Abstract: A magnetic disc device includes a moisture removing mechanism within an enclosure of the device. The mechanism employs a reversible desiccating agent which is capable of not only absorbing moisture but also discharging moisture depending on the surrounding conditions. The reversible desiccating agent cyclically absorbs and discharges moisture in response to a change in temperature and a change in humidity due to the intrusion of the moisture from outside the enclosure. The moisture removing mechanism can be used for a long period of time with a small amount of desiccating agent. Thus, it is possible to make the moisture removing mechanism small and to provide it with long life.

Abstract: A magnetic head actuating mechanism including a capstan attached to the shaft of a magnetic head driving motor, and an actuator arm supported on a pivot, adapted to be turned through a thin metallic band by the capstan and mounted fixedly at one end thereof with at least one magnetic head. The magnetic head actuating mechanism is designed so that the moment of the unbalanced mass of the turning assembly thereof about the pivot is within the predetermined range. The magnetic head is held stationary even while the magnetic head driving motor is not energized. Thus, the magnetic head actuating mechanism obviates the injurious state of contact between the magnetic head and a magnetic disk easily and need not have any magnetic head locking mechanism.