METHOD OF MANUFACTURING A MOULD FOR USE IN THE MANUFACTURE OF AN OPTICAL ELEMENT COMPRISING OPTICAL SUB-ELEMENTS MUTUALLY ARRANGED IN A PATTERN, AND DEVICE FOR IMPLEMENTING SUCH A METHOD

摘要

A method of manufacturing an optical element (69, 149, 171, 203, 225) provided with mutually adjoining optical sub-elements (71, 155, 193, 219, 241) which are mutually arranged in a pattern such as, for example, a microlens array (69, 171, 203) with a two-dimensional orthogonal or hexagonal matrix of spherical lenses (71, 193, 219) or a faceted lens (149, 225) with a two-dimensional orthogonal matrix of facets (155, 241). According to the method, the optical element (69, 149, 171, 203, 225) is manufactured by means of a mould (7, 147) by a replication technique. The mould (7, 147) is manufactured from a ductile metal and is given a mould shape (83, 161) which corresponds to the pattern of sub-elements (71, 155, 193, 219, 241) by means of a die (65, 129) having a die surface (67, 131) which corresponds to the optical sub-element (71, 155, 193, 219, 241) and which is imprinted in the mould (7, 147) with a predetermined force in consecutive positions in accordance with the pattern. The optical elements (69, 149, 171, 203, 225) manufactured by the method have a particularly high dimensional accuracy and a particularly large optically useful surface area.