JP3507150B2 - Optical information recording / reproducing device - 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 information recording / reproducing apparatus capable of optically recording / reproducing information.

[0002]

2. Description of the Related Art CD-R (Compact Disk)
2. Description of the Related Art An optical recording / reproducing apparatus called “Recordable” capable of additionally recording information forms a desired size by irradiating an optical pickup serving as a recording medium with laser light from an optical pickup to form irregularities called pits in a predetermined size. Information is written. Since the formation of the pits has a dependency on the light intensity emitted from the optical pickup, it is necessary to always set the optimum light intensity for the optical disc.

Generally, this is an OPC (Optimum).
This is called Power Control processing, and specifically, the following method is used. That is, since information regarding the recommended optimum recording light intensity for each optical disc is input in advance in the lead-in area of the optical disc, the first step is to reproduce the lead-in area with an optical pickup and recommend the optical disc to be used. Read the optimum recording light intensity. Next, as the second step, PMA (Pro
Information such as the past recording condition and the next recording position is obtained from the recording history in the Gramable Memory Area). As a third step, based on the read information on the recommended optimum recording light intensity, as shown in FIG. 8, the light intensity is changed by a constant amount around this recommended optimum recording light intensity.
Stepwise recording light is generated over five steps, and PCA (Power) of the optical disc is passed through an optical pickup.
Recording as a test pattern is performed in the Calibration Area).

At this time, in the contents recorded in steps, since it is necessary to compare the β value showing the symmetry between the recording light intensity and the reproduction signal, ATIP (Absolute Time In)
Pregroove (absolute real time) information must be synchronized. This ATIP information is read by an optical pickup, and stepwise recording light intensity is generated based on this synchronizing signal. Next, as a fourth step, the portion thus recorded is reproduced by an optical pickup, the maximum value and the minimum value of the reproduced signal are level-held, and the β value which is the symmetry of the signal is detected. That is,
The β value is the EFM that reproduces the information recorded on the optical disc.
(Eight Fourteen Modulatio
n) Maximum value (A1) and minimum value (A2) of the AC component of the signal
Is defined by the CD-R standard and is represented by the following equation. β = (A1 + A2) / (A1-A2)

Finally, the β value is converted into a digital value and sent to the control section, and the control section analyzes it to obtain bit information which is the optimum recording light intensity. By the way, the optimum recording light intensity is in a state where the absolute value of the maximum value and the minimum value of the reproduction signal becomes equal, that is, the β value becomes 0.
In the −R standard, 4% is recommended as the condition for β value. Therefore, the optimum recording light intensity can be obtained by obtaining the recording light intensity such that the β value becomes 4%.

[0006]

According to the conventional optical information recording / reproducing apparatus as described above, in order to obtain the optimum recording light intensity, the recording light as a test pattern is previously recorded on the optical disk as the recommended optimum recording light intensity. Since a specific range centered at is divided into 15 sections at equal intervals and changed in steps, recording is performed. Therefore, as shown in FIG. 8, the β value for obtaining the optimum recording light intensity is the recording light intensity. There is a problem in that the detection accuracy of the optimum recording light intensity for the obtained β value becomes coarse, especially since the rate of change becomes non-linear with respect to the change. The present invention has been made to solve such a problem, and provides an optical information recording / reproducing apparatus capable of subdividing a variable range of recording light intensity and setting an optimum recording light intensity with high accuracy. To aim. It is another object of the present invention to provide an optical information recording / reproducing apparatus capable of accurately setting the optimum recording light intensity even when the recording light intensity change classification is small.

[0007]

In an optical information recording / reproducing apparatus according to the present invention, an optical pickup for recording / reproducing information on / from an optical disc and a recording for varying the recording light intensity for recording information on the optical disc. The light intensity control means and the information recorded while changing the recording light intensity are read by the optical pickup to obtain a value indicating the symmetry of the reproduction signal based on the maximum value and the minimum value of the reproduction signal. And a first means based on the real-time information of the reproduction signal .
First sync signal generating means for generating a sync signal;
Based on the first sync signal, the first sync signal
A second system that generates a second sync signal with a higher frequency.
Corresponding to the link signal generating means and the second sync signal.
And means for setting a recording light intensity that changes stepwise,
Setting the recording light intensity in the means for setting the recording light intensity
When setting, the value indicating the symmetry and the recording light intensity are set.
The optimum light intensity based on the output from the
It is characterized by

[0008]

[0009]

[0010]

[0011]

In the optical information recording / reproducing apparatus configured as described above, the change range of the recording light intensity is made minute by further subdividing the change range of the recording light intensity specified in advance, and the reproduction signal is reproduced. The detection accuracy of the optimum recording light intensity with respect to the symmetry (β) is improved.

