Patent ID: 7417623

Claim:
A pointing device for a computer system, comprising: a photo capture device, capturing images sequentially to produce a first frame and a second frame; and a displacement detection circuit, predicting a velocity of the pointing device, and comparing the first frame and the second frame according to the predicted velocity to obtain a displacement of the pointing device, wherein the predicted velocity is estimated as: V → ⁢ p = ⁢ V ⇀ ⁢ ⁢ m ⁢ + ⁢ V ⇀ ⁢ n ⁢ 2 + ( V ⇀ ⁢ m - V ⇀ ⁢ n ) where V m and V n comprise average velocities by accumulating m and n instantaneous velocities respectively and m>n.