JPH11249427A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an excellent image by well a recovering residual toner on a photoreceptor, in the case of adopting a cleaning-less system. SOLUTION: In this image forming device, the toner 9 remaining on the photoreceptor 21 surface after transferring is scattered, by being disturbed on the photoreceptor 21 surface by a scattering brush 26 held in contact with the photoreceptor surface 21. This residual toner, in the case of being present in an area except the electrostatic latent image on the photoreceptor 21 surface after the charge and exposure is recovered by the developing device. In such a case, the toner 9 being captured by fiber members 28 of the scattering brush 26, is turned back on the photoreceptor 21 side through an opening 29-1 formed on a part of the scattering brush 26. Therefore, the toner 9 being captured by the scattering brush 26 staying in-between the sheet member 27, is prevented from being spilled down from the sheet member 27, and prevented from disturbing the image by dropping on the sheet at the image forming time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic system in which an electrostatic latent image formed on an image carrier is visualized with a toner as a colorant, and the image is transferred to a material to be transferred. The present invention relates to an image forming apparatus used.

[0002]

2. Description of the Related Art In an image forming apparatus employing an electrophotographic method, such as a copying machine or a printer, an electrostatic latent image is formed on a surface of a photosensitive member, which is a carrier for carrying a latent image, and this is visualized. A developing device is provided which supplies a developer such as a toner as a colorant to the photoreceptor side to form an image and selectively attaches the toner.

The developing device develops the electrostatic latent image formed on the photoreceptor, and the developed toner image is transferred to a transfer material, such as a sheet. And after the transfer,
Part of the toner that has not been transferred remains on the surface of the photoconductor. The remaining unnecessary toner is also removed from the photoreceptor surface in order to repeatedly perform the next image formation. Therefore, a cleaning device that removes the toner remaining on the surface of the photoconductor after the transfer is provided, and the unnecessary toner removed by the cleaning device is stored in a storage unit in the cleaning device.

Therefore, in an image forming apparatus employing the above-described electrophotographic system, unnecessary toner is removed at the same time as development at the developing device without cleaning the residual toner after transfer with a cleaning device. An image forming apparatus of a cleaning-less type which has been proposed is proposed in, for example, JP-A-62-203182. According to the image forming apparatus using the cleaning-less method, the size of the apparatus can be reduced as compared with a conventional electrophotographic image forming apparatus because the cleaning apparatus is unnecessary.
In addition, there is no need for a collection device that collects and discards the toner removed by the cleaning device. In addition, it becomes unnecessary to detect the fullness of the toner collected in the collection device.

In this image forming apparatus without cleaning, for example, as shown in FIG. 1, an electrostatic latent image formed on a Developing rollers 24 are arranged to face each other. The developing roller 24 is rotatably provided so as to face an opening of a developing device 25 including a developing tank containing a toner as a one-component developer. The developing roller 2
Reference numeral 4 denotes a part of which is exposed at the opening of the developing device 25 and is in contact with or non-contact with the photoconductor 21.
This contacting or facing area is the development area.

The developing roller 24 carries a one-component toner on its surface and conveys the toner to a developing area facing the photoreceptor 21. After the development, the toner not contributing to the development is conveyed into the developing tank of the developing device 25 and collected.

The one-component toner is attracted to the surface of the developing roller 24 via a supply roller (not shown), and a regulating member pressed against the surface of the developing roller 24 is provided to regulate the amount of the attracted toner. The amount of toner that has passed through the regulating member is regulated to a certain amount. The regulated fixed amount of toner reaches the developing area facing the photoconductor 21 as described above, and selectively adheres according to the electrostatic latent image formed on the surface of the photoconductor 21 to perform development. Will be

The image formed by the toner formed on the surface of the photoreceptor 21 is fed to the transfer position of the transfer roller 22 via the sheet feed roller 12 by feeding the sheets 1 stacked on the sheet feed tray 11. The image is transferred to the sheet 1 by the action of the transfer roller 22. The sheet 1 on which the toner image has been transferred is
The fixing unit 5 includes a heat roller 52 and a pressure sheet 51 that are separated from the photoreceptor 21 and controlled to be heated to a hundred and several degrees.
0, the transferred toner on the upper surface is melted and fixed by heat and pressure. The sheet 1 after the fixing is discharged out of the apparatus via a discharge roller 41.

