JP2002324332A - Optical disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of recording due to the difference between the set power and the actual light emitting power when recording for test at a high speed. SOLUTION: The laser controller circuit 15 retains the 1st light emitting period superimposed with high frequency waves at the level of the 1st power P1 before recording. It also retains a drive current difference (I difference) of the light source between the light emitting period not superimposed with high frequency waves at the 1st power P1 and the 2nd light emitting period that is the light emitting period at the level of the 1st power P1 superimposed with the high frequency waves of the amount to be superimposed when outputting the 2nd power P1 at recording. It calculates the correction efficiency η=(P2-P1)/(I2-I difference) of drive current at the 2nd power P2 when or after emitting light by the 2nd power P2, then calculates and determines the difference of the initial current I2'=(P2'-P1)/η+I difference when or after changing the 2nd power P2'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an optical disc device including a laser drive control circuit that alternately repeats a recording power for forming a pit and a reproducing power or an erasing power for not forming a pit during recording, such as a drive or a CD-RW drive.

[0002]

2. Description of the Related Art It is generally known that when return light enters a laser diode, the oscillation mode changes due to the return light and laser noise increases. In an optical disk device that handles reflected light, such as an optical disk, it is necessary to consider the effect of the return light to the laser diode.
Means for superimposing a high frequency of about 500 MHz is used in a general optical disk device. For example, Japanese Unexamined Patent Publication
According to the technique described in Japanese Patent Application Laid-Open No. 197994, in a semiconductor laser, when a focus servo pull-in operation is performed by a focus servo system, the amount of high-frequency current superimposed by a high-frequency superimposing circuit is increased so that the return light amount during focus pull-in fluctuation is reduced. 1 shows a laser noise reduction circuit capable of obtaining stable emission power of a semiconductor laser.

In the technique described in Japanese Patent Application Laid-Open No. Hei 6-223399, a high-frequency superimposing means indispensable for laser noise reduction is formed on the same wafer as a signal detecting means in a semiconductor laser case. An apparatus for miniaturizing a head is shown. On the other hand, due to the output limit of the laser diode, it is common practice to superimpose a high frequency at the time of light emission at the recording power or superimpose a high frequency having a smaller amplitude than at the time of reproduction.
As an example of the former, in the technology described in the above-mentioned Japanese Patent Application Laid-Open No. Hei 6-223399, there is shown a configuration in which high-frequency ON / OFF can be performed by an operation mode of recording and reproduction of an optical disk. As an example of the latter, Japanese Patent Application Laid-Open No. 2000-149302 discloses a configuration in which the superimposed frequency and the superimposed amplitude of the high-frequency superimposition are changed according to the recording and reproducing operation modes.

Here, the (drive current) of the laser diode
The relationship between the pair (light emission power) changes depending on the amount of high frequency superposition. FIG. 15 and FIG. 16 are diagrams showing the relationship between the driving current of the laser diode and the emission power, which is the light emission power, respectively. As shown in FIG. 15, when the recording power in which the high frequency is not superimposed and the reproduction power in which the high frequency is superimposed are alternately repeated during recording, the reproduction power is controlled in a state in which the high frequency is superimposed. Is determined from the relationship between (laser driving current) and (laser emission power: emission power) of the laser diode when a high frequency is superimposed. On the other hand, when the high frequency is not superimposed during the light emission at the recording power or when a small amount of the high frequency is superimposed, the current for the reproduction power is a larger value, but that amount is not supplied. The current corresponding to the recording power to be seen looks large as shown in FIG. That is, an error (an efficiency including the error in the figure) occurs in the current efficiency (true efficiency in the figure) for the recording power.

[0005] In the case of a CD-R drive or CD-RW drive for writing data on a CD-R or CD-RW disc,
In order to maintain the recording quality for disks having greatly different disk sensitivities, so-called trial writing is performed with varying power, and the optimum recording power is determined by reproducing the test writing. The Orange Book, which is a standard for CD-R / RW discs, shows a method in which a single trial write area is set to 15 sectors, recording is performed with different power in each sector, and reproduction is performed to determine the optimum recording power. I have. As described above, since the test writing area is standardized by the format, the test writing time is shortened, that is, the recording time with one power is shortened as the recording speed is increased. For reference, one sector of the CD is 1/75 second at 1 × speed.

[0006]

However, of course, 2
As the recording speed increases to half of 1/75 second at double speed and half of that at 4 × speed, the recording time of one power becomes shorter.
Here, when the power is changed from a certain value to a certain value unless the correct current efficiency is obtained, it takes time to reach the desired power because there is an error in the drive current of the light source initially applied. Conventionally, the recording speed was slow even with the above error, so that the desired power could be reached.However, the recording speed became faster and faster, and one recording power period ended before reaching the desired power. As a result, there is a problem that an optimum recording power cannot be obtained and recording quality deteriorates. JP-A-6-223399 and JP-A-2000-14930 mentioned above.
In the technique described in Japanese Patent Application Laid-Open Publication No. 2 (1999) -1995, the case where the recording speed is increased is not sufficiently considered.

[0007] Alternatively, when the recording power is changed together with the recording speed from a position such as Zone CLV recording, there is a problem that the recording quality is deteriorated until the change power reaches the desired power quickly and reaches the desired power. Was. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to prevent a decrease in recording quality due to a difference between a set power and an actual light emission power at the time of test recording at a high recording speed. And

[0008] The technique described in Japanese Patent Application Laid-Open No. 10-31570 discloses an apparatus for sharing a semiconductor laser drive control circuit for a CD-RW and a CD-R.
At the time of recording, the first power P1 and the second power P2 are controlled, and the current I2 when the second power P2 is controlled.
2 shows a device that easily controls the third power P3 by supplying a current I3 obtained by multiplying a predetermined ratio to the laser drive circuit. However, in such an apparatus, no consideration is given to the occurrence of an error in the current efficiency due to the amount of superposition of the high-frequency superposition, so that the correct third power P3 is not set, and the second power P3 is set like the CD-R. Power P2
In a system in which the ratio of the third power P3 and the third power P3 greatly contributes to the recording quality, there is a problem that the recording quality is reduced.

Further, the technique described in Japanese Patent Application Laid-Open No. 2000-30276 discloses an apparatus for accurately and quickly controlling the power of a light beam without requiring high-speed response and generation of a high-precision sampling pulse. The output of the optical output detection circuit at the first power P1 of the recording waveform is held by the bottom hold circuit, and the output of the optical output detection circuit at the third power P3 is held by the peak hold circuit. 1st power P1, 2nd power P2, 3rd power
An apparatus for controlling the level of the second power P2, which is difficult to sample and hold during high-speed recording, by determining the drive current of the second power P2 based on the ratio of the power P3 of the second power P2. However, in such a device, no consideration is given to the occurrence of an error in current efficiency due to the amount of superposition of the high-frequency superposition, and thus the correct second power P2
Is not set, and the second power P2 and the third power P2
In a system in which the power P3 ratio greatly contributes to the recording quality, there is a problem that the recording quality is reduced. Therefore, a second object is to obtain good recording quality even in a system in which ternary power is easily controlled by using binary samples.

