JP2003058007A - Image forming device - Google Patents

Abstract

(57) Abstract: An image carrier is charged, an electrostatic latent image is formed by exposing the charged image carrier, and the electrostatic latent image is visualized as a toner image. In an image forming apparatus that forms an image by transferring an image to a transfer material, a discharge product adhered to the surface of the image carrier is efficiently removed, and an abnormal image caused by the discharge product is prevented. SOLUTION: A product removal member 30 to which zeolite is fixed is brought into contact with the surface of an image carrier 1, and the zeolite is brought into contact with the surface of the image carrier, whereby discharge products adhered to the surface of the image carrier are removed. The toner adsorbed on the zeolite and adhered to the product removing member 30 is removed by the flicker member 4.
The product removal member 30 is cleaned by knocking it down with 0, and the discharge product removal performance of the product removal member 30 is kept high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having an image carrier.

[0002]

2. Description of the Related Art In an image forming apparatus constructed as a copying machine, a facsimile machine, a printer, or a multifunction machine having at least these two functions, a device which is discharged during operation is provided around an image carrier. Because
The discharge generates nitrogen oxides, which combine with substances in the air to form nitric acid compounds. If such discharge products adhere to the surface of the image carrier and the amount of adhesion increases,
The discharge product absorbs moisture in the air when the humidity is high to reduce the resistance and lowers the resistance of the surface of the image carrier. As a result, an abnormal image called image deletion or image blurring may occur on the image carrier. If a member that presses against the surface of the image carrier, for example, a cleaning member, is configured to scrape off the surface of the image carrier together with the discharge products in a relatively large amount, the occurrence of abnormal images can be prevented. Inevitably suffers from shortened body life.

Therefore, while suppressing the decrease in the life of the image carrier,
Conventionally, various configurations have been proposed for removing the discharge products attached to the surface of the image carrier. For example, a discharge product removing device having a water applying member for applying water to the surface of the image bearing member and a water removing member for removing water from the surface of the image bearing member is one example (Japanese Patent Laid-Open No. 60-49352). reference).
This discharge product removing device utilizes the property that the discharge product formed on the surface of the image carrier dissolves in water, and has the advantage of being able to remove the discharge product relatively effectively.

However, since the surface of the image carrier is generally hydrophobic, when water is applied to the surface of the image carrier, the water becomes sparse water droplets due to the hydrophobic property of the surface of the image carrier. It adheres to the surface of the image carrier. Therefore, when water is applied to the surface of the image carrier, even if the discharge product dissolves in the water, the aqueous solution containing the discharge product becomes water droplets and adheres to the surface of the image carrier in a sparse state. Such water droplets are wiped off.However, since the water droplets on the surface of the image carrier exist in a sparse state at the time of wiping off, the image carrier surface portion to which the water drops are attached and the image carrier on which no water drops exist. There may be a difference in the effect of removing the discharge products from the body surface portion, and the characteristics of the surface of the image carrier after wiping may become uneven.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to avoid the drawbacks of the conventional proposals and to efficiently remove the discharge products from the surface of the image carrier to prevent the formation of abnormal images. To provide a device.

[0006]

In order to achieve the above object, the present invention provides a product removing member to which a polar adsorbent for adsorbing a discharge product adhering to the surface of an image bearing member is fixed, and a product removing member. An image forming apparatus is proposed in which a cleaning means for cleaning the member is provided (Claim 1).

At this time, the product removing member includes a rotatable brush roller having a brush to which a polar adsorbent is fixed, and the cleaning means contacts the brush of the brush roller to cover the brush. It is advantageous to provide a flicker member for knocking down the cleaning material (claim 2).

Further, in the image forming apparatus according to the first aspect, it is advantageous that the cleaning unit is configured to electrostatically collect the object to be cleaned attached to the product removing member ( Claim 3).

Further, in the image forming apparatus according to claim 1 or 3, it is advantageous that the cleaning means includes a cleaning roller that comes into contact with the product removing member while rotating (claim 4).

