GB841875A - Improvements in reflectors, more particularly for use in electric lighting fittings - Google Patents

Abstract

841,875. Mirrors. GENERAL ELECTRIC CO. Ltd. May 7, 1958 [May 28, 1957], No. 16917/57. Class 97(1) An optical reflector comprises a flexible film of transparent plastic material carrying or covering the reflecting surface, the film being attached to the base of the reflector at regions which are everywhere away from the part of the reflector forming the reflecting surface and being arranged to be in tension at least over said part. This film may be of polyethylene terephthalate and have coated thereon, as by vacuum deposition, reflecting material, such as silver or aluminium. The film may be stretched across the base material, which may be in the form of a frame or have raised portions following substantially the outline of the reflecting area. This base may be partly flexible, and of hardboard, wood or mild steel; it may be perforated. In one method of forming a reflector; a metallised film of polyethylene terephthalate is cut to a larger size than a hardboard base and is cut away at four corners. Adhesive is then applied to the back of the hardboard, except for a peripheral strip round the edge thereof, and adhesive is applied to the edge portions of the metallised surface of the film, except for those parts which are to come into contact with the peripheral strip of 'the base. The edge portions of the film are then folded over and stuck to the back of the base, and thereafter the assembly is heated, so that a tension is set up in the film by shrinkage.