To provide a natural period measuring instrument for measuring a natural period of a pressure generation chamber fully highly precisely and extremely quickly.
The natural period measuring instrument is set to a head member 1 which has nozzle openings 13, the pressure generation chambers 16, and a piezoelectric member 2 for discharging liquid droplets from the nozzle openings 13 by changing a pressure of a liquid in the pressure generation chambers 16. The natural period measuring instrument is equipped with an electric driving means 30 for supplying an electric drive signal to the piezoelectric member 2, a counter-electromotive force period measuring means 31 for measuring a period of a counter-electromotive force signal based on residual vibration of the piezoelectric member 2 after the electric drive signal is supplied, and an operation part 32 for deriving a natural period of the liquid in the pressure generation chambers 16 on the basis of the period of the counter-electromotive force signal measured by the counter-electromotive force period measuring means 31.
Hiroyuki Nagai
Junpei Okada
Hirohito Katsunuma
Katsuomi Isogai
Next Patent: INKJET RECORDING DEVICE AND INKJET RECORDING METHOD