MAGNETO-OPTICAL REPRODUCING DEVICE

摘要

PURPOSE:To improve a C/N by correcting the birefringence of a P polarization and an S polarization, making an incident laser beam approximately into a straight line polarization and making a reproducing signal amplitude maximum. CONSTITUTION:A birefringence correcting means 9 is provided on a parallel light path to which a laser beam from a semiconductor laser 5 is made incident on a magneto-optical disk 1 and refrected. At least a part of the laser beam to reflect or transmit a magneto-optical disk 1 is divided into two and differential type photoelectric conversion systems 19 and 20 converting respective beams to an electric signal are provided. By operating the birefringence correcting means 9 so that a DC light quantity component can be detected from the differential output of a differential amplifier 23 through a band pass filter 25 and the absolute value of the DC light quantity component can be made minimum with this as a control signal, the birefringence correction is executed.