US Patent 10517190 Electronic device and control method thereof

A fan module includes a first casing, a driving motor disposed in the first casing, a first rotor connected to the first driving motor, a second casing, a second rotor pivotally configured in the second casing, at least one guiding member and a shift apparatus connected to the first casing and the second casing, the first rotor includes a first rotating shaft and a plurality of first blades, the second rotor includes a second rotating shaft and a plurality of second blades, the guiding member is disposed on the first blade and the second blade. The whole height of the blade is adjusted by adjusting the distance between the two group blades, then the efficiency of the fan is improved effectively to optimize the noise level and the air flow.