JP3472037B2 - 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 a rotationally driven image.
Forming an electrostatic latent image on the carrier by a latent image forming unit;
The electrostatic latent image is visualized as a toner image by a developing device.
The toner image formed on the surface of the image carrier.
The image is transferred to a recording medium by a copying device and the toner image is transferred.
The transfer residual toner on the carrier is collected by a cleaning member.
The invention also relates to an image forming apparatus for cleaning the surface of the image carrier.
It is. [0002] 2. Description of the Related Art Copiers, printers, facsimiles, or
An image forming apparatus of the above type configured as a multifunction machine or the like.
Since the image carrier is used repeatedly in
-Transfer residual toner adhering to the surface of the image carrier after image transfer
Is removed by a cleaning member and collected on the surface of the image carrier.
Need to be cleaned. For this reason, an image carrier has been conventionally used.
Various cleaning devices for cleaning have been proposed and put into practical use
However, conventional cleaning devices are generally
Stores the toner recovered from the carrier in a waste toner tank, etc.
And configured to discard it. Recently, an electrophotographic process has been adopted.
In this type of image forming apparatus, a further lower cost
And the amount of toner discarded as part of environmental measures
There is a demand for further reduction of the above. In view of such a point, the recording medium is moved from the image carrier to the recording medium.
100% transfer rate of toner image to body
If you try to eliminate the residual toner after the image is taken, the so-called
A knurling method can be adopted. As a result,
In addition to eliminating waste toner,
Cleaning device can be omitted, and the image forming system can be simplified.
Thus, the cost of the image forming apparatus can be reduced. I
However, at present, the transfer rate of the toner image is set to 100%.
It is difficult to do, and there is a problem in terms of reliability. Therefore, as a second best measure, a toner image is transferred.
Transfer residual toner remaining on the surface of the image carrier
And then collect it temporarily by electrostatically attaching it to the
The recovered toner is used to form an electrostatic latent image on the image carrier.
Electrostatically re-adheres to unaffected surface areas and further carries images
The toner that has re-adhered to the body surface is collected electrostatically by the developing device
However, a method of reusing this in a developing device has been proposed.
(For example, see Japanese Patent Publication No. Sho 61-30274).
See). Due to this, the collected toner is stored
Transfer the waste toner tank and collected toner to the developing device
This eliminates the need for dedicated transport means, and
Cost, and the toner is recycled.
Since it can be used, waste toner can be eliminated. By the way, in this type of conventional image forming apparatus,
In this case, the toner re-adhered to the image carrier is
For electrostatically recovering, the developer carrying member of the developing device
Was used. This developer-carrying and conveying member is attached to the developing container.
The stored developer is carried and transported. This conveyed
The developer causes the electrostatic latent image formed on the image carrier to
-Visualized as an image. At this time, it is formed on the image carrier.
To improve the image quality of the toner image
At the time of development, the image is transferred between the image carrier and the developer carrying member.
The developer carried on the developer carrying member moves the developer on the surface of the image carrier.
Move the developer so that it moves in the same direction as the moving direction.
Is being transported. Developing device for re-adhering toner on image carrier
When collecting the developer, the developer on the developer carrying member is
They were transported in the same direction as the image. However,
When the developer is formed, the developer on the developer carrying member
Mechanical scraping force applied to redeposited toner on the body, i.e.
The scavenging force decreases, and the toner
Collection efficiency is reduced, thereby causing a
There is a possibility that the background image may be stained on the toner image. [0007] SUMMARY OF THE INVENTION It is an object of the present invention to
The residual toner is electrostatically collected by a cleaning member, and
The collected toner is electrostatically reattached to the image carrier, and then
An image in a format in which the re-adhered toner is collected in the developing device
Solving the above-mentioned problems in the forming apparatus,
Image formation that can efficiently collect redeposited toner in the developing device
It is to provide a device. [0008] The present invention achieves the above object.
Image carrier that is driven to rotate, and
A latent image forming means for forming an electrostatic latent image;
The developer is carried on a developer carrying member, and the image carrier is
Between the developer carrying and conveying member, the developer carrying and conveying member
The held developer is in the same direction as the moving direction of the image carrier surface.
The transported developer is transported in the moving direction, and
Visualizes the electrostatic latent image as a toner image with the developer
And a toner image formed on the surface of the image carrier.
Transfer device for transferring to recording media and image bearing after transfer of toner image
The transfer residual toner on the body is temporarily collected electrostatically, and then
The collected toner is used to form an electrostatic latent image on the image carrier.
Cleanin electrostatically reattaches to unaffected surface areas
And a toner that has been reattached to the surface of the image bearing member.
In the image forming apparatus for collecting
Carrying and transporting the developer transferred from the developer carrying transport member,
The developer re-adhered to the image carrier is transported by the developer
And collect it in a developing container together with the developer.
