Of Residual Toner Patents (Class 399/129)
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Patent number: 6744994Abstract: An image forming apparatus includes an image bearing member, a first charging member for charging a residual developer on the image bearing member, a second charging member for charging the residual developer, an environmental condition detector, and a controller. The first charging member is disposed downstream of the transferring device and up stream of the charger, with respect to a movement direction of the image bearing member. A voltage having a polarity opposite to a polarity of the developer is applied to the first charging member. The second charging member is disposed downstream of the first charging member and upstream of the charger. A voltage having a polarity like a polarity of the developer is applied to the second charging member. The controller, in accordance with an output of the detector, controls at least one of the voltages applied to the first and second charging members.Type: GrantFiled: September 4, 2002Date of Patent: June 1, 2004Assignee: Canon Kabushiki KaishaInventors: Tadanobu Yoshikawa, Yasunari Watanabe, Motoki Adachi
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Publication number: 20040086298Abstract: Provided is an image forming apparatus, which includes a photosensitive drum, a charging roller, a transfer roller, and a toner charging brush, reciprocates the toner charging brush in a longitudinal direction of the photosensitive drum. In the image forming apparatus, when a number of rotations per a unit time of the image bearing member is assumed to be “a” and a number of times of reciprocation per unit time of the toner charging brush is assumed to be “b”, assuming that R=b/a, R is set to be in a range of {fraction (1/25)}≦R≦3. However, R=m/n (m and n are integers of 5 or less) is excluded. Consequently, generation of a periodic attachment pattern appearing on the photosensitive drum is eliminated.Type: ApplicationFiled: October 24, 2003Publication date: May 6, 2004Applicant: CANON KABUSHIKI KAISHAInventors: Masaki Ojima, Masahide Kinoshita, Motoki Adachi, Masao Uyama, Kazuhiro Okubo
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Publication number: 20040086297Abstract: An image formation apparatus has developing agent charging means situated downstream in the direction of motion of a photosensitive drum from a transfer roller and upstream from a charging roller, for charging residual developing agent remaining on the photosensitive drum. Applying AC voltage to the charging roller is started before a portion on the face of the photosensitive drum where application of voltage to the developing agent charging means has started reaches a position of coming into contact with the charging roller, and applying AC voltage to the charging means is ended after the portion on the face of the photosensitive drum where application of voltage to the developing agent charging means has ended reaches a position of coming into contact with the charging roller. This configuration prevents adhesion of developing agent to the photosensitive drum and charging roller, avoids resultant substandard images, and provides high-quality images for prolonged periods.Type: ApplicationFiled: October 16, 2003Publication date: May 6, 2004Applicant: Canon Kabushiki KaishaInventor: Yasunari Watanabe
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Publication number: 20030231899Abstract: An image forming apparatus includes a rotating photoconductive drum, charging roller, exposing unit, developing unit, transfer roller, cleaning blade, and controller. The charging member charges the surface of the photoconductive drum. The exposing unit illuminates the surface charged by the charging roller to form an electrostatic latent image. The developing unit develops the electrostatic latent image into a toner image. The transfer roller transfers the toner image onto a recording medium. The cleaning blade removes residual toner that failed to be transferred onto the recording medium. Prior to the discharge of deteriorated toner in the developing unit, the charging member charges the photoconductive drum which in turn charges the transfer roller. The toner discharged from the developing unit remains on the photoconductive drum when an area on the photoconductive drum passes by the transfer roller as the photoconductive drum rotates.Type: ApplicationFiled: January 31, 2003Publication date: December 18, 2003Applicant: OKI DATA CORPORATIONInventor: Akihiro Yamamura
