US-12623458-B2 - Method for cleaning liquid ejecting head

Abstract

There is provided a method for cleaning a liquid ejecting head including a nozzle plate in which a nozzle configured to eject a liquid is formed, a pressure chamber communicating with the nozzle, a vibration plate that defines a part of the pressure chamber, and a piezoelectric element that is laminated on the vibration plate, the method including: an ultrasonic cleaning step of ultrasonically vibrating a cleaning liquid in a cleaning tank by an ultrasonic vibrator in a state where the nozzle is immersed in the cleaning liquid in the cleaning tank and in a state where a gas is present in the pressure chamber.

Inventors

• Shunsuke Watanabe

Assignees

• SEIKO EPSON CORPORATION

Dates

Publication Date

20260512

Application Date

20240206

Priority Date

20230207

Claims (9)

1. 1 . A method for cleaning a liquid ejecting head including a nozzle plate in which a nozzle configured to eject a liquid is formed, a pressure chamber communicating with the nozzle, a vibration plate that defines a part of the pressure chamber, and a piezoelectric element that is laminated on the vibration plate, the method comprising: an ultrasonic cleaning step of ultrasonically vibrating a cleaning liquid in a cleaning tank by an ultrasonic vibrator in a state where the nozzle is immersed in the cleaning liquid in the cleaning tank and in a state where a gas is present in the pressure chamber.
2. 2 . The method for cleaning a liquid ejecting head according to claim 1 , in which the liquid ejecting head includes a flow path coupling section for coupling an outside of the liquid ejecting head and a flow path inside the liquid ejecting head, Wherein in the ultrasonic cleaning step, the gas is introduced through the flow path coupling section of the liquid ejecting head while the ultrasonic vibrator is ultrasonically vibrating.
3. 3 . The method for cleaning a liquid ejecting head according to claim 2 , wherein in the ultrasonic cleaning step, the gas is introduced through the flow path coupling section of the liquid ejecting head in such a manner that air bubbles are discharged from the nozzle while the ultrasonic vibrator is ultrasonically vibrating.
4. 4 . The method for cleaning a liquid ejecting head according to claim 2 , wherein in the ultrasonic cleaning step, the gas is introduced through the flow path coupling section of the liquid ejecting head in such a manner that air bubbles are not discharged from the nozzle while the ultrasonic vibrator is ultrasonically vibrating.
5. 5 . The method for cleaning a liquid ejecting head according to claim 1 , further comprising: a replacing step of replacing a liquid in the liquid ejecting head with a gas by discharging the liquid in the liquid ejecting head from the liquid ejecting head, before performing the ultrasonic cleaning step; and an impregnating step of immersing the liquid ejecting head in the cleaning tank such that a gas-liquid interface between the cleaning liquid and the gas is positioned between a tip end of the nozzle and the vibration plate that defines the pressure chamber, before the ultrasonic cleaning step and after the replacing step.
6. 6 . The method for cleaning a liquid ejecting head according to claim 5 , wherein the impregnating step is performed such that the gas-liquid interface is positioned between the nozzle and the vibration plate.
7. 7 . The method for cleaning a liquid ejecting head according to claim 1 , wherein in the ultrasonic cleaning step, it is detected whether or not the gas is present in the pressure chamber, and when the gas is present in the pressure chamber, the ultrasonic vibrator starts ultrasonic vibration.
8. 8 . The method for cleaning a liquid ejecting head according to claim 1 , wherein the piezoelectric element includes a thin film piezoelectric body.
9. 9 . The method for cleaning a liquid ejecting head according to claim 1 , wherein the ultrasonic cleaning step is performed in a state where the vibration plate does not directly contact the cleaning liquid in the cleaning tank due to the presence of the gas in the pressure chamber.

