Abstract: A panel (3) having an inlet (12) for a disc cartridge (13) is attached to the front side of a mechanism body (2) consisting of a chassis, a magnetic head, etc., and the mechanism body (2) is elastically attached to the inner sides of upper and lower cases (6) and (7) through the intermediation of a plurality of buffer rubber members (11). The upper and lower cases (6) and (7) are integrally joined together to form a casing (1), and a buffer member (5) is attached to an opening (4) formed on the front side of the casing (1). This buffer member (5) has a rectangular frame-like through-hole (17) at its center, and holding members (5a) and (5b) formed around it are inserted into holding grooves (7c) formed in the cases (6) and (7). Further, a frame member (5c) is formed on the back side of the buffer member (5) so as to surround the through-hole (17), and the panel (3) is inserted into the frame member (5c) and exposed through the opening (4).

Abstract: A door opening-and-closing mechanism of a recording/reproducing apparatus including a door axially supported at the back side of a front face plate so as to be capable of opening and closing an opening, and a lock member for preventing free rotational movement of the door. The lock member includes a supporting shaft rotatably supported at the back side of the front face plate, lock portions which engage and disengage the door, and a portion to be pushed that projects into the opening, which are formed into an integral structure. The portion to be pushed is pushed by a disk cartridge being inserted in order to disengage the lock portions and the door from each other.

Abstract: A disk cartridge and a disk cartridge drive mechanism are disclosed. The disk cartridge includes a flexible recording disk with a hub at the central portion thereof, and a cartridge case containing the recording disk, with the hub having formed therein a chucking hole and a positioning hole. In order to rotate the recording disk by loading it into the disk cartridge drive mechanism, the chucking hole is defined by two straight-line portions that intersect to form a corner against which a spindle shaft of the disk cartridge mechanism is capable of being pushed, and the positioning hole is defined by a contact portion with which a drive pin of the disk cartridge drive mechanism is capable of coming into contact only in the direction of rotation of the recording disk.

Abstract: An optical system comprises an objective lens for moving along a recording face of an optical disk in the radial direction of the optical disk so that an optical axis thereof is almost perpendicular to the recording face, a reflecting mirror for moving together with the objective lens and whose reflecting axis extends in the radial direction, a detection optical unit, a movable mirror located to incline with respect to the optical axis extending almost parallel to the recording face from the detection optical unit and the reflecting axis of the reflecting mirror, and a mirror drive portion for rotating the movable mirror on an axis almost parallel to the recording face and shaking a light beam radiated from the objective lens onto the recording face in the radial direction. The mirror drive portion rotates the movable mirror on an axis almost parallel to an optical axis extending from the detection optical unit or on an axis almost parallel to a reflecting face of the movable mirror.