JP2001256754A - Magnetic disk cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sealing performance when preserved in a magnetic disk cartridge which is constituted by rotatably accommodating a disk-shaped magnetic disk medium having a center core in a flat cartridge case provided with a window part for inserting a magnetic head and a shutter member for opening/ closing the window part and forming a hole part which makes a bottom surface of a cylindrical hub of the center core face to an outside at the lower surface of a cartridge case. SOLUTION: At a lower plate part 52 of the shutter member 5, a plate part 52a extending till the hole part 27 which makes the bottom surface of the cylindrical hub of the center core face to the outside is extendingly provided and the hole part 27 is opened/closed by the plate part 52a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin magnetic disk cartridge having a large recording capacity and containing a disk-shaped magnetic disk medium in a flat cartridge case.

[0002]

2. Description of the Related Art Conventionally, a magnetic disk medium (a so-called floppy disk) in which a magnetic layer is provided on both sides of a disk-shaped base made of a flexible polyester sheet or the like and magnetically recorded on the magnetic layer by a magnetic head while being driven to rotate. A magnetic disk cartridge in which a disk is accommodated in a flat case is provided, and is mainly used as a recording medium for a computer because of its advantages such as easy handling and low cost.

Further, the case is provided with a window for inserting a magnetic head for inserting and removing a magnetic head for magnetic recording / reproduction from one side or both sides of a magnetic disk medium for externally contacting or approaching from the outside. In order to prevent intrusion of dust and the like during operation (when not in operation), a shutter member slidable between an open position for opening the window and a closed position for closing the window is mounted.

By the way, the miniaturization of the computer using the above-mentioned magnetic disk cartridge has progressed, and the notebook type personal computer has become widespread. An external system without a built-in disk drive device is now being sold. The adoption of this external method is excellent in terms of portability of small personal computers.However, for example, there is a problem that a large amount of data cannot be recorded and reproduced because magnetic disk cartridges cannot be used at the carrying destination of small personal computers. This causes a problem that data cannot be recorded on a plurality of magnetic disk cartridges.

[0005] From these points, some small personal computers have a PC card slot (conforming to the PCMCIA specification) in which a PC card is mounted to support an external interface and additional memory. It has been proposed to configure an external storage device using a magnetic disk cartridge.

A PC that can be inserted into the PC card slot
The specifications of the card are type II, the thickness is 5.0 mm, and the magnetic disk cartridge and the disk drive are intended to be included in this thickness. Therefore, the thickness of the magnetic disk cartridge is about 2 to 3 mm. It must be made ultra-thin.

[0007]

Even when a thin magnetic disk cartridge as described above is constructed, a large recording capacity is required as a recording medium. To increase the transfer rate, it is necessary to rotate the magnetic disk medium at high speed.

[0008] Therefore, the magnetic disk medium is fixed to the center core at the center thereof, and the bottom surface of the cylindrical hub of the center core faces the outside on the lower surface of the case. A hole is formed to allow for chucking.

Further, when the magnetic head is inserted into the magnetic head insertion window during the operation of the thin magnetic disk cartridge as described above, the head can be precisely brought close to the magnetic disk medium and from the viewpoint of space. It is desirable to have a configuration in which the operation of opening and closing the carriage (to straddle the case) is avoided, and the magnetic head is linearly inserted into the window from the front end face of the cartridge case.

In this case, since the magnetic head moves in a direction parallel to the surface of the magnetic disk medium and is inserted into the window, it is necessary to cut out the case and the shutter member from the front end surface to the upper and lower surfaces. .

The shutter member for opening and closing the magnetic head insertion window has a substantially U-shaped cross-sectional shape in which an upper surface plate portion and a lower surface plate portion are connected by a front end connecting portion. In addition, a shutter window having a size substantially the same as that of the window of the cartridge case is formed by being cut out in a rectangular shape from the connecting portion to the upper and lower plate portions, and when the magnetic disk cartridge is stored (when not in operation). The window for inserting the magnetic head is completely closed by the shutter member.

However, the hole formed on the lower surface of the cartridge case, which exposes the bottom surface of the cylindrical hub of the center core to the outside, remains open even when the magnetic disk cartridge is stored (non-operating). Because
There is a possibility that dust or the like causing dropout or the like may enter the inside of the cartridge case from the hole.

