JP2007147708A - Cleaning device, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent electrostatic adverse effects due to the contact sequence of the conductive brushes on the image carrier while achieving downsizing, and maintain good cleaning performance over a prolonged period of time while preventing toner scattering from the brushes in a device for removing toner from the top of an image carrier using conductive brushes to which voltages of different polarities are applied. <P>SOLUTION: The cleaning device comprises: a plurality of electrically insulated conductive brushes 70; a rotatable brush support 71 which fixes and supports the plurality of conductive brushes in parallel in a rotation direction; and power sources 701, 702 which apply voltages of mutually different polarities to at least two of the plurality of conductive brushes, wherein when a region in which a toner image is formed on a photoreceptor 1 passes through a portion A' where it primarily confronts the cleaning device and a portion B' where it secondly confronts the device, the rotation of the brush support is stopped so that the region comes in contact with the first conductive brush A to which voltage of a predetermined polarity is applied and then it comes in contact with the second conductive brush B to which voltage of the opposite polarity is applied. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a fax machine, and a printer, and a cleaning device and a process cartridge employed therein.

  2. Description of the Related Art Conventionally, as a cleaning unit that removes toner remaining on a photoconductor after toner image formation, a blade cleaning system is known in which a rubber blade is brought into contact with the photoconductor to remove the toner. In the blade cleaning method, if the accuracy of adhesion between the blade and the surface of the photosensitive member is low, the toner slips and the cleaning property is liable to deteriorate. In order to prevent this, the blade is pressed against the photosensitive member with a strong contact pressure. However, when the blade is pressed against the photosensitive member with a strong contact pressure, the blade is turned up, causing a streak-like or strip-like cleaning failure, and it is difficult to keep stable cleaning performance. Further, in the long term, the surface film scraping of the photoreceptor is promoted and the life of the photoreceptor is shortened.

  In recent years, there has been an increasing demand for higher image quality, and there is a tendency to reduce the particle size of toner. Furthermore, in order to reduce the toner manufacturing cost and improve the transfer rate, an image forming apparatus that employs a spherical toner by a polymerization method from a pulverized (atypical) toner has been commercialized. When such a small particle size and spherical toner is used, it is known that the cleaning property is inferior to the pulverized toner in the blade cleaning method.

  In contrast, an electrostatic brush is a cleaning method that provides reliable cleaning even when cleaning small-sized toner and spherical toner, and suppresses mechanical rubbing to reduce the surface film abrasion of the photoreceptor. There is a cleaning method. In the electrostatic brush cleaning method, a conductive brush roller is disposed so as to contact and rub against the surface of the photosensitive member, a collection roller is disposed in contact with the conductive brush roller, and toner is collected from the collection roller by means such as a rubber blade. Remove. At this time, a voltage is applied to the conductive brush roller or both the conductive brush roller and the collecting roller, and the toner is removed from the photosensitive member by an electrostatic force in addition to the rubbing force. For this reason, the cleaning performance can be obtained even with respect to a small particle size toner or a spherical toner.

  By the way, in the image forming apparatus, since the toner on the photoconductor is transferred by applying a voltage having a polarity opposite to that of the developed toner in the transfer process, the toner remaining on the photoconductor after the transfer is not developed. It is a mixture of a toner with a toner polarity, a toner charged to a reverse polarity, or an uncharged toner. As a means for electrostatic brush cleaning of this mixture of bipolar and non-charged toners, in Patent Document 1, two conductive brush rollers to which positive and negative voltages are respectively applied are arranged and cleaned for each polarity toner. Proposed method.

  However, it is difficult to achieve the problem of downsizing the image forming apparatus by disposing two conductive brush rollers facing the photosensitive member and further disposing a toner collecting device attached to each brush. Therefore, Patent Document 2 proposes an electrostatic brush cleaner that cleans the toner for each polarity toner without increasing the size. The electrostatic brush cleaner includes a conductive core divided into a first region having a first polarity and a second region having a second polarity, and a plurality of conductive fibers attached thereto. It has a brush roller. The positive and negative voltages are respectively applied to the first region and the second region of the conductive core to divide the conductive fibers attached to the regions into regions having positive and negative polarities. Then, the brush roller divided into the positive and negative areas is rotated so that each of the brush rollers comes into contact with the surface of the photoconductor, and cleaning is performed for each polar toner from the surface of the photoconductor. Such an electrostatic brush cleaner has an advantage in terms of downsizing since only one brush roller needs to be disposed facing the photosensitive member.

Japanese Patent No. 3055801 JP 2005-157374 A

  As described above, in the electrostatic brush cleaner of Patent Document 2, the brush roller divided into the areas having the positive polarity and the negative polarity is rotated and brought into contact with the surface of the photoconductor to remove the toner from the photoconductor. Yes. For this reason, (1) the first positively biased brush contacts the photoconductor and then the negatively biased brush contacts, and (2) the first negatively biased brush contacts the photoconductor. Then, there are two cases where a positively biased brush comes into contact. Since the photoconductor after contact with the biased brush is charged according to the bias voltage, the surface potential of the photoconductor after passing through the brush differs between (1) and (2). Further, in the case of (2), if the photosensitive member is left positively charged, if the negatively charged photosensitive member is used, the photostatic discharge cannot be performed, and the charging potential is lowered in the next charging step. As described above, in the electrostatic brush cleaner of Patent Document 2, since the brush is brought into contact with the surface of the photosensitive member while rotating the brush, the contact order of the brushes cannot be made constant, and the charging potential is lowered on the photosensitive member. Electrostatic adverse effects will occur.

  Further, in the configuration of Patent Document 2, in order to rub the same portion on the photosensitive member with the brush roller divided into regions having positive polarity and negative polarity, the photosensitive member is moved at a low speed, or The brush must be rotated at high speed. When the photosensitive member is moved at a slow speed, the productivity of image formation is poor. On the other hand, when the brush is rotated at a high speed, the I.V. Generation of a toner cloud due to toner scattering from the brush reattaches to the photoconductor, thereby contaminating the photoconductor. II. The time for which the brush keeps rubbing the photoreceptor is short, and the cleaning efficiency is lowered. III. The time for switching the positive and negative polarity of the brush is short, and the cleaning efficiency is lowered. There are problems such as.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to reduce the size of an apparatus for removing toner from an image carrier using a conductive brush to which a voltage having a different polarity is applied. Cleaning device and process cartridge capable of maintaining good cleaning performance over a long period of time while preventing electrostatic adverse effects on the image carrier due to the contact order of the conductive brush and preventing toner scattering from the cleaning brush And an image forming apparatus.

