JPH0480454B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an optical information recording medium on which information can be recorded and reproduced using laser light. More specifically, the present invention relates to an optical information recording medium that is highly sensitive and capable of information reproduction and servo control. 2. Description of the Related Art A write-once optical disk memory, which records and reproduces information on a medium using a laser beam, has an excellent feature as a large-capacity recording device because of its high recording density. As a recording medium for such a write-once optical disk memory, semimetal thin films such as Te and Bi, and organic thin films are used. Organic thin films have thermal properties superior to semimetallic thin films, that is, low thermal conductivity and small heat capacity, so that the temperature rise of the film per absorbed energy density is large, and high recording sensitivity can be expected. However, organic thin films do not exhibit as large a reflectance as semimetallic thin films in the wavelength range of semiconductor lasers (~800 nm), so when using semiconductor lasers as light sources for reproduction, there are problems with the quality of reproduction signals and servo signals. be. As a method for improving this, a medium configuration in which a reflective film such as A1 is provided between the organic thin film and the substrate is known. By adopting this configuration and adjusting the thickness of the organic thin film, the change in reflectance before and after recording, that is, the amount of modulation, can be made as large as in the case of a semimetallic thin film. However, in an optical information recording medium having such a configuration, there is a restriction that the incident direction of the recording/reproducing light is limited to the surface side of the medium. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical information recording medium in which large reproduction signals and servo signals are incident on a substrate. Means for Solving the Problems The present invention is an optical information recording medium in which information is recorded and read by irradiation with a laser beam. a first spacer layer that is substantially transparent and has a refractive index at the wavelength of the laser beam that is greater than the refractive index of the substrate; and a first spacer layer that is substantially transparent to the laser beam and has a refractive index at the wavelength of the laser beam. In an optical information recording medium in which at least three layers are laminated, a second spacer layer having a smaller diameter than the first spacer layer, and a recording layer that absorbs the laser beam, the first spacer layer is different from the recording layer. Said second
The thickness of the second spacer layer is such that the substrate incident reflectance is maximum in a state where no spacer layer is formed, or thinner than that, and the second spacer layer is formed with the first spacer layer and the recording layer is It is characterized in that the thickness is made thinner than the thickness at which the substrate incident reflectance in an unformed state is minimal. Effect The reflectance of light incident on the substrate of a medium in which a recording layer is formed on a transparent substrate depends on the optical constants (complex refractive index) of the recording layer and the substrate and the thickness of the recording layer.
Various synthetic resins or glass are usually used as the transparent substrate. Their refractive index is approximately 1.5 in the visible to near-infrared light range, and is almost independent of wavelengths in this range. Therefore, the reflectance of the medium is determined by the optical constants and thickness of the recording layer. When using a dyed film or a resin film in which dyes are dispersed as the recording layer, the complex refractive index (n-ik) of these films is within the semiconductor laser wavelength range (~800 nm).
It is 2.6−i0.8 at most. For example, when the complex refractive index of the recording layer is 2.1-i0.6 and the refractive index of the substrate is 1.5, the medium reflectance for light incident on the substrate with a wavelength of 830 nm is determined by the thickness of the recording layer, as shown in Figure 36. Depends on. Therefore, the maximum reflectance is determined when the recording layer thickness is approximately
It can be seen that the value obtained when the wavelength is 100 nm is as small as about 15%, and the reproduction signal and servo signal are small. As described above, the present invention increases the intensity of the reproduced signal and the servo signal by increasing the reflectance and the amount of change thereof.The structure of the optical information recording medium of the present invention will be explained with reference to FIG. explain. As shown in FIG. 1, the optical information recording medium of the present invention has a substrate 1
0 and the recording layer 20, and the materials and thicknesses of the first spacer layer 30 and the second spacer layer 40 are as follows. The material was selected to satisfy the following conditions and succeeded in increasing the reflectance of the medium. First, consider a configuration as shown in FIG. 2 in which only the first spacer layer 30 is formed on the substrate 10. A portion of the light 100 incident through the substrate 10 is reflected at the interface between the substrate 10 and the first spacer layer 30 and the interface between the first spacer layer 30 and air, and becomes reflected light 200. Here, the reflected light 20
The magnitude (reflectance) of 0 is the first spacer layer 30
depends on the refractive index and thickness. The material and thickness of the first spacer layer 30 used in the present invention are selected to increase this reflected light 200. That is, first, the refractive index of the first spacer layer 30 needs to be larger than the refractive index of the substrate 10.
Further, the thickness needs to be a thickness that maximizes the size of the reflected light 200, or thinner than that. Next, a first spacer layer 30 is provided on the substrate 10 as described above, and a second spacer layer 40 is provided thereon.
Consider a configuration as shown in FIG. 3 in which . The light 100 incident through the substrate 10 is transmitted to the interface between the substrate 10 and the first spacer layer 30, the interface between the first spacer layer 30 and the second spacer layer 40,
A portion of the light is reflected at the interface between the second spacer layer 40 and air, and becomes reflected light 300. reflected light 3
The magnitude (reflectance) of 00 is the second spacer layer 4
0 refractive index and thickness. Therefore, the material and thickness of the second spacer layer 40 used in the present invention are such as to reduce this reflected light 300. That is, first, the refractive index of the second spacer layer 40 needs to be smaller than the refractive index of the first spacer layer 30. Next, the thickness of the second spacer layer 40 needs to be thinner than the thickness that minimizes the magnitude of the reflected light 300. By providing a first spacer layer and a second spacer layer that satisfy the above conditions and providing a recording layer thereon, a medium with high reflectance and high reproduction output can be obtained. FIG. 37 shows the thickness of the first spacer layer 30 with a refractive index of 1.7 on the substrate 10 (with a refractive index of 1.5) at which the substrate incident reflectance for light with a wavelength of 830 nm is maximum.
120 nm, and on top of that a second layer with a complex refractive index of 1.4.
The thickness of the spacer layer 40 at which the reflectance is minimal
This figure shows the dependence of the reflectance on the recording layer thickness when the recording layer 20 is formed to have a thickness of 150 nm and has a complex refractive index of 2.1-i0.6. By comparing with FIG. 36, it can be seen that the reflectance is increased and improved by inserting the first spacer layer and the second spacer layer. FIG. 4 shows a first spacer layer 30 made of the same material as the optical recording medium whose reflectance is shown in FIG. 37.
The thickness is set to 120 nm at which the reflectance is maximum,
The recording layer thickness of the reflectance when the thickness of the second spacer layer is 80 nm, which is thinner than the 150 nm thickness at which the reflectance is minimum, and the recording layer 20 with a complex refractive index of 2.1-i0.6 is provided on it. This shows the dependence on Comparing with FIG. 21, the thickness of the recording layer at which the reflectance becomes minimum shifts from 0 nm to 16 nm due to the structure of the present invention. When the recording layer is mainly composed of an organic thin film, generally 20 to 30% of the thickness before recording remains in the recording portion, and no holes are formed, but pits are formed. Therefore, it can be seen that the optical recording medium of the present invention having the characteristics shown in FIG. 4 can provide a larger reproduced signal than the characteristics shown in FIG. 37. Figure 5 shows a substrate with a refractive index of 1.7 on a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.5 is formed on the first spacer layer 30 with a thickness of 120 nm that maximizes the substrate incident reflectance.
The recording layer thickness of the reflectance when the second spacer layer 40 is formed with a thickness of 100 nm thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 with a complex refractive index of 2.1-i0.6 is provided on it. This shows the dependence. 36th
By comparing with the figure, it can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of around 13 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 6 shows a substrate with a refractive index of 1.9 on a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.4 is formed on the first spacer layer 30 with a thickness of 110 nm that maximizes the substrate incident reflectance.
The recording layer thickness of the reflectance when the second spacer layer 40 is formed to have a thickness of 70 nm, which is thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 with a complex refractive index of 2.1-i0.6 is provided on it. It shows dependence. By comparing with FIG. 36, it can be seen that the reflectance is increased and improved by inserting the first spacer layer and the second spacer layer. Also, the reflectance becomes minimum at a recording layer thickness of around 22 nm, so the recording layer thickness should be adjusted accordingly.
By setting the wavelength to 80 nm, a medium with a large reproduced signal can be obtained. Figure 7 shows a substrate 10 with a refractive index of 1.9 on top of a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.5 is formed on the first spacer layer 30 with a thickness of 110 nm that maximizes the substrate incident reflectance.
The recording layer thickness of the reflectance when the second spacer layer 40 is formed with a thickness of 80 nm thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 with a complex refractive index of 2.1-i0.6 is provided on it. It shows dependence. By comparing with FIG. 36, it can be seen that the reflectance is increased and improved by inserting the first spacer layer and the second spacer layer. Also, the reflectance becomes minimum at a recording layer thickness of around 16 nm, so the recording layer thickness should be adjusted accordingly.
