A magnetic head assembly for a flexible magnetic disk drive unit has a magnetic recording and retrieving head for carrying out magnetic recording onto and retrieving from a metallic thin-film type flexible magnetic medium rotating about a center of the medium by coming into contact with the medium at a contact position, a first group of non-magnetic supporting pads arranged to support a plurality of positions of the flexible magnetic medium and disposed so as to surround the contact position, and a second group of non-magnetic suppressing pads in contact with a different plurality of positions of the flexible magnetic medium outward of the plurality of supporting positions so that the suppressing pads suppress any undulation of the flexible magnetic medium during rotation of the medium. The support pads and the magnetic recording and retrieving head may be formed with a recess, respectively, for trappng dust and other foreign materials, thereby preventing an accumulation of dust and other foreign materials between the head and the medium.

A flexible magnetic disk device in which a solenoid is disposed in parallel with the surface of a magnetic disk, and a supporting arm to be turned perpendicularly to the disk surface by the solenoid is juxtaposed to the disk surface, whereby the magnetic disk device can be thinned.

A magnetic head assembly for a flexible magnetic disk drive unit has a magnetic recording and retrieving head for carrying out magnetic recording onto and retrieving from a metallic thin-film type flexible magnetic medium rotating about a center of the medium by coming into contact with the medium at a contact position, a first group of non-magnetic supporting pads arranged to support a plurality of positions of the flexible magnetic medium and disposed so as to surround the contact position, and a second group of non-magnetic suppressing pads in contact with a different plurality of positions of the flexible magnetic medium outward of the plurality of supporting positions so that the suppressing pads suppress any undulation of the flexible magnetic medium during rotation of the medium. The support pads and the magnetic recording and retrieving head may be formed with a recess, respectively, for trapping dust and other foreign materials, thereby preventing an accumulation of dust and other foreign materials between the head and the medium.

An apparatus for centering and driving a flexible disc includes a rotatable spindle and a cone which is insertable through a drive hole in the disc and then into an opening in the spindle whereby the disc is contained between the cone and spindle. A plurality of upstanding centering fingers are mounted in the spindle, extended to the threshold of the spindle opening and equally spaced from the spindle center. The fingers engage the cone as it enters the opening and bend elastically responsive to further cone movement into the opening. The fingers, when so bent, urge the cone toward a centered relation with the spindle. The fingers are adapted to engage any unsupported portion of the disc positioned over the spindle opening, and to support such portion against bending responsive to contact with the moving cone.

A device, provided on a recording/reproducing apparatus, for adjusting and fixing a detecting means relative to the index mark on a recording disc, which device comprises a holding device for the detecting means, the position of which can be altered and which can be aligned and fixed relative to the index mark, the holding device consisting of a slidably mounted member made of a suitable material and having at least one elongated hole, and of a spring which exerts a biassing force on the slidably mounted member which moves on an arcuate path.