JPH01248374A - Optical disk device - Google Patents

Abstract

PURPOSE:To prevent a focusing error from being generated by performing melt-stuck coupling by absorbing a dimension error on a coupling plane by providing a welding rib on one side of the joining plane of first and second ring shape members which comprise a disk hub. CONSTITUTION:The title device is provided with the first ring shape member 5 fitted in a central hole 2 from the non-information signal reading plane side of a disk substrate 1, and the second ring shape member 6 fitted in the central hole 2 from the information signal reading plane side of the disk substrate 1 and mounted on the disk substrate 1 with the first ring shape member 5 after being joined with the first ring shape member 5. And the welding rib 15 which welds those two ring shape members 5 and 6 is formed protrusively on one side of the joining part of them, and the melt-stuck coupling of the first and second ring shape members 5 and 6 is performed by the welding rib 15. In such a way, it is possible to perform the melt-stuck coupling surely by absorbing the dimension error at the coupling plane of the first and second ring shape members 5, 6.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of Application The present invention is applicable to a magnetic clamp type disk rotation drive device, which has a disk hub having a spindle hole in which a center spindle engages on the main surface of a disk substrate. The present invention relates to optical disk devices such as optical disks and magneto-optical disks that are mounted and rotated.

B0 Summary of the Invention The present invention involves fitting a first ring-shaped member into the center hole of a disk substrate from the non-information signal reading surface side, and attaching a magnetic plate having a spindle hole from the information signal reading surface side of the disk substrate. By fitting the second ring-shaped member into the center hole and joining it to the first ring-shaped member, the disk hub consisting of the first and second ring-shaped members can be attached to the disk substrate without any dimensional error. An object of the present invention is to provide an optical disc device that can be reliably mounted without the need for an optical disc device, and can be reliably rotated together with a disc rotation drive device.

C1 Prior Art Conventionally, optical disks for writing and/or reading predetermined information signals using optical means, magneto-optical disks using optical means and magnetic means, etc. have been used as recording media for recording various information signals. Optical disk devices are known.

As a disk rotation drive device that rotates this optical disk device to write and/or read information signals,
It is known that it uses a magnetic clamp method.

As shown in FIG. 4, an optical disk device that is rotated by a disk rotation drive device using the magnetic clamp method has conventionally used a disk substrate 1 on which a recording layer on which information signals are recorded and a center hole 2 is formed. It is known that a disk hub 4 is attached to the center thereof, and a metal plate 3, which is a magnetic material, is attached to the center of the disk table. The disk hub 4 includes a first ring-shaped member 5 that is fitted into the center hole 2 from the non-information signal reading surface side 1b of the disk substrate 1, and a first ring-shaped member 5 that is fitted into the center hole 2 from the non-information signal reading surface side 1b of the disk substrate 1; A second ring-shaped member 6 fits into the center hole 2 from 1a and is bonded to the first ring-shaped member 5 with a photocuring adhesive or the like to fit and sandwich the disk substrate 1. , the center spindle 3 is attached to the second ring-shaped member 5 facing the magnet 33 of the disk table 32.
There is one in which a metal plate 3 having a spindle hole 7 that is engaged with the spindle hole 7 is attached.

The disk hub 4 made up of the first and second ring-shaped members 5, 6 is conventionally attached to the disk substrate 1 in the following manner. That is, first, the first ring-shaped member 5
is adhered to the non-information signal reading surface side of the disk substrate 1 using a photocurable adhesive or the like, and then the second ring-shaped member 6 is inserted into the center hole 2 from the information signal recording surface side of the disk substrate 1.
The first and second ring-shaped members 5 are fitted into the central hole 2 at the contact surface with the first ring-shaped member 6.
By gluing 36, the disk hub 4 can be attached to the disk substrate 1. This is because if the second ring-shaped member 6 is directly bonded to the information signal reading surface side of the disk substrate 1, there is a risk that cranks may occur on the disk surface in the case of welding, and there is a risk that the bonding area is insufficient for bonding. This is because there is a risk that the strength will be insufficient due to insufficient strength.