In order to achieve the above object, a first aspect of the present invention provides a cleaning device for removing toner adhered on an image carrier with a conductive brush to which a voltage having a different polarity is applied. A plurality of conductive brushes, a rotatable brush support that fixes and supports the plurality of conductive brushes in parallel in a rotational direction, and voltages having different polarities are applied to at least two of the plurality of conductive brushes. And a voltage application means, and when the region where the toner image is formed on the image carrier passes through a portion facing the cleaning device, it contacts the first conductive brush to which a voltage of a predetermined polarity is applied. After that, the rotation of the brush support is stopped so as to come into contact with the second conductive brush to which a voltage having a different polarity is applied.
According to a second aspect of the present invention, in the cleaning device of the first aspect, a toner removing member for removing the toner adhering to the conductive brush is provided.
According to a third aspect of the present invention, in the cleaning device according to the first or second aspect, an insulating member for preventing leakage between a plurality of conductive brushes arranged adjacent to each other on the brush support is provided. It is provided between the conductive brushes.
According to a fourth aspect of the present invention, in the cleaning device according to the first, second, or third aspect, the image carrier is a photoconductor, and the polarity of the voltage applied to the first conductive brush is the charge of the photoconductor. The polarity is opposite to the polarity.
According to a fifth aspect of the present invention, in the cleaning device according to the first, second, third, or fourth aspect, the brush support rotates at a timing when the non-image portion on the image carrier in each printing operation faces the cleaning device. It is a characteristic to do.
According to a sixth aspect of the present invention, in the cleaning device according to the first, second, third, or fourth aspect, the brush support is provided at a timing when the non-image portion on the image carrier after printing a predetermined number of sheets faces the cleaning device. It is characterized by rotating.
According to a seventh aspect of the present invention, in the cleaning device of the first, second, third, or fourth aspect, the brush support rotates at a timing when the non-image portion on the image carrier after 1 job printing faces the cleaning device. It is a characteristic to do.
According to an eighth aspect of the present invention, in the cleaning device of the second, third, fourth, fifth, sixth, or seventh aspect, the toner removing member is a conductive member that is not in contact with the image carrier among the plurality of conductive brushes. The toner is removed from the conductive brush.
The invention according to claim 9 is the cleaning device according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the brush support is swingable in the axial direction. It is.
Further, the invention of claim 10 is the cleaning device of claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, over the entire longitudinal length of a part of the peripheral surface of the brush support. The conductive brush has a region where no conductive brush is disposed.
The invention according to claim 11 is the cleaning device according to claim 10, wherein after the image formation is completed, the portion of the brush support that is not disposed with the brush faces the image carrier. The rotation is stopped.
The invention of claim 12 is directed to an image carrier, a charging device for charging the image carrier, a latent image forming device for forming an electrostatic latent image on the image carrier, and a static image on the image carrier. Image forming apparatus comprising: a developing device that causes toner to adhere to an electrostatic latent image to be visualized; a transfer device that transfers a toner image on the image carrier to a transfer material; and a cleaning device that cleans the image carrier. In the apparatus, the cleaning apparatus according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11 is employed as the cleaning apparatus.
According to a thirteenth aspect of the present invention, in the image forming apparatus of the twelfth aspect, a multicolor image is formed on a single image carrier by a developing device comprising a plurality of developing units.
According to a fourteenth aspect of the present invention, there is provided an image forming apparatus according to the twelfth aspect, wherein the image forming apparatus includes a plurality of image forming portions each including one image carrier and one developing device, and the toner images formed by the plurality of image forming portions. A multicolor image is formed by superimposing the images.
According to a fifteenth aspect of the present invention, in the image forming apparatus according to the twelfth, thirteenth or fourteenth aspect, as a toner for forming a toner image on the image carrier, a shape factor SF-1 is in the range of 100 to 150. It is characterized by using a certain thing.
According to a sixteenth aspect of the present invention, in the image forming apparatus according to the twelfth, thirteenth, fourteenth, or fifteenth aspect, the image carrier is formed with a surface layer made of amorphous silicon.
The invention according to claim 17 is the image forming apparatus according to claim 12, 13, 14 or 15, wherein the image carrier is provided with a protective layer containing a filler (particulate matter). It is what.
According to an eighteenth aspect of the present invention, in the image forming apparatus of the seventeenth aspect, the binder resin of the protective layer has a crosslinked structure.
According to a nineteenth aspect of the present invention, in the image forming apparatus according to the eighteenth aspect, the structure of the binder resin having the crosslinked structure has a charge transporting portion.
According to a twentieth aspect of the present invention, there is provided a process cartridge in which a cleaning device and at least one selected from an image carrier, a charging device, and a developing device are integrally formed and detachable from an image forming apparatus main body. The cleaning device of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11 is employed as the cleaning device.

  In these inventions, the rotation of the brush support is stopped, and the region where the toner image is formed on the image carrier is brought into contact with the first conductive brush to which a voltage of a predetermined polarity is applied. Each of the polar toners is cleaned by bringing it into contact with a second conductive brush to which a voltage having a different polarity from that of the second conductive brush is applied. In addition, since a plurality of conductive brushes are fixedly supported on a rotatable brush support, the size can be reduced as compared with a configuration in which two brush rollers to which positive and negative voltages are respectively applied are arranged. Further, since the order of the polarity of the conductive brushes that come into contact with the image carrier is always constant, it is possible to prevent the image carrier from adversely affecting the electrostatic effect due to the contact order of the conductive brushes. In addition, since the brush support is not always rotated, the movement time of the brush can be shortened, and the occurrence of toner cloud due to toner scattering from the brush can be prevented. Further, when the region where the toner image is formed on the image carrier passes through the portion facing the cleaning device, the brush support stops rotating, and the first conductive brush, the second conductive brush, Is disposed so as to face the image bearing member, it is possible to secure a time for each polarity brush to continue rubbing the image bearing member and a time until the positive / negative polarity of the brush is switched, thereby improving the cleaning efficiency. Thereby, good cleaning performance can be obtained.

  According to the first to twentieth aspects of the present invention, in an apparatus for removing toner from an image carrier using conductive brushes to which voltages of different polarities are applied, an image based on the order of contact of the conductive brushes while reducing the size. There is an excellent effect that a good cleaning performance can be maintained over a long period of time while preventing electrostatic adverse effects on the carrier and preventing toner scattering from the cleaning brush.

  Hereinafter, an image forming apparatus as an embodiment to which the present invention is applied will be described. FIG. 1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention. In FIG. 1, a charging device 2, a developing device 4, a transfer device 6, a cleaning device 7, and a charge eliminating device (not shown) are sequentially arranged around a drum-shaped photoconductor 1 as an image carrier. An exposure device (not shown) is provided as a latent image forming unit that exposes the photoreceptor 1 to form an electrostatic latent image on the photoreceptor 1. The photoreceptor 1 rotates in the direction of the arrow at a speed of, for example, 250 mm / sec, and the surface is uniformly charged by the charging device 2. The charged photoreceptor 1 is irradiated with writing light such as light-modulated laser light emitted from an exposure device (not shown), and an electrostatic latent image is formed on the photoreceptor 1. The electrostatic latent image formed on the photoreceptor 1 is visualized as a toner image by the developing device 4. On the other hand, a transfer paper P as a transfer material is fed from a paper supply device (not shown), and a toner image on the photoreceptor 1 is transferred to the transfer paper P by the transfer device 6. The transfer paper P to which the toner image has been transferred is separated from the photosensitive member 1 and then conveyed to a fixing device (not shown), where heat and pressure are applied to the toner image on the transfer paper P to transfer the toner image. Fixed on paper. The transfer paper that has passed through the fixing device is discharged out of the apparatus. Further, the residual toner is cleaned by the cleaning device 7 on the surface of the photoreceptor 1 after the toner image is transferred. The photosensitive member 1 that has passed through the cleaning device 7 is irradiated with light from a static eliminator (not shown), its surface potential is initialized, and then prepared for image formation.