Re-attached toner recovery rotator to be returned to the contained developer
Is set in the developing device in a state where it faces the image carrier.
Between the reattached toner recovery rotating body and the image carrier.
The developer carried on the transfer member depends on the moving direction of the image carrier surface.
To transport the developer in the direction to move in the opposite direction
At the time of development to visualize the electrostatic latent image.
Is transported while being carried by the reattached toner recovery rotating body.
The developer makes the electrostatic latent image a visible image and
When collecting the toner that has re-attached to the carrier to the developing device,
Collecting the re-adhered toner also on the developer carrying conveyance member
The cleaning member includes a core member and the cleaning member.
Cleaner having an elastic body fixed to the surface of a core member
A transfer roller on the image carrier.
When collected by the cleaning member, the cleaning member
Rotates while rubbing against the surface of the image carrier and
Transfer residual toner to the same polarity as the toner during development
A cleaning member and an image bearing member on the core member.
Of the opposite polarity to the charge polarity of the toner that is frictionally charged with the body
A voltage is applied to remove the transfer residual toner from the cleaning member.
Collected by electrostatically attracting to the surface and cleaning
When attaching the collected toner to the image carrier again,
A voltage having the same polarity as the charged polarity of the toner during development is applied to the core member.
Image forming apparatus characterized in that
Suggest a location. [0009] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Will be described in detail. FIG. 1 shows an example of an image forming apparatus according to the present invention.
FIG. Referring to FIG.
A drum-shaped photoconductor 1 as a configuration example is driven by a drive (not shown).
The device is driven to rotate clockwise in the figure.
At the time of rotation, by the static elimination lamp 13 which is an example of the static elimination device
Initialized due to static elimination, and then an example of a charging device
Due to the action of a certain charging roller 2, the surface of the photoreceptor 1
To be uniformly charged. In this example, the charging roller 2 is
Voltage power supply E_TenIs connected to the photosensitive member 1 while rotating.
Thus, the surface of the photoconductor 1 is uniformly charged to a negative polarity. Electrification b
Due to the action of the roller 2, the surface of the photoconductor 1 becomes, for example, -85.
It is charged to 0V. Charge photoreceptor 1 uniformly
As a charging device, a charging device that is arranged separately from the photoconductor
For example, a corona discharger or the like can be used. Next, in the exposing section 3, not shown
Laser light modulated by an exposure scanning device
11 performs optical writing scanning,
A predetermined electrostatic latent image is formed on the surface of the body 1. Photoconductor 1
The portion A irradiated with the laser light 11 above, that is, the electrostatic latent
The surface potential of the image is, for example, about -150 V, and the laser
Part B not irradiated with light 11, that is, the background of the electrostatic latent image
The surface potential of the part is maintained at approximately -850V. like this
In this embodiment, the exposure scanning device and the charging roller 2
And an electrostatic charging device on the image carrier comprising the photosensitive member 1
It constitutes a latent image forming means for forming a latent image. The developing device 4 is arranged to face the photosensitive member 1.
A developing roller 5 which is an example of a developer carrying member;
Stirring paddles 10A and 10B and re-adhesion toner recovery rotation
And a re-adhering toner collecting roller 18 which is an example of a body.
These are provided in the developing container 15 of the developing device, respectively.
And is rotatably supported by the developing container 15.
The developing roller 5 and the toner recovery rotating body 18 are
Facing the photoreceptor 1 with a small gap
Extend in parallel. The developing roller 5 is made of a non-magnetic conductive cylinder.
And a plurality of magnets arranged in the
5B is provided. In the developing container 15, the toner
And a two-component developer D having a magnetic pole carrier,
The toner and the carrier are rotated by the stirring paddles 10A and 10B.
As a result, the toner particles are frictionally charged to opposite polarities. The toner is
A predetermined polarity, in this example, the same polarity as the charging polarity of the photoconductor 1,
That is, it is negatively charged. The toner and carrier charged in this way are
The developer having the toner is applied to the peripheral surface of the developing roller 5 and
The magnet 5B is magnetically supported by the action of the magnetic force of the magnet 5B provided.
And transported counterclockwise in FIG. In this example
Means that the magnet 5B is fixed so that it cannot rotate.
And the developing roller 5 is rotated in a counterclockwise direction
This is rotated by a drive device (not shown)
With the rotation of the developer, the developer on the developing roller 5 is
The roller 5 is transported in the same direction as the rotation direction. Photoconductor 1 and current
In a region opposed to the image roller 5, that is, in the developing unit 6,
The direction of movement of the developer on the developing roller 5 on the surface of the photoconductor 1
They are conveyed in the same direction. Fix developing roller 5
Then, rotate the magnet 5B, or
By relatively rotating the developer on the developing roller 5 as described above,
They can be transported in the same direction as the rollers. Developing carried and transported by developing roller 5
The developer is scraped by the developer regulating member 19.
