JP2000132939A - Disk cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk cartridge that can control the floating of a disk for preventing dust and dirt from being generated when the disk is to be carried or transported, and can sweep the dust and dirt being included into the case for adhering to the disk and damp the disk down while the disk is being rotated, and can ideally apply to a film-surface input system. SOLUTION: In an upper-side shell 2, a spindle motor access window 2A and a head access window 2B are provided. On the other hand, in a lower-side shell 3, the head access window is provided. Also, on the internal surface of the lower-side shell 3, a permanent magnet 6A that can attract a hub 5 of a disk 4, and an annular projection 6B that loosely supports the hub 5 for retaining at a fixed position are provided as a retention means 6. The attraction force of the permanent magnet 6A for the hub 5 is set weaker than that for the hub 5 of the spindle motor of a disk drive device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk cartridge, and more particularly to a disk cartridge which can prevent the generation of dust in a case by restricting the movement of the disk when carrying or carrying the disk cartridge. The present invention relates to a disk cartridge capable of exhibiting a function of wiping out dust adhering to a disk by being mixed into a case and a function of damping the disk, which is preferably applicable to a film surface input method.

[0002]

2. Description of the Related Art Generally, a disk cartridge is formed by rotatably storing a disk as an information recording medium in a case having a shell structure provided with a spindle motor access window opened and closed by a shutter and a head access window. As disks in this type of disk cartridge, in addition to magnetic disks, optical disks with large recording capacities, magneto-optical disks, and the like have become widespread.

On the other hand, as an information recording / reproducing method when the above-mentioned optical disk or magneto-optical disk is loaded into a disk drive and used, generally, a substrate surface on which an optical head is arranged on the side opposite to the recording / reproducing surface of the disk is used. The method is adopted. In this substrate surface incidence system, an objective lens movable in the focal axis direction is provided on the optical head so that light emitted from the optical head passes through the transparent disk substrate and focuses on the opposite recording / reproducing surface. Can be The distance between the optical head and the disk surface is usually set to about 1 mm to several mm.

[0004] However, in the above-mentioned substrate surface incidence method, the aberration of the light spot irradiated from the optical head increases due to the thickness error of the disk substrate and the inclination error of the disk substrate with respect to the optical head. As a result, the number cannot be increased, and as a result, there is a limit to an increase in recording capacity and an increase in access speed.

Therefore, as an information recording / reproducing method capable of increasing the recording capacity and increasing the access speed,
There has been proposed a film surface incidence system in which an optical head is arranged on the recording / reproducing surface side of a disk. In this film surface input method,
In order to increase the numerical aperture of the objective lens and reduce the light spot, the distance between the optical head and the surface of the optical disk is usually set to 3 μm or less.

[0006]

By the way, in the film surface input system in which the distance between the optical head and the disk surface is set to about 3 .mu.m, only 1 .mu.m
It has been confirmed that even when minute dust particles are adhered, the dust causes an error when reading and writing data by the optical head. Also, when a large external vibration is applied to the disk drive device and the optical disk is caused to run out, the relative position of the optical head to the track of the optical disk changes. In particular, when the frequency of the external vibration is substantially equal to the natural frequency of the optical disk and the optical disk undergoes surface deflection due to resonance, an error occurs because the relative position greatly fluctuates. In an extreme case, there is a possibility that the optical disk collides with the optical head and both are damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to prevent the generation of dust in a case by restricting the movement of a disk when carrying or carrying the disk.
Further, the present invention provides a disk cartridge which can exhibit a function of wiping dust adhering to the disk by being mixed into the case during rotation of the disk and a function of damping the disk, and which can be suitably applied to a film surface input method. Is to do.

In order to achieve the above object, a disk cartridge according to the present invention rotates a disk as an information recording medium in a case of a shell structure provided with a spindle motor access window opened and closed by a shutter and a head access window. A disk cartridge freely housed, wherein the spindle motor access window is provided only on one shell constituting the case, and a permanent magnet capable of adsorbing a hub of the disk is provided on an inner surface of the other shell. Wherein the attraction force of the permanent magnet to the hub is set to be weaker than the attraction force of the spindle motor of the disk drive device to the hub.

