Improvements in or relating to optical slide projectors and optical slide viewers

摘要

895,103. Optical slide projectors; lens mounts. KODAK Ltd. (Kodak A.G., and Missler, S.) Oct. 26, 1959 [Nov. 7, 1958], No. 35784/58. Class 97(1). An optical slide projector or viewer comprises a projection lens, a fixed gate member and an apertured plate forming a movable gate member between which a slide is resiliently clamped and a link or links acting on the movable gate member and lens so that the movement imparted to the movable gate member is transmitted to the lens to maintain constant the distance between the transparency plane and the lens for any pre-set position of the lens irrespective of the slide thickness. The slide projector shown has a fixed gate member 3 and a movable gate member 15 between which the slide 18 is inserted. The movable gate member 15 has lugs 19 to which links 21 are pivoted, the other end of each link having an open ended slot 22 embracing a fixed pin 23. Each link has a cam surface 24 engaging the flange 10 of a lens support 5 which is spring loaded at 9 and carries a screw threaded lens mount 12. When a slide of different thickness from that shown at 18 is inserted, the gate member 15 via the links 21 causes the lens support 5 to move axially so as to maintain constant the distance between the transparency plane and the lens.