You. As shown in FIG. 2, the developer regulating member 19
To the roller 5 and the reattached toner collecting roller 18, respectively.
Protrusions 19a and 19b are provided opposite each other with a gap.
The former protruding portion 19a is used for the development process.
The developer on the roller 5 is subjected to a scraping action. The transport amount is regulated by the developer regulating member 19.
The developed developer causes the developing roller 5 and the photoconductor 1 to be paired with each other.
The developer is transported to the developing unit 6 facing the developer. At this time,
Voltage power supply E₁As a result, development in the developing device 4
Having the same polarity as the charging polarity of the toner of the agent D, for example, -600 V
Bias voltage is applied. Therefore, the developing unit 6
The toner in the transported developer becomes a static latent image on the photoreceptor 1.
It is attracted electrically and adheres to that area. That is,
The toner charged to the same negative polarity as the charging polarity of the photoconductor
Electrostatically adheres to the photosensitive member surface A exposed to the laser light
And the electrostatic latent image is visualized as a toner image.
is there. Such a developing method is a reversal developing method (negative /
Developing method). As described above, the developing device 4 has a
The developer D contained in the container 15 is composed of a developing roller 5.
An image carrying member composed of a photoreceptor 1 carried on a developer carrying member
Between the body and the developer carrying member, that is, in the developing section 6,
The developer carried by the developer carrying member is moved to the surface of the image carrier.
In the direction of movement in the same direction as the surface
The image agent is conveyed, and the conveyed developer causes the image carrier to be conveyed.
The formed electrostatic latent image is visualized as a toner image. Feeling
With respect to the moving direction of the surface of the optical body 1, the current
Develop the electrostatic latent image while transporting the image agent in the above direction
As a result, the image quality of the toner image formed on the photoconductor 1
Can be improved. On the other hand, the re-attached toner recovery row shown in FIG.
The roller 18 is arranged between the charging roller 2 and the photosensitive member 1 in the rotation direction.
Downstream and upstream of the developing roller 5
The roller 18 is located in the developing container 15.
Has been deployed. Such a reattached toner collecting roller 18
Is made of a non-magnetic conductive cylinder like the developing roller 5.
And a plurality of magnets arranged in the
18B is provided. Two-component system in developing container 15
The developer D is also provided on the peripheral surface of the roller 18.
Carried by the action of the magnetic force of the magnet 18B
Then, it is conveyed clockwise in FIG. In this example,
The magnet 18B is fixed so as not to rotate, and the toner adheres again.
The collection roller 18 is clocked by a driving device (not shown).
The developer on the roller 18 is rotated clockwise.
Transported in the opposite direction. Reattach to photoconductor 1
Area 6A facing the toner collecting roller 18,
Of the reattached toner collecting roller 18
Developer moves in the direction opposite to the direction of movement of the surface of photoconductor 1
It is conveyed so that it does. The reattached toner collecting roller 18 is fixed,
Gnet 18B is rotated, or both are rotated relative to each other.
The developer on the reattached toner collecting roller 18
It can be transported in the same direction as described above. A developer regulating member carried on the developing roller 5
A part of the developer going to 19 is reattached toner collecting roller 1
8 and the rotation of the roller 18 carried by the roller
It is transported in the turning direction. At this time, the developer is
The control member 19 receives a scraping action. Shown in FIG.
Due to the protrusion 19b of the developer regulating member 19,
The developer on the deposited toner collecting roller 18 receives a scraping action.
I'm going. At this time, the electrostatic latent image on the photosensitive member 1 is visualized.
At the time of development,
Also voltage power supply E₆The polarity of the charged toner of the developer D
Voltage of the same polarity as, for example, -600 V is applied and
Opposite area 6A between deposited toner collecting roller 18 and photoconductor 1
Of the developer transported to the surface of the photosensitive member 1
A, that is, electrostatically attracted to the electrostatic latent image
The image is visualized as a toner image. Visualize electrostatic latent images
During development, the toner carried on the reattached toner collecting roller 18 is
Visualize electrostatic latent images even with developer transported
You do it. As described above, the image forming apparatus of this embodiment first
The developer carried on the adhered toner collecting roller 18 is
The operation of visualizing the electro-latent image is performed, and then the developing roller 5
A visible image operation is performed by the carried developer, and
A high quality toner image is formed on the optical body 1. Opposing area 6
The developer that has passed through A is re-adhered to the toner collecting roller.
Transported by the
The toner collection row reattached by the opposed scraper 20
And is stored in the developing container 15.
It is returned to the developer D. Below the photoconductor 1, an example of a transfer device is provided.
Transfer roller 7 is provided. The transfer roller 7
Both surfaces move in the same direction at the light body 1 and the opposing part
Direction, that is, in the forward direction with respect to the photoconductor 1
The transfer roller 7 and the photosensitive member 1 facing the transfer roller 7
The recording medium composed of the transfer paper 16 is
The transfer roller 7 is fed in the direction of the arrow P.
