JPH09204680A - Optical disk drive and recording level setting method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical disc drive for recording/reproducing a signal by projecting a light from a semiconductor laser to an optical disc in which an optimal recording level can be set in test recording regardless of fluctuation of ambient temperature. SOLUTION: A recording level setting circuit 7 sets a recording level while varying, a recording circuit 8 and an optical head 3 record a signal on a test track on an optical disc 1 separated by one or more track from a track on which a data is recorded previously by a track control circuit 9, the optical head 3, a reproduction circuit 4 and an error detection circuit 5 detect a reproduction signal error, and an error decision circuit 6 decides an error thus setting an optimal recording level. More specifically, an optical recording level can be set with no effect of crosstalk from adjacent track because test recording is performed while spacing apart by one track or more and the recording level is not set at too high level even if a disc is set immediately after turn on power and a recording level is set under low temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device for recording / reproducing a signal by irradiating the light of a semiconductor laser on an optical disk and an optical disk recording level setting method.

[0002]

2. Description of the Related Art In recent years, rewritable media such as magneto-optical or phase change have been put to practical use in optical disk devices. In these optical disk devices, the recording level applied to the disk has a great influence on the quality of the recorded signal, and a method for recording at the optimum recording level on the disk is important.

By the way, the optimum recording level for recording a signal on an optical disk differs depending on the material and structure of the disk. If the recording level is too low, recording cannot be performed reliably and many errors occur. Further, if the recording level is too high, the recording film is destroyed, and even if it is overwritten thereafter, erasing cannot be performed, and many errors occur.
Therefore, when recording on an optical disc, it is necessary to judge the material and structure of the mounted disc and perform recording at a recording level corresponding to this.

A conventional recording level setting method will be described. FIG. 4 is a configuration diagram of a conventional optical disc device, FIG. 5 is a flowchart showing the operation of the conventional optical disc device, and FIG. 6 is a relationship diagram between a recording level and an error of the conventional optical disc device. In FIG. 4, reference numeral 1 denotes an optical disk which is a recording medium,
Reference numeral 2 is a disk motor for rotating the optical disk 1, 3 is an optical head for outputting a laser beam to record and reproduce a signal on the optical disk 1, 4 is a reproduction circuit, 5 is an error detection circuit of a reproduction signal, 6 is an error determination circuit, 7 Is the recording level setting circuit,
Reference numeral 8 is a recording circuit, and 10 is a track control circuit.

The operation will be described with reference to the flowchart of FIG. 5 and the relationship diagram between the recording level and the error of FIG. First, the track control circuit 10 causes the optical head 3 to seek the test track. Next, the erasing level is set by the recording level setting circuit 7, and the test track is erased by recording the test track at the erasing level. In recording, the recording level setting circuit 7 sets an initial recording level P1. The recording level of the initial value is a sufficiently low value. A signal is recorded on the first test track by the recording circuit 8 at the recording level of the initial value. The reproduction circuit 4 reproduces the first track. The error detection circuit 5 detects an error. The error judgment circuit 6 judges whether the error is equal to or less than the usable error Er.

If the error is larger than the usable value Er, the track control circuit 10 seeks to the adjacent second track. The recording level setting circuit 7 sets the recording level P2 which is increased by α to the initial recording level. A signal is recorded by the recording circuit 8 on the second test track. Reproduction circuit 4
To play the second track. The error detection circuit 5 detects an error. The error determination circuit 6 determines whether the error is usable.

These are repeated until P1, P2, P3, P4, ... Until the error falls below the usable value Er.
When the error becomes equal to or less than the usable value Er, the value Pst2 obtained by multiplying the recording level Pb2 at that time by β is set as the optimum recording level. Here, in order to obtain the optimum recording level, the smallest recording level value Pb2 at which an error can be used is multiplied by β so as to be an appropriate level that is neither too high nor too low, including the recording level variation margin. doing.

[0008]

Since the optical disk device uses the laser beam to raise the temperature of the recording film to perform recording, the optimum recording level changes depending on the ambient temperature. At the same time, the focus of the servo shifts due to a change in ambient temperature, and the size of the laser beam spot changes.

