JP2003051141A - Optical recording medium for inspection, method of making the same and drive inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical recording medium for inspection optimum for inspecting a disk drive, a method of easily making the same and a method of inspecting the disk drive. SOLUTION: This optical recording medium for inspection is a phase transition type optical recording medium and is stepwise changed in the error rate average value permitting the correction processing in a recorded signal region. The optical recording medium is irradiated with a laser beam and information is recorded thereto by giving rise to a phase transition in its recording layer and the surface thereof is ground by stepwise changing the weighting of a needle-like object, by which the recording medium described above is made. The respective stepwise segments changed in the error rate average value permitting the correction processing of the optical recording medium subjected to recording and rewriting are reproduced by the disk drive previously set with recording power and pulse width and the recorded signals are compared. The reproducing capability of the disk drive is inspected by comparing the recording signals and deciding whether the recorded signals are defective or nondefective.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is directed to a phase change in a recording layer material by irradiating a laser beam,
The present invention relates to an optical recording medium for inspection, which uses a phase-change optical recording medium capable of recording / reproducing information and being rewritable, a manufacturing method thereof, and a disk drive inspection method using the same.

[0002]

2. Description of the Related Art With the recent increase in the amount of information, a CD-recorder capable of recording and reproducing a large amount of data at high density and high speed.
Disc drives such as R / RW and recording media for the drives are rapidly becoming popular.

An operation inspection is indispensable when shipping a disk drive, but among them, it is extremely important to inspect a reproduction characteristic by using an optical recording medium such as a CD-R / RW disk and a CD-ROM disk. is there.

Conventionally, various optical recording media for inspection have been used for inspection of reproduction characteristics of disk drives.
For example, there is an optical recording medium for inspection having a recording signal quality composed of a plurality of different patterns in one optical recording medium. The recording signal quality includes reflectance, jitter, radial contrast, I ₃ / I _TOP , I ₁₁ / I _TOP , push-pull signal strength, asymmetry, CNR of Wobble, error rate, crosstalk or radial noise. .

The inspection optical recording medium is also used for adjusting the output power of the inspection drive of the optical recording medium. During the inspection process of the optical recording medium, an inspection drive capable of recording / reproducing optical information with a specific recording power and reproducing power is installed. However, the drive for inspection has output power (laser power; recording power,
Since the reproduction power varies, it is necessary to adjust the output power (power of laser light). Therefore, in order to adjust the output power of the inspection drive, the inspection optical recording medium is used as a reference optical recording medium.

Further, recently, development of optical recording media compatible with multi-speed recording and multi-read by increasing linear velocity and disk drives for these optical recording media has become active. Therefore, such an optical recording medium and a disk drive (evaluator for disk (drive for inspection), etc.)
The optical recording medium for inspection has become indispensable because it is necessary to match the laser power and the reproducing ability of this disk drive and fine-tune it.

Such an optical recording medium for inspection has been manufactured by various kinds of methods so far. For example, on a stamper for molding an optical recording medium having a recording surface, a pattern in which a plurality of minute grooves are gathered so as to correspond to a pseudo defective portion is formed by a laser processing machine. Then, there is a method of manufacturing a substrate including a defective portion by molding an optical recording medium using this stamper. Also,
A plurality of combinations of recording power and pulse width at the time of recording are prepared and patterned, and laser light is irradiated while sequentially changing the pattern to manufacture an optical recording medium having a plurality of recording areas with different signal recording qualities. There is also a way to do it. The optical recording medium for inspection manufactured by these methods,
A plurality of different recording signal quality pattern data are stored. For example, it is possible to manufacture an optical recording medium for inspection in which a plurality of different jitters are recorded.

[0008]

However, the production of the optical recording medium for inspection is extremely difficult because it requires a dedicated device as described above. Further, the manufacturing apparatus also needs to meet the above-described performance, and therefore requires factory-level (large-scale, high-precision) equipment. In particular,
When manufacturing an optical recording medium for inspection that contains an error of a level that can be corrected (such as an error such as a scratch that allows information to be reproduced), make a medium in which the average value of the error rate during a certain time is finely changed. There must be. That is, since it is necessary to provide an error having various error rates and to search for an error rate in a range in which the drive can reproduce information, an optical recording medium for inspection provided with a plurality of areas having various levels of errors is provided. You need to prepare. Therefore, a medium manufacturing device with extremely high accuracy is required, and a skilled worker is required. As described above, in order to produce the optical recording medium for inspection, a large number of personnel, steps, and costs are required. Therefore, it is extremely difficult to obtain the optical recording medium for inspection when necessary.

Further, when the known method is used, a sufficient number of recording signal portions, in which the rate average value of correctable errors changes stepwise, are required to perform an accurate inspection. It is extremely difficult to manufacture the optical information recording medium for inspection that has this. Further, only the storage signal portion in which the change in the average value of the error rate is rough can be produced. When the inspection is performed using the optical recording medium for inspection having such a storage signal portion, for example, the area that greatly exceeds the error rate that the drive originally can correct (the average value of the error rate that becomes uncorrectable is greatly increased). Therefore, it is extremely difficult to carry out an accurate / precise inspection since the reproduction capability of the drive cannot be finely determined. That is, the optical information recording medium for inspection is used to determine whether or not it is possible to reproduce the correct information (which is originally recorded in the recording layer at the above-mentioned portion) from the information read from the portion where the optical recording medium has an error. Nevertheless, since the number of errors (recording signal portion) provided in the medium is small, it is extremely difficult to accurately grasp the range in which the drive can correct errors (error rate range).

The present invention has been made in view of the above problems, and requires a plurality of recording signal areas (in order to perform an accurate inspection) in which the rate average value of error that can be corrected is finely changed stepwise. It is an object of the present invention to provide an inspection optical recording medium using a phase change type optical recording medium that can be stored in a sufficient number. Another object of the present invention is to provide an inspection optical recording medium provided with a plurality of recording signal areas having different rates of change in average error rate and changed recording signal quality. Another object of the present invention is to make this optical recording medium for inspection easy and inexpensive to manufacture. It is another object of the present invention to provide an inspection method capable of determining the reproduction capability of a drive in detail by using the above inspection optical recording medium.

[0011]

In order to achieve the above object, the invention of an optical recording medium for inspection according to claim 1 is an optical recording medium having at least a phase change recording layer on a disk-shaped substrate, It is characterized in that the rate average value of errors that can be corrected in the recorded signal area is changed stepwise.

According to a second aspect of the present invention, in the optical recording medium for inspection according to the first aspect, the rate average value of errors that can be corrected in the recorded signal area changes in 5 to 10 steps.

According to a third aspect of the invention of an optical recording medium for inspection, an optical recording medium having at least a phase change recording layer on a disk-shaped substrate is provided with a plurality of error-processed recording signal areas. It is characterized by This error processing is performed on the surface (so-called label surface) of the optical recording medium on which the disk drive reads information. Hereinafter, the recording signal area subjected to the error processing will be referred to as a recording signal portion.

According to a fourth aspect of the invention, in the optical recording medium for inspection according to the third aspect, the average rate of errors of each recording signal area is a value within a range in which the disk drive can perform correction processing, and each error is different. It is characterized by having a rate average value of In other words, a standardized (standardized) disk drive is provided with an error at a plurality of locations at which the information recorded on the recording layer can be read. Further, the rate average value of the error is made different for each portion (recording signal portion) where the error is provided.

The invention according to claim 5 is the invention according to claim 3 or 4.
In the optical recording medium for inspection described above, each recording signal region is characterized in that the width of the substrate in the diameter direction is 2 mm or more and 3 mm or less.

According to a sixth aspect of the invention, in the optical recording medium for inspection according to any of the third to fifth aspects, a non-grinded portion in which an error is not significant is provided between each recording signal area. To do.

According to a seventh aspect of the invention, in the optical recording medium for inspection according to the sixth aspect, the diametrical width of the substrate in the non-ground portion is 1 mm or more and 2 mm or less.

According to the invention of a method of manufacturing an optical recording medium for inspection as set forth in claim 8, information is recorded by irradiating the optical recording medium with laser light to cause a phase change in the recording layer of the optical recording medium. The surface of the recorded optical recording medium is ground with a needle-shaped object,
Moreover, by performing this grinding by changing the weight of the needle-shaped object stepwise, the rate average value of the error that can be corrected in the signal area in the optical recording medium is changed stepwise. It is characterized by doing.

According to a ninth aspect of the present invention, in the method of manufacturing the optical recording medium for inspection according to the eighth aspect, the rate average value of the errors that can be corrected in the recorded signal area in the optical recording medium is 5 to 5. Try to change over 10 steps.

According to a tenth aspect of the invention of a method for producing an optical recording medium for inspection, a step of irradiating an optical recording medium with a laser beam to cause a phase change in a recording layer of the medium to record information, The step of contacting the ground portion of the recording signal area on the label surface of the recording medium with the ground portion of the needle-shaped object, and the pressure is applied from the needle-shaped object to the optical recording medium side, and the needle-shaped object is moved relative to the optical recording medium. To produce a recording signal area having an error within a rate average value of a range in which the information recorded on the recording layer can be decoded by the disk drive, and a plurality of recording signal areas are formed on the recording medium. Is produced.

According to an eleventh aspect of the present invention, in the method for producing an optical recording medium for inspection according to the tenth aspect, an error occurs in the recording signal area by moving the needle-shaped object from the grinding base point by a certain length in the radial direction of the optical recording medium. A feature is that a plurality of portions having different rate average values are produced.

According to a twelfth aspect of the present invention, in the method for producing an optical recording medium for inspection according to the tenth aspect, recording is performed by moving a needle-shaped object from a grinding base point in a radial direction of the optical recording medium within a range of 2 mm or more and 3 mm or less. It is characterized in that a plurality of portions having different average error rates are produced in the signal region.

The invention according to claim 13 is the method for producing an optical recording medium for search according to any one of claims 10 to 12, characterized in that a non-grinded portion having a predetermined distance or more is provided between respective recording signal areas. And

According to a fourteenth aspect of the present invention, in the method of manufacturing an optical recording medium for retrieval according to any of the tenth to twelfth aspects, a non-grinded portion having a distance of 1 mm or more and 2 mm or less is provided between each recording signal area. Is characterized by.

According to a fifteenth aspect of the present invention, there is provided a disk drive inspection method, wherein a rate average value of errors capable of correction processing of an optical recording medium recorded and rewritten by a disc drive having a recording power and a pulse width set in advance. The reproducing capability of the disk drive is inspected by reproducing each step portion in which is changed and comparing the recording signals of each step portion to judge the quality.

According to a sixteenth aspect of the present invention, in the disk drive inspection method according to the thirteenth aspect, each step portion in which the rate average value of the error that can be corrected is changing is 5 to 5.
There are 10 levels.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION The optical recording medium for inspection according to the present invention will be described below, and the manufacturing method and drive inspection method thereof will also be described in detail.

The optical recording medium for inspection according to the present invention is an optical recording medium having at least a phase change type recording layer on a disk-shaped substrate, and has a rate average value of errors that can be corrected in a recorded signal area. Is characterized by a gradual change. Further, it is characterized by having a plurality of regions provided with different error rate average values.

This optical recording medium for inspection uses what is called an optical memory medium capable of recording, reproducing and erasing by irradiation of a laser beam, which utilizes a transition between a crystalline phase and an amorphous phase or a crystalline phase. A phase change recording medium is used.

An example of the form of this phase change recording medium is shown in FIG.
Shown in. The basic configuration has, for example, a first protective layer 2, a recording layer 3, a second protective layer 4, a reflection / heat dissipation layer 5, and an overcoat layer 6 in order on a substrate 1 having a guide groove. Further, it is preferable to have a printed layer 7 on the overcoat layer and a hard coat layer 8 on the mirror surface of the substrate. The layer structure is
It can be arbitrarily changed according to the adopted standard.

The material of the substrate 1 is usually glass, ceramics, or resin. Among them, the resin substrate has moldability,
It is preferable in terms of cost. Examples of the resin include polycarbonate resin, acrylic resin, epoxy resin, polystyrene resin, acrylonitrile-styrene copolymer resin,
Examples thereof include polyethylene resin, polypropylene resin, silicone resin, fluorine resin, ABS resin and urethane resin. Among them, polycarbonate resin and acrylic resin, which are excellent in moldability, optical characteristics and cost, are preferable.

In the case of application to a rewritable compact disc (CD-RW), it is desirable to give the following specific conditions. The condition is that the width of the guide groove (groove) formed in the substrate used is 0.
25 to 0.65 μm, preferably 0.30 to 0.55 μm
The depth of the guide groove is 250 to 650Å, preferably 300 to 550Å. The thickness of the substrate is not particularly limited, but is preferably 1.2 mm or 0.6 mm.

For the recording layer 3, a material containing a quaternary phase-change recording material containing Ag, In, Sb and Te as a main component is used for recording (amorphization) sensitivity and speed,
It is suitable because the erasing (crystallization) sensitivity and speed and the erasing ratio are extremely good.

Further, the reproduction deterioration of the recording layer signal and the shortening of the signal life were caused by the crystallization of the amorphous mark, but in order to suppress the crystallization of the amorphous mark, the following is selected. It is effective to add at least one selected element to the recording layer. {Ga, Zn, Sn, Si, Pb, Co, Cr, Cu,
Ge, Au, Pd, Pt, S, Se, Ta, Nb, V,
Bi, Zr, Ti, Al, Mn, Mo, Rh, C, N,
O} The mechanism of suppressing the crystallization of the amorphous mark by adding these elements to the recording layer is not clear. It is believed that the formation of the compound acts as an additive that suppresses crystallization of the amorphous mark. Therefore, if an element having a small atomic radius, a large chemical bonding force with AgInSbTe, or a large number of chemical bonds is used as an additive, the amorphous mark crystal can be effectively prevented. In particular, C, N,
O, Si, Sn, and Ge effectively prevent reproduction deterioration of the recording layer signal and shortening of the signal life.

The thickness of the recording layer is 10 to 50 nm,
It is preferably 12 to 30 nm. When the thickness is less than 10 nm, the light absorption ability is remarkably lowered, and it cannot serve as a recording layer. If it is thicker than 50 nm, uniform phase change at high speed is unlikely to occur.

Such a recording layer is formed by various vapor deposition methods such as vacuum deposition method, sputtering method and plasma CV method.
It can be formed by the D method, the photo CVD method, the ion plating method, the electron beam evaporation method, or the like. Among them, the sputtering method is excellent in mass productivity and film quality.

Materials for the first dielectric layer (first protective layer) and the second dielectric layer (second protective layer) are SiO and SiO.
₂ , ZnO, SnO ₂ , Al ₂ O ₃ , TiO ₂ , In ₂
Metal oxides such as O ₃ , MgO and ZrO ₂ , Si
Nitride such as ₃ N ₄ , AlN, TiN, BN and ZrN,
ZnS, In ₂ S ₃ , TaS ₄ and other sulfides, SiC,
Carbides such as TaC, B ₄ C, WC, TiC and ZrC, diamond-like carbon, and mixtures thereof are preferably used. These materials may be used alone as the protective layer, but may be a mixture of two or more kinds. In addition, impurities may be included if necessary, and the dielectric layer (protective layer) can be multi-layered if necessary.

However, the melting points of the first dielectric layer (first protective layer) and the second dielectric layer (second protective layer) need to be higher than that of the recording layer. As a material for the first dielectric layer and the second dielectric layer, various vapor deposition methods such as vacuum deposition method, sputtering method, and plasma CVD method can be used.
Method, photo CVD method, ion plating method, electron beam evaporation method, or the like. Among them, the sputtering method is excellent in mass productivity and film quality.

The film thickness of the first dielectric layer (first protective layer) greatly affects the reflectance. The reflectance of 0.15 which is the standard of the CD-RW disc at the reproduction wavelengths of 780 nm and 650 nm.
In order to satisfy ˜0.25, the first dielectric layer is
It is required to be 130 nm. By setting this film thickness, the reflectance of the reproduction wavelength of the DVD of 650 nm is satisfied and the reproduction compatibility of the DVD can be obtained.

The thickness of the second dielectric layer is 15 to 45.
nm, preferably 20 to 40 nm. 15n
When the thickness is less than m, the function as the heat resistant protective layer is not fulfilled and the sensitivity is lowered. On the other hand, when the thickness is more than 45 nm, interfacial peeling is likely to occur and the repetitive recording performance is also deteriorated.

As the reflection / heat dissipation layer 5, Al, Au, A
A metal material such as g, Cu, Ta, Ti, W, or an alloy thereof can be used. Further, Cr, Ti, Si, Cu, Ag, Pd, Ta and the like are used as the additive element.

Such a reflection and heat dissipation layer can be formed by various vapor phase growth methods such as vacuum deposition method, sputtering method, plasma CVD method, photo CVD method, ion plating method and electron beam evaporation method.

The thickness of the alloy or metal layer is 70 to
The thickness is 200 nm, preferably 100 to 160 nm. It is also possible to have multiple layers of alloys or metal layers. In case of multiple layers, the thickness of each layer is at least 1
0 nm or more is required, and the total thickness of the multilayer film is 50 to 160
It is good to set it to nm.

It is desirable to have an overcoat layer 6 on the reflection / heat dissipation layer 5 to prevent its oxidation. The overcoat layer is generally formed by applying an ultraviolet curable resin by spin coating. The thickness of the reflective heat dissipation layer 5 is 3 to
15 μm is suitable. When the thickness is 3 μm or less, when a printing layer is provided on the overcoat layer, an unnecessarily large error may be observed. On the other hand, if the thickness is 15 μm or more, the internal stress becomes large, and the mechanical characteristics of the disk are greatly affected.

The hard coat layer 8 is generally formed by applying an ultraviolet curable resin by spin coating. A suitable thickness of the hard coat layer 8 is 2 to 6 μm. 2 μm
Below, sufficient abrasion resistance cannot be obtained. If the thickness is 6 μm or more, the internal stress becomes large, and the mechanical characteristics of the disk are greatly affected. The hardness of the hard coat layer 8 needs to be H or more, which is a pencil hardness that does not cause a large scratch even if it is rubbed with a cloth. In addition, it is also effective to mix a conductive material as necessary to prevent electrostatic charge and prevent adhesion of dust and the like.

In the optical recording medium having the above layer structure, information is recorded and reproduced by the recording / reproducing apparatus for the optical recording medium.

As shown in FIG. 4, in the recording / reproducing apparatus, a phase change type optical recording medium is rotationally driven by a driving means composed of a spindle motor, and a semiconductor laser is driven by a laser driving circuit as a light source driving means in a recording / reproducing pickup. The laser light source is driven to emit laser light, and the laser light is applied to the rotationally driven optical recording medium through an optical system (not shown). For example, a single recording pulse waveform as shown in FIG. 2 is repeatedly irradiated, or a plurality of frequency pulses are alternately and repeatedly irradiated.

By this irradiation, a phase change is caused in the recording layer of the optical recording medium, and the reflected light from the optical recording medium is received by the recording / reproducing pickup to record and reproduce information on the optical recording medium. The optimum recording power is set by the recording power setting circuit as the recording power setting means.

Further, this recording / reproducing apparatus is provided with recording means for recording information by modulating the signal to be recorded by the modulating section and recording it on the optical recording medium by the recording / reproducing pickup. The recording means including this pickup is
Information is recorded by a so-called PWM recording method in which a mark is recorded on the recording layer of the optical recording medium so that a signal is recorded as the width of the mark. The recording means uses a clock for a signal to be recorded in a modulator, for example, an EFM (Eight to Four) suitable for recording information on a rewritable compact disc.
teen Modulation) Modulation method or its improved modulation method.

In the recording means, when performing PWM recording, the signal width after modulation is nT (n is a predetermined value, T is clock time:
The recording light when recording or rewriting the 0 signal, which is the time corresponding to the cycle of the clock used for modulating the signal, is the continuous light of the power level e, and the recording signal of the 1 signal whose modulated signal width is nT or Pulse train of recording light for rewriting, pulse portion f having time width x and power level a
p, a low-level pulse of power level b and a high-level pulse of power level c having a time width of T in total alternately appear, and a multi-pulse part in which the duty ratio y is continuous (n−n ′) times in total. mp, and a laser wave pulse train composed of a pulse portion ep having a time width z and a power level d, where x, y,
z is 0.5T ≦ x ≦ 2.0T, 0.125T ≦
y ≦ 0.875T, 0.125T ≦ z ≦ 1.0T,
It is desirable that n is a positive integer of 1 or more, n ′ is a positive integer of n ′ ≦ n, and (a and c)>e> (b and d).

(Production of First Optical Recording Medium for Inspection) On the optical recording medium produced and recorded as described above, a predetermined position on the label surface of the medium is applied with a predetermined weight by a needle-shaped object. Grind. At this time, this weight is changed stepwise.
For example, by increasing the weight stepwise, it is possible to manufacture an optical recording medium for inspection in which the rate average value of errors that can be corrected in the optical recording medium changes stepwise. That is, the recording signal portion (portion that intentionally makes an error) is formed by a needle-shaped object on the label surface of the optical recording medium. A predetermined pressure is applied from the needle-shaped object to the label surface of the optical recording medium, and the needle-shaped object is relatively moved on the optical recording medium to produce an optical recording medium for inspection. At this time, by sequentially changing the pressure, it is possible to manufacture an optical recording medium for inspection provided with a plurality of recording signal portions having different average error rates. Further, if the pressure is set within a predetermined range, it is possible to provide a plurality of recording signal portions having an error rate average value in a range where the disk drive can perform error correction processing.

For example, by fixing a constant weight needle-shaped object at a certain radial position on the label surface of the recorded optical recording medium, and sliding the optical recording medium at a constant speed for a certain length, It is possible to easily manufacture an inspection medium (optical recording medium) in which the average value of the C1 error rate changes with the change in the weight of the needle-shaped object. It is necessary and sufficient to change the weight of the needle-like object in 5 to 10 steps to finely change the average value of the C1 error rate, and preferably to change in 7 steps such as 6 to 8 steps. Is desirable. Explaining with reference to FIG. 5, an optical recording medium is placed on the slide table. The label surface is made to face the surface opposite to the slide surface in FIG. 5 (the surface on which the needle-shaped object is installed). The needle-shaped object is set so as to apply a predetermined pressure to the optical recording medium. Then, the slide base is moved. This makes it possible to create a recording signal portion having an error rate different from that before grinding. Further, by changing the applied pressure, it is possible to produce a plurality of recording signal portions having different average error levels.

The recording signal portion in which the rate average value of correctable errors of the inspection medium manufactured by the above method is changed stepwise is reproduced, and the respective recording signals are compared to judge the quality of the recording signal. By doing so, it becomes possible to check the reproduction capability of each disk drive. This inspection is performed by inspecting the reproduction capability of the disc drive at the time of shipment and the reproduction capability of the inspection drive used in the manufacturing process of the optical recording medium, or the disc evaluation device used for the development of various optical recording mediums. And the inspection of the reproduction ability of various drives for matching is included. The recording signal portion in which the rate average value of the error that can be corrected by the inspection medium changes stepwise is 5 to 10 steps, preferably 6 to 8 steps.
It is desirable to regenerate about 7 stages.

In the conventional optical recording media for inspection, there are few recording signal portions in which the rate average value of error that can be corrected is changed stepwise, and the change in average value of error rate is coarse. The reproduction capability of the drive is roughly determined by reproducing the recorded signal portion that greatly exceeds the average value of the error rate at which the error cannot be corrected by passing through the originally correctable error rate for the drive.
However, in the optical recording medium for inspection manufactured according to the present invention, the average value of the error rate that can be corrected fluctuates finely, so that the reproducing ability of the drive can be finely grasped by reproducing, and It is also possible to fine-tune the playback laser power of the drive.

(Production of Second Optical Recording Medium for Inspection) The second optical recording medium for inspection can be produced in the same manner as the first optical recording medium for inspection except for the points described later. That is, a predetermined position on the label surface of the optical recording medium is ground by a needle-shaped object with a predetermined load. Providing multiple grinding parts,
The load on the needle-shaped object when searching each search portion is changed. Accordingly, it is possible to easily create an optical recording medium for inspection having a plurality of areas having different rate average values of correctable errors. For example, by fixing a constant weight needle-shaped object at a certain fixed radial position on the label surface of the optical recording medium on which recording has been performed, and sliding the optical recording medium at a constant speed in the radial direction for a certain length, It is possible to easily manufacture the inspection media in which the average values of the C1 error rates of the regions corresponding to the ground portion and the non-ground portion are different. For example,
When the weight of the needle-shaped object is increased or decreased for each grinding portion, not only the average value of the C1 error rate of each region changes according to the change of the weight of the needle-shaped object, but also the difference between the average values is remarkable. It is possible to easily produce the inspection medium shown in FIG.
This makes it possible to manufacture an optical recording medium for inspection in which the average value of the C1 error rate is changed in 5 to 10 steps. This medium has the necessary and sufficient ability to grasp the reproduction capability of the drive in detail.

In the second optical recording medium for inspection, the width of each recording signal portion (ground portion) in the radial direction (the length from the starting point of grinding to one end) is 2 to 3 mm. With such a width, each portion (area) is wide enough to perform the above-described inspection. Further, it becomes possible to provide a large number of areas having different rates on the medium. When the grinding portion is 3 mm or more, the recording signal portion on the optical recording medium (area where the rate average value of error that can be corrected is different)
The number of is reduced. Therefore, for example, when reproducing the recording signal portion in which the rate average value of the error that can be corrected by the inspection medium is changed stepwise, and comparing the respective recording signals to determine the quality of the recording signal, It is not possible to grasp the drive's playback capability in sufficient detail. If the grinding portion is 2 mm or less, it becomes difficult to manufacture the optical recording medium for inspection because the needle-shaped object or the optical recording medium must be controlled more precisely during grinding, and a sufficient area for reproduction is secured. become unable.

Further, it is desirable to provide a non-grinded portion having a constant length between the adjacent ground portions. The width of the non-searched part is
It is preferable to set it to 1 to 2 mm. If the non-grinded portion is not set or is set to 1 mm or less, it becomes difficult to determine the start and end positions of each area corresponding to the adjacent ground portion, and the drive reproduction capability cannot be accurately grasped.
Moreover, the rate average value of correctable errors changes depending on the start and end positions to be adopted. If the non-grinded portion is 2 mm or more, the area of the portion to be ground becomes narrow, and the number of recording signal portions having different average error rates that can be corrected decreases. For this reason,
When the recording signal portion in which the rate average value of the error that can be corrected by the inspection medium is changed step by step is reproduced and each recording signal is compared to judge the quality of the recording signal, It roughly grasps the reproduction ability.

(Examples) The present invention will be specifically described below with reference to examples.

Phase change type optical recording used for inspection optical recording medium
The recording medium has a guide groove with a width of 0.5 μm and a depth of 35 nm.
Mold a 1.2 mm thick polycarbonate substrate
A first protective layer, a recording layer, a second protective layer and a reflective layer are formed on the substrate.
The thermal layers are sequentially laminated by the sputtering method. First
ZnS-SiO is used for the protective layer and the second protective layer.₂Used by
And the film thickness is 90 nm and 30 nm, respectively.
The composition of Ag_4.0In _6.0Sb_61.0Te_29.0, Film thickness is 1
It was set to 8 nm. Aluminum alloy is used for the reflective heat dissipation layer
Substrate / ZnS-SiO₂(90 nm) / Ag_4.0I
n_6.0Sb_61.0Te_29.0(18 nm) / ZnS-SiO
₂Layer structure of (30 nm) / Al alloy (140 nm)
Was formed.

Further, an overcoat and a hard coat were formed by spin coating of an ultraviolet curable resin. The optical recording medium was crystallized on the entire surface of the recording layer of the optical recording medium by an initialization device having a large diameter LD. Further, a printing layer was formed on the overcoat layer.

This phase change type optical recording medium was entirely recorded with a pulse wave having a recording linear velocity of 4.8 m / s as shown in FIG. 3 and a duty ratio of 0.625 in the mp section.

The optical recording apparatus used for this recording is composed of a laser driving circuit, a recording power setting circuit, a driving unit including a spindle motor, and a wavelength of 780n as shown in FIG.
m, NA 0.5 pickup.

After recording, the surface of the above optical recording medium was ground by using a device having a driving unit as shown in FIG. 5 and a table which slides in a horizontal straight line direction.

The optical recording medium is fixed on the slide base, and the diamond needle-like object is aligned with the starting point of the radial position where the label surface of the optical recording medium is ground. The label surface was ground by moving in a straight line in the outer peripheral direction at a speed of 1 mm per second. As shown in Table 1, the weight of the needle-shaped object at each radial position of the optical recording medium was changed stepwise, and polishing was performed so that the ground portion and the non-ground portion were continuous.

A recording signal for one minute centered on the ATIP Time range corresponding to the position ground by each weighting, specifically, the ATIP Time corresponding to the middle point of the grinding range, is drawn at a linear velocity of 1.2 m / s. As a result of reproducing the data for 7 steps with the disk, as shown in Table 1, it is possible to manufacture a disk in which the average value of the C1 error rate for 1 minute increases finely stepwise as the weight of the needle-like object increases. did it.

Further, by reproducing each of the recording portions corresponding to the grinding area of the optical recording medium by different weighting in seven steps, the error reading ability of the disk drive used in the inspection process of the optical recording medium production line can be inspected. It became possible to do it in more detail. Furthermore, it could be used for fine adjustment of the reproduction laser power. That is, it was possible to use it as a standard optical recording medium for inspection.

[0067]

[Table 1]

[0068]

According to the present invention, an optical recording medium having at least a phase change recording layer is used, and after recording, the label surface of the optical recording medium is ground with a needle-shaped object, and at the same time, the weight of the needle-shaped object is stepped. It is possible to fabricate an optical recording medium in which the rate average value of errors that can be corrected in the recorded signal area changes stepwise by changing the rate.

Further, by holding the signal area in which the rate average value of the error which can be corrected by the optical recording medium is changed stepwise, the standard disk (optical recording medium) which is most suitable for the inspection of the disk drive. Can be. Specifically, by using this optical recording medium for inspection, it becomes possible to grasp the reproduction capability of the drive in detail and finely adjust the reproduction laser power of the drive.

Also, 2 to 3 m in the radial direction from the starting point of grinding.
It is possible to grasp the reproducing ability of the drive in detail by forming a recording signal portion by grinding a fixed length of m and providing an unground portion of 1 to 2 mm between adjacent grinding portions (recording signal portions). Fine adjustment of the reproduction laser power of the drive is possible.

[Brief description of drawings]

FIG. 1 shows an example of a layer structure of a phase change optical recording medium.

FIG. 2 shows an example of a recording pulse waveform.

FIG. 3 is a recording pulse waveform example of an optical recording medium according to the present invention.

FIG. 4 shows a configuration example of a recording / reproducing apparatus according to the present invention.

FIG. 5 shows a configuration example of a label surface grinding device for an optical recording medium according to the present invention.

[Explanation of symbols]

1 substrate 2 First protective layer 3 recording layers 4 Second protective layer 5 Reflective heat dissipation layer 6 Overcoat layer 7 printing layers 8 Hard coat layer

Claims (16)

[Claims] 1. An optical recording medium having at least a phase-change type recording layer on a disk-shaped substrate, wherein a rate average value of errors that can be corrected in a recorded signal region is changed stepwise. A characteristic optical recording medium for inspection. 2. The optical recording medium for inspection according to claim 1, wherein the rate average value of errors that can be corrected in the recorded signal area changes in 5 to 10 steps. 3. An optical recording medium for inspection, wherein an optical recording medium having at least a phase-change recording layer on a disk-shaped substrate is provided with a plurality of error-processed recording signal areas. 4. The inspection according to claim 3, wherein the error rate average value of each recording signal area is a value within a range in which the disk drive can perform correction processing, and each has a different error rate average value. Optical recording medium. 5. The optical recording medium for inspection according to claim 3, wherein the width of each recording signal area in the diameter direction of the substrate is 2 mm or more and 3 mm or less. 6. A non-grinding portion in which an error is not significant is provided between each recording signal area.
6. The optical recording medium for inspection according to any one of 1 to 5. 7. The optical recording medium for inspection according to claim 6, wherein the diametrical width of the non-ground portion of the substrate is 1 mm or more and 2 mm or less. 8. An optical recording medium is irradiated with laser light to cause a phase change in a recording layer of the optical recording medium to record information, and the surface of the optical recording medium on which the information is recorded is ground with a needle-shaped object. In addition, by performing this grinding by changing the weight of the needle-like object stepwise, the rate average value of the error that can be corrected in the signal area in the optical recording medium changes stepwise. A method for producing an optical recording medium for inspection characterized by the above. 9. A rate average value of errors that can be corrected in a recorded signal area in the optical recording medium is 5
9. The change is made over 10 steps.
A method for producing an optical recording medium for inspection according to item 4. 10. A step of irradiating an optical recording medium with a laser beam to cause a phase change in a recording layer of the medium to record information, and a needle at a grinding base point of a recording signal area of a label surface of the optical recording medium. A step of contacting a ground portion of a cylindrical object, applying pressure from the needle-shaped object to the optical recording medium side, and moving the needle-shaped object relative to the optical recording medium,
Forming a recording signal area having an error within a rate average value of a range in which a disc drive can decode the information recorded on the recording layer, and forming a plurality of recording signal areas on the recording medium. A method of manufacturing an optical recording medium for inspection, characterized in that 11. The plurality of portions having different average error rates are created in a recording signal area by moving the needle-shaped object from the grinding base point in a radial direction of the optical recording medium by a predetermined length. 10. The method for producing an optical recording medium for inspection according to 10. 12. A plurality of portions having different error rate average values are created in a recording signal area by moving the needle-shaped object from the grinding base point in a radial direction of the optical recording medium within a range of 2 mm or more and 3 mm or less. 11. The method for producing an optical recording medium for inspection according to claim 10. 13. The method of manufacturing an optical recording medium for search according to claim 10, wherein a non-grinded portion having a predetermined distance or more is provided between each recording signal area. 14. 1 mm or more and 2 m between each recording signal area
The method for producing an optical recording medium for search according to claim 10, wherein a non-grinded portion having a distance of m or less is provided. 15. A step unit in which a rate average value of errors capable of correction processing of an optical recording medium recorded and rewritten by a disk drive having a recording power and a pulse width set in advance is reproduced is reproduced. A disk drive inspection method characterized by inspecting the reproduction capability of the disk drive by comparing the recording signals of the respective stages and judging the quality thereof. 16. The disk drive inspection method according to claim 15, wherein each step portion in which the rate average value of the error that can be corrected is changed is 5 to 10 steps.