Patent ID: 8690281
Filing Date: 2014-04-08
Classification: B41J

Abstract:
1. A medical apparatus comprising: an actuator that is used for ejecting liquid; and a capacitive load driving circuit that generates a drive signal used for driving the actuator, The capacitive load driving circuit that applies the drive signal to the capacitive load, the capacitive load driving circuit comprising: a driving waveform signal output circuit that outputs a drive waveform signal that is a reference for the drive signal in a form of a digital signal; a digital arithmetic circuit that outputs a digital compensation signal generated in the form of the digital signal based on the drive signal to the drive waveform signal as negative feedback; a modulator that generates a modulated signal by performing pulse modulation of the output of the digital arithmetic circuit; a digital power amplifier circuit that generates a power-amplified modulated signal by performing power amplification of the modulated signal; a low pass filter that generates the drive signal applied to the capacitive load by smoothing the power-amplified modulated signal having a pulse wave form; a first analog compensation circuit that performs phase-leading compensation for the drive signal applied to the capacitive load; and a digital conversion circuit that converts an output of the first analog compensation circuit into the digital signal and supplies the converted digital signal to the digital arithmetic circuit as the digital compensation signal.