Piezoelectric driving circuit

#This invention relates to a piezoelectric driving circuit, and more particularly to, a piezoelectric driving waveform generating circuit with low consumed power and low heat generation.

#FIG. 1 shows an example of a conventional piezoelectric driving waveform generating circuit. As shown in FIG.1, it is composed such that to piezoelectric driving waveform generated in a reference waveform generating circuit, a current amplifying circuit supplies as much current as necessary.

#In this case, given that piezoelectric driving voltage (piezoelectric driving waveform output terminal voltage) is Vpzt (FIG. 2(a)), collector current of transistor Tr1 is i1 (FIG. 2(b) collector current of transistor Tr2 is i2 (FIG. 2(c)), and high-potential side power source (high-voltage side power source) is Vh, energies P1, P2 to be generated at transistors Tr1, Tr2, respectively are given by:

#The invention will be explained in more detail in conjunction with the appended drawings, wherein:

#FIG. 1 is a circuit diagram showing a conventional piezoelectric driving circuit,

#FIG. 2 is an illustrative diagram showing the operation timing waveform of the conventional piezoelectric driving circuit,

#The preferred embodiments of the invention are explained below.

#In a piezoelectric driving circuit of the preferred embodiment, a first switching element and a first resistor, which are in series connected, are inserted between a high-potential side power source and a piezoelectric element, whereby charging path by the on-off control is formed, and a second switching element and a second resistor, which are in series connected, are inserted between a low-potential side power source and the piezoelectric element.

#Whereby discharging path by the on-off control is formed, so that a desired piezoelectric driving voltage waveform is produced.