By setting the wavelength to 80 nm, a medium with a large reproduced signal can be obtained. Figure 8 shows a substrate 10 with a refractive index of 1.9 on a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.6 is formed on the first spacer layer 30 with a thickness of 110 nm that maximizes the substrate incident reflectance.
The recording layer thickness of the reflectance when the second spacer layer 40 is formed to have a thickness of 90 nm, which is thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 with a complex refractive index of 2.1-i0.6 is provided on it. It shows dependence. By comparing with FIG. 36, it can be seen that the reflectance is increased and improved by inserting the first spacer layer and the second spacer layer. Also, the reflectance becomes minimum at a recording layer thickness of around 15 nm, so the recording layer thickness should be adjusted accordingly.
By setting the wavelength to 80 nm, a medium with a large reproduced signal can be obtained. Figure 9 shows a substrate 10 with a refractive index of 1.9 on top of a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.7 is formed on the first spacer layer 30 with a thickness of 110 nm that maximizes the substrate incident reflectance.
The recording layer thickness of the reflectance when the second spacer layer 40 is formed with a thickness of 100 nm thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 with a complex refractive index of 2.1-i0.6 is provided on it. It shows dependence. By comparing with FIG. 36, it can be seen that the first spacer layer and the second spacer layer
By inserting a spacer layer, the reflectance increases,
I can see that it has improved. Further, since the reflectance becomes minimum at a recording layer thickness of around 11 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 10 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 2.0 is formed to a thickness of 105 nm at which the substrate incident reflectance is at a maximum, and a second spacer layer 40 at a refractive index of 1.4 is formed thereon at a thickness of 70 nm, which is thinner than the thickness at which the reflectance is at a minimum. This figure shows the dependence of the reflectance on the thickness of the recording layer when a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. Third
By comparing with FIG. 6, it can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of around 22 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 11 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 2.0 is formed to a thickness of 105 nm at which the substrate incident reflectance is at a maximum, and a second spacer layer 40 at a refractive index of 1.5 is formed thereon at a thickness of 70 nm, which is thinner than the thickness at which the reflectance is at a minimum. This figure shows the dependence of the reflectance on the thickness of the recording layer when a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. Third
By comparing with FIG. 6, it can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of around 21 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 12 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 2.0 is formed to a thickness of 105 nm at which the substrate incident reflectance is at a maximum, and a second spacer layer 40 at a refractive index of 1.6 is formed thereon at a thickness of 80 nm, which is thinner than the thickness at which the reflectance is at a minimum. This figure shows the dependence of the reflectance on the thickness of the recording layer when a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. Third
By comparing with FIG. 6, it can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of about 17 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 13 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 2.0 is formed at a thickness of 105 nm at which the substrate incident reflectance is at a maximum, and a second spacer layer 40 at a refractive index of 1.7 is formed thereon at a thickness of 80 nm, which is thinner than the thickness at which the reflectance is at a minimum. This figure shows the dependence of the reflectance on the thickness of the recording layer when a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. Third
By comparing with FIG. 6, it can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of about 18 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 14 shows a substrate 10 with a refractive index of 1.5.
2.2, the first spacer layer 30 is formed to a thickness of 95 nm that maximizes the substrate incident reflectance, and a refractive index layer is formed on it.
The recording layer thickness of the reflectance when the second spacer layer 40 of 1.4 is formed to a thickness of 60 nm, which is thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 of the complex refractive index of 2.1-i0.6 is provided on it. This shows the dependence on 36th
By comparing with the figure, it can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of about 28 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 15 shows a substrate 10 with a refractive index of 1.5.
2.2, the first spacer layer 30 is formed to a thickness of 95 nm that maximizes the substrate incident reflectance, and a refractive index layer is formed on it.
The recording layer thickness of the reflectance when the second spacer layer 40 of 1.5 is formed to a thickness of 60 nm, which is thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 of the complex refractive index of 2.1-i0.6 is provided on it. This shows the dependence on By comparing with FIG. 36, it can be seen that the first spacer layer and the second spacer layer
By inserting a spacer layer, the reflectance increases,
I can see that it has improved. Further, since the reflectance becomes minimum at a recording layer thickness of around 27 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 16 shows a substrate 10 with a refractive index of 1.5.
2.2, the first spacer layer 30 is formed to a thickness of 95 nm that maximizes the substrate incident reflectance, and a refractive index layer is formed on it.
The recording layer thickness of the reflectance when the second spacer layer 40 of 1.6 is formed to a thickness of 70 nm, which is thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 of the complex refractive index of 2.1-i0.6 is provided on it. This shows the dependence on 36th
By comparing with the figure, it can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of around 21 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 17 shows a substrate 10 with a refractive index of 1.5.
2.2, the first spacer layer 30 is formed to a thickness of 95 nm that maximizes the substrate incident reflectance, and a refractive index layer is formed on it.
The recording layer thickness of the reflectance when the second spacer layer 40 of 1.7 is formed to a thickness of 80 nm, which is thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 of the complex refractive index of 2.1-i0.6 is provided on it. This shows the dependence on 36th
The first spacer layer and the second spacer layer can be compared with the figure.
By inserting a spacer layer, the reflectance increases,
I can see that it has improved. Furthermore, since the reflectance becomes minimum at a recording layer thickness of around 17 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 18 shows a substrate 10 with a refractive index of 1.5.
2.2, the first spacer layer 10 is formed with a thickness of 95 nm at which the substrate incident reflectance is maximum, and a refractive index layer is formed on it.
The recording layer thickness of the reflectance when the second spacer layer 40 of 1.9 is formed to a thickness of 90 nm, which is thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 of the complex refractive index of 2.1-i0.6 is provided on it. This shows the dependence on 36th
By comparing with the figure, it can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of about 12 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 19 shows a substrate 10 with a refractive index of 1.5.
2.2, the first spacer layer 30 is formed to a thickness of 95 nm at which the substrate incident reflectance is maximum, and a refractive index layer is formed on it.
The recording layer thickness of the reflectance when the second spacer layer 40 of 2.0 is formed to a thickness of 90 nm, which is thinner than the thickness at which the reflectance becomes minimum, and the recording layer 20 of the complex refractive index of 2.1-i0.6 is provided on top of it. This shows the dependence on 36th
By comparing with the figure, it can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of around 13 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. The above results are summarized and shown in Table 1. In Table 1, t _nio is the thickness of the recording layer where the reflectance is minimum, and T _nio is the thickness of the second spacer layer where the reflectance is minimum in the structure shown in Figure 3. There is.

[Table] Next, according to the second aspect of the present invention, a case will be described in which the thickness of the first spacer layer is thinner than the thickness at which the reflectance becomes maximum. FIG. 38 shows a first spacer layer 30 with a refractive index of 2.0 on a substrate 10 (with a refractive index of 1.5) to a thickness of 105 nm at which the substrate incident reflectance for light with a wavelength of 830 nm is maximum.
A second spacer layer 40 with a refractive index of 1.5 is formed thereon to a thickness of 130 nm at which the reflectance is minimal, and a recording layer 20 with a complex refractive index of 2.1-i0.6 is formed thereon.
This figure shows the dependence of the reflectance on the thickness of the recording layer when . On the other hand, FIG. 20 uses the same material as the optical recording medium whose characteristics are shown in FIG.
The thickness of the second spacer layer is 85 nm, which is thinner than m, and the thickness of the second spacer layer is thinner than 130 nm, which is the minimum reflectance.
80 nm, and the dependence of the reflectance on the recording layer thickness when a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. Comparing with FIG. 38, the thickness of the recording layer at which the reflectance becomes minimum shifts from 0 nm to 23 nm by adopting the configuration of the present invention. When the recording layer is mainly composed of an organic thin film, generally 20 to 30% of the thickness before recording remains in the recording portion, and no holes are formed, but pits are formed. Therefore, it can be seen that a larger reproduced signal can be obtained with the characteristics shown in FIG. 20 of the present invention than with the characteristics shown in FIG. 38. Figure 21 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 2.0 is formed to have a thickness of 95 nm, which is thinner than the thickness of 105 nm at which the substrate incident reflectance is maximum, and a second spacer layer 40 with a refractive index of 1.4 is formed thereon.
This figure shows the dependence of the reflectance on the thickness of the recording layer when the recording layer 20 having a complex refractive index of 2.1-i0.6 is provided on the layer 20 formed with a thickness of 80 nm, which is thinner than the thickness at which the reflectance becomes minimum. By comparing with Figure 36, the first
It can be seen that the reflectance increases and is improved by inserting the spacer layer and the second spacer layer.
Furthermore, since the reflectance becomes minimum at a recording layer thickness of around 20 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 22 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 2.0 is formed to have a thickness of 95 nm, which is thinner than the thickness of 105 nm at which the substrate incident reflectance is maximum, and a second spacer layer 40 with a refractive index of 1.6 is formed thereon.
