Apparatus for recording and reproducing digital signals using a helical scan

摘要

An apparatus for recording and reproducing digital signals using a helical scan in which a drum of reduced diameter is employed without changing the tape format. Two heads are mounted on a drum at the same height in opposition to each other with a product of the diameter D of the drum and the wrap-around angle of the tape with respect to the rotary drum being constant while the speed of the drum is increased to a speed N times higher than a predetermined speed. One of the heads is mounted higher than the other by a distance of (1-1/N)P to provide a step, and the other head being is mounted at a position an angle behind the position at which the other head directly opposes the one of the heads, which angle is defined by: <IMAGE> where L is the track length in the tape format used when the rotary drum rotates at the predetermined rotational speed, THETA is the track angle, P is the track pitch, and C is a constant dependent on the drum diameter D and the wrap-around angle. Methods for performing high speed searches with this apparatus are also disclosed.