Range finder and view finder for photographic cameras

Claim 1

A RANGE FINDER AND VIEW FINDER FOR A PHOTOGRAPHIC CAMERA COMPRISING; A CASING HAVING FRONT AND REAR WALLS, SAID REAR WALL HAVING AN EYEPIECE APERTURE THEREIN, SAID FRONT WALL HAVING A RANGE FINDER APERTURE AND A SPACED VIEW FINDER APERTURE THEREIN, A FIRST PRISM POSITIONED BETWEEN SAID EYEPIECE APERTURE AND RANGE FINDER APERTURE AND HAVING AN ENTRANCE SURFACE RECEIVING LIGHT RAYS FROM SAID RANGE FINDER APERTURE, AN EXIT SURFACE ON SAID FIRST PRISM ADJACENT TO SAID EYEPIECE APERTURE AND PERPENDICULAR TO THE OPTICAL AXIS THEREOF, A BASE SURFACE INCLINED TO SAID EXIT SURFACE, AND ROOF SURFACES, FORMING A COMMON EDGE AND BEING INCLINED TO SAID EXIT SURFACE SO THAT THE LIGHT RAYS FROM SAID ENTRANCE SURFACE ARE REFLECTED BY SAID ROOF SURFACES ON TO SAID EXIT SURFACE WHEREFROM THEY ARE TOTALLY REFLECTED TOWARDS AND THROUGH SAID BASE SURFACE, A SECOND PRISM HAVING A CONCAVE MIRROR COATED SURFACE AND A BASE SURFACE WITH BOTH SAID SURFACES POSITIONED IN THE OPTICAL AXIS OF SAID EYEPIECE APERTURE, THE BASE SURFACE OF SAID SECOND PRISM BEING POSITIONED ADJACCENT TO THE BASE SURFACE OF SAID FIRST PRISM TO FORM AN AIR GAP THEREBETWEEN, AN ENTRANCE SURFACE ON SAID SECOND PRISM ADAPTED FOR RECEIVING LIGHT RAYS FROM SAID VIEW FINDER APERTURE. OPTICAL MEANS COMPRISING AN ANGULAR ROOF PRISM AND TELESCOPIC OBJECTIVE LENS MEANS BETWEEN SAID VIEW FINDER APERTURE AND SAID ENTRANCE SURFACE ON SAID SECOND PRISM FOR REFLECTING LIGHT RECEIVED FROM SAID VIEW FINDER APERTURE TOWARDS SAID LAST NAMED ENTRANCE SURFACE AND FOR FORMING A VIEW FINDER INTERMEDIATE IMAGE ADJACENT TO SAID LAST NAMED ENTRANCE SURFACE, TELESCOPE OBJECTIVE LENS MEANS ADAPTED FOR RECEIVING LIGHT RAYS FROM SAID RANGE FINDER APERTURE TO FORM AN INTERMEDIATE IMAGE ADJACENT TO SAID ENTRANCE SURFACE OF SAID SECOND PRISM, A RANGE FINDER MIRROR MEANS ARRANGED UPON THE SAID ENTRANCE SURFACE OF SAID SECOND PRISM ADJACENT TO THE PLANE OF THE RANGE FINDER INTERMEDIATE IMAGE, SAID RANGE FINDER MIRROR REFLECTING THE LIGHT RAYS FROM SAID RANGE FINDER APERTURE TOWARDS SAID BASE SURFACE AND SAID CONCAVE MIRROR COATED SURFACE OF SAID SECOND PRISM THEREBY COMBINING THE LIGHT RAYS FROM SAID RANGE FINDER AND VIEW FINDER APERTURES, THE SAID CONCAVE MIRROR COATED SURFACE AND SAID BASE SURFACE OF SAID SECOND PRISM BEING SO INCLINED WITH RESPECT OT EACH OTHER AND TO THE OPTICAL AXES OF THE VIEW FINDER TELESCOPIC OBJECTIVE LENS MEANS AND THE EYEPIECE APERTURE THAT THE COMBINED LIGHT RAYS FROM SAID INTERMEDIATE IMAGES AND SAID RANGE FINDER MIRROR MEANS IMPINGING UPON THE SAID BASE SURFACE ARE REFLECTED BY TOTAL REFLECTION TOWARDS SAID CONCAVE MIRROR COATED SURFACE FROM WHERE SAID LIGHT RAYS ARE REFLECTED TOWARDS SAID EYEPIECE APERTURE OPENING, SAID LIGHT RAYS REFLECTED BY SAID CONCAVE MIRROR COATED SURFACE PASSING THROUGH SAID AIR GAP, SAID CONCAVE MIRROR COATED SURFACE SERVING AS THE EYEPIECE FOR OBSERVING THE SAID INTERMEDIATE IMAGES AND THE SAID RANGE FINDER MIRROR MEANS.