GB418778A - Improvements in means for modifying the transmitted light in moving lens cinematograph machines - Google Patents

Abstract

418,778. Kinematograph apparatus. JOHN, W. E., National Bank Building, Market Street, Johannesburg, South Africa. Aug. 25, 1933, No. 23690. [Class 97 (i).] In continuous-feed apparatus having a single series of lenses moving with the film, and an exposure aperture, elongated in the direction of movement, at which several lenses are exposed simultaneously, a rotating disc, having spiral slots of such width that they reduce the amount of light passing through the lenses, is interposed in the light path and driven with the mechanism ; adjustable means for limiting the width of the aperture, and groups of colour filters contained within the slots, may be provided. As shown, the apparatus comprises a fixed lens 6, and lenses 8 in holders 7 moved through a straight guide 14 parallel with a long exposure aperture 4 in the manner described in Specifications 290,372, 319,302, and 334,033, [all in Class 97 (i)]. A disc 17 having spiral slots 20 is arranged between the lenses 6, 8, on a shaft 18, and is rotated by gearing 19 from a shaft 12 driving the lens system so as to provide narrow apertures moving with the lenses. Longitudinal shutters 21, 22 are adjustable by racks 24, 25, and a pinion 23 on a shaft rotatable by a hand wheel 26, to restrict the width of the light aperture. The colour filters may be arranged in the slots in recurring groups. According to the Provisional Specification, the widths of the slots, when provided with colour filters, may be variable, and a flexible endless band, driven by a sprocket and having circular apertures, may replace the slotted disc.