On the other hand, a part of the untransferred toner remains on the surface of the photoreceptor 21 after the transfer. The residual toner is then disturbed by a toner distribution brush 26, which is a distribution member made of a conductive brush or the like. The disturbed residual toner is removed at the position of the developing roller 24 at the time of subsequent image formation or the like.

That is, the surface of the photosensitive member 21 is uniformly charged by the charger 23 from the disturbed residual toner, and an electrostatic latent image is formed by irradiating the exposure light image 34, and development is performed in accordance with the latent image. The development is performed by the roller 24. At this time, the residual toner existing in the area where the light image 34 is not exposed is sucked toward the developing roller 24 and removed. The residual toner present at the position of the latent image is added to
At 4, the toner is further supplied and used for development.

[0011]

As described above, in recent years,
2. Description of the Related Art In image forming apparatuses for copying machines and printers, there has been a demand for miniaturization of the apparatuses. The adoption of a cleaning-less system has enabled the demand to be met. Further, the toner can be reused, and the trouble of disposal processing is eliminated. Therefore, there is a great merit.

However, if a sheet jam occurs during image formation, most of the developed toner is not transferred to the sheet but is disturbed by the toner scattering brush 26. Then, all the toner can be removed at the position of the developing device 25 by disturbing the toner on the surface of the photoconductor 21 after the jam processing. However, there is also a case where all the toner passes through the brush 26 and is not disturbed and is caught by the brush 26 in this area. The captured toner gradually accumulates between the brush 26 and the seal member 27 disposed on the upstream side of the scattering brush 26.

Then, as the seal jams overlap,
The amount of accumulated toner increases, and the sealing member 27 and the brush 2
6 cannot be accommodated. Then, the contained toner spills down from between the seal member 27 and the photosensitive member 21 and falls on the sheet 1 being conveyed during image formation,
This causes problems such as disturbing the image.

Although this can be dealt with by increasing the toner storage capacity of the seal member 27, the merit of using the cleaning-less system, that is, downsizing of the apparatus cannot be expected.

When the environment in which the apparatus is used is in a low humidity state, the charge amount of the toner becomes extremely high, and the residual toner after the transfer cannot be completely collected by the developing apparatus.
Image).

SUMMARY OF THE INVENTION In view of the above problems, it is a first object of the present invention to effectively prevent unnecessary toner after transfer from being captured by a brush portion and spilling therefrom.

That is, an object of the present invention is to ensure that even if a sheet jam or the like occurs and a large amount of toner remains on the photoreceptor, the toner can be surely collected in the developing device. The purpose of the present invention is to eliminate the accumulation of toner and prevent the toner from falling off.

Another object of the present invention is to prevent the above-mentioned ghost image from being generated, and to remove toner in a developing device.
This ensures that the collection can be performed.

[0019]

According to the present invention, there is provided an image forming apparatus for transferring a toner image formed on an image carrier to a transfer material, and then transferring the toner image remaining on the image carrier. In the image forming apparatus provided with a scattering member for disturbing the residual toner in order to collect the toner in the developing device, an opening through which the toner passes through a part of the scattering member and returns to the surface of the image carrier. Is formed.

According to the above configuration, the toner remaining on the image carrier after the transfer is disturbed by the scattering member.
At this time, some toner is captured in the area of the scattering member,
The captured toner gradually accumulates. If the accumulated amount increases, there is no place for the captured toner to go, and the captured toner or the like spills out from a seal member provided to prevent the fall of the captured toner. However, since an opening is formed in a part of the scattering member, it is returned to the image carrier through the opening. In other words, the captured toner passes through the opening and returns to the image carrier, and the toner captured in the area of the scattering member falls from that position, stains a sheet or the like during image formation, and disturbs the image. Can be resolved.

