JP3359171B2 - Developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used for an image forming apparatus such as a copying machine, a facsimile, a printer, etc., and more particularly, to a developing device formed on an image carrier using a two-component developer composed of toner and magnetic particles. And a developing device for developing the latent image.

[0002]

2. Description of the Related Art In recent years, a developing device for developing a latent image formed on an image carrier using a two-component developer (hereinafter, referred to as a "developer") composed of toner and magnetic particles has been reduced in size and size. From the viewpoint of cost reduction, there has been proposed an apparatus that controls the toner concentration and the toner charge amount without providing a complicated toner concentration control mechanism such as the developer stirring and conveying member and the toner concentration sensor. For example, JP-A-63-
Japanese Patent No. 4280 discloses a developing container which contains a developer, has a developer carrier having a magnetic field generating means in an opening portion, and allows a carry-out and carry-in of a developer, and a developer provided in a developer carry-out area. A regulating member, and a blocking member that is provided integrally with or separate from the developer regulating member and that is provided inside the developer container of the developer regulating member and that blocks movement of the developer; Having magnetic poles that form lines of magnetic force over the surface of the carrier,
A developing device has been proposed in which, as an upper layer of a surface of a developer carrier in a developing container, a moving layer that moves with the movement of the developer carrier and a substantial developer immobile layer is formed on the upper layer of the moving layer. .

[0003]

However, in the developing device proposed in JP-A-63-4280, most of the developer remaining on the upstream side of the developer regulating member forms an immobile layer. At the same time, since the moving layer made of the same developer is magnetically supported by the developer carrier and conveyed to the developing area, the developer used for development by the magnetic force supported on the developer carrier deteriorates extremely quickly. There is. The term “deterioration of the developer” as used herein refers to abrasion of the coating layer of the magnetic particles of the developer or adhesion of the toner-forming substance to the magnetic particles, and the deterioration of the developer lowers the ability to charge the toner, This causes background stains during image formation and stains due to toner scattering inside the apparatus.

In the developing device proposed above, since the movement of the developer in a direction substantially perpendicular to the direction in which the developer is transported on the developer carrier is very small, the toner consumption may be locally large. When the image forming operation is continuously performed on the same document, the supplied toner is locally insufficient, and there is a problem that uneven development is likely to occur.

[0005] The present invention has been made in view of the above problems, purpose of that is a inexpensive developing device complicated toner concentration control mechanism and compact which does not require the developer stirring and conveying mechanism, An object of the present invention is to provide a developing device capable of maintaining a charging effect of a toner and suppressing deterioration of a developer.

[0006]

In order to achieve the above object, the present invention is directed to a developer carrier for carrying a developer comprising toner and magnetic particles on a surface thereof, and the developer carrier. Magnetic field generating means disposed inside the developer, a developer regulating member for regulating the amount of developer carried on the developer carrying member,
A developer accommodating case for forming between the developer carrying member and a developer retaining portion in which the developer whose progress has been prevented by the developer regulating member is retained; and And a toner container having a toner supply port adjacent to the developer carrying member and having a toner supply port facing the developer carrying member in the developer carrying direction, the developer carrying speed is lower than the developer carrying speed on the developer carrying member. Within the range of the moving speed, as a developer movement promoting means for promoting the movement of the developer retained in the developer retaining section , by a developer circulating in the developer retaining section ,
The magnetic rotating member provided at a position encircled, magnetic
The magnetic flux density of the magnetic field generated by the magnetic field generating means on the rotating member
Is concentrated .

[0007]

[0008]

[0009]

According to the first aspect of the present invention, the developer carried on the developer carrier is conveyed on the developer carrier by the magnetic field generated by the magnetic field generating means, and the amount thereof is regulated by the developer regulating member. At the same time, the toner is charged by the frictional charging of the developer in a state where the internal pressure is applied during the regulation, and then is conveyed to a developing area facing the image carrier. The developer not used for the development in the developing area is further transported on the developer carrying member, takes in the toner from the toner supply port, and returns to the developer retaining section. On the other hand, the developer that is not supplied to the developing area and is prevented from progressing by the developer regulating member stays in the developer holding portion, and a part of the developer is stored in the developer holding portion by the internal pressure and gravity of the developer itself. Move toward the toner supply port of the set. The developer that has moved to the vicinity of the toner supply port moves so as to circulate to the developer regulating member along with the developer being conveyed on the surface of the developer carrier.

