JPH10340000A - Developing device, process cartridge and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress/prevent the leakage of a developer, a failure in coating and a defect in an image by regulating the width of the coating with the developer on a developer carrier. SOLUTION: In the opening part of a developing container 30, a composite sleeve 31 having a magnet roller 32 inside is arranged. The composite sleeve 31 consists of a nearly cylindrical nonmagnetic member 31a and two nearly annular magnetic members 31b and these two magnetic members 31b are restrained by the outside end of the nonmagnetic member 31a, to be integrally formed. Two magnetic members 31b are arranged in positions where their inner peripheries face the outer periphery at both ends of the magnet roller 32 and magnetic force in both end parts of the magnet roller 32 is shielded by the magnetic members 31b, to regulate a region coated with toner, on the composite sleeve 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device, a process cartridge and an image forming apparatus for developing and visualizing an electrostatic latent image formed on an image carrier by an electrophotographic recording method or an electrostatic recording method. .

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying apparatus, an electrostatic recording apparatus, and a magnetic recording apparatus, an electrostatic latent image or a magnetic latent image is formed on the surface of an image carrier, and the electrostatic latent image is formed on the image carrier. An electro-latent image or the like is developed by a developing device, the image is transferred to a transfer material, and then the image on the transfer material is fixed by a fixing device to obtain an image.

As a developing device for developing an electrostatic latent image or the like on an image carrier, a magnetic brush developing device is widely used. As an example of this magnetic brush developing device, a sleeve which is a non-magnetic cylinder as a developer carrier rotatably arranged in a developing container, and has a plurality of magnetic poles on its outer peripheral surface and is fixedly arranged in the sleeve. A magnet roller as a magnetic field generating means, and a regulating blade as a developer layer thickness regulating means capable of regulating a layer thickness of the developer carried on the sleeve, wherein a developing region in which the sleeve and the image carrier are opposed to each other. The developer is carried on the sleeve with almost the same width as the width of
It is widely known that the developer carried on the sleeve is transported by rotation of the sleeve.

[0004] In order to prevent the inside of the apparatus from being contaminated by the developer, the above-described developing apparatus carries the developer at both ends outside the coating area of the developer on the sleeve having the same width as the developing area. -At both ends of the sleeve, at both ends of the sleeve, end regulating means for preventing the supply of the developer is provided so as not to convey the developer. As an end regulating means, in order to prevent the developer supplied to the sleeve from flowing out to the end of the sleeve (outside the developer coating area on the sleeve),
At both ends of the rotating sleeve, seal members made of an elastic material such as felt or foam rubber are brought into contact with both ends of the sleeve to prevent the supply of the developer.

[0005]

However, in the conventional end regulating means using a seal member, since the seal member is strongly pressed against the sleeve, the developer carried on the sleeve is rotated by the rotation of the sleeve. However, there is a problem that the developer that moves toward the end and is restricted from moving at the position of the seal member may form a lump (aggregate) of the developer, or the developer may be fused to the sleeve. If the developer is agglomerated, the effect of preventing the supply of the developer cannot be sufficiently expected due to the formation of a gap in this portion, and the developer passes through the position of the seal member, and the developer is deposited on the end of the sleeve. There was a case that spilled.

Also, the agglomerated developer mass moves to the middle of the sleeve and is clogged between the surface of the sleeve and the developer layer thickness regulating means. There is a problem that the image may appear as white streaks. Also, when the developer is fused, there is a possibility that the regulation of the developer may not be sufficiently performed in the portion where the fusion has occurred, and the fused developer may be peeled off to the middle of the sleeve. In some cases, the toner may move and become clogged between the sleeve and the developer layer thickness regulating means, resulting in poor coating or white streaks in the image.

As described above, when the agglomeration and fusion of the developer occur, the scraping of the developer becomes insufficient at this portion, causing the developer to spill, and the agglomeration and fusion of the developer. In some cases, the kimono moves to the middle of the sleeve and is clogged by the means for regulating the thickness of the developer layer, resulting in defective coating and defective images.

In view of the above, the present invention regulates the width of the coating of the developer on the developer carrying member and suppresses / prevents aggregation, fusion, and spillage of the developer, thereby preventing leakage of the developer and coating defects. It is another object of the present invention to provide a developing device, a process cartridge, and an image forming apparatus capable of suppressing and preventing image defects.

Further, the present invention also regulates the width of the coating of the developer on the developer carrier to control the width of the coating of the developer on the developer carrier in a developing device in which the magnet in the developer carrier rotates. An object of the present invention is to provide a developing device, a process cartridge, and an image forming apparatus capable of suppressing and preventing leakage of a developer, coating defects, and image defects by suppressing and preventing spills.

[0010]

According to the first aspect of the present invention, the object is to provide a developing container for accommodating a magnetic developer, a plurality of rotatable containers arranged in the developing container, and a plurality of rotatable containers inside the developing container. In a developing device having a developer carrier capable of carrying a developer and transporting the developer in a predetermined direction by being fixedly arranged with a magnet having a magnetic pole, the developer carrier is formed from a non-magnetic member and a magnetic member, This is achieved by disposing the magnetic members at both longitudinal ends of the developer carrier.

Further, according to a second aspect of the present invention, there is provided a developing container for storing a magnetic developer, and a plurality of magnetic poles which are rotatably or fixedly arranged in the developing container and which are provided therein. And a developer carrier capable of carrying the developer and transporting the developer in a predetermined direction by rotatably disposing the magnet having the developer carrier, wherein the developer carrier is formed from a non-magnetic member and a magnetic member. This is achieved by disposing the magnetic members at both longitudinal ends of the developer carrier.

According to a third aspect of the present invention, the above object is attained by bringing a developer stripping member into contact with the surfaces of magnetic members disposed at both ends of a developer carrier. Is done.

Further, according to the fourth aspect of the present invention, the object is to receive the developer dropped from the magnetic member below the vicinity of the magnetic members disposed at both ends of the developer carrier. This can be achieved by providing a developer receiving member that can perform the following operations.

According to a fifth aspect of the present invention, the above object is achieved by providing a guide path for guiding a developer received below a magnetic member to a developer container in the developer receiving member. .

According to a sixth aspect of the present invention, there is provided a process cartridge which is detachably formed in an image forming apparatus main body and has at least an image carrier and a developing device. Developing device,
This is attained by using any one of the first to fifth inventions.

According to a seventh aspect of the present invention, at least the above object is achieved by providing a developing container accommodating a magnetic developer and a magnet disposed in the developing container and having a plurality of magnetic poles therein. An image forming apparatus provided with a developing device having a developer carrier that is arranged and can carry the developer and transport the developer in a predetermined direction, wherein the developing device is any one of the first to fifth inventions. This is achieved by using a developing device or by disposing the process cartridge of the sixth invention in the image forming apparatus.

In other words, according to the first aspect of the present invention, the magnetic members disposed at both ends of the developer carrier allow the magnetic force of the magnet in the developer carrier to move out of the surface of the developer carrier. Since the developer is not released, the developer is not carried on the surface of the developer carrier on which the magnetic member is disposed, and the width of the developer coating is regulated by a magnetic action, so that the development on the end side is performed. In addition to reducing the load on the developer, aggregation, fusion, and spillage of the developer are suppressed and prevented,
Coating defects and image defects during image formation are suppressed and prevented.

Further, according to the second aspect of the present invention, even when the magnet in the developer carrier is rotatably disposed, the magnetic members disposed at both ends of the developer carrier provide the magnetic member. Since the magnetic force of the magnet in the developer carrier is not released from the surface of the developer carrier, the developer is not carried on the surface of the developer carrier on which the magnetic member is arranged, and the magnetic force is applied. By regulating the width of the developer coating, the load on the developer at the end can be reduced, and aggregation, fusion, and spilling of the developer can be suppressed and prevented, resulting in poor coating during image formation. And image defects are suppressed and prevented.

Further, according to the third aspect of the present invention, the developer adhered to the surface of the magnetic member with a small force by contacting the developer peeling member with the surface of the magnetic member of the developer carrier. As the developer can be stripped, the pressing force of the developer stripping member and the load on the developer are reduced, and aggregation, fusion, and spilling of the developer are suppressed and prevented, and coating defects and image defects Defects are suppressed and prevented.

Further, according to the fourth aspect of the present invention, the developer spilled from the end of the developer carrier is provided by the developer receiving member provided below the developer carrier near the magnetic member. Since it can be collected and stored, contamination by the developer is suppressed and prevented.

According to the fifth aspect of the present invention, the developer collected by the developer receiving member can be collected in the developing container by the guide path provided in the developer receiving member. Along with effective use of the developer,
The contamination by the developer is suppressed and prevented.

Further, according to the sixth aspect of the present invention, the developing device disposed in the process cartridge includes:
Since the developing device is any one of the first to fifth aspects of the present invention, the load on the developer at the end of the developer carrier in the process cartridge can be reduced, and the developer can be effectively used. As well as coagulation, fusion,
Spills and the like are suppressed and prevented, and coating defects and image defects during image formation are suppressed and prevented.

Further, according to the seventh aspect of the present invention, any one of the first to fifth aspects of the invention is used as the developing device in the image forming apparatus, or Since the process cartridge of the sixth invention is installed in the apparatus, the load on the developer at the end of the developer carrier in the image forming apparatus can be reduced, and the developer can be effectively used. At the same time, aggregation, fusion, and spillage of the developer are suppressed and prevented, and coating defects and image defects during image formation are suppressed and prevented.

