JP2007328273A - Cleaning device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device making a contribution to the suppression of the degradation in image quality, and an image forming apparatus equipped with the cleaning device. <P>SOLUTION: The cleaning device comprises: a rotary brush which is disposed nearer on an upstream side in the rotating direction of an image holder than a charger in the state of maintaining contact with the image holder, recovers the residue remaining on the image holder surface after the transfer of the developed image to an object to be transferred while rotating and is given the charge of the polarity opposite to the polarity of the residue; a residue holding member which is disposed nearer on the upstream side in the rotating direction of the image holder than the rotary brush and nearer the downstream side than a transfer unit, rotates while coming into contact with the image holder surface, receives a part of the residue on the image holder surface, and polishes the image holder surface by the residue; and a film-like object which is disposed nearer the upstream side in the rotating direction of the image holder than the rotary brush and nearer the downstream side than the residue holding member and vibrates while in the sate of contacting the image holder. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image composed of a fixed image on a recording medium, and a cleaning device that is provided in the image forming apparatus and that cleans residues remaining on the surface of an image carrier.

  Conventionally, a conductive brush has been used as a means to remove the residue remaining on the surface of the photoconductor after transfer of the developed image formed on the surface of the photoconductor to the transfer target, which is opposite to the main charged polarity of the residue. 2. Description of the Related Art An image forming apparatus including a cleaning device that removes a residue from a surface of a photoreceptor by electrostatic force by charging to a polarity is known (see, for example, Patent Document 1).

  In order to improve image quality, it has been proposed to provide a mechanism for scraping discharge products adhering to the surface of the photoconductor on the upstream side of the above-described charging brush in the rotation direction of the photoconductor.

In the above proposal, the photosensitive drum surface rotates while being in contact with the surface of the photosensitive member, receives a part of the residue remaining on the surface of the photosensitive member after transfer of the developed image to the transfer target, and polishes the surface of the photosensitive member with the received residue. By providing the residue holding member upstream of the charging brush in the rotational direction of the photosensitive member, the discharge product is scraped off from the surface of the photosensitive member.
JP 2004-287329 A

  However, some of the residues held by the residue holding member deteriorate in charging performance due to contact with the photosensitive member, and agglomerate due to a decrease in electrostatic repulsive force and reattach to the photosensitive member side. Such a low-charge aggregation residue cannot be removed electrostatically by a downstream charging brush as it is, and thus may cause uniform charging and exposure on the surface of the photoconductor to cause deterioration in image quality. .

  In view of the above circumstances, an object of the present invention is to provide a cleaning device that contributes to suppression of deterioration in image quality, and an image forming apparatus including the cleaning device.

In order to achieve the above object, the cleaning device of the present invention comprises:
A rotating image carrier, a charger for applying a predetermined charge to the surface of the image carrier, an exposure device for forming a latent image by exposing the surface of the image carrier after the charge is provided, and the latent image as a toner A developing unit that forms a developed image on the surface of the image carrier and a transfer unit that transfers the developed image to a transfer target. The developed image formed on the surface of the image carrier is recorded on a recording medium. This image is obtained by transferring the developed image formed on the surface of the image carrier to the transfer target, which is provided in an image forming apparatus that forms an image consisting of a fixed image on the recording medium by transferring and fixing to the transfer medium. A cleaning device for cleaning the residue remaining on the surface of the holder,
Located upstream of the charger in the rotational direction of the image carrier, in contact with the image carrier, the residue remaining on the surface of the image carrier after the developed image is transferred to the transfer body is rotated. A rotating brush with a charge opposite to the polarity of the residue,
Rotate while contacting the surface of the image carrier disposed in contact with the image carrier, upstream of the rotating brush in the rotational direction of the image carrier and downstream of the transfer unit. A residue holding member for receiving a part of the residue on the surface of the image carrier and polishing the surface of the image carrier with the residue;
A film-like object that vibrates in contact with the image carrier, disposed upstream of the rotating brush in the rotational direction of the image carrier and downstream of the residue holding member. It is characterized by.

  In the cleaning device of the present invention, a film-like material that vibrates in contact with the image carrier provided on the upstream side in the rotation direction of the image carrier relative to the rotating brush and downstream of the residue holding member. The agglomerated residue that has been agglomerated in the residue holding member and reattached to the rear image carrier can be dispersed. Therefore, according to the cleaning apparatus of the present invention, non-electrostatic recovery by the rotating brush can be expected more than before by dispersing the aggregate residue, which can contribute to the suppression of image quality degradation.

  Here, it is preferable that the film-like material vibrates upon application of an alternating voltage.

  In this way, the film-like object can be vibrated with a simple configuration.

  Furthermore, it is also a preferred aspect that the film-like material vibrates upon application of a bias voltage in which a DC voltage is superimposed on the AC voltage.

