Patents by Inventor Toshiaki Kagawa

Toshiaki Kagawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8774667
    Abstract: An image forming apparatus is provided. The image forming apparatus includes an image forming section, an intermediate transfer section, a secondary transfer section, a fixing section, a power source, a voltage detection section, a temperature detection section, and a fixing section control circuit. The fixing section control circuit includes a switching control section, a voltage judgment section, a temperature judgment section, and a preparation control section. When the switching control section switches the current conduction state to the heat source and the driving section from an off conduction state to an on conduction state and the voltage judgment section judges to be less than a threshold voltage, the preparation control section controls the preparation operation of the heating section such that the switching control section continues the on conduction state over a given idle time after the temperature judgment section has judged to be a preset temperature or higher.
    Type: Grant
    Filed: March 18, 2011
    Date of Patent: July 8, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Mukai, Toshiaki Kagawa, Hiroyuki Yamaji
  • Patent number: 8532529
    Abstract: A fixing device includes a fixing portion provided with a fixing roller, a heating roller and a fixing belt; a pressing roller that presses a recording sheet to the fixing belt; a cleaning unit provided with a cleaning web that cleans up the pressing roller; and a contact/separation mechanism that separates fixing means from the pressing roller. Viscosity of silicone oil that impregnates the cleaning web is set to 3,000 cs or more, and the contact/separation mechanism separates the fixing belt from the pressing roller at the time of rotation operation before fixation.
    Type: Grant
    Filed: January 11, 2011
    Date of Patent: September 10, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroyuki Kageyama, Toshiaki Kagawa, Shinji Yamana
  • Patent number: 8526836
    Abstract: First, a first temperature difference and a second temperature difference are calculated. The first temperature difference is a difference between (a) a first detected temperature that is a current temperature of the fixing member and (b) a difference of a control target temperature for the fixing member. The second temperature difference is a difference between (a) the first detected temperature and (b) a past temperature of the fixing member which past temperature was detected a predetermined time earlier than the current time. Then, by reading out, from a table prepared in advance, an amount of power to be supplied to a heating member which amount corresponds to a combination of the first temperature difference and the second temperature difference, the amount of power to be supplied to the heating member is determined. In accordance with this amount of power determined, an actual amount of power supplied to the heating member is controlled.
    Type: Grant
    Filed: December 8, 2010
    Date of Patent: September 3, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tetsunori Mitsuoka, Toshiaki Kagawa
  • Patent number: 8452220
    Abstract: A laser fixing device, which is for use in an electrophotographic image forming apparatus, including: a carrying device for carrying a sheet; and a laser array section which is made up of a plurality of laser sources arrayed in a line, the plurality of laser sources irradiating a non-fixed toner image, which is attached to the sheet that is being carried by the carrying device, with a laser beam so that the non-fixed toner image is fused and fixed to the sheet. In the laser fixing device, an irradiation region length and a sheet carrying speed are set so that tn?0.259·mt1.5139, where mt is a maximum level of an attached-toner amount per unit area of the sheet (mg/cm2) in the image forming apparatus, and tn is an irradiation region crossing time (msec), which is found by dividing the irradiation region length by the sheet carrying speed, the irradiation region length being a length, in the direction in which the sheet is carried, of a region on the sheet which region is irradiated with the laser beam.
    Type: Grant
    Filed: August 23, 2010
    Date of Patent: May 28, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshiaki Kagawa
  • Patent number: 8391762
    Abstract: A fixing device of this invention includes: a fixing belt; a heating member for heating the fixing belt; a retaining member having (i) a convex surface which is curved and is in contact with an inner surface of the fixing belt and (ii) a flat surface which is opposite to the convex surface; and a ceramic heater provided on the flat surface of the retaining member. Therefore, the fixing device of this invention is excellent in safety and is capable of reducing a warm-up time.