[0012]

[0013]

[0014]

[0015]

【Example】

Example 1. FIG. 1 is a block diagram showing the configuration of an optical recording / reproducing apparatus which is an embodiment of the present invention. In the figure,
1 is an optical disc, 2 is an optical pickup for recording information on the optical disc 1 and reproducing the recorded information, 3 is an amplifier for amplifying the reproduced EFM signal, 4 is a peak level and a bottom level from the AC component of the EFM signal The peak hold / bottom hold section 5 is set to β from the value held by the peak hold / bottom hold section 4.
A β detection unit that detects a value, 6 is an A / D conversion unit that converts the analog output of the β detection unit 5 into a digital signal, and 7 is a control unit that controls the entire block.

Reference numeral 8 is a D / A converter for converting the digital output of the controller 7 to analog, 9 is a peak power controller for controlling the recording light intensity of the optical pickup 2 by the output of the D / A converter 8, and 10 is a peak power controller. A bottom power control unit that controls the reproduction light intensity of the optical pickup 2, 11 is an ATIP detection unit that detects absolute real-time information obtained from the reproduction signal, and 12 is a pseudo AT
IP sync generation unit 13 is pseudo ATIP sync generation unit 1
2 is a reference clock generator for 2.

As a result, the pseudo ATIP sync generation unit 1
In 2, the area of the limited 15 ATIP frame can be further miniaturized. That is, the ATIP detector 11
From the ATIP sync signal and the reference clock obtained in
A delay signal is created based on the ATIP sync signal, and a pseudo sync signal for changing the recording light intensity in steps is created by the delay signal. In the example shown in FIG. 2, one ATIP frame is divided into two, and the total is three.
It is possible to change the recording light intensity in 0 steps. Figure 3
Represents the change in the β value when the recording light intensity is changed in 30 steps, and as a result, the change in the recording light intensity is reduced by increasing the number of steps in which the recording light intensity changes,
The accuracy of β value detection is improved.

Further, since one ATIP signal uses a delay signal and the area of one frame can be subdivided into as many as necessary, the change amount of the recording light intensity per step is set to a smaller amount. It is also possible to obtain a more accurate optimum recording light intensity.

Example 2. FIG. 4 is a block diagram showing the configuration of an optical information recording / reproducing apparatus according to another embodiment of the present invention. In the figure, 7 is the same control unit as in the first embodiment, and a bit setting unit 20 for setting the recording light intensity is provided in this control unit.
A memory a21 that stores the bit data of the bit setting unit 20, a memory b22 that stores the bit data of the β value obtained by the β detection unit 5, a memory a21, and a memory b2.
It is provided with an approximate analysis calculation unit 23 which performs calculation using each data of 2.

According to the second embodiment configured as described above,
The optimum recording light intensity is estimated by storing the recording light intensity value at each step and the β value corresponding to each step and performing the calculation by the approximate analysis. That is, the bit setting section 20 of the control section 7 is a section for setting bit data for setting the recording light intensity, and sets the recording light intensity for each step. The bit data of the bit setting unit 20 can cause the peak power control unit 9 which is a control unit of the recording light intensity to operate as a stepwise change of the recording light intensity via the D / A conversion unit 8.

At this time, the step-shaped bit data is stored in the memory a21. Next, the step-like β value obtained by reproducing the recorded portion of the information is used as the β detector 5 and the A detector.
The data is stored in the memory b22 via the / D conversion unit 6. Finally, the approximate analysis calculation unit 23 performs an approximate analysis from the data for each step stored in the memory a21 and the memory b22. FIG. 5 shows the β value obtained by the approximate analysis. Note that, for example, the calculation formula in the case of the quadratic curve regression analysis is shown below.

[0022]

[Equation 1]

The recording light intensity corresponding to the recommended β value can be obtained by the above series of calculations. The bit data resulting from this calculation is sent again to the bit setting section 20 and the optimum recording light intensity is set. As a result, the optimum recording light intensity can be set accurately even if the recording light intensity changes in 15 steps. It is also possible to combine the second embodiment with the first embodiment, and the detection accuracy of the optimum recording light intensity is further improved.

Example 3. FIG. 6 shows characteristics of the recording light intensity and the β value when the bit information set by the bit setting unit 20 is logarithmically changed in the second embodiment. In this case, unlike the conventional case in which the step-up of the recording light intensity as the test pattern is fixed, the step-up amount is changed by an arbitrary function.
That is, as shown in FIG. 6, the step-up amount of the recording light intensity is changed logarithmically so that the rate of change of the β value is constant. Y = aLogX + b (5) Y: recording light power, X: bit setting section

As a result, the change in the β value obtained by the β detector 5 becomes linear rather than nonlinear as in the conventional case, and the detection accuracy of the optimum recording light intensity is improved. It is also possible to combine the third embodiment with the first and second embodiments,
The detection accuracy of the optimum recording light intensity is further improved.

