Abstract: A gemstone marking system includes a focus sensing unit sensing relative disposition between the marking surface of the gemstone and the focal plane of the laser beam. The focus sensing unit includes a light source emitting a collimated optical beam directed in parallel to the focal plane of the laser beam and overlapping regions positioned in close proximity to the focal plane of the laser beam, an optical detector measuring the power of the sensing optical beam (the power of the sensing optical beam depends on a relative disposition between the marking surface of the gemstone and the focal plane of the laser beam), and a signal processing unit operationally coupled to the output of the optical detector for receiving and processing data corresponding to the relative disposition of the marking surface of the gemstone and the focal plane of the laser beam. The signal processing unit, in response to the data obtained from the optical detector, automatically controls the position of the gemstone.

Abstract: A gemstone marking system includes a focus sensing unit sensing relative disposition between the marking surface of the gemstone and the focal plane of the laser beam. The focus sensing unit includes a light source emitting a collimated optical beam directed in parallel to the focal plane of the laser beam and overlapping regions positioned in close proximity to the focal plane of the laser beam, an optical detector measuring the power of the sensing optical beam (the power of the sensing optical beam depends on a relative disposition between the marking surface of the gemstone and the focal plane of the laser beam), and a signal processing unit operationally coupled to the output of the optical detector for receiving and processing data corresponding to the relative disposition of the marking surface of the gemstone and the focal plane of the laser beam. The signal processing unit, in response to the data obtained from the optical detector, automatically controls the position of the gemstone.

Abstract: All critical wheel wear measurements on a static or in-motion train wheel are taken using a non-contact method/system. The train wheel is measured using a modulated point beam of energy impinging the wheel surface from an orthogonal direction, moving the point beam across the wheel surface, and sensing the unique modulated reflection of the wheel using energy sensors that produce analog signals. The analog signals are digitized and processed to produce all critical wheel wear measurements without removing the wheel from the train.

Abstract: The invention comprises a digital frequency generator particularly adapted for use with acousto-optical scanning devices, and particularly for such devices as for producing a scan or a raster scan or the like. The invention electronic circuitry includes a precision timing generator which is made up of a tapped delay line which feeds a multiplexor to produce an output pulse of any desired configuration. The output pulses are produced in a stream, but each pulse is produced individually.