JP2001332053A - Magnetic disk cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a shutter member from being deformed when attaching the shutter member to a cartridge case in a magnetic disk cartridge. SOLUTION: While projectingly forming a pair of guide claws 56 and 56 in one of inner wall surfaces of upper and lower face-plate parts 51 and 52 of the shutter member 5, a guide groove 29 which engages with the guide claws 56 and 56 and guides opening and closing operation of the shutter member 5 and a pair of notches 28 and 28 which allow the passage of the guide claws 56 and 56 from a front tip of a base plate 2 to the guide groove 29 at the time of attachment of the shutter member 5 to the base plate 2 are formed in the base plate 2 of the cartridge case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin, large-capacity magnetic disk cartridge in which a disk-shaped magnetic disk medium is accommodated in a flat cartridge case, and more particularly to a magnetic disk cartridge for inserting a magnetic head into the cartridge case. The present invention relates to a structure of a portion where a shutter member for opening and closing a window portion and a shutter member of a cartridge case are mounted.

[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. (Registered Trademark) disk is provided in a flat case, 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 through which a magnetic head for magnetic recording and reproduction is brought in and out of one side or both sides of a magnetic disk medium from the outside so as to come into contact with or approach. In order to prevent intrusion of dust and the like during use, 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 are provided with a PC card slot (conforming to the PCMCIA specification) in which a PC card is mounted so as to support an external interface and an additional memory. Therefore, it has been proposed to configure an external storage device using a magnetic disk cartridge using the PC card slot.

A PC that can be inserted into the PC card slot
The specification of the card is type II, the thickness is 5.0 mm, and the magnetic disk cartridge and the disk drive are to be included in this thickness. Therefore, the thickness as a magnetic disk cartridge is 2-3 mm by design. It is necessary to make it ultra-thin.

[0007] Even when the magnetic disk cartridge is made thin in this manner, since a large recording capacity is required as a recording medium, the transfer rate is increased when the recording density is increased to secure the maximum recording capacity. From this point, it is necessary to rotate the magnetic disk medium at high speed.

The characteristics required as a large-capacity small magnetic disk cartridge include the following.

That is, first, the cartridge case has a strength for suppressing deformation of the cartridge case at the time of handling such as attachment / detachment operation to the drive device or at the time of transportation, and ensuring operation reliability. Since the temperature in the drive increases with high-speed rotation, the drive must have heat resistance to maintain rigidity and dimensional accuracy. It must be durable so that it is more frequently transported alone without being stored in a special case, so that it will not be deformed or damaged when a drop impact is applied directly. It must have dust-prevention, dust-prevention, and dust-removal functions to prevent dust, which may cause dropout, from entering from outside, and to prevent dust from being generated inside when subjected to a drop impact. Although the component parts are downsized, dimensional accuracy to ensure stable operation,
In addition to ensuring functional stability, the structure is easy to assemble even small components, and productivity can be ensured.

[0010]

In consideration of the above points, it is necessary to design the basic structure of the magnetic disk cartridge. In particular, it is necessary to design the magnetic disk cartridge inside while securing the strength of the cartridge case. It is important to secure a space for accommodating the media rotatably. In other words, in the case where the upper and lower shells of the divided structure are joined in a lid-like manner like the cartridge case of the conventional magnetic disk cartridge, the thickness of the flat case becomes thin as a result of the strict regulation in the thickness direction of the cartridge case, The mechanical strength decreases. Insufficient strength of the case portion causes deformation or the like during loading or unloading operation to or from the drive device, and handling during the outside of the drive device, and the magnetic disk medium rubs against the inner surface of the case, affecting the recording / reproducing characteristics, This may cause a decrease in reliability.

Therefore, a base plate made of synthetic resin,
A cartridge case is constituted by a pair of metal cover cases attached to the upper and lower surfaces of the base plate, a concave portion is provided on the upper surface of the base plate, and a magnetic disk medium is rotatably accommodated in the concave portion. Conceivable.

In this case, a metal shutter member having a substantially U-shaped cross-section formed by connecting the upper plate portion and the lower plate portion by a front end connecting portion is mounted on the base plate inside the upper and lower cover cases. However, in order to smooth the opening and closing operation of the shutter member and to prevent the shutter member from coming off the base plate, one of the upper and lower plate portions (usually the lower plate portion) of the shutter member, as in a conventional floppy disk, is used. It is necessary to project a pair of guide claws on the inner wall surface along the connecting portion, and to form a guide groove at the front edge of the base plate to engage with the guide claws to guide the opening and closing operation of the shutter member.

