发明授权
- 专利标题: Photo-detector amplifier circuit for optical disk device
- 专利标题(中): 用于光盘设备的光电检测放大器电路
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申请号: US10294573申请日: 2002-11-15
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公开(公告)号: US07133346B2公开(公告)日: 2006-11-07
- 发明人: Takanori Okuda , Takashi Yokoyama
- 申请人: Takanori Okuda , Takashi Yokoyama
- 申请人地址: JP Osaka
- 专利权人: Sharp Kabushiki Kaisha
- 当前专利权人: Sharp Kabushiki Kaisha
- 当前专利权人地址: JP Osaka
- 代理机构: Nixon & Vanderhye P.C.
- 优先权: JP2001-382104 20011214
- 主分类号: G11B7/00
- IPC分类号: G11B7/00 ; H01L31/00
摘要:
A two-stage amplifier of a first-stage amplifier 21 and second-stage amplifiers 22 and 23 is provided. A writing mode and reproducing modes are switched in the first-stage amplifier 21 by switching a parallel circuit of a feedback capacitor Cf1w and a feedback resistor Rf1w and a parallel circuit of a feedback capacitor Cf1r and a feedback resistor Rf1r. The second-stage amplifier 23 is provided with feedback resistors Rf22 and Rf23 that are connected to each other in parallel. The feedback resistor Rf23 is connected in the feedback loop by a switch transistor QSW only when reproducing a high-reflective disk. This enables an amplifier gain to be suitably set for each of writing, low-reflective disk reproducing, and high-reflective disk reproducing. As a result, desirable reproducing characteristics can be obtained for the low-reflective disk while accommodating high-speed writing with a large laser power.
公开/授权文献
- US20030112727A1 Photo-detector amplifier circuit for optical disk device 公开/授权日:2003-06-19