JPS6282573A - Disk type information recording medium and its rotary driving method - Google Patents

Abstract

PURPOSE:To use even the area corresponding to a through hole part as an information recording area and to increase the information quantity, by forming no through hole for rotary drive at the center part of a disk and applying the rotary drive force to the fringe part of the disk while supporting this fringe part. CONSTITUTION:An air sandwich type disk information recording medium 11 is composed of two disk substrates 14a and 14b set opposite to each other, the recording layers 15a and 15b provided to the inside surface side of each substrate respectively, and a ring-shaped spacer 16. A rotary driver 12 consists of a disk fixing member 17 and a rotary support member 18. The member 17 is stored in a ring-shaped groove 18a of the member 18 at a base part 17a and at the same time always energized in the reducing direction by springs 19a, 19b,... to support and fix an optical disk 11 attached to the inner circumferential face of the member 17. Then the member 18 revolves the member 17 and the disk 11 in a body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a disc-shaped information recording medium capable of loading and/or reading information, and a method for rotationally driving the disc-shaped information recording medium.

[Technical Background of the Invention] In recent years, disc-shaped information recording media that use high energy density beams such as laser light have been developed and put into practical use. This information recording medium is also called an optical disk, and is advantageously used for applications such as video recording disks, audio◆ disks, large-capacity still image files, and large-capacity computer disk memories.

The basic structure of an optical disk is a disk-shaped substrate made of plastic, glass, etc., and Bi, S, etc.
It has a structure including a recording layer made of a material such as a metal or semimetal such as n, In, or Te.

Information can be written to and read from an optical disc, for example, by the following method.

Information is written by rotating the optical disc at high speed and irradiating the optical disc with a laser beam.The irradiated area of the recording layer absorbs the light and locally rises in temperature, causing physical or chemical damage. Information is recorded by causing a change in the optical properties of the optical fiber. Also reading information from optical discs. Information is reproduced by irradiating a rotating optical disk with a laser beam, and by detecting reflected or transmitted light depending on changes in the optical characteristics of the recording layer. Note that information recording on a read-only optical disk may be performed at the same time as the optical disk is manufactured.

Furthermore, recently, an air sandwich structure has been proposed and used as a disk structure for protecting the recording layer. An optical disc with an air sandwich structure is composed of two disk-shaped substrates, and a recording layer is provided on the substrate-H (the recording layer may be provided on only one of the substrates). It has a basic structure in which a substrate is bonded via a ring-shaped inner spacer and a ring-shaped outer spacer so that the recording layer is located inside and a space is formed. In an optical disc having such a structure, the recording layer can record information without being in direct contact with the outside air.
Since reproduction is performed using laser light that passes through the substrate, there is generally no physical or chemical damage to the recording layer, or dust adhering to its surface, which would impede information recording and reproduction. It has the advantage of

As mentioned above, the disc-shaped information recording medium is extremely useful in various fields, and its recording sensitivity is high, and it is also possible to obtain read signals with a high S/N ratio. High levels of various characteristics are desired. Therefore, many studies have been carried out with the aim of improving these various characteristics, and disc-shaped information recording media that exhibit excellent characteristics in practical use have been commercialized.

On the other hand, research is also being conducted with the aim of increasing the amount of information recorded on disc-shaped information recording media. In other words, a major feature of disc-shaped information recording media such as optical discs is that they can record a large amount of information, and by increasing the amount of information recorded, the advantages of disc-shaped information recording media and the field of use can be improved. This is because expansion can be expected.

[Object of the Invention] The main object of the present invention is to provide a disk-shaped information recording medium in which the amount of information that can be recorded is increased.

SUMMARY OF THE INVENTION An object of the present invention is to provide a disk-shaped information recording medium that can increase the amount of information that can be recorded without having low recording characteristics such as recording sensitivity and S/N ratio.

Another object of the present invention is to provide a method for rotationally driving a disk-shaped information recording medium that increases the amount of information that can be recorded.

