JP3225114B2 - Optical disk drive - 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 apparatus for setting recording conditions of a semiconductor laser when recording desired data on a recording medium.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 63-25409 discloses that when desired information is recorded on a recording medium, a test pattern signal is recorded and reproduced by a recording light whose intensity is gradually changed in advance on the recording medium. A signal recording method for detecting the recording power at which the reproduction signal amplitude is optimal and controlling the power of the semiconductor laser to the recording power to obtain the optimal recording condition and record the information. Have been.

[0003]

In the above signal recording method, when desired information is recorded on a recording medium, recording and reproduction of a test pattern signal by a recording light whose intensity is gradually changed in advance on the recording medium. Then, the recording power at which the reproduced signal amplitude is optimal is detected, and the information of the information is recorded by determining the optimal recording condition by controlling the power of the semiconductor laser to the recording power. After recording the information, it must be reproduced to check the optimum amplitude of the reproduced signal, and it takes a long time to record information. In addition, the amount of recording light emitted from the semiconductor laser varies depending on the temperature, and there are differences in temperature and sensitivity between recording media.
It is not always possible to record information reliably.

FIG. 5 shows the state of the reproduction signal amplitude with respect to the recording power fluctuation. When the recording signal is data of a pattern followed by two or more '1's, data of a pattern followed by two or more'0's, data of one '1', data of a pattern followed by two '0's If the recording conditions fluctuate, the recording power becomes the optimum recording power P.
recording power Pw 'smaller than w or optimum recording power Pw
The recording domain fluctuates by fluctuating to a larger recording power Pw ", the amplitude of the reproduction signal fluctuates, and the reliability of the reproduction signal decreases.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a highly reliable optical disk apparatus capable of obtaining a recording power capable of always obtaining a stable reproduction signal with respect to fluctuations in recording conditions. .

[0006]

In order to achieve the above object, according to the first aspect of the present invention, light from a semiconductor laser is focused on a recording medium by an objective lens to record and reproduce information. When recording and reproducing test data on the recording medium when recording the data on the recording medium, an optical disc apparatus for setting recording conditions of the semiconductor laser at the time of desired data recording by a reproduced signal thereof. The test data is a first pattern data followed by two or more '1's and two or more'0's, and a modulation method of the recording medium which is independent of the first pattern data. Peak value detecting means for detecting the maximum value and the minimum value of the reproduction signal amplitude of the data of the first pattern as the data of the second pattern having the maximum frequency; and reproducing the data of the second pattern. Average value detection means for detecting the average value of the signal amplitude, and the average value of the reproduced signal amplitude of the data of the second pattern detected by the average value detection means as a reference, and the average detected by the peak value detection means Comparing means for comparing the center value between the maximum value and the minimum value of the reproduced signal amplitude of the data of the first pattern; and
When the center value is smaller than the average value as a result of the comparison
Reduce the recording power of the semiconductor laser and
When the center value is larger than the value, the recording power is increased.
Recording and reproduction of the test data,
Mean value detection by value detection means and ratio by the comparison means
Control means for performing the comparison, and the comparison result by the comparison means.
As a result, when the average value and the center value are substantially equal,
Set the recording power for recording to the recording power for data recording.
Is obtained by a that the recording power setting means.

According to a second aspect of the present invention, there is provided the optical disk device according to the first aspect, further comprising a temperature detecting means for detecting an internal temperature of the optical disk apparatus, wherein the recording power setting is performed in accordance with an output signal of the temperature detecting means. The operation is performed.

According to a third aspect of the present invention, in the optical disk device according to the first aspect, the operation of setting the recording power is performed according to a radial position of the recording medium.

[0009]

According to the first aspect of the present invention, when recording desired data on the recording medium, two or more '1's and two's
Test data consisting of data of a first pattern followed by at least '0' and data of a second pattern having a maximum frequency in a modulation method of the recording medium which is independent of the data of the first pattern Is performed on the recording medium, and the maximum value and the minimum value of the reproduction signal amplitude of the data of the first pattern are detected by the peak value detection means. The average value of the reproduction signal amplitude of the data of the second pattern is detected by the average value detection means, and the comparison means uses the average value of the reproduction signal amplitude of the data of the second pattern detected by the average value detection means as a reference. And a center value between the maximum value and the minimum value of the reproduced signal amplitude of the data of the first pattern detected by the peak value detecting means. The control means, as a result of the comparison by the comparing means,
If the center value is smaller than the average value, the semiconductor laser
Lower the recording power, and the center value is more than the average value.
If it is larger, increase the recording power and repeat the test.
Recording and reproduction of data for
Average value detection and comparison by the comparing means are performed. Record
The power setting means, as a result of the comparison by the comparing means,
If the average value is approximately equal to the center value,
Set the recording power to the recording power for data recording. Therefore, a recording power that can always obtain a stable reproduction signal with respect to the fluctuation of the recording condition is required, and a margin is provided for the reproduction signal amplitude, and a stable reproduction signal is always obtained and reliability is improved.

According to the second aspect of the present invention, the internal temperature of the optical disk device is detected by the temperature detecting means, and the operation of setting the recording power is performed according to the output signal of the temperature detecting means. Therefore, the reliability is further improved with respect to the change in the recording condition.

According to the third aspect of the present invention, the operation of setting the recording power is performed according to the radial position of the recording medium. Therefore, the reliability of the reproduced signal is always improved.

[0012]

FIG. 1 shows an embodiment of the present invention. When reproducing information from the disk-shaped recording medium 11, the recording medium 1
1 is driven to rotate by a motor, and the semiconductor laser 12 is driven by the
C lights up. Part of the light emitted from the semiconductor laser 12 is incident on the light-emitting power detection light-receiving element 15 by the beam splitter 14 and is detected by being converted into a current.

The remaining part of the light emitted from the semiconductor laser 12 is focused on the recording medium 11 by the objective lens 17 via the prism 16. The reflected light from the recording medium 11 passes through the objective lens 17 again, is guided to the signal detecting light-receiving element 18 by the beam splitter 14, and is detected by being converted into a current. The output signal of the signal detection light-receiving element 18 is subjected to current-voltage conversion by the detection amplifier 19, the amplitude of which is detected by the signal amplitude detection unit 30, and sent to the microcomputer (CPU) 22. The output signal of the light-emitting power detection light-receiving element 15 is supplied to the current
The voltage is converted to a reference voltage V
ref, and the semiconductor laser driver 13 is controlled by a control signal based on the comparison result.
2 is controlled to be constant.

When recording desired information on the recording medium 11, the recording medium 11 is rotated by a motor and
A set value corresponding to the recording power is set in the recording power setting unit 23 by the PU 22, and the recording power control unit 24 outputs a control signal such that the recording power becomes the set power of the recording power setting unit 23. This control signal is modulated by the modulation unit 25 in accordance with desired recording data, and is reproduced.
Laser driver 1 in a form superimposed on the control signal from
3, the light modulated by the recording data is emitted from the semiconductor laser 12, and the recording power is controlled to the set power.

In this embodiment, desired information is recorded on the recording medium 1.
Before recording the data in 1, the test data is recorded and reproduced. FIG. 2 shows the test data (modulated signal (for example, (2, 7) modulated) and a reproduced signal). FIG. 4 shows an operation flow for controlling recording power by recording and reproducing test data. The test data includes data of a pattern followed by two or more '1's, data of a pattern followed by two or more'0's, and the maximum frequency (modulation of the signal modulated by the modulation unit 25) in the modulation method of the recording medium. Pattern data (maximum frequency) pattern data (one '1' data, two consecutive '0' patterns), and in the recording mode, a pattern data followed by two or more '1's. The control signal from the recording power control unit 24 is modulated by the modulating unit 25 by the data of the long1,0 pattern composed of the data of the pattern followed by two or more '0's, long
Data of 1,0 patterns are recorded.

