JP2994811B2 - Image forming device - Google Patents

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 provided with a cleaning member for cleaning the surface of a photoreceptor by removing residual developer remaining on the surface of the photoreceptor.

[0002]

2. Description of the Related Art Conventionally, generally, an image forming apparatus such as an electrophotographic apparatus develops a toner image corresponding to an image pattern of a document on the surface of a photosensitive drum, and transfers the toner image to a transfer paper to form an image. The formation is performed. Also,
An image forming apparatus such as the electrophotographic apparatus described above is provided with a cleaning member. The cleaning member removes residual toner remaining on the surface of the photosensitive drum without being transferred onto transfer paper from the surface of the photosensitive drum. The photosensitive drum is removed and the surface thereof is cleaned.

As the above-mentioned cleaning member, for example, as disclosed in Japanese Utility Model Application Laid-Open No. 61-99176, a blade-shaped cleaning member used in an electrophotographic apparatus by applying the Carlson process,
There is known a brush-shaped one as disclosed in Japanese Patent Application Laid-Open No. H10-209,873.

As shown in FIG. 7, the blade-shaped cleaning member (hereinafter referred to as a doctor blade) 30 has its tip end pressed against the surface of the photosensitive drum 31 to remain on the surface of the photosensitive drum 31. The remaining toner is separated and accumulated. The peeled and accumulated toner is then transferred to the doctor blade 30 and the photosensitive drum 3
1 is released, the photosensitive drum 31 is released.
Is collected in the developing case 34 by the seal member 32 and the rotating roller 33 with the rotation of.

Further, a brush-like cleaning member 40 is provided.
As shown in FIG. 8, a brush 40b is implanted on an outer peripheral surface of a roller member 40a, and a portion upstream of a contact portion between the photosensitive drum 41 and the toner held by the toner holding member 42 is provided. Since the outer peripheral surface of the roller member 40a is provided in contact with the surface of the photosensitive drum 41, the adhesion of the residual toner to the photosensitive drum 41 is mechanically reduced by the rotation of the photosensitive drum 41. It has become.

[0006]

However, in the conventional cleaning mechanism using the doctor blade 30, the doctor blade 30 must be movable, and the seal member 32 and the rotating roller 33 must be provided for collecting the residual toner. This leads to an increase in the size of the device and an increase in cost. Further, in the case where the thickness of the sealing material 32 is increased in order to improve the ability to collect the residual toner,
While the recovery capability is improved, the electrostatic latent image formed on the surface of the photoconductor drum 31 is deteriorated, and as a result, there is a problem that the image quality is deteriorated.

Further, a cleaning mechanism using a brush-like cleaning member 40 is provided for cleaning the photosensitive drum 4 of the residual toner.
This is to mechanically reduce the adhesion to the photosensitive drum 1 and not to completely separate the residual toner from the photosensitive drum 41. For this reason, when the residual toner has a strong adhesive force to the photosensitive drum 41, a toner image is formed on the surface of the photosensitive drum 41 with the residual toner adhered, and as a result, the image quality is This causes a problem of lowering the image quality.

[0008]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a developing device for holding a developer stored in a developing tank by a developer holding member; together comprising, in Rukoto contacting the developer developer held on the holding member of the developing device to the photosensitive member surface
An image forming apparatus that charges the surface of the photoreceptor , and forms an image by exposing an image pattern from the inside of the photoreceptor at a contact portion between the surface of the photoreceptor and the developer held by the developer holding member Has taken the following measures.

That is, it is provided integrally in the developing device.
Remove the residual developer remaining on the photoconductor and remove the surface of the photoconductor.
One end of the cleaning member that cleans the surface
Before exposing the image pattern,
Abuts at a position upstream of the contact portion in the rotational direction.
You .

[0010] The image forming apparatus according to claim 2 is
An image form according to claim 1 for solving the above problem.
The following measures are taken in the synthesizing apparatus .

That is, a developer recovery section is provided in the developing device, and the residual developer cleaned by the cleaning member is removed by an alternating magnetic field generated by rotation of a magnetic roller as the developer holding member. The developer is conveyed to the developer collecting section and collected.

The image forming apparatus according to a third aspect of the present invention provides
In order to solve the above problems, the image forming apparatus according to the first aspect has the following measures.

That is, the cleaning member is disposed in communication with the developing tank in the developing device, and is provided to the cleaning member by an alternating magnetic field generated by rotation of a magnetic roller as the developer holding member. The cleaned residual developer is conveyed to a developing tank and stored again.