In the image forming apparatus having the above-described structure, according to the second aspect of the present invention, if a plurality of openings formed in the scattering member are partially formed, the returned toner can be partially removed. Can prevent concentration. As a result, the toner can be efficiently collected by the developing device, and a problem such as a ghost image can be solved by the uncollected toner. Further, by partially providing the plurality of openings, the mechanical strength of the scattering member can be sufficiently ensured.

According to the third aspect of the present invention, in the image forming apparatus having the above-described structure, the scattering member is formed of a conductive brush and has a resistance of 10%.
If the resistance is set to ⁵ (Ω) or less, the resistance value of the brush, which is a scattering member, can be maintained at a constant value or less by continuous use. As a result, the charge elimination of the toner including the charge elimination of the image carrier can be maintained. Therefore, it is possible to prevent a ghost image due to a defective collection of unnecessary toner by the developing device, and to maintain a stable image quality state.

Further, in the image forming apparatus having the above-mentioned configuration, according to the invention described in claim 4, if a voltage having a polarity opposite to that of the toner is supplied to the scattering member,
The static elimination effect can be further promoted. That is, the effect of removing static electricity from the toner is increased. Even in the case where the charging potential of the toner tends to increase particularly at low humidity or the like, the charge eliminating effect is enhanced,
It is possible to eliminate a collection failure caused by the developing device, thereby preventing a ghost image from being formed.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings. A first embodiment of an image forming apparatus using a cleaningless system according to the present invention will be described with reference to FIGS. FIG.
FIG. 4 is a view showing an example of a brush which is a scattering member for disturbing residual toner after transfer employing the cleaningless method according to the present invention. FIG. 2 is a diagram for explaining a toner scattering state according to the present invention. FIG. 3 is a configuration diagram showing a schematic configuration of an image forming apparatus provided with a distribution brush which is a distribution member shown in FIG.

First, a schematic configuration of the image forming apparatus will be described with reference to FIG. This image forming apparatus is a laser printer, and the present invention is not limited to such a laser printer, but can be applied to all image forming apparatuses using an electrophotographic system.

The image forming apparatus shown in FIG. 3 has a sheet feeding section 10 on the right side, an image forming section 20 for forming, ie, transferring, a toner image on a sheet fed in the center, and an image forming section on the top. A laser scanning unit 30 for irradiating an optical image to form an image in the unit 20; Fixing unit 50 for processing as a permanent image
And is configured.

The sheet feeding section 10 has a sheet feeding tray 11 for feeding the sheet 1 to the image forming section 20, and feeds the sheets 1 stacked on the sheet feeding tray 11 to a sheet feeding roller 12. Feed by rotation. The fed sheet 1 is conveyed to the image forming unit 20, so that a toner image described later is transferred. The sheet 1 after the transfer is further conveyed, and the fixing unit 50 fixes the toner image on the sheet. Thereafter, the sheet is discharged to the outside of the image forming apparatus main body by the discharge rollers 41 and 42. That is, the sheet 1 is sequentially discharged onto a discharge tray 43 formed by a part of the exterior of the image forming unit 20 via a path indicated by an arrow A indicated by a solid line in the drawing.

The sheet feeding section 10 includes the sheet feeding tray 11 and the sheet feeding roller 12 as described above, and is urged against the sheet feeding roller 12 by a pressure spring 14 composed of a spring to press and contact the sheet. , A sheet detection actuator 15 for detecting a fed sheet, a sheet detection sensor (optical sensor) 16, and a control circuit 17.

The sheets 1 stacked on the paper feed tray 11 are
In response to a print command from a host computer (not shown) connected to the outside, the paper feed roller 12 is driven to rotate. By this rotation, the sheet 1 is fed one by one by the action of the friction plate 13 to be pressed, and the image forming unit 20
Are sequentially conveyed to

The fed sheet 1 swings the sheet detection actuator 15 and outputs it as an electric signal by the sheet detection sensor 16 to instruct the start of image formation. The control circuit 17 activated by the swing (operation) of the sheet detection actuator 15 sends an image signal to the laser scanning unit 30.

