GB821272A - Improvements in or relating to photographic cameras - Google Patents

Abstract

821,272. Photographic cameras. DECKEL, H., and DECKEL, F. W. April 12, 1957 [April 20, 1956], No. 12041/57. Class 98(1) In a photographic camera, the diaphragm adjustment is connected to a range-finder which is not coupled for focusing the objective. As shown in Fig. 1, a photographic camera has a body 1 carrying a lens 2 and a shutter assembly 3. The lens is of the front-cell focusing type, and is focused by means of a ring 11 with a scale 12 read against fixed index mark 13. The shutter speed and diaphragm aperture are respectively set by means of rings 15, 17 associated with scales 16, 18 which are read against a common fixed mark 19. The rings 15, 17 may be connected together in known manner for adjustment, but must be uncoupled when the mechanism according to the invention is brought into use. As shown in Fig. 2, the aperture setting ring 17 is connected to a rotatable ring 31 connected to the iris diaphragm. It is also coupled to a ring 32 carrying a cam surface 33, which is in contact with a pin 35 slidable in the camera casing. The rear end of pin 35 bears against a lever 36 cooperating with a lever 37 upon which is mounted a mirror 39 pivoted on an axis 38. The movable mirror 39, together with a semi-transparent mirror 41 and an eyepiece 40, forms a combined view and range finder. The cam 33 is so shaped that the product of the distance to which the range finder is set and the diaphragm aperture is always a constant number, mainly the guide number of the flash bulb in use. The cam 33 is rotatable in respect to the diaphragm setting ring 17, and carries a pointer 44 which may be adjusted to a scale of guide numbers 45, and is resilient to grip the ring 17 so that the ring and the cam 33 rotate together in their adjusted relation. The camera may also be provided with a second range finder coupled to the focusing mechanism; a second movable mirror 54 being mounted under the mirror 39, and being connected through levers 37, 52, and a pin 51 slidable in the camera casing, to a cam surface formed on the inner side of the focusing ring 11. The image as viewed in the eyepiece 40 has two split fields corresponding to the mirrors 39, 54 respectively; when the focusing ring and the diaphragm adjusting ring have been adjusted to bring the image of the desired object into coincidence in the two split fields, the camera is correctly focused and the diaphragm aperture is correctly adjusted for the flash bulb in use. If desired, the range finders need not have the same base. When only one range finder is provided, the ring 32 carries a scale from which the focusing distance can be read and subsequently set by means of the focusing scale on the ring 11. Specification 676,075 is referred to.