This figure shows the dependence of the reflectance on the thickness of the recording layer when the recording layer 20 having a complex refractive index of 2.1-i0.6 is provided on the layer 20 formed with a thickness of 80 nm, which is thinner than the thickness at which the reflectance becomes minimum. By comparing with Figure 36, the first
It can be seen that the reflectance increases and is improved by inserting the spacer layer and the second spacer layer.
Also, since the reflectance becomes minimum at a recording thickness of around 20 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 23 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 2.0 is formed to have a thickness of 95 nm, which is thinner than the thickness of 105 nm at which the substrate incident reflectance is maximum, and a second spacer layer 40 with a refractive index of 1.7 is formed thereon.
A recording layer 20 with a complex refractive index of 2.1−i0.6 is formed on it to a thickness of 90 nm, which is thinner than the thickness at which the reflectance becomes minimum.
This figure shows the dependence of the reflectance on the thickness of the recording layer when . By comparing with FIG. 36, it can be seen that the reflectance is increased and improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of about 17 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 24 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.7 is formed to have a thickness of 110 nm, which is thinner than the thickness of 120 nm at which the substrate incident reflectance is maximum, and a second spacer layer 40 with a refractive index of 1.4 is formed thereon.
This figure shows the dependence of the reflectance on the thickness of the recording layer when the recording layer 20 having a complex refractive index of 2.1-i0.6 is provided on the layer 20 formed with a thickness of 90 nm, which is thinner than the thickness at which the reflectance becomes minimum. By comparing with Figure 36, the first
It can be seen that the reflectance increases and is improved by inserting the spacer layer and the second spacer layer.
Further, since the reflectance becomes minimum at a recording layer thickness of around 16 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 25 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.7 is formed to have a thickness of 110 nm, which is thinner than the thickness of 120 nm at which the substrate incident reflectance is maximum, and a second spacer layer 40 with a refractive index of 1.5 is formed thereon.
A recording layer 20 with a complex refractive index of 2.1−i0.6 is formed on it to a thickness of 110 nm, which is thinner than the thickness at which the reflectance becomes minimum.
This figure shows the dependence of the reflectance on the thickness of the recording layer when . By comparing with FIG. 36, it can be seen that the reflectance is increased and improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of around 11 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 26 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.9 is formed to have a thickness of 90 nm, which is thinner than the thickness of 110 nm at which the substrate incident reflectance is maximum, and a second spacer layer 40 with a refractive index of 1.4 is formed thereon.
A recording layer 20 with a complex refractive index of 2.1−i0.6 is formed on it to a thickness of 90 nm, which is thinner than the thickness at which the reflectance becomes minimum.
This figure shows the dependence of the reflectance on the thickness of the recording layer when . By comparing with FIG. 36, it can be seen that the reflectance is increased and improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of about 18 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 27 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.9 is formed at a thickness of 90 nm, which is thinner than the thickness of 110 nm at which the substrate incident reflectance is maximum, and a second spacer layer 40 with a refractive index of 1.5 is formed thereon at a thickness of 90 nm, which is thinner than the thickness at which the reflectance becomes minimum. This figure shows the dependence of the reflectance on the recording layer thickness when the recording layer 20 is formed to have a thin thickness of 90 nm and has a complex refractive index of 2.1-i0.6. By comparing with FIG. 36, it can be seen that the reflectance is increased and improved by inserting the first spacer layer and the second spacer layer. or
Since the reflectance becomes minimum at a recording layer thickness of around 18 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 28 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.9 is formed to have a thickness of 90 nm, which is thinner than the thickness of 110 nm at which the substrate incident reflectance is maximum, and a second spacer layer 40 with a refractive index of 1.6 is formed thereon.
A recording layer 20 with a complex refractive index of 2.1−i0.6 is formed on it to a thickness of 90 nm, which is thinner than the thickness at which the reflectance becomes minimum.
This figure shows the dependence of the reflectance on the thickness of the recording layer when . By comparing with FIG. 36, it can be seen that the reflectance is increased and improved by inserting the first spacer layer and the second spacer layer. Furthermore, since the reflectance becomes minimum at a recording layer thickness of around 20 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 29 shows a substrate 10 with a refractive index of 1.5.
A first spacer layer 30 with a refractive index of 1.9 is formed to have a thickness of 90 nm, which is thinner than the thickness of 110 nm at which the substrate incident reflectance is maximum, and a second spacer layer 40 with a refractive index of 1.7 is formed thereon.
A recording layer 2 with a complex refractive index of 2.1−i0.6 is formed on it with a thickness of 120 nm, which is thinner than the thickness at which the reflectance becomes minimum.
This figure shows the dependence of the reflectance on the recording layer thickness when 0 is provided. By comparing with Figure 36,
It can be seen that the reflectance increases and is improved by inserting the first spacer layer and the second spacer layer. Further, since the reflectance becomes minimum at a recording layer thickness of around 10 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 30 shows a substrate 10 with a refractive index of 1.5.
The first spacer layer 30 in 2.2 is formed to have a thickness of 75 nm, which is thinner than the thickness of 95 nm at which the substrate incident reflectance is maximum,
Reflection when a second spacer layer 40 with a refractive index of 1.4 is formed on top of the second spacer layer 40 with a thickness of 70 nm, which is thinner than the thickness at which the reflectance becomes minimum, and a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. This figure shows the dependence of the ratio on the recording layer thickness. By comparing with Figure 36, the first
It can be seen that the reflectance increases and is improved by inserting the spacer layer and the second spacer layer.
Further, since the reflectance becomes minimum at a recording layer thickness of around 30 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 31 shows a substrate 10 with a refractive index of 1.5.
The first spacer layer 30 in 2.2 is formed to have a thickness of 55 nm, which is thinner than the thickness of 95 nm at which the substrate incident reflectance is maximum,
Reflection when a second spacer layer 40 with a refractive index of 1.5 is formed thereon to a thickness of 100 nm, which is thinner than the thickness at which the reflectance becomes minimum, and a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. This figure shows the dependence of the ratio on the recording layer thickness. By comparing with Figure 36, the first
It can be seen that the reflectance increases and is improved by inserting the spacer layer and the second spacer layer.
Further, since the reflectance becomes minimum at a recording layer thickness of around 20 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 32 shows a substrate 10 with a refractive index of 1.5.
The first spacer layer 30 in 2.2 is formed to have a thickness of 55 nm, which is thinner than the thickness of 95 nm at which the substrate incident reflectance is maximum,
Reflection when a second spacer layer 40 with a refractive index of 1.6 is formed on top of the second spacer layer 40 with a thickness of 100 nm thinner than the thickness at which the reflectance becomes minimum, and a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided on top of the second spacer layer 40. This figure shows the dependence of the ratio on the recording layer thickness. By comparing with Figure 36, the first
It can be seen that the reflectance increases and is improved by inserting the spacer layer and the second spacer layer.
Further, since the reflectance becomes minimum at a recording layer thickness of around 22 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 33 shows a substrate 10 with a refractive index of 1.5.
The first spacer layer 30 in 2.2 is formed with a thickness of 65 nm, which is thinner than the thickness of 95 nm at which the substrate incident reflectance is maximum,
Reflection when a second spacer layer 40 with a refractive index of 1.7 is formed thereon to a thickness of 100 nm thinner than the thickness at which the reflectance becomes minimum, and a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. This figure shows the dependence of the ratio on the recording layer thickness. By comparing with Figure 36, the first
It can be seen that the reflectance increases and is improved by inserting the spacer layer and the second spacer layer.
Further, since the reflectance becomes minimum at a recording layer thickness of around 20 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 34 shows a substrate 10 with a refractive index of 1.5.
The first spacer layer 30 in 2.2 is formed to have a thickness of 75 nm, which is thinner than the thickness of 95 nm at which the substrate incident reflectance is maximum,
Reflection when a second spacer layer 40 with a refractive index of 1.9 is formed thereon to a thickness of 100 nm, which is thinner than the thickness at which the reflectance becomes minimum, and a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. This figure shows the dependence of the ratio on the recording layer thickness. By comparing with Figure 36, the first
It can be seen that the reflectance increases and is improved by inserting the spacer layer and the second spacer layer.
Further, since the reflectance becomes minimum at a recording layer thickness of around 16 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. Figure 35 shows a substrate 10 with a refractive index of 1.5.
The first spacer layer 30 in 2.2 is formed to have a thickness of 85 nm, which is thinner than the thickness of 95 nm at which the substrate incident reflectance is maximum,
Reflection when a second spacer layer 40 with a refractive index of 2.0 is formed thereon to a thickness of 100 nm, which is thinner than the thickness at which the reflectance becomes minimum, and a recording layer 20 with a complex refractive index of 2.1-i0.6 is provided thereon. This figure shows the dependence of the ratio on the recording layer thickness. By comparing with Figure 36, the first
It can be seen that the reflectance increases and is improved by inserting the spacer layer and the second spacer layer.
