JPH08314273A - Developing device - Google Patents

Abstract

PURPOSE: To stably perform excellent image forming without causing fogging or the like to an image formed by easily and surely detaching developer returned back to the inside of a device min body after developing from a developer carrier member and always using new developer guided to an image carrier by the developer carrier member for the developing. CONSTITUTION: As for a developing device where the developing is performed by carrying the developer 2 containing toner and carrier to the image carrier 1 by the developer carrier members 11 and 12, a magnetic member 18 detaching the developer returned back to the inside of the device main body 10 by the developer carrier member from the developer carrier member is provided at the inside of the device main body by forming a necessary gap with the developer carrier member in between.

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 developing an electrostatic latent image formed on an image carrier in an image forming apparatus such as a copying machine or a printer, and more particularly to a toner and a carrier. The present invention relates to a developing device configured to convey a developer including a developer to an image carrier by a developer conveying member.

[0002]

2. Description of the Related Art Conventionally, in image forming apparatuses such as copying machines and printers, various developing devices have been used to supply toner to an image carrier to perform development. In addition to a one-component developing type developing device using only toner as a developer, a two-component developing type developing device using a developer containing toner and carrier has been known.

Here, in a two-component developing system using a developer containing a toner and a carrier, the developer containing the toner and the carrier is conveyed to an image carrier by a developer conveying member for development. In this case, as shown in FIG. 1, a magnet roller 1 provided with a large number of magnetic poles N and S so as to face the image carrier 1 with a required gap.
1 is arranged, the magnet roller 11 is rotated, and the developer is conveyed while being constrained by the magnetic force of the magnet roller 11, and the amount of the conveyed developer is regulated by the regulating member 13. 2 is used to guide the image to the image carrier 1, and as shown in FIG. 2, the developing sleeve 12 is provided so as to face the image carrier 1 with a required gap, and the developing sleeve 1 is provided.
The magnet roller 11 provided with a large number of magnetic poles N and S is arranged on the inner peripheral side of the second roller 2, and the developing sleeve 12 is rotated to cause the developer to move from the magnet roller 11 provided on the inner peripheral side. After being conveyed while being restrained by a magnetic force, and the amount of the conveyed developer being regulated by the regulating member 13,
There have been those in which this developer is guided to the image carrier 1 to perform development.

Then, as described above, the magnet roller 1
1 and the developing sleeve 12 guide the developer to the image bearing member 1 to perform development, and then the remaining developer is returned to the inside of the apparatus main body 10 by the magnet roller 11 and the developing sleeve 12, and the above operation is repeated. It was supposed to be developed many times.

Here, as described above, the magnet roller 1 is used.
When the developer is conveyed by the magnet roller 11 and the developing sleeve 12 while the developer is constrained by the magnetic force of 1, the magnet roller 1 is as described above.
The developer returned to the inside of the apparatus main body 10 by the developing roller 1 and the developing sleeve 12 is not properly separated from the magnet roller 11 and the developing sleeve 12, and the same developer is repeatedly fed by the magnet roller 11 and the developing sleeve 12 to the image carrier 1. It was transported to and used for development.

As a result, the carrier in the developer carried by the magnet roller 11 and the developing sleeve 12 becomes spent, and the developer is gradually deteriorated, and development is carried out using the deteriorated developer. Then, a problem such as fogging of the formed image and a good image cannot be obtained occurs.

Therefore, even in the conventional case, the developer returned to the inside of the apparatus main body 10 by the magnet roller 11 and the developing sleeve 12 as described above is released, and a new developer is used for development. Therefore, for example, as shown in FIG. 1, a peeling plate 14 is provided in the device body 10 so as to come into contact with the magnet roller 11 rotating as described above, and the peeling plate 14 returns the device body 10 into the device body 10. The developer is removed from the magnet roller 11 or, as shown in FIG. 2, in the magnet roller 11 provided inside the rotating developing sleeve 12, the same pole is magnetized to a portion inside the apparatus main body 10. The magnetic poles N and N are provided to repel magnetic force lines between the magnetic poles N and N, and the developer returned to the inside of the apparatus main body 10 is magnetized to the magnetic poles. , Those to be detached from the developing sleeve 12 on the inter-N has been developed.

