Patent ID: 7439690

Claim:
A discharge lamp lighting apparatus comprising: a lamp voltage detection circuit configured to detect a lamp voltage of a discharge lamp; a lamp current detection circuit configured to detect a lamp current of the discharge lamp; a lamp voltage correction circuit, including a lamp voltage detection amplifier and a lamp current detection amplifier for suppressing errors in the detected lamp voltage; and a control circuit configured to perform a starting-time control that applies at least one of a current and power that is greater than a corresponding rated value of the discharge lamp, respectively, in order to light the discharge lamp substantially instantaneously, the control circuit also configured to perform a stable-time control to light the discharge lamp at a substantially constant rated power, and wherein the control circuit is configured to control at least one of lamp current and lamp power from a starting time to a stable time in accordance with a voltage value detected by the lamp voltage detection circuit, and the control circuit is configured to switch from the starting-time control to the stable-time control depending on an increase in the voltage value detected by the lamp voltage detection circuit from the starting time to the stable time and depending on a lapse of an arbitrary time from the starting time to a time greater then zero.