JPH07104574A - Developing device - Google Patents

Abstract

PURPOSE:To prevent developer from aggregating in a developer carry path and scattering from a developing device by smoothing developer carry in the developer carry path. CONSTITUTION:The cross-sectional area of a toner supply path 12 is made equal to or smaller than the smallest cross-sectional area of a toner carry path in the developing device 1, the cross-sectional area of an excess-toner carry path 13 is made larger than the smallest cross-sectional area of the toner carry path in the developing device 1. To be concrete, the order of smallest cross-sectional area to the largest cross-sectional area is the toner supply path 12, a toner supply/carry space 9, a communication path, a toner recovery/carry space 10, and the excess-toner carry path 13. Thus, because the toner carry path in the developing device increases in cross-sectional area as it goes downstream, scattering of toner in the toner supply/carry space 9 and clogging of the excess-toner carry path 13 with toner are prevented, and toner carry along the toner carry path in the developing device can be smoothed.

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 in an image forming apparatus such as a copying machine, a facsimile machine, a printer, etc., and more specifically, a developing method for developing a latent image on an image bearing member with a developer carried on the surface. A developing unit including a developer carrying member and a developer accommodating unit filled with the developer supplied to the developing unit are provided, and the developer in the developer accommodating unit is conveyed to the developing unit to perform the development. The present invention relates to a developing device which is carried on an agent carrier and is supplied from the developer carrier to the image carrier to develop a latent image.

[0002]

2. Description of the Related Art Conventionally, in this type of developing device, a toner hopper as a developer accommodating portion is arranged below a developing roller as a developer carrying member in order to downsize the device and prevent scattering of the developer. A developing device having a vertical structure is known (for example, JP-A-53-127553, JP-A-57-185052, and JP-A-58-2231).
58). However, in the developing device having the above-described structure, the developer may be scattered due to insufficient charging of the developer, or the load may be structurally increased by conveying the developer upward for a relatively long distance. There was a drawback to do.

Therefore, in order to solve the above drawbacks, the present applicant has previously proposed a developing device having a structure as shown in FIG. 4, for example. That is, the developing device shown in FIG.
1 and a toner tank (not shown) connected to the upper portion of the toner hopper 42 as a developer accommodating portion formed at one end of the developing device 41 in the longitudinal direction. An opening 44 is formed in the casing 43 of the developing device 41 at a portion facing a photoconductor as an image carrier (not shown). Then, in the casing 43, a developing roller 45 as a developer carrying member, which is partially exposed from the opening 44 in the longitudinal direction of the casing 43, and the exposed portion faces the photoconductor, and a developing roller. A supply roller 46 disposed below 45 so that the surface thereof rubs against the developing roller 45, and a downstream side of the opening 44 in the moving direction of the surface of the developing roller 45, and the developing roller 45 and the supplying roller 46. A supply toner conveying screw 47 as a developer supplying and conveying means which is arranged at a position upstream of a rubbing portion with
And a surplus toner conveying screw 48 as a surplus developer collecting and conveying means arranged below the supply roller 46.
And are provided respectively. In this developing device, toner is supplied from the supply roller 46 to the developing roller 45 at the sliding portion between the developing roller 45 and the supply roller 46.

In the above structure, the supply toner conveying screw 47 rotates in a predetermined direction to transfer the toner to the arrow A in the figure.
Then, the toner in the toner hopper 42 is fed over the entire width of the feed roller 46. Supply roller 46
The toner supplied to the developing roller 45 and the supplying roller 4 is
It is supplied from the supply roller 46 to the developing roller 45 at the sliding contact portion with 6, and is used for development. Further, the excess toner not used for the development falls through the communication path 49 formed at the end portion of the developing device where the toner hopper 42 is not provided, and the excess toner transport screw 48 rotates in a predetermined direction,
The toner hopper 42 is conveyed in the direction shown by the arrow B in the figure.
Returned to. According to the developing device having the above-described configuration, it is possible to prevent the developer from scattering due to insufficient charging of the developer, and to reduce the structural load.

