JP2000156060A - Cartridge for information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a recording medium suitable for high density recording having a high rigidity regardless of a thin type by forming at least one of projected parts and recessed parts for adjusting the flow of air at the time of rotating the recording medium on the upper surface and the lower surface of the inner surface of a cartridge to be symmetrical respectively. SOLUTION: Band-like projected parts 185a, 185b radially extending from the center of a disk respectively are formed symmetrically to the disk 183 in the inner side surface of upper shells 181a, 181b of a cartridge 181. The width of the projected parts 185a, 185b is widened into a sector shape as the projected parts advance toward the outside in the radial direction. The flow of air generated toward the circumferential direction of the disk at the time of rotating the disk is guided in the radial direction by preparing such projected parts 185a, 185b in the inner surface of the cartridge, a pressure in the outer peripheral part of the disk is raised, and the surface position of the outer peripheral part of the disk specially having a large fluctuation is stabilized by uniformly applying the raised pressure from the upper and lower surfaces of the disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium cartridge suitable for storing a thin recording medium.

[0002]

2. Description of the Related Art As one approach for increasing the density of an optical recording medium such as a compact disk or a magneto-optical disk, the numerical aperture NA (Numerical Aperture) of an objective lens for focusing a laser beam on the optical recording medium is increased. There is a way. However, increasing the NA of the objective lens increases the aberration of the lens. For example, spherical aberration is the fourth power of NA, coma is the third power of NA, and astigmatism is N.
A is proportional to the square of A (see "Optical Disc Technology" supervised by Morio Onoe, Radio Engineering Co., pp. 61-63). Therefore, in a reproducing apparatus or a recording / reproducing apparatus for an optical recording medium, an objective lens having an NA of 0.5 to 0.55 has been generally used. On the other hand, it is known that the NA can be increased by reducing the thickness of the substrate of the optical recording medium (ISOM / ODS'93 of T. SUGAYA et al.).
Digest (see pages 164 to 165). As a method using a thin substrate, for example, a method in which two substrates having a thickness of 0.6 mm are laminated as one of the digital video disc standards has been proposed. However, when the currently most common magneto-optical recording method is used as the recording method for such an optical recording medium of the two-sheet bonding method, Japanese Unexamined Patent Publication No.
603 and the like, and the magnetic field modulation overwrite method practically used in MD and the like cannot be applied.
This hinders an increase in the effective transfer rate during recording. Also,
The productivity of the two-layer bonding substrate is low. For this reason,
A substrate for an optical recording medium of a single sheet type and having a small thickness is desired.

At present, the thickness of a substrate used for an optical disk is about 1.2 mm. However, when the thickness of the substrate is reduced to improve the recording density as described above, the rigidity of the substrate is reduced. For this reason, when a recording medium such as an optical disk is driven to rotate by a drive, particularly vertical vibration (surface vibration) occurs.
In addition, it becomes difficult to record and reproduce the recording medium in a stable state.

On the other hand, when recording or reproducing data on or from a magnetic disk, the magnetic head is positioned at a distance of several tens of nm from the magnetic disk. For this reason, it is necessary to minimize the runout during rotation of the magnetic disk. recent years,
Similar to optical disks, magnetic disks using plastic substrates with excellent mass productivity have been devised.However, such substrates have lower rigidity than metal substrates such as aluminum. Such a problem of surface vibration becomes more serious.

[0005]

As the substrates of optical recording media and magnetic recording media have become thinner, there has been an increasing demand for thinner cartridges for recording media. FIG. 17 shows a cross-sectional structure of a conventional magneto-optical disk cartridge. During recording or reproduction on the magneto-optical disk 103, the cartridge 10
A sufficient gap is secured between the inner wall of the cartridge 1 and the surface of the magneto-optical disk 103, and the magneto-optical disk 103 rotates without contact with the inner wall of the cartridge 101.
In order to produce a thin cartridge, it is necessary to make the gap between the inner wall of the cartridge and the disk substrate narrower.
However, as described above, when the thickness of the substrate is reduced, the substrate tends to be deformed due to a decrease in rigidity of the substrate and difficulty in molding, and the disk and the inner wall of the cartridge may come into contact with each other, making it impossible to perform steady rotation. . When contact between the disc and the inner wall of the cartridge occurs, the information recording area is damaged,
There is also a problem that normal recording and reproduction cannot be performed.

As described above, when a substrate of an optical recording medium or a magnetic recording medium using a plastic substrate is thinned, the substrate is deformed due to thermal stress during molding of the substrate and stress from a metal thin film formed thereon. However, when the medium is rotationally driven, surface runout is likely to occur. In order to ensure good recording / reproducing even when such a wobble occurs, the driving device is equipped with an automatic focus control mechanism for maintaining the optical head at a constant interval with respect to the information recording surface of the medium. ing. In such an automatic focusing mechanism, the position of the optical head is controlled so that the signal intensity of light reflected from the medium surface or the like becomes constant. However, such an automatic focusing mechanism has a corresponding limit. For example, if the surface vibration exceeds a certain range, errors in recording / reproducing extremely increase. Therefore, in order to normally operate the automatic focusing mechanism, it is necessary to rotationally drive the recording medium so that the information recording surface of the recording medium is located within a certain range with respect to the reference position of the driving device. .

A first object of the present invention is to provide a recording medium substrate suitable for high-density recording and a recording medium using the same, such as an optical recording medium and a magnetic recording medium, even though it is thin. To provide.

A second object of the present invention is to provide a reproducing apparatus and a recording / reproducing apparatus suitable for reproducing a thin recording medium.

A third object of the present invention is to provide a cartridge suitable for a thin recording medium having a function of holding a surface of a thin recording medium being rotated at a predetermined position.

[0010]

According to a first aspect of the present invention, in a disk-shaped substrate used for a recording medium, a portion corresponding to a recording area of the recording medium and a portion outside the recording area. A substrate for a recording medium is provided, wherein the thickness of the substrate is different from that of the portion corresponding to the region. In the recording medium substrate of the present invention, the substrate thickness of the portion corresponding to the recording region of the recording medium is made different from the substrate thickness of the portion corresponding to the region outside the recording region. Even if the substrate thickness in the region is as thin as, for example, 0.85 mm or less, the rigidity of the entire substrate can be maintained. In the substrate for a recording medium, a portion corresponding to a recording region of the recording medium, a portion corresponding to a region outside the recording region, and a portion corresponding to a region inside the recording region are mutually different in thickness of the substrate. Can be different.

According to a second aspect of the present invention, in a disk-shaped substrate used for a recording medium, a portion corresponding to a recording region of the recording medium is more than a portion corresponding to a region inside the recording region. Also, there is provided a recording medium substrate characterized in that the substrate has a large thickness. Similarly to the first embodiment, the recording medium substrate can maintain the rigidity of the entire substrate even if the substrate thickness in the recording area is reduced to 0.85 mm or less for higher density.

According to a third aspect of the present invention, in a disk-shaped substrate used for a recording medium, a reinforcing member having a Young's modulus higher than the Young's modulus of the substrate is fixed to at least a part of the substrate surface. A substrate for a recording medium is provided. In the present invention, the rigidity of the thin substrate for high-density recording can be maintained by providing the reinforcing member on the substrate. The reinforcing member can be fixed to a portion corresponding to a region other than the recording region on the inner peripheral portion or the outer peripheral portion of the substrate.

In the present invention, the first, second or third aspect of the present invention is provided.
A recording medium suitable for high-density recording manufactured using the substrate according to the aspect is provided. As the recording medium, an optical recording medium or a magnetic recording medium using a plastic substrate is suitable.

According to a fourth aspect of the present invention, there is provided a reproducing apparatus for an optical recording medium for irradiating a light beam to the optical recording medium and detecting a change in reflected light from the optical recording medium as a change in light amount. There is provided an optical recording medium reproducing apparatus, comprising: an air gap forming member that faces an optical recording medium and forms an air gap having the same width during rotation with respect to upper and lower surfaces of the optical recording medium. In the reproducing apparatus of the present invention, as shown in FIG. 6 described later, sliders 66a, 66b, 66c, 66d as opposing air gap forming members are provided near the recording / reproducing heads 65, 67 with the disk 61 interposed therebetween. The slider is arranged so as to form air gaps 68a, 68b, 68c, 68d of the same width between the upper surface and the lower surface (both are designed positions) of the disk (optical recording medium) 61. If the position of the disk surface deviates from the designed position when the disk 61 is rotated, the air gap 68
A lift is generated on the upper or lower surface of the disk so that the air pressure of the air gap 68a becomes equal to the air pressure of the air gap 68a. It is restrained at an intermediate position between them. As a result, vertical fluctuation of the disk surface position during recording and reproduction can be suppressed, recording and reproduction can be performed reliably, and the stability of the focus servo can be increased. Further, when recording on a magneto-optical disk, it is possible to reduce the variation in the recording magnetic field intensity.

In the reproducing apparatus for an optical recording medium according to the present invention,
It is preferable that the air gap forming member is a pair of sliders facing each other with the optical recording medium interposed therebetween, and the pair of slider members is fixed to the optical head and the magnetic head of the reproducing apparatus, respectively. Further, it is preferable that the air gap forming member is disposed on the optical recording medium such that the air gap is 0.5 mm or less. The playback apparatus of the present invention is not limited to a playback-only optical recording medium, for example, a playback apparatus for an optical disc, and a recording / playback apparatus having a recording function for a write-once or rewritable optical recording medium, for example, a magneto-optical disc. This is a concept that also includes

According to a fifth aspect of the present invention, there is provided a recording medium cartridge accommodating a disk-shaped recording medium having a substrate thickness of at most 0.85 mm in a signal recording area. A recording medium cartridge having support means for supporting upper and lower surfaces of an outer peripheral portion of a recording medium is provided. The cartridge of the present invention has a substrate thickness of 0.85 mm.
In order to stabilize the surface position of the recording medium by suppressing surface runout during rotation of the thin recording medium surface described below, a support means for supporting upper and lower surfaces of an outer peripheral portion of the recording medium is provided. As a support means,
The outer peripheral portion of the medium may be a roller member rotatable with the rotation of the recording medium or a sliding member that slides on the upper and lower surfaces of the outer peripheral portion of the rotating disk-shaped recording medium. It is preferable that the cartridge of the present invention further includes a dust collecting means for collecting dust and the like generated by contact between the roller-shaped member or the sliding member and the medium.

According to a sixth aspect of the present invention, in a recording medium cartridge containing a disk-shaped recording medium,
At least one of a convex portion and a concave portion for adjusting the flow of air when the recording medium is rotated is formed symmetrically on the upper surface and the lower surface of the inner surface of the cartridge, respectively, on the inner surface of the cartridge. A cartridge is provided. In the cartridge of the present invention, a convex portion or a concave portion for adjusting the flow of air when the recording medium rotates is formed symmetrically on the inner surface of the cartridge. This protrusion or recess is
The flow velocity of the air flow flowing in the space between the convex or concave portion and the surface of the recording medium is changed, and the change in the flow velocity causes a pressure fluctuation in the space. The signal recording surface of the recording medium is subjected to a force from above or below the disk such that the fluctuated air pressure is equal on the upper and lower surfaces of the disk, whereby the signal recording surface is maintained at a fixed position (position in the height direction). You. Particularly, in an optical recording / reproducing method in which a laser beam is condensed on a transparent substrate in a non-contact and remote manner, and recording / reproducing is performed on a recording medium, the autofocus function is performed in an effective range. The method of the present invention for holding the signal recording surface of the disk at a fixed position by the air flow is effective.
The distance between the projection and the inner surface of the cartridge is preferably 0.8 mm or less, more preferably 0.6 mm or less.

In the cartridge according to the present invention, it is preferable that at least one of the convex portion and the concave portion is formed radially from the center of the recording medium accommodated in the cartridge on the inner surface of the cartridge.

In the cartridge according to the present invention, a window is formed in the cartridge so that a signal recording or reproducing head can access the cartridge. Preferably, they are formed symmetrically on the lower surface. With such a structure, the air pressure between the convex portion formed on the upper surface inside the cartridge and the upper surface of the recording medium and the air pressure between the convex portion formed on the lower surface inside the cartridge and the lower surface of the recording medium become equal. As described above, the recording / reproducing area is positioned at an intermediate position between the two convex portions before recording / reproducing by the head.

According to a seventh aspect of the present invention, there is provided a recording medium cartridge accommodating a disc-shaped recording medium having a substrate thickness of at most 0.85 mm in a signal recording area. The distance between the lower surface of the recording medium and the inner lower surface of the cartridge is equal in the radial direction of the recording medium, and the distance between the upper surface of the recording medium and the inner upper surface of the cartridge, and the distance between the lower surface of the recording medium and the cartridge. There is provided a cartridge for a recording medium, wherein the interval between the inner lower surface is smaller on the outer peripheral side than on the inner peripheral side of the recording medium. The cartridge of the present invention, similarly to the cartridge of the sixth aspect, equally rectifies the flow of air above and below the recording medium during the rotation of the recording medium, and particularly adjusts the surface position of the outer peripheral portion of the recording medium to a fixed position. Can be held.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

First Embodiment In this embodiment, specific examples of an optical recording medium and a substrate for a magnetic recording medium and an optical recording medium and a magnetic recording medium using the same to achieve the first object of the present invention will be described. explain.

Embodiment 1-1 FIG. 1 is a schematic view of an optical disk according to the present invention. The outer and inner diameters of the optical disc 1 are 120 mm and 15 mm, respectively. The optical disc 1 has a portion where information is not recorded / reproduced, that is, the inner area 16 of the lead-in 2.
The substrate thickness of the (clamping area) and the outer region 12 of the lead-out 4 is 1.2 mm, and the substrate thickness of the lead-in 2 and the lead-out 4 and the program region 14 sandwiched therebetween is 0.6 mm. . A portion connecting the lead-in 2 to the inner region 16, that is, the inner region 16
Are inclined at about 20 ° so that a plastic substrate having good shape, optical properties and mechanical properties can be easily manufactured by injection molding. For the same reason, the portion connecting the lead-out 4 to the outer region 12, that is, the side wall portion of the outer region 16 is also inclined at about 20 °. This inclination angle is preferably 45 ° or less. As shown in FIG. 1, the optical recording medium of the present invention can cope with high-density recording by making the recording / reproducing area thin, and at least the thickness of the outer peripheral portion where recording / reproducing is not performed. The rigidity of the thin optical recording medium can be increased by making the thickness larger (or thinner) than the thickness of the area where recording and reproduction are performed. The optical disk shown in FIG. 1 is obtained by, for example, injection molding a polycarbonate resin into a mold as shown in FIG. 1 in a mold equipped with a stamper on which a pre-fort mat pattern is formed. Can be manufactured by sequentially laminating a metal reflection film and a protective layer.

FIG. 2A is a sectional view of a polycarbonate substrate 10 used for manufacturing the optical disc 1 of FIG. The cross-sectional view of FIG. 2A is exaggerated in order to clarify the positions of the inner region 16a and the outer region 12a and the thickness difference between these regions and the region 14a where recording and reproduction are performed.

FIGS. 2B to 2G show modified examples of the sectional structure of the optical recording medium substrate of the present invention. FIG. 2B shows that only the thickness of the outer region 12b is different from that of FIG.
And the case where the thickness is larger than the thickness of the recording / reproducing area 14b, where the thickness of the outer area 12b is 1.2 mm, and the thickness of the area 14b where the recording / reproducing is performed and the inner area 16b are 0.6 mm. FIG. 2C shows a case where the thickness of the inner region 16c is smaller than the thicknesses of the outer region 12c and the recording / reproducing region 14c.
mm, and the thickness of the area 14b where recording and reproduction are performed and the outer area 12b is 0.6 mm. FIG. 2D shows a case where the thickness of the outer region 12d is smaller than the thickness of the inner region 16d and the recording region 14d. The thickness of the outer region 12d is 0.3 mm. The thickness of 16d is 0.6 mm. FIG. 2E
The case where the thickness of the outer region 12e and the inner region 16e is smaller than the thickness of the recording / reproducing region 14e is shown.
e and the inner region 12e have a thickness of 0.3 mm, and the recording / reproducing region 14e has a thickness of 0.6 mm.

