JPH1116317A - Disk cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent collision of a disk and the internal surface of a cartridge body without increase of thickness of the cartridge body by suppressing inclination of the disk within the cartridge body. SOLUTION: A projecting portion 8 being projected toward an upper half 7 of a cartridge body 2 is provided at the rotation center of a center hub 4 holding the center area of a disk 3 accommodated to rotate within a cartridge body 2. Simultaneously, a projecting portion 14 for pressing the disk 3 toward the lower half 7 of the cartridge body 2 is provided to a shutter member 5 having the rotation center at the position different from the rotation center of the center hub 4, in contact with the projecting portion 8 provided at the center hub 4 when the shutter member 5 closes an aperture for entry of magnetic head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk cartridge in which a disk-shaped recording medium is housed in a cartridge.

[0002]

2. Description of the Related Art Conventionally, disk-shaped recording media such as magnetic disks and optical disks (hereinafter simply referred to as disks).
There is known a disk cartridge which is not directly fixed to a spindle motor of a recording / reproducing device (hereinafter, referred to as a drive device) such as an information processing device, but is housed in a cartridge and made portable.

[0003] This disk cartridge 100 is similar to that shown in FIG.
As shown in FIG. 7, a disk 101 as a recording medium is housed in a cartridge body 102.

[0004] The disk 101 is formed in a disk shape having a center hole 101a, and a center hub 103 made of a magnetic material is attached to the center hole 101a. And
The disk 101 is rotatably accommodated in the cartridge main body 102 around the center of the center hub 103 as a center of rotation.

[0005] The cartridge body 102 includes an upper half 10
4 and a lower half 105. The disk 101 is accommodated in a space formed between the upper half 104 and the lower half 105 when they are combined. At the center of the lower half 105, a spindle motor insertion opening 106 for inserting the tip of the spindle motor of the drive device into the disk cartridge 100 when the disk cartridge 100 is mounted on the drive device. Is provided. The opening hole 106 for inserting the spindle motor is closed by the center hub 103 when the disk cartridge 100 is not mounted on the drive device.

The cartridge body 102 is provided with a magnetic head entry opening 107 for allowing the magnetic head device of the drive device to enter the disk cartridge 100 when the disk cartridge 100 is mounted in the drive device. ing.

The disk cartridge 100 is
A shutter member 108 for opening or closing the magnetic head entry opening 107 is provided. The shutter member 108 is, for example, an upper half 1 of the cartridge body 102.
04, and is urged by a spring member (not shown) in a direction to close the magnetic head entry opening 107.

When the disk cartridge 100 is mounted in the drive device, the shutter member 108 is rotated by a shutter rotation member provided in the drive device, and the magnetic head entry opening 107 is opened. Then, the magnetic head device of the drive device enters the disk cartridge 100 from the magnetic head entry opening 107.

Next, the spindle motor of the drive device is raised, and the tip is inserted into the disc cartridge 100 through the spindle motor insertion opening 106. Then, the center hub 103 is chucked by the spindle motor, and the disk 101 is lifted to be rotatably supported in the space between the upper half 104 and the lower half 105.

[0010]

By the way, the disk 1
As shown in FIG. 18, the cartridge body 1 is a cartridge body 1 so that the cartridge body 1 can rotate freely within the cartridge body 102.
02 without being fixed. The main surface of the disk 101 is located on the inner surface of the cartridge body 102.
They face each other via a predetermined gap t. The gap t between the main surface of the disk 101 and the inner surface of the cartridge main body 102 is sufficiently determined in consideration of a dimensional error during molding of the cartridge main body 102 and a variation in the height position at which the spindle motor chucks the center hub 103. Value is set to

Since the disk 101 is housed without being fixed in the cartridge body 102 such that the main surface thereof faces the inner surface of the cartridge body 102 with a predetermined gap t therebetween, the disk 101 during transportation is If an impact is received due to vibration, drop, or the like, the cartridge is tilted in the cartridge main body 102 as shown in FIG. And the disk 101
If the main surface is inclined in the cartridge body 102, the main surface may collide with the inner surface of the cartridge body 102 and be damaged. In addition, the disk 101 is
2 by contacting the inner surface of the cartridge body 102.
May be shaved, resulting in dust and the like.