However, when the peeling plate 14 is brought into contact with the surface of the rotating magnet roller 11 or developing sleeve 12 to separate the developer on the magnet roller 11 or developing sleeve 12 as described above, the peeling plate 14 is removed.
There is a problem in that the developer is pressed against the magnet roller 11 and the developing sleeve 12 by the contact with the toner and is fixed, which adversely affects the formed image.

On the other hand, as shown in FIG. 2, the magnet roller 11 provided inside the rotating developing sleeve 12 is provided with magnetized portions N, N of the same pole, and between the magnetized portions N, N of the same pole. When the developer returned to the inside of the apparatus main body 10 is separated from the developing sleeve 12, the developer is not fixed to the developing sleeve 12, but the returned developer is not attached to the developing sleeve 12. There is a problem that the toner cannot be sufficiently separated from the top, some of the developer always remains on the developing sleeve 12 and is used for many times of development, and good image formation cannot be performed. In particular, in order to prevent the toner image formed on the image carrier 1 from being disturbed by the magnetic brush of the developer carried by the developing sleeve 12, the developing sleeve 12 causes the image carrier 1 to move.
When the amount of the developer to be conveyed to is reduced, the developer is not sufficiently separated between the same-polarized portions N, N, and a large amount of the developer remains on the developing sleeve 12 as a There is a problem in that the developer on the sleeve 12 is gradually deteriorated and fogging or the like occurs in the image formed as described above, and good image formation cannot be performed.

[0010]

SUMMARY OF THE INVENTION The present invention is a developing device used in an image forming apparatus such as a copying machine or a printer, in which a developer containing a toner and a carrier is applied to an image carrier by a developer carrying member. It is an object of the present invention to solve the various problems described above in a developing device that is conveyed.

That is, according to the present invention, in the developing device as described above, when the developer returned to the inside of the device body after the development is released from the developer transport member,
The returned developer is not fixed on the developer transport member, and the developer can be easily and reliably separated from the developer transport member, and the developer transport member can always receive new development. It is an object of the present invention to supply the agent and to be guided to the image carrier so that fogging or the like does not occur in the formed image, and good image formation can be stably performed. is there.

[0012]

According to the present invention, in order to solve the above problems, a developing device for carrying out development by carrying a developer containing a toner and a carrier to an image carrier by a developer carrying member. In the above, since the magnetic member for separating the developer returned to the inside of the apparatus main body by the developer conveying member from the developer conveying member is provided in the main body of the apparatus via the developer conveying member and a required space. is there.

Here, as the magnetic member provided with a required space from the developer carrying member, one made of a ferromagnetic material such as iron, cobalt or nickel can be used. It is not preferable to use a material having magnetic force by itself because the developer stays in the magnet portion.

Further, in the developing device of the present invention, when the developer is carried to the image carrier by the developer carrying member, as described above, a plurality of magnetic poles are arranged so as to face the image carrier with a required gap. Is arranged so that the developer can be conveyed while being constrained by the magnetic force of the magnet roller or facing the image carrier with a required space. A magnet roller is provided on the inner peripheral side of the provided developing sleeve, the developing sleeve is rotated without rotating the magnet roller, and the developer is restrained on the developing sleeve by the magnetic force of the magnet roller. The developer is conveyed by the sleeve, and the magnet provided on the inner peripheral side of the developing sleeve does not rotate. Controller rotates the, it is possible to use a method such as to cause conveyed on said developing sleeve by the magnetic force of the developer in the magnet roller.

Here, when the developing sleeve is rotated without rotating the magnet roller provided on the inner peripheral side of the developing sleeve and the developer is conveyed by the developing sleeve, it is returned to the inside of the apparatus main body by the developing sleeve. In order to ensure that the developer is separated from the developing sleeve more surely, the magnetized portion having the same polarity is provided in the portion of the magnet roller inside the main body of the apparatus as described above, and the above-mentioned magnetic It is preferable that the member is provided at the magnetic pole portion on the upstream side in the developer conveying direction in the homopolarized portion.

[0016]

In the developing device according to the present invention, since the magnetic member is provided in the main body of the device so as to be spaced from the developer conveying member by a required distance, the developer containing the toner and the carrier is magnetically generated by the developer conveying member. After being conveyed to the image carrier while being restrained, the developer is returned by the developer conveying member into the apparatus main body and reaches the above-mentioned magnetic member portion. A magnetic force line toward the magnetic field is formed, and a chain of magnetic carriers is formed along the magnetic field line, so that the succeeding developer is blocked at this portion, thereby reliably separating the developer from the developer conveying member. Like
Then, a new developer is supplied to the developer transport member from which the developer returned in the apparatus main body is separated,
The new developer is guided to the image carrier by the developer transport member and used for development.