FIG. 2F shows the outer region 12f and the inner region 16
f and the thickness of the recording / reproducing area 14f are different from each other. The thickness of the outer area 12f is 1.2 mm, the thickness of the inner area 12f is 0.3 mm, and the thickness of the recording / reproducing area 14f is 0.6 mm. is there. FIG. 2G shows a case where the outer region 12g, the inner region 16g, and the recording / reproducing region 14g have different thicknesses, and the outer region 12g has a thickness of 0.3 mm.
The thickness of the inner area 12g is 1.2 mm, and the recording / reproducing area 14
g is 0.6 mm.

FIG. 2H shows a cross-sectional structure of a conventional optical disk, and shows a case where the disk has a uniform thickness of 1.2 mm. 2A to 2G, the inclination angle at the step between the respective regions is 20 ° as in FIGS. 1 and 2A.
The substrate having the cross-sectional structure shown in FIGS. 2A to 2G can be easily manufactured by injection-molding a resin such as polycarbonate using a mold having a shape corresponding to the cross-sectional structure. In addition, any of the upper surface and the lower surface of the substrate shown in FIGS. 2A to 2G may constitute a signal surface. In injection molding, a pit group of a preformat pattern is formed on a desired surface using a stamper. Can be formed.

Next, with respect to the substrate having the cross-sectional structure shown in FIGS. 2A, 2B, and 2C, the amount of surface runout during rotation on the drive was measured. The amount of surface run-out is measured by using an optical disk mechanical property measurement device (LM-1200 manufactured by Ono Sokki Co., Ltd.) to measure the fluctuation of the vertical position of the disk surface while the optical disk makes one rotation at a rotation speed of 1800 rpm (0 ° to 360 °). Examined. The results are shown in FIG. In the figure, curves A, B and C show the measurement results of the substrates shown in FIGS. A, 2B and 2C,
Curve P shows the result for the conventional substrate of FIG. 2H. FIG. 3 shows that the substrate of the present invention has a remarkably small surface runout.
The optical disc substrate according to the present invention shown in FIGS. 2A to 2G has a thickness of 0.6 mm in the recording / reproducing area, but has a different thickness in other areas. Compared with this, the rigidity of the substrate can be improved.
Therefore, the optical recording medium and the magnetic recording medium manufactured by using the recording medium substrate of the present invention can reduce the deformation of the substrate when the disk is rotated, thereby performing good recording and reproduction. In order to increase the rigidity of the substrate, in particular, FIG.
The structures shown in FIGS. 2B and 2G are preferred.

Embodiment 1-2 FIGS. 4A to 4H show another sectional structure of a recording medium substrate according to the present invention. 2A to 2G, the outer area 12, the recording / reproducing area 14, and the inner area 16 on the upper surface of the optical disc are shown.
The thickness was changed by adjusting the height of at least one of the areas. However, as shown in FIGS. 4A to 4H, the thickness of each area may be changed so that the upper surface and the lower surface of the optical disk are symmetrical. it can. Even when such a structure is employed, a predetermined level of rigidity of the thin substrate can be maintained as in the case of Example 1-1.

Embodiment 1-3 FIG. 5A shows another configuration example of a substrate for a recording medium of the present invention. This substrate 50 has a thickness of 0.6 mm and a diameter of 120 mm.
In the outer region 12 on the upper surface of the flat polycarbonate substrate for an optical disk, an annular rigid reinforcing member 5 concentric with the substrate 54 is provided.
2a is fixed by an adhesive or the like. Rigid reinforcing member 5
The thickness of 2a can be adjusted so that the total thickness of the disk at the portion where the rigid reinforcing member 52a is mounted is about 1.2 mm. It is preferable that the side wall on the inner side of the disk of the rigidity reinforcing member has an inclination of 45 ° or less similarly to the optical disk substrate of Example 1-1. As a material for the rigid reinforcing plate,
The same material as the substrate such as polycarbonate, aluminum, iron, aluminum oxide, silicon oxide, titanium oxide, silicon nitride, titanium nitride, silicon carbide and the like are suitable. In order to further increase the rigidity, it is preferable to use a material having a higher Young's modulus than the material of the substrate.

FIGS. 5B to 5G show modifications of the substrate shown in FIG. 5A. In FIG. 5B, an annular rigid reinforcing member 52 concentric with the substrate 54 is provided in the inner region 16 on the upper surface of the optical disk substrate 54.
b is fixed by an adhesive or the like. 5C, the outer region 12 and the inner region 1 on the upper surface of the optical disc substrate 54 are shown.
6, annular rigid reinforcing members 52c and 52c 'concentric with the substrate 54 are fixed to each other by an adhesive or the like. In FIG. 5D, an annular rigid reinforcing member 52 concentric with the substrate 54 is provided in the outer region 12 on the upper surface and the lower surface of the optical disk substrate 54.
d and 52d 'are respectively fixed by an adhesive or the like. In FIG. 5E, an annular rigid reinforcing member 52e concentric with the substrate 54 is fixed to the inner region 16 on the upper surface and the lower surface of the optical disk substrate 54 by an adhesive or the like. In FIG. 5F, annular rigid reinforcing members 52f and 52f ′ concentric with the substrate 54 are fixed to the outer region 12 and the inner region 16 on the upper surface and the lower surface of the optical disk substrate 54 with an adhesive or the like.

FIG. 5G shows an example of a substrate in which the outermost peripheral portion of the substrate shown in FIG. The vibration absorbing material can be made of, for example, a rubber material such as urethane, silicone resin, vinyl chloride, or butyl rubber, or an elastic member such as various polymer materials. The substrate structure shown in FIG. 5G is effective for a recording medium housed in a cartridge according to a third embodiment described later. Also, the vibration absorbing material is shown in FIGS.
By sticking in various shapes and arrangements to the rigid reinforcing member 52, the inner region 16, and the like used in each drawing of F, it is possible to cause vibration proof against various vibration modes. 2 and 4 can be selected as the shape of the substrate, and an optimum configuration can be obtained by combining the elastic modulus and the shape of the vibration absorbing material.

5B to 5G, the material of the reinforcing member 52 and the material and thickness of the substrate 54 are the same as those in FIG. 5A.

As shown in FIGS. 5A to 5G, the rigidity of the substrate 54 can be improved by fixing the rigidity reinforcing member 52 to an area other than the area where recording and reproduction are performed. Example 1 of the substrate shown in FIGS.
By the same method as that performed in -1, the amount of surface runout when the substrate was rotated was measured. As compared with a conventional flat substrate having a thickness of 0.6 mm, it was found that the substrates of FIGS. 5A to 5G have suppressed surface vibration. Accordingly, when an optical recording medium such as an optical disk or a magneto-optical recording medium manufactured from such a substrate is mounted on a drive and driven to rotate, the surface vibration of the disk surface can be reduced.

Using the substrates shown in Embodiments 1-1 to 1-3, various optical recording media can be manufactured by a method generally used according to the type of the optical recording medium. For example, in the case of an optical disk such as a CD, the optical disk can be manufactured by applying a reflective layer and a protective layer on the substrate manufactured in the embodiment. In the case of a magneto-optical disk, an enhancement layer, a recording layer,
It can be manufactured by laminating an intermediate layer, a metal layer, and the like in various orders by sputtering or the like.

In the embodiments 1-1 to 1-3, the optical disk and the optical disk substrate have been described as examples.
The present invention can also be applied to a magnetic disk using a plastic substrate. For example, JP-A-2-21801
It is particularly effective to apply the invention to a magnetic disk using an embossed plastic substrate as described in No. 0. The dimensions of the plastic substrate for the magnetic disk include, for example, an outer diameter of 95 mm, an inner diameter of 25 mm, and a thickness of 1.2.
mm. The substrate material is not particularly limited. For example, a material such as amorphous polyolefin can be used. By applying the present invention to a magnetic disk using a plastic substrate, it is possible to prevent surface runout that occurs when the magnetic disk rotates, and to ensure good recording and reproduction.

Second Embodiment In this embodiment, a specific example of a reproducing apparatus suitable for reproducing (or recording and reproducing) a thin recording medium for achieving the second object of the present invention will be described. The principle of a reproducing apparatus using the air gap forming member of the present invention will be described with reference to FIG. FIG. 6 is a diagram conceptually showing a portion near an optical head when the reproducing apparatus for an optical recording medium of the present invention is applied to a magneto-optical disk recording and reproducing apparatus. This magneto-optical disk recording / reproducing device, like a normal magneto-optical disk recording / reproducing device, has a magnetic head 65 and an optical head 6 on the upper and lower surfaces of the magneto-optical disk 61 during recording and reproduction, respectively.
7 is located. The optical head 67 has a built-in actuator 64 for autofocus, and the objective lens 62 can be moved toward or away from the surface of the magneto-optical disk 61 using the permanent magnets 63a and 63b.

The recording-medium reproducing apparatus of the present invention comprises two sets of magnetic heads 65 and optical heads 67, which are opposed to each other with the disk 61 interposed therebetween, with respect to the illustrated moving direction of the disk. Slider members 66a, 66b
And 66c, 66d. Slider member 6
6a, 66b and 66c, 66d are each formed by processing a rectangular parallelepiped member into a shape such that opposing corners have different inclinations or curvatures, as shown. By arranging the slider members 66a, 66b and 66c, 66d vertically symmetrically with respect to the magneto-optical disk 61 as shown in FIG.
Air gaps 68a, 68b, 68c, 6 at the same intervals between the upper and lower surfaces of the magneto-optical disk 6b, 66c, 66d and the upper and lower surfaces.
8d can be formed. Of the space sandwiched by the slider members 66a and 66b (slider members 66c and 66d), the disk inlet side (the space on the front side in the disk moving direction) has a wider interval than the disk outlet (the space on the rear side in the disk moving direction). Form an air gap.

When the magneto-optical disk 61 moves (rotates) at a high speed in the illustrated direction, the air flow in the tangential direction of the track of the magneto-optical disk 61 enters the air gaps 68a and 68b. At this time, since the width of the air gap becomes narrow near the middle between the disk inlet and the outlet, the pressure of the air that has entered each air gap increases. At this time, if the disk surface is deviated from a design position (an intermediate position between the slider members 66a and 66bb) due to deformation during molding or rotation of the disk, the air pressure in the air gap 68a and the air pressure in the air gap 68b are different. A force (lift) acts on the upper and lower surfaces of the disk so as to equalize the air pressures of those air gaps. The lift allows the disk surface to be positioned at the design position. Therefore, even when the disk becomes thin, the surface position thereof can be automatically held by the air gap forming member during rotation, and the disk surface of the thin disk is prevented from contacting the inner wall of the cartridge. Following the same principle between the sliders 66c and 66d,
The disk 61 is automatically positioned at an intermediate position between the slider members 66c and 66d during rotation.

The position of the slider member is such that the intermediate position of the opposing slider member is a position separated by a predetermined distance from the height of the spindle for rotating the disk, that is, the half of the thickness of the disk at the disk installation reference height. It is preferable to design so as to be at the added position. The slider member includes a magnetic head 65 and an optical head 67 as in a specific example described later.
Can be arranged at a predetermined position. The substrate thickness is 0.6 mm as the magneto-optical disk 61
Is used, air gaps 68a, 68b, 68c, 68d formed by each slider member and the disk surface are used.
Was set so that the narrowest distance between them was 0.1 mm.

Embodiment 2-1 FIGS. 7 and 8 show the slider members 66a and 66 shown in FIG.
An example of attachment of 6b, 66c and 66d to a magneto-optical disk reproducing device will be described. FIG. 7 shows a slider member 66 for forming air gaps 68b and 68d on the lower surface side of the disk 61.
FIG. 14 is a perspective view of the optical head 67 in which b and 66d are installed on a support 70 of the optical head 67. Slider members 66b, 6
6d was manufactured by processing a ceramic member having a length of 3 cm, a width of 8 mm, and a height of 8 mm so as to have a sectional shape as shown in FIG. The objective lenses 6 are arranged so that the slider members 66b and 66d are parallel to each other with the actuator 64 interposed therebetween.
2 were placed at positions 2 cm apart from the center.

FIG. 8 shows slider members 66a, 66a forming air gaps 68a, 68c on the upper surface side of the disk 61.
FIG. 6 is a perspective view of a magnetic head 67 in which 6c is mounted on a support 69 of the magnetic head 65. Slider members 66a, 66c
Are arranged parallel to each other at positions 2 cm away from the center of the magnetic head 65 with the magnetic head 65 interposed therebetween. The slider members 66a and 66c are the slider members 6
This is a ceramic member having the same size and shape as 6b and 66d. The optical head 67 equipped with the slider members 66b and 66d shown in FIG. 7 and the magnetic head 67 equipped with the slider members 66a and 66c shown in FIG. It was incorporated into a magneto-optical disk recording / reproducing device to form. The magnetic head 67 itself has an actuator (not shown) so that it can be retracted upward when the disk is attached or detached.
Made it movable. A magneto-optical disk having a substrate thickness of 0.6 mm is mounted on the magneto-optical disk recording / reproducing apparatus, and data can be recorded / reproduced by driving the magneto-optical disk at, for example, a rotation speed of 3600 rpm. Thereby, the stability of the focus servo can be increased.

Embodiment 2-2 In this embodiment, the slider members 66a, 66b, 66c, 6
6d without being fixed to the optical head 67 and the magnetic head 65,
An example is shown in which a head of a main body of a magneto-optical disk recording / reproducing apparatus is mounted on a fixed portion of a linear actuator for accessing the head. As shown in FIG. 9, the slider members 66a,
66b, 66c and 66d are arranged at positions sandwiching the outermost periphery of the magneto-optical disk 61. Then, a predetermined position based on the height of a spindle (not shown), that is, (the installation height of the magneto-optical disk 61 on the recording / reproducing apparatus) + (the thickness of the magneto-optical disk 61 × 0.5) 0.1 m in the vertical direction for each height (position)
m so that an air gap of m is formed.
a, 66b, 66c, and 66d. The slider members 66a, 66b, 66c, and 66d are connected to a loading motor or an electromagnetic actuator on the upper surface (the surface opposite to the surface facing the disk), so that the slider members are retracted vertically when the disk is attached or detached. be able to. After the disk is rotated, each slider member can be brought close to the disk by a loading motor or the like to a distance that gives a gap of 0.1 mm on the upper and lower surfaces of the disk. As in the case of the embodiment 2-1, since the surface of the disk is positioned at the intermediate position of the slider member by the air gap, even if the disk itself has a deformation such as distortion during molding, it is corrected at the time of recording / reproduction, that is, rotation. Up and down movement of the disc is suppressed. Therefore,
Even with a thin recording medium, recording and reproduction can be reliably performed, and the stability of focus servo can be increased.

In the above embodiment, a magneto-optical disk and its recording / reproducing apparatus have been described as examples of optical recording media. However, the present invention is not limited to this, and is applicable to various optical recording media such as CD, CD-R, DVD, and MD. it can. Further, the material, shape, arrangement, and the like of the slider member described in the embodiment are not limited to those specific examples, and any member may be used as long as it has the function and effect of the air gap forming member according to the principle description. Can be used in any position.

Third Embodiment In this embodiment, a specific example of a recording medium cartridge accommodating a thin recording medium having a substrate thickness of 0.85 mm or less will be described with reference to FIGS.