[0005]

However, according to this structure, for example, the supply toner conveying screw 4 having the same structure is used.
7 and the excess toner carrying screw 48, and by making the conditions such as the rotation speed of both screws the same,
When the two toners have the same toner carrying capacity, the toner carrying capacity of the excess toner carrying screw 48 becomes lower than the toner carrying capacity of the supplied toner carrying screw 47 due to the influence of the toner pressure in the toner hopper 42 and the communication path 49. There is a risk. When the toner carrying capacity of the surplus toner carrying screw 48 becomes lower than the toner carrying capacity of the supplied toner carrying screw 47, the toner in the toner carrying path of the developing device 41 is not smoothly carried, and the toner carrying There is a problem that toner agglomeration on the road and toner scattering from the developing device occur. Further, in the developing device having the above-described configuration, the driving of the supply toner transport screw 47 and the surplus toner transport screw 48 is stopped at the time of non-developing, so that the toner remains in the toner transport path at the time of non-developing. Then, in this state, when the developing operation is started, the driving of the supply toner transport screw 47 and the excess toner transport screw 48 is restarted, and when the excess toner transport screw 48 transports the toner to the toner transport path, the excess toner transport screw 48. The excess toner is not conveyed by the supply toner conveying screw 47 due to the supply toner so that the toner in the toner conveying path of the developing device 41 is not smoothly conveyed, and the toner agglomeration in the toner conveying path or the toner from the developing device occurs. There is a problem that toner is scattered.

The present invention has been made in view of the above problems, and an object of the present invention is to smoothly convey the developer in the developer conveying path to thereby prevent the developer from being conveyed in the developer conveying path. It is an object of the present invention to provide a developing device capable of preventing aggregation and scattering of a developer from the developing device.

[0007]

In order to achieve the above-mentioned object, the invention according to claim 1 is a development provided with a developer carrier for developing a latent image on the image carrier with a developer carried on the surface. Section, a developer accommodating section filled with the developer to be supplied to the developing section, a developer supplying / conveying means for conveying the developer in the developer accommodating section to the developing section, and a developer supplying / conveying section. Excessive development, which is arranged below the means and at a position where the pressure of the developer conveyed to the developing section by the developer supplying and conveying means can be received, and which is conveyed by the developer supplying and conveying means and does not contribute to the development. An excess developer collecting and conveying means for conveying the developer from the developing section to the developer accommodating section, and the cross-sectional area of the developer supply path from the developer accommodating section to the developing section is defined as the developer in the developing section. It is set so that it is smaller than the minimum sectional area of the transport path, and from the developing section to the developer accommodating section. It is characterized in that setting the cross sectional area of the surplus developer collecting path so as to be larger than the cross-sectional area of the developer conveying path of the developing portion.

According to a second aspect of the present invention, a developing section provided with a developer carrier for developing a latent image on the image carrier with the developer carried on the surface, and a developer supplied to the developing section are filled. A developer accommodating portion, a developer supplying / conveying means for conveying the developer in the developer accommodating portion to the developing part, and the developer supplying / conveying means below the developer supplying / conveying means. Excessive developer, which is disposed at a position where the pressure of the developer conveyed to the developer can be received and which is conveyed by the developer supplying and conveying means and does not contribute to the development, is conveyed from the developing section to the developer accommodating section. A developer collecting and conveying means is provided, and the developer conveying capacity of the surplus developer collecting and conveying means in the developer conveying path in the developing section is made larger than the developer conveying capacity of the developer supplying and conveying means. It is a feature.

According to a third aspect of the present invention, a developing section having a developer carrying member for developing a latent image on the image carrying body with the developer carried on the surface, and a developer supplied to the developing section are filled. A developer accommodating portion, a developer supplying / conveying means for conveying the developer in the developer accommodating portion to the developing part, and the developer supplying / conveying means below the developer supplying / conveying means. Excessive developer, which is disposed at a position where the pressure of the developer conveyed to the developer can be received and which is conveyed by the developer supplying and conveying means and does not contribute to the development, is conveyed from the developing section to the developer accommodating section. A developer collecting / conveying means is provided, the driving of the developer supplying / conveying means is stopped at the time of non-development, and only the surplus developer collecting / conveying means is driven. Here, non-development means that the driving of the developer supply / conveyance means is stopped and the driving of only the excess developer recovery / conveyance means does not interfere with the developing operation.

[0010]

In the inventions of claims 1 to 3, the developer in the developer accommodating portion is conveyed from the developer accommodating portion to the developing portion by the developer supplying and conveying means. Further, the developer conveyed to the developing unit is carried by the developer carrying member and contributes to the development. Then, the surplus developer that has not contributed to the development is conveyed from the developing section to the developer accommodating section by the surplus developer collecting and conveying means arranged below the developer supplying and conveying means.

