Patents by Inventor Masami Yamada

Masami Yamada 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: 5986387
    Abstract: This invention relates to a transmission type electron multiplier having a high secondary electron generation efficiency and having the structure capable of detecting positions of incidence of detected light, and also to an electron tube provided therewith. The electron tube comprises a closed container, an electron source, housed in the closed container, for emitting electrons into the closed container, an anode disposed so as to face the electron source, and a transmission type electron multiplier disposed between the electron source and the anode. Particularly, the transmission type electron multiplier comprises a thin film of diamond or a material containing a principal component of diamond, and a reinforcing member for reinforcing the thin film, the reinforcing member having an aperture for exposing a part of the thin film.
    Type: Grant
    Filed: November 5, 1997
    Date of Patent: November 16, 1999
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Toru Hirohata, Hirofumi Kan, Masami Yamada
  • Patent number: 5982094
    Abstract: A photocathode includes a first layer of polycrystalline diamond or a material mainly composed of polycrystalline diamond. The first layer of polycrystalline diamond may be terminated with hydrogen, or oxygen, and a second layer of an alkali metal or compound of an alkali metal, may be provided on the first layer of polycrystalline diamond whose surface is terminated with hydrogen or oxygen. The photocathode can be use for both reflection and transmission electron tubes and can yield a quantum efficiency higher than that in a monocrystal diamond thin film.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: November 9, 1999
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Toru Hirohata, Hirofumi Kan, Masami Yamada
  • Patent number: 5959400
    Abstract: The present invention relates to an electron tube having a configuration which can maintain its operating stability for a long period of time. The electron tube comprises, at least, a field emitter which is made of diamond or a material mainly composed of diamond and has a surface terminated with hydrogen, and a sealed envelope for accommodating the diamond field emitter. Due to the hydrogen termination, the electron affinity of the diamond field emitter is set to a negative state. Also, hydrogen is enclosed within the sealed envelope. Due to this configuration, the hydrogen-terminated state of the diamond field emitter surface is stabilized, and the electron affinity of the diamond emitter is restrained from changing for a long period of time.
    Type: Grant
    Filed: October 14, 1997
    Date of Patent: September 28, 1999
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Toru Hirohata, Hirofumi Kan, Masami Yamada
  • Patent number: 5939159
    Abstract: The invention provides an aqueous resin dispersion that comprises 1) an acrylic resin (A), 2) an aromatic epoxy resin (B), and 3) a bisphenol F product (C) that are dispersed in an aqueous medium at a pH of from about 4 to 11. The invention also provides an aqueous base-coat agent, coated substrates and coating methods that comprises the aqueous resin dispersion.
    Type: Grant
    Filed: September 16, 1996
    Date of Patent: August 17, 1999
    Assignee: Toyo Manufacturing Company, Ltd.
    Inventors: Teruo Shiono, Masami Yamada, Sanji Harada, Masahiro Ihara, Takeshi Tuyama, Tetsuhisa Nakamura
  • Patent number: 5747826
    Abstract: The present invention provides a photoemission device excellent in quantum efficiency of photoelectric conversion, a high-sensitive electron tube employing it, and a high-sensitive photodetecting apparatus. A photoemission device of the present invention is arranged to have a photon absorbing layer for absorbing incident photons to excite photoelectrons, an insulator layer layered on one surface of the photon absorbing layer, a lead electrode layered on the insulator layer, and a contact formed on the other surface of the photon absorbing layer to apply a predetermined polarity voltage between the lead electrode and the other surface of the photon absorbing layer, whereby the photoelectrons excited by the incident photons entering the photon absorbing layer and moving toward the one side are made to be emitted by an electric field formed between the lead electrode and the one surface by the predetermined polarity voltage.
