Patent Document ID: 5565658
Application ID: 08351008
Patent Flag: 1

Claim One:
1. A capacitance-based proximity sensor for locating the position of an object while rejecting a frequency of electrical interference, comprising: (a) an electrode array for forming capacitances which vary with movements of the object, (b) measurement means coupled to the electrode array for measuring the capacitances synchronously with a reference signal, and (c) generator means for supplying a reference signal to the measurement means, said reference signal having a frequency which is not coherent with the frequency of electrical interference, wherein the generator means comprises means for evaluating the electrical interference and for producing the reference signal, and wherein the evaluating means includes means for storing a table of frequencies of selected reference signals and measures of electrical interference IM for each of these frequencies, and for producing a reference signal whose frequency has the lowest IM associated therewith.