JPH0660433A - Information signal recording disk - Google Patents

Abstract

PURPOSE:To absorb distortion at the time of executing thermal deformation and to prevent the influence on an information signal recording layer by mounting a magnetic plate to be housed into a magnetic plate housing recessed part by means of the supporting pieces projecting to the magnetic plate housing recessed part. CONSTITUTION:The annular projecting parts 8 are erected to exist between the magnetic plate housing recessed part 5 formed on one main surface of a disk substrate 2 and the information signal recording layer. The regions between the annular projecting parts 8 and the magnetic plate housing recessed part 5 are formed as thermally deforming parts 9. The thermally deforming parts 9 are partly thermally deformed to project and form the supporting pieces 15 supporting the magnetic plate 10 housed in the magnetic plate housing recessed part 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc-shaped information signal recording disc capable of recording information signals such as tone signals and video signals, such as optical discs and magneto-optical discs. The present invention relates to an information signal recording disc that is chucked by a disc rotation drive device.

[0002]

2. Description of the Related Art Conventionally, there has been proposed an information signal recording disk, such as an optical disk or a magneto-optical disk, on which a desired information signal such as a tone signal or a video signal is recorded. This information signal recording disk is capable of high density recording of information signals,
For example, as a magneto-optical disk, an extremely small disk having a diameter of 64 mm or less has been proposed.

As described above, the information signal recording disk, which has an extremely small diameter and is capable of high density recording, is mounted on the disk rotation driving device and rotated at a high speed. Then, while being rotated at a high speed, a fine recording track provided on the information signal recording layer formed on one main surface of the information signal recording disk is irradiated with an optical beam emitted from the optical pickup. At the same time, a desired information signal is recorded by applying an external magnetic field that is magnetic field modulated according to the signal information to be recorded by the external magnetic field generator.

By the way, in order to accurately irradiate a fine recording track with a light beam while being rotated at a high speed,
The information signal recording disk needs to be surely integrated with the disk table of the disk rotation driving device and mounted with the rotation center accurately positioned on the axis of the disk table.

Conventionally, since the information signal recording disk is securely integrated with the disk table and positioned and mounted with high precision, a magnetic material such as a metal plate disposed on the information signal recording disk side is used for magnetic attraction. A disk chucking method has been proposed in which a plate is attracted by a magnet arranged on the disk table side to chuck a magnetic disk on the disk table.

A magneto-optical disk 100 used in a disk chucking system utilizing the attractive force of this magnet.
As shown in FIG. 9, the disk substrate 101 is provided with a disk substrate 101 molded in a disk shape from a transparent synthetic resin material such as a polycarbonate resin. An information signal recording layer on which a desired information signal is recorded is adhered to one main surface 101a side of the disk substrate 101, and the other main surface 101b opposite to this main surface 101a is written and read with an information signal. The information signal is recorded and reproduced by irradiating the information signal recording layer with a light beam from the information writing and reading surface side.

Further, in the central portion of the disc substrate 101,
As shown in FIG. 9, a center hole 102 is formed in which a centering member provided on the side of the disk rotation driving device engages. Further, one main surface 1 of the disk substrate 101
A magnetic plate 103 made of a metal material is housed in the central portion on the 01a side so as to close the center hole 102.

The magnetic plate 103 is a disk substrate 101.
It is arranged so as to be accommodated in a magnetic plate accommodating concave portion 104 formed on one main surface 101a side so as to surround the center hole 102, and a double-sided adhesive tape or an adhesive agent 105 is used to form a disk. It is attached so as to be bonded to the substrate 101.

As described above, in the magneto-optical disk 100 in which the magnetic plate 103 is attached to the disk substrate 101 by using the adhesive 105, the disk table of the disk rotation driving device is repeatedly attached to and detached from the disk table. The load at the time of attachment / detachment may be applied to the joint portion of the magnetic plate 103 to the disk substrate 101, causing deterioration of the adhesive agent 105, and the magnetic plate 103 may be separated from the disk substrate 101.

To solve this problem, there has been proposed an information signal recording disk in which a magnetic plate is attached to a disk substrate without using an adhesive. As shown in FIG. 10, this magneto-optical disk 200 has a center hole on one principal surface 201a on which an information signal recording layer of a disk substrate 201 formed of a synthetic resin material such as transparent polycarbonate resin is adhered and formed. A magnetic plate storage recess 204 is provided so as to surround 202, and the magnetic plate storage recess 20 is provided.
4, the magnetic plate 20 is formed so as to close the center hole 202.
3 is accommodated, and a plurality of convex portions 205 for supporting thermal deformation of the magnetic plate 203 are integrally provided at equal intervals on the outer peripheral side of the magnetic plate accommodating concave portion 204.

Then, the magnetic plate 2 is placed in the magnetic plate storage recess 204.
After housing 03, the convex portion 205 for supporting the thermal deformation,
For example, by pressing a heating iron or applying ultrasonic waves by ultrasonic swaging, a supporting piece 205A is bulged and formed on the magnetic plate housing recess 204 side, and the tips of these thermal deformation supporting projections 205 are formed. Support piece 20 formed on the base
The magnetic plate 203 is attached to the disk substrate 201 so as to be fixed in the magnetic plate housing recess 204 by 5A.

As described above, the magneto-optical disk 203 is configured to support the magnetic plate 203 by the supporting piece 205a formed by bulging by heating and pressurizing the convex portion 205 for supporting thermal deformation formed integrally with the disk substrate 201. In the disk 200,
Since the magnetic plate 203 is firmly supported by the disk substrate 201, even if the magnetic disk 203 is repeatedly attached to and detached from the disk table, the magnetic plate 203 can be securely attached to the disk substrate without any accident such as peeling. To be done.

[0013]

However, as described above, the convex portion 20 for supporting the thermal deformation for fixing the magnetic plate 203 to the one main surface 201a of the disk substrate 201.
In the case of a magneto-optical disk in which No. 5 is formed and a heating iron is pressed against this, or ultrasonic swaging processing is performed, heating, pressurization, or ultrasonic waves are applied to the periphery of the convex portion 205 for supporting thermal deformation. Distortion due to vibration may occur, and the influence may affect the information signal recording layer and deteriorate the optical characteristics of the disk substrate 201.

Further, in the magneto-optical disk in which the thermal deformation supporting convex portion 205 is heated or applied with ultrasonic waves so as to be deformed under pressure in a molten state, the thermal deformation supporting convex portion is formed. A part of 205 rises, and the disk substrate 20
The burr 206 protruding from the first main surface 201a is generated. As a result, when the magneto-optical disk 200 is mounted on the disk rotation driving device and rotationally driven, the burr 206
May be scraped by rubbing against the inner surface of the cartridge body that houses the magneto-optical disk 200, and the scraps may adhere to the surface of the magneto-optical disk 200 to make it impossible to read the information signal recorded in the information signal recording layer. Also occurs.

Therefore, according to the present invention, a part of the peripheral edge of the magnetic plate accommodating concave portion is heated or pressurized while applying ultrasonic waves while being melted, so that the magnetic plate supporting concave portion is provided with a magnetic plate supporting piece. It was proposed for the purpose of providing an information signal recording disk in which a magnetic plate is firmly mounted in a recess for accommodating the magnetic plate so as to form a protrusion and the influence of the thermal deformation treatment does not affect the information signal recording layer. It is a thing.

[0016]

An information signal recording disk according to the present invention, which has achieved this object, is made of a synthetic resin having a center hole and an information signal recording layer formed on one main surface side. A magnetic plate accommodating recess is formed on one main surface side of the disk substrate by surrounding the center hole to accommodate and dispose the magnetic plate, and an information signal recording layer and a magnetic plate accommodating recess are provided on one main surface side of the disk substrate. And a magnetic plate accommodating recessed portion is formed as an integrally formed projecting portion, and the region is surrounded by the projecting portion and the magnetic plate accommodating recessed portion is a heat deforming portion. One piece is formed so as to project into the magnetic plate accommodating recess, and the magnetic plate accommodated and arranged in the magnetic plate accommodating recess is held on the disk substrate.

[0017]

According to the information signal recording disk of the present invention,
Since the area surrounded by the annular or a plurality of protrusions and the magnetic plate accommodating recess is configured as a thermal deformation portion, the distortion generated when ultrasonic swaging is applied to the thermal deformation portion is a protrusion portion. It prevents the burrs from being absorbed by the inner surface of the cartridge main body and prevents the influence from reaching the information recording layer. Eliminates the possibility that shavings adhere to the information recording layer.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an information signal recording disc 1 according to the present invention includes a disc substrate 2 formed of a disc-shaped synthetic resin such as polycarbonate having an excellent light transmission characteristic. One main surface 2a of the disk substrate 2
On the side, an information signal recording layer on which a desired information signal is recorded is adhered and formed.

The disk substrate 2 is formed to have a thickness H of about 1.2 mm, and the other main surface 2b opposite to the one main surface 2a on which the information signal recording layer is formed is the information signal writing / reading surface. The information signal is recorded / reproduced by irradiating the information signal recording layer with a light beam from the writing / reading surface side. As shown in FIG. 1, a center hole 3 is bored in the central portion of the disk substrate 2 so as to match the center of curvature of a recording track formed concentrically or spirally in the information signal recording layer. Has been done. The center hole 3 is engaged with a centering member arranged at the center of a disk table which constitutes a disk rotation driving device arranged in the information recording / reproducing apparatus.