Embodiment 3-1 FIG. 10 shows a schematic configuration of a cartridge when the cartridge of the present invention is applied to a magneto-optical disk cartridge. The magneto-optical disk cartridge 100 mainly includes a cartridge main body 101 including an upper shell 101a and a lower shell 101b, a magneto-optical disk 103 accommodated therein, and a shutter 108 for opening and closing a shutter window 106 of the upper shell 101a. Have been. As the magneto-optical disk 103,
A thin disk having a substrate thickness of 0.6 mm and an outer diameter of 120 mm is used.

In order to suppress the deformation of the thin disk by supporting the upper and lower surfaces of the outer peripheral portion of the rotating magneto-optical disk 103, roller members 105a and 105b, which will be described later, are mounted on the shutter window 10 in the cartridge body 101.
6 are arranged on both sides. Given that the recording / reproducing magneto-optical head (not shown) approaches the area of the shutter window 106, the roller member 105a is used to suppress the position fluctuation of the portion where recording or reproduction is performed on the disk 103. , 105b are preferably arranged near the installation position of the magneto-optical head, that is, near the shutter window 106. Further, inside the cartridge body 101, the roller members 105a and 105b and the magneto-optical disk 1 are mounted.
When the abrasion powder is generated by contact with the disk 03, the liner 120a for wiping it is placed on the roller
It is installed on the side facing 05b. This liner 1
Numerals 20a and 120b (see FIG. 12) slide on the disk surface by the rotation of the disk 103, and also function as means for supporting the upper and lower surfaces of the outer peripheral portion of the rotating magneto-optical disk.
The structure of the liner 120a and the positional relationship with the disk 103 will be described later with reference to FIG.

FIG. 11 shows the cartridge 1 shown in FIG.
FIG. 10 is a sectional view of the cartridge when 00 is broken by a line connecting the center of the disk and the center of the roller member 105a. In the cartridge main body 101, the disk 103 is rotatably supported by the clamp ring plate 104. The disk 103 is attracted to the spindle 114 of the magneto-optical disk reproducing device and is driven by the rotation of the motor shaft 109 during the rotational driving. The roller member 105a is a cylindrical roller, and a rotary shaft 107 is embedded at the center of the roller. A groove 111 is formed on the outer periphery of the center of the roller. The roller groove 111 is engaged with the outermost peripheral portion of the disk 103, that is, the upper and lower surfaces of the disk 103 are supported by the roller groove 111, so that the position of the surface of the disk 103 in the height direction (rotation axis direction) is raised and lowered. Fluctuations can be suppressed. In this embodiment, the groove width of the roller member 105a is 0.7 mm with respect to the disk thickness of 0.6 mm. The groove width is 0.05 to 0.05 with respect to the disk thickness in order to ensure smooth rotation of the disk 105.
It is desirable to increase the width by 0.15 mm. Also, in order to allow the eccentricity of the disk 103 in the cartridge body 101 to some extent, for example, about 100 μm,
The bottom (depth) can be configured to be located outside the designed position of the outermost periphery of the disc in the cartridge main body 101. The end of the roller rotation shaft 107 is
Each of the upper shells 1 of the cartridge body 101
01a and the lower shell 101b are rotatably supported by holes 112a and 112b formed inside.

The material of the roller member 105a is preferably a material excellent in slipperiness and abrasion resistance in order to reduce abrasion and frictional force caused by contact with the disk 103, such as polyacetal, polypropylene, fluorine resin and the like. Is preferred. The roller member 103b has the same structure as the roller member 103a, and is made of the same material. In FIG. 10, two roller members are provided in the cartridge main body 101. However, three or more roller members identical to the roller members 103a and 103b may be provided on the outer peripheral portion of the disk.

FIG. 12 is a partial cross-sectional view of the cartridge in which the cartridge main body 101 is cut along a line connecting the rotation center of the disk 103 and the center of the liner 120 in FIG.
The liners 120a and 120b are respectively provided with liner support portions 123a formed inside the upper shell 101a and the lower shell 101b of the cartridge body 101.
And 123b. The liners 120a and 120b are installed so as to sandwich the outermost periphery of the disk. The liners 120a and 120b are
When abrasion powder is generated on the upper and lower surfaces of the disk due to the contact between the disks 05a and 105b and the disk 103, it is wiped off. As the material for the liners 120a and 120b, any material used as a liner for felt and floppy disk can be used, and for example, a nonwoven fabric is preferable.

The dust collecting chamber 130 provided in the cartridge main body 101 shown in FIG. 10 will be described with reference to FIG.
The dust collection chamber 130 is a room formed at one corner of the cartridge main body 101, and has an inlet 134 provided on an extension of the outermost periphery of the disk 103. Entrance 13 of dust collection chamber 130
Numeral 4 has a wedge-like shape in order to prevent dust and the like collected in the dust collecting chamber 130 from scattering again therefrom and adhering to the disk 103. Further, for example, a silicon-based adhesive 132 is applied to a part of the inner wall of the dust collection chamber 130, and the adhesive 132 adheres dust or the like that has entered the dust collection chamber 130.

Disk 103 and roller members 105a and 105b
In order to prevent the generation of static electricity due to contact with the disc, it is desirable to apply an antistatic coating on at least the disk surface. It is more preferable to apply an antistatic material to the inner wall of the cartridge and the liners 120a and 120b. It is also effective to mold the cartridge with a resin mixed with an antistatic material.

Embodiment 3-2 FIG. 14 shows the cartridge body 1 shown in FIGS.
01 shows an example in which different types of roller members are used. FIG. 14 is a cross-sectional view of the cartridge 100 shown in FIG. 10 cut at the same position as in FIG. In this example, the outermost peripheral portion of the disk 103 has a pair of roller members 140 that contact the upper and lower surfaces of the disk 103, respectively.
a, 140b. Roller member 140a,
The shape of 140b can be cylindrical or barrel-shaped. The roller rotation shafts 142a and 142b are rotatably supported by roller rotation shaft support members 146 formed inside the upper shell 101a and the lower shell 101b, respectively. Roller member 140a and roller member 14
The distance from 0b is the same as the groove width of the roller member shown in FIG. The configurations of the disk 103 and other cartridges are the same as those of the embodiment 3-1.

Embodiment 3-3 FIG. 15 shows the cartridge 100 shown in FIGS.
, The sliding members 150a, 15
An example using 0b is shown. FIG. 15 is a cross-sectional view of the cartridge 100 shown in FIG. 10 cut at the same position as in FIG. In this example, the outermost peripheral portion of the disk 103 is supported by a pair of hemispherical sliding members 150a and 150b that contact the upper and lower surfaces of the disk 103, respectively. In this case, in order to make the rotation of the disk 103 smooth, the coefficient of friction between the disk 103 and the sliding members 150a and 150b is preferably 0.3 or less, and more preferably 0.1 or less.
2 or less. The material of the sliding members 150a and 150b is as follows.
In order to reduce the coefficient of friction and improve the activity and wear resistance,
Polyacetal, polypropylene, fluororesin and the like are desirable. It is preferable that at least either the contact portion of the disk 103 with the sliding member or the sliding member itself be coated with a lubricant, for example, a silicon-based lubricant. The sliding members 150a and 150b are U-shaped support members 1 joined to the upper shell 101a and the lower shell 101b.
52 is mounted so as to face the end. Sliding member 15
The distance between Oa and the sliding member 150b is the same as the groove width of the roller shown in FIG. The configurations of the disk 103 and other cartridges are described in Example 3-1 and Example 3-2.
Is the same as The cartridge using the sliding members 150a and 150b can also stabilize the rotation operation of the thin disk by maintaining the position of the disk surface, thereby reliably performing recording and reproduction.

For the cartridge using the member for engaging the disk shown in Examples 3-1 and 3-3,
The vertical run-out of the rotating disk surface was measured. For the measurement, the same optical disk mechanical characteristic measuring device as used in Example 1 was used. As a comparative example, a conventional magneto-optical disk cartridge having no member for engaging the disk as shown in FIG. 17 was used. FIG. 16 shows the results. In FIG. 16, the measurement result of the cartridge of Example 3-1 is indicated by a curve 162, the measurement result of the cartridge of Example 3-3 is indicated by a curve 163, and the measurement result of the conventional cartridge is indicated by a curve 161. In the conventional cartridge, the variation in the circumference of the disc (the width of the runout) was 0.5 mm at maximum, whereas it was reduced to 0.12 mm at maximum in Example 3-1 and 0.13 mm in Example 3-3. We were able to. In addition, although the result of the cartridge of Example 3-2 was not shown, a curve substantially equivalent to that of Example 3-1 was obtained, and the maximum runout width was 0.11 mm.

