JP2002365908A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device, capable of preventing a faulty electrified thick toner layer on a developer carrier caused, when the developer carrier is reversely rotated from passing through a toner layer regulating member, and realizing image formation which is free from surface staining. SOLUTION: This imaging device has a photoreceptor belt 1, a developing roller 12, a supply roller 13 supplying toner to the roller 12, a reverse rotation causing drive means for making the roller 12 rotate in the direction reverse to the rotating direction thereof at developing time, a regulating roller 14 regulating the thickness of the toner layer carried on the roller 12, while abutting on the roller 12 at the developing time, and rotated with the roller 12 rotated in reverse by the reverse rotation drive means at non-developing time, and a seal 17 provided to prevent the toner from being leaked from a gap between a development container 11 and the roller 12. Then, a cleaning member 30 for recovering the toner on the roller 12 is provided between the roller 13 and the seal 17.

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 facsimile, and a printer. More specifically, the present invention relates to a layer of a toner carried on a developer carrying member during development. The present invention relates to an image forming apparatus provided with a developing device having a roller-shaped toner layer regulating member that regulates the thickness and rotates around the developer carrier that is reversely rotated by a reverse rotation driving unit during non-development. .

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus of this type, there are provided a photoconductor as a latent image carrier and a plurality of developing devices which contain toners of different colors from each other and perform a contacting / separating operation with respect to the photoconductor. Are known. In this image forming apparatus, a superimposed toner image on a photoreceptor formed by superimposing toner images of respective colors sequentially developed in respective developing areas is collectively transferred to a transfer material, or each color on a photoreceptor developed by each developing device is transferred. Are transferred onto the intermediate transfer body in a superimposed manner, and the superimposed toner image on the intermediate transfer body is collectively transferred to a transfer material, thereby forming a color image.

Further, as a developing device used in this type of image forming apparatus, a one-component developer composed of toner particles externally added with additives such as toner particles or auxiliary agents, that is, a developer containing no carrier particles is used. Is supplied to a developing roller as a developer carrying member, and a developing device of a one-component developing system in which a toner layer having a predetermined thickness is formed on the developing roller is known. This type of developing device does not need to control the toner concentration as compared with a two-component developing type developing device using a two-component developer composed of a toner and a carrier,
Further, since there is no need for a mixing and stirring means for mixing and stirring the toner and the carrier, it is possible to simplify the maintenance and management of the apparatus and to obtain an advantage that the structure of the apparatus can be reduced.

[0004] Among the above-mentioned developing devices of the one-component developing system, those using a non-magnetic toner and those using a magnetic toner as a one-component developer are known. Regardless of which toner is used, a toner layer regulating member for forming a toner layer having a predetermined thickness on the developing roller is provided. In an apparatus using a non-magnetic toner, the toner layer regulating member also performs triboelectric charging of the toner.

As the toner layer regulating member, a blade-like regulating blade is generally used. For example,
When a so-called hard roller made of metal or resin is used as the developing roller, an elastic member such as urethane rubber is used as the regulating blade, and at least the surface portion of the developing roller has rubber-like elasticity. When a so-called soft roller is used, a metal blade or the like is used as a regulating blade.

However, regardless of which regulating blade is used, the regulating blade is in contact with and pressed against the developing roller, so that the surface thereof wears over time, and it is difficult to extend the life of the regulating blade. . Also,
The toner staying at the contact portion between the developing roller and the regulating blade is melted by frictional heat generated between the blade and the rotating developing roller, and a toner mass is easily generated at the contact portion. In such a case, there is a problem that a streak-like mark is formed on the toner and white streaks are generated in the solid portion when the solid portion is developed. In particular, when a non-magnetic toner is used, the charging ability of the toner is degraded due to the wear of the regulating blade, the background of the non-image portion is stained due to insufficient charging of the toner, and the reproducibility of minute dots is reduced. There was a problem that would be.