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Patent number: 6640070Abstract: A method and apparatus for forming an image is provided by visualizing a latent image on a photosensitive member with a toner having an electrical resistance, transferring the visualized image to an image recording medium, cleaning with a cleaning blade a residual toner adhering to a surface of the photosensitive member after the transfer of the latent image to the image recording medium, and charge injecting a biasing voltage of a predetermined magnitude to the residual toner with a conductive polyester film, whereby at least part of a surface potential of the photosensitive member is removed. The conductive polyester film is fixedly attached to a tip end of the cleaning blade.Type: GrantFiled: December 20, 2001Date of Patent: October 28, 2003Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki KaishaInventor: Yoshinori Sanmonji
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Patent number: 6611668Abstract: In order not to expel toner excessively when bias is applied, a cleanerless image forming apparatus includes a first developer charge amount controlling device 7, provided on a downstream side of a transfer device 5 in a moving direction of an image bearing member 1, e.g. a photosensitive drum, for applying a DC bias for making uniform a charge amount of residual developer remaining on the image bearing member 1, and/or a second developer charge amount controlling device 8, provided on a downstream side of the first developer charge amount controlling device 7 in a rotating direction of the image bearing member 1, for applying a DC bias for charging the residual developer in a normal polarity. An absolute value of a slope of the DC voltage applied to the first developer charge amount controlling device 7 and/or an absolute value of a slope of the DC voltage applied to the second developer charge amount controlling device 8 are equal to 2000 V/sec or smaller.Type: GrantFiled: August 30, 2002Date of Patent: August 26, 2003Assignee: Canon Kabushiki KaishaInventors: Yasunari Watanabe, Motoki Adachi
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Publication number: 20030147659Abstract: An image forming apparatus includes an image bearing member; charging means for electrically charging the image bearing member; developing means for developing an electrostatic latent image formed on the image bearing member with a developer into a developed image; transferring means for transferring the developed image from the image bearing member onto an image receiving member; a first developer charging member for electrically charging a residual developer on the image bearing member, the first developer charging member being disposed downstream of the transferring means and upstream of the charging means, with respect to a movement direction of the image bearing member, and the first developer charging member being supplied with a voltage of a polarity opposite a regular polarity of the developer; a second developer charging for electrically charging the residual developer on the image bearing member to the regular polarity of the developer, the second developer charging member being disposed downstreamType: ApplicationFiled: September 4, 2002Publication date: August 7, 2003Applicant: Canon Kabushiki KaishaInventors: Tadanobu Yoshikawa, Yasunari Watanabe, Motoki Adachi
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Patent number: 6603941Abstract: An image forming apparatus includes an image bearing body, a charging device for charging the image bearing body, a developing device for forming a developer image by developing an electrostatic image formed on the image bearing body, a transferring device for transferring the developer image to an image-receiving member, and first and second charge-applying devices. The first charge-applying device is provided at a downstream side of the transferring device and at an upstream side of the charging device in a moving direction of the image bearing body, for charging a residual developer remaining on the image bearing body after a transfer effected by the transferring device to a polarity opposite to a normal charging polarity of the developer.Type: GrantFiled: September 21, 2001Date of Patent: August 5, 2003Assignee: Canon Kabushiki KaishaInventors: Yasunari Watanabe, Motoki Adachi
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Patent number: 6591075Abstract: A cleaning method of a toner image carrying body, includes the steps of: bringing a discharging member formed in a shape of flexible plate having electric conductivity, which is electrically grounded or to which a discharging voltage is applied, into contact with the toner image carrying body, thereby discharging a toner on the toner image carrying body; and operating a cleaning device on the toner image carrying body whereby cleaning the toner.Type: GrantFiled: February 20, 2002Date of Patent: July 8, 2003Assignee: Konica CorporationInventors: Junichi Koiso, Atsushi Ogane, Junichi Hamada, Yukiko Omori, Mitsugu Nemoto, Kazuhiko Sato
