Canon Denshi Kabushiki Kaisha

Nobuhiro Aizawa

Akio Hoshi

Shigeki Koizumi

Toru Wakazawa

Masaru Koyahara

Noriyuki Kawamura

Tetsuo Tomita

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.

Magnetic floppy disc drive receiving two discs having different sizes

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.

Seek method and apparatus

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.

Growing community of inventors

Chichibu, Japan

Nobuhiro Aizawa