JP2506922B2 - Transfer / transport equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic copying machine, a printer, a facsimile, and the like, and more specifically, electrostatically supports and conveys a transfer material, and electrostatically charges the transfer material. The present invention relates to a transfer / conveyance device that transfers a toner image on a photoconductor.

2. Description of the Related Art In recent years, transfer / conveyance devices have been used in output devices such as electrophotographic copying machines, printers, and facsimiles.
The demand for high reliability and high image quality is increasing. further,
These requirements are becoming stronger with the colorization of output devices. Further, as to the means for electrostatically transporting the transfer material by forming a belt with an insulating member such as a dielectric, some examples are already known, as shown in, for example, US Pat. No. 3,357,325. There is.

Hereinafter, an example of the above-described conventional transfer / conveyance device will be described with reference to the drawings.

FIG. 2 shows a schematic view of a conventional transfer / conveyance device. Reference numeral 1 denotes a drum-shaped photoreceptor, which is a drum-shaped conductor support made of aluminum or the like on which a photosensitive dielectric layer such as selenium is provided. Reference numeral 2 is a charging corotron that uniformly charges the surface of the dielectric layer of the photoconductor 1. Reference numeral 3 denotes an exposure unit that writes image information to form a desired electrostatic latent image on the photoconductor 1 that is uniformly charged by the charging corotron 2. This electrostatic latent image is formed by toner by the developing device 4. It becomes a visible image. A cleaning unit 5 removes unnecessary toner on the photoconductor 1, and a charge removal unit removes charges on the dielectric layer of the photoconductor 1. Reference numeral 7 is a dielectric single-layer belt at a position in contact with the dielectric layer of the photoconductor 1, and reference numerals 8 and 9 are support rollers for stretching and rotating the dielectric single-layer belt 7. Reference numeral 10 is a transfer material, and 11 is a pressing roller for guiding the transfer material 10 and pressing it against the dielectric single-layer belt 7. Reference numeral 12 is a charging corotron for attracting the transfer material 10 to the dielectric single-layer belt 7 by electrostatic force, and 13 is a charging corotron for transferring the toner image on the photoconductor 1 to the transfer material 10.