Description

The present application is based on, and claims priority from JP Application Serial Number 2023-017137, filed Feb. 7, 2023, the disclosure of which is hereby incorporated by reference herein in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to a method for cleaning a liquid ejecting head that ejects a liquid, and particularly to a method for cleaning an ink jet type recording head that ejects ink as a liquid. 2. Related Art An ink jet type recording head, which is an example of a liquid ejecting head, includes, for example, a pressure generation unit that causes a pressure change in ink in a pressure generation chamber on a flow path forming substrate provided with a pressure generation chamber communicating with a nozzle, and by drive of this pressure generation unit, a vibration plate that defines a pressure generation chamber is deformed to cause a pressure change in the ink within the pressure chamber, thereby causing ink droplets to be ejected from the nozzle. As a pressure generation unit, a liquid ejecting head using a vibration plate and a piezoelectric element in which a first electrode, a piezoelectric body layer, and a second electrode are laminated on the vibration plate by a film formation and lithography method was proposed (for example, refer to JP-A-2019-166767). Moreover, a method is proposed in which, in a state where the nozzle of the liquid ejecting head is immersed in a cleaning liquid in a cleaning tank, by ultrasonically vibrating the cleaning liquid, the area around the nozzle of the liquid ejecting head is cleaned (for example, refer to JP-A-2003-266719). However, when the liquid ejecting head having the piezoelectric element disclosed in JP-A-2019-166767 is cleaned by the cleaning method of JP-A-2003-266719, there is a problem in that the vibration plate and the piezoelectric element may be damaged by ultrasonic vibration. Such a problem is not limited to the method for cleaning the ink jet type recording head that ejects the ink, and is also similar to the liquid ejecting head that ejects the liquid other than ink. SUMMARY According to an aspect of the present disclosure, there is provided a method for cleaning a liquid ejecting head including a nozzle plate in which a nozzle for ejecting a liquid is formed, a pressure chamber communicating with the nozzle, a vibration plate that defines a part of the pressure chamber, and a piezoelectric element that is laminated on the vibration plate, the method including: an ultrasonic cleaning step of ultrasonically vibrating a cleaning liquid in a cleaning tank by an ultrasonic vibrator in a state where the nozzle is immersed in the cleaning liquid in the cleaning tank and in a state where a gas is present in the pressure chamber. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view illustrating a schematic configuration of a liquid ejecting apparatus according to Embodiment 1. FIG. 2 is an exploded perspective view of a liquid ejecting head according to Embodiment 1. FIG. 3 is a cross-sectional view of the liquid ejecting head according to Embodiment 1. FIG. 4 is an enlarged cross-sectional view of a main portion of the liquid ejecting head according to Embodiment 1. FIG. 5 is an exploded perspective view of a head chip according to Embodiment 1. FIG. 6 is a plan view of the head chip according to Embodiment 1. FIG. 7 is a cross-sectional view of the head chip and a cover head according to Embodiment 1. FIG. 8 is a schematic view illustrating an ultrasonic cleaning step according to Embodiment 1. FIG. 9 is a cross-sectional view of a main portion describing the ultrasonic cleaning step according to Embodiment 1. FIG. 10 is a schematic view describing a replacing step according to Modification Example 1 of Embodiment 1. FIG. 11 is a schematic view describing an ultrasonic cleaning step according to Modification Example 1 of Embodiment 1. FIG. 12 is a schematic view describing an ultrasonic cleaning step according to Modification Example 2 of Embodiment 1. DESCRIPTION OF EMBODIMENTS Hereinafter, the present disclosure will be described in detail based on embodiments. However, the following description shows one aspect of the present disclosure, and can be changed in any manner within the scope of the present disclosure. Those having the same reference numerals in each drawing indicate the same members, and the description thereof will be omitted as appropriate. In each of the drawings, X, Y, and Z represent three spatial axes orthogonal to each other. In the present specification, the directions along these axes are the X direction, the Y direction, and the Z direction. The direction in which the arrows in each drawing are oriented is described as the positive (+) direction, and the opposite direction of the arrows is described as the negative (−) direction. In addition, the directions of the three spatial axes that do not limit the positive direction and the negative direction will be described as the X-axis directi