The optical disc device having the disc hub 4 as described above can be rotated by a magnetic clamp type disc rotation drive device.

The magnetic clamp type disk rotation drive device for rotating the optical disk device has a magnet 33 that generates a uniform magnetic field in a disk table 32 formed around a center spindle 31, as shown in FIG. 4'. The metal plate 3 is attached to the first ring-shaped member 5 of the optical disc device using the magnet 33.
The optical disc device is integrated into the disc table 32 by magnetically adsorbing it, so that it can be rotated.

Note that at this time, the disc table 33 of the optical disc device
The upper rotational height position is determined by the reference surface section 34 provided on the outer circumference side of the disk table 32 coming into contact with the non-signal recording area IC provided on the inner circumference of the disk substrate 1 on the signal recording surface side.

D1 Problems to be Solved by the Invention By the way, when the optical disc device configured as described above is mounted on a disc table, the optical disc device is integrated with the disc table so that it can rotate.
It is necessary to mount the optical disc device on the disc table with stable suction force. Further, the spindle hole provided in the metal plate of the disk hub must be correctly centered with respect to the recording signal on the disk substrate.

Therefore, in order to maintain the above-mentioned stable attraction force and centering accuracy, the metal plate 3 shown in the HO dimension in FIG. Metal plate 3 at a certain position
must be able to face each other. Specifically, it is desirable that the dimensional error of the HO is within ±0', 05 m1.

However, since the disk hub attached to the center of the disk substrate is one in which the first ring-shaped member 5 and the second ring-shaped member 6 are butted and joined in the center hole 2 as described above, the disk hub 1 is attached to the center of the disk substrate 1. With respect to the thickness For example, if the sum (y+z) of the thicknesses of the fitting protrusions 10.11 is less than the thickness A gap g1 is created between the bonding surfaces of the two ring-shaped members 5.degree.6, making it impossible to maintain sufficient bonding strength. Also,
On the other hand, if the sum (y+z) of the thicknesses of the fitting projections 10°11 is larger than the thickness A gap g2 is generated, and the height position HO of the metal plate 3 disposed on the main surface side of the second ring-shaped member 6 relative to the disk substrate 1 cannot be kept constant. Furthermore, since the disk substrate cannot be sufficiently held between the first and second ring-shaped members, it is also impossible to sufficiently maintain the integration of the disk hub and the disk substrate.

Therefore, when a conventional optical disk device as shown in FIGS. 5A and 5B is clamped to a disk rotation drive device, it cannot be clamped with stable suction force, and the metal plate cannot be mounted at a height position. There is also a possibility that a focus error or the like may occur when writing and/or reading an information signal due to the variation in the information signal.

Therefore, the present invention provides the first ring-shaped member and the second ring-shaped member.
An optical disk device is provided which can solve the above-mentioned problems by forming a welding rib protrudingly on one of the joining surfaces of the ring-shaped member, and by welding and joining the first and second ring-shaped members with the welding rib. The purpose is to provide.

88 Means for Solving the Problems The optical disc device according to the present invention solves the above problems,
In order to achieve the above object, a disk substrate is provided with a recording layer on which information signals are recorded and has a center hole;
a first ring-shaped member that is fitted into the center hole from the non-information signal reading surface side of the disk substrate; and a first ring-shaped member that is fitted into the center hole from the information signal reading surface side of the disk substrate;
a second ring-shaped member joined to the ring-shaped member and attached together with the first ring-shaped member to the disk substrate; and a second ring-shaped member attached to the second ring-shaped member facing the magnet of the disk table and having a center portion thereof. a magnetic plate having a spindle hole, and a welding rib for welding the first ring-shaped member and the second ring-shaped member is formed protrudingly on one of the joint surfaces of the first ring-shaped member and the second ring-shaped member. It is.

F1 action The present invention provides a welding rib provided on either one of the joint surfaces of the first ring-shaped member and the second ring-shaped member constituting the disc hub, so that the first ring-shaped member and the second ring-shaped member are connected to each other. A reliable welding connection is achieved by absorbing dimensional errors in the joining surfaces of ring-shaped members.