The dust or the like generated as described above not only causes an error when the magnetic head of the drive device performs the writing or reading operation on the disk 101, but also causes the main surface of the disk 101 and the magnetic head It may cause damage.

To avoid such inconvenience, FIG.
As shown in FIG. 2, it is conceivable to increase the thickness of the cartridge main body 102 so that the disk 101 does not collide with the inner surface of the cartridge main body 102 even when the disc 101 is inclined in the cartridge main body 102.
Increasing the thickness of the device does not meet the recent demand for miniaturization of the device.

Accordingly, the present invention provides a disk cartridge which prevents the disk from colliding with the inner surface of the cartridge body without increasing the thickness of the cartridge body by suppressing the inclination of the disk in the cartridge body. Aim.

[0015]

In order to achieve the above-mentioned object, a disk cartridge according to the present invention has a center hub for holding a central portion of a disk-shaped recording medium rotatably housed in a cartridge body. At the center of rotation, a projection protruding toward the upper half side of the cartridge body is provided, and the shutter member closes an opening for magnetic head entry to a shutter member having a center of rotation at a position different from the center hub. At this time, a pressing protrusion for pressing the recording medium toward the lower half side of the cartridge body is provided in contact with the protrusion provided on the center hub.

When this disk cartridge is mounted on the drive device and the magnetic head entry opening is opened, the recording medium is made rotatable in the cartridge body. And this disk cartridge
When the shutter member is taken out of the drive device and the opening is closed by the rotation of the shutter member, the pressing protrusion provided on the shutter member comes into contact with the protrusion provided on the center of rotation of the center hub, and recording is performed. By pressing the medium toward the lower half of the disk cartridge main body, the inclination of the recording medium in the cartridge main body is suppressed.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in an overall perspective view in FIG. 1 and an exploded perspective view in FIG. 2, the disk cartridge 1 includes a cartridge main body 2 and a disk-shaped recording medium rotatably housed in the cartridge main body 2. Hereinafter, a disk 3), a center hub 4 provided at the center of the disk 3, and an opening 2a for rotatably attached to the cartridge main body 2 and provided in the cartridge main body 2 for entering a magnetic head. And a shutter member 5 for opening or closing the shutter.

The cartridge body 2 is formed by combining a pair of upper and lower halves 6 and 7 formed of, for example, synthetic resin as a material so as to have a substantially rectangular outer shape. The disk 3 is accommodated in the space formed.

The upper half 6 and the lower half 7 have notches 6a, 7a extending from one side surface to one side surface orthogonal thereto.
a are respectively formed in notches. These notches 6
a and 7a constitute a magnetic head entry opening 2a for allowing the magnetic head device of the drive device to enter the cartridge body 2 when the upper half 6 and the lower half 7 are combined. This magnetic head entry opening 2a is
When the disk cartridge 1 is not mounted on the drive device, it is closed by a shutter member 5 described in detail later.

The upper half 6 is provided with a mounting hole 6b for mounting the shutter member 5 to the cartridge body 2 at a position slightly deviated from the center thereof. The lower half 7 is provided at its center with an opening 7b for inserting a spindle motor for inserting the tip of the spindle motor of the drive device into the cartridge body 2.

The disk 3 housed in the cartridge body 2 is formed by depositing a magnetic film on a substrate made of, for example, a disk-shaped aluminum or the like. The disc 3 has a central hole 3a formed at the center thereof, which is concentric with the outer peripheral circle. A center hub 4 is attached to the center hole 3a. Here, as the disk 3,
Although an example using a magnetic disk in which a magnetic film is formed on a substrate such as aluminum is described, the present invention is not limited to this example. Alternatively, in addition to the magnetic disk, various disk-shaped recording media such as an optical disk and a magneto-optical disk may be used.

