Droplet ejection head driving circuit and method, and droplet ejection device

A driving method of a droplet ejection head which, by supplying an analog driving signal to a driving element, ejects a droplet from a nozzle provided in correspondence with the driving element, the droplet ejection head driving method comprising:

• generating at least a first analog driving signal, for ejecting a droplet from the nozzle, and a second analog driving signal, for vibrating a liquid surface of ink in the droplet ejection head, and selectively outputting either of the analog driving signals;
• pulse-modulating the analog driving signal that is output and outputting a digital signal;
• generating a switching signal;
• amplifying the digital signal by switching in accordance with the switching signal, and supplying the amplified digital signal to the driving element;
• and
• setting a switching frequency of the switching signal in accordance with a frequency selection signal, the switching frequency signal corresponding to the analog driving signal that is being output.

A droplet ejection device comprising:

• a droplet ejection head that, by supplying an analog driving signal to a driving element, ejects a droplet from a nozzle provided in correspondence with the driving element;
• a driving signal generation unit that generates at least a first analog driving signal for ejecting a droplet from the nozzle, and at least a second analog driving signal for vibrating a liquid surface of ink in the droplet ejection head, and selectively outputs either of the analog driving signals;
• a pulse modulation unit that pulse-modulates the analog driving signal output from the driving signal generation unit and outputs a digital signal;
• a switching signal generation unit that generates a switching signal;
• an amplification unit that amplifies the digital signal by switching in accordance with the switching signal, and supplies the amplified digital signal to the driving element;
• an output unit that instructs the driving signal generation unit so as to output the first analog driving signal when an operational mode of the droplet ejection device is a printing mode, and instructs the driving signal generation unit so as to output the second analog driving signal when the operational mode is a non-printing mode, and the output unit outputs a frequency selection signal in accordance with the operational mode;
• and
• a frequency-setting unit that sets a switching frequency of the switching signal in accordance with the frequency selection signal that is being output from the output unit.