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Publication number: 20030118362Abstract: In an image forming apparatus, an electrostatic latent image is reverse-developed by a developing device with a development bias applied, through conveying a two-component developer layer containing toner particles having a volume-average particle diameter of 3 to 5 &mgr;m by a developer carrying member rotatably provided, a developed toner image is transferred onto a recording medium or an intermediate transfer body, and untransferred toner particles remaining on an image forming body having passed a transfer region are removed by a cleaning member provided in pressure contact with the surface of the image forming body. The length in an axis direction of the image forming body of an useless toner image formed on the image forming body at the starting time and the ending time of an image formation sequence denoted by L, the total charge quantity of the toner particles making up the useless toner image is 0.04L &mgr;C or less.Type: ApplicationFiled: December 11, 2002Publication date: June 26, 2003Applicant: Konica CorporationInventors: Hiroshi Akita, Kunio Shigeta, Takenobu Kimura, Yotaro Sato
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Publication number: 20030118371Abstract: In order to form high-quality images, the positive residual charge on a small-diameter photosensitive drum is efficiently diselectified and the charge built-up is effected rapidly.Type: ApplicationFiled: December 20, 2001Publication date: June 26, 2003Applicant: TOSHIBA TEC KABUSHIKI KAISHAInventor: Yoshinori Sanmonji
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Publication number: 20030077088Abstract: The invention provides an image forming apparatus provided with an image bearing body, and developer charge providing device for providing a charge thereby charging residual developer, remaining on the image bearing body after image transfer, to a normal polarity. The developer charge providing device charges an area of the image bearing body, and such area is further charged by the charging device. When the voltage applied to the developer charge providing device for charging such area is, varied, the voltage applied to the charging means for charging such area is also varied. Thus the image forming apparatus can execute uniform charging in stable manner over a prolonged period.Type: ApplicationFiled: October 11, 2002Publication date: April 24, 2003Applicant: Canon Kabushiki KaishaInventors: Motoki Adachi, Yasunari Watanabe
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Publication number: 20030059231Abstract: In order not to expel toner excessively when bias is applied, a cleaner-less image forming apparatus comprises a first developer charge amount controlling device 7, provided on a downstream side of a transfer device 5 in a moving direction of an image bearing member 1, for applying DC bias for making uniform the charge amount of residual developer remaining on the image bearing member 1, and/or a second developer charge amount controlling device 8, provided on a downstream side of said first developer charge amount controlling device 7 in the rotating direction of the photosensitive drum 1, for applying DC bias for charging the residual developer in a normal polarity. The absolute value of the slope of the DC voltage applied to the first developer charge amount controlling device 7 and/or the absolute value of the slope of the DC voltage applied to the second developer charge amount controlling device 8 are equal to 2000 V/sec or smaller.Type: ApplicationFiled: August 30, 2002Publication date: March 27, 2003Applicant: Canon Kabushiki KaishaInventors: Yasunari Watanabe, Motoki Adachi
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Publication number: 20030049048Abstract: An image forming apparatus including: an image bearing member; an electrifying unit for electrifying the image bearing member at a contact portion in order to form an electrostatic image on the image bearing member, a voltage, in which a direct-current voltage and an alternating-current voltage are superimposed on each other, being applied to the electrifying unit; and a developing unit for developing the electrostatic image on the image bearing member using toner; where after a toner image on the image bearing member is transferred onto a transferring medium, residual toner residing on the image bearing member is carried to the contact portion in accordance with rotation of the image bearing member, and a peak to peak voltage of the alternating-current voltage applied to the electrifying unit in order to discharge the residual toner adhering to the electrifying unit to the image bearing member during a certain period of non-image forming is set so as to be higher than a peak to peak voltage applied during imType: ApplicationFiled: August 30, 2002Publication date: March 13, 2003Applicant: Canon Kabushiki KaishaInventors: Tadanobu Yoshikawa, Motoki Adachi
