Improvements in or relating to devices for varying the field seen in a view-finder for a photographic camera

摘要

668,673. Viewfinders for photographic cameras. PAILLARD SOC. ANON. Feb. 13, 1950 [Feb. 18, 1949], No. 3594/50. Class 98 (i). A control device for varying the field of view of a finder comprising a lens 6 in a mounting 7 movable along a guide 8, is characterized by a rotary control member driving a drum 10 around which passes a flexible connecting member 15 secured to the mounting 7 which is thereby moved along guide 8. The finder is mounted between the walls a, b of a casing, and has an objective lens 4 and an eyepiece 3 between which lens 6 moves, preferably within a tube, to vary the field visible through the finder. A control knob journalled in wall 1 of the casing drives drum 10 by direct connection, or through a gear train. A cable 15 passes round pulleys 12 mounted with their axes in a plane parallel to the optical axis c of the finder, and has its ends connected to drum 10, one end directly and the other end through a spring 14. The cable is connected to the mount 7 at e. In modifications, one end of the cable may be connected to drum 10, and the other end to a second spring- - loaded drum, the cable may be endless and pass round drum 10, or a cable passing round drum 10 may have its ends connected to mount 7. The cable ends may be connected to their points of attachment by springs, and the finder and its control device may comprise a unit readily removable from and attachable to a camera.