The operation of the transfer / conveyance apparatus configured as described above will be described below. First, the photoconductor 1 is rotated at a constant speed in the direction of arrow A by a driving means (not shown), and a negative charge is applied by the charging corotron 2 to uniformly charge it negatively. Here, the photoconductor 1 is formed by the exposure unit 3 including a light source, a lens, a mirror, etc. (not shown).
The image information for forming a desired electrostatic latent image on the surface of the dielectric layer is exposed, and the desired electrostatic latent image is formed on the surface of the dielectric layer of the photoconductor 1 by this light energy. The developing device 4 holds a toner that is a negatively charged charged particle, and the toner forms an electrostatic latent image into a visible image. Next, the dielectric single-layer belt 7 is stretched by the supporting rollers 8 and 9 and runs at the same speed and in the same direction as the photoconductor 1. The transfer material 10 conveyed by the paper feeding means (not shown) is pressed against the dielectric single-layer belt 7 by the pressing roller 11, and the transfer material 10, the pressing roller 11 and the dielectric single-layer belt 7 are pressed. Due to the frictional force with
It moves at the same speed and in the same direction as the dielectric single layer belt. The transfer material 10 is composed of the dielectric single layer belt 7 and the charging corotron.
Immediately after passing between the corona discharger 12 and the corona discharger 12, the corona discharger 12 gives a negative charge, and this charge and the dielectric layer belt 7 due to this charge.
The transfer material 10 is attracted to the dielectric single-layer belt 7 by the electrostatic attraction with the polarization charge of and is conveyed to the transfer position where the toner image on the photoconductor 1 is transferred to the transfer material 10. At the transfer position, the charging corotron 13 gives a positive charge to the inside of the dielectric single-layer belt 7, and the toner image on the photoconductor 1 is electrostatically attracted by the positive charge and the negative charge of the toner. Is attracted and transferred to the transfer material 10. Then, the transfer material 10 is conveyed to the next fixing process (not shown) while the toner image remains on the transfer material 10. Also, transfer material
The remaining toner on the photoconductor 1 that has not been transferred to 10 is
The electric charges remaining on the surface of the dielectric layer of the photoconductor 1 are removed by the cleaning unit 5, for example, a rubber blade, and the electric charges are removed by the static elimination unit 6, for example, a static elimination lamp or a static elimination brush.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the one described in U.S. Pat.No. 3,357,325, a charging corotron is one in which a transfer material is charged and adsorbed to a dielectric belt, and a toner image on a photoreceptor is electrostatically In order to perform the transfer to the transfer material, it is necessary to provide a plurality of charging corotrons, which are independent from each other, at the transfer position. In other words, since the toner is negatively charged and the transfer material is also negatively charged, there is no force to attract the toner to the transfer material, and the negatively charged toner must be positively charged by electrostatic attraction. It is necessary to attract them, and a charging corotron is required at the transfer position. Further, when the transfer material is charged enough to obtain a sufficient conveyance force, the toner image transferred onto the transfer material is disturbed at the separation position where the transfer material is separated from the transfer material conveyance belt. Occurs. This is because when the transfer material is separated from the transfer material transport belt, the gap between the two becomes wider, and as the gap becomes wider, the electrostatic capacitance created by both becomes lower and the potential difference between the both increases. To go. This increase in the potential difference exerts a force on the toner transferred to the transfer material, and moves the charges on the surface of the transfer material rearward with respect to the traveling direction of the transfer material to prevent the increase in the potential difference. However, since the electric charge of the dielectric single-layer belt cannot be easily moved, the electric charge on the surface of the transfer material is restricted by the electric charge of the dielectric single-layer belt and cannot move. As a result, the toner on the transfer material scatters backward, causing image distortion. Therefore, in the conventional transfer / conveyance device using the dielectric single-layer belt, the electric charges existing in the dielectric single-layer belt and the transfer material are removed at the separation position between the transfer material and the dielectric single-layer belt. The operation to do was essential. However, it is very difficult to remove all the electric charges existing in the dielectric single-layer belt and the transfer material, and, for example, as shown in US Pat. No. 3,244,083, the electric charges existing in the transfer material are removed. In order to remove it, there was a problem that another charging corotron connected to a special power source had to be used.

Further, JP-A-62-151877 is proposed to solve this problem. This is configured such that a transfer material is passed between a charged transport belt and a conductive member connected to a direct current power source, which is provided by being connected to the transfer belt prior to the transfer position. With this configuration, a special means is not used in the charging device, the charge of the transfer belt is effectively used to realize a strong transfer property of the transfer material, and a high-quality transfer image can be obtained without complicated static elimination operation. It is possible to obtain a transfer / transport device. However, in this invention,
As the material of the dielectric layer of the transfer material conveying belt, an organic polymer material is used to obtain a desired electric resistance value. When the surface of the dielectric layer is charged to a high potential, the corona impact breaks the bonds of the polymer on the surface of the organic polymer material, resulting in a low molecular weight. Hereinafter, such a state is referred to as deterioration. When this deteriorated transfer material transport belt is used, the low molecular weight substance on the surface of the dielectric layer of the transfer material transport belt is combined with water vapor in the air, resulting in a transfer material. The electric resistance value on the surface of the conveyor belt decreases. As a result, the ability to retain electric charges is reduced, and the transfer material conveyance force cannot be obtained sufficiently. Even with such a deteriorated transfer material transport belt, there is no problem if it is used in an environment of normal humidity or when it is used in an environment of high humidity and there is little deterioration. When the belt is used in a high humidity environment, there is a problem in that the transfer material conveyance force is reduced and paper jams occur.