The cartridge of the present invention is effective for a disk accommodated in a cartridge having an outer diameter of 80 mm or more and a disk substrate having a thinnest portion of 0.85 mm or less, and in particular, a disk outer diameter of 100 mm or less. The above is effective for a disk substrate having a minimum thickness of 0.65 mm or less.

In the third embodiment, the cartridge accommodating the magneto-optical disk is described. However, the type of the disk accommodated in the cartridge is not particularly limited.
ROM, CD-R, phase change optical disk, MD, DVD
And the like can be applied to various optical recording media. Also,
The present invention can be applied to a magnetic disk using a plastic substrate, and is effective for, for example, a removable magnetic disk cartridge. Regardless of the type of recording medium contained in the cartridge, the thickness is 0.85 mm.
The cartridge of the present invention can be applied to any recording medium as long as the recording medium uses the following thin substrate.

Fourth Embodiment In this embodiment, the air flow during rotation of the disk is adjusted by providing a projection or a depression on the inner surface of the cartridge for accommodating the recording medium, and recording and reproduction are performed by the adjusted air flow. A specific example of a cartridge for urging the signal recording surface of the disk to a constant height position will be described.

Embodiment 4-1 FIG. 18A shows a projection 1 on the inner surface of a cartridge 181 containing a magneto-optical disk 183 radially from the center of the disk.
Magneto-optical disk cartridge 1 provided with 85a
It is a top view of 81. In FIG. 18A, for convenience of explanation, a disk 183 housed in a cartridge 181 is shown.
And the projection 185a on the inner surface of the cartridge (upper shell) is seen through. FIG. 18 is a sectional view of the cartridge, taken along line AA in FIG. 18A.
B. The cartridge 181 includes an upper shell 181.
a and 181b, and FIG. 18A is a plan view of the upper shell 181a as viewed from above. A shutter window 187 is formed in the upper shell 181a so that the optical head can access the disk 183 during recording and reproduction (the shutter is not shown).
The cartridge 181 houses a magneto-optical disk 183 having a diameter of 120 mm and a substrate thickness of 0.6 mm.

As shown in FIGS. 18A and 18B, the upper shells 181a and 181b of the cartridge 181 are provided.
On the inner surface of the disk 183, there are provided band-shaped projections 185a and 185b extending radially from the center of the disk, respectively.
Are formed symmetrically with respect to. Convex portions 185a and 18
The width of the upper shell 5b is increased in a fan shape toward the outside in the radial direction, and the upper shell 1 of the convex portions 185a and 185b is formed.
The height from the inner surface of 81a and the lower shell 181b is 0.5 mm, respectively. Also, the upper shell 181
The distance between the convex part 185a of FIG. a and the upper surface of the disk 183 and the distance between the convex part 185b of the lower shell 181b and the lower surface of the disk 183 are each preferably 0.8 mm or less, and more preferably 0.6 mm or less. 0.5 mm. The convex portions 185a and 185b are formed so as to have a divergence angle of 20 ° from the center of the disk.
It is provided at every 45 ° on the circumference of the disk. Convex part 1
85a and 185b have a radius of 20 mm of the disk 183.
(The edge of the opening 189 for the clamping plate) to a position extending up to a radius of 61 mm from the position.

By providing the convex portions 185a and 185b on the inner surface of the cartridge, the flow of air generated in the circumferential direction of the disk during the rotation of the disk is guided in the radial direction, and the pressure on the outer peripheral portion of the disk is increased. By applying the increased pressure evenly from the upper and lower surfaces of the disk, it is possible to stabilize the surface position of the outer peripheral portion of the disk, which has particularly large fluctuations.

Embodiment 4-2 FIGS. 19A and 19B show a modification of the cartridge shown in FIGS. 18A and 18B. The cartridge 191 shown in FIG. 19A and the AA sectional view 19B thereof is composed of upper shells 191a and 191b similarly to the cartridge 181 of Example 4-1. The cartridge 191 has a diameter of 120 mm, A magneto-optical disk 183 having a thickness of 0.6 mm is stored. This cartridge 1
In 91, the convex portions 195a and 195b are
On the inner surface of the lower shell 91a and the lower shell 191b, in the direction of rotation of the disk from the center of the disk toward the outer circumference.
It is formed radially so as to draw 96. Convex part 195
The arc 196 defining a and 195b is centered on the circumference (120 mm in diameter) of the disk and is drawn with a radius of 60 mm. The center of the arc 196 is 1 /
A total of 16 arcs were drawn by setting every 16 laps. Arc 19
The cross-sectional shape of the convex section defined by 6 is saw-tooth-shaped as shown in FIG. 19B, protrudes at the position of arc 196, the distance between the inner surface of the cartridge and the disk surface is minimized at that point, and the next arc is formed. The interval gradually widens until. That is, arc 1
At a position 96, a step is generated between the adjacent convex portions, and the convex portions 19 are formed.
5 form a boundary. The protruding height at the position of the arc is 0.5 mm, and the protrusions 195a, 195 at that position are provided.
The distance between b and the surface of the disk 183 is 0.5 mm as in the case of Example 4-1. The projection 195 having such a structure
a and 195 b are placed on the inner surface of the cartridge 191.
3, the disk 183 is provided.
The air flow generated in the circumferential direction of the disk by the rotation of the disk is radially guided, the pressure at the outer peripheral portion of the disk is increased, and the increased pressure is uniformly applied from the upper and lower surfaces of the disk, so that the fluctuation is large. The surface position of the outer peripheral portion of the disk can be stabilized.

Embodiment 4-3 FIGS. 20A and 20B show a modification of the cartridge shown in FIGS. 19A and 19B. The cartridge 201 shown in FIG. 20A and the cartridge 201 shown in FIG. 20B which is a cross-sectional view taken along line AA of FIG.
And 205b are radially formed on the inner surface of the upper shell 201a and the lower shell 201b so as to draw an arc in the rotation direction of the disk from the center of the disk toward the outer periphery. Although the cross-sectional shapes of the convex portions 205a and 205b are symmetrical to each other with respect to the disk 183, as shown in FIG. 20B, unlike the case of Example 4-2, only the portion of the drawn arc 206 is convex. Is formed.

FIGS. 20C and 20D show FIGS.
Similarly to the cartridge 201 shown in FIG. 0B, a cartridge whose projections are radially formed on the inner surface of the upper shell and lower shell of the cartridge so as to draw an arc in the rotation direction of the disk from the center of the disk toward the outer periphery. 1 shows a cross-sectional structure. The method of drawing the arc is the same as that described in Example 4-2, but the cross-sectional shapes of the convex portions (or concave portions) defined by the arc are different. In FIG. 20C,
In the upper shell 201c and the lower shell 201d, the center of the arc 206 is set at every 1/16 turn on the outer peripheral portion of the disc, but the arc portion drawn by the center of the arc set at every 1/8 turn of the outer peripheral portion of the disc is the largest. The height of the projection 202 and the height of the arc portion adjacent thereto are the lowest.
a and the convex portion 202b were formed. In FIG. 20D, FIG.
In contrast to the case of B, the case where the portion of the arc 206 forms the recesses 203a and 203b on the inner side surfaces of the upper shell 201e and the lower shell 201f is shown. The distance between the protrusion on the inner surface of the cartridge and the disk surface is 0.8mm
Or less, more preferably 0.6 mm or less. In each of the cartridges shown in FIGS. 20A to 20D, the height of the projection was 0.5 mm, and the distance between the disk and the projection was 0.5 mm.

By providing protrusions or recesses having the structure shown in FIGS. 20A to 20D on the inner surface of the cartridge, the flow of air generated in the circumferential direction of the disk by the rotation of the disk 183 is guided in the radial direction, and By increasing the pressure of the portion and uniformly applying the increased pressure from the upper and lower surfaces of the disk, it is possible to stabilize the surface position of the outer peripheral portion of the disk where the fluctuation is particularly large.

Embodiment 4-4 This embodiment shows a specific example of a cartridge in which the distance between the surface of the disk housed in the cartridge and the inner surface of the cartridge is smaller at the outer periphery than at the inner periphery of the disk. .

FIG. 21 is a sectional view of the cartridge taken along a plane passing through the central axis of the disk 183. The cartridge 210 accommodates, for example, a magneto-optical disk having a diameter of 120 mm and a substrate thickness of 0.6 mm. The thicknesses of the upper shell 210a and the lower shell 210b constituting the cartridge 210 are equivalent at the disk radial position, and gradually increase from the inner peripheral side to the outer peripheral side of the disk 183. That is, a conical space is formed by the inner surface of the upper shell 210a and the upper surface of the disk, and a conical space is similarly formed by the inner surface of the lower shell 210b and the lower surface of the disk. As a result, the flow velocity of the air at the outer periphery of the disk 183 is increased, the pressure at the outer peripheral portion of the disk is increased, and the surface position of the outer peripheral portion of the disk can be stabilized. The disk surface near the outer peripheral portion and the cartridge (upper shells 210a and 210a)
0b is 0.5 mm, which is less than the thickness of the disk. The structure shown in FIG.
By using in combination with a structure in which the projections (or depressions) on the inner surface of the cartridge shown in -1, 4-2 or 4-3 are provided radially, it is possible to further improve the stabilization of the surface position of the thin disk. it can.

Embodiment 4-5 In this embodiment, in a cartridge for accommodating a recording medium such as a magneto-optical disk, the distance between the disk surface and the inner surface of the cartridge is different between the vicinity of the shutter window and other areas. A specific example of a cartridge having the following will be described. FIG. 22A is a plan view of a cartridge employing this structure, and FIG. 22B is a plan view of FIG.
FIG. 3 shows a cross-sectional view of the cartridge taken along line A.

The cartridge 220 contains the magneto-optical disk 1
83 (not shown in FIG. 22A), and the upper shell 220a and the lower shell 220b are joined.
A shutter window 187 is formed in the upper shell 220a so that the optical head can access the optical disk 183 when recording or reproducing. The edge 226 of the longitudinally facing edges 225 and 226 that define the shutter window 187
Is assumed to rotate in the direction of the edge 225 from the magneto-optical disk 183. As shown in the cross-sectional view of FIG. 22B, the inner side surface of the upper shell 220a is located behind the edge portions 225 and 226 of the shutter window 187 in the rotation direction of the disk 183 (arrow in the drawing) (the disk surface is the shutter window). A convex portion 222a protruding toward the disk 183 is formed in the vicinity of the edge portion 225 on the entrance side of the cartridge from the region 187 (into the cartridge), and a narrow air gap 228a is formed between the convex portion 222a and the disk 183.
Is formed. The inner surface of the lower shell 220b is provided with the convex portion 222a of the upper shell 220a and the disk 183.
Are formed symmetrically with respect to the projection 22b.
An air gap 228b is formed between 2b and the disk 183. In this embodiment, the thickness of the disk 183 is 0.1 mm.
6 mm, the air gap 228a between the protrusion 222a and the upper surface of the disk 183, and the protrusion 222b and the disk 1
The air gaps 228b between the lower surfaces of the 83 and the lower surface of each were set to 0.5 mm. Such an air gap is 0.8 mm or less, more preferably 0.6 mm or less, in order to achieve the effects of the present invention.

The inner side surface of the upper shell 220a is provided with an edge portion 22 at the front in the rotation direction of the disk 183 (exit side where the disk surface exits the area of the shutter window 187).
6, the inner surface of the upper shell 220a is the disk 1
A projection 221a protruding toward 83 is formed.
The distance between 21a and the upper surface of the disk 183 is 0.5 mm, which is the same as the air gap. Such an air gap is 0.8 mm or less to achieve the effect of the present invention, and more preferably 0.6 mm or less. The thickness of the upper shell 220a becomes thinner from the convex portion 221a toward the rear in the disk traveling direction, and the distance between the inner side surface of the upper shell 220a and the upper surface of the disk 183 gradually increases. On the inner surface of the lower shell 220b, a convex portion 221b is formed symmetrically with the convex portion 221a of the upper shell 220a, and an air gap of 0.5 mm is formed between the lower shell 220b and the lower surface of the disk 183. And upper shell 2
As with the inner surface of the lower shell 20a, the thickness of the lower shell 220b decreases from the convex portion 221b toward the rear in the disk advancing direction. The convex portions 222a, 222b and 221
a and 221b extend over the edges 225 and 226 of the shutter window 187, and therefore, regardless of the position (in the disk radial direction) of the shutter window 187, position control of a disk surface described later. A stable recording / reproducing characteristic is obtained by the action.

In the sectional structure shown in FIG. 22B, the distance between the inner surface of the cartridge and the disk surface is
a, since the convex portion 222b is narrower than the other portion, the pressure due to the air flow in this portion can be increased. When the distance between the inner surface of the cartridge and the disk surface fluctuates, if the distance between the inner surface of the cartridge and the disk surface becomes relatively small, the flow velocity of the air flow increases, the pressure increases, and the inner surface of the cartridge and the disk surface become larger. Is relatively large, the flow velocity of the air flow becomes slow and the pressure drops. The structure of the inner surface of the cartridge is symmetrical with respect to the disk in the upper shell and the lower shell, and the disk surface is located at an intermediate point between the convex portion formed on the inner surface of the upper shell and the convex portion formed on the inner surface of the lower shell. In this case, the increased air pressure becomes equal on the upper surface side and the lower surface side of the disk. On the other hand, during the rotation of the disk, the position (height) of the surface of the disk is changed to the reference position for recording and reproduction (the convex portion 22).
2a and the convex portion 222b), a difference in air pressure occurs between the upper and lower surfaces of the disk in the space between the convex portion 222a and the convex portion 222b. The disk 183 is moved to an intermediate position between the projection 222b and the space between the projection 222a and the space between the lower surface of the disk and the projection 222b. Therefore, vertical vibration of the disk surface due to rotation fluctuation can be suppressed. In addition, disk 1
Even if the 83 itself has some distortion, the convex portions 222a, 222
The surface position is corrected when passing between the points b.

Recording and reproduction are performed in the shutter window 187.
The scanning is performed by scanning the disk surface with the optical head in the area of (1). Therefore, it is desirable to increase the pressure applied to the upper and lower surfaces of the disk before the shutter window 187. In addition, the disk 183 is
After passing through 7, the distance between the inner surface of the cartridge and the disk surface can be reduced to increase the pressure applied to the disk surface.

In this embodiment, a disk 183 having a substrate thickness of 0.6 mm is used. However, the cartridge of the present invention can be applied to a disk having a substrate thickness of 0.85 mm or less, preferably 0.65 mm or less. This is particularly effective. Further, as such a thin disk, a disk (recording medium) whose substrate thickness described in the first embodiment is different between a recording area and another area is preferable. The cartridge structure of this embodiment can be used in combination with the structure of the embodiment 4-1, 4-2, 4-3 or 4-4, thereby further increasing the position of the surface of the disk during recording or reproduction. Can be stabilized.

In the embodiments 4-1 to 4-5, the description has been made by taking the magneto-optical disk cartridge as an example. However, the present invention is not limited to this, and all read-only, write-once, and rewritable optical recording media are accommodated. It can be applied to the cartridge that has been used.
Further, the present invention can be effectively used not only for optical recording media but also for cartridges containing magnetic recording media whose substrates are made of plastic, for example, removable magnetic disk cartridges. The material and dimensions of the cartridge body are not particularly limited, and any material including the material of the cartridge currently used can be used.

