JP2000231258A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device where a good image without any unevenness in image density can be formed by restricting the toner intake to be stopped when the toner covering ratio of carrier in developer is 80 to 100% in a developing device controlling the density of the developer by circulating movement of the developer. SOLUTION: In the developing device 2 where the toner density is automatically controlled by taking in toner into the developer by circulatory movement of the developer 3, a gap between a 2nd doctor blade 7 by which toner intake to the developer is restricted and a developing sleeve are set so that the taking in of the toner to the developer is accurately stopped when the toner covering ratio is in the range of 80 to 100%. Thus, developing with toner with deficient electrification and developing in a state where the toner density is not sufficient can always be avoided.

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 using a two-component developer composed of toner and magnetic particles. The present invention relates to a developing device that develops a formed latent image.

[0002]

2. Description of the Related Art Conventionally, in a developing apparatus for developing a latent image formed on an image carrier using a two-component developer composed of toner and magnetic particles, the toner is detected by the movement of the developer without using a toner density detecting means. There is known a developing device that captures image data. For example, in Japanese Patent Application Laid-Open No. 63-4280, a developer container which contains a developer, has a developer carrier having a magnetic field generating means in an opening portion, and permits a carry-out and carry-in of a developer; A developer regulating member provided in the region, 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; The magnetic field generating means has a magnetic pole for forming lines of magnetic force over the surface of the developer carrier, and as a top layer of the surface of the developer carrier in the developing container, a moving layer that moves with the movement of the developer carrier, and the moving layer There has been proposed a developing device in which a substantial developer immobile layer is formed as an upper layer. In this type of developing device, the toner is taken in with the movement of the whole developer existing on the surface of the developer carrier, and when the taking-in of the toner is not required, the whole developer becomes an almost immobile layer. To stop taking in the toner. Therefore, there is no need to provide a special member for stirring the developer, and the device is useful as a developing device capable of controlling the toner concentration while reducing the size and cost of the device.

Here, in the developing device having the above-described structure, the movement of the developer which influences the taking-in of the toner depends on the state of the toner on the surface of the developer, that is, the toner coverage. In other words, if the toner coverage of the developer upstream of the developer regulating member in the developer transport direction is low, the circulation of the developer is fast, the toner is actively taken in, and the circulation gradually increases as the toner coverage increases. It aims to stop the toner take-up when it becomes slow and almost 100%. here,
The toner coverage of 100% refers to a state in which the toner is further covered on the carrier surface in a close-packed oblique arrangement.

[0004]

However, in the developing device having the above structure, the exposed area of the developer in contact with the toner in the toner intake section for taking the toner from the storage section into the developer is large, and It is conceivable that a small change in the state of the developer on the carrier greatly affects the amount of toner taken in. Then, there is a tendency that a problem that the toner is taken in at a level higher than the desired toner density or the toner taking is stopped in a state where the toner density is insufficient is likely to occur. Further, if there is unevenness in the axial direction in the state of the developer on the surface of the developer carrier, unevenness occurs in the amount of taken-in toner in the axial direction, which may result in uneven toner density on the formed image. Was. For example, when viewed in the axial direction of the developer carrying member, toner is not taken in at a portion where a large amount of developer is collected, and conversely, a large amount of toner is taken in at a portion where the amount of developer is small. Uneven toner density occurs. In addition, when viewed from the developer carrying direction of the developer carrying member, the moving speed of the developer is almost 0 mm / sec at a place far from the surface of the developer carrying member, and the toner is not taken in. In the vicinity of the developing sleeve, the moving speed of the developer is high, so that the toner is taken in. As a result, the execution and stop of the taking-in of the toner cannot be precisely controlled, and the toner density cannot be precisely controlled. Then, when the toner density unevenness occurs, on the formed image, background problems occur at places where the density is high, and conversely, image problems such as a decrease in image density and unexpected carrier adhesion occur at places where the density is low.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to precisely control the incorporation of toner into a developer to form a good image without unevenness in image density. It is to provide a device.

