| 摘要 |
A signal processor and method are provided for detecting movement of a surface relative to an optical sensor having an array of photosensitive elements. Generally, the method involves: (i) sampling each of a number (M) of phase signals from the photosensitive elements, each of the M signals having a magnitude (A<SUB>i</SUB>) and including a tracking signal at a frequency being tracked and a background signal at other frequencies that offsets the tracking signal, where i, an index of the signals, is a whole number between 0 and M-1; (ii) eliminating the offset to the tracking signal due to the background signal to generate M non-offset phase signals having a magnitude (A'<SUB>i</SUB>); (iii) adjusting phase angles (theta<SUB>i</SUB>) of the non-offset phase signals to generate M weighted phase signals (A'<SUB>i</SUB>theta'<SUB>i</SUB>); and (iv) combining each of the M weighted phase signals (A'<SUB>i</SUB>theta'<SUB>i</SUB>) to generate an average weighted phase having a phase angle (theta), that when tracked over time indicates a direction and velocity of the movement of an image of the surface mapped to the array.
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