GB894659A - Improvements in and relating to optical image-projection systems - Google Patents

Abstract

894,659. Optical gauging-apparatus. WATSON, MANASTY & CO. Ltd. June 9, 1960 [June 24, 1959], No. 21743/59. Class 106 (2). [Also in Group XX] An optical image-projection system for examining the profile or contour of both sides 1, 2 of an object comprises two parallel reflecting surfaces 3, 4 associated with lenses 5, 6 so that images 7, 8 of the two sides are formed by the lenses 5, 6 in a common plane and with correct relative spacing and dimensions. The " objects " 1, 2 may be regarded as representing the tips or other reference points of assemblies of laminµ e.g. those shown in Specification 762,779, and may be illuminated as described in that Specification. Images of the objects are formed on a screen 12 by an optical system consisting of the mirrors 3, 4 and lenses 5, 6, an enlarging lens 9, and mirrors 10, 11. The images on the screen may be compared with a master outline drawn thereon, or alternatively a graticule with a representation of the desired outline may be placed in the plane of the images 7 formed by the lenses 5. The lens 9 may be replaced by two or more interchangeable lenses of differing magnification so that firstly the whole of both images may be viewed and secondly a selected part may be viewed at a higher magnification. The lens 9 may also be replaced by a lens providing a higher magnification in width than in length. As an alternative to this the plane mirrors 10, 11 may be replaced by cylindrical mirrors.