The laser scanning unit 30 has a light emitting unit 31 having a laser diode, a scanning mirror 32, a scanning mirror motor 33, and reflection mirrors 35, 36, and 37. Therefore, lighting and non-lighting of the laser diode of the laser diode light emitting unit 31 are controlled in accordance with an image signal sent via the control circuit 17. Thereby, the light (laser beam) 34 from the laser diode
Is to expose and scan the photoconductor 21 of the image forming unit 20 via the scanning mirror 32 and the reflection mirrors 35, 36, and 37.

The scanning mirror 32 is rotated at a high speed and a constant speed by a scanning mirror motor 33. That is, the laser beam 3
Reference numeral 4 denotes the photosensitive member 2 of the image forming unit 20 by the scanning mirror 32.
Optical scanning is performed in the direction of one rotation axis. The laser light 34 emitted from the laser diode light emitting unit 31 is applied to the photoconductor 21 via the reflection mirrors 35, 36, and 37 as described above. At this time, the laser light 34 is turned on and off from the control circuit 17, that is, an optical image for selectively exposing the photosensitive member 21 based on an image signal.

The image forming section 20 is disposed substantially at the center, and forms a photosensitive member which carries a drum-shaped electrostatic latent image which is driven to rotate at a constant speed in the direction of an arrow during an image forming operation. Various image forming process means are disposed so as to face the photoconductor 21.

The means (apparatus) constituting the image forming process includes a charger 23 for uniformly charging the surface of the photoreceptor 21.
The developing device 25 for visualizing the electrostatic latent image formed by scanning the surface of the photoconductor 21 by the laser scanning unit 30 described above, and the developed image (toner image) is appropriately conveyed. A transfer roller 22 for transferring to the coming sheet 1, a distribution brush 26 constituting a toner distribution member for disturbing residual toner not transferred to the surface of the photoconductor 21 after the transfer, and the like are arranged in the rotation direction of the photoconductor 21 in this order. ing.

The developing device 25 has a developing tank for storing, for example, one-component non-magnetic toner. And a developing roller 24 for transporting. The developing roller 24 is supplied with a developing bias voltage for causing the toner, which has been charged by stirring in the developing device 25, to adhere to the electrostatic latent image formed on the photoconductor 21. As a result, the toner is attracted to the electrostatic latent image by the action of the electric field generated by the potential of the electrostatic latent image formed on the surface of the photoconductor 21 and the developing bias voltage, and the toner image corresponding to the image signal is formed on the surface of the photoconductor 21. Is formed.

Then, the sheet 1 fed from the sheet feeding section 10 is sandwiched and sent between the photosensitive member 21 and the transfer roller 22, so that the toner image on the photosensitive member 21 is transferred.
In this case, a transfer voltage having a polarity opposite to that of the toner image is supplied to the transfer roller 22, and the toner image is electrically transferred to the sheet 1.
Is transferred to

After the transfer, a part of the toner not transferred on the surface of the photoreceptor 21 remains. This residual toner is then disturbed by the scattering brush 26. That is, the photoconductor 21
The toner image on the surface is disturbed on the photoconductor 21. Then, after charging and exposure, an electrostatic latent image is formed again on the photoconductor 21 and reaches the developing device 25, so that the toner disturbed by the developing roller 24 in a region other than the electrostatic latent image is removed. Then, the toner remaining on the portion of the electrostatic latent image is further adhered by the developing roller 24 to form a toner image.

On the other hand, the sheet 1 after the transfer is separated from the photoreceptor 1 and is conveyed to the fixing unit 50. This fixing unit 50
Is composed of a pressing member 51 and a heat roller 52 maintained at, for example, about 170 ° C., and the toner image on the sheet 1 is melted by heat and pressure and fixed on the surface of the sheet 1. The sheet 1 after the fixing is discharged to discharge rollers 41 and 4.
After that, the paper is discharged onto an external discharge tray 43.

(First Embodiment) Next, an embodiment of the present invention will be described with reference to FIGS. That is, in the image forming apparatus according to the present invention, an embodiment of the distribution brush 26 that disturbs the toner remaining on the surface of the photoconductor 21 after the transfer in the image forming unit 20 will be described in detail.

