JPS62167638A - Information storage medium - Google Patents

Abstract

PURPOSE:To attain stable information processing without eccentricity by providing a projection fitted to an information storage medium to a member to be absorbed and selecting the size of projection smaller than the thickness of the base. CONSTITUTION:A hub 8 has a center hole 10 fitting an alignment part 9a of a rotary shaft 9 of a medium drive means 3 and adhered to the bases 6, 6 by using an adhesives, e.g., an epoxy adhesives. Further, a projection 8a is formed to the hub 8, the outer diameter is fitted to the inner diameter 6a of the base 6 to be aligned to the base 6. Since the outer face has more accurate accuracy than that of the inner diameter of the base 6, the size h1 of the projection 8a of the hub 8 is selected smaller than the thickness h2 of the base 6 to fit the projection 8a of the hub 8 to the part only with high accuracy so as to keep excellent positional accuracy with less eccentricity. The inner diameter 6a of the base 6 is formed and processed with high accuracy in the coaxial state to the pre-group for recording/reproduction formed to the base 6 and the outer diameter of the projection 8a of the hub and the center hole 10 are processed coaxially with high accuracy. Thus, stable information processing is attained.

Description

[Detailed Description of the Invention] 1. Field of Industrial Application] The present invention is directed to driving an optical disk or other optical disk and recording, reproducing, or erasing information using a laser beam or the like during its rotation. The present invention relates to an improvement in an information storage medium used in an information processing device that facilitates information processing.

(Prior Art) In recent years, information processing devices that use optical disks as storage media have been able to significantly increase the information storage capacity compared to magnetic information processing devices that have been widely used in the past. In addition to obtaining extremely good and stable information playback conditions with minimal exposure to external influences, the storage condition is extremely stable, and information processing can be performed in a non-contact manner, preventing damage to the storage medium and information processing head. It is increasingly being used because it has the advantage of not having any negative effects.

In addition, with this trend toward increased use, there has recently been a demand for information processing devices of this type, such as information recording/reproducing devices, to be as thin, lightweight, and cost-effective as possible.

On the other hand, in the conventional apparatus, as shown in FIGS. 6 and 7, an information storage medium (optical disk) a is placed on a turntable b.
+: When fixed, the information storage medium (optical disk) a is pressed against the turntable b side via a clamper C.

The one shown in FIG. 6 is configured to apply a pressing force to the clamper C via a support means e equipped with a biasing body d such as a spring, and the one shown in FIG. f is attached, and a pressing force is applied to the clamper C by the magnetic attraction force generated between it and the turntable b made of a magnetic material.

[Problem that the invention seeks to solve]

However, all of these conventional devices not only require the clamper C, but also have to create a movement space necessary to move the clamper C, and also have to create a space for moving the clamper C. A number of structures, etc., are required. For this reason, the structure of this part becomes complicated and large, which not only becomes a major obstacle to achieving 3-type design, compactness, and cost reduction, but also the assembly process.

There were problems such as troublesome maintenance.

Furthermore, in the former case (Fig. 6), since the turntable a is always subjected to force, the turntable b and the rotating shaft Q that is integral with it must be made strong.
In addition, in the case of the latter (Fig. 7), the clamping force varies depending on the thickness of the information storage medium a, and if the information storage medium a is relatively thick, such as two sheets of substrate pasted together, There is a problem in that there are cases where it cannot be held.

Furthermore, conventionally, the inner diameter part i of the information storage medium a, that is, the inner diameter part of the synthetic resin substrate, is directly fitted into a positioning part j formed on the Coon table b side for positioning. Therefore, the diameter of the inner diameter part i of the information storage medium a may change due to wear over a long period of time. There is a serious problem in that the distance between the two ends of the disc becomes large, which adversely affects the recording/reproduction of information.

The present invention has been made based on the above circumstances, and its purpose is to reduce the thickness, weight, and cost of information storage media without using a clamper, which is an obstacle. Can be installed easily and securely regardless of thickness,
Furthermore, the present invention aims to provide an information storage medium that is free from eccentricity and capable of stable information processing.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention is a turntable that is HWed and rotationally driven by a turntable that houses magnetic circuit forming members that form a magnetic circuit in four parts, and a magnetic circuit is attached to the turntable side at the center of rotation. Attached is a member to be attracted which has a central hole that is attracted to the object and serves as a center of rotation.
An information storage medium having a recording layer and a substrate, wherein the attracted member has a convex portion that fits with the information storage medium, and the dimension of the convex portion is set to be smaller than the thickness of the substrate of the information storage medium. It is.