Further, since the reflectance becomes minimum at a recording layer thickness of around 13 nm, a medium with a large reproduced signal can be obtained by setting the recording layer thickness to 80 nm. The above results are summarized and shown in Table 2. In Table 2, T _nax is the thickness of the first spacer layer at which the reflectance is maximum in the structure shown in Figure 2, and T _nio is the thickness at which the reflectance is minimum in the structure shown in Figure 3. The thickness of the second spacer layer. Furthermore
t _nio is the thickness of the recording layer at which the reflectance is minimum.

【table】

[Table] As described above, the thickness of the first spacer layer used in the present invention is the thickness at which the substrate incident reflectance is maximum in the state where the recording layer and the second spacer layer are not formed, or The thickness of the second spacer layer is smaller than the thickness at which the substrate incident reflectance is minimal when the first spacer layer is formed and no recording layer is formed. do. The reasons for limiting the conditions for the first and second spacer layers will be explained below. In FIG. 39, a first spacer layer with a refractive index of 1.7 is formed on a substrate with a refractive index of 1.5 to a thickness of 120 nm, which maximizes the substrate incident reflectance for light with a wavelength of 830 nm.
A second spacer layer with a refractive index of 1.4 is formed thereon,
The dependence of the reflectance on the recording layer thickness when a recording layer with a complex refractive index of 2.1-i0.6 is provided thereon is shown for the cases where the second spacer layer thickness is 100 nm, 150 nm, and 200 nm. . The second spacer layer thickness T _nio = 150 nm at which the substrate incident reflectance becomes minimum when the first spacer layer is formed but no recording layer is formed
When the thickness of the spacer layer in FIG. 39 is thick, that is, when the thickness of the second spacer layer in FIG. becomes small, which is undesirable. In FIG. 40, a first spacer layer with a refractive index of 1.7 is placed on a substrate with a refractive index of 1.5 to a thickness of 170 nm, which is thicker than the 120 nm thickness at which the substrate incident reflectance is maximum.
A second spacer layer with a refractive index of 1.4 is formed thereon,
The dependence of the reflectance on the recording layer thickness when a recording layer with a complex refractive index of 2.1-i0.6 is provided thereon is shown for the cases where the second spacer layer thickness is 100 nm, 150 nm, and 200 nm. . By comparing the curve with the solid line in FIG. 39, it can be seen that when the thickness of the first spacer layer is thicker than the thickness at which the reflectance becomes maximum, the degree of decrease in reflectance when the recording layer thickness decreases. It can be seen that as the value becomes smaller, the reproduced signal output becomes smaller, which is not desirable. The first spacer layer and the second spacer layer used in the present invention
The lower limit of the thickness of the spacer layer is a thickness at which the objective of the present invention, which is an increase in reflectance and an increase in the amount of change in reflectance, cannot be substantially achieved. Table 3 shows an example of the relationship between the first spacer layer thickness, the second spacer layer thickness, and the reflectance increase amount. (In this example, the complex refractive index of the recording layer is 2.1−i0.6 and the thickness is
80nm).

[Table] In order to obtain a substantial effect of increasing reflectance according to the present invention, the film thickness of the spacer layer must be approximately λ/8n.
(λ is the wavelength of light, and n is the refractive index of the spacer material). That is, in the case of light having a wavelength of 830 nm as shown in Table 3, a thickness of 50 nm or more is a practically effective thickness for materials with a refractive index of 1.4 or more to around 2. Additionally, the first and second spacer layers used in the present invention are preferably substantially transparent at the readout laser wavelength. The first spacer layer may have a refractive index greater than that of the substrate. for example
_CeO2 , _Cr2O3 , _{Fe2O3 , Fe3O4 , GeO2 , In2O3 ,}
MgO, _MnO2 , _MoO3 , _{Nb2O3 , NiO2} , SiO,
_Sm2O3 , _SnO2 , _{Ta2O5 , TeO2 , TiO2} , _{V2O5 ,}
Various oxides such _{as WO3} , _Y2O3 , ZnO, _ZrO2 ,
Various nitrides such as Si ₃ N ₄ and ZrN, various carbides such as ZrC, various sulfides such as GeS and ZnS, various organic pigments such as cobalt phthalocyanine, copper phthalocyanine, magnesium phthalocyanine, nickel phthalocyanine, zinc phthalocyanine, and various magnetic garnets. Also, Si, Se, Ge, B, or a compound thereof can be used. As the second spacer layer, for example, AlF ₃ , BaF ₂ , CaF ₂ , CeF ₃ ,
DyF ₃ , ErF ₃ , EuF ₃ , GdF ₃ , HfF ₄ , HoF ₃ ,
LaF ₃ , LiF, MgF ₂ , NaF, NdF ₃ , PrF ₃ ,
Various fluorides such as SmF ₃ , SrF ₂ , YF ₃ , YbF ₃ ,
Al ₂ O ₃ , CeO ₂ , Cr ₂ O ₃ , Dy ₂ O ₃ , Er ₂ O ₃ , Eu ₂ O ₃ ,
Fe ₂ O ₃ , Fe ₃ O ₄ , Gd ₂ O ₃ , GeO ₂ , HfO ₂ , Ho ₂ O ₃ ,
_{In2O3 , Lu2O3} , MgO _{, MnO2} , _MoO3 , _{Nb2O3 ,}
NiO, SiO, _SiO2 , _{Sm2O3 , SnO2} , _{Ta2O5 ,}
Various oxides such as TiO ₂ , V ₂ O ₅ , WO ₃ , Y ₂ O ₃ , ZnO, ZrO ₂ , various nitrides such as ZrN, various carbides such as ZrC, various sulfides such as GeS, ZnS, cobalt phthalocyanine , various organic dyes such as copper phthalocyanine, molybdenum phthalocyanine, magnesium phthalocyanine, nickel phthalocyanine, zinc phthalocyanine, Sudan Black B, various foot resists, various electron beam resists, and various organic substances such as polystyrene. For example, when using SnO ₂ as the first spacer layer, AlF ₃ ,
BaF ₂ , CaF ₂ , CeF ₃ , DyF ₃ , ErF ₃ , EuF ₃ ,
_GdF3 , _HoF3 , _LaF3 , LiF, _MgF2 , NaF,
Fluorides such as NdF ₃ , PrF ₃ , SmF ₃ , SrF ₂ , YF ₃ , YbF 3 , Al ₂ O ₃ , CeO ₂ , Dy ₂ O ₃ , Er _{2 O 3 ,} Eu ₂ O ₃ ,
_GeO2 , _{Ho2O3 , Lu2O3 ,} MgO, _SiO2 , _{Sm2O3 ,}
Organic pigments such as Y ₂ O ₃ , oxides, Sudan Black B, etc., and organic substances such as guanine and crystal violet lactone can be used. The above-mentioned second spacer layer material can also be used when copper phthalocyanine is used as the first spacer layer. When using NiO as the first spacer layer, AlF ₃ , BaF ₂ ,
CaF ₂ , CeF ₃ , DyF ₃ , ErF ₃ , EuF ₃ , GdF ₃ ,
HoF ₃ , LaF ₃ , LiF, MgF ₂ , NaF, NdF ₃ ,
Fluorides such as PrF ₃ , SmF ₃ , SnF ₂ , YF _{3 , YbF 3 ,} Al ₂ O ₃ , Dy ₂ O ₃ , Er ₂ O ₃ , Eu ₂ O ₃ , Ho ₂ O ₃ ,
Lu ₂ O ₃ , MgO, SiO ₂ , Sm ₂ O ₃ , Y ₂ O ₃ and the like, oxides, organic pigments such as Sudan Black B, and organic substances such as crystal violet lactone can be used. The above-mentioned second spacer layer material can also be used when GeO ₂ is used as the first spacer layer. When MgO is used as the first spacer layer, a fluoride such as MgF ₂ or an oxide such as Al ₂ O ₃ or SiO ₂ can be used as the second spacer layer. When Si is used as the first spacer layer, AlF ₃ , BaF ₂ ,
CaF ₂ , CeF ₃ , DyF ₃ , ErF ₃ , EuF ₃ , GdF ₃ ,
_HfF4 , _HoF3 , _LaF3 , LiF, _MgF2 , NaF,
Fluorides such as NdF ₃ , PrF ₃ , SmF ₃ , SrF ₂ , YF ₃ , YbF 3 , Al ₂ O ₃ , CeO ₂ , Cr ₂ O ₃ , Dy _{2 O 3 ,} Er ₂ O ₃ ,
Eu ₂ O ₃ , Fe ₂ O ₃ , Fe ₃ O ₄ , Gd ₂ O ₃ , GeO ₂ , HfO ₂ ,
Ho ₂ O ₃ , In ₂ O ₃ , Lu ₂ O ₃ , MgO, MnO ₂ , MoO ₃ ,
Nb ₂ O ₅ , NiO, SiO, SiO ₂ , Sm ₂ O ₃ , SnO ₂ ,
Ta ₂ O ₅ , TiO ₂ , V ₂ O ₅ , WO ₃ , Y ₂ O ₃ , ZnO,
Oxides such as ZrO ₂ , nitrides such as ZrN, carbides such as ZrC, sulfides such as GeS and ZrS, and organic materials such as cobalt phthalocyanine, copper phthalocyanine, molybdenum phthalocyanine, magnesium phthalocyanine, nickel phthalocyanine, zinc phthalocyanine, Sudan Black B, etc. Pigments, guanine, crystal violet lactone, dianhydride 3, 4, 9, 10-
Organic substances such as perylenetetracarboxylic acid can be used. In the present invention, the first and second spacer layers are limited to substantially transparent layers. This is because the medium configuration of the present invention, ie, the provision of the first and second spacer layers, increases the reflectance but reduces the absorption rate of the recording layer. That is, compared to a medium having only a single recording layer, the medium structure of the present invention reduces transmittance and absorption and increases reflectance. Therefore, if the spacer layer is a light absorption layer, the absorption rate of the recording layer will further decrease, and the recording sensitivity of the medium will decrease, making it unusable. Therefore, the spacer layer must be substantially transparent. is necessary. The recording layer is preferably one containing an organic substance as a main component, and more preferably one that can be formed by vapor deposition or sputtering. Specifically, various squarylium dyes, various 5-amino-2,3
- various phthalocyanine dyes such as dicyano-1,4-naphthoquinone dyes, vanadyl phthalocyanine, titanyl phthalocyanine, aluminum phthalocyanine, aluminum chloride phthalocyanine, titanium phthalocyanine, lead phthalocyanine, platinum phthalocyanine, plasma polymerized organic membrane containing Te,
An organic film in which Te is surrounded by alkyl groups, an organic film in which Te is surrounded by fluorocarbons, etc. can be used. Among these, 5-amino-8-substituted anilino-2,3-dicyano-1,4-naphthoquinone dye, 5,8-substituted anilino-2,3-dicyano-
1,4-naphthoquinone dyes, mixtures thereof, or metal complexes thereof are preferable, and substituents include alkoxyl groups having 4 or less carbon atoms,
Alkyl groups are most preferred. Although various substrates can be used, synthetic resin, glass, and porcelain are generally preferred. Examples of synthetic resins include acrylic resins such as polymethyl methacrylate, polycarbonate, polyetherimide, polysulfone, epoxy resins, and vinyl chloride resins. The shape of the board is disc-shaped, sheet-shaped,
It can be in the form of a tape. In the optical recording medium of the present invention, information is recorded on the recording layer by forming pits in the recording layer. In a disk medium using a disk-shaped substrate, pits are recorded so as to form a large number of concentric or spiral tracks. In order to accurately record a large number of tracks at regular intervals, light guide grooves are usually provided on the substrate. When light enters a groove about the diameter of the beam, it is diffracted. As the beam center shifts from the groove, the spatial distribution of the diffracted light intensity changes, and a servo system can be configured to detect this and direct the beam to the center of the groove. Usually, the width of the guide groove is set in the range of 0.3 to 1.2 μm, and the depth is set in the range of 1/12 to 1/4 of the wavelength of the recording/reproducing laser used. In the optical recording medium of the present invention, guide grooves are preferably formed on the grooved surface of the substrate. Examples of the present invention will be described below. Example 1 Magnesium oxide was evaporated to a thickness of 121 nm on an acrylic resin disk substrate with an inner diameter of 15 mm, an outer diameter of 120 mm, and a thickness of 1.2 mm, with a thickness of 1.2 mm, magnesium fluoride was evaporated to a thickness of 82 nm, and 5-amino-8 −(p
-ethoxyanilino)-2,3-dicyano-1,
An organic thin film containing 85% or more of 4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of light incident on the substrate at a wavelength of 830 nm was monitored, and the reflectance of light incident on the substrate at the end of vapor deposition of the first spacer layer magnesium oxide was set to a thickness that had a maximum value of 10.7%. The substrate incidence reflectance at the end of the vapor deposition of the second spacer layer magnesium fluoride is 4.7%.
The thickness was set to be thinner than the minimum value. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 22.0%, the servo signal was large and the reproduced signal was also large and good. Example 2 Magnesium oxide was deposited to a thickness of 121 nm on an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, and silicon dioxide was deposited on top of it.
5-amino-8-(p-
ethoxyanilino)-2,3-dicyano-1,4
- An organic thin film containing 85% or more of naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
This was done while monitoring the substrate incident reflectance of 830 nm, and the substrate incident reflectance was set to a maximum value of 10.7% at the end of vapor deposition of the first spacer layer magnesium oxide, and the second spacer layer silicon dioxide was deposited. The substrate incident reflectance at the end of vapor deposition was set to 2.3%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus manufactured was as high as 21.5%, the servo signal was large and the reproduced signal was also large and good. Example 3 On an acrylic resin disk substrate with an inner diameter of 15 mm, an outer diameter of 120 mm, and a thickness of 1.2 mm, germanium oxide was deposited to a thickness of 113 nm, magnesium fluoride was deposited to a thickness of 69 nm, and 5-amino-8 −(p
-ethoxyanilino)-2,3-dicyano-1,
An organic thin film containing 85% or more of 4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of the incident light on the substrate at a wavelength of 830 nm was monitored, and the reflectance of the incident light on the substrate was set to a maximum value of 15.6% at the end of the vapor deposition of the first spacer layer germanium oxide. The substrate incidence reflectance at the end of the vapor deposition of the spacer layer 2 of magnesium fluoride is 9.4%.
The thickness was set to be thinner than the minimum value. Since the substrate incident medium reflectance of the optical disk thus manufactured was as high as 22.7%, the servo signal was large and the reproduced signal was also large and good. Example 4 Germanium oxide was deposited to a thickness of 113 nm on an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, and 80 nm of silicon dioxide was deposited on it.
On the recording layer, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830n.
The thickness was set to a maximum value of 15.6% at the end of the vapor deposition of the first spacer layer germanium oxide, and the thickness was set to a maximum value of 15.6%. The substrate incident reflectance at the end of vapor deposition was set to 6.4%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 23.1%, the servo signal was large and the reproduced signal was also large and good. Example 5 Germanium oxide was evaporated to a thickness of 113 nm on an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, and aluminum oxide was deposited on top of it.
88 nm, and 5-amino-8-(p-
ethoxyanilino)-2,3-dicyano-1,4
- An organic thin film containing 85% or more of naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
The reflectance of 830 nm incident on the substrate was monitored and the thickness was set to a maximum value of 15.6% at the end of the deposition of the first spacer layer germanium oxide. The substrate incident reflectance at the end of vapor deposition was set to 4.2%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 21.6%, the servo signal was large and the reproduced signal was also large and good. Example 6 Cerium oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
110nm vapor deposited and 88n aluminum oxide on top
On top of this, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830n.
The thickness was set to a maximum value of 17.0% at the end of the deposition of the first spacer layer cerium oxide, and the thickness was set to a maximum value of 17.0%. The substrate incident reflectance at the end of vapor deposition was set to 7.6%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 23.8%, the servo signal was large and the reproduced signal was also large and good. Example 7 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, copper phthalocyanine dye was evaporated to a thickness of 104 nm, magnesium fluoride was evaporated to a thickness of 68 nm, and 5-amino- 8-
(p-ethoxyanilino)-2,3-dicyano-
An organic thin film containing 85% or more of 1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of light incident on the substrate at a wavelength of 830 nm was monitored, and the reflectance of light incident on the substrate at the end of vapor deposition of the first spacer layer copper phthalocyanine dye was 20.7%.
The thickness was set to take a maximum value of , and the substrate incident reflectance at the end of vapor deposition of the second spacer layer magnesium fluoride was set to 13.6%, which is thinner than the thickness to take a minimum value. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 25.9%, the servo signal was large and the reproduced signal was also large and good. Example 8 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, copper phthalocyanine dye was deposited to a thickness of 104 nm, silicon dioxide was deposited to a thickness of 70 nm, and 5-amino- 8-(p
-ethoxyanilino)-2,3-dicyano-1,
An organic thin film containing 85% or more of 4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of light incident on the substrate at a wavelength of 830 nm was monitored, and the thickness was set to such a value that the reflectance of light incident on the substrate at the end of vapor deposition of the first spacer layer copper phthalocyanine dye had a maximum value of 20.7%. , the substrate incidence reflectance at the end of the deposition of the second spacer layer silicon dioxide is 11.6%.
The thickness was set to be thinner than the minimum value. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 24.4%, the servo signal was large and the reproduced signal was also large and good. Example 9 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, 104 nm of copper phthalocyanine dye was vapor-deposited, 78 nm of aluminum oxide was vapor-deposited thereon, and 5-amino-8 −
(p-ethoxyanilino)-2,3-dicyano-
An organic thin film containing 85% or more of 1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of light incident on the substrate at a wavelength of 830 nm was monitored, and the reflectance of light incident on the substrate at the end of vapor deposition of the first spacer layer copper phthalocyanine dye was 20.7%.
