Patent ID: 7372211
Filing Date: 2008-05-13
Classification: H05B

Abstract:
1. A cold cathode tube lighting device comprising: a first separately-excited inverter which comprises a first resonant circuit comprising a first transformer and a first resonance capacitor, connected to a first input terminal of a cold cathode tube; a second separately-excited inverter which comprises a second resonant circuit comprising a second transformer and a second resonance capacitor, connected to a second input terminal of said cold cathode tube; wherein a first driving pulse voltage is generated by said first resonant circuit in said first separately-excited inverter, and a second driving pulse voltage is generated by said second resonant circuit in said second separately-excited inverter, and wherein the first and the second driving pulse voltages are 180° out of phase with each other, and are applied alternately to said first input terminal and said second input terminal of said cold cathode tube from a transformer secondary side of said first transformer and a transformer secondary side of said second transformer to light said cold cathode tube, the device further comprising: a tube current controlling unit to detect a tube current flowing through said cold cathode tube, based on a first current flowing through said transformer secondary side of each of said first and said second transformers, and on a second current flowing through each of said first and said second resonance capacitors, and to exert control so that the tube current maintains a predetermined value, based on the detected result.