MANUFACTURE OF ASPHERIC LENSES SUCH AS SCHMIDT CORRECTOR LENSES

摘要

1481604 Grinding lenses CELESTRON PACIFIC Inc 3 Sept 1974 [4 Sept 1974] 38411/74 Heading B3D A method of making a Schmidt corrector lens comprises forming a master glass template 22 by grinding and polishing a surface of a glass block to produce the desired surface contour placing a thin glass workpiece 44, which constitutes the corrector, on the master template causing a vacuum between the workpiece and the contoured template surface to cause the workpiece to deform to the contoured surface, rotating together the workpiece and template and grinding and polishing the free side of the workpiece to produce a uniform accurate flatness and then releasing the vacuum to permit the workpiece to return to its undeformed condition to form the corrector lens. The Specification also describes the method of preparing the master glass template by the use of a thin test piece the repeated grinding and checking of which whilst used in conjunction with the master template enables the contour inaccuracies of the master template to be removed before the final workpiece is secured thereto and by grinding and polishing brought to the desired contour. Correctors with contours on each side of the thin plate may be produced.