The surface of the photoconductor 1 is transferred through the transfer paper 16 sent to the transfer unit 8.
The transfer roller 7 is pressed against the
The toner image formed on the body 1 is transferred onto the transfer paper 16
Is done. That is, the power source E_ThreeThe transfer roller 7
To the positive polarity opposite to the charging polarity of the toner on the photoreceptor 1
Voltage, for example, a voltage of +950 V is applied,
To form a toner image having a negative polarity to form a toner image on the photosensitive member 1
Is electrostatically attracted to the transfer paper 16 side, and
Adhere to. A transfer device separated from the photoconductor 1, for example,
A transfer device composed of a corona discharger can also be used. The transfer paper 16 on which the toner image has been transferred is shown in FIG.
Separated from the photoreceptor 1 by a separation device
The sheet is sent to a fixing device (not shown) where the transfer paper 1
6 is fixed. In this way, the transfer paper
Reference numeral 16 denotes a copy sheet which is discharged outside the image forming apparatus main body.
You. As described above, the image forming apparatus of the present embodiment
Image carrier composed of photoreceptor 1 driven in rotation and image carrier
Latent image forming means for forming an electrostatic latent image on a body;
Developing device 4 for visualizing the image as a toner image, and image bearing
Recording the toner image formed on the body surface on transfer paper 16
A transfer device comprising a transfer roller 7 for transferring to a medium.
And a cleaning roller 12 described below.
Cleaning member, and the aforementioned static elimination lamp 13
The static eliminator. Charging device, latent image forming hand
Exposure unit 3, developing device 4, transfer device for image carrier by step
Placement, cleaning member and static eliminator
It is arranged along the direction of rotation of the body. The toner image on the photoreceptor 1 is transferred by a transfer unit 8 to a transfer paper.
16 after the transfer of the toner image.
On the photoreceptor 1 without being transferred to the transfer paper 16
The retained toner is attached. Such transfer residual toner T₁
When the cleaning member 14 reaches
Temporarily collected on the surface of the cleaning roller 12 as an example
Is done. The cleaning roller 12 is made of a rigid body.
A core member 12a, fixed on the surface of the core member 12a;
Having a conductive or medium resistance elastic body 12b
In this example, the core member 12a is made of a round shaft-shaped conductive metal.
The elastic body 12b has a cylindrical shape concentric with the core member 12a.
Formed of a foam. Such cleaning row
La 12 is housed in the cleaning case 17 shown in FIG.
And each end of the core member 12a is
17 are rotatably supported by front and rear side walls 17a, respectively.
ing. The cleaning roller 12 includes a developing roller
5, the photosensitive roller 1 together with the charging roller 2 and the transfer roller 7
Are positioned substantially parallel to. Here, in FIG.
Most of the toner T of the toner image going to the portion 8 is
This is the charge polarity during development, in this case, the negative polarity toner.
ing. In contrast, the transfer roller 7 transfers the toner image.
During shooting, the polarity opposite to the toner charging polarity during development, in this example
Since a positive voltage is applied, after the toner image is transferred,
Toner remaining on the photoreceptor 1, ie, transfer
Remaining toner T₁Is a mixture of negative polarity and positive polarity
Toner. Transfer residual toner is positive and negative
When the toner of both polarities is mixed,
It is transferred to 14. The cleaning roller 12 is disposed on the photosensitive member 1
Transfer residual toner T₁Drive not shown when collecting
The apparatus is driven to rotate in an appropriate direction.
Clockwise direction (arrow a direction), that is,
In the opposing portion, the cleaning roller 12 and the photosensitive member 1
Surfaces move in opposite directions (counter direction)
The photosensitive member 1
It rotates while rubbing against the surface of. Cleaning roller 1
2 indicates that its surface is elastically deformed by the photoconductor 1.
So that it is pressed against the photoreceptor 1 and
Step region N is formed. The photoconductor in the nip area N
The width in the circumferential direction is, for example, about 1 mm.
The width of the nip region N is exaggerated. In the nip area N, the positive and negative polarities are reversed.
Residual toner T₁Are the cleaning roller 12 and the photoconductor 1
The same polarity as the toner during development while contacting the surface of
(Negative polarity).