Further, in the image forming apparatus described in claim 4, it is advantageous that a voltage having a polarity opposite to a charging polarity of the toner attached to the product removing member is applied to the cleaning roller (claim 5). ).

Further, in the image forming apparatus described in claim 1, 3, 4 or 5, it is advantageous to provide a cleaner for removing an object to be cleaned attached to the cleaning means from the cleaning means (claim 6). ).

Further, in the image forming apparatus according to the sixth aspect, it is advantageous that the cleaner includes a blade that comes into contact with the cleaning means to remove an object to be cleaned attached to the cleaning means (claim 7). ).

Further, in the image forming apparatus according to any one of claims 1 to 7, the polar adsorbent is at least one of zeolite, silica-alumina-based adsorbent, silica gel, alumina gel, activated alumina, and activated clay. 1
Advantageously, it consists of three (claim 8).

Further, in the image forming apparatus according to any one of claims 1 to 8, it is advantageous that the polar adsorbent is made of zeolite and the oxygen ring of the molecular structure of the zeolite is a 6-membered ring or more. (Claim 9).

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic partial sectional view showing an example of an image forming apparatus. The image forming apparatus shown here has an image carrier 1 configured as a drum-shaped photosensitive member provided in the main body thereof, and the image carrier 1 shown in FIG. It is rotationally driven in the clockwise direction (direction of arrow A). At this time, the surface of the image carrier is irradiated with the light from the static elimination lamp 2, and the surface of the image carrier is subjected to the static elimination action to initialize the surface potential thereof. On the other hand, a DC voltage or a charging voltage obtained by superimposing an AC voltage on a DC voltage is applied to a charging roller 3 which is an example of a charging device, and the discharge which is caused thereby causes the surface of the initialized image carrier to have a predetermined polarity. And is uniformly charged to, for example, -900V. The charging roller 3 contacts the surface of the image carrier or separates from the surface of the image carrier and rotates in the direction of the arrow.

Instead of the drum-shaped photoconductor, an image carrier made of an endless belt-shaped photoconductor wound around a plurality of rollers to be driven and driven, or an image carrier made of a dielectric can be used. In either case, the image carrier is supported so that its surface moves. Further, as a charging device, a charging charger having a corona wire which is arranged apart from the surface of the image carrier to which a charging voltage is applied, or a charging brush or a charging blade which contacts the surface of the image carrier and is applied with a charging voltage Etc. can also be used.

The surface of the image carrier charged as described above is irradiated with the light-modulated laser beam L emitted from the laser writing device 5 which is an example of the exposure device, whereby the surface of the image carrier is imaged. An electrostatic latent image corresponding to the signal is formed. The potential of the surface of the image carrier irradiated with the laser light is, for example, −150 V, which becomes an electrostatic latent image, that is, an image portion, and the potential of the surface of the image carrier which is not irradiated with the laser light is maintained at approximately −900 V. , Here is the bare skin. In this way, the charged image carrier is exposed to form an electrostatic latent image.

The electrostatic latent image is visualized by the developing device 6 as a toner image when the electrostatic latent image passes through the developing device 6. The developing device 6 shown as an example here includes a developing case 7 containing a dry two-component developer D having a toner and a carrier, a developing roller 8 arranged to face the image carrier 1 and rotating. While having the screws 9 and 10 for stirring the developer D. The toner is charged to a predetermined polarity by friction with the carrier, that is, a negative polarity in the illustrated example, and the developer D containing the toner is carried on the peripheral surface of the developing roller 8 and conveyed, and the developing roller 8 and the image carrier are carried. 1
To the development area between. At this time, the developing roller 8
Has a predetermined developing bias (for example, a voltage of -600V).
Is applied to the electrostatic latent image formed on the image bearing member 1, that is, the electrostatic latent image formed on the image bearing member 1 is electrostatically transferred to the electrostatic latent image formed on the image bearing member 1. The latent image is visualized as a toner image. In this way, the electrostatic latent image is visualized as a toner image to form an image. It is also possible to employ a developing device using a powdery one-component developer containing no carrier, a liquid developer, or the like.

