Patents by Inventor Hirofumi Ogawa

Hirofumi Ogawa 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: 6881927
    Abstract: An image forming apparatus including a fixing device that has a rotatable endless belt, a contacting member to contact the rotatable endless belt, a rotatable pressing member contacting the contacting member via the rotatable endless belt to form a nip region, a heating member to heat the rotatable endless belt, a detecting device to detect a temperature of the heating member, a controlling device to control a temperature of the heating member based on a detection result of the detecting device, and a determining device to determine that the sheet-like recording medium has passed through the fixing device. The controlling device controls such that the temperature of the heating member set for the fixing operation is decreased to a temperature set when the sheet-like recording medium has passed through the fixing device, immediately after a last sheet-like recording medium in a series of a job has passed through the fixing device.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: April 19, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Yoshinaga, Motokazu Yasui, Hideo Furukawa, Masanao Ehara, Hirofumi Ogawa
  • Patent number: 6785505
    Abstract: A fixing device includes an abutting member arranged at a position between an upstream side of a fixing roller and a downstream side of a heating roller in a moving direction of a fixing belt so as to abut against the fixing belt and expand a fixing region. The fixing device may also include a first supporting member and a second supporting member, which supports the fixing belt, etc., with respect to the first supporting member. An angle, formed between an approaching direction of a sheet-like recording medium and a line tangential to an upstream end of the fixing region in the moving direction of the fixing belt, is set equal to 20° or larger.
    Type: Grant
    Filed: June 19, 2003
    Date of Patent: August 31, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Motokazu Yasui, Masanao Ehara, Hideo Furukawa, Hiroshi Yoshinaga, Hirofumi Ogawa, Hiroyuki Gotoh
  • Publication number: 20030206758
    Abstract: A fixing device includes an abutting member arranged at a position between an upstream side of a fixing roller and a downstream side of a heating roller in a moving direction of a fixing belt so as to abut against the fixing belt and expand a fixing region. The fixing device may also include a first supporting member and a second supporting member, which supports the fixing belt, etc., with respect to the first supporting member. An angle, formed between an approaching direction of a sheet-like recording medium and a line tangential to an upstream end of the fixing region in the moving direction of the fixing belt, is set equal to 20° or larger.
    Type: Application
    Filed: June 19, 2003
    Publication date: November 6, 2003
    Inventors: Motokazu Yasui, Masanao Ehara, Hideo Furukawa, Hiroshi Yoshinaga, Hirofumi Ogawa, Hiroyuki Gotoh
  • Patent number: 6636709
    Abstract: A fixing device for fixing a toner image on a recording medium includes a heating roller, a fixing roller, an endless fixing belt extended around at least the heating roller and the fixing roller and configured to be heated by the heating roller, a pressing roller disposed opposite to the fixing roller via the fixing belt, a temperature detecting member configured to detect a surface temperature of the heating roller, and a control device configured to control a surface temperature of the fixing belt at a predetermined temperature based on a surface temperature of the heating roller detected by the temperature detecting member. The temperature detecting member contacts a circumferential surface of the heating roller where the fixing belt is not extended around, such that the temperature detecting member is held in a low frictional relation to the circumferential surface of the heating roller.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: October 21, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideo Furukawa, Takuya Ejiri, Motokazu Yasui, Hiroyuki Gotoh, Masanao Ehara, Hirofumi Ogawa, Hiroshi Yoshinaga
  • Patent number: 6628916
    Abstract: A fixing device includes an abutting member arranged at a position between an upstream side of a fixing roller and a downstream side of a heating roller in a moving direction of a fixing belt so as to abut against the fixing belt and expand a fixing region. The fixing device may also include a first supporting member and a second supporting member, which supports the fixing belt, etc., with respect to the first supporting member. An angle, formed between an approaching direction of a sheet-like recording medium and a line tangential to an upstream end of the fixing region in the moving direction of the fixing belt, is set equal to 20° or larger.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: September 30, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Motokazu Yasui, Masanao Ehara, Hideo Furukawa, Hiroshi Yoshinaga, Hirofumi Ogawa, Hiroyuki Gotoh
  • Publication number: 20030000933
    Abstract: An image forming apparatus including a fixing device that has a rotatable endless belt, a contacting member to contact the rotatable endless belt, a rotatable pressing member contacting the contacting member via the rotatable endless belt to form a nip region, a heating member to heat the rotatable endless belt, a detecting device to detect a temperature of the heating member, a controlling device to control a temperature of the heating member based on a detection result of the detecting device, and a determining device to determine that the sheet-like recording medium has passed through the fixing device. The controlling device controls such that the temperature of the heating member set for the fixing operation is decreased to a temperature set when the sheet-like recording medium has passed through the fixing device, immediately after a last sheet-like recording medium in a series of a job has passed through the fixing device.
    Type: Application
    Filed: March 29, 2002
    Publication date: January 2, 2003
    Inventors: Hiroshi Yoshinaga, Motokazu Yasui, Hideo Furukawa, Masanao Ehara, Hirofumi Ogawa
  • Publication number: 20020067936
    Abstract: A fixing device includes an abutting member arranged at a position between an upstream side of a fixing roller and a downstream side of a heating roller in a moving direction of a fixing belt so as to abut against the fixing belt and expand a fixing region. The fixing device may also include a first supporting member and a second supporting member, which supports the fixing belt, etc., with respect to the first supporting member. An angle, formed between an approaching direction of a sheet-like recording medium and a line tangential to an upstream end of the fixing region in the moving direction of the fixing belt, is set equal to 20° or larger.
    Type: Application
    Filed: November 20, 2001
    Publication date: June 6, 2002
    Inventors: Motokazu Yasui, Masanao Ehara, Hideo Furukawa, Hiroshi Yoshinaga, Hirofumi Ogawa, Hiroyuki Gotoh
  • Publication number: 20020018663
    Abstract: A fixing device for fixing a toner image on a recording medium includes a heating roller, a fixing roller, an endless fixing belt extended around at least the heating roller and the fixing roller and configured to be heated by the heating roller, a pressing roller disposed opposite to the fixing roller via the fixing belt, a temperature detecting member configured to detect a surface temperature of the heating roller, and a control device configured to control a surface temperature of the fixing belt at a predetermined temperature based on a surface temperature of the heating roller detected by the temperature detecting member. The temperature detecting member contacts a circumferential surface of the heating roller where the fixing belt is not extended around, such that the temperature detecting member is held in a low frictional relation to the circumferential surface of the heating roller.
    Type: Application
    Filed: June 28, 2001
    Publication date: February 14, 2002
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hideo Furukawa, Takuya Ejiri, Motokazu Yasui, Hiroyuki Gotoh, Masanao Ehara, Hirofumi Ogawa, Hiroshi Yoshinaga
  • Patent number: 6070695
    Abstract: A silencer comprising an outer sleeve made of a aluminum or an aluminum alloy, an inner sleeve made of a iron or steel, and acoustic material inserted between the outer sleeve and the inner sleeve. An end cap for closing a downstream end of the silencer comprising a first member made of iron or steel which is formed into a shape of the end cap, and a second member made of aluminum metal which is formed into the same shape as the outline of the first member, the peripheral portion of the first member and the peripheral portion of the second member being laminated. An end plate made of aluminum being mounted on an upstream end of the silencer. Clamping members made of iron or steel including female or male screws are secured to the end plate. An exhaust pipe is provided with a mounting seat at a fixed position thereof. The silencer can be secured to the mounting seat by means of the clamping members and bolts or nuts made of iron or steel. The end cap can be welded to a part of the outer sleeve.
    Type: Grant
    Filed: January 5, 1996
    Date of Patent: June 6, 2000
    Assignee: Kabushiki Kaisha Yutaka Giken
    Inventors: Akihiko Ohtaka, Nobuyuki Yoshitoshi, Hirofumi Ogawa
  • Patent number: 5625457
    Abstract: An apparatus for performing non-contact measurement of relative displacement includes a microscope having one objective lens and two fields of view in which two points of measurement on a test piece can be located separately, a pair of cameras for taking images obtained with the microscope, and an apparatus for measuring the relative displacement of the images of the two points of measurement obtained by the cameras.
    Type: Grant
    Filed: October 31, 1995
    Date of Patent: April 29, 1997
    Assignee: Agency of Industrial Science & Technology Ministry of International Trade & Industry
    Inventors: Hirofumi Ogawa, Yuichi Ishikawa, Tokio Kitahara
  • Patent number: 5335140
    Abstract: A drawer-type circuit interrupter is constructed with a first contact member having an open-and-close contact member, an open-and-close operation mechanism for operating said first contact member, an interrupter main body having a second contact member and a mounting frame having the external line contact terminals, wherein the second contact member is a movable-type provided with an open-and-close contact portion that is contactable with and separable from the first contact member on the one end thereof and a drawer contact member that contacts with an external line contact terminal on the other end thereof, and a compression spring for urging the second contact member into a direction for contacting the external line contact terminal on the other end of the second contact member. When the interrupter body is in the connected position the drawer contact portion on the other end of said second contact member and said external line contact terminal are into contact.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: August 2, 1994
    Assignee: Terasaki Denki Sangyo Kabushiki Kaisha
    Inventors: Toshihide Kamino, Junichi Sonoda, Hirofumi Ogawa, Takeshi Endo
  • Patent number: 5305559
    Abstract: A method of grinding a core blank which yields at least one head core each used for a magnetic head, each head core having an annular magnetic path having a magnetic gap, the core blank having a working surface that is to be opposed to a magnetic recording medium is disclosed. According to the present grinding method, at least one marker is formed by photolithography so that the marker(s) is/are embedded in the core blank. Each marker has two edges which are spaced from each other in a direction of width of the magnetic gap, by a first distance that continuously varies in a direction of depth of the magnetic gap, the two edges of each marker being located on the same side as viewed in the gap-width direction.
    Type: Grant
    Filed: April 29, 1993
    Date of Patent: April 26, 1994
    Assignee: NGK Insulators, Ltd.
    Inventor: Hirofumi Ogawa
  • Patent number: 5233265
    Abstract: A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property. In one aspect of the present invention, the amorphous semiconductor layer is amorphous Se. In another aspect of the present invention, the amorphous semiconductor layer is composed mainly of tetrahedral elements including at least an element of hydrogen or halogens. When using the amorphous semiconductor layer composed mainly of tetrahedral elements, the charge multiplication effect is produced mainly in the interior of the amorphous semiconductor, and thus it is possible to obtain a thermally stable photoconductive device having a high sensitivity while keeping a good photoresponse.
    Type: Grant
    Filed: August 1, 1990
    Date of Patent: August 3, 1993
    Assignees: Hitachi, Ltd., Nippon Hoso Kyokai
    Inventors: Yukio Takasaki, Kazutaka Tsuji, Tatsuo Makishima, Tadaaki Hirai, Sachio Ishioka, Tatsuro Kawamura, Keiichi Shidara, Eikyu Hiruma, Kenkichi Tanioka, Junichi Yamazaki, Kenji Sameshima, Hirokazu Matsubara, Kazuhisa Taketoshi, Mitsuo Kosugi, Shiro Suzuki, Takashi Yamashita, Masaaki Aiba, Yoshizumi Ikeda, Tsuyoshi Uda, Naohiro Goto, Yasuhiko Nonaka, Eisuke Inoue, Hirofumi Ogawa
  • Patent number: 5218264
    Abstract: An image pick-up apparatus is disclosed which includes a target portion having a photoconductive film on a substrate and a target electrode and reads video information converted into an electric signal in the photoconductive film by an electron beam. An insulating region is provided for the target portion such that carrier generated in an ineffective scanned region (a target region corresponding to an area not scanned by the electron beam) does not appear on a surface of the target portion.
    Type: Grant
    Filed: January 31, 1990
    Date of Patent: June 8, 1993
    Assignees: Hitachi, Ltd., Nippon Hoso Kyokai
    Inventors: Tadaaki Hirai, Hirofumi Ogawa, Kenji Sameshima, Yukio Takasaki, Takaaki Unnai, Junichi Yamazaki, Misao Kubota, Kenkichi Tanioka, Eikyu Hiruma
  • Patent number: 4952839
    Abstract: A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property.
    Type: Grant
    Filed: October 12, 1989
    Date of Patent: August 28, 1990
    Assignees: Hitachi, Ltd, Nippon Hoso Kyokai
    Inventors: Kenkichi Tanioka, Mitsuo Kosugi, Junichi Yamazaki, Keiichi Shidara, Kazuhisa Taketoshi, Tatsuro Kawamura, Eikyuu Hiruma, Shiro Suzuki, Takashi Yamashita, Masaaki Aiba, Yochizumi Ikeda, Tadaaki Hirai, Yukio Takasaki, Sachio Ishioka, Tatsuo Makishima, Kenji Sameshima, Tsuyoshi Uda, Naohiro Goto, Yasuhiko Nonaka, Eisuke Inoue, Kazutaka Tsuji, Hirofumi Ogawa
  • Patent number: 4888521
    Abstract: A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property.