  In this way, the potential of the low-charge residue can be increased, thereby enabling electrostatic recovery with a rotating brush, which can further contribute to the suppression of image quality degradation.

  The residue holding member is preferably a fiber aggregate in which fibers having a diameter of 10 μm or less are aggregated. The image carrier is composed of a conductive substrate and a photosensitive layer formed on the conductive substrate. It is also a preferable aspect that the outermost layer of the photosensitive layer is formed as a charge transport layer containing a resin having a crosslinked structure.

In order to achieve the above object, an image forming apparatus of the present invention comprises:
A rotating image carrier, a charger for applying a predetermined charge to the surface of the image carrier, an exposure device for forming a latent image by exposing the surface of the image carrier after the charge is provided, and the latent image as a toner A developing unit that forms a developed image on the surface of the image carrier and a transfer unit that transfers the developed image to a transfer target, and finally the developed image formed on the surface of the image carrier In an image forming apparatus for forming an image composed of a fixed image on a recording medium by transferring and fixing the recording medium on the recording medium,
A cleaning device for cleaning a residue remaining on the surface of the image carrier after the developed image formed on the surface of the image carrier is transferred to the transfer member;
The cleaning device is
Located upstream of the charger in the rotational direction of the image carrier, in contact with the image carrier, the residue remaining on the surface of the image carrier after the developed image is transferred to the transfer body is rotated. A rotating brush with a charge opposite to the polarity of the residue,
Rotate while contacting the surface of the image carrier disposed in contact with the image carrier, upstream of the rotating brush in the rotational direction of the image carrier and downstream of the transfer unit. A residue holding member for receiving a part of the residue on the surface of the image carrier and polishing the surface of the image carrier with the residue;
A film-like object that vibrates while being in contact with the image carrier, arranged upstream of the rotating brush in the rotational direction of the image carrier and downstream of the residue holding member It is characterized by being.

  According to the present invention, it is possible to provide a cleaning device that contributes to suppression of deterioration in image quality, and an image forming apparatus including the cleaning device.

  Hereinafter, embodiments of the cleaning device of the present invention will be described.

  FIG. 1 is a schematic configuration diagram showing a printer, which is an embodiment of an image forming apparatus of the present invention, provided with the first embodiment of the cleaning apparatus of the present invention.

  The printer 1 shown in FIG. 1 has an exposure generated by an exposure unit 12 based on image data transmitted to the surface of a photoconductor 10 that has been given a predetermined charge by a charger 11 and rotates in the direction of arrow A. An electrostatic latent image is formed by irradiating light, the formed electrostatic latent image is developed with toner stored in the developing device 13, and the developed image obtained by this development is transferred from the paper tray 16 to the paper transport device 17. This is a monochrome image dedicated machine that forms an image on a recording sheet by transferring it by a transfer unit 14 onto the recording sheet that has been pulled out and conveyed in the direction of arrow B and fixing it by a fixing unit 15.

  Further, in the printer 1 shown in FIG. 1, after the developed image formed on the surface of the photoconductor 10 is transferred to the recording paper by the transfer device 14, the residue remaining on the surface of the photoconductor is removed from the surface of the photoconductor. A cleaning device 18 having a housing 180 is provided.

  FIG. 2 is a block diagram of the cleaning device shown in FIG.

  The cleaning device 18 shown in FIG. 2 collects the residue remaining on the surface of the photoreceptor after the development image is transferred to the recording paper while rotating, and collects the electrostatic brush 181 charged to a polarity opposite to the charged polarity of the residue. The photosensitive brush 181 is disposed at a position in contact with the photoconductor 10 upstream of the electrostatic brush 181 in the rotation direction of the photoconductor 10 and rotates while contacting the photoconductor surface to partially receive the residue on the photoconductor surface. The surface of the photoconductor is polished by the received residue, the auxiliary cleaner 183 made of a roll base and a non-woven fabric wound around the roll base, and on the upstream side of the electrostatic brush 181 in the rotation direction of the photoconductor 10 and the auxiliary The conductive / insulating seal 184 is arranged downstream of the cleaner 183 and vibrates in contact with the photoreceptor 10.

  Further, the cleaning device 18 shown in FIG. 2 contacts the rotating electrostatic brush 181 while rotating, and the electrostatic brush 181 recovers the residual toner that is electrostatically removed from the surface of the photoreceptor. A scraper 185 that contacts the roll 182 and the collection roll 182 and scrapes off the residue collected by the collection roll 182 is provided.

  The electrostatic brush 181 is in the form of a roll having innumerable fibers arranged on the outer periphery of the rotating shaft, and is arranged so that the tip of the brush slightly bites into the photoreceptor 10. Further, the electrostatic brush 181 is in sliding contact with the photosensitive member 10 by rotating the peripheral surface of the electrostatic brush 181 in the direction opposite to the moving direction of the peripheral surface of the photosensitive member 10, so that residual toner and toner outside The adsorbent is adsorbed electrostatically.

