Patent ID: 8026900

Claim:
An optical pointing device comprising: an illumination unit for illuminating light on a working surface in response to an illumination signal during a calculation period, and generating light in a predetermined code in response to a code signal during a determination period, wherein the code signal repetitively turns on or off the illumination unit depending on a certain code value during the determination period; a control unit for outputting the illumination signal to detect an image on the working surface, detecting the image on the working surface to calculate a movement value, and outputting movement information in response to an input signal inputted from the outside and the calculated movement value during the calculation period, intermittently outputting a code generation signal to determine whether or not the optical pointing device is separated from the working surface during the determination period, and turning off the illumination unit when the optical pointing device is separated from the working surface in response to a determination signal; and a determination unit for outputting the code signal to determine whether or not the optical pointing device is separated from the working surface in response to the code generation signal, detecting the light, determining whether a code of the detected light matches the predetermined code to thus determine whether or not the optical pointing device is separated from the working surface, and outputting the determination signal depending on the determination result during the determination period, wherein the determination period does not overlap with the calculation period, and the light generated during the determination period is different from the light illuminated during the calculation period.