Here, particularly in the invention of claim 1,
The cross-sectional area of the developer supply path from the developer accommodating section to the developing section is set to be equal to or smaller than the minimum cross-sectional area of the developer conveying path in the developing section, and the developer accommodating section from the developing section is accommodated. Since the cross-sectional area of the excess developer recovery path to the developing section is set to be larger than the cross-sectional area of the developer conveying path in the developing section, the developer storing section returns to the developer storing section again via the developing section. The cross-sectional area of the developer transport path in the developing device of the path becomes larger toward the downstream side. As a result, even if the developer transport capacity of the excess developer collecting and transporting means is lowered due to the pressure of the developer, the developer is smoothly transferred from the developer accommodating section to the developing section and from the developing section to the developer accommodating section. It can be efficiently transported.

Further, particularly in the invention of claim 2, the developer carrying capacity of the surplus developer collecting and carrying means in the developer carrying path in the developing section is larger than the developer carrying capacity of the developer supplying and carrying means. Thus, the maximum amount of the developer is conveyed from the developer accommodating section to the developing section by the developer supplying / conveying means, and the developer conveying capacity of the surplus developer collecting / conveying means is affected by the pressure of the developer. Even if it decreases, it is possible to allow the developer carrying capacity of the surplus developer collecting and carrying means to have a margin, and the developer can be carried smoothly and efficiently from the developing section to the developer accommodating section. .

Further, particularly in the invention of claim 3, since the drive of the developer supplying and conveying means is stopped and only the excess developer collecting and conveying means is driven at the time of non-developing, the developer accommodating portion for the excess developer is held. It is possible to lengthen the transport time to, and to transport the excess developer to the developer accommodating section during non-development,
It is possible to secure a transport path for the excess developer. Therefore,
After that, the developer transported by the developer transport member can be transported smoothly and efficiently.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a developing device adopted in an electrophotographic copying machine (hereinafter referred to as a copying machine) which is an image forming apparatus will be described below. In the following description, a non-magnetic one-component toner (hereinafter,
(Called toner). FIG. 1 is a sectional view showing a schematic configuration of a developing section of the developing device according to the present embodiment.
FIG. 2 is a schematic configuration diagram of the appearance of the developing device according to the present embodiment. The developing device according to the present embodiment includes a developing device 1 as a developing unit and a toner supply path 12 as a developer supply path.
(See FIG. 2) and a surplus toner transport path 13 (see FIG. 2) as a surplus developer transport path, which is connected to one end in the longitudinal direction of the developing device 1 and serves as a developer accommodating portion communicating with the interior of the developing device 1. The toner hopper 11 (see FIG. 2) and a toner tank (not shown) connected to the upper part of the toner hopper 11. The casing 2 of the developing device 1 is provided with an opening 3 at a portion facing a photoconductor as an image carrier (not shown). The opening 3 is provided in the casing 2.
There is provided a developing roller 4 as a developer carrying member arranged so as to face the photoconductor. The developing roller 4 has a predetermined peripheral speed ratio with respect to the photoconductor, and is rotated in the same direction as the moving direction of the photoconductor surface in a region (developing region) facing the photoconductor as shown by an arrow A in FIG. It is configured.

Below the developing roller 4, there is provided a supplying roller 5 as a developer supplying member, the surface of which is rubbed against the developing roller 4. The supply roller 5 has a predetermined peripheral speed ratio with respect to the developing roller 4 so that it rotates in the same direction as the moving direction of the surface of the developing roller 4 at the sliding contact portion a with the developing roller 4, as indicated by the arrow B in FIG. Is configured. The rubbing portion a is the toner supply position of the supply roller 5 to the developing roller 4.

Further, urethane rubber or the like for restricting the amount of toner on the developing roller 4 to a predetermined amount is provided downstream of the sliding portion a in the moving direction of the surface of the developing roller 4 and in the vicinity of the opening 3. The blade 6 made of an elastic body is provided so that its end portion contacts the developing roller 4.

Further, as a developer supplying / conveying means, a position downstream of the opening 3 in the moving direction of the surface of the developing roller 4 and upstream of the sliding portion a and a position below the supply roller 5 serve as a developer supplying / conveying means. Supply toner transport screw 7 and excess toner transport screw 8 as excess developer recovery transport means.
Are provided respectively. Each of the supply toner transport screw 7 and the surplus toner transport screw 8 is provided with screw members 72 and 82 around shafts 71 and 81 as shown in FIG. 3 described later, and the toner hopper 11 of the developing device 1 is not connected. The toner supply path 12 from one end
Alternatively, it is disposed so as to extend in parallel with the developing roller 4 and the supply roller 5 through the surplus toner transport path 13 and over the end portion of the toner hopper 11. Further, the supply toner conveying screw 7 rotates in the direction indicated by arrow C in FIG. 1, and the surplus toner conveying screw 8 rotates in the direction indicated by arrow D in FIG. Is configured to.

