Patents by Inventor Takamasa Hase

Takamasa Hase 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).

  • Fixing device and image forming apparatus incorporating same
    Patent number: 9235177
    Abstract: A fixing device comprises a rotatable fixing member to apply heat to a recording medium bearing an unfixed image thereon, a heat source to heat the fixing member, and a rotatable pressing member pressing against the fixing member forming a nip therebetween. A driving source rotates and drives the fixing member and the pressing member. An overheat safety device has a relay to open and close a power supply path connected to the heat source. A temperature detector is connected to both the relay and the control unit to detect temperature of the fixing member. The overheat safety device turns off the relay and cuts off power supply to the heat source when the fixing member is overheated. The fixing member is allowed to radiate heat and cool down when the temperature detected by the temperature detector is more than a prescribed level.
    Type: Grant
    Filed: December 31, 2012
    Date of Patent: January 12, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Takuya Seshita, Masahiko Satoh, Masaaki Yoshikawa, Hiroshi Yoshinaga, Kenji Ishii, Tadashi Ogawa, Takahiro Imada, Hiromasa Takagi, Kazuya Saito, Naoki Iwaya, Toshihiko Shimokawa, Kensuke Yamaji, Teppei Kawata, Takamasa Hase, Shuutaroh Yuasa, Takeshi Uchitani, Arinobu Yoshiura, Hajime Gotoh, Akira Suzuki, Ryota Yamashina, Yasunori Ishigaya
  • FIXING DEVICE CAPABLE OF ENHANCING DURABILITY OF ENDLESS BELT AND IMAGE FORMING APPARATUS INCORPORATING THE SAME
    Publication number: 20150378290
    Abstract: A fixing device includes an endless belt rotatable in a predetermined direction of rotation and a nip formation assembly disposed opposite an inner circumferential surface of the endless belt. An opposed rotary body is pressed against the nip formation assembly via the endless belt to form a fixing nip between the endless belt and the opposed rotary body through which a recording medium bearing a toner image is conveyed. A belt holder contacts and supports each lateral end of the endless belt in an axial direction thereof. The belt holder is isolated from the opposed rotary body with a first interval interposed therebetween in the axial direction of the endless belt.
    Type: Application
    Filed: September 8, 2015
    Publication date: December 31, 2015
    Inventors: Teppei KAWATA, Masahiko Satoh, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Tadashi Ogawa, Takahiro Imada, Hiromasa Takagi, Kazuya Saito, Naoki Iwaya, Kensuke Yamaji, Takamasa Hase, Toshihiko Shimokawa, Shuutaroh Yuasa, Takuya Seshita, Takeshi Uchitani, Arinobu Yoshiura, Hajime Gotoh, Akira Suzuki
  • IMAGE FORMING METHOD, TONER, AND IMAGE FORMING APPARATUS
    Publication number: 20150378272
    Abstract: An image forming method is provided. The method includes the steps of forming an electrostatic latent image on a photoconductor; developing the electrostatic latent image into a toner image with a toner; transferring the toner image onto a recording medium having a smoothness of 20 s or less; and fixing the toner image on the recording medium. The toner exhibits an adhesion force of 100 gf or more, where the adhesion force is the maximum value of a pull force between a layer of the toner and standard paper determined by a tacking test with a probe temperature of 140° C.
    Type: Application
    Filed: June 3, 2015
    Publication date: December 31, 2015
    Inventors: Takamasa HASE, Yukiko IWASAKI, Minoru MASUDA, Tsuneyasu NAGATOMO, Kenji YONEDA
  • Image forming apparatus including a fixing device
    Patent number: 9207596
    Abstract: An image forming apparatus includes a fixing device. The fixing device includes a rotatable endless fixing member, a nip forming member arranged inside the fixing member, a pressing member in contact with the nip forming member via the fixing member, and a heating source configured to heat the fixing member. When an abnormality occurs in at least one of the fixing device and other devices included in the image forming apparatus, a rotation of the fixing member is stopped prior to stopping a rotation driving of a discharging unit and, after stopping, the fixing member is controlled to rotate.
