Patent ID: 7059836

Claim:
A pump, comprising: a movable wall including at least a diaphragm; an actuator to displace the movable wall; a driving device to control driving of the actuator; a pump chamber having a volume that is changeable by the displacement of the movable wall; at least one inlet flow path to allow an operating fluid to flow into the pump chamber; and at least one outlet flow path to allow the operating fluid to flow out of the pump chamber, the outlet flow path being opened to the pump chamber during operation of the pump, a combined inertance value of the at least one inlet flow path being smaller than a combined inertance value of the at least one outlet flow path, and the inlet flow path having a fluid resistor to cause a resistance to the flow of the operating fluid to be smaller when the operating fluid flows into the pump chamber than when the operating fluid flows out of the pump chamber; the driving device including a displacement controlling device to control movement of the movable wall based on detection information from pump pressure detecting means for detecting pressure inside the pump; and the displacement controlling device measuring time up to when the pump pressure detecting means detects a predetermined pressure change after completion of the displacement of the movable wall for one period, and controlling the movement of the movable wall based on information of the measured time.