JP2014102283A - Developing device, process cartridge, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To circulate a toner between toner storage chambers storing toner to suppress the occurrence of a reduction in image density.SOLUTION: A developing device 4 includes a toner storage chamber 40a, a toner storage chamber 40b, and a developing chamber 40c. The toner storage chamber 40a and the toner storage chamber 40b has a partition wall 45 provided therebetween; and the partition wall 45 is provided with a first opening 46 through which a toner can pass from the toner storage chamber 40b to the toner storage chamber 40a, the toner moving in a direction from the toner storage chamber 40b toward the toner storage chamber 40a in association with the rotation of a conveying member 44, and a second opening 47 through which a toner can pass from the toner storage chamber 40a to the toner storage chamber 40b, the toner moving in a direction from the toner storage chamber 40a toward the toner storage chamber 40b in association with the rotation of a conveying member 43.

Description

  The present invention relates to a developing device, a process cartridge including the developing device, and an image forming apparatus including the developing device.

2. Description of the Related Art Conventionally, in a developing device, in order to suppress the aggregation of a developer accommodated in a developer accommodating chamber, an agitation unit that agitates the developer is provided in the developer accommodating chamber. For example, Patent Document 1 discloses an agitation unit that includes an agitation shaft and a flexible agitation sheet, and agitates the developer in the developer storage chamber by rotating the agitation sheet as the agitation shaft rotates. ing.
FIG. 5 is a schematic view showing the developer storage chamber 40 and the stirring means 43 in the conventional developing device 4, and is a cross-sectional view when viewed from above in the vertical direction. Here, in FIG. 5, only the developer accommodating chamber 40, the stirring means 43, and the developing sleeve 41 as the developer carrying member are shown for easy understanding.
When the agitation shaft 43a is rotated in the direction of arrow D in FIG. 5 by a drive source (not shown), the agitation sheet 43b fixed to the agitation shaft 43a is also rotated accordingly, and the developer in the developer storage chamber 40 is moved to the agitation shaft 43a. On the other hand, it is conveyed in the vertical direction (the direction of arrow α in FIG. 5).
The developer conveyed in the direction of the arrow α by the rotation of the stirring sheet 43 b moves toward the developing sleeve 41 and prepares for development near the developing sleeve 41.
In the developing device 4 having the conventional configuration shown in FIG. 5, even if the circulation of conveying the developer in the developer accommodating chamber 40 toward the developing sleeve 41 by rotating the agitating member 43 is specified, the specific in the developer accommodating chamber 40 is specified. The developer may stay without being circulated at this point. Specifically, when the developer moves in the direction of the developing sleeve 41 by the rotation of the stirring sheet 43b, if there is a wall such as a developing container wall in the form of abutting in the moving direction, the movement of the developer is hindered by the wall. . The developer that hits the developing container wall or the like cannot move any more in the direction of the arrow α and stays at the wall.
Thereafter, a developer conveyed from the rear is further added to the staying developer near the wall, and the amount of the staying developer near the wall increases, but eventually reaches a saturation amount. In FIG. 5, the staying developer at the wall reaches the saturation amount and reaches the steady state, and the staying developer is indicated by β. Thus, the developer staying at the wall and reaching the steady state hardly moves afterwards even if the developing device 4 is continuously used, and stays at the wall in a substantially new state.
On the other hand, the developer other than the developer staying at the wall circulates in the developer accommodating chamber 40 by the rotation of the stirring sheet 43b, and the chargeability changes not a little in the process of repeating the circulation. This is because the developer resin in the developer container 40 is worn or deformed by mechanical rubbing while circulating. Alternatively, the external additive added to the surface is liberated or embedded in the developer resin. As a result, the chargeability of the developer other than the staying developer at the wall in the developer accommodating chamber 40 is different from that of the new one.
That is, if the developing device 4 having the above-described conventional configuration is continuously used, a developer whose charging property has been changed by repeated circulation and a developer that has stayed near the wall in a substantially new state in the developer storage chamber 40. Coexisting state. This means that developers having greatly different charging characteristics coexist in the same developer storage chamber 40. In this state, for example, when a substantially new developer staying near the wall of the developer storage chamber due to vibration caused by an image forming operation or the like is mixed with a developer whose surrounding charging property has changed, developers having different charging properties are mixed with each other. The so-called image density thinning, in which the density is partially reduced by mixing, may occur.

JP 2009-288458 A

In recent years, there has been an increasing number of cases where it is necessary to fill a large amount of developer in the developing device due to a request for improvement in the number of printed sheets. In order to meet such a demand, there is known a developing device provided with a plurality of developer accommodating chambers for accommodating a developer.
When a plurality of developer accommodating chambers are provided, it is difficult for the developer to be exchanged between the developer accommodating chambers, and developers having different charging properties may be mixed. In the developer accommodating chamber that communicates with the developing chamber in which the developer carrying member is provided in the developer containing chamber, the chargeability is likely to change because the developer is rubbed by the regulating member in contact with the developer carrying member, On the other hand, in other developer storage chambers, the chargeability of the developer is unlikely to change.
As described above, when a developer whose chargeability has changed and a substantially new developer whose chargeability has not changed coexist, a so-called image density thinning in which the density is partially reduced occurs as described above. End up.

  Accordingly, an object of the present invention is to suppress the occurrence of thin image density by circulating the developer between developer storage chambers that store the developer.

In order to achieve the above object, the present invention
In a developing device for developing a latent image formed on an image carrier,
A developer carrier;
A developing chamber provided with a regulating member provided in contact with the developer carrying body and regulating a layer thickness of the developer carried on the developer carrying body;
A first developer containing chamber containing developer and communicating with the developing chamber;
A second developer containing chamber containing a developer and communicating with the first developer containing chamber;
A first transport member rotatably provided in the first developer storage chamber and capable of transporting the developer from the first developer storage chamber to the development chamber;
A second conveying member rotatably provided in the second developer accommodating chamber and capable of conveying the developer from the second developer accommodating chamber to the first developer accommodating chamber;
Have
A partition wall is provided between the first developer storage chamber and the second developer storage chamber;
A developer that moves in the direction from the second developer accommodating chamber toward the first developer accommodating chamber by the rotation of the second conveying member is transferred from the second developer accommodating chamber to the first partition member. A first opening that can pass into the developer accommodating chamber, and a developer that moves in a direction from the first developer accommodating chamber toward the second developer accommodating chamber by the rotation of the first conveying member, And a second opening that can pass from the developer accommodating chamber to the second developer accommodating chamber.

  According to another aspect of the invention, a process cartridge that is detachable from the image forming apparatus includes the developing device and an image carrier on which a latent image is formed.

  In addition, the present invention is an image forming apparatus including the developing device and an image carrier on which a latent image is formed.

  According to the present invention, it is possible to suppress the occurrence of thin image density by circulating the developer between developer storage chambers that store the developer.

Schematic sectional view showing an image forming apparatus according to the present embodiment 1 is a schematic cross-sectional view illustrating a developing device according to a first embodiment. Schematic sectional view for explaining toner circulation in the configuration of the conventional example Schematic sectional view showing a developing device according to Embodiment 2. Schematic showing the developer storage chamber and the agitation means in the conventional developing device

(Image forming apparatus according to this embodiment)
First, an image forming apparatus 100 such as a laser beam printer according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view illustrating an image forming apparatus according to the present embodiment. As shown in FIG. 1, an image forming apparatus 100 includes an electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) 1 as a drum-shaped image carrier, a charging roller 2 as a charging device, an exposure device 3, a developing device 4, and a transfer device. A roller 5, a cleaning device 6, a fixing device 7, and a paper feeding device 8 are provided. In this embodiment, the photosensitive drum 1 is provided to be rotatable in the direction of arrow A in FIG. In this embodiment, the process speed, that is, the peripheral speed of the photosensitive drum 1 is set to 240 mm / sec. Further, magnetic toner was used as the developer.

