Patent ID: 7208885

Claim:
A dimming control method, the method implemented in a lighting system comprising an input unit for generating an intensity control signal and a light-emission unit, the method comprising the steps of: (a) when the intensity control signal varies from a first value higher than a first predetermined value to a second value higher than the first predetermined value, adjusting an amplitude of a current output to the light-emission unit and outputting a current having an amplitude corresponding to the second value; (b) when the intensity control signal varies from a third value lower than a second predetermined value to a fourth value lower than the second predetermined value, adjusting a duty cycle of the current output to the light-emission unit and outputting a current having a duty cycle corresponding to the fourth value; (c) when the intensity control signal varies from a fifth value higher than the second predetermined value to a sixth value lower than the second predetermined value, fixing the amplitude of the current output to the light-emission unit at a third predetermined value, adjusting the duty cycle of the current output to the light-emission unit, and outputting a current having a duty cycle corresponding to the sixth value; and (d) when the intensity control signal varies from a seventh value lower than the first predetermined value to an eighth value higher than the first predetermined value, fixing the duty cycle of the current output to the light-emission unit at a fourth predetermined value, adjusting the amplitude of the current output to the light-emission unit, and outputting a current having an amplitude corresponding to the eighth value.