    Type: Grant
    Filed: June 27, 1996
    Date of Patent: May 5, 1998
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Toru Hirohata, Tuneo Ihara, Masami Yamada
  • Patent number: 5732316
    Abstract: An image forming apparatus includes a first developing device, accommodating a first kind of toner without an offset preventing agent, a second developing device accommodating a second kind of toner containing an offset preventing agent, and a roller fixing device having a supply portion for supplying an offset preventing agent. The image forming apparatus changes the amount of the offset preventing agent to be supplied to the fixing roller between the case of fixing a copy image formed with the first kind of toner and the case of fixing a copy image formed with the second kind of toner.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: March 24, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Hiroyuki Yamasaki, Masahide Ueda, Yoshihisa Terasaka, Eiichi Sano, Masahiko Matsuura, Atsuto Hirai, Tomoo Izumi, Masami Yamada
  • Patent number: 5724629
    Abstract: This invention relates to a liquid developer monitoring device comprising a first electrode which contacts with a liquid developer comprising a liquid medium and electrically charged toner particles dispersed therein, a second electrode being either a developing roller or a separate roller which provides a fresh surface and immerses said surface in the liquid developer, an electric power source which applies a bias voltage between said first and second electrodes so as to deposit the toner particles on the second electrode, and a sensor which measures magnitude of current flowing between said first and second electrodes during the deposition of the toner particles. A cleaning device removes the deposited toner on the second electrode. The sensor includes an electric coil, a magnet inserted in the coil and a Hall element.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: March 3, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Shuji Iino, Toshimitsu Fujiwara, Hidetoshi Miyamoto, Masami Yamada
  • Patent number: 5710435
    Abstract: A photoelectric emission surface which is excellent in stability and reproducibility of photoelectric conversion characteristics and has a structure capable of obtaining a high photosensitivity is provided. A predetermined voltage is applied between an upper surface electrode and a lower surface electrode by a battery. Upon application of this voltage, a p-n junction formed between a contact layer and an electron emission layer is reversely biased. A depletion layer extends from the p-n junction into the photoelectric emission surface, and an electric field is formed in the electron emission layer and a light absorbing layer in a direction for accelerating photoelectrons. When incident light is absorbed in the light absorbing layer to excite photoelectrons, the photoelectrons are accelerated by the electric field toward the emission surface.
    Type: Grant
    Filed: December 20, 1995
    Date of Patent: January 20, 1998
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Toru Hirohata, Tomoko Suzuki, Masami Yamada
  • Patent number: 5680007
    Abstract: A photoelectric emission surface which is excellent in stability and reproducibility of photoelectric conversion characteristics and has a structure capable of obtaining a high photosensitivity is provided. A predetermined voltage is applied between an upper surface electrode and a lower surface electrode by a battery. Upon application of this voltage, a p-n junction formed between a contact layer and an electron emission layer is reversely biased. A depletion layer extends from the p-n junction into the photoelectric emission surface, and an electric field is formed in the electron emission layer and a light absorbing layer in a direction for accelerating photoelectrons. When incident light is absorbed in the light absorbing layer to excite photoelectrons, the photoelectrons are accelerated by the electric field toward the emission surface.
    Type: Grant
    Filed: July 27, 1995
    Date of Patent: October 21, 1997
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Toru Hirohata, Tomoko Suzuki, Masami Yamada
  • Patent number: 5652438
    Abstract: A light-emitting semiconductor device (10) consecutively has a sapphire substrate (1), an AlN buffer layer (2), a silicon (Si) doped GaN n.sup.+ -layer (3) of high carrier (n-type) concentration, a Si-doped (Al.sub.X2 Ga.sub.1-x2).sub.y2 In.sub.1-y2 N n.sup.+ -layer (4) of high carrier (n-type) concentration, a zinc (Zn) and Si-doped (Al.sub.x1 Ga.sub.1-x1).sub.y1 In.sub.1-y1 N emission layer (5), and a Mg-doped (Al.sub.x2 Ga.sub.1-x2).sub.y2 In.sub.1-y2 N p-layer (6). The AlN buffer layer (2) has a 500 .ANG. thickness. The GaN n.sup.+ -layer (3) is about 2.0 .mu.m thick and has a 2.times.10.sup.18 /cm.sup.3 electron concentration. The n.sup.+ -layer (4) is about 2.0 .mu.m thick and has a 2.times.10.sup.18 /cm.sup.3 electron concentration. The emission layer (5) is about 0.5 .mu.m thick. The p-layer 6 is about 1.0 .mu.m thick and has a 2.times.10.sup.17 /cm.sup.3 hole concentration. Nickel electrodes (7, 8) are connected to the p-layer (6) and n.sup.+ -layer (4), respectively.