    Type: Grant
    Filed: September 2, 2014
    Date of Patent: December 8, 2015
    Assignee: RICOH COMPANY, LIMITED
    Inventors: Takamasa Hase, Masahiko Satoh, Shinichi Namekata, Kenji Ishii, Takeshi Uchitani, Tadashi Ogawa, Teppei Kawata, Arinobu Yoshiura, Kazuya Saito, Toshihiko Shimokawa, Shuutaroh Yuasa, Kensuke Yamaji, Masaaki Yoshikawa, Hiroshi Yoshinaga, Hiromasa Takagi, Naoki Iwaya, Takuya Seshita, Takahiro Imada, Hajime Gotoh, Akira Suzuki
  • Fixing device capable of enhancing durability of endless belt and image forming apparatus incorporating the same
    Patent number: 9152108
    Abstract: A fixing device includes an endless belt rotatable in a predetermined direction of rotation and a nip formation assembly disposed opposite an inner circumferential surface of the endless belt. An opposed rotary body is pressed against the nip formation assembly via the endless belt to form a fixing nip between the endless belt and the opposed rotary body through which a recording medium bearing a toner image is conveyed. A belt holder contacts and supports each lateral end of the endless belt in an axial direction thereof. The belt holder is isolated from the opposed rotary body with a first interval interposed therebetween in the axial direction of the endless belt.
    Type: Grant
    Filed: October 7, 2014
    Date of Patent: October 6, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Teppei Kawata, Masahiko Satoh, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Tadashi Ogawa, Takahiro Imada, Hiromasa Takagi, Kazuya Saito, Naoki Iwaya, Kensuke Yamaji, Takamasa Hase, Toshihiko Shimokawa, Shuutaroh Yuasa, Takuya Seshita, Takeshi Uchitani, Arinobu Yoshiura, Hajime Gotoh, Akira Suzuki
  • Fixing device and image forming device
    Patent number: 9146512
    Abstract: When calculating an actual turn-on duty based on a required duty according to a feedback control, the actual turn-on duty is corrected using a correction table or a correction conversion formula such that a required turn-on duty and the actual turn-on duty coincide with each other. A fixing heater is controlled according to the corrected actual turn-on duty.
    Type: Grant
    Filed: February 7, 2013
    Date of Patent: September 29, 2015
    Assignee: Ricoh Company, Limited
    Inventors: Kazuya Saito, Takeshi Uchitani, Takamasa Hase, Shuutaroh Yuasa, Ippei Fujimoto, Shinichi Namekata, Ryota Yamashina, Hiroshi Seo, Takumi Waida
  • Fixing device and image forming apparatus
    Patent number: 9141047
    Abstract: A fixing device capable of shifting to a sleep state includes a heat source; a rotatable fixing member that is partly heated by the heat source to heat an unfixed image carrying surface of a recording medium; a rotatable pressing member that is in pressure contact with the fixing member to form a nip portion between the pressing member and the fixing member; a rotation drive unit that directly or indirectly rotates the fixing member; a temperature detecting unit that detects a temperature of the fixing member; and a controller configured to prohibit the fixing device from shifting to the sleep state when the temperature of the fixing member in a region facing the heat source is equal to or more than a predetermined temperature T1 at a point when a predetermined time period t1 has elapsed from the stop of rotation drive of the rotation drive unit.