[Summary of the Invention] The present inventor has changed the rotational drive of a disk-shaped information recording medium from a conventional method that utilizes the engagement between a through hole provided at the center of the recording body and a rotating shaft, to The amount of recording layer 112 of a disc-shaped information recording medium can be reduced by changing the method to a method using a combination of a rotation shaft and a peripheral edge rotation drive member, or a combination of a recess or a protrusion provided in the center of the recording medium and a rotating shaft. It has been discovered that this increase is possible without deteriorating the recording characteristics, and the present invention has been achieved.

That is, the present invention provides a disk-shaped information recording medium comprising a substrate and a recording layer on which information can be written and/or read, and in which a through hole for rotational driving is not provided in the center of the medium. To provide an information recording medium characterized by the following.

It is also preferable that the above disc-shaped information recording medium is provided with a recess or a protrusion instead of a through hole for rotational driving.

As a method for rotationally driving the disc-shaped information recording medium, for example, a method may be used in which the recording medium is rotated by applying rotational driving force to the peripheral edge while supporting the peripheral edge of the recording medium. I can do it.

In addition, when the above-mentioned disk-shaped information recording medium is provided with a recess or a protrusion instead of a through hole for rotational driving, a support fitting that fits into the recess or protrusion of the recording medium is used to perform the rotation. It is also possible to use a method of rotating the recording medium by changing the rotational driving force to the recording medium while supporting the recording medium.

[Effects of the Invention] The disc-shaped information recording medium of the present invention does not have a central through hole that is found in conventional recording media of the same type.

The area corresponding to the through hole can also be used as an information recording area. Therefore, the disk-shaped information recording medium of the present invention has the advantage that the amount of information that can be recorded is clearly increased compared to the conventional recording medium with holes.

Furthermore, the increase in the amount of information that can be recorded in the disc-shaped information recording medium of the present invention can be achieved without lowering recording characteristics such as recording sensitivity and S/N ratio. It's advantageous.

Furthermore, when manufacturing the disc-shaped information recording medium of the present invention, there is no need for the through-hole forming operation using punching in the manufacturing of conventional recording media with through-holes. There are no problems with chips, dust, etc. adhering to the disc, and there is no problem with recording or reproducing information.

Furthermore, when a recess or protrusion for rotational driving is provided in the disk-shaped information recording medium of the present invention, the tracking group and the recess or protrusion for rotational driving can be provided at the same time. Since no positional deviation occurs between the rotary drive recess or the protrusion, eccentricity of the trunking group does not occur, which is advantageous.

[Detailed Description of the Invention] A disc-shaped information recording medium and a rotational driving method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 to 5 are schematic diagrams showing typical aspects of the configuration of a disk-shaped information recording medium and its rotational drive device according to the present invention, and each is shown as a sectional view.

Figure 1 shows an air sandwich type disc-shaped information recording medium (optical disk) 1 that does not have not only a through hole for rotational drive but also a recess or protrusion for rotational drive in the central part.
1 shows the state in which it is attached to the rotational drive device 12. 13 is an objective lens for writing or reading.

In the air sandwich disk-shaped information recording system shown in FIG. 1, the medium 11 includes two opposing disk-shaped substrates 14a.

14b, a recording layer 15a attached to the inner surface of each substrate;
15b, and a ring-shaped spacer 16 that joins the two disk-shaped substrates 14a and 14b at the inner region of the peripheral edge of the disk-shaped substrate.

The disk-shaped substrate is a substrate formed by forming a glass plate, a plastic plate, a plastic sheet, or the like into a disk shape.

Note that, if desired, one or more intermediate layers (eg, 'F: coating layer, heat insulating layer) may be provided between the substrate and the recording layer.
Similarly, if desired, a protective film may be formed on the surface of the recording layer. In addition, when a recording layer is provided on only one side of the substrate, a material such as silicon oxide, tin oxide, fluoride, etc. is added to the surface opposite to the side on which the recording layer is provided in order to improve scratch resistance, moisture resistance, etc. A protective layer made of an inorganic substance such as magnesium chloride may be provided by vacuum 2pi, sputtering, or the like.

An example of the material used for the recording layer is Te.

Zn, In, Sn, Zr1, An, Ti, Cu, Ge
, Au, Pt and other metals: Bi, AS, Sb and other metalloids;
Semiconductors such as Ge and Si; and alloys thereof or combinations thereof can be mentioned. Compounds such as sulfides, oxides, borides, silicon compounds, carbides, and nitrides of these metals or semimetals; and mixtures of these compounds and metals can also be used in the recording layer.

