JP2661900B2 - Electrophotographic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial applications   In the present invention, a so-called camera for copying an original image on plain paper is used.
Related to electrophotographic apparatus using the Luelson process
Belt made of a semiconductor material capable of holding electric charges
Transfer device that can perform stable toner image transfer using
For cleaning belt means of an electrophotographic apparatus having
It is presented. Conventional technology   The development of transfer / transport equipment with good transferability and paper feedability
This is indispensable for stabilizing the shooting function.   With reference to the drawings below,
An example of the electrophotographic apparatus will be described.   FIG. 6 shows an electrophotographic apparatus having a conventional transfer / transport apparatus.
It is a front view which shows the structure of. In FIG. 6, 10 is a latent image.
The rotatable photoconductor as holding means, and 12
The first charger for applying a load, 14 is on the photoreceptor 10
Development to supply charged toner particles to the electrostatic latent image
And a supply unit 16 for supplying copy paper in the direction of the photoconductor 10.
Paper device, 17 is supplied by copy paper, 18 is supplied by paper feeder 16.
To provide a charge of opposite polarity to the toner particles
No. 2 charger, 20 is charged by No. 2 charger
AC to which AC voltage is applied to remove static electricity from
The charger 22 transports the paper 17 sent from the photoconductor 10.
Transport belt 24 fixes toner on paper 17 to paper 17
Fixing device for In FIG. 6, on the rotating photoconductor 10
After the charge is uniformly applied to the
Expose the original image via a required optical system (not shown)
The electrostatic latent image corresponding to the original image on the photoreceptor 10
Is formed. The developing unit 14 charges the toner particles substantially uniformly.
And supply it to the surface of photoreceptor 10
Is developed into a visible image. Paper feeder 16 is a photoconductor
Feeds copy paper 17 toward photoconductor 10 in synchronization with rotation of 10
I do. The second charger 18 interlocks with the operation of the sheet feeding device 16.
A uniform charge is applied to the paper 17. According to the second charger 18
The electric charge applied to the paper 17 adheres to the photoreceptor 10
Has a polarity opposite to the source polarity of the toner particles.
The charged paper 17 contacts the surface of the photoconductor 10 and is electrostatically attracted.
While the toner adheres to the surface of the photoconductor 10 and is charged
The particle image is electrostatically transferred onto paper 17. AC charger 20
Removes electricity from paper 17 electrostatically adsorbed on the surface of photoreceptor 10
And separate from the photoconductor 10 using the mechanical rigidity of the paper 17
It operates in synchronization with the second charger 18.
The transport belt is separated from the photoconductor 10 as the photoconductor 10 rotates.
It is sent in the direction of the default 22. The conveyor belt is usually
An opening in a portion facing the fan, through which the fan
(Not shown) configured to inhale air
I have. The paper 17 is transported by the conveyor belt by the suction force of this fan.
22 Adsorbed on the surface and sent from the photoconductor 10 to the fixing device 24
You. The fixing device 24 feeds the paper fed by the conveyor belt 22.
17 is sandwiched between two rollers and heated and pressed.
Therefore, the toner particles on the paper 17 are melted and pressed, and set on the paper.
The sheet 17 is discharged out of the apparatus while being attached.   In the conventional electrophotographic apparatus described above, toner 17
-No. 2 charge that gives the necessary charge to transfer the particle image
Provided by charger 18 and second charger 18
Corona discharge to the AC charger 20 for erasing and removing charges
It is common to use a corotron that uses electricity,
Is the second charger 18 and AC charger 20 functional?
In many cases, they are provided close to each other as shown in FIG.
The charging area of the second charger 18 and the AC charger
Often, the 20 static elimination areas are set to partially overlap.   The transport belt 22 must be provided near the photoconductor 10.
It is necessary to retain toner particles before being fixed
It has the function of transporting paper 17, so that toner particles
Adhesion and fouling are inevitable
Nevertheless, have no means to clean the surface
Was customary. Problems to be solved by the invention   In the conventional electrophotographic apparatus described above, the toner on the photoreceptor 10
The particle image is transferred to paper 17 and this paper 17 is
There are the following problems with sending to   FIG. 1 shows the transfer of the toner particle image on photoreceptor 10 to paper 17.
