| 摘要 |
<p>OPTICAL PROJECTOR An invention is disclosed for optically determining the position of an object in spacer using a single lens for triangulation, wherein an indexing light beam is projected to a lens on one side nonparallel to the optical axis of the lens. The lens focuses the indexing light beam at a known point on the other side of the lens at or near which reflection occurs by the object. Reflected light is captured by the lens and focused toward a photodetector which generates a signal indicating whether reflection occurred at the known point, thus indicating whether the object is present at the known point. If laser light is used, provision is made for, in effect, positioning the laser light source on the optical axis to reduce the effects of laser pointing instabilities. The invention can be used to measure the radii of rotating gas turbine engine rotors.</p> |