When assembling the shutter member to the cartridge case, the guide claw is set in the guide groove across the cartridge case, so that an excessive load is applied to the connecting portion and the upper and lower plate portions are opened. It is easy to adjust. In order to avoid this, conventionally, measures such as providing a tapered portion or a thin portion in the cartridge case to facilitate bending of the shutter member are taken. However, deformation of the shutter member is completely prevented. However, these countermeasures are contributing to the fact that the shutter member is easily detached from the cartridge case.

Further, when the cartridge case becomes extremely thin, the shutter member is required to be extremely thin. Accordingly, the leading end of the opening / closing lever provided in the drive device must be engaged with the connecting portion of the shutter member. Becomes difficult.

Further, when the metal shutter member slides on the inner surfaces of the metal upper and lower cover cases, there is a problem that abrasion metal powder is easily generated.

In view of such circumstances, an object of the present invention is to provide a magnetic disk cartridge which effectively overcomes the various problems described above.

[0017]

According to the present invention, a disk-shaped magnetic disk medium is rotatably accommodated in a flat cartridge case having a magnetic head insertion window, and an open position for opening the window is provided. In a magnetic disk cartridge comprising a shutter member slidably mounted on the case so as to be slidable between a closed position for closing the window portion, the cartridge case includes a base plate, and a pair of upper and lower members attached to the base plate. The base plate has a concave portion on its surface, and the magnetic disk medium is rotatably housed in a space defined by the concave portion and the pair of upper and lower cover cases, and the shutter member is provided. Has a substantially U-shaped cross section by an upper surface plate portion, a lower surface plate portion, and a connecting portion connecting the upper and lower surface plate portions on one side. It is formed, and is characterized in that it is housed inside the cover case.

According to one aspect of the present invention, a pair of guide claws project from at least one of the inner wall surfaces of the upper and lower plate portions of the shutter member, and engage with the guide claws on the base plate. A guide groove for guiding the opening and closing operation of the shutter member is formed, and a pair of notches are formed to allow the pair of guide claws to pass from the front edge of the base plate to the guide groove when the shutter member is assembled to the base plate. Have been.

In this case, the shutter member is urged in the closing direction by a spring member, and the pair of notches are located near the position of the guide claw in the guide groove when the shutter member is in the open position. Preferably, it is formed.

According to another aspect of the present invention, a notch is formed at one end of the connecting portion of the shutter member so as to engage with a shutter opening / closing member of the drive device.

In this case, it is desirable that a bent portion is formed in the notch portion so as to abut against the shutter opening / closing member.

According to still another aspect of the present invention, the front end portions of the upper and lower plate portions of the shutter member, that is, portions on the opposite side to the connecting portion side are bent in a direction to open each other.
The opened portion is configured so that the upper and lower cover cases are mounted on the base plate at the time of assembling the cartridge, so that they are pushed by the inner surface of the cover case and become substantially parallel.

In this case, it is preferable that the front ends of the upper and lower plate portions of the shutter member abut substantially linearly on the inner surfaces of the upper and lower cover cases. Also, on the outer surface of the upper and lower plate
It is preferable that a large number of minute projections are formed.

[0024]

According to the present invention, the cartridge case includes a base plate and cover cases respectively attached to the upper and lower surfaces of the base plate, and the base plate has a concave portion on its surface. Since the magnetic disk medium is rotatably housed in the space defined by the cover case and the cover case, the compression direction and the bending direction of the cartridge case are formed by forming the medium housing space by attaching the cover case to the base plate. Can be improved in strength. In particular, by configuring the cover case with a high-strength material such as a metal plate,
In combination with the base plate, the required strength as a flat case can be secured, the dimensional accuracy can be maintained without deformation such as warping even if it is thin, and the characteristics necessary for the usage mode as a magnetic disk cartridge are obtained and the reliability is obtained. Can be secured,
Moreover, 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.