Paper 17 needs to be charged
In order to separate the paper 17 from the photoconductor,
Need to be sufficiently neutralized
The action must be performed in a very close proximity
Poor transfer of toner particle image caused by photoreceptor 10
This is the occurrence of poor separation of the paper 17. In other words, transfer is assured
Voltage to the second charger 18
It is sufficient to increase the charge application to the comb paper 17, but
Then, the charge of paper 17 by AC charger 20 is insufficient.
The paper 17 does not separate from the photoconductor 10 and remains adsorbed on the photoconductor 10
There is a danger of rolling up
Strong action of AC charger 20 to prevent poor separation
Then, the static elimination action of the AC charger 20 becomes the second charger 18
And the second charger 18
The paper 17 is insufficiently charged and toner particles on the photoreceptor 10
The transfer of the image to the paper 17 will be impaired. Toner image
Performs good transfer and reliable separation of paper 17 from photoconductor 10
Has strong action of the second charger 18 and the AC charger 20
Adjustment is necessary, but the stable area is narrow and adjustment work is
Have difficulty.   Second, it is necessary to transfer the toner particle image on the photoconductor 10.
The paper 17 holds the necessary charge, and the paper 17
This is a problem caused by contact with the light body 10. Above
The second charger 18 and the paper that charge the paper 17 like
AC charger 20 for removing charges on 17 is provided close to
Paper 17 is the second channel as a charge supply source.
Charger 18 and the AC charger 20 as a charge absorption source
It will act as an electrical resistor, and the electrical resistance of the paper 17
The magnitude of the drag can change the amount of charge held by the paper 17.
And Therefore, the paper 17 also has the required charge required for transfer.
In accordance with the magnitude of the electrical resistance of paper 17,
It is necessary to adjust the charge application amount of the
The type of copying paper used in the true equipment is not one type,
The air resistance is also not constant. For one more copy
Paper may also be charged depending on the environment in which it is placed, especially humidity conditions.
It is well-known that the resistance changes significantly
Yes, for all types of copy paper, in any environment
Maintaining good toner image transfer underneath is extremely
Difficult. Normal paper is used to transfer the toner image.
It is necessary to apply a charge whose surface potential exceeds 2 KV for 17
However, the paper 17 having such a high potential true charge is
The photosensitive layer of the photoconductor 10
There is a possibility that dielectric breakdown occurs and the photosensitive layer is damaged.   Third, charged by the second charger 18
Copy paper 17 electrostatically attracted to photoconductor 10 is removed from photoconductor 10
The separating force depends on the mechanical rigidity of the paper 17 itself.
This is a problem caused by the filter. AC charger 20 has paper 17
One charge is removed, but the paper 17 is positively removed from the photoreceptor 10.
It does not provide a separating force. Therefore, the paper thickness
When using low-rigidity paper, a slight charge
Poor separation of paper from photoreceptor 10
There is a high risk of paper jams. In addition, paper 17 is required
Is it separated from photoreceptor 10 by the rigidity of paper itself?
In addition, the separation requires a certain time determined by the rigidity of the paper. Follow
When the rotation speed of the photoconductor 10 is high, the separation speed of the paper 17
Degree of separation becomes relatively slow, and poor separation or paper jam occurs
The danger increases.   Fourth, the transport force for transporting the paper 17 by the transport belt 22 is not sufficient.
Fan suction force and the size of the opening provided in the conveyor belt 22
Not necessarily enough
This is a problem caused by not being strong.
For paper with a small adsorption area, such as
Paper cannot be transported to the fuser 24
Often, paper jams occur.   Fifth, the toner particles adhered to the surface of the conveyor belt 22
Have no means to remove and clean the child
The problem is that it adheres to the surface of the conveyor belt 22.
Toner particles are attached to the back side of the copy paper to be sent next.
Of paper, causing the so-called back stain on the copy paper.
You.   In view of the above problems, the present invention provides an AC charger for static elimination.
No need for good quality regardless of the type of paper and environmental conditions
The toner image can be transferred and the paper after transfer is forcibly sensed.
New electrostatic with force to separate, hold and transport from light body
Electrophotographic equipment with a transfer and transport device
Open a cleaning device to keep the transfer / transport device clean at all times.
It is shown. Means to solve the problem   The electrophotographic apparatus of the present invention includes a toner charged on an electrostatic latent image.
A toner particle conveying means for holding and conveying the particles,
Developing means for supplying charged toner particles to the conveying means;
An electrode provided to have a contact portion with the transporting means.
