Endoscope with sensor

Claim 1

An endoscope for inspecting a wall surface of an industrial apparatus, said endoscope comprising a distal forward end adapted to inspect said wall surface, a rear end, a fiber optic bundle located in said endoscope between said distal forward end and said rear end, said fiber optic bundle comprising a light-transmitting optic bundle and a light-receiving optic bundle, said endoscope further comprising a light source for supplying light to said light transmitting optical bundle toward said wall surface, said light-receiving optical bundle optically coupled to carry light reflected from said wall surface to said rear end of said endoscope, optical measurement means located at said distal end being optically coupled to said transmitting and light-receiving optical bundles to sense the distance between said optical means and said wall surface, said optical measurement means comprising a common optical lens and at least one transmitting optical lens optically located between said common optical lens and said light transmitting optic bundle and at least one receiving optical lens optically located between common optical lens and said light-receiving optic bundle, said common lens and said transmitting and receiving optical lenses optical coupled to said fiber optic bundle for receiving reflected light from said wall surface at varying positions on the common lens responsive to the distance of said optical means from said wall surface for thereby varying the refraction angle of said transmitted light, means for sensing the refracted light and providing a display as a function of the angle of refraction to thereby indicate said distance.