[0006]

In order to achieve the above object, a developing device according to the present invention has a magnetic field generating means inside, and carries and transports a two-component developer containing a toner and a magnetic carrier. A developer carrying member, a first regulating member that regulates an amount of the developer carried and conveyed by the developer carrying member, and the developer scraped off by the first regulating member. A developer accommodating portion, a toner accommodating portion adjacent to the developer accommodating portion, the toner accommodating portion having a toner supply opening for supplying toner to the developer carrying member; A developing device that changes a contact state between the developer and the toner according to a change in density to change a toner take-in state of the developer on the developer carrying member. The developer carrying member as compared with the first regulating member; Second opposed with a predetermined interval from the surface of the developer carrying member in the conveying direction upstream side of the developer
In the developing device having the regulating member, the distance between the second regulating member and the surface of the developer carrying member is set such that the toner coverage of the carrier in the developer in the developer accommodating portion is 80%.
The setting is made such that the taking of the toner into the developer is stopped at the time of 〜100%.

Here, there is a method of calculating the toner coverage Th by, for example, the following equation (1).

(Equation 1) C: toner concentration r: toner radius R: carrier radius ρt: true specific gravity of toner ρc: true specific gravity of carrier However, various methods of calculating the toner coverage have been proposed.
The present invention is not limited to using the calculation method according to the above equation (1).

According to the first aspect of the present invention, the second regulating member for regulating the incorporation of the toner into the developer on the developer carrying member is configured such that the toner coverage of the carrier in the developer in the developer accommodating portion is 80%. The distance from the surface of the developer carrying member is set so that the intake of the toner is stopped in the range of about 100%. Here, in a two-component developer, since a well-charged toner is used for development, it is necessary that the newly replenished toner comes into contact with the carrier immediately and be charged. However, when the toner coverage of the carrier exceeds 100%, the toner replenished thereafter does not come into contact with the carrier but the toners come into contact with each other and are frictionally charged, so that an ideal charge amount for development is obtained. I will not be able to. On the other hand, the toner coverage of the carrier is 80%.
If the density is further reduced, the desired image density cannot be obtained, and the image will be blurred, or the toner will easily adhere to the latent image carrier in the image forming apparatus. In the present invention, the toner coverage of the carrier is 80 to 100.
%, The second regulating member regulates the toner intake so as to stop the toner intake accurately, so that it is possible to always avoid developing with insufficiently charged toner or developing with insufficient toner density. .

According to a second aspect of the present invention, in the developing device according to the first aspect, the distance between the second regulating member and the developer carrier is determined by adjusting a toner coverage of the carrier in the developer in the developer accommodating portion. Is set to restrict the passage of the developer at a position where the moving speed of the developer is 0 to 10 mm / sec when the ratio is 80 to 100%.

In the developing device according to the present invention, the passage of the developer is restricted at a position where the moving speed of the developer is 0 to 10 mm / sec.
Stop the toner take-up accurately at ~ 100%. Here, if the moving speed of the developer due to the transport of the developer carrier is high at the position regulated by the second regulating member, more toner than necessary is taken into the developer. Conversely, if the movement speed of the developer is 0 mm / sec, the movement of the developer is stopped, and the taking in of the toner is stopped. However, substantially when toner is not taken in at all, it takes about 10 tons at a position away from the developer carrier in the developer accommodating section.
The developer continues to circulate at a speed of about mm / sec, and if the movement of the developer is regulated by the second regulating member at a position of about 10 mm / sec or less, the movement speed of the developer becomes 0 mm / sec. sec
However, it was found that the intake of the toner stopped immediately. In the present invention, when it is not necessary to take in the toner into the developer in which the toner coverage of the carrier is 80 to 100%, the moving speed of the developer is always 0.
By restricting the passage of the developer at a position of 10 to 10 mm / sec, it is possible to accurately capture the toner as compared with regulating the passage of the developer at a position where the moving speed of the developer is faster than 10 mm / sec. Stop.

According to a third aspect of the present invention, in the developing device according to the first or second aspect, the position of the second regulating member for regulating the passage of the developer in the developer conveying direction is set in the direction normal to the surface of the developer carrying member. The magnetic flux density is set at a position where the magnetic flux density is 5 mT or less.

According to the third aspect of the present invention, in the position where the ears of the developer carried on the developer carrying member are lying, that is, the position where the magnetic flux density in the normal direction is 5 mT or less. Regulates the passage of developer. Here, when the magnetic flux density in the normal direction increases, the developer spikes on the surface rise, but when the toner is taken in at the surface of the developer carrier having the spikes, the developer spikes. There is a possibility that the toner may directly adhere to the body surface. Since it is difficult to remove the toner adhered to the surface of the developer carrying member in a subsequent process, the toner is conveyed to the developing area as it is, and tends to be stained on a formed image. The developing device of the present invention takes in the toner at a position where the magnetic flux density in the normal direction is 5 mT or less and the ears of the developer are lying, so that the taken-in toner adheres to the surface of the developer without fail. To do. Since the toner attached to the developer can be regulated at the regulation position by the first regulation member, as a result, the supply amount of the toner to the development area can be precisely controlled.

