Head unit and liquid dispensing apparatus
Provided is a head unit including a unit temperature detection circuit configured to output a unit temperature signal including unit temperature information indicating a temperature of the head unit, a print head configured to dispense liquid when receiving a drive signal, a dispensing counter configured to count a dispensing timing of the liquid from the print head, and a temperature information output circuit configured to acquire a temperature signal indicating a temperature of the print head and output a temperature information signal based on the temperature signal, in which the print head includes a temperature signal acquisition unit located at the other side in a stacking direction with respect to a vibration plate and configured to acquire temperature information corresponding to a temperature of a pressure chamber and output the acquired temperature information as the temperature signal, the temperature information output circuit includes a correction circuit configured to correct the temperature signal, and the correction circuit corrects the temperature signal based on the unit temperature information at a predetermined timing after a count value of the dispensing timing reaches a predetermined value.
1 . A head unit for dispensing liquid when receiving a drive signal corrected based on a temperature information signal, the head unit comprising:
a unit temperature detection circuit configured to output a unit temperature signal including unit temperature information indicating a temperature of the head unit;
a print head configured to dispense the liquid when receiving the drive signal;
a dispensing counter configured to count a dispensing timing of the liquid from the print head; and
a temperature information output circuit configured to acquire a temperature signal indicating a temperature of the print head and output the temperature information signal based on the temperature signal, wherein
the print head includes
a piezoelectric element including a first electrode, a second electrode, and a piezoelectric body 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, the piezoelectric element being configured to be driven when receiving the drive signal,
a vibration plate located at one side in the stacking direction with respect to the piezoelectric element and configured to be deformed when the piezoelectric element is driven,
a pressure chamber substrate located at the one side in the stacking direction with respect to the vibration plate and provided with a pressure chamber whose volume changes when the vibration plate is deformed,
a nozzle configured to dispense the liquid according to a change in volume of the pressure chamber, and
a temperature signal acquisition unit located at the other side in the stacking direction with respect to the vibration plate and configured to acquire temperature information corresponding to a temperature of the pressure chamber and output the acquired temperature information as the temperature signal,
the temperature information output circuit includes a correction circuit configured to correct the temperature signal, and
the correction circuit corrects the temperature signal based on the unit temperature information at a predetermined timing after a count value of the dispensing timing reaches a predetermined value.
2 . The head unit according to claim 1 , wherein
the temperature information output circuit includes an amplification circuit configured to amplify a difference between a reference potential signal and the temperature signal, and
the correction circuit corrects the temperature signal based on the unit temperature information by adjusting a voltage value of the reference potential signal supplied to the amplification circuit.
3 . The head unit according to claim 1 , wherein
the temperature information output circuit includes a storage circuit configured to store a conversion function for converting the temperature signal into the temperature information signal, and
the correction circuit corrects the temperature signal by adjusting the conversion function stored in the storage circuit.
4 . The head unit according to claim 1 , wherein
the predetermined timing is when power is turned on.
5 . The head unit according to claim 1 , wherein
the predetermined timing is after flushing processing is executed.
6 . A liquid dispensing apparatus comprising:
a drive circuit configured to output a drive signal corrected based on a temperature information signal; and
a head unit configured to dispense liquid when receiving the drive signal, wherein
the head unit includes
a unit temperature detection circuit configured to output a unit temperature signal including unit temperature information indicating a temperature of the head unit,
a print head configured to dispense the liquid when receiving the drive signal,
a dispensing counter configured to count a dispensing timing of the liquid from the print head, and
a temperature information output circuit configured to acquire a temperature signal indicating a temperature of the print head and output the temperature information signal based on the temperature signal,
the print head includes
a piezoelectric element including a first electrode, a second electrode, and a piezoelectric body 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, the piezoelectric element being configured to be driven when receiving the drive signal,
a vibration plate located at one side in the stacking direction with respect to the piezoelectric element and configured to be deformed when the piezoelectric element is driven,
a pressure chamber substrate located at the one side in the stacking direction with respect to the vibration plate and provided with a pressure chamber whose volume changes when the vibration plate is deformed,
a nozzle configured to dispense the liquid according to a change in volume of the pressure chamber, and
a temperature signal acquisition unit located at the other side in the stacking direction with respect to the vibration plate and configured to acquire temperature information corresponding to a temperature of the pressure chamber and output the acquired temperature information as the temperature signal,
the temperature information output circuit includes a correction circuit configured to correct the temperature signal, and
the correction circuit corrects the temperature signal based on the unit temperature information at a predetermined timing after a count value of the dispensing timing reaches a predetermined value.
7 . The liquid dispensing apparatus according to claim 6 , wherein
the temperature information output circuit includes an amplification circuit configured to amplify a difference between a reference potential signal and the temperature signal, and
the correction circuit corrects the temperature signal based on the unit temperature information by adjusting a voltage value of the reference potential signal supplied to the amplification circuit.
8 . The liquid dispensing apparatus according to claim 6 , wherein
the temperature information output circuit includes a storage circuit configured to store a conversion function for converting the temperature signal into the temperature information signal, and
the correction circuit corrects the temperature signal by adjusting the conversion function stored in the storage circuit.
9 . The liquid dispensing apparatus according to claim 6 , wherein
the predetermined timing is when power is turned on.
10 . The liquid dispensing apparatus according to claim 6 , wherein
the predetermined timing is after flushing processing is executed.