JP3529092B2 - Information recording device and controller for information recording 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 information recording apparatus such as an optical disk apparatus for irradiating a disk with a light beam to form an information recording mark and a controller for the information recording apparatus.

[0002]

2. Description of the Related Art In an information recording apparatus such as an optical disk apparatus that forms an information recording mark by irradiating a disk with a light beam, it is necessary to accurately control the recording power emitted from a laser.

As a first conventional technique for correcting the recording power, the recording power of the laser is changed in several steps to perform trial writing, the area in which the trial writing is performed is reproduced, and the quality of the reproduced signal is reproduced. An optical disk device has been already proposed in which the power at the time of trial writing in the area in which the index showing the highest value is the optimum recording power is set (for example, Japanese Patent Laid-Open No. 5-109077).

In this optical disk device, the second harmonic component is used as an index indicating the quality of the reproduced signal, and the power when this is the minimum is the optimum power.

According to this optical disk apparatus, it is possible to set the optimum recording power according to the difference in recording sensitivity between disks and the difference in sensitivity due to ambient temperature.

As a second conventional technique, recording power is controlled by controlling the recording power based on the intensity of the return laser beam (reflected light) when pits are formed during the actual recording operation by the recording laser beam. A control method of a recording laser beam has been already proposed in which an optimum pit is always formed even if the optimum recording power changes due to variations in the sensitivity of the medium, inclination, and the like (for example, Japanese Patent Laid-Open No. 4-1).
No. 0237).

According to this control method of the recording laser beam, it is possible to compensate for the difference in recording sensitivity in the disc, the fluctuation in laser wavelength that occurs during the actual information recording operation, and the fluctuation in recording efficiency due to beam positioning error. .

[0008]

According to the above-mentioned first prior art, the recording power is set by changing the recording power of the laser in several steps and executing the trial writing. It is possible to set the optimum recording power according to the difference in sensitivity and the difference in sensitivity due to the ambient temperature.

However, the difference in the recording sensitivity in the disc,
There remains a problem that the fluctuation of the recording efficiency due to the laser wavelength fluctuation, the beam positioning error, etc. which occurs during the actual information recording operation cannot be compensated.

When the recording power at which the second harmonic is minimized in the trial writing is the upper limit of the changed recording power range, the actual optimum power is probably higher than the detected power. Imagine being there.

Therefore, if recording is performed in the upper limit state of the detected recording power range, a recording mark with insufficient power is generated and a reproduction error increases.

Even with this method, it is possible to obtain the optimum power by extrapolation, but in that case, there is a possibility that the power may exceed the rated value of the laser, and the laser may be destroyed.

On the other hand, in the second prior art, since the power of the state where the pits are formed during the actual recording operation is detected by the recording laser beam, the difference in the recording sensitivity in the disc and the actual information are recorded. It is possible to compensate for variations in recording efficiency due to variations in laser wavelength and beam positioning errors that occur during recording operations.

However, even in this second conventional technique,
As with the first prior art, the recording power requirement may exceed the laser rating.

Therefore, a general CD-R (CD
In an optical disk device such as a recordable device, a method for determining the optimum power by trial writing as in the first conventional technique and a method for correcting the power during the recording operation as in the second conventional technique are combined. I am trying to use it.

In order to avoid such a problem,
If the recording power is limited so that it can be set within the laser rating, there is a disadvantage that the original power requirement cannot be met and good recording mark formation cannot be performed.

Further, in both the first and second prior arts, the rotational speed of the disk during recording, that is, the linear velocity remains at a predetermined value and does not change.

However, if the optimum power determined by the trial writing is lower than the rated upper limit, in principle, the linear velocity can be further increased by using at the rated full power.
It should be possible to shorten the recording time.

To summarize the above, a device having the function of determining the optimum power by trial writing described in the first conventional technique, and a device having the function of correcting the power during recording described in the second conventional technique, Alternatively, an apparatus provided with a combination of both functions does not make full use of the original laser performance and is used in a state where the efficiency is reduced.

An object of the present invention is to solve the problems in the first and second prior arts. Specifically, firstly, due to the difference in the recording sensitivity of the disc and the difference in the ambient temperature. That is, even if the optimum recording power is different, a good recording mark can be formed.

A second problem is to prevent laser breakage even if the optimum recording power exceeds the laser rating due to the difference in recording sensitivity between disks and the difference in ambient temperature.

A third problem is to perform high-speed recording when there is a margin in recording power due to a difference in recording sensitivity of the disc and a difference in ambient temperature.

The fourth problem is that during actual recording of information, even if the recording efficiency fluctuates due to a difference in recording sensitivity in the disc, a laser wavelength fluctuation, a beam positioning error, etc., it is always good. That is, it is possible to form various recording marks.

The fifth problem is that, even during the actual recording of information, even if the recording efficiency fluctuates due to a difference in recording sensitivity in the disc, a laser wavelength fluctuation, a beam positioning error, etc. The power requirement is to not exceed the laser rating and prevent laser damage.

A sixth problem is to perform high-speed recording when the recording power has a margin during the actual recording of information.

