Signal processing method for use with an optical navigation system
US7248345B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 2005 |
| Grant date | Jul 24, 2007 |
| Priority date | — |
| Expiry date | Feb 17, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0317
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
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 (Ai) 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′i); (iii) adjusting phase angles (θi) of the non-offset phase signals to generate M weighted phase signals (A′iθ′i); and (iv) combining each of the M weighted phase signals (A′iθ′i) to generate an average weighted phase having a phase angle (θ), that when tracked over time indicates a direction and velocity of the movement of an image of the surface mapped to the array.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.