    Type: Grant
    Filed: July 19, 1995
    Date of Patent: July 29, 1997
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Michinari Sassa, Makoto Tamaki, Masayoshi Koike, Naoki Shibata, Masami Yamada, Takahide Oshio
  • Patent number: 5591986
    Abstract: The present invention provides a photoemission device excellent in quantum efficiency of photoelectric conversion, a high-sensitive electron tube employing it, and a high-sensitive photodetecting apparatus. A photoemission device of the present invention is arranged to have a photon absorbing layer for absorbing incident photons to excite photoelectrons, an insulator layer layered on one surface of the photon absorbing layer, a lead electrode layered on the insulator layer, and a contact formed on the other surface of the photon absorbing layer to apply a predetermined polarity voltage between the lead electrode and the other surface of the photon absorbing layer, whereby the photoelectrons excited by the incident photons entering the photon absorbing layer and moving toward the one side are made to be emitted by an electric field formed between the lead electrode and the one surface by the predetermined polarity voltage.
    Type: Grant
    Filed: September 2, 1994
    Date of Patent: January 7, 1997
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Toru Hirohata, Tuneo Ihara, Masami Yamada
  • Patent number: 5568244
    Abstract: An image forming apparatus for forming an image onto a sheet includes a sheet supporting member; a charger which is positioned in a vicinity of the sheet supporting member; and a device for controlling the charger so that the charger charges a specific portion of the sheet supporting member corresponding to a leading edge portion of the sheet to an electrostatic potential higher than that of a remaining portion of the sheet supporting member. A method of adhering a sheet to a sheet supporting member during an image forming process includes charging a specific portion of the sheet supporting member corresponding to a leading edge portion of the sheet to a first electrostatic potential; charging a remaining portion of the sheet supporting member to a second electrostatic potential that is lower than the first electrostatic potential; and delivering the sheet to the sheet supporting member so that a leading edge portion of the sheet is aligned with the specific portion of the sheet supporting member.
    Type: Grant
    Filed: December 12, 1994
    Date of Patent: October 22, 1996
    Assignee: Minolta Co., Ltd.
    Inventors: Atsuto Hirai, Masahide Ueda, Yoshihisa Terasaka, Eiichi Sano, Masahiko Matsuura, Hiroyuki Yamasaki, Masami Yamada, Tomoo Izumi
  • Patent number: 5485257
    Abstract: The present invention relates to a method of producing a plurality sets of prints from a plural-page original in an image forming apparatus having an endless transfer member onto which images are transferred from an image retaining member. The endless transfer member is operable to support a predetermined number (X) of images during one cyclic movement thereof. In this method, a first printing operation is executed in which the predetermined number (X) of images of a first page of the original are formed on the endless transfer member during one cyclic movement thereof when a desired number (Y) of sets of prints exceeds said predetermined number (X). Second, the first printing operation is repeated until a remaining number (M) of image(s) of the first page becomes less than said predetermined number (X).
    Type: Grant
    Filed: October 19, 1994
    Date of Patent: January 16, 1996
    Assignee: Minolta Co., Ltd.
    Inventors: Masahide Ueda, Tomoo Izumi, Hiroyuki Yamasaki, Atsuto Hirai, Masahiko Matsuura, Eiichi Sano, Yoshihisa Terasaka, Masami Yamada, Satoshi Yoshida
  • Patent number: 5471051
    Abstract: There is disclosed a photocathode comprising:a photoelectric conversion layer for internally exciting photoelectrons in response to incident photons; a semiconductor layer having a photoelectron emission surface for emitting the photoelectrons generated and accelerated in the photoelectric conversion layer from the photoelectron emission surface; an upper surface electrode formed on the photoelectron emission surface of the semiconductor layer; and a lower surface electrode formed on the semiconductor layer so that the lower surface electrode is opposite to the upper surface electrode through the semiconductor layer, the upper surface electrode being divided so as to provide a plurality of pixel electrodes which are electrically insulated from each other, the plurality of pixel electrodes being respectively connected to a plurarity of bias application wires.
