Nippon Hoso' Kyokai

Nippon Kogaku K.k.

Asaca Corporation

Kabushiki Kaisha Asaka

Shozo Nakagawa

Hironobu Katayama

Katsuya Yokoyama

Akio Hayashi

Akihiro Takagi

Koichi Okabe

Shunichi Ohnishi

Tracking error detecting apparatus for use in multibeam optical disk

A recording and reproducing apparatus for a disk-type recording medium including an erase head and a record head which are arranged with a certain rotational angular spacing. The apparatus includes a controller for generating a first signal to operate the erase head and a second signal to operate the record head, and a timing adjusting circuit for delaying either one of the first and second signals to compensate for an error of the angular spacing.

Recording and reproducing apparatus for disk-type recording media

In a helical-scan magnetic record/playback system, n magnetic heads (where n is an integer greater than one) are disposed close to the outer wall of a head drum, spaced from one another by 2.pi./n radians with respect to the rotational axis of the head drum and also spaced from one another by approximately 1/n of the width of a magnetic tape in the axial direction of the head drum. The magnetic tape is wound around the head drum over an angle of 2.pi./n radians or more with respect to the rotational axis of the drum. With the rotation of the head drum, a video signal is time-sequentially divided for recording on n tracks of the tape and for reproduction therefrom. The invention results in reduced friction between the tape and the drum, thereby providing smooth travel and easy loading of the tape. According to this invention, a still or slow-motion picture can be reproduced without an external memory and the reciprocal travel of the tape.

PCM helical-scan magnetic record/playback systems

In a digital magnetic recording and reproducing apparatus, a digital code signal to be recorded is given a code conversion by means of modulo-2-adding another digital signal thereto to prevent a continuation of the same binary signal levels for a prolonged period. The signal level of the reproduced digital code signal is corrected by level comparison with a threshold level provided by applying the above reproduced digital code signal to a compensator and peak rectifiers, which have the same time-constant, and then the reproduced digital code signal is given another code conversion by means of modulo-2-adding still another digital signal provided for restoring the code conversion, so that it is possible to reproduce the original digital code signal faithfully.

Digital magnetic recording and reproducing apparatus

Growing community of inventors

Tokyo, Japan

Shozo Nakagawa