| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid jet apparatus which reduces the degree of a smoothing filter and which can obtain a high accuracy drive signal in case of power amplifying by using a digital power amplifier. SOLUTION: In order to smooth the power amplified power amplifying modulation signal APWM obtained by pulse modulating a drive waveform signal WCOM by a modulation circuit 26, power amplifying its modulation signal by a digital power amplifier circuit 28 and smoothing the power amplified power amplifying modulation signal APWM by a smoothing filter 29 to be output to a nozzle actuator 22; the digital power amplifier circuit 28 provides two stages of the digital power amplifier circuits 27a, 27b consisting of push-pull connected switching elements Q1, Q2 pair. The second digital power amplifier 27a is biased by the output of the first digital power amplifier 27a, and the number of steps of the reaching potential of the power amplifying modulation signal APWM is set to the signal of many values more than the number of the digital power amplifiers 27a, 27b. The second digital power amplifier 27b is bootstrapped by a bootstrap circuit 32. COPYRIGHT: (C)2010,JPO&INPIT
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