Patents by Inventor Hidekazu Tamura

Hidekazu Tamura 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).

  • Publication number: 20210057564
    Abstract: A parasitic capacitance and a leak current in a nitride semiconductor device are reduced. For example, a 100 nm-thick buffer layer made of AlN, a 2 ?m-thick undoped GaN layer, and 20 nm-thick undoped AlGaN having an Al composition ratio of 20% are epitaxially grown in this order on, for example, a substrate made of silicon, and a source electrode and a drain electrode are formed so as to be in ohmic contact with the undoped AlGaN layer. Further, in the undoped GaN layer and the undoped AlGaN layer immediately below a gate wire, a high resistance region, the resistance of which is increased by, for example, ion implantation with Ar or the like, is formed, and a boundary between the high resistance region and an element region is positioned immediately below the gate wire.
    Type: Application
    Filed: November 6, 2020
    Publication date: February 25, 2021
    Inventors: Hidekazu UMEDA, Kazuhiro KAIBARA, Satoshi TAMURA
  • Patent number: 10868167
    Abstract: A parasitic capacitance and a leak current in a nitride semiconductor device are reduced. For example, a 100 nm-thick buffer layer made of AlN, a 2 ?m-thick undoped GaN layer, and 20 nm-thick undoped AlGaN having an Al composition ratio of 20% are epitaxially grown in this order on, for example, a substrate made of silicon, and a source electrode and a drain electrode are formed so as to be in ohmic contact with the undoped AlGaN layer. Further, in the undoped GaN layer and the undoped AlGaN layer immediately below a gate wire, a high resistance region, the resistance of which is increased by, for example, ion implantation with Ar or the like, is formed, and a boundary between the high resistance region and an element region is positioned immediately below the gate wire.
    Type: Grant
    Filed: January 17, 2018
    Date of Patent: December 15, 2020
    Assignee: Panasonic Intellectual Property Management Co., Ltd.
    Inventors: Hidekazu Umeda, Kazuhiro Kaibara, Satoshi Tamura
  • Patent number: 10818656
    Abstract: A semiconductor device includes a first semiconductor region of a first conductivity type, second, third and fourth semiconductor regions of a second conductivity type, a first insulating film, a second insulating film, a first electrode contacting the first insulating film, and a second electrode contacting the second insulating film. The second and third semiconductor regions contact the first semiconductor region. The fourth semiconductor region contacts the first semiconductor region, is disposed between the second semiconductor region and the third semiconductor region. The first insulating film contacts a first portion of the first semiconductor region between the second semiconductor region and the fourth semiconductor region. The second insulating film contacts a second portion of the first semiconductor region between the third semiconductor region and the fourth semiconductor region. The second insulating film is thicker than the first insulating film.
    Type: Grant
    Filed: March 12, 2019
    Date of Patent: October 27, 2020
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
    Inventors: Hidekazu Inoto, Osamu Takata, Itaru Tamura, Naozumi Terada, Hiroyoshi Kitahara
  • Publication number: 20200083218
    Abstract: A semiconductor device includes a first semiconductor region of a first conductivity type, second, third and fourth semiconductor regions of a second conductivity type, a first insulating film, a second insulating film, a first electrode contacting the first insulating film, and a second electrode contacting the second insulating film. The second and third semiconductor regions contact the first semiconductor region. The fourth semiconductor region contacts the first semiconductor region, is disposed between the second semiconductor region and the third semiconductor region. The first insulating film contacts a first portion of the first semiconductor region between the second semiconductor region and the fourth semiconductor region. The second insulating film contacts a second portion of the first semiconductor region between the third semiconductor region and the fourth semiconductor region. The second insulating film is thicker than the first insulating film.