  Hereinafter, an outline of an image forming operation by the image forming apparatus 100 will be described. First, the surface of the photosensitive drum 1 is uniformly electrostatically charged by the charging roller 2. Then, the exposure device 3 irradiates the charged surface of the photosensitive drum 1 with laser light corresponding to the image information. The charged charge is canceled at the portion of the surface of the photosensitive drum 1 irradiated with the laser beam, and an electrostatic latent image is formed on the photosensitive drum 1.

  Then, the electrostatic latent image is developed by the developing device 4, and a toner image as a developer image is formed on the photosensitive drum 1 (on the image carrier). Further, in synchronization with the formation of the toner image, the transfer material P such as paper is transported from the paper feeding device 8, and a voltage having a polarity opposite to the toner charging polarity is applied to the transfer roller 5. The toner image thus transferred is transferred onto the transfer material P.

  Thereafter, the transfer material P onto which the toner image has been transferred is conveyed to the fixing device 7 and the toner image is fixed to the transfer material P by heat and pressure. On the other hand, when the transfer from the photosensitive drum 1 to the transfer material P is performed, the toner remaining on the photosensitive drum 1 is scraped (removed) by a cleaning blade 60 as a cleaning member provided in the cleaning device 6 and is discarded. The toner is stored in the waste toner storage chamber 61 as toner. Such a cleaning operation allows the photosensitive drum 1 to continue to form an image.

(Configuration of Developing Device According to Example 1)
Next, the developing device according to the first embodiment will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view illustrating the developing device according to the first embodiment. The developing device 4 is not limited to the configuration provided in the image forming apparatus 100, and may be provided in a process cartridge that can be attached to and detached from the image forming apparatus 100 integrally with the photosensitive drum 1, the charging roller 2, and the cleaning device 6. .

  The developing device 4 according to the first embodiment includes a toner storage chamber 40a as a first developer storage chamber for storing toner, a toner storage chamber 40b as a second developer storage chamber for storing toner, and development for developing. A chamber 40c is provided. The developing chamber 40c and the toner storage chamber 40a communicate with each other, and the toner storage chamber 40a and the toner storage chamber 40b communicate with each other.

In the developing chamber 40c, a developing sleeve 41 as a developer carrying member and a regulating blade 42 as a regulating member for regulating the toner layer thickness on the developing sleeve 41 (on the developer carrying member) are provided. Further, in the toner storage chamber 40a (first developer storage chamber), a first transport member capable of circulating toner between the development chamber 40c and the toner storage chamber 40a (between the first developer storage chamber). The stirring member 43 is rotatably provided in the direction of arrow D in FIG. In the toner storage chamber 40b (second developer storage chamber), a stirring member 44 as a second transport member capable of transporting toner from the toner storage chamber 40b to the toner storage chamber 40a is rotatable in the direction of arrow D in FIG. Is provided.

  The developing chamber 40 c is provided with a developing opening for supplying the toner in the toner storage chamber 40 to the photosensitive drum 1. The developing sleeve 41 is provided with a developing opening with a part of the surface exposed to the inside of the developing chamber 40c.

  The developing sleeve 41 that can carry the toner on the surface is a non-magnetic sleeve composed of a pipe such as aluminum or stainless steel, and the surface is processed to an appropriate roughness so that a desired amount of toner T can be conveyed. Yes. The developing sleeve 41 is rotatably provided in the direction of arrow C in FIGS. 1 and 2 and has a peripheral speed of 280 mm / sec. Further, the developing sleeve 41 has a magnet roller (not shown) in which a plurality of polarities are arranged.

