Patent GB-631271-A (GB)
Title: An improved method and means for securing registration of visual and sound records when making cinematograph pictures
IPC: G03B31/00
Filed: 1947-05-27
Abstract: 631,271. Kinematograph apparatus. D. & P. STUDIOS, Ltd., and ASHWORTH, G. T. May 27, 1947, No. 14067. [Class 97 (i)] In a method of enabling registration marks to be applied simultaneously to films recording visual and sound effects separately, a soundless indicator device is mechanically-connected to the camera so that it may be moved at will to a position immediately in front of the camera lens or alternatively to a position removed from the field of view of the camera and embodies an electric signalling lamp connected with a corresponding lamp in the sound-recording equipment, which lamps are adapted to impress respectively on the visual and sound records markings enabling the two films to be accurately registered. In one form of apparatus for carrying out the method, the indicator device h, Fig. 1, is carried by a manually-rotatable shaft i<SP>1</SP> in the lens hood b of the kinematograph camera so that it may lie either in front of the camera lens or out of the camera field of view by passage through an opening in the hood b. When the indicator is moved into the former position, a switch k connecting the device with light signal boxes e, g and f associated with the camera, the sound recorder d and the sound mixing panel c respectively, is closed. The indicator includes a chamber 7, Figs. 4 and 5, in which are disposed lamps 5, 8, light from which passes through a removable stencil plate 9 onto a reflector 4 which co-operates with a reflector 3 to direct the light onto a collimating lens 2 which is aligned with the camera lens. Above and below the chamber 7 are disposed cylindrical housings 10, 101, each of which includes one or more lamps 11 and around each of which is rotatable a number of stencil rings 15, each having a flange 16, which projects outside the housing, except for one ring of the series disposed around the housing 10<SP>1</SP>, which ring is in the form of a ratchet-wheel and is engaged by a pawl operated by a spring plunger 19, the movement of which is such that the ring rotates through one step as the plunger 19 engages a fixed stop, when the indicator h is moved to its inoperative position. Premature movement of the rings 15 of the housing 10 is obviated by a spring 17 which engages the flange on each ring. Light from each housing passes out through an elongated aperture 13 and is reflected at 14 on to the mirror 4. In use, the indicator h is moved into alignment with the camera lens and the switch k is closed, whereby the lamps in housings 10, 101 and the lamps 8 in the chamber 7 are lighted; also blue lamps l in the signal boxes e, f and g flight up and thus warn the operators in charge of the camera and the sound recorder. When the camera and the sound recorder are properly - synchronized, red signal lamps m associated with the boxes e, f, and g light up and the lamp 5 in the chamber 7 flashes in synchronism with a second lamp in the sound recorder d, whereby registration marks are impressed on the respective films. When lamps m light up, the indicator h is moved to its inoperative position and shooting of a scene may commence.