Patent attributes
The present invention provides inspection of a liquid ejection head which is equipped with plural nozzles at which piezoelectric elements are provided and which ejects recording liquid droplets from the individual nozzles in accordance with application of a driving signal voltage to the individual piezoelectric elements. A first voltage is applied to each individual piezoelectric element for measuring a resonance frequency of the individual piezoelectric element, a second voltage which is higher than the first voltage is applied to the individual piezoelectric element for measuring a resonance frequency of the individual piezoelectric element, and on the basis of the resonance frequencies at the times of application of the first voltage and the resonance frequencies at the times of application of the second voltage, piezoelectric elements that are likely to be susceptible to failure over time are detected.
