| 摘要 |
<p>1322880 Multiple lens COMPAGNIE GENERALE D'ELECTRICITE 29 June 1970 [24 Dec 1969] 43007/72 Heading G2J A multiple lens includes an array of individual lens elements 7, 10, each having at least three plane side faces, parallel to the optical axis, by which the element is joined to adjacent elements, the entire light-receiving end face 6 of some of the elements 7 being convex and part-spherical, and the end face 9 of the or each remaining element 10 being convex and part-cylindrical. The elements are preferably of rectangular cross-section, the elements 7 being preferably square. The focal points of the elements 7 and the focal lines of the elements 10 may lie on a curved surface but preferably will lie in a plane parallel to or coincident with the exit face of the system. In order to remove aberrations an element may be formed with a peripheral groove 12, Fig.4 (not shown) a cross-section 13 through the groove being circular (elements 7) or in the form of two semi-circles separated by a rectangle (elements 10). The elements may be cemented together, the cement containing absorbent particles such as carbon to prevent transfer of the light between the elements; in addition they may be held together by means of a frame or collars. The elements may be made from mono-crystals of magnesium fluoride or lithium fluoride, which are transparent in the far ultraviolet. The system may be used with a laser for producing a large number of very small perforations in a plate.</p> |
