GB1176355A - Improvements in Film Scanning Systems - Google Patents

Abstract

1,176,355. Telecine equipment. COMPAGNIE FRANCAISE THOMSON HOUSTON-HOTCHKISS BRANDT. 28 June, 1967 [28 June, 1966], No. 29919/67. Heading H4F. The Specification, describes telecine equipment of the type wherein a raster of flying spot tube T is focused by lens L 1 on a frame of a film F being scanned, the vertical scanning being aided by the movement of the film in the direction F shown, and the following raster, interlaced with the first, is focused by lens L 2 on said frame of film, now moved to the lower position F 2 . When the tube T is moved along the axis to T<SP>1</SP> say, Fig. 2, the positions of the focused frames F<SP>1</SP> 1 and F<SP>1</SP> 2 also move, and the focused frames, as projected on the moving film, no longer interlace. To overcome this and fix the positions F 1 and F 2 , the invention proposes the lateral movement of the lens L 1 and L 2 synchronously with the movement of the tube T. To enable this, the lenses L 1 and L 2 are supported by a cam C, Fig. 4, moving with the tube T, such that movement of the tube T towards the film causes the lenses to draw together and vice versa. Alternatively, the cam C may support only one lens, the other being fixed. The cam surfaces are ideally hyperbolic, but for small movements of the tube T may be tangents to the average point of said ideal hyperola.