发明名称 |
COMPOUND OBJECTIVE LENS, DIFFRACTION ELEMENT, OPTICAL HEAD DEVICE, OPTICAL INFORMATION DEVICE, OBJECTIVE LENS DRIVING METHOD AND CONTROL DEVICE |
摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical head device for using an objective lens having a large NA to record or playback a high-density optical disk, in which a sawtooth-shaped diffraction element is used to record and playback a conventional optical disk, such as a DVD and a CD. <P>SOLUTION: In one embodiment of a compound objective lens such as in an optical head device, a level difference in which optical path length is one wavelength or more for blue light, and optical path length is less than one wavelength for red light and infrared light is used to give an action reverse to the red light and the infrared light to the blue light. By an effect of making working distance to a CD and a DVD large, compatibility between the CD and the DVD can be achieved. An optical element is formed with an objective lens into a signal body to perform tracking servo tracking. <P>COPYRIGHT: (C)2012,JPO&INPIT |
申请公布号 |
JP2011253615(A) |
申请公布日期 |
2011.12.15 |
申请号 |
JP20110195094 |
申请日期 |
2011.09.07 |
申请人 |
PANASONIC CORP |
发明人 |
KANEUMA YOSHIAKI;TANAKA TOSHIYASU;YAMASAKI FUMITOMO |
分类号 |
G02B5/18;G02B13/00;G02B13/18;G11B7/135 |
主分类号 |
G02B5/18 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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