  The collection roll 182 is disposed such that a cleaning bias having an absolute value higher than that of the electrostatic brush 181 and the same polarity is applied, and the outer peripheral surface thereof is in contact with the outer peripheral surface of the electrostatic brush 181. The residual toner adsorbed by the toner is electrostatically collected. Residual toner collected by the collection roller 182 is scraped off by the scraper 185.

  The conductive / insulating seal 184 oscillates when an alternating voltage of 0.1 kHz to 3.2 kHz is applied to disperse the low-charge aggregate residue remaining on the photoreceptor 10 from the residue holding member 183. A film-like material that has been subjected to superimposed application of a direct current voltage of −100 V to 500 V for imparting electric charge to the low-charged aggregate residue. FIG. 2 shows a state where an AC power supply 1841 and a DC power supply 1842 are connected to the conductive / insulating seal 184.

  In the cleaning device 18 of the present embodiment, the conductive material disposed in a state where the tip of the photosensitive member 10 is in contact with the upstream side in the rotation direction of the photosensitive member 10 with respect to the electrostatic brush 181 and downstream of the auxiliary cleaner 183. The insulating seal 184 disperses and charges the low-charge aggregate residue that has aggregated and reattached to the photoreceptor 10 in the auxiliary cleaner 183. Therefore, according to the cleaning device 18 of the present embodiment provided in the printer 1 of the present embodiment, electrostatic collection by the electrostatic brush 181 can be expected by dispersing and charging the aggregate residue. Therefore, it is possible to contribute to suppression of deterioration in image quality.

  The cleaning device 18 may have a function of discharging to the photosensitive member side before the residue is excessively deposited on the conductive / insulating seal 184 by switching the DC voltage when the image is not formed. In addition, the so-called transfer residual toner remaining on the surface of the photoconductor after the transfer of the developed image has a variation in its potential due to the influence of the transfer electric field, and has been reversed from the negative polarity, which is the original charging polarity, to the opposite polarity. Even things exist. For the purpose of efficiently removing the transfer residual toner of the negative electrode and the transfer residual toner reversed to the reverse polarity, two cleaning units including the electrostatic brush 181, the recovery roll 182, and the scraper 185 are installed on the photoconductor 10. Different polarities can be given to each unit. Further, the photoconductor 10 and the cleaning device can be used as one process cartridge. In this way, the process cartridge can realize maintenance-free, and high-quality image formation can be easily repeated simply by replacing the process cartridge.

  FIG. 3 is a schematic configuration diagram of the second embodiment of the cleaning device of the present invention. 3 that are the same as the members shown in FIG. 2 have the same reference numerals as those in FIG.

  FIG. 3A shows a cleaning device 20 according to the present embodiment, which is applied to Example 2 described later. Differences between the cleaning device 20 and the cleaning device 18 according to the first embodiment. In the cleaning device 20, the superimposition of the DC voltage is omitted. In addition, the cleaning apparatus 18 which is 1st Embodiment is applied to Example 1 demonstrated later.

  FIG. 3B shows a cleaning device 30 applied to Comparative Example 1 described later, in which application of an AC voltage is omitted from the cleaning device 20 of the present embodiment, and FIG. In the cleaning device 20 of this embodiment, the conductive / insulating seal 184 disposed between the electrostatic brush 181 and the auxiliary cleaner 183 is moved between the charger (see FIG. 1) 11 and the electrostatic brush 181. In addition, a cleaning device 40 applied to Comparative Example 2 is shown, and FIG. 3D is applied to Comparative Example 2 in which the AC power supply 1841 is omitted from the cleaning device 40 shown in FIG. A cleaning device 50 is shown.

  FIG. 4 is a diagram showing the results of experiments conducted in a printer provided with these examples and comparative examples.

  FIG. 4A shows an AC voltage having a frequency of 0.05 to 6.4 kHz in the DocuCenter Color 500 (Fuji Xerox Co., Ltd.) in which the cleaning device 18 of the first embodiment, which is Example 1, is provided. 400Vp-p) and DC voltage of −50 to −700V are appropriately combined and applied, and evaluation of dot-like stains on 1 to 500 continuous prints is shown. , “No dot-like stain”, “×” means occurrence of dot-like stain, and “−” means no evaluation. The toner and developer used are those used in DocuCenter Color f450 (manufactured by Fuji Xerox Co., Ltd.). Under an environment of 22 ° C. and 55 RH%, the image pattern has a process direction length of 9 mm. A plurality of patches having a solid density of 100% and having an axial length of 27 mm were prepared. The average image density over the entire A4 sheet is 5%.

