GB605482A - Improvements in or relating to range finders - Google Patents

Abstract

605,482. Range-finders. KODAK, Ltd. Dec. 20, 1945, No. 34561. Convention date, Jan. 19, 1943. [Class 97 (i)] In a coincidence finder having two windows each with a reflector unit reflecting light to an objective forming two images in a comparison plane and means for effecting coincidence the ranging scale comprises two elements, e.g. scale and index, an image of one of which is formed adjacent the other by light which has passed through the objective and been reflected by each reflector unit and by auxiliary reflectors thereat. Errors of adjustment are thereby automatically corrected. As shown in Fig. 10, light from the object is reflected by mirror 20 and transparent mirror 21 to an objective 22 forming two images in the plane 24 viewed through eyepiece 26, mirror 20 being rotated to effect coincidence. The index in the plane 24 is illuminated by lamp 41 light from which passes via reflectors 61, 20 to prisms 56 and thence via reflector 21 to be focussed by the objective 22 adjacent a scale on the plane 24. The index image is moved on range adjusting. The mirror 61 may be omitted and observation made directly through mirror 21. In the modification shown in Fig. 11 coincidence of the object images is observed through eyepiece 26 while light from the lamp 64 illuminates the index an image of which is formed adjacent the scale 69 by lens 63, prism 66, the reflecting surface of a prism 33 on the reflector 20 and the reflector 21. Alternatively the eyepiece 26 may be omitted and scale and object images observed in the same eyepiece. Alternatively the mirror 21 may carry a dove prism for reflection as described in Specifications 605,481 and 605,486 and the spiral scale and fiducial mark therein described be employed. Specifications 605,483, 605,484 and 605,485 also are referred to.