Abstract: An electro-optical system for inspecting an object includes a source producing a beam of electromagnetic energy, for example, a laser. It also includes a means for discriminating between electromagnetic energy of the beam scattered from objects within a predetermined distance of a plane intersected by the beam of electromagnetic energy and electromagnetic energy not so scattered. Thus, spurious electromagnetic energy scatteed by other objects near the inspected object are ignored.

Abstract: In the invention, a light beam is scanned along a surface bearing data, such as a serial number. Reflected light is measured and processed for character recognition. The invention wobbles or dithers the light beam during the scan, and takes reflectivity measurements several times within a region on the surface, the region being called a pixel. This procedure enhances the reflectivity signature of edges, thus improving the ability to recognize characters.

Abstract: An invention is disclosed for optically determining the position of an object in space, 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.

Abstract: An opto-electronic apparatus for sensing the position or inspecting the condition of a target, which is capable of at least partially reflecting light in a scattered manner, includes an incident light source and means to direct light from the source in a narrow incident beam onto the target along an incident beam axis. A photoelectric sensor, which includes light collecting and focusing means as well as photosensitive means for receiving the focused light, provides for collecting and focusing the reflected scattered light along a reflected light axis of the light collecting and focusing means to the photosensitive means which provides an output signal including a portion which is a function of displacement of the focused light from a reference of the photosensitive means. Such reference represents the position of the axis intersection between the incident beam axis and the reflected light axis of the light collecting and focusing means.