The center hub 4 is formed of a magnetic metal such as stainless steel so as to be magnetically chucked on a turntable of the drive device. As shown in FIG. 3, the center hub 4 has a disk-shaped pedestal 4a having an outer diameter slightly larger than the center hole 3a of the disk 3, and a surface facing the upper half 6 of the pedestal 4a. An annular projection 4b having an outer diameter substantially equal to the diameter of the center hole 3a of the disk 3 is formed at the center. The center hub 4 is attached to the disk 3 from the lower half 7 side so that the annular projecting portion 4b fits into the center hole 3a of the disk 3, and holds the disk 3.

The lower half 7 side of the pedestal 4a is provided with an opening hole 7 for inserting a spindle motor provided in the center of the lower half 7.
The diameter is substantially the same as the opening diameter of b. When the disc cartridge 1 is not mounted on the drive device, the opening hole 7b for inserting the spindle motor is closed by the center hub 4.

In the center of the lower half 7 of the pedestal 4a, a concave portion 4c into which the rotating shaft of the spindle motor is inserted is provided.
Are formed. On the other hand, a projection 8 protruding toward the upper half 6 is formed at the center of the surface facing the upper half 6 of the pedestal 4a.

The center hub 4 is housed in the cartridge main body 2 together with the disc 3 such that the concave portion 4c and the projection 8 are located substantially at the center of the cartridge main body.
The center hub 4 is magnetically chucked by a spindle motor of the drive device, and the spindle motor is driven to rotate, so that the center hub 4 rotates about the concave portion 4c and the protrusion 8 as a center of rotation. Then, as the center hub 4 rotates, the disk 3 held by the center hub 4 also rotates in the cartridge body 2.

The shutter member 5 for opening or closing the magnetic head entry opening 2a provided in the cartridge body 2 is formed by, for example, pressing a metal plate, and closing the upper half 6 side. One shutter plate 5a and a second shutter plate 5b for closing the lower half 7 side
And a connecting plate 5c for connecting the first shutter plate 5a and the second shutter plate 5b.

The first shutter plate 5a has a size sufficient to close the notch 6a formed in the upper half 6, and has one end when attached to the upper half 6. Is formed in a substantially sector shape so as to be located near the center of the. The first shutter plate 5a is provided at one end thereof with a through hole 10 through which a shaft of a mounting pin 9 for mounting the shutter member 5 to the upper half 6 is inserted. In the first shutter plate 5a, a concave portion 11 is provided around the periphery of the through hole 10, and a coil spring 12 is accommodated in the concave portion 11. Further, a locking piece 13 for locking one end of the coil spring 12 is cut and raised in the concave portion 11.

The coil spring 12 has one end locked by a locking piece 13 formed on the first shutter plate 5a and the other end locked by a locking portion (not shown) of the upper half 6. The shutter member 5 is disposed between the upper half 6 and the shutter member 5 to urge the shutter member 5 in a direction to close the magnetic head entry opening 2a.

The first shutter plate 5a has a position facing the projection 8 formed on the center hub 4 when the shutter member 5 rotates in a direction to close the magnetic head entry opening 2a. And the disk 3 in contact with the projection 8
Is pressed toward the lower half 7 side to protrude toward the lower half 7 side. This pressing projection 14
May be formed integrally with the first shutter plate 5a by press working or the like, or may be formed integrally with the first shutter plate 5a.
May be formed separately and attached to the first shutter plate 5a.

A connecting plate 5c is provided upright on the outer peripheral portion of the first shutter plate 5a, that is, an arc-shaped portion, perpendicularly to the first shutter plate 5a. The second shutter plate 5b is provided at a position facing the first shutter member 5a via the connecting plate 5c.

The second shutter plate 5b has a separation distance substantially the same as the inner diameter of the cartridge body 2 in the thickness direction.
It is provided in parallel with the first shutter plate 5a.
The second shutter plate 5b has a size sufficient to close the cutout 7a formed in the lower half 7, and is formed in a shape corresponding to the cutout shape of the cutout 7a.

