Patent GB-852732-A (GB)
Title: Improvements in and relating to photographic cameras
Inventor: MEI WIETSE HENDRIK VAN DER
IPC: G03B7/00
Filed: 1957-01-09
Abstract: 852,732. Photographic cameras. VOIGTLANDER A. G. Jan. 9, 1957, No. 892/57. Class 98(1) In a photographic camera with the shutter speed and aperture stop adjustable in equal intervals corresponding to a constant ratio, the diaphragm has two control members, one connected to the shutter speed control member and the other to the diaphragm setting member. As shown in Fig. 1, one of the blades 1 of the iris diaphragm has an index 4 at its end 2 movable over a light intensity scale 5, and an index 6 at its end 3 movable over a fixed shutter speed scale 7, and also over an aperture scale 8 which is connected by a member 9 to the end 2 of blade 1. The end 3 of the blade is connected by a rod 10 to the shutter speed control mechanism 11. The blade end 2 is first set to an indication on scale 5 corresponding to the intensity of the light illuminating the subject to be photographed. Movement of the end 3 adjusts the diaphragm and the shutter speed by mutually compensating amounts, so that a desired combination of diaphragm aperture and shutter speed can be chosen. In Fig. 2, the ends 2, 3 of the blade 1 are connected respectively to a diaphragm adjusting ring 14 and a pointer 6 which moves over an aperture scale 8 on ring 14 and an exposure time scale 7 on a ring fixed to the camera, which also carries the light intensity scale 5. Ring 14 is set so that an index 4 thereon indicates the required light intensity value, whereupon index 6 is adjusted to a required combination of diaphragm aperture and shutter speed. Fig. 3 shows three iris diaphragm blades 1 connected at their ends 2 to a ring 13 and at their ends 3 to a ring 12, through a cam mechanism if required. Ring 13 is coupled to a diaphragm adjusting ring 14 bearing an aperture scale 8 and an index 4 co-operating with a fixed light intensity scale 5. Ring 12 has an index 6 co-operating with a fixed shutter speed scale 7 and with the adjacent aperture scale 8, and is coupled to a shutter speed control member 11. In another arrangement, the ring 14 is mounted to rotate within a fixed ring bearing the scales 5, 7, and the index 4 is movable in accordance with film speed. As shown in Fig. 9, a three-element lens is mounted in a shutter casing, which also houses the diaphragm blades, one of which is shown at 1 The blade 1 is pivoted at its end 2 to a ring 13, which is connected to the diaphragm adjusting ring 14 by screws 36 passing through slots 37 in the shutter casing 15. The other end 3 of blade 1 is pivoted to a ring 12 connected to a shutter speed setting ring 18 by a bolt 40 passing through slots 41, 42 in the casing. Ring 18 has cam grooves 43 which cooperate with pins 44 which adjust the setting of the shutter speed mechanism 11, which in turn actuates the shutter blades 19. The shutter speed setting ring 18 carries a pointer 6 cooperating with the shutter speed scale 7 on the casing 15 and the aperture scale 8 on the diaphragm ring 14. A pointer 4 on the ring 14 co-operates with a light intensity scale 5 on the casing 15. When the camera has a built-in exposure meter, teeth 48 on ring 14 mesh with a pinion 46 mounted on the camera casing to transmit the movement of ring 14 to a followup pointer of the meter. In this case, the light intensity scale 5 and the pointer 4 may be omitted.