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Publication number: 20030049049Abstract: A developer charging device for charging developer with electricity comprises a developer charging member arranged at a position downstream relative to a transfer means for transferring a developer image from an image carrier to an image receiving member and upstream relative to a charging means for electrically charging the image carrier as viewed in the moving direction of the image carrier and held in contact with the image carrier so as to electrically charge residual developer on the image carrier, a reciprocating means for reciprocating the developer charging member in the direction of a generating line of the image carrier, and an attitude maintaining means for maintaining the attitude of the developer charging member relative to the image carrier regardless of reciprocation of the developer charging member by the reciprocating means.Type: ApplicationFiled: September 6, 2002Publication date: March 13, 2003Applicant: Canon Kabushiki KaishaInventors: Nobuharu Hoshi, Kenji Matsuda, Akiyoshi Fujita
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Publication number: 20030007806Abstract: An image forming apparatus including at least one image carrier for carrying a visual image formed thereon, an intermediate transfer element for carrying the visual image from the at least one image carrier to a recording material, a primary transfer device for transferring the visual image from the at least one image carrier onto the intermediate transfer element, a secondary transfer device for transferring the visual image on the intermediate transfer element onto the recording material, a cleaning device for mechanically removing developer remaining on the intermediate transfer element, and a discharging device for discharging the intermediate transfer element. The discharging device is positioned in downstream of the secondary transfer device and upstream of the cleaning device in a moving direction of the intermediate transfer element.Type: ApplicationFiled: May 28, 2002Publication date: January 9, 2003Inventor: Shin Kayahara
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Publication number: 20020150406Abstract: A cleaning method of a toner image carrying body, includes the steps of: bringing a discharging member formed in a shape of flexible plate having electric conductivity, which is electrically grounded or to which a discharging voltage is applied, into contact with the toner image carrying body, thereby discharging a toner on the toner image carrying body; and operating a cleaning device on the toner image carrying body whereby cleaning the toner.Type: ApplicationFiled: February 20, 2002Publication date: October 17, 2002Inventors: Junichi Koiso, Atsushi Ogane, Junichi Hamada, Yukiko Omori, Mitsugu Nemoto, Kazuhiko Sato
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Patent number: 6442362Abstract: An image forming apparatus includes an image bearing member for bearing an electrostatic image. A developing device develops the electrostatic image on the image bearing member by toners charged with a predetermined polarity. A transfer device transfers a toner image on the image bearing member to a transferring material. An electrifying device inject-charges the image bearing member having transfer residual toners. An electrical conductive member provided and spaced apart from the image bearing member in a moving direction of the image bearing member downstream farther than the transfer means and upstream farther than the electrifying device. An electrical field forming device for forming an alternative electrical field between the electrical conductive member and the image bearing member.Type: GrantFiled: December 29, 2000Date of Patent: August 27, 2002Assignee: Canon Kabushiki KaishaInventors: Jun Hirabayashi, Harumi Ishiyama, Yasunori Chigono
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Publication number: 20020057925Abstract: An object of the present invention is to provide an image forming apparatus that has an image bearing body, charging device for charging the image bearing body, developing device for forming a developer image by developing, with developer, an electrostatic image formed on the image bearing body, transferring device for transferring the developer image to an image-receiving member, first charge-applying device, provided on a downstream side of the transferring device and on an upstream side of the charging device in a moving direction of the image bearing body, for charging a residual developer remaining on the image bearing body after a transfer effected by the transferring device to a polarity opposite to a normal charging polarity of the developer, and second charge-applying device, provided on a downstream side of the first charge-applying device and on the upstream side of the charging device in the moving direction of the image bearing body, for charging the residual developer charged by the first chargeType: ApplicationFiled: September 21, 2001Publication date: May 16, 2002Inventors: Yasunari Watanabe, Motoki Adachi
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Patent number: 6208819Abstract: A method involving a photoreceptor having a front surface and a rear surface, including: (a) creating an electrostatic latent image on an image area of the photoreceptor front surface; (b) developing the latent image with developer particles to form a developed image; (c) transferring the developed image off the photoreceptor wherein the photoreceptor retains residual charges in the image area after the transferring of the developed image off the photoreceptor; and (d) discharging at least a portion of the residual charges in the image area, after transferring the developed image off the photoreceptor, by directing charge dissipation emissions at a portion of the image area and at a corresponding region on the photoreceptor rear surface directly opposite the image area portion.Type: GrantFiled: December 7, 1999Date of Patent: March 27, 2001Assignee: Xerox CorporationInventors: Damodar M. Pai, Moritz P. Wagner, Neville R. Phillips, Dennis A. Abramsohn, Jimmy E. Kelly
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Patent number: 5991566Abstract: An image forming apparatus and method includes a first image-bearing member, a latent image-forming device for forming an electrostatic latent image on the first image-bearing member, developer for developing the electrostatic latent image with a toner to form a toner image, an intermediate transfer member for receiving the toner image by primary transfer and transferring the toner image onto a second image-bearing member by secondary transfer, a charging member for charging a residual toner remaining on the intermediate transfer member after the secondary transfer, and a recovery member for recovering the charged residual toner at a recovery position by voltage application. The intermediate transfer member exhibits a charging characteristic such that it has a surface potential of at most 500 volts as an absolute value at the recovery position.Type: GrantFiled: February 24, 1998Date of Patent: November 23, 1999Assignee: Canon Kabushiki KaishaInventors: Atsushi Tanaka, Hiroyuki Kobayashi, Akihiko Nakazawa, Tsunenori Ashibe, Takashi Kusaba
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Patent number: 5943533Abstract: A method of forming an electrostatic latent image includes printing operation and toner recovering operation. The printing operation includes charging, forming an electrostatic latent image, developing, and transferring operations. The toner recovering operation includes the step of charging the photosensitive drum in timed relation to the rotation of the photosensitive drum after printing operation so that reversely charged toner deposited on the charging roller migrates from the charging roller to the photosensitive drum. The toner migrated from the charging roller to the photosensitive drum is recovered into a developer. An apparatus for forming an image includes a charging roller, photosensitive drum, developing roller, and transfer roller.Type: GrantFiled: February 17, 1998Date of Patent: August 24, 1999Assignee: Oki Data CorporationInventors: Syuichiro Ogata, Yoshitatsu Okiyama, Kazuyoshi Yoshida, Toru Ishihara, Kuniharu Hayashi, Hiroyuki Yajima, Mikio Yamamoto, Takashi Itaya, Masanori Maekawa, Kazuhiko Nagaoka
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Patent number: 5943530Abstract: An image-forming apparatus is disclosed. Unstably charged toner contained in a developer is attached to the surface of an image carrier by a developing sleeve for use in a developer unit. This toner is allowed to pass through the transfer position while keeping from contacting a transfer material. The toner is then uniformly charged by a pre-transfer charger or a separating charger to the same polarity as the developed normal toner. This increases an adhesion force of the toner to the surface of the image carrier, thereby preventing its attachment to a separating claw.Type: GrantFiled: July 7, 1997Date of Patent: August 24, 1999Assignee: Canon Kabushiki KaishaInventor: Takeshi Ozasa
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Patent number: 5862432Abstract: An image forming apparatus having a cleaner, which can be a cleaning blade, for removing residual toner from the surface of a rotatable image-bearing member, and a charger for imparting a charge to the residual toner before the residual toner is removed by the cleaner. The amount of charge imparted to the residual toner is less than 10 .mu.c/g.Type: GrantFiled: February 26, 1997Date of Patent: January 19, 1999Assignee: Minolta Co., Ltd.Inventors: Yasunori Nakayama, Kuniaki Kashiwakura