[0026] A pair of guide claws are protruded from at least one inner wall surface of the upper and lower plate portions of the shutter member.
A guide groove that engages with the guide claw on the base plate to guide the opening and closing operation of the shutter member; and a pair of guide claws from a front edge of the base plate to the guide groove when the shutter member is attached to the base plate. When a pair of notches are formed to allow the passage of the shutter member, the guide claw is engaged with the guide groove without opening the upper and lower face plate portions when assembling the shutter member to the base plate. Since the shutter member can be mounted on the base plate, no load is applied to the connecting portion of the shutter member, and the shutter member is not deformed, so that the opening and closing operation of the shutter member is stabilized.

In this case, the shutter member is urged in the closing direction by the spring member, and the pair of cutouts of the base plate allow the guide claw to be inserted into the guide groove when the shutter member is in the open position. Since the shutter member is formed in the vicinity of the position, the notch portion and the guide claw are far apart in the direction along the guide groove when storing the cartridge in which the shutter member is held in the closed position by the spring member. Even when an impact such as that described above is applied to the shutter member, there is no possibility that the guide claw will come off the guide groove through the notch.

Further, since a notch is formed at one end of the connecting portion of the shutter member to be engaged with the shutter opening / closing member of the drive device, the distance between the upper and lower plate portions of the shutter member is extremely small. The shutter opening and closing member can be securely engaged with the end of the connecting portion,
Thereby, the opening and closing operation of the shutter member can be reliably performed.

In particular, when the notched portion is formed with a bent portion which comes into contact with the shutter opening / closing member in a plane, even if the shutter member has a small thickness, the notched portion can be formed. Since there is no possibility that a sharp edge is formed at the abutting portion of the tip of the shutter opening / closing lever, the risk of the shutter opening / closing member being scraped by the sharp edge can be avoided.

Further, the front end portions of the upper and lower plate portions of the shutter member, that is, portions opposite to the connecting portion side are bent in a direction to open each other, and this opened portion is used to assemble the upper and lower cover cases when assembling the cartridge. By being mounted on the base plate, it is pushed by the cover case so that it is substantially parallel, with the opening and closing operation of the shutter member, the inner surfaces of the upper and lower cover cases have the upper and lower plate portions of the shutter member. The leading edges are in sliding contact with each other, so that sliding resistance between the inner surfaces of the upper and lower cover cases and the outer surfaces of the upper and lower plate portions of the shutter member is prevented from increasing, and the generation of wear metal powder and the like are prevented. Further, since a large number of minute projections are formed on the outer surfaces of the upper and lower plate portions, the sliding contact area can be reduced and the sliding resistance can be reduced.

[0031]

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 an embodiment of a magnetic disk cartridge according to the present invention, showing a state in which a window for inserting a magnetic head 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 or the like, and magnetic layers are applied to both surfaces thereof, and a center core 11 is fixedly integrated at the center.

A hole 7 is provided on the lower surface of the cartridge case C to enable the chuck between the drive motor of the drive device and the center core 11. The magnetic disk is so positioned that the bottom of the rotary drive hub 11 faces the hole 7. Media 10
Are housed in the cartridge case C.

At the front end of the cartridge case C with respect to the direction of insertion D (arrow in FIG. 1) into the drive device, there is formed a window 8 accessible by the 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 the structure of the window 8 as described above, the recording / reproducing magnetic head can be inserted into the window 8 from the front end face side of the cartridge case C without largely opening and closing vertically. The use of 5 prevents the shutter member 5 from coming off due to insufficient strength due to miniaturization, becomes tough 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 center core accommodation hole 27 is opened at the center of the bottom plate of the recess 21. Further, the front portion of the bottom plate of the concave portion 21 is removed in a substantially rectangular shape to form a space 22 in which a lower plate portion 52 of the shutter member 5 described below can move, and the central portion of the front end portion of the base plate 2 extends in the front-rear direction. The window portion 8 that has been removed and communicates with the space 22 is vertically opened and opened. Then, the front surface of the front wall on one side (the left side in FIG. 3) of the window 8 of the base plate 2 is retracted from the front surface of the front wall on the other side (the right side in FIG. 3) to form a spring storage portion 23, In this portion, a shutter spring 6 described later is arranged. Further, a front corner 24 facing the window 8 of the front wall on the opposite side (the left side in FIG. 3) from the spring housing 23 is cut off obliquely,
The shutter member 5 is structured to be guided when the shutter member 5 is closed, so that the shutter member 5 is securely closed and the base plate 2 is not scraped by interference. The space 22 may be formed in a thin groove shape from the bottom surface side when there is a margin in the thickness direction of the base plate 2.

