Background of the Invention
This invention relates to the field of data recording and playback. More particularly, it relates to improvements in protective cartridges used to house data storage disks, such as optical, magneto-optical and magnetic disks.
Most conventional high density recording systems use data storage disks to store vast quantities of information in binary form. Owing to the high packing density of the stored bits of information, it is essential that the data-recording surfaces of these disks be protected from dirt, dust and other debris which can either obscure recorded bits or interfere with the recording of such bits. A variety of protective enclosures, referred to in the art as "cases," "cassettes," "cartridges," "caddies," etc., have been designed with this purpose in mind. The structural design and appearance of these cartridges is usually determined by the features of the disk drive units in which they are to be used. For example:
U.S. Pat. No. 4,433,410 (Siryi et al) discloses an optical disk cartridge which is intended for use in a disk drive unit of the type which includes means for rotating the disk within the cartridge. The cartridge comprises a plurality of spring loaded fingers which engage the rim of the disk and prevent the information-bearing surfaces from touching the inside surfaces of the cartridge. Upon being engaged by certain "pins" in the disk drive unit, the spring-loaded fingers are separated from the disk rim, thereby allowing the disk to rotate within the cartridge. A central circular aperture formed in the cartridge allows a spindle to engage the disk for rotation, and a radially extending slot or window allows an optical transducer to access all of the information tracks as the disk rotates.
In the commonly assigned U.S. Pat. No. 4,853,926 (Covington et al), a data storage disk is protectively packaged by a caddy/carrier assembly. The caddy is merely a temporary container for the disk during periods of non-use. The carrier comprises a rectangular frame which fits within the caddy and serves to support the disk at several locations along the disk's rim. A side wall of the caddy is provided with a pair of spring-loaded doors through which a disk-extracting mechanism of a suitable disk drive unit can enter and extract the disk/carrier assembly for utilization. Upon removing the disk/carrier assembly from the caddy, the disk is released from the carrier frame (by another disk drive mechanism), and the disk is loaded onto a spindle for rotation. After use, the disk is returned to the carrier frame, and the disk/carrier assembly is returned to the protective caddy through the caddy doors.
From the foregoing, it may be appreciated that the protective package surrounding a data storage disk determines the type of disk drive unit with which it can be used. Certainly, disks housed by cartridges of the type disclosed by Siryi et al cannot be used in the disk drive units designed to accept the Covington et al carrier/caddy assembly, and vice versa.
Summary of the Invention
In view of the foregoing, it is an object of this invention to provide a more versatile data storage disk cartridge, one which may be used with disk drive units adapted to remove a disk contained by the cartridge prior to rotating the disk on a drive spindle, as well as one which may be used with disk drive units adapted to rotate the disk within the confines of the cartridge.
The disk cartridge of the invention basically comprises a disk enclosure having two disk-access apertures, one for enabling a disk to be selectively inserted into and extracted from the disk enclosure, and the other for enabling access to the disk within the enclosure so that the disk may be rotatably driven within the disk enclosure and have information recorded and/or played back on all information tracks. Preferably, a pair of spring-loaded doors, one selectively covering each of the cartridge apertures, serve to maintain a dirt-free environment within the cartridge interior.
The invention and its various advantages will become more apparent to those skilled in the art from the ensuing detailed description of a preferred embodiment, reference being made to the accompanying drawings.
Brief Description of the Drawings
FIG. 1 is a perspective illustration of a data recording/playback system embodying the disk cartridge of the invention;
FIGS. 2A and 2B are top plan views of a data storage disk and carrier therefor;
FIGS. 3A and 3B are perspective views, from different viewpoints, of a preferred disk cartridge;
FIG. 4 is an enlarged perspective view showing a pair of cartridge doors in their closed position; and
FIG. 5 is a cross-sectional illustration showing the cartridge doors of FIG. 4 in an open position.
Detailed Description of Preferred Embodiments
Referring now to the drawings, FIG. 1 illustrates a data recording/playback system comprising a disk drive unit 2 and a data storage disk assembly 4. The latter basically comprises a rigid data storage disk 6, a disk carrier 8 and a protective cartridge 10. The particular disk carrier shown is that described in the commonly assigned U.S. Pat. No. 4,817,079 to R. G. Covington. As explained in that patent, disk carrier 8 serves to releasably capture disk 6 so that the disk is accurately and securely registered within the carrier structure, yet is capable of being readily released from the carrier for rotation. When not in use, the carrier and its captured disk are positioned within cartridge 10, whose structural details as described below, constitute the subject matter of this invention.