To solve such a problem, a developing device using a roller-shaped regulating roller as a toner layer regulating member instead of the regulating blade has been proposed. FIG. 6 is a configuration diagram showing an example of a developing device using such a regulating roller. The illustrated developing device includes a developing container 101 having an opening directed to a belt-shaped photoconductor 100, a developing roller 102,
The image forming apparatus includes a supply roller 103 for supplying toner onto the developing roller 102, a regulating roller 104 for regulating the toner layer on the developing roller 102, and the like. Then, the regulating roller 104 is stopped during the development, and the developing roller 102 is rotated in a direction opposite to the rotation direction at the time of non-developing, and the developing roller 102 is rotated by rotating the regulating roller 104. ing. Further, toner is stored in toner storage units 105 a, 105 b, and 105 c in the developing container 101, and each of the toner storage units 105 has a transport paddle 106 a that rotates and feeds the toner therein to the supply roller 103 side. , 106b, 106c and the developing container 1
In order to prevent toner from leaking from a gap between the developing roller 102 and the developing roller 102 disposed at the opening of the developing container 101, a seal 107 provided to abut the developing roller 102 is also provided.

In the developing device shown in FIG. 6, since the regulating roller 104 does not rotate at the time of development, the regulating roller 104 in the stopped state uses a blade-like regulating member as the toner layer regulating member. Demonstrate the same regulatory power. The regulating roller 104 is used only during non-developing.
Are configured to rotate, so that the deterioration of the surface of the regulating member with time and the stagnation of the toner, which are likely to occur when the blade-shaped regulating member is used, do not occur.

[0009]

However, in the above-described developing apparatus, when the developing roller 102 rotates in the direction opposite to the rotation direction during development during non-development, the gear is generally driven by the same drive source as the developing roller 102. Is also rotated at the same time, the toner is supplied onto the developing roller 102 by the supply roller 103 even when the developing roller 102 rotates in the reverse direction. as a result,
The developing roller 102 is provided upstream of the supply roller 103 in the toner transport direction during development, that is,
A thick toner layer having poor charging is formed between the supply roller 103 and the development area, which is the area opposed to 0. The thick toner layer formed by the reverse rotation of the developing roller 102 does not become thinner only by passing through the seal member 107 formed of a film or the like when the developing roller 102 rotates in the reverse direction. Even after passing through 103, the layer is not thinned. As a result, at the time of development, even if the thick toner layer formed on the developing roller 102 is thinned by the regulating roller 104, the toner is not sufficiently frictionally charged, and the non-image portion becomes dirty due to insufficient charging of the toner. Will occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to form a toner layer having a poor charge on a developer carrier which is generated when the developer carrier is rotated in the reverse direction. It is an object of the present invention to provide an image forming apparatus which can prevent an image from passing through a regulating member and can form an image without soiling.

[0011]

According to one aspect of the present invention, there is provided a latent image carrier, and a developer carrier for developing a latent image on the latent image carrier in a developing area. A toner supply member that supplies toner to the developer carrier, a reverse rotation driving unit that rotates the developer carrier in a direction opposite to a rotation direction during development, and A roller-shaped toner that is in contact with and regulates the layer thickness of the toner carried on the developer carrying member, and is rotatable around the developer carrying member that is reversely rotated by the reverse rotation driving means during non-development. In an image forming apparatus having a layer regulating member, a toner collecting member for collecting the toner on the developer carrying member is provided between the developing area and the toner supplying member.

In this image forming apparatus, the toner collecting member is provided between the developing area and the toner supplying member. When the developer carrier is rotated in the reverse direction, the toner supplied to the developer carrier by the toner supply roller is formed on the developer carrier between the development area and the toner supply member as a thick toner layer having poor charging. However, the toner collecting member scrapes and collects the thick toner layer. for that reason,
A thick toner layer generated when the developer carrier rotates in the reverse direction does not pass through the toner layer regulating member during development. Therefore, at the time of development, the toner layer on the developer carrier is sufficiently frictionally charged by the toner layer regulating member, so that it is possible to prevent the occurrence of background contamination due to insufficient charging of the toner.

[0013] In particular, the invention according to claim 2 is the image forming apparatus according to claim 1, wherein a toner is accommodated therein, and the developing container has an opening toward the surface of the latent image carrier. A seal member provided in contact with the developer carrier to prevent the toner from leaking from a gap between the developer carrier and the developer carrier disposed at the opening of the developing container; A member is provided between the seal member and the toner supply member.

In this image forming apparatus, before the thick toner layer having poor charging formed on the developer carrying member leaks out of the seal member when the developer carrying member rotates in the reverse direction, the toner collecting member is connected to the toner collecting member. Scrape off. Therefore, it is possible to prevent the toner from leaking from the seal member.

