Optical track scanner

Abstract

In an optical disc player or other apparatus in which a light beam is directed against a record medium surface for optically reading video or audio information recorded in a track on such surface; an optical scanning assembly is provided with an objective lens interposed in the path of the light beam with its optical axis coinciding substantially with such path therethrough, a lens holder including a first tubular member having the objective lens mounted therein and a second tubular member supporting the first member for rectilinear sliding movement relative thereto in a first direction parallel to the optical axis, a base member supporting the second tubular member of the lens holder for rectilinear sliding movement relative thereto in a second direction at right angles to the first direction, for example, in a direction across or along the track in which information is recorded, first and second coils mounted on the lens holder and being independently energizable, and permanent magnets for producing magnetic flux in linking relation to the first and second coils which are oriented so that energizing of one of the coils is controllable for effecting movements of the objective lens relative to the record medium in the direction of the optical axis for thereby focusing the light beam at the record medium surface and energizing of the other coil is controllable for effecting movement of the objective lens in the second direction whereby to correct for scanning or time base errors.