JP2770780B2 - Optical disk recording apparatus and recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording apparatus and method for recording and reproducing information using a phase change optical disk.

[0002]

2. Description of the Related Art Conventionally, a recording apparatus and a recording method for an optical disc perform recording by irradiating a laser beam to the optical disc and changing the state of a recording film by a local temperature rise due to light absorption. When recording a signal in an optical disk device, it is necessary to check whether the recorded content has been correctly recorded on the optical disk, that is, to perform verification. Generally, this verification is performed after the recording operation in the optical disk device is completed and the recording area is reproduced again to confirm the contents.

[0003] A plurality of light spots are formed in the above-mentioned optical disk device. For the formation of a plurality of spots,
No. 9024 or JP-A-3-41632, or a plurality of light sources. Verification is performed using one or two of the plurality of light spots.

As for a magneto-optical disk, as described in Japanese Patent Application Laid-Open No. 5-144112, a method has been proposed for realizing one-beam verification with a single light spot by utilizing properties inherent in magneto-optics. ing.

[0005]

However, in the above-mentioned conventional verifying method for an optical disk apparatus, the time required for recording is long if the verifying operation is performed again after the recording operation is completed. In the method using a plurality of light spots, the mechanism becomes complicated and the cost increases. Further, there is a problem that adjustment of the optical system becomes difficult.

With respect to a magneto-optical disk and a phase change optical disk having a different recording / reproducing principle, no specific proposal has yet been made on an effective measure for realizing one-beam verification with a single light spot.

The present invention uses an optical information recording medium in which the reflectance or optical phase of a recording film changes with light irradiation,
It is an object of the present invention to provide a recording apparatus and a recording method for an optical disk capable of simultaneously performing a recording operation and a verify operation with a single light spot.

[0008]

In order to achieve the above object, a recording apparatus for an optical disk according to the present invention uses an optical information recording medium in which the reflectance or optical phase of a recording film changes with light irradiation. A light spot irradiating means for creating and irradiating the light of the light spot, an irradiation light timing detecting means for detecting a timing of the irradiation light applied to the optical information recording medium, and a return light from the optical information recording medium by the irradiation light. Return light capturing means for capturing, having a return light amount measuring means for measuring the amount of return light captured by the return light capturing means,
The predetermined information is recorded on the optical information recording medium by the irradiation light of one light spot, and the irradiation light timing detecting means extracts the rising time and the falling time of the driving signal of the irradiation light, and extracts the rising time and the falling time. In this method, the return light amount measuring means measures the return light amount, and the recording and verification are performed substantially simultaneously by confirming the measurement result of the return light amount.

[0009] Further, the above-mentioned recording apparatus for an optical disk ,
It has a signal delay means for delaying the drive signal of the irradiation Shako, to confirm the measurement results may irradiation light is performed after a predetermined time after the irradiation.

The light spot irradiating means includes a laser light emitting means for emitting irradiation light, and the irradiation light timing detecting means includes a differentiating means, and the differentiating means differentiates a driving signal of the laser light emitting means. Thus, the rising time and the falling time may be detected.

The return light amount measuring means includes two comparators. The measurement of the return light amount at the time of rising and falling of the irradiation light is performed by comparison with a predetermined value by the comparator. It is preferable to use a phase change optical disk as the information recording medium.

According to the recording method for an optical disk of the present invention, a light spot irradiation for producing and irradiating one light spot irradiation light to an optical information recording medium whose reflectance or optical phase of a recording film changes with irradiation of light. A process, an irradiation light timing detecting step of detecting timings of rising and falling of a driving signal of irradiation light applied to the optical information recording medium, and a return capturing the return light from the optical information recording medium by the irradiation light. A light capturing step and a return light amount measuring step of measuring the amount of return light captured in the return light capturing step, and while recording predetermined information by irradiating the optical spot on the optical information recording medium, It is preferable to measure the amount of return light at the time of rising and falling, and to perform recording and verification substantially simultaneously by confirming the measurement result of the amount of return light.

