JP2000162869A - Developing equipment, process cartridge and image- forming device equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover developer into a developing container, while restraining the leakage and the scattering of the developer by providing a 1st magnetic field generating seal member whose magnetic pole having a polarity different from that of a magnetic field generating means is proximately facing opposite a developer carrier, so as to generate magnetic field nearer to the inner side of the developer container with respect to the magnetic pole of the magnetic field generating means in the vicinity of an aperture part. SOLUTION: A magnetic seal member 34 which is a 1st magnetic field generating seal member is disposed on a somewhat downstream side in the moving direction of a sleeve 31 from a pole N1 (on the downstream side in the moving direction of the sleeve 31), that is, on the inner side of the developing container 30 so as to nearly face the pole N1 below the sleeve 31. Therefore, the residual developer which has not been served for development at the time of developing processing is recovered and carried into the container 30, first in a state where it is still firmly held by the pole N1 at the entrance of the container 30. Furthermore, the developer held by the pole N1 is recovered more smoothly and carried into the container 30, because force attracting the developer to the member 34 side(inner side of the container 30) acts on the developer by the member 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image by an electrophotographic recording method or the like, and more particularly, to a developing device using a magnetic developer, a process cartridge having the developing device, and an image forming device. Things.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus for forming an image by an electrophotographic recording method or the like, an electrophotographic photosensitive member as a latent image carrier and a process means acting on the electrophotographic photosensitive member are integrally formed. As the cartridge, a process cartridge system in which the cartridge can be attached to and detached from the image forming apparatus main body is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a service person, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in image forming apparatuses.

In the developing device built in such a process cartridge, the developer on the developing sleeve flows out of the developing area on the peripheral surfaces of both ends of the developing sleeve, which is a rotating developer image carrier, in the axial direction. A sealing member is provided to prevent the occurrence of the above. Conventionally, elastic members such as felt and foam rubber have been widely used as seal members for preventing the developer from flowing out.

There is a regulating blade as a developer layer thickness regulating means at a position where the developer is supplied from the inside of the developing container to the developing sleeve, and it is possible to prevent development spillage and scattering at this portion to some extent by the regulating blade. it can.

On the other hand, at the entrance where the developer remaining on the developing sleeve without being subjected to the development is recovered into the developing container, in order to prevent the developer from spilling and scattering, FIG.
As shown in (1), there is known a means for contacting a flexible sheet member 41 with a developing sleeve while reinforcing the sheet member 41 with an elastic body disposed on the back surface thereof. Further, there is known a means for disposing a magnet seal member so as to be closely opposed to the developing sleeve along the axial direction of the developing sleeve.

[0006]

However, in an image forming apparatus using a flexible sheet member as described above, the sheet member may be deformed, the sealing effect may be weakened, and problems such as spilling and scattering of the developer may occur. was there.

Further, in the image forming apparatus using the above-described magnet seal member, since the magnet seal member is not sufficiently considered, the developer is also changed depending on the use condition, for example, by an impact when handling the process cartridge. There is a possibility that such problems may occur.

Accordingly, the present invention suppresses the leakage and scattering of the developer between the developing container and the developer carrying member due to an impact or the like, and furthermore, the developer not subjected to the developing process in the developing area. It is an object of the present invention to provide a developing device which can be collected in a developing container while suppressing leakage and scattering of the toner, or a process cartridge or an image forming apparatus provided with the developing device.

[0009]

According to the present application, the above object is to provide a developing device for applying a developer to a latent image carrier for carrying a latent image to convert the latent image into a visible image. A developer container having an opening formed therein for housing the developer, a developer carrier rotatably supported at the opening position of the developer container and carrying the developer, and a plurality of circumferentially fixedly disposed in the developer carrier; A magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means in the vicinity of the opening near the inside of the developer container. This is achieved by the first invention in which a first magnetic field generation sealing member that is long in the longitudinal direction of the developer carrying member and that is closely opposed to the body and generates a magnetic field is provided.

Further, according to the present application, the above object is achieved in the first aspect, wherein the developer carrier is a magnetic field generating means in a direction normal to a surface position of the developer carrier facing the first magnetic field generating seal member. The second invention is that the maximum value of the magnetic flux density due to the first magnetic field generation seal member in the normal direction of the surface position of the developer carrier facing the magnetic field generation seal member is set to be larger than the maximum value of the magnetic flux density due to Is also achieved by

Further, according to the present application, the above object is to provide a developing device for applying a developer to a latent image carrier for carrying a latent image to convert the latent image into a visible image, wherein the opening is formed. A developer container that accommodates the developer, a developer carrier that is rotatably supported at an opening position of the developer container and carries the developer, and has a plurality of circumferential magnetic poles that are fixedly arranged in the developer carrier. A magnetic field generating means for generating a magnetic field, wherein a magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening is closer to the inside of the developer container than the magnetic pole of the magnetic field generating means is in close proximity to the developer carrier. A first magnetic field generating seal member that is long in the longitudinal direction of the developer carrying member and generates a magnetic field; and a second magnetic field generating seal member that is disposed inside the first magnetic field generating seal member inside the developing container and generates a magnetic field. The third invention that comprises It is also achieved by.

Further, according to the present application, the above object is achieved in the third aspect, wherein the developer carrier is a magnetic field generating means in a direction normal to a surface position of the developer carrier facing the first magnetic field generating seal member. The fourth invention is that the maximum value of the magnetic flux density due to the first magnetic field generation seal member in the direction normal to the surface position of the developer carrier facing the magnetic field generation seal member is set to be larger than the maximum value of the magnetic flux density due to the first magnetic field generation seal member. Is also achieved by

Further, according to the present application, the above object is achieved in the third invention or the fourth invention, wherein the second magnetic field generating seal member is located at a position of the developer carrier surface facing the second magnetic field generating seal member. The maximum value of the magnetic flux density in the normal direction is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generation seal member in the normal direction of the developer carrier surface position facing the first magnetic field generation seal member. This is also achieved by the fifth invention.

Further, according to the present application, the above object is to provide a developing device for applying a developer to a latent image carrier for carrying a latent image to convert the latent image into a visible image, wherein the opening is formed. A developer container that accommodates the developer, a developer carrier that is rotatably supported at an opening position of the developer container and carries the developer, and has a plurality of circumferential magnetic poles that are fixedly arranged in the developer carrier. A developing device having a magnetic field generating means for generating a magnetic field, wherein the first magnetic field generating sealing member is disposed near the edge of the opening of the developing container, is closely opposed to the developer carrier, and generates a magnetic field; A first magnetic field generating seal member is disposed in close proximity to the first magnetic field generating seal member on the inner side of the developing container of the generating seal member,
A second magnetic field generating seal member that is disposed near the edge of the opening of the developing container and is close to and opposed to the developer carrier, and that generates a magnetic field; and a first magnetic field generating seal member and a second magnetic field generating seal member. This is also achieved by the seventh invention in which the magnetic poles of the opposing portions have the same polarity.

Further, according to the present application, the above object is attained in the sixth invention, wherein the magnetic field generating means is located outside the developer container with respect to a portion where the first magnetic field generating seal member and the second magnetic field generating seal member face each other. The maximum value of the magnetic flux density by the magnetic field generating means in the direction normal to the surface of the developer carrier facing the first magnetic field generating seal member and the second magnetic field generating seal member is closer to the first magnetic field generating seal member. The magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member and the second magnetic field generating seal member in the normal direction of the developer carrier surface position facing the seal member and the second magnetic field generating seal member. This is also achieved by the eighth invention.

Further, according to the present application, the object is a process cartridge which holds at least a latent image carrier and a developing device and is detachably supported by an image forming apparatus main body. The present invention is also achieved by a ninth invention including a device.

Further, according to the present application, the above object is attained in the eighth aspect, wherein the developer carrier is a magnetic field generating means in a direction normal to a surface position of the developer carrier facing the first magnetic field generating seal member. The maximum value of the magnetic flux density due to the first magnetic field generating seal member in the direction normal to the surface position of the developer bearing member facing the magnetic field generating seal member is set to be larger than the maximum value of the magnetic flux density. 9. The process cartridge according to 8.

