Inventors:
J. Kent Bowker - Essex MA
Stephen G. Miller - Great Falls VA
Stephen C. Lubard - Woodland Hills CA
John M. Wartman - Malibu CA
Clive Bolton - Melrose MA
Assignee:
Arete Associates - Sherman Oaks CA
International Classification:
G06K 900
Abstract:
Surface relief of a finger etc. is read using an optical-fiber prism unit, with fiber terminations at one end to contact the surface, and at the other for light passage along fibers from the first. Light enters where NA<0. 5 and fiber diameter is constant with longitudinal position. The device is in a 1. 4-2 L case, with a battery or power input, converter to form a corresponding data array for verifying, digital signal processor to do the verifying, and output to indicate or implement a decision. A video controller (with custom-programmed logic circuit) operates the sensors to develop the data array; an ADC digitizes the array; memory holds an authorized-user skin-pattern template, firmware for the processor, and data used in verifying; an output register holds the decision signal--all on a control, address, and data bus. High-power, radiative elements and a fast high-impedance data reader are on a common board in an isolating layout. The prism unit is cylindrical, held by a cylindrical-section cradle and forming a novel condenser lens to support lights and couple light to the prism.