This invention relates to magnetic disk cartridges and more particularly, to an improvement in cartridges for disk drives in which a flexible magnetic disk is rotated in read/write relationship with a magnetic head.
Magnetic disk drives for data storage systems are generally of two different types. Rigid magnetic disks are rotated adjacent to magnetic read/write heads which "fly" on an airbearing in very close proximity to the disk. Close proximity allows high data densities. Consequently, rigid magnetic disks are generally used in large data processing systems. These rigid disks are expensive and delicate to manufacture. Recently, magnetic disk drives which write and read digital data from flexible magnetic disks have been extensively used. These are frequently referred to as "floppy disks". The drives in which they are used have been extensively used for small, so-called microcomputer, systems, for word-processing applications and the like. Because the disk is not rigid it cannot be rotated in close proximity to a flying head. Accordingly, data densities and reliability are lower.
In another type of disk drive, a floppy disk is rotated in close proximity to a fixed, flat "Bernoulli" plate. The thin layer of air between the disk and the plate tends to rotate with the disk and to be thrown outwardly by centrifugal force. This creates a vacuum between the plate and disk which tends to pull the disk close to the plate and cause it to behave in a substantially rigid manner. A flying head can be used in conjunction with disks stabilized in this manner, providing the advantage of high data density, but without the expense associated with rigid magnetic disks. U.S. Pat. No. 4,074,330--Norton, et al shows a disk drive having a Bernoulli plate for stabilizing a flexible disk to prevent flutter and to maintain an airbearing.
"FLEXIBLE MAGNETIC DISK DRIVE USING A RIGID CARTRIDGE," Ser. No. 256,320 Bauck et al, filed Apr. 22, 1981, now U.S. Pat. No. 4,400,748 incorporated herein by reference, describes a disk drive using a Bernoulli plate to stabilize a flexible disk which is contained in a rigid cartridge which protects the disk. In such disk drives, it is desirable to texturize the surface of the Bernoulli plate so that the magnetic media will not cling to the surface, or "ring" as with a perfectly smooth plate. "BERNOULLI PLATE FOR STABILIZATION OF FLEXIBLE MAGNETIC DISK," Ser. No. 257,482, Radman, et al, filed Apr. 24, 1981, now abandoned describes a disk drive with a Bernoulli plate which has been texturized to prevent ringing.
It is an object of the present invention to provide a more reliable, less expensive technique for preventing ringing of flexible magnetic disks which are stabilized against a Bernoulli plate.
The cartridge described in the aforementioned Bauck, et al application has a slider which closes the opening through which the disk is accessed when it is inserted into the disk drive. A locking mechanism prevents opening of the slider except when the cartridge is properly inserted into the disk drive.
It is another object of the present invention to provide an improved locking mechanism for a rigid magnetic disk cartridge of this type.
It is another object of the present invention to reduce the Bernoulli attraction of the disk to the cartridge base so as to allow use of the Bernoulli technique in a smaller size cartridge.