The relationship between the (drive current) and the (emission power) of the laser diode greatly differs depending on whether the optical disk has return light or not. This is particularly remarkable when a laser diode and a light receiving element for signal detection are housed in the same package like a hologram laser and the amount of light returning to the laser is large. Therefore, it is desirable that the period for obtaining the drive current difference I be performed in a focus-on state by a focus servo system. Therefore, the drive current difference I
A third object is to enable the difference to be obtained more accurately.

Further, if a means for superimposing a high frequency is used to reduce laser noise as described above, when the high frequency is not superimposed, or when a small amount is superimposed even when the high frequency is superimposed, in the worst state, the focus is increased. Since laser noise is superimposed on the signal, the focus servo system cannot maintain the focus-on state, and the focus may be lost. In the normal state, the focus servo cannot be maintained. However, the above-described state may occur when the optical disk is rough or when disturbance occurs. Therefore, it is a fourth object of the present invention to remedy even if the focus state cannot be maintained and obtain the drive current difference I by retrying.

In a normal state, even if laser noise cannot be reduced due to superposition of high frequency, the focus-on state cannot be maintained in a general apparatus. However, when a disturbance occurs or the optical disk is deteriorated. If
Since the focus signal has a small so-called noise margin due to the laser noise, the focus-on state may not be maintained in the worst case. Temporary disturbances and the like can be avoided by retrying as described above, but in the case of continuous disturbances or bad optical disks, there is a possibility that the drive current difference I cannot be obtained even after retrying. is there. Therefore, even when the I difference is not obtained in the focus state, the drive current difference I is simply obtained from the drive current difference FoI difference having a value different from the drive current difference I, and the pseudo correct correction efficiency is obtained. A fifth purpose is to be required.

Further, the recording speed of CD-R / RW devices has been increased year by year, and accordingly, a large recording power has been required. Here, increasing the recording power naturally requires increasing the drive current of the laser, and switching between the first power and the second power during recording causes an increase in the noise level. In a device for detecting a servo signal during recording by sampling when reproducing power is emitted and holding the signal when recording power is emitted, the S / N of the detection signal is increased when the recording power is increased. To increase the signal component to increase S /
Means of earning N are generally taken. For example, JP-A-8-
In the technique described in Japanese Patent Application Laid-Open No. 102078, there is disclosed an apparatus for changing a reproduction power for reproducing a wobble signal according to a recording power at the time of recording.

However, since the driving current difference I differs depending on the power here, when the reproducing power at the time of recording is varied from the light emitting power at the time of reproducing, the driving obtained at the time of superimposing / not superimposing a high frequency with the light emitting power at the time of reproducing is used. If the current difference I difference is used for calculating the correction efficiency, there arises a problem that the correction efficiency cannot be obtained correctly. Therefore, it is a sixth object of the present invention to correctly determine the correction efficiency even when the light emission power during reproduction is different from the reproduction power during recording. Furthermore, (drive current) vs. (emission power) of the laser diode
Is dependent on the temperature, the drive current difference I obtained before the recording is small, but there is a problem that it changes due to self-heating during laser recording. Therefore, a seventh object is to enable correction efficiency to be obtained with high accuracy.

[0015]

In order to achieve the first object, the present invention provides a light source such as a laser diode, current supply means for the light source, and a light output for monitoring a light emission output level of the light source. An optical disc apparatus for recording data on an optical disc by alternately repeating light emission of a first power P1 and a second power P2 higher than the first power P1 by the light source during a recording operation, wherein the current supply means comprises: Means for adding and outputting the current I1 for the light emission at the first power P1, the current I2 of the difference between the second power P2 and the first power P1, and the first power P
At one time, means for superimposing the high-frequency current Ihf on the current I1 and means for turning off the superposition of the high-frequency current Ihf at the second power P2 or switching to a different current Ihf2. Means for holding the light emission output level Vm2 monitored by the light output detection means during light emission by P2, means for holding the light emission output level Vm1 monitored by the light output detection means during light emission by the first power P1, Control means for controlling the current supply means so that the light emission output level Vm1 and the light emission output level Vm2 held by the respective means become desired values; and a high frequency superimposed during light emission by the first power P1 during recording. In the second power P2, the high frequency is not superimposed or superimposed. An amount different from the high frequency to be superimposed at the time of light emission by the first power P1 is superimposed, and a first light emission period in which the high frequency is superimposed at the level of the first power P1 before recording, A light emitting period in which no high frequency is superimposed at a level or a second light emitting period which is a light emitting period at the level of the first power P1 in which an amount of high frequency is superimposed at the time of output of the second power P1 during recording. Holding the driving current difference I of the light source between the first light emitting period and the second light emitting period;
During or after the light emission by the power P2, the correction efficiency η of the driving current of the second power P2 = (P2−P1) /
(I2−I difference) is obtained, and when the second power P2 is changed, the initial current I2 ′ of the changed second power P2 ′ =
Provided is an optical disk device including means for obtaining and determining a difference of (P2′-P1) / η + I.

In order to achieve the second object,
A light source such as a laser diode, current supply means for the light source, light output detection means for monitoring the light emission output level of the light source, and a first power P1 higher than the second power P1 by the light source during a recording operation. An optical disk device for recording data on an optical disk by emitting light at a power P2 of the first power P3 and a third power P3 higher than the power P2, wherein the current supply means comprises a current I1 corresponding to the light emission at the first power P1.
Means for adding and outputting a current I2 of a difference between the second power P2 and the first power P1 and a current I3 of a difference between the third power P3 and the second power P2; 1 at the time of power P1, the high-frequency current Ihf
1 and means for switching off the superposition of the high-frequency current Ihf at the time of the second power P2 and the third power P3 or switching the current to a different current Ihf2. Means for holding a light emission output level Vm2 monitored by the light output detection means during light emission by P2; means for holding light emission output level Vm1 monitored by the light output detection means during light emission by the first power P1; Control means for controlling the current supply means so that the light emission output level Vm1 and the light emission output level Vm2 held by the respective means become desired values; and a high frequency superimposed during light emission by the first power P1 during recording. , The second power P2 and the third power P3 emit light at the first power P1. A first light emitting period in which the high frequency is superimposed at the level of the first power P1 before recording, and a high frequency is superimposed at the level of the first power P1 before recording. A second light emission period which is a light emission period in which no superimposition is performed or a light emission period at the level of the first power P1 in which an amount of high frequency superimposed at the time of outputting the second power P2 and the third power P3 during recording is superimposed. To maintain the difference I in the drive current of the light source between the first light emission period and the second light emission period, and to correct the drive current of the second power P2 during the light emission by the second power P2. Efficiency η = (P2−P1) /
(I2−I difference), an optical disk having means for obtaining and determining drive current I3 = (P3−P2) / correction efficiency for emission of the third power P3 and providing the current to the current supply means Provide equipment.

