Patent ID: 8270677

Claim:
A method of detecting a click event for sensing a motion of a finger corresponding to a click on a sensing area of an optical pointing device, the method comprising: obtaining an image of the finger from the sensing area; sensing a change in the image of the finger; analyzing a horizontal movement of the finger based on the change in the image of the finger; and generating a click signal when the analyzed horizontal movement of the finger is within a predetermined range, wherein the sensing comprises comparing a current shutter value SV crr with a previous shutter value SV pst at a predetermined time interval to thereby determine the finger motion as placing of the finger when a ratio SV r of the current shutter value SV crr to the previous shutter value SV pst , SV r =SV crr /SV pst , is less than a first lower limit reference and determine the finger motion as lifting of the finger when the ratio SV r of the current shutter value SV crr to the previous value SV pst is greater than a first upper limit reference, the first lower limit reference being less than 1 and the first upper limit reference being greater than 1.