GB903528A - Improvements in or relating to automatic exposure control apparatus for photographiccameras - Google Patents

Abstract

903,528. Photo-electric exposure control. KABUSHIKI KAISHA KOPARU KOKI SEISAKUSHO. June 23, 1960 [June 24, 1959], No. 22035/60. Class 40 (3). [Also in Group XX] In a camera in which the aperture is set automatically in dependence upon an exposure meter and a manually set exposure time, if the correct exposure is not possible even with the smallest aperture, the exposure time is automatically shortened. The camera is coked by mechanism (not shown) rotating a ring 29, Fig. 8, carrying lugs 29d-29h, Fig. 2, anticlockwise to the position shown in Fig. 2. Actuation of the release 5 permits ring 29 to run down under the action of a spring 44 and a governor G. Lug 29h permits the exposure time control cam 12 to rotate clockwise until a lug 15a on a plate 15 contacts the lug 24a. The relative position of cam 12 and plate 15 is controlled by the exposure time setting lever 7, a toothed segment on which meshes with a cog 14, Fig. 3, of a differential gear 13, 14, 17, 18. Cam 12 thus sets the exposure time governor S via the lever 10. During this setting, the shaft 16 rotates a drum 30 through a collar 32 and a differential gear 42, 37, 39, 40. As lugs 15a and 24a connect a pin 15b releases, via a lever 23, an aperture setting cam 20 which rotates drum 30 through the same differential gear until drum 30 contacts the pointer 31 of an exposure meter L. Cam 20 arrests the aperture setting member 25. If cam 20 rotates to the minimum aperture position before drum 30 contacts pointer 31, a pin 21b actuates the lever 24 to release lug 15a which allows the exposure time to be adjusted through the differential gear 42, 37, 39, 40 until drum 30 contacts pointer 31. Finally, lug 29d contacts a lever 4 to operate the shutter.