    Type: Grant
    Filed: April 22, 2015
    Date of Patent: September 22, 2015
    Assignee: RICOH COMPANY, LIMITED
    Inventors: Takeshi Uchitani, Masahiko Satoh, Masaaki Yoshikawa, Kenji Ishii, Tadashi Ogawa, Takahiro Imada, Hiromasa Takagi, Hiroshi Yoshinaga, Arinobu Yoshiura, Teppei Kawata, Takamasa Hase, Hajime Gotoh, Takuya Seshita, Kazuya Saito, Toshihiko Shimokawa, Kensuke Yamaji, Shuutaroh Yuasa, Akira Suzuki, Shinichi Namekata, Ryota Yamashina, Yasunori Ishigaya
  • FIXING DEVICE AND IMAGE FORMING DEVICE
    Publication number: 20150234329
    Abstract: According to an embodiment, provided is a fixing device that includes: a rotatable fixing member that heats a recording medium on a side carrying an unfixed image; a rotatable pressing member that is pressed and is contacted with the fixing member to form a nip portion between the pressing member and the fixing member; a heat source heating the fixing member; a relay switch provided in an energizing path for the heat source; a temperature detection sensor detecting a temperature of the fixing member; and a control unit that controls energization of the heat source according to the temperature detected by the temperature detection sensor. The control unit keeps the relay switch in an off state if the temperature of the fixing member is equal to or more than a predetermined temperature when the fixing member has stopped rotation.
    Type: Application
    Filed: May 4, 2015
    Publication date: August 20, 2015
    Inventors: Takamasa HASE, Kenji ISHII, Tadashi OGAWA, Teppei KAWATA, Arinobu YOSHIURA, Toshihiko SHIMOKAWA, Kensuke YAMAJI, Takeshi UCHITANI, Shuutaroh YUASA, Masaaki YOSHIKAWA, Hiroshi YOSHINAGA, Hiromasa TAKAGI, Naoki IWAYA, Takahiro IMADA, Hajime GOTOH, Takuya SESHITA, Ryota YAMASHINA, Yasunori ISHIGAYA
  • TONER, DEVELOPER, AND IMAGE FORMING APPARATUS
    Publication number: 20150234304
    Abstract: A toner including a crystalline resin wherein the crystalline resin contains a crystalline resin having a urethane bond, a urea bond or both thereof, and wherein the crystalline resin has an average crystallite diameter of 20 nm to 70 nm.
    Type: Application
    Filed: September 10, 2013
    Publication date: August 20, 2015
    Inventors: Kousuke Nagata, Masahide Yamada, Shinya Nakayama, Akiyoshi Sabu, Tatsuya Morita, Takamasa Hase, Suzuka Amemori, Rintaro Takahashi
  • FIXING DEVICE AND IMAGE FORMING APPARATUS
    Publication number: 20150227095
    Abstract: A fixing device capable of shifting to a sleep state includes a heat source; a rotatable fixing member that is partly heated by the heat source to heat an unfixed image carrying surface of a recording medium; a rotatable pressing member that is in pressure contact with the fixing member to form a nip portion between the pressing member and the fixing member; a rotation drive unit that directly or indirectly rotates the fixing member; a temperature detecting unit that detects a temperature of the fixing member; and a controller configured to prohibit the fixing device from shifting to the sleep state when the temperature of the fixing member in a region facing the heat source is equal to or more than a predetermined temperature T1 at a point when a predetermined time period t1 has elapsed from the stop of rotation drive of the rotation drive unit.
    Type: Application
    Filed: April 22, 2015
    Publication date: August 13, 2015
    Inventors: Takeshi UCHITANI, Masahiko SATOH, Masaaki YOSHIKAWA, Kenji ISHII, Tadashi OGAWA, Takahiro IMADA, Hiromasa TAKAGI, Hiroshi YOSHINAGA, Arinobu YOSHIURA, Teppei KAWATA, Takamasa HASE, Hajime GOTOH, Takuya SESHITA, Kazuya SAITO, Toshihiko SHIMOKAWA, Kensuke YAMAJI, Shuutaroh YUASA, Akira SUZUKI, Shinichi NAMEKATA, Ryota YAMASHINA, Yasunori ISHIGAYA
  • FIXING DEVICE AND IMAGE FORMING APPARATUS INCLUDING SAME
    Publication number: 20150212459
    Abstract: A fixing device including a fixing member, an opposing member, a plurality of heat sources, and a voltage detector. The opposing member is disposed opposite the fixing member to contact the fixing member to form a nip portion at which an unfixed image on a recording medium is fixed. The plurality of heat sources heats the fixing member. The voltage detector detects an applied voltage of at least one of the plurality of heat sources. Upon detection of the applied voltage of the heat sources by the voltage detector, a voltage is applied to at least one of the heat sources.