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 drop acts, the corner portion 25 can absorb the shock, and can be inserted into the drive device and inserted. 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 deformation that does not hinder recording and reproduction of the magnetic disk medium 10. It is preferable that the base plate 2 is made of an elastic plastic from the viewpoint of absorbing the impact, and it is preferable that the base plate 2 contains a lubricant from the viewpoint of sliding with the shutter member 5 to improve dimensional accuracy. From the viewpoint of improving the assemblability with the cover cases 3 and 4, it is preferable to include a filler material.

As shown in FIG. 1, 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, and this concave portion 15 is used for positioning when mounted on the 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.

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 are substantially symmetrical, 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 side is inserted into the slit 18 and moves along the slit 18 to open the shutter member 5. A notch is formed in the front wall portions 31 and 41 on the opposite side (the right side in FIGS. 1 and 3 and the left side in FIG. 2) with respect to the window portion 8, that is, the end portion side of the portion located in front of the spring storage portion 23. Then, a rectangular spring insertion port 19 (see FIGS. 1 and 2) is formed in a state where the front wall portions 31 and 41 of the upper and lower cover cases 3 and 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. A hole 7 corresponding to the center core housing hole 27 of the base plate 2 is opened at the center of the lower cover case 4.

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 fixing method of assembling the base plate 2 and the upper and lower cover cases 3 and 4 is such that the contact portions of the upper and lower cover cases 3 and 4 are joined to each other by spot welding as shown by a reference symbol S in FIGS. Done by

The shutter member 5 is inserted between the base plate 2 and the upper and lower cover cases 3 and 4 and into the moving space 22 opened to the base plate 2 on the lower surface side, and is slidably mounted in the left and right opening and closing directions. . The shutter member 5 is made of metal, for example, formed in a substantially U-shaped cross section from a stainless steel plate or an aluminum plate.
The lower plate 52 and the lower plate 52 are connected by a connecting portion 53 at the front end, and the height of the connecting portion 53 is substantially equal to the thickness of the front portion 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.

As shown in FIG. 4, 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 closed area side.
A shutter spring 6 made of a coil spring is contracted on the back in the opening and closing direction, and the shutter member 5 is urged in the closing direction. A pair of guide claws 56, 56 are formed in the lower surface plate portion 52 near the connecting portion 53 by cutting and raising inward at predetermined intervals along the connecting portion 53.

On the other hand, on the back surface of the base plate 2, a guide groove 29 is formed along the front edge of the base plate 2 to engage with the guide claws 56 and guide the opening and closing operation of the shutter member 5. 2 has a pair of notches 28, which lead from the front edge thereof to the guide groove 29,
28 are formed corresponding to the guide claws 56, 56. These notches 28 are formed near the positions of the guide claws 56 in the guide groove 29 when the shutter member 5 is in the open position. When the shutter member 5 is attached to the base plate 2, Guide claws 56 and 5 from the leading edge side of 2 to guide groove 27
6 is allowed.

Due to the presence of the notches 28, 28, when the shutter member 5 is assembled to the base plate 2, the guide claws 5 can be opened without opening the upper and lower plate portions 51, 52.
Since the shutter member 5 can be mounted on the base plate 2 in a state where the shutter members 6 and 56 are engaged with the guide grooves 27, no load is applied to the connecting portion 53 of the shutter member 5.
Since no deformation occurs in the shutter member 5, there is an effect that the opening and closing operation of the shutter member 5 is stabilized.

Further, since the notches 28 are formed near the positions of the guide claws 56 in the guide groove 29 when the shutter member 5 is in the open position, the shutter member 5 is During storage of the cartridge held in the closed position, the notch 28 and the guide claw 56 are far apart in the direction along the guide groove 29. Therefore, even if an impact such as a drop is applied to the shutter member 5 during storage, The guide claws 56, 56 are notched portions 28, 28
There is no possibility of the guide groove 29 coming out of the guide groove 29 through the hole.

Further, at one end of the connecting portion 53 of the shutter member 5, as shown in FIG. 5 (a), a cutout portion 57 is formed which engages with the tip of the shutter opening / closing lever of the drive device. Due to the presence of the notch 57, the tip of the shutter opening / closing lever can be securely engaged with the end of the connecting portion 53, even though the distance between the upper and lower plate portions 51, 52 of the shutter member 5 is extremely small. Thus, the opening and closing operation of the shutter member 5 can be reliably performed.