Therefore, unlike the conventional case, the developer does not stay on the developer conveying member for a long time and the developer is not deteriorated, and the magnetic member is provided with a predetermined distance from the developer conveying member. Therefore, the developer is not pressed against the developer conveying member to be fixed, and the developer is not deteriorated due to a large stress applied thereto, and the good development can be stably performed.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A developing device according to an embodiment of the present invention will be specifically described below with reference to the accompanying drawings.

(Embodiment 1) In the developing device of this embodiment, when a developer containing a toner and a carrier is conveyed to an image carrier by a developer conveying member, FIG.
As shown in FIG. 2, a magnet roller 11 provided with a large number of magnetic poles N and S is arranged so as to face the image carrier 1 with a required gap, and the magnet roller 11 is rotated to remove the developer. The magnet roller 11 is constrained by the magnetic force to be conveyed.

In the main body 10 of the developing device in this embodiment, the partition wall 17 conveys the developer containing the toner and the carrier while mixing and agitating the first convey path 15a and the second convey path. 15b are provided separately from each other vertically, and first and second agitating / conveying members 16a, 16b are respectively rotated in the first and second conveying paths 15a, 15b to convey the developer while mixing and agitating the developer. I decided to provide it.

Then, in the first conveying path 15a located on the upper side of the apparatus main body 10, the developer is mixed and stirred by the first stirring and conveying member 16a and is supplied to the magnet roller 11 while being conveyed. I decided to do it.

Further, while the developer thus supplied is conveyed to the image carrier 1 by the magnet roller 11 rotating as described above, the developer is regulated so as to be separated from the magnet roller 11 by a required distance (D1). Member 1
3, the magnet roller 1 is provided by the regulating member 13.
After the amount of the developer conveyed to the image carrier 1 is regulated by 1, the magnet roller 11 guides the developer to the image carrier 1 to perform the development.

On the other hand, in the second transport path 15b located on the lower side of the apparatus main body 10, the image carrier 1 as described above.
After the developer is guided to the developing unit and is developed, the developer returned to the apparatus main body 10 is recovered by the magnet roller 11 rotating as described above, and the developer thus recovered is transferred to the second transport unit. The second agitating and conveying member 16b provided in the passage 15b conveys the mixture while agitating and mixing, and returns the mixture to the first conveying passage 15a.

Here, in recovering the developer returned to the apparatus main body 10 in the second transport path 15b as described above, in this embodiment, the first transport path 1 is used.
A magnetic member 18 made of iron or the like is provided at a portion of the partition wall 17 separating the 5a and the second transport path 15b so as to be spaced from the magnet roller 11 by a required distance (D2). A bias power source 19 applies a bias voltage to the magnetic member 18.
When a bias voltage is applied from the bias power source 19 to the magnetic member 18, a voltage having a polarity opposite to the charging polarity of the toner in the developer is applied to the magnetic member 18.

In this way, magnetic lines of force are formed between the magnetic member 18 and the magnet roller 11 at the portion facing the magnetic member 18, and a chain of magnetic carriers is formed along the lines of magnetic force. become,
Subsequent developer is blocked at this portion, so that the developer returned to the inside of the apparatus main body 10 by the magnet roller 11 as described above is separated from the magnet roller 11 at the portion facing the magnetic member 18. Further, the toner remaining on the magnet roller 11 is also attracted to the magnetic member 18 by the above bias voltage, and is reliably separated from the magnet roller 11 and collected.

After recovering the developer from the magnet roller 11 to the second transport path 15b in this manner, the recovered developer is transferred from the second transport path 15b to the first transport path as described above. While returning to 15a, a new developer is supplied to the magnet roller 11 from which the developer has been collected as described above in the first transport path 15a as described above.

In this way, the magnet roller 11
The developer above does not remain and deteriorate for a long period of time, and new developer is constantly supplied to the magnet roller 11. The new developer thus supplied is conveyed to the image carrier 1 by the magnet roller 11. Development was carried out, and good image formation could be stably carried out.

