Invention Grant
- Patent Title: Optical pickup device and optical disc device
- Patent Title (中): 光拾取装置和光盘装置
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Application No.: US12334698Application Date: 2008-12-15
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Publication No.: US07929399B2Publication Date: 2011-04-19
- Inventor: Hiroaki Matsumiya , Kazuo Momoo
- Applicant: Hiroaki Matsumiya , Kazuo Momoo
- Applicant Address: JP Osaka
- Assignee: Panasonic Corporation
- Current Assignee: Panasonic Corporation
- Current Assignee Address: JP Osaka
- Agency: Renner, Otto, Boisselle & Sklar, LLP
- Priority: JP2007-324341 20071217
- Main IPC: G11B7/135
- IPC: G11B7/135

Abstract:
When recording on and/or reproducing from an information recording medium having a plurality of recording layers is performed, there has been a problem in appropriately detecting a control signal at the time of the recording and/or reproducing, since reflected light from a recording layer, which does not undergo the recording and/or reproducing, enters a photodetector concurrently with reflected light from a recording layer which undergoes the recording and/or reproducing. In the present invention, a polarization hologram is used to diffract light outputted from a light source and to generate a main beam, which is a zeroth-order light beam, and a pair of sub beams, which is a positive first-order light beam and a negative first-order light beam each having a polarization direction perpendicular to a polarization direction of the main beam. Accordingly, it is possible to prevent the reflected sub beams from a recording layer, which is a target undergoing recording and/or reproducing, from interfering with the reflected main beam from a recording layer, which is a non-target not undergoing the recording and/or reproducing. Therefore, it is possible to obtain an accurate control signal based on the sub beams, and also possible to realize an optical pickup device having a preferable recording performance.
Public/Granted literature
- US20090154323A1 OPTICAL PICKUP DEVICE AND OPTICAL DISC DEVICE Public/Granted day:2009-06-18
Information query
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