发明名称 |
Current mirror amplifier for use in an optical data medium driving apparatus and servo-circuit |
摘要 |
An optical data medium driving apparatus which constitutes amplifiers for an output current signal of a photosensor including a plurality of current mirror circuits having different amplification factors in order to switch, in a wide range, the output current signal of the photosensor. The photosensor detects a quantity of the reflected light corresponding to a variation of the quantity of reflected light from an optical data medium having various characteristics. The output is obtained with high accuracy and in a wide band. A servo-circuit is used for an AGC circuit and normalizes a difference signal from each light receiving surface at a photosensor having a plurality of light receiving surfaces. An A/D converter is given the difference signal as an analog input signal and the sum signal as the reference input signal. The A/D converter outputs an offset binary type digital signal, thereby being inexpensive to produce, easy to be integrated having high function, and high in reliability.
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申请公布号 |
USRE34769(E) |
申请公布日期 |
1994.11.01 |
申请号 |
US19920983088 |
申请日期 |
1992.11.27 |
申请人 |
MITSUBISHI DENKI KABUSHIKI KAISHA |
发明人 |
YOSHIMOTO, KYOSUKE;SHIMODA, KYOUJI |
分类号 |
G11B7/09;H03K17/62;(IPC1-7):G01J1/20 |
主分类号 |
G11B7/09 |
代理机构 |
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主权项 |
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地址 |
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