Abstract: A magnetic disc is housed for rotation in a flat casing having a metal shell. The magnetic disc is supported for rotation in the casing by a tubular shaft formed by barring of a metal blank for forming the metal shell. A hole is formed in a part of the metal blank where the tubular shaft is to be formed. A plurality of slits are formed prior to barring in the part where the tubular shaft is to be formed.

Abstract: A magnetic disk cartridge including a flexible magnetic disk, a hub, disk-holding protrusions, and an anti slip-out member. The hub has a disk-holding surface on which the central portion of the magnetic disk is held. The disk-holding protrusions are formed on the disk-holding surface of the hub, and are inserted through holes formed in the magnetic disk. The anti slip-out member is used to prevent the magnetic disk from slipping out from the disk-holding protrusions.

Abstract: A magnetic disk cartridge comprising a magnetic disk medium, a casing for rotatably housing the magnetic disk medium, and dust-removing liners fixed on the inner surfaces of the casing which face both sides of the magnetic disk medium. Each of the liners has an outer circumferential portion that is not fixed on the inner surface of the casing.

Abstract: A magnetic disk cartridge comprising a magnetic disk medium, a casing for rotatably housing the magnetic disk medium, and liners mounted on the inner surfaces of the casing that face both sides of the magnetic disk medium. Each liner is provided with a portion protruding toward the magnetic disk medium, and an adhesive portion adjacent to the protruding portion and formed at a position lower than the protruding portion.

Abstract: Faulty engagement due to low surface precision of the engaging surfaces of a center core of a disk cartridge and a drive spindle is resolved. The center core 10 is positioned on the drive spindle 20 in a state where the center core 10 is in point contact with the drive spindle 20 at a minimum of three spots upon chucking. A minimum of three protrusions 10d are provided on the bottom surface of the center core 10, and lower ends P of the protrusions 10d are in point contact with the upper surface 21a of the drive spindle 20.

Abstract: A magnetic disk cartridge including a flexible magnetic disk, a hub, disk-holding protrusions, and an anti slip-out member. The hub has a disk-holding surface on which the central portion of the magnetic disk is held. The disk-holding protrusions are formed on the disk-holding surface of the hub, and are inserted through holes formed in the magnetic disk. The anti slip-out member is used to prevent the magnetic disk from slipping out from the disk-holding protrusions.

Abstract: A magnetic disk cartridge including a flexible magnetic disk, a hub, disk-holding protrusions, and an anti slip-out member. The hub has a disk-holding surface on which the central portion of the magnetic disk is held. The disk-holding protrusions are formed on the disk-holding surface of the hub, and are inserted through holes formed in the magnetic disk. The anti slip-out member is used to prevent the magnetic disk from slipping out from the disk-holding protrusions.

Abstract: A magnetic disk cartridge including a flexible magnetic disk, a hub, disk-holding protrusions, and an anti slip-out member. The hub has a disk-holding surface on which the central portion of the magnetic disk is held. The disk-holding protrusions are formed on the disk-holding surface of the hub, and are inserted through holes formed in the magnetic disk. The anti slip-out member is used to prevent the magnetic disk from slipping out from the disk-holding protrusions.

Abstract: A disk cartridge is provided, in which occurrence of distortion is prevented in a data region located at the radially outer part of a disk-shaped flexible information recording medium secured on a center core. A protrusion is formed integrally with the rotary shutter on a facing surface of the rotary shutter on the side facing an information recording medium. A liner for wiping off dirt deposited on the information recording medium is affixed to the protrusion.

Abstract: The cleaning effect of an information recording medium by liners is improved in a disk cartridge. The liners are constituted by non-woven fabric, formed by divided fibers, which are obtained by subjecting a compound divided fiber to a fiber division process.

Abstract: To improve the reliability of an engagement and ejection mechanism of a drive device having an accommodating portion for accommodating therein a magnetic disk.

