Patent ID: 7239302

Claim:
A pointing device, comprising: a light source for irradiating light along a light path; a ball rotating by movement of the entire pointing device; an optical image sensor for detecting the movement of the pointing device using an image; a plurality of bearing balls arranged to come into contact with the ball, thus facilitating rotation of the ball; a support for supporting the bearing balls to form a space being structured and arranged so as to permit at least one of the bearing balls, when contacting the ball, to (i) move with respect to the support in the direction in which the ball rotates; and (ii) rotate; a guard for preventing the bearing balls from crossing the light path from the light source to the ball; and wherein the pointing device irradiates light onto the ball through the light source, acquires an image formed on a surface of the ball through the optical image sensor, and outputs data on movement direction and distance of the ball by comparing and analyzing previous and current images.