[0014]

According to the structure of the first aspect, the inside of the developing device is provided.
The cleaning member integrally provided at the one end thereof
Near the contact area between the photoconductor surface and the developer, especially
It is arranged so as to contact at the upstream position in the rolling direction . For this reason, the exposure position of the exposure pattern and the cleaning member
The entire device can be miniaturized without any intervening parts, and at the time of exposing the image pattern, the residual developer is always removed and cleaned so that the contact between the clean photoreceptor surface and the supplied developer can be achieved. Exposure of the image pattern in the section can be continued, and deterioration in image quality due to this exposure can be avoided.

According to the second aspect of the present invention, the residual toner removed from the surface of the photoreceptor by the cleaning member is recovered by the action of an alternating magnetic field generated by rotation of a magnetic roller as a developer holding member. Section and collected. For this reason, the rotation of the magnetic roller as the developer holding member can be used for conveying the residual developer to the developer collecting section, and the cleaning mechanism of the photosensitive member surface can be simplified.

According to the third aspect of the present invention, the residual toner removed from the surface of the photoreceptor by the cleaning member is transferred to the developing tank by the action of the alternating magnetic field generated by the rotation of the magnetic roller as the developer holding member. It is transported and stored again. Therefore, the residual developer remaining on the surface of the photoreceptor can be reused as a developer for image formation.

[0017]

[Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the image forming apparatus according to the present embodiment includes a photosensitive drum 1 which is a cylindrical photosensitive member rotatable in the direction A in the apparatus. The developing device 2 is disposed on the right side of the image forming apparatus, the exposure device 10 is disposed in the photosensitive drum 1, and the dielectric belt 11 is disposed above the photosensitive drum 1.

As shown in FIG. 3, the photosensitive drum 1 is provided on the surface of an optically transparent cylindrical transparent support 1a.
A transparent conductive layer 1b made of a sputtered film of In ₂ O ₃ or SnO ₂ ,
A photoconductive layer 1c made of a photoconductive material such as Se, ZnO, CdS, or amorphous Si is sequentially laminated.
In this embodiment, as the transparent conductive layer 1b, a film thickness
An In ₂ O ₃ layer having a thickness of 0.5 μm is formed, and an amorphous Si layer having a thickness of 3 μm is formed as the photoconductive layer 1c.

The developing device 2 includes a developing tank 3 for storing a conductive toner T as a developer, a stirring roller 4 rotatably provided in the developing tank 3 and stirring the conductive toner T,
A toner holder 5 as a developer holding member disposed at a position facing the photosensitive drum 1 at an opening 3 a of the developing tank 3, and a toner holder 5 at a position below the toner holding member 5 at the opening 3 a of the developing tank 3. The doctor blade 6 provided and the developing tank 3
A cleaning member 7 disposed at a position above the toner holding member 5 in the opening 3a of the cleaning member 7; a toner collecting portion 8 as a developer collecting portion provided in the developing tank 3 on the right side of the cleaning member 7; The member 7 is replaced with a toner collection unit 8
And a holding member 9 for holding the holding member.

The toner holder 5 extends in the longitudinal direction of the photosensitive drum 1 and has N polarity and S polarity in the circumferential direction.
A magnetic roller 5a in which magnets having polarities are alternately arranged; and a developing sleeve 5b made of non-magnetic material such as aluminum or martensitic stainless steel and provided so as to cover the outer peripheral surface of the magnetic roller 5a. Consists of The toner holding member 5 holds the conductive toner T on the surface of the developing sleeve 5b by an alternating magnetic field generated by the rotation of the magnetic roller 5a in the B direction in the apparatus, and The sheet is conveyed in the direction B 'opposite to the direction B. The doctor blade 6 adjusts the transport amount of the conductive toner T held on the surface of the developing sleeve 5b and transported in the direction B 'as described above to a predetermined amount.

The above-mentioned conductive toner T is prepared by kneading resin such as styrene-acryl copolymer with magnetic powder such as iron powder and ferrite, carbon black, and the like.
It is composed of powder having a size of several μm to several tens μm.

The cleaning member 7 is made of urethane rubber having a thickness of 2 mm in order to obtain a sufficient cleaning effect on the surface of the photosensitive drum 1 as described later. One end of the cleaning member 7 is in contact with the surface of the photosensitive drum 1. On the other hand, as described above, the other end side is connected to the toner collecting section 8 via the holding member 9.
Is held in. Further, as described later, the holding member 9 is made of non-magnetic material such as aluminum or martensitic stainless steel in order to improve the transportability of the residual toner (residual developer) by the rotation of the magnetic roller 5a. . The material and thickness of the cleaning member 7 and the holding member 9 are not particularly limited to those described above.