In view of the above problems, the present invention effectively uses the charging charge of the transfer material transport belt without using a plurality of charging corotrons in the charging device, and has strong transportability of the transfer material and transfer of the toner image to the transfer material. And a high-quality transfer image without toner image disturbance at the separation position can be obtained without complicated static elimination operation, and when used in a high humidity environment after long-term use. Also in the above, there is provided a transfer / conveyance device capable of stably maintaining the above characteristics.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides an endless transfer material conveying belt comprising at least two layers of a dielectric layer and a dielectric layer, the outer layer being the dielectric layer. A transfer means for rotating the transfer material transfer belt, an application means for grounding the dielectric layer of the transfer material transfer belt or applying an arbitrary bias voltage thereto, and a charging for charging the dielectric layer of the transfer material transfer belt. Means, a charge injecting means made of a conductive member, which is arranged so as to contact the dielectric layer of the transfer material transport belt, and a position in contact with the dielectric layer of the transfer material transport belt,
The electrostatic latent image holding means on which the electrostatic latent image is formed, the toner that makes the electrostatic latent image on the electrostatic latent image holding means a visible image, and the dielectric layer of the transfer material conveying belt are pressed against each other. And a toner replenishing means for replenishing the toner upstream of the toner holding means, and a charge injection means for transferring the transfer material. When the transfer material passes between the belt and the charge injection means, the transfer material is conveyed to the transfer material through the charge injection means by the electrostatic force of the charge applied to the dielectric layer of the transfer material transfer belt by the charging means. It is configured to inject a charge having a polarity opposite to that of the charge that the belt has. In addition, as a material for the dielectric layer of the transfer material transport belt, an organic polymer material is used to obtain a desired electric resistance value. When this organic polymer material is used, transfer is performed by a charging means. When the surface of the dielectric layer of the material conveying belt is charged to a high potential, the surface of the organic polymer material deteriorates due to corona impact. When this deteriorated transfer material transport belt is used, the low molecular weight substance on the surface of the dielectric layer of the transfer material transport belt is combined with water vapor in the air,
As a result, the electric resistance value on the surface of the transfer material transport belt is reduced, and the ability to retain electric charges is reduced, so that the transfer material transport force cannot be sufficiently obtained. As described above, even in the case of using the deteriorated transfer material conveying belt, there is no problem in the decrease of the conveying force when used in a normal humidity environment, and there is no problem in a case where the deterioration is small even when used in a high humidity environment. However, when the transfer material transport belt, which is severely deteriorated, is used in a high humidity environment, the transport force is considerably reduced. Therefore, the toner replenished by the toner replenishing means before the toner holding means is pressed against the surface of the dielectric layer of the transfer material conveying belt, and the charging means is used to charge the dielectric layer of the transfer material conveying belt to a high potential. A structure is provided in which the deteriorated portion of the surface of the dielectric material layer of the transfer material conveying belt due to impact is always removed to maintain the surface of the dielectric material layer of the transfer material conveying belt in a desired state.