According to a fourth aspect of the present invention, in the developing device of the first, second or third aspect, the distance between the second regulating member and the surface of the developer carrier is set to 0.5 to 2.0 mm. It is characterized by having done.

According to a fourth aspect of the present invention, the distance between the second regulating member and the surface of the developer carrier is 0.5 to 2.0 mm.
Set to. If the interval is smaller than 0.5 mm, the interval is too small, and the aggregate of the carrier and the toner is clogged there, and there is a possibility that the smooth intake of the toner may be prevented. On the other hand, if this interval is larger than 2.0 mm, the interval is too wide, and the toner coverage of the carrier is 80 to 10%.
Even at 0%, it is difficult to stably regulate the moving speed of the developer at a position of 0 to 10 mm / sec. Therefore, the second
The distance between the regulating member and the surface of the developer carrier is 0.5 to 2.
The distance is set to 0 mm so that the toner can be smoothly taken into the developer and the stopping of the toner can be accurately stopped.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a developing device of an image forming apparatus such as a copying machine, a facsimile, a printer and the like will be described below. First, in order to clarify the object and configuration of the present invention, FIG. 1 and FIG.
With reference to (c), a developing device disclosed in Japanese Patent Application Laid-Open No. 9-197833 previously proposed by the present application will be described.

In FIG. 1, a developing device 2 disposed beside a photosensitive drum 1 serving as a latent image carrier has a support case 1.
0, a developing sleeve 4 as a developer carrying member, a developer accommodating member 11, a first doctor blade 6 as a first developer regulating member, and the like.

A support case 10 having an opening on the side of the photosensitive drum 1 forms a toner hopper 8 as a toner storage section for storing the toner 3b therein. A developer accommodating member 11 forming a developer accommodating portion A for accommodating the developer 3 including the toner 3b and the carrier as the magnetic particles is integrated with the support case 10 near the photosensitive drum 1 side of the toner hopper 8. Is provided. Here, in the present embodiment, a low-resistance carrier having a particle size of 20 to 50 μm is used as the carrier. Further, the support case 10 located below the developer accommodating member 11 is formed with a protruding portion 10a having an opposing surface 10b, and a space between the lower portion of the developer accommodating member 11 and the opposing surface 10b provides Toner 3b
The toner supply opening 20 for supplying the toner is formed.

Inside the toner hopper 8, there is provided a toner agitator 9 as toner supply means which is rotated by a driving means (not shown). The toner agitator 9 sends out the toner 3 b in the toner hopper 8 while stirring it toward the toner supply opening 20. Further, on the side of the toner hopper 8 facing the photosensitive drum 1, there is provided a toner end detecting means 10c for detecting when the amount of the toner 3b in the toner hopper 8 becomes small.

In a space between the photosensitive drum 1 and the toner hopper 8, a developing sleeve 4 is provided. The developing sleeve 4, which is rotationally driven in the direction of the arrow in the figure by a driving means (not shown), has a magnet (not shown) as a magnetic field generating means, which is disposed inside the developing sleeve 4 so as to be fixed relative to the developing device 2. I have.

A first doctor blade 6 is integrally attached to a side of the developer accommodating member 11 opposite to the side attached to the support case 10. The first doctor blade 6 is arranged with a certain gap kept between its tip and the outer peripheral surface of the developing sleeve 4.

A second doctor blade 7 as a second regulating member is provided at a portion of the developer accommodating member 11 located near the toner supply opening 20. The second doctor blade 7 has a free end that keeps a constant gap with respect to the outer peripheral surface of the developing sleeve 4 in a direction that obstructs the flow of the layer of the developer 3 formed on the surface of the developing sleeve 4, that is, in a free direction. The base is integrally attached to the developer accommodating member 11 with the end facing the center of the developing sleeve 4.

The developer accommodating portion A is configured to have a sufficient space for circulating the developer 3 within a range where the magnetic force of the developing sleeve 4 can reach.

The facing surface 10b is connected to the toner hopper 8
It is formed over a predetermined length so as to be inclined downward from the side toward the developing sleeve 4 side. Accordingly, when vibrations, uneven magnetic force distribution of a magnet (not shown) provided inside the developing sleeve 4, a partial increase in toner concentration in the developer 3, and the like occur, the second doctor blade 7
Even if the carrier 3a in the developer accommodating section A falls from between the peripheral surface of the developing sleeve 4 and the carrier 3a, the dropped carrier 3a is received by the facing surface 10b and moves to the developing sleeve 4 side, and the developing sleeve is moved by the magnetic force. 4 and is supplied again into the developer accommodating section A. As a result, it is possible to prevent a decrease in the amount of the carrier in the developer accommodating portion A,
The occurrence of uneven image density in the axial direction of the developing sleeve 4 can be prevented.

With the above configuration, the toner 3 sent out from the inside of the toner hopper 8 by the toner agitator 9 is
b is supplied to the developer 3 carried on the developing sleeve 4 through the toner supply opening 20, and is carried to the developer accommodating section A. Then, the developer 3 in the developer accommodating portion A is carried by the developing sleeve 4 and transported to a position facing the outer peripheral surface of the photosensitive drum 1, and only the toner 3 b is transferred to the photosensitive drum 1.
The toner image is formed on the photosensitive drum 1 by electrostatically coupling with the electrostatic latent image formed thereon.

Here, the behavior of the developer 3 and the self-control mechanism of the toner concentration during the formation of the toner image are shown in FIG.
This will be described with reference to (a) to (c). When a starting agent consisting of only the magnetic carrier 3a is set in the developing device 2, the magnetic carrier 3a is magnetically attached to the surface of the developing sleeve 4 and housed in the developer accommodating portion A as shown in FIG. Divided into things to be done. The magnetic carrier 3a accommodated in the developer accommodating portion A circulates in the direction of arrow b by the magnetic force from inside the developing sleeve 4 as the developing sleeve 4 rotates in the direction of arrow a. Then, an interface X is formed at a boundary between the surface of the magnetic carrier 3a magnetically attached to the surface of the developing sleeve 4 and the surface of the magnetic carrier 3a moving in the developer accommodating portion A.

Next, when the toner 3b is set in the toner hopper 8, the toner 3b is supplied from the toner supply opening 20 to the magnetic carrier 3a carried on the developing sleeve 4. Therefore, the developing sleeve 4 carries the developer 3 which is a mixture of the toner 3b and the magnetic carrier 3a. While the toner concentration in the developer is low, the toner 3b is taken in from a short distance (A1 in FIG. 2A) from the surface of the developing sleeve 4, and the moving speed αmm of the developer 3 at this position is taken. / sec is fast and the amount of toner 3b taken in is large.

On the other hand, in the developer accommodating portion A, a force for stopping the conveyance of the developer 3 conveyed by the developing sleeve 4 acts due to the presence of the stored developer 3. I have. Then, as the taking-in of the toner 3b progresses, the developer 3
Is transported to the interface X when the toner 3b present on the surface of
The frictional force between the developers 3 near the interface X decreases, and the transport force of the developer 3 near the interface X decreases.
The transport amount of the developer 3 in the vicinity decreases. On the other hand, the developer 3 conveyed by the developing sleeve 4 has no force acting on the developer 3 on the upstream side in the rotation direction of the developing sleeve 4 to stop the conveyance.
2A, the balance of the transport amount of the developer 3 collapses, and a collision state of the developer 3 occurs. As shown in FIG. 2B, the layer thickness of the developer 3 including the interface X increases, and the moving speed β mm of the developer 3 increases. / sec is slower than αmm / sec in FIG. Also, the first
The layer thickness of the developer 3 passing through the doctor blade 6 also gradually increases, and the increased developer 3 is scraped off by the second doctor blade 7.

When the developer 3 that has passed through the first doctor blade 6 reaches a predetermined toner concentration, FIG.
As shown in FIG. 2, the increased amount of the developer 3 which has been scraped off by the second doctor blade 7 to form a layer is supplied to the toner supply opening 2.
0, and the moving speed γ mm / sec of the developer 3 is further slower than β mm / sec in FIG. 2B and becomes almost 0 mm / sec, and in this state, the taking-in of the toner 3b is completed. At this time, the bulk of the developer 3 is increased due to the increase in the toner concentration in the developer accommodating section A, and the space in the developer accommodating section A is narrowed. Speed also decreases. However, even at this time, the developer 3 continues to circulate at a speed of about 10 mm / sec at a position apart from the developing sleeve 4 in the developer accommodating portion A. As described above, the toner concentration of the developer 3 can be automatically controlled.

In the developing device 2 having the above structure, the presence or absence of the toner 3b in the developer 3 depends on the state of the developer 3 on the developing sleeve 4 in the vicinity of the toner supply opening 20, and the toner coverage is changed. Is done. The toner coverage of the developer 3 actually used for development is 80 to 100%.
When a document having a large image area is continuously developed with the developer 3 having a toner coverage that is too low, the toner 3b cannot follow the toner density enough to recover the toner density, so that the image becomes thinner or the carrier 3a becomes less dense. Adhesion may occur. On the other hand, if development is performed with the developer 3 having an excessively high toner coverage, background stain and image fogging tend to occur. Therefore, while the toner coverage of the developer 3 is small, the toner 3b is positively taken in, and the toner coverage is 8%.
It is preferable that the control can be precisely performed so that the take-up of the toner 3b is stopped at 0 to 100%. Therefore, the developing device 2 of the present invention has a configuration that can control the toner coverage within a range suitable for development. Next, features of the present invention will be described.

FIG. 3 is a partially enlarged view of the developing device according to the present invention. In this figure, the toner coverage of the carrier 3a in the developer 3 in the developer accommodating section A is 80 to 100.
%, The moving speed of the developer 3 is 0 to 10 mm / s
The gap Gp between the developing sleeve 4 and the tip of the second doctor blade 7 is set so that the passage of the developer 3 is restricted by the second doctor blade 7 at the position where ec is set. Here, if the moving speed of the developer 3 due to the transport of the developing sleeve 4 is high at the position regulated by the second doctor blade 7, more toner 3b than necessary is taken into the developer. Conversely, if the movement speed of the developer 3 is 0 mm / sec, the movement of the developer 3 stops, and the taking in of the toner 3b stops. However, at a position away from the developing sleeve 4 in the developer accommodating portion A, the developer 3 circulates at a speed of about 10 mm / sec even when the toner 3b is not taken in at all as described above. continuing. Therefore, the developer 3
If the movement of the developer 3 is restricted by the second doctor blade 7 at a position where the moving speed of
It was found that even if the speed was not mm / sec, the intake of the toner 3b stopped immediately. Therefore, as described above, the gap Gp
Is set, the toner coverage of the carrier 3a is 80-1.
At 00%, the taking in of the toner 3b can be stopped accurately. According to the developing device of the present invention, when it is not necessary to take in the toner 3b into the developer 3, the taking-in of the toner 3b can be stopped accurately, so that the toner density is precisely controlled and a good image is stabilized. Can be formed.

FIG. 4 is a partially enlarged view of a developing device according to a first modification of the developing device of the present invention. In this example, the configuration shown in FIG. 3 is provided. Further, the passage restriction position of the developer 3 in the circumferential direction of the developing sleeve by the second doctor blade 7 is determined by the method between the P3 pole and the P4 pole of the magnet roller 5. It is set at a position where the magnetic flux density in the linear direction is 5 mT or less. At the position where the magnetic flux density in the normal direction is 5 mT or less, the ears of the developer 3 carried on the developing sleeve 4 are in a lying state. At this position, the toner 3 b is taken into the developer 3. By setting the position of the tip of the second doctor blade 7, it is possible to prevent the taken-in toner 3b from directly adhering to the surface of the developing sleeve 4,
It can be reliably adhered to the surface of the developer. Developer 3
Since the toner 3b attached to the toner can be regulated at the regulation position by the first doctor blade 6, the amount of the toner 3b supplied to the developing area can be precisely controlled as a result. According to this modified example, it is possible to form a good image without image density unevenness by precisely controlling the incorporation of the toner 3b into the developer 3.

FIG. 5 is a partially enlarged view of a developing device according to a second modification of the developing device of the present invention. In this example, the configuration shown in FIG. 3 is provided, and the gap Gp between the second doctor blade 7 and the surface of the developing sleeve 4 is set to 0.5 to 2.0 mm. By setting the gap Gp to 0.5 mm or more, the carrier 3a
Thus, it is possible to prevent the aggregates of the toner 3b from being clogged there and to uniformly and smoothly take in the toner 3b throughout the axial direction of the developing sleeve. Further, by controlling the gap Gp to 2.0 mm or less, when the toner coverage of the carrier 3a becomes 80 to 100%, the moving speed of the developer 3 at the toner take-in position becomes exactly 0 to 10 mm / s.
It is stable within the range of ec, and can stop taking in the toner 3b. According to this modification, the incorporation of the toner 3b into the developer 3 is precisely controlled over the entire area in the axial direction of the developing sleeve, and a good image without image density unevenness can be formed.

[0033]

According to the first aspect of the present invention, the amount of toner taken into the developer can be automatically controlled in accordance with the toner coverage of the carrier, so that the amount of toner taken into the developer can be precisely controlled. There is an excellent effect that a good image free from image density unevenness can be formed by controlling.

According to the second aspect of the present invention, when it is not necessary to take in the toner into the developer, the taking of the toner can be stopped accurately. There is an excellent effect that a good image free of the like can be formed.

According to the developing device of the third aspect, there is an excellent effect that a good image without image density unevenness can be formed by precisely controlling the taking-in of toner into the developer. Further, since it is possible to prevent the toner from directly adhering to the surface of the developer carrying member, there is an excellent effect that it is possible to prevent background contamination on the image at the toner adhering portion.

According to the developing device of the fourth aspect, there is an excellent effect that a good image without image density unevenness can be formed by precisely controlling the intake of the toner into the developer.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a main part of an image forming apparatus according to an embodiment.

FIGS. 2A to 2C are diagrams illustrating behavior of a developer.

FIG. 3 is a partially enlarged view of a developing device according to a characteristic portion of the present invention.

FIG. 4 is a partially enlarged view of a developing device according to a first modified example of the developing device of the present invention.

FIG. 5 is a partially enlarged view of a developing device according to a second modified example of the developing device of the present invention.

[Explanation of symbols]

 Reference Signs List 1 photosensitive drum 2 developing device 3 developer 3a magnetic carrier 3b toner 4 developing sleeve 5 magnet roller 6 first doctor blade 7 second doctor blade 8 toner hopper 11 developer accommodating member 20 toner supply opening A developer accommodating section A

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hideo Yoshizawa 1-3-6 Nakamagome, Ota-ku, Tokyo Stock inside Ricoh Company (72) Inventor Shinji Tamaki 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Inside Ricoh Company (72) Inventor Masayuki Yamane 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Tsuyoshi Imamura 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh F Terms (reference) 2H077 AB04 AB07 AD02 AD06 AD13 AD18 AD32 AE06 DA16 DA35 EA03

Claims (4)

[Claims] A developer carrying member having a magnetic field generating means therein for carrying and transporting a two-component developer including a toner and a magnetic carrier; and a developer carrying member carried and carried by the developer carrying member. A first regulating member for regulating the amount of the developer, a developer accommodating portion for accommodating the developer scraped off by the first regulating member, and a developer carrier adjacent to the developer accommodating portion; A toner container having a toner supply opening for supplying toner to the developer carrier, and by changing the toner concentration of the developer on the developer carrier, changing the contact state between the developer and the toner, A developing device for changing a toner take-in state of a developer on the developer carrier, wherein the developer accommodating portion is located upstream of a first regulating member in a transport direction of the developer on the developer carrier. A predetermined distance from the surface of the developer carrier The distance between the second regulating member and the surface of the developer carrying member is set such that the toner coverage of the carrier in the developer in the developer accommodating portion is 80 to 100. %, Wherein the setting of the percentage of the toner in the developer stops. 2. The developing device according to claim 1, wherein the distance between the second regulating member and the developer carrier is set so that the toner coverage of the carrier in the developer in the developer accommodating portion is 80 to 100%. In this case, the moving speed of the developer is 0
A developing device characterized in that it is set so as to regulate the passage of the developer at a position of 10 mm / sec to 10 mm / sec. 3. The developing device according to claim 1, wherein a position of the second restricting member where the passage of the developer in the developer conveying direction is regulated is 5 mT or less in a direction normal to the surface of the developer carrier. A developing device set at a predetermined position. 4. The developing device according to claim 1, wherein an interval between the second regulating member and the surface of the developer carrier is set to 0.5 to 2.0 mm. Developing device.