GB634317A - Improvements in or relating to photographic cameras fitted with range finders - Google Patents

Abstract

634,317. Range-finders for photographic cameras. KODAK, Ltd. Dec. 31, 1946, No. 38145. Convention date, Jan. 5. [Classes 97 (i) and 98 (i)] In a camera in which a range-finder of the split field type coupled to focusing means includes a pair of coaxially arranged lenses movable together to the same extent for effecting coincidence of the images, the lenses are rigidly supported by a yoke member pivotally mounted on an axis parallel to the axis of the lenses, and from which an arm projects to engage a movable part of the focusing means. As shown, the light rays L<SP>1</SP>, L<SP>2</SP> are reflected by prisms 1, and pass through lenses 2 and coincidence prisms 19 to form an image at or near the prism faces 20, which is viewed by means of a field lens 21, erecting lens 22 and eyepiece 23. The lenses 1 are mounted coaxially on a yoke 4 which is pivoted about an axis parallel to, and below and in front of, the common axis of the lenses. The lenses 1 are thus free to move in arcuate paths. By appropriate choice of the pivotal axis, the horizontal component of the movement serves to bring the images into coincidence, while the vertical component provides corresponding parallax correction. The yoke has an extension 5 engaging a movable part of the focusing means, e.g. a cam 15, under the action of a spring. The yoke 4 may be axially adjusted by means of screw pivots 7 carried by a bracket 9, itself adjustable on a plate 10, forming part of the camera,. The arm 5 has a thin portion 5a enabling it to flex in the plane of the pivots 7, and is retained in engagement with the cam 16 by a slot 18 in a plate 17. To reduce the length of the range-finder, reflectors may be placed between the prisms 19 and lens 22, and between lenses 22 and 23 to " fold " the optical system. A frame 24 may be placed in front pf lens 23 to indicate the field of view.