  The regulating blade 42 is configured by fixing an elastic member 42a such as urethane rubber or silicone rubber to the support metal plate 42b, and is in contact with the developing sleeve 41 with a predetermined pressure. The toner T attracted to the developing sleeve 41 by the magnetic force of the magnet roller is frictionally charged and the layer thickness is regulated between the developing sleeve 41 and the regulating blade 42, and an appropriate charge is given.

  Here, although the stirring member 43 and the stirring member 44 are demonstrated, since those structures are the same, detailed description of a structure is performed only about the stirring member 43. FIG. The stirring member 43 includes a rotating shaft 43a whose both ends are pivotally supported by the side wall of the toner storage chamber 40a, and a stirring portion 43b provided on the rotating shaft 43a. Then, as the rotating shaft 43a rotates, the agitating portion 43b agitates the toner accommodated in the toner accommodating chamber 40a and conveys the toner toward the developing opening in order to carry the toner on the developing sleeve 41. The stirring unit 43b is a flexible sheet-like member, and for example, a resin such as PET (polyethylene terephthalate) can be used. The sheet-like stirring portion 43b is devised so that the toner in the lower portion of the toner storage chamber 40a can be reliably conveyed by being provided to slide and rotate in the lower portion of the toner storage chamber 40a. Further, a resin such as polyacetal can be used for the rotating shaft 43a. The rotation speed of the stirring member 43 of this embodiment is 60 rpm.

(Toner circulation)
Next, toner circulation will be described with reference to FIG. FIG. 3A to FIG. 3C are schematic cross-sectional views for explaining toner circulation in the configuration of the conventional example.

  The toner in the toner storage chamber 40b far from the development chamber 40c is conveyed to the toner storage chamber 40a near the development chamber 40c by the rotation of the stirring member 44. The agitating portion 44b of the agitating member 44 is a flexible sheet member and slides below the toner accommodating chamber 40b, so that the toner below the toner accommodating chamber 40b can be reliably conveyed to the toner accommodating chamber 40a. When there is sufficient toner in the toner storage chamber 40a, the toner conveyed by the stirring member 44 is scooped up and circulated in the toner storage chamber 40b.

The toner in the toner storage chamber 40a close to the developing chamber 40c is conveyed to the developing chamber 40c by the rotation of the stirring member 43. Similarly to the agitating member 44, the agitating portion 43b of the agitating member 43 is a flexible sheet member and slides at the lower part of the toner accommodating chamber 40a. 40c can be conveyed. Further, the toner storage chamber 40a and the developing chamber 40c are switched regardless of the amount of toner, that is, circulation is actively performed. In order to reliably circulate the toner between the developing chamber 40c and the toner storage chamber 40a, when the stirring member 43 rotates, the tip of the stirring portion 43b enters the inside of the developing chamber 40c. May be.

  The toner storage chamber 40 is configured so that the amount of toner necessary for image formation is surely present in the development chamber 40c. In some cases, as shown in FIG. In some cases, the toner may be unevenly present.

  Conventionally, as shown in FIG. 3C, a partition wall 45 having an opening in the vertical direction is provided between the toner storage chamber 40a and the toner storage chamber 40b, and the toner storage chamber 40b is transferred to the toner storage chamber 40a. A configuration that regulates the amount of toner conveyed was employed. With such a configuration, it is possible to prevent the toner from being biased to the developing chamber 40c side.

  Further, when the circulation of the toner was confirmed with the configuration shown in FIG. 3A, when sufficient toner is present, the toner is circulated in the toner storage chambers 40a and 40b, but the toner storage chamber 40a and the toner It was found that there was almost no replacement between the storage chambers 40b. Further, even when the toner is decreased, the state as shown in FIG. 3B continues, and the toner is not actively exchanged between the toner storage chamber 40a and the toner storage chamber 40b. I understood.

