Optical laser scanning micrometer

摘要

The present invention provides multiple improvements to optical-based laser scanning micrometers and providing a small handheld version laser scanning micrometer based on the these improvements. For added accuracy and reduction in unit size, a double sided coated mirror receiver reflects the beam back into the transmitter light source. For added accuracy, a Ronchi rule is repositioned one or more times to calibrate additional lookup table correction values. To compensate for barometric pressure change and temperature, two additional reference edges are added to be combined with the reference edges in the transmitter to generate to null out pressure and temperature at the passline measurement area. To minimize beam errors and for part locating, a third derivative is detected. Two or more parallel scanning beams are generated to null out cosine errors and to measure, taper and spherical parts.

主权项

1. An optical scanning laser micrometer having a laser beam transmitter and receiver for measuring the size of an object placed in a measurement field, the micrometer having a transmitter comprising a laser shining a beam on a rotating scanner mirror wherein the rotating scanner mirror scatters light which diverges in an arc into a collimator lens creating collimator scanning beam, the receiver comprising:
a) a receiver mirror having a top and bottom positioned to receive the columnar laser beam wherein the object is placed between the lens and the mirror for measurement, the mirror comprising a front surface facing the lens, the front surface having reflectivity of between about 1 percent and 50 percent and a back surface facing the lens, the back surface having a reflectivity of between about 5 percent and 100 percent; b) wherein the front and back surface are farther apart at the top than the bottom in a manner that the angle between the beam hitting the front surface and the back surface is each greater than 90 degrees and less than about 125 degrees; and c) wherein there is a pair of spaced apart light detecting diodes that are positioned between the laser and the rotating mirror further positioned to receive the beam reflected off of the front and back surface of the receiver mirror which passes back through the collimator lens to the scanner mirror which reflects it to the light detecting diodes wherein the light-detecting diode can be of one or more active surfaces.