In view of such circumstances, an object of the present invention is to provide a magnetic disk cartridge which can close the above-mentioned hole with a very simple structure during storage.

[0014]

According to the present invention, a member for opening and closing a hole for exposing the bottom surface of the hub of the center core to the outside in conjunction with opening and closing of the window for inserting a magnetic head is provided in the shutter member. It is characterized by being attached.

The cartridge case includes a base plate, and upper and lower cover cases respectively attached to upper and lower surfaces of the base plate, and the shutter member slides between the upper surface of the base plate and the upper cover case. It is preferable to include an upper plate part that is inserted as possible, and a lower plate part that is slidably inserted between the lower surface of the base plate and the lower cover case.
In this case, it is preferable that the member that opens and closes the hole that exposes the bottom surface of the hub of the center core to the outside comprises a plate extending from the lower surface plate of the shutter member to the hole.

Further, a tapered surface is formed on the outer peripheral surface of the cylindrical hub of the center core so that the edge of the hole opening / closing plate abuts when the hole opening / closing plate is closed by the hole opening / closing plate. It is preferable that the center core be deflected inward of the cartridge case by this contact, so that the hole can be closed.

Preferably, the center core is chucked by magnetic attraction to a rotary drive member such as a drive spindle of a drive device.

[0018]

According to the present invention, in the shutter member for opening and closing the window for inserting the magnetic head, the hole for exposing the bottom surface of the hub of the center core to the outside is opened and closed in conjunction with the opening and closing of the window. Since the member is provided, the hole can be reliably opened and closed without providing a separate driving means, and the sealing performance of the magnetic disk cartridge during storage (when not operating) can be improved. it can.

When the cartridge case includes a base plate and cover cases respectively attached to the upper and lower surfaces of the base plate, the strength of the cartridge case in the compression direction and the bending direction can be improved. In particular, by forming the cover case from a high-strength material such as a metal plate, the required strength as a flat case can be secured in combination with the base plate, and the dimensional accuracy can be maintained without deformation such as warpage even in the thin case. The characteristics required for the manner of use as a magnetic disk cartridge can be obtained, reliability can be secured, and good assemblability can be obtained.

Since the shutter member is housed inside the cover case, the shutter member is prevented from coming off due to insufficient strength due to the miniaturization of the shutter member, and is resistant to impacts such as dropping, and is easy to assemble. It will be good.

Further, when the opening / closing member for the hole is formed of a plate extending from the lower surface plate of the shutter member to the hole, the intended purpose can be achieved with a simple structure. .

Further, the cylindrical hub of the center core 2 has a tapered surface on the outer peripheral surface with which the edge of the hole opening / closing plate comes into contact when the hole opening / closing plate is closed by the hole opening / closing plate. If the center core is configured to be deflected inward of the cartridge case by this contact, the closing operation of the hole opening / closing plate can be reliably performed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a perspective view of a magnetic disk cartridge according to an embodiment of the present invention, showing a state in which a magnetic head insertion window is closed by a shutter member, as viewed from above. FIG. 2 is a perspective view of a state in which the magnetic head insertion window is opened as viewed from the lower surface side. FIG. 3 is an exploded perspective view of the magnetic disk cartridge. In addition, in order to clarify the structure, the thickness and the like of each part in the drawings are shown in proportions different from actual dimensions.

The magnetic disk cartridge 1 has a disk-shaped magnetic disk medium 10 (see FIG. 3) rotatably housed in a flat cartridge case C.
The cartridge case C includes a base plate 2 serving as a central member.
And a substantially planar upper cover case 3 and a lower cover case 4 attached to the top and bottom of the base plate 2. The magnetic disk medium 10 has a disk-shaped base made of a flexible polyester sheet and the like, on both surfaces of which magnetic layers are provided, and a metal center core 11 is fixedly integrated at the center.

Base plate 2 of cartridge case C
The center of the center core 11 is provided with a hub accommodation hole 27 for accommodating the cylindrical hub, and the lower cover case 4 is provided with the hole 27 substantially at the position overlapping the hub accommodation hole 27. A hole 7 having an equal size is formed, and the bottom surface of the hub of the center core 11 faces the outside from the hole 7.
The magnetic disk medium 10 is housed in a cartridge case C.