A transfer roller 11, which is an example of a transfer device, is opposed to the image carrier 1. The transfer roller 11 is rotationally driven counterclockwise in FIG. 1 while contacting the surface of the image carrier. Between the transfer roller 11 and the image carrier 1, the transfer material P fed from a sheet feeding unit (not shown) and fed in the direction of arrow B at a predetermined timing by the rotation of the registration roller pair 12 passes. To do. At this time, the transfer roller 11 is applied with a transfer voltage having a polarity opposite to that of the toner of the toner image on the image carrier, that is, a positive transfer voltage in this example. As a result, the toner image is transferred onto the transfer material P sent out at a timing that can be aligned with the toner image formed on the surface of the image carrier.

The transfer material P passing between the transfer roller 11 and the image carrier 1 is separated from the image carrier 1 by the separating claw 13 and passes through a fixing device (not shown). By the action, the transferred toner image is fixed on the transfer material. Next, the transfer material P is discharged outside the main body of the image forming apparatus. Further, instead of the transfer roller 11, for example, a transfer charger, a transfer brush, a transfer blade, or a transfer device having these and a transfer belt may be used.

In the image forming apparatus shown in FIG. 1, a recording medium such as paper, a resin sheet or a resin film is used as the transfer material P, but a transfer material composed of a belt-shaped or drum-shaped intermediate transfer member is used. , The toner image on the image carrier is primarily transferred to a transfer material composed of the intermediate transfer member, and then the toner image on the intermediate transfer member is secondarily transferred to a recording medium composed of paper or a resin sheet, and the secondary The transferred toner image may be fixed by a fixing device. In this way, the toner image formed on the image carrier is
An image is formed by transferring the image onto a recording medium or a transfer material composed of an intermediate transfer member.

The transfer residual toner adhering to the surface of the image carrier that has passed the transfer position where the toner image is transferred as described above is removed by the cleaning device 14. The cleaning device 14 shown as an example here includes a cleaning case 16, a cleaning blade 17 made of an elastic material such as rubber whose base end portion is supported by the case 16 and whose front end edge portion is pressed against the surface of the image carrier. A toner discharge screw 18 is provided, and the cleaning blade 17 scrapes off and removes the toner on the image carrier. The removed toner is discharged to the outside of the cleaning case by the rotating toner discharging screw 18. In this way, the untransferred toner remaining on the surface of the image carrier without being transferred to the transfer material is removed from the surface of the image carrier.

The cleaning blade 17 is an example of a cleaning member that comes into contact with the surface of the image carrier to remove the toner adhering to the surface. It is also possible to use a cleaning device using a cleaning member other than the cleaning blade, or a cleaning device using a cleaning blade in combination with another cleaning member.

As described above, the image forming apparatus of this embodiment forms the electrostatic latent image on the image carrier, the charger for charging the image carrier, and the image carrier charged by the charger. An exposure device, a developing device that visualizes the electrostatic latent image as a toner image, a transfer device that transfers the toner image to a transfer material, and an image carrier that has passed a transfer position where the toner image is transferred. And a cleaning device for removing the transfer residual toner adhering to the surface. It is also possible to omit the cleaning device and remove the transfer residual toner from the surface of the image carrier by, for example, a developing device. In addition, the surface of the charged image bearing member is image-exposed, the part where the absolute value of the surface potential is reduced is the background part, and the part where the absolute value is maintained high is the electrostatic latent image. The image forming apparatus may be configured to form a toner image by using the image forming apparatus.