Then, the movement of the developer retained in the developer retaining section is promoted by the developer movement promoting means. In particular, when mainly promoting the circulating movement of the developer in the developer retaining section, the developer layer carried on the developer carrying member and the developer layer circulating in the developer retaining section are The developer is exchanged between, and all the developers are used evenly for development. Here, by promoting the circulation movement of the developer within a range of the movement speed that is lower than the developer conveyance speed on the developer carrier, the developer is gradually replaced in the developer stagnation portion, and abruptly. As in the case where the developer is replaced, the portion where the density of the developer is low does not occur, and the amount of the developer by the developer regulating member is reduced without reducing the internal pressure of the developer in the developer retaining portion. Maintain the toner charging effect during regulation.

In particular, when the movement in the direction substantially perpendicular to the developer conveying direction on the developer carrying member is promoted,
Stirring of the developer in the orthogonal direction is performed gradually. Here, by promoting the movement of the developer within a range of a moving speed lower than the developer conveying speed on the developer carrying member, the developer is gradually stirred in the developer accumulating portion, and abruptly. As in the case where the developer is agitated, the portion where the density of the developer is low does not occur, and the amount of the developer by the developer regulating member is reduced without reducing the internal pressure of the developer in the developer retaining portion. Maintain the toner charging effect during regulation.

[0012]

[0013] In particular, the magnetic flux density of the magnetic field generated in the magnetic rotating member provided in the upper Symbol developer accumulation portion by the magnetic field generating means is concentrated, the distance from the magnetic field generating means in the region far than magnetic member flux The density is reduced, the developer is easily moved in the area, and the circulation and movement of the developer in the developer retaining portion are promoted. By promoting the circulating movement of the developer, the developer is exchanged between the developer layer carried on the developer carrier and the developer layer circulating in the developer retaining section, and all the developer is changed. Is used evenly for development. Here, by making the developer easily move in a region where the distance from the magnetic field generating means is farther than the magnetic rotating member, the developer was gradually replaced, and the developer was rapidly replaced. In such a case, the toner charging effect at the time of regulating the amount of the developer by the developer regulating member without lowering the internal pressure of the developer in the developer stagnation portion without generating a portion where the density of the developer is low is generated. maintain.

[0014]

[0015]

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a developing device used in an electrophotographic copying machine as an image forming apparatus will be described below. [Embodiment 1] FIG. 1 is a partial sectional view showing a schematic configuration of a developing device according to the present embodiment. The developing device is provided on a side of a cylindrical photosensitive drum 1 serving as an image carrier, and has a support case 2 having an opening formed toward the photosensitive drum 1, and a part of the developing case is exposed from the opening. , A developing sleeve 4 made of a non-magnetic material as a developer carrying member carrying a developer 3 made of toner and magnetic particles on the surface, and a magnetic field generating means fixedly disposed inside the developing sleeve 4 so as to have the magnetic poles shown And a doctor 6 as a developer regulating member that regulates the amount of developer carried and conveyed on the developing sleeve 4. A developer storage case 7 and a toner hopper 8 as a toner storage section are provided.

A portion of the support case 2 located above the developing sleeve 4 is not supplied to the developing position of the portion facing the photosensitive drum 1 between the developing case 4 and the progress thereof is prevented by the doctor 6. The formed developer stagnant portion A is formed. Further, a part of the support case 2 located on the right side of the developing sleeve 4 forms a toner hopper 7 as a toner storage section for storing toner. The toner hopper 7 has a toner supply port 7a adjacent to the upstream side of the developer stagnation section A in the developer transport direction on the development sleeve 4 and facing the surface of the development sleeve 4.
A toner agitator 8 as an agitating member for agitating and sending out the toner 3a toward the toner replenishing port 7a is provided in a space adjacent to a.

