Pressure damper, liquid jet head, and liquid jet apparatus

摘要

A pressure damper includes a main body portion having a recessed portion with an opening and a communication hole that opens to an inner surface of the recessed portion and communicates to an external region. A flexible thin film closes the opening of the main body portion for reducing pressure fluctuations of fluid in the recessed portion. A detecting portion is engaged with the main body portion for detecting electromotive force generated by electromagnetic induction to thereby detect a relative positional change between the flexible thin film and the main body portion.