Qi is 10^Ten~Ten¹³Part consisting of semiconductive material of Ωcm
Endless belt means having
Belt driving means, and a semiconductor material portion of the belt means
A charge of the opposite polarity to the charge polarity of the toner particles
And a grounding conductive member.
In the semiconductor material portion of the
Charge relaxing means for relaxing the charge imparted by the step;
So that it can be inserted into the contact area between the conveying means and the belt means.
Means for feeding a copy sheet for feeding the copy sheet;
The belt means is disposed downstream of the mitigation means, and
Cleaning hand to clean the surface facing the feeding means
And a copy fed by the paper feeding means.
Toner particles held and conveyed on the surface of the conveying means on paper
Is transferred by the electrostatic force acting in the direction of the belt means.
Separation on the downstream side of the contact part between the conveying means and the belt means
In the portion, the copy paper is electrostatically attracted to the belt means and held.
Between the belt means and the transport means so that
At least above near the contact portion and the downstream separation portion
The surface potential of the belt means is of the same polarity as the transport means,
To the charge applying means so that the potential difference becomes 1.2 kV or more.
Therefore, the above-described charge providing means is provided so as to hold the given charge.
And the charge relaxation means, and
Belt means facing the transport means of the belt means.
Is configured to remove toner particles attached to the surface
It is. In addition, the contact part upstream of the belt means and the conveying means
The conductive member grounded by the semiconductor material of the belt means
The belt means and the transport means.
At least above near the contact portion and the downstream separation portion
The surface potential of the belt means is of the same polarity as the transport means,
Control to control the potential difference to be 1.2kV or more
It is configured to include means. In addition,
To clean the surface of the
The leaning means is provided with respect to the driving direction of the belt means.
It is configured to be installed on the tension side.
You. Action   According to the present invention, with the above-described configuration, a toner particle transporter is provided.
In the vicinity of the proximity of the step and the belt means,
Step is 10 of the above belt means^Ten~Ten¹³Ω-cm electrical resistance
Charge to a portion made of a semiconductive material
Charge is directly applied to the copy paper sent by the paper feeding means.
Polarization charge due to electrostatic induction of copy paper without giving
Up the copy paper due to the electrostatic attraction of the
It is designed to be sucked and transported on the belt means.
You. When transferring the toner particles, the charging means is attached to the belt means.
The applied charge is opposite to the charge of the toner particles on the carrier.
This is done by setting the polarity of That is, belt means
The toner is charged by electrostatic attraction between the
-Particles are sucked in the direction of the belt means and are sucked on the belt means.
The image is transferred onto the copied copy sheet. Also, copy paper
Has no true charge and is adsorbed on the belt means by polarized charge
Between the toner particle transport means and the copy paper.
Separation does not require neutralization of copy paper.
The electrostatic attraction of the copy paper to the belt means for copying
It acts as a force to separate the paper from the toner particle transport.
Is dependent on the mechanical rigidity of the copy paper
Stable separation of copy paper compared to other electrophotographic devices
It is what is done.   Furthermore, it is arranged in close proximity to the toner particle conveying means.
Bell that cannot avoid surface contamination by toner particles
By providing cleaning means for
The surface is always kept clean and good copying operation can be maintained.
Things. Example   Hereinafter, an electrophotographic apparatus according to an embodiment of the present invention will be described with reference to the drawings.
This will be described with reference to FIG.   FIG. 1 is a configuration of an electrophotographic apparatus according to an embodiment of the present invention.
FIG. 2 is a front view showing the electronic photograph in the embodiment of the present invention.
FIG. 3 is an exploded perspective view of a main part of the true device, and FIG.
Transfer operation of toner particles of an electrophotographic apparatus
FIG. In FIG. 1 and FIG.
10 is a rotatable photosensitive member as a latent image holding means, 11 is a photosensitive member.
A grounded conductor portion provided on the back of the body 10, 12 is a photoconductor
No. 1 charger for applying electric charge to 10, photoreceptor 14
10 to supply charged toner particles to the electrostatic latent image on
Developing device 16 for supplying copy paper in the direction of photoconductor 10
Paper feeder, 17 is copy paper, and 26 is paper feeder 16.