Further, the invention according to claim 3 provides a latent image carrier,
A developer carrying member for developing the latent image on the latent image carrying member, a toner supply member for supplying toner to the developer carrying member, and a direction opposite to a rotation direction during development for rotating the developer carrying member. A reverse rotation driving means for rotating, and a developing means, which is in contact with the developer carrier during development to regulate the layer thickness of the toner carried on the developer carrier, and is reversely rotated by the reverse rotation driving means during non-development In an image forming apparatus having a roller-shaped toner layer regulating member rotatable with the developer carrier, the toner supply member is formed on the developer carrier when the developer carrier is rotated in a reverse direction. The obtained toner layer is collected so as to have a predetermined thickness or less when the developer carrier is rotated.

In this image forming apparatus, when the developer carrier rotates in the reverse direction, the toner supplied to the developer carrier by the toner supply roller is formed on the developer carrier as a thick toner layer having poor charging. However, when the developer carrier rotates during development, the toner supply member scrapes the thick toner layer to collect the developer. Therefore, the thick toner layer generated when the developer carrier rotates in the reverse direction does not pass through the toner layer regulating member during development. Therefore,
Since the toner layer on the developer carrier is sufficiently frictionally charged by the toner layer regulating member, it is possible to prevent the occurrence of background contamination due to insufficient charging of the toner. It is needless to say that the toner supply member is configured to supply the toner onto the developer carrying member during normal development in which the thick toner layer having poor charging is not formed on the developer carrying member. Nor. Further, in this image forming apparatus, as described in the first and second aspects, the size of the apparatus is smaller than that in the case where a toner collecting member for collecting the thick toner layer formed on the developer carrier is separately provided. Can be achieved.

According to a fourth aspect of the present invention, in the image forming apparatus of the third aspect, the toner supply member includes a toner layer formed on the developer carrier when the developer carrier is rotated in the reverse direction. It is characterized in that 90% or more is recovered when the developer carrier rotates.

In this image forming apparatus, the toner supply member collects at least 90% of the toner layer formed on the developer carrying member when the developer carrying member rotates in the reverse direction when the developer carrying member rotates. It is possible to reliably prevent the occurrence of background soiling due to insufficient charging of the toner.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a full-color printer as an image forming apparatus will be described below. First, the configuration and operation of the entire full-color printer according to the present embodiment will be described. FIG. 1 is a schematic configuration diagram of the entire printer. In FIG. 1, this printer includes a photosensitive belt 1 as a latent image carrier wound around a plurality of support rollers. The photoreceptor belt 1 is driven to rotate in a clockwise direction indicated by an arrow in the figure, and around the charger, a photoreceptor cleaning device 3, an optical writing unit 4, and four developing devices 5Bk, 5C, 5M, 5M
Y, an intermediate transfer belt 6 as an intermediate transfer body and the like are arranged. An organic photosensitive layer is formed on the surface of the photosensitive belt 1.

When an image forming operation (printing operation) is performed by the printer, a high voltage is applied to the charger 2 so that the photosensitive belt 1 is uniformly charged. In an image signal processing unit (not shown), color image information, for example, a color image signal sent from an external computer is converted into an optical write signal, and the optical write unit 4
Sent to In the optical writing unit 4, a laser as a light source is controlled based on the optical writing signal, and is transmitted through a polygon mirror, an f / θ lens, a reflection mirror, and the like to Black (Bk), Cyan (C), and Magen.
Optical writing corresponding to the image signals of ta (M) and Yellow (Y) is performed, and an electrostatic latent image is formed on the photosensitive belt 1.

The electrostatic latent images on the photoreceptor belt 1 are developed by developing devices 5Bk, 5C, 5C each having a color toner as a developer charged with a charge having a polarity opposite to that of the latent images.
Each color is developed by M, 5Y. This allows
On the photoreceptor belt 1, a toner image is formed for each color.

At the contact portion between the photosensitive belt 1 and the intermediate transfer belt 6, the toner image on the photosensitive belt 1 is applied to the intermediate transfer belt 6 by applying a charge having a polarity opposite to that of the toner to the intermediate transfer belt 6. Is transferred to By repeating this toner image formation and transfer operation four times, a four-color superimposed color toner image is formed on the intermediate transfer belt 6.
The color toner image on the intermediate transfer belt 6 is transferred by a paper transfer roller 9 as a secondary transfer member onto transfer paper as a recording material sent from a paper feed cassette 7 or a manual feed tray by a pair of conveying rollers 8. You. The transfer paper to which the color toner image has been transferred is conveyed to a fixing unit including a pair of fixing rollers 10, and the toner image is fused and fixed.