Further, a light source such as a laser diode, a current supply means for the light source, a light output detecting means for monitoring a light emission output level of the light source, and a first power P1 and a first power P1 by the light source during a recording operation. An optical disk device for recording data on an optical disk by emitting light at a second power P2 higher than the first power P2 and emitting light at a third power P3 higher than the second power P2, wherein the current supply means emits light at the first power P1 Minute current I1, the second power P2, and the first power
The current I2 of the difference between the power P1 and the third power P3
Means for adding and outputting the current I3 of the difference between the second power P2 and the second power P2; means for superimposing the high-frequency current Ihf on the current I1 at the time of the first power P1; Means for turning off the superposition of the high-frequency current Ihf at the third power P3 or switching the current to a different current Ihf2.
Means for holding the light emission output level Vm3 monitored by the light output detection means at the time of light emission by No. 3, means for holding the light emission output level Vm1 monitored by the light output detection means at the time of light emission by the first power P1, Control means for controlling the current supply means so that the light emission output level Vm1 and the light emission output level Vm3 held by the respective means become desired values; and a high frequency superimposed during light emission by the first power P1 during recording. , The second power P2 and the third power P3
In a first light emitting period in which a high frequency is superimposed at a level of the first power P1 before recording, a different amount from the high frequency to be superimposed at the time of light emission by the first power P1 is superimposed, or no high frequency is superimposed. The first power P1
Or a light emission period at the level of the first power P1 in which an amount of high frequency is superimposed at the time of output of the second power P2 and the third power P3 during recording. Providing a certain second light emitting period, and holding a drive current difference I difference that is a proportional value proportional to the drive current difference of the light source or the drive current I difference between the first light emitting period and the second light emitting period; At the time of light emission by the third power P3, the correction efficiency η of the driving current of the third power P3 = (P3-P1) / (I2 + I3-I
Difference), and the driving current I2 for emitting light of the second power P2 = (P2-P1) / correction efficiency + I and the driving current I3 = (P3) for emitting light of the third power P3.
-P2) / correction efficiency is determined, and the optical disk device may be provided with a means for providing the current supply means.

Further, in order to achieve the third object,
In the optical disk device as described above, the first power P is set before recording for maintaining the drive current difference I.
A first light emitting period in which a high frequency is superimposed at the level of 1 and a light emitting period in which no high frequency is superimposed at the level of the first power P1 or an amount of the high frequency to be superimposed when the second power P2 is output during recording are superimposed. An optical disk device is provided in which the second light emission period, which is the light emission period at the first power P1, is performed in a state where the focus is turned on by a focus servo system.

Further, in order to achieve the fourth object, in the above-mentioned optical disk apparatus, the light emitting period in which no high frequency is superimposed at the level of the first power P1 or the second power P2 during recording is used. In the second light emitting period, which is the light emitting period at the first power P1 in which the amount of the high frequency to be superimposed at the time of output is superimposed, when the focus servo system cannot keep the focus on and enters the focus off state, There is provided an optical disk apparatus in which the focus servo system is again turned on to obtain the drive current difference I.

In order to achieve the fifth object,
In the optical disk device as described above, a third light emitting period in which a high frequency is superimposed at the level of the first power P1 during a focus-off state, and a light emitting period or recording in which no high frequency is superimposed at the level of the first power P1. And a fourth light emitting period which is a light emitting period at the level of the first power P1 in which an amount of high frequency superimposed when the second power P2 is output is provided, and the third light emitting period and the fourth light emitting period are provided. The drive current difference FoI difference between the light source and the light emission period is held, and the focus on state cannot be maintained by the focus servo system during the light emission period in which the drive current difference I difference is obtained in the focus on state. If the driving current difference I is not obtained or the driving current difference I is not obtained by acquiring the driving current difference again, the driving The current difference I-difference driving current difference FoI
Provided is an optical disk device that determines a value obtained by multiplying the difference by a certain value.

Furthermore, in order to achieve the sixth object, in the above-described optical disk apparatus, when the light emission power during reproduction is different from the first power P1 during recording, the drive before recording is performed. Provided is an optical disk apparatus wherein the drive current difference I is obtained after the power is changed from the emission power at the time of reproduction to the first power P1 at the time of recording when the current difference I is obtained.

Furthermore, in order to achieve the seventh object, in the above-mentioned optical disk apparatus, at the time of recording,
An optical disc in which a period during which no high frequency is superimposed at the time of emission of the first power P1 or a period during which superimposed amounts of high frequency are superimposed at the time of the second power P2 and the third power P3 are provided at the time of recording. Provide equipment.

[0023]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an optical disk device according to an embodiment of the present invention. This optical disk device is a CD-R which is a disk compliant with the CD format which can be written only once.
(CD-Recordable) A CD-R drive for recording and reproducing data on and from a disc. CD
(Compact Disc), CD-ROM, CD-
In an optical disc 1 such as an R, a data sequence is expressed by the presence or absence of a hole called a pit on an optical disc substrate, and a laser beam is applied to this to read data by a change in reflected light. This data string is spirally arranged on the optical disk substrate like a record, and the spirally arranged line is called a track. The distance between adjacent tracks is 1.6 microns.

The optical disk 1 is driven to rotate by a spindle motor 2. The spindle motor 2 is a motor driver (Mot
or Driver 3 and the servo unit (Servo) 4 are controlled so as to have a constant speed. The optical pickup (Pick Up) 5 moves a lens position in a direction perpendicular to the optical disk so that a laser light source of a known technology (not shown), an optical system such as a lens, and a laser beam are focused on the optical disk. It has a built-in focus actuator as a mechanism, a track actuator as a mechanism for moving a lens in the radial direction (sledge direction) of an optical disk such that the focal point of a laser beam traces a track, a light receiving element, a position sensor, and the like. Is irradiated on the optical disc 1.

The entire optical pickup 5 can be moved in the sledge direction by a seek motor (not shown). These focus actuator, track actuator, and seek motor are controlled by a motor driver 3 and a servo unit 4 based on signals obtained from a light receiving element and a position sensor so that a laser spot is located at a target location. In the case of data reading, a reproduced signal obtained by the optical pickup 5 is read by a read amplifier (R
After being amplified by an E.Amp (head Amp) 6 and equalized or binarized (digitized), a CD decoder (CD De)
and EFM demodulation.

EFM is Eight to Fourte
en Modulation, which is an optical disk 1
Describes data obtained by modulating 8-bit data into 14-bit data so as to facilitate optical reproduction or recording. The EFM-demodulated data undergoes deinterleaving (rearrangement) and error correction processing. Thereafter, this data is stored in the buffer manager (Buffer Manager).
er) 8 once to buffer RAM (Buffer
RAM) 9 and at the stage when it is prepared as sector data, an interface (I / I /
F) The data is sent to the host computer at a stretch via 10. In the case of music data, data output from the CD decoder 7 is input to the D / A converter 11, and an analog audio signal is extracted.

When writing data, the data sent from the host computer through the I / F 10 is temporarily stored in the buffer RAM 9 by the buffer manager 8. Writing is started when a certain amount of data is stored in the buffer RAM 9, but before that, the laser spot must be positioned at the writing start point. This point is obtained by a wobble signal which has been engraved on the optical disc 1 in advance by meandering of the track. The wobble signal contains absolute time information called ATIP,
The ATIP decoder 12 can take out the information.
The synchronization signal generated by the ATIP decoder 12 is a CD.
The data is input to the encoder 13 and enables writing of data at an accurate position.

The data in the buffer RAM 9 is a CD-RO
After the error correction code is disabled or interleaved (rearranged) is performed by the M encoder 14 or the CD encoder 13, the EFM modulation is performed, and the laser controller circuit (Laser
Controller 15 and the optical pickup 5 to record the data on the optical disc 1. ROM 16 is a CPU
Reference numeral 18 denotes a read-only memory for storing a program for controlling recording and reproduction of data in the optical disk device. The RAM 17 is a readable / writable memory that is a work area when the CPU 18 controls recording and reproduction of data in the optical disk device. CPU
Reference numeral 18 controls recording and reproduction of data in the optical disk device. The laser controller circuit 15 of such an optical disk device has the features according to the present invention.