Here, the supply roller 5 is the developing roller 4
Not only is it arranged so as to contact the casing 2. As a result, the developing roller 4, the supply roller 5, and the casing 2 form a toner supply / transport space 9 surrounding the supply toner transport screw 7 and a toner recovery / transport space 10 surrounding the surplus toner transport screw 8.
Here, the toner supply / transport space 9 communicates with the toner supply path 12 and the toner recovery / transport space 10 communicates with the surplus toner transfer path 13. Further, at the end of the developing device 1 on the back side (the right side in FIG. 2) of the drawing in FIG. 1, the toner conveyed in the toner supply / conveyance space 9 drops and reaches the toner collection / conveyance space 10.
(Not shown in FIGS. 1 and 2; see FIG. 3, which will be described later). The toner supply path 12, the toner supply / conveyance space 9, the communication path 14, the toner recovery / conveyance space 10 and the surplus toner conveyance path 13 form a toner conveyance path in the developing device.

In the above-described structure, when the supplied toner conveying screw 7 rotates in the direction of the arrow C, the toner in the toner hopper 11 is conveyed by the supplied toner conveying screw 7 in the toner supply path 12 and the toner conveying space of the developing device 1. In FIG. 1, the inside 9 is from the front side to the back side in FIG.
(From left to right), and is supplied over the entire area of the supply roller 5 in the axial direction. The toner supplied to the supply roller 5 is charged in the rubbing portion a by the rotation of the supply roller 5 in the direction of the arrow B, and the developing roller 4 is charged.
And is carried on the surface of the developing roller 4. And
The toner carried on the developing roller 4 is made uniform by the blade 6 into a thin toner layer having a predetermined thickness, and the electrostatic latent image formed on the surface of the photoconductor is developed by contact or non-contact development.

Among the toners conveyed by the supply toner conveying screw 7, toners not used for development (not supplied to the supply roller 5) are supplied by the supply toner conveying screw 7 to the toner hopper 1 of the developing device 1.
1 is conveyed to the end opposite to the end to which it is connected, and falls to the lower part of the developing device 1 at a connecting path 14 (see FIG. 3 described later) formed at the end opposite to the end. The excess toner transport screw 8 provided at the lower portion of the toner rotates in the direction of the arrow D to move the toner in the toner collecting and transporting space 10 from the back side to the front side in FIG. 1 (right side in FIG. 2). From the developing unit 1 to the toner hopper 11 through the surplus toner transport path 13.

By the way, in the above configuration, for example, the supply toner transport screw 7 and the surplus toner transport screw 8 having the same configuration are used, and the conditions such as the rotational speeds of the supply toner transport screw 7 and the excess toner transport screw 8 are made the same. If the two screws have the same toner carrying capacity, the toner carrying capacity of the surplus toner carrying screw 8 is lower than the toner carrying capacity of the supplied toner carrying screw 7 due to the influence of the toner pressure in the toner hopper 11 and the communication path 14. There is a risk of becoming. And
If the toner carrying capacity of the surplus toner carrying screw 8 becomes lower than the toner carrying capacity of the supplied toner carrying screw 7, the toner in the toner carrying path of the developing device will not be carried smoothly, and toner aggregation in the toner carrying path will occur. Toner scattering from the developing device may occur.

Therefore, in the developing device having the above structure,
In order to smoothly carry the toner in the toner carrying path and prevent the toner aggregation and the toner scattering, the cross-sectional area of the toner supply path 12 from the toner hopper 11 to the developing device 1 is set to the toner supply carrying space 9 and the connecting path. 14 and the toner collecting / conveying space 10 in the developing device 1 is set to be equal to or smaller than the minimum sectional area of the toner conveying path, and the sectional area of the excess toner conveying path 13 from the developing device 1 to the toner hopper 11 is set to the developing device. It is set to be larger than the cross-sectional area of the toner conveyance path in 1. Specifically, in this embodiment, the toner supply path 12, the toner supply / transport space 9, and the communication path 1 are provided.
4, toner collecting and conveying space 10, surplus toner conveying path 1
The cross-sectional area is increased in the order of 3.