Next, the developing device according to this embodiment will be described with reference to FIG. The developing device according to the present embodiment includes:
The developing device is a one-component developing system using a non-magnetic one-component toner (hereinafter, referred to as toner). Each developing device 5 has a developing container 1 having an opening facing the photosensitive belt 1.
1. A developing roller 12 serving as a developer carrier, a supply roller 13 for supplying toner onto the developing roller 12, and a layer thickness of the toner carried on the developing roller 12 which is in contact with the developing roller 12 and is regulated. A regulating roller 14 as a toner layer regulating member for forming a toner layer having a thickness of
Toner storage sections 15a, 15b, 15c in developing container 11
The transport paddles 16a, 16b, 16c, etc., which send out the toner contained in the toner cartridge to the supply roller 13 side. Further, in order to prevent toner from leaking from a gap between the developing container 11 and the developing roller 12, a film-shaped sealing member extending on the inner surface of the developing container 11 so as to abut on the surface of the developing roller 12 is provided. A seal 17 is provided.

The developing roller 12 is partly exposed from the opening of the developing container 11 and is installed so as to be rotatable at a predetermined linear speed in a clockwise direction shown by an arrow in FIG. The latent image formed on the photoreceptor belt 1 is developed by being carried and conveyed to a developing area which is a contact portion with the photoreceptor belt 1. The supply roller 13 is provided so as to be rotatable clockwise as indicated by an arrow in the drawing at a predetermined linear speed during development, and is in contact with the development roller 12 at a predetermined pressure. It is made of polyurethane. Further, a toner regulating member 18 is brought into contact with the supply roller 13 so that the amount of toner supplied to the developing roller 11 is regulated. Each transport paddle 16 is installed so as to be rotatable clockwise as shown by the arrow in the figure, and sends the toner to the supply roller 13 side by this rotation. As a material of each transport paddle 16, for example, a soft and elastic material such as polypropylene can be used. By utilizing the elasticity, the transport paddle 16 rotates in a state of being in close contact with the inner wall of the developing container 11 and reliably transports the toner. .

The regulating roller 14 regulates the toner on the developing roller 11 to a predetermined layer thickness, and frictionally charges the toner by slidingly contacting the toner. The toner charged on the developing roller 12 develops the electrostatic latent image on the photoreceptor belt 1. In the present embodiment, urethane rubber coated with resin is used as the material of the surface of the regulating roller 14. Further, a regulating roller cleaning blade 19 is in contact with the regulating roller 14 so that the surface of the regulating roller 14 that has passed through the contact portion with the developing roller 11 is cleaned. Further, the regulating roller 14 is provided with a spring 20 as an urging means in order to absorb a change in the outer diameter of the developing roller 11 and the regulating roller 14 due to an environmental change such as humidity. 12 is pressurized.

Behind each of the developing devices 5, a not-shown contact / separation cam, which can rotate independently, and a separation spring (not shown) are provided. Each developing device 5 rotates the developing roller 1 prior to development by rotation of the contact / separation cam.
2 is configured to perform a contacting / separating operation to move to a developing position where the photosensitive drum 1 comes into contact with the photoreceptor belt 1 in a predetermined positional relationship. When the electrostatic latent image on the photoconductor belt 1 is developed, for example, when an electrostatic latent image of Bk is formed on the photoconductor belt 1, when the electrostatic latent image of Bk is formed on the photoconductor belt 1, The cam is rotated 180 degrees by a drive control unit (not shown), and the developing device 5Bk
Side, and the developing roller 12Bk is
To the development position where it comes into contact with. Developing device 5 for other colors
The same applies to C, 5M, and 5Y.

Each of the developing devices 5 rotates the developing roller 12 clockwise as indicated by the arrow in the drawing (hereinafter referred to as forward rotation) at the time of development, and rotates the developing roller 12 at the time of non-development. It is configured to be able to rotate in a direction opposite to the direction (hereinafter, referred to as reverse rotation). The reverse rotation driving means of the developing roller for reverse rotation of the developing roller 12 is performed by rotating the motor in the reverse direction. The developing roller 12 pressed by the spring 20 against the developing roller 12 is brought into contact with the rotating developing roller 12 at the time of development in a state where the regulating roller 14 is stopped, and the developing roller which rotates in the reverse direction during non-developing. 12 is rotated so as to rotate in the clockwise direction in the figure.