In the image forming apparatus of the above-mentioned type,
A predetermined charging voltage is applied to the charging device, in the illustrated example, the charging roller 3, and the surface of the image carrier is charged by the discharge at this time, but ozone and nitrogen oxides (NOx) are generated during the discharge. The nitrogen oxides combine with substances in the air to form nitric acid compounds such as ammonium nitrate, and the discharge products adhere to the surface of the image carrier. This is the same when a charging device other than the charging roller is used. In this way, since the discharge product composed of the nitric acid compound attached to the surface of the image carrier is water-soluble, it absorbs moisture in the air when the humidity is high and reduces the resistance value of the surface of the image carrier. Therefore, when a large amount of such discharge products adheres to the image part and the background part of the surface of the image bearing member, if they are left unattended, for example, the image becomes blurred or a blank area at high humidity. An abnormal image, also called image deletion, occurs. If the cleaning blade is configured to wear the surface of the image bearing member in a relatively large amount, the discharge products are also removed from the image bearing member, so that the occurrence of an abnormal image can be prevented. The life of the carrier is shortened.

Therefore, in the image forming apparatus of this example,
Even when the amount of wear of the image carrier is suppressed or the image carrier is configured not to be scraped, an abnormal image does not occur,
A product removing member 30 to which a polar adsorbent that adsorbs the discharge product attached to the surface of the image carrier is fixed is provided, and the product removing member 30 is brought into contact with the surface of the image carrier to image the polar adsorbent. The discharge product adhered to the surface of the image carrier by contacting the surface of the carrier is removed.

The product removing member can be constructed in various forms, but the product removing member 30 shown in FIG.
As also shown in FIG. 3, a core shaft 31 made of a rigid body such as metal,
It is composed of a brush roller 38 having a brush 36 having a base end fixed to the outer periphery thereof, and a polar adsorbent is fixed to each fiber of the brush 36, or a polar adsorbent is kneaded into each fiber, thereby forming a polar adsorbent. Can be fixed to the brush 36. In the product removing member 30, each end portion in the longitudinal direction of the core shaft 31 of the product removing member 30 is, as shown in FIG.
7 is rotatably supported, and the brush 36 of the product removing member 30 is pressed against the surface of the image carrier 1, whereby the polar adsorbent comes into contact with the surface of the image carrier.

Although the positions where the product removing members 30 are provided and the number thereof can be set as appropriate, the product removing members 3 shown in FIG.
The reference numeral 0 indicates a charger which charges the image carrier on the downstream side of the cleaning device 14 in the moving direction of the surface of the image carrier, that is, on the surface of the image carrier on the upstream side of the charging roller 3 in the illustrated example. It is placed in contact.

When the image carrier 1 rotates, the product removing member 30 abutting on the surface of the image carrier 1 is driven to rotate in the direction indicated by the arrow E in FIG. 2 or rotated in the direction indicated by the arrow E by a driving device (not shown). Driven. On the other hand, a discharge product made of, for example, ammonium nitrate adheres to the surface of the image carrier in the discharge region. When the cleaning device 14 having the cleaning blade 17 is adopted as in the example shown in FIG. 1, the discharge products adhering to the surface of the image carrier are the image carrier 1.
Although it is possible to mechanically remove the discharge products by the cleaning blade 17 when passing through the cleaning blade 17 with the rotation of the cleaning blade 17, if the cleaning blade 17 is configured to remove all the discharge products. , The surface of the image bearing member is the cleaning blade 1
A large amount is scraped off early by 7 and the life of the image carrier is shortened. Therefore, in the image forming apparatus shown in FIG. 1, at least a part of the discharge products attached at the time of discharge, for example, about 50% thereof, is attached to the surface portion of the image carrier that has passed through the cleaning blade 17. As described above, the pressure contact force of the cleaning blade with respect to the surface of the image carrier is set. The discharge product that has passed through the cleaning device 14 is rotated by the image carrier, and thus the image carrier 1 is discharged.
And the product removing member 30 are brought into contact with each other. At this time, the discharge product is adsorbed by the polar adsorbent fixed to the product removing member 30 and removed from the surface of the image carrier.
In this way, the surface of the image bearing member, which has no discharge products or the amount of which is very small, is charged and exposed, so that the amount of wear on the surface of the image bearing member is small or the surface is completely scraped. It is possible to prevent the occurrence of an abnormal image even when configured not to.