Further, according to the present invention, the object is to provide a process cartridge which holds at least a latent image carrier and a developing device and is detachably supported by an image forming apparatus main body. The present invention is also achieved by a tenth invention including a device.

Further, according to the present application, the above object is achieved according to the tenth aspect, in which the developer carrier is provided with a magnetic field generating means in a direction normal to a surface position of the developer carrier facing the first magnetic field generating seal member. The tenth aspect is that the maximum value of the magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generation seal member in the normal direction of the developer carrier surface position facing the first magnetic field generation seal member. This is also achieved by one invention.

According to the present application, the above object is achieved in the tenth invention or the eleventh invention, in which the second magnetic field generating sealing member is provided with a method for determining a surface position of the developer carrier facing the developer carrier. The maximum value of the magnetic flux density in the linear direction is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generation seal member in the normal direction of the developer carrier surface position facing the first magnetic field generation seal member. This is also achieved by the twelfth invention.

Further, according to the present application, the object is a process cartridge which holds at least a latent image carrier and a developing device and is detachably supported by an image forming apparatus main body. The present invention is also achieved by a thirteenth invention including a device.

Further, according to the present application, the above object is achieved in the thirteenth invention in that the magnetic field generating means is located outside the developer container more than an opposing portion between the first magnetic field generating seal member and the second magnetic field generating seal member. A magnetic pole is disposed closer to the side, and the maximum value of the magnetic flux density by the magnetic field generating means in the normal direction of the surface position of the developer carrier facing the first magnetic field generating seal member and the second magnetic field generating seal member is the first magnetic field. The magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member and the second magnetic field generating seal member in the normal direction of the developer carrier facing the generating seal member and the second magnetic field generating seal member. This is also achieved by the fourteenth invention.

Further, according to the present application, the above object is achieved by applying a developer to a latent image carrier for carrying a latent image to convert the latent image into a visible image, and then recording the visible image on a recording medium. The present invention is also achieved by an image forming apparatus according to a fifteenth invention that includes the developing device according to the first invention or the process cartridge according to the eighth invention.

Further, according to the present application, the above object is achieved in the fifteenth aspect of the present invention in which the developer carrying member is configured to generate a magnetic field in a direction normal to a surface position of the developer carrying member facing the first magnetic field generating seal member. The maximum value of the magnetic flux density by the means is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generation seal member in the normal direction of the developer carrier surface position facing the magnetic field generation seal member. The invention is also achieved by the invention of (1).

Further, according to the present application, the above object is achieved by applying a developer to a latent image carrier for carrying a latent image to convert the latent image into a visible image, and then recording the visible image on a recording medium. The present invention is also achieved by an image forming apparatus according to a seventeenth aspect of the present invention, which includes the developing device of the third aspect of the invention or the process cartridge of the tenth aspect of the invention.

Further, according to the present application, the above object is achieved in the seventeenth aspect of the present invention in that the developer carrier has a magnetic field generation direction in a direction normal to the developer carrier surface position facing the first magnetic field generation seal member. The maximum value of the magnetic flux density by the means is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member in the normal direction of the developer carrier surface position facing the first magnetic field generating sealing member. This is also achieved by the eighteenth invention.

Further, according to the present application, the above object is achieved in the seventeenth invention or the eighteenth invention in that the second magnetic field generating seal member is provided at a position of the surface of the developer carrier facing the developer carrier. The maximum value of the magnetic flux density in the normal direction is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generation seal member in the normal direction of the developer carrier surface position facing the first magnetic field generation seal member. This is also achieved by the nineteenth invention.

According to the present application, the above object is also achieved by applying a developer to a latent image carrier for carrying a latent image to convert the latent image into a visible image, and then recording the visible image on a recording medium. An image forming apparatus, comprising: a developing device according to the sixth invention;
Alternatively, the present invention is also achieved by a twentieth invention including the process cartridge of the thirteenth invention.

Further, according to the present application, the above object is achieved in the twentieth invention in that the magnetic field generating means is located outside the developer container more than the opposed portion between the first magnetic field generating seal member and the second magnetic field generating seal member. A magnetic pole is disposed closer to the side, and the maximum value of the magnetic flux density by the magnetic field generating means in the normal direction of the surface position of the developer carrier facing the first magnetic field generating seal member and the second magnetic field generating seal member is the first magnetic field. The magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member and the second magnetic field generating seal member in the normal direction at the developer carrier surface position facing the generating seal member and the second magnetic field generating seal member. This is also achieved by the twenty-first invention.

That is, in the first invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means is closer to the inside of the developing container than the magnetic pole, and closely opposes the developer carrier to generate a magnetic field.

In the second invention according to the present application, the magnetic field generating means causes the developer to be carried on the developer carrying member at an opposing portion between the developer carrying member and the first magnetic field generating seal member. The first magnetic field generating seal member causes a magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means in the vicinity of the opening of the developing container to be closer to the inside of the developing container and to closely face the developer carrier to generate a magnetic field.

Further, in the third invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means is closer to the inside of the developing container than the magnetic pole and is opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating seal member is used for developing the first magnetic field generating seal member. A magnetic field is generated inside the container.

In the fourth invention according to the present application, the magnetic field generating means causes the developer to be carried on the developer carrying member at an opposing portion between the developer carrying member and the first magnetic field generating seal member. A first magnetic field generation sealing member, wherein a magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening of the developing container is closer to the inside of the developing container than the magnetic pole and generates a magnetic field. The second magnetic field generating seal member generates a magnetic field inside the first magnetic field generating seal member inside the developing container.

Further, in the fifth invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means is closer to the inside of the developing container than the magnetic pole and is opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating seal member is used for developing the first magnetic field generating seal member. A magnetic field stronger than the first magnetic field generating seal member is generated inside the container.

In the sixth invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member and the second magnetic field generating seal member comprise The magnetic field generating means generates a magnetic field in which the lines of magnetic force are concentrated in the direction facing the developer carrier in the vicinity of the developer carrier near the opening of the developing container. The first magnetic field generating seal member and the second magnetic field generating seal member carry the developer on the developer supporting member at a portion where the developer magnetic carrier faces the first magnetic field generating seal member and the second magnetic field generating seal member. However, the opposing portions of the first magnetic field generating seal member and the second magnetic field generating seal member face the developer carrier closer to the inside of the developing container with respect to the magnetic pole of the magnetic field generating means near the opening of the developing container, and the lines of magnetic force are developed. Concentrated in the direction facing the agent carrier Further, in the eighth invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means is located closer to the inside of the developing container than the magnetic pole and opposes the developer carrier to generate a magnetic field, and it is also necessary to repair the latent image carrier and replace the developing device. Maintenance is performed by replacing the process cartridge with a new one.

In the ninth invention according to the present application, the magnetic field generating means causes the developer to be carried on the developer carrying member at an opposing portion between the developer carrying member and the first magnetic field generating seal member. A first magnetic field generating seal member, a magnetic pole having a different polarity from the magnetic pole near the inside of the developing container with respect to the magnetic pole of the magnetic field generating means near the opening of the developing container is closely opposed to the developer carrier to generate a magnetic field, In addition, maintenance such as repair of the latent image carrier and replacement of the developing device is performed by replacing the process cartridge with a new one.

Further, in the tenth invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means is closer to the inside of the developing container than the magnetic pole and is opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating seal member is used for developing the first magnetic field generating seal member. Generate a magnetic field inside the container,
In addition, maintenance such as repair of the latent image carrier and replacement of the developing device is performed by replacing the process cartridge with a new one.

In the eleventh invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member at an opposing portion between the developer carrying member and the first magnetic field generating seal member. The first magnetic field generating seal member causes the magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening of the developing container to be closer to the inside of the developing container and generates a magnetic field by closely opposing the developer carrier. Along with the second magnetic field generating seal member generates a magnetic field inside the developing container of the first magnetic field generating seal member,
In addition, maintenance such as repair of the latent image carrier and replacement of the developing device is performed by replacing the process cartridge with a new one.

