Liquid ejecting head and liquid ejecting apparatus
A liquid ejecting head includes: a piezoelectric element that includes a first drive electrode, a piezoelectric body, and a second drive electrode in a lamination direction; a vibration plate that is provided on one side of the lamination direction with respect to the piezoelectric element and is deformed by driving of the piezoelectric element; a pressure chamber substrate that is provided on the one side of the lamination direction with respect to the vibration plate and is provided with a plurality of pressure chambers; an interlayer that is laminated on at least one of the piezoelectric body, the vibration plate, or the pressure chamber substrate and of which capacitance changes according to humidity; a first detection electrode that is in contact with the interlayer; and a second detection electrode that is in contact with the interlayer and is disposed to be separated from the first detection electrode.
1. A liquid ejecting head comprising:
a piezoelectric element that includes a first drive electrode, a second drive electrode, and a piezoelectric body, the piezoelectric body being provided between the first drive electrode and the second drive electrode in a lamination direction in which the first drive electrode, the second drive electrode, and the piezoelectric body are laminated;
a vibration plate that is provided on one side of the lamination direction with respect to the piezoelectric element and is deformed by driving of the piezoelectric element;
a pressure chamber substrate that is provided on the one side of the lamination direction with respect to the vibration plate and is provided with a plurality of pressure chambers;
an interlayer that is laminated on at least one of the piezoelectric body, the vibration plate, or the pressure chamber substrate and of which capacitance changes according to humidity;
a first detection electrode that is in contact with the interlayer; and
a second detection electrode that is in contact with the interlayer and is disposed to be separated from the first detection electrode.
2. A liquid ejecting apparatus comprising:
the liquid ejecting head according to claim 1 ;
a capacitance measurement section that measures capacitance between the first detection electrode and the second detection electrode; and
a humidity management section that acquires information on humidity of the interlayer by using the capacitance which is measured by the capacitance measurement section.
3. The liquid ejecting head according to claim 1 , wherein
at least one of the first detection electrode or the second detection electrode is formed of the same material as a material of the first drive electrode.
4. The liquid ejecting head according to claim 1 , wherein
at least one of the first detection electrode or the second detection electrode is formed of the same material as a material of the second drive electrode.
5. The liquid ejecting head according to claim 1 , further comprising:
a protective film that is disposed on another side of the lamination direction with respect to the pressure chamber substrate and contains a resin material, the other side of the lamination direction being a side of the lamination direction opposite to the one side on which the vibration plate is provided, wherein
the interlayer is formed of the same material as a material of the protective film.
6. The liquid ejecting head according to claim 5 , wherein
the first detection electrode is disposed on one side of the lamination direction with respect to the interlayer, and
the second detection electrode is disposed on the other side of the lamination direction with respect to the interlayer.
7. The liquid ejecting head according to claim 6 , wherein
the second detection electrode includes a first electrode portion that extends along a first direction on a surface of the interlayer and a plurality of second electrode portions that are coupled to the first electrode portion on the surface of the interlayer, the plurality of second electrode portions extending in a second direction intersecting with the first direction and arranged to be separated from each other.
8. The liquid ejecting head according to claim 5 , wherein
in plan view of the liquid ejecting head in the lamination direction, the protective film is disposed at a drive electrode end portion position overlapping an end portion of the first drive electrode or an end portion of the second drive electrode,
the first detection electrode is disposed on the one side of the lamination direction with respect to the protective film that is disposed at the drive electrode end portion position and serves as the interlayer, and
the second detection electrode is disposed on the other side of the lamination direction with respect to the protective film that is disposed at the drive electrode end portion position and serves as the interlayer.
9. The liquid ejecting head according to claim 1 , wherein
the interlayer is formed of the same material as a material of the piezoelectric body.
10. The liquid ejecting head according to claim 9 , wherein
the first detection electrode is disposed on the one side of the lamination direction with respect to the interlayer, and
the second detection electrode is disposed on another side of the lamination direction with respect to the interlayer, the other side of the lamination direction being a side of the lamination direction opposite to the one side.
11. A liquid ejecting apparatus comprising:
the liquid ejecting head according to claim 10 ;
a capacitance measurement section that measures capacitance between the first detection electrode and the second detection electrode; and
a humidity management section that acquires information on humidity of the interlayer by using the capacitance which is measured by the capacitance measurement section.
12. The liquid ejecting apparatus according to claim 11 , wherein
the humidity management section applies, to the first detection electrode and the second detection electrode, a voltage for generating an electric field closer to a negative coercive electric field of the piezoelectric body than an electric field generated in the piezoelectric body by a drive voltage applied to the piezoelectric body from the first drive electrode and the second drive electrode to drive the piezoelectric element.
13. The liquid ejecting head according to claim 1 , wherein
the interlayer is formed of the same material as a material of the vibration plate.
14. The liquid ejecting head according to claim 1 , wherein
in plan view of the liquid ejecting head in the lamination direction,
the plurality of pressure chambers are arranged in a first pressure chamber row along a first arrangement direction and in a second pressure chamber row along a second arrangement direction parallel to the first arrangement direction, and
the interlayer, the first detection electrode, and the second detection electrode are disposed at at least one position of positions adjacent to the first pressure chamber row along the first arrangement direction and positions adjacent to the second pressure chamber row along the second arrangement direction.
15. The liquid ejecting head according to claim 1 , wherein
in plan view of the liquid ejecting head in the lamination direction,
the plurality of pressure chambers are arranged in a first pressure chamber row along a first arrangement direction and in a second pressure chamber row along a second arrangement direction parallel to the first arrangement direction,
a wiring substrate that is electrically coupled to the liquid ejecting head is disposed between the first pressure chamber row and the second pressure chamber row, and
the interlayer, the first detection electrode, and the second detection electrode are disposed at positions adjacent to the wiring substrate along the first arrangement direction.