Patent ID: 6050692
Filing Date: 2000-04-18
Classification: G02B,Y10S

Abstract:
A method of constructing a thin film mirror with a non-circular edge, where all of the non-circular edge lies on an intersection of a required mirror surface with a single surface developed from a plane, which method comprises:(a) providing a suction chamber which has:(i) top and bottom edges which lie on a surface of one of a cone and a cylinder and which also lie on the required mirror surface;(ii) permanent ends that each has a contact surface for a thin plastics film that lies on the required mirror surface and which are able to be developed from a plane so that the thin plastics film is able readily to be attached without the need for pre-distortion or stretching of the thin plastics film; and(iii) no abrupt discontinuities in a mirror film edge part of the suction chamber; and(b) providing the thin plastics film on the suction chamber;(c) attaching the thin plastics film to the said top and bottom edges and the said ends of the suction chamber; and(d) applying suction to the suction chamber such that the thin plastics film lies on the required mirror surface without the said pre-distortion or stretching of the thin plastics film.