Magnetic recording and reproducing apparatus with device for tracking control of rotary magnetic heads

A magnetic recording and reproducing apparatus comprising:

• a rotary swinging member rotating unitarily with a rotary shaft, said rotary swinging member having integrally therewith a pair of arcuate yoke parts at positions which are opposed in a diametric direction of a rotating plane of the rotary swinging member about a rotation center thereof, said yoke parts having U-shaped cross sections and accordingly having respective grooves therealong;
• permanent magnets respectively fixed to said pair of yoke parts in a state where their opposite polarities are opposed, said permanent magnets being respectively fixed to inner wall surfaces of said grooves;
• a pair of rotary magnetic heads supported on the rotary swinging member at positions opposed in a diametric direction of a rotating plane of the rotary swinging member about a rotation center thereof in a state where tips of said heads project outwards from outer surface of the yoke parts;
• fulcrum means for supporting said rotary swinging member in a freely swinging manner and acting as a fulcrum for swinging, said fulcrum being in a direction perpendicular, at a rotation center, to a line connecting said pair of rotary magnetic heads;
• and
• a control coil of cylindrical shape disposed at a position where said control coil exists in a magnetic field formed by the permanent magnet rotating with the rotary swinging member, said control coil being inserted relatively in said grooves, said control coil being supplied with a control signal;
• said rotary swinging member swinging in response to the control signal with said fulcrum means as a fulcrum for swinging.