G. Embodiments Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that members similar to those of the conventional one are given the same numbers and their explanations are omitted.

The optical disc device according to the present invention is applied as a single-sided type optical disc on which predetermined information signals are written and/or read using optical means, and the optical disc device is used as a one-sided type optical disc for writing and/or reading predetermined information signals using optical means. A disk hub 4 consisting of first and second ring-shaped members 5 and 6 for clamping this disk device to a disk rotation drive device is removed at the center of the main surface on the recording surface side. It is.

The disk substrate 1 is formed by molding synthetic resin such as polycarbonate, glass material, etc. into a disk shape, and
A recording layer, a reflective film, and a protective film layer are laminated so that information signals can be recorded or reproduced on one side thereof. A center hole 2 is bored in the center of the disk substrate 1.

The disk hub 4 attached to the center of the disk substrate 1 is composed of first and second ring-shaped members 5°6G.

The first ring-shaped member 5 can be removed from the non-information signal reading surface side 1b of the disk substrate 1, and
For mounting to the disk substrate 1, use the center hole 2 in the center of the surface side.
A fitting protrusion 10 is provided to be fitted into the fitting protrusion 10, and a flange portion 12 is provided around the outer periphery of the fitting protrusion 10.
The fitting protrusion side of No. 2 is the adhesive surface 12a to the disk base Fj, ■
It is said that

Next, the second ring-shaped member 6 is shown in FIG. 2A.

As shown in I3, a disk table 32 is installed to clamp this optical disk device to a disk rotation drive device.
A metal plate 3, which is a magnetic material that is magnetically attracted by the magnet 33, is integrally attached to the side facing the magnets 1 to 33 by insert molding or the like.

The metal plate 3 is formed by punching into a flat disk shape, and a spindle hole 7 is provided at the center of its main surface, into which a center spindle 31 of a disk rotation drive device engages. . Further, the outer periphery of the metal plate 3 is half-blanked to provide a stepped portion 8 as shown in FIGS. 3A and 3B, and the stepped portion 8 is provided with the second ring-shaped member 6. A plurality of cutout recesses 9 are provided to improve the resin circulation when integrally attached to the IJ by insert molding or the like.

The main surface portion 3a of the metal plate 3 faces the magnet 33 of the disk table 32 provided in the disk rotation drive device, and its flatness is maintained with high precision so that it can receive uniform magnetic attraction. There is.

Further, when the second ring-shaped member 6 is attached to the disk substrate 1, a fitting protrusion 11 that is fitted into the center hole 2 is provided at the center of the surface side, and this fitting protrusion 11
A flange portion 13 around the outer periphery of the disk substrate 1 serves as an abutting surface 13a to the disk substrate 1. In this second ring-shaped member 6, the tip end surface of the fitting protrusion 11 is a joint surface 14 with the tip of the fitting protrusion 11 of the first ring-shaped member 5,
As shown in FIG. 2B, welding ribs 15 are formed on the joint surface 14 in a concentric manner rising up from the center of the ring-shaped member 6. When welding the first ring-shaped member 5 and the second ring-shaped member 6, this welding rib 15 absorbs the error in the thickness of the two fitting protrusions 10.11 and always maintains a constant thickness. The installation is done in the first and second positions.
The ring-shaped members 5 and 6 are to be joined while sandwiching the disk substrate 1.

Note that a plurality of the welding ribs 15 may be arranged intermittently on concentric circles.

The first and second ring-shaped members 5 and 6 configured as described above are attached to the disk substrate 1 in the following order to integrate the disk substrate 1 and the disk hub 4. There is.

First, the first ring-shaped member 5 is attached to the disk substrate 1 from the non-information signal reading surface side 1b of the disk substrate 1. The attachment of the first ring-shaped member 5 to the disk substrate 1 is as follows:
For example, the disk substrate 2 can be
Adhesive surface 12a between the peripheral edge of the center hole 2 and the first ring-shaped member 5
This is done by joining.

