发明授权
US5754512A Correction elements to lower light intensity around an optical axis of
an optical head with a plurality of focal points
失效
校正元件，用于使具有多个焦点的光学头的光轴周围的光强度降低
- 专利标题： Correction elements to lower light intensity around an optical axis of an optical head with a plurality of focal points
- 专利标题（中）： 校正元件，用于使具有多个焦点的光学头的光轴周围的光强度降低
-
申请号： US654771申请日： 1996-05-29
-
公开(公告)号： US5754512A公开(公告)日： 1998-05-19
- 发明人: Yoshiaki Komma , Sadao Mizuno , Hideki Hayashi , Kenichiro Urairi
- 申请人： Yoshiaki Komma , Sadao Mizuno , Hideki Hayashi , Kenichiro Urairi
- 申请人地址： JPX Kadoma
- 专利权人： Matsushita Electric Industrial Co., Ltd.
- 当前专利权人： Matsushita Electric Industrial Co., Ltd.
- 当前专利权人地址： JPX Kadoma
- 优先权： JPX7-131360 19950530
- 主分类号： G11B7/00
- IPC分类号： G11B7/00 ; G11B7/135
摘要：
An optical head apparatus which records or reproduces signals stably on optical disks having different thicknesses. A correction hologram element or a correction filter is provided between a light source and a 2-focus lens in order to decrease optical intensity at a portion distant from the optical axis or to change the optical path length. The light which passes the correction hologram element or a correction filter is converged by the 2-focus lens as a micro-spot on an optical disk. The 2-focus lens comprises a hologram lens which diffracts a part of the light beam and an object lens.
信息查询
IPC分类:
