Patent ID: 6151015
Filing Date: 2000-11-21
Classification: G06F

Abstract:
A hand held pointing device for a computer or the like, said pointing device comprising:a body, said body being generally cylindrical with a tapering end, said tapering end also having a tip;an illumination source, said illumination source being disposed inside said body and providing light that passes through a translucent portion of said body and illuminates a work surface;an optical motion detection circuit mounted within the interior of the body and proximate to said translucent portion of said body, the motion detection circuit producing motion indication signals indicative of motion in the directions along a first and a second axes and relative to illuminated imageable features visible through said translucent portion of said body; andwherein the optical motion detection circuit comprises a plurality of photo detectors each having an output, a memory containing a reference frame of digitized photo detector output values and a sample frame of digitized photo detector output values obtained subsequent to the reference frame, and further wherein a plurality of comparison frames, each being a shifted version of the reference frame, is correlated with the sample frame to ascertain motion in the directions along the first and second axes.