Plano-concave and plano-convex lens system for deflecting read beam in optical recording system

Abstract From the Canadian patent

An apparatus is described for optically reading a record carrier. Deflection of the read ???? over the record carrier can be achieved with the ??? of an assembly of a plano-concave and a plano-convex lens the, radiu??s of curvature of the curved surfaces of the lenses being equal, and the distances between the curved surfaces being very small. The beam-deflection element is compact, may be disposed near the read objective and, need not ?eet stringent requirements as regards surface quality.