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Patent number: 5809373Abstract: An image forming apparatus has an image bearing member; toner image forming unit for forming a toner image with non-magnetic toner on an image bearing member; intermediate transfer member contactable to the image bearing member and movable along an endless path; primary transfer unit for effecting primary image transfer of the toner image formed on the image bearing member onto the intermediate transfer member at a first transfer position; secondary transfer unit for effecting a secondary image transfer of the toner image from the intermediate transfer member on the transfer material at a second transfer position; and a residual toner charger for charging the residual toner remaining on the intermediate transfer member to a polarity opposite from a regular polarity thereof.Type: GrantFiled: May 21, 1996Date of Patent: September 15, 1998Assignee: Canon Kabushiki KaishaInventors: Yasuo Yoda, Katsuhiko Nishimura, Koichi Hiroshima, Shinichi Tsukida, Toru Kosaka
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Patent number: 5752130Abstract: An image forming apparatus includes a first image-bearing member, latent image-forming unit for forming an electrostatic latent image on the first image-bearing member, developer for developing the electrostatic latent image with a toner to form a toner image, an intermediate transfer member for receiving the toner image by primary transfer and transferring the toner image onto a second image-bearing member by secondary transfer, a charging member for charging a residual toner remaining on the intermediate transfer member after the secondary transfer, and a recovery member for recovering the charged residual toner at a recovery position by voltage application. The intermediate transfer member exhibits a charging characteristic such that it has a surface potential of at most 500 volts as an absolute value at the recovery position.Type: GrantFiled: July 3, 1996Date of Patent: May 12, 1998Assignee: Canon Kabushiki KaishaInventors: Atsushi Tanaka, Hiroyuki Kobayashi, Akihiko Nakazawa, Tsunenori Ashibe, Takashi Kusaba
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Patent number: 5722015Abstract: Residual toner on a photoconductive or intermediate image member is adjusted in charge prior to cleaning by a roller which is rolled by the image member. The roller is biased to either apply charge to the toner or reduce charge, depending upon the type of cleaning. The roller includes a compliant blanket made of polyurethane covered by a thin coat of material having a Young's Modulus greater than 1.times.10.sup.7 Pascals.Type: GrantFiled: April 30, 1996Date of Patent: February 24, 1998Assignee: Eastman Kodak CompanyInventor: Thomas N. Tombs
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Patent number: 5715503Abstract: Magnetic carrier particles are removed from a photoconductive image member by subjecting the carrier particles to a magnetic field while or after exposing the photoconductive image member to erasing radiation in the absence of a substantial electrical field affecting the carrier particles.Type: GrantFiled: May 30, 1996Date of Patent: February 3, 1998Assignee: Eastman Kodak CompanyInventors: Salvatore Leone, Donald S. Rimai, Orville C. Rodenberg, Catherine Newell, Andrew J. Mauer, Susan P. Farnand
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Patent number: 5678142Abstract: An image forming apparatus comprises a contact charging member for contacting a photosensitive drum and charging it with electricity, an exposer for exposing the charged photosensitive drum to light and forming an electrostatic latent image thereon, a developing device for visualizing the electrostatic latent image formed on the photosensitive drum by means of coloring powder, a transferring device for transferring the image visualized by the developing device onto a recording medium and a deelectrifier for deelectrifying the photosensitive drum after transferring the image by the transferring device. Any residual coloring powder remaining on the surface of the photosensitive drum after transfer is collected and cleaned by the developing device simultaneously with the developing operation.Type: GrantFiled: November 1, 1995Date of Patent: October 14, 1997Assignee: Kabushiki Kaisha TECInventor: Hisayoshi Saegusa
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Patent number: 5659849Abstract: A method and apparatus for eliminating the accumulation of triboelectric negative toner that occurs between the cleaning edge of the cleaning blade and the photoreceptor surface. After image transfer, the residual toner particles on the photoreceptor surface are then charged to a uniform polarity using either a preclean corotron or a biased conductive blade. A UCA is used to dislodge the residual toner particles away from the photoreceptor surface. The polarity of the particles is opposite to that of the collection roll positioned to attract the toner particles levitated by the UCA onto the collection roll.Type: GrantFiled: July 3, 1996Date of Patent: August 19, 1997Assignee: Xerox CorporationInventors: Nero R. Lindblad, David B. Montfort, Christopher W. Curry