  The charging device 2 shown in FIG. 1 includes a charging roller having a conductive base 13 and a resistance layer 14 provided on the surface thereof. The charging device 2 is pressed at a predetermined pressure by a pressing means (not shown) and is brought into pressure contact with the surface of the photoreceptor 1 with a force of, for example, 500 gf. The charging device 2 does not have a separate driving unit, and is configured to rotate with the rotation of the photosensitive member 1. However, if the static friction coefficient of the surface of the charging device 2 is sufficiently small, the charging device 2 may not be rotated. In such a case, in order to obtain a stable contact state, the driving device that rotationally drives the charging device 2. May be provided separately. Further, the charging device 2 composed of a charging roller is set such that its longitudinal (axial) dimension is slightly longer than the maximum image width A4 (about 300 mm). A power source (not shown) is connected to the base 13 of the charging device 2 and applies a voltage at which the potential difference between the photosensitive member 1 and the charging device 2 is equal to or higher than the discharge start voltage. In the present embodiment, a voltage that charges the surface potential of the photoreceptor 1 to −700 V is applied to the charging device 2. As a result, discharge occurs in the vicinity of the contact portion between the charging device 2 and the photosensitive member 1, and the surface of the photosensitive member is uniformly charged. A voltage obtained by superimposing an AC voltage on a DC voltage is used as the applied voltage. In this embodiment, a frequency: 1.8 kHz, a peak voltage: 2 kV, and an offset voltage: -740 V are applied. However, since the amount of NOx generated is smaller when the DC voltage is applied than the AC superposition type, it is better to apply the DC voltage when it is desired to suppress the generation of ozone and NOx. However, a more uniform surface potential can be obtained with AC superposition than with DC voltage application. In FIG. 1, the charging device 2 is in contact with the surface of the photosensitive member 1, but the charging device 2 made of, for example, a charging roller may be disposed close to the surface of the photosensitive member 1 with a minute gap. Even when such a non-contact type charging device is used, by applying a predetermined voltage to the charging device, a discharge is generated between the charging device and the photosensitive member 1 to charge the photosensitive member 1 to a predetermined polarity. can do. In addition to the charging roller, the charging device 2 may be a charging blade or a charging brush.

  The developing device 4 includes a developing roller 5 that carries and conveys a dry developer having toner and a carrier. The toner frictionally charged to a predetermined polarity in the developing device 4 is carried on the developing roller 5 as a developer and conveyed to a portion facing the photoreceptor 1. Then, the toner in the developer is electrostatically transferred to the electrostatic latent image on the photoreceptor 1 to be visualized. In the image forming apparatus according to the present exemplary embodiment, a toner that is triboelectrically charged to a negative polarity is used.

  The transfer device 6 includes a transfer belt that can be brought into contact with and separated from the surface of the photoreceptor 1, a bias roller for applying a transfer voltage, a support roller that stretches the transfer belt, a drive roller that drives the transfer belt, and the like. A belt transfer device. In this transfer device 6, the transfer paper P fed from a paper feed cassette (not shown) is conveyed so that the transfer belt passes through a transfer position facing the photosensitive member 1, and the toner charging polarity of the toner image is set to the bias roller. A toner image on the photosensitive member 1 is transferred onto the transfer paper P by applying a transfer voltage having a reverse polarity (positive polarity in this embodiment). The transfer device 6 in FIG. 1 is a belt transfer device that can be brought into contact with and separated from the surface of the photoreceptor 1, but other appropriate transfer devices can also be used. Here, among the transfer residual toner adhering to the surface of the photosensitive member 1 after passing through the transfer position where the toner image is transferred, the toner is influenced by the transfer voltage and is opposite in polarity to the charge polarity at the time of development, that is, positive polarity. May be charged. Therefore, the transfer residual toner charged with positive polarity and the transfer residual toner charged with negative polarity are mixed on the photoreceptor 1.

  The cleaning device 7 includes a rotatable brush support 71 that supports a plurality of fixed brushes 70 such as A, B, C, and D formed in a strip shape in parallel with one axis of the photosensitive member, and a plurality of brushes that apply a voltage to the brush. Power sources 701 and 702, and a driving device (not shown) that intermittently rotates a brush support 71 on which a plurality of brushes 70 are fixed. Further, as toner removing members for removing toner adhering to the brush, the toner collecting rollers 73 and 74, a plurality of power sources 703 and 704 for applying a voltage to the toner collecting rollers 73 and 74, and the toner collecting rollers 73 and 74 from the toner Scrapers 75 and 76 are provided. In the plurality of fixed brushes 70 supported by the brush support 71, the two brushes A and B that are in contact with the photosensitive member 1 and the fixed brushes other than A and B are not electrically contacted. It is supported. Further, the brush support 71 may have a prismatic shape having a bottom surface of a polyhedron such as a quadrangular column, a hexagonal column, or an octagonal column as long as it is rotatable, as long as it is rotatable. Of the plurality of brushes 70 fixed to the brush support 71, two brushes A and B are simultaneously in contact with the photosensitive member 1, and two of the other brushes are in contact with the toner collection rollers 73 and 74, respectively. It is configured as follows. By applying voltages having different polarities from the power sources 701 and 702 to the two brushes A and B that are in contact with the photoconductor 1, the transfer residual toner having the opposite sign polarity is cleaned. FIG. 2 is a schematic configuration diagram of the brush support 71 to which the fixed brushes A, B, C, and D are fixed. Further, the number of fixed brushes supported by the brush support 71 may be any number as long as the width of the brush nip contacting the photoconductor 1 is 2 to 3 mm or more, and can be determined appropriately depending on the diameter of the brush support 71. Further, in order to maintain good cleaning performance for a long period of time, it is advantageous for the life of the cleaning device that the number of brushes arranged on the brush support 71 is large.

  Next, prevention of leakage between fixed brushes will be described. As described above, voltages having different polarities are applied to the two fixed brushes A and B, respectively, so that the two adjacent fixed brushes A and B may come into contact with each other and leak. Therefore, an insulating member 72 made of an insulating material is sandwiched between all the brushes including the brushes A and B. By sandwiching such an insulating member 72, leakage due to contact with an adjacent brush having a different polarity is prevented. The insulating member is preferably a sheet-like flexible member, and may be an insulating brush or the like.