  From FIG. 4A, among the combinations in the above range, a superimposed voltage obtained by combining an AC voltage (400 Vp-p) with a frequency of 0.1 to 3.2 kHz and a DC voltage of −100 to −500 V is shown. When applied to the conductive / insulating seal 184, no spot-like stains are observed on the print, and it is clear that dispersion and charging with respect to the aggregate residue are optimally performed. In addition, when the frequency of the AC voltage is set to 0.05 kHz and when it is set to 6.4 kHz, the evaluation is “Δ” because the vibration period is delayed for the former, and the aggregation residue This is because it becomes difficult to disperse the object, and the latter is because the conductive / insulating seal 184 becomes difficult to follow. In addition, when the DC voltage is set to −50 V and when it is set to −700 V, the evaluation is “Δ” because it is difficult to give charge to the former, and the latter This is because a discharge occurred between the surface of the photoconductor and the conductive / insulating seal 184, and the surface of the photoconductor was somewhat deteriorated.

  In FIG. 4B, 500 sheets are taken out from the print sample, and visual evaluation of dot-like stains on the print is shown. The initial value here is an evaluation of 1 to 500 continuous prints. Yes, 20 kPV is an evaluation of 19500 to 20000 continuous prints. '◎' indicates zero point stains, '○' indicates very little point stains, '△' indicates point stains are slightly noticeable, and '×' indicates point stains. Means stand out.

  In Example 1, it is presumed that, in both the initial stage and 20 kPV, spot-like stains were not generated during printing, and the dispersion and charging of the aggregated residue were performed satisfactorily. In Example 2, although the dispersion was performed but the charging was not performed, the evaluation was lower than that in Example 1, but there was very little spot-like contamination. On the other hand, in Comparative Example 1, since the conductive / insulating seal 184 was not vibrated, the aggregated residue was deposited with time and then reattached to the surface of the image carrier. At 20 kPV, spot-like stains are slightly noticeable. About the comparative example 2, since the deployment position of the electroconductive / insulating seal 184 to which the AC voltage is applied is on the downstream side of the electrostatic brush 181, spot-like stains are slightly noticeable at the initial stage and through 20 kPV. In Comparative Example 3, the non-vibrating conductive / insulating seal 184 is disposed downstream of the electrostatic brush 181, so that the point-like stains are slightly noticeable in the initial stage, but the aggregation remains with time. Since the objects accumulated and then reattached to the surface of the image carrier, spot-like stains are noticeable at the stage of 20 kPV.

  FIG. 4C shows the evaluation results of image flow and filming when 20000 sheets are continuously printed in each example and each comparative example. The evaluation of image flow is performed by visually observing the printed image quality after standing overnight in a high temperature and high humidity (28 ° C., 85 RH%) environment, and the image quality evaluation sample is 300 lines and 20%. Filming was evaluated by visually observing the surface of the photoreceptor. Regarding evaluation, ‘◎’ does not occur, ‘◯’ is very slight, ‘△’ is slightly conspicuous, and ‘×’ is conspicuous.

  In Example 1 and Example 2, both image flow and filming hardly occur and are good, but these are gradually generated from Comparative Example 1 to Comparative Example 3.

  Based on the above experimental results, it is necessary to vibrate the conductive / insulating seal 184 and to dispose it between the electrostatic brush 181 and the auxiliary cleaner 183. Further, the conductive / insulating seal 184 is imparted with charging performance. This proved to contribute most to the suppression of image quality degradation. The following are the detailed conditions of the above experiment.

The electrostatic brush 181 is made of polyester resin having a thickness of 2d, an electric resistance of 1.0 × 10 ⁸ Ω, a hair length of 3.5 mm, and a density of 12,000 pieces / inch ^2. The photosensitive member 10 was rotated in the reverse direction with respect to the rotation direction at a peripheral speed of 0.5 mm and a peripheral speed of 171 mm / s. The bias applied to the electrostatic brush 181 was + 260V.

The recovery roll 182 is made of a conductive resin dispersed in a phenol resin and has an electric resistance of 1.0 × 10 ⁸ Ω, a flexural modulus of 100 Mpa, and a Rockwell hardness of 120, and the amount of biting into the electrostatic brush 181 is determined. The rotation speed was 1.0 mm, and the rotation speed was reverse rotation with respect to the rotation direction of the electrostatic brush 181 at a peripheral speed of 201 mm / s. The applied bias was + 660V.

  The scraper 185 was made of SUS304 and had a thickness of 80 μm. The amount of biting into the collecting roll 182 was 1.3 mm, and the free length was 8.0 mm.

  As the auxiliary cleaner 183, a nonwoven fabric WP8085 (manufactured by Nippon Vilene Co., Ltd.) made of nylon and having a fiber thickness of 3 to 5 μm and a thickness of 430 μm was used.

  The conductive / insulating seal 184 is made of a PET / aluminum hybrid sheet having a thickness of 110 μm, the amount of biting into the photoreceptor is 2.0 mm, the free length is 6.0 mm, and the frequency is 0.05 to 6 A 4 kHz applied AC voltage (400 Vp-p) and a DC offset voltage of −50 to 700 V were superimposed and applied.

