GB921731A - Stereoscopic viewer - Google Patents

Abstract

921,731. Stereoscopic viewers. NEW-MAX S.r.1. Nov. 23, 1960 [Dec. 17, 1959; July 4, 1960; Sept. 17, 1960], No. 40250/60. Class 97 (1). A stereoscopic viewer comprises a box-shaped frame containing a translucent wall, a film track in said box-shaped frame, two eyepieces, the axes of which are spaced from one another by a distance substantially equal to the average spacing of a pair of human eyes, the film track having two windows spaced from one another substantially as the above-mentioned eye-pieces, and at least one intermittent film feed device which includes a stop tooth fixed to the frame and co-operating with perforations provided in the film so as to cause alignment of any steroscopic pair of picture frames on the film with the said windows and means for successively disengaging the perforations from the stop and effecting instantaneous displacement of the film from one picture pair to the next successive picture pair to obtain cinematographic viewing. As shown, a stereoscopic viewer comprises a housing 1 providing a track 4 for film 5 and having two eye-pieces 2-3 for viewing steroscopically related pairs of images by way of light admitted through windows 8. In the case of film having pairs of images arranged in laterally adjacent rows as in Fig. 12, deflecting prisms 80 are provided in the eye-pieces 2, 3. The eye-piece lenses g may be eccentrically mounted in a rotatable mount 41 (Fig. 7, not shown) to compensate for differences in individual inter-pupillary distances. The film may be in loop form (as in Fig. 1) or in the form of a strip accommodated on spools. At least one row of perforations are provided. The intermittent film feed device operates as follows. By means of a winding crank 13 coupled to a sprocket wheel 11 (Figs. 1 and 4) the tension in the film between members 10 and 13 is increased thereby bending a leaf spring 23, about its pivot 22, said spring having a stiff limb 23b engaging the film and a relatively elastic limb 23a bearing against a fixed surface 1b. Eventually the film disengages one of its perforations from a tooth 10, and under tension of spring 23, is advanced until the tooth 10 engages the next perforation. This process is repeated. In modifications the spring 23 is replaced by a lever urged to rotate magnetically. The tooth is provided with one inclined face to facilitate rewinding of the film. Two such intermittent feed devices may be provided-one for each direction of feed-as in Figs. 10 and 11 (not shown).