Next, in the developing device described above, when a non-magnetic member made of a non-magnetic material is provided instead of the magnetic member 18 (Experimental Example 1), the magnetic member 18 is provided as described above. However, when the bias voltage is not applied from the bias power source 19 (Experimental Example 2), and when the magnetic member 18 is provided as described above and the bias voltage having the opposite polarity to the toner is applied to the magnetic member 18. (Experimental example 3)
In the above, the developer returned to the inside of the apparatus main body 10 by the magnet roller 11 is the magnet roller 1
I tried to find out the rate of getting out of 1.

In carrying out these experiments, the distance (D1) between the regulating member 13 and the magnet roller 11 is set to 0.5 mm, while the magnet roller 11 and the non-magnetic member or magnetic member are set. The interval (D2) with respect to 18 was changed as shown in Table 1 below, the replacement rate of the developer on the magnet roller 11 was measured, and the results are also shown in Table 1. When measuring the replacement rate of the developer, the developer supplied onto the magnet roller 11 is regulated by the regulating member 13 as described above.
After being regulated by the second transport path 1, the developer on the magnet roller 11 is separated from the magnet roller 11 by the non-magnetic member or the magnetic member 18.
5 (b), the weight of the developer on the magnet roller 11 after being regulated by the regulation member 13 is X, and the amount of the developer collected in the second transport path 15b is Y. [(X−Y ) / X] × 100 (%).

[0030]

[Table 1]

As is clear from this result, when the developer on the magnet roller 11 is released and collected, the second experimental example in which the magnetic member 18 is provided in the main body 10 of the apparatus with the magnet roller 11 at a required interval. In addition, in the case of Experimental Example 3 in which a bias voltage having a polarity opposite to that of the toner is applied to the magnetic member 18, the magnet roller is not required to be narrowed in the distance (D2) between the magnetic member 18 and the magnet roller 11. The developer was sufficiently separated from No. 11, and new developer was supplied to the magnet roller 11.

On the other hand, in the case of Experimental Example 1 in which the non-magnetic member is provided in the main body 10 of the apparatus with the magnet roller 11 interposed at a required interval, the interval between the non-magnetic member and the magnet roller 11 must be extremely narrow. For example, magnet roller 11
If the developer on the magnet roller 11 cannot be sufficiently separated and the distance between the non-magnetic member and the magnet roller 11 is extremely narrow, the developer on the magnet roller 11 is magnetized by the non-magnetic member. Problems such as being pressed against the roller 11 to deteriorate, being fixed on the magnet roller 11 and being clogged with the non-magnetic member to suppress the rotation of the magnet roller 11 have occurred.

(Embodiment 2) In the developing device of this embodiment, the developer containing the toner and the carrier is conveyed to the image carrier by the developer conveying member as shown in FIG.
As shown in FIG. 3, the developing roller 12 is provided so as to face the image bearing member 1 with a required gap, and the magnet roller 11 is provided with a large number of magnetic poles N and S on the inner peripheral side of the developing sleeve 12. Place this magnet roller 1
The developing sleeve 12 is rotated in a state where 1 is fixed, and the developer is conveyed while being restrained by the magnetic force of the magnet roller 11 provided on the inner peripheral side thereof.

Further, in the developing device in this embodiment, the magnet body 11 is used as the main body 1 of the device.
A portion in which the same-pole magnetized portions N, N magnetized to the same pole are provided in the portion within 0, and the portion of the magnetic pole N on the upstream side in the developer conveying direction in the same-polarized portion N, N is used. The magnetic member 18 made of iron or the like is provided so as to face the developing sleeve 12 with a required space (D2) therebetween.

Also in the developing device of this embodiment, the developer is carried in the first carrying path 15a while being mixed and stirred by the first stirring and carrying member 16a, and the developer is carried to the developing sleeve 12 described above. The developer thus supplied is conveyed to the image carrier 1 side while being restrained by the magnetic force of the magnet roller 11 provided on the inner peripheral side of the developing sleeve 12 by the rotation of the developing sleeve 12 as described above. I did it.

Further, in the course of transporting the developer to the image carrier 1 side in this way, a regulating member 13 is provided so as to be spaced from the developing sleeve 12 by a required distance (D1).
After the regulating member 13 regulates the amount of the developer conveyed to the image carrier 1 by the developing sleeve 12, the developing sleeve 12 guides the developer to the image carrier 1 to perform development.

