Abstract: An optical gauging device wherein a laser beam is deflected to produce a bidirectional scan; a measuring portion of the split beam scans an object being inspected while the other portion scans a calibration reticle having alternating opaque and transparent bands. The alternating transmission and occultation of the beam through the reticle is used to generate calibration pulses, each representing a predetermined increment of movement of the calibration beam. The measuring portion of the beam is converted into parallel light beams which in turn are occulted by the workpiece being measured. A series of high and low square wave pulses are generated that are operative to start and stop the count of the calibration pulses. The count of the calibration pulses is directly related to the dimension of the workpiece being measured. A detector pulse enhancement circuit converts the measured signals to an accurate set of timing pulses independent of scan velocity, part size, part composition and interfering noise.

Abstract: An optical triangulation gauging system utilizing the position of a scanned laser beam to determine the position of an unknown surface or material thickness by optical triangulation. The scanned laser beam is split into two components by a beam splitter, one component, the reference beam, is passed through a calibration reticle having alternate opaque and transparent bands. The alternate transmission and occultation of the beam viewed through the reticle is used to generate calibration pulses that accurately describe the location of the gauging beam. The gauging component of the scanned beam is projected on to the surface to be measured. The back scattered light from this surface is viewed at a given angle, through a lens system that focuses the light onto a split photo detector. The position of the reference beam is interrogated as the scan beam image passes from one side of the split detector to the other.