The electrical resistance for transporting the fed paper 17 is 10^Ten~Ten¹³
Endless belt hand made of Ω-cm semiconductor material
The conveyor belt as a step, 28 drives the conveyor belt
The driving roller 30 is driven to rotate, and 30 is inside the transport belt 26.
The part in contact with
Rotating ground roller, 31 is a guide for the ground roller 30
A ground spring for grounding the body part, 32
Winding to contact photoreceptor 10 at required winding angle
The charging roller 34 has a charge for applying a charge to the conveyor belt 26.
The transfer charger as a means for providing the transfer belt,
This is a cleaning device for cleaning the surface.   Regarding the electrophotographic apparatus configured as described above,
The operation will be described below. In FIG. 1, on the rotating photoconductor 10
After the charge is uniformly applied to the
Expose the original image via a required optical system (not shown)
The electrostatic latent image corresponding to the original image on the photoreceptor 10
Is formed. The developing unit 14 charges the toner particles substantially uniformly.
And supply it to the surface of photoreceptor 10
Then, the electrostatic latent image is developed into a visible image. Paper feeder 16 is a photoconductor
Feeds copy paper 17 toward photoconductor 10 in synchronization with rotation of 10
I do. The drive roller 28 is driven to rotate in conjunction with the sheet feeding device 16.
At the same time, the transfer charger 34 supplies electric charges to the transport belt 26.
Pay. The transfer charger 34 is a thin tongue as a discharge body
It is a corona discharge device consisting of a ten wire and a photoconductor 10
The photosensitive member 10 and the discharge surface are contacted with each other through the contact point with the conveyor belt 26.
It is arranged to face and provided on the back of the photoconductor 10
The corona is used as the grounded conductor 11
Occurs, and an electric charge is applied to the conveyance belt 26 near the contact point with the photoconductor 10.
It is configured to apply a load. At this time
When the roller 32 is made of a grounded conductive material,
Is also used as a counter electrode for the discharge of the transfer charger.
Transfer belt from transfer charger 34
The amount of charge applied to 26 can be controlled. Conveyor bell
G 26 has an electrical resistance of 10^Ten~Ten¹³Ω-cm semiconductor material
Ground roller 30 is provided or
The setting roll 32 is formed of a grounded conductive material.
Also, the transfer charger 34 and the charge relaxation source as the charge supply source
Between the ground roller 30 and the winding roller 32
Acts as a stable resistor, providing a charge source and a charge mitigation source
The transfer charger 34 by adjusting the distance of
The supplied charge is transferred to the vicinity of the contact point with the photoreceptor 10.
Hold stably for the required amount. According to the measurement,
When the voltage applied to the charger 34 is +6.5 KV,
The surface potential of the conveyor belt 26 near the contact point of
2.5KV ~ 3KV can be obtained. FIG. 3 shows the toner particles
This shows the transfer operation. In FIG. 3, the transfer is performed by the transfer charger 34.
An electric charge is given to the feeding belt 26. With this charge
The copy paper 17 is polarized and the true charge on the transport belt 26 and the copy paper
Copy paper 17 is transported by generating electrostatic attraction with the polarization charge of 17
Adsorb on the belt 26. Charged toner on photoconductor 10
The particles are transported near the contact point between the photoreceptor 10 and the transport belt 26.
Between the true charge on the feed belt 26 or the polarization charge of the paper 17
It is sucked in the direction of the conveyor belt 26 by electrostatic attraction, and
The image is transferred onto the copy sheet adsorbed on the belt 26.
When selenium is used as the photoconductor 10, the surface potential is 80
Normally, it is charged until the voltage drops to about 0 V.
To transfer toner particles overcoming surface potential
The surface potential of the conveyor belt 26 needs to be 2 kV or more.
This is because the surface potential of the conveyor belt 26 is the surface potential of the photoconductor 10.
Of the same polarity as the photoconductor 10 and a potential difference of 1.2 kV or more
Means that As described above, the transport belt of this embodiment is
3, the photoreceptor 10 and the conveyor belt 26 are connected as shown in FIG.
Abutting part including the contact part and the downstream separated part
In the vicinity, a high potential of 2.5 kV to 3 kV can be obtained,
It is possible to realize the separation of the copy paper 17 from the photoreceptor 10
it can.   As described above, the toner particles on the photoreceptor 10
The transfer force is determined by the charge applied to the conveyor belt 26.