(1) Embodiment of the First Embodiment of the Invention FIG. 2 is a diagram for monitoring the internal configuration of the laser controller circuit 15 shown in FIG. 1, the LD mounted on the optical pickup 5, and the emission power of the LD. PD (Photo
o Detector). FIG. 3 is a diagram showing a change in the output current with respect to the amount of incident light of the PD 21 shown in FIG. Part of the laser light emitted from the LD 20 is incident on a PD 21 which is a power monitor. Here, the PD 21 outputs a current proportional to the amount of incident laser light, as shown in FIG.

When recording on a CD-R, the LD 20 repeatedly emits a first power P1 and a second power 02 higher than the first power P1. First power P
The output time of the first and second powers P2 is recorded by EFM.
It is based on the signal. In other words, the emission time is a length obtained by multiplying T by an integer multiple of 3 to 11, where T is a certain unit. Actually, the time length that is an integral multiple of 3 to 11 is slightly shortened or slightly lengthened in order to improve the recording quality, but the description is omitted because it is not related to the gist of the present invention. The first power P1 is generally a reproduction power Pr for reading data (information) from the optical disc 1, and the second power P2 is to apply sufficient heat to an organic dye which is a recording film of the optical disc 1 1 is the recording power Pw for forming a good pit.

FIG. 4 is a waveform diagram showing a light emission waveform emitted from the LD 20 shown in FIG. In the figure, the waveform before the time t write start is a light emission waveform when data is read from the optical disk 1, and the waveform after the time t write start is a light emission waveform when data is written to the optical disk 1. When reading data, LD20
From 1 mW or less (more specifically, 0.4 mW
) Is output with a constant light amount. on the other hand,
At the time of recording, light emission of the reproduction power Pr and the recording power Pw is repeated. The recording power Pw is generally several mW to several tens m.
W (more specifically, a power with good recording characteristics is selected by actually performing test writing between 5 mW and 40 mW). The recording power Pw is the same as that of the reproduction power Pr.
It is controlled and a constant light quantity is maintained. That is, the recording power Pw corresponds to the first power P1, and the reproduction power Pr corresponds to the second power P2.

Next, the APC control will be described with reference to FIG. First, the laser light incident on the PD 21 is output in the form of a current proportional to the amount of light by photoelectric conversion. That is, the laser beam emitted from the LD 20 is
In the case of the light emission waveform as shown in FIG. 4, a waveform in which the vertical axis of FIG. Next, the current is converted into a voltage by an I / V converter (I / V conversion circuit) 22. The output voltage corresponding to the reproduction power is represented by V
(Pr) and V (Pw) corresponding to the recording power. That is, this V (Pr) is the light emission output level V
m1 and V (Pw) correspond to the light emission output level Vm2, respectively. This output is a signal having only the V (Pr) level during reproduction, but is V (Pr) and V (Pw) during recording.
V (Pr) and V (P) by the S / H circuit R (may be a bottom hold circuit) 23 and the S / H circuit W (may be a peak hold circuit) 24
w).

The sample signal R is a signal for turning on (ON) the switch SW in the S / H circuit R23 at the time of reproduction, and during recording or during a period when the reproduction power level at the time of recording is emitted. The switch SW in the S / H circuit R23 is turned on only during a slightly shorter period, and the switch SW in the S / H circuit R23 is turned off (OFF) during the period in which the recording power level is being emitted. The voltage V (P
r) is a signal that is controlled to extract only.

On the other hand, the sample signal W is always S
/ H signal for turning off the switch SW in the H / W circuit W24. During recording, the switch in the S / H circuit W24 is used only during a period during which the recording power level at the time of recording is emitted or slightly shorter than that. The switch SW in the S / H circuit W24 is turned off (OFF) while the reproduction power level at the time of recording is being emitted, and the recording power level is set by the capacitor C in the S / H circuit W24. Is a signal that is controlled to take out only the voltage V (Pw) corresponding to. Each V (Pr) and V (Pw) separated by this sample hold is A /
The data is converted into a data form by the D converter R25 and the A / D converter W26, and is supplied to the CPU 18 as an input. The respective data are AD (Pr) and AD (Pw).

The CPU 18 controls AD (Pr) and AD (Pr).
The data output to the D / A converter R27 and the D / A converter W28 are varied so that w) becomes a desired value (a reference value R and a reference value W), respectively. Each of the data is transferred to DA (P
r) and DA (Pw). D / A converter R27 and D /
Each output of the A converter W28 is connected to a V / I converter R29.
Then, the current is converted into a current by the V / I converter W30 and the current is amplified and input to the current adder 31. The current added by the current adder 31 flows to the LD 20, and the LD 20 emits a laser beam. Since the emitted light enters the PD 21, a feedback loop is formed around the error amplifier. With the feedback loop configured as described above, the constant power determined by the reference value is set to the LD20.
From the light source.

Actually, the relationship between the reference value and the output power is determined in the manufacturing process of the optical disk device or the like.
Alternatively, adjustment is made so as to have a relationship between the determined reference value and the output power. Controlling the power emitted from the LD 20 to be constant is referred to as APC (Auto Pow).
er Control). When it is desired to vary the power emitted from the LD 20, it can be realized by varying this reference value. The switch SW inserted into the output of the V / I converter R29 is turned on when emitting laser light from the LD 20, and the switch SW inserted into the output of the V / I converter W30 is used for recording. Is controlled by a write pulse signal that is turned on only during the period of the recording power level. The control signals of the switches SW, that is, the sample signal R, the sample signal W, and the write pulse signal are signals output by the CD encoder 13 shown in FIG.

The steady light emitting state has been described above. Next, the case where the reproducing power level is emitted from the state where the laser beam is not emitted from the LD 20 and the case where the recording is performed from the state where only the reproducing power level is emitted are described. The case where the emission waveform at the time is emitted will be described. FIG.
FIG. 8 is a waveform chart showing a change in Vr output from FIG. FIG.
5 is a waveform diagram showing a change in Vw output from the CPU 18. FIG. First, as shown in FIG. 5, V (Pr) = 0 when no laser light is emitted from the LD 20. Next, when light emission is started by the reproduction power, the switch SW is turned on by the LD on signal of the LD driver unit with DA (Pr) from the CPU 18 set to 0 at the start of reproduction light emission. Of course, since V (Pr) = 0, the CPU 18 determines that AD (Pr) is smaller than the reference value R.
r) is gradually increased until AD (Pr) becomes equal to the reference value R (VrefR).
D (Pr) is maintained at the reference value R.

Similarly, as shown in FIG. 6, when the emission waveform at the time of recording is emitted from the emission state of only the reproduction power level, the switch of the sample hold circuit is turned on.
Although there are repetition of ON / OFF and repetition of ON / OFF by the write pulse signal of the LD driver unit, similarly,
(Pw) increases from 0 to an increase in DA (Pw), and eventually AD (Pw) becomes equal to the reference value W (VrefW).
Control to maintain. In FIG. 2, the output of the high frequency superimposing circuit 32 for superimposing a high frequency at the time of reproduction power is indicated by LD2.
It is configured to be superimposed on 0.