Further, in the twelfth invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole of a different polarity from the magnetic pole of the magnetic field generating means is located near the inside of the developing container and is closely opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating seal member is formed of the first magnetic field generating seal member. A magnetic field stronger than the first magnetic field generating seal member is generated inside the developing container, and maintenance such as repair of the latent image carrier and replacement of the developing device is performed by replacing the process cartridge with a new one.

In the thirteenth invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member and the second magnetic field generating seal member comprise , Near the opening of the developing container, the magnetic field lines are concentrated in the direction opposite to the developer carrier due to the opposition to the developer carrier, and maintenance such as repair of the latent image carrier and replacement of the developing device. Is performed by replacing the process cartridge with a new one. Further, in the fourteenth invention according to the present application, the magnetic field generating means includes a developer carrier, a first magnetic field generating seal member, and a second magnetic field generating seal member. The developer is carried on the developer carrying member at a portion facing the magnetic field generating seal member, and the first magnetic field generating seal member and the second magnetic field generating seal member serve as the first magnetic field generating seal member and the second magnetic field generating seal member. The opposite part is The magnetic pole of the magnetic field generating means near the opening is close to the developer carrier toward the inside of the developing container, and generates a magnetic field in which the magnetic lines of force are concentrated in the direction facing the developer carrier. Maintenance such as repair and replacement of the developing device is performed by replacing the process cartridge with a new one. Further, in the fifteenth invention according to the present application, the magnetic field generating means is provided on the developer carrier. The first magnetic field generating seal member is arranged such that a magnetic pole having a different polarity from the magnetic pole near the opening of the developing container is closer to the inside of the developing container than the magnetic pole of the magnetic field generating means near the opening of the developing container. To generate a magnetic field.

In the sixteenth invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member at an opposing portion between the developer carrying member and the first magnetic field generating seal member. The first magnetic field generating seal member causes the magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening of the developing container to be closer to the inside of the developing container and generates a magnetic field by closely opposing the developer carrier. .

Further, in the seventeenth invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole of a different polarity from the magnetic pole of the magnetic field generating means is located near the inside of the developing container and is closely opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating seal member is formed of the first magnetic field generating seal member. A magnetic field is generated inside the developing container.

According to the eighteenth aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member at an opposing portion between the developer carrying member and the first magnetic field generating seal member. The first magnetic field generating seal member causes the magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening of the developing container to be closer to the inside of the developing container and generates a magnetic field by closely opposing the developer carrier. At the same time, the second magnetic field generating seal member generates a magnetic field inside the first magnetic field generating seal member inside the developing container.

Further, in the nineteenth invention according to the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole of a different polarity from the magnetic pole of the magnetic field generating means is located near the inside of the developing container and is closely opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating seal member is formed of the first magnetic field generating seal member. A stronger magnetic field is generated inside the developing container than the first magnetic field generating seal member.

Further, in the twentieth invention according to the present application, the magnetic field generating means carries the developer on the developer carrier, and the first magnetic field generating seal member and the second magnetic field generating seal member comprise In the twenty-first invention according to the present application, furthermore, a magnetic field line is generated in the vicinity of the opening of the developing container in the vicinity of the developer carrier to generate a magnetic field concentrated in the direction facing the developer carrier. A magnetic field generating means for causing the developer to be carried on the developer carrying member at an opposing portion between the developer carrying member and the first magnetic field generating seal member and the second magnetic field producing seal member; The generating seal member is such that the opposing portions of the first magnetic field generating seal member and the second magnetic field generating seal member are close to the developer carrier near the inside of the developing container with respect to the magnetic pole of the magnetic field generating means near the opening of the developing container. The lines of magnetic force gather in the direction facing the developer carrier. To generate the magnetic field

[0046]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) First, an image forming apparatus according to a first embodiment of the present invention will be described.

FIG. 1 is a central sectional view showing a schematic configuration of an image forming apparatus according to the present embodiment, and is an example of a laser beam printer using a transfer type electrophotographic process of a process cartridge detachable type to which the present invention is applied. FIG.

In FIG. 1, reference numeral 1 denotes an electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) as a rotating photosensitive drum-type latent image carrier, which is driven to rotate clockwise as indicated by an arrow a.
Around the photosensitive drum 1, a charging device 2, an image exposing device E, a developing device 3, a transfer device 4, and a cleaning device 6
And so on.

After the photosensitive drum 1 is uniformly charged by the charging device 2, a laser beam E corresponding to the image information signal is emitted.
Image exposure is performed to form an electrostatic latent image on the photosensitive drum 1, and then the developing device 3 develops the electrostatic latent image into a visible image. This visible image is transferred onto a transfer material P as a recording medium by a transfer roller T as a transfer unit at a transfer portion T by electrostatic force and pressing force, and is conveyed to a fixing device (not shown) of a heat fixing type or the like. Then, the visible image on the transfer material P is fixed, and is discharged out of the apparatus as an image formed product (print, copy).

After the transfer of the toner image to the transfer material P, the surface of the photosensitive drum 1 is cleaned by the cleaning device 6 to remove adhered contaminants such as residual toner, and is repeatedly used for image formation.

The image forming apparatus according to the present embodiment is a process in which the four process devices of the photosensitive drum 1, the charging device 2, the developing device 3 and the cleaning device 6 are collectively attached to and detached from the main body for image formation. There is a cartridge 10. In FIG. 1, reference numeral 9 denotes a cartridge housing in which the above-mentioned four process devices are incorporated at predetermined positions.
Reference numeral 8 denotes a process cartridge insertion / removal guide / holding unit on the image forming apparatus main body side. When the process cartridge 10 is attached to the image forming apparatus main body in a predetermined state, the process cartridge 10 and the image forming apparatus main body are mechanically and electrically coupled to each other. The lower surface of the drum 1 comes into contact with the transfer roller 4 on the image forming apparatus main body side in a predetermined manner, and the image forming apparatus is ready for image formation.

The process cartridge is a unit in which a charging unit, a developing unit, a cleaning unit, and an electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is detachable from the image forming apparatus main body. or,
At least one of charging means, developing means, and cleaning means
And an electrophotographic photosensitive member, which is integrally formed into a cartridge so that the cartridge can be attached to and detached from the image forming apparatus main body. Further, at least the developing means and the electrophotographic photosensitive member are integrally formed into a cartridge so as to be detachable from the image forming apparatus main body.

Next, the developing device 3 will be described with reference to FIGS.
It will be described based on. 2 is a central cross-sectional view of the developing device, FIG. 3 is a longitudinal cross-sectional view of a main part of the developing device, and FIG. 4 is a schematic diagram for explaining a magnetic pole configuration of the main part and a state of lines of magnetic force. .

In FIG. 2, reference numeral 30 denotes a developing container containing a magnetic toner T as a magnetic developer. Reference numeral 31 denotes a nonmagnetic cylinder (hereinafter, referred to as a sleeve) as a developer carrier made of aluminum, stainless steel, or the like, in which a magnet roller 32 as a roller-shaped magnetic field generating means is fixedly disposed.
It is rotatably attached to the developing container 30 via a sleeve bearing (not shown).

As shown in FIG. 2, the magnetic roller 32 has two N poles N1, N2 and two S
It has poles S1 and S2.

The sleeve 31 rotates in the counterclockwise direction indicated by the arrow, and the magnetic toner T supplied in the developing container 30 adheres to the surface of the sleeve 31 by the magnetic force of the magnet roller 32 and is conveyed.

In FIG. 2, reference numeral 33 denotes a regulating blade (elastic blade) as a developer layer thickness regulating means, which presses the sleeve 31 at the outlet of the developing container 30 in the presence of the N2 pole, and the sleeve 31 The thickness of the developer layer to be carried and transported is regulated.

The magnetic toner T carried and conveyed visualizes a latent image formed on the photosensitive drum 1 moving in the direction of the arrow (the developing magnetic pole S1) in the developing area.

An oscillating bias voltage obtained by superimposing a DC voltage on an AC voltage is applied to the sleeve 31 by the power supply P2. Note that a rectangular wave, a sine wave, or the like can be used as the waveform of the vibration bias voltage.

