Discharge lamp lighting device, and illumination apparatus and vehicle including same

A discharge lamp lighting device light which drives a discharge lamp with an alternating power, comprising:

• a DC-DC converter configured to convert a voltage of a DC power source into a DC power and output the DC power, by changing a PWM signal inputted to a switching element;
• an inverter configured to convert the DC power into the alternating power having a frequency low than a switching frequency of the DC-DC converter;
• a voltage detector which detects an output voltage of the DC-DC converter;
• a current detector which detects an output current of the DC-DC converter;
• a controller configured to control the switching frequency of the DC-DC converter according to a detection value of at least one of the voltage detector and the current detector;
• and
• a PWM ON signal controller which increases the DC power by lengthening an ON duty of the PWM signal during a predetermined period after a start of polarity inversion of the alternating power,
• wherein when at least one of the voltage detector and the current detector detects a predetermined detection value, the controller changes an increase amount of the DC power increased by the PWM ON signal controller according to the detection value.