Patent ID: 9723411
Date: 2017-08-01
CPC Classifications: G10K,H04R

Claim:
1. A piezoelectric speaker driving system, comprising: a band splitter having a plurality of output ends, the band splitter receiving a first audio signal and splitting the first audio signal into a plurality of band signals, wherein the band signals have different bands and are outputted from the output ends; a plurality of gain producers coupling with the output ends to generate a plurality of gains respectively to gain the band signals; an adder coupling with the gain producers, wherein the gained band signals are added together by the adder to generate a second audio signal; a piezoelectric speaker coupling with the adder to output a sound according to the second audio signal; a sound compensator receiving the sound to analyze a sound pressure level of the sound to generate a control signal; and a gain-adjusting device coupling with the sound compensator, and configured to adjust the gains of the gain producers according to the control signal, wherein the sound compensator compares the sound pressure level with a required sound pressure level to generate the control signal, wherein the required sound pressure level identifies the band signals in which the sound pressure level of the sound generated by the piezoelectric speaker has loss, wherein when the sound pressure level of one of the band signals is lower than the required sound pressure level, the gain-adjusting device increases a corresponding gain to gain the one of the band signals to make the piezoelectric speaker output an adjusted sound with a sound pressure level reach the required sound pressure level, and when the sound pressure level of one of the band signals is higher than the required sound pressure level, the gain-adjusting device decreases a corresponding gain to gain the one of the band signals to make the piezoelectric speaker output an adjusted sound with a sound pressure level reaching the required sound pressure level.