The residual magnetic toner T after the development is applied to the developing container 30 at the take-in pole N1 at the entrance of the developing container 30.
The toner is collected inside, and is stirred and mixed with the magnetic toner in the developing container 30 via the pumping pole S2.

In FIG. 2 and FIG. 3, reference numeral 34 denotes a magnet sealing member as a first magnetic field generating sealing member.
, And slightly downstream of the N1 pole with respect to the moving direction of the sleeve 31 (hereinafter, downstream is referred to as the moving direction of the sleeve 31), that is, the developing container 3
0 It is arranged inside.

As shown in FIG. 3, the magnet seal member 3
Numeral 4 is disposed below the sleeve 31 in the longitudinal direction, with a gap g from the outer peripheral surface of the sleeve 31, and attached to the developing container 30.

Next, the magnet seal member 34 used in this embodiment will be described in detail.

The magnet seal member 34 is an injection-molded product having a width of 5 mm provided with a nylon binder containing magnetic powder of ferrite. At this time, the peak value of the magnetic flux density on the surface of the sleeve 31 of each magnetic pole of the magnet seal member 34 in the direction normal to the surface of the sleeve 31 is 200 to 600 ×
It is 10 ^-4 T (Tesla).

As the magnet roller 32 and the magnet seal member 34 that can be suitably applied to the present invention, known magnets such as ferrite magnets, alnico magnets, iron-cobalt magnets, and rare earth magnets can be used, but cost and weight are low. In view of the above, a ferrite magnet dispersed in resin or rubber is preferable.

FIG. 4 is a schematic diagram for explaining the configuration of the magnetic poles and the state of the lines of magnetic force of the main part of the developing device.

A magnet seal member 34 is disposed slightly downstream (inside the developing container) below the take-in pole N1 of the magnet roller 32 with the S3 pole substantially opposed to the N1 pole.
An S forward magnetic field is formed. Therefore, the magnetic field lines are N1 pole, S
Since the three poles extend in a direction perpendicular to the sleeve 31 (a direction intersecting with the sleeve moving direction), the leakage of the developer can be suppressed or prevented by the shielding effect of the lines of magnetic force.
That is, even if the user gives an impact or the like when handling the process cartridge, it is possible to suppress or prevent the leakage of the developer. The present inventor has studied and found that the developer is taken into and collected in the developing container, and that the developer spills and scatters is related to the magnetic flux density on the sleeve 31.

The magnetic flux was measured only by the magnet roller 32 with the magnet seal member 34 removed, and the peak (maximum value) of the magnetic flux density in the normal direction at the surface position of the developer carrier due to the N1 pole in the density sleeve 31 was measured. On the other hand, the magnetic seal density is measured only by the magnet seal member 34 by removing the sleeve 31 containing the magnet roller 32, and the magnet seal member is disposed substantially outside the sleeve 31 substantially opposite to the N1 pole. When the peak of the magnetic flux density in the normal direction at the surface position of the sleeve 31 by Br2 is Br2, by setting Brl> Br2, the developer on the sleeve 31 is taken into the developing container 30, collected, and spilled. Prevention of scattering was improved.

The following can be considered as the reason.

In the case of Br2> Brl, the developer is attracted to the magnet seal member 34 and accumulates more and more, and the stagnated developer hinders the transport of the developer. It is considered that spills and scattering occur.

On the other hand, when Br1> Br2, the developer is attracted onto the sleeve 31. However, since the sleeve 31 is driven to rotate, the developer is attracted onto the sleeve 31 and enters the developing container 30. It is considered that the developer is collected and conveyed, and the developer does not stay in this portion.

The position of the N1 pole in the sleeve 31 and the position of the magnet seal member 34 relate to the loading and collection of the developer into the developing container 30. It is preferable that the magnet seal member 34 be disposed slightly inside the developing container 30 from the N1 pole. With such a configuration, the residual developer that has not been subjected to development during the development processing is first collected and transported into the developing container 30 while being firmly held at the N1 pole at the entrance of the developing container 30. Further, the developer held at the N1 pole exerts a force to attract the magnet seal member 34 toward the magnet seal member 34 (the inside of the developer container 30), so that the collection and transport into the developer container 30 is performed more smoothly.

Next, numerical examples will be described.

In the present embodiment, the peripheral speed of the photosensitive drum 1 is 94
mm / sec, the outer diameter was 30 mm, the peripheral speed of the sleeve 31 was 111 mm / sec, and the outer diameter of the sleeve 31 was 16 mm. The rotation direction of the sleeve 31 was set to the forward direction with respect to the photosensitive drum 1. Distance h between photosensitive drum 1 and sleeve 31
Was 0.3 mm. At this time, the peak value of the magnetic flux density on the surface of the sleeve 31 of each magnetic pole of the magnet roller 32 fixed in the sleeve 31 in the direction normal to the surface of the sleeve 31 is 400 to 900 × 10 ⁻⁴ T (tesla). Was. The gap g between the magnet seal member 34 and the sleeve 31 is 1
５5 mm. At this time, the peak value of the magnetic flux density on the surface of the sleeve 31 of each magnetic pole of the magnet seal member 34 in the direction normal to the surface of the sleeve 31 is 200 to 600 × 1.
0 ^-4 T (tesla).

Using the image forming apparatus of this embodiment, 20
When 00 images were formed, the developer spilled,
There was no scattering, the image density was sufficiently high, there was no fog, and a good image was obtained. Further, the developer did not leak even when the process cartridge was handled.

According to the above-described embodiment, good sealing performance is ensured so that the developer does not leak even when a shock is applied when the process cartridge is attached to or detached from the image forming apparatus main body by the user. can get. Further, the spilling and scattering of the developer can be suppressed and prevented, and a satisfactory image having a sufficiently high image density can be obtained.

(Second Embodiment) Next, a second embodiment of the present invention will be described. The description of the same configuration as that of the first embodiment is omitted.

FIG. 5 is a central sectional view showing a schematic configuration of a developing device provided in the image forming apparatus according to the present embodiment, and shows a development example in which the present invention is applied to a digital electrophotographic copying machine. It is a center sectional view of an important section of a device.

This embodiment has the same configuration as that of the first embodiment except that the second magnet seal member 35 is provided in the developing device of the first embodiment.

In FIG. 5, reference numeral 35 denotes a second magnet sealing member which is a second magnetic field generating sealing member. The N3 pole is provided below the sleeve 31 downstream of the magnet sealing member 34 (inside the developing container 30). It is arranged substantially opposite to the side. That is, the magnet seal member 34 is disposed slightly downstream (inside the developing container 30) below the N1 pole, with the S3 pole substantially facing the N1 pole, and further downstream (inside the developing container 30). In addition, a second magnet seal member 35 is disposed so that the N3 pole is substantially opposed to the sleeve 31 side.

FIG. 6 is a schematic diagram for explaining the configuration of the magnetic poles of the main part and the state of the lines of magnetic force. A magnet seal member 34 is disposed slightly below the take-in pole N1 of the magnet roller 32 and inside the developing container 30 with the S3 pole substantially opposed to the N1 pole, and both form an NS forward magnetic field. The S3 pole of the magnet seal member 34 and the N3 pole of the second magnet seal member 35 form an NS forward magnetic field.

The N3 pole of the magnet seal member 35 and the N1 pole of the magnet roller 32 have a repulsive magnetic field relationship. Lines of magnetic force are concentrated between the N1 pole and the S3 pole, the lines of magnetic force are connected to the S3 pole and the N3 pole, and the lines of magnetic force radiated from the N3 pole are repelled from the N1 pole and directed in a direction perpendicular to the sleeve 31. . That is, since the magnetic lines of force extend in the perpendicular direction of the sleeve 31 at two places, the S3 pole and the N3 pole, the leakage of the developer can be more effectively suppressed and prevented by the shielding effect of the magnetic lines. That is, for example, even if the user gives an impact or the like when handling the process cartridge, the leakage of the developer can be more effectively suppressed and prevented.