When the disc cartridge 1 is inserted into the drive device, the shutter member 5
An engaging portion (not shown) that engages with a tip portion of a shutter opening member of the drive device is provided.

The shutter member 5 formed as described above
Is housed in the cartridge body 2 such that the disc 3 is disposed between the first shutter plate 5a and the second shutter plate 5b, and is attached to the upper half 6 of the cartridge body 2 by, for example, attachment pins 9. .

The mounting pin 9 is inserted into the cartridge main body 2 from a mounting hole 6b provided in the upper half 6. The mounting pin 9 passes through the coil portion of the coil spring 12 and the through hole 10 provided in the first shutter plate 5a, and passes through the second shutter hole of the first shutter plate 5a.
Is locked by the lock member 15 on the surface facing the shutter plate 5b.

The shutter member 5 is attached to the upper half 6 by the attachment pins 9 in this manner, so that the cartridge body 2
Is rotatable in a direction to open or close the magnetic head entry opening 2a provided in the head. The mounting pin 9 is provided so as to be inserted into a mounting portion 6 b formed at a position slightly deviated from the center of the upper half 6, that is, a center of rotation of the center hub 4. The center of rotation is a position shifted from the center of rotation of the center hub 4. The upper half 6 and the shutter member 5
By providing the coil spring 12 therebetween, the shutter member 5 is urged in a direction to close the magnetic head entry opening 2a.

The disk cartridge 1 configured as described above is used by being mounted on a drive device 20 as shown in FIG.

The drive device 20 includes a cartridge loading unit 21 for loading the disk cartridge 1 and a spindle motor 22 for rotating the disk 3 of the disk cartridge 1 loaded in the cartridge loading unit 21.
A rotating operation member 23 on which a magnetic head for recording / reproducing information on / from the disk 3 is mounted;
And a shutter opening member 25 for opening the magnetic head entry opening 2a of the disk cartridge 1.

In the drive device 1, when the disk cartridge 1 is inserted, the leading end of the shutter release member 25 engages with the engagement portion provided on the shutter member 5, and the shutter member 5 is rotated to operate the magnetic member. The head entry opening 2a is opened.

Then, the ramp 24 and one end of the rotating operation member 23 supported by the ramp 24 enter the disk cartridge 1 through the magnetic head entry opening 2a.

When the disc cartridge 1 is loaded at a predetermined position of the loading section 21, the spindle motor 22 moves upward to chuck the center hub 4. At the same time, the rotary operation member 23 rotates toward the inside of the disk cartridge 1, and the dimple plate 26 provided at one end of the rotary operation member 23 slides down from the ramp 24 to bring the flying slider 27 into contact with the disk 2.

Then, while the spindle motor 22 is rotated, the flying slider 27 is moved in the radial direction of the disk 2, and information is recorded / reproduced on / from the disk 3 by the magnetic head provided on the flying slider 27.

When the disk cartridge 1 is not mounted in the drive device 20, the shutter member 5 is urged by the coil spring 12 to open the magnetic head entry opening 2a, as shown in FIGS. Is closed. At this time, the pressing projection 14 provided on the shutter member 5 is connected to the projection 8 provided on the center hub 4.
, And presses the center hub 4 and the disc 2 held by the center hub 4 toward the lower half 7.

Center hub 4 pressed toward lower half 7
Is positioned with the pedestal 4a closing the spindle motor insertion opening 7b provided in the lower half 7, and rattling in the cartridge body 2 is prevented. The disc 2 is stably held in the cartridge body 2 by the center hub 4. 5 is a plan view schematically showing the disk cartridge 1 in which the magnetic head entry opening 2a is closed, FIG. 6 is a sectional view taken along the line AA in FIG. 5, and FIG. It is a B sectional view.

When the disk cartridge 1 is mounted on the drive device 20, the shutter member 5 is opened by the shutter opening member 25 of the drive device 20, and the magnetic head enters as shown in FIGS. 8, 9 and 10. Opening 2
a is in an open state. Then, the rotation operation member 23 enters from the magnetic head entry opening 2a.

