JP2001075364A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a stain on a formed image and soiling the inside of a device owing to the scattering of toner by restraining the toner from directly sticking on the developer carrier by preventing the toner from flowing out from the toner replenishing open part when a developing device is newly installed in a developing device capable of self controlling the toner density and the image forming device provided with the developing device. SOLUTION: An opening/closing member (shutter) 20 for opening and closing the toner replenishing open part 10 in interlock with the attaching/detaching work of the developing device 2 to/from the image forming device main body is provided. When the developing device 2 is not attached to the image forming device main body, the toner is prevented from flowing out from the open part 10 even when vibration is applied during transport or at the attaching/detaching to/from the image forming device, since the toner replenishing open part 10 is closed by opening/closing member 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer and a facsimile, and a developing device used in the image forming apparatus. More specifically, the present invention relates to a two-component developer containing toner and magnetic particles. A developing device that self-controls the toner concentration by changing the state of the toner taken into the developer based on the change in the toner concentration of the developer on the developer carrier, and taking in the toner by the movement of the developer; and And an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as a developing device of this type, the amount of a two-component developer carried and conveyed by a developer carrier having a magnetic field generating means disposed therein is regulated by a developer regulating member.
A developing device that accommodates a regulated developer in a developer accommodating portion and replenishes toner from a toner accommodating portion adjacent to the developer accommodating portion to the developer on the developer carrying member through a toner replenishing opening. Therefore, a developing device that changes the contact state between the developer and the toner by changing the toner concentration of the developer on the developer carrier to change the state of taking in the toner into the developer is known. (See, for example,
22178). In particular, the publication discloses that in such a developing device, a magnetic toner is used as a toner constituting a developer, and a toner replenishment is carried out substantially from a center between a toner regulating opening of the developer accommodating portion and a regulating position by a developer regulating member. There has been proposed one that regulates the density of the developer in a region up to the opening for use.

In this type of developing device, when the toner is supplied to the developer on the developer carrier and the toner concentration increases, the filling rate of the developer in the developer accommodating portion increases, and The transport resistance applied by the developer in the developer accommodating section to the developer increases, and the developer in the developer accommodating section hardly moves. Stops. Conversely, when the toner is consumed and the toner concentration decreases, the filling rate of the developer in the developer accommodating portion decreases, and the developer becomes easy to move. It becomes incorporated into the agent. The toner taken in the developer is carried by the developer carrier, and is conveyed to a development area of the image forming apparatus, which is a portion facing the latent image carrier, and is used for development. As described above, the toner concentration self-control mechanism controls the taking-in of the toner by the movement of the developer and keeps the toner concentration constant at all times.

According to this type of developing device, the toner can be automatically replenished directly to the developer on the developer carrier by the bulk of the developer which changes according to the toner concentration.
This eliminates the need for a toner density sensor and simplifies the toner supply device. Further, compared to the conventional two-component developing method, the number of magnetic carriers can be reduced, and the torque of the apparatus can be greatly reduced. For these reasons, the means for detecting and adjusting the mixture ratio of toner and magnetic carrier has been simplified,
There is an advantage that a stirring member such as a screw can be omitted, and the size and cost of the apparatus can be reduced. Further, since the distance between the toner supply port and the developer carrying member is short, there is an advantage that the toner replenishing property with respect to toner consumption is excellent and the black solid followability is good.

On the other hand, this type of developing device is configured to be detachable from the image forming apparatus main body as a single developing device or as a process unit in which the developing device and other components are unitized. It is known that the developing device is replaced with a new one at the time of deterioration or the like.