Further, there is provided a developer movement accelerating means for accelerating the movement of the developer accumulated in the developer accumulation section A within a range of a moving speed lower than the developer conveying speed on the developing sleeve 4. In the present embodiment, as a specific example of the developer movement accelerating means, a rotating member 9 for promoting the circulation movement of the developer 3 in the staying part A is provided in the developer holding part A. The surface of the rotating member 9 has an uneven shape in the rotating direction. The outermost peripheral speed of the rotating member 9 is set to be smaller than the developer conveying speed on the developing sleeve 4, that is, the peripheral speed of the developing sleeve 4. For example, the peripheral speed of the developing sleeve 4 is set to about a fraction to a hundredth.

The rotational driving force of the rotating member 9 is obtained from the driving system of the developing sleeve 4. FIG. 2 shows the rotating member 9.
FIG. 2 is a front view showing a schematic configuration of a drive transmission system for rotational drive of the present invention. At the end of the drive shaft 4a of the developing sleeve 4, a driving gear 4b for driving the rotating member 9 and a driving gear 4c for driving the toner agitator 8 are fixed. A gear 9b meshing with the gear 4b on the developing sleeve 4 side is fixedly provided at the end of the drive shaft 9a of the rotating member 9, and a gear meshing with the gear 4c on the developing sleeve 4 side at the end of the driving shaft 8a of the toner agitator 8. 8b
Is fixed. In this drive transmission system, when the developing sleeve 4 is rotated in the direction of the arrow, the rotational driving force is applied to the gear 4.
The drive shaft 9a of the rotating member 9 and the driving shaft 8a of the toner agitator 8 are transmitted via the gears b and 4c, the gear 9b and the gear 8b, and the rotating member 9 and the toner agitator 8 rotate in the direction of the arrow in the figure.

In the developing device having the above structure, the developer 3 on the developing sleeve 4 is conveyed with the rotation of the roller 4 in the direction of the arrow, and is regulated by the doctor 6 to be thinned. The thinned developer 3 is conveyed to a development area facing the photosensitive drum 1 rotating in the direction of the arrow. Then, in the developing area, toner is supplied to the electrostatic latent image formed on the photosensitive drum 1, and the electrostatic latent image is visualized. Developer 3 not used for visualization
Is transported with the rotation of the developing sleeve 4, takes in the new toner 3a sent out by the agitator 8 and supplied from the toner supply port 7a, and returns to the developer retaining section A. Then, the internal pressure of the developer 3 containing the new toner 3a is increased in the regulating section by the doctor 6, whereby the toner of the developer 3 is charged. As described above, the developer retaining portion A
Because the toner in the developer 3 on the developing sleeve 4 can be charged by the internal pressure of the developer in the above, a complicated stirring and conveying mechanism for charging or stirring the developer such as a paddle or a screw is not required.

On the other hand, a part of the developer 3 which is not supplied to the developing area and is prevented from proceeding by the doctor 6 is supplied to the toner hopper 7 by the internal pressure and gravity of the developer 3 in the developer retaining section A. It moves toward the mouth 7a. The developer 3 that has moved to the vicinity of the toner supply port 7a is transported so as to circulate toward the doctor 6 with the rotation of the developing sleeve 4.

In the developing device having the above structure, when the amount of toner supplied to the developer 3 increases and the toner concentration increases, the bulk of the developer 3 increases accordingly. The toner drops to the opening 7a, and covers the opening of the toner supply opening 7a. Therefore, the amount of toner taken into the developer 3 on the developing sleeve 4 is reduced.
Due to this decrease in the amount of toner taken in, the toner density of the developer 3 is always kept below a certain density. Conversely, when the toner concentration of the developer 3 decreases, the bulk of the developer 3 decreases,
Since the developer 3 does not block the toner supply port 7a, a predetermined amount of toner is taken into the developer 3 on the developing sleeve 4,
The toner density of the developer 3 is always kept at a certain level or more. Since the toner density can be controlled within a substantially constant range in this way, a toner density sensor and an optical image density sensor for detecting the image density of a reference toner image formed on the photosensitive drum 1 in order to know the developing ability of the developer. This eliminates the need for a complicated toner density control mechanism using a toner supply member or the like.