The thickness was set to take a maximum value of , and the substrate incident reflectance at the end of vapor deposition of the second spacer layer aluminum oxide was set to 8.2%, which is thinner than the thickness to take a minimum value. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 24.2%, the servo signal was large and the reproduced signal was also large and good. Example 10 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, 104 nm of copper phthalocyanine dye was vapor-deposited, 81 nm of yttrium oxide was vapor-deposited thereon, and 5-amino-8 −
(p-ethoxyanilino)-2,3-dicyano-
An organic thin film containing 85% or more of 1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of the substrate incident at a wavelength of 830 nm was monitored, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer copper phthalocyanine dye was 20.7%.
The thickness was set to take the maximum value, and the substrate incident reflectance at the end of the deposition of the second spacer layer yttrium oxide was set to 6.8%, which is thinner than the thickness that takes the minimum value. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 23.4%, the servo signal was large and the reproduced signal was also large and good. Example 11 Copper phthalocyanine dye was evaporated to a thickness of 104 nm on an acrylic resin disk substrate with an inner diameter of 15 mm, an outer diameter of 120 mm, and a thickness of 1.2 mm, with a thickness of 83 nm, and 5-amino-8 −
(p-ethoxyanilino)-2,3-dicyano-
An organic thin film containing 85% or more of 1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of light incident on the substrate at a wavelength of 830 nm was monitored, and the reflectance of light incident on the substrate at the end of vapor deposition of the first spacer layer copper phthalocyanine dye was 20.7%.
The thickness was set to take a maximum value of , and the substrate incident reflectance at the end of vapor deposition of the second spacer layer magnesium oxide was set to 5.6%, which is thinner than the thickness to take a minimum value. Since the substrate incident medium reflectance of the optical disk thus manufactured was as high as 21.7%, the servo signal was large and the reproduced signal was also large and good. Example 12 Nickel oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
103nm vapor deposition and magnesium fluoride on top of it.
5-amino-8-(p-
ethoxyanilino)-2,3-dicyano-1,4
- An organic thin film containing 85% or more of naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
This was done while monitoring the reflectance of 830 nm incident on the substrate, and the thickness was set to a maximum value of 21.4% for the substrate incident reflectance at the end of the deposition of the first spacer layer nickel oxide, and the thickness was set to a maximum value of 21.4%. The substrate incident reflectance at the end of magnesium evaporation was set to 13.8%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus manufactured was as high as 27.2%, the servo signal was large and the reproduced signal was also large and good. Example 13 Nickel oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
103nm evaporated and 71nm silicon dioxide on top.
Thereon, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was vapor-deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830nm.
This is done while monitoring the reflectance of the substrate incident on it.
The substrate incident reflectance at the end of the vapor deposition of the first spacer layer nickel oxide is set to a maximum value of 21.4%, and the substrate incident reflectance at the end of the vapor deposition of the second spacer layer silicon dioxide is 11.9%. The thickness was set to be thinner than the minimum value. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 25.3%, the servo signal was large and the reproduced signal was also large and good. Example 14 Nickel oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
103nm vapor deposited and 80n aluminum oxide on top
On top of this, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830n.
The thickness was set to a maximum value of 21.4% at the end of the deposition of the first spacer layer of nickel oxide, and the thickness of the second spacer layer of aluminum oxide was set to a maximum value of 21.4%. The substrate incident reflectance at the end of vapor deposition was set to 8.0%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 25.3%, the servo signal was large and the reproduced signal was also large and good. Example 15 Nickel oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
103nm vapor deposited and 83n magnesium oxide on top.
On top of this, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830n.
The thickness was set to a maximum value of 21.4% at the end of the deposition of the first spacer layer of nickel oxide, and the thickness of the second spacer layer of magnesium oxide was set to a maximum value of 21.4%. The substrate incident reflectance at the end of vapor deposition was set to 5.8%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 22.4%, the servo signal was large and the reproduced signal was also large and good. Example 16 94 nm of tin oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
An organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye on which magnesium fluoride is vapor-deposited to a thickness of 62 nm. was deposited to a thickness of 80 nm as a recording layer. During this film formation, the reflectance of light incident on the substrate at a wavelength of 830 nm was monitored, and the reflectance of light incident on the substrate was set to a maximum value of 27.8% at the end of vapor deposition of the first spacer layer tin oxide. The substrate incidence reflectance at the end of vapor deposition of the second spacer layer magnesium fluoride was set to 21.0%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 28.7%, the servo signal was large and the reproduced signal was also large and good. Example 17 An acrylic resin disk substrate with a guide groove of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness was coated with 94 nm of tin oxide.
On top of that, silicon dioxide is deposited to a thickness of 64 nm, and on top of that, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye is formed. as a recording layer
80nm was deposited. During this film formation, the reflectance of the substrate at a wavelength of 830 nm was monitored.
The substrate incident reflectance at the end of the vapor deposition of the spacer layer tin oxide was set to a thickness of 27.8%, which is the maximum value.
The substrate incident reflectance at the end of vapor deposition of the spacer layer silicon dioxide was set to 18.7%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus manufactured was as high as 27.7%, the servo signal was large and the reproduced signal was also large and good. Example 18 Tin oxide was applied to an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness to a thickness of 94 nm.
On top of that, aluminum oxide is deposited to a thickness of 73 nm, and on top of that, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye is formed. as a recording layer
80nm was deposited. During this film formation, the reflectance of the substrate at a wavelength of 830 nm was monitored.
The substrate incident reflectance at the end of the vapor deposition of the spacer layer tin oxide was set to the maximum value of 27.8%, and the second
The substrate incident reflectance at the end of vapor deposition of the spacer layer aluminum oxide was set to 14.0%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 28.9%, the servo signal was large and the reproduced signal was also large and good. Example 19 Tin oxide was applied to an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness to a thickness of 94 nm.
On top of that, magnesium oxide is deposited to a thickness of 80 nm, and on top of that, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye is formed. as a recording layer
80nm was deposited. During this film formation, the reflectance of the substrate at a wavelength of 830 nm was monitored.
The substrate incident reflectance at the end of the vapor deposition of the spacer layer tin oxide was set to the maximum value of 27.8%, and the second
The substrate incident reflectance at the end of vapor deposition of the spacer layer magnesium oxide was 9.1%, which was set to be thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus manufactured was as high as 27.7%, the servo signal was large and the reproduced signal was also large and good. Example 20 Tin oxide was applied to an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness to a thickness of 94 nm.
On top of that, germanium oxide is deposited to a thickness of 88 nm, and on top of that, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye is formed. as a recording layer
80nm was deposited. During this film formation, the reflectance of the substrate at a wavelength of 830 nm was monitored.
The substrate incident reflectance at the end of the vapor deposition of the spacer layer tin oxide was set to the maximum value of 27.8%, and the second
The substrate incident reflectance at the end of vapor deposition of the spacer layer germanium oxide was set to 4.1%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 24.7%, the servo signal was large and the reproduced signal was also large and good. Example 21 Tin oxide was applied to an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness to a thickness of 94 nm.
Copper phthalocyanine dye with a thickness of 90 nm is deposited on it.
Thereon, an organic thin film containing 85% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was vapor-deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830nm.
This is done while monitoring the reflectance of the substrate incident on it.
The substrate incident reflectance at the end of the vapor deposition of the first spacer layer tin oxide is set to a thickness that takes a maximum value of 27.8%.
The substrate incident reflectance at the end of vapor deposition of the second spacer layer copper phthalocyanine dye was set to 2.7%, which is thinner than the minimum thickness. Since the substrate incident medium reflectance of the optical disk thus manufactured was as high as 20.2%, the servo signal was large and the reproduced signal was also large and good. Example 22 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, copper phthalocyanine dye was deposited to a thickness of 104 nm, silicon dioxide was deposited to a thickness of 68 nm, and 5-amino- 8-(p
-methylanilino)-2,3-dicyano-1,4
- An organic thin film containing 85% or more of naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
This was done while monitoring the reflectance of 830 nm incident on the substrate, and the thickness was set to such a value that the substrate incident reflectance at the end of vapor deposition of the first spacer layer copper phthalocyanine dye had a maximum value of 20.7%, and the second spacer layer 2 The substrate incidence reflectance at the end of silicon oxide deposition is 12.0%.
The thickness was set to be thinner than the minimum value. Since the substrate incident medium reflectance of the optical disk thus produced was as high as 28.5%, the servo signal was large and the reproduced signal was also large and good. Example 23 Magnesium oxide was evaporated to a thickness of 121 nm on an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, and silicon dioxide was deposited on top of it.