    Type: Application
    Filed: April 9, 2015
    Publication date: July 30, 2015
    Applicant: Ricoh Company, Ltd.
    Inventors: Takamasa HASE, Masahiko SATOH, Masaaki YOSHIKAWA, Kenji ISHII, Hiroshi YOSHINAGA, Tadashi OGAWA, Takeshi UCHITANI, Hiromasa TAKAGI, Naoki IWAYA, Teppei KAWATA, Takuya SESHITA, Arinobu YOSHIURA, Takahiro IMADA, Hajime GOTOH, Kazuya SAITO, Toshihiko SHIMOKAWA, Shuutaroh YUASA, Kensuke YAMAJI, Akira SUZUKI
  • Image forming apparatus
    Patent number: 9069304
    Abstract: In the present invention, upon return from a standby mode or sleep mode, image data is acquired as warming-up time estimate information for estimating the warming-up time to increase the temperature of a fixing belt to a target fixing temperature and, if the acquired image data is the data on a black-and-white image, control is performed to delay the heating start timing of the fixing belt.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: June 30, 2015
    Assignee: Ricoh Company, Limited
    Inventors: Takuya Seshita, Masahiko Satoh, Masaaki Yoshikawa, Hiroshi Yoshinaga, Naoki Iwaya, Hiromasa Takagi, Takahiro Imada, Hajime Gotoh, Akira Suzuki, Kenji Ishii, Tadashi Ogawa, Teppei Kawata, Arinobu Yoshiura, Toshihiko Shimokawa, Kensuke Yamaji, Takeshi Uchitani, Takamasa Hase, Shuutaroh Yuasa
  • Fixing device, image forming device, and separating member
    Patent number: 9063480
    Abstract: In an embodiment, provided is a fixing device that includes: a fixing belt rotatable and endless; a belt holding member holding the fixing belt at each end part in an axial direction; a heat source heating the fixing belt; a nip forming member provided inside the fixing belt; an opposing rotator forming a nip portion between the opposing rotator and the fixing belt via the fixing belt; and a separating member that extends near the nip portion and separates a recording medium from a surface of the fixing belt. A leading end of the separating member is provided with a receding portion and an approaching portion that is at a different position from a position of the receding portion different in the axial direction. The approaching portion is provided nearer to the nip portion than the receding portion is provided.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: June 23, 2015
    Assignee: Ricoh Company, Limited
    Inventors: Arinobu Yoshiura, Masahiko Satoh, Masaaki Yoshikawa, Kenji Ishii, Tadashi Ogawa, Takahiro Imada, Hiromasa Takagi, Kazuya Saito, Naoki Iwaya, Toshihiko Shimokawa, Kensuke Yamaji, Teppei Kawata, Takamasa Hase, Shuutaroh Yuasa, Takuya Seshita, Takeshi Uchitani, Hajime Gotoh, Akira Suzuki, Hiroshi Yoshinaga
  • Fixing device
    Patent number: 9063493
    Abstract: A fixing device includes an endless flexible belt, an elongated stationary pad, a rotary pressure member, and a low-friction sheet. The endless flexible belt is looped into a generally cylindrical configuration extending in an axial direction thereof for rotation in a rotational, circumferential direction thereof. The elongated stationary pad is stationarily disposed inside the loop of the belt. The rotary pressure member is disposed parallel to the belt. The rotary pressure member presses against the stationary pad via the belt to form a nip therebetween, through which a recording medium is conveyed in a conveyance direction. The low-friction sheet of lubricant-impregnated material covers the stationary pad to supply a lubricant between the stationary pad and the belt across the nip. The low-friction sheet has one or more flow channels defined therein.