When the disk cartridge of the present invention is carried or transported, the permanent magnet of the holding means provided on the inner surface of the shell attracts the hub of the disk, thereby restricting the floating of the disk and allowing the disk and the case to move. To prevent frictional contact. Further, the permanent magnet of the holding means allows the hub to be attracted to the spindle motor and driven to rotate when the disk cartridge is loaded in the disk drive device.

In the disk cartridge of the present invention,
As a preferred mode for reliably restricting the movement of the disk during carrying or transportation, the holding means is provided with an annular projection for loosely fitting a hub attracted to a permanent magnet. In this disk cartridge, the annular projection loosely fits the hub of the disk and the permanent magnet attracts the hub, thereby holding the disk in place.

In a preferred embodiment of the disk cartridge of the present invention, a function of wiping dust adhered to the disk and a function of damping the disk during rotation of the disk is provided. A plurality of radial ribs extending from the corresponding position toward the outer peripheral side corresponding position are arranged, and annular ribs surrounding the outer periphery of the disk are formed with a predetermined gap between the outer ends of the radial ribs, and Each radial rib has a function of generating an airflow directed radially outward with the rotation of the disk and suppressing the surface runout of the disk.

In the above-mentioned disk cartridge, as the disk rotates, the pressure at the outer end of each radial rib becomes lower than that at the inner end in accordance with the peripheral speed difference between the inner peripheral side and the outer peripheral side. As a result, each radial rib generates an airflow flowing radially outward of the disk, and the airflow wipes off dust adhering to the surface of the disk. An annular rib surrounding the outer periphery of the disk guides the air flow to the head access window side, so that the wiped dust is smoothly discharged to the outside from the head access window. The radial ribs oppose the disk surface, thereby suppressing the disk runout.

In the disk cartridge of the present invention,
As a preferred mode for smoothly flowing the air flow generated by the rotation of the disk, each of the radial ribs is formed in an arc shape curved in the rotational direction of the disk with respect to the radial direction.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A disk cartridge according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view showing the entire structure of a disk cartridge according to a first embodiment of the present invention. FIG. 2 is a partial sectional view showing the structure of the disk of the disk cartridge. FIG. 3 is a cross-sectional view showing the operation of the disc cartridge when carrying. FIG. 4 is a sectional view showing the operation of the disk cartridge loaded in the disk drive. FIG. 5 is an exploded perspective view showing the entire structure of the disk cartridge according to the second embodiment of the present invention. FIG. 6 is a plan view showing the inner surface of the upper shell of the disk cartridge.

First, a disk cartridge according to a first embodiment of the present invention will be described. As shown in FIG. 1, the disk cartridge of the present invention has a shell-structured case provided with a spindle motor access window (2A) opened and closed by a shutter (1) and head access windows (2B) and (3B). , A disk cartridge as an information recording medium is rotatably accommodated in a case composed of an upper shell (2) and a lower shell (3). The spindle motor access window (2A)
Is provided only on one shell constituting the case, for example, only the upper shell (2). A holding means (6) having a permanent magnet (6A) capable of attracting the hub (5) of the disk (4) is provided on the inner surface of the lower shell (3), which is the other shell. Then, the attraction force of the permanent magnet (6A) to the hub (5) is set to be weaker than the attraction force to the hub (5) of the spindle motor (9) of the disk drive device shown in FIG.

As shown in FIG. 1, the shutter (1) is formed in a substantially U-shaped cross-sectional shape sandwiching a case composed of an upper shell (2) and a lower shell (3). A slider (7) slidably engaged along the side edge of the case is fixed. This slider (7)
Usually, it is injection-molded with a synthetic resin such as Teflon or Delrin having excellent sliding characteristics and wear resistance. Such a slider (7) is urged in one direction by a torsion coil spring (8) installed inside the case, and accordingly, the shutter (1) opens the spindle motor access window (2A) and the head access window. The windows (2B) and (3B) are urged in the closing direction.