At the front end of the cartridge case C with respect to the direction of insertion D (arrow in FIG. 1) with respect to the drive device, there is formed a window 8 accessible by a recording / reproducing magnetic head. The window 8 is vertically penetrated and opened from the front end faces of the base plate 2 and the upper and lower cover cases 3 and 4 toward the center thereof in a rectangular shape (see FIG. 2). A shutter member 5 for opening and closing the portion 8 is built inside the upper and lower cover cases 3 and 4 so as to be slidable in the left-right direction.

With such a structure of the window 8, the recording / reproducing magnetic head can be inserted into the window 8 from the front end side of the cartridge case C without opening and closing greatly up and down.
Moreover, the adoption of the built-in shutter member 5 prevents the shutter member 5 from coming off due to insufficient strength due to miniaturization, becomes strong against dropping, etc., and has good assemblability.

Next, the structure of each component will be specifically described with reference to FIG.

First, the base plate 2 is made of a synthetic resin such as acrylonitrile-butadiene-styrene copolymer (ABS resin) or POM resin, and has a substantially rectangular flat plate shape. A circular recess 21 for accommodating the disk medium 10 is formed, and a circular hub accommodation hole 27 is opened at the center of the thin bottom plate of the recess 21. Also, the central portion of the front end portion of the base plate 2 is removed in the front-rear direction, so that the window portion 8 is formed.
The window 8 is extended on the thin bottom plate of the recess 21 so as to communicate with the hub receiving hole 27 to form a keyhole-shaped notch. And
The front surface of the front wall on one side (the right side in FIG. 3) of the window portion 8 of the base plate 2 is retracted from the front surface of the front wall on the other side (the left side in FIG. 3) to form a spring housing portion 23. In addition, a shutter spring 6 described later is arranged.

Further, the corner portions 25 at the four corners of the base plate 2 are formed so as to protrude in the vertical direction and have a large thickness and project outward. The four corner portions of the upper and lower cover cases 3 and 4 correspond to the corner portions. When the upper and lower cover cases 3 and 4 are fitted to the base plate 2, the corner portions 25 of the base plate 2 are exposed to the outside. Each corner portion 25 is provided in a shape in which the surface protrudes flush or outward with the surface of the upper and lower cover cases 3 and 4.

By exposing the corner portion 25 of the base plate 2 to the outside as described above, when a shock or the like at the time of a drop is applied, the corner portion 25 can absorb the shock, and can be inserted and inserted into the drive device. At the time of unloading operation, it is prevented from getting stuck and stable operation is ensured. In each corner 25, a hole 26 penetrating in the vertical direction (a hole having an intermediate depth without penetrating) may be used.
Is provided so as to obtain a larger buffering action at the time of a drop impact. The base plate 2 has a strength that allows a deformation that does not hinder the recording and reproduction of the magnetic disk medium 10. However, from the viewpoint of shock absorption, the base plate 2 is preferably made of an elastic plastic. In addition, a material containing a lubricant is preferable in terms of sliding with respect to the shutter member 5, and a material containing a filler material is used in order to improve dimensional accuracy and improve assemblability with the cover cases 3 and 4. Is good.

A notch-shaped concave portion 15 is formed on the side surface of the corner portion 25 on both sides of the front portion of the base plate 2 as shown in FIG. 1, and this concave portion 15 is used for positioning when mounted on a drive device. Alternatively, it is provided to prevent erroneous insertion in the front-back direction or the front-back direction. The recess 15 may be provided only on one side surface or on the side surface of the rear corner portion 25. In the case of the present embodiment, the corner of one of the front corners 25 is notched diagonally to form the erroneous insertion prevention part 16.

Also, on the side of the cartridge case C,
At a position different from the concave portion 15, for example, as shown in FIG. 1, an identification portion 17 for disc type (for example, type of recording capacity) is provided on the side wall portions of the cover cases 3 and 4 near the rear corner portion 25. Is provided, but a write protector section may be provided here. Furthermore, the identification section 17 may be provided with an identification piece that enables the detection function to be turned on / off so as to be able to be inserted or inserted / extracted. By forming the concave portion 15 and the identification portion 17 on the side surface, a drive-side detection mechanism or the like having no installation space in the vertical direction can be arranged on the side.