By doing so, the toner carrying path in the developing device is taken from the toner hopper 11 through the toner supply path 12 to the developing device 1 and from the developing device 1 through the surplus toner carrying path 13 to the toner hopper 11. Has a larger cross-sectional area on the downstream side. Thereby, for example, toner scattering in the toner supply / conveyance space 9 and toner clogging in the excess toner conveyance path 13 can be prevented, and the toner can be smoothly conveyed in the toner conveyance path in the developing device.

Next, another embodiment will be described in which the toner is smoothly conveyed in the toner conveying path to prevent the toner aggregation and the toner scattering. FIG. 3 is a schematic internal configuration diagram of the developing device according to the present embodiment. Unlike the developing device shown in FIGS. 1 and 2, the developing device shown in the figure has a toner hopper 11 at one longitudinal end of the developing device 1, and has the toner supply path 12 and the surplus toner transport path 13. Absent. Since the other points are basically the same as those of the developing device in FIGS. 1 and 2, the same members and the like in FIGS. However, the description is omitted.

In the developing device according to the present embodiment, the pitch p of the screw member 72 of the supply toner conveying screw 7 is set to the screw member 8 of the surplus toner conveying screw 8.
The pitch q is smaller than 2.

By doing so, even if the rotational speeds of the supplied toner conveying screw 7 and the surplus toner conveying screw 8 are the same, the toner conveying speed by the surplus toner conveying screw 8 can be adjusted without complicating the apparatus. Can be made faster than the toner transport speed. As a result, clogging of the toner in the toner collecting / conveying space 10 (see FIG. 1) is prevented, and the toner in the developing device 1 constituted by the toner supply / conveying space 9, the connecting path 14 and the toner collecting / conveying space 10 is prevented. The toner can be smoothly transported on the transport path.

Further, in the developing device shown in FIG. 3, when the pitch p of the screw member 72 of the supply toner transport screw 7 and the pitch q of the screw member 82 of the excess toner transport screw 8 are the same, the excess toner transport is performed. By increasing the rotation speed of the screw 8 above the rotation speed of the supply toner transport screw 7, the toner transport speed of the excess toner transport screw 8 is increased.
As described above, the toner clogging in the toner collecting and conveying space 10 (see FIG. 1) can be prevented, and the toner supplying and conveying space 9, the communication path 14 and the toner collecting and conveying space 10 can be prevented. The toner can be smoothly transported in the toner transport path in the developing device 1 configured. (Hereafter, margin)

Further, the pitch p of the screw member 72 of the supply toner carrying screw 7 and the pitch q of the screw member 82 of the surplus toner carrying screw 8 are the same, and
When the rotation speed of the excess toner transport screw 8 and the rotation speed of the supply toner transport screw 7 are the same, the diameter of the screw member 82 of the excess toner transport screw 8 is smaller than the diameter of the screw member 72 of the supply toner transport screw 7. By increasing the amount, the amount of toner conveyed by the surplus toner conveying screw 8 can be made larger than the amount of toner conveyed by the supplied toner conveying screw 7, and the toner clogging in the toner collecting and conveying space 10 (see FIG. 1) is achieved as described above. Therefore, it is possible to smoothly carry the toner in the toner carrying path in the developing device 1, which is composed of the toner supplying and carrying space 9, the communication path 14 and the toner collecting and carrying space 10.

In the developing device according to FIG. 3, the method of setting the pitches p and q of the screw members 72 and 82 of the supply toner conveying screw 7 and the surplus toner conveying screw 8, the supply toner conveying screw 7 and the surplus toner. Two or more of the methods of setting the rotation speed of the transport screw 8 and the methods of setting the diameters of the screw members 72 and 82, or all of them may be combined.

Further, by stopping the driving of the supplied toner carrying screw 7 during non-developing and driving only the surplus toner carrying screw 8, the carrying time of the surplus toner by the surplus toner carrying screw 8 to the toner hopper 11 is reduced. It is possible to increase the length and convey the excess toner to the toner hopper 11 at the time of non-development, so that the toner collecting and conveying space 10 can be secured. So after that,
The toner carried by the supply toner carrying screw 7 can be carried smoothly. Here, non-development refers to the time when the driving of the supply toner transport screw 7 is stopped and the drive of only the excess toner transport screw 8 does not interfere with the developing operation.

As described above, according to the above-described embodiment, the toner in the toner conveying path of the developing device can be smoothly conveyed, and it is possible to prevent the toner aggregation and the toner scattering from the developing device in the toner conveying path. it can.

