GB367641A - Improvements in apparatus for setting lenses in photographic cameras - Google Patents

Abstract

367,641. Photographic cameras. KODAK, Ltd., Kodak House, Kingsway, London.-(Assignees of Mihalyi, J. ; 333, State Street, Rochester, New York, U.S.A.) May 7, 1931, No. 13454. Convention date, May 14, 1930. [Classes 97 (i) and 98 (i).] Apparatus for facilitating the setting of lenses in cameras in correct focus comprises a support for the lens, a holder for a camera part with which the lens is to be assembled, an illuminated slit near the principal focus of the lens, means for moving the slit and lens towards or away from each other, and for simultaneously imparting a similar movement to the camera part, optical means to detect when the slit is at the principal focus, and means for adjusting automatically the relative position of the lens and camera part in accordance with these movements. As shown, a bracket 5 supports a frame 6 carrying a motor 7 with a cutter 8. The telescope 10 has an eccentric opening 11 above which is the rhomboid prism 12, the green and red filters 13, 14, the objective 15, the graticule 16, lenses 18, 17, and a prism 19 to reflect the light into the viewing telescope 20. The tube 23 carries an adapter 24 for the camera lens 25 and a mirror 26 reflecting light from the source 27 through the lens 25. The movable member 28 has an arm 29 with an opening 30 over which the shutter-board 31 is supported, and a second clamping arm 32. The end of the arm 29 carries an adjustable tube 34 with a target 35, preferably comprising a mirror with transparent lines, which also detects defective lenses. The roller 38 on the arm 37 of the member 28 is held against the cam 39 on the handle 40 by the spring 36. Light passing through the target 35 and the lens 25 is split by the prism 12 between the green and red filters, and the separate images only appear superimposed in the telescope 20 providing that the target 35 is at the principal focus of the lens 25. In order to bore the shutter-board 31 to the correct depth the handle 40 is depressed until the red and green images are superimposed. Modifications are described for focusing lenses of the type comprising axially adjustable elements, for focusing folding type cameras and for adjusting a focusing scale.