| 摘要 |
PROBLEM TO BE SOLVED: To avoid a carrier ripple from being superposed on a driving signal of capacitive load.SOLUTION: A liquid injection device injects liquid flowing into a liquid chamber from a nozzle by changing a volume of the liquid chamber. In the liquid injection device, a capacitive load drive circuit 200 comprises: a drive waveform signal generation circuit generating a drive waveform signal serving as a reference of a driving signal; a modulation circuit for pulse modulating the drive waveform signal and generating a modulation signal; a digital power amplifier for power amplifying the modulation signal and generating a pulse wave-like power amplification modulation signal; a smoothing filter 250 generating the driving signal by smoothing the pulse wave-like power amplification modulation signal; and a wiring cable 150 connecting the smoothing filter 250 and a capacitive load 116 and being provided so as to be able to replace at least one of the smoothing filter 250 and the capacitive load 116. A capacitor Cas is provided to the wiring cable 150. |