The exposure device 10 is constituted by an LED array in which a light-emitting diode and a short focus lens are combined, and in accordance with an image pattern signal of a document from an exposure control device (not shown), the developing device 2 described above. The irradiation light is focused on the photoconductive layer 1c through the transparent support 1a and the transparent conductive layer 1b of the photosensitive drum 1.

The dielectric belt 11 is formed in an endless belt shape using a film material mainly composed of a polyimide resin having excellent mechanical strength and high heat resistance. As shown in FIG. 1, the dielectric belt 11 includes a transfer roller 12 disposed above the photosensitive drum 1,
In the drawing of the transfer roller 12, a heating device 13, which will be described later, is disposed at a position slightly above the left side, and the heating device 1
3 and the tension roller 14 disposed further below and to the left of the photosensitive drum 1 and the transfer roller 12 so as to surround the three members 12.13.14 from the outside. Between these photosensitive drums 1
And the transfer roller 12.

The dielectric belt 11 is made of a film-like polyimide resin as its material.
In particular, the material is not limited to this, and any material may be used as long as at least the surface onto which the conductive toner T is transferred has an insulating property as described later. It may be a metal belt with a fluorine coating. The thickness of the dielectric belt 11 is not particularly limited, but is 10 μm to 200 μm in consideration of thermal conductivity and mechanical strength.
The thickness is preferably as small as possible, and the surface may be roughened to make the gloss of the image appropriate.

The heating device 13 is for heating and melting the conductive toner T transferred to the surface of the dielectric belt 11, as will be described later. The heating device 13 has a planar Mo-based heating resistor (surface) on an alumina ceramic substrate. A heating element 13a is printed, and a glass heater is printed and laminated thereon to form a ceramic heater. The heating device 13 is configured to quickly raise the temperature to a predetermined heating temperature by energizing the heating resistor 13a, and is arranged such that the heating surface is in direct contact with the surface of the dielectric belt 11. Have been.

A pressure roller 15 that rotates while applying a pressing force in a direction toward the heating device 13 via the dielectric belt 11 is disposed at a position above the heating device 13. The pressure roller 15 sandwiches a transfer sheet P as a recording material conveyed by a recording material conveying unit 17 described later in a pressure contact portion with the dielectric belt 11.

Further, in the image forming apparatus of this embodiment, as shown in FIG. 2, a stepping motor 16 which is a drive source of the apparatus, and a transfer paper P is applied to a pressure contact portion between the dielectric belt 11 and the pressure roller 15. Recording material transporting means 17 for transporting
A paper output means 24 for discharging the transfer paper P from the inside of the apparatus is provided.

The recording material conveying means 17 is disposed above the photosensitive drum 1, the developing device 2, and the dielectric belt 11, and as a component thereof, from a transfer paper supply opening (not shown). Dielectric belt 11 and pressure roller 1
Transport guide plate 1 that forms a transport path that connects to the press-contact portion with the transfer guide plate 5
8, a paper feed detection actuator 19, a paper feed detection switch 20, and a paper feed roller 21 arranged near the transfer paper supply opening, and a registration roller 22 arranged in the middle of the path of the transport guide plate 18. A registration solenoid 23 for controlling the rotation of the registration roller 22;

The paper output means 24 is disposed on the left side of the pressure contact portion between the dielectric belt 11 and the pressure roller 15,
Its components are a dielectric belt 11 and a pressure roller 1
A paper output guide plate 25 that forms a paper output path connecting the pressure contact portion with the transfer belt 5 to a transfer paper discharge opening (not shown), and the dielectric belt 1
A sheet ejection detection actuator 26 and a sheet ejection detection switch 27 disposed near a pressure contact portion between the pressure roller 1 and the pressure roller 15;
And a paper discharge roller 28 disposed on the end side of the paper output guide plate 25.

The operation of the image forming apparatus having the above configuration will be described.
Next, a description will be given.

First, 1 is supplied by a transfer paper supply means (not shown).
When a sheet of transfer paper P is fed from the transfer paper supply opening,
When the leading end of the transfer paper P pushes up the paper input detection actuator 19, the paper input detection switch 20 detects the supply of the transfer paper P, and outputs a paper input detection signal to the stepping motor 16.
And the stepping motor 16 as a driving source is rotationally driven.

