Patents by Inventor Hirotake Ohta

Hirotake Ohta 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).

  • Silicon cleaning method for semiconductor materials and polycrystalline silicon chunk
    Patent number: 7223303
    Abstract: A cleaning method cleans silicon for semiconductor materials using pure water treated by a reverse osmosis treatment and by ion exchange treatment and reduces the aluminum and iron remaining on the silicon surface.
    Type: Grant
    Filed: August 26, 2004
    Date of Patent: May 29, 2007
    Assignees: Mitsubishi Materials Corporation, Mitsubishi Polycrystalline Silicon America Corporation
    Inventor: Hirotake Ohta
  • Silicon cleaning method for semiconductor materials and polycrystalline silicon chunk
    Publication number: 20060042539
    Abstract: A cleaning method cleans silicon for semiconductor materials using pure water treated by a reverse osmosis treatment and by ion exchange treatment and reduces the aluminum and iron remaining on the silicon surface.
    Type: Application
    Filed: August 26, 2004
    Publication date: March 2, 2006
    Applicants: Mitsubishi Materials Corporation, Mitsubishi Polycrystalline Silicon America Corporation
    Inventor: Hirotake Ohta
  • Web printing press with replaceable print unit
    Patent number: 4955299
    Abstract: A blanket to blanket Typed Printing Press for separately using, one at a time, a plurality of printing units each of which includes two sets of plated and blanket cylinders, where one printing unit has different standard sizes of cylinders with respect to another printing unit, and a pair of ink feeding units. Each printing unit, being disposed between the ink feeding units is replaceable and the space inbetween each of the ink feeding units, is controlable so as to feed adequately the ink required for each portion of the printing unit.
    Type: Grant
    Filed: November 20, 1989
    Date of Patent: September 11, 1990
    Assignee: Taiyo Kikai Ltd.
    Inventor: Hirotake Ohta