National Computer Systems, Inc.

George E Carsner

John V McMillin

A method and apparatus for discriminating bar codes for an optical mark reader is provided comprising a scanning means for scanning a target area on a scannable form and producing a signal in response to certain indications, i.e., marks or spaces, in the target area, detection means for detecting indications having a width within a preselected range of widths, first comparator means for comparing the number of detected indications to a specified range of valid numbers of detected indications, and second comparator means for comparing the output of the first comparator means for two consecutive sweeps of the scanning means and enabling means for producing an enabling signal when the output of the first comparator means is valid for two consecutive sweeps, such that the enabling signal enables a bar code scanner to scan and decode the bar code, and a picking signal when the output of the first comparator means is not valid for two consecutive sweeps during a scan of the entire target area, such that the picking signal enables the optical mark reader to begin mark scanning of the scannable form.

Method and apparatus for discriminating or locating bar codes for an

The present invention relates generally to the field of optical mark readers and mark scanning systems. More particularly, the present invention relates to a method and system for checking the velocity of a scannable document as it travels under the read head of a mark scanning system.

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Iowa City, IA, United States of America

George E Carsner