Patent ID: 7753497

Claim:
A piezoelectric element recovery apparatus comprising: a piezoelectric element comprising: a single piezoelectric body layer which is deformed by an applied electric field; a first metal oxide layer which is disposed directly adjacent to the piezoelectric body layer on the lower potential side when an electric field in a predetermined direction is applied to the piezoelectric body layer, and which suppresses degradation of the piezoelectric body layer that is caused by application of the electric field, the first metal oxide layer contacting an outer face of the piezoelectric body layer; and a second metal oxide layer which is disposed directly adjacent to the piezoelectric body layer on the higher potential side of the electric field which is applied to the piezoelectric body layer, and which, by applying an electric field in the direction reverse to the electric field, repairs the piezoelectric body layer degraded, the second metal oxide layer contacting an opposite outer face of the piezoelectric body layer; an electric field application section which applies an electric field to the piezoelectric element; a degradation detection section which detects a degradation level of the piezoelectric element; and a control section which controls the electric field application section such that, when the degradation level detected by the degradation detection section is under a predetermined level and the ink liquid droplets are caused to be ejected, an electric field in the predetermined direction is applied to the piezoelectric element, and when the degradation level detected by the degradation detection section is equal to or over the predetermined level, an electric field in the direction reverse to the predetermined direction is applied to the piezoelectric element.