The switch SW provided at the output of the high frequency superimposing circuit 32 is turned off at the time of recording power and turned on at the time of reproducing power in conjunction with a write pulse signal. Although the high frequency superimposition is turned off by the write pulse signal, when the superposition of the high frequency is not turned off at the time of the write pulse and the amount of superimposition is varied, the output of the high frequency superimposition circuit 32 is changed by the write pulse signal to the resistance. It is necessary to attenuate by pressure or the like, or to prepare two high-frequency superposition circuits and switch between them, or to switch the current gain of the output of the oscillator inside the high-frequency superposition circuit (not shown).

Here, as described above, high-frequency superimposition is turned on.
With / OFF, the relationship between (drive current) and (emission power) of the LD 20 changes as shown in FIG. Therefore, by providing a mechanism for turning off the output of the high-frequency superimposing circuit 32 shown in FIG. 2 during the read period shown in FIG. 4 and performing APC, DA (PrON) when the high-frequency superimposition is ON and when the high-frequency superimposition is OFF are performed. Of DA (PrOFF) and obtain the difference DA
(Pr difference) = DA (PrOFF) -DA (PrON) is obtained in advance. Next, light emission is started, APC control is performed, and the current efficiency of the write power is obtained from DA (Pw). At this time, the correction efficiency η = (Pw−Pr) / (DA (P
w) −DA (Pr difference) × α), and is stored in a memory (not shown) in the CPU 18 of FIG. The above α is calculated as DA (P) when the current gain is different between the reproduction power control side and the recording power side in FIG.
r difference) is a coefficient for converting the current gain on the recording power side.

The D / A converter is officially a Digit
al to Analog converter, digital value,
For example, it is a circuit that converts 10000000 (80 hex in hexadecimal) into an analog value (for example, 2.0 [V]). An LD (Laser Diode) 20 is an element driven by current, and is an element that emits 1 mW with a length of 40 mA, for example. Therefore, in FIG. 2, V / A converters R27 and W /
I converter (voltage to current converter) R29 and V / I converter W
30 are provided. Here, the number of volts input and the amount of mA output in a V / I converter generally used for driving a laser beam generally means that the sensitivity differs between the drive for reproducing power and the drive for recording power. It is a target. This is because the driving power of the reproducing power is smaller than that of the recording power.

For example, for reproduction power, 40 m at 2 V input
A, for recording power, 80 mA at 2 V input. That is, the same digital value (DA (**) above), for example, 80
The current that can be driven by hex is 40 mA and 80 mA, and the sensitivity to digital values is different. For example, the reproduction power 20
When mA is passed as part of the current on the recording power side, a digital value of 20 hex of the recording power is sufficient for a digital value of 40 hex of the reproducing power. When converting to a digital value, it is necessary to multiply the sensitivity difference. This is set as the coefficient α. In the above example, the sensitivity is twice as high with the write power, so that the coefficient α becomes １ ／. That is, since the units of DA (Pw) and DA (Pr) are different, they are adjusted by this coefficient α.

Next, at the time of trial writing or ZoneCLV
When the recording power is changed in recording or the like, the correction efficiency η is used. For example, when (Pw-Pr) is doubled, D
A (Pw 2 times) is DA (Pw 2 times) = 2 × (Pw−P
r) / correction efficiency + DA (Pr difference) × α. With the above configuration, even when the recording power is variable, light emission can be performed with almost the same power as the power finally set by the APC. Therefore, even when the recording time with one power is short during test writing, the APC control can be followed. In addition, ZoneCLV
When the recording power is switched, the recording can be started with the desired power even after the switching, so that the recording quality at the switching point can be maintained.

In this manner, the efficiency of the drive current of the recording power can be accurately obtained. When recording is performed with the write power varied, when the next power is changed, the power finally becomes almost controlled. Since light emission can be started from a near power value, even when one power recording time of test writing is short, such as during high-speed recording, the final control power is reached, so that test writing can be performed correctly and recording quality can be maintained. .

(2) Embodiment of the Second Embodiment of the Invention FIG. 7 is a diagram for monitoring the internal configuration of the laser controller circuit 15 shown in FIG. 1, the LD mounted on the optical pickup 5, and the emission power of the LD. FIG. 13 is a block diagram showing another example of the configuration of the PD which is the element of FIG. In the circuit configuration shown in the figure, a circuit for adding and outputting a peak power current to the circuit shown in FIG. 2 is added. Here, the peak power will be described. FIG. 8 is an explanatory diagram of light emission actually emitted from a laser light source when data is recorded on an optical disc in a CD-R drive. This way of emitting light is CD
It is shown in the Orange Book which is a standard of -R.

As shown in FIG. 8, a light emission period with a peak power higher than the write power is provided at the leading edge of the recording power, and the starting portion is slightly raised so that the heat of the dye is sharply increased with particularly strong power. In the circuit of FIG. 7, a D / A converter P33, a V / I converter P34, and a switch SW are provided in the above-described circuit, and the peak power does not take out V (Pp) by the S / H circuit. / A converter P3
3 and the V / I converter P34 perform a control to obtain DA (Pp) by calculating DA (Pw). Then, the correction efficiency η is obtained in the same manner as described above, DA (Pp) = (Pp−Pw) / correction efficiency η is calculated using the correction efficiency η, and the data is output to the D / A converter P33.

As described above, the efficiency of the drive current of the second power is corrected by the difference in the drive power for the reproduction power due to the difference in the amount of high-frequency superimposition between the first power and the second power. , I2 determined by controlling the second power
I3 is more accurately determined, and therefore, even in a system in which ternary power is easily controlled by binary samples, a desired ratio between P2 and P3 can be obtained, and a decrease in recording quality can be prevented.

(3) Embodiment of the Third Embodiment of the Invention FIG. 9 is a diagram for monitoring the internal configuration of the laser controller circuit 15 shown in FIG. 1, the LD mounted on the optical pickup 5, and the emission power of the LD. FIG. 10 is a block diagram showing still another example of the configuration of the PD which is the element of FIG. In the circuit configuration shown in the figure, the S / H circuit W24 and the A / D converter W26 of the circuit shown in FIG. 2 are changed to a peak hold circuit P35 for peak power detection and an A / D converter P36, respectively. I have. As described above, the peak hold circuit P3
5 is stored in the data A by the A / D converter P36.
It is converted to D (Pp) and can be processed by the CPU 18.
The CPU 18 obtains and holds DA (Pr difference) in the same manner as described above.

Since only the driving current when the high frequency superimposition is ON flows through DA (Pr), an extra DA (Pr difference) between the high frequency OFF and the high frequency ON is applied to DA (Pw). Therefore, DA (Pw) to DA (Pw)
It is preferable that DA (Pp) is equal to the value obtained by subtracting (r difference). That is, DA (Pp) = DA (Pw) using DA (Pp), DA (Pw) and DA (Pr difference).
APC is performed while maintaining a state of −DA (Pr difference),
Correction efficiency η = (Pp−Pr) / (DA (Pp) + DA
(Pw) -DA (Pr difference)), and DA (Pp)
= (Pp−Pw) / correction efficiency η, DA (Pw) = (Pw
−Pr) / correction efficiency + DA (Pr difference).

