JPS5864651A - Spacer of optical disk for recording and reproducing information - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spacer for an optical disc for recording and reproducing information. An optical disc device is a device that uses a laser to write and read information in a non-contact manner.

Therefore, the optical disc according to the present invention is an optical disc for recording and reproducing information in which information is written on the disc base and read out as necessary for business use, and is different from the original disc which is made into a replica and is used only for drinking. ing.

Figure 1 is a front view of an optical disc, and (c) is an x-
The cross-sectional view along the x' line is enlarged in the vertical direction to explain the structure.

That is, it is made of a material with good light transmittance, such as glass, acrylic resin, or vinyl chloride resin, and has a thickness of 1 to 2 mm.
rrm disc-shaped substrate l, one side of which is made of tellurium (
, Te), bismuth (Bi), etc.
is deposited to a thickness of several hundred.

The optical disc according to the present invention has a structure in which the surface on which the recording medium is formed is placed on the inside, and two disc-shaped substrates 1 are pasted together at a constant interval of 1 to 2 licards with a spacer 3, so that it does not suffer from damage or wear. . Since the optical disc is donut-shaped with a hole in the center, the spacer 3 for making the two disc-shaped difference plates 1 face each other at a constant distance is made of two ring-shaped pieces, one large and one small, each having a width of several squares. Depending on the type, the two ring-shaped spacers, large and small, are further positioned by a large number of spacers that have the same width and extend radially from the small ring, so that accurate surface finish can be obtained. It is composed of

The reason for this is that when information is written in an optical disk device, the light from the argon laser passes through a modulator, which modulates the light intensity according to the recording signal, and then the objective lens produces a circular spot with a diameter of less than 1 μm. The condensed light irradiates the recording medium 2 of the rotating disk-shaped substrate 1, causing the recording medium in the irradiated portion to evaporate, forming a through hole consisting of an oblong bit in a spiral shape or a six-circular shape. Information is recorded by forming holes on the bit recording surface of the optical disk using a helium-neon laser, and information is read out based on the presence or absence of holes.

In such an optical disc, it is essential to accurately focus the laser beam onto the rotating recording medium section 2, and a focus servo mechanism is provided for this purpose.

However, when the disc-shaped substrate has significant unevenness, the focus servo mechanism does not operate sufficiently, resulting in a decrease in the reliability of the optical disc device.The object of the present invention is to provide a disc-shaped substrate with highly accurate flatness. The method is to improve the structure of the spacer that attaches two disc-shaped substrates, and to provide a U-shaped groove with a semicircular shape on the upper and lower surfaces where the spacer and the disk substrate are bonded. The main purpose of this method is to fill this area with adhesive and bond it in this area to ensure flatness.

Hereinafter, the present invention will be explained with reference to the drawings.

Figure m2 shows the conventional cross-sectional structure of the outer periphery of the original disk substrate.
It is something.

In other words, two disk-shaped substrates l with a recording medium 2 inside are formed so as to be kept at a constant distance by a spacer 3. Conventionally, adhesive is applied to the upper surface 4 and lower surface 5 of the spacer 3 to separate the upper and lower surfaces. A T optical disk substrate having an air side switch structure was fabricated by positioning the substrate on a disk-shaped substrate 1 and applying pressure from the outside.

However, if this method is used, there is a risk that the excess adhesive may spill out into the internal recording medium section 2, and the disk may become distorted due to uneven pressure, which may cause the board surface to warp, resulting in stiffness. This was the cause of the deterioration of the focus servo characteristics.

Fig. 3 shows a structure according to the present invention in which a ring-shaped spacer or a radial spacer is provided, and each spacer, including this, has U-shaped, ■-shaped grooves 6 on the upper and lower surfaces, respectively. The upper and lower surfaces except for the upper and lower surfaces are flattened to a high N degree, so that the flatness of the two disk substrates sandwiching the spacer 3 is not impaired even after the spacer is bonded.

Next, adhere the two disc substrates to the spacer 3 with pressure applied! 5H adhesive is injected and cured.

FIG. 4 is a front view showing the state after the adhesive is injected into the grooves 6 of the spacer 3, and FIG. 5 is a front view showing the state where the adhesive is filled into the grooves 6 of the spacer. It has a U-shaped groove.

Now, the method of filling the grooves with adhesive will be explained as follows.

This ring-shaped spacer is provided with a plurality of guide layers, one of which serves as an adhesive injection groove and the other serves as an adhesive discharge groove. In order to inject the adhesive into the ring-shaped spacer, it is necessary to prepare a syringe that fits into the guide groove and can apply considerable pressure.

Now, the adhesive injection method for the embodiment shown in Fig. 4, which has two radial spacers connecting the inner ring-shaped spacer and the outer ring-shaped spacer and has a guide groove at the intersection, is as follows. become.

First, fill the outer ring-shaped spacer 7 with the guide groove of the inner ring-shaped spacer 8 covered with a jig, for example, by injecting it from the guide tube until the adhesive flows out from the guide groove opening. Continue infusion. In addition, to fill radial spacers, for example, with the guide grooves of the outer ring-shaped spacer excluding the guide groove A closed, the adhesive is injected under pressure through the guide groove A, and the adhesive flows out from the guide groove C of the inner spacer. Just keep going until.

Note that the upper and lower disk-shaped substrates must be held under pressure while the adhesive is injected and until the heat curing process is completed.

FIG. 5 shows a cross section of the spacer 3 formed in this manner. Since the upper and lower disk-shaped substrates l are bonded only at the groove portions 6, the adhesive does not protrude to the 1ζ recording medium portion 2. Further, the flatness of the disk-shaped substrate remains unchanged from the state before the adhesive was injected.

The present invention is an optical disc device! This invention was made by focusing on the fact that the cause of the deterioration of the focus servo characteristics and the decrease in reliability in i1# is due to the "waviness" of the substrate that occurs during the manufacture of the optical disk. i+! From 1tII, I was able to obtain the expected focus servo characteristics.

[Brief explanation of the drawing]

Figure 1 is the front view of the optical disc, and (c) is the front view of the optical disc.
Figure 2 is a cross-sectional structure of the outer peripheral part of a conventional optical disk, Figure 3 is a cross-sectional structure of the outer peripheral part according to the present invention, and Figure 4 is a partial view of a ring spacer and a radial spacer. Further, FIG. 5 is a perspective view of the spacer. In the figure, 1 is a disk-shaped substrate, 2 is a recording medium, 3 is a surface, 6 is a groove, 7 is an outer ring-shaped spacer, and 8 is an inner ring-shaped spacer. After 157 (A) 41 4 figures? 4 fig. 1000 7

Claims (2)

[Claims] (1) In an optical disk for information storage and reproduction, in which two disk substrates made of resin or glass having metal vapor-deposited films on the inner surfaces are fixed to each other with a certain gap in between, the spacers are attached to the disk substrates. 8. A spacer for an optical disc for information recording and reproducing, characterized in that a spacer for an optical disc for information recording and reproducing is provided with a groove on a surface in contact with the bar, and the bar groove is bonded to the disk substrate at the bar groove by filling the bar groove with an adhesive. (2) An even number of guide grooves are provided on the side surfaces of the spacer provided at the inner and outer edges of the optical disk to serve as adhesive injection grooves and discharge grooves, and each injection is performed until the adhesive is discharged from the discharge grooves. 82. An optical disk spacer for information recording and reproducing as claimed in claim 81, wherein the groove portion of the spacer is filled by continuous pressure injection from the groove and bonded to the disk substrate.