In the developing device having the above structure, the developer 3 is guided by the rotating member 9 provided in the developer retaining portion A at the outermost peripheral speed smaller than the developer conveying speed on the developing sleeve. The circulation movement of the developer 3 in the developer retaining section A is promoted. By promoting the circulation of the developer, the developer 3 is gradually exchanged between the developer layer carried on the developing sleeve 4 and the developer layer circulating in the developer retaining portion A, All the developer 3 is used evenly for development without reducing the pressure of the developer 3 in the developer retaining section A.

As described above, according to the present embodiment, toner concentration control and toner charging can be performed without the need for a complicated toner concentration control mechanism and a developer stirring / conveying mechanism, and a compact and inexpensive developing device can be constructed. .

According to the present embodiment, the rotation member 9 promotes the circulating movement of the developer in the developer storing portion A, so that the developer layer carried on the developing sleeve 4 and the developer storing The developer 3 is gradually exchanged between the developer layer and the developer layer circulating in the section A, and all the developer 3 is used evenly in the development.
The deterioration of the developer 3 can be suppressed while maintaining the charging effect of the toner without lowering the pressure.

A developing device having a relatively small amount of developer,
For example, even in a developing apparatus using a developer of 100 g or less as in the present embodiment, while the developer accumulation effect on the upstream side of the doctor 6 for providing the toner charge rising function at the time of high toner concentration is maintained, By using the developer in the part A evenly, the deterioration of the developer 3 can be suppressed.

Further, according to the present embodiment, since the rotational driving force of the rotating member 9 is obtained from the driving shaft 4a of the developing sleeve 4 via the gears 4b and 9b, the rotating member 9 rotates with the rotation of the developing sleeve 4. 9 rotates reliably.

In the above embodiment, the rotating member 9 is rotated by the driving force from the drive shaft 4a of the developing sleeve 4. However, the rotational driving force is obtained by the movement of the developer 3 magnetically supported by the developing sleeve 4. It may be configured as follows. Specifically, the rotating member 9 is disposed so that the lower portion of the rotating member 9 enters the transport region of the developer 3 on the developing sleeve 4.
In this configuration, the developer 3 magnetically supported on the developing sleeve 4 collides with the convex portion on the surface of the rotating member 9, and the rotating member 9 is rotated by the collision force.
The circulation movement of the developer 3 in the developer retaining section A is promoted. According to this configuration, there is no need to provide a drive transmission member between the rotation shaft 4a of the developing sleeve 4 and the drive shaft 9a of the rotation member 9, so that the drive transmission member such as the gear 9b is provided. And a simple and inexpensive configuration.

[Embodiment 2] FIG. 3A is a front view showing a schematic structure of a developing device according to the present embodiment. The same reference numerals are given to the same parts as those in the developing device of FIG. Shown,
Since their functions are the same, a description of them will be omitted.

In the developing device of this embodiment, instead of arranging the rotating member 9 in the developing stagnation portion A, the developer 3 circulates in the developing stagnation portion A as the developer movement promoting means. The magnetic member 10 is provided in a portion surrounded by. Examples of the material of the magnetic member 10 include iron, steel, and silicon steel having higher magnetic permeability than the magnetic particles of the developer 3.

In the developing device of the present embodiment, FIG.
As shown in (b), the magnetic flux density of the magnetic field generated by the magnet roller 5 is concentrated on the magnetic member 10 provided in the developer retaining portion A, and the distance from the magnet roller 5 is farther than the position of the magnetic member 10. The magnetic flux density in the region (the region between the magnetic member 10 and the inner surface of the support case 2) is reduced, the developer 3 is easily moved in the region, and the circulation movement of the developer 3 in the developer retaining portion A is reduced. Promote. (Hereinafter, margin)

According to the present embodiment, the developer layer carried on the developing sleeve 4 and the developer layer circulating in the developer retaining portion A are promoted by promoting the circulation movement of the developer 3. , The developer 3 is gradually replaced, and all the developer 3
Is used for development evenly, so that it is possible to suppress the deterioration of the developer 3 while maintaining the charging effect of the toner without lowering the pressure of the developer 3 in the developer retaining portion A.