Alternatively, a combination of dyes and polymers can be utilized.

The recording layer is formed by vapor deposition and sputtering of material listed in L.

It can be formed directly on the substrate by a method such as ion blasting or via a F coating layer or the like. The recording layer may be a single layer or a multilayer, but its layer thickness is generally from 100 to 55 mm in view of the optical density required for optical information recording.
00 angstroms, preferably 200 angstroms.
and 1000 angstroms.

The spacer is generally made of a metal material such as aluminum or a synthetic resin material such as polycarbonate.

In FIG. 1, the L-shaped portion of the peripheral edge of the optical disk 11 is chamfered to facilitate attachment to the rotational drive device 12.

The rotation drive device 12 includes a disk fixing member 17 and a rotation support member 18 that rotates while supporting the fixing member 17. The disk fixing member 17 is configured to be able to expand or contract concentrically around the rotation center axis of the rotation support member 18, and is housed in a ring-shaped groove 18a of the rotation support member 18 at its base 17a. , and is constantly biased in the contraction direction by springs 19a, 19b, and 1111. That is, the disk fixing member 17 is connected to the spring 1 via its base 17a.
9a, 19b, . . . to support the optical disc 11 mounted on the inner peripheral surface thereof.
Fix it. The rotation support member 18 has a function of rotating the disk fixing member 17 shown in L and the optical disk 11 mounted on the inner circumferential surface of the disk fixing member 17 as one body. When such a configuration is adopted, information is written to the optical disk 11 and information read from the optical disk 11 using a laser beam from the side opposite to the side where the one-turn support member 18 is located, as shown in FIG. It is done by irradiating light.

In the I-type optical disc shown in FIG. 1, the recording layer can be provided on the entire surface of the substrate except for the spacer bonding area at the periphery and its surroundings, so that the recordable area is limited to a through hole in the center. It is clear that this is increased compared to the case of some conventional optical discs.

Fig. 2 has a configuration similar to the optical disc shown in Fig. 1, but has a recess (conical depression) 2 that assists rotational drive.
An optical disc 21 with 0a and 20b in the center is shown mounted on its rotational drive device 22. In the embodiment of FIG.

The optical disc 21 has not only a peripheral portion but also a rotational drive device 2.
Since the center is supported and fixed by the protrusion 22a provided at the center of the optical disc 21, there is an advantage that eccentricity can be substantially prevented even if the outer diameter accuracy of the optical disc 21 is low. However, in this case, there is a disadvantage that it becomes difficult to record information on the recording layer directly below the central recesses 20a and 20b of the optical disc.

However, even in this case, the area occupied by the recess can be made smaller than the area occupied by conventional through-holes, making it possible to increase the recordable area compared to conventional optical discs. Become. FIG. 3 shows a state in which an optical disk 31 having recesses 30a and 30b in the center similar to those of the optical disk shown in FIG. 2 is mounted on its rotational drive device 32 and rotational drive auxiliary device 32a. It shows. In the embodiment of FIG. 3, the optical disc 31
is the rotational drive device 32. and rotational drive auxiliary device 3
It is supported, fixed, and rotationally driven by a protrusion 32b provided at the center of 2a.

Similarly to the embodiment shown in FIG. 2, the embodiment shown in FIG. 3 also has the disadvantage that it is difficult to record information on the recording layer directly below the concave portion at the center of the optical disc. However, even in this case, the area occupied by the recesses can be made smaller than the area occupied by conventional through holes, making it possible to increase the recordable area compared to conventional optical discs. Become.

The optical disc 41 shown in FIG.
A recording layer 46 is provided within a tracking group 45 provided on one side. This optical disc 41
A recess 40 is provided at the center of the tracking group side. This optical disc 41 has a projection 42a in the center.
It is supported and fixed by a rotational drive device 42 equipped with a rotary drive device 42 and driven one rotation. Writing information to the optical disk 41 and reading information from the optical disk 41, such as 7g in FIG.
This is done by irradiating laser light from the side opposite to the side where 2 is located.