  Next, the operation of the cleaning 7 will be described in detail. When a print signal is input and an image forming operation is started, after the charging, writing, developing, and transferring steps, the transfer residual toner on the photosensitive member 1 is sent to a portion facing the cleaning device 7. In the cleaning device 7, drive means (not shown) that rotates the brush support 71 intermittently before the position of the leading end of the image portion of the photosensitive member 1 reaches the A ′ portion in the drawing that first faces the cleaning device 7. The brush support 71 is rotated and stopped so that the brush A moves to a position facing the A ′ portion. Along with this rotation, the brush B adjacent to the brush A is configured to move to a position facing the cleaning device 7 and the B ′ portion facing next. Next, the rotation of the brush support 71 is stopped and the positions of the brushes A and B are fixed until the image portion front end of the photoreceptor 1 reaches the A ′ portion and the rear end of the image portion passes the B ′ portion. Leave. At this time, a positive voltage is applied to the stopped brush A to clean the negatively charged toner on the opposing photoreceptor 1, and a negative voltage is applied to the stopped brush B. Then, the positive toner is cleaned. Then, between the images after the rear end of the image portion passes the B ′ portion (= between sheets), the driving means rotates the brush support 71 to a position where the brush C faces the A ′ portion and stops. With this rotation, the brush D adjacent to the brush C moves to a position facing the B ′ portion. This rotation operation ends before the leading edge of the next image portion reaches the A ′ portion. As in the first image formation, a positive voltage is applied to the brush C from the time when the leading edge of the image portion of the photoreceptor 1 reaches the A ′ portion until the trailing edge of the image portion passes the B ′ portion. The negatively charged toner on the opposing photoreceptor 1 is cleaned, and a negative voltage is applied to the brush D to clean the positive toner.

  The fixed brushes A and B that have been cleaned during the first image formation reach the positions of the collection rollers 73 and 74, respectively, as the brush support 71 rotates between images. A positive voltage is applied to the collecting roller 73 from the power source 703 to collect the negative toner attached to the brush A. Thereafter, the toner on the collection roller 73 is removed by the scraper 75. A negative voltage is applied to the collecting roller 74 from the power source 704 to collect the positive toner adhering to the brush B. Thereafter, the toner on the collection roller 74 is removed by the scraper 76. The toner scraped off from the collection rollers 73 and 74 falls to a toner discharge member (not shown) installed below the collection rollers 73 and 74 and is discharged out of the cleaning device 7 by a conveying action generated by the rotation of the toner discharge member. The When the toner is collected, if the brushes A and B are electrically grounded, a potential difference between the collection rollers 73 and 74 and the brushes A and B is secured, and the collection efficiency is improved. Further, since the uncharged toner contained in the transfer residual toner has no electrostatic adhesive force, it is easily removed from the photoreceptor 1 by the rubbing of the brushes A and B, and the brush 70 accompanying the rotation of the brush support 71. , It is dropped from the brush 70 onto the toner discharge member and collected. Thus, since the toner of the brush 70 not in contact with the photoreceptor 1 is removed, the polarity of the brush-attached toner is not reversed, and there is no possibility that the brush-attached toner is reattached on the photoreceptor 1.

Specific conditions of the cleaning device 7 of the present embodiment are as follows.
Brush material: Conductive polyester brush yarn resistance: 10 ⁸ Ω · cm
Brush flocking density: 100,000 / inch ²
Brush hair length: 5mm
Collection roller material: SUS
Collection roller diameter: 10 mm
Scraper contact angle: 20 °
1mm scraper bite into collection roller
Scraper material: Polyurethane rubber In the cleaning device 7 configured as described above, even if the transfer residual toner includes a mixture of positive and negative charged ones, the brush that first contacts the negative transfer residual toner The transfer residual toner that is electrostatically collected and charged positively can be electrostatically collected by the brush that comes into contact next. In the cleaning device 7, under the condition that the transfer residual toner is reversed positively, +200 V is applied to the brush A and −300 V is applied to the brush B, and the surface of the photoreceptor 1 that has passed through the cleaning device 7 is observed. It was confirmed by experiment that this was done. Note that an optimum applied voltage is appropriately selected as the applied voltage in accordance with changes in transfer conditions and other process conditions.

  As the fibers constituting the brush, in addition to the above conductive polyester, fibers such as nylon, acrylic and the like with a conductive material such as carbon added can be used, and the fibers are not limited to these fibers as long as they are conductive fibers. . Examples of the method for imparting conductivity to the fiber include, but are not limited to, a method in which a conductive material is coated on the surface of the fiber, or dispersed and inserted into the fiber. The toner collection rollers 73 and 74 need to be conductive because they apply a voltage for attracting toner from the fixed brush. Specifically, for example, a metal such as SUS, or a fluorine-based resin coated or dispersed or subjected to eutectoid plating with a metal so as to reduce the static friction coefficient of the surface thereof is desirable. Moreover, you may comprise with conductive rubber, a conductive resin, etc. As the scrapers 75 and 76, when the toner collection rollers 73 and 74 are made of metal, it is preferable to use, for example, a nylon sheet material or a rubber blade. When the toner collection rollers 73 and 74 are made of nonmetal such as conductive rubber or conductive resin, it is preferable to use a metal blade. A toner discharge member (not shown) is constituted by a conveying coil.

  Further, the brush support 71 that supports the brush 70 may include a mechanism that swings in the axial direction of the photoreceptor 1. As a result, it is possible to prevent local deterioration of the cleaning performance due to toner concentration.

  Further, as described above, the image area of the photoreceptor 1 is first contacted with a brush biased to a positive polarity opposite to the charged polarity (negative polarity) of the photoreceptor 1, and then the same polarity as the charged polarity. The negatively biased brush is in contact. As a result, the photosensitive member 1 after passing through the cleaning device 7 is charged with the same polarity as the charging polarity. As a result, light neutralization by a static eliminator (not shown) can be performed, and the influence on the next image forming cycle can be prevented.

  Further, the cleaning device 7 of FIG. 1 is a cleaning device that uses electrostatic force, unlike a cleaning device that uses a cleaning blade. For this reason, it is possible to simultaneously control the surface potential of the photoreceptor 1 after passing through the cleaning device 7. Specifically, by controlling the voltage applied to the brushes A and B, it is possible to omit the static eliminator, thereby further reducing the cost and space of the image forming apparatus.

  Thus, since the brush support 70 is not always rotated, the movement time of the brush 70 can be shortened, and the occurrence of toner cloud due to the scattering of toner from the brush 70 can be prevented. Further, when the region where the toner image is formed on the photosensitive member 1 passes through the portion facing the cleaning device 7, the brush support stops rotating and the brush A and the brush B face the photosensitive member 1. Therefore, it is possible to secure the time for the brushes A and B having the respective polarities to keep rubbing against the photosensitive member 1 and the time until the positive and negative polarity of the brush is switched, thereby improving the cleaning efficiency. Thereby, good cleaning performance can be obtained.

