Abstract: An optical rangefinder having a photosensor adapted to transform the image projected thereon into an electronic image, an imaging system for projecting an image of an object on the photosensor, an optical arrangement to modulate the incoming light forming the image on the photosensor, means for providing the spatial spectrum of the image and means for deriving the distance from the object to the rangefinder on the degree of defocus of the image, wherein the optical arrangement is adapted to modulate the incoming light such that the degree of defocus of the image on the photosensor relative to the in-focus image plane results in displacement of the spatial spectrum of the image relative to a reference pattern and wherein the rangefinder has means for deriving the degree of defocus from the degree of displacement.

Abstract: An optical rangefinder having a photosensor adapted to transform the image projected thereon into an electronic image, an imaging system for projecting an image of an object on the photosensor, an optical arrangement to modulate the incoming light forming the image on the photosensor, means for providing the spatial spectrum of the image and means for deriving the distance from the object to the rangefinder on the degree of defocus of the image, wherein the optical arrangement is adapted to modulate the incoming light such that the degree of defocus of the image on the photosensor relative to the in-focus image plane results in displacement of the spatial spectrum of the image relative to a reference pattern and wherein the rangefinder has means for deriving the degree of defocus from the degree of displacement.