Next, the fitting protrusion 11 of the second ring-shaped member 6 is fitted into the center hole from the information signal reading surface side 1a of the disk substrate 1, and
The fitting protrusion 10 of the first ring-shaped member 5 and the welding rib 15 are brought into contact.

Then, the first ring-shaped member 5 and the second ring-shaped member 6 are welded using ultrasonic welding or the like.

During this welding, the welding ridge 15 provided on the joint surface 14 of the fitting protrusion 11 of the second ring-shaped member 6 melts, and the second ring-shaped member 6 and the first ring-shaped member 5 are bonded together. At the same time, the contact surface 132 of the second ring-shaped portion 16 is brought into contact with the disk substrate 1, so that the disk substrate 1 can be reliably held between the first ring-shaped member 5. Do it like this.

That is, the thickness y of the fitting protrusion 11 of the second ring-shaped member 6 is the sum of the thickness Z of the first ring-shaped member 5 (
y+z) is set to be slightly smaller than the thickness X of the disk substrate 1, and the welding ribs 15 make up for the insufficient thickness, so that the disk substrate 1 can be reliably held. Eggplant.

The fitting protrusion 12 of the second ring-shaped member 6 has a diameter that allows it to fit into the center hole 2 of the disk substrate 1 with a slight clearance. Then, when attaching the second ring-shaped member 6 to the disk substrate 1, the spindle hole 7 provided in the metal plate 3 or the disk substrate
It shall be positioned and installed so that it is located at the center of recording.

In this way, by welding and joining the first and second ring-shaped members 5°6 with the welding ribs 15, the abutment surface 13a of the second ring-shaped member 6 with the disk substrate 1 can be reliably bonded. The second ring-shaped member 6 can be brought into contact with the disk substrate 1, and the second ring-shaped member 6 can be always positioned at a predetermined mounting position to ensure reliable attachment of the second ring-shaped member 6 to the disk substrate 1. . Therefore, the mounting height position HO of the metal plate 3 with respect to the disk substrate 1 can always be kept constant.

Further, since the disk substrate 1 can be firmly held between the second ring-shaped member 6 and the first ring-shaped member 5, the disk hub 4 consisting of the first and second ring-shaped members 5. Reliable integration with the disk substrate 1 can be achieved.

H. EFFECTS OF THE INVENTION Therefore, according to the present invention, either of the joint surfaces of the first ring-shaped member and the second ring-shaped member constituting the disk hub can be bonded to the first by the welding rib provided on one side. Since it is possible to weld and bond the ring-shaped member and the second ring-shaped member by absorbing dimensional errors in the coupling surfaces, stable suction force can be generated when this optical disk device is clamped to a disk rotation drive device. At the same time, it is possible to prevent focus errors from occurring when writing and/or reading information signals.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of the optical disk device according to the present invention, FIGS. 2A and B are a plan view and a bottom view of the second ring-shaped member, and FIGS. 3A and 3B are a sectional view of the metal It is a partial plan view of a board, and its sectional view. FIG. 4 is a cross-sectional view of main parts showing a state in which a conventional disk device is clamped to a disk table of a disk rotation drive device, and FIGS. FIG. 3 is a sectional view of main parts showing a joined state. 1...Disk substrate 2...Center hole 3...Metal plate 4...Disk hub 5...First ring-shaped member 6...Second ring-shaped member 7...Spindle hole 10 ...Fitting protrusion 11...Fitting protrusion 15...Welding rib

Claims (1)

[Scope of Claims] A disk substrate on which a recording layer for recording information signals is formed and has a center hole, and a first ring fitted into the center hole from the non-information signal reading side of the disk substrate. and the first member is fitted into the center hole from the information signal reading surface side of the disk substrate, and
a second ring-shaped member joined to the ring-shaped member and attached together with the first ring-shaped member to the disk substrate; and a second ring-shaped member attached to the second ring-shaped member facing the magnet of the disk table and having a center portion thereof. an optical disk comprising a magnetic plate having a spindle hole at the top thereof, and a welding rib for welding the first ring-shaped member and the second ring-shaped member protrudingly formed on one of the joint surfaces of the first ring-shaped member and the second ring-shaped member. Device.