[0024]

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

(First Embodiment) First, a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic structural view showing the vicinity of a developing device when the developing device of the present embodiment is applied to an image forming apparatus using a drum type photosensitive member. 2. Description of the Related Art An image forming apparatus such as an electrophotographic printer has a photosensitive drum 1 as an image carrier, which is a drum-type photosensitive member, provided on a surface of the image forming apparatus. Charging means for performing an electrophotographic process, image exposure means,
A transfer device, a cleaning device, a charge removing device, and the like are appropriately disposed, and a developing device G that develops and visualizes an electrostatic latent image on the photosensitive drum 1 is disposed at a position facing the photosensitive drum 1.

A developing device G for developing an electrostatic latent image includes a developing container 30 for storing a magnetic toner as a magnetic developer, and an opening provided at a position facing the photosensitive drum 1 of the developing container 30. Composite sleeve 3 which is a cylindrical developer carrier
1 is arranged so as to be rotatable in the counterclockwise direction of the arrow in FIG. Also, as shown in FIG.
One outer end is rotatably held by a sleeve bearing 38 provided at a predetermined position of the developing container 30. In addition, a regulating roller 37 is provided as a regulating member at both ends of the composite sleeve 31 so that a predetermined interval can be maintained between the photosensitive drum 1 and the composite sleeve 31.

In the composite sleeve 31, a magnet roller 32, which is a magnet having a plurality of magnetic poles on its outer peripheral surface, is fixedly arranged. The magnetic force of the magnet roller 32 causes the surface of the composite sleeve 31 to carry magnetic toner. With the rotation of the composite sleeve 31, the photosensitive drum 1 and the composite sleeve 31 are rotated.
Can be conveyed to a development area facing the same. The magnet roller 32 has two N poles N1 and N2 and two S poles S1 and S2 on its surface.

Further, a regulating blade 33 as a developer layer thickness regulating means is arranged on the upstream side in the rotation direction of the composite sleeve 31 with respect to the developing area to form a developing device G.
At the opening position of the developing container 30 of the composite sleeve 31, the thickness of the magnetic toner carried on the composite sleeve 31 is regulated to a predetermined thickness by the regulating blade 33 so that the magnetic toner can be conveyed to the developing area.

As shown in FIG. 2, a substantially cylindrical composite sleeve 31 includes a substantially cylindrical non-magnetic member 31a made of, for example, aluminum, stainless steel, or the like;
The two magnetic members 31b, which are made of an iron alloy or the like, are arranged at both ends of the composite sleeve 31 by being locked to the outer end of the non-magnetic member 31a, and the magnet roller 32 And the inner peripheral surface of the magnetic member 31b is disposed so as to face the outer peripheral positions of both ends in the longitudinal direction. The length of the non-magnetic member 31a along the longitudinal direction of the composite sleeve is adjusted to be equal to or greater than the longitudinal width of the developing region, and the magnetic member 31b is
It does not cover the magnetic toner coating area on the sleeve corresponding to the width of the developing area.

A developer receiving member 35 is provided below the connection between the non-magnetic member 31a and the magnetic member 31b in the vicinity of the magnetic member 31b so as to receive the magnetic toner dropped from the magnetic member 31b. It has become.
The developer receiving member is connected to the developing container so that the toner received by the developer receiving member can be collected in the developing container. By the way, since the amount of toner spilling from the composite sleeve is small, the developer receiving member may not be provided. In that case, since the conventional case can be used for the developing container, the object can be achieved without increasing the cost.

According to the developing device G having the above structure, the magnetic toner in the developing container 30 is carried on the surface of the non-magnetic member 31a of the composite sleeve 31 by the magnetic force of the magnet roller 32 in the composite sleeve 31. The magnetic toner carried on the non-magnetic member 31 is conveyed in the direction of the regulating blade 33 by the rotation of the composite sleeve 31 and regulated by the regulating blade 33 to a predetermined layer thickness.

The magnetic toner regulated to a predetermined layer thickness by the regulating blade 33 visualizes a latent image formed on the photosensitive drum 1 moving in the clockwise direction indicated by the arrow in FIG. 1 in the developing area. At this time, a vibration bias voltage in which a DC voltage is superimposed on an AC voltage is applied to the composite sleeve 31 from a power supply. Note that a rectangular wave, a sine wave, or the like can be used as the waveform of the vibration bias voltage.

