JP2003346337A - Optical disk recording method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce errors in a reproduction signal due to the leakage of an LPP signal to an RF signal. <P>SOLUTION: When an optical disk, having land prepits a1 and a2 that contain various information, such as an address and are periodically arranged on a land L1 between record tracks is irradiated with laser beams where output is controlled based on a record signal for forming a series of record pit rows b1 and b2 on a groove G2 along the record track, the recording output of a recording laser beam for forming the pit is controlled to intensity H2 or pulse width W2 which is different from the recording output of laser beams for forming another record pit, when the record pit whose amplitude value is smaller than the maximum value of an eye pattern or the record pit whose length can be accommodated in a spot of the laser beams is formed substantially directly beside the LPP. <P>COPYRIGHT: (C)2004,JPO

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 method and apparatus, and more particularly, to an optical disk recording method and apparatus for preventing deterioration of a reproduction signal due to leakage of an LPP signal into an RF signal.

[0002]

2. Description of the Related Art Generally, a DVD-R (Digital Versatil
The e-Disc-Recordable disc has a multilayer structure in which each layer such as a recording layer (dye film), a reflective layer (metal film), and a protective layer is formed on a transparent resin substrate by sputtering. I have.

A guide groove for a laser beam called a groove is formed on the surface of the transparent resin substrate, and a pit (recording pit) based on a recording signal is formed in the groove to record data. A region between the grooves is called a land, and the land has a pit (L) including address information and the like.
PP: Land Pre-Pit) are arranged according to a predetermined cycle. This LPP is used for acquiring various information required at the time of recording and for highly accurate recording position control.

In general, the spot diameter of a beam spot formed by a laser beam on a recording surface of a DVD-R is larger than the groove width, and a part of the beam spot leaks to a land adjacent to the groove. With this, DVD-
The reflected light of the laser beam for irradiating R includes an information component (RF signal) from the groove and an information component (LPP signal) from the LPP formed on a land adjacent to the groove.

Therefore, the reflected light of the laser beam applied to the optical disk is received by a light receiving element divided at least by a dividing line optically parallel to the tangential direction of the groove, and an output signal from each area of the light receiving element is received. Calculates the difference in the direction perpendicular to the groove, and this difference signal (push-pull signal)
Is binarized by a predetermined threshold value to detect an LPP signal, and an RF signal is detected based on the sum of output signals from the respective regions of the light receiving element.

[0006]

When a recording pit exists almost right next to the LPP, the RF signal acts as noise with respect to the LPP signal. May be difficult to detect.

On the other hand, on the contrary, the LPP signal acts as noise on the RF signal, and it may be difficult to reproduce the data on the groove recorded by the user with high accuracy.

[0008] The RF signal has various pit lengths from 3T to 14T.
When the P signal acts as noise, the rate of amplitude change increases, and the P signal is easily affected by the noise.

In order to accurately detect the LPP signal and the RF signal, various measures have been taken in a disk and a reading device.

However, no measures have been taken in the recording apparatus, and the LPP signal and the R
By taking measures in consideration of the stability of the F signal, it is possible to further enhance the stability of the detection of the LPP signal and the RF signal.

Accordingly, an object of the present invention is to solve the above-mentioned problem by using a recording strategy in a recording apparatus.

[0012]

According to the optical information recording method of the present invention, a recording signal is recorded on an optical disk having land pre-pits periodically arranged in a land portion between recording tracks including various kinds of information such as addresses. An optical information recording method for forming a series of pit rows along the recording track by irradiating a laser beam whose output is controlled based on the amplitude of a reproduction signal formed adjacent to the land prepits Is smaller than the maximum value of the eye pattern or the recording output of the laser beam for a recording pit having a length that falls within the spot of the laser beam, the laser beam for the recording pit formed at a position not adjacent to the land pre-pit. It is characterized in that the intensity or the pulse width is different from the recording output.

Further, the optical information recording apparatus of the present invention outputs to an optical disk having land pre-pits periodically arranged including various information such as addresses in lands between recording tracks based on recording signals. An optical information recording apparatus that forms a series of pit rows along the recording track by irradiating a controlled laser beam, wherein the amplitude value of the reproduced signal is formed adjacent to the land pre-pits, and Recording signal detecting means for detecting a recording signal corresponding to a recording pit having a length smaller than a maximum value or within a spot of the laser beam; and a laser beam corresponding to the recording signal detected by the specific signal detecting means. The recording output of the recording based on the recording signal corresponding to the recording pit formed at a position not adjacent to the land pre-pit. Characterized by comprising an output control means for controlling the different intensity or pulse width and the recording output of the beam.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an optical disk recording apparatus and an optical disk recording method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram for explaining the basic principle of an optical disk recording apparatus and an optical disk recording method according to the present invention.

In FIG. 1, FIG. 1 (a) is an enlarged view of a part of the optical disk surface, and a1 and a2 are land pre-pits (LPP) formed in advance on a land L1 on the optical disk surface. b1 and b2 are recording pits formed on the groove G2 by laser beam irradiation based on the recording data. Also, s indicates a spot of the laser beam, and the spot diameter (1 / e2) is 0.8 to 0.9 μm.

FIG. 1 (b) and FIG. 1 show signal waveforms obtained by scanning such an optical disk with a laser beam.
It is shown in (c).

FIG. 1C shows a waveform of a signal (RF signal) obtained from the recording pit strings b1 and b2 formed on the groove G2, and FIG.
7 shows a waveform of a signal (LPP signal) obtained from land pre-pit strings a1 and a2 formed on two adjacent lands L1.

Now, as shown in FIG.
FIG. 1 shows a case where a recording pit b2 is formed adjacent to the recording pit b2.
As shown in (b) and (c), at the time of signal reading,
The RF signal acts as noise on the LPP signal and LP
The amplitude of the P signal decreases while the LPP
The signal acts as noise, reducing the amplitude of the RF signal.

Particularly, in the RF signal, a waveform corresponding to, for example, a 4T pit becomes indistinguishable from a waveform corresponding to a 3T pit due to a decrease in amplitude, causing a problem that an error occurs in a reproduced signal. The decrease in the amplitude of the RF signal due to the influence of the LPP signal is caused by a recording pit having a smaller amplitude value than the maximum value of the eye pattern (3T, 4T pits in DVD) or a recording pit having a length that fits within the spot of the laser beam ( In the case of DVD, it is noticeable in 3T to 6T).

This is because, as described above, in the RF signal, the shorter the pit length, the greater the rate of amplitude change when the LPP signal acts as noise. Has a size of about 0.4 μm to about 0.5 μm, and about 0.1 μm.
Since it is close to the size of the LPP formed at about 2 μm to 0.3 μm, when adjacent to each other, a laser beam is irradiated at a spot that covers both pits. The amplitude is reduced, and pit reading errors are likely to occur.

Therefore, according to the present invention, as shown in FIG. 1 (d), the length of a recording pit adjacent to the LPP and having a smaller amplitude value than the maximum value of the eye pattern or the length of a recording pit or a laser beam spot. When a recording pit having a pit is formed, the intensity of a laser beam forming the recording pit, for example, a 3T pit, is set to 3
It is characterized in that the intensity (H2) is set to be higher than the intensity (H1) of the laser beam forming the T pit by considering the fact that the LPP signal acts as noise.

Accordingly, a recording pit formed adjacent to the LPP and having a smaller amplitude value than the maximum value of the eye pattern or a recording pit having a length that can be accommodated in the spot of the laser beam is larger than usual. The reproduced signal thus formed has an amplitude value appropriate for the result of the amplitude reduction due to the LPP signal acting as noise.

In the above example, the recording pit is LPP
In this case, the intensity of the laser beam is made different when the recording pit is adjacent to the recording pit.
When adjacent to P, the pulse width corresponding to the recording pit may be made different.

In this case, as shown in FIG.
The pulse width W2 corresponding to the recording pit adjacent to the LPP, for example, the 3T pit, is set wider than the pulse width W1 of the 3T pit when not adjacent to the LPP.

Even in this case, the 3T pit adjacent to the LPP is formed to be larger than the normally recorded 3T pit, and the reproduced signal of the 3T pit has an appropriate amplitude due to the decrease in amplitude due to the LPP signal acting as noise. Value.

Depending on the disc design, LPP
When the laser beam is irradiated between the land and the groove where only the laser beam is formed, there is a case where the waveform of the RF signal has an amplitude that does not cause a reading error as shown in FIG.

In such a case, it is preferable to control the laser beam intensity of the recording pit adjacent to the LPP to be low.

FIG. 2 is a block diagram showing an embodiment of the optical disk recording apparatus according to the present invention.

In FIG. 2, the optical disk recording apparatus includes a recording reference clock (CK) generating circuit 19, an encoder 1
1. Pulse width measurement circuit, delay circuit 12, optical disk 30
Pickup 1 that irradiates laser beam to
8. An LD driver 17 for driving a laser diode (LD) (not shown) included in the optical pickup 18, an LPP signal detection circuit for detecting an LPP signal from a light reception signal output from the optical pickup 18, and detection by an LPP signal detection circuit LPP periodic signal generation circuit 16 for generating an LPP periodic signal based on the LPP signal, specific pulse detection circuit 1
4. At least a recording strategy circuit 20 for generating a recording pulse based on a signal to be recorded.

FIG. 3 is a diagram showing waveforms of signals output from various parts of the optical disk recording apparatus shown in FIG.

In FIG. 3, the signal (a) is a recording signal that is obtained by subjecting the recording data to 8/16 modulation in the encoder 11, and the signal (b) is input from the delay circuit 12 to the LD driver 17. The laser output control signal, the signal (c) is a specific width pulse detection signal output when the pulse width measurement circuit 13 detects the 3T pulse and the 4T pulse, and the signal (d) is an LPP periodic signal generation unit. , The LPP periodic signal generated based on the LPP signal detected by the LPP signal detecting circuit, the signal of (e) is output from the specific pulse detecting circuit 14 to the specific width pulse detecting signal (c) and the LPP periodic signal (d). The specific pulse detection signal (f) generated on the basis of the laser output control signal (b) and the specific pulse detection signal (e) is used as a recording strategy circuit. It illustrates an example of a waveform of the laser drive signal generated in 0.

The recording reference clock 19 outputs a clock signal (CK) for synchronizing each part in the optical information recording apparatus shown in FIG.

After encoding the input recording data, the encoder 11 modulates the recording data by 8/16 and outputs it as a recording signal (a).

The recording signal (a) output from the encoder 11 is delayed by a predetermined time ΔT by the delay circuit 12 to generate a laser output control signal (b) for controlling the output of the laser beam in two stages.

The pulse width measuring circuit 13 measures the pulse width of the input recording signal (a) and records the recording signal (a) adjacent to the LPP and having a smaller amplitude value than the maximum value of the eye pattern from the recording signal (a). It has a function of detecting a pit, that is, a pulse of 3T width or 4T width, and detects a 3T width from the recording signal (a).
When a pulse having a width or a 4T width is detected, a specific width pulse detection signal (c) is output.

The LPP periodic signal generating circuit 16 outputs the LP extracted from the read signal in the LPP signal detecting section 15.
An LPP periodic signal (d) indicating the detection cycle of the P signal is generated.

The specific pulse detection circuit 14 outputs a specific width pulse detection signal (c) output from the pulse width measurement circuit 13,
And LP output from LPP periodic signal generation circuit 16
From the recording signal (a) based on the P-periodic signal (d), LP
A pulse corresponding to a recording pit formed right beside P is detected, and a specific pulse detection signal is output.

The recording strategy circuit 20 includes a delay circuit 12
A recording pulse is output based on a signal to be recorded, based on the laser output control signal generated in step (1) and the specific pulse detection signal generated by the specific pulse detection circuit.

Here, when the specific pulse detection signal from the specific pulse detection circuit 14 is input, the recording strategy circuit 20 outputs the intensity (high) corresponding to the pulse of the recording pulse signal input in synchronization with this detection signal. Is output at H2, which is even stronger than H1 (see FIG. 3 (f)).

The LD driver 17 is configured to control the output of the laser beam to at least three values.
A laser diode (not shown) included in the optical pickup 18 is driven based on the recording pulse signal output from the recording strategy circuit 20, and the output intensity of the laser beam applied to the optical disk 20 is controlled in two stages, H1 and L. When a recording pulse of the intensity H2 is input from the recording strategy circuit 20 in response to the output of the specific pulse detection signal from the specific pulse detection circuit 14, the laser beam corresponding to this pulse is made stronger than the normal intensity H1. Output with intensity H2.

In the above embodiment, when the pulse width measuring circuit 13 detects a recording pit having an amplitude smaller than the maximum value of the eye pattern, that is, a pulse having a 3T width or a 4T width, a pulse having a specific width is detected. Although the signal (c) is configured to be output, a recording pit having a length that fits within the spot of the laser beam (3 in the case of DVD).
T to 6T), a specific width pulse detection signal (c) may be output when a pulse is detected.

In the recording strategy circuit 20, when a specific pulse detection signal is input from the specific pulse detection circuit 14, the intensity (high) corresponding to the pulse of the recording pulse signal input in synchronization with the detection signal is input. Is output at H2, which is even stronger than H1, so that the laser beam intensity of the recording pit adjacent to the LPP is controlled to be high. However, depending on the design of the disk, the land / groove in which only the LPP is formed is used. When the waveform of the RF signal has such an amplitude that a reading error does not occur when the laser beam is irradiated during the interval, the laser beam intensity of the recording pit adjacent to the LPP may be controlled to be low.

In the above embodiment, when a recording pit is adjacent to the LPP, the pulse intensity corresponding to the recording pit is made different, but when the recording pit is adjacent to the LPP, the recording pit is changed. May be made different.

FIG. 4 is a block diagram showing another embodiment of the optical disk recording apparatus according to the present invention configured as described above.

In FIG. 4, the parts performing the same functions as those of the optical disk recording apparatus shown in FIG. 2 are denoted by the same reference numerals as those used in FIG. 2, and redundant description will be omitted.

In the optical disk recording device shown in FIG. 4, when the recording strategy circuit 21 receives a specific pulse detection signal from the specific pulse detection circuit 14, the recording strategy signal The configuration is such that the pulse width W1 corresponding to the pulse is expanded to the pulse width W2 and output, and the other configuration is the same as that of the optical disk recording apparatus shown in FIG.

FIG. 5 is a diagram showing a waveform of a signal output from each unit of the optical disk recording apparatus shown in FIG. 4. In FIG. Recording signal output after 16 modulation,
The signal (b) is a laser output control signal input from the delay circuit 12 to the LD driver 17, and the signal (c) is output when the pulse width measurement circuit 13 detects a 3T pulse and a 4T pulse. Specific width pulse detection signal,
The signal of (d) is generated by the LPP periodic signal generation unit.
The LPP periodic signal, which is generated based on the LPP signal detected by the signal detection circuit, and the signal (e) are output from the specific pulse detection circuit 14 to the specific width pulse detection signal (c) and the LPP signal.
The specific pulse detection signal (f) generated based on the periodic signal (d) and the signal (f) are generated in the recording strategy circuit 21 based on the laser output control signal (b) and the specific pulse detection signal (e). 4 shows an example of a waveform of a laser drive signal.

As shown in FIG. 5F, when the specific pulse detection signal from the specific pulse detection circuit 14 is inputted, the recording strategy circuit 21 outputs the recording pulse signal in synchronization with the detection signal. The pulse width W1 corresponding to the pulse is set to a pulse width W2 wider than the pulse width W1.
To output.

As a result, in the LD driver 17, when a recording pulse having a pulse width W2 is input from the recording strategy circuit 20 in response to the output of the specific pulse detection signal from the specific pulse detection circuit 14, the pulse corresponds to this pulse. The laser beam is output with a pulse width W2 wider than the normal pulse width W1.

In the above-described embodiment, when the pulse width measuring circuit 13 detects a recording pit having an amplitude smaller than the maximum value of the eye pattern, that is, a pulse having a 3T width or a 4T width, a specific width pulse is detected. Although the signal (c) is configured to be output, a recording pit having a length that fits within the spot of the laser beam (3 in the case of DVD).
T to 6T), a specific width pulse detection signal (c) may be output when a pulse is detected.

In the recording strategy circuit 21, when the specific pulse detection signal from the specific pulse detection circuit 14 is input, the pulse width of the recording pulse signal input in synchronization with this detection signal is changed from W1. Wider W2
The pulse width of the laser beam of the recording pit adjacent to the LPP is controlled to be wide by outputting the laser beam. However, when the laser beam is irradiated between the land and the groove where only the LPP is formed due to the design of the disk. To R
When the waveform of the F signal has an amplitude that does not cause a reading error, the pulse width of the laser beam of the recording pit adjacent to the LPP may be controlled to be narrow.

The above recording apparatus is merely an embodiment for realizing the optical disk recording method of the present invention, and the present invention is not limited to the above embodiment.

[0054]

As described above, according to the present invention, when a recording pit having a large amplitude fluctuation is formed adjacent to the LPP, the laser beam forming the pit is recorded at a position not adjacent to the LPP. Since the output is controlled for the laser beam forming the pit, LP
It is possible to form recording pits on the premise that the P signal acts as noise, and as a result, it is possible to reduce errors in the reproduced signal due to the LPP signal leaking into the RF signal.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the basic principle of an optical disk recording device and an optical disk recording method according to the present invention.

FIG. 2 is a block diagram showing an embodiment of an optical disk recording device according to the present invention.

FIG. 3 is a diagram showing a waveform of a signal output from each unit of the optical disc recording apparatus shown in FIG. 2;

FIG. 4 is a block diagram showing another embodiment of the optical disk recording apparatus according to the present invention.

FIG. 5 is a diagram showing waveforms of signals output from respective units of the optical disc recording apparatus shown in FIG.

[Explanation of symbols]

11 Encoder 12 Delay circuit 13 Pulse width measurement circuit 14 Specific pulse detection circuit 15 LPP signal detector 16 LPP periodic signal generation circuit 17 LD Driver 18 Optical pickup 19 Recording reference clock 20 Recording strategy circuit 21 Recording Strategy Circuit 30 optical disk a1, a2 Land pre-pit (LPP) b1, b2 recording pit s Laser beam spot L1, L2 Land G1, G2, G3 Groove

   ────────────────────────────────────────────────── ─── Continuation of front page    F term (reference) 5D090 AA01 BB03 BB04 CC01 DD03                       DD05 HH01 KK03                 5D119 AA12 AA23 BA01 BB02 FA05                       HA16 HA45 HA60 HA68                 5D789 AA12 AA23 BA01 BB02 FA05                       HA16 HA45 HA60 HA68

Claims (14)

[Claims] An optical disk having land prepits periodically arranged including various information such as addresses on lands between recording tracks is irradiated with a laser beam whose output is controlled based on a recording signal. An optical information recording method for forming a series of pit rows along the recording track, wherein a laser beam is formed adjacent to the land prepits and the amplitude value of a reproduction signal is smaller than the maximum value of an eye pattern. An optical disc recording method, wherein the recording output of a beam is controlled to a different intensity from the recording output of a laser beam for a recording pit formed at a position not adjacent to the land prepit. 2. A laser beam whose output is controlled based on a recording signal is applied to an optical disk having land prepits periodically arranged including various information such as addresses on lands between recording tracks. An optical information recording method for forming a series of pit rows along the recording track, wherein a laser beam is formed adjacent to the land prepit and has a length that fits within the spot of the laser beam. An optical disc recording method, wherein the recording output is controlled to have a different intensity from the recording output of a laser beam for a recording pit formed at a position not adjacent to the land pre-pit. 3. The intensity of the recording output of the laser beam for a recording pit formed adjacent to the land pre-pit is determined by the intensity of the recording output of the laser beam for a recording pit formed at a position not adjacent to the land pre-pit. 2. The method according to claim 1, wherein the intensity is controlled to be higher than the intensity.
Or the optical disk recording method according to 2. 4. The intensity of the recording output of the laser beam,
3. The optical disk recording method according to claim 1, wherein the control is performed by a measured value of a pulse width of the recording signal and a periodic signal detected based on the land prepit. 5. The optical disk recording method according to claim 1, wherein the recording pits whose intensity of the recording output of the laser beam is controlled have a pit length of 3T or 4T. 6. An optical disk having land prepits periodically arranged including various information such as addresses on lands between recording tracks is irradiated with a laser beam whose output is controlled based on a recording signal. An optical information recording method for forming a series of pit rows along the recording track, wherein a laser beam is formed adjacent to the land prepits and the amplitude value of a reproduction signal is smaller than the maximum value of an eye pattern. An optical disc recording method, wherein a recording output of a beam is controlled to a pulse width different from a recording output of a laser beam for a recording pit formed at a position not adjacent to the land prepit. 7. An optical disk having land prepits periodically arranged including various information such as addresses on lands between recording tracks is irradiated with a laser beam whose output is controlled based on a recording signal. An optical information recording method for forming a series of pit rows along the recording track, wherein a laser beam is formed adjacent to the land prepit and has a length that fits within the spot of the laser beam. An optical disc recording method, wherein a recording output is controlled to a pulse width different from a recording output of a laser beam for a recording pit formed at a position not adjacent to the land pre-pit. 8. A pulse width of a recording output of the laser beam for a recording pit formed adjacent to the land prepit, and a recording output of the laser beam for a recording pit formed at a position not adjacent to the land prepit. 8. The optical disk recording method according to claim 6, wherein the pulse width is controlled to be wider than said pulse width. 9. The pulse width of the recording output of the laser beam is controlled by a measured value of the pulse width of the recording signal and a periodic signal detected based on the land prepit. The optical disc recording method according to the above. 10. The optical disk recording method according to claim 6, wherein the recording pit for controlling the Hals width of the recording output of the laser beam has a pit length of 3T or 4T. 11. A laser beam whose output is controlled based on a recording signal is applied to an optical disk having land pre-pits periodically arranged including various information such as addresses on lands between recording tracks. An optical information recording device that forms a series of pit rows along the recording track, wherein the recording information corresponds to recording pits that are formed adjacent to the land pre-pits, and where the amplitude value of the reproduction signal is smaller than the maximum value of the eye pattern. Recording signal detecting means for detecting a recording signal to be recorded, and a recording output of a laser beam corresponding to the recording signal detected by the specific signal detecting means corresponding to a recording pit formed at a position not adjacent to the land prepit. And an output control means for controlling the intensity of the laser beam based on the recording signal to be different from the recording output. Click recording device. 12. A laser beam whose output is controlled based on a recording signal is applied to an optical disk having land pre-pits periodically arranged including various information such as addresses on lands between recording tracks. An optical information recording device for forming a series of pit rows along the recording track, wherein the optical information recording device is formed adjacent to the land prepit and corresponds to a recording pit having a length that fits within the spot of the laser beam. Recording signal detecting means for detecting a recording signal; and a recording output of the laser beam corresponding to the recording signal detected by the specific signal detecting means, corresponding to the recording pit formed at a position not adjacent to the land prepit. Output control means for controlling the intensity of the laser beam to be different from the recording output of the laser beam based on the recording signal to be output. The optical disc recording apparatus according to symptoms. 13. A laser beam whose output is controlled based on a recording signal is applied to an optical disk having land pre-pits periodically arranged including various information such as addresses on lands between recording tracks. An optical information recording device that forms a series of pit rows along the recording track, wherein the recording information corresponds to recording pits that are formed adjacent to the land pre-pits, and where the amplitude value of the reproduction signal is smaller than the maximum value of the eye pattern. Recording signal detecting means for detecting a recording signal to be recorded, and a recording output of a laser beam corresponding to the recording signal detected by the specific signal detecting means corresponding to a recording pit formed at a position not adjacent to the land prepit. An output control means for controlling a pulse width different from a recording output of a laser beam based on a recording signal. Disk recording device. 14. A laser beam whose output is controlled based on a recording signal is applied to an optical disk having land prepits periodically arranged including various information such as addresses on lands between recording tracks. An optical information recording apparatus for forming a series of pit rows along the recording track, wherein recording corresponding to a recording pit formed adjacent to the land prepit and having a length that fits within the spot of the laser beam. Recording signal detecting means for detecting a signal; and recording the laser beam corresponding to the recording signal detected by the specific signal detecting means for recording a recording pit corresponding to a recording pit formed at a position not adjacent to the land prepit. Output control means for controlling a pulse width different from a recording output of the laser beam based on a signal. Optical disk recording apparatus for.