Patent attributes
A pump includes a vibrating plate, a flow path forming member, a pump chamber, and a film valve. The vibrating plate is provided with a piezoelectric element, vibrates due to distortion of the piezoelectric element, and has a gap on an outer periphery. The flow path forming member is disposed so as to face the vibrating plate, and has a hole in a portion facing the vibrating plate. The pump chamber is surrounded by the vibrating plate and the flow path forming member, and has a central space communicating with the hole and an outer edge space communicating with the gap. The film valve is disposed in the pump chamber. The film valve is in contact with the vibrating plate and the flow path forming member when a pressure in the central space is lower than a pressure in the outer edge space.