[Effect]

That is, with the above configuration, the present invention enables the information storage medium to be magnetically attached to the turntable, thereby making the device thinner, lighter, and lower in cost than conventionally required. It becomes possible to eliminate the need for a clamper that becomes an obstacle. Further, the dimension of the convex portion of the attracted member is set smaller than the thickness of the substrate of the information storage medium so that it can be fitted only to a portion with a good finish rather than a portion with a poor finish caused by the molding conditions of the substrate. Accordingly, it is possible to easily obtain eccentricity with good accuracy, and stable information processing becomes possible.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 shows the book in the installed state, and FIG. 2 shows the uninstalled state. In the figure, 1 is an information storage medium (hereinafter referred to as a disk) housed in a cartridge 2. This disk 1 is inserted together with the cartridge 2 into a medium insertion/ejection opening formed in the main body (not shown) of the information processing device. It has become so.

The disk 1 inserted together with the cartridge 1-ridge 2 is automatically taken into a predetermined position and in a horizontal state by a medium take-in mechanism (not shown).
The center of rotation is opened so that a part of the disk 1 is exposed. Thereafter, the cartridge 2 is displaced in the plane direction, and the disk 1 is automatically mounted on the turntable 4 of the medium drive means 3.

The disk 1 includes two substrates 6 having an information recording layer 5.
, 6 are bonded across the inner spacer 7 and the outer spacer (not shown) so that the information recording layer 5.5 is on the inside, and an attracted member (14i It has a configuration in which a metal member (hereinafter referred to as a hub) 88 is attached as a flexible material.

The substrate 6.6 is made of an injection-molded transparent synthetic resin plate, and is bonded to the inner spacer 7 and the outer spacer via an ultraviolet curing adhesive.

Further, the hub 8 has a shape having a center hole 10 that fits into the centering portion 9a of the rotating shaft 9 of the medium drive means 3, and has an adverse effect on the substrate 6.6. It is bonded with an adhesive that does not give any damage, such as an epoxy adhesive.

Further, the hub 8 is formed with a convex portion 8a, as shown in detail in FIG. There is.

FIG. 4 shows the state of the substrate 6 during molding, and in order to shorten the processing time, the inner diameter portion 6a, which is the center hole, is simultaneously drilled.

In the figure, A is a fixed type, B is a movable type, and C is a sprue bushing (die) guided by a bushing guide D on a fixed type A.
, and E is a punch guided by a punch guide F.

In the state shown in the figure, the molten synthetic resin material a flows into the sprue bush (die) C as shown by arrow A.
After pouring into the cavity H formed on the mutually opposing surfaces of the fixed mold A and the movable mold B through the sprue G formed in the hole, the punch E moves in the direction of the arrow to form the inner diameter part 6a. Become.

At this time, as shown in FIG. 5, a stepped portion 6b is formed on the inner diameter portion of the substrate 6. This is caused by the resin in the gate portion being peeled off when it is cut by the punch E, and the stepped portion 6b protrudes from the surface opposite to the outer surface of the substrate so that its inner diameter becomes smaller.

Although the difference in level of this step portion 6b is small, the surface is not smooth and the accuracy is poor.

In this way, since the inner diameter of the substrate 6 has better accuracy on the outer surface side of the substrate 6, the dimension h1 of the convex portion 8a of the hub 8 is
The thickness h2 of the hub 8 is set to be smaller than the thickness h2, and the convex portion 8a of the hub 8 is fitted only in a highly accurate part, thereby maintaining good positional accuracy with little eccentricity.

The inner diameter portion 6a of the substrate 6 is precisely molded to be coaxial with a pre-group for recording and reproduction (not shown) formed on the substrate 6, and the outer diameter portion of the convex portion 8a of the hub 8 and the hub 8 The center hole 10 of is coaxially machined with high precision, so that the center of the pre-group and the rotation axis of the rotation shaft 9 can be aligned. This makes it possible to prevent problems such as a decrease in recording/reproducing accuracy and an increase in access time caused by eccentricity.

Further, the medium driving means 3 includes an outer rotor type brushless DC motor 11 having a motor shaft as the rotation shaft 9, and a turntable 4 attached to the rotation shaft 9 of the motor 11. ing.

The turntable 4 is made of a non-magnetic metal material, and has a recess 4a formed on its upper surface. A magnetic circuit forming member 14 consisting of a magnet 12 and a yoke 13 that magnetically attracts the center hub 8 of the information storage medium 1 is housed in the recess 4a. This is to ensure that sufficient force is exerted to mount the disc 1 on the turntable 4 and to prevent leakage of magnetism to the outside.

Further, the hub 8 has an outer diameter smaller than the outer diameter of the recess 4a formed on the upper surface of the turntable 4, and is configured to rotate through the center hole 10 of the center hub 8 as shown in FIG. When the disk 1 is mounted while being fitted into the positioning portion 9a of the shaft 9, the hub 8 is accommodated in the recess 4a. The substrate 6 having the information recording layer 5 of the disc 1 is brought into direct contact with the outer annular table surface 4b of the turntable 4.

Then, the substrate 6 having the information recording layer 5 of the disk 1 is firmly pressed against the turntable 4, and the vibration in the direction perpendicular to the surface of the substrate 6 is reduced, thereby ensuring stable information. It has a configuration that allows recording and reproduction.

