Brush Patents (Class 399/175)
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Patent number: 7480474Abstract: A charging apparatus for electrically charging a chargeable member while magnetic particles contact to the chargeable member, includes first and second magnetic particle carrying members, the second being downstream of the first with respect to a magnetic particle feeding direction at an opposed portion where the first member and the chargeable member oppose each other. The apparatus also includes a regulating portion for regulating the amount of the magnetic particles carried on the first member, at a position upstream of the opposed portion, and first and second positioning portions for regulating movement of the first and second members. The first portion regulates the first member against movement in a moving direction of the chargeable member, and the second portion regulates the second member against its movement in a direction of contact to the chargeable member while permitting movement in the direction of movement of the chargeable member.Type: GrantFiled: December 7, 2005Date of Patent: January 20, 2009Assignee: Canon Kabushiki KaishaInventor: Kenji Muto
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Publication number: 20080304866Abstract: A charging brush unit includes a brush and a conductive holder. The brush includes a plurality of flexible conductive fibers. The plurality of flexible conductive fibers is supplied with a charging bias to generate electrical discharge between a top of the plurality of conductive fibers and a latent image carrier across a gap formed between the top of the plurality of conductive fibers and the latent image carrier. The gap is provided with an electrode. The electrode includes a plurality of openings opposing the top of the plurality of conductive fibers and is supplied with a bias different from the charging bias applied to the plurality of conductive fibers. The conductive holder holds the brush.Type: ApplicationFiled: March 12, 2008Publication date: December 11, 2008Inventors: Kohta TAKENAKA, Kazunori Bannai, Hidehiko Fujiwara, Yu Wakabayashi
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Publication number: 20080273898Abstract: An image forming apparatus that is more capable of preventing the occurrence of image quality deterioration caused by defective charging of a photoreceptor than the conventional one. As a charging device, there is used a member which has: a conductive sheet that causes the surface thereof applied with a predetermined bias to abut against the surface of the photoreceptor after passing through a primary transfer nip obtained by abutment between the photoreceptor and an intermediate transfer belt and before entering a development step performed by a developing device; a conductive brush member that applies a predetermined bias to the surface of the photoreceptor obtained after passing through the position of abutment with the sheet and before entering the development step; and a charging roller that uniformly charges the surface of the photoreceptor after passing through the position of abutment with the brush and before entering the development step.Type: ApplicationFiled: December 12, 2007Publication date: November 6, 2008Inventors: Yoshio Sakagawa, Tetsumaru Fujita, Yuji Nagatomo
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Publication number: 20080253807Abstract: Provided is an image forming apparatus having a charge brush for charging a transfer residual toner remaining on an intermediate transfer member. A toner is adhered to the charge brush. While a charge voltage is applied to the charge brush, the toner adhered to the charge brush is attracted by an electric field onto the charge brush. However, when the charge voltage is not applied to the charge brush, the toner adhered to the charge brush is moved to the intermediate transfer member. When a subsequent toner image is formed on the toner adhered to the intermediate transfer member, the quality of the subsequent image is deteriorated. Accordingly, the charge voltage is applied to the charge brush when an intermediate transfer area to which the toner image is transferred onto the intermediate transfer member immediately afterward faces the charge brush.Type: ApplicationFiled: April 2, 2008Publication date: October 16, 2008Applicant: CANON KABUSHIKI KAISHAInventor: Takamitsu Soda
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Patent number: 7395011Abstract: An image forming apparatus has a charge roller, a charge erasing device and a preliminary voltage-applying member disposed around a rotationally movable photosensitive member. The charge roller subjects a surface of the photosensitive member to a charge process while contacting the surface of the photosensitive member. The charge erasing device is on an upstream side of the photosensitive member relative to the charge roller and erases the charged area in the photosensitive member. The preliminary voltage-applying member is on an upstream side of photosensitive member relative to the charge erasing device and applies to the surface of the photosensitive member a voltage of the same polarity as the voltage applied from the charge roller to the surface, while contacting the surface. The preliminary voltage-applying member is reciprocated along the surface of the photosensitive member and in a direction orthogonal to the movement direction of the surface.Type: GrantFiled: May 30, 2006Date of Patent: July 1, 2008Assignee: Kyocera Mita CorporationInventor: Nariaki Tanaka