    Type: Grant
    Filed: July 2, 1987
    Date of Patent: December 19, 1989
    Assignees: Hitachi Ltd., Nippon Hoso Kyokai
    Inventors: Kenkichi Tanioka, Keiichi Shidara, Tatsuro Kawamura, Junichi Yamazaki, Eikyuu Hiruma, Kazuhisa Taketoshi, Shiro Suzuki, Takashi Yamashita, Mitsuo Kosugi, Yochizumi Ikeda, Masaaki Aiba, Tadaaki Hirai, Yukio Takasaki, Sachio Ishioka, Tatsuo Makishima, Kenji Sameshima, Tsuyoshi Uda, Naohiro Goto, Yasuhiko Nonaka, Eisuke Inoue, Kazutaka Tsuji, Hirofumi Ogawa
  • Patent number: 4883562
    Abstract: A method of making an image pickup tube target (FIG. 1A), etc., using an amorphous photoconductive layer. When an electrode, an amorphous semiconductor layer, etc., are provided on a substrate, the steps of ion etching away a surface of the substrate and forming the electrode are performed so that a target (FIG. 1A) is produced in which no defects are substantially caused in a reproduced image even if a high electric field is applied across the target.
    Type: Grant
    Filed: January 26, 1989
    Date of Patent: November 28, 1989
    Assignees: Hitachi, Ltd., Nippon Hoso Kyokai
    Inventors: Hirofumi Ogawa, Kenji Sameshima, Tadaaki Hirai, Takaaki Unnai, Masanao Yamamoto, Keiichi Shidara, Junichi Yamazaki, Eikiyu Hiruma, Shirou Suzuki
  • Patent number: 4636682
    Abstract: A high velocity electron beam scanning negatively charge biased image pickup tube has a target which includes at least a transparent conductive layer, a photoconductor layer and a layer for secondary electron emission on a light-transmissive insulating substrate, and in which the transparent conductive layer is arranged on a light incidence side, the photoconductor layer being made of amorphous silicon.
    Type: Grant
    Filed: May 5, 1983
    Date of Patent: January 13, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Chushirou Kusano, Sachio Ishioka, Yoshinori Imamura, Yukio Takasaki, Hirofumi Ogawa, Tatsuo Makishima, Tadaaki Hirai
  • Patent number: 4626885
    Abstract: A photosensor including a transparent electrode for transmitting incident light and a photoconductive layer receiving light from the transparent electrode for performing photoelectric conversion, is disclosed in which the photoconductive layer is made of amorphous silicon, the amorphous silicon contains 5 to 30 atomic percent hydrogen and is doped with at least one selected from elements belonging to the groups II and III in such a manner that a region remote from the transparent electrode is higher in the concentration of the selected element than another region proximate to the transparent electrode, and a voltage is applied across the photoconductive layer so that a surface of the photoconductive layer facing the transparent electrode is at a positive potential with respect to another surface of the photoconductive layer opposite to the surface facing the transparent electrode.
    Type: Grant
    Filed: July 29, 1983
    Date of Patent: December 2, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Sachio Ishioka, Yoshinori Imamura, Tsuyoshi Uda, Yukio Takasaki, Chushirou Kusano, Hirofumi Ogawa, Tatsuo Makishima, Tadaaki Hirai
  • Patent number: 4609846
    Abstract: An image pick-up tube has a photoelectric conversion target including a transparent substrate, and a transparent electrode and a photoconductive layer formed on the transparent substrate. An electron beam is scanned on the photoelectric conversion target. A first electrode is formed on a beam scanning surface of the photoconductive layer so as to be segmented in stripe or grid with its electrode segments electrically connected to each other. A second electrode is formed on the first electrode through an insulating layer with its electrode segments electrically connected to each other. An insulating layer may be interposed between the first electrode and the photoconductive layer.
    Type: Grant
    Filed: September 20, 1984
    Date of Patent: September 2, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Chushirou Kusano, Sachio Ishioka, Yasuharu Shimomoto, Yoshinori Imamura, Hirofumi Ogawa