Patent ID: 7952779

Claim:
A method of controlling a torsion oscillator for stabilizing the oscillation amplitude comprising the steps of: driving the torsion oscillator at a predetermined frequency with a drive energy level by a control module to generate a scanning angle of an incident light beam; comparing the scanning angle corresponding to the drive energy level with a designate scanning angle by the control module; and adjusting the drive energy level based on the compared result until the scanning angle of the torsion oscillator is equal to the designate scanning angle, wherein the predetermined frequency and the drive energy level are determined by the steps of: driving the torsion oscillator by a first set of drive energy levels to obtain a first set of frequency response curves under a first environment condition, and defining a first set of frequency intervals according to the designate scanning angle; driving the torsion oscillator with a second set of drive energy levels to obtain a second set of frequency response curves under a second environment condition, and defining a second set of frequency intervals according to the designate scanning angle; driving the torsion oscillator with a third set of drive energy levels to obtain a third set of frequency response curves under a third environment condition, and defining a third set of frequency intervals according to the designate scanning angle; overlapping the second set of frequency intervals corresponding to the second set of drive energy levels with the third set of frequency intervals corresponding to the third set of drive energy levels to define a predetermined frequency interval; and selecting the predetermined frequency from the predetermined frequency interval.