Then, as described above, the developer is added to the image carrier 1.
After the development is conducted by introducing the developer into the apparatus main body 10 by the developing sleeve 12 which rotates as described above, the developer thus returned is transferred to the magnet roller 11 as described above. By the action of the above-mentioned magnetic member 18 provided at a position facing the magnetic pole N on the upstream side in the developer transport direction in the pole magnetized portions N, N, the magnetic member 18 is separated from the developing sleeve 12 and is fed to the second transport path 15b. I tried to collect it.

Here, as described above, the magnet roller 1 is used.
If the magnetic member 18 is provided so as to face the magnetic pole N on the upstream side in the developer conveying direction in the homopolarized portions N, N of No. 1, magnetic force lines repel between the homopolarized portions N, N of the magnet roller 11. At the same time, a magnetic force line is formed from the magnetic pole N on the upstream side toward the magnetic member 18, and a chain of magnetic carriers is formed along the magnetic force line, whereby the succeeding developer is blocked at the portion facing the magnetic member 18. The developer returned in this portion is surely removed from the developing sleeve 12.

Although not shown, also in the developing device of this embodiment, as in the case of the first embodiment, when a bias power source 19 applies a voltage having a polarity opposite to that of the toner to the magnetic member 18 described above. The toner remaining on the developing sleeve 12 is also applied to the magnetic member 18 by the reverse bias voltage.
Then, it is surely removed from above the developing sleeve 12.

Next, in the above developing device, the above-mentioned magnetic member 18 was not provided (Experimental Example 4) and the magnetic member 18 was provided as described above (Experimental Example 5). The rate at which the developer returned to the inside of the apparatus main body 10 by the developing sleeve 12 is separated from the developing sleeve 12 is examined.

In conducting these experiments, the distance (D1) between the regulating member 13 and the developing sleeve 12 was changed as shown in Table 2 below, and
In Experimental Example 5, the gap (D2) between the magnetic member 18 and the developing sleeve was set to 0.5 mm, and the replacement rate of the developer on the developing sleeve 12 was measured in the same manner as in Example 1 above. The results are shown in Table 2.

[0042]

[Table 2]

As is clear from this result, the regulating member 1
When the amount of the developer conveyed by the developing sleeve 12 is reduced by reducing the distance between the developing sleeve 12 and the developing sleeve 12 in Experimental example 4 in which the magnetic member 18 is not provided,
The replacement rate of the developer is greatly reduced, and the developing sleeve 12
While the developer above gradually deteriorates, in Experimental Example 5 in which the magnetic member 18 is provided, a high replacement rate of the developer is maintained, and the developer after development is reliably separated from the developing sleeve 12. Then, new developer is supplied to the developing sleeve 12.

Therefore, according to the developing device of Embodiment 2, the toner image formed on the image carrier 1 is conveyed by the developing sleeve 12 in order to prevent the toner brush from being disturbed by the magnetic brush of the developer. Even when the amount of the developer is reduced, the developer after the development is the developing sleeve 12
New developer is constantly supplied to the developing sleeve 12 without being removed from above and remaining for a long period of time, and the new developer thus supplied is conveyed to the image carrier 1 by the developing sleeve 12. Then, it was used for development, and good image formation could be stably performed.

In the second embodiment, the developing sleeve 12 is rotated while the magnet roller 11 is fixed, and the developer is conveyed by the developing sleeve 12, but conversely, the developing sleeve 12 is rotated. It is also possible to rotate the magnet roller 11 in a state where the magnetic roller 11 is fixed and to convey the developer on the developing sleeve 12 by the magnetic force of the magnet roller 11. In this case also, as described above, By providing the member 18 in the main assembly 10 of the apparatus with an appropriate distance from the developing sleeve 12, the developer returned to the main assembly 10 of the apparatus is reliably removed from the developing sleeve 12 by the magnetic member 18. , The new developing agent is constantly supplied to the developing sleeve 12, and the new developing agent thus supplied is used as the image carrier. Are transported is used for development, good image formation is performed stably.

Further, in the developing devices of Embodiments 1 and 2 described above, an example in which the first carrying path 15a and the second carrying path 15b are provided above and below by the partition wall 17 provided inside the apparatus main body 10 Although shown, the developing device of the present invention is not particularly limited to such a developing device.