On the inner surface of the lower shell (3), an annular rib (3C) surrounding the outer periphery of the disk (4) is formed. On the other hand, a similar annular rib (not shown) joined to the annular rib (3C) is formed on the inner surface of the upper shell (2). The upper shell (2) and the lower shell (3) are integrally formed by injection molding of a synthetic resin, and are vertically joined by screwing or high-frequency welding.

As the synthetic resin, a polycarbonate resin, an ABS resin, a polypropylene resin or the like is used. Among them, polycarbonate resin is preferable because of its high wear resistance. The upper shell (2) and the lower shell (3) made of the synthetic resin are preferably subjected to an appropriate antistatic treatment in order to prevent adhesion of fine dust particles due to generation of static electricity. For example, if the surface resistivity is 1
The ^{0 8 Ω / □ ~10 13 Ω} / □ degree of conductivity imparting.

The spindle motor access window (2A)
And the head access window (2B) are formed continuously. The spindle motor access window (2A) is a substantially circular window for receiving the spindle motor (9) (see FIG. 4) of the disk drive device into which the disk cartridge of the present invention is loaded, and is provided at the center of the disk (4). It is formed at a position where the mounted hub (5) faces. The head access windows (2B) and (3B) are band-shaped windows for receiving a laser head and a magnetic coil (not shown) of the disk drive device, and are formed along the radial direction of the disk (4).

The disk (4) is, as shown in FIG.
This is a disk having a diameter of 130 mm in which two optical disks (4A) and (4B) having a center hole and having a thickness of 1.2 mm are bonded together and the hub (5) is bonded to the center of the outer surface. The recording / reproducing surfaces of the optical disks (4A) and (4B) are formed on their outer surfaces. The recording / reproducing surface is formed by forming a recording film on one surface of a transparent resin substrate. Examples of the resin constituting the transparent resin substrate include a polycarbonate resin, a polyethylene resin, a polyolefin resin, a norbornene resin, and a polymethyl methacrylate resin. For example, a polycarbonate resin is preferably used.

The surface of the disk (4) is preferably subjected to an appropriate antistatic treatment. For example, conductivity having a surface resistivity of about 10 ⁸ Ω / □ to 10 ¹³ Ω / □ is provided.
As a result, dust particles hardly adhere to the surface of the disk (4), and even if minute dust particles adhere, they can be easily wiped off.

The hub (5) has a center hole (5A) for positioning with the spindle motor (9) (see FIG. 4) of the disk drive. A suction disk (5B) made of magnetic metal that is attracted to the electromagnet on the spindle motor side is embedded in the hub (5). When the hub (5) is attracted to the spindle motor (9) and driven to rotate, the disk (4) is driven to rotate clockwise as indicated by an arrow in FIG.

In the disk cartridge of the present invention,
As shown in FIGS. 1 and 3, the holding means (6) is provided with an annular projection (6B) for loosely fitting the hub (5) attracted to the permanent magnet (6A). This annular projection (6B)
Is formed integrally at the center of the inner surface of the lower shell (3), and the permanent magnet (6A) is arranged inside the lower shell (3). The permanent magnet (6A) is formed in a disk shape, and is fixed to the lower shell (3) by bonding or thickening the annular projection (6B).

The annular projection (6B) is provided on the disk (4).
The hub (5) is formed to have an inner diameter and a protruding height at which the hub (5) can be loosely fitted and positioned, and protrudes higher than the upper surface of the permanent magnet (6A). The attraction of the permanent magnet (6A) to the hub (5) is such that the disk (4) can be prevented from floating when the disk cartridge is carried or transported, and the spindle motor (9) of the disk drive device. Is set to be much weaker than the suction force on the hub (5).

When the disk cartridge of the present invention is not loaded in a disk drive (not shown), as shown in FIG. 3, the annular projection (6B) of the holding means (6) has the hub of the disk (4). (5) is loosely fitted, and the permanent magnet (6A) attracts the hub (5). Therefore, the disk (4) is held at a fixed position without floating in the case. For this reason, when carrying or carrying the disc, it is possible to prevent the disc (4) from being in frictional contact with the upper shell (2) or the lower shell (3), and as a result, to prevent minute dust from being generated in the case. I can do it.

