Patents by Inventor Kantarou Nakamura

Kantarou Nakamura 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: 8472301
    Abstract: Provided is an objective optical element which can appropriately correct degradation from spherical aberration upon fluctuation of a light source wavelength while maintaining light use efficiency, just by changing the magnification of the objective optical element, and which can record/reproduce information to/from different optical discs. Also provided is an optical pickup device using the objective optical element. When a light flux having two different wavelengths ?11, ?12 (wherein ?11<?12 and ?12??11=5 nm) within a range of wavelength ?1 is introduced to the objective optical element to measure the wavefront aberration, the following third order and fifth order spherical aberrations in unit of ?rms are obtained: SA3(?11), SA5(?11), SA3(?12), SA5(?12). If ?SA3=|SA3(?12)?SA3(?11)|, ?SA5=|SA5(?12)?SA5(?11)|, the following expression is satisfied 0.18>?SA3>?SA5>0 (1).
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: June 25, 2013
    Assignee: Konica Minolta Opto, Inc.
    Inventor: Kantarou Nakamura