In the above description, the example in which the non-magnetic one-component toner is used as the developer has been described, but the present invention is also applicable to the developing device using the magnetic one-component toner.

[0033]

According to the first aspect of the present invention, even if the developer transporting capability of the excess developer collecting and transporting means is lowered due to the pressure of the developer, the developer accommodating portion transfers to the developing portion and then the developing portion. Since the developer can be smoothly and efficiently conveyed to the developer accommodating portion, it is possible to prevent the aggregation of the developer in the developer conveying path of the developing device and the scattering of the developer from the developing device. is there. According to the second aspect of the present invention, the maximum amount of the developer is conveyed from the developer accommodating portion to the developing portion by the developer supplying and conveying means, and the developer of the surplus developer collecting and conveying means receives the pressure of the developer. Even if the developer carrying capacity is lowered, it is possible to allow the developer carrying capacity of the excess developer collecting and carrying means to have a margin, so that the developer can be smoothly and efficiently carried from the developing section to the developer accommodating section. Since it can be performed, there is an effect that it is possible to prevent the aggregation of the developer in the developer transport path from the developing device and the scattering of the developer in the developing device. According to the third aspect of the present invention, by ensuring the transport path for the excess developer during non-development, the developer transported by the developer supply / transport means can be transported smoothly and efficiently. Therefore, there is an effect that it is possible to prevent the aggregation of the developer on the developer transport path in the developing device and the scattering of the developer from the developing device.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a developing unit of a developing device according to an embodiment.

FIG. 2 is a schematic configuration diagram of an appearance of the developing device.

FIG. 3 is an internal schematic configuration diagram of a developing device according to another embodiment.

FIG. 4 is a schematic diagram of an internal structure of a conventional developing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 developing device 2 casing 3 opening 4 developing roller 5 supply roller 6 blade 7 supply toner transport screw 8 surplus toner transport screw 9 toner transport space 10 toner recovery transport space 11 toner hopper 12 toner supply channel 13 surplus toner transport channel 14 communication path

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuhiro Aoki 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Inventor Umitsu Fujishiro 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company Ricoh

Claims (3)

[Claims] 1. A developing section provided with a developer carrying body for developing a latent image on an image carrying body with a developer carried on the surface, and a developer containing section filled with the developer supplied to the developing section. And a developer supplying and conveying means for conveying the developer in the developer accommodating section to the developing section, and a development conveyed to the developing section by the developer supplying and conveying section below the developer supplying and conveying section. Excessive developer collecting / conveying means, which is arranged at a position where the pressure of the developer can be received, and conveys, from the developing section, the excessive developer which has been conveyed by the developer supplying / conveying means and has not contributed to the development, to the developer accommodating section. And a cross-sectional area of the developer supply path from the developer accommodating section to the developing section is set to be equal to or less than the minimum cross-sectional area of the developer transport path in the developing section, and The cross-sectional area of the excess developer recovery path to the developer accommodating section is equal to the cross-sectional area of the developer transport path in the developing section. Developing apparatus is characterized in that set to be larger. 2. A developing section provided with a developer carrying body for developing a latent image on an image carrying body with a developer carried on the surface, and a developer containing section filled with the developer supplied to the developing section. And a developer supplying and conveying means for conveying the developer in the developer accommodating section to the developing section, and a development conveyed to the developing section by the developer supplying and conveying section below the developer supplying and conveying section. Excessive developer collecting / conveying means, which is arranged at a position where the pressure of the developer can be received, and conveys, from the developing section, the excessive developer which has been conveyed by the developer supplying / conveying means and has not contributed to the development, to the developer accommodating section. And a developer carrying capacity of the surplus developer collecting and carrying means in the developer carrying path in the developing section is larger than the developer carrying capacity of the developer supplying and carrying means. . 3. A developing section provided with a developer carrying body for developing a latent image on an image carrying body with a developer carried on the surface, and a developer containing section filled with the developer supplied to the developing section. And a developer supplying and conveying means for conveying the developer in the developer accommodating section to the developing section, and a development conveyed to the developing section by the developer supplying and conveying section below the developer supplying and conveying section. Excessive developer collecting / conveying means, which is arranged at a position where the pressure of the developer can be received, and conveys, from the developing section, the excessive developer which has been conveyed by the developer supplying / conveying means and has not contributed to the development, to the developer accommodating section. And a driving means for stopping the supply of the developer at the time of non-development and driving only the surplus developer collecting and conveying means.