In this case, as shown in FIG. 5 (b), it is desirable that a bent portion 58 is formed in the notch portion 57 so as to abut against the tip of the shutter opening / closing lever. When the bent portion 58 is formed, even when the thickness of the shutter member 5 is small, there is no possibility that a sharp edge is formed at the contact portion of the notch 57 at the tip of the shutter opening / closing lever. Therefore, it is possible to avoid the danger that the tip of the shutter opening / closing lever is shaved by the sharp edge.

Further, in another embodiment of the present invention, as shown in FIG.
1 and 52 (parts on the side opposite to the connecting part 53 side)
Are bent from the lines L ₁ and L ₂ parallel to the connecting portion 53 in a direction in which they open from each other to form an angle θ. When the upper and lower cover cases 3 and 4 are mounted on the base plate 2 when assembling the magnetic disk cartridge, these open portions are pushed by the inner surfaces of the cover cases 3 and 4 so as to be substantially parallel to each other. Face plate 51,
52 is substantially equal to the interval d.

According to this configuration, as the shutter member 5 is opened and closed, the inner edges of the upper and lower cover cases 3 and 4 have the leading edges 51 of the upper and lower plate portions 51 and 52 of the shutter member 5.
a and 52a are in sliding contact with each other, and the sliding contact between the inner surfaces of the upper and lower cover cases 3 and 4 and the outer surfaces of the upper and lower plate portions 51 and 52 of the shutter member 5 increases sliding resistance or generates abrasion metal powder. Is prevented. Further, by forming a large number of minute projections 59 at appropriate positions on the outer surfaces of the upper and lower plate portions 51 and 52, the sliding contact area can be reduced and the sliding resistance can be reduced.

Referring again to FIG. 3, a protective sheet 12 made of a plastic sheet or the like obtained by subjecting the surface of a PET sheet to slipping (Teflon (registered trademark) processing) is interposed above and below the magnetic disk medium 10. . The protective sheet 12 has a substantially C-shape by removing a portion corresponding to the window portion 8 in the radial direction, and has an opening 12 a formed in a portion opposite to the window portion 8.
Are fixed to the inner surface of the upper cover case 3 and the bottom surface of the base plate 2 from the magnetic disk medium 10 side.
2 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.

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 connected to the guide claws 56,
56 is fitted to the guide groove 29 of the base plate 2 from the front. Subsequently, the upper cover case 3 is attached to the base plate 2 from above with the lower cover case 4 from below.
Are fitted and held, respectively, to be integrated. As a result, the upper surface of the circular recess 21 of the base plate 2 is covered with the upper cover case 3, and the flat space defined by the bottom surface of the upper cover case 3 and the upper surface of the circular recess 21 becomes a storage space for the magnetic disk medium 10. , Magnetic disk media 1
0 is stored rotatably. 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 loaded in the drive device, the tip of the shutter opening / closing lever is inserted into the slit 18 at the front end, engages with the notch 57 at the end of the shutter member 5, and moves it in the opening direction. I do. The drive unit has a magnetic head at the back, and a drive unit is provided at the bottom so as to be able to move up and down, and the spindle is locked by the rotation drive hub 11 of the magnetic disk medium 10 of the inserted magnetic disk cartridge 1. It is configured to be driven to rotate.

According to the embodiment, the cartridge case C includes the base plate 2 and the cover cases 3 and 4 attached to the base plate 2, and the base plate 2 has the circular recess 21 having a planar shape. Since the magnetic disk medium 10 is rotatably accommodated in the space defined by the circular concave portion 21 and the cover case 3, necessary components such as the shutter member 5 and the like are provided on the base plate 2 together with the magnetic disk medium 10. By attaching the cover cases 3 and 4 to the base plate 2, the strength of the cartridge case C in the compression direction and the bending direction can be improved while defining a medium accommodation space. In particular, cover cases 3 and 4
Is made of a high-strength material such as a metal plate, the strength required as a flat case can be secured in combination with the base plate 2, and even if it is thin, there is no deformation such as warpage, and dimensional accuracy can be maintained. 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 miniaturization of the shutter member 5, and is resistant to impacts such as dropping. It becomes stronger and the assemblability becomes better.