    Type: Grant
    Filed: January 24, 2013
    Date of Patent: June 23, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Kensuke Yamaji, Masahiko Satoh, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Tadashi Ogawa, Takeshi Uchitani, Hiromasa Takagi, Takuya Seshita, Teppei Kawata, Arinobu Yoshiura, Takahiro Imada, Hajime Gotoh, Takamasa Hase, Toshihiko Shimokawa, Shuutaroh Yuasa, Akira Suzuki
  • FIXING DEVICE CAPABLE OF MINIMIZING DAMAGE OF ENDLESS ROTARY BODY AND IMAGE FORMING APPARATUS INCORPORATING SAME
    Publication number: 20150168897
    Abstract: A fixing device includes at least one heater disposed opposite an inner circumferential surface of an endless rotary body to heat the endless rotary body and a shield interposed between the endless rotary body and the at least one heater to shield the endless rotary body from heat radiated from the at least one heater. A first size recording medium passes over a first passage region of the endless rotary body and a second size recording medium passes over a second passage region of the endless rotary body. The shield includes a notch disposed opposite a lateral end of the second passage region of the endless rotary body in an axial direction thereof. The lateral end of the second passage region overlaps a non-passage region of the endless rotary body in the axial direction thereof where the first size recording medium does not pass.
    Type: Application
    Filed: February 25, 2015
    Publication date: June 18, 2015
    Inventors: Tadashi OGAWA, Masahiko Satoh, Masaaki Yoshikawa, Hiroshi Yoshinaga, Kenji Ishii, Takeshi Uchitani, Hiromasa Takagi, Naoki Iwaya, Takuya Seshita, Takahiro Imada, Hajime Gotoh, Takamasa Hase, Toshihiko Shimokawa, Shuutaroh Yuasa, Teppei Kawata, Arinobu Yoshiura, Kensuke Yamaji, Akira Suzuki
  • FIXING DEVICE AND IMAGE FORMING APPARATUS
    Publication number: 20150160591
    Abstract: A fixing device includes a rotary endless fixing belt; a nip forming member disposed in an interior of the fixing belt; a rotary opposed member to contact the nip forming member via the fixing belt to form a nip together with the fixing belt; a heat source to directly heat the fixing belt at a portion other than the nip, including at lease one heat-generation part disposed outside lateral ends of a maximum area of the fixing belt where a recording medium passes through, wherein a recording medium carrying an unfixed image is conveyed to the nip and the fixing device fixes the unfixed image onto the recording medium; and a shielding member disposed between the fixing belt and the heat generation part of the heat source and configured to shield heat from the heat source at least at an area outside the maximum passing area of the recording medium.
    Type: Application
    Filed: December 29, 2014
    Publication date: June 11, 2015
    Inventors: Takamasa HASE, Hiroshi YOSHINAGA, Takeshi UCHITANI, Yutaka IKEBUCHI, Takuya SESHITA, Shuutaroh YUASA
  • Fixing device with a temperature detector adjacent an easily deformable location and image forming apparatus including same
    Patent number: 9052658
    Abstract: A fixing device for fixing an unfixed image onto a recording medium includes a fixing belt, a nip forming member, an opposing rotary member, a heater, and a temperature detector. The fixing belt is formed into a loop to move endlessly and fix the unfixed image on the recording medium. The nip forming member is disposed inside the loop formed by the fixing belt. The opposing rotary member contacts the nip forming member via the fixing belt to form a nip portion therebetween while rotating. The heater heats the fixing belt at a place other than the nip portion. The temperature detector detects a temperature of the surface of the fixing belt. The temperature detector detects the temperature near a place of the fixing belt that easily deforms as the fixing belt is heated by the heater.
