×

Signal processing method for optical sensors

  • US 7,435,942 B2
  • Filed: 12/02/2005
  • Issued: 10/14/2008
  • Est. Priority Date: 12/02/2004
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method for detecting motion of an optical sensor relative to a surface along a plurality of directions, the method comprising steps of:

  • generating sets of signals responsive to motion along each of at least a first, second, and third direction, said directions not necessarily all different, each of said sets of signals consisting of a plurality of signals, said plurality including a main signal and one or more secondary signals, said main and secondary signals representing at least partially independent components of a complex signal whose complex phase changes in response to motion along one of said directions, wherein the sets of signals are generated from an array including a plurality of groups of photosensitive elements, which serve as a filter on spatial frequencies of light received on the array, and wherein at least one set of the sets of signals is generated using a spatial frequency different from that of the remaining sets of signals;

    combining said sets of signals to generate a first complex signal for each of said directions at a first time;

    combining said sets of signals to generate a second complex signal for each of said directions at a second time subsequent to said first time;

    computing a third complex signal for each of said directions wherein each of said third complex signals is a predicted value for each of said second complex signals, said predicted signal depending on a number of values representing distance moved; and

    determining the optimum values of said values representing distance moved by the step of minimizing the differences between said second and third complex signals.

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