Next, the data of the long1,0 pattern is reproduced from the recording medium 11 in the reproduction mode in the same manner as in the above reproduction, and the reproduction signal from the detection amplifier 19 is sent to the peak voltage detection unit 26. The peak voltage detector 26 samples the reproduced signal from the detection amplifier 19 at predetermined sampling positions A and B to obtain the maximum value Va and the minimum value Vb of the amplitude of the reproduced signal, and the maximum value Va and the minimum value Vb are A / A. A / D converter
The data is D-converted and sent to the CPU 22.

Next, in the recording mode, the short-circuit data consisting of the data of the pattern of the maximum frequency in the modulation method of the recording medium is used.
Recording power control unit 2 based on rt1,0 pattern data
The control signal from No. 4 is modulated by the modulation unit 25, and the data of the short 1, 0 pattern is recorded on the recording medium 11 in the same manner as in the recording.

Next, the short 1, 0 pattern data is reproduced from the recording medium 11 in the reproduction mode in the same manner as in the above reproduction, and the reproduction signal from the detection amplifier 19 is sent to the average voltage detection unit 28 through the low-pass filter 27. An average voltage Vave of the reproduction signal is detected. This average voltage V
The ave is A / D converted by an A / D converter and sent to the CPU 22.

As shown in FIG. 3, the CPU 22 calculates the center value (Va + Va) of the maximum value Va and the minimum value Vb of the amplitude of the reproduced signal fetched from the peak voltage detecting section 26 via the A / D converter.
Vb) / 2 is calculated, and (Va + Vb) / 2 is compared with (Va + Vb) / 2 and the average voltage Vave fetched from the average voltage detection unit 28 via the A / D converter.
If (Va + Vb) / 2> Vave, the setting power of the recording power setting unit 23 is increased (Va + Vb).
The recording power is changed so that / 2 ≒ Vave.

Such control of the recording power is performed while repeating the operations of the recording mode and the reproduction mode described above. Assuming that the recording power when (Va + Vb) / 2 ≒ Vave is PW, the CPU 22 calculates (Va + Vb)
After the time when / 2 ≒ Vave, (Va + Vb) / 2 =
The recording power is changed so as to be Vave. As described above, the control of the recording power is performed by (Va + Vb) / 2 ≒ Vav.
If the recording power becomes e, a sufficient margin is provided for the reproduction signal amplitude with respect to the fluctuation of the recording conditions, and a stable reproduction signal is always obtained.

A temperature sensor 29 is installed near the recording medium 11 to detect a temperature, and the CPU 22 monitors a temperature detection signal from the temperature sensor 29 to detect a change in environmental temperature (for example, a temperature change of 10 ° C.). When the desired information is recorded on the recording medium 11, the operation performed before that is performed to obtain a more stable reproduction signal. Further, a position at which recording and reproduction of information on the recording medium 11 is detected by a position sensor or the like, or a track number of a position at which recording and reproduction of information on the recording medium 11 is read is sent to the CPU 22 as a position signal. , CPU22
The desired information described above is recorded on the recording medium 1 by the position signal.
In the operation performed before recording on the recording medium 1, for each radial position (for example, track position) of the recording medium 11, (V
The recording power is set in the recording power setting unit 23 so that a + Vb) / 2２３Vave.

[0022]