Further, as shown in FIG. 2, an annular bulging portion 4 is integrally formed so as to surround the center hole 3 in the central portion on the other main surface 2b side of the disk substrate 2. The bulging portion 4 has a center hole 3 formed in the thin disk substrate 2.
By increasing the depth dimension of the information signal recording disk 1, the centering member arranged on the disk table side on which the information signal recording disk 1 is mounted is engaged with the center hole 3 with a large protrusion amount. The centering operation is performed so that the center of rotation of the disk table is aligned with the axis of the disk table and mounted.

The bulging portion 4 is also formed at least in the non-signal recording area where the information signal recording layer on the inner peripheral side of the disc substrate 2 is not formed, and the protrusion amount is approximately equal to the thickness H of the disc substrate 2. Is formed so as to protrude toward the main surface 2b side of the disc substrate 2, and therefore the portion of the disc substrate 2 on which the bulging portion 4 is formed has a thickness twice that of the main body portion of the disc substrate 2. There is.

A magnetic plate 10 made of a metal material surrounds the center hole 3 at the center of the one main surface 2a side of the disk substrate 2.
An annular magnetic plate accommodating recess 5 for accommodating and storing is formed. The inner diameter S of the recess 5 for accommodating the magnetic plate is smaller than the outer diameter R of the bulging portion 4 formed on the other main surface 2b side, and is formed to a depth substantially equal to the thickness H of the disk substrate 2. ing. In addition, the magnetic plate housing recess 5 has a wide opening on the opening edge 5a side with respect to the inner part, which facilitates insertion of the magnetic plate 10 disposed in the magnetic plate housing recess 5.

Further, the bottom surface portion 5b of the recess 5 for accommodating the magnetic plate is formed.
Functions as a mounting surface of the magnetic plate 10 that is stored and arranged,
A chamfered step portion 6 is formed on the inner peripheral side of the mounting surface 5b. This chamfered stepped portion 6 prevents protrusions such as burrs from being generated on the mounting surface 5b of the magnetic plate 10 when the magnetic plate housing recess 5 is formed, and maintains the mounting surface 5b as a smooth surface. It works.

On the other hand, on one main surface 2a of the disk substrate 2, as shown in FIG. 1, an annular stamper groove portion 7 is provided so as to surround the recess 5 for accommodating the magnetic plate. The stamper groove portion 7 forms a pit or a pre-groove that constitutes a recording track, which is a concave-convex pattern corresponding to an information signal, on the one main surface 2a of the disk substrate 2. It is a groove formed by.

That is, when the disc substrate 2 is molded, the stamper is assembled in a molding die by a stamper holder having a stamper supporting claw portion that supports the peripheral edge of the center hole 3, and one of the disc substrates 2 is formed. Main surface 2a
A stamper groove portion 7 is formed on one main surface 2 a of the disk substrate 2 in order to allow the stamper supporting claw portion that protrudes into the cavity forming the above to escape.

On one main surface 2a of the disk substrate 2, as shown in FIG. 1, an outer peripheral wall is formed with an annular protruding portion 8 which rises from the bottom surface of the stamper groove portion 7 on the inner peripheral side. That is, the annular protruding portion 8 is erected inside the stamper groove portion 7, in other words, inside the information signal recording layer so as to surround the magnetic plate accommodating concave portion 5, and as shown in FIG. It is projected to h above one main surface 2a of the substrate 2.

The annular region 9 formed between the opening edge of the magnetic plate accommodating recess 5 and the inner peripheral wall of the annular protruding portion 8 serves as a later-described heat deformable portion on one main surface 2a of the disk substrate 2.
Is composed of.

On the other hand, the metal plate 10 accommodated and disposed in the magnetic plate accommodating recess 5 is a disc-shaped metal material plate such as a stainless steel plate (SUS-430) which is a magnetic material having a thickness t of about 0.4 mm. Punching, and forming a flange portion 12 bent at the outer peripheral edge portion so as to hang down toward the peripheral edge,
It is formed in a disk shape that is entirely concave. As shown in FIG. 2, the magnetic plate 10 has an outer diameter W of the flange portion 12 large enough to be housed in the magnetic plate housing recess 5, and as shown in FIG. The central main surface portion 11 is formed to have a height dimension U that is flush with one main surface 2a of the disk substrate 2 when the disk substrate 2 is housed in the disk.