Effect of the Invention With the above-described structure, when the transfer material passes between the transfer material transport belt and the charge injecting means, the transfer material is transferred by the electrostatic force of the electric charge applied to the dielectric layer of the transfer material transport belt by the charging means. A charge having a polarity opposite to that of the charge of the transfer material conveying belt is injected into the material through the injection means, and electrostatic attraction of these charges realizes strong attraction between the transfer material and the transfer material conveying belt. The toner image on the electrostatic latent image holding means is transferred onto the transfer material by the electrostatic attraction between the charge applied to the transfer material transport belt and the charge possessed by the toner. Further, the toner holding means is brought into pressure contact with the transfer material conveying belt, the toner is replenished in front of the toner holding means, and the replenished toner is held in front of the toner holding means. Due to the action of the toner applied from the toner holding means, the deteriorated portion of the surface of the dielectric material layer of the transfer material conveying belt due to the corona impact when the charging means charges the dielectric material layer of the transfer material conveying belt to a high potential. Is constantly removed, and the surface of the dielectric layer of the transfer material conveying belt is maintained in a desired state, so that a strong transfer material conveying force can be maintained even in a high humidity environment.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of the transfer / conveyance apparatus of the present invention. In FIG. 1, reference numeral 1 denotes a drum-shaped photoreceptor, which is a drum-shaped conductor support made of aluminum or the like on which a photosensitive dielectric layer such as selenium is provided. Reference numeral 2 is a charging corotron that uniformly charges the surface of the dielectric layer of the photoconductor 1. Reference numeral 3 denotes an exposure means for writing image information on the photoconductor 1 uniformly charged by the charging corotron 2 so as to form a desired electrostatic latent image by a light source, a lens, a mirror, etc. (not shown). Composed. This electrostatic latent image becomes a visible image of toner by the developing device 4. Reference numeral 5 denotes a cleaning unit that removes unnecessary toner on the photoconductor 1.
Reference numeral 6 denotes a charge removing unit that removes charges on the dielectric layer of the photoconductor 1. The outer layer 21 is a dielectric layer, and the inner layer 21 is a dielectric layer.
It is an endless paper transport belt formed of layers, the dielectric layer as an outer layer is arranged at a position in contact with the photoreceptor 1,
22 is attracted by electrostatic force and transported. Paper conveyor belt 23 and 24
1 is a grounded conductive roller that supports 1. Reference numeral 25 is a charging corotron that charges the surface of the dielectric layer of the paper transport belt 21. Reference numeral 26 is a grounded charge injection roller, which is pressed against the paper conveyance belt by means of a spring or the like (not shown). Further, 27 is a rubber blade, which is arranged so as to contact in a direction opposite to the running direction of the paper carrying belt, and in the vicinity of its upstream side with respect to the running direction of the paper carrying level 21 by a driving means (not shown). There is a rotating fur brush 28 that rotates in the opposite direction. Further, on the upstream side thereof, there is a grounded conductive brush 29 for static elimination, which is arranged so as to be in contact with the surface of the dielectric layer of the paper transport belt 21.

 Next, the operation of the configuration of the embodiment will be described.

First, the photosensitive member 1 is rotated at a constant speed in the direction of the arrow A by a driving unit (not shown), and a negative charge is applied by the charging corotron 2 to be uniformly negatively charged. Here, the exposure means 3 exposes image information for forming a desired electrostatic latent image on the surface of the dielectric layer of the photoconductor 1, and this light energy causes the desired electrostatic image on the surface of the dielectric layer of the photoconductor 1. Form a latent image. The developing device 4 holds a toner that is a negatively charged charged particle, and the electrostatic latent image becomes a visible image by this toner. The paper carrying belt 21 is supported by the conductive rollers 23 and 24, and is stretched by means such as a spring (not shown). In the example, the thickness of the dielectric layer of the paper transport belt is
Polyethylene terephthalate is 60 μm and has an electrical volume resistance value of 10 ¹⁵ Ω · cm, and the capacitance of the dielectric layer determines the capacitance of the dielectric layer. That is, the thinner the thickness is, the larger the electrostatic capacity is. If the larger the electrostatic capacity is, the same paper carrying force can be obtained.
The surface potential of 21 is low, and in the case of giving the same amount of electric charge in terms of the impact of corona, the lower surface potential requires less deterioration. Therefore, it is desirable that the thickness of the dielectric layer of the paper transport belt is thin. However, in view of dielectric breakdown strength, mechanical strength, and manufacturing difficulty of the dielectric layer of the paper transport belt 21, the thickness of the dielectric layer of the paper transport belt 21 is set to 60 μm in this embodiment. Further, the electrical volume resistance value determines the charge retention time, and the higher the resistance value, the longer the retention time. Therefore, the dielectric layer is
The electrical volume resistance value is 10 ¹³ Ωcm or more, preferably 10
Nylon or Teflon may be used as the material as long as it is ¹⁴ Ω · cm or more. The dielectric layer of the paper transport belt 21 passes through the conductive roller 23 and is grounded. Conductive roller
An appropriate bias voltage may be applied to 23 depending on the situation. This dielectric layer may be made of any material as long as it is a conductor having an electrical volume resistance value of 10 ⁶ Ω · cm or less. The conductive roller 23 is
It is rotated by driving means (not shown), and the paper transport belt 21 travels in the same direction as the photoconductor 1 at the same peripheral speed by the conductive roller 23. The surface of the dielectric layer of the paper transport belt 21 is charged by the charging corotron 25 to the opposite polarity to the toner. In this embodiment, since the toner is negatively charged, the surface of the dielectric layer of the paper carrying belt 21 is positively charged. This is because the toner image on the photoconductor 1 is electrostatically attracted and transferred to the paper 22 by the electric field due to the positive charge on the surface of the dielectric layer.