If the hub 8 and the table surface 4b of the turntable 4 are in contact with each other, the parallelism between the surface of the hub 8 and the surface of the substrate 6 must be made very precisely.
Since the runout increases, the wall thickness of the hub 8 and the thickness of the adhesive must be made uniform, which is an extremely difficult task.

On the other hand, the length of the centering part 9a of the rotating shaft 9 of the medium drive means 3 is limited to a length that fits only into the center hole 10 of the hub 8 on the turntable 4 side, and ，
The configuration is such that the coaxiality of the center holes 10 and 10 of 8 does not pose much of a problem.

In addition, the inner diameter portions of the two substrates 6.6 and the two hubs 8,
Making the center holes 10 and 10 of 8 coaxial is a very difficult task, and if the length of the centering part 9a is longer than necessary, it will take time to attach it to the turntable 4, and it will cause wear and tear. This becomes a problem from the viewpoint of

In addition, since a magnetic circuit is formed in the recess 4a of the turntable 4, magnetic leakage to the outside is minimized, so powder of magnetic materials such as iron powder may adhere to the rotating shaft 9. This prevents the hub 8 from being unable to fit properly.

Further, an appropriate gap G is formed between the hub 8 and the magnet 12 and yoke 13 housed in the recess 4a of the turntable 4, so that the substrate 6 of the disk 1 and the table surface 4b are in direct contact with each other. It becomes. In addition, the above-mentioned gap G is an appropriate gap that allows the driving force of the turntable 4 to be reliably transmitted to the disk 1, and also allows the disk 1 to be easily removed from the turntable 4 by simply lifting the cartridge 2 containing the disk 1. This is to mount the disc 1 with a strong suction force (mounting force).

Note that 15 shown in FIG. 2 is a frame on which the motor of the medium driving means 3 is mounted, and 16 is a control board for controlling the drive of the motor 11.

Further, 17 shown in FIG. 3 is a head that moves in the radial direction of the disk 1 by a head moving means such as a linear motor (not shown). Information processing such as recording or reproduction is performed on the information recording layer 5 formed in the tf6.

In addition, in one embodiment of the above, both the inner diameter part and the outer diameter part are used as the yoke 13 of the magnetic circuit forming member 14 that is housed in the recess 4a of the turntable 4 that magnetically attracts the information storage medium of the present invention. Although the configuration has been described with respect to the structure having the raised portions 13a and 13b, the structure is not limited to this, and for example, the structure may have the raised portion only on one of the inner diameter portion or the outer diameter portion.

In general, the center hub 8, which is a member to be attracted and which is attached to the center of rotation of the disk 1, is not limited to being machined, and may be, for example, pressed.

〔Effect of the invention〕

As explained above, the present invention is mounted on a turntable that accommodates a magnetic circuit forming member that forms a magnetic circuit in a recessed part and is driven to rotate, and is magnetically attracted to the turntable at its center of rotation. The information storage medium has a recording layer and a substrate, the attraction member having a central hole serving as a center of rotation attached thereto, the attraction member having a convex portion that fits into the information storage medium. However, the dimensions of the convex portion are set to be smaller than the thickness of the substrate of the information storage medium. Therefore, since the information storage medium can be magnetically attached to the turntable, it is possible to eliminate the need for a clamper, which is an obstacle to making the device thinner, lighter, and cheaper than previously required. becomes. Also,
The dimension of the protrusion for positioning the above-mentioned member to be attracted is set smaller than the thickness of the substrate of the information storage medium. By making this possible, it is possible to easily obtain an information storage medium with good eccentricity accuracy, and it is possible to provide an information storage medium that is free from eccentricity and allows stable information processing.

[Brief explanation of drawings]

Figures 1 to 5 show one embodiment of the present invention.
The figure is a cross-sectional view showing the state in which the hub, which is the main part, is installed. Figure 2 is a schematic configuration explanatory diagram partially sectionally showing the state in which the information storage medium is not installed. Figure 3 is a cross-sectional view showing the state in which the information storage medium is installed. 4 is an explanatory diagram showing the state of the disk substrate during molding; FIG. 5 is an enlarged sectional view showing the state of the inner diameter portion of the substrate after molding; FIGS. 6 and 7. The figure is a schematic cross-sectional view showing a state in which a conventional example is attached. 1... Information storage medium (disk), 4... Turntable, 4a... Recessed part, 8... Attracted member (hub)
, 8... Convex portion, 10... Center hole, 14... Magnetic circuit forming member. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 4 Figure 5

Claims (1)

[Claims] It is mounted on a turntable that houses a magnetic circuit forming member that forms a magnetic circuit in its recess and is driven to rotate.The center of rotation has a center hole that is magnetically attracted to the turntable and serves as the center of rotation. an information storage medium having a recording layer and a substrate, wherein the attraction member has a convex portion that fits with the information storage medium, and the size of the convex portion is set according to the size of the substrate. An information storage medium characterized in that the thickness is set to be smaller than the thickness of the information storage medium.