As a result of many experiments conducted by the inventor of the present invention, when discharge products adhere to the surface of the image carrier, the friction coefficient of the surface increases, and the amount of wear of the image carrier by the cleaning blade pressed against the surface also increases. It turns out to be. Therefore, by removing the discharge products from the surface of the image carrier by the product removing member 30 as described above, an increase in the friction coefficient of the surface of the image carrier is suppressed, and the amount of abrasion of the surface of the image carrier by the cleaning blade 17 is suppressed. Therefore, the life of the image bearing member can be extended.

As the polar adsorbent, zeolite, silica-alumina-based adsorbent, silica gel, alumina gel, activated alumina, activated clay and the like can be used, but it is particularly preferable to use zeolite.

The operation of removing the discharge products adhering to the surface of the image bearing member by using zeolite will be described below.

In general, zeolite crystals contain water molecules and exchangeable cations in large cavities of condensed anions having a three-dimensional structure of aluminosilicate. It has various structures depending on the type and number of cations. Therefore, as the properties of zeolite, the molecular sieving action by the cavity of the cyclic structure due to oxygen in the crystal, a reversible ion exchange action, further, depending on the shape and size of the molecule by the action of the molecular sieving or cation, Alternatively, it exhibits an action of adsorbing and separating a dipole, a quadrupole, a substance having an unsaturated bond, a substance having strong polarization, and the like (adsorption separation action). Also,
A substance can move in an electron potential energy field in a cavity that constitutes a crystal (intracavity diffusion). Even the smallest 3A-type zeolite in the crystal at the present time (about 3Å diameter) has a drying action by absorbing water (drying action) and also adsorbs ammonia, hydrogen, methanol, etc. . Zeolite 1
Since the molecular sieve (trade name), which is a seed, has a cation in the crystal, it has a stronger affinity for polar molecules due to electrostatic attraction with this cation than for activated alumina or silica gel (ion affinity action). . Furthermore, it also exhibits a catalytic action that causes various chemical reactions.

Zeolite having the above-mentioned general performance can be used as a brush as shown in FIGS. 1 to 3, paper, cloth,
It is a causative substance of an abnormal image when it is carried on felt, plastics, rubber, etc. and brought into contact with the image carrier surface in the form of roller, sheet, plate, stick, honeycomb, etc. The discharge products can be effectively removed.

The reason why zeolite is effective in removing the causative substance of the abnormal image is not clear in detail, but it is considered as follows.

Ammonium nitrate, which has absorbed moisture in the air, is ionized (this ionization causes the resistance of the surface of the image bearing member to be lowered and causes image deletion). When zeolite comes into contact with ammonium nitrate ionized with water,
The ammonium cations are adsorbed on the zeolite due to the ion exchange action, the adsorption separation action, and the diffusion in the cavities of the zeolite, and the remaining nitrate ions become nitric acid together with water. However, the nitric acid is dehydrated by the drying action of the zeolite. Dehydrated nitric acid has a property of decomposing by light and heat, and it is considered that it eventually decomposes into nitrogen dioxide and scatters in the air, or nitric acid containing water is adsorbed by the zeolite carrier. To be In any case, the ammonium nitrate is removed by the combined action of the zeolite and the discharge product, which is the causative agent of the image blur, from the surface of the image carrier.

Although non-polar adsorbents such as activated carbon also have the ability to absorb molecules, such non-polar adsorbents cannot electrostatically adsorb discharge products, and thus adsorb discharge products. Not suitable for. By bringing a polar adsorbent such as zeolite into contact with the surface of the image carrier, the discharge products can be efficiently adsorbed and the discharge products can be effectively removed from the surface of the image carrier.

As the polar adsorbent for adsorbing the discharge product, at least one of zeolite, silica-alumina-based adsorbent, silica gel, alumina gel, activated alumina and activated clay can be used. In particular, zeolite is As described above, the discharge product can be electrostatically adsorbed in the cavity, and the removal effect can be enhanced. The oxygen ring of the molecular structure of zeolite is 3, 4, 5, 6, 8, 10,
There are 8 types of 12 and 18, and any oxygen ring zeolite can be adopted, but the oxygen ring has a 6-membered ring or more, especially 8 rings.
If it is a member ring or more, the inlet diameter of the cavity is large, so that the discharge product can be effectively adsorbed.