  Further, in the above-described example, the brush support 71 is set to the timing at which the non-image portion on the photosensitive member 1 in each printing operation rotates between images facing the cleaning device (= paper interval). By rotating the brush 70 for each print in this way, the brush 70 is cleaned by the collection rollers 73 and 74 for each print, so even when the amount of input toner is large, the toner adhering to the brush 70 is saturated. This can prevent the cleaning performance from deteriorating.

  Further, in a high transfer efficiency system in which the amount of toner input to the cleaning device is small, the rotation of the brush support 71 that has been performed for each print may be performed for each predetermined number of prints. The rotation of the brush support 71 can be reduced, and the deterioration of the brush fibers due to the collision caused by the rotation between the brush 70 and the collection rollers 73 and 74 and the photoreceptor 1 in contact with the brush 70 can be prevented. Further, since the rotation time is reduced, toner scattering from the brush can be suppressed. Note that the predetermined number can be used without degrading the cleaning performance by determining the transfer efficiency of the image forming apparatus and the ease of soiling.

  Further, instead of the determined number of prints, it can be rotated every one job. In this case, when there is a scumming toner adhering to the inter-paper portion of the photoreceptor 1, the inter-paper toner can also be cleaned. In this case, the rotation and stop operation of the brush support 71 is performed after the end of 1 job, and the two brushes come into contact with the collection rollers 73 and 74 while the brush support 71 is stopped, and the collection rollers 73 and 74 rotate for a predetermined time. Thus, the toner is collected from the brush.

  Furthermore, as shown in FIG. 4, a portion where the brush 70 is not disposed is provided over the entire longitudinal width of a part of the peripheral surface of the brush support 71. Then, after the image formation for 1 job is completed, the rotation of the brush support 71 is stopped so that the portion where the brush 70 is not disposed is located at a position facing the A ′ portion and the B ′ portion of the photoreceptor 1. Accordingly, when the image forming apparatus is stopped for a long time such as when the image forming apparatus is warmed up or when the power is turned off, the brush 70 does not come into contact with the photosensitive member 1, so that the brush fibers can be prevented from falling. Therefore, the cleaning performance can be kept good during the next cleaning operation.

  Further, the cleaning device 7 can efficiently remove the toner from the photoreceptor 1 even after the transfer process, even when the amount of toner input on the photoreceptor 1 increases. For example, generally, a pattern toner image is formed on the photosensitive member 1 and its image density is detected by a sensor (not shown) to control image forming conditions of the image forming apparatus. When such a pattern toner image is formed and cleaned as it is, a large amount of toner is input to the cleaning device 7. In addition, when the transfer paper is jammed with the toner image formed on the photosensitive member 1 and the operation of the image forming apparatus is resumed after the transfer paper is removed, a large amount of toner is transferred to the cleaning device 7. Entered. In these cases, the two brushes cleaned by the collection rollers 73 and 74 before each toner image is input to the A ′ portion are moved to the A ′ and B ′ portions, respectively. The support 71 is rotated and stopped. A large amount of toner is efficiently removed from the surface of the photoreceptor 1 by the two brushes.

  In addition to the toner collecting rollers 73 and 74, a flicker bar can be used as a toner removing member for removing the toner adhering to the brush 70. FIG. 3 is a schematic configuration diagram of a cleaning device 7 that collects toner using a flicker bar. Conductive flicker bars 77 and 78 are provided so as to come into contact with the brush moved to a position separated from the photoreceptor 1 by the rotation of the brush support 71 after the toner on the photoreceptor 1 has been cleaned. An AC voltage is applied to the flicker bars 77 and 78 from the power source 705 and brought into contact with a grounded brush so that the toner charge amount converges in the vicinity of 0 [C / g], and the electrostatic force between the toner and the brush is eliminated to flicker. Sift out with effect. In this case, two flicker bars 77 and 78 are used as one conductive plate member or one rotating body 79 so that two brushes are brought into contact with each other (see FIG. 5). Can also be reduced.

  Further, when the amount of toner input to the cleaning device 7 is very small, the collecting rollers 73 and 74 and the scrapers 75 and 76 are not provided, and the flicker bar is vibrated as a toner removing member for removing the toner and the toner is removed. It may be configured. As a result, it is possible to reduce the cost and size.

  In the image forming apparatus, the image forming unit including the cleaning device 7 may be a process cartridge. FIG. 7 shows a schematic configuration diagram of an example of a process cartridge. In FIG. 7, the photosensitive member 1, the charging device 2, the developing device 4, and the cleaning device 6 are integrally coupled to form a process cartridge 10, and the process cartridge 10 is configured as an image forming apparatus main body. It is comprised so that attachment or detachment is possible. As a result, an image forming apparatus that has high user maintenance and is unlikely to generate abnormal images over a long period of time can be obtained.

  Next, a toner that is preferably used in the image forming apparatus of the present embodiment will be described. In order to obtain a high-definition image, it is preferable that the particle size distribution of small particles is sharp. With a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, a high-quality image with little background fogging can be obtained, and the transfer rate can be increased.

The toner shape factor SF-1 is preferably in the range of 100 to 150. Here, the shape factor SF-1 is a numerical value indicating the ratio of the roundness of the shape of the spherical material, and the square of the maximum length MXLNG of the elliptical shape formed by projecting the spherical material on a two-dimensional plane is defined as a graphic area AREA. Divided by and multiplied by 100π / 4.
That is, it is defined by the following equation (1).

When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases. In general, when the shape of the toner is close to a sphere, the contact state between the toner and the toner or the toner and the photoconductor becomes point contact, so that the adsorption force between the toners is weakened and the fluidity is increased. The adsorption force between the toner and the photosensitive member is also weakened, and the transfer rate is increased. The inventor forms an image on the photosensitive member 1 by the same method using toner having an SF-1 coefficient of 100, toner having an SF-1 coefficient of 150, and toner having an SF-1 coefficient of 160, and a transfer device. A comparative experiment of the residual toner on the photosensitive member 1 after the transfer at 6 was performed. However, the circularity of the toner was circularity = perimeter of a circle having the same area as the particle projection area / perimeter of the particle projection image. A solid image was formed on the photoreceptor 1 under the same image forming conditions (charging, exposure, development), and then a toner image was transferred to the intermediate transfer member by applying a voltage to the belt transfer device 6. The developing bias was adjusted so that the amount of the developing toner adhered per unit area was the same. The graph of FIG. 6 shows the developed toner adhesion amount M1 and the transfer toner adhesion amount M2 transferred to the intermediate transfer member measured by a suction jig, and the transfer residual toner adhesion amount M3 calculated. In FIG. 6, the horizontal axis represents the transfer bias. As can be seen from FIG. 6, the amount of residual toner remaining on the photoreceptor 1 was the smallest for the SF-1 coefficient of 100. Next, toner with an SF-1 coefficient of 150, and the toner with the SF-1 coefficient of 160 having the largest amount of untransferred toner. Thus, it can be seen that the toner amount input to the cleaning device 7 is smaller as the SF1 coefficient is closer to 100. It has also been found that the amount of toner input to the cleaning device can be stably reduced by using toner having a high degree of circularity with a shape factor SF-1 in the range of 100 to 150. Accordingly, it is possible to extend the life of the cleaning device by using toner having a high degree of circularity with a shape factor SF-1 in the range of 100 to 150.

