Patents by Inventor Akihiko Koyama

Akihiko Koyama 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: 20220291472
    Abstract: An optical fiber (10) capable of minimizing strength deterioration includes a core (11) and a clad (12) arranged around the core (11) such that part of the core (11) is exposed. A rough surface portion is provided at least at part of an outer surface of the exposed portion (11a) of the core (11) exposed through the clad (12). The arithmetic surface roughness Ra of the rough surface portion is equal to or greater than 0.2 ?m. The average length Rsm of a rough curve element of the rough surface portion is equal to or greater than 17 ?m.
    Type: Application
    Filed: August 28, 2020
    Publication date: September 15, 2022
    Inventors: Hideyuki HIRANO, Keiichiro HIROSE, Syoji NAKAZONO, Akihiko KOYAMA, Takaya KONISHI, Ai TAKAHASHI, Masakatsu SETOGUCHI
  • Publication number: 20160166757
    Abstract: Liquid leakage is certainly detected and abnormality in an installation state is detected. A liquid detecting device 10 includes a liquid detection sensor 1 including an insulation sheet 14 exhibiting conductivity in the presence of liquid, electrode members 15 electrically isolated from each other, and a resistance member 18 connected to join the electrode members 15 together. In the liquid detecting device 10, the measurement device 2 measures a value of resistance between the electrode members 15. Based on the value of resistance between the electrode members 15, the liquid detecting device 10 identifies a liquid leakage state in which the insulation sheet 14 exhibits conductivity, a disconnected state in which the electrode members 15 are disconnected from the measurement device 2, and a measurement preparation completed state, and outputs identification information which corresponds to each identified state.
    Type: Application
    Filed: October 18, 2013
    Publication date: June 16, 2016
    Inventors: Akihiko KOYAMA, Keisho SHINOHARA, Junichi INOUE, Takashi MORITA
  • Patent number: 7459805
    Abstract: An image forming apparatus for forming an image with an electrophotographic process, that includes: a power source; a first drive unit having a capacitative load and driving each part of the apparatus; a second drive unit having a capacitative load and driving each part of the apparatus; and a power supply control circuit that is provided on a power supply path between the power source and the second drive unit, that switches whether or not electric power is supplied to the second drive unit. The power supply control circuit includes: a field-effect transistor with its source connected to the power source side of the power supply path, and its drain connected to the second drive unit side of the power supply path; a first resistive element connected between the field-effect transistor's gate and its source; a second resistive element and a capacitative element that are connected in parallel with the first resistive element, and connected with each other in series between the gate and the source.
    Type: Grant
    Filed: January 19, 2006
    Date of Patent: December 2, 2008
    Assignee: Seiko Epson Corporation
    Inventors: Tsuyoshi Kowari, Akihiko Koyama, Yasushige Hori
  • Publication number: 20060177236
    Abstract: An image forming apparatus for forming an image with an electrophotographic process, that includes: a power source; a first drive unit having a capacitative load and driving each part of the apparatus; a second drive unit having a capacitative load and driving each part of the apparatus; and a power supply control circuit that is provided on a power supply path between the power source and the second drive unit, that switches whether or not electric power is supplied to the second drive unit. The power supply control circuit includes: a field-effect transistor with its source connected to the power source side of the power supply path, and its drain connected to the second drive unit side of the power supply path; a first resistive element connected between the field-effect transistor's gate and its source; a second resistive element and a capacitative element that are connected in parallel with the first resistive element, and connected with each other in series between the gate and the source.
    Type: Application
    Filed: January 19, 2006
    Publication date: August 10, 2006
    Inventors: Tsuyoshi Kowari, Akihiko Koyama, Yasushige Hori
  • Patent number: 4744093
    Abstract: A method of detecting the levels of phase pulse signals involves the establishment of a pilot channel in addition to channels into which phase pulse signals are injected. Prior to the injection of the phase pulse signals, a transmitter injects a pilot signal into the pilot channel. A receiver sets a reception threshold level to a level somewhat lower than the peak level of the pilot signal, and a detection of the levels of the phase pulse signals is carried out by comparing the phase pulse signals with the reception threshold level established by the pilot signal so that ghost signals below the threshold level are eliminated.
    Type: Grant
    Filed: June 13, 1986
    Date of Patent: May 10, 1988
    Assignee: Osaki Electric Co., Ltd.
    Inventors: Yukio Arai, Masatoshi Takagi, Akihiko Koyama