JPS6334839B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording medium for an optical information recording device, and particularly to an optical recording medium that is highly sensitive to laser light.

FIG. 1 is a front view for explaining a conventional optical information recording device.

In the figure, 1 is a laser light source, 2 is a laser beam,
3 is a modulator, 4 is an optical lens, 6 is a reflector, 7 is a recording medium, and 8 is a motor.

A laser beam 2 from a laser light source 1 is modulated by a modulator 3, and is irradiated onto a recording medium 7 through an optical lens 4, a reflecting plate 5, etc., and information is transmitted by perforating the recording medium 7. are recorded.

Many materials have been proposed for the recording medium 7, including metal thin films and organic thin films. In particular, low melting point metals such as bismuth Bi and tellurium Te are deposited thinly (several hundred Å) on a transparent glass substrate 9 as shown in FIG. It is said to be effective in this respect.

However, even with these materials, when used as ultra-high-speed information recording media currently required, Ar lasers must be used as light sources because of insufficient sensitivity. Therefore, since a high power Ar laser naturally requires cooling and the device itself becomes large, a device that can record with a light source such as a low power semiconductor laser is desired.

An object of the present invention is to provide an optical recording medium in which a composite film containing a mixture of tellurium atoms and copper phthalocyanine molecules is deposited on a substrate, and the recording sensitivity is improved.

A feature of the present invention is that in an optical recording medium, the information medium layer is coated with a composite film formed by co-evaporating tellurium atoms and copper phthalocyanine molecules on a substrate, thereby achieving the above-mentioned object.

FIG. 3 is a sectional view showing the structure of one embodiment of the optical recording medium according to the present invention.

In the figure, 10 is a transparent substrate, and 11 is a composite film containing a mixture of tellurium atoms and copper phthalocyanine molecules.

Tellurium atoms and copper phthalocyanine molecules are simultaneously deposited on a transparent substrate 10, and a composite film in which they are completely mixed at the atomic level constitutes an optical recording medium. Copper phthalocyanine is an organic dye with a temperature of 400℃ to 500℃
sublimes at a temperature of Tellurium Te has a melting point of 450°C, and when irradiated with laser light, the copper phthalocyanine molecules in the composite film configured as described above sublimate, and at the same time, the tellurium atoms that melt at the same temperature are dissolved and holes are formed. .

In this case, the sublimation pressure of the copper phthalocyanine molecules sublimated adjacent to the tellurium atoms in the molten state has the effect of helping melt and remove the tellurium atoms, and compared to an optical recording medium composed only of tellurium atoms, as will be described later. It seems that the sensitivity has been improved several times.

FIG. 4 is a diagram for explaining one embodiment of the production of an optical recording medium according to the present invention, in which A is a front view and B is a sectional view.

In the figure, a glass disk 12 with a diameter of 300 mm and a thickness of 5 mm, whose surface has been sufficiently cleaned to remove dust and dirt, is mounted in a vacuum evaporator 13 with a vacuum level of ^{10 -4} to ^{10 -5} Pa. While rotating the glass disk 12 at 180 rpm, the purity of the copper phthalocyanine from the box-shaped boat 14 of the W furnace containing the copper phthalocyanine was increased.
They are evaporated from a Mo furnace boat 15 containing 99.999% tellurium and simultaneously deposited on the glass disk 12. In addition, the box board 14 of the W furnace and Mo
A shielding plate 16 is provided directly above each furnace board 15 to prevent large chunks from adhering to the disk 12 from the boards 14,15. A partition plate 17 is provided between the two evaporation sources to prevent the copper phthalocyanine and tellurium vapors from mixing.
Furthermore, a shutter 18 and a mask 19 are provided, and a required amount of vapor deposition film is applied to the disk 12. In addition, W
A small hole 20 is provided in the upper part of the boat 14 of the furnace to ensure uniform sublimation and evaporation of the copper phthalocyanine.

Copper phthalocyanine and tellurium glass disk 12
The deposition rate is controlled by the power applied to each boat 14,15. The amount of vapor deposited is 300 Å of tellurium and 400 Å of copper phthalocyanine in terms of their respective substances.
This is the amount to form a film thickness of Å.

Information was written on the optical recording medium made of the composite film of tellurium and copper phthalocyanine prepared as described above using an optical information recording apparatus as shown in FIG. That is, using light with a wavelength of 488 nm emitted from the Ar laser light source 1, a spot (with a diameter of 1 μm or less) was irradiated onto the medium 7 to record information. In addition,
This recording medium 7 is rotated by a motor 8 at 1800 rpm.

The laser power threshold for forming information pits was 25 mw on the conventional tellurium film with a thickness of 300 Å, but was 8 mw on the composite film of the present invention. Therefore, the sensitivity has been improved by about 2.5 times compared to the conventional one. Furthermore, the S/N ratio is 42dB when converted to a video signal, which is almost unchanged from the conventional model.

The present invention has been described above with reference to the embodiments. According to the present invention, the information medium layer of an optical recording medium is made of a composite film formed by co-evaporating tellurium atoms and copper phthalocyanine molecules on a substrate. A highly sensitive optical recording medium can be provided, and information can be recorded using a low-power laser light source, which is highly effective.

[Brief explanation of the drawing]

Figure 1 is a front view for explaining recording on a conventional recording medium using an optical information recording device;
The figure is a sectional view showing the structure of a conventional recording medium.
The figure is a cross-sectional view showing the structure of a recording medium according to the present invention, and FIG. Inside, 10 is a transparent substrate, 11 is a composite film containing a mixture of tellurium atoms and copper phthalocyanine molecules, 12 is a glass disk, 13 is a vacuum evaporator, 14
is a box-shaped boat of W furnace, 15 is a boat of Mo furnace, 1
6 is a shielding plate, 17 is a partition plate, 18 is a shutter, 1
9 is a mask, and 20 is a small hole.

Claims (1)

[Scope of Claims] 1. An optical recording medium in which information is recorded by selectively removing a part of an information medium layer coated on a substrate with a laser beam, wherein the information medium layer is coated on the substrate with tellurium atoms and An optical recording medium comprising a composite film formed by simultaneous vapor deposition of copper phthalocyanine molecules. 2. The optical recording medium according to claim 1, characterized in that tellurium and copper phthalocyanine have a thickness of 100 to 800 Å and a thickness of 100 to 5000 Å, respectively, formed by simultaneous vapor deposition. .