Patent ID: 6636296
Filing Date: 2003-10-21
Classification: G01C

Abstract:
A range finder for determining distance to a desired object, said range finder comprising:a first member containing a transparent viewing portion therein including means changing linearly in width and positionable to accommodate a dimension of said object transverse to a line from said object to said range finder when viewed through said viewing portion; means indicating the distance to said object when the object appears to just fill said viewing portion; wherein said distance indicating means are determined in accordance with the formula z=xy/d, where z is the width of said viewing portion, x is the approximately determined linear dimension of said object, y is the defined distance from the user's eye to said device, and d is the actual distance from said object to said user's eye; and wherein the determination of said actual distance is adjusted in accordance with the formula a2=b2+c2, where a is the distance from said object to the user's eye, b is the distance from the user's eye to a second object located on approximately the same level as said object, and c is the distance from said object to said second object.