发明名称 |
Optical record and reproduction apparatus. |
摘要 |
<p>An optical record and reproduction apparatus, in which a light beam generated by a light source is concentrated onto an information recording medium by a focusing device, and the light beam reflected by the information recording medium is detected by a light detector to obtain a tracking error signal. A liquid crystal panel having a transparent electrode aligned in a striped form and a polarizing plate or birefringent phase difference plate constitute a beam divider for obtaining a main beam and supplementary beams without any accompanying mechanical movement. The beam divider is arranged between the light source and the focusing device. By selectively applying a voltage to the transparent electrode, the liquid crystal panel is made to function in the same manner as a diffraction grating. Another transparent electrode aligned in a striped form at an inclined angle may also be provided. <IMAGE></p> |
申请公布号 |
EP0459790(A2) |
申请公布日期 |
1991.12.04 |
申请号 |
EP19910304870 |
申请日期 |
1991.05.30 |
申请人 |
MITSUBISHI DENKI KABUSHIKI KAISHA |
发明人 |
TOIDE, EIICHI;YOSHIHARA, TORU |
分类号 |
G11B7/09;G11B7/13;G11B7/135 |
主分类号 |
G11B7/09 |
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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