Apparatus for detecting position of a reproducing transducer in a rotary recording medium reproducing apparatus

摘要

An apparatus for detecting position of a reproducing transducer in a rotary recording medium reproducing apparatus which reproduces an information signal recorded in a rotary recording medium by a reproducing transducer which is transferred towards the radial direction of the rotary recording medium, comprises a single photo-detector having a light-emitting element and a light-receiving element, provided in a manner so as to be transferred unitarily with the reproducing transducer, a light interrupting plate provided at a fixed part of the rotary recording medium reproducing apparatus, for operating together with the photo-detector, and a position detection signal producing circuit for producing a position detection output signal according to an output of said photo-detector, to indicate that the reproducing transducer has passed a position corresponding to the outermost peripheral position and the innermost peripheral position of the recorded region in the rotary recording medium. The light interrupting plate has a configuration so as to change state between a light interrupting state and a non-interrupting state with respect to the photo-detector, as the reproducing transducer passes a position corresponding to an outermost peripheral position and an innermost peripheral position of a recorded region in the rotary recording medium.