In the developing device shown in FIG. 3A, the magnetic member 10 is provided in the developer retaining portion A. Instead of the magnetic member 10, the magnetic member 10 is rotated in the rotational direction as shown in FIG. A rotatable magnetic rotating member 11 having an uneven surface and made of a magnetic material having a higher magnetic permeability than the magnetic particles of the developer 3 may be provided. The magnetic rotating member 11 may drive the rotating shaft by an external rotating drive unit, or the developing sleeve 4
The driving force may be obtained from the developer layer on the developing sleeve 4 by arranging such that a part thereof enters the developer layer conveyed above. In order to make the magnetic rotating member 11 easy to rotate, it is preferable that the surface of the magnetic rotating member 11 is made of a non-magnetic material.

In the developing device of this configuration, FIG.
As shown in FIG. 5, the magnetic flux density of the magnetic field generated by the magnet roller 5 is concentrated on the magnetic rotating member 11 provided in the developer retaining portion A, and the distance from the magnet roller 5 is farther than the position of the magnetic rotating member 11. The magnetic flux density in the (region between the magnetic rotating member 11 and the inner surface of the support case 2) is reduced, the developer 3 is easily moved in that region, and the circulation movement of the developer 3 in the developer retaining portion A is reduced. Promote. Further, the developer 3 in the developer retaining portion A is also rotated by the rotation of the magnetic rotating member 11.
To promote the circulatory movement of By promoting the circulation movement of the developer 3 by the rotation of the magnetic rotary member 11, the circulation movement between the developer layer carried on the developing sleeve 4 and the developer accumulating portion A is more reliably performed than the developing device of FIG. The developer 3 is gradually replaced between the developer layer and the developer layer, and all the developers 3 can be used for development evenly. And
The deterioration of the developer 3 can be suppressed while maintaining the toner charging effect without reducing the pressure of the developer 3 in the developer retaining portion A.

[Embodiment 3] FIG. 5 is a front view showing a schematic structure of a developing device according to the present embodiment, and the same parts as those of the developing device of FIG. 1 are denoted by the same reference numerals. Since these functions are the same, the description of them is omitted.

In the developing device of this embodiment, instead of arranging the rotating member 9 in the developing stagnation section A as the developer movement promoting means, a magnetic field generated by the magnet roller 5 as shown in FIG. A magnetic force holding / transporting unit that magnetically retains the developer in the developer retaining portion A with a magnetic field different from that of the developer retaining portion A and moves the developer at a speed lower than the developer transport speed on the developing sleeve 4 is used. It is provided within. The magnetic force holding and transporting means includes a rotatable small non-magnetic rotating sleeve 12 and a small magnet roller 13 fixedly arranged in the rotating sleeve 12. The peripheral speed of the rotating sleeve 12 is desirably about several to several hundredths of the peripheral speed of the developing sleeve 4. More preferably,
It is preferable that the peripheral speed of the developing sleeve 4 is about one-hundredth to several tenths.

In the developing device of this embodiment, the developer 3 in the developer retaining portion A is developed on the developing sleeve 4 while being magnetically held on the rotating sleeve 12 by the magnetic field generated from the magnetic pole of the magnet roller 13. The developer 3 is moved at a lower speed than the developer transport speed to promote the circulation of the developer 3 in the developer retaining section A.

According to this embodiment, by promoting the circulation of the developer 3, the developer layer carried on the developing sleeve 4 and the developer layer circulating in the developer retaining portion A are moved. , The developer 3 is gradually replaced, and all the developer 3
Is used for development evenly, so that it is possible to suppress the deterioration of the developer 3 while maintaining the charging effect of the toner without lowering the pressure of the developer 3 in the developer retaining portion A.

In the developing device shown in FIG.
2 is rotated, and the magnet roller 13 is fixedly arranged. Conversely, the rotating sleeve 12 is fixedly arranged,
The magnet roller 13 may be rotated.

In the developing device shown in FIG. 5, the magnetic force holding / transporting means is constituted by the rotating sleeve 12 and the magnet roller. Alternatively, as shown in FIG. A small rotatable multi-pole magnet roller 14 may be provided outside the case 2 close to the support case 2. This multi-pole magnet roller 14
Is rotated in a direction indicated by an arrow in the drawing so as to move the developer on the developing sleeve 4 in a direction opposite to the developer conveying direction while holding the developer on the support case side in the developer retaining portion A with magnetic force.
The multi-pole magnet roller 14 can also promote the circulation movement of the developer 3 in the developer retaining section A.

