JPH0644363B2 - Optical storage disk substrate - Google Patents

Description

The present invention relates to an optical storage disk substrate for a memory disk that records / reproduces information by light or light and magnetism.

In such an optical storage disk substrate, a guide groove pattern is transferred to the surface of a substrate such as glass by using a molded body for preforming guide grooves (information recording tracks) and a photopolymer resin. At this time, centering within a certain accuracy between the pattern molded body and the disk substrate is an essential item for forming a track pattern with small eccentricity deviation.

The present invention provides a disk substrate structure that facilitates pattern transfer with less eccentricity.

[Problems to be solved by conventional technology and invention]

FIG. 4 is a perspective view of a conventional optical storage disk substrate (hereinafter simply referred to as a substrate).

The substrate 10 is made of glass, acrylic resin, or polycarbonate and has a thickness of 0.6 to 1.5 mm and an outer diameter of, for example, 3 mm.
It is made of flat disc material with a diameter of 00 mm and an inner diameter of 35 mm.

A surface 11 surrounded by an alternate long and short dash line shown on one surface of the substrate 10 is an infinite number of concentric guide grooves (guide grooves not shown) forming surface 11 for stamper molding for recording / reproducing optical information. In the figure, 12 is a through hole in the substrate.

The through hole 12 serves as a reference hole for centering the substrate, particularly when the pattern is transferred by the stamper molding die forming the guide groove.

However, when the substrate material is glass, for example, dimensional tolerance ±
The 50 μm reference hole processing or the polishing of the inner surface of the hole requires a lot of man-hours, which is problematic from the viewpoint of processing.

Further, when acrylic resin or polycarbonate is used as the substrate material, there is a problem that such a polymer molded substrate is soft and it is difficult to obtain the hole machining accuracy of the dimensional tolerance.

[Means for solving problems]

In order to facilitate the centering of the substrate whose processing accuracy is difficult to obtain, the preformed substrate through-hole is coarsely formed with a substrate through-hole having an inner diameter r ₄ slightly larger than the final inner diameter, and has a predetermined dimensional tolerance. A metal ring having a bored inner diameter r ₁ inserted into the through hole of the substrate, and an inner diameter r ₂ (r ₂ > for connecting the metal ring and the substrate across the surface).
r ₁ ), an outer diameter r ₅ (r ₅ > r ₄ ), and an optical storage disk substrate having a metal ring connection structure having a substrate hole with an inner diameter r ₁ by a reinforcing ring.

[Work]

Since the substrate through-holes can be drilled with coarse precision, the work is easy. On the other hand, the metal ring finished to the final substrate through-hole inner diameter is extremely easy to machine to the required dimensional tolerance precision. Since the metal ring and the substrate material are connected to each other via the reinforcing ring, the optical storage disc substrate with a small eccentricity can be realized very easily.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of a metal ring and a reinforcing ring showing a component structure before being assembled to a substrate and connected to a substrate material.

FIG. 2 is a sectional view of an embodiment of the disk substrate assembly.

In both figures, 1 is a metal ring for forming a finished substrate through hole diameter r ₁ within a specified dimension tolerance of at least ± 50 μm or less, and 2 is a reinforcing ring.

The metal ring 1 has the same thickness as the substrate, and its outer diameter r ₃ is formed in an inner metal ring smaller than the through hole 13 (see the sectional view of the assembly in FIG. 2) of the inner diameter r ₄ roughly formed in the substrate material 10. It becomes. The reinforcing ring 2 has a thickness of about 0.1 mm, an inner diameter r ₂ ,
The metal ring 1 and the substrate material 10 are formed to have an outer diameter r _5.
It is a flat plate ring that serves as a mutual connecting member. The inner diameter r ₂ is set to be slightly larger than the through hole diameter r ₁ of the metal ring.

A connecting structure extending between the ring 1 and the substrate material 10 by the flat plate-shaped reinforcing ring 2 will be described from the cross-sectional view of FIG.

First, the metal ring 1 is bonded to the reinforcing ring 2 formed to have the inner diameter r _{2 and the} outer diameter r ₅ (bonding surface 5). Next, the substrate material 10 having the inner diameter r ₄ and the reinforcing ring 2 are surface-bonded as shown in FIG.

In the substrates connected by the adhesive, the rough precision of the through hole 13 is replaced with the high precision processed hole r ₁ of the metal ring 1.

The accuracy of the through hole r ₁ of the metal ring 1 is ±
It can be processed within the tolerance of about 10 μm.

FIG. 3 is a sectional view showing another embodiment of the metal ring provided on the inner peripheral portion of the substrate of the present invention.

As is apparent from comparison with FIG. 2, the metal ring 3 has a hole height of the through hole r ₁ that is thicker by the thickness of the reinforcing ring 2 by 4 so that the shaft that fits with the stamper molding die spindle is formed. There is an advantage that the orientation is enhanced.

〔The invention's effect〕

The optical storage disk substrate of the present invention described in detail above has a remarkable effect that the dimensional accuracy of the substrate centering required for the substrate is arbitrarily set by the metal ring mounted in the inner peripheral hole of the substrate. As a secondary effect, since the substrate inner peripheral hole is made of metal, it has an effect of protecting the inner peripheral edge when the substrate is set in the optical storage disk device.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a metal ring and an auxiliary ring connected to a substrate material of the present invention. 2 is a sectional view of a disk assembly as an embodiment of the connection structure of the present invention, FIG. 3 is a sectional view of another embodiment different from FIG. 2, and FIG. 4 is a perspective view of a conventional optical storage disk substrate. . In the figure, 1 and 3 are metal rings having a hole inner diameter r ₁ , 6 is a reinforcing ring, and 10 is a disk substrate material (or substrate material).

Claims (1)

[Claims] 1. A disk substrate material having an inner diameter r ₄ becomes preformed, metal rings having an outer diameter r ₃ and the inner diameter r ₁ of the predetermined dimensional tolerances inscribed to the inner diameter r _4, span each of the disk substrate material and the metal ring Inner diameter r ₂ (r
₃ > r ₂ > r ₁ ) and an outer diameter r ₅ (r ₅ > r ₄ ), which is a reinforcing ring.