GB412488A - Improvements in or relating to lens systems particularly adapted for use with optical compensators in motion picture apparatus - Google Patents

Abstract

412,488. Kinematograph apparatus; optical systems. LEVENTHAL PATENTS, Inc., 175, Varick Street, New York, U.S.A. Nov. 25, 1933, Nos. 33034 and 33035. Convention dates, Nov. 25, 1932 and Dec. 24, 1932. [Class 97 (i).] A lens system for use with a multiplestage optical compensator in continuous-feed kinematograph apparatus, and for producing, at one point, images of spaced compensated image points, or vice versa, comprises a main lens and auxiliary spaced lens segments rotatable into operative positions in timed relation to the movements of the compensator. The compensator may successively produce two or more stationary virtual images of each picture spaced apart, and may be a rotating parallel sided plate, or of the type described in Specification 403,956. The lens system comprises a main fixed lens l producing virtual images o<1>1o<1>2 from such images o1 o2, and lens segments L1 L2 rotatable about axes through their optical centres to produce images at o<11> successively from the images o<1>1, o<1>2. Figs. 5 and 6 show a construction of apparatus in which, to facilitate focusing, the main lens 10 and a 45‹ prism 12 are mounted on a support 11 adjustable in position by a screw 15, and the lens segments 18 are mounted on shafts 20 perpendicular to the axis of the lens 10 ; a mirror, adjustable by rotation of a knob 27, may also be provided. The film is fed through a gate 4 between a condenser 2 and rotating compensator 5, and is masked by a shutter 9. A motor 29 drives the various members through the gearing shown. The lens segments may be negative.