JPH10268632A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device that an perform development and recovery of residual toner without contaminating the surface of a photoreceptor drum and is capable of forming a distinct image, and an image forming device equipped therewith. SOLUTION: A process unit 7 is at least quipped with the photoreceptor drum 25, a developing roller 27 performing the development in contact with the drum 25, and a cleaning roller 29 recovering the residual unused toner for transfer after the development in contact with the drum 25; and constituted so that the development is performed by an electrophotographic method by using the electrified toner. And further, the residual toner is recovered from the roller 29 through the drum 25 so as to be reused. In such a case, the surfaces of all the rollers coming in contact with the drum 25 are formed of non- migration material, for example, polyurethane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention belongs to the technical field of a developing device in an image forming apparatus for forming an image by an electrophotographic method using a charged toner.

[0002]

2. Description of the Related Art Conventionally, a photosensitive drum as a photosensitive member,
Using a developing device including a developing roller that contacts the photosensitive drum to develop the electrostatic latent image on the photosensitive drum and a transfer roller that contacts the photosensitive drum and transfers the developed toner to recording paper, 2. Description of the Related Art An image forming apparatus such as a printer that forms and records an image on a recording sheet by a so-called electrophotographic method is widely used.

In recent years, in the above-described image forming apparatus, toner remaining on the photosensitive drum without being used in one image formation from the viewpoint of saving resources (hereinafter referred to as residual toner). Research on collecting and reusing this is active.

At this time, as one of the effective methods for collecting the residual toner, there is a so-called cleaning in which the residual toner on the photosensitive drum which has not been used for the transfer by the transfer roller after development is brought into contact with the photosensitive drum and rotated. The roller is temporarily collected, and at a predetermined timing at which recording on a recording sheet is not performed, is transferred again from the cleaning roller to the photosensitive drum, and further transferred from the photosensitive drum to the developing roller using the rotation of the photosensitive drum itself. There is a system for collecting by the developing roller.

Incidentally, as a photosensitive drum in a conventional developing device, for example, a photosensitive drum in which a photoconductive layer is formed by coating a resin as a photosensitive material on an aluminum cylindrical surface is generally used. As for the surface material of each of the developing roller, the transfer roller and the cleaning roller, it is common to use silicone rubber for at least two of the rollers.

[0006]

However, when the roller using the silicone rubber comes into contact with the photosensitive drum to perform development, transfer, or recovery of residual toner, the silicone rubber itself has unevenness in the degree of polymerization. As a result, some of the components of the silicone rubber (such as low-polymerization degree siloxane and non-functional silicone oil) leak out (bleed) from the rollers and migrate to the surface of the photosensitive drum to contaminate the photosensitive drum. There was a problem that it might be.

If the photosensitive drum is contaminated, the electrostatic latent image cannot be visualized, that is, high-quality image development cannot be performed. As a result, a clear image cannot be formed on recording paper. Leads to.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to perform development and recovery of residual toner without contaminating the surface of the photosensitive drum. An object of the present invention is to provide a developing device capable of forming a clear image and an image forming apparatus provided with the developing device.

[0009]

According to an aspect of the present invention, there is provided a photoconductor such as a photosensitive drum, a developing roller for performing development by contacting the photoconductor, and A developing roller that includes at least a collection roller such as a cleaning roller that collects residual toner that is not used for transfer after development by contacting the photoconductor, and performs development by electrophotography using the charged toner. An apparatus, wherein the residual toner is collected from the collection roller via the photoconductor, and is reused.
At least the surface of all the rollers that contact the photoconductor is in contact with the photoconductor, and is formed of a non-migrating material.

According to the operation of the first aspect of the present invention, at least the surface of all the rollers that come into contact with the photoreceptor is in contact with the photoreceptor is formed of a material having non-migration properties. Is not contaminated with the material forming the surface of each roller, and high-quality image development can be performed.

According to a second aspect of the present invention, there is provided a developing device according to the first aspect, wherein at least surfaces of all rollers that come into contact with the photoreceptor are provided.
It is formed of polyurethane.

According to the function of the invention described in claim 2, in addition to the function of the invention described in claim 1, at least the surfaces of all the rollers that come into contact with the photoreceptor are formed of polyurethane. High quality image development can be performed without the surface of the body being contaminated by the substance forming the surface of each roller.

According to a third aspect of the present invention, there is provided a developing device according to the second aspect, wherein the surface of the recovery roller is formed of polyurethane foam, and The surface is formed by polyurethane rubber.