Here, the paper 22 is fed between the paper carrying belt 21 and the charge injection roller 26 by a paper feeding means (not shown) at the same timing as the rotation of the photoconductor 1. In this embodiment, the injecting means 26 has an electric resistance value of about 10 ⁶ Ω between the surface of the charge injecting roller 26 and the grounded position, and the paper conveying belt 21 is provided by means of a spring or the like (not shown). Has been pressed.
When the paper 22 passes between the paper transport belt 21 and the charge injection roller 26, the charge injection roller in the grounded state is attracted by the positive charge of the paper transport belt 21 provided by the charging corotron 25. Negative charge is injected from 26 to paper 22. Due to the attractive force of the positive charge on the paper transport belt 21 and the negative charge on the paper 22, the paper 22 after passing through the charge injection roller 26 is strongly attracted to the paper transport belt 21 and on the photoconductor 1. Toner image on paper 22
It is transported to the transfer position where it is transferred to. At this time, paper
How much electric charge is injected into 22 depends on the capacitance of the air gap layer formed by the paper transport belt 21 and the paper 22, the electric resistance against discharge between the electric charge injection roller 26 and the paper 22 in the ground state, and It is determined by the nip width when the charge injection roller 26 is pressed against the paper transport belt 21, the traveling speed of the paper transport belt 21, and the like. The charge injection roller 26 transfers charges to the paper 22, and the same effect can be expected as long as it is a conductive member regardless of the material and shape. For example, a metal fiber conductive brush may be used.

For the paper 22 that has been transported to the transfer position,
The toner image formed on the photoconductor 1 is electrostatically transferred by the electric field generated by the upper charge and the electric charge on the paper 22, and the transfer is completed while the paper 22 is in close contact with the paper conveyance belt 21. After that, the paper 22 is separated from the paper conveyance belt by the curvature of the conductive roller 24 by the rigidity of the paper 22 itself, and is conveyed to the next fixing process. Paper transport belt 21 in general
When the paper 22 and the paper 22 are separated from each other, the electrostatic capacity formed by the voids between the two and the paper 22 decreases, and the potential difference between the both increases. This spatial change in electric potential exerts a force on the toner on the paper 22 and disturbs the transferred image. However, in the present embodiment, due to the function of the dielectric layer of the paper transport belt 21, the charge on the surface of the paper 22 easily moves while maintaining the balance of the positive and negative charges as a whole, so that the toner is disturbed during separation. A high-quality transferred image can be obtained without performing a complicated static elimination operation to prevent In addition, by the charging corotron 25, the paper transport belt 21
By effectively utilizing the positive electric charge given to the paper 1, the single charging corotron 25 can be used to suck and carry the paper 22 by the paper carrying belt 21 and the photoconductor 1 without using a plurality of charging corotrons. Of the toner image can be transferred to the paper 22.

