发明授权
- 专利标题: Short wavelength optical disk head having a changeable aperture
- 专利标题(中): 具有可变孔径的短波长光盘头
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申请号: US996033申请日: 1992-12-23
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公开(公告)号: US5281797A公开(公告)日: 1994-01-25
- 发明人: Kimio Tatsuno , Shigeru Nakamura , Hisataka Sugiyama , Masahiko Takahashi
- 申请人: Kimio Tatsuno , Shigeru Nakamura , Hisataka Sugiyama , Masahiko Takahashi
- 申请人地址: JPX Tokyo
- 专利权人: Hitachi, Ltd.
- 当前专利权人: Hitachi, Ltd.
- 当前专利权人地址: JPX Tokyo
- 优先权: JPX3-344729 19911226
- 主分类号: G11B7/125
- IPC分类号: G11B7/125 ; G11B7/00 ; G11B7/004 ; G11B7/0045 ; G11B7/005 ; G11B7/09 ; G11B7/135 ; G11B11/10 ; G11B11/105 ; G01S1/20
摘要:
An optical disk head having a short wavelength light source has an aperture diaphragm placed in the course of its focusing optical system which can change its aperture diameter depending on the pit size on an optical disk in order to allow recording on and reproducing from not only a short wavelength optical disk, but also a long wavelength optical disk. The aperture diameter is made larger for the smaller pit size and vice versa, and the light source output is adjusted depending on the aperture diameter so that the light amount coming from the disk surface to a photodetector cannot be changed with the aperture diameter.