Patents by Inventor Masaharu Muramatsu

Masaharu Muramatsu 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: 6031274
    Abstract: A back irradiation type light-receiving device, on which light is incident from the back side with respect to a charge-reading section of a semiconductor thin plate, is provided with a reinforcement member on the charge-reading section side. Electric signals are fed in and out from the charge-reading section by way of a polysilicon lead having a short wiring length and a low-resistance aluminum lead which is formed, after the completion of all the steps requiring a high-temperature treatment, so as to be physically and electrically direct-connected to the polysilicon lead. Accordingly, a charge generated in response to the received light can be read out with a high efficiency, while enabling a high-speed operation.
    Type: Grant
    Filed: October 10, 1997
    Date of Patent: February 29, 2000
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Masaharu Muramatsu, Hiroshi Akahori
  • Patent number: 5780913
    Abstract: When light is incident on the photoelectric surface of this electron tube, photoelectrons are emitted. These photoelectrons are accelerated and incident on an electron beam irradiation diode. A reverse voltage of about 100 V is applied to the electron beam irradiation diode to form a depletion region almost throughout an anode layer and near the p-n junction interface of a silicon substrate. The incident accelerated electrons release a kinetic energy in a heavily doped p-type layer having an electron incidence surface and the depleted anode layer to form electron-hole pairs. In this case, since the heavily doped p-type layer having the electron incidence surface is very thin, the energy is hardly released in this layer, and almost all energy is released in the depletion region. Signal charges extracted from the electron-hole pairs formed upon releasing the energy are output as a signal from two electrodes.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: July 14, 1998
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Masaharu Muramatsu, Motohiro Suyama, Koei Yamamoto
  • Patent number: 5654536
    Abstract: In a photomultiplier of the present invention, a semiconductor device arranged in an envelope to oppose a photocathode is constituted by a semiconductor substrate of a first conductivity type, a carrier multiplication layer of a second conductivity type different from the first conductivity type, which is formed on the semiconductor substrate by opitaxial growth, a breakdown voltage control layer of the second conductivity type, which is formed on the carrier multiplication layer and has a dopant concentration higher than that of the carrier multiplication layer, a first insulating layer formed on the breakdown voltage control layer and said carrier multiplication layer while partially exposing the surface of the breakdown voltage control layer as a receptor for photoelectrons and consisting of a nitride, and an ohmic electrode layer formed on a peripheral surface portion of the receptor of the breakdown voltage control layer.
    Type: Grant
    Filed: November 14, 1995
    Date of Patent: August 5, 1997
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Motohiro Suyama, Masaharu Muramatsu, Makoto Oishi, Yoshitaka Ishikawa, Koei Yamamoto
  • Patent number: 5347443
    Abstract: An inverter apparatus and method having a restarting function at an instantaneous power failure includes a residual voltage detector for detecting a frequency and a phase of a residual voltage of an induction motor based on a direction of a current flowing in an induction motor connected to an output of the inverter apparatus by ON/OFF control of switching elements in an upper arm or a lower arm of an inverter portion simultaneously from a time after elapse of a predetermined period of time from occurrence of the power failure until a time of determination of restarting timing. A restart unit is provided for restarting the induction motor at the frequency and the phase detected by the residual voltage detector in determining the restart timing based on said residual voltage detector and the recovery timing of the power failure.
    Type: Grant
    Filed: March 19, 1993
    Date of Patent: September 13, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Masaharu Muramatsu, Hiroshi Fujii