Example 4. Figure 7 shows OPC conducted in the past.
The processing flow when the data by processing is statistically processed and the variation | change_quantity of the recording light intensity as a test pattern is specified from this processing result is shown. The recommended optimum recording light intensity for the optical disc is recorded in advance in the lead-in area of the optical disc, and the actual recording light intensity is set by referring to this information. However, due to the temperature dependency and position dependency of the optical disc and the difference in the characteristics of the optical pickup used, trial writing is actually required before recording. The OPC process in PCA consisting of this trial writing is
The past history is recorded in each of the test area used for detecting the optimum recording light intensity and the count area for monitoring the number of recordings.

Therefore, such O
From the PC processing, it is possible to specify the amount of change in the recording light intensity as the test pattern. Therefore, first, the record information is read from the lead-in area, then the record history of the PMA area is checked, and then the count area of the PCA is accessed. Next, it is determined whether or not the past OPC process has been performed. At this time, in the case of the first processing, the OPC processing is performed with the change amount of the recording light intensity kept constant as usual. On the other hand, when the count process has already been performed and the recording is performed, the past optimum recording light intensity set value stored in the lead-in area or the PMA area is detected, and the data is stored. The data stored here is subjected to a predetermined statistical process, and the variation amount of the set value of the recording light intensity obtained here is used as the variation amount of the recording light intensity when the OPC process is finally performed. .

[0028]

Since the present invention is configured as described above, it is possible to subdivide the change of the recording light intensity in the test pattern recording area specified in advance and further reduce the change amount. It is possible to accurately set the optimum recording light intensity.

[0029]

[0030]

[0031]

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an optical information recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram for explaining the generation principle of the pseudo ATIP sync in the optical information recording / reproducing apparatus in Embodiment 1 of the present invention.

FIG. 3 is a characteristic diagram illustrating the relationship between the recording light intensity and β value of the optical information recording / reproducing apparatus according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of an optical information recording / reproducing apparatus in Embodiment 2 of the present invention.

FIG. 5 is a characteristic diagram illustrating the relationship between the recording light intensity and the β value of the optical information recording / reproducing apparatus according to the second embodiment of the present invention.

FIG. 6 is a characteristic diagram illustrating the relationship between the recording light intensity and the β value of the optical information recording / reproducing apparatus in Embodiment 3 of the present invention.

FIG. 7 is a flow chart for explaining the operation of the optical information recording / reproducing apparatus in Embodiment 4 of the present invention.

FIG. 8 is a characteristic diagram illustrating the relationship between recording light intensity and β value in a conventional optical information recording / reproducing device.

[Explanation of symbols]

1 optical disk, 2 optical pickup, 3 amplifier, 4
Peak hold / bottom hold part, 5β detection part,
6 A / D conversion unit, 7 control unit, 8 D / A conversion unit, 9
Peak power control unit, 10 Bottom power control unit, 1
1 ATIP detection unit, 12 pseudo ATIP sync generation unit, 13 reference clock generation unit, 20 bit setting unit,
21 memory a, 22 memory b, 23 approximate analysis calculation unit

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-3-40236 (JP, A) JP-A-61-239441 (JP, A) JP-A-5-225567 (JP, A) JP-A-4-40 67436 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G11B ^7/ 00-7/125 G11B 20/10-20/16

Claims (4)

(57) [Claims] 1. An optical pickup for recording and reproducing information on and from an optical disc, a recording light intensity control means for varying the recording light intensity for recording information on the optical disc, and information recorded while changing the recording light intensity. the maximum and minimum values of the reproduction signal read by the optical pickup
Means for determining a value indicative of the symmetry of the reproduced signal based on the first sync signal based on the real-time information of the reproduction signal
And a first sync signal generating means for generating the first sync signal based on the first sync signal.
A second sync signal of higher frequency than the second
Sync signal generation means and recording that changes stepwise in response to the second sync signal
And a unit for setting the recording light intensity in the unit for setting the recording light intensity.
When setting, the value indicating the symmetry and the recording light intensity are set.
The optimum light intensity based on the output from the
The optical information recording and reproducing apparatus, characterized in that that. 2. A method for storing a value indicating the symmetry of a reproduced signal.
The light according to claim 1, further comprising a molybdenum.
Information recording and reproducing device. 3. The recording light intensity setting means outputs from the detecting means.
Keep the rate of change of the value indicating the symmetry of the reproduced signal applied
The recording light intensity is set so that
1. The optical information recording / reproducing apparatus described in 1. 4. A lead-in area or a drive of an optical disc.
Multiple prerecorded pre-recorded in the programmable memory area
A means for reading the recommended optimum recording light intensity and the recommended optimum recording light intensity read by this reading means
The recording light intensity is changed stepwise based on
A procedure for recording on the optical disk and setting the optimum light intensity.
Stage and the maximum set by the means for setting the optimum light intensity.
Means for recording the set value of the optimum light intensity on the optical disc, and the optimum light intensity recorded in the past by the recording means.
Further equipped with means to perform statistical processing based on the set value of degree
The optical recording / reproducing according to claim 1, wherein
apparatus.