Abstract: A method of profiling a rough surface of an object includes moving the object along a z axis so that a highest point of the rough surface is optically aligned with and outside of the focus range of a solid-state imaging array. An interferogram of the rough surface then is produced by means of a two beam interferometer. The solid-state imaging array is operated to scan the rough surface along x and y axes to produce intensity data for each pixel of the solid-state imaging array for a plurality of frames each shifted from the other by a preselected phase difference. The modulation for each pixel is computed from the intensity data. The most recently computed modulation of each pixel is compared with a stored prior value of modulation of that pixel. The prior value is replaced with the most recently computed value if the most recently computed value is greater.
May 6, 1992
Date of Patent:
April 20, 1993
Donald K. Cohen, Paul J. Caber, Chris P. Brophy
Abstract: An edge sensitive set-reset flip-flop is implemented by providing a conventional cross-coupled coincident gate flip-flop with an input means consisting of an inverter, a noninverting delay element and a coincident gate. The input means buffers binary input signals such that the cross-coupled coincident flip-flop will change state only in response to binary transitions of a prescribed direction.