The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 10, 1981
Filed:
Aug. 27, 1979
Frank P Carau, Sr, Loveland, CO (US);
Henry T Hetzel, Loveland, CO (US);
Michael A Tremblay, Loveland, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A digitizer shifts long and short wavelength square waves across x and y grids in a platen to perform upon a cursor signal time measurements that represent coarse and fine cursor position data. The periodic staircase cursor signal is filtered before use to permit time measurements that resolve cursor positions to locations between lines in the grids. The contribution of the filter to the coarse and fine time measurements is obtained in a special reference measurement, so that it may be removed. A processor combines these data into Cartesian coordinates, and implements procedures for error reduction. These include averaging of consecutive time measurements, dynamic adjustment of a timing reference to remove ambiguities inherent in measuring very small or very large cyclic quantities, and correction of coordinates for the effects of cursor motion during measurement and for any non-perpendicularity of the x and y grids.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile