Disk Jacket

The present invention relates to a disk jacket receiving a photo-magnetic disk, or a disk-like medium and more particularly to an opening and closing mechanism of a recording and reproducing head insert opening of the jacket.

A conventional floppy disk, having a diameter of 3 or 3.5 inches, is protected from dust by a cover jacket. The jacket has a recording and regenerating or reproducing head insert opening, and the opening is closed by a cover to protect an information recording surface of the floppy disk from dust when the floppy disk is in an inoperative position.

Such a conventional disk jacket is shown in FIG. 9. The disk jacket 40 has a central spindle insert opening 41 and a head insert opening 42. A cover plate 43 made of a thin metal sheet has an opening 44 and is slidable on the jacket 40. Between the cover 43 and the jacket 40, a tension spring 45 is connected to maintain the cover 43 to a direction A shown in FIG. 9, to close the opening 42 of the jacket 40 in the inoperative position of the jacket 40. When the jacket 40 is set in a recording and regenerating apparatus, the cover plate 43 is pushed to a direction shown by an arrow B in FIG. 9, until the jacket opening 42 is aligned with the opening 44 of the cover plate 42 to allow inserting of the recording and regenerating head not shown.

When such a mechanism is utilized to a large recording and regenerating optical head of a photo disk apparatus a photo-magnetic disk apparatus, radial dimension of the jacket opening 44 must be increased to cover all information recording portion of the disk so that a width of the cover plate 43, in the radial direction of the disk, must be increased. Also, when the disk dimension is increased, the radial dimension of the cover plate must be increased.

In every case, the conventional cover plate having the cantilever support slide mechanism guided by a jacket edge portion can not be adapted to such increased dimension so that sliding of the cover plate can not be smoothly performed. Further, the opening 42 can not allow sufficient radially inward movement of the head, especially when the head is large.

An object of the present invention is to provide an improvement of the disk jacket to eliminate above mentioned disadvantages, in which the disk jacket has a sufficiently large opening to allow the head to move to a radially inner most portion of the disk, and also in which the disk has shutter means positively open and close the large opening.

Another object of the present invention is to provide the disk jacket having the shutter means which has disk retainer means for preventing the disk from rattling when the jacket is in an inoperative position.

To attain the above-mentioned objects, the disk jacket, according to the present invention, comprises one opening serving as the head insert opening and the central spindle opening.

The disk jacket also comprises two shutter blades relatively pivotable in the jacket so as to open and close the opening.

The shutter means has disk retainer means to retain the disk in an inoperative position.

FIG. 1 is a plan view of the disk jacket, according to the present invention,

FIG. 2 and FIG. 3 are sectional views of the jacket of FIG. 1 showing double blades shutter,

FIG. 4 is a sectional view along line X--X in FIG. 1,

FIG. 5 is a sectional view showing a disk retainer mounted on the shutter blade shown in FIGS. 1 and 2,

FIG. 6 is a sectional view showing disk stopper means cooperating with the disk retainer shown in FIG. 5, when the disk is in an inoperative position of the disk,

FIG. 7(a) is a sectional view showing a guidance of a hook by a jacket edge,

FIG. 7(b) is a partial plan view of FIG. 7(a),

FIG. 8 is an illustration showing inserting of the disk jacket shown in FIG. 1 to a recording and reproducing apparatus, and

FIG. 9 is a diagramative plan view of a conventional disk jacket.

FIG. 1 shows a plan view of the disk jacket according to the present invention. 1 designates a jacket body which is formed by an upper generally rectangular jacket section 1a and a lower generally rectangular jacket section 1b as will be described later. According to the present invention, in the upper jacket 1a, an opening 2 to insert a recording and reproducing head is formed. The opening 2 communicates with an opening 2a to insert a spindle. Thus, the recording and reproducing head can be displaced from an outermost end to an innermost portion of the disk. The openings 2 and 2a are contiguous with one another and define a single, continuous opening having a central opening portion 2 and a radial opening portion 2a.

The opening 2 to insert the recording and reproducing head may be formed in one or both of the upper and lower jackets 1a and 1b, according to the device to be used. In the illustrated embodiment the openings 2 are formed in both jackets 1a and 1b. However, one opening may be communicated with the spindle opening 2a, according to the present invention, and the other opening may be similar to a conventional opening.

As the jacket opening 2 according to the present invention is very large compared with the conventional opening described in FIG. 9, shutter blades 3 and 4 are mounted to open and close the jacket opening 2, according to the present invention.

The shutter blades 3 and 4 comprise boomerang-shaped bent plates pivotably supported by shafts 5 and 6 which are secured with the jacket body 1 respectively. Fixed pins 9 and 10 secured with the jacket body 1 and fixed pins 11 and 12 secured with the shutter blades 3 and 4 respectively, are engaged by tension springs 7 and 8 respectively to urge the blades 3 and 4 in opposite directions to close the opening 2. Hooks 15 and 16 are slidable along side edges of the jacket body 1. As will be described later, when the jacket is set in a recording and reproducing apparatus, hooks 15 and 16 are engaged with means in the apparatus and are slideable along the side edges of the jacket 1 as shown by an arrow B in FIG. 1. Wires 19 and 20 are connected to the hooks 15 and 16, and extend through guide rollers 17 and 18 to blade retainers 13 and 14 which are connected to the blades 3 and 4 respectively. Thus, as the hooks 15 and 16 slide, the blades 3 and 4 are moved to open the opening 2 against the biasing force of the springs 7 and 8.

Disk stoppers 21 and 22 are secured to the shutter blades 3 and 4 and contact with the disk 25 when the blades 3 and 4 are in the closed position. Thus, when the disk 25 is not used, stoppers 21 and 22 urge the disk to stoppers 23 and 24 to prevent the disk 25 from moving.

FIG. 2 shows a cross section of the shutter blades 4 along the pivot shaft 5 and the blade retainer 14 and FIG. 3 shows a cross section of the shutter blade 3 along the pivot shaft 6 and the blade retainer 13.

As shown, the shutter blades 3 and 4 are formed by pairs of double blades shutter made of blades 3a and 3b, and blades 4a and 4b respectively. The base portions of the blades 3a and 3b are secured with the pivot shaft 6 and end portions of the blades 3a and 3b are secured with the blade retainer 13. Similarly the base portions of the blades 4a and 4b are secured with the pivot shaft 5 and the end portions of the blades 4a and 4b are secured with the blade retainer 14. As described, the blade retainers 13 and 14 are connected to the wires 19 and 20 respectively which are connected to the hooks 15 and 16 so as to open the blades.

The distance between the double blades of the blades 3 and 4 is shown in FIG. 4. As shown, the distance between the blades 4a and 4b is larger than the distance between the blades 3a and 3b. As the shutter blades 3a and 3b are fit between the blades 4a and 4b, and all the shutter blades slidably engage with inside surfaces of the jackets 1a and 1b, an effective sealing is achieved to keep the interior space of the jacket free from dust.

The above mentioned disk stoppers 21 and 22 are shown in FIG. 5. The disk stoppers 21 and 22 maintain the distance between the double blades of the shutter blades 3 and 4. The stoppers 21 and 22 have V-shaped recess as shown. Soft retainer material such as felt is adhered on the V shaped recess so that the disk 25 is urged laterally to the stoppers 23 and 24 when the disk is in the inoperative position.

Disk stoppers 23 and 24 are formed, as shown in FIGS. 1 and 6, on the lower jacket 1b, and prevent the disk 25 from rattling. Soft elastomer is adhered on the stopper to contact with the disk 25 softly when the disk contact with the stoppers.

FIGS. 7(a) and 7(b) show the slide mechanism of the hooks 15 and 16. As shown, upper and lower recesses 15a and 15b on the hook 15 engage with guide rail means 26 formed between the upper and lower jackets 1a and 1b.

Operation of the disk jacket will be described.

At first a disk 25 in the jacket 1 is introduced into a drive mechanism of a recording and reproducing apparatus into a phantom line position shown in FIG. 8 in a direction as shown by an arrow C in FIG. 8. The inserting position is determined such that the jacket 1 is not disturbed by a disk spindle. As the jacket 1 is inserted, the hooks 15 and 16 engage with engage means in the apparatus so that relative movement between the hooks and the jacket 1 causes pulling of the wires 19 and 20 to open the shutters 3 and 4. Then the jacket 1 is lowered as shown by an arrow D in FIG. 8, into a disk spindle portion of the apparatus. The rotation center of the disk 25 is determined by a disk guide 29, and the disk 25 is retained between a disk receiver 30 and a disk retainer 28 so that the disk 25 is accurately positioned in the apparatus. An auxiliary magnet 27 is inserted in the opening 2 and is positioned accurately to absorb vertical clearance of the disk 25.

Then, a head 31 is inserted in the lower opening 2 of the jacket 1 to record and reproduce desired information corresponding to a desired position in the disk 25.

It will be appreciated that, according to the present invention, the disk jacket has one opening which serves as a recording and reproducing head insert opening and a spindle insert opening so that the jacket can be used for an apparatus having a large head such as an photo disk or photo magnetic disk apparatus to allow free displacement of the head to the innermost portion of the disk. Thus, the recording and reproducing area of the disk can be fully utilized and information quantity recorded on the disk is also increased.

Further, the shutter blades of the jacket, according to the present invention, are relatively pivotted to open or close the opening of the jacket. Compared with the conventional slidable shutter, the large opening of the jacket can be easily and positively closed. Also, when in the inoperative position, the disk in the jacket is retained by cooperation of the stopper in the jacket with the disk retainer mounted on the shutter blade so that the disk is held in position without rattling and without undesired damage.

As the shutter blades are similar to each other, and as only a few component parts are necessary to produce the shutter assembly, the jacket according to the invention can be manufactured at low cost.