According to the function of the invention described in claim 3, in addition to the function of the invention described in claim 2, the surface of the collection roller is formed of polyurethane foam.
Since the surface of the developing roller is made of polyurethane rubber, it is possible to satisfactorily collect the residual toner and develop the image with high image quality.

According to a fourth aspect of the present invention, there is provided a developing device according to the first aspect, wherein the developing device includes an electrostatic latent image corresponding to an image to be recorded. Forming means such as a scanner unit formed on the photoconductor,
Transfer means such as a transfer roller for transferring the toner adhered on the photoreceptor corresponding to the formed electrostatic latent image onto a recording sheet on which the image is to be recorded, and transferring the toner onto the recording sheet Fixing means such as a fixing unit for fixing the toner thus obtained.

According to the operation of the invention described in claim 4, in addition to the operation of the invention described in any one of claims 1 to 3, the forming means includes an electrostatic latent image corresponding to an image to be recorded. An image is formed on the photoreceptor.

The transfer means transfers the toner adhered on the photoreceptor to the recording paper corresponding to the formed electrostatic latent image.

Finally, the fixing means fixes the toner transferred onto the recording paper.

Accordingly, high-quality development can be performed without contaminating the surface of the photoreceptor with the material forming the surface of the roller in contact with the photoreceptor, thereby forming a clear image. be able to.

[0020]

Next, a preferred embodiment of the present invention will be described with reference to the drawings. The following embodiment is an embodiment in which the present invention is applied to a so-called laser printer.

(I) Overall Configuration and Operation First, the overall configuration of the laser printer according to the embodiment will be described with reference to FIGS. FIG. 1 is an external perspective view of the laser printer according to the embodiment, and FIG.
Is a longitudinal sectional view of a central portion thereof.

As shown in FIGS. 1 and 2, the laser printer 1 of the embodiment comprises a main body case 2 and the main body case 2.
A first paper feed tray unit 3 and a second paper feed tray unit 4 provided on the rear upper surface, a paper transport mechanism 5 provided in the main body case 2, a scanner unit 6 as forming means, and a developing device Process unit 7, a fixing unit 8 as a fixing unit, a first paper feed tray unit 3, a second paper feed tray unit 4, a paper transport mechanism 5,
A drive unit (not shown) accommodated in a left front portion of the main body case 2 for driving the process unit 7 and the fixing unit 8 and the like is configured.

A top cover 10 capable of opening the inside of the laser printer 1 is provided on a front upper surface of the main body case 2.
A paper discharge tray 11 is provided. Among them, the paper discharge tray 11 is freely switchable from a closed position indicated by a solid line in FIG. 2 to an open position indicated by a chain line, and functions as a tray for receiving and accumulating recorded sheets when in the open position.

In the above-described configuration, the scanner unit 6, the process unit 7, and the fixing unit 8 constitute a printing mechanism for actually performing recording.

The process unit 7 houses a photosensitive drum 25, a charger 26, a developing roller 27, a transfer roller 28 as a transfer unit, a cleaning roller 29 as a collection roller, and the like in a casing 24. 2 has a cartridge structure that can be attached to and detached from a predetermined portion.

Further, the first paper feed tray unit 3 is fixedly provided on the upper surface near the rear end of the main body case 2, and the second paper feed tray unit 4 is It is detachably provided on the upper surface of the front surface of one sheet feed tray unit 3.

On the other hand, the paper transport mechanism 5 is for transporting the paper alternatively fed from the first paper feed tray unit 3 or the second paper feed tray unit 4 to the process unit 7. A pair of feed rollers 12a and 12b provided on the lower end side of the paper feed tray unit 3 and a registration roller 1 provided on the front surface of the lower end of the second paper feed tray unit 4
3a and 13b. Among these, the feed roller 12a is a driving roller and the feed roller 12b is a driven roller. The registration roller 13a is a driving roller, and the registration roller 13b is a driven roller.

The paper transport path 14 from the first paper tray unit 3 to the registration rollers 13a and 13b is
In the state where the second paper feed tray unit 4 is detached from the main body case 2, the lower paper feed path 14 a is included.
Is open to the outside.

Further, the paper fed from the first paper feed tray unit 3 is fed and driven by feed rollers 12a and 12b, passes through a lower-side transport path 14a, and passes through registration rollers 13a.
a and 13b, and are fed and driven after the registration and conveyed to the process unit 7.