In the composite sleeve 31, the non-magnetic member 31a
The portion carries and conveys the magnetic toner by the magnetic force of the magnet roller 32. In the magnetic member 31b of the composite sleeve 31, the magnetic force of the magnet roller 32 is shielded by the magnetic member 31b, so that the magnetic toner is not sufficiently carried on the surface of the magnetic member 31b and the magnetic toner is not transported. The coating area can be limited to only the non-magnetic member 31a, so that aggregation, fusion and spillage of the magnetic toner from both ends of the composite sleeve 31 can be prevented.

At this time, a small amount of magnetic toner may adhere to the magnetic member 31b and be conveyed due to electrical adhesion or the like. In this case, the magnetic toner that has adhered to the magnetic member 31b may fall from the developing area around the lowest point of the composite sleeve 31 on the downstream side in the rotation direction of the composite sleeve 31 due to the rotation of the composite sleeve 31. The dropped toner is collected and stored in the developer receiving member 35 to prevent leakage and scattering of the magnetic toner.

FIG. 6 is a schematic diagram showing lines of magnetic force by the magnet roller. FIG. 6A shows a case where a magnet roller is disposed in a composite sleeve comprising a non-magnetic member and a magnetic member according to the present embodiment, and FIG. 6B shows a conventional non-magnetic member comprising only a non-magnetic member. This embodiment is compared with a conventional example, showing a case where a magnet roller is arranged in a sleeve.

As shown in FIG. 6A, in this embodiment, when the magnetic members 31b are provided at both ends of the non-magnetic member 31a, the magnetic force at the end of the magnet roller 32 is applied by the magnet member 31b. Shielded. That is, the magnet roller 3
The magnetic line of force at the end of No. 2 is concentrated on the magnetic member 31b, does not radiate to the outside of the composite sleeve 31, and the magnetic line of force is shielded, so that the magnetic toner cannot be sufficiently held at the magnetic member 31b, so the magnetic toner is conveyed. It is not considered.

Conversely, as shown in FIG. 6B, in the conventional non-magnetic sleeve, at the end of the magnet roller 32, the line of magnetic force is directed outward from the surface of the non-magnetic sleeve 40 from the end of the sleeve. Since the magnetic toner is carried, the magnetic toner is carried on the surface of the end of the non-magnetic sleeve 40 and conveyed by the magnetic force of the magnet roller 32. Therefore, when the aggregation, fusion, or spillage of the magnetic toner occurs at both ends of the sleeve. Conceivable. In this case, in order to prevent the developer from being carried on the end of the non-magnetic sleeve, since the lines of magnetic force are radiated outward from the end of the magnet roller, the length of the non-magnetic sleeve is increased by the length of the magnet roller. It must be much longer than the length, which leads to an increase in the size of the developing device.

As described above, in the present embodiment, the magnetic member 31b disposed at the longitudinal end of the composite sleeve 31 prevents the developer from being carried and conveyed by a magnetic action, and As the width of the coating is regulated, the load on the developer at the end side can be reduced with a composite sleeve whose length is not much different from the length of the magnet roller.
Fusion and spills can be suppressed and prevented, and coating defects and image defects can be suppressed and prevented.

Furthermore, since the developer receiving member is disposed below the magnetic member, even if the magnetic toner spills from the end of the composite sleeve, it can be collected and stored in the developer receiving member, and the Pollution can be suppressed and prevented.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, a developer peeling member is brought into contact with the surface of the magnetic member of the first embodiment. In addition, the developer receiving member is not provided, and each member of the developing device such as a composite sleeve and a magnet roller other than that the developer stripping member is disposed and the developer receiving member is not provided is different from each other. First
This is the same configuration as that of the embodiment.

FIG. 7 is a schematic configuration diagram showing the vicinity of the longitudinal end of the developing device when the developing device of the present embodiment is applied to an image forming apparatus using a drum type photosensitive member. As shown in FIG. 7, the magnetic member 3 of the composite sleeve 31
1b so as to be in contact with the surface of the developer
Numerals 4 are disposed at both ends of the regulating blade 33 so that the developer on the magnetic member 31b can be peeled off by the developer peeling member 34.

In the present embodiment, similarly to the first embodiment, the magnetic member 3 disposed on the longitudinal end side of the composite sleeve 31
1b, the magnetic action prevents the magnetic toner from being carried / conveyed to the magnetic member 31b of the composite sleeve 31. Therefore, the developer does not exist much on the magnetic member 31b, and the developer does not exist on the magnetic member 31b. Since the magnetic force for holding the magnetic toner is small, the developer peeling member 3
4 can sufficiently remove the developer and collect it in the developing container even if the magnetic member 31b contacts the magnetic member 31b with a small pressure;
Magnetic toner does not spill from the end of the composite sleeve. Although the developer stripping member is provided at the end of the regulating blade, the present invention is not limited to this. Any member may be used as long as the magnetic toner on the magnetic member of the composite sleeve can be collected in the developing container.

