Device for the stabilization of flexible discs and more particularly of videodiscs and reading apparatus adapted to this device

An apparatus for reproducing information recorded on an annular band of a flexible video disc, comprising:

• means for driving said disc at a high velocity about an axis of rotation;
• means for mounting said disc on said driving means;
• a transducer head for electro-optically reproducing said recorded information having means for optically focussing a beam of coherent light and mounted for displacement along a line perpendicular to said axis of rotation from one end to another of said annular disc band;
• and
• means for accurately positioning a portion of said disc facing said transducer head in relation to said focussing means, said positioning means including:
• a fixed plate having a substantially flat lower face extending perpendicular to and substantially symmetrical to said axis of rotation and located at a predetermined distance above said disc mounting means for aerodynamically prestabilizing said disc in rotation to a substantially constant distance in relation to said lower face, said plate having a central inlet opening coaxial with said axis for providing an air cushion between said lower face and the upper face of the disc in rotation and a rectangular, elongated slot perpendicular to the axis of rotation for displacing said transducer head above and substantially in parallel to a radius of said disc in rotation;
• pump means for providing a source of fluid under pressure above ambient pressure;
• a fluid-tight casing for housing said transducer head connected by flexible pipe means to said pump means and including a lower portion penetrating through said slot and having a width smaller than that of said slot for providing gaps on each side thereof and a bottom face including a substantially flat, rectangular portion facing the upper face of the disc and a substantially centrally located outlet aperture for providing a passage for both said light-beam and said fluid under pressure, said bottom face of said casing being situated below the lower face of said plate at such a distance from the upper face of said disc in rotation that the force exerted by the flow of said fluid through said aperture and between said bottom face and the portionof said disc facing it is in a range where the Bernouilli force of attraction, produced by a relative pressure difference due to the deceleration of the fluid flow between the center and the periphery thereof, is predominant, whereby said facing disc portion is drawn towards said bottom face to a distance where the equilibrium is established between the forces of attraction and repulsion acting thereupon.