Abstract: A disk drive apparatus includes a spindle motor which has a rotatable hub. The hub has an annular flange. A magnetic disk is fitted on the hub and urged against the flange by a clamp with a predetermined fixing force. A buffer member is interposed between the magnetic disk and the engagement portion. The buffer member has a thermal expansion coefficient which is substantially a intermediate value between thermal expansion coefficients of the magnetic disk medium and the engagement portion. A difference between the thermal expansion coefficients of the magnetic disk and the engagement member is larger than 10.times.10.sup.-6 ?1/.degree. C!.

Abstract: A disk drive apparatus comprises a disk for recording data and a drive motor for rotating the disk. The disk has obverse and reverse sides, a center hole, an unlevel portion with an uneven flatness on the obverse and reverse sides, situated around the center hole, and a level portion situated outside the unlevel portion and having level surfaces on the obverse and reverse sides. The disk is mounted on a hub of the motor such that the hub is passed through the center hole. The hub has at its one end a supporting portion facing the level portion of the disk. A disk retainer, having a press portion facing the level portion of the disk, is attached to the other end of the hub so as to press the disk toward the supporting portion.

Abstract: A hard disk drive for recording/reproducing data to and from a magnetic disk. The hard disk drive includes a base, a magnetic disk disposed on the base, a magnetic head which records/reproduces data to and from the magnetic disk, and a carriage assembly freely rotatably mounted on a rotation axis. The magnetic head is connected to a carriage with a suspension therebetween, and is positioned to predetermined positions on the magnetic disk. A rotation axis of the carriage is placed inside an outer circumference of the magnetic disk to achieve further compactness of the hard disk drive.

Abstract: A printer includes a printer body and an automatic sheet feeder. The printer body has a case in which a printing mechanism and a continuous paper feeding mechanism are arranged. An upper wall of the case has a cut sheet supply port and a paper discharge port formed therein, both of which are located close to the printing mechanism. The sheet feeder is mounted on the case such that it can be pivoted between an actuating position, where it covers the supply and discharge ports, and a non-actuating position, where it does not interfere with the discharging of the continuous paper from the discharging port. At the actuating position, the sheet feeder supplies a cut sheet through the supply port to the printing mechanism.