Patent ID: 8747079

Claim:
A liquid conveying apparatus for driving liquid to move in a fluid channel provided in a substrate of a micro-fluid device, the fluid channel having a surface defined by a deformable wall for transmitting vibration to the fluid channel, the apparatus comprising: an oscillator having a plurality of electro-mechanical energy converting devices; a holding section arranged on the oscillator and connected to the plurality of electro-mechanical energy converting devices, the holding section having a contact surface adapted to be brought into area contact with the deformable wall of the fluid channel such that a holding step is performed in which at least part of the fluid channel of the micro-fluid device is tightly held in contact with the oscillator by way of the holding section; a signal generator for applying at least two voltage signals to the oscillator such that the at least two voltage signals are (A) synchronized in terms of frequency and phase and (B) amplitude-modulated at one and the same frequency and in different phases; and a frequency adjuster constructed to determine a resonance frequency by outputting a sinusoidal wave showing a constant amplitude and a varied frequency from the signal generator while observing oscillation of the micro fluid device and/or a part of an apparatus system for driving liquid, wherein a retry of the determination by the frequency adjuster is repeated for a plurality of times and determination of a resonance frequency is finalized when the determined resonance frequencies and the amplitude are found within a predetermined range, and wherein when the determined resonance frequencies and the amplitude exceed the predetermined range, the retry number is counted such that the holding step and a step of counting the retry number are executed again when the retry number is less than a predetermined number whereas when the retry number is not less than the predetermined number the micro-fluid device held by the holding section is collected by means of a carrier unit.