  As the scraper 185, SUS304 having a thickness of 80 μm was used, the amount of biting into the collecting roll 182 was 2 mm, and the free length was 8.0 mm.

  The photoreceptor 10 has 100 parts by mass of a zirconium compound (trade name: Olgatrix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.), 10 parts by mass of a silane compound (trade name: A1100, manufactured by Nihon Unicar Co., Ltd.), 400 parts by mass of isopropanol, A coating solution for forming an undercoat layer obtained by mixing 200 parts by mass of butanol and dip-coated on a cylindrical aluminum substrate having an outer diameter of 84 mmφ subjected to a honing treatment, and dried by heating at 150 ° C. for 10 minutes. A subbing layer of 0.1 μm is formed, and the Bragg angles (2θ ± 0.2 °) in the Xf-ray diffraction spectrum are 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18. 1 part by mass of hydroxygallium phthalocyanine having strong diffraction peaks at 6 °, 25.1 °, and 28.3 °, and 1 part by mass of polyvinyl butyral (ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.) And a coating solution for forming a charge generation layer obtained by mixing 100 parts by weight of n-butyl acetate and dispersing with glass beads for 1 hour by a paint shaker, dip-apply on this undercoat layer at 100 ° C. A charge generation layer having a film thickness of about 0.15 μm was formed by heating and drying for 10 minutes. To this, 2 parts by mass of a charge transport material represented by the following chemical formula 1, 3 parts by mass of a polymer compound (viscosity average molecular weight 39,000) having a structural unit represented by the following chemical formula 2, and 20 parts by mass of chlorobenzene A coating solution for forming a charge transport layer obtained by mixing the parts was applied onto this charge generation layer by a dip coating method and heated at 110 ° C. for 40 minutes to form a charge transport layer having a thickness of 20 μm. 2.5 parts by mass of the compound represented by the following chemical formula 3, 3 parts by mass of Shonor BRL-204 (manufactured by Showa Polymer Co., Ltd.), and 0.02 of a hindered phenol antioxidant (AO-80: manufactured by Asahi Denka) 1 part by mass, 0.2 part by mass of a fluorine graft polymer (ZX007C: manufactured by Fuji Kasei) and 0.1 part by mass of a fluorine coupling agent (KBM-7803: manufactured by Shin-Etsu Chemical) are mixed, and isopropyl alcohol A coating solution for forming a protective layer obtained by dissolving in 5 parts by mass of methyl butyl ketone and 5 parts by mass of methyl butyl ketone was applied by a ring-type dip coating method and air-dried at room temperature for 30 minutes. A material obtained by curing by heating for a period of time to form a protective layer having a thickness of about 3 μm was used.

In addition to the polyester resin fibers used in the present embodiment, examples of the material of the electrostatic brush 181 include resin fibers such as nylon, acrylic, and polyolefin. It is possible to use a material having a conductive layer formed inside or outside of each fiber. The resistance value is preferably 10 ² to 10 ⁹ Ω as a single fiber, more preferably 10 ⁴ to 10 ⁵ Ω, and the fiber thickness is 30 d (denier) or less, preferably 20 d or less, more preferably. Is 2d to 10d, and the density of the fibers is 20,000 / inch ² or more, preferably 30,000 / inch ² or more, more preferably 60,000 / inch ² or more. Specific examples include Beltron (manufactured by Kanebo), SA-7 (manufactured by Toray), and UU nylon (manufactured by Unitika). Furthermore, it is more preferable that the material imparting conductivity is uniformly blended in the fiber because of excellent cleaning maintenance. Further, the amount of biting between the electrostatic brush 181 and the photoreceptor 10 is desirably 0.1 to 2.5 mm, preferably 0.5 to 2.0 mm, and more preferably 0.9 to 1.8 mm.

  The recovery roll 182 is a thermosetting resin and is cured (cross-linked) by heating. Therefore, the recovery roll 182 is extremely superior to the dimensional accuracy required to hardly cause shrinkage after molding. Examples of the thermosetting resin used for the recovery roll 182 include urea resins, melamine resins, unsaturated polyesters, epoxy resins, polyimide resins, etc. in addition to the phenol resins used in the present embodiment. It is optimal as a material because it has high dimensional accuracy, is easy to mold, has excellent surface smoothness, and is inexpensive.