Occur. Therefore, when the electric resistance value of the transport belt 26 is determined,
If so, the type of copy paper 17 to be used and the copy paper 17
Maintain stable toner particle transfer regardless of environment
Can be. Furthermore, copy paper like the conventional example is essentially used.
No need for an AC charger to remove electricity
Stable transfer of toner particles because there is no component to prevent
I can.   Paper on which toner particles are transferred and held from the surface of photoconductor 10
17 is transported by the drive of the transport belt 26, and is
At the position 30, it is separated from the conveyor belt 26 and sent to the fixing unit 24.
Be included. The transport belt 26 that separated the paper 17 is cleaned.
Cleaning is performed on the surface by the
The child is driven to the transfer position. As a cleaning device
Use the method used to clean the photoconductor 10
Cleaning blade, ferb
Rashi and the like are useful. In the embodiment shown in FIG.
Cleaning blade 38 is used.
An elastic body is provided on the back of the conveyor belt 26 where the
And the surface has low sliding resistance with the conveyor belt 26
By providing a support member 40 made of a material,
Contact between the cleaning blade 38 and the conveyor belt 26
Condition and at the same time increase the driving load of the conveyor belt 26
I try not to.   At this time, the cleaning blade 38 drives the transport belt 26.
If it is arranged on the tension side for movement, the cleaning
Leveling is ensured by the contact between the blade 38 and the conveyor belt 26
It is convenient to maintain good cleaning. Real truth
In the embodiment, as shown in FIG. 1 and FIG.
Close to the upstream side, that is, the side where tension is
A cleaning blade is installed to maintain cleaning performance.
I'm sorry.   FIG. 4 shows the cleaning means for the transport belt 26.
Another embodiment of the present invention using the fur brush 42 that is driven to rotate
This shows an example of the cleaning blade 38 described above.
Good cleaning of the surface of the conveyor belt 26
Can be performed.   The important thing here is that the transport belt 26 is 10^Ten~Ten¹³Ω-cm
It is made of semiconductive material with electrical resistance.
And As described above, the transport belt 26
Contact with the photoreceptor 10 to transfer the toner particles to the paper 17
It is necessary to have a surface potential of 2KV or more near the place
However, at the same time, it passes near the contact point with the photoconductor 10 and
After that, we can gradually relax the retained charge
desirable. One of the reasons is that the transport belt
The paper 17 to be fed is transported by the conveyor belt 26 at the position of the ground roller 30.
Must be separated and sent to the fuser 24.
Conveyor belt 26 still holds high charge at roller 30
The paper 17 is separated from the conveyor belt 26.
It is difficult. Also, the transfer belt 26 is charged toner
-As long as it functions to transfer particles,
It is inevitable that the toner particles adhere,
The cleaning device 36 is provided for
Cleaning, but the conveyor belt 26 is high.
Strong electrostatic attraction between the particles and the toner particles
The toner particles from the surface of the conveyor belt 26
・ It becomes difficult to remove. For example, cleaning blur
If the contact pressure of the blade 38 against the conveyor belt 26 is increased,
Cleaning is possible, but the conveyor belt 26 and the cleaning
The frictional resistance between the conveyor belt 26 and the
Dynamic load increases, and the surface of the conveyor belt 26
Of the cleaning blade 38 and the conveyor belt 26
Increases wear and shortens the life of cleaning
Problems arise. Transfer belt 26 to 10⁹Ω-cm or lower
If it is made of a material with air resistance, the
Necessary for transfer to the surface of the conveyor belt 26
High potential cannot be obtained. Ground roller 30 for example 10⁸About Ω
Conveyor bell by grounding through high resistance
It is possible to raise the surface potential of
However, in this case, the transport belt 26 via the ground roller 30
These charges are prevented from relaxing, and the above-mentioned problems occur.
The danger increases, which is inconvenient. The transfer belt 26
Lowering the electrical resistance of the
The true charge of the conveyor belt 26 is transferred to the paper 17
17 has the same polarity charge as the transport belt 26,
The suction force between the paper 17 and the conveyor belt 26 decreases, and the paper 17
Observation of poor separation from 10 and poor conveyance of paper 17
It is not suitable for practical use. Conversely, transfer belt 26 to 10¹⁴
When composed of a material with high electrical resistance of Ω-cm or more
Indicates that the surface potential of the conveyor belt 26 is
Since the relaxation of the charge from la 30 is extremely small,
In addition to the above problems, the transport belt
As the charge from the transfer charger 34 is added to 26,
As the surface potential of the conveyor belt 26 rises,
Dielectric breakdown of the photoconductor 10 occurs near the contact part with the photoconductor 10.