In the developing device having the above structure, the developer on the magnetic member of the composite sleeve can be peeled off by the developer peeling member with a small pressure, so that the load on the developer can be reduced and the aggregation of the developer can be reduced. -Fusion and spillage can be suppressed and prevented, and coating defects and image defects can be suppressed and prevented.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. In this embodiment,
The developing device of the first embodiment is used as a developing device of a process cartridge.

FIG. 8 is a schematic configuration diagram showing an image forming apparatus of a process cartridge detachable type according to the present embodiment.

A process cartridge 10 which is detachably installed in an image forming apparatus such as a laser beam printer utilizing a transfer type electrophotographic process has a rotary photosensitive member as an image carrier on which an electrostatic latent image is formed. A photosensitive drum 1, which is a drum-type electrophotographic photosensitive member, is arranged so as to be rotatable in a clockwise direction, and a charging device 2, a developing device 3, and a cleaning device 6 are provided around the photosensitive drum 1. Two process devices are collectively arranged at a predetermined position of the cartridge housing 9.

When the process cartridge 10 is mounted in the image forming apparatus main body in a predetermined manner, the process cartridge 10 and the image forming apparatus main body are mechanically and electrically coupled to each other.
The lower surface of the photosensitive drum 1 of the process cartridge 10 comes into contact with the transfer roller 4 disposed in the image forming apparatus main body in a predetermined manner, and the image forming is enabled. Further, when the process cartridge 10 is installed in the image forming apparatus, the process cartridge insertion / removal guide / holding portion 8 of the image forming apparatus main body comes into contact with a predetermined position of the cartridge housing 9.

The above-mentioned process cartridge is one in which a charging means, a developing means or a cleaning means, and a photosensitive drum are integrated into a cartridge, and this cartridge is made detachable from the image forming apparatus main body. However, the present invention is not limited to this, and at least one of the charging unit, the developing unit, and the cleaning unit and the photosensitive drum may be integrally formed as a cartridge so as to be detachable from the image forming apparatus main body. Further, at least the developing unit and the photosensitive drum may be integrally formed as a cartridge so as to be detachable from the image forming apparatus main body.

When the image forming apparatus forms an image using the process cartridge having the above-described structure, the photosensitive drum 1 is uniformly charged by the charging device 2 and then is moved out of the process cartridge 10 in accordance with the image information signal. The surface of the photosensitive drum 1 is exposed to laser light from the provided image exposing means E to perform image exposure, whereby an electrostatic latent image is formed on the photosensitive drum 1.

The electrostatic latent image formed on the photosensitive drum 1 is
The image is developed by the developing device 3. This visible image is transferred to a transfer unit, which is a transfer unit facing the photosensitive drum 1, located outside the process cartridge 10 at a position facing the photosensitive drum 1. The image is transferred onto the transfer material by the pressing pressure. The transfer material onto which the image has been transferred is conveyed to a fixing device 5 such as a heat fixing method, where the visible image on the transfer material is fixed, and is discharged out of the device as an image formed product (print, copy). ing. Further, the surface of the photosensitive drum after the transfer of the toner image to the transfer material is cleaned by the cleaning device 6 of the process cartridge 10 by removing the adhered contaminants such as residual toner on the photosensitive drum 1 and repeatedly used for image formation. It has become so.

The developing device 3 arranged in the process cartridge 10 will be described with reference to FIGS. 9 is an explanatory view of a main part showing a main part of the developing device, FIG. 10 is a partially sectional explanatory view showing an end in the longitudinal direction of the developing device, and FIG. 11 is a view showing a developer receiving member. It is a side explanatory view and a front explanatory view.

The developing device 3 for developing an electrostatic latent image includes a developing container 30 for storing a magnetic toner as a magnetic developer, and an opening provided at a position facing the photosensitive drum 1 of the developing container 30. Composite sleeve 3 which is a cylindrical developer carrier
1 is rotatably arranged in the counterclockwise direction of the arrow in FIG. As shown in FIG. 10, the outer end of the composite sleeve 31 is rotatably held by a sleeve bearing 38 provided at a predetermined position of the developing container 30. In addition, a regulating spacer 3 is provided on both ends of the composite sleeve 31 as a regulating member.
7 ′ is provided so that a predetermined interval can be maintained between the photosensitive drum 1 and the composite sleeve 31.

In the composite sleeve 31, a magnet roller 32, which is a magnet having a plurality of magnetic poles on its outer peripheral surface, is fixedly arranged, and the magnetic force of the magnet roller 32 causes the surface of the composite sleeve 31 to carry magnetic toner. With the rotation of the composite sleeve 31, the photosensitive drum 1 and the composite sleeve 31 are rotated.
Can be conveyed to a development area facing the same. The magnet roller 32 has two N poles N1 and N2 and two S poles S1 and S2 on its surface.