Next, the rotation of the stepping motor 16 is transmitted to the paper feed roller 21 via a rotation transmission mechanism (not shown), so that the paper feed roller 21 is rotated. The transfer paper P is a registration roller 2
2 is transferred.

The transfer paper P conveyed to the registration rollers 22 as described above is temporarily stopped by the rotation of the registration rollers 22 controlled by the registration solenoid 23. At this time, the paper feed rollers 21 are in a state where the rear end side of the transfer paper P is sandwiched and the resistance of the roller surface is small. It is in a state of slipping on both sides.

Next, the developing process of the conductive toner T will be described with reference to FIGS.

First, the conductive toner T stored in the developing tank 3 is changed by the alternating magnetic field generated by the rotation of the magnetic roller 5a in the direction B, as shown in FIG.
The photosensitive drum 1 is conveyed on the surface of the developing sleeve 5b in the direction B 'opposite to the direction A which is the rotation direction of the photosensitive drum 1 while being held on the surface b. At this time, the conductive toner T held on the surface of the developing sleeve 5b and the photosensitive drum 1
In the contact portion between the developing sleeve 5b and the transparent conductive layer 1b, a potential difference of several tens of volts is applied between the developing sleeve 5b and the transparent conductive layer 1b.
b, the charge is injected into the photosensitive drum 1 through the conductive toner T, and the surface of the photosensitive drum 1 is charged to substantially the same potential as the developing sleeve 5b.

The conductive toner T contacted with the photosensitive drum 1 as described above is subjected to a magnetic force generated by the magnetic roller 5a when the surface of the photosensitive drum 1 and the developing sleeve 5b become equipotential. Since it is dominantly applied, it does not adhere to the photosensitive drum 1.

Next, as shown in FIG.
Immediately before or apart from the conductive toner T, or at a portion C in the vicinity thereof, the LEDs corresponding to the image pattern of the document are sequentially selected from the exposure device 10 and the exposure is performed. The charged electric charge is neutralized, and a potential difference is generated between the surface of the photosensitive drum 1 and the developing sleeve 5b.

Thereafter, charge is injected into the photosensitive drum 1 again from the developing sleeve 5b through the conductive toner T due to the potential difference as described above, but before the charge injection is sufficiently performed, the photosensitive drum 1 is electrically connected to the photosensitive drum 1. As shown in FIG. 5, the conductive toner T is separated from the conductive toner T by the action of an electric field acting between the developing sleeve 5b and the surface of the photosensitive drum 1 in a charged state, as shown in FIG. The magnetic force is shaken off and adheres to the surface of the photoconductor drum 1, and is developed on the surface of the photoconductor drum 1 as a toner image corresponding to the image pattern of the document.

The toner image developed on the surface of the photosensitive drum 1 as described above is applied to the transfer roller 12 by applying a voltage having a polarity opposite to that of the injected charge of the toner image. The photosensitive drum 1 and the transfer roller 12 are transferred to the surface of the dielectric belt 11 at the pressure contact portion between the photosensitive drum 1 and the transfer roller 12. On the other hand, the dielectric belt 11 on the heating device 13 and the pressure roller 1
A signal is output from a CPU (Central Processing Unit) of an engine controller (not shown) to the registration solenoid 23 so that the toner image on the surface of the dielectric belt 11 and the transfer paper P correspond to each other at the pressure contact portion with the registration solenoid 5. The rotation stop state of the roller 22 is released, and the transfer paper P is transported to the pressure contact portion between the dielectric belt 11 and the pressure roller 15.

Then, the dielectric belt 11 onto which the toner image has been transferred and the transfer paper P are superposed and conveyed between the heating device 13 and the pressure roller 15 so that the toner on the transfer paper P is transferred. Image transfer and fixing are performed simultaneously. That is, when the transfer paper P is sent out in pressure contact between the dielectric belt 11 and the pressure roller 15, the surface of the dielectric belt 11 is contacted with the conductive toner T heated and melted by the heating device 13. However, since the releasability is better than that of the transfer paper P, most of the conductive toner T on the surface of the dielectric belt 11 is transferred and fixed onto the transfer paper P.

Thereafter, the transfer paper P on which the toner image has been transferred and fixed is pushed up by the paper ejection detection actuator 26, and is discharged from the apparatus through the transfer paper discharge opening by the rotation of the discharge roller 28. Then, the paper input detection switch 2
After a predetermined period of time when the detection of the paper input detection signal from 0 and the paper output detection signal from the paper output detection switch 27 are stopped, the power supply to the heating resistor 13a of the heating device 13 and the driving of the stepping motor 16 are started. The operation is stopped, and the above-described series of operations is completed.

