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Magneto-optical pickup device having phase compensating circuitry

  • US 5,625,725 A
  • Filed: 12/22/1994
  • Issued: 04/29/1997
  • Est. Priority Date: 12/28/1993
  • Status: Expired due to Fees
First Claim
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1. A magneto-optical pickup device, comprising:

  • a) a substrate;

    b) a light emitting device;

    c) a filter polarizing light emitted by said light emitting device to generate a first polarized component of light;

    d) a differential photo-detecting unit which separates light into first and second polarized components of light;

    e) an optical waveguide operatively configured and disposed on said substrate to guide said first polarized component of light from said filter onto a magneto-optical recording medium, and to guide light reflected back from said medium to said differential photo-detecting unit;

    f) a differential amplifying circuit coupled to an output of said differential photo-detecting unit, said differential amplifying circuit providing an output signal which varies according to a magnetization direction of magnetization information recorded on the magneto-optical recording medium;

    g) a feedback circuit coupled to said differential amplifying circuit, which feedback circuit is configured to generate a phase compensating signal that correlates to a phase difference between said first and second polarized components of light in said light reflected from said magneto-optical recording medium; and

    h) phase compensating means for receiving said phase compensating signal and minimizing said phase difference.

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