    Type: Grant
    Filed: July 9, 2010
    Date of Patent: March 5, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshiaki Kagawa
  • Patent number: 8355659
    Abstract: A fixing device of the present invention includes: an external heating belt which is to contact with a surface of a fixing roller so as to heat up the fixing roller; and a cleaning member (a scraper and/or cleaning pad) which is to contact with the external heating belt. The cleaning pad which is impregnated with silicone oil is to contact with a surface of the external heating belt, thereby applying the silicone oil (release agent) to the surface of the external heating belt. This makes it possible to prevent generation of an offset.
    Type: Grant
    Filed: January 13, 2010
    Date of Patent: January 15, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshiaki Kagawa, Susumu Murakami, Masashi Hirai, Atsushi Ide, Takashi Mukai
  • Patent number: 8320811
    Abstract: An image recording medium that can be repeatedly used by removing the toner image has a three-layered structure formed of a heat-resistant resin sheet and a pair of releasing and light absorptive layers coated on both sides of the heat-resistant resin sheet. The releasing and light absorptive layer generates heat by absorbing laser so as to fuse and fix the toner image formed on the special sheet surface at the time of image forming, and assures pertinent releasing performance at the time of image removal so as to facilitate removal of the re-fused toner image. Each releasing and light absorptive layer may be split into a light absorptive layer and a releasing layer. The heat-resistant resin sheet may be produced by adding an infrared absorbent to a heat-resistant resin sheet to serve as a heat-resistant sheet and a light absorptive layer.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: November 27, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshiaki Kagawa
  • Patent number: 8295726
    Abstract: In a fixing device including (i) an external heat belt which abuts against a surface of a fixing roller so as to heat the fixing roller and (ii) a cleaning member which abuts against the external heat belt, a fixing temperature, which is a surface temperature of the fixing roller during a fixing process, is set per group into which recording media to be subjected to the fixing process are divided according to their widths in a direction of a rotary axis of the fixing roller, in such a way that the fixing temperature is set to a lower temperature for a group of narrower widths. This makes it possible to prevent a reduction in releasability of the fixing roller caused by a material, which is scraped off from the external heat belt by the cleaning member and then adhered to the fixing roller, thereby preventing the high-temperature offset.
    Type: Grant
    Filed: December 2, 2009
    Date of Patent: October 23, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshiaki Kagawa, Susumu Murakami, Masashi Hirai, Atsushi Ide, Takashi Mukai
  • Patent number: 8295753
    Abstract: A fixing device having a fixing belt which satisfies 42.2?ER?0.1044×D×??0.5174, where: D represents an inner diameter of the fixing belt; A represents a second inner diameter of the fixing belt; ER represents an elongation rate of the fixing belt and is formulated as ER=(A?D)/D×100; and ? represents a coefficient of kinetic friction between the fixing belt and the fixing roller. The fixing device is thus arranged so that the fixing belt is driven by the fixing roller to rotate in a state where the pressing roller is separated from the fixing belt. This makes it possible to lengthen a life of a fixing belt, to shorten a warm-up time, and to reduce power consumption in a fixing device using a belt fixing method.
    Type: Grant
    Filed: April 13, 2010
    Date of Patent: October 23, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshiaki Kagawa
  • Patent number: 8238779
    Abstract: A color multifunction printer of the present invention includes a volatile chemical substance catching device, provided in an exhaust duct provided above a fixing unit, which generates an electric field in an atmosphere with use of an electric-field generating and catching member, which attracts volatile chemical substances contained in the atmosphere to a surface of the electric-field generating and catching member by the action of the electric field, and which catches the volatile chemical substances. This makes it possible to realize a volatile chemical substance catching device and an electronic apparatus that hardly suffer from aged deterioration in performance and can catch volatile chemical compounds such as VOCs and odors over a long period of time.