In the series of operations described above, the residual toner remaining on the surface of the photosensitive drum 1 without being transferred to the dielectric belt 11 in the toner image developed on the surface of the photosensitive drum 1 is cleaned. The toner is removed from the surface of the photosensitive drum 1 by the member 7, and is conveyed in the D direction on the cleaning member 7 and the holding member 9 by an alternating magnetic field generated by the rotation of the magnetic roller 5 a, and is collected in the toner collecting unit 8. It has become.

As described above, in the image forming apparatus of the present embodiment, the cleaning member 7 for removing the residual toner remaining on the surface of the photosensitive drum 1 and cleaning the surface of the photosensitive drum 1 has one end of the photosensitive member. Conductive toner T on one surface
Upstream of the contact portion with the photosensitive drum, that is, as shown in FIG.
It is integrally provided in the developing device 2 in a state of being in contact with an upstream position in front of the contact portion with respect to one rotation direction A. The residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 7 is
The toner is collected in the toner collecting unit 8 by the action of the alternating magnetic field generated by the rotation of the rotation a.

For this reason, the rotation of the magnetic roller 5a for developing the toner image on the surface of the photosensitive drum 1 can be used together with the rotation of the magnetic roller 5a for transporting the residual toner to the toner collecting section 8, so that the surface of the photosensitive drum 1 The cleaning mechanism can be simplified, and the size of the apparatus can be reduced due to the reduction in the number of parts. Furthermore, since the residual toner on the surface of the photosensitive drum 1 is removed upstream of the contact portion with the conductive toner T on the surface of the photosensitive drum 1, there is a possibility that the charging of the surface of the photosensitive drum 1 in accordance with the image pattern is deteriorated. As a result, deterioration of image quality can be avoided.

Embodiment 2 Another embodiment of the present invention will be described below with reference to FIG. In the second embodiment, except for the toner collecting unit 8 provided in the developing device 2 of the first embodiment,
Since the configuration is the same as that of the first embodiment, the description of the configuration other than the developing device 2 is omitted, and
Members having the same functions as in the first embodiment are denoted by the same reference numerals.

As shown in FIG. 6, the developing device 2 'of this embodiment is disposed on the right side of the photosensitive drum 1, and its constituent members include the developing device 2' of the first embodiment. Similarly to the above, the image forming apparatus includes a developing tank 3, a stirring roller 4, a toner holder 5, a doctor blade 6, a cleaning member 7, and a holding member 9.

The holding member 9 is fixed to a side wall of the developing tank 3 (not shown) in a direction perpendicular to the plane of FIG. The cleaning member 7 has one end side abutting on the surface of the photoreceptor drum 1 and the other end side held by the holding member 9 to provide the conductive toner T.
Is in communication with the developing tank 3 that stores the developer.

In the above configuration, in the developing device 2 ′, the toner image developed on the surface of the photosensitive drum 1 is not transferred to the dielectric belt 11 without being transferred to the dielectric belt 11, as in the first embodiment. After the residual toner remaining on the surface of the drum 1 is removed from the surface of the photosensitive drum 1 by the cleaning member 7, the alternating magnetic field generated by the rotation of the magnetic roller 5 a in the direction B causes the cleaning member 7 and the holding member 9 to move on the cleaning member 7 and the holding member 9.
Conveyed in the direction.

The residual toner conveyed in the direction D by the alternating magnetic field as described above is charged into the developing tank 3 in which the unused conductive toner T is stored. Mixed with the above conductive toner T,
It is reused as the conductive toner T for forming a toner image.

As described above, in the image forming apparatus of this embodiment, the cleaning member 7 for removing the residual toner remaining on the surface of the photosensitive drum 1 and cleaning the surface of the photosensitive drum 1 is integrated with the developing device 2 '. The residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 7 is again thrown into the developing tank 3 by the action of the alternating magnetic field generated by the rotation of the magnetic roller 5a. ing.

For this reason, the residual toner remaining on the surface of the photosensitive drum 1 can be reused as the conductive toner T for forming the toner image. As a result, in addition to the effects of the first embodiment, This makes it possible to use the conductive toner T economically.

The present invention is not limited to the first and second embodiments, and various changes can be made within the scope of the present invention. For example, in the first and second embodiments, the conductive toner T is used as the developer. However, the present invention is not particularly limited to this, and the toner other than the conductive toner T used in the electrophotographic method may be used. It is also possible to adopt a configuration in which development is performed by using.

