Patent ID: 6466306
Filing Date: 2002-10-15
Classification: B60T,G01C,G01S

Abstract:
A reticle adapter for judging distance from an object, the adapter being used in combination with a viewing apparatus of the type adapted to detect relative positions of signals from at least two spaced apart marker devices formed on a first object, each marker device providing a signal, and the viewing apparatus being further adapted to create an image of the relative positions of the markers within a field of view, the viewing apparatus further having an image path therethrough with a scene input end and an output image, the invention comprising:a reticle projecting member adapted for removable mounting on the viewing apparatus; the reticle projecting member projecting a reticle signal forming a reticle suitable to be detected by the viewing apparatus and to be superimposed on the field of view at the scene input end of the viewing apparatus; the reticle selected to form a control area within which simultaneous appearance of at least two images of the spaced apart markers indicates that the first object is at a distance at least as great as a desired distance from the viewing apparatus; and, simultaneous appearance of less than two images of the spaced apart markers within the control area indicates that the first object is at a distance less than the desired distance from the viewing apparatus; and, the reticle including a spaced apart first and second indicator segments forming the boundaries for the control area; spacing between the first and second indicator segments being calculated by the formula L*SIN(A) where L is a distance between an eyepiece of the viewing apparatus to a retina of an operator of the viewing apparatus and SIN(A) equals the result of a distance from the viewing apparatus to a plane formed by the spaced apart markers divided into a distance between at least two of the spaced apart markers; and the operator during use of the viewing apparatus forms a vertex of an isosceles triangle composed the operator and two of the spaced apart markers with the viewing apparatus having the superimposed reticle being located between the operator and the markers.