As shown in FIG. 3, a one-way clutch 21 and a housing 22 into which the one-way clutch 21 is press-fitted are provided at the end of the regulating roller 14 as a regulating roller rotation regulating means for regulating the rotation of the regulating roller 14. A stopper 23 projecting from the developing container 11 is provided on the rotation locus of the projection of the housing 22. When the developing roller 12 is rotating forward, the housing 22 rotates counterclockwise in the drawing, and the stopper 23 hits the protrusion of the housing 22 to stop the rotation of the housing 22 and lock the one-way clutch 21. Then, the rotation of the regulating roller 14 is stopped. Thus, the regulating roller 14 is separated from the photoreceptor belt 1 during non-development, and rotates with the developing roller 12 only when the developing roller 12 is rotating in the reverse direction. .

As described above, by using the one-way clutch 70, at the time of development, the stopped regulating roller 14 comes into contact with the developing roller, and the layer thickness of the toner layer carried on the developing roller 12 is reduced to a predetermined layer thickness. Can be regulated. On the other hand, at the time of non-development, by causing the regulating roller 14 to rotate along with the developing roller 11, it is possible to prevent deterioration of the blade surface with time and accumulation of toner, which are likely to occur when the regulating blade is used.

However, when the developing roller 12 rotates in the reverse direction,
The supply roller 13 that is rotating via a gear by the same drive source as the developing roller 12 also rotates in the direction opposite to that during development. Therefore, even when the developing roller 12 rotates in the reverse direction, the toner is supplied from the supply roller 13 to the developing roller 12, and a thick toner layer with poor charging is formed on the developing roller 12 between the supply roller 13 and the developing area. Will be. Even if the thick toner layer having poor charging is thinned by the regulating roller 14 due to the normal rotation of the developing roller 12, the toner is not sufficiently frictionally charged, and insufficient charging of the toner occurs.

Therefore, in the printer according to the present embodiment, a cleaning member is provided between the toner supply roller 13 and the seal 17 as a recovery member for recovering a thick toner layer having poor charging formed on the developing roller 12. 30
Is provided. The cleaning member 30 is made of an elastic material such as foamed polyurethane or rubber, and is brought into contact with the rotating developing roller 12 so that the developing roller 12
The toner layer formed thereon is collected.

Therefore, when the developing roller 12 rotates in the reverse direction, the thick toner layer with poor charging formed on the developing roller 12 is collected by the cleaning member 30. Can be prevented from passing through the regulating roller 14. As a result, at the time of development, a predetermined amount of toner is supplied onto the developing roller 12 by the toner supply roller 13, and the toner layer is sufficiently frictionally charged by the regulating roller 14. It is possible to prevent the generation of dirt. Further, since the cleaning member 30 is provided between the toner supply member and the seal 17, it is possible to prevent the toner from leaking from the seal 17 when the developing roller 12 rotates in the reverse direction.

In the present embodiment, the cleaning member 30 is always in contact with the developing roller 30. However, the cleaning member may be in contact only during non-development. Of course, the shape may be a roller shape.

Next, a developing device according to another embodiment will be described with reference to FIG. In this example, the above-described cleaning member and the supply roller are integrated. Note that the same parts as those of the developing device described above are denoted by the same reference numerals, and description thereof will be omitted.

The supply roller 31 according to this embodiment supplies the toner in the toner container 15 to the developing roller 12 when the developing roller 12 rotates forward, and also supplies the developing roller 12 when the developing roller 12 rotates reversely. It is configured to collect the thick toner layer with poor charging formed thereon. Specifically, at the time of forward rotation after the reverse rotation of the developing roller 12, the supply roller 31 recovers 90% or more of the thick toner layer with poor charging formed on the developing roller 12 during the reverse rotation of the developing roller 12. Then, during normal development in which a thick toner layer with poor charging is not formed on the developing roller 12, the toner in the toner container 15 is supplied.