5-amino-8-(p-
propoxyanilino)-2,3-dicyano-1,
An organic thin film containing 90% or more of 4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of light incident on the substrate at a wavelength of 830 nm was monitored, and the thickness was set to a maximum value of 10.7%, the reflectance of light incident on the substrate at the end of vapor deposition of the first spacer layer magnesium oxide. , the substrate incidence reflectance at the end of the deposition of the second spacer layer silicon dioxide is 2.4%.
The thickness was set to be thinner than the minimum value. Since the substrate incident medium reflectance of the optical disk thus manufactured was as high as 19.0%, the servo signal was large and the reproduced signal was also large and good. Example 24 Magnesium oxide was evaporated to a thickness of 110 nm on an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, and silicon dioxide was deposited on top of it.
5-amino-8-(p-
ethoxyanilino)-2,3-dicyano-1,4
- An organic thin film containing 90% or more of naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
This was done while monitoring the reflectance of 830 nm incident on the substrate, and the substrate incident reflectance at the end of vapor deposition of the first spacer layer magnesium oxide was set to be thinner than the maximum value of 10.6%, and the second spacer layer 2 The substrate incidence reflectance at the end of silicon oxide deposition is 2.1
%, which was set to be thinner than the minimum thickness. The medium reflectance of the optical disk thus produced was as high as 21.6%, so the servo signal was large and the reproduced signal was also large and good. Example 25 Magnesium oxide was evaporated to a thickness of 110 nm on an acrylic resin disk substrate with an inner diameter of 15 mm, an outer diameter of 120 mm, and a thickness of 1.2 mm, and 90 nm of magnesium fluoride was evaporated thereon, and 5-amino-8 −(p
-ethoxyanilino)-2,3-dicyano-1,
An organic thin film containing 90% or more of 4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of light incident on the substrate at a wavelength of 830 nm was monitored, and the reflectance of light incident on the substrate at the end of vapor deposition of the first spacer layer magnesium oxide was 10.6%, which was thinner than the maximum thickness. The incident reflectance of the substrate at the end of the vapor deposition of the second spacer layer magnesium fluoride was set to 4.4%, which is thinner than the thickness at which it takes the minimum value. The medium reflectance of the optical disk thus produced was as high as 22.4%, so the servo signal was large and the reproduced signal was also large and good. Example 26 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, 95 nm of copper phthalocyanine dye was vapor-deposited, 80 nm of magnesium fluoride was vapor-deposited thereon, and 5-amino- 8-
(p-ethoxyanilino)-2,3-dicyano-
An organic thin film containing 90% or more of 1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of the substrate incident at a wavelength of 830 nm was monitored, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer copper phthalocyanine dye was 20.4%.
The thickness was set to be thinner than the maximum value, and the substrate incident reflectance at the end of vapor deposition of the second spacer layer magnesium fluoride was set to 12.2%, which was thinner than the thickness that took the minimum value. The medium reflectance of the optical disc thus produced was as high as 28.1%, so the servo signal was large and the reproduced signal was also large and good. Example 27 Copper phthalocyanine dye was deposited to a thickness of 85 nm on an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, and silicon dioxide was deposited on top of it.
5-amino-8-(p-
ethoxyanilino)-2,3-dicyano-1,4
- An organic thin film containing 90% or more of naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
This was done while monitoring the reflectance of 830 nm incident on the substrate, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer copper phthalocyanine dye was set to be thinner than the maximum value of 19.6%. The substrate incident reflectance at the end of the vapor deposition of the silicon dioxide layer was set to 11.5%, which is thinner than the thickness at which it takes the minimum value. The medium reflectance of the optical disk thus produced was as high as 23.0%, so the servo signal was large and the reproduced signal was also large and good. Example 28 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, 95 nm of nickel phthalocyanine dye was vapor-deposited, 80 nm of aluminum oxide was vapor-deposited thereon, and 5-amino-8
-(p-ethoxyanilino)-2,3-dicyano-
An organic thin film containing 90% or more of 1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of the substrate incident at a wavelength of 830 nm was monitored, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer nickel phthalocyanine dye was
The thickness was set to 20.4%, which is thinner than the maximum value, and the substrate incident reflectance at the end of the deposition of the second spacer layer aluminum oxide was set to 9.2%, which is thinner than the thickness which takes the minimum value. The medium reflectance of the optical disk thus produced was as high as 23.0%, so the servo signal was large and the reproduced signal was also large and good. Example 29 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, 95 nm of cobalt phthalocyanine dye was vapor-deposited, and 90 nm of magnesium oxide was vapor-deposited thereon, and 5-amino-8
-(p-ethoxyanilino)-2,3-dicyano-
An organic thin film containing 90% or more of 1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of the substrate incident at a wavelength of 830 nm was monitored, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer cobalt phthalocyanine dye was
The thickness was set to 20.4%, which is thinner than the maximum value, and the substrate incident reflectance at the end of vapor deposition of the second spacer layer magnesium oxide was set to 5.5%, which is thinner than the thickness which takes the minimum value. The medium reflectance of the optical disk thus produced was as high as 21.7%, so the servo signal was large and the reproduced signal was also large and good. Example 30 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, copper phthalocyanine dye was evaporated to a thickness of 95 nm, yttrium oxide was evaporated to a thickness of 85 nm, and 5-amino-8 −(p
-ethoxyanilino)-2,3-dicyano-1,
An organic thin film containing 90% or more of 4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of the substrate incident at a wavelength of 830 nm was monitored, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer copper phthalocyanine dye was 20.4%, which is thinner than the maximum thickness. The substrate incident reflectance at the end of the deposition of the second spacer layer yttrium oxide was set to 7.3%, which is thinner than the thickness at which the second spacer layer yttrium oxide takes the minimum value. The medium reflectance of the optical disk thus produced was as high as 22.8%, so the servo signal was large and the reproduced signal was also large and good. Example 31 Germanium oxide was evaporated to a thickness of 90 nm on an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, and magnesium fluoride was deposited on top of it.
5-amino-8-(p-
ethoxyanilino)-2,3-dicyano-1,4
- An organic thin film containing 90% or more of naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
This was done while monitoring the reflectance of 830 nm incident on the substrate, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer germanium oxide was set to be 14.7%, which is thinner than the maximum thickness. The substrate incidence reflectance at the end of magnesium chloride vapor deposition is
The thickness was set at 7.6%, which is thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 24.5%, so the servo signal was large and the reproduced signal was also large and good. Example 32 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, 90 nm of germanium oxide was deposited, and 90 nm of silicon dioxide was deposited on it.
On top of this, an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830n.
This was done while monitoring the substrate incident reflectance of m, and the substrate incident reflectance at the end of vapor deposition of the first spacer layer germanium oxide was set to be 14.7%, which is thinner than the maximum thickness, and the second spacer layer The substrate incidence reflectance at the end of silicon dioxide deposition is 6.8%.
The thickness was set to be thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 21.6%, so the servo signal was large and the reproduced signal was also large and good. Example 33 Germanium oxide was deposited to a thickness of 90 nm on an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, and aluminum oxide was deposited on top of it.
5-amino-8-(p-
ethoxyanilino)-2,3-dicyano-1,4
- An organic thin film containing 90% or more of naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
This was done while monitoring the reflectance of 830 nm incident on the substrate, and the substrate incident reflectance at the end of vapor deposition of the first spacer layer germanium oxide was set to be 14.7%, which is thinner than the maximum thickness, and the second spacer layer The substrate incidence reflectance at the end of aluminum oxide deposition is
The thickness was set at 6.4%, which is thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 18.7%, so the servo signal was large and the reproduced signal was also large and good. Example 34 Cerium oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
90nm of silicon dioxide is deposited on top of that.
On top of this, an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was vapor-deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830nm.
This is done while monitoring the reflectance of the substrate incident on it.
The substrate incident reflectance at the end of the vapor deposition of the first spacer layer cerium oxide is set to 16.2%, which is thinner than the maximum thickness, and the substrate incident reflectance at the end of the vapor deposition of the second spacer layer silicon dioxide is set to 16.2%. The thickness was set at 7.3%, which is thinner than the minimum value. The medium reflectance of the optical disc thus produced was as high as 23.2%, so the servo signal was large and the reproduced signal was also large and good. Example 35 Nickel oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
95nm vapor deposition and magnesium fluoride on top
5-amino-8-(p-
ethoxyanilino)-2,3-dicyano-1,4
- An organic thin film containing 90% or more of naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
This was done while monitoring the reflectance of 830 nm incident on the substrate, and the substrate incident reflectance at the end of the deposition of the first spacer layer nickel oxide was set to be 21.2%, which is thinner than the maximum thickness, and the second spacer layer The substrate incidence reflectance at the end of magnesium fluoride vapor deposition is
The thickness was set at 12.7%, which is thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 28.9%, so the servo signal was large and the reproduced signal was also large and good. Example 36 Nickel oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
85nm evaporated and 80nm silicon dioxide on top.
On top of this, an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was vapor-deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830nm.
This is done while monitoring the reflectance of the substrate incident on it.
The substrate incident reflectance at the end of the vapor deposition of the first spacer layer nickel oxide is set to 20.3%, which is thinner than the maximum thickness, and the substrate incident reflectance at the end of the vapor deposition of the second spacer layer silicon dioxide is set to 20.3%. The thickness was set at 11.9%, which is thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 23.8%, so the servo signal was large and the reproduced signal was also large and good. Example 37 Nickel oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
95nm vapor deposited and 80n aluminum oxide on top
On top of this, an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830n.
This was done while monitoring the reflectance of the substrate incident on the substrate of m, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer nickel oxide was set to be 21.2%, which is thinner than the maximum thickness, and the second spacer layer The substrate incidence reflectance at the end of aluminum oxide deposition is 9.4%.
The thickness was set to be thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 23.8%, so the servo signal was large and the reproduced signal was also large and good. Example 38 Nickel oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
95nm vapor deposited and 90n magnesium oxide on top.
On top of this, an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830n.
This was done while monitoring the reflectance of the substrate incident on the substrate of m, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer nickel oxide was set to be 21.2%, which is thinner than the maximum thickness, and the second spacer layer The substrate incidence reflectance at the end of magnesium oxide evaporation is 5.5%.
The thickness was set to be thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 22.5%, so the servo signal was large and the reproduced signal was also large and good. Example 39 75 nm of tin oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
On top of that, magnesium oxide is deposited to a thickness of 70 nm, and on top of that, an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye is formed. as a recording layer
80nm was deposited. During this film formation, the reflectance of the substrate at a wavelength of 830 nm was monitored.
The substrate incident reflectance at the end of the vapor deposition of the spacer layer tin oxide is 25.9%, which is set thinner than the maximum thickness, and the substrate incident reflectance at the end of the vapor deposition of the second spacer layer magnesium fluoride is 20.5%. The thickness was set to be thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 25.3%, so the servo signal was large and the reproduced signal was also large and good. Example 40 55 nm of tin oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
100 nm of silicon dioxide is deposited on the organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye. as a recording layer
80nm was deposited. During this film formation, the reflectance of the substrate at a wavelength of 830 nm was monitored.
The substrate incident reflectance at the end of the vapor deposition of the spacer layer tin oxide is set to 20.5%, which is thinner than the maximum thickness, and the substrate incident reflectance at the end of the vapor deposition of the second spacer layer silicon dioxide is 12.0%. The thickness was set to be thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 26.3%, so the servo signal was large and the reproduced signal was also large and good. Example 41 55 nm of tin oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
On top of that, aluminum oxide is deposited to a thickness of 100 nm, and on top of that, an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye is formed. A recording layer of 80 nm was deposited. During this film formation, the reflectance of the substrate incident at a wavelength of 830 nm was monitored, and the substrate incident reflectance at the end of the deposition of the first spacer layer tin oxide was set to 20.5%, which is thinner than the thickness that takes the maximum value. However, the substrate incident reflectance at the end of vapor deposition of the second spacer layer aluminum oxide was set to 11.0%, which is thinner than the thickness at which the aluminum oxide layer takes the minimum value. The medium reflectance of the optical disk thus produced was as high as 23.9%, so the servo signal was large and the reproduced signal was also large and good. Example 42 65 nm of tin oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
On top of that, magnesium oxide is deposited to a thickness of 100 nm, and on top of that, an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye is formed. A recording layer of 80 nm was deposited. During this film formation, the reflectance of the substrate at a wavelength of 830 nm was monitored, and the reflectance of the substrate at the end of the deposition of the first spacer layer tin oxide was 23.6%, which was set to be thinner than the maximum thickness. However, the substrate incidence reflectance at the end of the vapor deposition of the second spacer layer magnesium oxide was set to 8.7%, which is thinner than the thickness at which it takes the minimum value. The medium reflectance of the optical disk thus produced was as high as 24.8%, so the servo signal was large and the reproduced signal was also large and good. Example 43 75 nm of tin oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
Germanium oxide is deposited to a thickness of 100 nm, and an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye is formed on top of it. A recording layer of 80 nm was deposited. During this film formation, the reflectance of the substrate at a wavelength of 830 nm was monitored, and the reflectance of the substrate at the end of the deposition of the first spacer layer tin oxide was 25.9%, which was set to be thinner than the maximum thickness. However, the substrate incident reflectance at the end of the vapor deposition of the second spacer layer germanium oxide was set to 5.0%, which is thinner than the thickness at which the second spacer layer germanium oxide takes the minimum value. The medium reflectance of the optical disk thus produced was as high as 23.5%, so the servo signal was large and the reproduced signal was also large and good. Example 44 85 nm of tin oxide was applied to an acrylic resin disk substrate with guide grooves of 15 mm inner diameter, 120 mm outer diameter, and 1.2 mm thickness.
evaporate and add 100n of copper phthalocyanine dye on it.
On top of this, an organic thin film containing 90% or more of 5-amino-8-(p-ethoxyanilino)-2,3-dicyano-1,4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength is 830n.
This was done while monitoring the substrate incident reflectance of m, and the substrate incident reflectance at the end of the evaporation of the first spacer layer tin oxide was set to be 27.3%, which is thinner than the maximum thickness, and the second spacer layer The substrate incidence reflectance at the end of vapor deposition of copper phthalocyanine dye is 2.3%.
The thickness was set to be thinner than the minimum value. The medium reflectance of the optical disk thus produced was as high as 20.1%, so the servo signal was large and the reproduced signal was also large and good. Example 45 On an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, copper phthalocyanine dye was deposited to a thickness of 95 nm, magnesium oxide was deposited to a thickness of 90 nm, and 5-amino-8 −(p
-ethoxyanilino)-2,3-dicyano-1,
An organic thin film containing 90% or more of 4-naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the reflectance of the substrate incident at a wavelength of 830 nm was monitored, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer copper phthalothianine dye was 20.4%, which is thinner than the maximum thickness. The incident reflectance of the substrate upon completion of vapor deposition of the second spacer layer magnesium oxide was set to 5.5%, which is thinner than the thickness at which the second spacer layer magnesium oxide takes a minimum value. The medium reflectance of the optical disk thus produced was as high as 21.7%, so the servo signal was large and the reproduced signal was also large and good. Example 46 Copper phthalocyanine dye was deposited to a thickness of 85 nm on an acrylic resin disk substrate with a guide groove of 15 mm in inner diameter, 120 mm in outer diameter, and 1.2 mm in thickness, and silicon dioxide was deposited on top of it.
5-amino-8-(p-
methylanilino)-2,3-dicyano-1,4-
An organic thin film containing 95% or more naphthoquinone dye was deposited as a recording layer to a thickness of 80 nm. During this film formation, the wavelength
This was done while monitoring the reflectance of 830 nm incident on the substrate, and the substrate incident reflectance at the end of the vapor deposition of the first spacer layer copper phthalocyanine dye was set to be 19.6%, which is thinner than the maximum thickness, and the second spacer layer was The substrate incident reflectance at the end of the vapor deposition of the silicon dioxide layer was set to 11.5%, which is thinner than the thickness at which it takes the minimum value. The medium reflectance of the optical disk thus produced was as high as 27.8%, so the servo signal was large and the reproduced signal was also large and good. Effects of the Invention As is clear from the above embodiments, the present invention provides an optical information recording medium with large reproduction signals and servo signals.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an optical information recording medium which is an embodiment of the present invention, FIGS. 2 and 3 are schematic diagrams for explaining the principle of the optical information recording medium of the present invention, and FIGS. FIG. 35 is a diagram showing changes in the reflectance of an optical information recording medium depending on the recording layer thickness, and FIGS. 36 to 40 are diagrams showing changes in the reflectance depending on the recording layer thickness for comparison. (Main reference numbers), 10...Substrate, 20...Recording layer, 30...First spacer layer, 40...Second
spacer layer, 100...incident light, 200, 30
0...Reflected light.

Claims (1)

[Scope of Claims] 1. An optical information recording medium on which information is recorded and read by irradiation with a laser beam, which is provided on a substrate that is substantially transparent to the laser beam and is transparent to the laser beam. a first spacer layer having a refractive index at the wavelength of the laser light that is greater than the refractive index of the substrate; and a first spacer layer that is substantially transparent to the laser light and has a refractive index at the wavelength of the laser light An optical information recording medium in which at least three layers are laminated, a second spacer layer smaller than the spacer layer, and a recording layer that absorbs the laser beam, wherein the first spacer layer includes the recording layer and the second spacer layer.
The thickness of the second spacer layer is such that the substrate incident reflectance is maximum in a state where no spacer layer is formed, or is thinner than that, and the second spacer layer is formed with the first spacer layer and the recording layer is 1. An optical information recording medium characterized in that the thickness is thinner than the thickness at which the substrate incident reflectance in an unformed state is minimal.