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:
Oct. 09, 2001
Filed:
Feb. 26, 1998
Gideon Shenholz, Tel Aviv, IL;
Yitzhak Zloter, Holon, IL;
Electronics for Imaging, Inc., Foster City, CA (US);
Abstract
A presentation board digitizer system for large boards preferably employs at least three spaced-apart ultrasound receivers assemblies. A current position of an ultrasound transmitter is assigned as a weighted centroid of time of-flight position measurements based on at least two pairs of receiver assemblies. The weighting used varies as a function of the position of the transmitter across the board. A preferred structure of an ultrasound receiver assembly for use in the system employs a pair of ultrasound receivers arranged side-by-side in a line perpendicular to the surface of the presentation board. The receivers are connected so as to generate a total output signal corresponding to the instantaneous sum of the ultrasound signals received at each, such that the receiver assembly is most sensitive to ultrasound signals incident from a plane adjacent to the presentation board. Also described are a transmitter device for use with a conventional pen in which the ultrasound transmitter is a cylindrical element lying coaxial with the pen and adjacent to its tip, and a jointed eraser structure.