GB454296A - Improvements in means for determining the correct exposure in photographic apparatus - Google Patents

Abstract

454,296. Photographic exposure meters. RISZDORFER, O., 1, Gellerthegy utca, Ungarn, Budapest. March 18, 1935, No. 14275/36. Convention date, March 16, 1934. Divided out of 453,845. [Class 98 (i)] Exposure determining means comprises an iris diaphragm arranged in front of a photoelectric cell and positively coupled to means for controlling one of the variable factors of the exposure, e.g. the camera diaphragm, and a variable electrical resistance included in the circuit of the photo-electric cell influenced in accordance with another variable factor, e.g. the shutter speed. As shown, the adjustment ring 18 of the diaphragm 17 is coupled by toothed segments 21, 22 to the adjustment ring 20 of the diaphragm 19 of the photo-cell. The circuit of the photo-cell includes an oscillating coil 24 having a pointer 25, and an adjustable resistance 26, the moving contact 27 of which is connected with the speed setting device 28. The variables are adjusted to bring the pointer 25 to a fixed mark 29. Other factors may be taken into account by additional resistances or by the use of variable diaphragms or light filters. In a modification (not shown), other factors are taken into account by making the diaphragm ring of the photo cell removable, so that it can be taken out and reset in accordance with the scale graduated in Scheiner. degrees or other suitable units. Specification 411,814 is referred to. The Specification as open to inspection under Sect. 91 comprises also, as shown in Fig. 2 (Cancelled), a diaphragm for the photocell 30 made of laminations 31, each having one end connected to a rotatable ring 32, and the other to a rotatable ring 33, the rings 32, 33 being connected by toothed segments to the camera diaphragm 34 and speed setting ring 36 respectively. This subject-matter does not appear in the Specification as accepted.