[0075]

The substrate for a recording medium and the recording medium using the same according to the present invention are optical recording media for high density recording, for example,
It is effective for CD, CD-R, CD-ROM, MD, DVD, MO, and removable magnetic recording media, and is particularly effective for thin high-density recording media with a substrate thickness of 0.85 mm or less. In addition, since the reproducing apparatus for an optical recording medium of the present invention includes an air gap forming member that acts to hold the surface position of the thin optical recording medium at a constant position, the thin optical recording medium can be kept in a stable state. Can be recorded and reproduced. Further, the cartridge of the present invention is suitable for accommodating a thin high-density recording medium, and can maintain a signal recording surface at a constant height during recording and reproduction. By applying the recording medium of the present invention to the cartridge of the present invention, the cartridge can be further reduced in thickness, and the thin recording medium can be recorded and reproduced in a more stable state.

[Brief description of the drawings]

FIG. 1 is a schematic view of an optical disc according to the present invention.

FIG. 2 is a cross-sectional view of the carbonate substrate for manufacturing an optical disk shown in FIG. 1 and cross-sectional views showing modifications (B to G) thereof.

FIG. 3 is a graph showing a measurement result of a surface runout amount of a substrate having a cross-sectional structure shown in FIGS. 2A to 2C during rotation on a drive.

4A to 4H are cross-sectional views showing another structure of the recording medium substrate according to the present invention.

5A to 5G are cross-sectional views showing still another structure of the recording medium substrate according to the present invention.

FIG. 6 is a principle diagram of an optical recording medium reproducing apparatus according to the present invention.

FIG. 7 is a conceptual diagram showing an example of attaching slider members 66b and 66d to an optical head in Example 2-1.

FIG. 8 is a conceptual diagram showing an example of attaching slider members 66a and 66c to a magnetic head in Example 2-1.

FIG. 9 is a schematic configuration diagram of an optical recording medium reproducing device according to Example 2-2.

FIG. 10 is a schematic configuration diagram of a recording medium cartridge of the present invention.

FIG. 11 is a partial cross-sectional view showing a structure of a roller member used in the recording medium cartridge of the present invention.

FIG. 12 is a partial sectional view of the cartridge showing the structure of the liner used in the recording medium cartridge of the present invention.

FIG. 13 is a partial cross-sectional view of the cartridge showing the structure of the dust collection chamber used in the recording medium cartridge of the present invention.

FIG. 14 is a partial cross-sectional view illustrating the structure of another roller member used in the recording medium cartridge of the present invention.

FIG. 15 is a partial sectional view showing the structure of a sliding member used in the recording medium cartridge of the present invention.

FIG. 16 is a graph illustrating the effect of the cartridge according to the third embodiment of the present invention.

FIG. 17 is a sectional view showing the structure of a conventional magneto-optical disk cartridge.

FIGS. 18A and 18B are a plan view and a sectional view taken along line AA, respectively, showing the structure of a recording medium cartridge according to Example 4-1 of the present invention.

FIGS. 19A and 19B are a plan view and a cross-sectional view taken along line AA, respectively, showing the structure of a recording medium cartridge according to Example 4-2 of the present invention.

FIGS. 20A and 20B are a plan view and a cross-sectional view taken along line AA, respectively, showing the structure of a recording medium cartridge according to Example 4-3 of the present invention. ~
(E) is a sectional view showing a modification of the sectional structure of (B).

FIG. 21 is a cross-sectional view illustrating a structure of a cartridge according to Example 4-4 of the present invention.

FIGS. 22A and 22B are a plan view and a cross-sectional view taken along line AA, respectively, showing the structure of a recording medium cartridge according to Example 4-5 of the present invention.

[Explanation of symbols]

 Reference Signs List 10 disk substrate 14 recording area 64 actuator 66a-d slider member 157a, b convex part 181 cartridge 183 disk 187 window 222a, 222b convex part 225,226 edge part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Toshiki Sugiyama 126-1-1, Tanaka, Tsukuba, Ibaraki (72) Inventor, Takeshi Onuki 381-13, Kamiwaba, Chiyogawa-mura, Yuki-gun, Ibaraki Prefecture

Claims (18)

[Claims] 1. A recording medium cartridge accommodating a disk-shaped recording medium, wherein at least one of a convex portion and a concave portion for adjusting the flow of air during rotation of the recording medium is provided on the inner surface of the cartridge. A recording medium cartridge formed so as to be symmetrical with respect to the upper surface and the lower surface, respectively. 2. The recording medium cartridge according to claim 1, wherein the disk-shaped recording medium has a substrate thickness of 0.85 mm or less at least in a signal recording area. 3. The recording medium cartridge according to claim 1, wherein the disc-shaped recording medium has a substrate thickness of 0.6 mm or less at least in a signal recording area. 4. The recording medium according to claim 1, wherein the distance between the convex portion formed on the upper surface of the inner surface of the cartridge and the upper surface of the recording medium is equal to the distance between the convex portion formed on the lower surface of the inner surface of the cartridge and the lower surface of the recording medium. Recording medium cartridge. 5. A signal recording surface of a recording medium according to claim 1, wherein at least one of the projections and the depressions adjusts the flow of air when the recording medium is rotated to maintain a signal recording surface of the recording medium at a fixed position. Recording medium cartridge. 6. The cartridge according to claim 1, wherein at least one of the convex portion and the concave portion is formed on the inner surface of the cartridge so as to be radial from the center of the recording medium accommodated in the cartridge. The recording medium cartridge according to the item. 7. The method according to claim 1, wherein at least one of the convex portion and the concave portion is
7. The recording medium cartridge according to claim 6, wherein the inner surface of the cartridge is radially formed so as to draw an arc in the rotation direction of the recording medium from the center to the outer periphery of the recording medium accommodated in the cartridge. -Tridge. 8. The distance between the convex portion and the surface of the recording medium is set to 0.
7. The recording medium cartridge according to claim 6, which is not more than 6 mm. 9. The recording medium cartridge according to claim 6, wherein the recording medium is an optical recording medium or a magnetic recording medium using a plastic substrate. 10. A window for accessing a signal recording or reproducing head to the cartridge is formed, and at least an entrance side of a recording medium of the window is provided.
2. The recording medium cartridge according to claim 1, wherein the convex portions are formed symmetrically on the upper surface and the lower surface inside the cartridge. 11. The recording medium cartridge according to claim 9, wherein a distance between the projection and the surface of the recording medium is 0.6 mm or less. 12. The recording medium cartridge according to claim 10, wherein the recording medium is an optical recording medium or a magnetic recording medium using a plastic substrate. 13. The recording medium cartridge according to claim 10, wherein the disc-shaped recording medium has different substrate thicknesses in a signal recording area and a portion outside the signal recording area. 14. A recording medium cartridge accommodating a disc-shaped recording medium, wherein the distance between the upper surface of the recording medium and the inner upper surface of the cartridge is equal to the distance between the lower surface of the recording medium and the inner lower surface of the cartridge, and in the radial direction of the recording medium. The distance between the upper surface of the recording medium and the inner upper surface of the cartridge and the distance between the lower surface of the recording medium and the inner lower surface of the cartridge are smaller at the outer peripheral portion than at the inner peripheral portion of the recording medium. Recording medium car
Tridge. 15. The method according to claim 15, wherein a distance between an upper surface of the recording medium and an inner upper surface of the cartridge and a distance between a lower surface of the recording medium and an inner lower surface of the cartridge gradually decrease from an inner peripheral portion to an outer peripheral portion of the recording medium. The cartridge of a recording medium according to claim 14, wherein 16. The recording medium cartridge according to claim 14, wherein the recording medium is an optical recording medium or a magnetic recording medium using a plastic substrate. 17. The recording medium cartridge according to claim 15, wherein the disc-shaped recording medium has a substrate different in thickness from a signal recording area and a portion outside the signal recording area. 18. The recording medium cartridge according to claim 14, wherein the disk-shaped recording medium has a substrate thickness of 0.85 mm or less at least in a signal recording area.