[Embodiment 4] FIG. 7A is a front view showing a schematic structure of a developing device according to the present embodiment, and the same parts as those of the developing device of FIG. Shown,
Since their functions are the same, a description of them will be omitted.

In the developing device of this embodiment, as the developer movement promoting means, a direction (hereinafter referred to as a “longitudinal direction”) in the developing stagnation section A is substantially perpendicular to the direction in which the developer is conveyed on the developing sleeve 4.
) Is provided with a developer reciprocating means for reciprocating the developer 3. As the developer reciprocating means, FIG.
The drive shaft 1 is provided at both ends in the longitudinal direction as shown in the perspective view of FIG.
A reciprocating plate member 15 to which 5a is attached can be used. The drive shaft of the reciprocating plate member 15 is supported by the back side and near side plates (not shown) of the support case 2 and is driven to reciprocate in the longitudinal direction.

In the developing device of the present embodiment, the developer 3 in the developer retaining portion A is reciprocated in the longitudinal direction by the reciprocating plate member 15 reciprocally driven in the longitudinal direction. The movement of the developer 3 in the longitudinal direction at A is promoted.

According to this embodiment, by promoting the movement of the developer 3 in the longitudinal direction, the developer is gradually agitated (laterally agitated) in the longitudinal direction, so that the developer 3 Suppresses toner unevenness in the longitudinal direction due to local lack of toner replenishment while maintaining the toner charging effect without reducing pressure, and prevents development unevenness and consequently image density unevenness during image formation. can do.

In the developing device shown in FIG. 7A, a reciprocating member 15 reciprocally driven in the longitudinal direction is used as a reciprocating means for the developer in the developer retaining portion A, but FIG. As shown in (a) and (b), the brush 1 which is an elastic body having flexibility on the surface of the rigid plate member on the side of the developing sleeve 4.
FIG. 8 shows a reciprocating member 16 in which a projection is formed by implanting 6a.
As shown in (c), a reciprocating member 17 in which a plurality of rubber blades 17a or films 17a, which are elastic bodies, are attached to form convex portions may be used. In the case of this configuration, the horizontal stirring of the developer 3 can be performed more effectively than when the developer 3 is reciprocated only by the reciprocating member 15. Further, since the convex portion on the surface of the reciprocating member 16 or 17 is an elastic body, an excessive driving load can be prevented as compared with the case where the convex portion is also formed of a rigid body.

Further, the reciprocating member 15 is reciprocated in the longitudinal direction via the drive shafts 15a attached to both ends of the reciprocating member 15 in FIG. 7 in the longitudinal direction.
As shown in (b), the drive shaft 18a is pivotally supported outside the support case 2, and the drive shaft 18a and the movable plate 18b in the developer retaining portion A are connected to each other by a connecting member penetrating through the through hole of the support case 2. The reciprocating members 18 connected by 18c may be used. In this configuration, since the drive shaft 18a does not come into contact with the developer, leakage of the developer through the through hole of the support case 2 is prevented by a simple sealing member (such as foamed urethane rubber) having a relatively small sliding load. Meanwhile, the developer in the developer retaining section A can be reciprocated.

In each of the above embodiments, the developing sleeve 4
The magnet roller 5 is fixedly disposed inside the developing sleeve 4 and the developing sleeve 4 is rotationally driven to carry the developer 3 on the developing sleeve 4 with a magnetic force. The present invention is also applicable to a device in which the developer 3 is carried on the developing sleeve 4 with a magnetic force by rotating the magnet roller 5.

[0048]

According to the first aspect of the present invention, it is possible to control the toner concentration and charge the toner without requiring a complicated toner concentration control mechanism and a developer stirring / conveying mechanism. There is an effect that it can be configured. Further, when the developer movement promoting means promotes the circulation movement of the developer in the developer retaining portion within a range of a movement speed lower than the developer conveyance speed on the developer carrier, the developer carrier Since the developer is gradually exchanged between the developer layer carried thereon and the developer layer circulating in the developer retaining section, all the developer is used evenly for development. Therefore, there is an effect that deterioration of the developer can be suppressed while maintaining the charging effect of the toner without lowering the pressure of the developer. Further, when the movement in the direction substantially perpendicular to the developer carrying direction on the developer carrying member is promoted within the range of the moving speed lower than the developer carrying speed on the developer carrying member, The developer is gradually agitated in the direction, so that the toner charging effect is maintained without reducing the pressure of the developer in the developer accumulation part, and the occurrence of uneven development due to local insufficient toner supply is prevented. There is an effect that can be.

