A discharge lamp operating device includes a voltage application unit that
applies to a discharge lamp an alternating-current (AC) voltage for
operation of the discharge lamp, and a frequency setting unit that sets a
frequency of the AC voltage to a first frequency for ignition of the
discharge lamp and sets the frequency of the AC voltage to a second
frequency during operation of the discharge lamp after the ignition. In
the discharge lamp operating device, the second frequency is lower than
the first frequency.