Convertible binocular/stereoscope device

Abstract

A dual purpose optical device that is convertible between binocular and stereoscope modes of operation while using a common eyepiece arrangement for both. The device includes a housing containing a pair of optic supports mounted side-by-side for lateral movement towards and away from one another. Each support preferably carries three lenses. Two lenses on each support serve as the eyepiece and are aligned in a common plane with an eyepiece opening through the housing and a rotatable mirror assembly. The assembly pivots substantially ninety degrees from opposing forty-five degree angle positions with respect to the plane through the eyepiece opening and the eye and field lenses so as to fold the lines of sight either up or down within the housing. A circular photo transparency reel is received horizontally in a slot provided on an upper side of the housing. Each optic support is provided with three fixed mirrors which fold the lines of sight directed downward by the rotating mirror through an objective lens located at an opposite end of the housing. The three lenses on each optic support collectively form a binocular lens train while two of the lenses of each set form a magnifying lens train. A spring biases the optic supports together and against tapered, longitudinally extending sides of a cam mounted for longitudinal movement in the housing. A wheel projects partially through the bottom of the housing and supports pinions that are engaged with racks on the cam to provide manual interpupillary spacing adjustment of the optic supports. In the stereosope mode of operation, the interpupillary distance between the eyepieces is automatically set in response to converting between the two modes so that it matches the distance separating corresponding stereo pairs.