That is, the transfer residual toner on the photoconductor 1 after the transfer of the toner image
Is a cleaning member comprising a cleaning roller 12
An electrostatic latent image between the image bearing member and the photosensitive member 1
The charge polarity (original polarity) of the toner during development to visualize
They are triboelectrically charged so that they are aligned. Toner image on recording medium consisting of transfer paper 16
Transfer residual toner T on photoreceptor 1 after transfer₁Is on the photoconductor 1
Cleaning roller 12 that rotates while being pressed against
Is collected by the cleaning member
The core member 12a of the cleaning roller 12 has
Of the toner frictionally charged between the photosensitive drum 1 and the photoconductor 1
Polarity opposite to the polarity, positive voltage in this example, for example +200
V voltage is the voltage power supply E_FourIs applied. Therefore,
The residual toner after the transfer of the toner image that has passed the
The frictional charge between the photosensitive member 1 and the cleaning roller 12
Transfer residual toner T₁Indicates that the positive polarity voltage has been applied.
Electrostatically attracted to the surface of the leaning roller 12
And adheres to the surface of the roller 12 and temporarily
Will be collected. The surface of the photosensitive member 1 that has passed through the transfer roller 7
The potential is affected by the transfer roller 7 to which the positive voltage is applied.
To about -50 V, but +200
A cleaning roller 12 to which a voltage of V is applied;
Transfer residual toner T₁Between the photoconductor surface to which
The transfer residual toner T of negative polarity is determined by₁But chestnut
Electrostatically attracted to the surface of the
It is. As a result, the surface of the photoconductor 1 is cleaned.
Will be in a state. As described above, the cleaning roller 12
Is the transfer residual toner T on the photoconductor between the photoconductor 1 and
₁Is electrostatically attracted to the surface of the cleaning roller 12.
Toner during development so that a possible electric field is formed.
Voltage of opposite polarity (positive in this example) is applied
It is done. As described above, the cleaning roller 12
In the figure, the symbol T_TwoTo
It is shown attached. FIGS. 3 to 9 show the transfer on the photoconductor 1.
Remaining toner T₁Is collected on the cleaning roller 12, and then
As described later, the collected toner T_TwoTo the surface of photoconductor 1
FIG. 7 is an explanatory view showing an example of an operation of reattaching to the
3 shows that the toner image on the photoreceptor 1 is
Is transferred to the transfer paper 16 conveyed in the
ー T₁Is collected on the surface of the cleaning roller 12.
FIG. The cleaning roller 12 cleans
The surface portion of the photoreceptor 1 which has been
And the surface potential is reduced to the reference value.
It is. The static elimination lamp 13 continues to light during the image forming operation.
I have. The surface of the photoreceptor that has been charged
And the image forming operation described above is continued.
Can be In this manner, the photosensitive member 1 is moved several times, for example.
During the rotation, one toner image is formed on the photoconductor 1,
This is continuously transferred to the transfer paper 16.
The circumferential area on the photoconductor 1 where the toner image is formed is an image.
This is an image forming area. In FIG. 3, reference numerals are used for the image forming areas.
X is attached, and the leading end of the photoreceptor in the rotation direction is given a code Y.
It is. Similarly, FIG.
The symbol Z is attached to the rear end in the body rotation direction. The leading end Y of the image forming area X is a cleaner.
When the cleaning roller 1 reaches the
2 transfer residual toner T₁Collection operation is started, and
In the example shown, the rear end Z of the image forming area X is cleaned.
The operation of collecting the transfer residual toner continues until the roller 12 is reached.
Be killed. Image formation passing through cleaning roller 12
Area X is already cleared by the cleaning roller.
It is in a state of having been trained. As shown in FIG.
When the rear end Z in the body rotation direction passes through the charging roller 2,
The charging roller 2 moves away from the surface of the photoconductor 1
(See FIG. 5). At the same time, the switch shown in FIG.
Switch S_TenIs switched, and the voltage is applied to the charging roller 2.
Is turned off. At the time of developing the electrostatic latent image into a visible image,
The charging polarity of toner during development is also applied to the deposited toner collecting roller 18.
Voltage of the same polarity as
The rear end Z of the area is, as shown in FIG.
When the switch S shown in FIG._ThreeCut
The reattached toner collecting roller 18 is connected to the voltage power source E.₇
And the toner attached to the reattached toner collecting roller 18
Charge polarity of the toner so that the toner does not adhere to the photoreceptor 1.
And a voltage of the opposite polarity is applied. Recovery of reattached toner
For example, a voltage of +500 V is applied to the roller 18.
Because Similarly, the rear end Z of the image forming area is
When the switch S shown in FIG.
₁Is switched, and the developing roller 5_TwoContact
The toner is also applied to the photoconductor 1 by the developing roller 5.
To prevent the toner from charging.
A voltage of, for example, +500 V is applied. Subsequently, as shown in FIG.
When the rear end Z passes through the transfer section 8, the transfer roller 7
The voltage application to is stopped. At this time, in this example, the transfer
The roller 7 is separated from the photoconductor 1 (see FIG. 7). The cleaning roller 12 is moved as described above.
Transfer residual toner T on photoconductor 1 after transfer of toner image₁The electrostatic
The surface of the photoreceptor 1 is temporarily collected and cleaned.
And the recovered toner T_TwoOf the electrostatic latent image on the photoreceptor 1
Reattach to those parts of the surface that do not affect formation. Illustrated example
Now, the image formation after the toner image is transferred to the transfer paper 16
As shown in FIG.
2, the switch S shown in FIG._TwoSwitches
The cleaning roller 12 is driven by a voltage power supply E._FiveConnected to
The core member 12a of the cleaning roller 12 has
The same negative polarity as the charging polarity of the toner during development, for example, -3
A voltage of 000 V is applied. Cleanini in this way
Roller 12 and the photosensitive member 1 from the rear end Z of the image forming area.
Non-image forming area W (see FIG.
7), the toner T on the cleaning roller 12_Two
Is formed in the direction in which the light is emitted toward the photoconductor 1.
It is. By such an electric field, as shown in FIG.
Toner temporarily collected on cleaning roller 12
T_TwoIs attached again to the non-image forming area W on the photoreceptor 1 and returned.
Is done. At this time, the cleaning roller 12 of the present example
In the forward direction (counterclockwise direction in FIG. 8) with respect to photoconductor 1
It is driven to rotate. Toner T redeposited on photoconductor 1
_ThreeIs caused by the subsequent rotation of the photoreceptor 1 as shown in FIG.
As a result, the charging row separated from the charge removing lamp 13 and the photoconductor 1
, And passes under the toner 2 as shown in FIG.
It reaches the collecting roller 18. At this time, the reattached toner is collected
As described above, the roller 18 is charged with toner at the time of development.
Since a positive voltage opposite to the polarity is applied,
Negative toner T re-adhered to body 1_ThreeThat reattach
The toner is electrostatically transferred to the toner collection roller 18 side. In the figure
As shown, on the peripheral surface of the reattached toner collecting roller 18
The developer D is carried and transported in the rotation direction of the roller 18.
However, the developer D
Reattached toner T_ThreeIs collected electrostatically. As shown in FIG. 1, provided in the developing container 15
And the leading edge portion is reattached to the toner collecting roller 18.
By the action of the scraper 20 arranged to face
Developer on Reattached Toner Collection Roller 18 shown in FIG.
D is the toner T_ThreeWith roller 18
And is returned into the developing container 15 (FIG. 1).
Is done. As described above, the surface of the image carrier composed of the photoreceptor 1
The reattachment tray provided in the developing device 4 is
Re-attached toner recovery rotator comprising a toner recovery roller 18
The toner carrying and transporting the developer and re-adhering to the image carrier
Na T_ThreeIs electrostatically collected by the transported developer.
And the developer is stored in the developing container 15 together with the developer.
The developer D is returned. Thus, the image carrier surface
Toner T reattached to surface_ThreeIs collected in the developing device 4 and
Is reused in the developing device 4. This
Configuration eliminates waste toner, and
The toner collected by the cleaning roller 12 is
It is not necessary to provide a toner transport pipe or the like for returning the toner to the container. Further, the re-adhered toner collecting roller 18
And cannot pass through the reattached toner collecting roller 18
Reattached toner T₃If present, its redeposited toner
Is a positive voltage opposite to the charging polarity of the toner, for example,
When the voltage reaches +500 V to the developing roller 5
Is collected electrostatically in the developer on the developing roller 5
You. When the toner re-adhered to the photoconductor is collected in the developing device
At this time, the developing roller also collects this reattached toner.
It is configured as follows. When the image forming operation is continuously performed,
The next image forming area X1 shown in FIG. 9 and FIG.
Receiving the charge removal action of the charge removal lamp 13 and
When the tip Y1 in the rolling direction moves to the charging roller 2
When the charging roller 2 comes into contact with the surface of the photoreceptor 1, the next image
The formation region X1 is charged to a negative polarity, and then
In the same manner as described above, an electrostatic latent image is formed in the next image forming area X1.
Formed in the developing device 4 as shown in FIG.
The toner image is visualized as a toner image. At this time,
A negative voltage is applied to the toner collecting roller 18 and the developing roller 5.
Has been applied. Then, the tip Y1 of the image forming area is
When the transfer unit 8 is reached, the transfer roller 7
And the leading edge of the next transfer paper 16 reaches the transfer section 8 and
The toner image formed in the image forming area X1 of the transfer paper
16 is transferred. The transfer residual toner at this time is described earlier.
As described above, the cleaning roller 12 is electrostatically temporarily
And the operation described above is repeated. Like this
Thus, the image forming operation is repeated a predetermined number of times. Note that, in the state shown in FIG.
In the formation region X1, both the electrostatic latent image and the toner image are still formed.
Not exactly, the area X1 shown in FIG.
It can be said that the region is to be a formation region. Also figure
1 and FIGS. 3 to 11, the photoconductor 1
Are the toners T, T on the cleaning roller 12₁, T_Two, T
_ThreeAre schematically enlarged. As described above, the cleaning roller 12
Collected toner T_TwoRepresents the non-image forming area W on the photoconductor 1
To the toner T._ThreeBy
In addition to the electrostatic latent image during the image forming operation described above,
There is no effect on the resulting electrostatic latent image. Transfer residual toner to cleaning roller 12
Collection and reattachment of the collected toner to the photoreceptor 1
Can be performed at different timings, but in either case,
Toner collected on the surface of the body 1 that does not affect the formation of the latent image
Must be reattached. Incidentally, in the conventional image forming apparatus,
Is a developing device for applying the toner re-adhered to the photoreceptor 1 (FIG. 1).
4, the developing roller 5 was exclusively used. You
In other words, conventionally, a reattached toner collecting roller 18 is provided.
And the current state of being transported while being carried on the peripheral surface of the developing roller 5.
The toner re-attached to the image agent was collected. The developing roller 5 is used to improve the image quality.
For the purpose, during development, the part facing the photoreceptor,
That is, in the developing unit 6, both surfaces move in the same direction.
Is rotated in the direction
When the developer is recovered, the developing roller 5 rotates in the same direction.
You. However, only the developing roller 5 is used on the photosensitive member 1.
When the re-attached toner is collected electrostatically, the toner on the developing roller 5
Mechanical scraping of the developer to the reattached toner on the photoreceptor 1
Since the picking action (scavenging force) decreases,
The efficiency of collecting attached toner is reduced. On the other hand, in the image forming apparatus of this embodiment,
Is a toner collecting roller 18 other than the developing roller 5.
And a reattachment toner recovery rotator
Between the recovery rotator and the image bearing member
The developer carried on the rotator moves the image carrier on the surface.
Transports the developer in the direction opposite to the
The toner T re-adhered to the surface of the image carrier in the developer_ThreeThe quiet
The toner is configured to be collected electrically,
Provides great scavenging power to the developer
The toner is efficiently reattached to the toner recovery rotating body.
The toner can be collected electrostatically in the developer, and the toner image
The generation of dirt can be effectively prevented. And now
The image roller 5 is located at a portion facing the photoconductor 1 during development.
And the two surfaces rotate in the same direction.
Therefore, deterioration of the image quality of the toner image formed on the photoconductor 1 is prevented.
Can be stopped. Do not switch the rotation direction of the developing roller 5
The transfer residual toner can be efficiently collected in the developing device.
is there. Further, at the time of development, a re-attached toner collecting roller
18, the voltage source E₆The same as the developing roller 5
By applying a voltage for various developments,
The developer carried and conveyed on the collection roller 18 causes
The electrostatic latent image formed on the optical body 1 is cooperated with the developing roller 5
The toner image can be visualized as a toner image.
A step developing method can be adopted. However, during development,
-The collection roller 18 is largely separated from the surface of the photoconductor,
Alternatively, supply of the developer to the reattached toner collecting roller 18 is stopped.
Stopped, and the development carried on the reattached toner collecting roller 18 is stopped.
Can be configured to prohibit development operation with
You. In addition, the re-attached toner collecting roller shown in FIG.
Roller 18 with respect to the rotation direction of the photoconductor 1
Downstream of the transfer roller 7
Of the reattached toner collecting roller 18
1 as in the case of the photoreceptor 1.
Can be collected. In the embodiment described above, one image
Cleaning roller 1 removes transfer residual toner for each formation area X
2 and re-attached to the photoreceptor 1 each time.
Transfer residual toner in a plurality of image forming areas
Each time the image is formed, the cleaning roller 12
Collected, collectively reattach each collected toner to photoconductor 1
You may let it. That is, the cleaning roller 12 is
For example, by rotating in the direction a in FIG.
Was collected every time each image was formed, and multiple collections were completed.
Thereafter, the cleaning roller 12 is moved, for example, by an arrow a in FIG.
Rotate in the direction opposite to the direction shown in
The collected toner may be collectively adhered to the photoconductor 1.
It is. Further, according to the present invention, the cleaning member is stopped.
While the toner is being collected from the image carrier,
Image formation configured to reattach collected toner to image carrier
It is also applicable to devices. Further, the present invention provides a cleaning member
Use a roller-shaped thing, an endless belt-like thing, etc.
Image forming apparatus or a drum-shaped image carrier
In addition to the above, the image forming apparatus using an endless belt
Can also be applied, and using an intermediate transfer body as a recording medium,
The toner image is transferred from the image carrier to this intermediate transfer body,
It is also suitable for image forming devices that transfer this to a transfer material.
Can be used. Further, the present invention provides an image bearing member using a charging device.
After charging, the surface is not irradiated with light during image exposure.