FIG. 5 shows the recovery rate at which the thick toner layer having poor charging formed on the developing roller 12 when the developing roller 12 rotates in the reverse direction is recovered by the supply roller 31, and the background contamination on the photosensitive belt 1 at that time. FIG. 7 is a characteristic diagram illustrating a relationship between a toner amount (a value obtained by measuring a difference between a density of a background stained portion and a density of a tape itself using a densitometer after transferring the tape and using a densitometer). Since the amount of background toner not on the recording paper is 0.01 or less, FIG.
As shown in the figure, the toner recovery rate by the supply roller 31 is 9
It is preferably 0% or more.

The characteristics of the supply roller 31 can be adjusted according to the material (hardness, cell density of the foam) of the supply roller 31, the amount of bite of the supply roller 31 with respect to the developing roller 12, the linear velocity difference, the rotation direction, and the like. As a result, a desired toner recovery rate can be obtained. For example, by using a material having a higher coefficient of friction than the above-described supply roller 30 as the supply roller 31, the supply roller 31 can be provided with a toner collecting property when the developing roller 12 rotates forward.

[0038]

According to the first and second aspects of the present invention,
There is an excellent effect that a thick toner layer generated at the time of reverse rotation of the developer carrying member does not pass through the toner layer regulating member at the time of development, thereby making it possible to prevent occurrence of background contamination due to insufficient charging of toner. .

In particular, according to the second aspect of the present invention, it is possible to prevent the thick toner layer having poor charging formed on the developer carrier from leaking out of the seal member when the developer carrier is rotated in the reverse direction. Has an effect.

According to the third and fourth aspects of the present invention, the thick toner layer generated when the developer carrier rotates in the reverse direction does not pass through the toner layer regulating member during development, and the toner is not charged sufficiently. There is an excellent effect that it is possible to prevent the occurrence of background dirt. Further, as compared with the first and second aspects of the present invention, there is an excellent effect that the size of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a schematic configuration of a full-color printer according to an embodiment.

FIG. 2 is a schematic configuration diagram illustrating a schematic configuration of a developing device of the printer.

FIG. 3 is an explanatory diagram illustrating a structure that regulates the rotation direction of a regulation roller of the developing device.

FIG. 4 is a schematic configuration diagram illustrating a schematic configuration of a developing device according to another embodiment.

FIG. 5 is a characteristic diagram showing a relationship between a toner recovery rate by a toner supply roller and a background toner amount in the developing device.

FIG. 6 is a schematic configuration diagram showing a schematic configuration of a conventional developing device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoreceptor belt 11 developing container 12 developing roller 13 supply roller 14 regulating roller 15 toner container 16 transport paddle 17 seal 30 cleaning member 31 supply roller

Claims (4)

[Claims] A latent image carrier, a developer carrier for developing a latent image on the latent image carrier in a development area, a toner supply member for supplying toner to the developer carrier, and a developing device. Reverse rotation driving means for rotating the developer carrier in the direction opposite to the rotation direction during development, and regulating the layer thickness of the toner carried on the developer carrier by contacting the developer carrier during development. An image forming apparatus comprising: a roller-shaped toner layer regulating member rotatable around the developer carrier rotated in the reverse direction by the reverse rotation driving means during non-development; An image forming apparatus, wherein a toner collecting member for collecting toner is provided between the developing area and the toner supplying member. 2. The image forming apparatus according to claim 1, further comprising: a developing container containing toner therein and having an opening toward the surface of the latent image carrier; and a developing container and an opening formed in the developing container. A seal member provided in contact with the developer carrier to prevent toner from leaking from a gap between the developer carrier and the toner recovery member. An image forming apparatus provided between the image forming apparatus and a toner supply member. 3. A latent image carrier, a developer carrier for developing a latent image on the latent image carrier, a toner supply member for supplying toner to the developer carrier, and a developer carrier. Reverse rotation driving means for rotating in the opposite direction to the rotation direction during development; and, during development, abutting on the developer carrier to regulate the thickness of the toner carried on the developer carrier, and during non-development. An image forming apparatus comprising: a roller-shaped toner layer regulating member rotatable around the developer carrier that is reversely rotated by the reverse rotation drive unit; An image forming apparatus comprising: recovering a toner layer formed on a developer carrier during reverse rotation so as to have a predetermined thickness or less when the developer carrier rotates. 4. The image forming apparatus according to claim 3, wherein said toner supply member rotates a toner layer formed on said developer carrier when said developer carrier is rotated in a reverse direction. An image forming apparatus, wherein 90% or more is collected.