  Further, even in the configuration in which the partition wall 45 and the opening shown in FIG. 3C are provided, the deviation of the toner is improved, but the toner replacement between the toner storage chamber 40a and the toner storage chamber 40b is still performed. I found that there was almost no.

(Experiment on density change in conventional developing device)
Here, an experiment was conducted on the density change accompanying the toner circulation in the conventional configuration shown in FIG. The toner storage chambers 40a and 40b are filled with toner so as to be filled up to the vicinity of the stirring shafts 43a and 44a of the stirring members 43 and 44. At this time, the weight of the toner was about 1 kg. Then, the developing device 4 filled with the toner was mounted on the main body of the image forming apparatus 100, and the non-sheet-passing idle rotation operation was performed. As described above, the reason why the non-sheet-passing idle rotation operation is performed is that the toner on the developing sleeve 41 is rubbed by the regulating blade 42 by rotating the stirring members 43 and 44 without consuming the toner. This is to change sex. This non-sheet-passing idle rotation operation was performed for about 24 hours so that the change in the charging property of the toner became apparent.

  Since the circulation is actively performed between the developing chamber 40c and the toner storage chamber 40a, the chargeability of the toner in the developing chamber 40c and the toner in the toner storage chamber 40a changes to the same extent.

  After idling without paper passing for about 24 hours, 50 g each of the toner in the toner storage chamber 40a and the toner in the toner storage chamber 40b are collected. The collected toner is mixed and filled in the empty developing device 4 again to output a solid black image. The difference in charging property between the toner in the toner storage chamber 40a and the toner in the toner storage chamber 40b is determined based on the solid black density at that time. Here, RD-916 made by Bacbeth was used for concentration measurement.

As shown in Table 1, the concentration in the new state is 1.5, whereas in the mixed state, the concentration is reduced to 0.8. On the other hand, the respective densities before mixing the toner in the toner storage chamber 40a and the toner in the toner storage chamber 40b after the non-sheet-passage idling operation were as shown in Table 2 below.

  As shown in Table 2, the toner concentration in the toner storage chamber 40a communicating with the developing chamber 40c including the regulating blade 42 is slightly lowered. That is, it can be said that the developability is slightly lowered by the non-sheet-passing idle rotation operation. On the other hand, the toner concentration in the toner storage chamber 40b is the same as that of a new product, and it can be seen that the chargeability of the toner is not changed by the non-sheet-passing idle rotation operation. In this way, it can be seen that mixing the toners having different chargeability changes results in a density decrease that is greater than the change in toner chargeability.

(Characteristic configuration of the developing device according to Embodiment 1)
Therefore, in the developing device 4 according to the first embodiment, as illustrated in FIG. 2, a partition wall is provided between the toner storage chamber 40 a and the toner storage chamber 40 b, and openings are provided vertically below and above the partition wall 45. 46 and 47 are provided. Specifically, the partition wall 45 has an opening through which toner moving in the direction from the toner storage chamber 40b toward the toner storage chamber 40a by the rotation of the stirring member 44 can pass from the toner storage chamber 40b to the toner storage chamber 40a. A portion (first opening) 46 is provided. Further, the partition wall 45 has an opening (a second portion) through which toner moving in the direction from the toner storage chamber 40a toward the toner storage chamber 40b by the rotation of the stirring member 43 can pass from the toner storage chamber 40a to the toner storage chamber 40b. 2 openings) 47 are provided.

  The state of toner circulation in the configuration of Example 1 shown in FIG. 2 is observed. The toner circulation between the developing chamber 40c and the toner storage chamber 40a was active as in the conventional example. On the other hand, it was confirmed that a toner flow that was not found in the prior art occurred between the toner storage chamber 40a and the toner storage chamber 40b. That is, the toner in the toner storage chamber 40b is pushed into the toner storage chamber 40a from the first opening 46 in the vertical direction by the stirring member 44. At that time, the toner is pushed from the second opening 47 in the vertical direction at the same time. The toner is returned to the toner storage chamber 40b. As a result, it was found that the uneven distribution of the toner in the toner storage chamber 40 was improved.

