Of Residual Toner Patents (Class 399/129)
  • Patent number: 7796907
    Abstract: Disclosed are an electrophotographic apparatus for forming images on sheets, and corresponding methods. The electrophotographic apparatus includes a fuser web for fusing toner particles to the sheets to form the images, a sensor for detecting a defect position of at least one defect in the fuser web, and a controller that receives the defect position of the at least one defect on the fuser web from the sensor, wherein the controller positions the fuser web relative to the sheets to avoid the at least one defect from coming into contact with the toner on the sheets during fusing of the toner particles to the sheets.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: September 14, 2010
    Assignee: Xerox Corporation
    Inventor: Anthony Salvatore Condello
  • Patent number: 7796919
    Abstract: For an electrostatic latent image formed on an image carrier (31b), besides an operation forming an “image forming electrostatic latent image” used to form the primary image, an operation is executed that forms an “electrostatic latent image for removing developer” for removing developer that resides on a developer supply member (53a) for a predetermined time period onto the image carrier (31b). Thus, developer is nearly eliminated from residing on this developer supply member (53a) in an overcharged state for a long period of time, and generation of a fogged image is avoided as much as possible.
    Type: Grant
    Filed: May 17, 2004
    Date of Patent: September 14, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Susumu Murakami, Yoshiaki Kojoh, Takahisa Narikiyo, Kuniaki Nakano, Yoshie Iwakura
  • Patent number: 7792462
    Abstract: An image formation apparatus which includes a rotating image-bearing body, a charging section, an exposure section, a developing section, a transfer section, and a residue toner-charging section. The charging section charges the image-bearing body. The exposure section forms an electrostatic latent image on the image-bearing body that has been charged. The developing section develops the electrostatic latent image and forms a toner image. The transfer section transfers the toner image to a transfer body. The residue toner-charging section is provided upstream of the charging section and downstream of the transfer section and, after the transfer, charges transfer residue toner to a normal polarity. The transfer residue toner that has been charged to the normal polarity by the residue toner-charging section is recycled at the developing section. The residue toner-charging section is provided with a nonwoven fabric, which features conductivity and touches against the image-bearing body.
    Type: Grant
    Filed: December 8, 2008
    Date of Patent: September 7, 2010
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Jin Iwasaki, Koya Tanaka
  • Patent number: 7778573
    Abstract: An image forming apparatus includes an image carrier, a toner image forming unit configured to form a toner image having a predetermined polarity on the image carrier, an intermediate transfer body facing the image carrier, a primary transfer member configured to transfer the toner image on the image carrier onto the intermediate transfer body, a secondary transfer member configured to transfer the toner image on the intermediate transfer body onto a recording medium, and a contacting member in contact with the image carrier and configured to remove residual toner remaining on the image carrier after the toner image is transferred by the primary transfer member onto the intermediate transfer body and to pass the removed residual toner to the intermediate transfer body. A bias voltage with the same polarity as the predetermined polarity of the toner image is applied to the contacting member.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: August 17, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Yamashita, Takafumi Miyazaki, Tomoya Adachi, Yoshie Tsuchida
  • Patent number: 7761034
    Abstract: An image forming apparatus capable of reducing white streaks in gray images and an image forming method using the same are provided. The image forming apparatus including a charging means, a developing means, a transferring means, and a discharging means which are arranged in sequence around a monolayer type electrophotographic photoconductor. The charging means is a means for positively charging the surface of the monolayer type electrophotographic photoconductor, and the pre-charging means has a conductive brush composed of a conductive substrate and conductive brush filaments and is arranged between the charging means and the discharging means. The conductive filaments on the surface of the photoconductor have a bending ratio that is calculated so that the conductive brush filament tips are properly curved near the surface of the photoconductor so as to reduce abnormal discharge between the conductive brush and the surface of the photoconductor.
    Type: Grant
    Filed: November 20, 2006
    Date of Patent: July 20, 2010
    Assignee: Kyocera Mita Corporation
    Inventors: Makoto Shishido, Shiho Okawa
  • Patent number: 7756446
    Abstract: A pulse-like DC voltage is applied from two power sources to transfer residual toner uniformizing means and toner charge amount control means, respectively, to expel transfer residual toner deposited on these means from these means onto a photosensitive drum. In a low humidity environment, the number of application of the DC voltage is increased so as to sufficiently expel the transfer residual toner because the transfer residual toner is less liable to be expelled even when the pulse-like DC voltage is applied to the above two means in the low humidity environment in which an absolute moisture content in atmosphere is small and electrical resistances at portions of a photosensitive drum contacting the above two means.
    Type: Grant
    Filed: April 8, 2008
    Date of Patent: July 13, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Tadanobu Yoshikawa
  • Patent number: 7684732
    Abstract: An image forming apparatus includes at least a latent image carrier, a latent image forming mechanism, a developing mechanism and a charger. The latent image carrier bears a latent image. The latent image forming mechanism forms the latent image on the latent image carrier. The developing mechanism develops the latent image on the latent image carrier with toner. The charger includes a conductive member supplied with a bias voltage while contacting a surface of the latent image carrier, and charges at least one of the surface of the latent image carrier and a toner adhering to the surface thereof through the conductive member. A tensile strength of the conductive member at break is no less than 10 MPa and no more than 40 MPa, and a contact pressure between the conductive member and the latent image carrier is no less than 4 kN/m2 and no more than 15 kN/m2.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: March 23, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Tetsumaru Fujita, Yoshio Sakagawa, Yuji Nagatomo
  • Patent number: 7664430
    Abstract: An image forming apparatus includes an image carrier that rotates in a predetermined direction so as to carry a toner image, a charging member that charges the image carrier by a discharge operation, a toner holding member that is disposed to be in contact with the image carrier so as to hold toner in a portion being in contact with the image carrier and that removes a discharge product generated on the image carrier, and a holding amount adjusting unit that adjusts a toner holding amount of the toner holding member. The holding amount adjusting unit includes an estimation unit that estimates a current toner holding amount of the toner holding member, and a correction unit that corrects the toner holding amount of the toner holding member on a basis of an estimation result obtained from the estimation unit.
    Type: Grant
    Filed: April 13, 2006
    Date of Patent: February 16, 2010
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Takayuki Yamashita, Yutaka Kiuchi
  • Patent number: 7657197
    Abstract: An image forming apparatus performs a control sequence in which an AC voltage having a peak-to-peak voltage is applied to a charging member so that a relationship between an absolute value of a surface potential of an image bearing member at a portion under a transfer residual toner remaining on the image bearing member which has been electrically charged by the charging member during non-image formation and an absolute value of a surface potential of a developer carrying member is reversed with respect to a relationship between these absolute values during image formation.
    Type: Grant
    Filed: November 29, 2007
    Date of Patent: February 2, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Tadanobu Yoshikawa
  • Publication number: 20100008699
    Abstract: An image forming apparatus includes: an image carrier; an exposure device; a developing device that develops the latent image on the image carrier by using a toner charged to a predetermined polarity and having an external additive; a transfer device that transfers a toner image developed on the image carrier to a transfer medium; a first charging member that charges the external additive and the transfer residual toner remaining on the image carrier and the image carrier after transfer to the same polarity as a polarity of the toner; a cleaning member that electrostatically attracts the external additive and the transfer residual toner charged by the first charging member; and a second charging member that charges the image carrier to an electric potential smaller in absolute value than an electric potential of the image carrier generated after the image carrier passes the cleaning member.
    Type: Application
    Filed: July 6, 2009
    Publication date: January 14, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Masaru KOBASHI, Yoichi YAMADA, Koji MIGITA, Takatomo FUKUMOTO
  • Patent number: 7627269
    Abstract: An image forming apparatus includes an image bearing member; a charging member for contacting a peripheral surface of the image bearing member to electrically charge the peripheral surface; a first developing device for forming a first developed image on the peripheral surface of the image bearing member charged by the charging member; a second developing device for forming a second developed image on the peripheral surface, wherein a combined developed image is formed by superimposing the first developed image and the second developed image on a common transfer material, wherein when the combined image is being formed, the charging member is cleaned by transferring, by an electric field, material deposited on the charging member to a region between the first developed image and the second developed image on the peripheral surface of the image bearing member, and wherein the first developed image and the second developed image are not formed in the region.
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: December 1, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Minoru Matsuguma, Kenji Matsuda, Masaki Ojima, Katsuhiro Kojima, Hideki Matsumoto
  • Patent number: 7593669
    Abstract: An image forming apparatus includes an exposure device for exposing an electrically charged surface of an image bearing member to light to form an electrostatic image; a developing device capable of collecting a transfer residual developer remaining on the image bearing member; a transferring device for transferring a developer image from the image bearing member onto a transfer medium at a transfer position; and a controller for executing, during non-image formation, a developer collecting mode in which a developer of an opposite polarity is collected into the developing device by driving the image bearing member and by causing the developer carrying member to stop its rotation or rotate at a speed slower than a rotational speed thereof during image formation while generating a potential difference capable of transferring the developer of the opposite polarity from the image bearing member onto the developer carrying member.
    Type: Grant
    Filed: September 13, 2007
    Date of Patent: September 22, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventor: Koji Shigehiro
  • Patent number: 7469116
    Abstract: An image forming apparatus includes a rotatable image bearing member; a charging member for electrically charging the image bearing member; developing device means for developing an electrostatic latent image formed on said image bearing member into a toner image and for collecting toner from the image bearing member; transfer device means for transferring the toner image onto a transfer material; a brush member rotatable in a direction identical or opposite to a rotational direction of the image bearing member and disposed downstream from the transfer device means and upstream from the charging member in the rotational direction of the image bearing member, the brush member contacting transfer residual toner while being supplied with a DC voltage of an opposite polarity to a normal charge polarity of the toner; and a moving member for moving the toner in a rotational axis direction of the brush member while contacting the brush member.
    Type: Grant
    Filed: November 27, 2006
    Date of Patent: December 23, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kenichiro Kitajima
  • Patent number: 7324776
    Abstract: A color printer including, a conductive brush roller to contact a photosensitive drum at a position downstream of a transferring apparatus and upstream of a charging apparatus, wherein at least part of residual toner is collected after temporarily transferring on the photosensitive drum, and the collected toner is expelled onto the photosensitive drum, a charge electrode facing the brush roller at a position other than the contact position of the photosensitive drum and the brush roller, and a power source to apply voltage to the charge electrode, wherein the polarity of the voltage applied from the power source to the charge electrode with respect to the average voltage of the surface of the photosensitive drum after transferring is the same as a charging polarity of the toner at developing.
    Type: Grant
    Filed: January 5, 2005
    Date of Patent: January 29, 2008
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Akira Hirota, Hiroaki Umemoto, Noritoshi Hagimoto, Kuniya Matsuura, Naotoshi Kawai, Kentaro Katori
  • Patent number: 7319835
    Abstract: An image forming device, including a charging unit to electrically charge a surface of an organic photoconductive medium; a light exposure unit to form an electrostatic latent image on the surface of the organic photoconductive medium; a developing unit to develop the electrostatic latent image formed with a developer; a transfer roller to transfer an image developed by the developing unit to a recording paper; a light array having a plurality of light sources arranged in a predetermined pattern; a first light path providing unit to form a light path to receive a first light portion emitted from the light sources and to allow the light to be projected on the organic photoconductive medium between the developing unit and the transfer roller; and a second light path providing unit to form a light path to receive a second portion of the light emitted from the light sources and to allow the light to be projected onto the organic photoconductive medium passing through the transfer roller, thereby removing an elect
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: January 15, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Dong-cheol Ahn
  • Patent number: 7313337
    Abstract: Disclosed is a method and apparatus for sensing residual toner mass after transfer of a xerographic image, to facilitate the identification and characterization of different types of transfer defects. The technique employed utilizes a nominal residual mass signature, measured at the start of a job, in conjunction with subsequent residual mass signature, where the calculated difference between the nominal and subsequent signatures is used to indicate transfer defects and changes in transfer efficiency.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: December 25, 2007
    Assignee: Xerox Corporation
    Inventors: Aaron M. Burry, Gerald M. Fletcher, Eric S. Hamby, Peter Paul
  • Patent number: 7286788
    Abstract: An image forming apparatus includes a photosensitive drum, a charge roller for charging the photosensitive drum, a developing device for developing an electrostatic latent image formed on the charged photosensitive drum with a developer, a first auxiliary charging brush which is located upstream from the charge roller in a movement direction of a surface of the photosensitive drum and applies a voltage of a polarity opposite to a normal polarity of a polarity opposite to a normal polarity of the developer, and a second auxiliary charging brush which is located downstream from the first auxiliary charging brush and upstream from the charge roller and applies a voltage of a polarity identical to the normal polarity of the developer. In the image forming apparatus, the first auxiliary charging brush is supplied with an AC voltage to be improved in recovery performance of a transfer residual developer, and contamination of charging means can be prevented.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: October 23, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masahide Kinoshita, Masaki Ojima, Motoki Adachi, Masao Uyama, Kazuhiro Okubo
  • Patent number: 7236711
    Abstract: A defect analysis system for a xerographic print engine includes a residual mass sensor that senses the two-dimensional signature structure of residual mass remaining on a photoconductive or other substrate surface after image transfer. Preferably, the sensor is a full width array that spans substantially an entire width of the photoconductive surface. This information is then processed and analyzed to determine a specific type of transfer defect present. This may include the quantified level of defect for each detected type. The defect analysis system may also include a closed-loop control system that can adjust various xerographic process parameters using feedback based on the identification and optionally magnitude of each specific defect type. The identified print quality defect, such as mottle, streaks, point deletions, graininess, etc.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: June 26, 2007
    Assignee: Xerox Corporation
    Inventors: Aaron M. Burry, Christopher A. Dirubio, Gerald M. Fletcher, Eric S. Hamby, Martin Krucinski, Robert J. Mead, Bruce J. Parks, Peter Paul, Palghat S. Ramesh, Eliud Robles Flores, Fei Xiao
  • Patent number: 7218879
    Abstract: An image forming apparatus includes an image carrier, a charging device configured to uniformly charge a surface of the image carrier with a charging member applied with a bias of a first polarity (e.g. a negative polarity) for charging. A latent image forming device forms a latent image on the surface of the image carrier uniformly charged. A developing device develops a latent image by depositing toner grains of the first polarity on the latent image to thereby form a corresponding toner image. A transferring device forms an electric field between the image carrier and a moving member that serves as a movable contact with the image carrier to thereby transfer the toner image from the surface of the image carrier to the moving member or to a recording member nipped between the image carrier and the moving member. A polarity controlling device sets residual toner to a second polarity (e.g.
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: May 15, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigekazu Enoki, Koji Suzuki, Yasushi Koichi, Osamu Ariizumi, Kumiko Hatakeyama, Koichi Kato, Masahide Yamashita, Toshiyuki Kabata, Jun Yura
  • Patent number: 7146123
    Abstract: An image forming apparatus includes an image bearing member, charging device which is in contact with the image bearing member and charges the image bearing member, development device which forms a toner image on the image bearing member and recovers a residual toner remaining after the transfer from the image bearing member, transfer device which transfers the toner image on the image bearing member onto a transfer material, auxiliary charging device which is positioned at a downstream side of the transfer device and at an upstream side of the charging device in a rotating direction of the image bearing member, which is in contact with the image bearing member and which is given a voltage of a polarity opposite to that of the developing toner, and voltage selecting device which selects the voltage applied to the auxiliary charging device based on the potential of the image bearing member after the transfer.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: December 5, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hiroyuki Kidaka
  • Patent number: 7130564
    Abstract: An image forming apparatus includes an image bearing member configured to form an electrostatic latent image on a surface thereof, and a separating mechanism configured to separate an irregular charge toner from a residual toner remaining on the surface of the image bearing member after a completion of an image forming process, to provide an extra travel passage to give a time delay to the irregular charge toner, and to return the irregular charge toner with the time delay to the surface of the image bearing member.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: October 31, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Eisaku Murakami, Toshio Koike, Masato Yanagida, Naohiro Kumagai, Takeshi Shintani, Masanori Kawasumi, Atsushi Sampe, Masami Tomita, Hiroyuki Nagashima, Takeshi Uchitani
  • Patent number: 7110699
    Abstract: An image forming apparatus of the present invention includes a sheet affixed at one edge portion and including a flat surface in the other edge portion. The flat surface is formed with a plurality of grooves each extending over the image forming range of a photoconductive drum perpendicularly to the direction in which the surface of the drum moves. The sheet is deformed such that the flat portion contacts the surface of the drum. In this condition, the downstream edges of the grooves in the above direction shave off the surface of the drum a plurality of times during one rotation of the drum, thereby obviating filming on the drum.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: September 19, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideo Yoshizawa, Eisaku Murakami, Hiroyuki Nagashima, Yoshiyuki Kimura, Hideki Zemba, Eiji Kurimoto
  • Patent number: 7058338
    Abstract: An image forming apparatus includes a photosensitive drum, a charging roller, a transfer roller, and a toner charging brush, wherein the toner charging brush reciprocates 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 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: Grant
    Filed: June 10, 2005
    Date of Patent: June 6, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Ojima, Masahide Kinoshita, Motoki Adachi, Masao Uyama, Kazuhiro Okubo
  • Patent number: 7031641
    Abstract: An image-forming apparatus includes a pre-charge exposure device which removes electric charge from a photoconductor drum to increase a potential contrast between the surface of the photoconductor drum and the surface of a charge roller in an upstream region of a nip region between the photoconductor drum and the charge roller in the rotating direction of the photoconductor drum, so that toner accumulating in an upstream region of the nip region in the rotating direction of the photoconductor drum is restrained and prevented from being discharged onto an image-forming region. When the toner accumulating in the upstream region of the nip region in the rotating direction of the photoconductor drum is to be discharged onto a non-image-forming region, the pre-charge exposure device is turned off so that the potential contrast decreases.
    Type: Grant
    Filed: April 28, 2004
    Date of Patent: April 18, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hisashi Nakahara, Yasunori Chigono, Yasuhiro Nakata
  • Patent number: 6996355
    Abstract: An image formation apparatus has developing agent charging device 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 device has started reaches a position of coming into contact with the charging roller, and applying AC voltage to the charging device is ended after the portion on the face of the photosensitive drum where application of voltage to the developing agent charging device 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: Grant
    Filed: October 16, 2003
    Date of Patent: February 7, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasunari Watanabe
  • Patent number: 6996356
    Abstract: An image forming apparatus includes an image bearing member capable of being rotated, a first charging unit, an electrostatic image forming unit, a developing unit, and a second charging unit. The first charging unit is capable of being rotated in the same direction as a rotational direction of the image bearing member with being in contact with the image bearing member, and is capable of charging the image bearing member and toner on the image bearing member. The electrostatic image forming unit is capable of forming an electrostatic image on the image bearing member charged by the first charging unit. The developing unit is capable of collecting the toner on the image bearing member and visualizing the electrostatic image.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: February 7, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventor: Tetsuya Atsumi
  • Patent number: 6987939
    Abstract: An image forming apparatus includes an image bearing member; a charging device for electrically charging the image bearing member at a contact position; a transferring device for transferring a developed image on the image bearing member onto a transfer material; and a developer charging device for electrically charging a developer remaining on the image bearing member after the image is transferred. The developer charging device is disposed downstream of the transferring device and upstream of the charging device with respect to a moving direction of the image bearing member. An electric field forming device forms a cleaning electric field in a direction of transferring the developer from the developer charging device onto a predetermined region of the image bearing member and forms a cleaning electric field for transferring the developer from the charging device onto the image bearing member after the predetermined region passes through the contact portion.
    Type: Grant
    Filed: October 2, 2003
    Date of Patent: January 17, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tatsunori Ishiyama, Yasuo Yoda, Kenichi Iida
  • Patent number: 6975823
    Abstract: An image forming apparatus includes an image carrier rotatable in a predetermined rotative direction, a charging unit for charging a surface of the image carrier, a precharging device disposed upstream from the charging unit with respect to the predetermined rotative direction of the image carrier for precharging the surface of the image carrier; and a voltage supply unit for supplying a voltage to the precharging device.
    Type: Grant
    Filed: August 26, 2003
    Date of Patent: December 13, 2005
    Assignee: Oki Data Corporation
    Inventors: Akihito Onishi, Takao Mizutani, Masayuki Suzuki
  • Patent number: 6963707
    Abstract: An image forming apparatus includes a photosensitive drum, a charge roller for charging the photosensitive drum, a developing device for developing an electrostatic latent image formed on the charged photosensitive drum with a developer, a first auxiliary charging brush which is located upstream from the charge roller in a movement direction of a surface of the photosensitive drum and applies a voltage of a polarity opposite to a normal polarity of a polarity opposite to a normal polarity of the developer, and a second auxiliary charging brush which is located downstream from the first auxiliary charging brush and upstream from the charge roller and applies a voltage of a polarity identical to the normal polarity of the developer. In the image forming apparatus, the first auxiliary charging brush is supplied with an AC voltage to be improved in recovery performance of a transfer residual developer, and contamination of charging means can be prevented.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: November 8, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masahide Kinoshita, Masaki Ojima, Motoki Adachi, Masao Uyama, Kazuhiro Okubo
  • Patent number: 6954600
    Abstract: 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: Grant
    Filed: September 29, 2003
    Date of Patent: October 11, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akiyoshi Fujita, Atsushi Numagami, Takahito Ueno
  • Patent number: 6952546
    Abstract: A image forming apparatus includes an image bearing member to be moved rotationally, charging means for electrically charging the image bearing member and toner remaining on the image bearing member, electrostatic latent image forming means for forming an electrostatic latent image on the image bearing member charged by the charging means, developing means for visualizing the electrostatic latent image while recovering the toner remaining on the image bearing member, toner charging means which is disposed upstream from the charging means in a rotational direction of the image bearing member and is to be supplied with a voltage of a polarity identical to that of a voltage to be applied to the charging means to electrically charge the toner remaining on the image bearing member, recording means for recording an operation history of the image forming apparatus, and control means for controlling the voltage to be supplied to the toner charging means on the basis of the operation history of the image forming appar
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: October 4, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventor: Tadanobu Yoshikawa
  • Patent number: 6950620
    Abstract: 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 im
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: September 27, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tadanobu Yoshikawa, Motoki Adachi
  • Patent number: 6944416
    Abstract: A cleaner-less image forming apparatus serves to prevent excessive expellation of toner from a photosensitive drum at the time of application of a bias voltage. A developer charging member for charging residual toner on the photosensitive drum is disposed in contact with the photosensitive drum at a location downstream of a transfer device and upstream of a charging device in a direction in which the photosensitive drum is rotating. A DC voltage of a polarity opposite to a normal charging polarity of the developer is applied to the developer charging member and has a slope whose absolute value at the start of voltage application is selectable from a first value and a second value which is greater than the first value.
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: September 13, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasunari Watanabe
  • Patent number: 6928253
    Abstract: An image forming apparatus includes a photosensitive drum, a charging roller, a transfer roller, and a toner charging brush, wherein the toner charging brush reciprocates 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 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: Grant
    Filed: October 24, 2003
    Date of Patent: August 9, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Ojima, Masahide Kinoshita, Motoki Adachi, Masao Uyama, Kazuhiro Okubo
  • Patent number: 6922539
    Abstract: A process cartridge includes an image bearing member, a developing device developing an electrostatic image on the member using developer to form a developer image on the member and a developer charger charging residual developer on the member disposed downstream of a transferring position at which the developer image is transferred onto a transfer destination member and upstream of a position at which the electrostatic image is formed on the member with respect to the moving direction of the member. The developer charger is in contact with the member and is movable in the longitudinal direction of the member upon charging the residual developer. L1+d?L2 when L1 is the developing width of the developing device, L2 is the contact width of the developer charger with the member, and d is the width of movement of the developer charger in the longitudinal direction of the member.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: July 26, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masao Uyama, Masahide Kinoshita, Masaki Ojima, Motoki Adachi, Kazuhiro Okubo
  • Patent number: 6856777
    Abstract: The present invention provides an image forming apparatus comprising an image bearing member for bearing a toner image, a movable intermediate transferring member, a first charging member for charging toner on the intermediate transferring member when it is applied with a voltage including an AC component, and a second charging member for charging toner on the intermediate transferring member when it is applied with a DC voltage, the second charging member being located on an upstream side of the first charging member with respect to a moving direction of the intermediate transferring member, wherein a toner image on the image bearing member is temporarily transferred to the intermediate transferring member and then transferred to a transfer material.
    Type: Grant
    Filed: September 16, 2002
    Date of Patent: February 15, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Naoki Enomoto, Takashi Shibuya, Masaru Shimura, Seiji Saito
  • Patent number: 6832058
    Abstract: 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: Grant
    Filed: December 11, 2002
    Date of Patent: December 14, 2004
    Assignee: Konica Corporation
    Inventors: Hiroshi Akita, Kunio Shigeta, Takenobu Kimura, Yotaro Sato
  • Publication number: 20040223784
    Abstract: An image-forming apparatus includes a pre-charge exposure device which removes electric charge from a photoconductor drum to increase a potential contrast between the surface of the photoconductor drum and the surface of a charge roller in an upstream region of a nip region between the photoconductor drum and the charge roller in the rotating direction of the photoconductor drum, so that toner accumulating in an upstream region of the nip region in the rotating direction of the photoconductor drum is restrained and prevented from being discharged onto an image-forming region. When the toner accumulating in the upstream region of the nip region in the rotating direction of the photoconductor drum is to be discharged onto a non-image-forming region, the pre-charge exposure device is turned off so that the potential contrast decreases.
    Type: Application
    Filed: April 28, 2004
    Publication date: November 11, 2004
    Applicant: Canon Kabushiki Kaisha
    Inventors: Hisashi Nakahara, Yasunori Chigono, Yasuhiro Nakata
  • Patent number: 6816690
    Abstract: 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: Grant
    Filed: January 31, 2003
    Date of Patent: November 9, 2004
    Assignee: Oki Data Corporation
    Inventor: Akihiro Yamamura
  • Patent number: 6778794
    Abstract: 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: Grant
    Filed: May 28, 2002
    Date of Patent: August 17, 2004
    Assignee: Ricoh Company, Ltd.
    Inventor: Shin Kayahara
  • Publication number: 20040141769
    Abstract: An image forming apparatus includes an image bearing member capable of being rotated, a first charging unit, an electrostatic image forming unit, a developing unit, and a second charging unit. The first charging unit is capable of being rotated in the same direction as a rotational direction of the image bearing member with being in contact with the image bearing member, and is capable of charging the image bearing member and toner on the image bearing member. The electrostatic image forming unit is capable of forming an electrostatic image on the image bearing member charged by the first charging unit. The developing unit is capable of collecting the toner on the image bearing member and visualizing the electrostatic image.
    Type: Application
    Filed: January 9, 2004
    Publication date: July 22, 2004
    Applicant: Canon Kabushiki Kaisha
    Inventor: Tetsuya Atsumi
  • Publication number: 20040136749
    Abstract: An image forming apparatus includes a photosensitive drum, a charge roller for charging the photosensitive drum, a developing device for developing an electrostatic latent image formed on the charged photosensitive drum with a developer, a first auxiliary charging brush which is located upstream from the charge roller in a movement direction of a surface of the photosensitive drum and applies a voltage of a polarity opposite to a normal polarity of a polarity opposite to a normal polarity of the developer, and a second auxiliary charging brush which is located downstream from the first auxiliary charging brush and upstream from the charge roller and applies a voltage of a polarity identical to the normal polarity of the developer. In the image forming apparatus, the first auxiliary charging brush is supplied with an AC voltage to be improved in recovery performance of a transfer residual developer, and contamination of charging means can be prevented.
    Type: Application
    Filed: September 22, 2003
    Publication date: July 15, 2004
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Masahide Kinoshita, Masaki Ojima, Motoki Adachi, Masao Uyama, Kazuhiro Okubo
  • Publication number: 20040131385
    Abstract: A image forming apparatus includes an image bearing member to be moved rotationally, charging means for electrically charging the image bearing member and toner remaining on the image bearing member, electrostatic latent image forming means for forming an electrostatic latent image on the image bearing member charged by the charging means, developing means for visualizing the electrostatic latent image while recovering the toner remaining on the image bearing member, toner charging means which is disposed upstream from the charging means in a rotational direction of the image bearing member and is to be supplied with a voltage of a polarity identical to that of a voltage to be applied to the charging means to electrically charge the toner remaining on the image bearing member, recording means for recording an operation history of the image forming apparatus, and control means for controlling the voltage to be supplied to the toner charging means on the basis of the operation history of the image forming appar
    Type: Application
    Filed: September 24, 2003
    Publication date: July 8, 2004
    Applicant: Canon Kabushiki Kaisha
    Inventor: Tadanobu Yoshikawa
  • Publication number: 20040120729
    Abstract: A process cartridge adapted to be detachably attached to a body of an image forming apparatus comprises an image bearing member, developing means for developing an electrostatic image formed on the image bearing member by using developer to form a developer image on the image bearing member and developer charging means for charging residual developer on the image bearing member disposed downstream of a transferring position at which said developer image is transferred onto a transfer destination member and upstream of a position at which the electrostatic image is formed on said image bearing member with respect to the moving direction of said image bearing member. The developer charging means can be in contact with the image bearing member and is movable in a direction substantially the same as a longitudinal direction of the image bearing member upon charging the residual developer.
    Type: Application
    Filed: September 24, 2003
    Publication date: June 24, 2004
    Applicant: Canon Kabushiki Kaisha
    Inventors: Masao Uyama, Masahide Kinoshita, Masaki Ojima, Motoki Adachi, Kazuhiro Okubo
  • Patent number: 6754461
    Abstract: 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: Grant
    Filed: September 6, 2002
    Date of Patent: June 22, 2004
    Assignee: Canon Kabushiki kaisha
    Inventors: Nobuharu Hoshi, Kenji Matsuda, Akiyoshi Fujita
  • Publication number: 20040109705
    Abstract: A cleaner-less image forming apparatus serves to prevent excessive expellation of toner from a photosensitive drum at the time of application of a bias voltage. A developer charging member for charging residual toner on the photosensitive drum is disposed in contact with the photosensitive drum at a location downstream of a transfer device and upstream of a charging device in a direction in which the photosensitive drum is rotating. A DC voltage of a polarity opposite to a normal charging polarity of the developer is applied to the developer charging member and has a slope whose absolute value at the start of voltage application is selectable from a first value and a second value which is greater than the first value.
    Type: Application
    Filed: September 26, 2003
    Publication date: June 10, 2004
    Applicant: Canon Kabushiki Kaisha
    Inventor: Yasunari Watanabe
  • Patent number: 6744994
    Abstract: 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: Grant
    Filed: September 4, 2002
    Date of Patent: June 1, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tadanobu Yoshikawa, Yasunari Watanabe, Motoki Adachi
  • Publication number: 20040086297
    Abstract: 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: Application
    Filed: October 16, 2003
    Publication date: May 6, 2004
    Applicant: Canon Kabushiki Kaisha
    Inventor: Yasunari Watanabe
  • Publication number: 20040086298
    Abstract: 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: Application
    Filed: October 24, 2003
    Publication date: May 6, 2004
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Masaki Ojima, Masahide Kinoshita, Motoki Adachi, Masao Uyama, Kazuhiro Okubo
  • Publication number: 20030231899
    Abstract: 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: Application
    Filed: January 31, 2003
    Publication date: December 18, 2003
    Applicant: OKI DATA CORPORATION
    Inventor: Akihiro Yamamura