Lighting driver for discharge lamp

A lighting driver for a discharge lamp designed to be ignited in response to application of a voltage higher than a given set voltage and to maintain stable emission of light through supply of a current having a given value, comprising:

• a piezoelectric transformer connected electrically to the discharge lamp, said piezoelectric transformer being responsive to application of a first voltage having a first driving frequency to develop a voltage higher than the given set voltage required to ignite the discharge lamp and also responsive to application of a second voltage having a second driving frequency to supply a current to the discharge lamp which allows the discharge lamp to maintain stable emission of light;
• a lighting detecting circuit detecting a status of the discharge lamp to provide a signal indicating whether the discharge lamp has been ignited or not;
• a first voltage source circuit generating the first voltage having the first frequency;
• a second voltage source circuit generating the second voltage having the second frequency;
• and
• an applied voltage switching circuit switching between a first communication of said first voltage source circuit with said piezoelectric transformer and a second communication of said second voltage source circuit with said piezoelectric transformer, when it is required to ignite the discharge lamp, said applied voltage switching circuit establishing the first communication between said first voltage source circuit and said piezoelectric transformer to apply the first voltage having the first frequency to said piezoelectric transformer, after the discharge lamp is ignited, said applied voltage switching circuit being responsive to the signal from said lighting detecting circuit indicating that the discharge lamp has been ignited to block the first communication while establishing the second communication between said second voltage source circuit and said piezoelectric transformer to apply the second voltage having the second frequency to said piezoelectric transformer.