GB1437715A - Synchronising of cinematorgraphic cameras with projectors - Google Patents

Abstract

1437715 Cinematography BOLEX INTERNATIONAL SA 18 April 1973 [21 April 1972] 18784/73 Addition to 1355756 Heading G2E A cine camera has a pre-selector mechanism for setting, before filming is initiated, the number of frames to be recorded and means for recording on the film strip, at a predetermined position clear of the film frames, a marking for indicating that each of the pre-set number of frames is to be projected for an extended time. A pre-selector mechanism, Fig.4c, consists of a disc bearing a printed circuit embodying six concentric tracks A-F each contacted by a flexible finger I-VI. The disc is integral with a ratchet wheel 117 which co-operates with a pawl 138 oscillated during filming by mechanical connection to the shutter mechanism. The selector may be rotated manually to one of nineteen positions. Positions 1 to 4 correspond to normal projection at 18 frames/ second, normal projection at 9 frames/second, slowed-down projection and speeded-up projection respectively. On rotation to any of positions 5-19 filming is at 36 frames/second and, since the disc is gradually returned by the pawl 138, for the preset time and therefore the desired number of frames. Simultaneously the film is marked via the fingers V and VI and light emitting diodes to indicate that it should be projected at say 1 frame/second.