On the other hand, the paper fed from the second paper feed tray unit 4 reaches the registration rollers 13a and 13b, is fed and driven after registration, and is conveyed to the process unit 7.

Next, the first paper feed tray unit 3 will be described in detail. The first paper feed tray unit 3 is provided with a tray case 36 capable of storing a plurality of papers P upward and inclined.
A sheet receiving plate 37 provided at the bottom of the tray case 36 for receiving the lower surface side of the sheet P; a compression coil spring 38 for urging the sheet receiving plate 37 forward;
And a tray cover 39 which is rotatably mounted near the lower end of the tray case 36 and can be opened and closed at a predetermined angle, and the sheet receiving plate 37 is moved in conjunction with the opening operation of the tray cover 39 by the compression coil spring 38. The release mechanism 40 includes a release mechanism 40 that releases the actuator backward against the urging force, a paper feed roller 41, and the like.

Further, the second paper feed tray unit 4 is provided with a tray case 56 capable of storing a plurality of papers P in an upwardly inclined shape, and a paper receiving tray provided at the bottom of the tray case 56 for receiving the lower surface side of the papers P. A plate 57, a compression coil spring 58 for urging the sheet receiving plate 57 forward, and a tray opposing the front side of the sheet receiving plate 57 and rotatably mounted near the lower end of the tray case 56 and capable of opening and closing at a predetermined angle. The cover 59 includes a cover 59, a release mechanism 60 that releases the sheet receiving plate 57 rearward against the urging force of the compression coil spring 58 in conjunction with the opening operation of the tray cover 59, and a paper feed roller 61. Note that a manual paper feed port 80 for manually feeding paper P is provided on the front surface of the second paper feed tray unit 4.

Next, the process unit 7 will be described more specifically. The process unit 7 is formed on the surface of the photosensitive drum 25 in accordance with image data to be recorded by a laser optical system provided in the scanner unit 6 and described later. And a toner supply unit for supplying toner to the electrostatic latent image.

That is, the process unit 7 includes a photosensitive drum 25 and a transfer roller 28 in contact with the upper surface thereof, a scorotron-type charger 26 disposed below the photosensitive drum 25, and an upstream of the photosensitive drum 25 in the sheet feeding direction. A developing chamber including a developing roller 27 and a toner supply roller 31 disposed on the side, a detachable toner cartridge 30 serving as a toner storage section disposed further upstream, and a downstream side in the paper feeding direction from the photosensitive drum 25. It is composed of a cleaning roller 29 and the like arranged.

Here, the photosensitive drum 25 is constituted by forming a photoconductive layer by coating a resin as a photosensitive member on a surface of, for example, an aluminum cylinder.

In the developing chamber of the developing device (the portion including the toner supply roller 31, the development roller 27, the upper auger 42, the lower auger 43, and the like, which will be described later, the same applies hereinafter). , A pair of lower augers 43 and upper augers 42 are rotatably arranged.
The lower auger 43 supplies the toner supplied from the toner cartridge 30 into the developing chamber via the toner supply port 30a (formed by a hole formed at a substantially central position of the toner cartridge 30 and a hole formed in the casing 24). To
The upper auger 42 serves to convey the toner in the direction of both ends of the toner supply roller 31 above the toner supply roller 31.
Are the toner supply ports 3 from both ends of the toner supply roller 31.
It has a function of transporting toner toward 0a. As described above, the toner supplied from the toner supply port 30a to the developing chamber via the lower auger 43 and the upper auger 42 is conveyed and circulated in both directions above the toner supply roller 31. Is supplied while adhering to the toner supply roller 31 during the transportation and circulation. In addition,
In this embodiment, in order to promote the function of the upper auger 42, the auger partition plate 44 is provided between the upper auger 42 and the lower auger 43 in a direction parallel to the rotation axis of each auger.

On the other hand, the blade 33 is fixed to the lower surface of the casing 24 above the developing roller 27 by an L-shaped blade fixing member 33a. This blade 33
Is for charging the toner supplied from the toner supply roller 31 to the developing roller 27 to a predetermined polarity and for regulating the layer thickness of the toner layer to a predetermined thickness.