First, the configuration of an embodiment of the distribution brush 26 will be described with reference to FIG. Before that, the charger 23 that uniformly charges the surface of the photoconductor 21 charges the photoconductor 1 by supplying a predetermined voltage to, for example, a conductive brush implanted on a roll-shaped surface. In particular, the conductive brush is formed by winding conductive fibers obtained by dispersing carbon in rayon around a metal shaft. By supplying a charging voltage to the metal shaft, the surface of the photoconductor 21 is charged via the conductive brush.

Accordingly, when the charger 23 rotates, the conductive brush contacts the surface of the photoconductor 21 to charge the photoconductor 21 to a predetermined polarity. For example, an organic photoconductor (OPC) for negative charging is used as the photoconductor 21, and a voltage controlled at a constant voltage of about -1100 V is supplied to the conductive brush. Thereby, the charged potential can be uniformly charged to approximately -550V.

The uniformly charged photoreceptor 21 is irradiated with laser light 34 by the laser scanning unit 30 to form an electrostatic latent image. Thereafter, the developing device 25 develops the electrostatic latent image with toner.

The toner to be used for the development is contained in the developing device 25, and a predetermined amount of charge is given by stirring the toner. Then, the photosensitive drum 21 is conveyed to a developing area which is attracted to the surface of the developing roll 24 and faces the photoconductor 21. The developing roller 24 is made of, for example, conductive elastic urethane rubber, and is supplied with a developing bias voltage of, for example, about -400V. Thereby, the toner is attracted to the electrostatic latent image on the surface of the developing roller 24 by the electric field of the potential of the electrostatic latent image on the surface of the photoconductor 21 and the developing bias voltage to form a toner image.

The toner image on the photoreceptor 21 is electrostatically transferred to the sheet 1 conveyed appropriately by a transfer voltage supplied to the transfer roller 22. The transfer roller 22 is made of a conductive urethane sponge, and has an appropriate elasticity so that the toner is efficiently transferred. In other words, a region (nip width) in contact with the photoconductor 21 can be secured for a predetermined length, and transfer efficiency is improved.

Therefore, a part of the toner that has not been transferred remains on the surface of the photoreceptor 21 after the transfer. The residual toner is scattered and disturbed on the surface of the photoconductor 21 in order to remove and collect the residual toner at the position of the developing device 25 described above. In order to disturb the toner, a conductive scattering brush 26 is provided in contact with the surface of the photoconductor 21.

The scattering brush 26 uses, for example, a bundle of a large amount of fibers in which carbon is dispersed in rayon, and has a resistance value of about 10 ³ (Ω). As shown in FIG. 1, the dispersing brush 26 is configured such that a large number of fiber members are bundled in a bundle 28 and held and held by a U-shaped metal holding member 29 by caulking or the like. Is done. Then, one end of the holding member 29 is fixed to the support 60 as shown in FIG. 2 so that the end of the fiber member 28 on the free end side that is not held by the holding member 29 is opposed to the surface of the photoconductor 21. doing.

As shown in FIG. 2, a seal member 27 is fixed to the end of the support 60, and the end of the seal member 27 is arranged close to the surface of the photoreceptor 21.
The seal member 27 is formed of a resin film or the like, and plays a role of disturbing the toner on the surface of the photoreceptor 21 with the scattering brush 26 and receiving the toner 9 captured when the toner is dispersed or the toner 9 falling. Is provided.

The distribution brush 26 having the above-described structure has a large number of openings 29-1 in the region of the metal holding member 29.
Are formed. A plurality of the openings 29-1 are formed at equal intervals in the longitudinal direction of the holding member 29.

The distribution brush 26 configured as described above
2 will be described with reference to FIG. 2. The toner 9 remaining on the surface of the photoconductor 21 after the transfer is disturbed by the scattering brush 26 contacting the surface of the photoconductor 21, and
Scattered on the surface. This faces the developing device 25 through a charging and exposure process, so that the toner 9 scattered in the area other than the formed electrostatic latent image is collected in the developing device 25.

