Liquid discharging apparatus, head unit, integrated circuit device for capacitive load driving, capacitive load driving circuit, and control method of liquid discharging apparatus
There is provided a liquid discharging apparatus including: a modulation portion which generates a modulation signal pulse-modulated from a source signal; a gate driver which generates an amplification control signal based on the modulation signal; a transistor which generates an amplification modulation signal amplified from the modulation signal based on the amplification control signal; a low pass filter which demodulates the amplification modulation signal and generates a driving signal; a feedback circuit which sends back the driving signal to the modulation portion; a boosting circuit which supplies a voltage which has been boosted based on any one of a first clock signal and a second clock signal to the gate driver; a boosting control portion which controls boosting in the boosting circuit; and a piezoelectric element which is displaced as the driving signal is applied.
1. A liquid discharging apparatus comprising:
a modulation portion which generates a modulation signal pulse-modulated from a source signal;
a gate driver which generates an amplification control signal based on the modulation signal;
a transistor which generates an amplification modulation signal amplified from the modulation signal based on the amplification control signal;
a low pass filter which demodulates the amplification modulation signal and generates a driving signal;
a feedback circuit which sends back the driving signal to the modulation portion;
a boosting circuit which supplies a voltage which has been boosted based on any one of a first clock signal and a second clock signal to the gate driver;
a boosting control portion which controls boosting in the boosting circuit;
a piezoelectric element which is displaced as the driving signal is applied;
a cavity in which the inside is filled with liquid and an internal volume changes due to the displacement of the piezoelectric element; and
a nozzle which communicates with the cavity, and discharges the liquid inside the cavity as liquid droplets in accordance with the change in the internal volume of the cavity,
wherein the boosting control portion controls the boosting based on the second clock signal after controlling the boosting based on the first clock signal, and
wherein a switching point of rising or falling of the second clock signal is synchronized with the modulation signal.
2. The liquid discharging apparatus according to claim 1 ,
wherein the boosting control portion generates the second clock signal based on the modulation signal and the first clock signal.
3. The liquid discharging apparatus according to claim 2 ,
wherein the boosting control portion controls the boosting based on the first clock signal in a first mode, shifts from the first mode to a second mode, controls the boosting based on the first clock signal before a predetermined period elapses after shifting to the second mode in the second mode, and controls the boosting based on the second clock signal after the predetermined period elapses.
4. The liquid discharging apparatus according to claim 2 ,
wherein the boosting control portion controls the boosting based on the second clock signal when at least one pulse included in the modulation signal is input to the boosting control portion.
5. The liquid discharging apparatus according to claim 1 ,
Wherein the frequency of the modulation signal is 1 MHz to 8 MHz.
6. The liquid discharging apparatus according to claim 1 ,
wherein the boosting circuit is a charge pump circuit.
7. A head unit comprising:
a modulation portion which generates a modulation signal pulse-modulated from a source signal;
a gate driver which generates an amplification control signal based on the modulation signal;
a transistor which generates an amplification modulation signal amplified from the modulation signal based on the amplification control signal;
a low pass filter which demodulates the amplification modulation signal and generates a driving signal;
a feedback circuit which sends back the driving signal to the modulation portion;
a boosting circuit which supplies a voltage which has been boosted based on any one of a first clock signal and a second clock signal to the gate driver;
a boosting control portion which controls boosting in the boosting circuit;
a piezoelectric element which is displaced as the driving signal is applied;
a cavity in which the inside is filled with liquid and an internal volume changes due to the displacement of the piezoelectric element; and
a nozzle which communicates with the cavity, and discharges the liquid inside the cavity as liquid droplets in accordance with the change in the internal volume of the cavity,
wherein the boosting control portion controls the boosting based on the second clock signal after controlling the boosting based on the first clock signal, and
wherein a switching point of rising or falling of the second clock signal is synchronized with the modulation signal.