Abstract: During the storing of a tracking error signal and an index detection signal in memories in relation to rotating means for a recording medium, an error is detected when the number of index detection signals is other than one and afrer the storing of the signal in the memory the missing reproduced index detection signal is interpolated in accordance with the index signal stored in the memory. Also, the stored index detection signal and the reproduced index detection signal are compared in phase so as to determine whether the stored tracking error signal is to be applied to a tracking control system. The memory for storing tracking error signal and the memory for storing index detection signal are combined in one unit.

Abstract: During the storing of a tracking error signal and an index detection signal in memories in relation to rotating means for a recording medium, an error is detected when the number of index detection signals is other than one and after the storing of the signal in the memory the missing reproduced index detection signal is interpolated in accordance with the index signal stored in the memory. Also, the stored index detection signal and the reproduced index detection signal are compared in phase so as to determine whether the stored tracking error signal is to be applied to a tracking control system. The memory for storing tracking error signal and the memory for storing index detection signal are combined in one unit.

Abstract: A system for recording or reproducing a signal by focusing and irradiating a light beam on a record carrier from a light source while controlling the light beam to always scan the track on the record carrier is disclosed. A track jump that may occur during recording or reproducing a signal on the record carrier is accurately detected. The reliability of the system is thus improved in such a way as to take appropriate action in case of a track jump.

Abstract: A recording and reproduction apparatus for recording signals on a recording medium or reproducing signals recorded on the recording medium, which is so arranged that, with acceleration detectors being provided for detecting accelerations of the apparatus by vibrations or impacts applied from outside, signals from the acceleration detectors are applied to control section for stabilization of the control system and also, for proper treatment upon application of excessively large external vibrations or impacts, with consequent improvements of reliability and stability of the apparatus.

Abstract: In a device for reproducing the information, especially the video signal optically, magnetically or otherwise recorded on the spiral or concentric track on a disk-shaped recording medium, a control system for controlling the radially inward or outward shift or jump of a reproduction transducer from one track to another for effecting, in addition to the normal reproduction, the special effect reproductions such as still picture, slow, fast and reverse motions. The control system comprising a shifting means for shifting or jumping the transducer in the radial directions substantially perpendicular to the tracks, a control means for maintaining the transducer to scan the desired track, and a detecting means for detecting whether or not the transducer has been shifted or jumped and brought to the desired track and generating the output signal in response to which the shifting means is disabled to decelerate and stop the shifting or jumping of the transducer.