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:
Apr. 24, 2001
Filed:
Sep. 18, 1998
Max V. Mathews, Stanford, CA (US);
Thomas E. Oberheim, Orinda, CA (US);
Interval Research Corporation, Palo Alto, CA (US);
Abstract
A position sensor is used in conjunction with one or more batons, each baton having a transmitter that transmits a distinct radio frequency signal at a position in space. The position sensor determines the current position of each baton transmitter in terms of X, Y, and Z coordinates. The position sensor includes a tablet having a flat support member, with at least two pairs of electrodes coupled to the flat support member. Each of the electrodes is a separate antenna. A first pair of the electrodes is shaped so that the amount of capacitive coupling between each baton transmitter and the first pair of electrodes corresponds to the position of the baton transmitter with respect to the X axis. A second pair of the electrodes is shaped so that the amount of capacitive coupling between each baton transmitter and the second pair of electrodes corresponds to the position of the baton transmitter with respect to the Y axis. The regions forming the first pair electrodes are preferably interleaved with the regions forming the second pair of electrodes. The X, Y position of the baton can be computed with uniform accuracy anywhere in the X-Y plane by measuring the capacitance values between the baton and the four antennae.