    Type: Application
    Filed: March 12, 2019
    Publication date: March 12, 2020
    Inventors: Hidekazu Inoto, Osamu Takata, Itaru Tamura, Naozumi Terada, Hiroyoshi Kitahara
  • Patent number: 10396224
    Abstract: According to one embodiment, a solar cell integrated film material includes a film material, a solar cell, a glass fiber sheet and bonding layers. The film material includes a heat-resistant fabric and a fluorocarbon resin layer formed on both sides of the heat-resistant fabric. The glass fiber sheet is provided between the film material and the solar cell. The bonding layers are provided between the film material and the glass fiber sheet, and between the glass fiber sheet and the solar cell.
    Type: Grant
    Filed: June 5, 2015
    Date of Patent: August 27, 2019
    Assignee: Chukoh Chemical Industries, Ltd.
    Inventors: Hidekazu Funo, Yoshihisa Fujita, Taisuke Yumura, Shigenori Tamura
  • Publication number: 20190186578
    Abstract: A damper device includes a case that is filled with oil, a weight that is stored in the case and includes a central through hole, a central guide rod that is inserted into the central through hole of the weight and configured to allow the weight to slide in the oil, and at least one flow passage that is formed in the weight and through which the oil flows.
    Type: Application
    Filed: December 13, 2018
    Publication date: June 20, 2019
    Inventors: Hidekazu TAMAKI, Takumi SATO, Hideki HITOMI, Junko KAWAKAMI, Naoharu TAMURA
  • Patent number: 7539440
    Abstract: The present invention provides a magnetic monocomponent developer which can obtain a stable conveying performance for a long period and an image forming method which uses the developer. In a magnetic monocomponent developer which is used in a developing unit which includes a developing vessel which accommodates a magnetic monocomponent developer therein, a developer carrying body which carries the magnetic monocomponent developer and conveys the magnetic monocomponent developer to a developing region, and a developer layer thickness restricting member which restricts a layer thickness of the magnetic monocomponent developer, the magnetic monocomponent developer includes toner particles which contain at least a binder resin and magnetic powder, and also includes following constitutions (a) to (c). (a) an average particle size of the toner particles may being set to a value which falls within a range from 6 to 9 ?m.
    Type: Grant
    Filed: April 19, 2006
    Date of Patent: May 26, 2009
    Assignee: Kyocera Mita Corporation
    Inventor: Hidekazu Tamura
  • Patent number: 7400849
    Abstract: A magnetic one-component toner of the invention contains at least a binding resin and a magnetic powder, and has a volume average particle size of 6.0 to 9.0 ?m, a compressibility of 15 to 50%, and a mean roundness of 0.950 to 0.960. The magnetic powder has at its surface a phosphorus element of 0.10 to 0.50% by weight. This toner is suitable for use in an image forming apparatus provided with a developer carrier made of stainless steel, or an image forming apparatus provided with an amorphous silicon photosensitive material. This toner has high transfer efficiency and less fog, thereby enabling to maintain image density for a long period of time, and form high image-quality image.
    Type: Grant
    Filed: June 23, 2005
    Date of Patent: July 15, 2008
    Assignee: Kyocera Mita Corporation
    Inventor: Hidekazu Tamura
  • Publication number: 20060240348
    Abstract: The present invention provides a magnetic monocomponent developer which can obtain a stable conveying performance for a long period and an image forming method which uses the developer. In a magnetic monocomponent developer which is used in a developing unit which includes a developing vessel which accommodates a magnetic monocomponent developer therein, a developer carrying body which carries the magnetic monocomponent developer and conveys the magnetic monocomponent developer to a developing region, and a developer layer thickness restricting member which restricts a layer thickness of the magnetic monocomponent developer, the magnetic monocomponent developer includes toner particles which contain at least a binder resin and magnetic powder, and also includes following constitutions (a) to (c). (a) an average particle size of the toner particles may being set to a value which falls within a range from 6 to 9 ?m.
