Patent ID: 7653297

Claim:
An AF lens position determination system, comprising: an anti-dazzling screen comprising first and second areas, where the length of a respective covered sub-area in the first area from a first border to a second boarder of the first area is determined according to a first function, and the length of a respective uncovered sub-area in the first area from the first border to the second boarder of the first area is determined according to a second function, the length of a respective uncovered sub-area in the second area from a third border to a fourth boarder of the second area is determined according to a third function, and the length of a respective covered sub-area in the second area from the third border to the fourth boarder of the second area is determined according to a fourth function, wherein the first function and the second function are different, and the third function and the fourth function are different; a sensor moving within a range, and generating low and high signals based on the covered sub-areas and the uncovered sub-areas of the anti-dazzling screen; and a processing module determining a position of an AF lens according to the low signals and high signals generated by the sensor.