| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide drive switching system at a piezoelectric transformer starting time which does not impart an influence to a luminance level regulating range when the piezoelectric transformer is utilized for cold-cathode dimming. <P>SOLUTION: The drive device for the piezoelectric transformer comprises an oscillation circuit 4 having a predetermined oscillation frequency to output a first signal; the piezoelectric transformer 1 having primary side electrodes 11, 12 and a secondary side electrode 13, inputting the first signal to the electrodes 11, 12 to drive a load; a counter circuit 7 for counting the predetermined number of a predetermined period pulse of the circuit 4; and a selector circuit 3 having a resonance frequency of the transformer itself, output from the electrode 13 in response to the output signal of the circuit 7, and switching the waveform shaped second signal to the first signal to input the first signal to the electrodes 11, 12. <P>COPYRIGHT: (C)2004,JPO |
