Video disc stabilisation system which removes distortion - has disc held in contact with supporting table by external force to assure flatness

摘要

A table for the support of gramophone discs, especially thin non-rigid discs for video recordings, which ensures that the record remains flat against the supporting table and removes distortion due to unevenness of the disc itself, which may be particularly disturbing in optical scanning for reproduction. External force is applied to keep the disc in contact with the table. This may be effected by forming the table as a very funnel, so that the disc is forced in contact with it by centrifugal force as it revolves, or the materials of the table surface and the disc may be so chosen that the suffer a mutual electrostatic attraction. A further alternative is to use induced currents to provide attraction to a metallic surface.