Patent GB-1138211-A (GB)
Title: Cinematographic or photographic camera
IPC: G03B7/085
Filed: 1966-05-05
Abstract: 1,138,211. Photographic cameras. AGFAGEVAERT A.G. May 5, 1966 [May 11, 1965], No.19956/66. Heading G2A. a A A camera has an electric circuit comprising a current source, a photo-cell, a series resistor and a device for controlling the camera diaphragm including at least two setting devices for a plurality of exposure factors which devices vary the resistance in the circuit by means of switches. As shown in. Figs. and 2, the diaphragm in a cine camera consists of two plates 3, 4 the aperture defined thereby being controlled by a moving coil galvanometer 12 connected in series with a resistor 27, a cell 32 and a photo-cell 14 which receives light deflected from an imaging beam X-X by a beam splitter 13. On inserting a cartridge 18 containing a film 20 into the camera, sensing levers 67 and 68 are rotated by surfaces 21a and 22a of the cartridges, the distance, if any, of these surfaces from the wall 18a of the cartridge being indicative of the type and sensitivity of the film; levers 67 and 68 are connected to spring- biased discs 62, 66 which are rotably mounted on a shaft 63, disc 62 bears three contact arms 43- 45 which are selectively connectible into the galvanometer circuit and which each engage a series of contacts 46-49, 50-53 and 54-57 respectively on disc 66 so as to connect one of the resistors A to E or no resistor at all, into the circuit, the particular resistor selected being dependant of the frame speed, and the relative rotation of the discs 62 and 66 determined by the cartridge 18 in accordance with the film 20 therein. When a daylight film is used recess 22 is absent so that disc 62 is rotated such an amount that a daylight correction filter 15 on a support 16 is moved out of the imaging beam X-X by means of a pin 77 on an angled arm 76 mounted on a radial arm 75 of disc 62; the arm 76 is held in position by a recess 83 in a lever 80 and is releasable therefrom by the rotation of an arm 103 on disc 66 which pivots lever 83 as the cartridge is withdrawn from the camera. When an artificial light film is used the filter 15 is not moved out of the beam X-X on insertion of the cartridge, but may be moved, in order to take a photograph in artificial light by depressing a key 69 which rotates the arm 76 and hence the filter 15 and the disc 62 until the arm is caught in the detent 83; the rotation of disc 62 alters the resistor connected into the circuit thus compensating for the absorption of the filter, the filter is returned by depressing a key 86 which pivots the lever 80 to release the arm 67 from detent 83. The filter is also pivoted out of the beam X-X by fitting a lamp 88 on to the camera thus depressing a key 86 and 91, the latter causing rotation of the arm 76 fixed to disc 62 by means of levers 93 and 97; on removing the lamp the key 92 is released after key 86 so that arm 76a is not retained by detent 83. Lever 97 moves whenever filter 15 is moved causing a cover plate 100 to mask one of two transparent index marks on a carrier 101 to indicate whether the camera is set for day-or artificial-light. In another embodiment Fig. 5 a pair of corresponding resistors from the series I-F and I'-F' are selectively connected into a circuit containing a cell 159, a galvanometer 158 for controlling the diaphragm, a resistance 162 and a photo-cell 161 by means of switches 110a, 1106 and 157a-157f. Switches 110a and b are mounted on a spring- biased slider 115 and are set according to the frame speed by a cam 118. Switches 157a-f are mounted on a spring-biased slider 138 having one end connected to an integrating gear consisting of levers 165-167; lever 167 co-operates with a control surface 177 of a cassette 176 which indicates film sensitivity; lever 166 co-operates with a spring-biased lever 170 bearing a filter 172 and having a feeler 174 which co-operates with a control surface 175 of the cassette which indicates the film type. The filter may thus be moved out of an imaging beam by the cassette, or manually by an arm 182 which is held in the required position by a spring catch 185 biased against the arm by the cassette. In a modification of Fig. 5, Fig.6 6 (not shown) the circuit is arranged so that one of resistors F-I is connected in series with resistor 162, and one of resistors F'-I' is connected in series with galvanometer 158.