Further, a regulating blade 33 ′ as a developer layer thickness regulating means is disposed on the upstream side in the rotation direction of the composite sleeve 31 from the developing region, and the tip of the regulating blade 33 ′ is formed on the surface of the composite sleeve 31. The developing device 3 is formed in such a manner that the thickness of the magnetic toner carried on the composite sleeve 31 by the regulating blade 33 ′ at the opening position of the developing container 30 of the composite sleeve 31 is reduced to a predetermined thickness. And transported to the developing area.

As shown in FIG. 10, similarly to the first embodiment, a composite sleeve 31 formed in a substantially cylindrical shape includes a nonmagnetic member 31a made of, for example, aluminum, stainless steel, or the like, and iron or an iron alloy. The magnetic member 31b is disposed at both ends in the longitudinal direction of the composite sleeve 31 and at the outer peripheral positions of both ends in the longitudinal direction of the magnet roller 32. The length of the non-magnetic member 31a along the longitudinal direction of the composite sleeve is adjusted so as to be equal to or greater than the longitudinal width of the developing region. Of the court area.

Further, a developer receiving member 39 is provided below the composite sleeve 31 so that the magnetic toner dropped from the magnetic member 31b can be received and collected in the developing container.

As shown in FIG. 11, the developer receiving member 3 receives and collects the magnetic toner dropped from the magnetic member 31b.
Reference numeral 9 denotes two developer intake portions 39a having a plurality of guide grooves 39c as a developer guide path, and a developer intake portion 3
And a developer collecting section 59b for collecting the developer received at 9a. Two developer intake sections 39a are provided below the magnetic members 31b disposed at both ends of the composite sleeve 31. A developer collecting section 39b is provided below the middle of the composite sleeve 31, and both ends of the developer collecting section 39b are connected to the inner ends of the two developer intake sections 39a.

The developer take-up section 39a provided below the magnetic member 31b allows the magnetic toner received by the developer take-up section 39a to move toward the developer collection section 39b provided below the composite sleeve 31. Is provided with an inclination. Further, the developer guide 39a is guided at an angle from a line along the longitudinal direction of the composite sleeve 31 so that the developer received by the developer take-up unit 39a can be efficiently moved to the developing container side of the development collection member 39b. A groove 39c is provided.

The magnetic toner dropped from the magnetic member 31b by the developer receiving member 39 and received by the developer take-in portion 39a moves toward the developing container along the guide groove 39c to the developer collecting portion 39b. Will be accommodated. The magnetic toner moved to the developer collecting section 39b is conveyed into the developing container by the magnetic force of the magnet roller 32 and collected.

According to the developing device 3 having the above structure, the magnetic toner in the developing container 30 is carried on the surface of the non-magnetic member 31a of the composite sleeve 31 by the magnetic force of the magnet roller 32 in the composite sleeve 31. The magnetic toner carried on the non-magnetic member 31 is conveyed in the direction of the regulating blade 33 'by the rotation of the composite sleeve 31, and regulated to a predetermined layer thickness by the regulating blade 33'.

The magnetic toner regulated to a predetermined layer thickness by the regulating blade 33 'visualizes a latent image formed on the photosensitive drum 1 moving in the clockwise direction indicated by the arrow in FIG. 1 in the developing area. At this time, the composite sleeve 31
An oscillating bias voltage in which a DC voltage is superimposed on an AC voltage is applied by a power supply. Note that a rectangular wave, a sine wave, or the like can be used as the waveform of the vibration bias voltage.

In the composite sleeve 31, as in the first embodiment, the non-magnetic member 31a can carry and convey the magnetic toner by the magnetic force of the magnet roller 32, but the magnetic member 31b of the composite sleeve 31 Since the magnetic force of the roller 32 is shielded by the magnetic member 31b, the magnetic toner is not sufficiently carried on the surface of the magnetic member 31b, and the magnetic toner is not transported. Thus, aggregation, fusion and spillage of the magnetic toner from both ends of the composite sleeve 31 can be prevented.

At this time, if a small amount of magnetic toner adheres to the magnetic member 31b due to electrical adhesion or the like and is conveyed, the magnetic toner dropped around the lowest point of the composite sleeve 31 is transferred to the developer receiving member. The magnetic toner is collected and stored at 39 to prevent leakage and scattering of the magnetic toner. Note that the developer peeling member may be brought into contact with the surface of the magnetic member of the composite sleeve so that the magnetic toner on the magnetic member portion is reliably removed.