Further, the scanner unit 6 irradiates the outer peripheral surface of the photosensitive drum 25 with a laser beam while scanning the charged layer formed by the charger 26 while scanning the laser beam. An electrostatic latent image is formed.
At this time, the toner in the toner cartridge 30 is agitated by the agitator 32 and is discharged from the toner supply port 30a.
And the thickness of the toner layer is regulated by the blade 33. As a result, the electrostatic latent image formed on the photosensitive drum 25 is visualized by the toner adhered by the developing roller 27, and is transferred to the paper P passing between the transfer roller 28 and the photosensitive drum 25. After that, the remaining toner remaining on the photosensitive drum 25 is
After being temporarily held on the paper 2, the photosensitive drum 2 is moved at a predetermined timing (for example, between the conveyed paper P and the next paper P) at which image recording on the paper P is not performed.
5 and is carried by the developing roller 27 and collected in the developing chamber.

Next, the scanner unit 6 will be described.

As shown in FIG. 2, the scanner unit 6 has a known laser optical system. The scanning of the laser optical system is performed based on input image data to be recorded, and the surface of the photosensitive drum 25 is statically scanned. This is a unit that forms an electrostatic latent image.

More specifically, the scanner unit 6
The scanner unit 6 is disposed below the process unit 7, and a scanner cover 45 is attached to an upper surface of the scanner unit 6. The scanner cover 45 is fixed to the main body case 2 on the upstream side of the bottom plate 46 in the sheet feeding direction so as to cover most of the opening. The scanner unit 6 serving as an exposure unit has a laser light emitting unit (not shown) such as a semiconductor laser on the lower surface side of the scanner cover 45.
Scanner motor 47, polygon mirror 20, lens 22
The laser light passes through a glass plate 49 fitted in a horizontally long scanner hole 48 formed by a scanner cover 45 so as to extend along the rotation axis of the photosensitive drum 25. Then, the light is irradiated on the outer peripheral surface of the photosensitive drum 25. As a result, an electrostatic latent image is formed on the outer peripheral surface of the photosensitive drum 25 by exposure according to the image data. In this way, the toner is supplied to the electrostatic latent image formed on the photosensitive drum 25 by the laser optical system of the scanner unit 6 through the process unit 7, and the toner of the electrostatic latent image is developed.

Next, the sheet P conveyed to the process unit 7 is exposed to the photosensitive drum 2 in the process unit 7.
The toner image corresponding to the electrostatic latent image formed on the toner image 5 is transferred, and then is conveyed to the fixing unit 8. The fixing unit 8 fixes the toner transferred to the sheet P to the sheet P by heating, and includes a heating roller 34,
Pressing roller 35 pressed by the heating roller 34
And a pair of discharge rollers 15 a and 15 b provided downstream of the heating roller 34 and the pressing roller 35 and discharging the sheet P to the outside of the main body case 2.

In FIG. 2, the registration rollers 1
The path R of the sheet P from the portions 3a and 13b to the sheet discharge tray 11 on the downstream side in the sheet feeding direction is indicated by a broken line.

(II) Detailed Configuration and Machine of Process Unit
Ability Next, the detailed configuration of the process unit 7 according to the present invention will be described with reference to FIG. FIG. 3 is an enlarged longitudinal sectional view of the process unit 7.

The development performed in the process unit 7 of the present invention is reversal development by an impression development system using a so-called non-magnetic one-component toner.

As described above, during image formation, the toner is discharged from the toner supply port 30 a of the toner cartridge 30 while being stirred by the stirring body 32, and
By the action of the upper auger 42 and the auger partitioning plate 44, the toner is distributed almost evenly in the direction of the central axis on the toner supply roller 31 and supplied to the developing roller 27. At this time, the toner supply roller 31 and the developing roller 27 rotate in opposite directions at the contact portion, and the toner is supplied to the developing roller 27 while being charged by the contact of the blade 33.

The surface of the developing roller 27 is formed of a non-migratory material such as a thermoplastic polyurethane elastomer (polyurethane rubber). Further, the material of the developing roller 27 is not limited to a polyurethane-based thermoplastic elastomer, but may be a thermosetting polyurethane rubber.

Next, the toner supplied to the developing roller 27 adheres to the photosensitive drum 25. At this time, the photosensitive drum 2 charged by the charger 26 is placed on the photosensitive drum 25.
5 is an electrostatic latent image (corresponding to the potential of the photosensitive drum 25 when charged to a predetermined level by the charger 26) corresponding to image data formed by a laser beam that has scanned the outer peripheral surface of the photosensitive drum 25.
There is an electrostatic latent image formed by lowering the electric potential only in the portion irradiated with the laser beam, and the toner (the toner supply roller 31 and the developing roller 27) charged to a predetermined polarity is applied to the electrostatic latent image. Is electrically charged to the same polarity as the potential of the electrostatic latent image due to friction or the like of the electrostatic latent image.