In this way, the efficiency of the driving current of the third power is corrected by the difference between the reproduction power driving currents due to the difference in the amount of high frequency superimposition between the first power and the second and third powers. Therefore, the currents I3 and I2 can be correctly obtained from the current value determined by the control of the third power. Therefore, even in a system in which the ternary power is controlled by the binary sample, the desired second value is obtained. The ratio between the power P2 and the third power P3 is obtained, so that a decrease in recording quality can be prevented.

(4) Embodiment of the Present Invention According to Claim 4 FIG. 10 is a flowchart showing processing according to claim 4 of the present invention. This processing is determined by determining the drive current difference I, and can be implemented in the circuits shown in FIGS. 2, 7, and 9 described above. In step (indicated by "S" in the figure) 1, 0 is first set in the D / A converter to set DA (Pr) to 0, and in step 2
The D ON signal is turned on, and in step 3, DA (Pr) is increased so that desired reproduction power is obtained, and AD (Pr) is increased.
Is incremented until the value reaches the reference value R. In step 4, focus pull-in is performed, and in step 5, AD (P
After r) reaches the reference value R, DA (Pr) is increased or decreased so as to maintain this relationship, and APC of the reproduction power is continued. Next, after turning on the focus servo (ON), A
DA (Pr) maintained by the PC is converted to DA (PrO
N).

In step 6, the output of the high frequency superposition is turned off (O
FF), and in step 7, DA (Pr) maintained by the reproduction power APC is held as DA (PrOFF). In step 8, DA (PrON) and DA (Pr
OFF), and the DA (Pr difference) is used when calculating the correction efficiency during recording power emission. In step 9, the output of the high frequency superposition is turned on (ON), and the process proceeds to the next step. In this way, a difference occurs in the drive current difference I due to the difference between the presence or absence of the optical disk and the difference in the reflectance of the optical disk. However, since the drive current difference I is determined in the focus ON state before recording, the difference is obtained. The driving current difference I can be accurately obtained, and thus the correction efficiency η can be correctly obtained.
In the optical disk device provided with the circuit described in (1), it is possible to maintain good recording quality.

(5) Embodiment of Claim 5 of the Present Invention FIG. 11 is a flowchart showing processing according to claim 5 of the present invention. In this process, the high frequency superimposition is OFF.
A subsequent out-of-focus determination process is added, and when out-of-focus is detected, the process is performed again from focus retraction. In step (indicated by “S” in the figure) 11, 0 is first set in the D / A converter to set DA (Pr) to 0, and in step 12
To turn on the LD ON signal, and in step 13, increase DA (Pr) so that the desired reproduction power is obtained, and
It is incremented until (Pr) reaches the reference value R.
At step 14, focus pull-in is performed.
After AD (Pr) reaches the reference value R in step 5, DA (Pr) is increased or decreased so as to maintain this relationship, and the reproduction power A
Continue PC. Next, after the focus servo is turned on (ON), DA (Pr) maintained by the APC is changed to D (Pr).
A (PrON) is held.

In step 16, the output of the high frequency superposition is turned off (OFF). In step 17, it is determined whether or not the focus is out of focus. If the focus is out of focus, the process returns to step 14 and the above processing is repeated. DA maintained by the playback power APC
(Pr) is held as DA (PrOFF). At step 19, the difference D between DA (PrON) and DA (PrOFF)
A (Pr difference) is held, and the DA (Pr difference) is used when calculating the correction efficiency when the recording power is emitted. In step 20, the output of the high frequency superposition is turned on (ON), and the process proceeds to the next step. In this way, when the drive current difference I is obtained, if the focus servo is deviated, the drive current difference I may not be obtained, but the retry is performed as described above. , The drive current difference I can be obtained, and the above-described correction efficiency can be obtained correctly. In the optical disc apparatus provided with the circuits shown in FIGS. 2, 7, and 9, the recording quality is maintained well. It becomes possible.

(6) Embodiment of the Present Invention According to Claim 6 FIG. 12 is a flowchart showing processing according to claim 6 of the present invention. In this processing, DA (Pr) of high frequency superimposition ON and OFF is acquired before focusing is performed, and DA (Pr difference OFF) is calculated. Also, if the out-of-focus state is detected when the high-frequency superimposition is turned off after the focus is pulled, DA (Pr difference) becomes DA (Pr difference OF).
F) is held as a constant multiplied, and high-frequency superimposition ON
And return to the following routine.
At step (indicated by "S" in the figure) 31, the D / A converter is first set to 0 to set DA (Pr) to 0, the LD ON signal is turned on at step 32, and the LD ON signal is turned on at step 33. DA (Pr) is increased so as to have a desired reproduction power, and is incremented until AD (Pr) reaches the reference value R.

After AD (Pr) reaches the reference value R in step 34, DA (Pr) is increased or decreased so as to maintain this relationship, and APC of the reproduction power is continued. Next, after the focus servo is turned on (ON), DA (Pr) maintained by APC is held as DA (PrON). In step 35, the output of the high frequency superposition is turned off (OFF).
AD (Pr) = reference value R at step 36
A (Pr) is held as DA (PrOFF). In step 37, the difference DA (Pr difference OFF) between DA (PrOFF) and DA (PrON) is held, the output of high-frequency superposition is turned on (ON) in step 38, focus is pulled in step 39, and AD is pulled in step 40. DA (Pr) satisfying (Pr) = reference value R is held as DA (PrON).

At step 41, the output of the high frequency superposition is turned off (OFF). At step 42, it is determined whether or not the focus is out of focus.
A (Pr difference OFF) × α is held, and the DA (Pr difference) is used when calculating the correction efficiency at the time of recording power emission. If the focus is not out of focus in step 42, DA (Pr) maintained by the reproduction power APC is held as DA (PrOFF) in step 43. D in step 44
A (PrOFF) and DA (PrON) difference DA (Pr
Difference), and the DA (Pr difference) is used when calculating the correction efficiency at the time of recording power emission. In step 45, the output of the high frequency superposition is turned on (ON), and the process proceeds to the next step.

In the above-described processing, the process goes to step 46 when the focus is lost once. However, DA (Pr) when the high-frequency superposition is OFF in a plurality of focus ON states is performed.
May be retried in order to obtain In this way, in the case of a continuous disturbance or a bad optical disk in the above-mentioned optical disk device, the drive current difference I
There is a possibility that the difference may not be obtained. Even when the driving current difference I is not obtained in the focus state, the driving current difference FoI having a value different from the driving current difference I is determined in advance by an experiment or the like. It is possible to easily obtain the drive current difference I by multiplying the obtained relationship between the drive current difference FoI and the drive current difference I by a fixed factor, and obtain the pseudo correct correction efficiency to maintain the recording quality.

(7) Embodiment of Claim 7 of the Present Invention FIG. 13 is a flowchart showing processing according to claim 7 of the present invention. This process can be performed in the circuits shown in FIGS. 2, 7, and 9. In this processing, after the focus is pulled in, the reproduction power A at the time of recording is
D is set to a value that maintains AD (Pr) by PC.
A (Pr) is controlled to change the reproduction power to the reproduction power for recording. DA maintained by this APC
(Pr) is held as DA (PrON). Next, the high frequency superimposition is turned off with the same reproduction power, and the reproduction power A
DA (Pr) maintained by the PC is converted to DA (Pr
OFF). This DA (PrON) and DA
(PrOFF) difference DA (Pr difference) is held, and the DA (Pr difference) is calculated when calculating the correction efficiency at the time of recording power emission.
Is used.