The upper and lower cover cases 3 and 4 are formed of a high-strength material such as a pressed stainless steel plate. The upper cover case 3 and the lower cover case 4 have a substantially symmetric shape, and the four corners are rectangular. It is removed, a flat rectangular window 8 is opened in the center of the front part, and the front, rear, left and right edges are bent at right angles, and the front walls 31, 41, both side walls 32, 42, respectively.
The rear wall portions 33 and 43 are configured. The front wall portion 3 on one side (the left side in FIGS. 1 and 3 and the right side in FIG. 2) with respect to the window portion 8.
The slits 18 (see FIG. 1) are formed between the upper and lower front wall portions 31 and 41 when the upper and lower cover cases 3 and 4 are attached to the base plate 2. It has become. The shutter opening / closing member on the drive device side is inserted into the slit 18 and moves along the slit 18 to open the shutter member 5. The front walls 31 and 4 on the opposite side of the window 8 (the right side in FIGS. 1 and 3 and the left side in FIG. 2).
1, that is, a notch is formed at the end side of the portion located in front of the spring storage portion 23, and the upper and lower cover cases 3,
A rectangular spring insertion opening 19 (see FIGS. 1 and 2) is formed in a state where the front wall portions 31 and 41 of the shutter 4 are fitted together, and is used for mounting the shutter spring 6.

On the upper surface of the central portion of the upper cover case 3,
A concave portion 35 serving as a label attaching portion is formed, and a bottom surface of the concave portion 35 projects downward. The recess 35 is provided in the rotation area of the magnetic disk medium 10 in an assembled state. The depth of the concave portion 35 is set at the center of the space between the lower surface of the concave portion 35 facing the bottom surface of the circular concave portion 21 of the base plate 2 and the bottom surface of the circular concave portion 21 in the thickness direction of the base plate 2. 10 is set to be located. That is, the magnetic disk medium 1 located at the center in the thickness direction of the base plate 2
0 so that the upper and lower clearances are substantially equal.
By setting the depth, the rotational stability of the magnetic disk medium 10 is improved, and the presence of the concave portion 35 improves the strength of the upper cover case 3.

Above and below the magnetic disk medium 10, a protective sheet 12 made of a plastic sheet or the like having a PET sheet surface subjected to a sliding process (Teflon process) is interposed. The protective sheet 12 has a substantially C-shape by removing a portion corresponding to the window portion 8 in the radial direction.
An opening 12a is formed in a portion opposite to the above, and a cleaning member 13 is fixed to this portion from the magnetic disk medium 10 side to the inner surface of the upper cover case 3 and the bottom surface of the base plate 2. 12 is fixed. The cleaning member 13 is brushed on the side facing the magnetic disk medium 10 and comes into contact with the surface of the magnetic disk medium 10 to remove dust on the surface. An adhesive is applied to the opposite surface of the cleaning member 13.

FIGS. 4A to 4C show the shutter member 5.
FIG. 2 is a plan view, a bottom view, and a perspective view as viewed from the bottom side, showing the configuration of FIG. The shutter member 5 is made of metal, for example, is formed in a substantially U-shaped cross section from, for example, a stainless steel plate or an aluminum plate, and has an upper surface plate portion 51 slidably inserted between the upper surface of the base plate 2 and the upper cover case 3. A lower plate 52 slidably inserted between the lower surface of the base plate 2 and the upper cover case 3, and a connecting portion 53 connecting the upper and lower plates 51, 52 on the front end side.
The height of 3 is substantially equal to the thickness of the front part of the base plate 2. Then, a shutter window 54 is formed by being cut out in a substantially rectangular shape from the connecting portion 53 to the upper surface plate portion 51 and the lower surface plate portion 52. The shutter window 54 has a size substantially corresponding to the window 8 of the cartridge case C, and is communicated with the shutter window 54 during the opening operation. The shutter window 54 is provided at a position deviated from the center of the shutter member 5, and a closing area for closing the window 8 of the cartridge case C together with the connecting portion 53 is formed adjacent to the shutter window 54.

