×

Object position detection system and method

  • US 6,239,389 B1
  • Filed: 06/21/1999
  • Issued: 05/29/2001
  • Est. Priority Date: 06/08/1992
  • Status: Expired due to Term
First Claim
Patent Images

1. A method for providing an electrical signal representative of the position of an object in a two dimensional plane, comprising the steps of:

  • providing a sensing plane including a matrix of conductor elements arranged as a plurality of rows and a plurality of columns of spaced apart row conductive lines and column conductive lines, said sensing plane characterized by an inherent capacitance on associated with the various ones of said row conductive lines and column conductive lines, said capacitance varying according to the proximity of an object to said row and column conductors;

    developing a first set of digital signals proportional to the value of said capacitance for each of said row conductive lines when no object is located proximate to said sensing plane;

    developing, simultaneously with said first set of digital signals, a second set of digital signals proportional to the value of said capacitance for each column conductive lines when no object is located proximate to said sensing plane;

    developing, simultaneously with said first and second sets of digital signals, a third set of digital signals proportional to the value of said capacitance for each of said row conductive lines when an object is located proximate to said sensing plane;

    developing, simultaneously with said first, second and third sets of digital signals, a fourth set of digital signals proportional to the value of said capacitance for each column conductive lines when said object is located proximate to said sensing plane;

    computing a first weighted average of the difference between said first set of digital signals and said third set of digital signals; and

    computing a second weighted average of the difference between said second set of digital signals and said fourth set of digital signals.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×