In the optical disc of the embodiment shown in FIG. 4, the recording layer can be provided on the entire surface of the substrate except for the spacer bonding area at the periphery and its surroundings, and therefore the recordable area is different from that of the conventional optical disc having a through hole in the center. It is clear that this has increased compared to the case of optical discs.

The optical disk 51 shown in FIG. 5 has a recording layer 56 within a tracking group 55 provided on one surface of a single substrate 54, similar to the optical disk shown in FIG. However, the central portion of the optical disc 51 on the side of the tracking group is provided with a protrusion 50 instead of a recess. This optical disk 51 is supported and fixed by a rotational drive device 52 having a recess 52a in the center, and is rotationally driven. To write information to the optical disk 51 and read information from the optical disk 51 in the embodiment shown in FIG. 5, as shown in FIG. It is done by irradiation.

Even in the optical disc of the embodiment shown in FIG. 5, the recording layer can be provided on the entire surface of the substrate except for the spacer bonding area at the periphery and its surroundings. It is clear that this has increased compared to the case of optical discs.

In addition, in FIGS. 1 to 5, various combinations of the disc-shaped information recording medium and its rotational drive device according to the present invention are illustrated, but these combinations may vary depending on the type and size of the intended disc-shaped information recording medium. It is possible to change the status of the term to the term of duty due to such reasons. Further, it is clear that the disc-shaped information recording medium according to the present invention has various embodiments other than those exemplified here, and the disc-shaped information recording medium of such embodiments is also included in the present invention.

For example, disc-shaped information recording media include information recording media that have a recording layer on one or both sides of a single substrate;
Various types of information recording media are known, such as information recording media with a structure in which information recording media having a recording layer on one side are bonded back to back or with the recording layers facing each other, and information recording media with an air sandwich structure. Any of these disc-shaped information recording media are targets of the improved disc-shaped information recording medium of the present invention.

[Brief explanation of drawings]

FIGS. 1 to 5 are schematic diagrams each showing a combination of the configuration of a disk-shaped information recording medium and its rotational driving method according to the present invention. 11.21, 31, 41, 51: Disc-shaped information recording medium (
Optical disk) 12.22, 32, 42.52: Disc-shaped information recording medium (
(Optical disc) rotational drive device 13: Objective lenses 14a, 14b, 44, 54: Substrates 15a, 15b, 46, 56: Recording layer 16: Ring-shaped spacer 17: Disc fixing member 17a: Base of disc fixing member 18: Rotation Support member 18a: ring-shaped grooves 19a, 19b, ass: springs 20a, 20b, 30a, 30b, 40° 50: recess (
Conical recess) 22a, 32b, 42a, 52a Two protrusions 23 Spring 32a Two-rotation drive auxiliary device 45.55:) Racking group patent applicant Tomise Photo Film Co., Ltd. Agent Patent attorney Yasushi Yanagawa Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A disc-shaped information recording medium comprising a recording layer on a substrate on which information can be written and/or read, characterized in that a through hole for rotational driving is not provided in the center of the medium. recoding media. 2. 2. The information recording medium according to claim 1, wherein the disc-shaped information recording medium is an air sandwich type information recording medium. 3. 2. The information recording medium according to claim 1, wherein a recess or protrusion for rotational driving is provided in the center of the disc-shaped information recording medium. 4. 4. The information recording medium according to claim 3, wherein the central recess or protrusion for rotational driving is provided on both sides of the disk-shaped information recording medium. 5. When rotating a disc-shaped information recording medium that is provided with a recording layer on a substrate on which information can be written and/or read and that does not have a through hole for rotational driving in the center, 1. A method for rotationally driving a disc-shaped information recording medium, comprising rotating the recording medium by applying a rotational driving force to the peripheral edge while supporting the peripheral edge. 6. When a disk-shaped information recording medium is provided with a recording layer on a substrate on which information can be written and/or read, and a recess or protrusion for rotational driving is provided in the center, the recording layer is A disk-shaped information recording medium characterized in that the recording medium is rotated by applying a rotational driving force to the recording medium while supporting the recording medium with a support that fits into the recess or protrusion of the medium. rotational drive method.