Signature verification apparatus and method utilizing relative angle measurements

US6236740A · kind A · utility

Inventor

• Michael E. Lee · Eugene, US

Key dates

• Filing date: Mar 23, 1998
• Grant date: May 22, 2001
• Expiry date: Mar 23, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G06V40/30
• WIPO field: IT methods for management
• WIPO sector: Electrical engineering

Abstract

A signature verification system consisting of a durable pressure sensitive data input stylus, signal processing, and computer algorithms for enrollment of signatures, digits and verification. The stylus contains two transducers placed so that axial force and lateral force are measured simultaneously. Combining the two signals at digitized sample points yields a ratio of pressures indicative of the angle of the stylus to the writing surface at that moment, controlling for variations in actual force. The ratio, called a relative angle, is calculated for the entire signal train of a signature and for various simple divisions, or segments. Segments are equal divisions of the signal train by various divisions. While the relative angle of the whole signature may vary unpredictably between signings, the unique variations around the average relative angle form unique signature discriminates. Variations are measured by comparing relative angle measurements of segments, one to another, in all mathematical combinations. The combinations are called measurement points and each measurement point has a value based on the comparison. Some measurement point values, out of many sampled by computer, …