Patent ID: 6749377
Filing Date: 2004-06-15
Classification: B24B,B29D,G01B,Y10T

Abstract:
A method of edge-machining an edge of an optical lens, which is rotatable in an angularly controlled manner about a rotational axis of a workpiece to form the lens, the method comprising the steps:preliminary machining of the edge of the lens by means of a first edge-machining tool that is adjustable at least radially relative to the rotational axis of the workpiece, wherein the lens is provided with a circumferential contour which corresponds to a circumferential contour of a holder for the lens apart from a slight degree of oversizing, contactless measurement of the edge of the preliminarily machined lens, and finish-machining of the edge of the lens, taking account of the detected edge data for the preliminarily machined lens, by means of a second edge-machining tool that is adjustable at least radially relative to the rotational axis of the workpiece, wherein the lens is provided with a circumferential contour substantially complementary to the circumferential contour of the holder, wherein, during preliminary machining of the edge of the lens, a surface which is definedly matt in the dry state is produced at the edge, wherein, when preliminary machining of the edge of the lens is performed with cooling liquid supply, at least the edge of the preliminarily machined lens is dried before the edge is measured, and wherein, to measure the edge, a bundle of laser beams is directed towards the dry, definedly matt surface of the edge by means of a laser in a predetermined positional relationship to the rotational axis of the workpiece, and an image of the point of impact of the laser beams is recorded by means of a video camera in a predetermined positional relationship to the rotational axis of the workpiece, wherein the recorded image is then evaluated with respect to a distance of the point of impact from the rotational axis of the workpiece, in order to determine the edge data of the preliminarily machined lens.