Patent ID: 8482215

Claim:
A control method of a light emitting apparatus, the light emitting apparatus having a semiconductor device for emitting light, the control method comprising the following steps: stepwise and gradually reducing a driving power of the semiconductor device to an ideal power, wherein the semiconductor device continually emits the light by the reduced driving power within a predetermined time after every time the driving power of the semiconductor device is reduced; sensing a temperature of the semiconductor device; comparing the temperature of the semiconductor device with a safe temperature value, wherein the temperature of the semiconductor device is higher than the safe temperature value before every time reducing the driving power; wherein the step of stepwise and gradually reducing the driving power of the semiconductor device to the ideal power comprises: determining whether the temperature of the semiconductor device decreases in the predetermined time after every time reducing the driving power; determining whether an amount of a variation of the temperature of the semiconductor device is higher than a predetermined value if the temperature of the semiconductor device decreases in the predetermined time and the temperature of the semiconductor device is still higher than the safe temperature value after the predetermined time; and adjusting the driving power of the semiconductor device if the amount of the variation of the temperature of the semiconductor device is higher than the predetermined value in the predetermined time.