Is not suitable for practical use.
No.   As described above, in the present embodiment, the transport belt 26 is^Ten~Ten
¹³Be composed of semiconductive material with electrical resistance of Ω-cm
Is essential. The grounding roller 30 is held by the conveyor belt 26.
It is useful for reducing electric charges. In this embodiment
Is a driving means for driving this by stretching the transport belt 26.
To simplify the configuration of the device.
However, of course, a driving means for the transport belt 26 may be provided separately.
Besides the ground roller
Use of a member having an electric function is also conceivable.   In this embodiment, as shown in FIG.
At the position where the conveyor belt 26 is separated from the
The ground roller 30 inside the conveyor belt 26.
To reduce the charge held on the conveyor belt 26,
The electrostatic force acting between the printer 26 and copy paper 17 is rapidly reduced.
Can be made. Further, on the traveling route of the transport belt 26,
The curvature of the copy paper 17
The copy paper 17 is naturally separated from the conveyor belt 26
Can be   In this embodiment, a corona discharger is used as the transfer charger 34.
Used. Bring the conductive brush into contact with the conveyor belt 26
The current is applied by applying a voltage to the conductive brush.
There is also a method of applying a load, but this method of applying electricity is
Insulation resistance is reduced due to scratches such as pinholes on body 10
Sometimes, too much current flows from the damaged part, so-called leakage
And it is difficult to maintain stable charge application,
If not, there is a risk of damaging the photoconductor 10
There is a problem in practical use.   When a corona discharger is used as the transfer charger 34,
In this case, the conductor 11 on the back of the photoconductor 10 is
It can be used as a counter electrode. Transfer belt 26 is transferred
It is important to note that the charger 34 and the photoreceptor 10
It does not impair the function of the Rona discharger. Of course, photosensitive
Actively provide other counter electrodes other than the conductor 11 on the back of the body 10.
It is also possible to adjust and control the operation of the corona discharger.
However, it is transported near the contact point between the transport belt 26 and the photoconductor 10.
In order to charge the transfer belt 26, the transfer belt
Transferred so that it almost faces the conductor 11 of the photoconductor 10 via 26
It is convenient to arrange the charger 34.   Further, in the present embodiment, the transport belt 26 is partially
Is provided so as to be in contact with
It does not necessarily need to be in contact with the light body 10,
Transfer of toner particles is performed even if they are separated by a gap
It is. At this time, the copy paper 17 is pressed against the transport belt 26.
If auxiliary means are provided to make contact,
The adhesion between the belt and the paper 17 is improved, and toner particles are transferred.
Separation of photo and paper 17 from photoconductor and transportability are improved.
You. The invention's effect   As described above, the present invention relates to a toner charged on an electrostatic latent image.
Means for transporting and holding toner particles, and
Developing means for supplying charged toner particles to the feeding means;
Electricity provided to have a contact portion with the transport means.
Resistance is 10^Ten~Ten¹³Ω · cm of semiconductor material
Endless belt means having, and driving this belt means
Belt drive means and semiconductive material portion of the belt means
To the toner particles.
Charge applying means, and the grounded conductive member
Means for inwardly contacting the semiconductor material portion of the means,
Charge relaxing means for relaxing the charge given by
Make sure to insert it so that it is inserted into the contact between the conveying means and the belt means.
A copy sheet feeding means for feeding a copy sheet;
The belt means is disposed downstream of the summing means,
Cleaning means for cleaning the surface facing the means
For copying sent by the paper feeding means.
The toner particles held and conveyed on the surface of the conveying means on paper are
Transfer by electrostatic force acting in the direction of the belt means, and
Separation part on the downstream side of the contact part between the conveying means and the belt means
In minutes, the copy paper is electrostatically attracted to the belt means and held.
Contact between the belt means and the transport means so that the belt is transported
In the vicinity of the contact portion and the downstream separation portion, at least
The surface potential of the filtering means is of the same polarity as the transport means, and
The above-mentioned charge applying means is used so that the potential difference becomes 1.2 kV or more.
