Method for driving liquid ejecting apparatus and liquid ejecting apparatus

A liquid ejecting apparatus comprising:

• a head including a nozzle configured to eject a liquid, a pressure chamber communicating with the nozzle, and a pressure generating element configured to generate a pressure fluctuation in a liquid within the pressure chamber;
• a signal generator configured to generate an inspection signal that causes a pressure fluctuation of the liquid within the pressure chamber by being supplied to the pressure generating element;
• a detector configured to detect a residual vibration that occurs in the pressure chamber when the inspection signal is supplied to the pressure generating element;
• a storage storing initial information on the residual vibration that is detected by the detector when the inspection signal is supplied at a first timing to the pressure generating element, determination target information on the residual vibration that is detected by the detector when the inspection signal is supplied at a second timing later than the first timing to the pressure generating element, and correspondence information on, for each viscosity of a liquid within the pressure chamber, a correspondence between an amplitude of a residual vibration and a displacement amount of the pressure generating element;
• and
• a determiner configured to:
• estimate a viscosity of the liquid in the pressure chamber at the second timing based on a damping ratio of the residual vibration indicated by the determination target information or based on a period of the residual vibration indicated by the determination target information,
• estimate a displacement amount of the pressure generating element at the second timing based on the estimated viscosity, the determination target information, and a correspondence information on, for each viscosity of the liquid in the pressure chamber, a correspondence between an amplitude of a residual vibration and a displacement amount of the pressure generating element, and
• determine a property change in the pressure generating element based on the estimated displacement amount and the initial information.

A method for driving a liquid ejecting apparatus including a head and a signal generator, the head including a nozzle configured to eject a liquid, a pressure chamber communicating with the nozzle, and a pressure generating element configured to generate a pressure fluctuation in a liquid within the pressure chamber, the signal generator being configured to generate an inspection signal that causes a pressure fluctuation of the liquid within the pressure chamber by being supplied to the pressure generating element, the method comprising:

• storing initial information on a residual vibration that occurs in the pressure chamber when the inspection signal is supplied at a first timing to the pressure generating element;
• storing determination target information on a residual vibration that occurs in the pressure chamber when the inspection signal is supplied at a second timing later than the first timing to the pressure generating element;
• estimating a viscosity of the liquid in the pressure chamber at the first timing based on the initial information;
• estimating a viscosity of the liquid in the pressure chamber at the second timing based on the determination target information;
• estimating a displacement amount of the pressure generating element at the first timing based on an amplitude of the residual vibration indicated by the initial information, the viscosity of the liquid in the pressure chamber at the first timing, and correspondence information on, for each viscosity of the liquid in the pressure chamber, a correspondence between an amplitude of a residual vibration and a displacement amount of the pressure generating element;
• estimating a displacement amount of the pressure generating element at the second timing based on an amplitude of the residual vibration indicated by the determination target information, the viscosity of the liquid in the pressure chamber at the second timing, and the correspondence information;
• and
• determining a property change in the pressure generating element based on the displacement amount of the pressure generating element at the first timing and the displacement amount of the pressure generating element at the second timing.