Referring additionally to FIGS. 2A and 2B, disk carrier 8 basically comprises a pair of crescent-shaped frame members 8A, 8B having arcuate surfaces S, S', respectively, which cooperate to define a generally circular aperture 11 for receiving data storage disk 6. As explained in the aforementioned Covington patent, the crescent-shaped frame members are slidably connected by a tongue groove arrangement T so that the size of the circular aperture can be varied. By this arrangement, a data storage disk can be captured within the aperture when the frame members are relatively close together, as shown in FIG. 2A, and released from the aperture when the frame members are relatively far apart, as shown in FIG. 2B. A pair of coil springs 12 serve to resiliently urge the frame members toward each other, i.e., toward disk-capturing positions. Capture of a disk within aperture 11 is effected by a pair of grooves G formed in arcuate surfaces S, S'. Each carrier frame member is provided with a structure which facilitates movement of the frame members apart to enable release of the disk for use. In the carrier shown, such structure comprises a plurality of rectangular apertures 14, each having a bevelled edge 14A which is adapted to be engaged by a like plurality of release pins 15, shown in FIG. 1, the latter being a part of the disk drive unit. The interaction of such release pins and apertures to effect disk release is fully described in the aforementioned Covington patent. Briefly, however, downward movement of the release pins into apertures 14 causes cam surfaces 15A to engage the bevelled edges 14A of apertures 14. As the release pins move through these apertures, cam surfaces 15a exert lateral forces on the frame members, thereby tending to move such members apart against the biasing forces provided by springs 12.
As indicated above, disk cartridge 10 is specially designed to accommodate a disk/carrier assembly of the type shown in the drawings. It will be appreciated, however, that the cartridge may take different forms depending, for example, on the shape of the disk carrier or on the peculiarities and structural features of the disk drive unit. Generally, however, cartridge 10 comprises a box-like container which, as shown in FIGS. 3A and 3B, includes confronting and coextensive top and bottom walls, 20A and 20B, respectively, and a plurality of spaced, parallel side walls, 20C, 20D, 20E and 20F. Side wall 20E has an opening 21 (FIG. 5) through which the disk/carrier assembly can enter and exit from the cartridge interior. By virtue of this opening, the cartridge is adapted for use with disk drive units of the type disclosed in the U.S. Pat. No. 4,773,058, i.e., disk drive units including a mechanism designed to withdraw a disk/carrier assembly through the end of a cartridge prior to use, and to return such assembly to the cartridge after use. A pair of spring-loaded doors 22, 24, arranged in cartridge opening 21, serve to keep dirt and debris from the cartridge interior. As described more thoroughly in the above-mentioned Covington patent, doors 22, 24 are pivotally mounted on shafts 26, 28, respectively, which span between the cartridge side walls 20C and 20D. Torsion springs (not shown) serve to urge these doors toward their cartridge-closing positions, as shown in FIGS. 3B and 4.
To enable cartridge 10 to be used in disk drive units of the type in which the disk is rotated within the cartridge, a second disk-access door 40 is provided. Door 40, which is best shown in FIGS. 3A and 3B, comprises a U-shaped member 42 which wraps around the cartridge's side wall 20F. Door member 42 is slidably mounted in a cartridge indentation 20H (formed in top and bottom sides 20A and 2B) for movement between a closed position, shown in FIGS. 1 and 3B, and an open position, shown in FIG. 3A. Spring means (not shown) serve to urge door member 42 towards its closed position, and a pair of inwardly extending tabs 42A on door member 42 slidably engage a groove 30 in cartridge top wall 20A to control the direction of movement of the member 42 relative to the cartridge. In its closed position, the respective legs of the U-shaped door member 42 entirely cover slotted openings 20G formed in cartridge's top and bottom walls. That is, opening 20G extends through the cartridge so that, when door member 42 is in its open position (as shown in FIG. 3A), both sides of the cartridge-enclosed disk are exposed. Opening 20G is sized so as to expose all of the disk's data tracks along a radius defined by the door. Moreover, opening 20G is sufficiently large to expose the disk's central aperture 6A, thereby allowing access to the disk by a rotatably driven spindle of a disk drive unit.
When cartridge 10 is used to house a disk carrier 8 of the type described above, it is necessary to provide a means for releasing the disk from the carrier so that it may be rotated within the cartridge. Such means for achieving this function takes the form of a plurality of apertures 20J passing through the top and bottom walls of the cartridge, such apertures aligning with the disk carrier release apertures 14. Disk-release pins associated with the disk drive unit enter apertures 20J and 14 and function to spread the carrier halves 8A and 8B apart, thereby releasing the disk for rotation within the cartridge interior. As shown in FIG. 5, a plurality of corregated resilient strips 44 serve to assure that the carrier is retained at a position equally spaced from the cartridge's top and bottom walls. Such strips slidably engage the disk carrier as it enters and exists the cartridge.
While the preferred cartridge of the invention is adapted to house a disk/carrier assembly of the type described, it will be apparent that the carrier component of this assembly could be eliminated, i.e., the disk would be loosely contained by the cartridge. In this case, it is still preferred that the cartridge interior be modified to achieve the function of the carrier, e.g., by including releasable fingers for centering the disk within the cartridge interior. Also, while the slotted openings 20 in the cartridge's top and bottom walls are disclosed as being continuous openings spanning the spacing between the disk's central aperture 6A and the disk periphery, it may be desirable, from a structural standpoint, to provide a plurality of discrete openings in these walls, such as a circular opening concentric with disk aperture 6A, and a radially-extending narrow slot which only exposes a radially-extending strip on the disk surface, a strip just wide enough to enable access to the data tracks by a record/playback transducer. Preferably, all such apertures are covered by door member 42 whenever the disk is not being used within the cartridge.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.