The present application is based on, and claims priority from JP Application Serial Number 2019-139491, filed Jul. 30, 2019, 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 driving a liquid ejecting apparatus and the liquid ejecting apparatus.

2. Related Art

In liquid ejecting apparatuses ejecting liquid, such as ink, to a medium, such as a printing sheet, there arises a problem in viscosity of the liquid caused by evaporation of moisture included in the liquid, for example. JP-A-2000-117993 discloses a liquid ejecting apparatus executing a flushing operation of ejecting liquid having increased viscosity after executing a micro vibration operation of improving a local viscosity state in the vicinity of openings of nozzles by performing micro vibration on the liquid having the increased viscosity.

However, when the general technique described above is used, the liquid having the increased viscosity may not be efficiently ejected. The liquid having the increased viscosity is dispersed in a large range by the micro vibration operation, for example, and therefore, to sufficiently eject the liquid having the increased viscosity, the flushing operation is required to be more frequently performed when compared with an example in which the micro vibration operation is not executed.

SUMMARY

According to an aspect of the present disclosure, a method for driving a liquid ejecting apparatus is provided. The liquid ejecting apparatus includes a liquid ejecting section including a nozzle ejecting liquid, a pressure chamber communicated with the nozzle, and a driving element applying a pressure change to the liquid included in the pressure chamber, a driving signal generation section configured to generate a micro vibration signal which is supplied to the driving element and which applies a pressure change to such an extent that the liquid is not ejected from the nozzle, a first flushing signal which is supplied to the driving element and which applies a pressure change to the liquid included in the pressure chamber to such an extent that the liquid is ejected from the nozzle, and a second flushing signal which is supplied to the driving element and which applies a pressure change to the liquid included in the pressure chamber to such an extent that the liquid is ejected from the nozzle, and a thickening determination section configured to determine a thickening state of the liquid included in the nozzle. The pressure change by the second flushing signal is larger than the pressure change by the first flushing signal. An amount of liquid ejected from the nozzle when the first flushing signal is supplied to the driving element once is larger than an amount of liquid ejected from the nozzle when the second flushing signal is supplied to the driving element once. When the thickening determination section determines that a thickening state of the liquid included in the nozzle is a first state, the micro vibration signal is not supplied to the driving element and the second flushing signal is supplied to the driving element a first number of times. When the thickening determination section determines that the thickening state of the liquid included in the nozzle is a second state in which viscosity of the liquid is higher than viscosity of the liquid in the first state, the micro vibration signal is supplied to the driving element, the second flushing signal is supplied to the driving element the first number of times after the micro vibration signal is supplied, and the first flushing signal is supplied to the driving element a second number of times after the second flushing signal is supplied.

According to another aspect of the present disclosure, a liquid ejecting apparatus includes a liquid ejecting section including a nozzle ejecting liquid, a pressure chamber communicated with the nozzle, and a driving element applying a pressure change to the liquid included in the pressure chamber, a driving signal generation section configured to generate a micro vibration signal which is supplied to the driving element and which applies a pressure change to such an extent that the liquid is not ejected from the nozzle, a first flushing signal which is supplied to the driving element and which applies a pressure change to the liquid included in the pressure chamber to such an extent that the liquid is ejected from the nozzle, and a second flushing signal which is supplied to the driving element and which applies a pressure change to the liquid included in the pressure chamber to such an extent that the liquid is ejected from the nozzle, a driving circuit configured to supply a signal generated by the driving signal generation section to the driving element, and a thickening determination section configured to determine a thickening state of the liquid included in the nozzle. The pressure change by the second flushing signal is larger than the pressure change by the first flushing signal. An amount of liquid ejected from the nozzle when the first flushing signal is supplied to the driving element once is larger than an amount of liquid ejected from the nozzle when the second flushing signal is supplied to the driving element once. When the thickening determination section determines that a thickening state of the liquid included in the nozzle is a first state, the micro vibration signal is not supplied to the driving element and the second flushing signal is supplied to the driving element a first number of times. When the thickening determination section determines that the thickening state of the liquid included in the nozzle is a second state in which viscosity of the liquid is higher than viscosity of the liquid in the first state, the micro vibration signal is supplied to the driving element, the second flushing signal is supplied to the driving element the first number of times after the micro vibration signal is supplied, and the first flushing signal is supplied to the driving element a second number of times after the second flushing signal is supplied.

