Patent 6323846 Issued on November 27, 2001. Estimated Expiration Date: January 25, 2019. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
Apparatus and methods are disclosed for simultaneously tracking multiple finger and palm contacts as hands approach, touch, and slide across a proximity-sensing, compliant, and flexible multi-touch surface. The surface consists of compressible cushion, dielectric, electrode, and circuitry layers. A simple proximity transduction circuit is placed under each electrode to maximize signal-to-noise ratio and to reduce wiring complexity. Such distributed transduction circuitry is economical for large surfaces when implemented with thin-film transistor techniques. Scanning and signal offset removal on an electrode array produces low-noise proximity images. Segmentation processing of each proximity image constructs a group of electrodes corresponding to each distinguishable contact and extracts shape, position and surface proximity features for each group. Groups in successive images which correspond to the same hand contact are linked by a persistent path tracker which also detects individual contact touchdown and liftoff. Combinatorial optimization modules associate each contact's path with a particular fingertip, thumb, or palm of either hand on the basis of biomechanical constraints and contact features. Classification of intuitive hand configurations and motions enables unprecedented integration of typing, resting, pointing, scrolling, 3D manipulation, and handwriting into a versatile, ergonomic computer input device.
Other References
Subutai Ahmad, "A Usable Real-Time 3D Hand Tracker," Proceedings of the 28th Asilomar Conference on Signals,Systems, and Computers--Part 2 (of 2), vol. 2 (Oct. 1994)
Sarah A. Douglas and Anant Kartik Mithal, The Ergonomics of Computer Pointing Devices (1997)
Donald L. Fisher et al., "Repetitive Motion Disorders: The Design of Optimal Rate-Rest Profiles," Human Factors, 35(2):283-304 (Jun. 1993)
Masaaki Fukumoto and Yoshinobu Tonomura, "Body Coupled Fingering: Wireless Wearable Keyboard," CHI 97, pp. 147-154 (Mar. 1997)
Frederick S. Hillier and Gerald J. Lieberman, Introduction to Operations Research (1986)
Robert J. K. Jacob et al., "Integrality and Separability of Input Devices," ACM Transactions on Computer-Human Interaction, 1:3-26 (Mar. 1994)
Seonkyoo Lee, "A Fast Multiple-Touch-Sensitive Input Device," Master's Thesis, University of Toronto (1984)
January 25, 2019. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