Then, the image visualized by the adhesion of the toner on the photosensitive drum 25 is transferred to the paper P conveyed by the transfer roller 28, and then the paper P is conveyed to the fixing unit 8. .

The transfer roller 28 has at least its surface formed of a non-migratory material such as polyurethane foam.

Next, the residual toner remaining on the photosensitive drum 25 is electrically attracted to the cleaning roller 29 and is temporarily held. At the timing when the paper P is not conveyed, the remaining toner is removed by the cleaning roller 2.
By applying an electric field between the photosensitive drum 25 and the cleaning roller 29 in a direction opposite to that when the toner adheres to the photosensitive drum 9, the residual toner adsorbed on the cleaning roller 29 is returned to the photosensitive drum 25.

The cleaning roller 29 has at least a surface formed of non-migrating polyurethane foam, for example.

Then, the remaining toner carried on the photosensitive drum 25 is carried to the developing roller 27 as it is, scraped off from the photosensitive drum 25 by the developing roller 27, collected in the developing chamber, and reused.

By repeating the above operations, image formation is continuously performed.

In the present embodiment, the reason why the cleaning roller 29 is provided to temporarily collect the residual toner is that the photosensitive drum 25 is used when an image is recorded on one sheet of paper P.
Is repeatedly rotated and used continuously. If the residual toner adhering to the photosensitive drum 25 is to be collected by the developing roller 27 as it is, the laser beam is blocked in the residual toner portion. Will be lost
As a result, an image to be recorded on a part of the sheet P remains as an afterimage in a part after the sheet P.

Further, in the process unit 7, in addition to the above-described structure, as shown in FIG. 3, the toner collected in the developing chamber is prevented from leaking out of the developing chamber. Forward direction of rotation (direction in which the contact direction and the rotation of the developing roller 27 are the same direction)
The base of the seal 50 is fixed to the lower half portion of the casing 24 via the base material 51. As shown in FIG. 3, the residual toner is included on the upper end surface of the base material 51 on the front side (the upstream side in the residual toner transport direction) of the portion where the tip of the seal 50 contacts the developing roller 27. A cleaner 52 made of a non-woven fabric or the like for removing dust, paper fibers, and the like is disposed.

As described above, according to the process unit 7 of the embodiment, the developing roller 27, the transfer roller 28, and the cleaning roller 29 in contact with the photosensitive drum 25 are provided.
Since at least the surface in contact with the photosensitive drum 25 is made of non-migrating polyurethane, the surface of the photosensitive drum 25 is not contaminated by the migration of the material forming each roller, and the Image quality development can be performed.

Further, since the surface of the cleaning roller 29 is formed of polyurethane foam and the surface of the developing roller 27 is formed of polyurethane rubber (polyurethane elastomer), the residual toner can be satisfactorily collected. Developing with high image quality.

Further, an electrostatic latent image is formed on the photosensitive drum 25 by the scanner unit 6, and the toner adhered on the photosensitive drum 25 is transferred onto the paper P by the transfer roller 28 in accordance with the electrostatic latent image. Then, the toner transferred onto the sheet P by the fixing unit 8 is fixed, so that the photosensitive drum 25
The surface of the roller is not contaminated by the material forming the surface of the contacting roller, high-quality development can be performed, and a clear image can be formed.

In the above-described embodiment, the charger 26 is used as a method for charging the photosensitive drum 25. However, the present invention is not limited to this, and it is possible to use a charged roller to contact the photosensitive drum 25. The present invention can be applied to a case where charging is performed by forming the roller from polyurethane.

In the above-described embodiment, the case where the present invention is applied to the process unit 7 for transferring and collecting the remaining toner from the cleaning roller 29 to the developing roller 27 via the photosensitive drum 25 has been described. In addition, the present invention can be applied to, for example, a process unit configured to transfer residual toner from a cleaning roller to a collection roller dedicated to collection via a photosensitive drum and collect the remaining toner in the developing chamber.

Further, if all the rollers that contact the photosensitive drum 25 including the developing roller 27, the transfer roller 28, and the cleaning roller 29 are made of polyurethane, the inside of each roller should be It may be formed of a foam material or a rubber material. More specifically, for example, the developing roller 27 may be formed by a multilayer structure of a foam and an elastomer based on urethane.