    Type: Grant
    Filed: January 28, 2013
    Date of Patent: June 9, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Uchitani, Masahiko Satoh, Masaaki Yoshikawa, Kenji Ishii, Tadashi Ogawa, Takahiro Imada, Hiromasa Takagi, Kazuya Saito, Naoki Iwaya, Toshihiko Shimokawa, Kensuke Yamaji, Teppei Kawata, Takamasa Hase, Takuya Seshita, Shuutaroh Yuasa, Arinobu Yoshiura, Hajime Gotoh, Akira Suzuki, Hiroshi Yoshinaga
  • Fixing device and image forming apparatus
    Patent number: 9042761
    Abstract: A fixing device capable of shifting to a sleep state includes a heat source; a rotatable fixing member that is partly heated by the heat source to heat an unfixed image carrying surface of a recording medium; a rotatable pressing member that is in pressure contact with the fixing member to form a nip portion between the pressing member and the fixing member; a rotation drive unit that directly or indirectly rotates the fixing member; a temperature detecting unit that detects a temperature of the fixing member; and a controller configured to prohibit the fixing device from shifting to the sleep state when the temperature of the fixing member in a region facing the heat source is equal to or more than a predetermined temperature T1 at a point when a predetermined time period t1 has elapsed from the stop of rotation drive of the rotation drive unit.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: May 26, 2015
    Assignee: RICOH COMPANY, LIMITED
    Inventors: Takeshi Uchitani, Masahiko Satoh, Masaaki Yoshikawa, Kenji Ishii, Tadashi Ogawa, Takahiro Imada, Hiromasa Takagi, Hiroshi Yoshinaga, Arinobu Yoshiura, Teppei Kawata, Takamasa Hase, Hajime Gotoh, Takuya Seshita, Kazuya Saito, Toshihiko Shimokawa, Kensuke Yamaji, Shuutaroh Yuasa, Akira Suzuki, Shinichi Namekata, Ryota Yamashina, Yasunori Ishigaya
  • Fixing device and image forming apparatus
    Patent number: 9042799
    Abstract: A fixing device includes a rotary endless fixing belt; a nip forming member disposed in an interior of the fixing belt; a rotary opposed member to contact the nip forming member via the fixing belt to form a nip together with the fixing belt; a heat source to directly heat the fixing belt at a portion other than the nip, including at lease one heat-generation part disposed outside lateral ends of a maximum area of the fixing belt where a recording medium passes through, wherein a recording medium carrying an unfixed image is conveyed to the nip and the fixing device fixes the unfixed image onto the recording medium; and a shielding member disposed between the fixing belt and the heat generation part of the heat source and configured to shield heat from the heat source at least at an area outside the maximum passing area of the recording medium.
    Type: Grant
    Filed: January 10, 2013
    Date of Patent: May 26, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Takamasa Hase, Hiroshi Yoshinaga, Takeshi Uchitani, Yutaka Ikebuchi, Takuya Seshita, Shuutaroh Yuasa
  • Image forming apparatus
    Patent number: 9042802
    Abstract: An image forming apparatus includes: an image bearing member; a charger; an irradiator; a development device having an accommodation unit to accommodate toner to obtain a visible image; a transfer device; and a fixing device to fix the visible image transferred onto a recording medium. The fixing device having a fixing rotation member; and a pressure rotation member to form a nipping portion by contacting the fixing rotation member, wherein the surface pressure of the nipping portion is 1.5 kgf/cm2 or less, wherein the fixing rotation member has a Martens hardness of 1.0 N/mm2 or less at 23° C., wherein the ratio of the projected area of a single particle of the toner onto the recording medium at 120° C. to the projected area of a single particle of the toner onto the recording medium at 23° C. is 1.60 or less.
    Type: Grant
    Filed: February 26, 2014
    Date of Patent: May 26, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Takamasa Hase, Shinya Nakayama, Atsushi Yamamoto, Hideyuki Santo, Minoru Masuda, Yukiko Iwasaki, Tsuneyasu Nagatomo