INFORMATION RECORDING MEDIUM DRIVING DEVICE AND FILTER UNIT

PROBLEM TO BE SOLVED: To provide an information recording medium driving device capable of preventing the vibration of an information recording medium as much as possible by suppressing a disturbed air flow in the outer periphery of the information recording medium. SOLUTION: Flow straightening walls 31 and 32 are provided in the corners 30 of a casing 13 for flow-straightening an air flow generated along the outer periphery of a rotating magnetic disk 23 and in its rotational direction. In the backside of the flow straightening wall 32, a circulating filter is arranging for capturing dusts contained in the air flow introduced from an inlet opening. By adjusting a relationship d/L between the length L of the flow straightening wall 32 and the width (d) of the inlet opening, the resonance vibration component of the rotating magnetic disk 23 is set equal to a permissible value or lower calculated based on a permissible tracking error. Since a permissible tracking error is secured even if the magnetic disk 23 is vibrated, sure reading/ writing of information is performed.