At step (indicated by "S" in the figure) 51, the D / A converter is first set to 0 to set DA (Pr) to 0, and at step 52 the LD ON signal is turned on. In step 53, DA
(Pr) is increased and incremented until AD (Pr) reaches the reference value R. At step 54, the focus is pulled, and at step 55, AD (Pr) is set to the reference value R.
After that, DA (Pr) is increased or decreased so as to maintain this relationship, and APC of the reproduction power is continued. Next, after the focus servo is turned on (ON), DA (Pr) maintained by APC is held as DA (PrON).

At step 56, the output of the high frequency superposition is turned off (OFF). At step 57, DA (Pr) maintained by the reproduction power APC is changed to DA (PrOFF).
Hold as. In step 58, the difference DA (Pr difference) between DA (PrOFF) and DA (PrON) is held, and the DA (Pr difference) is used when calculating the correction efficiency during recording power emission. In step 59, output of high frequency superposition is turned on (ON)
In step 60, AD (Pr) is increased to
DA (Pr) is adjusted until (Pr) becomes the reference value R,
Proceed to the next step. In this manner, by determining the drive current value difference I before and after recording by superimposing / not superimposing a high frequency with the reproducing power at the time of recording (a different amount even when superimposed), the correction efficiency is correctly obtained, and thus the above-described optical disk apparatus Thus, even when the light emission power during reproduction is different from the reproduction power during recording, good recording quality can be maintained.

(8) Embodiment of Claim 8 of the Present Invention FIG. 14 is a flowchart showing processing according to claim 8 of the present invention. This process can be performed in the circuits shown in FIGS. 2, 7, and 9. In this process, the drive current value difference I is updated during recording. During normal recording, high frequency is superimposed to reduce laser noise to detect signals at the playback power level, etc.
The reproduction power is APC. Step 7 in this state
1, DA (Pr) currently controlled by DA (PrON
Record), the high-frequency superposition is turned off (OFF) in step 72, DA (Pr) obtained by the reproduction power APC is stored as DA (PrOFF record) in step 73, and DA (Pr difference) = DA in step 74. (PrO
FF recording)-DA (PrON recording)
(Pr difference) is updated. Then, in step 75, the high frequency superimposition is turned on (ON), the state is returned to the state where the high frequency is superimposed at the time of the reproduction power, and the normal recording state is returned.

By performing the processing of this routine periodically, it is possible to obtain the correct correction efficiency by updating the drive current value difference I due to the temperature rise at the time of recording. In the above processing, high-frequency superimposition ON at reproduction power and high-frequency superposition OFF at recording power have been described. However, even when high-frequency superimposition at recording power is ON, a smaller amount of superposition than at reproduction power is superposed. can do. In this manner, in the above-described optical disc device, the relationship between (drive current) and (emission power) that changes due to self-heating during recording of laser light corresponds to, for example, the drive current value difference I during regular recording. By reacquiring again, more accurate correction efficiency can be obtained, and therefore, the recording quality can be maintained with higher accuracy.

[0064]

As described above, according to the optical disc apparatus of the first aspect of the present invention, the recording quality is degraded due to the difference between the set power and the actual light emission power during test recording when the recording speed is high. Can be prevented. Further, according to the optical disk device of claim 2 or 3 of the present invention,
Good recording quality can be obtained even in a system in which ternary power is easily controlled by sampled values. Further, according to the optical disk device of the fourth aspect of the present invention, the drive current difference I can be obtained more accurately.

According to the optical disk apparatus of the fifth aspect of the present invention, even when the focus state cannot be maintained, the drive current difference I can be obtained by rescuing by retrying. Further, according to the optical disk device of the sixth aspect of the present invention, even when the I difference is not obtained in the focus state, the correct correction efficiency can be obtained in a pseudo manner. Further, according to the optical disk device of the present invention, even when the light emission power at the time of reproduction is different from the reproduction power at the time of recording, the correction efficiency can be correctly obtained. Further, according to the optical disk device of the present invention, the correction efficiency can be obtained with high accuracy.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing an internal configuration of a laser controller circuit 15 shown in FIG.

FIG. 3 is a diagram showing a change in an output current with respect to an incident light amount of the PD 21 shown in FIG. 2;

FIG. 4 is a waveform diagram showing a light emission waveform emitted from the LD 20 shown in FIG.

FIG. 5 is a waveform chart showing a change in Vr output from CPU 18 shown in FIG.

FIG. 6 is a waveform chart showing a change in Vw output from CPU 18 shown in FIG.

FIG. 7 is a block diagram showing another example of the internal configuration of the laser controller circuit 15 shown in FIG. 1, the LD mounted on the optical pickup 5, and the configuration of a PD which is an element for monitoring the emission power of the LD. FIG.

FIG. 8 is an explanatory diagram of light emission actually emitted from a laser light source when data is recorded on an optical disc in a CD-R drive.

FIG. 9 shows still another example of the internal configuration of the laser controller circuit 15 shown in FIG. 1, the LD mounted on the optical pickup 5, and the configuration of a PD which is an element for monitoring the output power of the LD. It is a block diagram.

FIG. 10 is a flowchart showing a process according to claim 4 of the present invention.

FIG. 11 is a flowchart showing a process according to claim 5 of the present invention.

FIG. 12 is a flowchart showing a process according to claim 6 of the present invention.

FIG. 13 is a flowchart showing a process according to claim 7 of the present invention.

FIG. 14 is a flowchart showing a process according to claim 8 of the present invention.

FIG. 15 is a diagram showing a relationship between a driving current of a laser diode and an emission power which is a light emission power.

FIG. 16 is a diagram showing the relationship between the drive current of the laser diode and the emission power, which is the light emission power.

[Explanation of symbols]

1: Optical disc 2: Spindle motor 3: Motor driver 4: Servo unit 5: Optical pickup 6: Read amplifier 7: CD decoder 8: Buffer manager 9: Buffer RAM 10: Interface (I /
F) 11: D / A converter 12: ATIP decoder 13: CD encoder 14: CD-ROM encoder 15: Laser controller circuit 16: ROM 17: RAM 18: CPU 20: LD 21: PD 22: I / V converter 23 : S / H circuit R 24: S / H circuit W 25: A / D converter R 26: A / D converter W 27: D / A converter R 28: D / A converter W 29: V / I Converter R 30: V / I converter W 31: Current adder 32: High-frequency superposition circuit 33: D / A converter P 34: V / I converter P 35: Peak hold circuit P 36: A / D converter P

Claims (8)