When the shutter member 5 is opened, the position of the pressing projection 14 provided on the shutter member 5 and the position of the projection 8 of the center hub 4 are shifted. Both are disengaged. Then, the disk 3 held by the center hub 4 is rotatable in the cartridge body 2. FIG.
FIG. 9 is a plan view schematically showing the disk cartridge 1 with the magnetic head entry opening 2a opened, and FIG.
FIG. 10 is a sectional view taken along line AA in FIG.
It is a line sectional view.

As described above, when the disk cartridge 1 is not mounted on the drive device 20 and the shutter member 5 closes the magnetic head entry opening 2a, the pressing member provided on the shutter member 5 is closed. The center hub 4 is pressed toward the lower half 7 by the projection 14. By preventing rattling of the center hub 4 in the cartridge body 2, the inclination of the disk 3 held by the center hub 4 is suppressed.

Further, since the disk cartridge 1 is provided with the pressing projection 14 for pressing the center hub 4 integrally with the shutter member 5, it is not necessary to use another new member such as a cam member. And the inclination of the disc 3 can be suppressed without increasing the thickness of the cartridge body 2.

In the above description, the magnetic head entry opening 2 extends from one side of the cartridge body 2 to the other side.
a notch is formed, and the magnetic head entry opening 2 is formed.
Although the disk cartridge 1 has been described in which a is closed by the shutter member 5 having a substantially fan-shaped planar shape,
The shapes of the magnetic head entry opening and the shutter member are not limited to this example.
As shown in (1), a magnetic head entry opening 31 may be formed on one side surface of the cartridge body 2, and the magnetic head entry opening 31 may be closed by a sliding shutter member 32.

This disk cartridge 30 has the same configuration as the above-described disk cartridge 1 except for the magnetic head entry opening 31 and the shutter member 32. Therefore, the same reference numerals are used for the same configuration as the disk cartridge 1. Detailed description is omitted.

The magnetic head entry opening 31 is formed on one side surface of the cartridge body 2 as a rectangular opening. When the disk cartridge 30 is not mounted on the drive device, the magnetic head entry opening 31 is closed by the shutter member 32, and when the disk cartridge 30 is mounted on the drive device, the shutter member 32 rotates. To be released.

A slit is formed in the vicinity of the magnetic head entry opening 31. When the shutter member 32 rotates in a direction to open the magnetic head entry opening 31, a shutter member to be described later is formed. 32 shutters 34
The cartridge is pulled out of the cartridge body 2 through the slit.

The shutter member 32 is connected to the cartridge main body 2.
Operation plate 3 rotatably attached to upper half 6
3, a shutter 34 that can be elastically displaced, and a shutter operation piece 35 to which one end of the shutter 34 is attached at one end side and the other end side of which is supported by a rotation operation plate 33 so as to be movable in the radial direction of the disk 3. ing.

The rotation operation plate 33 extends from the vicinity of the center of the cartridge body 2 to the vicinity of the magnetic head entry opening 31, and the base end near the center of the cartridge body 2 rotates to the upper half 6. Mounted as possible. The rotating operation plate 33 movably supports the shutter operation piece 35 at the distal end near the magnetic head entry opening 31.

When the shutter member 32 is rotated in a direction to close the magnetic head entry opening 2a, the rotation operation plate 33 is located at a position facing the projection 8 provided on the center hub 4. A pressing projection 36 that comes into contact with the projection 8 and presses the disk 3 toward the lower half 7 is provided so as to project toward the lower half 7. The pressing protrusion 36 may be formed integrally with the turning operation plate 33 by press working or the like, or may be formed separately from the turning operation plate 33,
You may make it attach to the rotation operation plate 33.

As in the case of the disk cartridge 1 described above, the rotating operation plate 33 is provided with the magnetic head entry opening 31 by the coil spring 12 disposed between the rotating operation plate 33 and the upper half 6. Is urged in the direction to close. A concave portion 37 for accommodating the coil spring 12 is formed in the rotation operation plate 33.

