Patent ID: 7440121

Claim:
An apparatus for measuring the perimeter shape of an interior cavity, said interior cavity having a first edge at a position in said interior cavity and a second edge positioned opposite said first edge, comprising: an image plane that presents the image of a test object cavity plane slice to either the distal end of a flexible fiber optic endoscope or a rigid borescope, a single element image forming optic that collects the image light and brings it into a focused image at said image plane, the image rays collected by the image forming optical element passing from the object plane slice thru a finite space and impinge upon the image forming optic and be focused onto said image plane, the object plane slice being in best focus at a fixed distance from said image plane and a fractional region represented by the space between the near and far ends of an object depth of focus being in an acceptable image focus as to be recognizable as representing the depth of focus region for said image forming optic, the individual volumetric slice collected by an optical system being defined by a geometric space bounded perimeter of a near in-focus plane at one end and a far in-focus plane at the other end, a finite depth, vertical planar slice of the interior cavity being collected by an imaging system at any given point along a trajectory of an image collection system for each image collected.