[0055]

As described above, according to the present invention, an image forming apparatus according to claim 1 of the present invention, in the developing device located at the contact portion upstream of the developer of the photoreceptor surface, residual remaining on the photosensitive member surface One end of the cleaning member, which removes the developer and cleans the photoreceptor surface, is brought into contact with the photoreceptor surface to form an integral part.
A structure provided on.

Thus, the developer remaining on the surface of the photoreceptor
When exposing an image pattern from the inner surface of the photoreceptor,
Has been removed upstream. Therefore, the photoconductor surface
Residual development in a developing device that exposes and develops image patterns
Remove the cleaning agent and clean the image.
As a result, there is an effect that it is possible to provide a small-sized image forming apparatus that avoids deterioration of image quality due to residual developer.

Further, according to the image forming apparatus of the present invention,
2. The image forming apparatus according to claim 1, wherein a developer collecting unit is provided in the developing device, and the residual developing material is cleaned by the cleaning member by an alternating magnetic field generated by rotation of a magnetic roller as a developer holding member. 3. This is a configuration in which the developer is transported to a developer collection unit and collected.

Thus, there is no need to separately provide a collecting container for collecting the residual developer, and the rotation of the magnetic roller as the developer holding member is also used for conveying the residual developer to the developer collecting section. Therefore, it is possible to simplify the cleaning mechanism for cleaning the surface of the photoreceptor, and it is possible to reduce the size of the apparatus due to the reduction in the number of parts.

The image forming apparatus according to claim 3 is
2. The image forming apparatus according to claim 1, wherein the cleaning member is disposed in communication with the developing tank in the developing device, and is cleaned by an alternating magnetic field generated by rotation of a magnetic roller as a developer holding member. In this configuration, the residual developer that has been cleaned on the member is transported to a developing tank and stored again.

As a result, the residual developer remaining on the surface of the photoreceptor can be reused as a developer for image formation, so that there is an effect that the developer can be economically utilized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a photosensitive drum, a developing device, an exposing device, and a dielectric belt constituting an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing various components constituting the image forming apparatus.

FIG. 3 is an explanatory diagram showing a state in which the surface of the photosensitive drum is charged by contact with a conductive toner.

FIG. 4 is an explanatory diagram showing a state in which the surface of the photosensitive drum is neutralized by exposure of an exposure device.

FIG. 5 is an explanatory diagram showing a state in which a toner image has been developed on the surface of the photosensitive drum.

FIG. 6 is a longitudinal sectional view showing a photosensitive drum, a developing device, an exposing device, and a dielectric belt constituting an image forming apparatus according to another embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing an image forming apparatus provided with a conventional blade-shaped cleaning member.

FIG. 8 is a longitudinal sectional view showing another image forming apparatus including a conventional brush-shaped cleaning member.

[Explanation of symbols]

 Reference Signs List 1 photoconductor drum (photoconductor) 2 developing device 3 developing tank 5 toner holder (developer holding member) 5a magnetic roller 7 cleaning member 8 toner collecting unit (developer collecting unit) T conductive toner (developer)

Claims (3)

(57) [Claims] A developing device for holding a developer stored in a developing tank on a developer holding member, wherein the developer held by the developer holding member of the developing device is applied to a surface of a photoreceptor to be rotated. The contact of the surface of the photoreceptor by contact
Performed, and, by exposing the image pattern from inside the photoreceptor at the contact portion with the developer held on the photosensitive member surface and the developer holding member in an image forming apparatus for forming an image, in the developing device Provided integrally and remains on the photoconductor
To remove the residual developer and clean the photoreceptor surface.
One end of the cleaning member has the above-described image pattern.
Before the exposure, and in the rotation direction of the photoconductor,
An image forming apparatus contacted at an upstream position of the contact portion . 2. A developing device according to claim 1, further comprising a developer collecting section provided in said developing device, wherein an alternating magnetic field generated by rotation of a magnetic roller as said developer holding member removes said residual developer cleaned by said cleaning member. The image forming apparatus according to claim 1, wherein the image forming apparatus conveys and collects the developer to the developer collecting section. Wherein said cleaning member is disposed in communication with the developing tank in the developing apparatus, the developer
2. The image forming apparatus according to claim 1, wherein the residual developer cleaned by the cleaning member is transported to the developing tank and stored again by an alternating magnetic field generated by rotation of a magnetic roller serving as a holding member. .