  Further, the flexural modulus of the collection roll 182 in JIS-K7203 is preferably 700 Kpa or more. If the bending elastic modulus is less than 700 Kpa, the collection roller 182 is bent, and it is difficult to keep the contact position and the amount of biting with the electrostatic brush 181 and the scraper 185 constant. If a material having a low bending elastic modulus is used to increase the wall pressure of the recovery roller 182 to maintain rigidity, molding shrinkage increases and desired dimensional accuracy cannot be obtained, and weight and molding time increase. This causes problems such as the need for processing, resulting in increased costs. Further, since the collection roll 182 is constantly in contact with the electrostatic brush 181 and the scraper 185, it is required that the collection roll 182 be made of a material that is resistant to wear. If the wear amount exceeds 20 mg according to JIS-K6902, the collection roll 182 is collected. The life of the roller 182 is shortened and must be replaced frequently. Further, when the wear amount is small, the contact pressure and the biting amount of the electrostatic brush 181 and the scraper 185 can be set large, and the photoconductor 10 can be stably cleaned over a long period of time. Therefore, the wear amount in JIS-K6902 is 20 mg or less. It is preferable that Further, in order to make the roller extremely resistant to scraping, it is preferable that the Rockwell hardness of the collection roll 182 in JIS-K7202 is 100 M or more. In addition, for the purpose of increasing the rigidity and adjusting the electric resistance to a predetermined range, either one or a plurality of organic fillers or inorganic fillers in the collection roll 182 and both of the organic fillers and the inorganic fillers are used. Plural kinds may be filled. The organic filler mentioned here is carbon black, carbon powder, graphite, magnetic powder, zinc oxide, tin oxide, metal oxides such as titanium oxide, metal sulfides such as copper sulfide and zinc sulfide, strontium, barium, rare earth, etc. So-called hard ferrite, magnetite, ferrite such as copper, zinc, nickel and manganese, or those whose surfaces are subjected to conductive treatment if necessary, copper, iron, manganese, nickel, zinc, cobalt, barium, aluminum, tin, Metal oxide solid solution, so-called composite metal oxidation, selected from oxides, hydroxides, carbonates or metal compounds containing different metal elements such as lithium, magnesium, silicon, phosphorus, etc. Inorganic fillers include metal powders such as tin, iron, copper, and aluminum, metal fibers, and glass fibers. It is below.

When the electrical resistance of the collection roll 182 is lower than 1 × 10 ⁵ Ω, the polarity of fine powder such as toner or paper powder adsorbed by the electrostatic brush 181 is reversed and is electrically adsorbed. Will not be able to. Conversely, if the electrical resistance of the collection roll 182 exceeds 1 × 10 ¹⁰ Ω, charge is accumulated in the collection roller 182, so-called charge-up occurs, and fine powder such as toner and paper powder is also electrically adsorbed. to become impossible, the electrical resistance at 500V applied recovery roll 182 is used in a range of ^{1 × 10 5 ~1 × 10 10} Ω, preferably ^{1 × 10 6 ~1 × 10 8} Ω.

  Further, in order to efficiently attract and move fine powders such as toner and paper dust, the electrostatic brush 181 disposed in contact with the surface of the photosensitive member and the collection disposed in contact with the electrostatic brush 181 are collected. It is preferable to apply a cleaning bias having a potential difference to the roll 182. The potential difference between the electrostatic brush 181 and the collecting roll 182 is | 100V | or more, preferably | 200V | or more. The upper limit is regulated by the bias leak limit, and is preferably suppressed to | 650V | or less.

  The auxiliary cleaner 183 is made of ultrafine fibers with a fine surface, and by forming a micro gap between the surface and the contact surface of the photoconductor, it is easy to keep the residual toner remaining on the photoconductor surface densely. The discharge products and external additives attached to the surface are uniformly removed. Here, the ultrafine fiber means 0.2d to 1.0d, typically 0.2d to 0.5d, and the fiber of 0.2d or less is called a superfine fiber. The fiber diameter of the ultrafine fiber is about 1 μm to 5 μm, and those of 1 μm or less are called ultrafine fibers. In the present embodiment, ultra fine fibers can be handled in the same manner as the ultra fine fibers, but the fiber diameter may be 10 μm or less. The ultrafine fibers are composed of polyester fiber, polyamide fiber, polyvinyl alcohol fiber, polyvinylidene chloride fiber, polyvinyl chloride fiber, acrylic fiber, polyolefin fiber, polyurethane fiber, polyethylene fiber, polypropylene fiber, synthetic fiber, acetate, etc. , Semi-synthetic fibers, regenerated fibers such as rayon, cupra and polynosic, natural fibers made of pulp, silk, cotton, hemp, asbestos and wool can be used. Moreover, a core-sheath type or a side-by-side type composite fiber obtained by combining a plurality of these fibers can also be used. These ultrafine fibers can be obtained, for example, by a melt-blowing method in which fibers are spun from a nozzle and compressed air is applied to make the fibers finer. The cross-sectional shape is, for example, a sea-island type fiber in which other components are arranged in islands in one component, a multi-bimetal type in which different components are alternately layered, or one component is arranged radially in the other components The obtained chrysanthemum type (orange type) fiber can be obtained by splitting (hereinafter, these composite fibers that can be split into ultrafine fibers are referred to as “splitable fibers”). As a combination of resin components constituting the splittable fiber, for example, when two resin components are used, different materials such as a polyamide resin and a polyester resin, a polyamide resin and a polyolefin resin, a polyester resin and a polyacrylonitrile resin are used. There are similar resins, such as polyethylene and polypropylene. These split fibers are mechanically actuated (for example, splitting by a fluid flow such as water flow, splitting by pressing a pair of rolls, splitting by pressing a flat plate press device, etc.) and chemical action (for example, removal of resin components by a solvent or It is also possible to obtain ultrafine fibers by dividing by swelling or the like.

