JPH05776B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method of manufacturing an optical memory disk in which information is recorded, reproduced, erased, etc. using light such as a laser beam.

<Prior Art> In recent years, optical memory is expected to have great potential as a high-density, large-capacity memory, and various research and development efforts are being carried out in various fields. Generally, a disk-shaped optical memory (optical memory disk) is formed by forming a transparent donut-shaped substrate as shown in FIG. 3 on one side of which a thin film for recording information is formed.

1 is an optical memory disk. This optical memory disk 1
is set in a recording/reproducing apparatus as shown in FIG. 4 to record and reproduce information. As shown in the figure, motor 2
The inner hole 1a of the optical memory disk 1 is fitted into the convex portion of the saucer 3 which is directly connected to the holder 3, and is fixed with a presser foot 4. In this fixed state, the optical memory disk 1 is rotated by the motor 2. Then, the laser beam 5 is focused on a desired portion of the optical memory disk 1 by a condensing lens 6, and a laser spot is irradiated to record/reproduce information. A partially enlarged sectional view of the optical memory disk 1 is shown in FIG. 5, which is formed by providing an uneven guide groove 8 on the surface of a glass substrate 7, and coating the recording medium thin film 9 thereon. Above guide groove 8
is a particularly necessary structure for additional recording type optical discs (recording media such as TeOx) and rewritable optical discs (recording media such as rare earth/transition metal amorphous alloy thin films), and its width is usually 0.7 to 1 μm. , the width is set to 1.4 to 3 μm, the depth is set to about 500 to 800 Å, and is formed in a concentric or spiral shape. Place the above laser spot on optical memory disk 1.
When recording, reproducing, and erasing information by irradiating the laser beam, the laser spot is made to follow along the guide groove 8. At this time, the following characteristics of the laser spot with respect to the optical memory disk 1 depend not only on the tracking mechanism of the optical head that houses the laser device, but also on the whirling of the guide groove 8 when the optical memory disk 1 rotates. . Therefore, it is desirable that the concentricity between the inner hole 1a of the optical memory disk 1 and the guide groove 8 is as accurate as possible (for example, the concentricity is
(about 10μm). However, it is difficult to increase this degree of concentricity, and there is a risk that the glass substrate 7 will break due to machining distortion when providing the inner hole.

<Purpose> The present invention has been made in view of the above-mentioned conventional points, and provides a disk structure that has never been used in optical memory disks in the past. The purpose of the present invention is to provide a manufacturing method that dramatically improves the concentricity.

<Example> An example of the optical memory disk according to the present invention will be described in detail.

FIG. 1 is a partial front view showing the structure of an optical memory disk according to the present invention. Reference numerals 10 and 10 are flat glass disks without an inner hole, and concentric or spiral guide grooves are formed inside the glass disks 10 and 10, and recording medium thin films 11,
11 are formed, and they are bonded together with an adhesive 12. After the adhesive 12 has hardened, while observing the guide grooves through the substrates of the glass disks 10, 10, align the guide grooves and the inner holes 1 of the centering jigs 13, 13.
The centering jigs 13, 13 are adhered to the glass discs 10, 10 while performing centering between them.

Next, an embodiment of the method for manufacturing an optical memory disk according to the present invention will be described in detail.

FIG. 2 is an explanatory diagram of the configuration of an example of a manufacturing apparatus for bonding the centering jigs 13, 13 to the glass substrates 10, 10 with high precision. 14 is a rotary table for centering, and the centering jig 13 is placed on the rotary table 14 for centering, and the optical memory disk body 15 is placed on top of the centering jig 13. In this state, the centering rotary table 14 is rotated at a low speed, and the optical memory disc main body 15 is irradiated with the observation light beam 16. 1
7 is an objective lens for observation. The optical memory disc body 1 is rotated by the centering rotary table 14.
The optical memory disc main body 15 is positioned so that the guide groove 5 does not move within the field of view of the observation objective lens 17, and the state thereof (i.e., the relative positional relationship in the lateral direction between the optical memory disc main body 15 and the centering jig 13) is determined. The centering jig 13 is adhered to the glass disk 10 by an adhesive means while maintaining the centering jig 13. According to this method, the centering jig 1
The centering accuracy of No. 3 depends only on the fitting accuracy between the centering rotary table 14 and the centering jig 13, and it is easy to make the centering accuracy within 10 μm.

Moreover, according to the above method, the optical memory disk main body 15
Since it is not necessary to provide an inner hole in the inner hole, this is extremely convenient especially when constructing an optical memory disk using a glass substrate. In other words, the advantage is that the number of processing steps when cutting out a glass disk from a glass flat plate is reduced, and since the distortion caused by the processing when drilling an inner hole in the glass substrate does not remain on the substrate, warping of the disk is improved and durability is improved. This provides the advantage of improved performance.

In the method for manufacturing the optical memory disk of the present invention described above, the material of the centering jig is a transparent resin such as acrylic resin (PMMA) with surface hardening treatment, or stainless steel or iron with surface treatment such as Cu. You can use what you have prepared. Further, the optical memory disk may be a double-sided disk or a single-sided disk.

<Effects> According to the method for manufacturing an optical memory disk of the present invention described above, a centering jig is adhered to the substrate of the optical memory disk,
The centering jig is used to center the concentric or spiral guide groove formed on the substrate of the optical memory disk, and the centering jig is placed on the centering rotary table, and the centering jig is placed on the centering rotary table. Place the optical memory disk body and observe the guide groove formed on the substrate of the optical memory disk body while rotating them, and position the optical memory disk body so that the guide groove does not move within the observation field. Since the centering jig is bonded, it is possible to bond the centering jig to the optical memory disc body, which is positioned with high accuracy, through a simple manufacturing process.

[Brief explanation of the drawing]

FIG. 1 is a partial front view showing the structure of an embodiment of an optical memory disk according to the present invention, FIG. 3 is a perspective view of a conventional optical memory disk, FIG. 4 is an explanatory diagram of the configuration of a recording/reproducing device, and FIG. 5 is a partially enlarged sectional view of the conventional optical memory disk. In the figure, 1...optical memory disk, 2...motor,
3... saucer, 4... presser foot, 5... laser beam, 6
... Condensing lens, 7 ... Glass substrate, 8 ... Guide groove, 9 ... Recording medium thin film, 10 ... Glass substrate,
11...Recording medium thin film, 12...Adhesive, 13...
...Centering jig, 14...Rotary table for centering,
15... Optical memory disc main body, 16... Light beam for observation, 17... Objective lens for observation.

Claims (1)

[Scope of Claims] 1. A method for manufacturing an optical memory disk in which concentric or spiral guide grooves are formed on a substrate and information is recorded, reproduced, erased, etc. by irradiation with light such as a laser beam, comprising: a core; a first step of placing a centering jig on a rotary table for centering, and further placing the optical memory disc body thereon; and in this state, rotating the rotary table for centering, and forming the centering jig on the substrate of the optical memory disc body; a third step of positioning the optical memory disc main body so that the guide groove to be observed does not move within the field of view in the rotational state; a fourth step of adhering the centering jig to the substrate of the optical memory disk main body while maintaining the same state.