JPH11203728A - Information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recording medium capable of warning a user to make the backup of the recorded information before the recorded information is damaged. SOLUTION: In an information recording medium having the recording area 2 of information, a life deciding area 3 having a shorter life than the recording area 2 is provided. The life deciding area 3 is formed by recording a signal having the quality inferior to the signal recorded in the recording area 2, the signal being worse in quality is formed by recording it in the life deciding area 3 with a power other than the optimum power for recording in the recording area 2. In this case, a magnetooptical disk 1, having the data recording area 2 and the life deciding area 3, having the shorter life than the data recording area 2, on the inner peripheral side or on the outer peripheral side, is prepared.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium, and more particularly to an optical recording medium for recording / reproducing information by irradiating a light beam to change the properties of a recording layer material.

[0002]

2. Description of the Related Art With the recent development of the information society, magnetic media, optical recording media, and the like have rapidly spread. In particular, as the optical recording medium, a magneto-optical recording medium using the magneto-optical effect, a write-once optical recording medium that can be written only once, and a phase-change optical recording medium that can be read and written many times have been put to practical use. Characteristics of these optical recording media include a large recording capacity, a higher access speed than a magnetic tape, good storage reliability due to non-contact, and easy portability.

[0003] Applications such as magnetic media and optical recording media include computer memory, video disks, document files, and the like.
There are electronic albums. In particular, the write-once optical recording medium is used for public documents, hospital charts, life insurance, etc., in which falsification prevention is important because data cannot be erased once written. Since the storage reliability of these recording media is important, studies have been made to improve the storage reliability.

[0004] As a typical example, in order to obtain a recording medium having a long storage life, a buffer layer is provided between an upper protective layer and a reflective layer (Japanese Patent Laid-Open No. 5-174421). Bonded to a protective substrate through a layer (Japanese Unexamined Patent Publication No.
JP-A-231490), the active energy of deterioration is 1.
Use a recording layer composition of 1 eV or more (Japanese Unexamined Patent Publication No. 8-2638)
No. 71) has been proposed.

At present, the life of an optical disk is guaranteed for several tens of years. However, since these recording media are easy to carry, they are left on the dashboard of the car.
They can be exposed to poor environments and do not always have the expected lifetime. Further, there is no means for judging whether the user can continue to use the recording medium as it is even after the guaranteed life has expired.

Therefore, it is important to determine the life of the recording medium and to notify the user before the data is damaged. As a typical proposal example, in a magnetic tape or the like, a deterioration state is determined based on the number of times of recording and reproduction, and a warning message is issued (Japanese Patent Laid-Open No. 6-59822).
In order to determine structural defects such as peeling and cracking in an optical card or the like, an information recording carrier having a discoloration portion that changes color when exposed to air around a recording area (Japanese Patent Laid-Open No. 5-318975) is known. No. It has also been proposed to monitor the reflectance of the reproduction light and prohibit rewriting or overwriting of information on the phase-change optical disk when the reflectance is out of the reflectance variation range (Japanese Patent Application Laid-Open No. 3-269826). I have.

[0007]

As described above, there has been proposed a method of judging the life of a recording material in the case of a structural defect such as peeling or cracking. It is not possible to know the state of the recording medium after the lapse. Therefore, an object of the present invention is to provide an information recording medium that can determine deterioration of a recording medium itself and warn a user before information is damaged.

[0008]

The structure and operation of the present invention will be described below. The information recording medium according to the first aspect is characterized in that an information recording medium having an information recording area is provided with a life determining area. According to this information recording medium, the life judgment area reaches the end of its life before the recording area whose deterioration has progressed due to long-term storage reaches the end of its life. Therefore, it is possible to know the progress of the deterioration of the recording area, and warn the user. Can be emitted. Therefore, the user
Backups can be made before information is corrupted.

[0009] The information recording medium according to the second aspect is the first aspect.
In the information recording medium, a recording area comprising at least a recording layer and a reflection layer is provided on a substrate, and a phase change type recording / reproducing information is performed by causing a phase change in a recording layer material. And

[0010] The information recording medium according to the third aspect is the first aspect.
Or 2) a signal characterized by recording a signal of lower quality than the signal recorded in the recording area in the life determination area. In this information recording medium, the life determination area reaches the end of its life before the recording area reaches its end of life, so that the progress of the deterioration of the recording area can be known, and therefore, a warning can be issued to the user.

[0011] The information recording medium according to the fourth aspect is the third aspect of the invention.
In which a signal of inferior quality is created by recording in the life determination area with a power other than the optimum recording power for recording in the recording area. This makes it possible to obtain a signal whose deterioration is faster than that of the signal recorded in the recording area.

According to a fifth aspect of the present invention, there is provided an information recording medium.
Wherein a signal of poor quality is created by repeatedly overwriting the signal. By repeatedly overwriting the signal, it is possible to obtain a signal whose deterioration progresses at a high speed.

[0013] The information recording medium according to the sixth aspect is the third aspect.
Wherein a signal of poor quality is created by irradiating weak DC light after recording. This makes it possible to obtain a signal of lower quality than the signal recorded in the recording area.

According to a seventh aspect of the present invention, there is provided an information recording medium.
Is characterized in that the life determination region has a plurality of different DC light irradiation regions. By doing this,
It is possible to know the degree of progress of deterioration.

[0015] The information recording medium according to the eighth aspect is the first aspect.
Alternatively, in the second aspect, the life determination area is an area having lower storage characteristics than the recording area. Therefore,
Since the life determination area reaches the end of its life before the recording area reaches its end of life, it is possible to know the progress of deterioration of the recording area and to issue a warning to the user.

According to a ninth aspect of the present invention, in the information recording medium according to the eighth aspect, the information recording medium has an environmental protection layer, and the life determining area is between the recording area and an end of the environmental protection layer. Therefore, it is possible to create a life determination area having a shorter life than the recording area.

In the information recording medium according to the present invention, in the information recording medium having the information recording area, the life determining area is provided, so that the life of the recording medium can be determined and a backup is taken before the information is damaged. So that the user can be warned. The recording layer in the life determination area has the same storage characteristics as the information recording area, or is inferior to one or more of light resistance, corrosion resistance, heat resistance, temperature resistance, impact resistance, etc. It has.
The judgment of the life is made based on the deterioration of the quality of the recording signal in the life judgment area. That is, deterioration or not is determined by measuring at least one of reflectance, modulation, asymmetry, hit error rate, in-circumference of reflectance, jitter, and the like depending on the quality of a recording signal.

[0018]

Next, an embodiment of the present invention will be described. Example 1 A magneto-optical disk was manufactured as an optical disk. An optical disc 1 shown in FIG. 1 has a data recording area 2 on which data is recorded, and a data recording area 2 on the inner or outer peripheral side thereof.
And a life determination area 3 having a shorter life. The life determination region 3 was formed by irradiating an ion beam.

Example 2 A phase change optical disk was manufactured. That is, as shown in FIG. 2, on a substrate 11 (made of polycarbonate and having a thickness of 0.6 mm), a first protective layer 12 (made of ZnSSiO ₂ and having a thickness of 200 nm) and a recording layer 13 (AgInS
bTe, the thickness is 20 nm), the second protective layer 14
(Made of ZnSSiO ₂ and having a thickness of 20 nm), a reflective layer 15 (made of an Al alloy and having a thickness of 100 nm), and an environmental protection layer 16 (made of an ultraviolet curable resin and having a thickness of 4 μm).
An optical disk of a phase change type laminated in the order of m) was produced by sputtering. However, the ultraviolet curable resin was applied by spin coating.

In order to determine the optimum recording power of the optical disk, a wavelength of 635 nm, an NA of 0.63, and a linear velocity of 3.5
The recording power dependence when a random pattern of EFM modulation was recorded at m / s was measured. FIG. 4 shows the recording strategy of FIG. 3 and the jitter σ / Tw [%] when a signal was recorded with the recording power of [Table 1]. From FIG.
The optimum recording power is Pw1 = 10 to 12 [mW],
It can be seen that when it is less than 10 [mW], the jitter rises sharply.

[0021]

[Table 1]

A signal was recorded in the data recording area 2 of FIG. 1 at the optimum recording power determined by the above experiment. Further, the optimum recording power Pw1 = 10 is set in the life determination area 3 of FIG.
Signals were recorded below [mW]. As a result, the quality of the signals recorded in the data recording area 2 and the life determination area 3 is inferior to that of the life determination area 3, and the signal recorded in the life determination area 3 reaches the life earlier. did.

Embodiment 3 FIG. 5 shows the O / W power margin characteristics of the phase change type optical disk of Embodiment 2. Optimal recording power 10-12 [mW]
In this case, the jitter characteristics after writing 1000 times or more deteriorated. A phase-change type optical disk having the same layer configuration as that of the second embodiment is manufactured, and a signal is recorded at the optimum recording power Pw1 = 10 to 12 [mW] in the recording area 2 and the life determination area 3 in FIG. Only 3 was overwritten 1000 times.
As a result, the quality of the signals recorded in the data recording area 2 and the life determination area 3 is inferior in the life determination area 3, and the signal recorded in the life determination area 3 has reached the life earlier. .

Embodiment 4 A signal is recorded on the phase-change optical disk of Embodiment 2 at an optimum recording power Pw1 = 10 [mW], and a DC light of 1.5 to 2.5 [mW] is superimposed on this signal. Fig. 6 shows the result of
It was shown to. As can be seen from this figure, 1.5 to 2.0 [m
W], the jitter characteristics did not change even when irradiated with DC light, whereas the jitter sharply increased at 2.1 [mW] or more.

A phase-change type optical disk having the same layer structure as that of the second embodiment is manufactured, and the recording area 2 and the life determining area 3 shown in FIG.
Then, a signal was recorded at an optimum recording power Pw1 = 10 [mW], and only the life determination area 3 was irradiated with DC light of 2.1 [mW]. As a result, the quality of the signals recorded in the data recording area 2 and the life determination area 3 is inferior to that of the life determination area 3, so that the signal recorded in the life determination area 3 reaches the life earlier. did.

Embodiment 5 In the same phase change type optical disc as in Embodiment 4, the life judging area 3 is divided into four areas, each having a recording power of 1.9.
[MW], 2.0 [mW], 2.1 [mW], 2.2
DC light of [mW] was sequentially applied. These are 2.2
[MW], 2.1 [mW], 2.0 [mW], 1.9
The life reached in the order of [mW]. As a result, it was possible to know the degree of progress of the deterioration.

Example 6 A phase change optical disk was manufactured. That is, as shown in FIG. 2, on a substrate 11 (made of polycarbonate and having a thickness of 0.6 mm), a first protective layer 12 (made of ZnSSiO ₂ and having a thickness of 200 nm) and a recording layer 13 (AgInS
bTe, the thickness is 20 nm), the second protective layer 14
(Made of ZnSSiO ₂ and having a thickness of 20 nm), a reflective layer 15 (made of an Al alloy and having a thickness of 100 nm), and an environmental protection layer 16 (made of an ultraviolet curable resin and having a thickness of 4 μm).
An optical disk of a phase change type laminated in the order of m) was produced by sputtering. However, the ultraviolet curable resin was applied by spin coating so that the coating thickness at the end portions was reduced. Further, the life determining area was provided so as to be located between the recording area and the end of the environmental protection layer.

The optimum recording power Pw1 = 10 [mW] and Pw2 = 11 for the data recording area 2 and the life determination area 3
The signal was recorded at [mW], Pe = 5.5 [mW]. In this optical disk, since the life determination area is between the recording area and the end of the environment protection layer, the environment protection layer in the life determination area is thinner than the environment protection layer in the recording area. As a result, the signal in the life determination area reaches the life earlier than the signal in the recording area.

[0029]

As is apparent from the above description, according to the present invention, in the information recording medium having the information recording area, the life judgment area having a shorter life than the recording area is provided, so that the deterioration proceeds due to long-term storage. Since the life determination area reaches the end of its life before the recording area reaches its end of life, an information recording medium that can warn the user to back up the recorded information before the information in the recording area is damaged is obtained. .

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of a magneto-optical disk according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a layer configuration of a phase-change optical disc according to a second embodiment.

FIG. 3 is an explanatory diagram of a strategy (procedure) for recording information on the optical disc of FIG. 2;

FIG. 4 is a graph showing a relationship between recording power of information recording on the optical disc of FIG. 2 and jitter σ / Tw.

FIG. 5 is a graph showing O / W power margin characteristics of a phase change optical disc according to Example 3.

FIG. 6 is a graph showing the relationship between DC light power and jitter σ / Tw according to the phase change optical disc of Example 4.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 2 Data recording area 3 Life determination area 11 Substrate 12 First protective layer 13 Recording layer 14 Second protective layer 15 Reflective layer 16 Environmental protective layer 21 Pw1 22 Pw2 23 Pe

Claims (9)

[Claims] 1. An information recording medium having an information recording area, wherein a life determining area is provided. 2. The information recording medium according to claim 1, wherein
An information recording medium comprising: a recording area including at least a recording layer and a reflective layer on a substrate; and a phase change type recording / reproducing information by causing a phase change in a recording layer material. 3. The information recording medium according to claim 1, wherein a signal having lower quality than a signal recorded in the recording area is recorded in the life determining area. 4. The information recording medium according to claim 3, wherein
An information recording medium produced by recording a signal of inferior quality in a life determination area with a power other than the optimum recording power for recording in a recording area. 5. The information recording medium according to claim 3, wherein
An information recording medium, wherein a signal of poor quality is created by repeatedly overwriting a signal. 6. The information recording medium according to claim 3, wherein
An information recording medium characterized in that a signal of poor quality is created by irradiating weak DC light after recording. 7. The information recording medium according to claim 3, wherein
An information recording medium, wherein the life determination area has a plurality of different DC light irradiation areas. 8. The information recording medium according to claim 1, wherein the life determining area is an area having lower storage characteristics than the recording area. 9. The information recording medium according to claim 8, wherein
An information recording medium having an environmental protection layer, wherein a life determination area is between a recording area and an end of the environmental protection layer.