  There are two methods for processing fibers into fabrics: a method in which yarns are knitted to form a two-dimensional material, and a method in which fabrics are made directly from fibers. The latter allows fibers to be bonded to each other or mechanically entangled. This is processed into a sheet shape, which is called a non-woven fabric. Either method can be used as the auxiliary cleaner 183 of the present embodiment, but a nonwoven fabric is desirable in that the cloth has a high strength and density, high flexibility, and good retention of residual toner between the fibers.

  The manufacturing process of the nonwoven fabric generally comprises two steps, a fiber web forming step and an interfiber bonding step. As a method for forming the fiber web, for example, a short fiber (15 to 100 mm) is used using a machine called a card, or A dry method called air array, which is formed by arranging air flow in a fixed direction or randomly, a wet method in which very short fibers are dispersed in water and rolled up into a net-like net, and a melted raw resin is directly applied to the tip of the nozzle. There is a spunbond method in which a fleece is formed by continuous long fibers that are eluted and spun. As a method of bonding between fibers, a chemical bond method in which an adhesive resin of an emulsion system is attached to a fiber web by a method such as impregnation or spraying, heated and dried to bond the intersections of the fibers, and thermocompression bonding is performed between hot rolls. Alternatively, a thermal bond method that applies hot air to bond the fibers together, a needle punch method that repeatedly stabs with a needle that moves up and down at a high speed, and entangles the fibers with protrusions called barbs engraved on the needle, a high-pressure water stream is jetted into a columnar shape, and the fibers are There is a water entanglement method to entangle.

  When a fiber web is formed from mechanically splittable fibers and the fibers are entangled with each other by needle punching or fluid flow, the fibers can be split at the same time, which is preferable in manufacturing.

  Here, it is preferable that the ultrafine fiber is contained in an amount of 20 parts by mass or more, but the more the fiber is, the more uniform the fiber sheet surface is. Examples of such non-woven fabrics include Toraysee, Exene (more from Toray Industries, Inc.), Sabina Minimax, Klausen (more from Kanebo), Miemie (produced by Mitsubishi Rayon), Microstar (produced by Teijin), Benise, Luxer, Bencott (made by Asahi Kasei Kogyo Co., Ltd.), biodegradable non-woven fabric (made by Kanai Important Industry Co., Ltd.), FLEXILON (made by Veratech Japan Co., Ltd.), Kuraray Flex (made by Kuraray Co., Ltd.), Saffron (made by Sansho Co., Ltd.), Miracle Cloth (Manufactured by Daiwa Spinning Co., Ltd.), Sontara (manufactured by DuPont Japan), KF paper (manufactured by Toyobo Co., Ltd.), Pulcross (manufactured by Honshu Paper Co., Ltd.), and the like.

Further, it is desirable that the ultrafine fiber cloth is attached to a pressing member having elasticity as a backup material, and the surface thereof is pressed against the photoconductor 10 with a predetermined pressure. Examples of the backup material include urethane foam, urethane rubber, and silicone rubber. The pressure for pressing the ultrafine fibers against the photoconductor 10 by the backup material is preferably in the range of 0.5 to 6.0 gf / mm ² . A more preferable range is 1.0 to 4.0 gf / mm ² . Pressing pressure can not be exhibited low and sufficient rubbing functions than 0.5 gf / mm ^2, and rubbing is too strong with the photoreceptor 10 is higher than 6.0gf / mm ² member itself and the photosensitive member Degradation of 10 is caused, and on the contrary, filming and the like are induced.

  Alternatively, the pressing member may be formed in a roll shape, and an ultrafine fiber cloth may be attached to the periphery thereof. Such an ultra-fine fiber cloth roll can be rotated at an arbitrary peripheral speed difference with respect to the rotating photoreceptor surface, promote uniform wear on the photoreceptor surface, and change the rotation speed. The amount of wear on the surface of the photoreceptor can also be controlled.

  The scraper 185 may be a thin metal plate of phosphor bronze in addition to stainless steel, and the thickness is about 0.02 to 2 mm, preferably 0.05 to 1 mm.