As described above, according to the first aspect of the present invention, light from a semiconductor laser is focused on a recording medium by an objective lens to record and reproduce information, and desired data is recorded to the recording medium. In an optical disc apparatus for recording and reproducing test data on the recording medium upon recording on the medium, and setting a recording condition of the semiconductor laser at the time of desired data recording by a reproduced signal, the test data Is the first pattern data followed by two or more '1's and two or more'0's, and the second frequency of the maximum frequency in the modulation method of the recording medium which is independent of the first pattern data. Peak value detecting means for detecting the maximum value and the minimum value of the reproduced signal amplitude of the first pattern data, and detecting the average value of the reproduced signal amplitude of the second pattern data. Average value detecting means for outputting, and the average value of the reproduced signal amplitude of the data of the second pattern detected by the average value detecting means as a reference, and the data of the first pattern detected by the peak value detecting means. the comparing means for comparing the center value between the maximum value and the minimum value of the reproduction signal amplitude, as a result of the comparison the that by the comparison means, the average
If the center value is smaller than the value, the semiconductor laser
Lower the recording power and make the center value larger than the average value.
If not, raise the recording power and repeat the test.
Data recording, reproduction, average value by the average value detection means
Control means for performing detection and comparison by the comparing means
And the result of comparison by the comparing means, the average value and the
If the median value is approximately equal, the recording power at that time is
Recording power setting means for setting the recording power at the time of data recording , so that there is a margin in the amplitude of the reproduction signal in order to obtain a recording power that can always obtain a stable reproduction signal with respect to fluctuations in recording conditions. Therefore, a stable reproduction signal can be always obtained, and the reliability can be improved.

According to a second aspect of the present invention, in the optical disk device of the first aspect, there is provided a temperature detecting means for detecting an internal temperature of the optical disk apparatus, and the recording power is changed in accordance with an output signal of the temperature detecting means. Since the setting operation is performed, it is possible to further improve the reliability with respect to the fluctuation of the recording condition.

According to the third aspect of the present invention, in the optical disk device according to the first aspect, since the operation of setting the recording power is performed according to the radial position of the recording medium, the reliability of the reproduced signal is always improved. Can be done.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of the present invention.

FIG. 2 is a timing chart showing test data and a reproduction signal of the embodiment.

FIG. 3 is a diagram for explaining the same embodiment.

FIG. 4 is a flowchart showing a part of the operation flow of the embodiment.

FIG. 5 is a diagram for explaining a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Recording medium 12 Semiconductor laser 13 Semiconductor laser drive part 14 Beam splitter 15 Light emitting power detection light receiving element 17 Objective lens 18 Signal detection light receiving element 21 Reproduction power control part 22 CPU 23 Recording power setting part 24 Recording power control part 25 Modulation part 26 Peak voltage detector 27 Low pass filter 28 Average voltage detector 29 Temperature sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B ^7/ 00-7/013 G11B 7/125

Claims (3)

(57) [Claims] 1. A method for recording and reproducing information by condensing light from a semiconductor laser on a recording medium by an objective lens, and performing a test on the recording medium when recording desired data on the recording medium. In the optical disc apparatus for performing recording and reproduction of test data and setting recording conditions of the semiconductor laser at the time of desired data recording by the reproduction signal, the test data includes two or more '1's and two or more'1's. The data of the first pattern followed by 0 'and the data of the first pattern are the data of the second pattern of the maximum frequency in the modulation method of the recording medium which is separate and independent from the data of the first pattern. Peak value detection means for detecting the maximum value and the minimum value of the reproduction signal amplitude, average value detection means for detecting the average value of the reproduction signal amplitude of the data of the second pattern, and the average value detection means The center of the maximum value and the minimum value of the reproduction signal amplitude of the data of the first pattern detected by the peak value detection means and the average value of the reproduction signal amplitude of the data of the second pattern detected by comparing means for comparing the values, the result of the comparison that by the said comparison means,
When the center value is smaller than the average value, the semiconductor
Lower the recording power of the laser
If the value is large, increase the recording power and repeat
Recording and reproduction of test data,
Average value detection and comparison by the comparing means.
Control means and a result of comparison by the comparing means, the average value
And the center value is approximately equal, the recording power at that time
A recording power setting means for setting a recording power to a recording power for data recording . 2. The optical disk device according to claim 1, wherein
An optical disk device, comprising: temperature detecting means for detecting an internal temperature of the optical disk device, wherein the recording power setting operation is performed according to an output signal of the temperature detecting means. 3. The optical disk device according to claim 1, wherein
An optical disc device, wherein the operation of setting the recording power is performed according to a radial position of the recording medium.