In the present embodiment, the magnetic flux density is measured by removing the sleeve 31 containing the magnet roller 32, and the peak of the magnetic flux density in the normal direction at the surface position of the sleeve 31 by the magnet seal member 34 is defined as Br2. When the peak of the magnetic flux density in the normal direction at the surface position of the sleeve 31 by the magnet seal member 35 is Br3, Br
3> Br2.

In other words, since the magnetic flux density of the magnet seal member 35 is made larger than that of the magnet seal member 34 and the magnet seal member 35 is disposed on the inner side of the developing container 30 with respect to the magnet seal member 34, the magnet seal member The force acts in the direction of collecting and transporting the developer near the S3 pole of No. 34 into the developing container,
The collection and transport into the developing container 30 is performed more smoothly.

With the configuration as in the present embodiment, in addition to the effects of the first embodiment, the leakage of the developer due to impact or the like can be more effectively suppressed and prevented, and the developer can be transferred to the developing container. Can be more effectively taken up and recovered.

(Third Embodiment) Next, a third embodiment of the present invention will be described. The description of the same configuration as that of the first embodiment is omitted.

FIG. 7 is a central sectional view showing a schematic configuration of a developing device provided in the image forming apparatus according to the present embodiment, and shows a development example in which the present invention is applied to a digital electrophotographic copying machine. It is a center sectional view of an important section of a device.

This embodiment is the same as the second embodiment except that the magnetic pole configuration of the developing device is different from that of the second embodiment. In the second embodiment, there is no magnetic pole at a position facing the magnet seal member 35 of the magnet roller 32, but in the present embodiment, the S3 pole is arranged.

FIG. 8 is a schematic diagram for explaining the configuration of the magnetic poles of the main part and the state of the lines of magnetic force. A magnet seal member 34 is disposed slightly downstream (inside of the developing container 30) of the inlet of the developing container substantially opposite to the N1 pole, with the S3 pole being substantially opposed to the N1 pole. A magnetic field is formed. Further, the S2 pole is disposed slightly downstream of the N1 pole of the magnet roller 32, and the N3 pole of the magnet seal member 35 is substantially opposite to the S2 pole and slightly downstream (inside of the developing container 30). The NS2 pole and the N3 pole form an NS forward magnetic field. As described above, since the NS forward magnetic field is formed at two places near the entrance of the developing container, the shielding effect by the lines of magnetic force is further improved, and the leakage of the developer can be more effectively suppressed and prevented. That is, even if the user gives an impact or the like when handling the process cartridge, the leakage of the developer can be more effectively suppressed and prevented.

With the configuration as in this embodiment, in addition to the effects of the second embodiment, leakage of the developer due to impact or the like can be more effectively performed.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. The description of the same configuration as that of the first embodiment is omitted.

FIG. 9 is a central sectional view showing a schematic configuration of a developing device provided in the image forming apparatus according to the present embodiment, and shows a development example in which the present invention is applied to a digital electrophotographic copying machine. It is a center sectional view of an important section of a device.

This embodiment has the same configuration as the first embodiment except that the configuration of the magnet seal member is different from the first embodiment. In the first embodiment, the magnetic pole of the magnet seal member 34 is oriented in the direction perpendicular to the sleeve 31 (N1 pole direction). In the present embodiment, the opposing surfaces of the magnet seal member 34 and the magnet seal member 35 have the same polarity. It is arranged to become.

FIG. 10 is a schematic diagram for explaining the configuration of the magnetic poles of the main part and the state of the lines of magnetic force.

As shown in FIG. 10, a magnet seal member 34 is disposed substantially opposite to the N1 pole at the entrance of the developing container 30. The magnet seal member 34 is disposed close to and immediately downstream of the magnet seal member 34. 35 are provided. Therefore, the boundary between the magnet seal members 34 and 35 is located slightly downstream of the N1 pole (inside the developing container 30). The magnet seal members 34 and 35 have magnetic poles arranged substantially parallel to the sleeve 31. The S3 pole of the magnet seal member 34 and the S4 pole of the magnet seal member 35 face each other, and the N3 pole and N4
The poles are facing in opposite directions. When the opposing surfaces of the two magnets are arranged so as to generate a repulsive magnetic field, the lines of magnetic force are considerably concentrated in a direction perpendicular to the sleeve 31 in a narrow region at the boundary of the repulsive magnetic field. As a result, the shielding effect by the lines of magnetic force is considerably improved, and leakage of the developer can be more effectively suppressed and prevented. That is, even if the user gives an impact or the like when handling the process cartridge, the leakage of the developer can be more effectively suppressed and prevented.

Further, as shown in this embodiment, when the opposing surfaces of the magnet seal member 34 and the magnet seal member 35 are arranged so as to have the same polarity, the N1 pole at the entrance of the developing container and the magnet seal member 34 are opposed to each other. In the region, the sleeve 31
A force acts in the direction of collecting and transporting the above developer into the developing container, and the collecting and transporting into the developing container is performed quite smoothly.

According to the structure of this embodiment, in addition to the effects of the first embodiment, the leakage of the developer due to impact or the like can be suppressed and prevented quite effectively, and the developer can be transferred to the developing container. Uptake and recovery can be performed quite effectively.

In the first to fourth embodiments, the case where a magnetic toner is used as the magnetic developer has been described as an example. However, a two-component developer composed of a non-magnetic toner and magnetic particles (carrier) is used. Similar effects can be obtained by using a magnetic developer.

[0100]

As described above, according to the first aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member comprises: Since the magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening of the developing container is closer to the inside of the developing container than the magnetic pole and is opposed to the developer carrier to generate a magnetic field, In addition to suppressing the leakage and scattering of the developer between the developing container and the developer carrying member due to an impact or the like, the magnetic field generating means places the developer that has not been subjected to the development in the developing area on the developer carrying member. After being transported to the inside of the opening developing container while being carried, the magnetic field by the first magnetic field generating seal member is further transported to the inside of the developing container, and leakage of the developer,
It can be collected in the developing container while suppressing scattering.

According to the second invention of the present application,
The magnetic field generating means causes the developer to be carried on the developer carrier at a portion where the developer carrier and the first magnetic field generating seal member face each other, and the first magnetic field generating seal member generates the magnetic field near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the means is located closer to the inside of the developing container than the magnetic pole and opposes the developer carrier so as to generate a magnetic field. Leakage of the developer between the carrier,
While suppressing the scattering, the developer that has not been subjected to development in the development area, after the magnetic field generating means is effectively carried on the developer carrying member and conveyed to the inside of the opening developing container,
The magnetic field generated by the first magnetic field generating seal member is further conveyed to the inside of the developing container, and the developer can be effectively collected in the developing container while suppressing leakage and scattering of the developer.

Further, according to the third aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member serves as the magnetic field near the opening of the developing container. A magnetic pole having a polarity different from that of the magnetic pole near the inside of the developing container with respect to the magnetic pole of the generating means is closely opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating sealing member is a developing container of the first magnetic field generating sealing member. Since the magnetic field is generated on the inner side, the leakage of the developer between the developer container and the developer carrying member due to the impact of the magnetic field by the first magnetic field generating seal member and the second magnetic field generating seal member due to an impact or the like. The magnetic field generating means conveys the developer not subjected to the development in the developing area to the inside of the opening developing container while the magnetic field generating means carries the developer not subjected to the development in the developing area. Member and second magnet It can be the magnetic field by generating the sealing member is conveyed to further developing container interior side, and collected into the developing container while preventing leakage of the developer, the scattering.

According to the fourth invention of the present application,
The magnetic field generating means causes the developer to be carried on the developer carrier at a portion where the developer carrier and the first magnetic field generating seal member face each other, and the first magnetic field generating seal member generates the magnetic field near the opening of the developing container. A magnetic pole having a polarity different from that of the magnetic pole is closer to the inside of the developing container than the magnetic pole of the means, and the magnetic pole is generated in such a manner that the magnetic field is generated while the second magnetic field generating seal member is inside the developing container. Side, so that the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member may cause the leakage of the developer between the developer container and the developer carrier even by impact or the like, While suppressing scattering, the developer not used for development in the development area
After being conveyed to the inside of the opening developing container while the magnetic field generating means is effectively carried on the developer carrying member, the magnetic field generated by the first magnetic field generating sealing member and the second magnetic field generating sealing member is further transferred to the inside of the developing container. And the developer can be effectively collected in the developing container while suppressing leakage and scattering of the developer.