A plate 52a for opening and closing the hub receiving hole 27 of the base plate 2 extends from the lower plate 52 of the shutter member 5.

A spring receiving projection 55 bent from the connecting portion 53 of the shutter member 5 is provided on the inner surface of the front end of the shutter window 54 on the side of the closed area, and the shutter spring 6 formed by a coil spring in the opening and closing direction is provided on the back thereof. When contracted, the shutter member 5 is urged in the closing direction. Although not shown, at least one of the upper surface plate portion 51 and the lower surface plate portion 52 is cut and raised, and is engaged with a guide groove extending in the left and right direction on the base plate 2 so as to be assembled. Is prevented from coming off.

When the upper and lower cover cases 3 and 4 are assembled to the base plate 2, a shutter member 5 is provided between the upper and lower surfaces of the base plate 2 and the inner surfaces of the upper and lower cover cases 3 and 4 at the front portion thereof. The dimension is set so that a thin space in which the slidable member extends can be formed extending in the left-right direction. The method of fixing the base plate 2 and the upper and lower cover cases 3 and 4 is as follows:
It is carried out by joining by caulking or the like, or by fixing the upper and lower cover cases 3 and 4 to the base plate 2 by caulking, bonding or the like.

FIG. 5 shows that the magnetic head insertion window 8 and the hub accommodation hole 27 of the base plate 2 are
FIG. 6 is a perspective view showing a state in which the lower cover case 4 is closed, as viewed from the lower surface side with a part of the lower cover case 4 cut away. On the bottom surface of the base plate 2, a concave portion 22 that forms a moving space for the lower plate portion 52 of the shutter member 5 is provided.

FIGS. 6A and 6B are a sectional view of the center core 11 and a perspective view seen from the bottom side thereof.
The center core 11 includes a cylindrical hub 11a having a spindle hole 11b into which a spindle of the drive device is inserted, and a sticking surface 11d of the magnetic disk medium 10.
11c having an upper surface and a spindle hole 11b
And a flat magnetic attracting surface 11e which is coaxially recessed on the bottom surface of the hub 11a and is magnetically attracted to the spindle. The outer peripheral surface of the hub 11a below the flange 11c has a smaller diameter toward the lower side. 11f.

The magnetic disk cartridge 1 as described above
Is assembled by fixing the protection sheet 12 to the circular recess 21 of the base plate 2 and the lower surface of the upper cover case 3 in advance by fixing the cleaning member 13, and setting the magnetic disk medium 10 in the circular recess 21 of the base plate 2. The shutter member 5 is mounted from the front.
Subsequently, the upper cover case 3 is fitted to the base plate 2 from above and the lower cover case 4 is fitted and held from below to integrate them. Thereby, the base plate 2
The upper surface of the circular concave portion 21 is covered by the upper cover case 3, and a flat space defined by the bottom surface of the upper cover case 3 and the upper surface of the circular concave portion 21 becomes a storage space for the magnetic disk medium 10, and Are rotatably stored. Thereafter, the coiled shutter spring 6 is inserted into the internal spring accommodating portion 23 while bending the coiled shutter spring 6 from the spring insertion opening 19 in the front wall portion of the upper and lower cover cases 3, 4. , And pushed into the storage portion 23 while shrinking the rear end to complete the assembly. The shape of the spring insertion opening 19 prevents the assembled shutter spring 6 from coming off.

The magnetic disk cartridge 1 as described above
When mounted on the drive device, the pawl of the opening / closing mechanism is inserted into the slit 18 at the front end, engages with the end of the shutter member 5, and moves the shutter member 5 in the opening direction. Along with this, the window 8 of the base plate 2 is opened,
The hub receiving hole 27 of the base plate 2 is opened, and the bottom surface of the center core 11 is exposed from the hole 7 of the lower cover case to the state shown in FIG.

The drive unit has a magnetic head at the back of the drive unit, and a drive unit is provided below the drive unit so as to be able to move up and down, and a spindle is magnetically mounted on the center core 11 of the magnetic disk medium 10 of the inserted magnetic disk cartridge 1. And is configured to be driven to rotate.