When the disk cartridge of the present invention is loaded into a disk drive (not shown), the shutter (1) opens the spindle motor access window (2A) and the head access windows (2B) and (3B). Thereafter, the spindle motor (9) on the disk drive unit attracts the hub (5) facing the spindle motor access window (2A) against the attraction force of the permanent magnet (6A) (see FIG. 4). Then, the spindle motor (9) moves the disk (4) clockwise as indicated by an arrow in FIG.
It is driven at a rotational speed of 0, 5400 or 7200 rpm. The laser head and the like (not shown) of the disk drive device are provided with upper and lower head access windows (2B),
Data recording / reproducing is performed on the recording / reproducing surfaces of the optical disks (4A) and (4B) through (3B).

In recording and reproducing data, the laser head and the like are brought close to the recording and reproducing surfaces of the optical discs (4A) and (4B) with a gap of about 3 μm. In order to prevent this, a combination of a coarse movement by a cam provided on the laser head and a fine movement by a voice coil motor provided on the laser head makes the operation extremely precise.

Next, a disk cartridge according to a second embodiment of the present invention will be described. This disk cartridge is configured substantially the same as the disk cartridge shown in FIG. 1. In the following description, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the disk cartridge of the present invention, as shown in FIG. 5, only the upper shell (2) has a spindle motor access window (2A) and a head access window (2A).
B) is formed, and is different from the first embodiment in that it is not formed on the lower shell (3). Correspondingly, the disc (4) has a single optical disc (4A) in which a recording film is formed only on the surface on the upper shell (2) side, and hubs (5) are provided at the center of both sides. Each is glued.

As shown in FIGS. 5 and 6, on the inner surfaces of the upper shell (2) and the lower shell (3) facing the disk (4), a position corresponding to the inner peripheral side of the disk (4) is provided. Radial ribs (2
D) and (3D) are arranged in plurality. These radial ribs (2D) and (3D) have a function of generating an airflow directed radially outward with the rotation of the disk (4) and suppressing the surface deflection of the disk (4).

The radial ribs (2) of the upper shell (2)
D) is a head access window (2B) between the spindle motor access window (2A) and the annular rib (2C).
Are formed in a region excluding the opening portion of the disk (4), and four are arranged at 90 ° angular intervals in the circumferential direction of the disk (4). Further, the radial ribs (3D) of the lower shell (3) are formed in a region between the annular projection (6A) and the annular rib (3C).
Similarly, four are arranged at 90 ° angular intervals.

The protruding height of each of the radial ribs (2D) and (3D) is 0.1 to 2 between the opposing surface and the recording / reproducing surface of the disk (4) in the rotating state of the disk (4).
The height is set so that a gap of mm is formed.
The planar shape of each radial rib (2D), (3D) is
It is formed in a belt-like arc shape that curves in the rotational direction of the disk (4) with respect to the radial direction. This arc shape is
An arc, a cycloid curve, an involute curve, a parabolic spiral curve, and the like can be appropriately combined.

The annular ribs (2C) and (3C) are 0.5 to 5 mm apart from the outer ends of the radial ribs (2D) and (3D).
They are formed with a predetermined gap of about mm. The heights of the annular ribs (2C) and (3C) are the same as the heights of the ribs forming the joint surface between the upper shell (2) and the lower shell (3), and the upper shell (2) and the lower shell In the joined state of the shell (3), it completely surrounds the periphery of the disk (4).

In the disk cartridge of the present invention, the annular projection (6B) of the holding means (6) loosely fits the hub (5) of the disk (4), and the permanent magnet (6A) attracts the hub (5). Therefore, when carrying or carrying, it is possible to prevent minute dust from being generated in the case as described above.

