JPS58177536A - Recording disk - Google Patents

Abstract

PURPOSE:To generate a signal for tracking with high precision at low cost by providing a layer where a spiral porjection-recess signal for tracking is provided concentrically on a recording medium provided on a base disk. CONSTITUTION:A recording film 12 is formed over the base disk 11 and the layer 13 having the projection-recess signal for tracking is provided thereupon. This layer 13 serves as a protection layer and is irradiated with laser light 14 from the layer side 13 for recording and reproduction. For manufuacture, a Te-C film as the recording medium is formed on a polycarbonate base plate by sputtering in an atmosphere of gaseous CH4 and this Te-C film is coated with a photopolymer uniformly. Then, a transparent original disk where the projection-recess signal for tracking is recorded is placed on the photopolymer to press the transparent original disk against the base disk tightly, and then the transparent original disk side is irradiated with ultraviolet rays in said state to polymerize and cure the photopolymer, and thus the porjection-recess signal on the transparent original disck surface is provided onto the Te-C film as the recording medium.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention #! A relates to an improvement of an optical recorder type recording disk provided with concentric circular or spiral tracking unevenness signals.

[Prior art and problems]

In order to record information signals and facilitate random access, uneven signals for tracking, such as groups, pits, and addresses, are provided on the substrate. These are many replicas (duplicated discs) based on the M disc on which uneven signals for tracking have been recorded in advance.
How to create a replica #
In the usual case, the injection topography method, the compression method, the cylindrical method, the photoformalization method, etc. are used. Among the existing replica production methods, methods other than the casting method and the photopolymerization method are used when creating a large number of replicas, but there are problems in that perfect transcription cannot be obtained, and there are problems during molding. Birefringence occurs due to residual stress, and the equipment becomes larger due to the necessity of pressure treatment. In particular, in the case of an optical recording/reproduction type recording disk, as shown in FIG. 1, the laser beam 1 for recording and reproduction is projected onto the recording medium 3 through the substrate 2, so the substrate 2 is birefringent? It must be optically uniform with no r-rate.

As the recording density of information signals increases, the uneven signals of tracking groups, bits, addresses, etc. provided on the substrate will also become finer, improving transferability.

In order to remove the birefringence at the same time, the material for replicas used for extrusion molding and pressure molding is fIIti! Improvements in I2I properties are eliminated from the use of gold iron, and it is not possible to address the drawbacks that normally occur, such as a decrease in heat resistance and a decrease in #mulberry d6 properties.

The casting method is used to make 9 noodles (r-1), and its advantages are that the transfer fWk is excellent and that the light character ifJ has no refraction and is homogeneous. However, since it requires a negative time (5 hours or more) to heat and harden the replica material, the workability is extremely low.

Products made using the injection molding method, pressure molding method, or casting method C usually have a shape similar to that of a second layer. 4 is the created replica.

In addition, in the photoformalization method, which is a method that uses a replica material in which the resin is made into 9 bags by exposing it to external radiation, the photopolymer is quite expensive, and the photopolymer is thin and 7 lexiple. Even if it's a record #iI it's still 47 Otopoli! However, manufacturing thick, rigid recording discs alone poses a major problem in terms of cost.

On the other hand, #3 Figure 6 = @! for tracking consisting of a 6-nitropolymer on a rigid substrate 5 as described. A signal recording layer 6 is provided, and on the signal recording layer 6 (a second recording medium 7 is disposed) a laser beam 8 for use in the recording medium is composed of base #/15 and photo poly!-. Since the signal is focused on the recording medium 7 through the signal recording layer 6, the substrate used must also be transparent and homogeneous with no birefringence. I: A big problem arises in terms of cost, including processing.On the other hand, there is a need to prevent scratches on the recording medium, and a decrease in B/N due to dirt adhesion.
Nineth, to prevent film deterioration due to oxidation of the recording medium,
In this case, the laser beam [0] is focused on the recording medium 7N through the condenser layer 9 provided on the recording medium 7.

Although the problem of optical homogeneity and transparency of the substrate is solved, the formation of a replica made of photopoly-CR on the substrate, the attachment of a recording medium by vapor deposition or sputtering, and the formation of a clarity layer are difficult. The disadvantage was that the process was complicated.

[Purpose of the invention]

The present invention was made in order to eliminate the above-mentioned drawbacks, and it requires less time and energy for manufacturing, is inexpensive, can form a signal for simple coffin vibration, and is optically transparent. The purpose of the present invention is to provide a homogeneous recording disc with no bending properties. This is a recording disc on which a layer on which a concave-convex signal for tracking is arranged is arranged, and the layer on which a concave-convex signal for tracking is arranged is made of a photosensitive resin layer. [More specifically, it is a recording disc made of glass, metal, or glass. [Embodiments of the Invention] Hereinafter, an embodiment of the present invention will be described using the drawings. I will clarify.

Figure 4 shows a simple embodiment of the present invention, and a record 812 is formed on this base mll at 11#i basis in figure 0. Then, this recording [layer 1 having unevenness signals for tracking on layer 12]
3 is provided. Here, 413 also serves as the first layer. For recording and reproducing on the recording disk of the present invention having such a configuration,
As shown in this figure, for example, the layer 13- is irradiated with a laser beam 14 to grow the bamboo.

Next, a method for manufacturing a recording disk according to the present invention will be described. 4mm thick polycarpone) AM 1-2 To- as a recording medium
am is sputtered in OH4 gas, and this τe-a
7 Otobori I- was applied uniformly on the ll.

Next, a transparent master disc on which the uneven signal for tracking has been recorded is placed on top of the photopolymer, and after the transparent VA master disc and the base are brought into tight contact, ultraviolet rays are irradiated from the tube/transparent master side in this state to coat the photopolymer. Cr on the To-C film, which is a recording medium that produces uneven signals on the transparent master surface by polymerization and hardening! &
It is molded by applying heat. After that, Tooru 911
If the disc is peeled off, a recording disc with an uneven tracking signal transferred thereto can be obtained.

The main components of the photopolymer were a radically polymerizable prepolymer with an unsaturated group and a polymer with an ethylenically unsaturated group, with some polymerization initiators and auxiliaries added. The main ingredients are acrylic or methacrylic acid monoesters, diesters, triesters, and tetraester monomers and oligomers, with the addition of Asahi's polymerization initiator and Asahi.
It is not limited by the material quality of the sign (, 2bO ~ 37
Irradiation with ultraviolet light of 0 nrn will make it more difficult.
Alternatively, it may be one that forms a three-dimensional network structure.

The ideal base is a Fi rigid body with no deformation.
For example, in the case of recording and reproducing from the layer 131 full as shown in Figure 4, f2 is made of Tanigusu gold, glass, and a gelastec material that is thermoset in a heat molding process, and its thickness is 0.5 ~
The range of lO■ is preferably fjM.

Recording media include heat mode methods such as Te-C, organic fermentation, metal acid, semi-alloy thin films, and composite films.

Photon mode method, magneto-optical method, etc. are not particularly useful.

As explained above, the present invention has a recording medium split into two parts on a substrate, and a circular or spiral tracking unevenness signal is provided on the recording medium. Since recording and reproduction are performed through the uneven signal layer, the substrate is not limited to the A size, and can be selected from a wide range of widths as long as it is flat. Furthermore, C: The injection molding method and compression molding method, which are considered to be necessary to create a large number of replicas, have problems with transferability and birefringence. Because it is not only accumulated, the base material can be widely selected and is heat resistant.

Chemical resistance 9 Dimensional stability, moisture resistance C It is possible to choose from a wide range of tested materials. In addition, as shown in FIG. 1-C: The uneven signal layer 13 for tracking consisting of photo holes 17-v- on the recording medium can also serve as a recording layer, so that the recording medium can be This has the advantage of simplifying the configuration and manufacturing process.

Therefore, according to the present invention, it is possible to form a recording disk with high a-axis properties, which is easy to mass produce, is inexpensive, and has excellent transfer of unevenness signals for tracking.

[Brief explanation of drawings]

Figure 181 is a cross-sectional view of a recording disk with a conventionally known optical recording/reproducing layer, Figure 2 is a cross-section Tki diagram of a molded replica, and Figure 3 is a conventionally known optical recording disc. FIG. 4 is a sectional view of a II# reproduction type recording disc according to the present invention C2. 11-...Base 12...Record screw 13...
・Irregularities for tracking
or 1 person) Figure 1 Figure 2

Claims (2)

[Claims] (1) On board A - on the diagonal recording edge - the layer on which an in-core or spiral tracking unevenness signal is provided Arrangement of academic formula h pirou nyu type 1 (2) A record disc containing a No. 1D unevenness for tracking. 1,! An optical recording/reproducing type recording disc described in J.