  In addition, the toner used in this example is obtained by dissolving or dispersing a binder resin containing a modified polyester resin that can be urea-bonded in an organic solvent, and a toner composition containing a colorant. And a polyaddition reaction, and the toner obtained by removing the solvent of the dispersion, washing, and drying was used. In addition, as a method for increasing the average circularity and obtaining a so-called spherical toner, a known polymerization method such as an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method may be used in addition to the above-described manufacturing method. A toner obtained by spheroidizing treatment by heat treatment may be used.

  Next, a photoconductor preferably used in the image forming apparatus of this embodiment will be described. As the photoreceptor, a photoreceptor having an amorphous silicon surface layer can be used. When a photoconductor having an amorphous silicon-based surface layer is used, the wear of the photoconductor surface over time can be eliminated or the amount of wear can be minimized, and the life of the photoconductor can be extended. As an amorphous silicon photoconductor (hereinafter referred to as “a-Si photoconductor”), a conductive support is heated to 50 ° C. to 400 ° C., and a vacuum deposition method, a sputtering method, an ion plate is formed on the support. A film having a photoconductive layer made of a-Si by a film forming method such as a coating method, a thermal CVD method, a photo CVD method, or a plasma CVD method is used. Among them, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferably used.

  As the photoreceptor, a photoreceptor having a photosensitive layer on a conductive substrate directly or via an intermediate layer can be used. This photosensitive layer contains at least a charge generating substance, a charge transporting substance, and particulate matter, and the particulate matter of the photosensitive layer increases the content on the surface side farthest from the conductive substrate side, thereby improving wear resistance. And stabilization of electrical characteristics can be achieved, and a highly sensitive and highly durable photoreceptor can be obtained.

(Photoreceptor layer structure)
The basic structure of the photoreceptor comprises a conductive support, a latent image carrying layer, and a surface layer containing a particulate material. Further, the latent image bearing layer needs to be electrically insulative which can be charged, but a non-photoconductive dielectric layer or a photoconductive photosensitive layer can be used.

(How to make a surface layer containing particulate matter)
The particulate material is pulverized, dispersed, and coated with a binder resin, a low molecular charge transport material, and a high molecular charge transport material. The content of the particulate matter in the particulate matter-containing surface layer is 5 to 50% by weight, preferably 10 to 40% by weight, and if it is 10% by weight or less, the wear resistance is not sufficient, but 50% by weight. The average particle size is preferably 0.05 to 1.0 [mu] m, preferably 0.05 to 0.8 [mu] m, and the transparency of the photosensitive layer is impaired when the above is satisfied.

(Specific examples of materials used)
Further, as the particulate material, any particulate material that is harder than the constituent resin of the surface layer can be used, and ineffective materials and organic materials can be used.
Examples include metal oxides such as titanium oxide, silica, tin oxide, alumina, zirconium oxide, indium oxide, silicon nitride, calcium oxide, zinc oxide, and barium sulfate. Zirconium etc. are mentioned. These particulate materials may be surface-treated with an inorganic material or an organic material for reasons such as improving dispersibility. Generally treated with a silane coupling agent as a water repellency treatment, treated with a fluorinated silane coupling agent, or treated with a higher fatty acid. As the inorganic treatment, a filler surface treated with alumina, zirconia, tin oxide, or silica can be used.

(Crosslinked type protective layer)
Moreover, the protective layer which consists of a crosslinked structure is also used effectively as a binder structure of a protective layer. Regarding the formation of a cross-linked structure, a reactive monomer having a plurality of cross-linkable functional groups in one molecule is used to cause a cross-linking reaction using light or thermal energy to form a three-dimensional network structure. is there. This network structure functions as a binder resin and exhibits high wear resistance. From the viewpoint of electrical stability, printing durability, and life, it is a very effective means to use a monomer having a charge transporting ability in whole or in part as the reactive monomer. By using such a monomer, a charge transporting site is formed in the network structure, and the function as a protective layer can be sufficiently expressed. The reactive monomer having charge transporting ability includes a compound containing at least one charge transporting component and a silicon atom having a hydrolyzable substituent in the same molecule, and a charge transporting component in the same molecule. A compound containing a hydroxyl group, a compound containing a charge transporting component and a carboxyl group in the same molecule, a compound containing a charge transporting component and an epoxy group in the same molecule, a charge transporting component in the same molecule And a compound containing an isocyanate group. These charge transport materials having a reactive group may be used alone or in combination of two or more. More preferably, a reactive monomer having a triarylamine structure is effectively used as the monomer having a charge transporting ability because of high electrical and chemical stability and high carrier mobility. In addition to this, monofunctional and bifunctional polymerizable monomers and polymerizable oligomers are used in combination for the purpose of viscosity adjustment during coating, stress relaxation of the cross-linked charge transport layer, low surface energy, and reduction of friction coefficient. be able to. As these polymerizable monomers and oligomers, known ones can be used.

  In addition, the hole transporting compound is polymerized or cross-linked using heat or light, but when the polymerization reaction is performed by heat, the polymerization reaction proceeds only with thermal energy or a polymerization initiator is required. However, in order to advance the reaction efficiently at a lower temperature, it is preferable to add an initiator. In the case of polymerization by light, it is preferable to use ultraviolet light as light, but the reaction rarely proceeds only by light energy, and a photopolymerization initiator is generally used in combination. The polymerization initiator in this case mainly absorbs ultraviolet rays having a wavelength of 400 nm or less to generate active species such as radicals and ions, and initiates polymerization. In the present invention, the aforementioned heat and photopolymerization initiator can be used in combination.

  The charge transport layer having a network structure formed in this manner has high wear resistance, but has a large volume shrinkage during the crosslinking reaction, and if it is too thick, it may cause cracks. In such a case, the protective layer may be a laminated structure, a low molecular dispersion polymer protective layer may be used for the lower layer (photosensitive layer side), and a protective layer having a crosslinked structure may be formed on the upper layer (surface side). good.

<Electrophotographic photoreceptor A>
In the electrophotographic photosensitive member 1, an electrophotographic photosensitive member A was prepared in the same manner as the electrophotographic photosensitive member 1, except that the protective layer coating solution, film thickness, and preparation conditions were changed as follows.
182 parts of methyltrimethoxysilane, 40 parts of dihydroxymethyltriphenylamine, 225 parts of 2-propanol, 106 parts of 2% acetic acid, and 1 part of aluminum trisacetylacetonate were mixed to prepare a coating solution for the protective layer. This coating solution was applied onto the charge transport layer and dried, and then heat-cured at 110 ° C. for 1 hour to form a protective layer having a thickness of 3 μm.