However, in a developing device that controls the toner concentration by itself, as described above, a toner supply opening for supplying toner to the developer on the developer carrying member is formed in the toner storage section. Vibration during transportation of the developing device or when the developing device is attached to the image forming apparatus may cause toner to flow out of the opening. When the developing device is new, the developer is not carried on the developer carrier, so when the toner flows out of the toner supply opening toward the developer carrier, the toner adheres directly to the surface of the developer carrier. There is a risk of doing it. Then, when the toner is directly adhered, the toner density in that portion becomes 100%, so that it is not possible to control the toner density to an appropriate level, and a problem such as background stain occurs in the formed image. Further, if the toner directly adheres to a part of the circumferential direction of the developer carrying member, periodic image unevenness occurs with the rotation of the developer carrying member. Further, it is considered that the apparent toner concentration of the developer on the developer carrier becomes an appropriate value by directly attaching the toner and further attaching the developer to the attached portion.
Since the high-resistance toner layer is formed on the surface of the developer carrying member, the electric field in the effective developing area is increased, which also causes a problem such as background contamination. Further, in a state where the developer is not carried on the developer carrier, there is a gap near the developer carrier because the developer is not carried. If the toner flows out vigorously, there is also a problem that the toner is scattered in the gap to contaminate the inside of the apparatus.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object the following:
When the developing device is new, preventing toner from flowing out of the toner supply opening prevents toner from directly adhering to the developer carrying member, thereby contaminating the inside of the device due to background contamination of the formed image and toner scattering. It is an object of the present invention to provide a developing device and an image forming apparatus which can prevent such a problem.

[0008]

According to a first aspect of the present invention, there is provided a magnetic recording medium having a magnetic field generating means therein for carrying and transporting a two-component developer containing a toner and a magnetic carrier. A developer carrying member, a developer regulating member that regulates an amount of the developer carried and conveyed by the developer carrying member, and a developer accommodating portion that accommodates the developer scraped by the regulating member. And a toner container having a toner supply opening adjacent to the developer container and for supplying toner to the developer on the developer carrier, and a change in toner concentration of the developer carrier, In a developing device that changes a contact state between the developer and the toner in the toner storage unit to change a state of taking in the toner into the developer, the developing device is linked to an attaching / detaching operation of the developing device to / from the image forming apparatus main body. Opening and closing member for opening and closing the toner supply opening It is characterized in that provided.

Here, the attachment / detachment to / from the image forming apparatus main body is not limited to the case where the developing apparatus is attached / detached alone,
This includes the case where the developing device and other components are attached and detached as a unitized process unit.

In this developing device, an opening / closing member for opening / closing the toner supply opening is provided so as to open / close the toner supply opening in conjunction with the attaching / detaching operation of the developing device to / from the image forming apparatus main body. Accordingly, in a state in which the developing device is not mounted on the image forming apparatus main body, the toner supply opening is closed by the opening / closing member even if the developing device is subjected to vibration during transportation or attachment / detachment to the image forming apparatus. This prevents the toner from flowing out of the opening. Therefore, when the developing device is replaced with a new one, toner can be prevented from directly adhering to the developer carrying member, so that background contamination of the formed image and contamination inside the device due to toner scattering can be prevented.

According to a second aspect of the present invention, in the developing device of the first aspect, the developer carrier is configured to rotate in conjunction with the mounting operation of the developing device to the image forming apparatus main body. Is what you do.

In this developing device, the developer carrier is rotated while the developing device is mounted on the image forming apparatus main body,
A developer carrying member is loaded with a starting agent composed of only a carrier.

According to a third aspect of the present invention, in the developing device of the second aspect, the rotation angle is 360 ° or more.

In this developing device, the developer carrier is rotated by 360 ° or more, and a start agent consisting of only a carrier is carried on the entire periphery of the developer carrier.

According to a fourth aspect of the present invention, in the developing device of the second or third aspect, the toner supply opening is opened after the rotation of the developer carrier is completed. Is what you do.

In this developing device, the rotation of the developer carrier is completed, and the toner replenishing opening is opened in a state where the developer carrier carries the starting agent consisting of only the carrier.

According to a fifth aspect of the present invention, there is provided an image forming apparatus for forming an image by developing a latent image formed on a latent image carrier using a developing device.
A third or fourth developing device is used.

In this image forming apparatus,
By using the developing device of 2, 3, or 4, the toner does not flow out of the toner supply opening when the developing device is replaced with a new developing device. Can be prevented from being soiled on the formed image due to direct adhesion of toner and the inside of the apparatus due to toner scattering.

According to a sixth aspect of the present invention, in the image forming apparatus of the fifth aspect, a guide rail for guiding the opening / closing member is provided in the image forming apparatus main body, and is linked with the mounting operation of the developing device to the image forming apparatus. The opening / closing member is guided by a guide rail, so that the opening / closing member is moved in a direction to open the toner supply opening.

In this image forming apparatus, the opening / closing member is guided by the guide rail provided in the image forming apparatus during the mounting on the image forming apparatus main body.
It moves in a direction to open the toner supply opening. here,
The opening / closing member opens the toner supply opening with a simple configuration and operation in which the opening / closing member is guided by a guide rail provided on the image forming apparatus main body in conjunction with the mounting operation to the image forming apparatus. In comparison with the case where toner is provided, the outflow of toner can be prevented at a small space and at low cost.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a developing device used in an electrophotographic image forming apparatus will be described below. FIG. 1 is a schematic configuration diagram illustrating a state in which a developing device according to an embodiment of the present invention is mounted on an image forming apparatus main body. A developing device 2 disposed on the side of the photosensitive drum 1 serving as a latent image carrier carries on its surface a two-component developer (hereinafter referred to as "developer") 3 containing a toner 3b and a magnetic carrier 3a. A developing sleeve 4 as a developer carrier, a magnet roller (not shown) composed of a group of fixed magnets as a magnetic field generating means fixedly disposed inside the developing sleeve 4, and a developer 3 carried and conveyed on the developing sleeve 4 A doctor 6 as a developer regulating member for regulating the amount, an eaves member 7 provided above the developing sleeve 4 so as to form a developer accommodating portion A between the surface of the sleeve and the doctor 6, and a toner. A toner hopper 8 and the like as a storage unit are provided. The toner hopper 8 has a toner supply port 8a adjacent to the upstream side of the developer accommodating portion A in the developer conveying direction on the developing sleeve 4 and facing the surface of the developing sleeve. Further, inside the toner hopper 8, there is provided a toner agitator 9 as a stirring member for sending out the toner 3a while stirring it toward the toner supply port 8a.

The tip of the eaves member 7 close to the developing sleeve 4 is regulated on the toner replenishing side which regulates the amount of developer to which toner is replenished from the toner hopper 8 and travels toward the developer accommodating portion A. It is a predoctor 7a as a member. Further, the developer accommodating portion A formed by the eaves member 7 or the like accommodates the developer that is not supplied to the developing position of the portion facing the photosensitive drum 1 but is prevented from proceeding by the doctor 6. Magnetic poles are formed on the magnet roller so that a magnetic force of a magnetic field reaches the developer accommodating portion A.

FIG. 2 is a perspective view of the developing device 2. The drive gear 40 receives drive from a drive source (not shown) provided on the image forming apparatus main body side, and rotates the toner agitator 9 in the direction of arrow C. The drive of the drive gear 40 causes the sleeve rotation gear 43 to rotate in the direction of arrow B via the idle gears 41 and 42. That is, the developing sleeve 4 is also rotated in conjunction with the rotation of the toner agitator 9.

The developing device 2 according to the present embodiment can be divided into a developing unit 2a and a toner storage unit 2b, as shown in FIG. The developing unit 2a includes a developing sleeve 4, a doctor 6, and an eaves member 7.
And the like, and the toner storage unit 2b includes a toner hopper 8 and the like. When the two units are combined, the toner supply openings formed in the respective units communicate with each other at the combined position, and the toner supply opening 10 is formed as shown in FIG. (See FIG. 1). Further, a shutter 20 as an opening / closing member that opens and closes the toner supply opening 10 is provided in the toner supply opening on the side of the developing unit 2a in conjunction with the attaching / detaching operation of the developing device 2 to / from the image forming apparatus main body. I have. The developing device 2 shown in FIG. 1 is mounted on the main body of the image forming apparatus, and the shutter 20 slides to the upper retreat position to open the opening 10. The opening / closing mechanism of the shutter 20 and the attaching / detaching operation of the developing device 2 to / from the image forming apparatus main body will be described later in detail.