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Publication number: 20080131154Abstract: A charger includes: a primary charging member which is rotatably provided and is brought into contact with an image carrier to charge the surface of the image carrier; a secondary charging member which is brought into contact with the image carrier at a portion on the downstream side relative to the first charging member in the rotational direction of the image carrier to charge the surface of the image carrier; and a controller which controls voltages applied to the first and second charging members, wherein at the time of image formation, the controller applies, to the first charging member, a voltage whose absolute value is higher than the absolute value of the discharge start voltage of the first charging member and applies, to the second charging member, a voltage whose absolute value is lower than the absolute value of the discharge start voltage of the second charging member and whose absolute value is lower than the voltage applied to the first charging member, and at the time when an image is not forType: ApplicationFiled: December 12, 2007Publication date: June 5, 2008Applicant: SEIKO EPSON CORPORATIONInventors: Masaru KOBASHI, Koji MIGITA, Masashi NAKATSU, Shinichi KAMOSHIDA
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Publication number: 20080131155Abstract: A charger includes: a charging brush which is rotatably provided and is brought into contact with an image carrier to charge the surface of the image carrier; a charging roller which is brought into contact with the image carrier at a portion on the downstream side relative to the charging brush in the rotational direction of the image carrier to charge the surface of the image carrier; and a controller which controls voltages applied to the charging brush and charging roller, wherein the controller controls voltages applied to the charging brush and charging roller such that one-fifth of the absolute value of a charging brush current flowing between the image carrier and charging brush is lower than the absolute value of a charging roller current flowing between the image carrier and charging roller.Type: ApplicationFiled: December 12, 2007Publication date: June 5, 2008Applicant: SEIKO EPSON CORPORATIONInventors: Masaru KOBASHI, Koji MIGITA, Masashi NAKATSU, Shinichi KAMOSHIDA
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Publication number: 20080107450Abstract: There is provided a charging technique in which the generation of ozone is suppressed and charging efficiency can be improved. A charging device includes a contact unit configured to include a magnetic brush coming in contact with a body to be charged, the contact unit including, as a magnetic particle forming the magnetic brush, the magnetic particle containing at least a particle having a negative electronegativity, and a voltage application unit configured to negatively charge the body to be charged by applying a specified bias voltage through the magnetic brush in the contact unit to the body to be charged.Type: ApplicationFiled: November 8, 2006Publication date: May 8, 2008Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHAInventors: Takeshi Watanabe, Masashi Takahashi, Mitsuaki Kouyama
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Publication number: 20080050150Abstract: A charging apparatus for charging a member to be charged by contacting magnetic particles to the member to be charged, includes a magnetic particle carrying member for magnetically carrying the magnetic particles, wherein the magnetic particle carrying member is provided at a longitudinal end portion of the magnetic particle carrying member with an insulative portion for electrically insulating from the magnetic particles carried by the magnetic particle carrying member; and an electroconductive member disposed for contacting the magnetic particles carried on the insulative portion, wherein an absolute value of a potential of the electroconductive member is lower than an absolute value of a voltage applied to the magnetic particle carrying member.Type: ApplicationFiled: August 13, 2007Publication date: February 28, 2008Applicant: CANON KABUSHIKI KAISHAInventors: Shingo Horita, Ryo Nakamura, Koichi Hashimoto
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Publication number: 20080038017Abstract: An image forming apparatus, performing a corresponding method of image forming, includes an image carrier, a charging unit including a first charging member for discharging a given amount of bias to a portion contacting the image carrier and uniformly charging the surface of the image carrier while contacting the surface of the image carrier, a charge bias applying unit for applying a charge bias including at least an alternating current voltage to the first charging member, a writing unit, and a developing unit. In the image forming apparatus, a ratio of a frequency of the alternating current voltage to a surface linear velocity of the image carrier is within a range of from approximately 1.5:1 to approximately 4:1 and a ratio of a surface linear velocity of the first charging member to the surface linear velocity of the image carrier is at least 2:1.Type: ApplicationFiled: August 10, 2007Publication date: February 14, 2008Inventors: Tetsumaru FUJITA, Yuji Nagatomo
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Publication number: 20080019733Abstract: To provide a technique that can realize recycling of a developing agent without deteriorating productivity in a charging device capable of switching and executing charging processing for a photosensitive surface of a photosensitive member and collection processing for a developing agent remaining on the photosensitive surface.Type: ApplicationFiled: July 24, 2006Publication date: January 24, 2008Applicants: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki KaishaInventor: Keiji Yuge
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Publication number: 20070280735Abstract: A charging unit available in a process unit detachably attached to an image forming apparatus includes a charging member configured to uniformly charge a surface of an image carrying member while contacting the image carrying member, and a charge bias applying unit configured to apply a charge bias superimposing a direct current voltage on an alternating current voltage to the charging member. The alternating current voltage satisfies a relational expression of “Vpp×0.4/t?8.8×103”, “Vpp” representing a peak-to-peak voltage of the alternating current voltage in the charge bias, and “t” representing a time period from a first point of a swing of a wave component starting to swing by a large amount to a same polarity as the direct current voltage of the charge bias to a second point of the swing of the wave component reaching approximately 80% of an amplitude of the wave component.Type: ApplicationFiled: June 6, 2007Publication date: December 6, 2007Inventors: Yuji Nagatomo, Tetsumaru Fujita
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Publication number: 20070274738Abstract: In the invention, oxidation-treated carbon black having good dispersibility is used to obtain a conductive brush having a uniform resistance even when it is finely processed. An image forming process is carried out by using the conductive brush, whereby abnormal discharge to a photoreceptor is suppressed, and an image defect due to charging unevenness is prevented from occurring without damaging the photoreceptor, so as to improve image quality. The photoreceptor is scraped uniformly and smoothly to prevent filming from occurring, whereby the maintenance property is improved.Type: ApplicationFiled: May 23, 2006Publication date: November 29, 2007Applicants: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki KaishaInventors: Takeshi Watanabe, Masashi Takahashi, Mitsuaki Kouyama
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Patent number: 7289753Abstract: An image forming apparatus includes an image bearing member, and first and second chargers. Each of the chargers includes a magnetic member for generating magnetism, has a holding member for holding magnetic particles by a magnetic force, and charges the image bearing member by bringing the magnetic particles in contact therewith. The magnetic member of each of the chargers has a magnetic pole facing the image bearing member. The second charger is located at the tail end in the image bearing member rotational direction, but before a position at which an image is formed on the image bearing member. In the image bearing member rotation direction, and relative to a position at which the image bearing member comes closest to the holding member, the first charger's magnetic member has a peak magnetic force positioned downstream, and the second charger's magnetic member has a peak magnetic force positioned upstream.Type: GrantFiled: December 2, 2004Date of Patent: October 30, 2007Assignee: Canon Kabushiki KaishaInventor: Ryo Inoue
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Publication number: 20070172259Abstract: A charging device for applying a voltage to a latent image carrier of an image forming apparatus includes a brush roller, a voltage applying mechanism, and a driving mechanism. The brush roller includes a shaft and a brush. The brush has an oblique brush amount, and is disposed on an outer surface of the shaft while being disposed to a surface of the latent image carrier such that the brush roller is abutted with a brush contact amount. This brush is configured to uniformly charge the surface of the latent image carrier. The voltage applying mechanism is configured to apply a charging voltage to the brush roller. The driving mechanism is configured to drive the brush roller at a predetermined rotation number to satisfy a relationship Z>150?50 A, where Z is a rotation number (rpm) of the brush roller, and A is the oblique brush amount (mm).Type: ApplicationFiled: January 22, 2007Publication date: July 26, 2007Inventor: Tetsumaru Fujita
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Patent number: 7248821Abstract: A charging device includes magnetic particles, a magnetic particle carrying member that magnetically carries the magnetic particles into contact with a member to be charged, and a magnetic particle adjusting unit for adjusting an amount per unit area of magnetic particles carried on the magnetic particle carrying member so that the amount per unit area of magnetic particles carried is larger in end regions of the magnetic particle carrying member in the longitudinal direction than in a central region of the magnetic particle carrying member in the longitudinal direction.Type: GrantFiled: June 2, 2005Date of Patent: July 24, 2007Assignee: Canon Kabushiki KaishaInventors: Ryo Nakamura, Hiroyuki Suzuki
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Patent number: 7244485Abstract: A seamed flexible belt having a substrate and a seam having interlocking seam members, wherein the interlocking seam members are held together by an adhesive having polyamide and an optional electrically conductive filler, for use in electrostatographic, contact electrostatic, digital and other like printing machines.Type: GrantFiled: April 11, 2001Date of Patent: July 17, 2007Assignee: Xerox CorporationInventors: Ralph A. Mosher, T. Edwin Freeman, Theodore Lovallo, Damodar M. Pai, John F. Yanus, Timothy J. Fuller, Markus R. Silvestri, Gerald M. Fletcher, Antonio DeCrescentis, Ihor W. Tarnawskyj
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Patent number: 7245847Abstract: A cleaning apparatus for a rotatable brush that contacts upon or slides along a carrier of electrostatic latent images in order to apply an electric potential to the carrier of the electrostatic latent images, includes, an elastic foam body pressed by the bristles of the rotating brush provided downstream in a direction of a rotation of the rotating brush from a position of contact with the carrier of the electrostatic latent images, and a slide member pressed by the bristles of the rotating brush downstream in the direction of the rotation of the rotating brush from the elastic foam body, wherein the elastic foam body has a contact face that presses the rotatable brush, a discharge face that discharges developer or the like that enters the elastic foam body, and all faces other than the contact face and the discharge face are sealed.Type: GrantFiled: March 24, 2005Date of Patent: July 17, 2007Assignee: Sharp Kabushiki KaishaInventors: Yoichi Takesawa, Hiroshi Ishii
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Patent number: 7232635Abstract: A method of forming a toner image employing a photoreceptor is described. The photoreceptor comprises a photosensitive layer on a cylindrical conductive substrate, Formula (1) and Formula (2) are held, 0<Pmax<2P??Formula (1) 2?(Pmax/D)×100?50??Formula (2) wherein P (?m) is the average of the coating layer thickness in central section in the width direction of the photoreceptor, Pmax (?m) is average of the image forming region, and D (?m) is average of distance between point, at which said maximum value is obtained, and edge of the coating layer.Type: GrantFiled: January 24, 2003Date of Patent: June 19, 2007Assignee: Konica CorporationInventors: Nobuaki Kobayashi, Masao Asano
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Patent number: 7233755Abstract: An image forming apparatus which reduces abrasion of a photosensitive drum caused by a rotary brush such as an charging brush for electrically charging the surface of a photosensitive drum or a cleaning brush for cleaning the surface of a photosensitive drum. The rotary brush is in contact with the photosensitive drum. During the period of charging the photosensitive drum or cleaning its surface, the rotary brush is rotated in a first mode in which the brush rotates rubbing and sliding the surface of the photosensitive drum, and during other periods, in a second mode in which the brush is rotated passively as driven by rotation of the photosensitive drum. Abrasion of the photosensitive drum is reduced by properly controlling the width of contact between the rotary brush and photosensitive drum and the amount of push for pressing the brush against the photosensitive drum.Type: GrantFiled: March 31, 2004Date of Patent: June 19, 2007Assignee: Konica Minolta Business Technologies, Inc.Inventors: Makiko Tango, Yuji Nagatomo
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Patent number: 7130565Abstract: A charging apparatus includes first and second magnetic particle carrying members. The second member is upstream of the first member in a particle feeding direction at a nip between the first member and a member to be charged. The particles are commonly used by the first and second members, which move in the same peripheral direction relative to the member to be charged such that the peripheral movement directions of the first and second members are opposite to a peripheral movement direction of the member to be charged at a portion where they are opposed to the member to be charged. The amount of the particles on the second member at a nip between the second member and the member to be charged is larger than the amount of particles on the first member at a nip between the first member and the member to be charged.Type: GrantFiled: June 3, 2004Date of Patent: October 31, 2006Assignee: Canon Kabushiki KaishaInventors: Ryo Nakamura, Hiroyuki Suzuki
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Patent number: 7103303Abstract: A charging apparatus includes a first magnetic particle carrying member for carrying magnetic particles; a second magnetic particle carrying member for carrying the magnetic particles, the second magnetic particle carrying member being disposed downstream of the first magnetic particle carrying member with respect to a moving direction of a member to be charged, wherein the magnetic particle are commonly used by the first magnetic particle carrying member and the second magnetic particle carrying member, and the member to be charged is electrically charged by contacting the magnetic particles carried on the first magnetic particle carrying member and the second magnetic particle carrying member to the member to be charged; and current measuring means for measuring a current flowing between the first and second magnetic particle carrying members through the magnetic particles which exist between the first and second magnetic particles.Type: GrantFiled: May 20, 2004Date of Patent: September 5, 2006Assignee: Canon Kabushiki KaishaInventors: Hiroyuki Suzuki, Ryo Nakamura
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Patent number: 7082277Abstract: A contact charger for charging a charging target (e.g., a photosensitive member) includes a charging brush to be in contact with the charging target, and auxiliary charging particles to be interposed between the brush and the charging target. The auxiliary charging particle takes an acicular form having an aspect ratio from 2 to 10000, and satisfies a relationship of (L2/T?200) between a length L (?m) of a long axis of the particle and a thickness of T (deniers) of a brush fiber of the brush.Type: GrantFiled: March 4, 2004Date of Patent: July 25, 2006Assignee: Konica Minolta Business Technologies, Inc.Inventors: Yuji Nagatomo, Makiko Tango
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Patent number: 6999699Abstract: A contact charger for charging a charging target (e.g., a photosensitive member) includes a brush to be in contact with the charging target, and auxiliary charging particles to be interposed between the brush and the charging target. Fibers of the brush have a volume resistivity from 1×101 ?·cm to 1×108 ?·cm, a primary particle diameter of the auxiliary charging particles is in a range from 0.01 ?m to 10 ?m, and a push-in amount of the brush with respect to the charging target is in a range from 0.1 mm to 2.0 mm. The brush moves relatively to the charging target for charging the charging target. An image forming apparatus includes a photosensitive member to be charged by the charger.Type: GrantFiled: December 29, 2003Date of Patent: February 14, 2006Assignee: Konica Minolta Business Technologies Inc.Inventors: Yuji Nagatomo, Makiko Tango
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Patent number: 6954600Abstract: The present invention relates to an electric contact member applying a voltage from a voltage applying device to a charger reciprocally moving in a longitudinal direction of an image carrier. The member includes a securing portion electrically connected to a side of the voltage applying device, a moving portion reciprocally movable and connected electrically to a side of the charger, and a buffer portion formed between the securing portion and the moving portion.Type: GrantFiled: September 29, 2003Date of Patent: October 11, 2005Assignee: Canon Kabushiki KaishaInventors: Akiyoshi Fujita, Atsushi Numagami, Takahito Ueno
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Patent number: 6915093Abstract: An image forming apparatus includes a charging device that, by allowing a brush roller to be rotated so as to be set in contact with a surface of a photosensitive body, charge the surface of an image carrier, a light exposure device that radiates image information light onto the surface of the image carrier to form an electrostatic latent image, a developing device that develops the electrostatic latent image into a developing agent image, a transfer device that transfers the developing agent to a sheet, and a guide device that guides an outer periphery of the brush roller so as to prevent the image information light from being blocked by the brush roller.Type: GrantFiled: March 10, 2003Date of Patent: July 5, 2005Assignees: Kabushiki Kaisha Toshiba, Toshiba TEC Kabushiki KaishaInventor: Takashi Hatakeyama
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Patent number: 6909859Abstract: A charging apparatus includes plural charging devices including a first charging device and a second charging device, in which an absolute value of a current flowing from the second charging device to a member to be charged is 25% or less of an absolute value of a sum of currents respectively flowing from the plural charging devices to the member to be charged, thereby achieving uniform charging of the member to be charged.Type: GrantFiled: May 6, 2003Date of Patent: June 21, 2005Assignee: Canon Kabushiki KaishaInventors: Ryo Nakamura, Hiroyuki Suzuki, Ryo Inoue
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Patent number: 6909868Abstract: A brush charger for static-charging a photosensitive drum by a contact method has a charging brush roller. The charging brush roller has a brush of a large number of conductive fibers, and the brush is wound around a conductive support spirally. The conductive fibers are 1.5 to 4 deniers in thickness D, are 2 mm in length L and are planted at a density not less than 150,000 filaments/inch2, and the thickness D and the length L of the conductive fibers meet the condition, D?0.71L?1.61.Type: GrantFiled: June 18, 2003Date of Patent: June 21, 2005Assignee: Minolta Co., Ltd.Inventors: Chiaki Yamada, Keiko Momotani
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Patent number: 6873809Abstract: A cleaning device including a brush roller that contacts the surface of a charge roller for cleaning it and an image forming apparatus including the cleaning device are disclosed. The brush roller has a brush contacting the charge roller due to the weight of the brush roller. The brush roller rotates by following the rotation of the charge roller. The cleaning device has a simple configuration while the brush roller has high durability.Type: GrantFiled: January 24, 2002Date of Patent: March 29, 2005Assignee: Ricoh Company, Ltd.Inventors: Ken Amemiya, Yukiko Iwasaki
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Patent number: 6832062Abstract: A charging apparatus includes a charging member for charging a member to be charged while forming a nip with the member to be charged, and electroconductive particles disposed in the nip. The charging member is supplied with a voltage of a certain polarity, a surface of the member to be charged is triboelectrically charged by a surface of the charging member so as to have a polarity opposite from that of the voltage, and the electroconductive particles are triboelectrically charged in the nip so as to have a polarity opposite from that of the voltage.Type: GrantFiled: February 4, 2003Date of Patent: December 14, 2004Assignee: Canon Kabushiki KaishaInventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi, Norio Takahashi
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Publication number: 20040240900Abstract: An image forming device is provided that is capable of easily preventing occurrence of stripe-like image noise that may be caused by intimate contact between a contact electrifying member and an image carrier even when an image forming operation is stopped for a while. In the image forming device having an electrifying roller in contact with a photoconductor, AC voltage is applied to the electrifying roller before the image carrier and the electrifying roller start rotating.Type: ApplicationFiled: May 27, 2004Publication date: December 2, 2004Applicant: Konica Minolta Business Technologies, Inc,Inventor: Masayasu Haga
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Publication number: 20040202494Abstract: An image forming apparatus is provided, which includes: an image bearing member, a charging member for charging the image bearing member, the charging member bearing electrically conductive particles that contact the image bearing member, and a developer carrying member for carrying a developer provided with toner and electrically conductive particles, the developer carrying member being applied a voltage to develop an electrostatic image formed on the image bearing member with the developer and being capable of collecting a residual developer on the image bearing member, wherein the developer carrying member is provided in such a manner that the developer carrying member opposes the image bearing member via a gap of 150 &mgr;m or more and 250 &mgr;m or less.Type: ApplicationFiled: July 9, 2001Publication date: October 14, 2004Inventors: Masahiro Yoshida, Junichi Kato, Yasushi Shimizu, Hiroshi Sato, Hiroyuki Oba
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Publication number: 20040179863Abstract: An image forming apparatus comprises a charging device configured to, by allowing a brush roller to be rotated in such a state as to be set in contact with a surface of a photosensitive body, charge the surface of that image carrier, a light exposure device configured to radiate image information light onto the surface of the image carrier charged by the charging device to form an electrostatic latent image, a developing device configured to develop the electrostatic latent image formed by the light exposure device into a developing agent image, a transfer device configured to transfer the developing agent image which is developed by the developing device to a sheet, and a guide device configured to guide an outer periphery of the brush roller so as to prevent the image information light which is radiated toward the photosensitive body from being blocked by the brush roller of the charging device.Type: ApplicationFiled: March 10, 2003Publication date: September 16, 2004Applicant: TOSHIBA TEC KABUSHIKI KAISHAInventor: Takashi Hatakeyama
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Patent number: 6792232Abstract: To provide a charging apparatus including: a first charging unit for charging a body to be charged, the first charging unit including a magnetic brush that contacts the body to be charged; and a second charging unit that is provided on a downstream side of the first charging unit with respect to a moving direction of the body to be charged, the second charging unit including a magnetic brush that contacts the body to be charged, in which a contact width, with which the magnetic brush of the first charging unit contacts the body to be charged, is wider than a contact width with which the magnetic brush of the second charging unit contacts the body to be charged.Type: GrantFiled: February 24, 2003Date of Patent: September 14, 2004Assignee: Canon Kabushiki KaishaInventors: Hiroyuki Suzuki, Ryo Inoue, Ryo Nakamura
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Patent number: 6788911Abstract: A charging device includes a charging member for electrically charging a member to be charged which is adapted to form a nip with a member to be charged which has a surface layer having a volume resistivity of 1×109-1×1014 &OHgr;cm, said charging member having an elastic member and movable with a peripheral speed difference relative to the member to be charged; and electroconductive particles carried on said charging member to the nip, wherein a peripheral speed Vd (mm/sec) of said member to be charged, a peripheral speed Vc (mm/sec) of said charging member, a width N (mm) of the nip measured in a moving direction of said charging member, and a coverage ratio Rc of said electroconductive particles on said charging member, satisfy: N·Rc·|Vc−Vd|/Vd≧1.Type: GrantFiled: May 9, 2002Date of Patent: September 7, 2004Assignee: Canon Kabushiki KaishaInventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi
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Publication number: 20040136752Abstract: A brush charger for static-charging a photosensitive drum by a contact method has a charging brush roller. The charging brush roller has a brush of a large number of conductive fibers, and the brush is wound around a conductive support spirally. The conductive fibers are 1.5 to 4 deniers in thickness D, are 2 mm in length L and are planted at a density not less than 150,000 filaments/inch2, and the thickness D and the length L of the conductive fibers meet the condition, D≧0.71L−1.61.Type: ApplicationFiled: June 18, 2003Publication date: July 15, 2004Applicant: Minolta Company, Ltd.Inventors: Chiaki Yamada, Keiko Momotani
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Patent number: 6754461Abstract: A developer charging device for charging developer with electricity includes a developer charging member a reciprocating unit, and an attitude maintaining unit. The developer charging member is arranged at a position downstream relative to a transfer device transferring a developer image from an image carrier to an image receiving member and upstream relative to a charging device for electrically charging the image carrier as viewed in the moving direction of the image carrier. The developer charging member is held in contact with the image carrier so as to electrically charge residual developer on the image carrier. The reciprocating unit reciprocates the developer charging member in a direction of a generating line of the image carrier. The attitude maintaining unit maintains an attitude of the developer charging member relative to the image carrier regardless of a reciprocation of the developer charging member by the reciprocating unit.Type: GrantFiled: September 6, 2002Date of Patent: June 22, 2004Assignee: Canon Kabushiki kaishaInventors: Nobuharu Hoshi, Kenji Matsuda, Akiyoshi Fujita
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Patent number: 6751427Abstract: A charger of the present invention includes a charging member contacting or adjoining an image carrier for charging the image carrier. A conductive facing member faces a portion of the charging member other than a portion of the same that faces the image carrier. Discharge occurs between the charging member and the facing member to thereby remove impurities deposited on the charging member. An image forming apparatus including the charger is also disclosed.Type: GrantFiled: May 6, 2002Date of Patent: June 15, 2004Assignee: Ricoh Company, Ltd.Inventor: Kenji Sugiura
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Patent number: 6701118Abstract: An image forming apparatus includes an image carrying member, an intermediate transfer member, a charging member, a transfer mechanism, a discharging member, a direct current voltage source, and a direct current voltage controller. The intermediate transfer member is deposited at a position facing and in contact with the image carrying member rotatably carrying a toner image on a rotating surface, and receives the toner image therefrom during a first transfer operation. The charging member applies a charge to the intermediate transfer member to cause an electric field around a region where the image carrying member and the intermediate transfer member contact with each other, where the electric field generates a force for initiating the first transfer operation. The transfer mechanism performs a second transfer operation for transferring the toner image from the intermediate transfer member to a transfer sheet.Type: GrantFiled: October 25, 2002Date of Patent: March 2, 2004Assignee: Ricoh Company, Ltd.Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
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Patent number: 6697591Abstract: An electrophotographic apparatus, includes: an electrophotographic photosensitive member and a charging device. The charging device includes a conductor particle-carrying member having an electroconductive and elastic surface, and conductor particles having a particle size of 10 nm-10 &mgr;m and carried on the carrying member so as to be disposed in contact with the photosensitive member, thereby directly injecting charges to the photosensitive member to charge the photosensitive member. The photosensitive member includes a photosensitive layer and a charge injection layer as a surface layer disposed in this order on a support, the charge-injection layer having a thickness d (&mgr;m) and an elastic deformation percentage We (OCL) (%) satisfying a relationship of formula (1) below with an elastic deformation percentage We (CTL) (%) of the photosensitive layer: −0.71×d+We(CTL)≦We(OCL)≦0.03×d3−0.89×d2+8.43×d+We(CTL) (1).Type: GrantFiled: June 18, 2002Date of Patent: February 24, 2004Assignee: Canon Kabushiki KaishaInventors: Yosuke Morikawa, Kouichi Nakata, Kimihiro Yoshimura, Daisuke Tanaka
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Publication number: 20040022558Abstract: A charging system is provided with a rotatable member to be charged, and a rotatable charging member provided with electroconductive particles thereon and forming a nip part with the member to be charged and disposed in the nip part to charge the member to be charged, wherein when the diameter of the member to be charged is defined as LD (mm) and the diameter of the charging member is defined as LC (mm), LD≦25 and LD×LC≧350 are satisfied. Thereby, in the charging system, a process cartridge and an image forming apparatus, an image bearing member can be made small in diameter.Type: ApplicationFiled: April 18, 2003Publication date: February 5, 2004Applicant: CANON KABUSHIKI KAISHAInventors: Keiji Okano, Masahiro Yoshida
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Publication number: 20030228172Abstract: The charging apparatus includes plural charging devices including a first charging device and a second charging device, in which an absolute value of a current flowing from the second charging device to a member to be charged is 25% or less of an absolute value of a sum of currents respectively flowing from the plural charging devices to the member to be charged, thereby achieving uniform charging of the member to be charged.Type: ApplicationFiled: May 6, 2003Publication date: December 11, 2003Applicant: CANON KABUSHIKI KAISHAInventors: Ryo Nakamura, Hiroyuki Suzuki, Ryo Inoue
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Patent number: 6654579Abstract: An image forming apparatus including an image carrier including a conductive support, at least a photoconductive layer formed on the conductive support, and a surface protection layer formed on the photoconductive layer and including a charge injection layer. Also included is a charge member for charging the image carrier in contact with the surface protection layer when applied with a voltage. Further, the surface protection layer has a diamond-like structure or an amorphous structure containing hydrogen with a volume resistance of 109 &OHgr;·cm to 1012 &OHgr;·cm and a Knoop hardness of 400 Kg/mm2 or greater, and the charging member includes magnetic particles for charging having a mean particle size ranging from 20 &mgr;m to 150 &mgr;m. Also, a light transmission of the surface protective layer is 50% or more of a wavelength of light used for exposing the image carrier.Type: GrantFiled: October 25, 2002Date of Patent: November 25, 2003Assignee: Ricoh Company, Ltd.Inventors: Masahiko Shakuto, Kei Yasutomi, Hirokatsu Suzuki, Nobutaka Takeuchi, Toshihiko Baba
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Patent number: 6640072Abstract: An image forming apparatus includes an image bearing member, a charging member, disposed so as to be contactable with the image bearing member, for charging the image bearing member with a peripheral velocity difference between the charging member and the image bearing member, and a controller for variably controlling the peripheral velocity difference at the time when an area which becomes an image forming area of the image bearing member is charged by the charge member.Type: GrantFiled: December 6, 2001Date of Patent: October 28, 2003Assignee: Canon Kabushiki KaishaInventor: Ryo Inoue
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Publication number: 20030198484Abstract: A charging member for charging a member to be charged and an image forming apparatus provided with the same have electrically conductive particles and an electrically conductive particle bearing member having elasticity and bearing the electrically conductive particles thereon, and the degree of cohesion of the electrically conductive particles is 0.1 to 85%. Thereby, the non-uniformity of a halftone image peculiar to particle charging can be improved.Type: ApplicationFiled: April 15, 2003Publication date: October 23, 2003Applicant: Canon Kabushiki KaishaInventors: Yasunori Chigono, Koichi Okuda, Yasushi Shimizu, Masahiro Yoshida
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Publication number: 20030198485Abstract: An image forming apparatus according to the present invention includes an image bearing member, and a charging member for forming a nip with the image bearing member thereby charging the image bearing member, wherein conductive particles are provided in the nip, wherein a time factor a represented by a following equation satisfies a condition &agr;>15:Type: ApplicationFiled: April 18, 2003Publication date: October 23, 2003Applicant: Canon Kabushiki KaishaInventors: Masaki Ojima, Noboru Kashimura, Keiji Okano, Junichi Kato
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Publication number: 20030185593Abstract: To provide a charging apparatus including: a first charging unit for charging a body to be charged, the first charging unit including a magnetic brush that contacts the body to be charged; and a second charging unit that is provided on a downstream side of the first charging unit with respect to a moving direction of the body to be charged, the second charging unit including a magnetic brush that contacts the body to be charged, in which a contact width, with which the magnetic brush of the first charging unit contacts the body to be charged, is wider than a contact width with which the magnetic brush of the second charging unit contacts the body to be charged.Type: ApplicationFiled: February 24, 2003Publication date: October 2, 2003Applicant: CANON KABUSHIKI KAISHAInventors: Hiroyuki Suzuki, Ryo Inoue, Ryo Nakamura
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Publication number: 20030180073Abstract: A charging apparatus includes a charging member for charging a member to be charged while forming a nip with the member to be charged, and electroconductive particles disposed in the nip. The charging member is supplied with a voltage of a polarity, a surface of the member to be charged is triboelectrically charged by a surface of the charging member so as to have a polarity opposite from that of the voltage, and the electroconductive particles are triboelectrically charged in the nip so as to have a polarity opposite from that of the voltage.Type: ApplicationFiled: February 4, 2003Publication date: September 25, 2003Applicant: CANON KABUSHIKI KAISHAInventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi, Norio Takahashi
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Patent number: 6615010Abstract: An electrifier for electrifying a member to be charged includes a charge rotary member that forms a first nip with the member to be charged, to charge the member to be charged, and that holds and carries charge particles to the first nip, and a nip forming member that forms a second nip with the charge rotary member, the nip forming member having a bias charge having the same polarity as the developer.Type: GrantFiled: September 28, 2001Date of Patent: September 2, 2003Assignee: Canon Kabushiki KaishaInventors: Jun Hirabayashi, Harumi Ishiyama, Yasunori Chigono
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Publication number: 20030113134Abstract: An image forming apparatus includes an image bearing member; a rotatable charging member, forming a nip with the image bearing member, for electrically charging the image bearing member; developing means for developing an electrostatic image formed on the image bearing member to form a toner image, the developing means supplying electroconductive particles to the image bearing member, wherein the electroconductive particles are fed to the nip by the image bearing member; transferring means for transferring the toner image onto a recording material at a transfer position; wherein the developing means is capable of feeding the electroconductive particles of a region of the image bearing member which corresponds to a region between a first recording material and a second recording material immediately subsequent to the first recording material, and a time period from passage of a trailing end of the first recording material through the transfer position to arrival of a leading end of the second recording materiaType: ApplicationFiled: August 6, 2002Publication date: June 19, 2003Applicant: CANON KABUSHIKI KAISHAInventors: Hiroyuki Oba, Junichi Kato, Yasushi Shimizu, Hiroshi Satoh, Masahiro Yoshida