Record face identifying device for optical magnetic record medium.

摘要

In an optical magnetic record signal processing system in which a linearly polarized light beam is projected on an optical magnetic medium and a recorded signal is reproduced by using polarized conditions of a reflected light beam from the medium, the processing system includes a novel type of record face identifying device for the optical magnetic record medium according to the invention comprising: an initialized area projecting means which projects a light beam on an initialized area of an optical magnetic record medium; a transducing means which converts a slant of a polarization plane of a reflected light beam from the initialized area (5, 7) into a light intensity; a photo-detecting means (9, 13, 14) which detects the light intensity outputted from the transducing means; a comparing means (11, 17) which compares an output from the photo-detecting means with a reference level.