As described above, in the present embodiment, the coating and coating of the developer is prevented by preventing the carrying and transport of the developer by the magnetic action at the magnetic member 31b disposed at the longitudinal end of the composite sleeve 31. The width of the toner is regulated, so the load on the developer at the end can be reduced, and the aggregation, fusion, and spillage of the developer can be suppressed and prevented, and coating defects and image defects can be suppressed and prevented. And a toner cartridge that can be used. If this toner cartridge is used in an image forming apparatus, the image forming apparatus can suppress and prevent aggregation, fusion, and spillage of the developer, and can suppress and prevent coating defects and image defects.

Further, in the present embodiment, the developer receiving member is provided below the magnetic member, and the developer receiving member is provided with a guide groove for guiding the developer taken in by the developer receiving member to the developing container side. For this reason, even if the magnetic toner spills out of the composite sleeve, it can be collected in the developing container, so that the developer can be used effectively and contamination by the developer can be suppressed / prevented.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the magnet roller in the composite sleeve is rotatably arranged.

FIG. 12 is a schematic configuration diagram showing the vicinity of the developing device when the developing device of the present embodiment is applied to an image forming apparatus such as an electrophotographic printer. In the present embodiment, the composite sleeve, the regulating blade, and the like have the same configuration as that of the first embodiment except for the magnet roller inside the composite sleeve.

As shown in FIG. 12, the magnet roller 32 disposed in the composite sleeve 31 has four N poles N
1, N2, N3, N4 and four south poles S1, S2, S
3 and S4.
It is provided so as to be able to rotate in the clockwise direction of arrow a shown in FIG. The composite sleeve 31 is provided so as to rotate in a counterclockwise direction indicated by an arrow b in FIG. 12. The magnetic force of the magnet roller 32 causes the magnetic toner to adhere to the surface of the composite sleeve 31, It can be conveyed in the counterclockwise direction of arrow b.

Since the composite sleeve 31 has a structure in which the magnetic members 31b are connected to both ends of the non-magnetic member as in the first embodiment, the magnetic member 31b has
The magnetic force of the magnet roller 32 is shielded by the magnetic member 31b so that the surface of the magnetic member 31b does not sufficiently carry the magnetic toner. A developer receiving member 35 is provided below the magnetic member 31b of the composite sleeve 31 as in the first embodiment, so that the magnetic toner spilled from the end of the composite sleeve 31 can be received. Has become.

In the developing device having the above-described structure, similarly to the first embodiment, the load on the developer at the end of the composite sleeve 31 can be reduced, and the aggregation, fusion, spillage, etc. of the developer can be suppressed. -It can be prevented, and coating defects and image defects can be suppressed and prevented. Note that a developer stripping member may be provided so as to be in contact with the magnetic member of the composite sleeve. Further, the developing device of the present embodiment can be used as a developing device in a process cartridge.

In each of the above embodiments, the magnetic member is locked to the outer end of the non-magnetic member. In addition, the magnetic member is connected to the outer peripheral surface or the inner peripheral surface of both ends of the non-magnetic member. The outer peripheral surface or the inner peripheral surface of both ends of the non-magnetic member may be coated with a magnetic member. Also, the case where a magnetic toner is used as the magnetic developer has been described as an example, but the same effect can be obtained by using a two-component magnetic developer composed of a non-magnetic toner and magnetic particles (carrier).

[0073]

As described above, according to the first aspect of the present invention, the magnetic members arranged at both ends of the developer carrier allow the surface of the developer carrier having the magnetic members arranged thereon. The width of the coating of the developer can be regulated by the magnetic action without the developer being carried on the surface, so that the load on the developer on the end side is reduced, and the aggregation and Fusion and spillage are suppressed and prevented, and coating defects and image defects during image formation can be suppressed and prevented.

Further, according to the second aspect of the present invention, even when the magnet in the developer carrier is rotatably disposed, the magnetic members disposed at both ends of the developer carrier provide Since the developer is not carried on the surface of the developer carrying member on which the magnetic member is disposed, the width of the coating of the developer can be regulated by a magnetic action, and the width of the developer on the end side can be reduced. The load can be reduced, and aggregation, fusion, and spilling of the developer can be suppressed and prevented, and coating defects and image defects during image formation can be suppressed and prevented.

Further, according to the third aspect of the present invention, the developer stripping member is brought into contact with the surfaces of the magnetic members at both ends of the developer carrier, so that the surface of the magnetic member can be applied with a small force. Since the adhered developer can be peeled off, the pressing force of the developer peeling member and the load on the developer are reduced, and the aggregation, fusion, spillage, etc. of the developer are suppressed and prevented. Coating defects and image defects can be more effectively suppressed and prevented.

Further, according to the fourth aspect of the present invention, the developer spilled from the end of the developer carrier by the developer receiving members disposed below the magnetic members at both ends of the developer carrier. Since the developer can be collected and stored, contamination by the developer can be suppressed or prevented.