Then, a large amount of the residual toner 9 is
Is present, all the residual toner 9 can be disturbed and scattered on the surface of the photoreceptor 21. Some of the toner 9 is captured by the fiber member 28 constituting the brush 26, Captured by This captured toner 9
When the amount of the ink increases, the opening 2 provided in the distribution brush 26 is increased.
The toner is sent to the surface of the photoconductor 21 via 9-1, is attracted to the photoconductor 21, and is collected by facing the developing device 25.

Therefore, the sealing member 27 and the scattering brush 2
6, the toner trapped gradually accumulates, and there is no place to go, so that it is possible to prevent the toner from spilling from between the seal member 27 and the photosensitive member 21. That is, the scattering brush 26
Without being disturbed, the captured toner 9 gradually accumulates, and when the amount increases, the toner 9 is supplied to the surface of the photoconductor 21 through the opening 29-1 as described above. This allows
It is possible to prevent the captured toner 9 from falling off from the seal member 27 between the photoconductors 21 and falling.

(Another Embodiment of Distributing Brush) The plurality of openings 29-1 formed in the metallic holding member 29 constituting the distributing brush 26 may be formed as one opening communicating with the longitudinal direction. . However, in the case of one communicating opening, in view of the strength of the distribution brush 26, for example, when the opening is provided at the center, the opening area needs to be reduced. In this case, the toner supplied to the photoconductor 21 through the opening 29-1 may be concentrated.

Therefore, as shown in FIG.
As 1, the dispersing brush 26 can secure sufficient mechanical strength by providing a plurality of openings 29-1 at equal intervals instead of one communicating opening. Also, a plurality of openings 2
By providing 9-1, the toner captured by the scattering brush 26 can be evenly supplied to the photoconductor 21 through the respective openings 29-1. Therefore, it is possible to prevent the toner 9 from being concentrated and adsorbed on the photoreceptor 21, thereby enabling the developing device 25 to reliably collect the toner 9.

The shape of the opening 29-1 is formed in a rectangular shape, but is not limited to such a shape. For example, if it is formed in a parallelogram, each opening 29
An overlap occurs at the adjacent ends of -1. The interval between the openings 29-1 can be increased so as to eliminate the overlapping portion. Therefore, the opening 29
Even if −1 is formed, the mechanical strength of the scattering brush 26 can be sufficiently ensured.

(Other Embodiments) On the other hand, the distribution brush 26
Uses a brush whose resistance value is as low as about 10 ³ (Ω). This efficiently removes the residual toner 9 during continuous use, and increases the collection efficiency of the developing device 25. Thereby, ghost images can be prevented.

For example, a voltage having a polarity opposite to that of the toner is supplied to the distribution brush 26. According to the above-described example, negatively charged toner is used because the toner is attracted to the electrostatic latent image by the developing device 25. Therefore, a positive voltage is supplied to the distribution brush 26. Therefore, a voltage of about +400 V is always supplied to the scattering brush 26, thereby increasing the effect of scattering the toner image remaining on the surface of the photoconductor 21. In addition, the recoverability of the developing device 25, particularly by the developing roller 24, can be improved.

That is, since the residual toner is discharged by the scattering brush 26, the recoverability to the developing roller 24 is improved. Thereby, the image defect due to the ghost image can be eliminated.

Here, in the present invention, the resistance value of the distribution brush 26 is set low. In addition, a voltage having a polarity opposite to that of the toner is supplied to the distribution brush 26. Therefore, the resistance value of the conductive scattering brush 26 tends to change and increase with time. For example, it has been confirmed that when the charge removing effect of the toner remaining on the surface of the photoconductor 21 is reduced, the recoverability of the toner in the developing device 25 is reduced.

Therefore, the resistance of the distribution brush 26 was changed variously, and the resistance change of the distribution brush 26 during the continuous energizing time was examined. Table 1 shows the results. All units are (Ω).

[0060]

[Table 1]

As shown in Table 1, the resistance value is 10 ⁶
Five types of scattering brushes 26 of 10 ² (Ω) were prepared. As a result, the resistance value of the scattering brush 26 tends to gradually increase in accordance with the energization time. This is considered to be due to the toner adsorbing to the brush 26. Therefore,
It can be seen that the lower the resistance value of the scattering brush 26 is at the beginning, the smaller the resistance value rises.

Therefore, the resistance value of the scattering brush 26 is 10
^{When the} resistance is ⁹ (Ω) or more, no current flows between the photosensitive member 21 and the charge removing effect of the toner including the charge removal on the surface of the photosensitive member 21 is reduced. Therefore, considering continuous use, the resistance value of the scattering brush 26 may be set to at least 10 ⁵ (Ω) or less, which does not exceed 10 ⁹ (Ω) from Table 1. This makes it possible to reduce the resistance value of the scattering brush 26 due to continuous use to a predetermined value or less, to obtain a stable static elimination effect,
Unnecessary toner can be collected and stable image quality can be obtained.

As described above, the voltage supplied to the distribution brush 26 has a polarity opposite to that of the toner. When the resistance value of the distribution brush 26 is set to be low, a leak may occur between the distribution brush 26 and the photosensitive member 21 in a high humidity environment during image formation, and image formation failure may occur. Conceivable.

In this regard, as described above, the scattering brush 26
Is supplied with a voltage having a polarity opposite to that of the toner, and the supply voltage is set to about 400 V. This makes it possible to prevent leakage at high humidity and stabilize image formation. In addition, a static elimination effect can be obtained, and image defects such as ghost images can be prevented.

It is effective if the supply voltage is set within the range of 300 V to 600 V in absolute value.

[0066]

According to the image forming apparatus of the present invention, an opening is provided in a part of a member for scattering and disturbing the toner remaining after the transfer, particularly in the clean grease method, so that the toner which cannot pass through the scattering member is removed. Since the toner is returned to the image carrier through the opening, it is possible to prevent the toner captured by the scattering member from gradually collecting and spilling. And the image defect due to this can be prevented.

By providing a plurality of openings, the mechanical strength of the scattering member can be maintained at a certain level or more, and at the same time, when the toner is returned to the image carrier, the toner can be returned uniformly. It is also possible to prevent the toner collecting property from being lowered due to concentration.

Further, since the scattering member is formed of a conductive brush and its resistance is reduced, it is possible to prevent the effect of eliminating unnecessary toner and the like from being lowered due to an increase in resistance value due to continuous use, and to maintain a stable image quality. In addition, it is possible to prevent image defects due to a decrease in toner recovery.

Further, by supplying a voltage having a polarity opposite to that of the toner to the scattering member, the static elimination effect can be enhanced, and an image defect in a low humidity state, that is, a ghost image can be prevented together.

[Brief description of the drawings]

1A and 1B show a structure according to an embodiment in which a member for disturbing and scattering toner remaining after transfer according to the present invention is configured by a brush, wherein FIG. 1A is a plan view of a scattering brush, and FIG. () Is a sectional view taken along line AA.

FIG. 2 is a diagram for explaining a state in which toner is scattered by a scatter brush shown in FIG. 1 and a state in which toner captured by the scatter brush is returned to a photoconductor;

FIG. 3 is a configuration diagram illustrating an entire structure of an image forming apparatus including a cleaning brush of a cleaningless type according to the present invention.

[Explanation of symbols]

 9 Residual toner after transfer 10 Sheet feeding unit 20 Image forming unit 21 Photoconductor (image carrier) 22 Transfer roller 23 Charger 24 Developing roller 25 Developing device 26 Dispersing member (dispersing brush) 27 Seal member 28 Fiber member 29 Holding Member 29-1 Opening 30 Laser Scanning Unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuhi Yui 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka

Claims (4)

[Claims] And a dispersing member for disturbing the residual toner in order to collect the toner remaining on the image carrier by a developing device after transferring the toner image formed on the image carrier to a transfer material. An image forming apparatus, comprising: an opening for allowing toner to pass through and return to the surface of an image carrier in a part of the scattering member. 2. The image forming apparatus according to claim 1, wherein a plurality of openings formed in said distributing member are partially formed. 3. The image forming apparatus according to claim 1, wherein the scattering member is formed of a conductive brush, and has a resistance value of 10 ⁵ (Ω) or less. 4. The image forming apparatus according to claim 1, wherein a voltage having a polarity opposite to that of the toner is supplied to the scattering member.