Further, according to the fifth aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member serves as the magnetic field near the opening of the developing container. A magnetic pole having a polarity different from that of the magnetic pole near the inside of the developing container with respect to the magnetic pole of the generating means is closely opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating sealing member is a developing container of the first magnetic field generating sealing member. Since the inner side generates a stronger magnetic field than the first magnetic field generating seal member, the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member may cause the developing container and the developer carrying member to be in contact with each other due to impact or the like. While the developer is not leaked or scattered during the development, the magnetic field generating means effectively carries the developer that has not been subjected to the development in the developing area on the developer carrying member while the opening inside the developing container. Transport to the side Then, the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member is effectively transported further to the inside of the developing container, and the developer is more effectively collected inside the developing container while suppressing leakage and scattering of the developer. can do.

According to the sixth aspect of the present invention,
Magnetic field generating means for carrying the developer on the developer carrying member,
The first magnetic field generating seal member and the second magnetic field generating seal member are closely opposed to the developer carrier near the opening of the developer container, and generate a magnetic field in which the lines of magnetic force are concentrated in the direction facing the developer carrier. Therefore, the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member effectively suppresses leakage and scattering of the developer between the developing container and the developer carrying member due to impact or the like, and The first magnetic field generating seal member and the second magnetic field generating seal are provided after the developer not subjected to the development in the developing area is conveyed to the inside of the opening developing container while the magnetic field generating means is carried on the developer carrying member. The magnetic field generated by the member is further transported to the inside of the developing container, and the developer can be collected in the developing container while suppressing leakage and scattering of the developer.

Further, according to the seventh aspect of the present invention, the magnetic field generating means is provided on the developer carrying member at a portion where the developer carrying member faces the first magnetic field generating seal member and the second magnetic field generating seal member. The first magnetic field generation seal member and the second magnetic field generation seal member are opposed to the first magnetic field generation seal member and the second magnetic field generation seal member. The first magnetic field generating seal member and the second magnetic field generating member generate a magnetic field concentrated in the direction in which the magnetic field lines are opposed to the developer carrier with the magnetic poles being close to and facing the developer carrier closer to the inside of the developing container. The leakage of the developer between the developer container and the developer carrier even when the magnetic field by the magnetic field generating seal member is impacted or the like is effectively suppressed, and the developer that has not been subjected to development in the development area is effectively reduced.
After the magnetic field generating means is carried on the developer carrying member and transported to the inside of the opening developing container, the magnetic field generated by the first magnetic field generating sealing member and the second magnetic field generating sealing member is effectively further transferred to the developing container internal side. And the developer can be effectively collected in the developing container while suppressing leakage and scattering of the developer.

Further, according to the eighth aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member serves as the magnetic field near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the generating means is located closer to the inside of the developing container and is closely opposed to the developer carrier to generate a magnetic field. The above-described opening portion developing container is configured to suppress leakage and scattering of the developer between the developer carrying member and the developer that has not been subjected to the development in the developing region, while the magnetic field generating means carries the developer on the developer carrying member. After being conveyed to the inside, the magnetic field generated by the first magnetic field generating seal member is further conveyed to the inside of the developing container, and the developer can be collected in the developing container while suppressing leakage and scattering of the developer. Improving operability Kill.

According to the ninth invention of the present application,
The magnetic field generating means causes the developer to be carried on the developer carrier at a portion where the developer carrier and the first magnetic field generating seal member face each other, and the first magnetic field generating seal member generates the magnetic field near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the means is located closer to the inside of the developing container than the magnetic pole and opposes the developer carrier so as to generate a magnetic field. Leakage of the developer between the carrier,
While suppressing the scattering, the developer that has not been subjected to development in the development area, after the magnetic field generating means is effectively carried on the developer carrying member and conveyed to the inside of the opening developing container,
The magnetic field generated by the first magnetic field generating seal member is further conveyed to the inside of the developing container, so that the developer can be effectively collected in the developing container while suppressing the leakage and scattering of the developer, and the maintenance operability is improved. can do.

Further, according to the tenth aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member serves as the magnetic field near the opening of the developing container. A magnetic pole having a polarity different from that of the magnetic pole near the inside of the developing container with respect to the magnetic pole of the generating means is closely opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating sealing member is a developing container of the first magnetic field generating sealing member. Since the magnetic field is generated on the inner side, the leakage of the developer between the developer container and the developer carrying member due to the impact of the magnetic field by the first magnetic field generating seal member and the second magnetic field generating seal member due to an impact or the like. The magnetic field generating means conveys the developer not subjected to the development in the developing area to the inside of the opening developing container while the magnetic field generating means carries the developer not subjected to the development in the developing area. Member and second magnet And conveyed to the magnetic field is further developing container interior side due to the occurrence seal member, leakage of the developer can be collected into the developing container while suppressing scattering, also, it is possible to improve the maintenance operability.

Further, according to the eleventh aspect of the present invention, the magnetic field generating means causes the developer to be carried on the developer carrying member at an opposing portion between the developer carrying member and the first magnetic field generating seal member. A first magnetic field generation sealing member, wherein a magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening of the developing container is closer to the inside of the developing container than the magnetic pole and generates a magnetic field. Since the second magnetic field generating seal member generates a magnetic field inside the developing container inside the first magnetic field generating seal member, the magnetic fields generated by the first magnetic field generating seal member and the second magnetic field generating seal member Also, while suppressing leakage and scattering of the developer between the developing container and the developer carrying member, the magnetic field generating means effectively removes the developer that has not been subjected to the development in the developing area onto the developer carrying member. Opening development while carrying After being conveyed to the inside of the container, the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member is further conveyed to the inside of the developing container, so that the developer is effectively prevented from leaking and scattering inside the developing container. The maintenance operability can be improved.

Further, according to the twelfth invention of the present application, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means is closer to the inside of the developing container than the magnetic pole and is opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating seal member is used for developing the first magnetic field generating seal member. Since the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member is stronger on the inner side of the container than the first magnetic field generating seal member, the developing container and the developer carrier are not affected by the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member. The developer container, which suppresses leakage and scattering of the developer between the developing container and the developer that has not been subjected to the development in the developing area, is effectively supported by the magnetic field generating means on the developer carrier. Conveyed inside After that, the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member is effectively further conveyed to the inside of the developing container, and the developer is more effectively prevented inside the developing container while preventing leakage and scattering of the developer. It can be collected, and maintenance operability can be improved.

Further, according to the thirteenth aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member and the second magnetic field generating seal member comprise: The first magnetic field generation seal member and the second magnetic field generation are provided because the magnetic field lines are concentrated in the direction facing the developer carrier in the vicinity of the developer carrier in the vicinity of the opening of the developing container. The magnetic field generated by the sealing member effectively suppresses the leakage and scattering of the developer between the developing container and the developer carrying member due to an impact or the like, and also causes the developer not subjected to the development in the developing area to generate a magnetic field. After the means is carried on the developer carrying member and transported to the inside of the opening developing container, the magnetic field generated by the first magnetic field generating sealing member and the second magnetic field generating sealing member is further transported to the developing container internal side, and Leakage and scattering of developer Won while can be collected into the developing container, also, it is possible to improve the maintenance operability.

Further, according to the fourteenth aspect of the present invention, the magnetic field generating means is provided at the portion where the developer carrying member faces the first magnetic field generating seal member and the second magnetic field generating seal member. A first magnetic field generating seal member and a second magnetic field generating seal member; and a facing portion of the first magnetic field generating seal member and the second magnetic field generating seal member is a magnetic field generating means near an opening of the developing container. The first magnetic field generating seal member and the second magnetic field generating member generate a magnetic field concentrated in the direction in which the magnetic field lines are opposed to the developer carrier with the magnetic field lines concentrated near the developer container with respect to the magnetic poles. (2) The magnetic field generated by the magnetic field sealing member effectively suppresses the leakage and scattering of the developer between the developing container and the developer carrying member due to an impact or the like, and also removes the developer not used for the development in the developing area. ,
After the magnetic field generating means is carried on the developer carrying member and transported to the inside of the opening developing container, the magnetic field generated by the first magnetic field generating sealing member and the second magnetic field generating sealing member is effectively further transferred to the developing container internal side. The developer can be effectively collected in the developing container while suppressing leakage and scattering of the developer, and maintenance operability can be improved.

Further, according to the fifteenth aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. The magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means is arranged closer to the inside of the developing container and is close to and opposed to the developer carrier to generate a magnetic field. In addition to suppressing leakage and scattering of the developer between the developer carrying member and the developer, the magnetic field generating means carries the developer which has not been subjected to the development in the developing area onto the developer carrying member. After being conveyed to the inside of the container, the magnetic field generated by the first magnetic field generating seal member is further conveyed to the inside of the developing container, and the developer can be collected in the developing container while suppressing leakage and scattering of the developer.

Further, according to the sixteenth aspect of the present invention, the magnetic field generating means causes the developer to be carried on the developer carrying body at a portion where the developer carrying body and the first magnetic field generating seal member face each other. The first magnetic field generating seal member is arranged such that a magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening of the developing container is closer to the inside of the developing container than the magnetic pole and generates a magnetic field. The above magnetic field suppresses the leakage and scattering of the developer between the developing container and the developer carrier even when the magnetic field is subjected to an impact or the like. After the generating means is effectively carried on the developer carrier and conveyed to the inside of the opening developing container, the magnetic field generated by the first magnetic field generating seal member is further conveyed to the inside of the developing container, and the developer is conveyed. Effective in the developer container while suppressing leakage and scattering It can be recovered.

Further, according to the seventeenth aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means is closer to the inside of the developing container than the magnetic pole and is opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating seal member is used for developing the first magnetic field generating seal member. Since the magnetic field is generated inside the container, the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member may cause the developer to flow between the developing container and the developer carrying member even by an impact or the like. The magnetic field generating means conveys the developer which has not been subjected to the development in the developing area to the inside of the opening developing container while suppressing the leakage and scattering, while carrying the developer on the developer carrying member. Seal member and second Can be the magnetic field by the field generating sealing member is conveyed to further developing container interior side, and collected into the developing container while suppressing leakage, the scattering of the developer.

Further, according to the eighteenth aspect of the present invention, the magnetic field generating means causes the developer to be carried on the developer carrying member at an opposing portion between the developer carrying member and the first magnetic field generating seal member. A first magnetic field generation sealing member, wherein a magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening of the developing container is closer to the inside of the developing container than the magnetic pole and generates a magnetic field. Since the second magnetic field generating seal member generates a magnetic field inside the developing container inside the first magnetic field generating seal member, the magnetic fields generated by the first magnetic field generating seal member and the second magnetic field generating seal member Also, while suppressing leakage and scattering of the developer between the developing container and the developer carrying member, the magnetic field generating means effectively removes the developer that has not been subjected to the development in the developing area onto the developer carrying member. Opening development while carrying After being conveyed to the inside of the container, the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member is further conveyed to the inside of the developing container, so that the developer is effectively prevented from leaking and scattering inside the developing container. Can be collected.

Further, according to the nineteenth aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member is provided near the opening of the developing container. A magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means is closer to the inside of the developing container than the magnetic pole and is opposed to the developer carrier to generate a magnetic field, and the second magnetic field generating seal member is used for developing the first magnetic field generating seal member. Since the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member is stronger on the inner side of the container than the first magnetic field generating seal member, the developing container and the developer carrier are not affected by the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member. The developer container, which suppresses leakage and scattering of the developer between the developing container and the developer that has not been subjected to the development in the developing area, is effectively supported by the magnetic field generating means on the developer carrier. Conveyed inside After that, the magnetic field generated by the first magnetic field generating seal member and the second magnetic field generating seal member is effectively conveyed further to the inside of the developing container, and more effectively in the developing container while suppressing leakage and scattering of the developer. Can be recovered.

Further, according to the twentieth aspect of the present invention, the magnetic field generating means carries the developer on the developer carrying member, and the first magnetic field generating seal member and the second magnetic field generating seal member comprise: The first magnetic field generation seal member and the second magnetic field generation are provided because the magnetic field lines are concentrated in the direction facing the developer carrier in the vicinity of the developer carrier in the vicinity of the opening of the developing container. The magnetic field generated by the sealing member effectively suppresses the leakage and scattering of the developer between the developing container and the developer carrying member due to an impact or the like, and also causes the developer not subjected to the development in the developing area to generate a magnetic field. After the means is carried on the developer carrying member and transported to the inside of the opening developing container, the magnetic field generated by the first magnetic field generating sealing member and the second magnetic field generating sealing member is further transported to the developing container internal side, and Leakage and scattering of developer It can be recovered into the developer container while won.

Further, according to the twenty-first invention of the present application, the magnetic field generating means is provided with the developer carrying member at a portion where the developer carrying member faces the first magnetic field generating seal member and the second magnetic field generating seal member. The developer is carried on the body, and the first magnetic field generating seal member and the second magnetic field generating seal member are opposed to the first magnetic field generating seal member and the second magnetic field generating seal member. The first magnetic field generating seal member and the magnetic field lines are arranged so as to generate a magnetic field concentrated in the direction facing the developer carrier with the lines of magnetic force facing the developer carrier closer to the inside of the developing container with respect to the magnetic poles of the means. The developer that has not been subjected to development in the developing area while effectively suppressing leakage and scattering of the developer between the developing container and the developer carrier even when the magnetic field generated by the second magnetic field generating seal member is subjected to impact or the like. And the magnetic field generating means After being conveyed to the inside of the opening developing container while being carried on the image agent carrier, the magnetic field by the first magnetic field generating seal member and the second magnetic field generating seal member is effectively conveyed further to the inside of the developing container, Leakage of the developer,
It can be effectively collected in the developing container while suppressing scattering.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a schematic configuration of a laser beam printer using a transfer type electrophotographic process of a process cartridge detachable type as an example of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a schematic configuration of a developing device provided in the image forming apparatus of FIG.

3 is a cross-sectional view of a main part of the developing device in FIG. 2 in a longitudinal direction.

FIG. 4 is a schematic diagram for explaining a state of magnetic lines of force between a developer carrying member and a magnetic field generating seal member according to the first embodiment of the present invention.

FIG. 5 is a schematic sectional view showing a schematic configuration of a developing device provided in an image forming apparatus according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram for explaining a state of lines of magnetic force between a developer carrying member and a magnetic field generating seal member according to a second embodiment of the present invention.

FIG. 7 is a schematic sectional view illustrating a schematic configuration of a developing device provided in an image forming apparatus according to a third embodiment of the present invention.

FIG. 8 is a schematic diagram for explaining a state of magnetic lines of force between a developer carrying member and a magnetic field generating seal member according to a third embodiment of the present invention.

FIG. 9 is a schematic sectional view illustrating a schematic configuration of a developing device provided in an image forming apparatus according to a fourth embodiment of the present invention.

FIG. 10 is a schematic diagram for explaining a state of lines of magnetic force between a developer carrying member and a magnetic field generating seal member according to a fourth embodiment of the present invention.

FIG. 11 is a schematic sectional view showing a schematic configuration of a conventional developing device.

[Explanation of symbols]

 Reference Signs List 1 latent image carrier (electrophotographic photoreceptor, photoreceptor drum) 3 developing device 10 process cartridge 30 developing container 31 developing sleeve (developer carrier) 32 magnet roller (magnetic field generating means) 34 magnet seal member (first magnetic field generation) Seal member) 35 Second magnet seal member (Second magnetic field generation seal member) N1, N2, S1, S2 Magnetic pole N3, N4, S3, S4 Magnetic pole T Magnetic toner (developer)

Claims (21)

[Claims] 1. A developing device for forming a latent image into a visible image by applying a developer to a latent image carrier for carrying a latent image, comprising: a developing container having an opening formed therein to accommodate the developer;
A developer carrying member rotatably supported at an opening position of the developing container and carrying the developer; and a magnetic field generating means fixedly arranged in the developer carrying body and having a plurality of magnetic poles in a circumferential direction to generate a magnetic field. In the developing device, a magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means in the vicinity of the opening is closer to the inside of the developer container than the magnetic pole and is opposed to the magnetic pole of the developer container to generate a magnetic field. A developing device comprising a first magnetic field generating seal member that is long in a longitudinal direction of the developing device. 2. The developer bearing member according to claim 1, wherein the maximum value of the magnetic flux density by the magnetic field generating means in a direction normal to the surface of the developer bearing member facing the first magnetic field generating seal member is equal to the developing force facing the magnetic field generating seal member. 2. The developing device according to claim 1, wherein the magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member in the normal direction of the agent carrier surface position. 3. A developing device for applying a developer to a latent image carrier for carrying a latent image to make the latent image a visible image, comprising: a developing container having an opening formed therein to accommodate the developer;
A developer carrier rotatably supported at an opening position of the developer container and carrying the developer; and a magnetic field generating means fixedly arranged in the developer carrier and having a plurality of magnetic poles in a circumferential direction to generate a magnetic field. In the developing device, a magnetic pole having a different polarity from the magnetic pole of the magnetic field generating means near the opening is closer to the inside of the developer container than the magnetic pole, and the magnetic pole generates a magnetic field. A developing device comprising: a first magnetic field generating seal member that is long in the longitudinal direction of the body; and a second magnetic field generating seal member that is disposed inside the first magnetic field generating seal member inside the developing container and generates a magnetic field. . 4. The developing device according to claim 1, wherein the maximum value of the magnetic flux density by the magnetic field generating means in the normal direction of the surface position of the developer carrying member facing the first magnetic field generating sealing member is equal to the developing force facing the magnetic field generating sealing member. 4. The developing device according to claim 3, wherein the magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member in the normal direction of the agent carrier surface position. 5. The developing device according to claim 1, wherein a maximum value of a magnetic flux density in a normal direction of a surface position of the developer carrier facing the second magnetic field generating seal member is opposite to the first magnetic field generating seal member. 5. The method according to claim 3, wherein the magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member in the normal direction of the agent carrier surface position.
3. The developing device according to claim 1. 6. A developing device for forming a latent image into a visible image by applying a developer to a latent image carrier for carrying a latent image, comprising: a developing container having an opening formed therein for housing the developer;
A developer carrier rotatably supported at an opening position of the developer container and carrying the developer; and a magnetic field generating means fixedly arranged in the developer carrier and having a plurality of magnetic poles in a circumferential direction to generate a magnetic field. In the developing device, a first magnetic field generating seal member that is disposed near the edge of the opening of the developing container and is in close proximity to the developer carrying member and generates a magnetic field; A second magnetic field generating seal member, which is disposed in close proximity to the magnetic field generating seal member, is disposed near the edge of the opening of the developing container, is in close proximity to the developer carrier, and generates a magnetic field; A developing device, wherein the magnetic poles at opposing portions of the one magnetic field generating seal member and the second magnetic field generating seal member have the same polarity. 7. A magnetic field generating means, wherein a magnetic pole is disposed closer to the outside of the developer container than an opposing portion between the first magnetic field generating seal member and the second magnetic field generating seal member. (2) The maximum value of the magnetic flux density by the magnetic field generating means in the direction normal to the surface of the developer bearing member facing the magnetic field generating seal member is the developer bearing member facing the first magnetic field generating seal member and the second magnetic field generating seal member. 7. The developing device according to claim 6, wherein the magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member and the second magnetic field generating seal member in the normal direction of the surface position. 8. A process cartridge holding at least a latent image carrier and a developing device and detachably supported by an image forming apparatus main body, comprising a developing device according to claim 1. cartridge. 9. The developer carrier, wherein the maximum value of the magnetic flux density by the magnetic field generating means in the direction normal to the surface position of the developer carrier opposed to the first magnetic field generating seal member is set to a value corresponding to that of the developing device facing the magnetic field generating seal member. 9. The process cartridge according to claim 8, wherein the magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generation sealing member in the normal direction of the agent carrier surface position. 10. A process cartridge holding at least a latent image carrier and a developing device and detachably supported by an image forming apparatus main body, wherein the process cartridge includes the developing device according to claim 3. cartridge. 11. The developer carrying member has a maximum magnetic flux density by a magnetic field generating means in a direction normal to a surface position of the developer carrying member facing the first magnetic field generating seal member. The process cartridge according to claim 10, wherein the magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generation seal member in the normal direction of the developer carrier surface position. 12. The second magnetic field generating seal member, wherein the maximum value of the magnetic flux density in the normal direction of the surface position of the developer carrier facing the developer carrier is such that the developer carrying member facing the first magnetic field generating seal member has a maximum value. The process cartridge according to claim 10, wherein the magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generation seal member in the normal direction of the body surface position. 13. A process cartridge which holds at least a latent image carrier and a developing device and is detachably supported by an image forming apparatus main body, comprising a developing device according to claim 6. cartridge. 14. A magnetic field generating means, wherein a magnetic pole is disposed closer to the outside of the developer container than an opposing portion between the first magnetic field generating seal member and the second magnetic field generating seal member. (2) The maximum value of the magnetic flux density by the magnetic field generating means in the direction normal to the surface of the developer bearing member facing the magnetic field generating seal member is the developer bearing member facing the first magnetic field generating seal member and the second magnetic field generating seal member. 14. The process cartridge according to claim 13, wherein the magnetic flux density is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member and the second magnetic field generating seal member in the normal direction of the surface position. 15. An image forming apparatus for applying a developer to a latent image carrier for carrying a latent image to convert the latent image into a visible image, and then recording the visible image on a recording medium,
An image forming apparatus comprising the developing device according to claim 1 or the process cartridge according to claim 8. 16. The developer carrier, wherein the maximum value of the magnetic flux density by the magnetic field generating means in the normal direction of the surface position of the developer carrier facing the first magnetic field generating seal member is equal to that of the developing device facing the magnetic field generating seal member. The image forming apparatus according to claim 15, wherein the magnetic flux density is set to be larger than a maximum value of a magnetic flux density by the first magnetic field generating seal member in a normal direction of the agent carrier surface position. 17. An image forming apparatus for applying a developer to a latent image carrier for carrying a latent image to convert the latent image into a visible image, and then recording the visible image on a recording medium,
An image forming apparatus comprising the developing device according to claim 3 or the process cartridge according to claim 10. 18. The developer carrying member has a maximum magnetic flux density of the magnetic field generating means in a direction normal to a surface position of the developer carrying member facing the first magnetic field generating seal member. 18. The magnetic flux density in the normal direction of the surface position of the developer carrier to be set is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member.
An image forming apparatus according to claim 1. 19. The second magnetic field generating seal member has a maximum value of a magnetic flux density in a normal direction of a position of a surface of the developer bearing member facing the developer bearing member. 19. The image forming apparatus according to claim 17, wherein the magnetic flux density is set to be larger than a maximum value of the magnetic flux density by the first magnetic field generating seal member in a normal direction of the body surface position. 20. An image forming apparatus for applying a developer to a latent image carrier for carrying a latent image to convert the latent image into a visible image, and then recording the visible image on a recording medium,
An image forming apparatus comprising the developing device according to claim 6, or the process cartridge according to claim 13. 21. A magnetic field generating means, wherein a magnetic pole is disposed closer to the outside of the developer container than an opposing portion between the first magnetic field generating seal member and the second magnetic field generating seal member. (2) The maximum value of the magnetic flux density by the magnetic field generating means in the direction normal to the surface of the developer bearing member facing the magnetic field generating seal member is the developer bearing member facing the first magnetic field generating seal member and the second magnetic field generating seal member. 21. The image forming apparatus according to claim 20, wherein the magnetic flux density in the normal direction at the surface position is set to be larger than the maximum value of the magnetic flux density by the first magnetic field generating seal member and the second magnetic field generating seal member.