That is, the height dimension U of the magnetic plate 10 is the depth dimension of the magnetic plate accommodating concave portion 5, in other words, the disk substrate 2.
Is almost equal to the thickness T of.

As shown in FIG. 3, the metal plate 10 having the above-described structure is arranged such that the peripheral surface of the flange portion 12 is applied to the mounting surface 5b of the magnetic plate storage recess 5 so that the magnetic plate storage recess is formed. 5 is stored and arranged from the opening side. After that, several locations of the thermal deformation portion 9 formed in the area surrounded by the magnetic plate storage recess 5 and the annular protruding portion 8, for example, four locations which are displaced from each other by 90 ° as shown in FIG. As shown in FIGS. 5 and 7, the four support pieces 1 projecting into the magnetic plate storage recess 5 are thermally deformed by a method described later.
5 are formed so as to project.

Therefore, the magnetic plate 10 has four circumferences.
At the location, the flange portion 12 is sandwiched between the support piece 15 projectingly formed at the opening edge of the magnetic plate storage recess 5 and the mounting surface 5b of the magnetic plate storage recess 5,
As shown in FIGS. 5 and 6, it is housed and supported in the magnetic plate housing recess 5 and fixed to the disk substrate 2.

In this embodiment, the support piece 15
As shown in FIG. 7, four magnetic disk storage recesses 5 are formed at equal intervals on the peripheral edge of the opening of the magnetic disk storage recess 5.
It suffices to support them, and they may be formed at appropriate locations of at least two locations.

By the way, a part of the heat deforming portion 9 formed on the peripheral edge of the opening of the magnetic plate accommodating recess 5 is thermally deformed to support the support piece 15.
The protrusion is formed in the magnetic plate accommodating recess 5 by, for example, applying pressure while applying a heating iron, or performing swaging on the thermal deformation portion 9. Swing the support piece 15
A case where the magnetic plate housing concave portion 5 is formed so as to project by the edging processing method will be described. As shown in FIG. 4, a contact for applying an ultrasonic wave of an ultrasonic welding machine is provided on the thermal deformation portion 9 of the disk substrate 2. 20 is applied. Then, when ultrasonic waves are applied to the thermal deformation portion 9 from the contactor 20, the resin of the thermal deformation portion 9 in contact with the contactor 20 generates heat due to ultrasonic vibration and is melted. By pressurizing, the part of the thermal deformation portion 9 projects into the magnetic plate accommodating recess 5 and the support piece 15 is bulged.

As described above, the support piece 15 has the thermal deformation portion 9
Since a part of the contact is melted and deformed under pressure, the supporting piece 15 is bulged by the contact 20, and at the same time, the molten resin around the contact 20 rises. The heat-cured portion 9 is hardened and the burr 16 is generated on a part of the thermal deformation portion 9. The burr 16 rises above the thermal deformation portion 9, but an annular protrusion 8 is formed on the outer peripheral side of the thermal deformation portion 9. As shown in FIG. 6, the top surface of the annular protrusion 8 is formed. There is no excitement beyond.

Further, by performing the swaging process, the thermal deformation portion 9 to which the ultrasonic waves are applied vibrates ultrasonically to generate heat and melt, so that a distortion phenomenon of the resin occurs. However, this resin distortion phenomenon is also absorbed by the annular protrusion 8 formed on the outer peripheral side of the thermal deformation portion 9, and the disk substrate 2
Does not extend to the information signal recording layer.

By the way, the information signal recording disk is rotatably housed in a housing which is vertically divided. In general, annular ribs that rotatably accommodate an information signal recording disk by being abutted against each other are integrally provided on the inner surfaces of the upper and lower housings that face each other. These annular ribs support the main surface of the disc substrate in the non-signal recording area where the information signal recording layer on the inner peripheral side of the disc substrate is not formed.

In the above-described information signal recording disk 1 of the embodiment, as shown in FIG. 6, it is located in the vicinity of the outer peripheral portion of the bulging portion 4 formed on the main surface 2b side of the disk substrate 2 from the lower housing 30b. Correspondingly, an annular rib 31b is formed so as to project, but from the upper housing 30a, the main surface 2 of the disc substrate 2
It is difficult to form the annular rib in the non-signal recording area of a because the center hole 3, the magnetic plate housing recess 5, the annular protrusion 8 or the stamper groove 7 is provided in this area.

Thus, an annular rib 31a is erected from the upper housing 30a so as to correspond to the outer peripheral position of the magnetic plate 10, and the annular protrusion 8 of the disc substrate 2 corresponds to the annular rib 31b of the lower housing 30b. It is arranged to face the inner surface of the upper housing 30a.