In the developing device having the above structure, the developer 3 on the developing sleeve 4 is conveyed with the rotation of the sleeve 4 in the direction of arrow B, and is regulated by the doctor 6 to be thinned. In the present embodiment, the toner 3b is
Using a magnetic toner having a particle size of 4 to 15 μm and a low-resistance carrier having a particle size of 20 to 50 μm as a magnetic carrier 3 a,
The toner coverage of the carrier 3a in the developer 3 in the developer accommodating section A is set to about 100%. The thinned developer 3 is conveyed to a developing position facing the photosensitive drum 1 rotating in the direction of arrow C. At this developing position, toner is supplied to the electrostatic latent image formed on the photosensitive drum 1, and the electrostatic latent image is visualized. The developer on the developing sleeve 4 that has passed the developing position is further transported with the rotation of the sleeve 4 and is supplied to the toner supply opening 10.
It reaches the position facing a. This toner supply opening 1
0, the toner 3a in the toner hopper 8
And stays in contact with the developer on the developing sleeve 4. The developer 3 returns to the developer accommodating section A after taking in new toner 3a at a contact portion between the toner 3a and the developer in the developer accommodating section A. Then, the internal pressure of the developer 3 containing the new toner 3a increases in the regulating section by the doctor 6. The toner is charged by the carrier in the developer having the increased internal pressure. On the other hand, a part of the developer 3, which is not supplied to the developing position and is prevented from moving by the doctor 6, is supplied to the toner supply opening 10 of the toner hopper 8 by the internal pressure and gravity of the developer 3 in the developer accommodating section A. Move towards. The developer 3 having moved to the vicinity of the toner supply opening 10 is rotated by the doctor 6
Transported to circulate to the side.

In the developing device having the above structure, while the toner concentration in the developer is low, the toner 3b is taken in from a short distance from the surface of the developing sleeve 4, and the developer 3b at this position is taken. Movement speed is high, toner 3
b is actively taken up. When the amount of toner incorporated in the developer 3 increases and the toner concentration increases, the bulk of the developer 3 increases accordingly, so that the developer 3 stays in the toner supply port 8a and the toner supply opening 10 is closed. I will cover it. 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, and the developer 3 does not block the toner supply opening 10. The toner is taken in, and the toner density of the developer 3 is always maintained at a certain level or more. Since the toner density can be controlled within a substantially constant range in this manner, 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.

Next, the opening / closing mechanism of the shutter 20, which is a feature of the present embodiment, will be described. In the developing device of the present embodiment, as shown in FIG. 3 described above, the shutter 20 has support portions 20 a formed at both ends thereof, and the support portion 20 a is urged downward by a spring 30. The toner supply opening on the side of the developing unit 2a is always closed. FIGS. 4 and 5 show the state of the toner supply opening 10 when the developing unit 2a and the toner storage unit 2b are combined in this state. As illustrated, the shutter 20 closes the toner supply opening 10 before being mounted on the image forming apparatus main body. In FIG. 5, in order to make the configuration of the shutter 20 easy to understand, FIG.
All the gear groups indicated by are omitted.

Further, in the developing device of the present embodiment,
As shown in FIG. 4, a developing device support portion 12 for supporting the developing device 2 is formed in the developing unit 2a and the toner storage unit 2b. On the other hand, as shown in FIG. 6, guide rails 110 and 120 are provided on both side plates of the image forming apparatus 100 main body. Then, the developing device support portion 12 of the developing device 2 is
The developing device 2 is configured to be detachable from the main body of the image forming apparatus 100 by sliding the developing device 2 in the direction of arrow D while supporting the shutter supporting portions 20a with the guide rails 120, respectively. A bent portion 120a is formed on the guide rail 120 that guides the shutter support portion 20a on the back side of the image forming apparatus 100, the bent portion 120a being gradually bent upward toward the back side.

When the developing device 2 is new, as shown in FIG. 4, a start agent consisting only of the carrier 3a is stored in a start agent storage portion B, and the start agent storage portion B and the developer storage portion A A seal member 50a is provided therebetween. Further, a seal member 50b is also provided at the toner supply opening of the toner hopper 8.