When the temperature is low immediately after the power is turned on, the laser beam spot is large without being narrowed down due to the focus shift of the servo. When the disc is mounted in that state and test recording is performed, crosstalk from adjacent tracks is mixed into the signal as noise, and errors increase. The broken line shows the relationship between the recording level and the error when the laser beam spot becomes large at low temperature.
The solid line shows the relationship between the recording level and the error when the temperature inside the housing rises and the laser beam spot becomes smaller.

When the error decreases and becomes less than the usable value Er, the recording level Pb2 is multiplied by a certain constant β to set the optimum recording level Pst2, which is higher than the original optimum setting level Pst. It will be set. After that, as time elapses and the temperature inside the housing rises, the laser beam spot is narrowed down. At this time, in addition to the high recording level, the laser beam spot is narrowed down and the housing temperature is also high, and when recording, the recording film will be destroyed and it will not be possible to erase by subsequent overwriting. Error will increase.

As described above, when the temperature in the apparatus rises after the disc is mounted and the test recording is performed to set the optimum recording level, the recording level is largely deviated from the optimum value.
There is a problem that the optical disc is destroyed or cannot be erased thereafter. The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an optical disk device and an optical disk recording level setting method capable of setting an optimum recording level in test recording even when the ambient temperature changes. .

[0012]

An optical disk apparatus according to the present invention comprises an optical head for recording and reproducing a signal by applying a laser beam spot, a recording level setting circuit for setting a recording level and an erasing level, and a different recording level. A recording circuit for test recording, a reproducing circuit for reproducing a signal from the optical disc, an error detecting circuit for detecting an error from the reproduced signal, an error judging circuit for judging whether the error is a usable value, and a test recording time. In addition, a track control circuit is provided to control so that test recording is performed using one or more open tracks without using adjacent tracks.

Further, in order to determine the recording level of the optical disc, in the optical disc recording level setting method, a signal is recorded on the optical disc at a plurality of types of recording levels, and the optimum recording level is obtained from the frequency of errors contained in the reproduced signal. When changing and recording, there is a method of performing test recording on a track which is one or more tracks away from the previously recorded track and reproducing it to set the recording level so that the error falls within the usable range. .

As a result, it is possible to obtain an optical disk device and an optical disk recording level setting method capable of setting an optimum recording level in test recording even if the ambient temperature changes.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises an optical head for recording and reproducing a signal by applying a laser beam spot to an optical disk, and a recording level setting circuit for setting a recording level and an erasing level. A recording circuit that erases multiple tracks in the test recording area beforehand and changes the recording level for test recording, a reproduction circuit that reproduces the signal from the optical disk, an error detection circuit that detects an error from the reproduction signal, and an error is used. An error judgment circuit that judges whether the value is possible or not, and when performing test recording, test using multiple tracks that have been erased in advance in the test recording area without using adjacent tracks and using tracks that are one or more tracks apart. It is an optical disk device provided with a track control circuit for controlling recording so that the crosstalk from adjacent tracks It is possible to set the optimum recording level without setting, even if the disc is mounted immediately after turning on the power and the recording level is set at a low temperature, the set recording level does not become too high and can be set to the optimum value. Have an effect.

According to a second aspect of the present invention, in order to determine the recording level of the optical disc, an optical disc recording is performed in which a signal is recorded on the optical disc at a plurality of types of recording levels and an optimum recording level is obtained from the frequency of errors contained in the reproduced signal. In the level setting method, when recording is performed while changing the recording level, an optical disk recording level setting method is characterized in that recording is performed on a track which is separated from the previously recorded track by one track or more, and test recording is performed by one or more tracks. By performing at intervals, it is possible to set the optimum recording level without the influence of crosstalk from adjacent tracks,
Even if the disc is mounted immediately after the power is turned on and the recording level is set at a low temperature, the set recording level does not become too high, and the optimum value can be set.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a block diagram of an optical disk device according to an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the optical disk device according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. 7 shows a relationship between a recording level and an error in the optical disc device according to the embodiment.

In FIG. 1, 1 is an optical disk which is a recording medium, 2 is a disk motor for rotating the optical disk 1,
Reference numeral 3 is an optical head for outputting a laser beam to record / reproduce a signal on / from the optical disc 1, 4 is a reproducing circuit, 5 is an error detecting circuit of a reproduced signal, 6 is an error judging circuit, 7 is a recording level setting circuit, and 8 is a recording circuit. , 9 are track control circuits. The operation will be described with reference to the flowchart in FIG. 2 and the relationship diagram between the recording level and the error in FIG.

First, the track control circuit 9 seeks the optical head 3 to the test track. Next, the erasing level is set by the recording level setting circuit 7, and the test track is erased by recording the test track at the erasing level. In recording, the recording level setting circuit 7 sets an initial recording level P1. The recording level of the initial value is a sufficiently low value. A signal is recorded on the first test track by the recording circuit 8 at the recording level of the initial value. The reproduction circuit 4 reproduces the first track. The error detection circuit 5 detects an error. The error determination circuit 6 determines whether the error is usable.

If the error is larger than the usable value Er, the track control circuit 9 seeks to the second track at intervals of at least one track. The recording level P increased by α to the recording level of the initial value by the recording level setting circuit 7.
Set 2. A signal is recorded by the recording circuit 8 on the second test track. The reproduction circuit 4 reproduces the second track. The error detection circuit 5 detects an error. The error determination circuit 6 determines whether the error is usable.

These are repeated until P1, P2, P3, P4, ... Until the error becomes equal to or less than the usable value Er.
When the error becomes equal to or less than the usable value Er, the value obtained by multiplying the recording level Pb at that time by β is set as the optimum level Pst. This Pst is the recording level at the center of the low error area, and the optimum recording level can be obtained.

Although the erasing operation is first performed on the entire test area here, it may be performed each time recording / reproducing is performed. At this time, if the track to be recorded and the tracks on both sides are erased, the same operation is performed. The effect is obtained. Here, in order to obtain the optimum recording level, the smallest recording level value Pb at which an error can be used is multiplied by β so as to be an appropriate level that is neither too high nor too low, including the recording level variation margin. However, a certain value in Pb may be added to set the optimum value.

Further, in order to obtain the optimum recording level, at the time of test recording, after obtaining the smallest recording level value Pb at which an error can be used, the test recording is continued by further increasing the recording level and recording. Obtain the recording level Pt at which the error is unusable because the level is too high. Pb and P
An intermediate value of t may be set as the optimum recording level.

[0024]

As described above, according to the present invention, by carrying out test recording at intervals of one track or more, it is possible to eliminate the influence of crosstalk from adjacent tracks and set an optimum recording level. An optical disk device and an optical disk recording level setting method can be provided. Even if the disc is loaded immediately after the power is turned on, the recording level is set at a low temperature, and then even if the temperature rises, the set recording level will not become too high, and the optical disc will be destroyed or overwritten. There will be no problems such as being unable to erase with.

According to the present invention, in the recording / reproducing of the optical disk device which is required to have high reliability, an optimum recording level can be set even when the temperature of the operating environment is drastically changed, and a stable recording / reproducing state can be secured. The reliability is improved and its practical effect is great. INDUSTRIAL APPLICABILITY In the recording / reproducing of the optical disc device which requires high reliability, the present invention can ensure compatibility when the optical discs are used by being exchanged between various optical disc devices, and its practical effect is great.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical disc device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the optical disc device according to the embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a recording level and an error in the optical disc device according to the embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional optical disk device.

FIG. 5 is a flowchart showing the operation of a conventional optical disc device.

FIG. 6 is a diagram showing a relationship between a recording level and an error in a conventional optical disc device.

[Explanation of symbols]

 1 optical disk 2 disk motor 3 optical head 4 reproduction circuit 5 error detection circuit 6 error determination circuit 7 recording level setting circuit 8 recording circuit 9 track control circuit

Claims (2)

[Claims] 1. An optical head for recording and reproducing a signal by applying a laser beam spot to an optical disk, recording level setting means for setting a recording level and an erasing level, recording means for performing test recording while changing the recording level, and an optical disk. The reproducing means for reproducing the signal of, the error detecting means for detecting an error from the reproduced signal, the error determining means for determining whether the error is a usable value, and the test recording,
An optical disk device provided with track control means for controlling so as to perform test recording using tracks separated by one or more tracks without using adjacent tracks. 2. An optical disc recording level setting method for determining a recording level of an optical disc, wherein a signal is recorded on the optical disc at a plurality of types of recording levels, and an optimum recording level is obtained based on the frequency of errors contained in the reproduced signal.
An optical disk recording level setting method, characterized in that, when recording is performed while changing the recording level, the recording is performed on a track separated by at least one track from a previously recorded track.