Next, 0.2 mm is applied to the non-image portion on the photoconductor 1, that is, the portion that directly contacts the paper transport belt 21 without contacting the paper 22.
A width toner image was formed each time the paper passed. This toner image forming method does not need to have a particularly complicated structure, and the exposure unit 3 exposes the light corresponding to the toner image having a width of 0.2 mm onto the photoconductor 1 by adjusting the timing when the paper 22 passes. Good. In this case, if the exposure means is of a digital type using a semiconductor laser or the like as the light source, the semiconductor laser ON-
It suffices to perform the OFF control at the same timing as the passage of the paper 22, and even with the conventional analog exposure means, the light to be exposed on the photoconductor 1 is blocked at the same timing as the passage of the paper 22. All that is required is to provide means. This 0.2 mm wide toner image is transferred to the paper transport belt by the charging corotron 25.
The electrostatic charge is applied to the surface of the dielectric layer 21 and is transferred to the paper transport belt 21 by the electrostatic force, and is transported to and held by the rubber blade 27. The retained toner receives a force from the rubber blade 27 and is strongly pressed against the paper transport belt 21. Due to the frictional force between the toner and the surface of the dielectric layer of the paper conveyance belt 21, the paper conveyance belt deteriorated due to the corona impact of the charging corotron 25.
The surface of the dielectric layer of 21 is polished to remove the deteriorated layer, and the surface of the dielectric layer of the paper conveyance belt 21 can always keep a new surface which is not deteriorated. As a result, it is possible to obtain a transfer / conveyance device having a very simple structure, in which not only the environment of normal humidity but also the environment of high humidity does not decrease the conveyance force of paper. According to the experiment, the deeper the press contact angle of the rubber blade 27 with respect to the paper transport belt 21, the more
The larger the pressure contact force, the more the rubber blade
27 The larger the amount of toner held before the paper transport belt
It was confirmed that the polishing power of the deteriorated part on the surface of the 21 dielectric layers was large. It goes without saying that the pressure contact angle and the pressure contact force are limited because the load for driving the paper transport belt 21 increases. Further, it was also confirmed by experiments that the polishing power was drastically increased when a toner containing a certain amount of abrasive grains was used. As the abrasive grains, for example, cerium oxide, alumina or the like can be used. In this embodiment, as a toner replenishing means upstream of the rubber blade 27,
A method of forming a toner image on a portion of the photosensitive member 1 which directly contacts the transfer material conveying belt without a transfer material and which corresponds to at least one of before and after each transfer material passage is used. A method of supplying toner mechanically may be used. In that case, a method of utilizing the toner collected by the cleaning means 5 is considered to be an economically preferable method.

Further, the rotary fur brush 28, which is a toner collecting means,
The amount of toner held in front of the rubber blade 27 is kept substantially constant. Then, the toner scraped off by the rotary fur brush 28 is collected in a waste toner collection box (not shown). In this embodiment, the dielectric layer of the paper conveying belt 21 has a thickness of 60 μm in terms of dielectric breakdown strength, mechanical strength, and manufacturing difficulty of the dielectric layer of the paper conveying belt 21, but the paper conveying belt 21 has a thickness of 60 μm. If the surface of the dielectric layer of the belt 21 is shaved too much, the layer thickness of the dielectric layer decreases and the capacitance increases. This change in the capacitance gives a change in the paper 22 conveyance force of the paper conveyance belt 21, the transfer force for transferring the toner image on the photoconductor 1 to the paper 22, and the like. Therefore, in order to obtain the same output image as in the initial stage, the applied voltage of the charging corotron 25 is changed according to the reduction amount of the dielectric layer thickness of the paper transport belt 21, or the charging corotron 25 and the paper transport belt are changed. It is considered that complicated operations such as changing the distance from 21 are required. Therefore, rather than performing such a complicated operation, it is considered preferable to stably scrape the dielectric layer surface by an optimum amount without overcutting the dielectric layer surface of the paper transport belt 21. . Further, if there is no toner collecting means in front of the rubber blade 27, the toner overflows in front of the rubber blade 27, so that maintenance for periodically collecting toner is required. Therefore, if a rotary fur brush 28 is provided, the rubber blade 27
The amount of toner held before can be kept substantially constant. Further, by changing the distance between the rotary fur brush 28 and the dielectric layer of the paper transport belt 21, the amount of toner held before the rubber blade 27 can be freely set. That is,
The larger the distance between the rotary fur brush 28 and the surface of the dielectric layer of the paper carrying belt 21, the larger the amount of toner held, and the smaller the distance, the smaller the amount of toner held. It has been confirmed by experiments that the amount of held toner and the amount of polishing are in a proportional relationship, and the larger the amount of held toner, the greater the amount of polishing. Therefore, by providing the rotary fur brush 28, the polishing amount can be kept constant and the polishing amount can be freely set. Therefore, it is possible to maintain a stable desired polishing amount without excessively scraping the surface of the dielectric layer of the paper conveyance belt 21, and to perform maintenance such that the toner held in front of the rubber blade 27 is periodically removed. Will be unnecessary. A rotating fur brush
28 is supposed to rotate in the direction opposite to the traveling direction of the paper transport belt 21, but it does not matter even if it rotates in the same direction as long as desired toner can be collected. Also a rotating fur brush
28 is forcibly rotated by the driving means,
The rotary fur brush 28 is used as a paper transport belt without providing a driving means.
Even if the method is such that the rotary fur brush 28 is rotated by the frictional force with the paper transport belt 21 by bringing it into contact with 21, there is no problem as long as desired toner can be collected. A method of using a conductive brush for the rotating fur brush 28, applying an appropriate bias voltage to the rotating fur brush 28, and attracting toner by electrostatic force is quite effective when it is necessary to collect a large amount of toner. Is. Further, the toner collecting means may be a method of sucking and collecting toner by air instead of the rotating fur brush 28, or a method of collecting toner by a mechanical means other than the rotating fur brush 28 without any problem.