<Electrophotographic photoreceptor B>
In the electrophotographic photosensitive member 1, an electrophotographic photosensitive member B was prepared in the same manner as the electrophotographic photosensitive member 1, except that the protective layer coating solution, film thickness, and preparation conditions were changed as follows.
30 parts of a hole transporting compound (structural formula (I)), 0.6 part of an acrylic monomer (structural formula (II)) and a photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone) are added to 50 parts of monochlorobenzene. Part / dichloromethane in a mixed solvent of 50 parts to prepare a coating material for the surface protective layer. This paint was applied on the previous charge transport layer by spray coating, and cured for 30 seconds with a light intensity of 500 mW / cm ² using a metal halide lamp to form a surface protective layer having a thickness of 5 μm.

  In this embodiment, the example in which the drum-shaped photosensitive member 1 is used as the image carrier has been described. However, the present invention can be applied to an image carrier having another shape. For example, the present invention can be similarly applied to an apparatus using a belt-like photoreceptor that is stretched between two rollers and moves endlessly. In addition, the case where the photosensitive member 1 has a negative charging potential and a developing device that employs a reversal developing method using a two-component developer has been described. The present invention is not limited to those having a negative polarity, but can also be applied to those having a negative charge potential. Further, the present invention can be similarly applied to one using a one-component developer or one using a regular development system.

In the present embodiment, the brush member has been described as an example of the cleaning member. However, the present invention is not limited to this, and a conductive elastic member such as a foam can also be used.

  In this embodiment, the toner image on the photosensitive member 1 is directly transferred to the transfer material. However, the toner image on the photosensitive member 1 is transferred to the intermediate transfer member, and the intermediate transfer member is transferred to the intermediate transfer member. It can also be configured to transfer the toner image onto transfer paper.

  For example, the present invention can be applied to a color image forming apparatus that constitutes a tandem image forming unit by arranging four toner image forming units of magenta, cyan, yellow, and black side by side. Each of the toner image forming units constituting the tandem image forming unit includes a photoconductor. Also provided is an intermediate transfer belt for intermediate transfer of the toner image formed on the photoreceptor of each toner image forming means. In this image forming apparatus, the toner images formed on the photoreceptor of each toner image forming unit are sequentially transferred onto the intermediate transfer belt. As a result, a composite color image is formed by the toner image superimposed on the intermediate transfer belt, and the superimposed toner image on the intermediate transfer belt is secondarily transferred onto the recording medium by the secondary transfer device. At this time, the cleaning device 7 can also be applied as an intermediate transfer member cleaning device for cleaning the transfer residual toner adhering to the intermediate transfer belt, and has the same effect. As the intermediate transfer member, in addition to a belt-shaped intermediate transfer belt, a drum-shaped intermediate transfer drum or the like can be used. The electrical characteristics (volume resistivity, surface resistivity, etc.), thickness, structure (single layer, double layer, multiple layers), material, material, etc. of the intermediate transfer member are appropriate depending on the imaging conditions. Can be selected and employed. Needless to say, the present invention can also be applied to a photoconductor cleaning device that cleans the transfer residual toner on the photoconductor of the toner image forming means.

  In addition, the image forming apparatus includes a developing device including a plurality of developing units for one photosensitive member, and forms a color image by superimposing toner images developed by the developing units on the photosensitive member or the intermediate transfer member. It can also be applied to devices. Also in this case, application as a photosensitive member cleaning device and an intermediate transfer member cleaning device is possible, and the same effect is obtained.

As described above, in the image forming apparatus according to the present embodiment, the plurality of electrically conductive brushes 70 and the rotatable brush support 71 that fixes and supports the plurality of conductive brushes in parallel in the rotation direction. And voltage applying means 701 and 702 for applying voltages having different polarities to at least two of the plurality of conductive brushes. Then, when the region where the toner image is formed on the photosensitive member 1 passes through the B ′ portion from the A ′ portion which is the portion facing the cleaning device 7, a first voltage to which a certain polarity is applied is applied. After the contact with the conductive brush A, the rotation of the brush support 71 is stopped so as to come into contact with the second conductive brush B to which a voltage having a different polarity is applied. Then, after the area where the toner image is formed on the photoreceptor 1 is brought into contact with the first conductive brush A, it is brought into contact with the second conductive brush B and cleaned for each polarity toner. With such a configuration, it is possible to prevent the photosensitive member 1 from being adversely affected by the contact order of the polarity of the brush while reducing the size. Further, since the brush support 71 is not always rotated, it is possible to prevent toner cloud from being generated due to toner scattering from the brush 70. Further, it is possible to secure a time during which the brush 70 of each polarity keeps rubbing against the photosensitive member, thereby improving the cleaning efficiency. Thereby, good cleaning performance can be obtained.
Further, collection rollers 73 and 74 are provided as toner removing members for removing the toner adhering to the brush 70. As a result, the toner adhering to the brush 70 is removed and refreshed, so that a potential difference can be stably formed between the brush 70 and the surface of the photoreceptor 1 during the next cleaning operation, and the toner can be efficiently cleaned. Therefore, stable cleaning performance can be obtained over a long period of time.
In addition, an insulating member 72 for preventing leakage between a plurality of brushes arranged adjacent to each other on the brush support 71 is provided between the plurality of conductive brushes. Thereby, the leak by the contact of a brush fiber is prevented and the stable cleaning is performed.
In addition, the polarity of the voltage applied to the first conductive brush A is opposite to the charging polarity of the photoreceptor 1. As a result, the brush first biased to the opposite polarity to the charged polarity comes into contact with the photosensitive member, and then the brush biased to the same polarity as the charged polarity comes into contact. Therefore, the photosensitive member after passing through the cleaning device is charged with the same polarity as the charging polarity, so that the light can be eliminated and the influence on the next process can be prevented.
Further, the brush support 71 rotates at a timing when the non-image portion on the photosensitive member of each printing operation faces the cleaning device. Accordingly, since the brush 70 is cleaned for each print, it is possible to prevent the brush adhering toner from being saturated and the cleaning performance from being deteriorated even when the amount of input toner is large.
Further, the brush support 71 rotates at a timing when the non-image portion on the photoconductor for the predetermined number of printing operations faces the cleaning device. As a result, not only the transfer residual toner in the image area but also the dirt between the sheets can be cleaned up to a predetermined number of sheets. By determining the predetermined number according to the transfer efficiency of the image forming apparatus and the ease of soiling, it is possible to always use the image without reducing the cleaning performance.
The brush support 71 rotates at the timing when the non-image portion on the photoconductor after 1 job printing faces the cleaning device. Thereby, not only the transfer residual toner in the image portion but also the dirt toner between the papers can be cleaned during 1 job.
The collection rollers 72 and 73 remove toner from brushes that are not in contact with the photoreceptor 1 among the plurality of conductive brushes. Thus, since the toner of the conductive brush that is not in contact with the photoreceptor 1 is removed, the polarity of the brush-attached toner is not reversed, and the cleaning brush-attached toner does not adhere to the photoreceptor 1 again.
Further, the brush support 71 can swing in the axial direction. As a result, even if there is a belt-like portion in which the toner adheres in the moving direction of the photosensitive member 1, the concentration of the input toner can be prevented and the local cleaning performance can be prevented from being lowered.
In addition, an area where the brush 70 is not disposed is provided over the entire longitudinal width of a part of the peripheral surface of the brush support 71. Thereby, the hair fall of a brush fiber does not occur and cleaning performance is maintained over a long period of time.
Further, after the image formation is completed, the rotation of the brush support is stopped so that the portion of the brush support 71 where the brush is not disposed faces the photoreceptor 1. At the time of long-term stop, the brush support is stopped so that the portion where the brush is not disposed is opposed to the photoconductor 1, so that the brush fibers do not fall down and the cleaning performance is maintained for a long time.
The cleaning device 7 is used in an image forming apparatus including the photosensitive member 1, the charging device 2, the latent image forming device, the developing device 4, the transfer device 6, and the cleaning device 7. Thereby, an image forming apparatus having a long life and high image quality can be provided.
A toner having a shape factor SF-1 in the range of 100 to 150 is used as a toner for forming a toner image. As a result, the amount of cleaning input is reduced, the margin is improved, and a high-quality image is obtained. In addition, the life of the cleaning device can be extended.
Further, by using a surface layer made of amorphous silicon as a photoconductor, the surface film scraping amount of the photoconductor can be further reduced. Further, a protective layer containing a filler (particulate matter) is formed as a photoconductor. By using one, the surface film shaving amount of the photoreceptor can be further reduced.
Further, since the binder resin of the protective layer has a cross-linked structure, the surface film scraping amount of the photoreceptor can be further reduced.
In addition, the photoreceptor is electrically stabilized by having a charge transporting portion in the structure of the binder resin having the crosslinked structure.
Further, the cleaning device 7 and at least one selected from the photosensitive member 1, the charging device 2, or the developing device 4 are integrally configured to be a process cartridge 10 that is detachable from the main body of the image forming apparatus. As a result, an image forming apparatus that has high user maintenance and is unlikely to generate abnormal images over a long period of time can be obtained.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. The schematic block diagram of a conductive brush and a brush support body. FIG. 6 is a schematic configuration diagram of an image forming apparatus using a toner removing member as a modification. FIG. 6 is a schematic configuration diagram of an image forming apparatus using a brush as a modification. FIG. 6 is a schematic configuration diagram of an image forming apparatus using a toner removing member as a modification. The graph which shows the relationship between SF1 coefficient and a transfer residual toner. FIG. 2 is a schematic configuration diagram of a process cartridge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 4 Developing device 5 Developing roller 6 Transfer device 7 Cleaning device 10 Process cartridge 70 Conductive brush 71 Brush support 72 Insulating member 73, 74 Recovery roller 75, 76 Scraper 77, 78 Flicker bar 701, 702 Power supply 703, 704 Toner removing member power source 705 Toner removing member AC power source