Further, a through hole 38 through which the mounting pin 9 is inserted is formed in the rotation operation plate 33. The rotation operation plate 33 is attached to the mounting pin 9 inserted through the mounting hole 6 b of the upper half 6 into the cartridge body 2.
Is locked on the back surface of the rotary operation plate 33 by a lock member or the like (not shown) through a through hole 38 provided in the rotary operation plate 33, so that the mounting pin 9 is used as a rotation axis to the upper half 6. Mounted rotatable.

Since the mounting hole 6b is formed at a position slightly deviated from the center of the cartridge body 2 as described above, the mounting pin 9 inserted into the mounting hole 6b is used as a rotation axis. The positions of the rotation operation plate 33 and the center hub 4 and the disk 3 having a rotation shaft at the center of the cartridge body 2 are different.

The other end of the shutter operation piece 35 is attached to the tip side of the rotation operation plate 33 so as to be movable in the radial direction of the disk 3. And this shutter operation piece 3
A shutter 34 is attached to one end of the shutter 5.

The shutter 34 is made of a thin metal plate such as aluminum, and is formed in a rectangular shape slightly larger than the magnetic head entry opening 31. And this shutter 34
When the disk cartridge 30 is not mounted in the drive device, the disk cartridge 30 is overlapped on one side where the magnetic head entry opening 31 is formed from inside the cartridge main body 2 to close the magnetic head entry opening 31.

When the disk cartridge 30 configured as described above is not mounted on the drive device, the disk cartridge 30 shown in FIG.
As shown in FIG. 1, FIG. 12 and FIG.
Is urged by the coil spring 12 to close the magnetic head entry opening 31. At this time, the pressing projection 36 provided on the shutter member 32 comes into contact with the projection 8 provided on the center hub 4, and presses the center hub 4 and the disc 3 held thereon toward the lower half 7.

Center hub 4 pressed toward lower half 7
Is positioned with the pedestal 4a closing the spindle motor insertion opening 7b provided in the lower half 7, and rattling in the cartridge body 2 is prevented. The disc 3 is stably held in the cartridge body 2 by the center hub 4. 11 is a plan view schematically showing the disk cartridge 30 in which the magnetic head entry opening 31 is closed, FIG. 12 is a cross-sectional view taken along line AA in FIG. 11, and FIG. 13 is a magnetic head entry opening. FIG. 3 is a side view of the disk cartridge 30 as viewed from a portion 32 side.

When the disk cartridge 30 is mounted on the drive device, the shutter 34 is pulled by the shutter opening member of the drive device. And shutter 3
4 is drawn out of the cartridge body 2 from a slit formed near the magnetic head entry opening 31. Accordingly, the rotation operation plate 33 rotates, and the shutter operation plate 35 moves in the radial direction of the disk 3 to adjust the distance between the rotation operation plate 33 and the shutter 34.

Thus, the disk cartridge 3
0 indicates that the magnetic head entry opening 31 is opened as shown in FIGS. 14, 15 and 16. Then, the rotation operation member of the drive device enters from the magnetic head entry opening 31.

Further, the disk cartridge 30 is rotated in a direction in which the rotation operation plate 35 opens the magnetic head entry opening 31, so that the pressing projection 36 provided on the rotation operation plate 33. Is displaced from the position of the protruding portion 8 of the center hub 4, and the engagement between the two is released. Then, the disk 3 held by the center hub 4 is rotatable in the cartridge body 2. FIG. 14 is a plan view schematically showing the disk cartridge 30 with the magnetic head entry opening 31 opened, and FIG.
3, and FIG. 16 is a side view of the disk cartridge 30 as viewed from the magnetic head entry opening 32 side.

