Abstract: The discharge lamp lighting apparatus includes: a direct current power supply E; switching elements Q1 and Q2 for switching a direct current supplied from the direct current power supply E so as to generate a high frequency current; a discharge lamp load circuit LAC1 which is constructed in a manner that a discharge lamp LA and a coupling capacitor C4 are connected in series, and the discharge lamp LA is lit by a high frequency current generated by the switching elements Q1 and Q2; a switching element control circuit IC1 for controlling the switching elements Q1 and Q2. The discharge lamp lighting apparatus is further provided with a protective circuit NP2 which distinguishes a fault of the discharge lamp LA by detecting a voltage generated in the coupling capacitor C4, and outputs a control signal to the switching element control circuit IC1.

Abstract: A discharge lamp lighting device in which dim control can be performed for a discharge lamp continuously and stably in a wide range, and which is simple in circuit configuration and low in price. The discharge lamp lighting device comprises: an inverter (IV) for turning on/off switching elements (Q2, Q3) by an oscillation output signal of an IV control integrated circuit (IC2) to thereby invert a voltage of a DC power supply (E) into high-frequency electric power, a discharge lamp (LA) capable of being lighted by the high-frequency electric power from the inverter (IV), a feedback circuit (FB) having delay time T (unit: second) expressed by 1/f≦T≦1/10,000 when the frequency of the high-frequency electric power is f, the feedback circuit (FB) including a reference value setting means (R15) for setting a reference value, the feedback circuit outputting a voltage for controlling the IV control integrated circuit (IC2) to make the high-frequency electric power equal to the reference value.