Claims (20)

In a cleaning device that removes toner adhering to an image carrier with a conductive brush to which a voltage of a different polarity is applied,
A plurality of electrically conductive brushes that are electrically insulated, a rotatable brush support that fixes and supports the plurality of conductive brushes in parallel in the rotation direction, and at least two of the plurality of conductive brushes Voltage applying means for applying voltages of different polarities to each other, and a voltage having a predetermined polarity is applied when the region where the toner image is formed on the image carrier passes through the portion facing the cleaning device. After the contact with the first conductive brush, the cleaning device stops the rotation of the brush support so as to come into contact with the second conductive brush to which a voltage of a different polarity is applied. .   The cleaning apparatus according to claim 1, further comprising a toner removing member that removes toner adhering to the conductive brush.   3. The cleaning device according to claim 1, wherein an insulating member for preventing leakage between the plurality of conductive brushes arranged adjacent to each other on the brush support is provided between the plurality of conductive brushes. A cleaning device characterized.   4. The cleaning device according to claim 1, wherein the image carrier is a photoconductor, and a polarity of a voltage applied to the first conductive brush is opposite to a charge polarity of the photoconductor. And a cleaning device.   5. The cleaning device according to claim 1, wherein the brush support rotates at a timing when the non-image portion on the image carrier for each printing operation faces the cleaning device.   5. The cleaning device according to claim 1, wherein the brush support rotates at a timing when a non-image portion on the image carrier after printing a predetermined number of sheets faces the cleaning device.   5. The cleaning device according to claim 1, wherein the brush support rotates at a timing when the non-image portion on the image carrier after 1 job printing faces the cleaning device.   8. The cleaning device according to claim 2, wherein the toner removing member removes toner from a conductive brush that is not in contact with an image carrier among the plurality of conductive brushes. A cleaning device characterized.   9. The cleaning device according to claim 1, wherein the brush support is swingable in the axial direction.   10. The cleaning device according to claim 1, wherein no conductive brush is disposed over the entire width in the longitudinal direction of a part of the peripheral surface of the brush support. A cleaning device having a region.   11. The cleaning device according to claim 10, wherein after the image formation is finished, the rotation of the brush support is stopped so that a portion of the brush support where the brush is not disposed faces the image carrier. Cleaning device. An image carrier, a charging device for charging the image carrier, a latent image forming device for forming an electrostatic latent image on the image carrier, and a toner attached to the electrostatic latent image on the image carrier. In an image forming apparatus comprising: a developing device that visualizes; a transfer device that transfers a toner image on the image carrier to a transfer material; and a cleaning device that cleans the image carrier.
An image forming apparatus comprising the cleaning device according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11.   13. The image forming apparatus according to claim 12, wherein a multicolor image is formed on a single image carrier by a developing device comprising a plurality of developing units.   13. The image forming apparatus according to claim 12, wherein a plurality of image forming portions each including one image carrier and one developing device are provided, and a multicolor image is formed by superimposing toner images formed by the plurality of image forming portions. An image forming apparatus that forms the image.   15. The image forming apparatus according to claim 12, 13, or 14, wherein a toner having a shape factor SF-1 in the range of 100 to 150 is used as a toner for forming a toner image on the image carrier. Image forming apparatus.   16. The image forming apparatus according to claim 12, wherein the image carrier is formed with a surface layer made of amorphous silicon.   16. The image forming apparatus according to claim 12, wherein the image bearing member is formed with a protective layer containing a filler (particulate matter).   The image forming apparatus according to claim 17, wherein the binder resin of the protective layer has a crosslinked structure.   19. The image forming apparatus according to claim 18, wherein the structure of the binder resin having the crosslinked structure has a charge transporting portion. In a process cartridge that integrally forms a cleaning device and at least one selected from an image carrier, a charging device, and a developing device, and is detachable from an image forming apparatus main body,
A process cartridge using the cleaning device according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11 as the cleaning device.

Images