DISCHARGE TUBE LIGHTING CIRCUIT AND IMAGE DISPLAY DEVICE USING THIS LIGHTING CIRCUIT

摘要

PURPOSE:To correct the dispersion of the characteristics of individual main ballast inductors and discharge tubes, and to display color images with high fidetity. CONSTITUTION:In a discharge tube lighting circuit wherein a main power supply is connected to the anode electrode of an discharge tube 9 via a series circuit comprising main ballast inductors 4, 5 and a switching transistor 8 and a filament power supply is connected to the filament electrode of the discharge tube 9, a variable resistor 14 for correcting dispersions is connected between the switching transistor 8 and the anode electrode of the discharge tube 9. The base of the switching transistor 8 is connected to the connection point of the variable resistor 14 and the anode electrode of the discharge tube 9 via a constant current control transistor 15 and a voltage regulation diode 15 and the base of the constant current control transistor 15 is connected to the connection point of the switching transistor 8 and the variable resistor 14. A control transistor 12 is connected between the base of the switching transistor 8 and the ground and a display switching control signal S2 is input to the base of the control transistor 12 to light the discharge tube 9.