    Type: Grant
    Filed: June 1, 1994
    Date of Patent: November 28, 1995
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Katsuyuki Kinoshita, Toru Hirohata, Tuneo Ihara, Masami Yamada, Norio Asakura, Yasuharu Negi, Tomoko Suzuki
  • Patent number: 5336902
    Abstract: This invention relates to a semiconductor photo-electron-emitting device for emitting photoelectrons excited from the valence band to the conduction band by incident photons on a semiconductor layer. The device includes a Schottky electrode formed on the emitting surface on a surface of the semiconductor layer, and a conductor layer formed on a surface opposite to the emitting surface. A set bias voltage is applied between the Schottky electrode and the conductor layer to accelerate photoelectrons generated by the excitation of incident photons to the emitting surface and to transfer the accelerated photoelectrons from an energy band of a smaller effective mass to an energy band of a larger effective mass.
    Type: Grant
    Filed: October 5, 1992
    Date of Patent: August 9, 1994
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Nigaki, Tuneo Ihara, Toru Hirohata, Tomoko Suzuki, Kimitsugu Nakamura, Norio Asakura, Masami Yamada, Yasuharu Negi, Tomihiko Kuroyanagi, Yoshihiko Mizushima
  • Patent number: 5240664
    Abstract: The present invention is directed to a door weather strip in which the corner portions thereof are integrally formed with straight portions thereof. In order to obtain a predetermined sealing interference, the cross sectional shape of the corner portions of hollow sealing portion and the lip seal of the weather strip is arranged to be longer than that in the straight portion. Alternatively, the sealing portion is raised as to have a predetermined shape when the corners are formed. Said formed shapes are solidified by vulcanization after the weather strip has been plastically deformed before the vulcanization.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: August 31, 1993
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Keizo Hayashi, Masami Yamada, Masahiro Nozaki
  • Patent number: 5099612
    Abstract: The present invention is directed to a door weather strip in which the corner portions thereof are integrally formed with straight portions thereof. In order to obtain a predetermined sealing interference, the cross sectional shape of the corner portions of hollow sealing portion and the lip seal of the weather strip is arranged to be longer than that in the straight portion. Alternatively, the sealing portion is raised as to have a predetermined shape when the corners are formed. Said formed shapes are solidified by vulcanization after the weather strip has been plastic deformed before the vulcanization.
    Type: Grant
    Filed: March 6, 1991
    Date of Patent: March 31, 1992
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Keizo Hayashi, Masami Yamada, Masahiro Nozaki
  • Patent number: 5099291
    Abstract: An image forming apparatus which has a contact glass, an original transporting part for transporting a sheet of original onto the contact glass, an optical exposure system for scanning the sheet of original placed on the contact glass by reciprocating movement below the contact glass, an image forming part for forming an image of the original obtained by the optical exposure system on a recording sheet, and a part for supplying the recording sheet to the image forming part.
    Type: Grant
    Filed: November 9, 1990
    Date of Patent: March 24, 1992
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Yoshiki Yoshioka, Masami Yamada, Hiroyuki Tsuji, Tadashi Fujioka, Koji Ujino
  • Patent number: 5078376
    Abstract: A copying machine having a binding function capable of automatically binding discharged copied sheets using a predetermined holding device includes a binding function selection unit and a maximum bindable sheet count displaying unit. Since the maximum bindable number of sheets of an original can be displayed according to a copying mode prior to copying, the binding function of the copying machine can be utilized more effectively.
    Type: Grant
    Filed: July 17, 1990
    Date of Patent: January 7, 1992
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Masami Yamada, Yoshiki Yoshioka
  • Patent number: 4939542
    Abstract: An image forming apparatus having a potential sensor for measuring a potential at the surface of a photoreceptor drum; a voltage generation circuit for generating a voltage lower than a voltage to be actually induced at the surface of the photoreceptor drum in the course of image formation; switching means for switching a condition so that the photoreceptor is connected to the voltage generation circuit or earthed; and charger-output control means for obtaining a value of a surface potential of the photoreceptor measured by the potential sensor at the time when a voltage form the voltage generation circuit is applied to the photoreceptor by operating the switching means, estimating by arithmetic operation, on the basis of the measured value thus obtained, a value to be measured by the potential sensor when a high voltage is actually induced at the photoreceptor surface in the course of the image formation, and controlling an output from the charger based on the value estimated by the above arithmetic operatio
    Type: Grant
    Filed: May 10, 1989
    Date of Patent: July 3, 1990
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Shigeo Kurando, Hiromi Sakata, Masami Yamada, Hidehiro Tabuchi, Yukio Hashimoto, Yoshinobu Takemura