发明名称 LAMINATED WAVE PLATE AND OPTICAL PICKUP DEVICE USING THE SAME
摘要 <P>PROBLEM TO BE SOLVED: To obtain a laminated quarter-wave plate having a bandwidth of a plurality of wavelengths to be a phase difference of 90&deg; broadened. <P>SOLUTION: A laminated wave plate includes a first wave plate having a phase difference of &Gamma;1 and a second wave plate having a phase difference of &Gamma;2 with respect to a wavelength &lambda;. The first wave plate and the second wave plate are bonded together so that an optical axis of the first wave plate and an optical axis of the second wave plate are intersected each other to function as a quarter-wave plate as a whole. The laminated wave plate comprises following equations from (1) to (6): &Gamma;1=360&times;(n1+1) (1); &Gamma;2=90&times;(2&times;n2+1) (2); &Delta;&Gamma;1=(&Gamma;12a-&Gamma;11a)/(&lambda;12-&lambda;11) (3); &Delta;&Gamma;2=(&Gamma;12b-&Gamma;11b)/(&lambda;12-&lambda;11) (4); cos 2&theta;1=1-(1-cos &Delta;&Gamma;2)/2(1-cos &Delta;&Gamma;1) (5); and &theta;2=45&deg;&plusmn;5&deg; (6), wherein &theta;1 is an optic axis azimuth of the first wave plate, &theta;2 is an optic axis azimuth of the second wave plate, and each of &lambda;11&le;&lambda;&le;&lambda;12, n1, and n2 is a natural number starting from 1. <P>COPYRIGHT: (C)2008,JPO&INPIT
申请公布号 JP2007311012(A) 申请公布日期 2007.11.29
申请号 JP20070106754 申请日期 2007.04.16
申请人 EPSON TOYOCOM CORP 发明人 OTO MASAYUKI
分类号 G11B7/135;G02B5/30 主分类号 G11B7/135
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