Yet another example of Dr. Lindquist's passion for clever inventions and being deeply involved in the 'early days' of MRC Engineering development and design of OMR scanners. True, we on the MRC engineering staff sometimes regarded Lin's ideas as a bit on the Rube Goldberg side of the aisle, and as I recall, this was one of them, and we never implemented this particular idea of his, nor did he apply for a patent. However, this original Lindquist paper does describe a basic and fundamental problem - with respect to document registration - in the accurate scanning of position-encoded OMR marks therein, and fortunately, the problem was solved more than a decade later when CCD arrays became commercially available. Refer to McMillin/Schroeder U. S. Patent No. 4,300,123, issued 10 NOV 1981