[0049]

[0050] Particularly, the magnetic flux density of the magnetic field generated in the magnetic rotating member provided in the upper Symbol developer accumulation portion by the magnetic field generating means is concentrated, the distance from the magnetic field generating means in the region far than magnetic member flux The density is reduced, the developer is easily moved in the area, and the circulation and movement of the developer in the developer retaining portion are promoted. By promoting the circulating movement of the developer, the developer is gradually exchanged between the developer layer carried on the developer carrying member and the developer layer circulating in the developer retaining section, and all the developer is moved. Since the developer can be used evenly for development, there is an effect that deterioration of the developer can be suppressed while maintaining the charging effect of the toner without reducing the pressure of the developer in the developer retaining portion.

[0051]

[0052]

[Brief description of the drawings]

FIG. 1 is a front view illustrating a schematic configuration of a developing device according to an embodiment.

FIG. 2 is a front view showing a drive transmission system to a rotating member provided in a developer retaining portion of the developing device.

FIG. 3A is a front view illustrating a schematic configuration of a developing device according to another embodiment. (B) is an explanatory view of a magnetic field line distribution on a developing sleeve of the developing device.

FIG. 4A is a front view illustrating a schematic configuration of a developing device according to still another embodiment. (B) is an explanatory view of a magnetic field line distribution on a developing sleeve of the developing device.

FIG. 5 is a front view showing a schematic configuration of a developing device according to still another embodiment.

FIG. 6 is a front view showing a schematic configuration of a developing device according to still another embodiment.

FIG. 7A is a front view illustrating a schematic configuration of a developing device according to still another embodiment. FIG. 3B is a perspective view of a reciprocating member provided in a developer retaining portion of the developing device.

FIG. 8A is a front view illustrating a schematic configuration of a developing device according to still another embodiment. 4B and 4C are perspective views of a reciprocating member provided in a developer retaining portion of the developing device.

FIG. 9A is a front view illustrating a schematic configuration of a developing device according to still another embodiment. FIG. 3B is a perspective view of a reciprocating member provided in a developer retaining portion of the developing device.

[Explanation of symbols]

 Reference Signs List 1 photosensitive drum 2 support case 3 developer 3a toner 4 developing sleeve 5 magnet roller 5a magnetic pole 6 doctor 7 toner hopper 7a toner supply port 8 toner agitator 9 rotating member 10 magnetic member 11 magnetic rotating member 12 rotating sleeve 13 magnet roller 14 multipole Magnet roller 15-18 Reciprocating member A Developer retention section

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-243981 (JP, A) JP-A-63-226675 (JP, A) JP-A-2-114283 (JP, A) JP-A-5-114 150628 (JP, A) JP-A-2-140776 (JP, A) JP-A-64-61776 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 13/08-13 / 095 G03G 15/08-15/095

Claims (1)

(57) [Claims] 1. A developer carrier for carrying a developer comprising toner and magnetic particles on a surface thereof, a magnetic field generating means disposed inside the developer carrier, and a developing device carried on the developer carrier. A developer regulating member for regulating the amount of developer, and a developer accommodating case for forming between the developer carrying member and a developer retaining portion in which the developer whose progress has been prevented by the developer regulating member is retained. And a toner container having a toner supply port adjacent to the developer retaining section from the upstream side in the developer conveying direction on the developer carrying member and having a toner supply port facing the developer carrying member. As a developer movement accelerating means for accelerating the movement of the developer accumulated in the developer accumulation section within a range of a movement speed lower than the developer conveyance speed on the developer carrier, the developer accumulation means
The area surrounded by the developer circulating inside
A magnetic rotating member , and the magnetic rotating member has a magnetic field generated by the magnetic field generating means.
A developing device characterized in that the bundle density is concentrated .