US Patent 7119323 Error corrected optical navigation system

An optical navigation system. The optical navigation system includes an image sensor capable of optical coupling to a surface of an object, a data storage device, and a navigation circuit. The data storage device is capable of storing successive images captured by the image sensor. The navigation circuit includes a first digital circuit capable of determining an optical displacement estimate for a relative displacement between the image sensor and the object obtained by comparing the images, a second digital circuit capable of determining a mechanical displacement estimate for the relative displacement obtained from consideration of a mechanical characteristic associated with the optical navigation system, and a third digital circuit capable of determining an adjusted displacement estimate obtained from the optical displacement estimate and the mechanical displacement estimate.