The latent image potential and the polarity of the latent image potential
Attach toner charged to the opposite polarity to the electrostatic latent image
So-called positive-positive development image formation
It can also be applied to devices. [0059] According to the image forming apparatus of the first aspect,
For example, the transfer residual toner on the image carrier is
And collects the collected toner on the image carrier electrostatically.
Attached and electrostatically collects the re-attached toner to the developing device
Toner formed on image carrier in image forming apparatus
Reattaching toner on the image carrier without deteriorating the image quality
Can be efficiently collected in the developing device. This allows the statue
Effectively prevents background contamination of toner image formed on carrier
Can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional explanatory view of an image forming apparatus according to an embodiment of the present invention, schematically showing a photosensitive member and toner on a cleaning roller in an enlarged manner. FIG. 2 is a diagram illustrating a relative positional relationship between a photoconductor, a developing roller, and a re-adhesion toner collecting roller. FIG. 3 is an explanatory diagram illustrating a relative positional relationship between a charging roller, a developing roller, a transfer roller, and a cleaning roller, and a photoconductor, and illustrating a state where transfer residual toner on the photoconductor is collected by a cleaning roller. It is. FIG. 4 is an explanatory diagram similar to FIG. 3, showing a state when a rear end of an image forming area reaches a portion facing a charging roller. FIG. 5 is an explanatory view similar to FIG. 3, showing a state when the rear end of the image forming area reaches a portion facing the reattached toner collecting roller. FIG. 6 is an explanatory diagram similar to FIG. 3, showing a state when a rear end of an image forming area reaches a portion facing a transfer roller. FIG. 7 is an explanatory diagram similar to FIG. 3, showing a state when a rear end of an image forming area reaches a portion facing a cleaning roller. FIG. 8 is an explanatory diagram similar to FIG. 3, showing a state in which the collected toner on the cleaning roller is re-adhered to the photosensitive member. FIG. 9 is an explanatory view similar to FIG. 3, illustrating a state in which the re-adhered toner on the photosensitive member is transported toward the developing device. FIG. 10 is an explanatory view similar to FIG. 3, showing a state in which the re-adhered toner on the photosensitive member is collected by the re-adhered toner collecting roller. FIG. 11 is an explanatory view similar to FIG. 3, showing a state when the leading edge of the next image forming area reaches a portion facing the transfer roller. [Description of Signs] 4 Developing Device 15 Developing Container D Developer T ₁ Toner T ₂ Toner T ₃ Toner

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masako Yoshii 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-6-194945 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 21/00

Claims (1)

(57) Claims 1. An image carrier which is driven to rotate, a latent image forming means for forming an electrostatic latent image on the carrier, and a developer housed in a developing container. The developer is carried by the developer carrying member, and the developer carried by the developer carrying member moves between the image carrier and the developer carrying member in the same direction as the moving direction of the surface of the image carrier. A developing device that transports the carried developer and visualizes the electrostatic latent image as a toner image with the transported developer, and a transfer device that transfers the toner image formed on the surface of the image carrier to a recording medium The apparatus and an apparatus for temporarily recovering the transfer residual toner on the image carrier after the transfer of the toner image, and then collecting the recovered toner on the surface of the image carrier that does not affect the formation of the electrostatic latent image. And a cleaning member for electrostatically re-adhering to the portion, and re-adhering to the surface of the image carrier. In the image forming apparatus for collecting the toner in the developing device, the developer transferred from the developer carrying and conveying member is carried and conveyed, and the toner re-attached to the image carrier is electrostatically charged in the conveyed developer. A re-attachment toner recovery rotator is provided in the developing device in a state where the rotator collects the toner and returns it to the developer contained in the developing container together with the developer, in a state facing the surface of the image carrier. Between the toner recovery rotating body and the image carrier,
The developing device is configured to transport the developer in a direction in which the developer carried by the rotating body moves in a direction opposite to the moving direction of the surface of the image carrier, and to develop the electrostatic latent image into a visible image. At times, even when the developer is carried and transported by the reattached toner recovery rotating body, the electrostatic latent image is visualized, and when the toner re-adhered to the image carrier is collected by the developing device, The developer carrying conveyance member is also configured to collect the re-adhered toner, and the cleaning member is configured by a cleaning roller having a core member and an elastic body fixed on the surface of the core member, and When the transfer residual toner on the carrier is collected by the cleaning member, the cleaning member rotates while rubbing against the surface of the image carrier, and transfers the transfer residual toner to and from the image carrier in the same manner as the toner during development. Polarity triboelectrically charged and before A voltage having a polarity opposite to that of the charged toner frictionally charged between the cleaning member and the image carrier is applied to the core member, and the transfer residual toner is electrostatically attracted to the surface of the cleaning member and collected. Then, when the toner collected by the cleaning member is re-adhered to the image carrier, the core member
An image forming apparatus configured to apply a voltage having the same polarity as the charge polarity of toner during development.