(Experiment on density change in developing device according to example 1)
Next, an experiment was performed on the density change accompanying the toner circulation in the configuration of Example 1 shown in FIG. The experimental results are shown in Table 3 below. Note that the experimental conditions are the same as those of the experiment performed with the above-described conventional configuration. That is, after performing the non-sheet-passing idle rotation operation for about 24 hours, 50 g of the toner in the toner storage chamber 40a and the toner in the toner storage chamber 40b are sampled, mixed together, and again an empty developing device. 4 and a solid black image was output.

  As shown in Table 3, it was confirmed that the density of the solid black image output using the mixed toner was improved as compared with the configuration of the conventional example. Further, when the density of each of the toner storage chambers 40a and 40b after the non-sheet-passing idle rotation operation is confirmed, a change in density of the toner in the toner storage chamber 40b is also confirmed. Further, with respect to the toner storage chamber 40a, a slight improvement was observed in the change in the charging property of the toner. This can be said to be a result of the circulation between the toner storage chamber 40a and the toner storage chamber 40b being activated and the change in the charging property of the toner progressing uniformly.

  As described above, in the developing device according to the first exemplary embodiment, the toner circulation between the toner storage chamber 40a and the toner storage chamber 40b can be activated. As a result, it is possible to make the change in chargeability of the toner uniform and suppress the occurrence of thin image density.

  In the first embodiment, the description has been given of the case where there are two toner storage chambers. That is, even when three or more toner storage chambers are provided, the partition walls 45 are provided between the toner storage chambers, and the openings 46 and 47 are provided above and below the respective partition walls 45 in the vertical direction. The same effect as the configuration described in Example 1 can be obtained. That is, the toner circulation between each of the plurality of toner storage chambers can be activated.

  Furthermore, the area of the opening of the partition wall and the stirring force of the stirring member are not limited to those described in the first embodiment, that is, those shown in FIG. The change rate of the charging property of the toner due to the sheet passing varies depending on various conditions such as the construction of the developing device and the life, usage environment, and printing speed associated with the toner filling amount. The effect described in the first embodiment can be obtained by optimizing the area of the opening and the stirring force in accordance with the change rate of the chargeability of the toner accompanying the paper passing.

(Example 2)
Next, the developing device 4 according to the second embodiment will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view illustrating the developing device according to the second embodiment. The developing device according to the second embodiment is different from the configuration of the first embodiment in that the partition wall 45 is provided to be inclined, but the other configurations are the same, and thus the same reference numerals are used to omit the description. .

  As shown in FIG. 4, the partition wall 45 is provided so as to be inclined so as to come into contact with the transport members 43 and 44 in the counter direction with respect to the rotation direction of the transport members 43 and 44. In other words, the partition wall 45 is provided so that the edge of the second opening abuts on the stirring member 43 at a position closer to the rotation center than the tip of the stirring member 43. By adopting such a configuration, the agitating member 43 is surely brought into contact with the partition wall 45, so that the toner in the toner storage chamber 40a is more reliably passed through the second opening 47 to the toner storage chamber 40b. Will move. That is, it can be said that the toner circulation between the toner storage chamber 40a and the toner storage chamber 40b becomes more active.

  Next, an experiment was conducted on the density change accompanying the toner circulation in the configuration of Example 2 shown in FIG. The experimental results are shown in Table 4 below. Note that the experimental conditions are the same as those of the experiment performed in the configuration of Example 1 described above. That is, after performing non-sheet-passing idle rotation for about 24 hours, 50 g each of the toner in the toner storage chamber 40a and the toner in the toner storage chamber 40b are sampled, mixed together, and again an empty developing device. 4 and a solid black image was output.

  As can be seen from Table 4, a decrease in density could be suppressed as compared with the configuration of the conventional example. Further, even when compared with the configuration of Example 1, a slight improvement effect could be confirmed.

  As described above, in the developing device according to the second embodiment, by providing the partition wall 45 with an inclination, the toner between the toner storage chamber 40a and the toner storage chamber 40b is compared with the configuration of the first embodiment. The circulation of can be made more active. As a result, the change in chargeability of the toner can be made uniform, and the occurrence of thin image density can be further suppressed.

  In the second embodiment, the case where there are two toner storage chambers has been described. However, the present invention is not limited to this. That is, even when three or more toner storage chambers are provided, the partition walls 45 are provided between the toner storage chambers, and the openings 46 and 47 are provided above and below the respective partition walls 45 in the vertical direction. The same effect as the configuration described in Example 2 can be obtained. That is, the toner circulation between each of the plurality of toner storage chambers can be activated.

  Furthermore, the inclination of the partition wall 45 is not limited to that shown in FIG. 4 as long as the partition wall 45 is configured to be in contact with the stirring member in the counter direction at least with respect to the rotation direction of the stirring member. Changing the inclination angle changes the activeness of toner circulation, but it has been confirmed that a sufficient effect can be obtained at any angle.

  Furthermore, the area of the opening of the partition wall and the stirring force of the stirring member are not limited to those described in the second embodiment, that is, those shown in FIG. The change rate of the charging property of the toner due to the sheet passing varies depending on various conditions such as the construction of the developing device and the life, usage environment, and printing speed associated with the toner filling amount. The effect described in the second embodiment can be obtained by optimizing the area of the opening and the stirring force in accordance with the change rate of the charging property of the toner accompanying the paper passing.

Toner storage chamber 40a, 40b, developing sleeve 41, regulating blade 42, stirring member 43, 44, partition wall 45

Claims (8)

In a developing device for developing a latent image formed on an image carrier,
A developer chamber comprising: a developer carrier; and a regulating member that is provided in contact with the developer carrier and regulates a layer thickness of the developer carried on the developer carrier;
A first developer containing chamber containing developer and communicating with the developing chamber;
A second developer containing chamber containing a developer and communicating with the first developer containing chamber;
A first transport member rotatably provided in the first developer storage chamber and capable of transporting the developer from the first developer storage chamber to the development chamber;
A second conveying member rotatably provided in the second developer accommodating chamber and capable of conveying the developer from the second developer accommodating chamber to the first developer accommodating chamber;
Have
A partition wall is provided between the first developer storage chamber and the second developer storage chamber;
A developer that moves in the direction from the second developer accommodating chamber toward the first developer accommodating chamber by the rotation of the second conveying member is transferred from the second developer accommodating chamber to the first partition member. A first opening that can pass into the developer accommodating chamber, and a developer that moves in a direction from the first developer accommodating chamber toward the second developer accommodating chamber by the rotation of the first conveying member, And a second opening capable of passing from the developer storage chamber to the second developer storage chamber.   The developing device according to claim 1, wherein the first conveying member contacts an edge of the second opening formed by the partition wall when the first conveying member rotates.   The partition wall is provided so that an edge of the second opening is in contact with the first transport member at a position closer to the rotation center of the first transport member than the tip of the first transport member. The developing device according to claim 2.   4. The developing device according to claim 1, wherein the first conveying member circulates the developer between the developing chamber and the first developer storage chamber. 5.   5. The developing device according to claim 1, wherein when the first conveying member rotates, a leading end portion of the first conveying member enters the inside of the developing chamber. 6.   6. The developing device according to claim 1, wherein, when the developing device is used, the first opening is positioned below the second opening. 7. In a process cartridge detachable from an image forming apparatus,
A developing device according to any one of claims 1 to 6,
An image carrier on which a latent image is formed;
A process cartridge comprising: A developing device according to any one of claims 1 to 6,
An image carrier on which a latent image is formed;
An image forming apparatus comprising:

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