发明名称 |
OPTICAL ELEMENT, OPTICAL DISC AND ROTARY ENCODER WITH THE OPTICAL ELEMENT |
摘要 |
A waveguide path type optical pickup is provided for preventing a returning light from returning back to a light source. A filter for selectively allowing either Te polarized light or TM polarized light to pass through the filter is provided in an optical path from a light source to an optical path deflector. An optical part for changing the polarized state of light is provided in an optical path from the optical path changing part to an information recording medium, thereby prevent a reduction in S/N ratio or reproducing signal. |
申请公布号 |
AU3520589(A) |
申请公布日期 |
1990.01.25 |
申请号 |
AU19890035205 |
申请日期 |
1989.05.25 |
申请人 |
HITACHI LTD. |
发明人 |
HIROYUKI MINEMURA;YOSHIO SATO;NOBUYOSHI TSUBOI;HIROAKI KOYANAGI;SHINJI OHYAMA |
分类号 |
G11B7/135;G01P3/486;G11B7/12 |
主分类号 |
G11B7/135 |
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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