Further, the recording method of the optical disk described above ,
It has a signal delay process for delaying the drive signal of the irradiation Shako, to confirm the measurement results may irradiation light is performed after a predetermined time after the irradiation.

In the returning light amount measuring step, the returning light amount at the time of rising and falling of the irradiation light is measured.
This may be performed by comparison with a predetermined value. It should be noted that the first reference voltage CLV at the time of the rise of the predetermined value is represented by (0.7 × Ic × Pw) / Pr <CLV <(Ic × Pw) / Pr, where Pw: recording laser power, Pr: reproduction power, Ic A return light amount monitor signal output when reproducing a recording film in a crystalline state.

Further, the second reference voltage CTV at the time of falling of the predetermined value is calculated as (IA × PE) / Pr <CTV <(Ic × PE) / Pr or (Ic × PE) / Pr <CTV < (IA × PE) / Pr, where: PE; erasing laser power, Pr: reproducing power, Ic: return light amount monitor signal output when reproducing a recording film in a crystalline state, IA: reproducing a recording film in an amorphous state The output of the amount of return light at the time of this is preferably obtained from the relationship.

[0016]

Therefore, according to the optical disk recording apparatus of the present invention, irradiation light of one light spot is formed and irradiated on an optical information recording medium whose reflectance or optical phase of the recording film changes with irradiation of light. Then, the timing of the irradiation light irradiated to the optical information recording medium is detected, the return light of the irradiation light from the optical information recording medium is captured, and the captured return light amount is measured. Accordingly, predetermined information is recorded on the optical information recording medium by the irradiation light of one light spot, and at the time of rise and fall of the drive signal of the irradiation light, the amount of return light is measured. The confirmation allows recording and verification to be performed substantially simultaneously.

According to the optical disk recording method of the present invention,
The irradiation light of one light spot is created and irradiated on the optical information recording medium in which the reflectance or the optical phase of the recording film changes with the light irradiation, and the drive signal of the irradiation light irradiated on the optical information recording medium is generated. The rising and falling timings are detected, the return light of the irradiation light from the optical information recording medium is captured, and the captured return light amount is measured. Therefore, predetermined information is recorded on the optical information recording medium by the irradiation light of one light spot, the amount of return light is measured at the time of rise and fall of the irradiation light, and the recording is performed by confirming the measurement result of the return light amount. And verification can be performed substantially simultaneously.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a recording apparatus and a recording method for an optical disk according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of an optical disk recording apparatus and a recording method to which the optical disk recording apparatus and the recording method of the present invention are applied. FIG. 1 is a view schematically showing an optical disk device according to an embodiment of the present invention.

In FIG. 1, the optical disk apparatus includes a laser light source 1, lenses 2, 4, a beam splitter 3, a phase change optical disk 5, a laser driver 6, a differentiating circuit 8, a delay circuit 9, comparators 11, 11, 15, 16, AND. It is composed of circuits 17, 18 and a pulse count circuit 21.

The laser light source 1 is a light source device that emits a laser beam for generating a light spot for recording and reproduction on the phase-change optical disk 5. The laser light source 1 is driven by a laser driver 6.

The lenses 2 and 4 are condensers for converging laser light emitted from the laser light source 1 on the phase-change optical disk 5 as a light spot. Beam splitter 3
Is a laser beam separator. It is arranged on the optical axis light of the incoming reflected light, and separates and extracts the return light from the optical disk. In this embodiment, the light emitted from the laser light source 1 goes straight, and the reflected light from the phase change optical disk 5 is refracted by 90 degrees to separate and separate the light.
Extract. The phase change optical disk 5 is an optical disk for recording information by irradiating a laser beam. Recording is performed by changing the state of the recording film formed on the optical disc by a local temperature rise due to light absorption of the laser beam. The laser driver 6 is a circuit unit that drives the laser light source 1 and generates laser light.

The differentiating circuit 8 is a circuit section for extracting a 0/1 state change point of an output signal of the laser driver 6 for driving the laser light source 1. The delay circuit 9 is a signal delay circuit for timing the drive signal and the reflected signal. The comparators 11, 11, 15, and 16 are comparators that compare the compared signal with a predetermined value. In the present embodiment, the state change points of the drive signal and the reflection signal are generated as pulse signals using a comparator.

The AND circuits 17 and 18 are AND circuits, and synchronize the state change points of the drive signal of the laser driver 6 with the laser light emitted from the laser light source 1 and the reflected light from the phase-change optical disk 5. Do. By this sliding, confirmation of emission of laser light and execution of recording, that is, verification, is performed. Pulse count circuit 21
Is a circuit unit for confirming whether or not the recording confirmation signal and the reproduction confirmation signal are reliably generated. This confirmation increases the reliability of the verification.

FIG. 2 is a timing chart showing the verify operation. The signals in each figure are shown in relation to FIG. 1. A waveform (a) is a laser light source driving signal 51, a waveform (b) is a gate signal 52 corresponding to a rising portion of a recording signal, and a waveform (c) is The gate signal 53 corresponding to the falling part of the recording signal, the waveform (d) is the return light signal 54 from the phase-change optical disc during recording, and the waveform (e) is the return light amount monitor output IL at the rise of the recording signal. The comparison signal 55 and the waveform (f) obtained by the comparison with the reference voltage CLV are as follows.
A comparison signal 56 obtained by comparing the return light amount monitor output IT when the recording signal falls with a reference voltage,
Respectively.

Further, using these signals, an AND circuit 1
7 is an AND signal of the gate signal 52 of the waveform (b) and the compare signal 55 of the waveform (e), and is represented by a symbol VL in the following description. With this signal,
It can be confirmed that the desired laser power has been applied to the recording film of the phase change optical disk 5.

The output signal 58 of the AND circuit 18 is
This is an AND signal of the gate signal 53 of the waveform (c) and the comparator signal 56 of the waveform (f), and is represented by a symbol VT in the following description. With this signal, it can be confirmed that the recording film of the phase change optical disk 5 has melted and writing has been performed normally.

Furthermore, by taking the logical product of the recording signal 61 delayed by the delay circuit 9 and the logical product signals VL and VT again, it is possible to improve the accuracy of the verification. In this embodiment, the number of pulses generated in the gate of the output signal 57 of the AND circuit 17 and the output signal 58 of the AND circuit 18 is counted using the recording signal 61 delayed by time as a gate signal. If two pulses, one pulse for VL and one pulse for VT, are counted in this count, it is determined that normal writing has been executed. Here, the reason why the recording signal is delayed is that the rise time of the laser beam and the time required for the recording film to melt are taken into consideration.

(Embodiment 1) In this embodiment, the phase change optical disk 5 has the structure shown in FIG. In this structure, 150 nm and ZnS-SiO ₂ in polycarbonate based Sakagami, G
e ₂ Sb ₂ Te ₅ to 20 nm, 20 nm and ZnS-SiO _2, Al
Were sequentially laminated by sputtering. The phase change optical disk 5 was rotated at a linear velocity of 7.5 m / s, the recording pulse width was set to 50 ns, and (2-7) modulated random data was recorded. The recording power Pw was 14 to 16 mW, the erasing power Pe was 7 mW, and the reproducing power Pr was 1 mW.

When the recording film is in a crystalline state, the reflectance is 25.
%, And the reflectance in the non-crystalline state was 8%. The amount of return light Ic from the phase change optical disk 5 when the recording film is in a crystalline state during reproduction is 1.5 (V), and the amount of return light IA from the phase change optical disk 5 when in a non-crystalline state is 0.48.
(V). CLV is (0.9 × Ic × Pw) / Pr, CTV is
FIG. 4 shows the number of write error occurrences at the time of recording power writing when 0.5 × (Ic + IA) × (PE) / Pr is set. Note that the comparison is the result of examining a write error by reproducing the recorded area after writing is completed, as in the conventional example. As can be seen from FIG. 4, the number of write error occurrences detected by the present embodiment matches the conventional example.

In the same manner as above, verification was performed by changing the reference voltage CLV and the reference voltage CTV, and the optimum values of the reference voltages CLV and CTV were examined. As a result, the reference voltage CLV was (0.7 × Ic × Pw) When the condition of / Pr <CLV (Ic × Pw) / Pr is satisfied, the number of detected write errors coincides with the conventional example. For the reference voltage CTV,
When the condition of (IA.times.PE) / Pr <CTV <(Ic.times.PE) / Pr was satisfied, the number of detected write errors coincided with the conventional example.

Embodiment 2 As the phase change optical disk 5,
100nm the ZnS-SiO ₂ in polycarbonate based on Sakagami,
Ge ₁ Sb ₂ Te ₄ 25 nm, ZnS—SiO ₂ 20 nm, A
An optical disk was used in which 60 nm was sequentially laminated by sputtering. This optical disk was rotated at a linear velocity of 7.5 m / s, the recording pulse width was set to 50 ns, and (2-7) modulated random data was recorded. Recording power Pw is 16 ~
18 mW, erasing power Pe is 8 mW, reproduction power Pr is 1 mW
And

When the recording film is in a crystalline state, the reflectance is 20.
%, And the reflectance in the non-crystalline state was 6%. The amount of return light Ic from the phase change optical disk 5 when the recording film is in a crystalline state during reproduction is 1.2 (V), and the amount of return light IA from the phase change optical disk 5 when in a non-crystalline state is 0.36.
(V).

When the reference voltage CLV is set to (0.8 × Ic × Pw) / Pr and the reference voltage CTV is set to 0.4 × (Ic + IA) × (Pe) / Pr, the recording power and the number of write error occurrences at the time of writing are shown. It is shown in FIG. Note that the comparison is the result of examining a write error by reproducing the recorded area after writing is completed, as in the conventional example. As can be seen from FIG. 5, the number of write error occurrences detected by the present embodiment matches that of the conventional example.

In the same manner as described above, verification was performed by changing the reference voltage CLV and the reference voltage CTV, and the optimum values of the reference voltages CLV and CTV were determined in the same manner as in the first embodiment. As a result, as for the reference voltage CLV, (0.7 × Ic × Pw) / Pr <CLV <
When the condition of (Ic × Pw) / Pr was satisfied, the detected number of occurrences of the write error coincided with the conventional example. Further, for the reference voltage CTV, (IA × PE) / Pr <CTV <(Ic × PE)
When the condition of / Pr is satisfied, the detected number of write errors coincides with the conventional example.

(Embodiment 3) In this embodiment, the phase-change optical disk 5 is configured as shown in FIG. In this structure, 10 nm of Au and ZnS-
SiO ₂ of 150 nm, Ge ₂ Sb ₂ Te ₅ of 20 nm, ZnS−
45 nm of SiO ₂ and 100 nm of Al were sequentially laminated by sputtering. The phase change optical disk 5 was rotated at a linear velocity of 7.5 m / s, the recording pulse width was set to 50 nm, and (2-7) modulated random data was recorded. The recording power Pw was 18 to 20 mW, the erasing power Pe was 9 mW, and the reproducing power Pr was 1 mW.

In this medium configuration, the reflectance in the amorphous state is higher than that in the amorphous state. The reflectance when the recording film is in the crystalline state is 10%, and the reflectance when the recording film is in the amorphous state is 30. %Met. The amount of return light Ic from the phase change optical disk 5 when the recording film is in the crystalline state during reproduction is 0.6 (V), and the amount of return light IA from the phase change optical disk 5 when the recording film is in the amorphous state is 1.8 (V). V).

When the reference voltage CLV is set to (0.9 × Ic × Pw) / Pr and the reference voltage CTV is set to 0.5 × (Ic + IA) × (PE) / Pr, the recording power and the number of write error occurrences at the time of writing are shown. FIG. Note that the comparison is the result of examining a write error by reproducing the recorded area after writing is completed, as in the conventional example. As can be seen from FIG. 6, the number of write error occurrences detected by the present embodiment matches the conventional example.

In the same manner as above, verification was performed by changing the reference voltage CLV and the reference voltage CTV, and the optimum values of the reference voltages CLV and CTV were determined. As a result, as for the reference voltage CLV, (0.7 × Ic × Pw) / Pr <CLV <(Ic × Pw) / P
r, and when the reference voltage CTV satisfies the condition (Ic × PE) / Pr <CTV <(IA × PE) / Pr, the number of write error occurrences detected is Consistent with the example.

In order to perform the verification as described above, it is necessary to confirm whether the recording film is actually irradiated with a laser beam having a predetermined intensity and whether the recording film is actually melted. In order to confirm whether or not the laser light having the predetermined intensity has been irradiated, the intensity of the return light amount monitor output IL from the optical disk at the time of the rise of the recording signal may be checked. Further, whether or not the recording film has melted can be determined by checking the return light amount monitor output IT from the optical disc when the recording signal falls. Assuming that the reflectance of the recording film in a crystalline state is Rc, the reflectance in an amorphous state is Ra, and the reflectance in a molten state is Rm, Rc> Rm in an optical disc where Rc> Ra. > Ra, and Rc <R in an optical disc satisfying Rc <Ra.
The relationship of Rm <Ra holds. If the erasing power is PE, the intensity of the light quantity monitor output IT can be expressed as IT = PE × Pm, so that Rc <(IT / PE) <Ra or Ra <(IT
By checking whether or not (/ PE) <Ra holds, it is possible to check whether or not the recording film has melted.

According to each of the above embodiments, the verification can be performed while recording is performed with a single light spot, so that the time required for recording is reduced, and complicated adjustment of the optical system is not required. Thus, the cost can be reduced.

Although the above-described embodiment is a preferred embodiment of the present invention, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.

[0042]

As is clear from the above description, the recording apparatus and recording method of the optical disk of the present invention can be applied to an optical information recording medium in which the reflectance or optical phase of a recording film changes with light irradiation. Irradiation light of the light spot is created and irradiated. Using the irradiation light, predetermined information is recorded on the optical information recording medium, and the information recorded on the optical information recording medium is verified. This verification procedure involves capturing the return light from the optical information recording medium at the rising and falling edges of the drive signal of the irradiation light applied to the optical information recording medium and measuring the captured return light amount. Performed by Therefore, recording and verification are performed substantially simultaneously by one light spot, the time required for recording is shortened, complicated adjustment of the optical system becomes unnecessary, and the cost of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an optical system for describing an embodiment of a recording apparatus and a recording method of an optical disc according to the present invention.

FIG. 2 is a diagram schematically showing a verify operation in the embodiment of FIG. 1;

FIG. 3 is a diagram showing a configuration of a phase change optical disk used in FIG.

FIG. 4 is a diagram showing the relationship between the number of write error occurrences and the recording power in FIG.

FIG. 5 is a diagram showing the relationship between the number of write error occurrences and the recording power in FIG.

FIG. 6 is a diagram showing an example of a configuration of a phase change optical disk used in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser light source 2, 4 lens 3 beam splitter 5 optical disk 6 laser driver 8 differentiator 9 delay circuit 10, 11, 15, 16 comparator 17, 18 AND circuit 51 laser light source drive signal 52, 53 gate signal 54 return light signal 55, 56 Comparing signal 57, 58 Output signal of AND circuit 61 Recording signal delayed by time

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ identification code FI G11B 20/18 572 G11B 20/18 572F (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 7/00 G11B 7 / 125

Claims (11)

(57) [Claims] 1. An optical information recording medium in which the reflectance or optical phase of a recording film changes with irradiation of light, a light spot irradiating means for forming and irradiating irradiation light of one light spot, and said optical information recording Irradiating light timing detecting means for detecting the timing of irradiating light applied to a medium; returning light capturing means for capturing return light from the optical information recording medium by the irradiating light; Returning light amount measuring means for measuring the amount of light, and recording predetermined information on the optical information recording medium by the irradiation light of the one light spot, and the irradiation light timing detecting means driving the irradiation light The rising time and the falling time of the signal are extracted, and the returning light amount measuring means measures the returning light amount at the rising time and the falling time, and the measurement result of the returning light amount is obtained. Recording device of an optical disk which is characterized in that substantially simultaneously with the recording and verifying by the certification. 2. The recording apparatus for an optical disk, further comprising :
The apparatus according to claim 1, further comprising a signal delay unit that delays a drive signal of the irradiation light, wherein the confirmation of the measurement result is performed after a predetermined time after the irradiation of the irradiation light. An optical disk recording device according to claim 1. 3. The light spot irradiating means includes a laser light emitting means for emitting the irradiating light, and the irradiation light timing detecting means includes a differentiating means. 3. The recording apparatus for an optical disk according to claim 1, wherein the rise time and the fall time are detected by differentiating a drive signal. 4. The return light amount measuring means includes two comparators, and the return light amount measurement at the time of rising and falling of the irradiation light is performed by comparison with a predetermined value by the comparator. 4. The recording apparatus for an optical disk according to claim 1, wherein the recording is performed. 5. The optical information recording medium according to claim 1, wherein the optical information recording medium is a phase change optical disk.
An optical disk recording device according to item 13. 6. A light spot irradiating step in which irradiation light of one light spot is formed and irradiated on an optical information recording medium whose reflectance or optical phase of the recording film changes with irradiation of light; An irradiation light timing detection step of detecting a rising and falling timing of a drive signal of the irradiation light applied to a medium; and a return light capturing step of capturing return light from the optical information recording medium due to the irradiation light. And a return light amount measuring step of measuring the amount of return light captured in the return light capturing step, while recording predetermined information on the optical information recording medium by irradiation light of the one light spot, Measuring the return light quantity at the time of rising and falling, and performing the recording and verification substantially simultaneously by confirming the measurement result of the return light quantity. Recording method of the disk. 7. The recording method of the optical disk, further comprising :
It has a signal delay process for delaying the drive signal of the irradiation light in claim 6 in which the confirmation of the measurement result is the irradiation light and executes a later time at <br/> constant after being irradiated Recording method of the optical disc according to the above. 8. The method according to claim 6, wherein the returning light amount measuring step is performed by measuring the returning light amount at the time of rising and falling of the irradiation light, and comparing the measured value with a predetermined value. Or a recording method for an optical disk according to item 7. 9. The first reference voltage CLV at the rise of the predetermined value is defined as: (0.7 × Ic × Pw) / Pr <CLV <(Ic × Pw) / Pr, where Pw: recording laser power, Pr: reproduction power. 9. The recording method for an optical disk according to claim 8, wherein the relationship is determined by the following relationship: Ic; a return light amount monitor signal output when reproducing a recording film in a crystalline state. 10. The second reference voltage CTV at the time of falling of the predetermined value is defined as: (IA × PE) / Pr <CTV <(Ic × PE) / Pr, where PE: erase laser power, Pr: reproduction power, 9. A return light amount monitor signal output when a recording film in a crystalline state is reproduced, and a return light amount output when a recording film in an amorphous state is reproduced. Recording method of the optical disc according to the above. 11. The second reference voltage CTV at the time of falling of the predetermined value is represented by: (Ic × PE) / Pr <CTV <(IA × PE) / Pr, where PE: erase laser power, Pr: reproduction power, 9. A return light amount monitor signal output when a recording film in a crystalline state is reproduced, and a return light amount output when a recording film in an amorphous state is reproduced. Recording method of the optical disc according to the above.