    Type: Grant
    Filed: May 19, 2009
    Date of Patent: August 7, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Doshoda, Toshiaki Kagawa
  • Patent number: 8233831
    Abstract: In a fixing device including a fixing roller, a pressure roller and an external heating section, a scraper is arranged to contact a circumferential surface of an external heating belt and scrape toner and the like on the circumferential surface to thereby clean the circumferential surface. In addition, a material that has higher adherence to toner than on a circumferential surface of the fixing roller is used for the external hating belt to thereby peel the toner and the like on the circumferential surface of the fixing roller and clean the circumferential surface of the fixing roller. Further, as a vibration applying section adapted to apply vibration to the scraper, a first contact/separation section adapted to contact/separate the external heating section with/from the fixing roller is provided. Vibration is applied to the scraper by the first contact/separation to peel the toner and the like off the scraper.
    Type: Grant
    Filed: June 10, 2009
    Date of Patent: July 31, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Atsuyoshi Nakayama, Toshiaki Kagawa
  • Patent number: 8165485
    Abstract: A fixing apparatus includes a heating element with an NTC characteristic in which an electric resistance value decreases as a temperature increases, which extends (i) in a direction parallel to a recording paper and (ii) in a width direction perpendicular to a carrying direction of the recording paper, and which has a longer length, in the width direction, than a width of the recording paper. The fixing apparatus further includes electrode sections provided in close proximity to both ends of the heating element in the width direction), the electrode sections being connected to the heating element, so that a current flows in the heating element in a direction substantially perpendicular to the carrying direction of the recording paper. This makes it possible to restrain excessive increase in temperature at the both ends of the heating element and to obtain a uniform temperature distribution.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: April 24, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kenji Asakura, Toshiaki Kagawa
  • Patent number: 8150304
    Abstract: A fixing device includes a fixing belt for fixing an unfixed toner image onto a recording medium, a planar heating member for heating the fixing belt, and a pressure roller. The heating member includes a ceramic heat generating element having a PTC characteristic, and a high-thermal-conductive heat diffusion member. The fixing belt is formed in an endless shape and is supported around, at least, the high-thermal-conductive heat diffusion member, thereby to be heated. The ceramic heat generating element comes into contact with the fixing belt over the full width thereof with the high-thermal-conductive heat diffusion member interposed therebetween. The high-thermal-conductive heat diffusion member comes into contact with the fixing belt over the full width thereof and diffuses heat generated by the heat generating element, in the traveling direction of the fixing belt.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: April 3, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshiaki Kagawa, Hiroyuki Kageyama
  • Patent number: 8126383
    Abstract: A planar heat-generating body 42 of a fixing apparatus of the present invention includes (i) a resistive heat-generating body 43a containing small heat-generating bodies electrically connected in parallel and aligned in a direction perpendicular to a direction in which a fixing belt 32 moves and (ii) a PTC element and a corresponding small heat-generating body being provided to be connected in series with a power source 36, the PTC element having a resistance value increasing at a predetermined temperature or higher. The PTC element 37 and the small heat-generating body are provided in an area corresponding to a non-sheet passing area of the fixing belt 32, the non-sheet passing area being an area where a smallest-size sheet does not pass, the smallest-size sheet being smallest among sheets that the fixing apparatus deals with. This allows for prevention of a temperature increase in the non-sheet passing area with a simple arrangement.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: February 28, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshiaki Kagawa
  • Patent number: 8068765
    Abstract: A fixing device of the present invention is arranged so that: (i) at least both ends of a planar heat-generating member come close to or touch an outer surface of a fixing roller, said both ends being in a circumferential direction when viewed in an axial direction of the fixing roller; and (ii) the planar heat-generating member has, in the vicinity of both the ends, shapes formed gently with respect to the outer surface of the fixing roller when viewed in the axial direction. An almost whole inner surface area of the fixing belt wound around the planar heat-generating member and the fixing roller touches the planar heat-generating member or the fixing roller. The fixing belt is naturally formed, without being distorted at an area where the fixing belt touches the heating member. This allows a fixing device using a planar heat-generating belt type fixing method, which provides a short warm-up time, to be excellent in heat efficiency, consume less power, and have a fixing belt which does not slip easily.
    Type: Grant
    Filed: January 12, 2009
    Date of Patent: November 29, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshiaki Kagawa
  • Patent number: 8068768
    Abstract: In an ion generating element, (i) an induction electrode and a heater electrode are provided away from each other on one surface of an insulating base material such that the induction electrode and the heater electrode are insulated from each other, (ii) a dielectric layer is provided on the surface of the insulating base material, and (iii) the dielectric layer has a length covering the insulating base material and the dielectric layer has openings above a ground terminal of the induction electrode and above a ground terminal and a power supply connection terminal of the heater electrode so that the terminals are exposed. As a result, it is possible to provide an ion generating element for generating ions along with creeping discharge, a charging device, and an image forming apparatus, each of which can be produced at low costs and prevent damages when unexpected troubles occur, and each of which is excellent in terms of safety.
    Type: Grant
    Filed: June 9, 2009
    Date of Patent: November 29, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Katsumi Adachi, Shoutaro Okamoto, Toshiaki Kagawa
  • Patent number: 8064814
    Abstract: Provided is a fixing apparatus employing an external heating method in which a scratch on a belt member and slippage of the belt member are prevented. The fixing apparatus includes: a fixing roller; a pressure member pressed against the fixing roller; an endless belt which is rotatably supported and contacts the fixing roller surface for heating the fixing roller; and heating means for heating the endless belt. By passing a recording material through a nip between the fixing roller and the pressure member, the fixing apparatus fixes an unfixed toner image on the recording material on which the unfixed toner image is transferred. The fixing apparatus further includes a cleaning member for removing dirt adhered to a surface of the endless belt by contacting the surface of the endless belt in a region where the endless belt is not supported.
    Type: Grant
    Filed: August 21, 2009
    Date of Patent: November 22, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshiaki Kagawa
  • Publication number: 20110236048
    Abstract: An image forming apparatus is provided. The image forming apparatus includes an image forming section, an intermediate transfer section, a secondary transfer section, a fixing section, a power source, a voltage detection section, a temperature detection section, and a fixing section control circuit. The fixing section control circuit includes a switching control section, a voltage judgment section, a temperature judgment section, and a preparation control section. When the switching control section switches the current conduction state to the heat source and the driving section from an off conduction state to an off conduction state and the voltage judgment section judges to be less than a threshold voltage, the preparation control section controls the preparation operation of the heating section such that the switching control section continues the on conduction state over a given idle time after the temperature judgment section has judged to be a preset temperature or higher.
    Type: Application
    Filed: March 18, 2011
    Publication date: September 29, 2011
    Inventors: Takashi MUKAI, Toshiaki Kagawa, Hiroyuki Yamaji
  • Patent number: 8027608
    Abstract: A fixing device which can reduce an overshoot of the surface temperature of a main heating section without lengthening a warming-up period of time, an image forming apparatus equipped therewith, and a recording medium on which is recorded the temperature control program are provided. In a standby mode, control is performed to stop an operation of a halogen lamp which is an internal heat source, when a surface temperature of a heating roller reaches a certain temperature lower than a target temperature, or when the operating period of time of the halogen lamp reaches a certain period of time. By so doing, as the heating roller ceases to be heated at a point at which it reaches a temperature lower than the target temperature, it is possible to reduce the overshoot of the surface temperature of the heating roller.
    Type: Grant
    Filed: August 25, 2009
    Date of Patent: September 27, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Mukai, Toshiaki Kagawa, Atsuyoshi Nakayama
  • Publication number: 20110188904
    Abstract: A fixing device includes a fixing portion provided with a fixing roller, a heating roller and a fixing belt; a pressing roller that presses a recording sheet to the fixing belt; a cleaning unit provided with a cleaning web that cleans up the pressing roller; and contact/separation mechanism that separates fixing means from the pressing roller. Viscosity of silicone oil that impregnates the cleaning web is set to 3,000 cs or more, and the contact/separation mechanism separates the fixing belt from the pressing roller at the time of rotation operation before fixation.
    Type: Application
    Filed: January 11, 2011
    Publication date: August 4, 2011
    Inventors: Hiroyuki Kageyama, Toshiaki Kagawa, Shinji Yamana