The discharge products adhering to the image carrier can be removed by bringing the product removing member 30 carrying the polar adsorbent into contact with the surface of the image carrier as described above.
Since the discharge product is removed by using the polar adsorbent, it is not necessary to use water for removing the discharge product, which results in non-uniform characteristics of the image carrier surface after the removal of the discharge product. Can also be prevented.

As described above, the discharge products adhered to the surface of the image carrier can be efficiently removed by the product removing member 30, but when foreign matter such as toner adheres to the product removing member 30, the fibers of the brush 36 are removed. The surface of the polar adsorbent adhered to is covered with foreign matter, and the probability of contact between the discharge product adhering to the surface of the image carrier and the product removing member is reduced, and the discharge product removing function is reduced.

In the image forming apparatus shown in FIG. 1, the product removing member 30 is brought into contact with the surface of the image carrier after being cleaned by the cleaning device 14, but the cleaning device 14 removes 100% of the transfer residual toner. It is difficult to do so, and a very small amount of transfer residual toner passes through the cleaning device 14. Therefore, if a small amount of this toner adheres to the product removing member 30 and accumulates,
As described above, the function of removing the discharge products deteriorates and an abnormal image is generated.

Therefore, the image forming apparatus of this embodiment is provided with cleaning means for cleaning the product removing member. The cleaning means can be configured in an appropriate form, but in the example shown in FIGS. 1 and 2, the cleaning means is configured by the flicker member 40 fixedly fixed to the main body of the image forming apparatus or the like. That is, the product removing member 30 includes the rotatable brush roller 38 having the brush 36 to which the polar adsorbent is fixed as described above, and the cleaning unit contacts the brush 36 of the brush roller 38. From the brush,
It has a flicker member 40 that knocks off a cleaning object such as toner. A flicker member arranged so that the brush 36 of the rotating brush roller 38 comes into contact with the surface of the image carrier 1 to remove the discharge product, and at this time, the cleaning object attached to the brush 36 bites into the brush 36. Four
Hit with 0. The flicker member 40 is formed in, for example, a rod shape extending over the entire axial length of the brush 36.

As described above, the flicker member 40 can remove the object to be cleaned such as the powdery toner adhered to the product removing member 30 from the product removing member 30.
It is possible to prevent deterioration of the discharge product removing performance of the product removing member 30 and to efficiently remove the discharge product from the surface of the image carrier. Moreover, the cleaning means including the flicker member has a small installation space and can keep the cost low.

Further, if the cleaning means is configured to electrostatically collect the object to be cleaned attached to the product removing member, the efficiency of cleaning the product removing member can be further enhanced. FIG. 4 is a diagram showing an example thereof, and the cleaning means illustrated here includes a cleaning roller 41 that contacts the product removing member 30 while rotating. The cleaning roller 41 is rotatably but immovably arranged and bites into the brush 36 of the brush roller 38. In addition, the brush 3 of the product removing member 30 including the brush roller 38
6 is made of conductive fiber, and the cleaning roller 41
On the other hand, a voltage having a polarity opposite to the charging polarity of the toner attached to the product removing member 30 is applied. The product removing member 30 has conductivity, and the cleaning means electrostatically sucks and collects an object to be cleaned such as toner attached to the product removing member 30.