[Claims] 1. A light source such as a laser diode, a current supply unit for the light source, a light output detection unit for monitoring a light emission output level of the light source, and a first power P1 and a first power P1 by the light source during a recording operation. An optical disk device for recording data on an optical disk by alternately repeating light emission of a second power P2 higher than the second power P2, wherein the current supply means comprises: a current I1 corresponding to a light emission at the first power P1; Means for adding and outputting the power P2 of the first power P1 and the current I2 of the difference between the first power P1 and the high-frequency current Ihf at the time of the first power P1.
Means for superimposing the high-frequency current Ihf at the time of the second power P2,
2, a light emission output level Vm monitored by the light output detection means at the time of recording operation and at the time of light emission by the second power P2.
2, a means for holding a light emission output level Vm1 monitored by the light output detection means at the time of light emission with the first power P1, a light emission output level Vm1 and a light emission output level Vm2 held by the respective means. And control means for controlling the current supply means so as to obtain desired values, respectively. A high frequency is superimposed at the time of light emission by the first power P1 during recording, and a high frequency is not superimposed at the second power P2. Or the first power P1
A different amount from the high frequency to be superimposed at the time of light emission is superimposed, and a high frequency is not superimposed at the level of the first power P1 and a first light emission period in which the high frequency is superimposed at the level of the first power P1 before recording. The light emitting period or the second
The second period, which is a light emission period at the level of the first power P1 in which an amount of high frequency is superimposed when the power P1 is output.
A light emitting period is provided, and a driving current difference I of the light source between the first light emitting period and the second light emitting period is held, and the second power P2 is emitted during or after the light emission by the second power P2. Η = (P2-
P1) / (I2-I difference) is obtained, and the second power P2 is calculated.
, The initial current I of the second power P2 'after the change
2 '= (P2'-P1) /. Eta. + I. An optical disk device comprising means for obtaining and determining a difference. 2. A light source such as a laser diode, current supply means for the light source, light output detection means for monitoring a light emission output level of the light source, and a first power P1 by the light source during a recording operation. An optical disk device for recording data on an optical disk by emitting a second power P2 higher than the first power P2 and a third power P3 higher than the second power P2; The current I1 for light emission, the current I2 of the difference between the second power P2 and the first power P1, and the current I3 of the difference between the third power P3 and the second power P2 are added and output. Means for superimposing a high-frequency current Ihf on the current I1 at the time of the first power P1, and means for superposing the second power P2
Means for turning off the superposition of the high-frequency current Ihf at the time of the third power P3 or switching to a different current Ihf2. During the recording operation, the light emission monitored by the light output detection means at the time of light emission by the second power P2. Output level Vm
2, a means for holding a light emission output level Vm1 monitored by the light output detection means at the time of light emission with the first power P1, a light emission output level Vm1 and a light emission output level Vm2 held by the respective means. Control means for controlling the current supply means so as to obtain desired values, respectively; and a high frequency is superimposed at the time of light emission by the first power P1 during recording, and the second power P2 and the third power P
In No. 3, a different amount from the high frequency to be superimposed at the time of light emission by the first power P1 is superimposed or not superimposed, and a first light emission period in which the high frequency is superimposed at the level of the first power P1 before recording; The light emission period during which no high frequency is superimposed at the level of the first power P1 or the second period during recording.
And a second light emitting period which is a light emitting period at the level of the first power P1 in which an amount of high frequency superimposed upon output of the power P2 and the third power P3 is superimposed.
The driving current difference I of the light source between the light emitting period and the second light emitting period is held, and at the time of light emission with the second power P2, the correction efficiency η of the driving current of the second power P2 = (P2−P1 ) / (I2
−I difference), and a drive current I3 = (P3-P2) / correction efficiency for emitting the third power P3 is determined and provided to the current supply means. Optical disk device. 3. A light source such as a laser diode, current supply means for the light source, light output detection means for monitoring a light emission output level of the light source, and a first power P1 and a first power P1 generated by the light source during a recording operation. A second power P2 higher than the third power P3
An optical disc device for recording data on an optical disc by emitting light at a power P3, wherein the current supply means comprises a current I1 corresponding to an emission at the first power P1, the second power P2, and the first power P2. Means for adding and outputting the current I2 of the difference between the power P1 and the current I3 of the difference between the third power P3 and the second power P2; and outputting the high-frequency current Ihf at the time of the first power P1. Means for superimposing on I1 and said second power P2
Means for turning off the superposition of the high-frequency current Ihf at the third power P3 or switching the current to a different current Ihf2. During the recording operation, the light emission monitored by the light output detection means at the time of light emission at the third power P3. Output level Vm
3, a light output level Vm1 monitored by the light output detecting means at the time of light emission by the first power P1, a light output level Vm1 and a light output level Vm3 held by the respective means. Control means for controlling the current supply means so as to obtain desired values, respectively; and a high frequency is superimposed at the time of light emission by the first power P1 during recording, and the second power P2 and the third power P
In No. 3, the amount different from the high frequency to be superimposed at the time of light emission by the first power P1 is superimposed or the high frequency is not superimposed, and the first light emission period in which the high frequency is superimposed at the level of the first power P1 before recording , During the light emission period during which no high frequency is superimposed at the level of the first power P1 or during the second
And a second light emitting period which is a light emitting period at the level of the first power P1 in which an amount of high frequency superimposed upon output of the power P2 and the third power P3 is superimposed.
A driving current difference of the light source between the light emission period and the second light emission period or a drive current difference I difference that is a proportional value proportional to the drive current I difference is held, and the light emission by the third power P3 is performed. 3 power P3 drive current correction efficiency η = (P3-P1) / (I2
+ I3−I difference), and the drive current I2 for emitting the second power P2 = (P2−P1) / correction efficiency + I
Difference and the driving current I for emitting the third power P3.
3 = (P3−P2) / correction efficiency. 4. The optical disk device according to claim 1, wherein a high frequency is superimposed at a level of the first power P1 before recording for maintaining the drive current difference I. One light emission period and light emission at the first power P1 in which a high frequency is superimposed at the level of the first power P1 or in which no high frequency is superimposed at the output of the second power P2 during recording. An optical disc device, wherein a second light emitting period, which is a period, is performed in a state where focus is turned on by a focus servo system. 5. The optical disk device according to claim 4, wherein an amount of high-frequency waves is superimposed at the level of the first power P1 in an emission period in which no high-frequency waves are superimposed or in an amount of superimposition when outputting the second power P2 during recording. The first power P1
In the second light emission period, which is the light emission period in the above, when the focus servo system cannot maintain the focus on and the focus is turned off, the focus servo system sets the focus on again and the drive current difference I An optical disc device characterized by acquiring a difference. 6. The optical disk device according to claim 4, wherein a third light emitting period in which a high frequency is superimposed at a level of the first power P1 during a focus-off state, and a level of the first power P1. A light emitting period in which no high frequency is superimposed or a fourth light emitting period which is a light emitting period at the level of the first power P1 in which an amount of superimposed high frequency is superimposed when the second power P2 is output during recording; The drive current difference FoI difference of the light source between the third light emission period and the fourth light emission period is held, and the focus on state by the focus servo system is changed during the light emission period for acquiring the drive current difference I difference in the focus on state. If the driving current difference I cannot be obtained due to the focus-off state because the current cannot be maintained and the driving current difference I cannot be obtained, or the driving current difference I may be obtained again. If is not, the optical disc apparatus, characterized in that the drive current difference I difference and to determine the driving current difference FoI difference constant multiplied by the value. 7. The optical disk device according to claim 1, wherein when the light emission power at the time of reproduction is different from the first power P1 at the time of recording, the difference of the drive current I before recording is obtained. Is obtained from the emission power at the time of reproduction to the first power P1 at the time of recording.
An optical disk device characterized in that the drive current difference I is obtained after the power is changed. 8. The optical disk device according to claim 1, wherein at the time of recording, a period during which a high frequency is not superimposed upon emission of the first power P1, or the second power P2 is superimposed even when the high frequency is superimposed. An optical disc device, wherein a period of superimposing an amount of high frequency superimposed at the time of the third power P3 is provided at the time of recording.