When the disk cartridge of the present invention is loaded into a disk drive (not shown), the shutter (1) opens the spindle motor access window (2A) and the head access window (2B). Thereafter, the spindle motor (9) on the disk drive device side moves the hub (5) facing the spindle motor access window (2A) to the permanent magnet (6).
The disc (4) is attracted against the attracting force of A) (see FIG. 4), and the disc (4) is rotated clockwise as shown by an arrow in FIG.
It is driven at a rotational speed of 0, 5400 or 7200 rpm. At this time, data is recorded on the optical disk (4A) by a laser head or the like (not shown) of the disk drive device facing the recording / reproducing surface of the optical disk (4A) at an interval of about 3 μm through the head access window (2B). Playback is performed.

In the disk cartridge of the present invention, a plurality of arc-shaped radially curved curved portions in the rotational direction of the disk (4) are provided on the inner surfaces of the upper shell (2) and the lower shell (3) facing the disk (4). Rib (2D), (3D)
Are formed respectively. Therefore, the disk (4)
Rotates, for example, in the gap between the upper shell (2) and the disk (4), the air pressure on the outer end side of each radial rib (2D) varies according to the peripheral speed difference between the inner peripheral side and the outer peripheral side. Lower than the inner end. As a result, each radial rib (2D)
A high velocity air flow radially outward of the disk (4) is generated between the disk (4) and the inner surface of the upper shell (2). Similarly, each radial rib (3) of the lower shell (3)
D) produces a high velocity airflow radially outward of the disk (4) between the disk (4) and the inner surface of the lower shell (3).

The high-speed airflow generated between the disk (4) and the upper shell (2) and the lower shell (3) reduces the dust adhering to the surface of the disk (4) to minute dust of about 1 μm. Wipe off the particles. The high-speed air flow is guided toward the head access window (2B) by the annular ribs (2C) and (3C), so that the wiped dust is smoothly discharged from the head access window (2B) to the outside of the case. I do.

In the disc cartridge of the present invention, the radial ribs (2D) and (3D) have an air flow layer of 0.1 to 2 mm between the projection height of the radial ribs and the surface of the disc (4). Because it is set to the height that forms
Each of the radial ribs (2D) and (3D) suppresses the runout of the disk (4). Therefore, according to the disk cartridge of the present invention, the magnitude of the vibration amplitude generated at the time of resonance of the disk (4) when a large external vibration is applied to the disk drive device (not shown) can be suppressed. For example, when the disk (4) is driven at a rotation speed of 4500 rpm,
When an external vibration of about 0.5 G is applied, the amplitude due to the vibration of the outer peripheral portion of the disk (4) can be suppressed to 100 μm or less.

That is, according to the disk cartridge of the present invention, it is possible to obtain a dust wiping function and a disk damping function during the rotation of the disk (4). As a result, even when a head (not shown) on the disk drive device side is arranged close to the recording / reproducing surface of the optical disk (4A) on the micron order, occurrence of a data error is prevented, and the disk (4) and the head (Not shown) can be prevented.

In the disk cartridge of the present invention,
The permanent magnet constituting the holding means is not limited to a disk shape but may have an appropriate planar shape. Further, the material of the permanent magnet may be a so-called plastic magnet in which magnetic powder is mixed into a resin, and in this case, the permanent magnet may be constituted by a coating layer of the plastic magnet.

The disk cartridge of the present invention is not limited to the above-described nominally 5-inch cartridge, but is also applicable to a nominally 3.5-inch cartridge. Further, the disk (4) is an optical disk (4A), (4B)
The present invention is not limited to this, and may be a magnetic disk or a magneto-optical disk.

[0042]

As described above, according to the disk cartridge of the present invention, when carrying or carrying the disk cartridge, the permanent magnet of the holding means provided on the inner surface of the shell attracts the hub of the disk. Accordingly, the play of the disk is restricted to prevent frictional contact between the disk and the case. Therefore, generation of dust inside the case due to frictional contact between the disc and the case can be prevented. When the disk cartridge is loaded in the disk drive, the permanent magnet permits the hub to be attracted to the spindle motor of the disk drive and the disk to be driven to rotate. That is, according to the disk cartridge of the present invention, it is possible to prevent the occurrence of an error due to dust particles even in a film surface input method in which the head of the disk drive device is arranged close to the disk on the order of microns.