The charge polarity of the very small amount of transfer residual toner that has passed through the cleaning device 14 shown in FIG. 1 may be negative, which is its original polarity, or the polarity of the toner may be reversed when the toner image is transferred. As a result, the polarity may be opposite to the original polarity. Alternatively, positive and negative polarity toners may be mixed, but in either case, the polarity is opposite to the polarity that the toner that has passed through the cleaning device 14 has most, and in the example of the figure, a voltage of positive polarity is used. Is applied to the cleaning roller 41. As a result, the toner can be efficiently collected from the product removing member 30. Further, when the cleaning roller 41 is used as the cleaning means, the contact area between the cleaning roller and the product removing member 30 can be increased, so that the object to be cleaned can be efficiently removed from the product removing member. The cleaning roller 41 also has a function of knocking off an object to be cleaned attached to the product removing member 30.

Further, by providing a cleaner for removing the object to be cleaned attached to the cleaning means from the cleaning means, the cleaning means can be always kept in a cleaned state.
The object to be cleaned attached to the product removing member can be more efficiently removed by the cleaning means, and the effect of removing the discharge product by the product removing member can be further enhanced. For example, as shown in FIG. 4, the cleaning roller 41 is provided with a cleaner including a blade 42 that is in pressure contact with the peripheral surface of the cleaning means including the cleaning roller 41.
The cleaning object such as toner adhering to the peripheral surface of is cleaned. The cleaner is composed of a blade that comes into contact with the cleaning means and removes the object to be cleaned attached to the cleaning means. According to this structure, the cleaning object such as the toner attached to the product removing member 30 can be easily transferred to the cleaning roller 41, and the product removing member 30 can be removed or reduced. .

Although an appropriate cleaner other than the blade 42 can be used, if the blade 42 is used, it can be arranged in a small space and the cost of the cleaner can be kept low.

FIG. 5 is a graph showing an example of the discharge product removing performance of the product removing member 30, in which the horizontal axis represents the number of sheets of transfer material passed and the vertical axis represents the abnormal image (image deletion) rank. It is a figure. In FIG. 5, a circle indicates that the product removing member is not provided, a cross indicates that the product removing member is provided, but a cleaning means is not provided on the removing member, a triangle indicates the product removing member and the cleaning member. The case where the cleaning means to perform is provided is each shown. From these, it can be understood that the occurrence of an abnormal image can be suppressed by providing the product removing member and the cleaning means.

As described above, the product removing member 30 can be configured in various forms, and FIG. 6 shows another form of the product removing member 30. Product removal member 3 shown here
Reference numeral 0 denotes a core shaft 31, an elastic body 32 made of sponge or the like fixed to the outer peripheral surface thereof, and a sheet 33 made of rubber, paper, cloth, resin sheet or the like wound around the outer peripheral surface of the elastic body 32. The sheet 33 has a polar adsorbent fixed thereto. The product removing member 30 also rotates in contact with the surface of the image carrier 1, and the polar adsorbent comes into contact with the surface of the image carrier to remove the discharge product adhering to the surface of the image carrier. The sheet 33 may be omitted, and the polar adsorbent may be fixed to the elastic body 32, and the elastic body 32 may be brought into contact with the surface of the image carrier to bring the polar adsorbent into contact with the image carrier. Further, the product removing member is configured so as not to rotate, and the product removing member is supported so as to be able to come in contact with and separate from the surface of the image bearing member, and the product removing member is removed only when the discharge products are removed. You may make it contact with the surface of an image carrier. Further, the product removing member can be swung in the longitudinal direction. As described above, the product removing member can be configured in an appropriate form, but whichever product removing member 30 is used, the above-described configurations such as the cleaning unit and the cleaner can be adopted. FIG. 6 shows, as an example, a cleaning roller 41 to which a voltage is applied and a blade 42.

Further, as described above, the position where the product removing member is provided can be appropriately set, but in the case of the image forming apparatus provided with the cleaning device 14, the moving direction of the surface of the image carrier is more than that of the cleaning device 14. On the downstream side, the product removing member is brought into contact with the surface of the image carrier on the upstream side of the exposure position L1 (FIG. 1) of the exposure device (the laser writing device 5 in the example of FIG. 1). When the removing member is arranged, the product removing member comes into contact with the surface of the image carrier after being cleaned by the cleaning device 14.
The amount of toner attached to the product removing member can be reduced. Moreover, since the surface of the image carrier after the discharge products are removed by the product removing member is exposed, the occurrence of an abnormal image can be suppressed more effectively. Further, the discharge products attached to the surface of the image carrier are first removed by the cleaning device 14, and the discharge products not completely removed here are removed by the product removing member.
The amount of the discharge products removed by the product removing member is reduced, the discharge product removing function of the product removing member 30 can be maintained for a long time, and the life of the product removing member 30 can be extended.

As the image carrier 1, carriers having various constitutions can be used. The image carrier is a photoreceptor having an amorphous silicon type surface layer, or an alumina powder of 0.1 μm or less, for example. When a photoreceptor having a surface layer in which a filler is dispersed is used, the surface of the image bearing member has a high hardness, and thus the surface of the image bearing member is not scraped by a cleaning blade or is difficult to scrape, so the life of the image bearing member is greatly extended. In addition, the polar adsorbent can remove the discharge products attached to the surface of the image carrier to prevent the occurrence of abnormal images. As described above, it is advantageous that the image bearing member is a photoconductor having an amorphous silicon-based surface layer or a photoconductor having a surface layer in which a filler is dispersed.

Although the preferred embodiment of the present invention has been described above, the present invention should not be limited to this embodiment but can be modified in various ways.

[0054]

According to the present invention, the discharge product adhered to the surface of the image carrier can be efficiently removed by using the product removing member to which the polar adsorbent is fixed. Moreover, since the product removing member is cleaned by the cleaning means, the discharge product removing performance of the product removing member can be kept high.

[Brief description of drawings]

FIG. 1 is a schematic partial cross-sectional view showing an example of an image forming apparatus.

FIG. 2 is an enlarged cross-sectional view of the product removing member shown in FIG.

FIG. 3 is a vertical sectional view of a product removing member.

FIG. 4 is a view similar to FIG. 2, showing an example using a cleaning unit including a cleaning roller and a cleaner including a blade.

FIG. 5 is a diagram illustrating effects of a removing member and a cleaning unit.

FIG. 6 is a view similar to FIG. 2, showing another example of the product removing member.

[Explanation of symbols]

1 Image carrier 30 Product removal member 36 brushes 38 brush roller 40 flicker member 41 cleaning roller 42 blade

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiromitsu Takagaki             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Kiyoshi Tanikawa             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F term (reference) 2H134 GA01 GB02 GB06 HB01 HB12                       HB13 KB02 KH01

Claims (9)

[Claims] 1. A product removing member to which a polar adsorbent for adsorbing a discharge product adhering to the surface of the image carrier is fixed, and a cleaning means for cleaning the product removing member. Image forming apparatus. 2. The product removing member includes a rotatable brush roller having a brush to which a polar adsorbent is fixed, and the cleaning means contacts the brush of the brush roller to be cleaned from the brush. The image forming apparatus according to claim 1, further comprising a flicker member that knocks down an object. 3. The image forming apparatus according to claim 1, wherein the cleaning unit is configured to electrostatically collect the object to be cleaned attached to the product removing member. 4. The cleaning means comprises a cleaning roller that contacts the product removing member while rotating.
The image forming apparatus according to item 1. 5. The image forming apparatus according to claim 4, wherein a voltage having a polarity opposite to a charging polarity of the toner attached to the product removing member is applied to the cleaning roller. 6. A cleaner for removing an object to be cleaned attached to the cleaning means from the cleaning means.
The image forming apparatus according to 4 or 5. 7. The image forming apparatus according to claim 6, wherein the cleaner includes a blade that comes into contact with the cleaning unit and removes an object to be cleaned attached to the cleaning unit. 8. The image forming method according to claim 1, wherein the polar adsorbent is at least one of zeolite, silica-alumina-based adsorbent, silica gel, alumina gel, activated alumina, and activated clay. apparatus. 9. The polar adsorbent comprises zeolite
The image forming apparatus according to claim 1, wherein the oxygen ring of the molecular structure of the zeolite is a 6-membered ring or more.