic member. 3. The developing cartridge according to claim 2, wherein said filling member has at least one rib-shaped portion on an outer periphery thereof. 4. A sealing member for sealing a gap between the shaft body and the filling member, wherein the sealing member includes a boundary between the filling member and the developing frame and a sealing member for the end peripheral surface sealing member. 4. The developing cartridge according to claim 2, wherein the developing cartridge also serves as a member for sealing a gap between the developing cartridges. 5. The developing cartridge according to claim 2, wherein said filling member has a rubber hardness (JIS) of 30 to 100. 6. A developer carrier that receives one end of a drive from a drive source and rotates, a developer supply member that receives the drive at one end and rotates to supply a developer to the developer carrier, and a developing device. A developing cartridge having a developer carrier that supports a developer carrier and the developer supply member, and a bearing member that is attached to the developer frame and rotatably supports a shaft of the developer supply member is detachable. In the electrophotographic image forming apparatus to be mounted, the developing frame body is formed on both side walls in the longitudinal direction, has two openings through which the shaft body penetrates, and the shape of the opening is such that a drive transmitting side receiving the drive is driven by the drive transmitting side. An electrophotographic image forming apparatus having a round hole and a non-drive transmitting side being a U-shaped groove. 7. A flexible end peripheral surface sealing member for sealing a gap between the developing frame and a peripheral surface of the developer carrier at both ends of the developer carrier, and a U-groove. The electrophotographic image forming apparatus according to claim 6, further comprising: a filling member that forms a seat surface for attaching the end peripheral seal member and penetrates the shaft body, wherein the filling member is an elastic member. 8. The electrophotographic image forming apparatus according to claim 7, wherein said filling member has at least one rib-shaped portion on an outer periphery thereof. 9. A sealing member for sealing a gap between the shaft body and the filling member, wherein the sealing member includes a boundary between the filling member and the developing frame and a sealing member for the end peripheral surface sealing member. 9. An electrophotographic image forming apparatus according to claim 7, wherein said electrophotographic image forming apparatus also functions as a member for sealing a gap between the two. 10. The filling member is made of rubber (JIS).
The electrophotographic image forming apparatus according to claim 7, 8 or 9, wherein K-6301 type A) is 30 to 100.