In addition, the conductive brush 29 is a charged paper transport belt.
It is for removing the charge from the 21 dielectric layers. If the conductive brush 29 is not provided, the surface potential of the dielectric layer of the paper transport belt 21 after passing through the charging corotron 25 is about +2000 V under the environment of normal temperature and humidity, and the rubber blade 27 Then, about + 1500V is applied to the portion in contact with the paper 22, and about + 500V is applied to the portion not in contact with the paper 22. Rubber blade 27
The higher the surface potential of the dielectric layer of the paper transport belt 21 in the foreground, the greater the force of the toner held in front of the rubber blade 27 to the paper transport belt 21 by the electrostatic force, and the slower the movement of the toner. Become. Conductive brush 29
If there is, the surface potential of the dielectric layer of the paper transport belt 21 before the rubber blade 27 is about +500 V regardless of the part contacting the paper 22 and the part not contacting the paper 22, and the toner before the rubber blade 27 is always active. Keep moving. According to the experiment,
It was confirmed that the lower the surface potential of the dielectric layer of the paper transport belt 21 before the rubber blade 27, the greater the polishing power of the deteriorated portion of the paper transport belt 21 due to the action of the rubber blade 27 and the toner. Therefore, the presence of the conductive brush 29 for static elimination means that the dielectric layer of the paper transport belt 21 in front of the rubber blade 27 is sufficiently polished regardless of whether it is in contact with the paper 22 or not. . Further, when using paper 22 of different sizes, for example, when the A4 size paper 22 is continuously used in the vertical feed and then the A3 size paper 22 is used in the vertical feed, the conductive brush 29 is If there is not, there is considerable unevenness in the running direction of the transfer material transport belt 21 between the portion where the A4 size paper 22 is in contact with the paper transport belt 21 and the portion where it is not in contact. The electrostatic capacity of the dielectric layer becomes uneven, which adversely affects the transferred image of the A3 size paper 22. However, because of the conductive brush 29, even in such a state, it is possible to carry out stable polishing without unevenness and always maintain a stable transporting force of the paper 22. Although the paper 22 is configured to pass above the photoconductor 1 in this embodiment, a configuration may be used in which the paper 22 passes laterally or below the photoconductor 1.

