Head unit and liquid ejecting apparatus

1 . A head unit that ejects a liquid by receiving a drive signal corrected based on a temperature information signal, the head unit comprising:

a print head that ejects the liquid by receiving a logic signal and the drive signal;

a temperature information output circuit that outputs the temperature information signal indicating a temperature of the print head; and

a head substrate coupled to the print head, wherein

the print head includes:

a piezoelectric element including a first electrode, a second electrode, and a piezoelectric body, having the piezoelectric body that is located between the first electrode and the second electrode in a stacking direction in which the first electrode, the second electrode, and the piezoelectric body are stacked, and driven by receiving the drive signal;

a vibration plate located on one side of the piezoelectric element in the stacking direction and deformed due to drive of the piezoelectric element;

a pressure chamber substrate located on one side of the vibration plate in the stacking direction and provided with a pressure chamber having a volume that changes due to deformation of the vibration plate;

a nozzle for ejecting the liquid according to change in the volume of the pressure chamber; and

a temperature detection section located on another side of the vibration plate in the stacking direction to detect head temperature information corresponding to a temperature of the pressure chamber and output the head temperature information as a head temperature signal,

the logic signal is a signal for controlling ejection of the liquid from the print head,

the temperature information output circuit outputs the temperature information signal based on the head temperature signal acquired during a period when a logic level of the logic signal does not change,

the temperature information output circuit is provided on the head substrate,

the head substrate includes wiring through which a residual vibration signal according to an ejection state of the liquid from the print head propagates, and

in the head substrate,

at least a part of wiring through which the logic signal propagates is located adjacent to at least a part of wiring through which the head temperature signal propagates, and

wiring through which a ground signal propagates is located between the wiring through which the head temperature signal propagates and the wiring through which the residual vibration signal propagates.

2 . The head unit according to claim 1 , wherein

the logic signal is a signal that defines an ejection cycle of the liquid from the print head.

3 . The head unit according to claim 1 , wherein

the drive signal includes a first drive waveform and a second drive waveform, and

the logic signal is a signal that defines a switching timing between the first drive waveform and the second drive waveform, which are supplied to the print head.

4 . The head unit according to claim 1 , wherein

the logic signal is a signal that defines waveform selection of a drive waveform of the drive signal supplied to the print head.

5 . The head unit according to claim 1 , wherein

the piezoelectric body continuously extends from a center position at which the piezoelectric body covers the pressure chamber to an outer position located outward beyond an inner wall of the pressure chamber substrate that defines the pressure chamber,

the temperature detection section is embedded in the piezoelectric body at a location between a position corresponding to the inner wall of the pressure chamber substrate and the outer position, and

at least a part of the temperature detection section is stacked on the vibration plate.

6 . A liquid ejecting apparatus comprising:

a drive signal output circuit that outputs a drive signal corrected based on a temperature information signal; and

a head unit that ejects a liquid by receiving the drive signal, wherein

the head unit includes:

a print head that ejects the liquid by receiving a logic signal and the drive signal;

a temperature information output circuit that outputs the temperature information signal indicating a temperature of the print head; and

a head substrate coupled to the print head,

the print head includes:

a piezoelectric element including a first electrode, a second electrode, and a piezoelectric body, having the piezoelectric body that is located between the first electrode and the second electrode in a stacking direction in which the first electrode, the second electrode, and the piezoelectric body are stacked, and driven by receiving the drive signal;

a vibration plate located on one side of the piezoelectric element in the stacking direction and deformed due to drive of the piezoelectric element;

a pressure chamber substrate located on one side of the vibration plate in the stacking direction and provided with a pressure chamber having a volume that changes due to deformation of the vibration plate;

a nozzle for ejecting the liquid according to change in the volume of the pressure chamber; and

a temperature detection section located on another side of the vibration plate in the stacking direction to detect head temperature information corresponding to a temperature of the pressure chamber and output the head temperature information as a head temperature signal,

the logic signal is a signal for controlling ejection of the liquid from the print head,

the temperature information output circuit outputs the temperature information signal based on the head temperature signal acquired during a period when a logic level of the logic signal does not change,

the temperature information output circuit is provided on the head substrate,

the head substrate includes wiring through which a residual vibration signal according to an ejection state of the liquid from the print head propagates, and

in the head substrate,

at least a part of wiring through which the logic signal propagates is located adjacent to at least a part of wiring through which the head temperature signal propagates, and

wiring through which a ground signal propagates is located between the wiring through which the head temperature signal propagates and the wiring through which the residual vibration signal propagates.

7 . The liquid ejecting apparatus according to claim 6 , wherein

the logic signal is a signal that defines an ejection cycle of the liquid from the print head.

8 . The liquid ejecting apparatus according to claim 6 , wherein

the drive signal includes a first drive waveform and a second drive waveform, and

the logic signal is a signal that defines a switching timing between the first drive waveform and the second drive waveform, which are supplied to the print head.

9 . The liquid ejecting apparatus according to claim 6 , wherein

the logic signal is a signal that defines waveform selection of a drive waveform of the drive signal supplied to the print head.

10 . The liquid ejecting apparatus according to claim 6 , wherein

the piezoelectric body continuously extends from a center position at which the piezoelectric body covers the pressure chamber to an outer position located outward beyond an inner wall of the pressure chamber substrate that defines the pressure chamber,

the temperature detection section is embedded in the piezoelectric body at a location between a position corresponding to the inner wall of the pressure chamber substrate and the outer position, and

at least a part of the temperature detection section is stacked on the vibration plate.