Abstract: A magnetic disk cartridge which is used with a high density recording magnetic disk and which provides good recording and reproducing properties. The magnetic disk cartridge has a flexible magnetic disk having a disk-like center core. The upper surface of the disk-like center core is centrally affixed to the magnetic disk. The magnetic disk is rotatably retained in a flat housing. The magnetic disk has a surface recording density of at least about 158.7 Mbit/cm2. The disk wobbling value of the magnetic disk measured at a radial position located 5 mm outward from the outer diameter of the center core of the magnetic disk while rotating the magnetic disk by means of a drive device via the center core is not more than 20 &mgr;m.

Abstract: A magnetic disk cartridge having a shutter formed in a stepped configuration, which is capable of preventing damage to a data area of the magnetic disk by the step formed in the shutter, for example, when the magnetic disk cartridge is inserted into a drive. The magnetic disk cartridge has a housing constituted by a resin frame and upper and lower shell halves formed of metal sheets. The housing rotatably accommodates a magnetic disk and a rotary shutter therein. The rotary shutter is constituted by upper and lower shutter halves, each of which is formed in a stepped configuration. Junctures between surface regions located closer to the magnetic disk and transition regions of the upper and lower shutter halves are positioned at radial positions corresponding to areas other than the data area of the magnetic disk 5.

Abstract: A disk cartridge includes a casing, a recording disk, and a liner which is fixed to an inner surface of the casing or a shutter member interposed between the disk and the casing at a site opposed to the disk in order to clean the surface of the disk. The liner is supported away from the inner surface of the casing or the shutter member so that the liner can be deflected when the disk is brought into abutment against the liner due to impact applied to the disk cartridge.

Abstract: A magnetic disc is housed for rotation in a flat casing having the metal shell. The magnetic disc is supported for rotation in the casing by a tubular shaft formed by barring of a metal blank for forming the metal shell. A hole is formed in a part of the metal blank where the tubular shaft is to be formed. A plurality of slits are formed prior to barring in the part where the tubular shaft is to be formed.

Abstract: A disk cartridge comprising a disk medium fixedly attached on a center core, a casing with a spindle hole through which the center core is exposed to the exterior, and a dust-removing liner. The center core includes a large-diameter portion, which has an outside diameter greater than the inside diameter of the spindle hole of the casing, a thickness greater than that of the dust-removing liner, and a surface on which said disk medium is fixedly attached.

Abstract: Faulty engagement due to low surface precision of the engaging surfaces of a center core of a disk cartridge and a drive spindle is resolved. The center core 10 is positioned on the drive spindle 20 in a state where the center core 10 is in point contact with the drive spindle 20 at a minimum of three spots upon chucking. A minimum of three protrusions 10d are provided on the bottom surface of the center core 10, and lower ends P of the protrusions 10d are in point contact with the upper surface 21a of the drive spindle 20.

Abstract: In a disk cartridge provided with a rotary shutter, incorporating suitability is improved as an initial speed of ejection and a balance of the cartridge are ensured by a coil spring which urges the rotary shutter to a closed position. A coil spring 14 is formed to have an effective length shorter than a rotation stroke of the rotary shutter 7. Acompanying ejection of the disk cartridge from a disk drive, a shutter knob 7b of the rotary shutter 7 engages with the shutter closing means, which is made of an elastic member provided in the disk drive. Thus, the rotary shutter 7 is led to the closed position.

Abstract: A magnetic disk cartridge comprising a magnetic disk medium, a casing for rotatably housing the magnetic disk medium, and dust-removing liners fixed on the inner surfaces of the casing which face both sides of the magnetic disk medium. Each of the liners has an outer circumferential portion that is not fixed on the inner surface of the casing.

Abstract: A magnetic disk cartridge comprising a magnetic disk medium, a casing for rotatably housing the magnetic disk medium, and liners mounted on the inner surfaces of the casing that face both sides of the magnetic disk medium. Each liner is provided with a portion protruding toward the magnetic disk medium, and an adhesive portion adjacent to the protruding portion and formed at a position lower than the protruding portion.