EFFECTS OF THE INVENTION As described above, according to the present invention, an endless transfer material transport belt having at least two layers of a dielectric layer and a dielectric layer, and an outer layer being a dielectric layer, and a transfer material transport belt rotating running. The running means to be driven and the dielectric layer of the transfer material transport belt are grounded,
Alternatively, the applying means for applying an arbitrary bias voltage thereto, the charging means for charging the dielectric layer of the transfer material carrying belt, and the charging means are arranged so as to be in contact with the dielectric layer of the transfer material carrying belt. A charge injection unit made of a conductive member, an electrostatic latent image holding unit at a position in contact with the dielectric layer of the transfer material conveyance belt, on which an electrostatic latent image is formed, and an electrostatic latent image holding unit. Toner that makes the latent image a visible image, toner holding means that is arranged so as to be pressed against the dielectric layer of the transfer material transport belt, and that holds the toner on the dielectric layer of the transfer material transport belt, and toner A charge replenishing means for replenishing upstream of the holding means, wherein the charge injecting means is a dielectric of the transfer material conveying belt by the charging means when the transfer material passes between the transfer material conveying belt and the charge injecting means. The electrostatic force of the charge applied to the layer is configured to inject into the transfer material a charge having a polarity opposite to that of the charge possessed by the transfer material transport belt. To the transfer material. By being configured to press against the surface of the dielectric layer of the feeding belt, the transfer material is strongly attracted to the transfer material conveying belt, and the transfer material can be stably conveyed without deviation and the toner image can be reliably transferred. Good separation of the belt and transfer material without image disturbance without any special static eliminator, and due to corona impact when the dielectric layer of the transfer material transport belt is charged to a high potential by the charging means. By constantly removing the deteriorated portion of the conveyor belt, it is possible to always obtain a strong conveying force not only in the initial stage but also in a high humidity environment.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a transfer / transport device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a conventional transfer / transport device. 1 ... photosensitive member, 2 ... charging corotron, 3 ... exposure means, 4 ... developing device, 5 ... cleaning means, 6 ... static elimination means, 21 ... paper transport belt, 23,24 ... conductive Roller, 25 …… Corotron for charging, 26 …… Charge injection roller,
27 …… Rubber blade, 28 …… Rotating fur brush, 29 ……
Conductive brush.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Taka ▼ Shinichi No. 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Seiichiro Tachikawa 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. Sangyo Co., Ltd. (72) Inventor Yoshikazu Kawabe, 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP 62-151877 (JP, A) JP 63-83764 (JP) , A)

Claims (7)

(57) [Claims] 1. An endless transfer material transport belt comprising at least two layers of a dielectric layer and a dielectric layer, the outer layer of which is a dielectric layer, and a running means for rotating the transfer material transport belt. An applying unit that grounds the dielectric layer of the transfer material transport belt or applies an arbitrary bias voltage to the dielectric layer; a charging unit that charges the dielectric layer of the transfer material transport belt; An electrostatic latent image holding device, which is arranged so as to be in contact with the dielectric layer, is formed in contact with the charge injecting means made of a conductive member and the dielectric layer of the transfer material transport belt, and an electrostatic latent image is formed. And a toner that makes the electrostatic latent image on the electrostatic latent image holding means a visible image and the dielectric material layer of the transfer material transport belt, and the toner is transferred to the transfer material transport means. Toner retention held on the dielectric layer of the belt And a toner replenishing means for replenishing the toner upstream of the toner holding means, wherein the toner retaining means conveys the toner replenished upstream of the toner retaining means by the toner replenishing means with the transfer material. A transfer / conveyance device configured to press against a surface of a dielectric layer of the belt, wherein a deteriorated portion of the transfer material conveyance belt is removed by sliding of the toner and the transfer material conveyance belt. 2. The transfer / conveyance apparatus according to claim 1, further comprising a toner collecting unit upstream of the toner holding unit. 3. A grounded conductive brush is provided in the vicinity of the upstream side of the toner holding means and in contact with the outer layer of the transfer material conveying belt. The transfer / transport device according to item (2). 4. The transfer / conveyance apparatus according to claim 1, wherein the toner holding means is a blade. 5. The toner replenishing means is means for forming a toner image on a portion of the electrostatic latent image holding means which is in direct contact with the transfer material conveying belt without passing through the transfer material, every time a predetermined number of transfer materials have passed. The transfer / conveyance apparatus according to any one of claims (1), (2), and (3). 6. The toner replenishing means is a portion which is in direct contact with the transfer material conveying belt on the electrostatic latent image holding means without the transfer material.
6. The transfer / conveyance apparatus according to claim 5, wherein the transfer / conveyance apparatus is means for forming a toner image on a portion corresponding to at least one of before and after each transfer of the transfer material. 7. The transfer / conveyance device according to claim 1, wherein the toner contains a desired proportion of abrasive grains.