JPS62256244A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To increase the erasing speed of information with a recording film by irradiating laser light on the recording film and irradiating lamp light on a solar batter in the stage of erasing. CONSTITUTION:A transparent electrode 2 is formed on a transparent substrate 1. The recording film 4 and the solar battery 5 are juxtaposed on the electrode 2. An electrode 3 is further formed thereon. The lamp light 7 is irradiated through the transparent electrode 2 on the solar battery 5 and the laser light 6 is irradiated on the recording film 4 in the stage of erasing the information. Electromotive force is generated in the solar batter 5 by the irradiation of the lamp light 7. An electric field is generated in the recording film 4 by such electromotive force. Since the laser light for erasing is irradiated in this state on the recording film 4, the erasing speed of the information with the recording film is increased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical information recording medium capable of recording, erasing, and reproducing information by incident convergent light, and in particular, the present invention relates to an optical information recording medium that is capable of recording, erasing, and reproducing information by incident convergent light. This invention relates to an optical information recording medium that is excellent and suitable for high-density and large-capacity storage.

[Conventional technology]

Optical disk memories that use focused laser light are used as high-density, large-capacity information recording media, and important issues for such optical disk memories include increasing the CZN ratio and improving the recording/erasing speed. It will be done. Conventionally, as an optical disk memory that can obtain a high C/N ratio, a method of transitioning between two states with different optical constants was developed using 1%.
As described in Japanese Patent No. 8740, since the phenomenon of heating and cooling is used to erase records, it is necessary to irradiate the erase laser beam several times, and the time required for erasing is long. This is not practical for real-time recording due to the insufficient erasing speed. In addition, as an example of improving the erasing speed, the Institute of Electronics and Communication Engineers branch axis Vo184° Yang 205. MR-84
19 ('84.11), there is a magneto-optical disk that utilizes the Kerr rotation angle associated with magnetic field reversal of the recording film, but because the Kerr rotation angle is small, a high C/N ratio is achieved. I can't get it.

[Problem that the invention seeks to solve]

In the above conventional technology, there is a problem that insufficient consideration is given to information erasing speed in the former example and high C/N ratio in the latter example, and it is difficult to effectively utilize the advantages of each. there were.

The purpose of the present invention is to solve the above-mentioned problems of the prior art, and to
The object of the present invention is to provide an optical information recording medium that has a high N ratio, a high erasing speed, a high density, and a large capacity.

[Means for solving problems]

By the way, the recording film used for optical information recording media is
It is heated by focused laser irradiation, and depending on the heating and cooling process, it takes on two states: crystalline and amorphous. Information is reproduced by detecting the difference in optical constants (reflectance, transmittance) between these two states using a weak laser beam. Here, the size of the laser beam is
When recording information, an energy gap greater than or equal to that required to change from crystalline to amorphous is required, and when erasing information, an energy gap greater than or equal to that required to change from amorphous to crystalline is required. be. The former produces a rapid cooling effect with short-time irradiation, and the latter produces a gradual cooling effect with long-term irradiation. Now, electrodes (
The inventors formed a transparent electrode on the laser irradiation side and applied an electric field to the recording gland to perform the above recording and erasing, and obtained the following results. In other words, during recording, there was no difference in recording characteristics from the conventional one, but when erasing,
The laser irradiation time required for erasing is shortened.

The erasure rate was observed to be fast. This is presumed to be because the electric field applied to the recording film promoted rearrangement from amorphous to crystalline, resulting in faster erasing speed than when irradiated with laser light alone.

Therefore, focusing on such a phenomenon, in the present invention, a recording film and a solar cell electrically connected to both electrodes are arranged side by side between two layers of electrodes on a transparent substrate, and the electrodes on the substrate side are arranged side by side. When erasing information by making it transparent, 6. At the same time, the recording film is irradiated with laser light from the substrate side, and the LE
The above object is achieved by irradiating the solar cell with light from a lamp such as a D lamp.

[Effect]

When the recording film is irradiated with the erasing laser light, the photovoltaic force generated in the solar cells by irradiating the light onto the solar cells arranged in line with the recording film generates an electric field in the recording film. Thus, an optical information recording medium with a high C/N ratio and a high erasing speed can be obtained by increasing the erasing speed of information in the recording film.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

As shown in FIG. 1, first, a conductive film 2 that will become a transparent electrode is formed on a transparent substrate 1 made of glass, acrylic resin, etc.
On top of that, a recording film 4 made of a chalcogenide compound or the like and an amorphous silicon solar cell 5 are arranged side by side, and further on top of that, AJ, 4.

is formed as the other electrode 3 to a thickness of 1 μm by sputtering. As the conductive film 2, ca2sno4 was formed to a thickness of 1100 nm by sputtering, and as the recording film 4, a 5s-8b-Bi compound (chalcogenide compound) was formed.
is formed to a thickness of 100 nm by sputtering, and the solar cell has an area of 1 am' and is in ohmic contact with the conductive film 2.

In the optical information recording medium thus constructed, since the recording film 4 is amorphous after being formed by the sputtering method, it is crystallized and initialized in advance by a method similar to erasing, which will be described later.

Now, when recording information on an optical information recording medium configured in this way, an optically modulated laser beam (wavelength 830 nm) 6 with an output of 8 mW is focused as shown in Fig. 1 and placed on a substrate 1 on the recording medium. Irradiate from side to side. Irradiation time is 10 ron6θ
By irradiating for a time equal to or less than C, the recording film 4 becomes amorphous and enters a recording state.In addition, when recording information, it is necessary to move the laser beam 6 and the information recording medium relatively. Needless to say.〇Next, we will explain the case of erasing the information recorded in this way.

To erase information, use a laser beam with a 5mW output (wavelength 8
30nm) 6 and irradiates the area to be erased,
At the same time, a 30 mW 0 mW output LED lamp (not shown) emits lamp light 7 from the substrate 1 side to the solar cell 5.
irradiate. As a result, the recording film 4 was irradiated for 100n.
It crystallizes within seconds and enters the erased state.

That is, by the above-described operation, the solar cell 5 irradiated with the lamp light 7 generates an electromotive force of approximately α6V, applies a voltage between the conductive film 2 and the electrode 3 at both ends, and creates a voltage between the recording film 4 of approximately 6
Generate an electric field of KV/mm.

As a result, since the recording film is irradiated with the erasing laser light while an electric field is applied, the recording film 4
crystallizes at a high speed and becomes an erased state.

As explained above, according to this embodiment, at the time of erasing,
By irradiating the recording film 4 with focused laser light 6 while irradiating the solar cell 5 with the light 7 of the LED lamp, the recording film 4 is
Because it can change from amorphous to crystalline at high speed, the erasing performance is much better than before. Also,
In recording, since a recording film with which a conventionally high C/N ratio can be obtained is used, a higher C/N ratio than conventionally can be obtained.

Next, another embodiment of the present invention will be described with reference to FIGS. 2 and 6.

In this embodiment, the information recording medium is shaped like a disk, and FIG. 2 shows a top view thereof, and FIG. 6 shows a sectional view of its mounting part. The main configuration is the same as the embodiment described above.

As shown in FIG. 3, a recording film 4 and a solar cell 5 are arranged side by side on a transparent electrode 2 provided on an acrylic substrate 1, and an electrode 3 is formed thereon.

The information recording medium configured in this manner performs recording, erasing, and reproducing while rotating around the attachment hole 8. Here, the shape of the solar cell 5 is donut-shaped as shown in FIG. 2, and the solar cell 5 is provided on the outer circumferential side of the mounting hole 8 used for rotating the disk during recording and erasing.・7. This is to ensure that an electric field is applied to the recording film 4 during rotation even when the lamp light 7 from the LED lamp is single during erasing.

Now, in this embodiment, recording is performed by irradiating a laser beam 6 with an output of 8 mW, and erasing is performed by irradiating a laser beam 6 with an output of 5 mW.
This is performed by irradiating the solar cell 5 with 30 mW 0 mW output LED lamp light 7 while irradiating the solar cell 5 with .

In addition, the rotation speed of the recording medium is 1800 rpm in both cases.
Let it be m. As a result, in the signal recording of 5MHIZ, 55a
A high C/N ratio of B is obtained, and the erasure is reduced from 55 dB to 20 dB during one rotation, which is practically an erasure state.

By the way, since it is difficult to obtain a large donut-shaped solar cell 5, as the primary solar cell 5,
The case where a small-sized one is used will be explained using FIG. 4.

As shown in FIG. 4, as the solar cell 5 becomes smaller, a space becomes open, so an insulating material 9 is formed in that space to prevent a short circuit between the electrode 6 and the transparent electrode 2. ing. What is the recording, erasing, and reproducing of the information recording medium configured in this way?

The process is carried out in the same manner as the embodiments shown in FIGS. 2 and 6, but with regard to the LED rungs, by arranging a large number of LED rungs in a donut shape around the mounting hole 8, and making them all emit light,
The solar cell 5 is made to generate an electromotive force. It goes without saying that in this embodiment as well, a high C/N ratio can be obtained and the erasing speed can be increased.

In addition to the recording films used in the embodiments described above, similar effects can be obtained with, for example, TEIOX (x=1 to 2).

〔Effect of the invention〕

According to the present invention, since information can be erased at high speed, real-time recording (
This enables high-density, large-capacity recording with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a cross section of a main part in one embodiment of the present invention, FIG. 2 is a top view showing another embodiment of the invention, and FIG. 3 is a cross section of a main part in FIG. The sectional view shown in FIG. 4 is an upper opening showing another embodiment of the present invention. 1... Transparent substrate, 2... Transparent electrode, 3... Electrode,
7! - recording layer, 5... solar cell, 6... laser light,
7...Lamp source, 8...Mounting hole, 9...Insulator. 11. Part 1 Part 3: Ran-osho

Claims (1)

[Claims] 1. A transparent first electrode is provided on a transparent substrate, and a solar cell electrically connected to the first electrode is placed on a part of the first electrode. A recording film is formed on the solar cell and the recording film is further provided with a second film electrically connected to the solar cell.
In an optical information recording medium, the optical information recording medium is provided with an electrode and is capable of recording or erasing information on the recording film using convergent light incident from the transparent substrate side, during erasing, light is transmitted from the transparent substrate side to the solar cell. 1. An optical information recording medium characterized in that information is erased in a state where an electromotive force is generated in the solar cell and an electric field is generated in the recording film upon incidence of the solar cell.