In the disk cartridge of the present invention,
On the inner surface of the case, a plurality of radial ribs extending from a position corresponding to the inner circumference of the disk to a position corresponding to the outer circumference are arranged,
When the annular ribs surrounding the outer periphery of the disk are formed with a predetermined gap between the outer ends of the radial ribs and the outer periphery of the disk, the peripheral speed of the inner and outer peripheral sides is increased with the rotation of the disk. According to the difference, the pressure at the outer end of each radial rib becomes lower than that at the inner end. As a result, each radial rib generates an airflow flowing radially outward of the disk, and the airflow wipes off dust adhering to the surface of the disk. An annular rib surrounding the outer periphery of the disk guides the air flow to the head access window side, so that the wiped dust is smoothly discharged to the outside from the head access window. Therefore,
The dust adhering to the surface of the disk is wiped off by the air flow, and the dust can be smoothly discharged to the outside from the head access window.

The radial ribs oppose the disk surface, thereby suppressing disk runout. Therefore, the magnitude of the amplitude of the vibration of the disk due to the external vibration can be suppressed. That is, according to the disk cartridge of the present invention, it is possible to exhibit a dust wiping function and a disk vibration control function during rotation of the disk,
Even in a film surface input method in which the head of the disk drive device side is arranged close to the disk on the order of microns, it is possible to prevent errors from occurring and damage to the disk and the head.

In the disk cartridge of the present invention,
When each of the radial ribs is formed in an arc shape curved in the rotation direction of the disk with respect to the radial direction, the generated air flow can be smoothly circulated, and the dust wiping function can be improved. I can do it.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing the entire structure of a disk cartridge according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view showing a structure of a disk of the disk cartridge.

FIG. 3 is a cross-sectional view showing the operation of the disc cartridge when the disc cartridge is carried.

FIG. 4 is a sectional view showing the operation of the disk cartridge loaded in the disk drive device.

FIG. 5 is an exploded perspective view showing the entire structure of a disk cartridge according to a second embodiment of the present invention.

FIG. 6 is a plan view showing the inner surface of the upper shell of the disk cartridge.

[Explanation of symbols]

 1: shutter 2: upper shell 2A: spindle motor access window 2B: head access window 2C: annular rib 2D: radial rib 3: lower shell 3B: head access window 3C: annular rib 3D: radial rib 4: disk 4A: optical disk 4B: Optical disk 5: Hub 5A: Center hole 5B: Suction disk 6: Holding means 6A: Permanent magnet 6B: Annular projection 7: Slider 8: Torsion coil spring 9: Spindle motor

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[Procedure amendment]

[Submission date] October 26, 1998 (1998.10.
26)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 5

[Correction method] Change

[Correction contents]

Claims (5)

[Claims] 1. A disk cartridge comprising a disk as an information recording medium rotatably housed in a shell-structured case provided with a spindle motor access window opened and closed by a shutter and a head access window, wherein the spindle is The motor access window is provided only on one shell constituting the case, and on the inner surface of the other shell, holding means having a permanent magnet capable of adsorbing the hub of the disk is provided. A disk cartridge, wherein a suction force to a hub is set to be weaker than a suction force to a hub of a spindle motor of a disk drive device. 2. The disk cartridge according to claim 1, wherein the holding means is provided with an annular projection for loosely fitting a hub attracted to the permanent magnet. 3. A plurality of radial ribs extending from a position corresponding to the inner peripheral side of the disk to a position corresponding to the outer peripheral side thereof are arranged on an inner surface of the case, and annular ribs surrounding the outer periphery of the disk are formed at outer ends of the respective radial ribs. The radial ribs have a function of generating a radially outward airflow along with the rotation of the disk and suppressing the surface runout of the disk. The disk cartridge according to claim 1 or 2, wherein 4. The disk cartridge according to claim 3, wherein each of the radial ribs is formed in an arc shape curved in a rotational direction of the disk with respect to a radial direction. 5. The gap between opposing surfaces of the disk and each radial rib is 0.1 to 2 mm when the disk is rotated.
The disk cartridge according to any one of claims 3 to 5, wherein