The developing device 2 having the above configuration is connected to the image forming apparatus 10.
The operation at the time of mounting on the main body will be described. First, immediately before mounting, the sealant 50a of the start agent is peeled off, and the start agent is set in the developer accommodating portion A. The upstream side of the doctor 6 in the developer conveyance direction and the downstream side of the pre-doctor 7a in the developer conveyance direction. Is magnetically attached to the surface of the developing sleeve 4. Next, the seal member 50b of the toner hopper 8 is peeled off.

In this state, the developing device 2 is connected to the image forming device 1
When mounted on the main body, the shutter support portion 20a guided by the guide rail 120 becomes the bent portion 120a on the back side.
After reaching, the shutter 20 slides upward against the urging force of the spring 30 upward. As a result, the toner supply opening 10 closed by the shutter 20 is opened. When the developing device 2 is detached from the main body of the image forming apparatus 100, the shutter 20 is slid downward by the urging force of the spring 30 and the like, and the toner supply opening 10 is closed. Is done. The spring 3
Instead of providing 0, the toner supply opening may be closed using the weight of the shutter 20.

As described above, according to the present embodiment, the shutter 2
0 is provided so as to open and close the toner supply opening 20 in conjunction with the attachment / detachment operation of the developing device 2 to / from the image forming apparatus 100 main body.
In a state where the shutter 20 is not attached to the main body, the shutter 20 is not affected even when being subjected to vibration during transportation or attachment / detachment to the image forming apparatus 100.
The opening 20 is closed by the
0 can be prevented from flowing out of the toner. As a result, when the developing device 2 is new, the toner 3b is prevented from directly adhering to the developing sleeve 4, and contamination of the inside of the device due to background contamination of the formed image and toner scattering can be prevented. In addition, the guide rail 120 is provided on the image forming apparatus main body side.
Is provided, and the toner supply opening 20 is opened with a simple configuration and operation of guiding the shutter 20 in conjunction with the mounting operation to the image forming apparatus. Therefore, compared to the case where a complicated opening / closing mechanism is provided, space saving is achieved. The outflow of toner can be prevented at low cost.

FIG. 7 is a partially enlarged view of a developing device according to a modification of the developing device of the present invention. In this example, FIG.
5 to the drive gear 40.
Are provided with a plurality of projections 40a. As shown in FIG. 8, a plurality of protrusions 1 are also provided on the slide path of the protrusions 40a above the guide rail 120 of the image forming apparatus 100 main body.
30 are provided. In this modification, the developing device 2
The projection 40a and the projection 1
As the gear 30 meshes with a gear, the drive gear 40 rotates in the direction of arrow C, and the developing sleeve 4 rotates in the direction of arrow B, which is the same as during development. Further, the protrusion 130 is disposed on the near side in the mounting direction with respect to the bent portion 120a of the guide rail 120 so that the upward movement of the shutter 20 is started after the rotation of the developing sleeve 4 is completed. According to this modification, since the developing sleeve 4 rotates in conjunction with the mounting operation of the developing device 2, the starting agent consisting of only the carrier 22a can be carried on the sleeve 4, and the rotation of the developing sleeve 4 After the completion of the operation, the opening of the toner supply opening 10 is started, so that the toner 3b can be more reliably prevented from directly adhering to the developing sleeve 4. The developing sleeve 4
Is rotated when the toner supply opening 10 is opened.
It is sufficient to rotate the developing sleeve 22a so that at least a portion of the developing sleeve 22a facing the opening 10 carries the carrier 22a. It is more preferable that the starting agent is securely carried over the entire surface. The rotation angle of the developing sleeve 4 can be adjusted by adjusting the interval between the projections 40a and the projections 130.

In the above embodiment, the case where the developing device 2 is detachably attached to the main body of the image forming apparatus 100 has been described, but the developing device 2 and other components are unitized as a process unit. The same can be applied to a case in which is attached and detached.