Further, even if the roller that contacts the photosensitive drum 25 is other than the above-mentioned rollers, for example, a blade, the same effect as that of the present invention can be obtained by forming the blade from polyurethane.

[0064]

As described above, according to the first aspect of the present invention, at least the surface of all the rollers that come into contact with the photoreceptor is made of a non-migrating material. The surface of the photoreceptor
High quality image development can be performed without being contaminated by the material forming the surface of each roller.

Accordingly, it is possible to form a high-quality image on recording paper or the like.

According to the invention described in claim 2, according to claim 1
In addition to the effects of the invention described in the above, since at least the surface of all the rollers that come into contact with the photoreceptor is formed of polyurethane, the surface of the photoreceptor may be contaminated with the material forming the surface of each roller. And high quality image development can be performed.

Accordingly, it is possible to form a high quality image on a recording paper or the like.

According to the invention of claim 3, according to claim 2,
In addition to the effects of the invention described in the above, the surface of the collection roller is formed of polyurethane foam, and the surface of the development roller is formed of polyurethane rubber, so that the remaining toner can be collected well, Development can be performed with high image quality.

According to the invention of claim 4, according to claim 1,
4. In addition to the effects of the invention described in any one of 3 to 3, an electrostatic latent image is formed on the photoreceptor by the forming unit, and the electrostatic latent image Transfer the toner on the recording paper and fix the toner transferred on the recording paper by the fixing means, so that the surface of the photoreceptor is contaminated by a material forming the surface of the roller that contacts the photoreceptor. Therefore, high-quality development can be performed, and a clear image can be formed.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an appearance of a laser printer.

FIG. 2 is a longitudinal sectional view illustrating a configuration of a laser printer.

FIG. 3 is a longitudinal sectional view illustrating a configuration of a process unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Laser printer 2 ... Main body case 3 ... 1st paper feed tray unit 4 ... 2nd paper feed tray unit 5 ... Paper conveyance mechanism 6 ... Scanner unit 7 ... Process unit 8 ... Fixing unit 10 ... Top cover 11 ... Discharge tray 12a, 12b: feed rollers 13a, 13b: registration rollers 14: paper transport path 14a: lower transport path 15a, 15b: discharge rollers 20: polygon mirrors 21, 23 ... reflecting mirrors 22 ... lenses 24 ... casing 25: photosensitive drums 26 ... Charging device 27 ... Developing roller 28 ... Transfer roller 29 ... Cleaning roller 30 ... Toner cartridge 31 ... Toner supply roller 32 ... Stirring body 33 ... Blade 33a ... Blade fixing member 34 ... Heating roller 35 ... Pressing rollers 36 and 56 ... Tray case 37, 57 ... paper receiving plate 38, 58 ... Compression coil springs 39, 59 ... Tray covers 40, 60 ... Release mechanism 41, 61 ... Feed roller 42 ... Upper auger 43 ... Lower auger 44 ... Auger partition plate 45 ... Scanner cover 46 ... Bottom plate 47 ... Scanner motor 48 ... Scanner Hole 49: glass plate 50: seal 51: base material 52: cleaner 80: manual feed port P: paper R: path

Claims (4)

[Claims] 1. A photoreceptor, a developing roller for developing by contacting the photoreceptor, and a collecting roller for collecting residual toner that is not used for transfer after the development by contacting the photoreceptor. A developing device that develops by electrophotography using the charged toner, wherein the developing device collects the remaining toner from the collecting roller via the photoconductor, and reuses the remaining toner. A developing device, wherein at least the surface of all the rollers that contact the photoconductor is in contact with the photoconductor, and is formed of a non-migrating material. 2. The developing device according to claim 1, wherein at least surfaces of all rollers that come into contact with the photoconductor are formed of polyurethane. 3. The developing device according to claim 2, wherein a surface of said collecting roller is formed of polyurethane foam, and a surface of said developing roller is formed of polyurethane rubber. . 4. The developing device according to claim 1, further comprising: a forming unit configured to form an electrostatic latent image corresponding to an image to be recorded on the photoconductor; Transfer means for transferring the toner adhering to the photoconductor corresponding to the electrostatic latent image onto recording paper on which the image is to be recorded; and fixing means for fixing the toner transferred on the recording paper. An image forming apparatus comprising: