JPS60147391A - Optical-type information recording medium - Google Patents

Abstract

PURPOSE:To enable excellent photosensitive characteristics for laser light, by a construction wherein a plurality of recording layers are laminated, and the adjacent recording layers are formed respectively of different photosensitive materials. CONSTITUTION:The recording medium comprises a plurality of recording layers, the adjacent ones of which are formed respectively of different photosensitive materials. The recording layers 22, 23 and 24 are sequentially laminated on a base 21. Namely, the base 21 is spin-coated with an IR- and UV-absorbing material A by using a solvent (a) which does not attack the base 21, followed by evaporating off the solvent (a) to provide the recording layer 22, which is spin-coated with a near infrared ray absorbing material B by using a solvent (b) which does not attack the layer 22, and the solvent (b) is evaporated off to provide the recording layer 23. Then, the recording layer 24 is provided in a similar manner. With the construction wherein the material B is sandwiched by the layers of the material A, the shapes of pits formed in the recording layer upon sublimation complement each other, and the shapes at the boundary of a pit and a non-pit part as a whole are not seriously affected by noise wavelength components of the laser light used, so that generation of noise at the time of reproduction can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION 111 The present invention relates to an information recording carrier, and particularly to an optical information recording carrier having a recording layer sensitive to laser light.

1. An optical recording and reproducing method is well known, which is a method of recording and reproducing information such as video and audio using an optical information recording carrier having a recording layer sensitive to laser light. . In such an optical recording/reproducing method, in order to record information,
Information is recorded by irradiating the surface of the recording layer of an optical information recording carrier such as an optical recording/disc with a laser beam modulated in a predetermined manner according to an information signal to form a row of pits. . A conventional optical information recording carrier usually has a cross-sectional structure as shown in FIG. The base 1 is made of glass, acrylic resin, vinyl resin, polyether 461.
1ft, epoxy resin, polycarbonate resin, □ polybutyral resin, cellulose acetate butyrate resin, nido 0 cellulose 4! It is made of materials selected from Jllll and others. As a record 11!2 for forming pits on this base 11A1, an IN made of a material that sublimates when exposed to laser light is provided.As a material that sublimes by laser light, for example, Sensitizer (
Examples include those in which a dye) and a binder such as nitrocellulose are dissolved in a ketone solvent. Further, in order to make the thickness of the recording layer 2 uniform, the recording layer is formed by a method such as a spin code method. In this case, the above group lA1
For example, 200r, D, I around the center circle.
.

The solution of the photosensitive material on which the recording layer 2 is to be formed is dripped onto the substrate through a nozzle that moves gently in the radial direction while rotating in steps. The rotational speed is increased to about 1000 yen, the excess solution is shaken off, and a uniform solution layer containing the photosensitive material is formed on the substrate 1.Then, the solution layer is dried to volatilize the solvent components, and recording is performed. Form layer 2.

However, it became clear that it was difficult to obtain a recording layer with good photosensitivity to a laser beam of a certain wavelength using a single photosensitive material, and a photosensitive material P! of 2171 or more was used.
It has been considered to form a recording layer by mixing I.

However, in order to form a recording layer made of two or more types of photosensitive materials, it is necessary to obtain a solution using a solvent that is compatible with the two desired photosensitive materials and perform spin coating. There is a problem in that the freedom of choice of photosensitive materials is limited. Furthermore, when selecting a compatible solvent, consideration must be given to the condition that it does not have an adverse effect on the substrate 1, such as dissolution or swelling, and there are severe restrictions on the combination of photosensitive materials and solvents. It exists.

An object of the present invention is to solve the above-mentioned problems and to provide an optical information recording carrier that has superior photosensitivity to laser light.

'In the optical information recording carrier according to the present invention, a plurality of recording layers are stacked and at least adjacent recording layers are formed of different photosensitive materials.

Big JE defeat- An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a cross section of an information record carrier according to the invention. That is, 1121 is glass, acrylic resin, vinyl resin, polyether resin, Evo: 1 resin, polycarbonate resin, polybutico 2. resin, 13. ,.

-Near T car, 7chi, -8 resin, 7 Nitrocell[]-
It is made of a material selected from plastics, etc. first recording layer 2
Reference numeral 2 denotes a thin film layer of an infrared ray and mushroom external ray absorbing material formed on a substrate 21 by a spin code method.

The second recording layer 23 is a film layer of near-infrared absorbing material B formed by thinning the recording layer 22 by a spin coating method.The third recording layer 24 is a recording layer. 23 years old.

A recording layer formed by registering IQ using the bottle coating method.

It is a thin film layer of the same infrared and ultraviolet absorber FIA as No. 22.

In the process of forming the plurality of recording layers 22, 23 and 24, they are sequentially laminated on the substrate 21. Zunawachi WIi! The recording layer 22 is formed by spin-coding the infrared and ultraviolet absorbing material using a solvent a that does not affect the recording layer 21, and after drying the solvent a, the near-infrared absorbing material is coated with a solvent a that does not affect the recording layer 22. After spin-coding the material and drying the solvent, a record m23 is formed. Next, the recording layer 24 is formed using the same FA as the recording layer 22. In this way, by forming the infrared and ultraviolet absorbing material to sandwich the near infrared absorbing material B, the shapes of the bits after the recording layer are complementary to each other, and the bit and non-bit portions are complementary to each other. As a whole, the shape at the boundary is not significantly affected by the noise wavelength component of the laser light used, and noise during reproduction can be prevented.

It goes without saying that the adjacent recording layers are made of different materials and are dissolved in different solvents and formed by a spin coding method or the like.

In addition, in the example described in "-", an infrared and ultraviolet absorbing/photosensitive material was used as the photosensitive material 11, but a material having water resistance, solvent resistance, and 1ρ resistance in addition to photosensitivity was used for the recording layer at °C. It is also possible to form each layer using a composite material thereof. Such as water resistance, solvent resistance,
The photosensitive material that determines weather resistance is not shown in FIG.
It is preferable to stack the recording TlI 23 between them as shown in FIGS. .

For example, Fig. 3 shows the transmittance (I
), (II), (III) different photosensitive materials (I
>, (II)1. When (■) is used, a photosensitive TUG is spin-coded into 33131-J- using a different solvent and laminated. By doing so, the mutual photosensitive characteristics are complemented, and good overall characteristics can be obtained for laser light having a wavelength of 8301 m, for example.

In other words, each recording layer having sensitivity characteristics of (■) and (III) does not respond to low-frequency laser light, and has sensitivity characteristics of (I) without being affected by low-frequency laser light. This makes it possible to compensate for the shape deterioration at the boundary between the sublimated bit and the non-pit portion of the recording layer having a good pit boundary shape that penetrates the entire recording layer.

According to the present invention, by laminating photosensitive materials that could not be catalyzed due to the lack of a common compatible solvent to form an i\ film, laser light It is possible to obtain a recording layer that is not adversely affected by the noise wavelength component in the recording layer and has a steep overall absorption characteristic for a predetermined wavelength component. In general, it has become possible to use a combination of materials with various UV resistance, infrared ray resistance, water resistance, solvent resistance, and weather resistance, and the complementary effects of these materials can be used to improve overall performance. It becomes possible. In other words, it is possible to obtain an information recording carrier that is less susceptible to deterioration due to external light that is applied after the recording process.In addition, the base recording layer material, which is dense to the substrate, is mixed with a material that dissolves in a solvent that does not have any harmful effects. If J- is used, the material of the recording layer to be laminated on the base recording layer can be used with a solvent that does not have an adverse effect on the base, and the degree of freedom in material selection can be improved. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a conventional optical information recording carrier, FIG. 2 is a partial cross-sectional view of the optical information recording carrier of the present invention, and FIG. 3 is a partial cross-sectional view of a conventional optical information recording carrier. 3 is a graph showing a characteristic curve of transmittance. Explanation of symbols of main parts 1 and 21...Base 2...Recording layer 22...First recording layer 23°°°゛°°Second recording layer r=24 ...Third recording layer applicant Pioneer Co., Ltd. agent Patent attorney Motohiko Fujimura 1' 1st page of Jyo 1 ( #l #2 1!-, 31 yen 1, Indication of the case 1982 'I' S ft'r Application No. 003118 2,
Name of the invention: Optical information recording carrier 3, person making the amendment, etc. Patent applicant's office: Meguro 1-4ft 1, Meguro-ku, Tokyo Name (
501) Pioneer Stock Co., Ltd. 4, Agent 104 Address: 3-1019-6, Ginza, Chuo-ku, Tokyo Subject of amendment F1 of the drawing (no change in content) 7 Contents of amendment As attached

Claims (1)

[Claims] 1. An optical information recording carrier comprising a plurality of overlapping recording layers, and at least adjacent layers of the first two recording layers are formed of different photosensitive materials.