[0035]

According to the first to third aspects of the present invention, when the developing device is new, the toner is prevented from flowing out of the toner supply opening, thereby preventing the toner from directly adhering to the developer carrying member. As a result, there is an excellent effect that contamination of the inside of the apparatus due to background contamination of the formed image and scattering of toner can be prevented.

In particular, according to the second to fourth aspects of the present invention, there is an excellent effect that the toner can be more reliably prevented from directly adhering to the developer carrying member.

According to the fifth and sixth aspects of the present invention, there is an excellent effect that an image can be formed without a background stain and the inside of the apparatus can be prevented from being scattered by scattered toner.

In particular, according to the invention of claim 6, there is an excellent effect that the outflow of toner can be prevented at a small space and at low cost as compared with the case where a complicated opening / closing mechanism is provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a state in which a developing device according to an embodiment is mounted on an image forming apparatus.

FIG. 2 is a perspective view of the developing device.

FIG. 3 is a perspective view illustrating a divided state of the developing device.

FIG. 4 is an explanatory diagram showing a state before the developing device is mounted on an image forming apparatus.

FIG. 5 is a perspective view of a developing device for explaining a characteristic portion of the present invention.

FIG. 6 is a perspective view of the image forming apparatus according to the embodiment.

FIG. 7 is a perspective view of a developing device according to a modification.

FIG. 8 is a perspective view of an image forming apparatus according to a modification.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor drum 2 developing device 2a developing unit 2b toner storage unit 3 developer 3a magnetic carrier 3b toner 4 developing sleeve 4a rotation bearing 6 doctor 7 eaves member 7a predoctor 8 toner hopper 9 toner agitator 10 toner replenishing opening 12 developing device Supporting part 15 Start agent accommodating part 20 Shutter 20a Shutter supporting part 30 Spring 40 Drive gear 40a Projection 41, 42 Idle gear 43 Sleeve rotating gear 50a Seal member (for start agent) 50b Seal member (for toner) 100 Image forming apparatus 110 Guide Rail (for supporting the developing device) 120 Guide rail (for supporting the shutter) 120a Bent portion 130 Projection

 ──────────────────────────────────────────────────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 Junichi Terai 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Kazuhisa Sudo 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company ( 72) Inventor Masayuki Yamane 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Shinichi Kawahara 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Tsuyoshi Imamura 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Company (reference) 2H077 AA14 AA18 AD06 AD13 AD18 BA09 CA11 DA10 DB02 EA03 FA19

Claims (6)

[Claims] 1. A developer carrier having a magnetic field generating means therein for carrying and transporting a two-component developer containing a toner and a magnetic carrier, and a developer carrier carried and transported by the developer carrier. A developer regulating member for regulating the amount of the developer, a developer accommodating portion for accommodating the developer scraped off by the regulating member, and a developer accommodating portion adjacent to the developer accommodating portion and on the developer carrying member. A toner container having a toner replenishing opening for replenishing toner to the developer, and changing the contact state between the developer and the toner in the toner container by changing the toner concentration of the developing carrier, In the developing device for changing the state of taking in the toner into the developer, interlocking with the attaching / detaching operation of the developing device to / from the image forming apparatus main body,
A developing device provided with an opening and closing member for opening and closing the toner supply opening. 2. The developing device according to claim 1, wherein the developing device is mounted on the image forming apparatus main body in an interlocking manner.
A developing device, wherein the developer carrier is configured to rotate. 3. The developing device according to claim 2, wherein said angle of rotation is 360 ° or more. 4. The developing device according to claim 2, wherein the toner supply opening is opened after the rotation of the developer carrier is completed. 5. An image forming apparatus for forming an image by developing a latent image formed on a latent image carrier using a developing device, wherein the developing device according to claim 1, 2, 3, or 4 is used as the developing device. An image forming apparatus using: 6. The image forming apparatus according to claim 5, wherein a guide rail for guiding the opening and closing member is provided in the image forming apparatus main body, and the opening and closing member is guided in conjunction with the mounting operation of the developing device to the image forming apparatus. An image forming apparatus, wherein an opening / closing member is moved in a direction to open the toner supply opening by guiding with a rail.