According to the fifth aspect of the present invention, the developer collected by the developer receiving member is conveyed and collected to the developing area side of the developing container by the guide path provided in the developer receiving member. Can effectively utilize the developer and suppress contamination by the developer.
Can be prevented.

According to the sixth aspect of the present invention, the developing device arranged in the process cartridge is
Since the developing device is any one of the first to fifth aspects of the invention, the load on the developer at the end of the developer carrier in the process cartridge is reduced, and the developer is effectively used. In addition, it is possible to obtain a process cartridge in which aggregation, fusion, and spillage of the developer can be suppressed and prevented, and coating defects and image defects during image formation can be suppressed and prevented.

Further, according to the seventh aspect of the present invention, any one of the first to fifth aspects of the present invention is used as a developing device in the image forming apparatus, or Since the process cartridge of the sixth invention is installed in the apparatus, the load on the developer on the end side of the developer carrier in the image forming apparatus is reduced, and the developer is effectively used. In addition, an image forming apparatus is provided in which aggregation, fusion, and spillage of the developer are suppressed and prevented, and coating defects and image defects during image formation are suppressed and prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing the vicinity of the center of a developing device according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional explanatory view showing the vicinity of an end in a longitudinal direction of a developing device.

FIG. 3 is a view as viewed in the direction of arrows AA in FIG. 2;

FIG. 4 is a perspective view showing a composite sleeve.

FIG. 5 is an explanatory perspective view showing a composite sleeve installation portion of the developing container.

FIGS. 6A and 6B are a schematic diagram showing magnetic lines of force by a magnet roller when the composite sleeve of the present embodiment is used and a schematic diagram of FIG. 6B showing magnetic lines of force by a magnet roller when a conventional non-magnetic sleeve is used. is there.

FIG. 7 is a partial cross-sectional explanatory view showing the vicinity of an end in a longitudinal direction of the developing device when a developer stripping member is provided.

FIG. 8 is a schematic configuration diagram illustrating an image forming apparatus of a third embodiment of a process cartridge detachable type.

FIG. 9 is an explanatory view of a main part showing a main part of the developing device.

FIG. 10 is a partial cross-sectional explanatory view showing the vicinity of an end in a longitudinal direction of the developing device.

FIG. 11 is an explanatory side view showing a developer receiving member;
It is front explanatory drawing (b).

FIG. 12 is a schematic configuration diagram illustrating a developing device according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum (image carrier) 3 Developing device 10 Process cartridge 30 Developing container 31 Composite sleeve (developer carrier) 31a Non-magnetic member 31b Magnetic member 32 Magnet roller (magnet in developer carrier) 34 Developer stripping member 35 developer receiving member 39 developer receiving member 39a developer intake section 39b developer recovery section 39c guide groove (guide path) G developing device

Claims (7)

[Claims] 1. A developer container containing a magnetic developer, and a magnet rotatably disposed in the developer container and having a plurality of magnetic poles in the developer container. In a developing device having a developer carrier that can be transported, the developer carrier is formed of a non-magnetic member and a magnetic member, and the magnetic members are disposed at both ends in the longitudinal direction of the developer carrier. A developing device. 2. A developer container containing a magnetic developer and a developer rotatably or fixedly disposed in the developer container and having a magnet having a plurality of magnetic poles rotatably disposed therein to carry the developer. And a developer carrier that can be conveyed in a predetermined direction, the developer carrier is formed from a non-magnetic member and a magnetic member, and the magnetic members are provided at both longitudinal ends of the developer carrier. A developing device, wherein the developing device is disposed. 3. The developing device according to claim 1, wherein a developer stripping member is in contact with surfaces of magnetic members disposed at both ends of the developer carrier. 4. A developer receiving member which can receive the developer dropped from the magnetic member portion is provided below the vicinity of the magnetic member disposed at both ends of the developer carrying member. The developing device according to any one of claims 1 to 3. 5. The developing device according to claim 4, wherein the developer receiving member is provided with a guide path for guiding the developer received below the magnetic member to a side of the developing container. 6. A process cartridge which is detachably formed in an image forming apparatus main body and has at least an image carrier and a developing device, wherein the developing device is any one of claims 1 to 5. A process cartridge, which is the developing device according to any one of claims 1 to 3. 7. A developer that contains at least a magnetic developer and a magnet that is disposed in the developer container and that has a plurality of magnetic poles therein and that can carry the developer and transport the developer in a predetermined direction. An image forming apparatus provided with a developing device having a carrier, wherein the developing device according to any one of claims 1 to 5 is used as the developing device, or in the image forming device. An image forming apparatus comprising the process cartridge according to claim 6.