For example, as shown in FIG.
Similar to the developing device of No. 1, a magnet roller 11 having a large number of magnetic poles N and S is provided on the inner peripheral side of the developing sleeve 12, and the developing roller 12 is rotated to fix the developer 2 with the magnet roller 11 fixed. In a developing device which is adapted to be conveyed to the image carrier 1, a partition wall 17 is erected in the main body 10 of the developing device along the axial direction of the developing sleeve 12, and the partition wall 17 allows the developer 2 to move to the first position. The first stirring and feeding member 16a feeds the developer 2 while partly mixing and stirring the developer 2 and supplies it to the developing sleeve 12.
And a second transport path 15b for transporting the developer 2 in the opposite direction to the first transport path 15a while mixing and stirring the developer 2 by the second stirring transport member 16b.
It is also possible to circulate the developer 2 between the first transport path 15a and the second transport path 15b.

Incidentally, also in the developing device shown in FIG.
After the developer 2 is guided to the image carrier 1 by the developing sleeve 12 and developed, the developer 2 returned to the inside of the apparatus main body 10 by the developing sleeve 12 is developed.
In order to separate the developing roller 12 from the magnetic roller 11, the developing sleeve 12 is required in the first conveying path 15a at a position facing the magnetic pole S on the upstream side in the conveying direction of the developer 2 in the homopolarized portions S, S of the magnet roller 11. The magnetic member 18 is provided via the space (D2), and the bias power source 19 is connected to the magnetic member 18.
A bias voltage having a polarity opposite to that of the toner is applied to the toner, and the toner remaining on the developing sleeve 12 is also attracted to the magnetic member 18 to be sufficiently collected.

Then, after the developer 2 returned to the inside of the apparatus main body 10 by the magnetic member 18 is separated from the developing sleeve 12 and collected in the first conveying path 15a, the inside of the first conveying path 15a. 2 is supplied to the developing sleeve 12, while the developer 2 collected as described above is mixed and stirred with the developer 2 in the first conveying path 15a by the first stirring and conveying member 16a. While being conveyed, it is guided to the second conveyance path 15b and circulated between the first conveyance path 15a and the second conveyance path 15b.

Also in this case, the developing sleeve 12
A new developer 2 is constantly supplied to the developing device for development, and the developer 2 on the developing sleeve 12 does not remain and deteriorate for a long period of time, and good image formation can be stably performed. Became.

[0051]

As described above in detail, in the developing device according to the present invention, the developer carrying member guides the developer to the image carrier to carry out the development, and thereafter, the developer carrying member is provided in the main body of the apparatus. When the returned developer after the development is separated from the developer transport member, a magnetic member is provided in the main body of the apparatus with a required gap from the developer transport member, so that magnetic force lines are formed toward the magnetic member. Then, a chain of magnetic carriers is formed along the lines of magnetic force so that the succeeding developer can be blocked at this portion, and the developer returned to the inside of the main body of the device is the developer at the portion of this magnetic member. It came to be reliably separated from the transport member.

As a result, in the developing device according to the present invention, the developer after development is reliably separated from the developer transport member, and new developer is supplied to the developer transport member, and thus supplied. A new developer is conveyed to the image carrier and used for development, and as in the conventional case, the developer stays on the developer conveying member for a long time and deteriorates, and fogging or the like occurs in the formed image. Therefore, good image formation can be stably performed.

Further, in the developing device according to the present invention, the magnetic member is provided with a predetermined distance from the developer conveying member, so that the developer is fixed on the developer conveying member or a great stress is applied to the developer. Good development can be stably performed without being deteriorated by addition.

[Brief description of drawings]

FIG. 1 is a partial explanatory view of a conventional developing device that rotates a magnet roller to convey a developer to an image carrier.

FIG. 2 is a partial explanatory view of a conventional developing device that rotates a developing sleeve provided with a magnet roller on the inner peripheral side and conveys a developer to an image carrier.

FIG. 3 is a schematic sectional view of the developing device according to the first embodiment of the present invention.

FIG. 4 is a partial explanatory view of a developing device according to a second embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of a developing device according to another embodiment of the present invention in which the state of a developing device of Embodiments 1 and 2 and a conveying path for conveying a developer while mixing and stirring the toner is changed.

[Explanation of symbols]

 1 Image Carrier 2 Developer 10 Device Main Body 11 Magnet Roller 12 Development Sleeve 18 Magnetic Member

Claims (1)

[Claims] 1. A developing device in which a developer containing a toner and a carrier is carried to an image carrier by a developer carrying member for developing, and the developer returned to the inside of the main body by the developer carrying member. A developing device characterized in that a magnetic member for separating the developer carrying member from the developer carrying member is provided in the main body of the apparatus with a predetermined gap from the developer carrying member.