Liquid ejecting apparatus and liquid ejecting method

A liquid ejecting apparatus comprising:

• a reference drive signal generation section that generates a reference drive signal;
• a signal modulation section that modulates the reference drive signal to generate a modulation reference drive signal;
• a signal amplification section that amplifies the modulation reference drive signal using switching elements to generate a modulation drive signal;
• a signal conversion section that converts the modulation drive signal to a drive signal;
• and
• a head which includes a piezoelectric element that deforms in response to the drive signal, a pressure chamber that expands and contracts due to the deformation of the piezoelectric element, and has a Helmholtz resonance frequency of a period Tc, and a nozzle opening portion that communicates with the pressure chamber and ejects a liquid;
• wherein the drive signal includes
• a first interval for causing the pressure chamber to be expanded for the time equal to or less than the Tc;
• a second interval for holding an expanded state of the pressure chamber for the time of one half or less of the Tc;
• and
• a third interval for causing the pressure chamber which is in the expanded state to be contracted;
• wherein a period of an alternating current component contained in the modulation drive signal is a common divisor of a length of the first interval, a length of the second interval and a length of the third interval;
• wherein the signal modulation section inputs the reference drive signal and a comparison signal to a voltage comparator to generate the modulation reference drive signal, the comparison signal being configured by a triangular wave or a saw-tooth wave of which a frequency varies depending on a voltage of the reference drive signal;
• wherein an alternating current component of a plurality of frequencies is contained in the modulation drive signal;
• and
• wherein among frequencies of the alternating current component contained in the modulation drive signal, a period of a frequency of an alternating current component which is most frequently contained is a common divisor of the length of the first interval, the length of the second interval and the length of the third interval.