Further, as shown in FIG. 4, guide claws 56 of the shutter member 5 are provided on the back surface of the base plate 2.
A guide groove 29 is formed along the front edge of the base plate 2 to guide the opening and closing operation of the shutter member 5 by engaging
The base plate 2 has a guide groove 29 from its front edge.
A pair of notches 28, 28 communicating with the guide claws 56,
The guide pawls 56 and 56 are engaged with the guide grooves 27 without opening the upper and lower plate portions 51 and 52 when the shutter member 5 is attached to the base plate 2 by being formed corresponding to the guide members 56. Since the shutter member 5 can be mounted on the base plate 2, no load is applied to the connecting portion 53 of the shutter member 5 and no deformation occurs in the shutter member 5, so that the opening and closing operation of the shutter member 5 is stabilized. .

Further, as shown in FIG. 5, a notch portion 57 is formed at one end of the connecting portion 53 of the shutter member 5 so as to engage with the tip of the shutter opening / closing lever of the drive device. 5 upper and lower plate portions 5
Although the distance between the shutter levers 1 and 52 is extremely small, the tip of the shutter opening / closing lever can be securely engaged with the end of the connecting portion 53, so that the shutter member 5 can be reliably opened and closed. Can be.

As shown in FIG. 6, the tips of the upper and lower plate portions 51 and 52 of the shutter member 5 (the portions opposite to the connecting portion 53) are parallel to the lines L ₁ and L parallel to the connecting portion 53. ₂ are formed so as to form an angle θ by being opened from each other, and these opened portions are formed by attaching the upper and lower cover cases 3 and 4 to the base plate 2 when assembling the magnetic disk cartridge. Case 3,
When the shutter member 5 is configured to be substantially parallel by being pressed against the inner surface of the shutter member 5, the upper and lower plate portions 51, 52 of the shutter member 5 are provided on the inner surfaces of the upper and lower cover cases 3, 4. Of the upper and lower cover cases 3 and 4 and the outer surfaces of the upper and lower plate portions 51 and 52 of the shutter member 5 to increase sliding resistance or wear metal powder. Is prevented from occurring.

[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;

FIG. 4 is an exploded perspective view of a base plate, a shutter member attached to the base plate, and a rear surface side.

FIG. 5 is an enlarged perspective view of a shutter member.

FIG. 6 is an enlarged perspective view showing another embodiment of the shutter member.

[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 12 Protective sheet 13 Cleaning member 19 Spring insertion opening 21 Circular recess 23 Spring storage part 25 Corner part 28 Notch part 29 Guide groove 35 Depression of upper cover case 51 Upper plate part of shutter member 52 Upper plate part of shutter member 53 Connecting part of shutter member 54 Shutter window part 56 Guide claw of shutter member 57 Notch of shutter member

Claims (4)

[Claims] 1. A disk-shaped magnetic disk medium is rotatably accommodated in a flat cartridge case having a magnetic head insertion window, and an open position for opening the window and a closed position for closing the window. A magnetic disk cartridge including a shutter member slidably mounted between the case and the case, wherein the cartridge case includes a base plate, and a pair of upper and lower cover cases attached to the base plate, The base plate has a concave portion on its surface, and the magnetic disk medium is rotatably housed in a space defined by the concave portion and the pair of upper and lower cover cases. The shutter member has an upper plate portion and a lower plate member. A face plate portion and a connecting portion that connects the upper and lower surface plate portions on one side are formed to have a substantially U-shaped cross section, and the inside of the cover case is formed. Magnetic disk cartridge characterized in that it is housed in. 2. A pair of guide claws projecting from at least one inner wall surface of the upper and lower plate portions of the shutter member,
A guide groove for guiding the opening and closing operation of the shutter member by engaging with the guide claw on the base plate; and a pair of guides from a front edge of the base plate to the guide groove when the shutter member is attached to the base plate. 2. The magnetic disk cartridge according to claim 1, wherein a pair of notches are formed to allow the pawl to pass therethrough. 3. The magnetic disk cartridge according to claim 1, wherein a notch portion is formed at one end of the connecting portion of the shutter member so as to be engaged with a shutter opening / closing member of the drive device. 4. A portion of the upper and lower plate portions of the shutter member opposite to the connecting portion side is bent in a direction to open each other, and the opened portion is formed by the upper and lower cover cases when assembling the magnetic disk cartridge. 2. The magnetic disk cartridge according to claim 1, wherein the magnetic disk cartridge is configured to be mounted on a base plate so as to be pressed by an inner surface of the cover case so as to be substantially parallel.