Information signal recording disk 1 of the above embodiment
In the above description, the annular protrusion 8 is provided upright between the information signal recording layer and the magnetic plate accommodating recess 5, but the present invention is not limited to this. For example, the information signal recording disk 40 shown in FIG. 8 as another embodiment,
On one main surface 42 of the disk substrate 41, a plurality of arc-shaped protrusions 44a to 44d are integrally formed on a concentric circle, located between the information signal recording layer and the magnetic plate accommodating recess 43. Therefore, the regions between the inner peripheral surfaces of the ridges 44a to 44d and the opening of the magnetic plate storage recess 43 are respectively configured as the thermal deformation portions 45, and the magnetic plate 10 stored in the magnetic plate storage recess 43 is disposed. Is supported by a support piece formed by subjecting the heat deformable portion 45 to swaging.

Of course, the other structure of the information signal recording disk 40 is the same as that of the first embodiment, and the description thereof will be omitted.

Although the above embodiment has been described with reference to an example applied to an information signal recording disc, the present invention has a disc substrate made of a synthetic resin and various information having a metal plate to be magnetically chucked. It is widely applicable to signal recording disks.

[0042]

As described above in detail, the information signal recording disk according to the present invention has the protruding portion located between the information signal recording layer and the magnetic plate accommodating concave portion on one main surface side of the disk substrate. Is integrally formed, and at least a part of the heat-deformable portion in the area surrounded by the protrusion and the magnetic plate storage recess is thermally deformed to project the support piece into the magnetic plate storage recess to form the magnetic plate. Since it is attached to the substrate, the magnetic plate is firmly fixed and held on the disc substrate. Further, since the distortion of the heat deformable portion is absorbed by the protruding portion and does not affect the information signal recording layer, the optical characteristics are maintained. further,
Since the interval between the burr generated in the heat deformable portion and the inner surface of the housing is held by the protruding portion, the burr is not scraped on the inner surface of the housing.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an information signal recording disk according to the present invention.

FIG. 2 is a cross-sectional view showing a disk substrate and a magnetic plate that form the information signal recording disk.

FIG. 3 is a cross-sectional view showing a state where a magnetic plate is housed in the disc substrate.

FIG. 4 is a schematic cross-sectional view showing a state where a magnetic plate is attached to a disc substrate by using a swaging method.

FIG. 5 is a cross-sectional view showing a state where a magnetic plate is attached to the disc substrate.

FIG. 6 is a cross-sectional view of essential parts showing a state where an information signal recording disk is housed in a housing.

FIG. 7 is a plan view of the mounting surface side of the magnetic plate of the information signal recording disk according to the present invention.

FIG. 8 is an exploded perspective view of another embodiment of the information signal recording disk according to the present invention.

FIG. 9 is a cross-sectional view of a conventional information signal recording disc.

FIG. 10 is an exploded perspective view showing another example of a conventional information signal recording disk.

FIG. 11 is a cross-sectional view of the information signal recording disc.

[Explanation of symbols]

 1 information signal recording disk 2 disk substrate 3 center hole 4 bulge 5 magnetic plate storage recess 6 chamfered step 7 stamper groove 8 annular protrusion 9 heat deforming section 10 magnetic plate 15 support piece 16 burr 20 contactor 30 housing 40 information Signal recording disk 41 Disk substrate 43 Magnetic plate housing recessed portion 44 Ridge 45 Thermal deformation portion

Claims (3)

[Claims] 1. A disk substrate made of synthetic resin having a center hole formed therein and an information signal recording layer formed on one main surface side, and the center hole is surrounded on one main surface side of the disk substrate. A magnetic plate accommodating concave portion formed by the above-mentioned, and a magnetic plate accommodating and disposed so as to close the center hole, and between the information signal recording layer and the magnetic plate accommodating concave portion on one main surface side of the disk substrate. The protrusion is integrally formed at a position, the region surrounded by the protrusion and the magnetic plate accommodating recess is a thermal deformation portion, and at least a part of the thermal deformation portion is thermally deformed, so that the magnetic plate accommodating recess An information signal recording disk in which a protruding piece protruding from the magnetic disk is formed to support the magnetic plate housed in the magnetic plate housing recess. 2. A protrusion formed integrally on one main surface side of the disc substrate between the information signal recording layer and the magnetic plate accommodating recess is formed as an annular protrusion. Information signal recording disk described. 3. A protrusion formed integrally on one main surface side of the disk substrate between the information signal recording layer and the magnetic plate accommodating recess is composed of a plurality of protrusions arranged concentrically. The information signal recording disk according to claim 1, wherein