Abstract: A disc drive device includes a base, a rotary member rotatably supported on the base and a first chucking mechanism for holding a first kind of disc-shaped recording medium while coinciding a rotational center of the first kind of recording medium with a rotational center of the rotary member. The first chucking mechanism is arranged at one end of the rotary member. A second chucking mechanism holds a second kind of disc-shaped recording medium different from the first kind of recording medium with respect to size or disc formatting while coinciding a rotational center of the second kind of recording medium with a rotational center of the rotary member. The second chucking mechanism is arranged at the other end of the rotary member. A driving mechanism is mounted on the base for driving the rotary member.

Abstract: A seek method and an apparatus using a stepping motor, which can eliminate disadvantages of the two-phase excitation (large seek noise and great power consumption) while maintaining advantages of the two-phase excitation (large torque and high stop accuracy). A stepping motor is driven by two-phase exciting signals, each of which includes a short term one-phase excitation state whose duration is shorter than a pulse interval of a step pulse train. The one-phase excitation state is inserted between two consecutive two-phase excitation states. A two-phase exciting signal associated with a start or a change in seek direction may exclude the one-phase excitation state so that the stepping motor can produce large torque.

Abstract: A head position control device capable of controlling the position of mutually cooperating plural heads with a circuit provided in a drive thereby reducing the burden of the attached system and enabling independent seeking operations of the heads on a magnetic disk. The head position control device of the present invention performs track seeking operation within a minimum time regardless of the access time of the attached system thereby reducing the head switching time, and also allows reduction in the dimension and weight of the entire system.