As described above, the disc cartridge 30 is similar to the disc cartridge 1 described above.
When the shutter member 32 is not mounted on the drive device and the magnetic head entry opening 31 is closed, the center hub 4 is pressed toward the lower half 7 by the pressing protrusion 36 provided on the shutter member 32. You. By preventing rattling of the center hub 4 in the cartridge body 2, the inclination of the disk 3 held by the center hub 4 is suppressed.

Further, this disk cartridge 30
By providing the pressing projection 36 for pressing the center hub 4 integrally with the shutter member 32, it is not necessary to use another new member such as a cam member, so that the configuration is simplified and the thickness of the cartridge body 2 is reduced. The collision between the disk 3 and the inner surface of the cartridge body 2 is suppressed without increasing the size of the cartridge 3.

[0068]

The disk cartridge according to the present invention has the following features.
When the shutter member rotates in a direction to close the magnetic head entry opening, the pressing member has a pressing protrusion that presses the center hub toward the lower half side by contacting the protrusion of the center hub. When the disc is not mounted on the apparatus, the inclination of the disc held by the center hub in the cartridge body is suppressed.

Further, since this disc cartridge has the pressing projections provided on the shutter member and the projections provided on the center hub, it is not necessary to use another new member such as a cam member. Easy and
Collision of the disc with the inner surface of the cartridge body can be avoided without increasing the thickness of the cartridge body.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing a disk cartridge of the present invention.

FIG. 2 is an exploded perspective view showing the disk cartridge.

FIG. 3 is a sectional view showing the disk cartridge.

FIG. 4 is a perspective view showing a drive device.

FIG. 5 is a plan view schematically showing the disk cartridge in a state in which a magnetic head entry opening is closed by a shutter member.

FIG. 6 is a sectional view taken along line AA in FIG.

FIG. 7 is a sectional view taken along line BB in FIG. 5;

FIG. 8 is a plan view schematically showing the disk cartridge in a state where the magnetic head entry opening is opened.

FIG. 9 is a sectional view taken along line AA in FIG.

FIG. 10 is a sectional view taken along the line BB in FIG. 8;

FIG. 11 is a plan view schematically showing another disk cartridge in a state in which a magnetic head entry opening is closed by a shutter member.

FIG. 12 is a sectional view taken along line AA in FIG. 11;

FIG. 13 is a side view showing the disk cartridge.

FIG. 14 is a plan view schematically showing another disk cartridge in which the magnetic head entry opening is opened.

15 is a sectional view taken along line AA in FIG.

FIG. 16 is a side view showing the same disk cartridge.

FIG. 17 is an exploded perspective view of a conventional disk cartridge.

FIG. 18 is a sectional view of a conventional disk cartridge.

FIG. 19 is a sectional view of the disk cartridge showing a state where the disk has collided with the inner surface of the cartridge main body.

FIG. 20 is a sectional view showing a disk cartridge in which the thickness of the cartridge body is increased.

[Explanation of symbols]

1, 30 disk cartridge, 2 cartridge body, 3 disk, 4 center hub, 5, 32 shutter member, 6 upper half, 7 lower half, 8 protrusion, 1
1,37 concave portion, 12 coil spring, 14,3
6 Pressing projection

Claims (3)

[Claims] 1. A recording medium comprising a disk-shaped recording medium, a center hub for holding a central portion of the recording medium, and an upper half and a lower half. The recording medium held by the center hub is rotatably accommodated. A cartridge body having an opening for entry of a magnetic head, a center of rotation at a position different from the center of rotation of the center hub, the cartridge body being rotatably supported by an upper half of the cartridge body, A shutter member that opens or closes a portion of the cartridge. A projection that projects toward the upper half of the cartridge body is provided at the center of rotation of the center hub, and the shutter member includes the shutter member. When closing the opening, it contacts the protrusion provided on the center hub and presses the recording medium toward the lower half of the cartridge body. Disk cartridge characterized in that the pressure projections are provided. 2. A spring member for urging the shutter member in a direction to close the opening is provided between the upper half of the cartridge body and the shutter member. Disk cartridge. 3. The disk cartridge according to claim 2, wherein said shutter member has a housing portion for housing said spring member.