Rotary cylinder device.

摘要

A rotary cylinder device (1) for helical scan type magnetic recording/reproducing apparatus. The device comprises a rotary cylinder (2) having an axis of rotation and arranged to oppose a stationary cylinder (3) in the direction of the axis of rotation leaving a small gap (35) therebetween. The rotary cylinder has an end surface (2a) facing the stationary cylinder and an outer peripheral surface (2b), and recesses (11, 11') formed in the end surface (2a) and opening in the outer peripheral surface (2b) such as to extend therefrom radially inwardly over a small distance. Each of the recesses has a leading end wall (11b) and a trailing end wall (11a) as viewed in the direction of rotation of the rotary cylinder. The rotary head device further comprises magnetic heads (10, 10') fixed to the rotary cylinder and positioned in the recesses and having outer extremities projecting beyond the outer peripheral surface (2b) of the rotary cylinder. The distance between the leading end wall and the trailing end wall of each recess is progressively decreased towards the axis of rotation of the rotary cylinder such that the distance is greatest at the outer end of the recess adjacent the magnetic head and the smallest at the inner end of the recess remote from the magnetic head.