发明申请
US20110176403A1 OPTICAL HEAD DEVICE, OPTICAL INFORMATION PROCESSING DEVICE, AND SIGNAL DETECTION METHOD
审中-公开
光学头装置,光信息处理装置和信号检测方法
- 专利标题: OPTICAL HEAD DEVICE, OPTICAL INFORMATION PROCESSING DEVICE, AND SIGNAL DETECTION METHOD
- 专利标题(中): 光学头装置,光信息处理装置和信号检测方法
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申请号: US12919395申请日: 2009-01-06
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公开(公告)号: US20110176403A1公开(公告)日: 2011-07-21
- 发明人: Hiroaki Yamamoto , Masayuki Ono , Masahiko Nishimoto
- 申请人: Hiroaki Yamamoto , Masayuki Ono , Masahiko Nishimoto
- 优先权: JP2008-168479 20080627
- 国际申请: PCT/JP2009/000019 WO 20090106
- 主分类号: G11B20/18
- IPC分类号: G11B20/18
摘要:
An optical head device includes a light source (30) configured to emit a light beam, a light collecting optical system configured to converge the light beam onto an information recording medium (10), a hologram element (20) configured to diffract the light beam reflected from the information recording medium (10), and a photodetector (40) having a plurality of detection regions configured to receive the light beam diffracted by the hologram element (20). The hologram element (20) has two diffraction regions (261 and 262) separated from each other by a straight line (260) extending in a radial direction of the information recording medium (10). At least one of the two diffraction regions has a pattern which introduces coma aberration in the radial direction. The light diffracted by the diffraction region having the coma aberration has coma aberration in the radial direction.
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