The charge providing means so as to hold the charge given by
The charge easing means, and the cleaning
Facing the conveying means of the belt means
Constructed to remove toner particles attached to the surface
It is. Also, upstream of the contact portion between the belt means and the transport means
The grounded conductive member is made of a semiconductor material for the belt means.
And the contact between the belt means and the conveying means.
In the vicinity of the contact portion and the downstream separation portion, at least
The surface potential of the filtering means is of the same polarity as the transport means, and
A charge control method that controls the potential difference to be 1.2 kV or more.
It is configured to have a step. Furthermore, bell
To clean the surface of the printer
The belt means in the driving direction of the belt means.
It is configured to be arranged on the tension side of the force.
Transfer toner to copy paper, transport toner particles on copy paper
Separation from the means can be realized stably, and
One that can maintain good copying operation without dirt on the back of the paper
It is.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing the structure of an electrophotographic apparatus according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of a main part of the electrophotographic apparatus according to one embodiment of the present invention, FIG. FIG. 3 is a partial front view for explaining the transfer operation of the toner particles of the electrophotographic apparatus in one embodiment of the present invention, FIG. 4 is a front view showing the configuration of the electronic apparatus in another embodiment of the present invention, FIG. 5 is a front view showing an example of the configuration of a conventional electrophotographic apparatus. 10 photoconductor, 11 conductor, 12 charger No. 1,
14 ... Developer, 16 ... Paper feeder, 17 ... Copy paper, 18 ...
... No. 2 charger, 20 ... AC charger, 22 ... Conveyor belt, 24 ... Fixer, 26 ... Conveyer belt, 28 ... Drive roller, 30 ... Ground roller, 31 ... Ground spring, 32 ... Winding roller, 34 transfer charger, 36 cleaning device, 38 cleaning blade, 40 supporting member, 42 fur brush.

Continuation of front page    (72) Inventor Akira Kumon               1006 Kadoma Kadoma Matsushita Electric Industrial               Inside the corporation                (56) References JP-A-53-96838 (JP, A)                 JP-A-57-172369 (JP, A)                 JP-A-56-66869 (JP, A)                 JP-A-49-62135 (JP, A)

Claims (1)

(57) [Claims] A toner particle conveying means for holding and conveying the charged toner particles on the electrostatic latent image, a developing means for supplying the charged toner particles to the conveying means, and a contact portion with the conveying means are provided. The electric resistance is 10 ¹⁰ to 10 ¹³ Ω
endless belt means having a portion made of a semiconductor material of cm, a belt driving means for driving the belt means, and applying a charge having a polarity opposite to the charge polarity of the toner particles to the semiconductor material portion of the belt means. A charge providing means, a charge relaxing means for insulating a grounded conductive member to the semiconductor material portion of the belt means, and relaxing the charge provided by the charge providing means; and Copy paper feed means for feeding the copy paper so as to be inserted into the contact portion; cleaning means disposed downstream of the charge relaxation means and cleaning the surface of the belt means facing the transport means; And transports the toner particles held and conveyed on the surface of the conveying means onto the copy paper fed by the paper feeding means by electrostatic force acting in the direction of the belt means. And a contact portion between the belt means and the conveying means, so that the copy sheet is electrostatically attracted to the belt means and held and conveyed in a separated portion on the downstream side of a contact portion between the conveying means and the belt means; In the vicinity of the downstream separated portion, at least the surface potential of the belt means has the same polarity as that of the transport means, and the electric charge is applied so as to retain the electric charge given by the electric charge applying means so that the potential difference becomes 1.2 kV or more. An electrophotographic apparatus comprising: a cleaning unit; and a cleaning unit configured to remove toner particles attached to a surface of the belt unit facing the conveyance unit. 2. A conductive member that is grounded upstream of the contact portion between the belt means and the transport means is inscribed in the semiconductor material portion of the belt means, and at least in the vicinity of the contact portion between the belt means and the transport means and the downstream separated portion. The surface potential of the belt means is the same polarity as the transport means, and the potential difference is 1.
2. The electrophotographic apparatus according to claim 1, further comprising a charge amount control means for controlling the electric charge to be 2 kV or more. 3. The cleaning means for cleaning the surface of the belt means facing the transport means is disposed on the side where tension is applied with respect to the driving direction of the belt means. The electrophotographic apparatus according to the item 2).