Invention Grant
US07948854B2 Optical head apparatus and optical information recording/reproducing apparatus 有权
光头装置和光信息记录/重放装置

  • Patent Title: Optical head apparatus and optical information recording/reproducing apparatus
  • Patent Title (中): 光头装置和光信息记录/重放装置
  • Application No.: US12091799
    Application Date: 2006-10-27
  • Publication No.: US07948854B2
    Publication Date: 2011-05-24
  • Inventor: Ryuichi Katayama
  • Applicant: Ryuichi Katayama
  • Applicant Address: JP Tokyo
  • Assignee: NEC Corporation
  • Current Assignee: NEC Corporation
  • Current Assignee Address: JP Tokyo
  • Agency: Young & Thompson
  • Priority: JP2005-314219 20051028; JP2006-277256 20061011
  • International Application: PCT/JP2006/321489 WO 20061027
  • International Announcement: WO2007/049738 WO 20070503
  • Main IPC: G11B7/00
  • IPC: G11B7/00
Optical head apparatus and optical information recording/reproducing apparatus
Abstract:
An optical head apparatus of an optical information recording/reproducing apparatus is provided with a light source. An objective lens focuses an output light emitted by said light source on a disc optical recording medium for which a groove or a pit for tracking is provided. T photo-detector receives a reflected light reflected by said optical recording medium. A polarizing splitter unit splits said output light and said reflected light. A quarter-wave plate disposed between said polarizing splitter section and said objective lens. A birefringence compensating unit reduces a change in an amplitude of a track error signal caused by birefringence in a protective layer of said optical recording medium.
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