| 摘要 |
PROBLEM TO BE SOLVED: To extend a life of a light source and to stabilize ignition, by making the positive polarity wave height and negative polarity wave height of a current flowing into the light source for a display uniform. SOLUTION: This driving arrangement of a light source for a display to display image data based on a horizontal synchronizing signal includes an oscillator to generate a pulse width modulation reference signal of a prescribed frequency, a control part to generate a drive signal obtained by applying pulse width modulation to the reference signal, and a voltage supply part to light the light source by applying an ac voltage synchronizing with the drive signal. In addition, the driving arrangement includes a phase comparator comprising a XOR gate or a XNOR gate to compare the phases of the drive signal or a dividing signal with the horizontal synchronizing signal, a low pass filter to remove the high frequency component of the output of the phase comparator, a proportional integrator to provide the output of the low pass filter to the oscillator by proportionally integrating it, and also a reset part to initialize the proportional integrator when the power supply is applied. The oscillator synchronizes the reference signal with the horizontal synchronizing signal by changing the frequency of the reference signal based on a detected signal. Thereby, the positive polarity wave height and negative polarity wave height of a current flowing into the light source are made uniform to extend the life of the lamp and to stabilize ignition. COPYRIGHT: (C)2005,JPO&NCIPI |