  Examples of the conductive / insulating seal 184 include a metal sheet or a conductive sheet in which volume resistivity is adjusted by dispersing carbon black, metal particles, an organic conductive material, or the like in rubber.

  Note that a charging member that controls charging of residual toner remaining on the surface of the photoconductor, which is not provided in the present embodiment, may be provided on the upstream side of the rotation direction of the photoconductor 10 of the cleaning device 18. . Examples of the charging control member include a brush-like brush, a conductive roll member, a charging charger member, and a sheet-like member. This brush-like brush is a brush made of a conductive material such as carbon fiber or a plastic material imparted with conductivity. The shape of the brush is not limited to this, and may be a roller-shaped brush. Further, in the case of a roller-shaped brush, it is configured to be rotatably mounted so as to rotate around the photosensitive member, or to be rotationally driven by providing a driving device. The roll member is a roller in which a metal core is covered with a conductive layer made of an elastic material such as a conductive rubber, and is disposed close to or in contact with the photoreceptor. A bias is applied to the core bar to charge the residual toner and adjust the polarity. Examples of the charging charger include a corotron and a scorotron, which are arranged in a non-contact manner with the photosensitive member 10.

  In the above-described embodiment, the conductive / insulating seal 184 has been described with reference to an example in which a voltage in which an AC voltage and a DC voltage are superimposed is described. However, the present invention is not limited to this. As long as the insulating seal 184 vibrates, even if no DC voltage is applied, it may be vibrated by means other than the application of AC voltage.

1 is a schematic configuration diagram illustrating a printer that is an embodiment of an image forming apparatus according to the present invention and includes a first embodiment of a cleaning apparatus according to the present invention; FIG. It is a block diagram of the cleaning apparatus shown in FIG. It is a schematic block diagram of 2nd Embodiment etc. of the cleaning apparatus of this invention. It is a figure which shows the result of the experiment conducted in the printer provided with these Examples and the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 10 Photoconductor 11 Charger 12 Exposure device 13 Developing device 14 Transfer device 15 Fixing device 16 Paper tray 17 Paper transport device 18, 20 Cleaning device 180 Housing 181 Electrostatic brush 182 Collection roll 183 Auxiliary cleaner 184 Conductive / insulating seal 1841 AC power supply 1842 DC power supply 185 Scraper

Claims (2)

A rotating image carrier, a charger for applying a predetermined charge to the surface of the image carrier, an exposure device for forming a latent image by exposing the surface of the image carrier after the charge is provided, and developing the latent image A developing device that forms a developed image on the surface of the image carrier by developing with an agent, and a transfer device that transfers the developed image to a transfer target, and the developed image formed on the surface of the image carrier is a recording medium An image forming apparatus for forming an image composed of a fixed image on the recording medium by transferring and fixing the image on the recording medium, and transferring the developed image formed on the surface of the image carrier to the transfer target. A cleaning device for cleaning residues remaining on the surface of an image carrier,
Located upstream of the charger in the rotation direction of the image carrier, in contact with the image carrier, the residue remaining on the surface of the image carrier after transfer of the developed image to the transfer member is rotated. A rotating brush with a charge opposite to the polarity of the residue,
Rotating while contacting the surface of the image carrier disposed in contact with the image carrier, upstream of the rotating brush in the rotational direction of the image carrier and downstream of the transfer unit. A residue holding member for receiving a part of the residue on the surface of the image carrier and polishing the surface of the image carrier with the residue;
A film-like object that vibrates while being in contact with the image carrier, arranged upstream of the rotating brush in the rotational direction of the image carrier and downstream of the residue holding member. A cleaning device characterized by. A rotating image carrier, a charger for applying a predetermined charge to the surface of the image carrier, an exposure device for forming a latent image by exposing the surface of the image carrier after the charge, and the latent image as a toner A developing unit that forms a developed image on the surface of the image carrier and a transfer unit that transfers the developed image to the transfer target, and finally the developed image formed on the surface of the image carrier In an image forming apparatus for forming an image composed of a fixed image on a recording medium by transferring and fixing the recording medium on the recording medium,
A cleaning device for cleaning a residue remaining on the surface of the image carrier after the developed image formed on the surface of the image carrier is transferred to the transfer target;
The cleaning device is
Located upstream of the charger in the rotation direction of the image carrier, in contact with the image carrier, the residue remaining on the surface of the image carrier after transfer of the developed image to the transfer member is rotated. A rotating brush with a charge opposite to the polarity of the residue,
Rotating while contacting the surface of the image carrier disposed in contact with the image carrier, upstream of the rotating brush in the rotational direction of the image carrier and downstream of the transfer unit. A residue holding member for receiving a part of the residue on the surface of the image carrier and polishing the surface of the image carrier with the residue;
A film-like object that vibrates while being in contact with the image carrier, arranged upstream of the rotating brush in the rotation direction of the image carrier and downstream of the residue holding member An image forming apparatus.

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