    Type: Application
    Filed: April 19, 2006
    Publication date: October 26, 2006
    Inventor: Hidekazu Tamura
  • Publication number: 20050287456
    Abstract: A magnetic one-component toner of the invention contains at least a binding resin and a magnetic powder, and has a volume average particle size of 6.0 to 9.0 ?m, a compressibility of 15 to 50%, and a mean roundness of 0.950 to 0.960. The magnetic powder has at its surface a phosphorus element of 0.10 to 050% by weight. This toner is suitable for use in an image forming apparatus provided with a developer carrier made of stainless steel, or an image forming apparatus provided with an amorphous silicon photosensitive material. This toner has high transfer efficiency and less fog, thereby enabling to maintain image density for a long period of time, and form high image-quality image.
    Type: Application
    Filed: June 23, 2005
    Publication date: December 29, 2005
    Inventor: Hidekazu Tamura
  • Patent number: 6760560
    Abstract: A developing apparatus has a developer supporting member 41 with a surface roughness RZ in the range from 3.0 to 5.5 &mgr;m and a one-component developer T with a bulk density in the range from 0.35 to 0.55 g/ml, and an image is developed by forming a layer of the developer T on the developer supporting member 41. This makes it possible to form a thin toner layer stably despite changes in ambient conditions, and to prevent low image density and fogging. The absolute value of the amount of electric charge with which the developer T is charged is preferably in the range from 3.0 to 10.0 &mgr;C/g. The developer supporting member 41 is made preferably of stainless steel.
    Type: Grant
    Filed: May 30, 2002
    Date of Patent: July 6, 2004
    Assignees: Kyocera Mita Corporation, Kyocera Corporation
    Inventors: Takashi Nagai, Hidekazu Tamura, Seiji Kikushima, Toru Takatsuna, Hiroko Higuchi, Hiroaki Moriyama, Kouzou Teramoto, Noriya Okamoto
  • Publication number: 20030031482
    Abstract: A developing apparatus has a developer supporting member 41 with a surface roughness RZ in the range from 3.0 to 5.5 &mgr;m and a one-component developer T with a bulk density in the range from 0.35 to 0.55 g/ml, and an image is developed by forming a layer of the developer T on the developer supporting member 41. This makes it possible to form a thin toner layer stably despite changes in ambient conditions, and to prevent low image density and fogging. The absolute value of the amount of electric charge with which the developer T is charged is preferably in the range from 3.0 to 10.0 &mgr;C/g. The developer supporting member 41 is made preferably of stainless steel.
    Type: Application
    Filed: May 30, 2002
    Publication date: February 13, 2003
    Inventors: Takashi Nagai, Hidekazu Tamura, Seiji Kikushima, Toru Takatsuna, Hiroko Higuchi, Hiroaki Moriyama, Kouzou Teramoto, Noriya Okamoto
  • Publication number: 20020172882
    Abstract: A toner for electrophotography is so prepared that a wax in a binder resin has an average diameter in the range from 0.1 to 3.0 &mgr;m so as to alleviate hot offsetting and filming, and that the toner contains 1.0 to 2.5% by volume of a fine particle toner with particle diameters of 5.04 &mgr;m or smaller so as to grind, at an early stage, the toner components that have attached to a photoconductor and thereby prevent filming.
    Type: Application
    Filed: January 31, 2002
    Publication date: November 21, 2002
    Inventors: Takahiro Ishihara, Masami Tsujihiro, Yoichiro Watanabe, Norio Kubo, Hidekazu Tamura, Akinori Koyama, Takeshi Arakawa, Hiroshi Shimoyama
  • Patent number: 5670287
    Abstract: A magnetic carrier for electrophotographic developing agent wherein the surfaces of the magnetic core particles are partly coated with a thermosetting resin and a small amount of a low-melting or low-softening thermoplastic resin or wax, and at least recessed portions of the core particles are filled with these coating materials. The magnetic carrier has an electric resistance that is maintained within a range that is suited for forming the image, and suppresses the occurrence of spent toner.
    Type: Grant
    Filed: July 24, 1995
    Date of Patent: September 23, 1997
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Hideaki Kawata, Tomohide Iida, Yoshiteru Hatase, Hidekazu Tamura, Nobuaki Kawano