When the magnetic disk cartridge 1 is removed from the drive device, the shutter member 5 is closed by the urging force of the shutter spring 6 and the shutter member 5 is extended on the lower plate 52 of the shutter member 5. Plate 52
a closes the hub receiving hole 27 of the base plate 2. At this time, the edge E (FIG. 4C) of the plate portion 52a comes into contact with the tapered surface 11f of the hub 11a of the center core 11, and
The center core 11 is biased inward of the cartridge case C, and the plate portion 52a can close the hub housing hole 27.

As is apparent from the above description, in the present embodiment, the bottom surface of the hub 11a of the center core 11 is provided on the lower plate 52 of the shutter member 5 for opening and closing the window 8 for inserting the magnetic head. Since the plate portion 52a that opens and closes the hub housing hole portion 27 to be opened and closed in conjunction with the opening and closing of the window portion 8 is extended, the opening and closing of the hole portion 27 can be reliably performed by a simple mechanism. In addition, the sealing performance during storage (when not operating) can be improved.

Further, since the cartridge case C has the base plate 2 and the cover cases 3 and 4 attached to the upper and lower surfaces of the base plate 2, respectively, the strength of the cartridge case C in the compression direction and the bending direction is improved. Can be improved. In particular, cover case C
Is made of a high-strength material such as a metal plate, the strength required as a flat case in combination with the base plate 2 can be secured, the dimensional accuracy can be maintained without deformation such as warping even when the magnetic disk cartridge is thin. As a result, it is possible to obtain the characteristics required for the mode of use, to ensure reliability, and to obtain good assemblability.

Since the shutter member 5 is housed inside the cover cases 3 and 4, the shutter member 5 is prevented from coming off due to insufficient strength due to the downsizing of the shutter member 5, and has a strong resistance against a drop or the like. And the assemblability becomes good.

Further, when the hole 27 is closed by the hole opening / closing plate 52a, the center core 11 is provided on the lower outer peripheral surface of the cylindrical hub 11a at the edge E of the hole opening / closing plate 52a.
Is provided with a tapered surface 11f with which the
Since the center core 11 is configured to be biased inward of the cartridge case C, the closing operation of the hole opening / closing plate portion 52a can be reliably performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of a magnetic disk cartridge according to the present invention, showing a state where a window for inserting a magnetic head is closed by a shutter member, as viewed from above.

FIG. 2 is a perspective view of the magnetic disk cartridge shown in FIG. 1, showing a state in which a window for inserting a magnetic head is opened, as viewed from a lower surface side;

FIG. 3 is an exploded perspective view of the magnetic disk cartridge shown in FIGS. 1 and 2;

4A is a plan view of a shutter member, FIG. 4B is a bottom view, and FIG. 4C is a perspective view as viewed from the bottom side.

FIG. 5 is a perspective view showing a state in which a magnetic head insertion window and a hub accommodating hole of a base plate are closed by a shutter member, viewed from a lower surface side with a part of a lower cover case cut away;

6A is a cross-sectional view of the center core, and FIG. 6B is a perspective view of the center core as viewed from the bottom side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic disk cartridge C cartridge case 2 Base plate 3 Upper cover case 4 Lower cover case 5 Shutter member 6 Shutter spring 8 Magnetic head insertion window 10 Magnetic disk media 11 Center core 11a Center core hub 11f Tapered surface 12 Protective sheet 13 Cleaning Member 19 Spring insertion opening 21 Circular recess 23 Spring storing portion 25 Corner portion 35 Recess 51 Upper surface plate portion of shutter member 52 Upper surface plate portion of shutter member 52a Opening / closing plate portion 53 Shutter member connecting portion 54 Shutter window portion

Claims (1)

[Claims] 1. A disk-shaped magnetic disk medium having a center core is rotatably housed in a flat cartridge case having a magnetic head insertion window and a shutter member for opening and closing the window. In a magnetic disk cartridge having a hole formed on a lower surface of a cartridge case to expose a bottom surface of a cylindrical hub of the center core to the outside, the shutter member is interlocked with opening and closing of the magnetic head insertion window. A magnetic disk cartridge, further comprising an opening and closing member for opening and closing the hole.