[0026]

According to a first aspect of the invention, in an information recording apparatus for forming an information recording mark by irradiating a disk with a light beam, means for performing trial writing by changing the recording power of the light beam. And with the result of the trial writing
If the obtained optimum recording power is larger than a predetermined value, information
The recording power at the time of recording is set to the predetermined value, and the rotation speed of the disc at the time of trial writing, the optimum recording power and the predetermined
A rotation speed determining means for determining the rotation speed at the time of recording information is provided by calculation using the ratio with the value .

[0027]

[0028]

[0029] In the invention of claim 2, the information recording apparatus according to claim 1, Pwo the optimum recording power, ULIM the predetermined value, the rotational speed of the test writing at the disk f
o, where fo'is the number of revolutions of the disk at the time of recording information, the calculation is fo '= fo * (Ulim / Pwo) ² .

[0030]

According to a third aspect of the present invention, in the information recording apparatus according to the first or second aspect , the detecting means for detecting the rotational speed of the disk, the rotational speed detected by the detecting means and the rotational speed determining means are used. A comparison means for comparing the determined rotation numbers is provided, and the rotation of the disk is controlled based on the comparison result by the comparison means.

According to a fourth aspect of the present invention, in the information recording apparatus according to any one of the first to third aspects, the power control means for varying the recording power of the light beam within a predetermined range and the disk have a predetermined value. When rotating at the number of revolutions, the recording power is varied within the predetermined range to perform trial writing, and an optimum recording power determining unit that determines the optimum recording power based on the result is provided. Is when the optimum recording power is out of the predetermined range,
The rotation speed is set to be different from the predetermined rotation speed.

According to a fifth aspect of the present invention, in the information recording apparatus of the fourth aspect , the optimum recording power determining means sets the power of the light beam within the range when the optimum recording power is outside the predetermined range. I try to limit it.

[0034]

[0035]

[0036]

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the information recording apparatus of the present invention will be described in detail with reference to the drawings.

The first to second embodiments will be sequentially described below.

<First Embodiment> The first embodiment is characterized in that the recording power is varied to perform trial writing, and the rotation speed at the time of information recording is determined based on the result. There is.

As described above, the first reason for changing the recording power and performing the trial writing to determine the rotation speed is that the recording sensitivity of the disc and the ambient temperature are different. This is so that a good recording mark can be formed even if the optimum recording power is different.

The second reason is to prevent laser breakage even if the optimum recording power exceeds the laser rating due to the difference in recording sensitivity between disks and the difference in ambient temperature.

The third reason is that high-speed recording is performed when there is a margin in recording power due to a difference in recording sensitivity of the disc or a difference in ambient temperature.

First, the information recording apparatus of the present invention will be described.

FIG. 1 is a functional block diagram showing an example of an embodiment of the main configuration of the information recording apparatus of the present invention. In the figure, 1 is a disk, 2 is a rotation motor, 3 is an optical head, 4 is a reproduction signal detecting means, 5 is an upper and lower amplitude detecting means, 6 is a laser power control means, 7 is a rotation control means, and 8 is a controller, WData indicates write data.

In the information recording apparatus shown in FIG. 1, a vertical amplitude detecting means 5 is added and a controller 8 is provided.
The basic configuration is the same as that of the conventional device except that the control is performed according to the flow of FIG. Also in the second embodiment, the hardware configuration is the same, and the controller 8 controls according to the flow of FIG. 4 described later.

The configuration and operation of each unit will be briefly described.

The disk 1 is rotationally driven by the rotary motor 2.

The optical head 3 is composed of a laser light source, an optical system, etc., which are not shown, and can access any information track of the disk 1.

A recording mark is formed on the recording surface of the disk 1 by the heat of the laser beam emitted from the optical head 3.

The reflected light of the laser beam is also detected by the optical head 3, and the reproduced signal detecting means 4 converts the reflected light from the recording mark into an electric signal.

Normally, at the time of recording, a laser beam having a strong power is emitted to form a recording mark, and at the time of reproduction, reading is performed with a power weaker than that.

From the output of the reproduced signal detecting means 4, the upper and lower envelope levels of the reproduced signal are detected by the upper and lower amplitude detecting means 5.

The upper and lower envelope levels can be read by the controller 8.

The controller 8 is composed of a known microprocessor, A / D converter, D / A converter and the like.

The controller 8 also outputs a recording power command to the laser power control means 6.

The laser power control means 6 determines the recording data (write take WDat) based on this recording power command value.
The laser of the optical head 3 is caused to emit light with the recording power in synchronization with a).

More specifically, the laser power control means 6
Is a power detection means for detecting the laser emission power,
Comparing means for comparing the recording power command value with the detected emission power is provided, and the recording laser is driven based on the comparison result.

Therefore, the recording laser can emit light with a power proportional to the recording power command value.

The controller 8 not only outputs a recording power command value to the laser power control means 6, but also outputs a rotation command to the rotation control means 7.

The rotation control means 7, based on the rotation command value,
The rotation motor 2 is rotated.

More specifically, the rotation control means 7 comprises detection means for detecting the rotation speed or linear velocity of the disk 1, and comparison means for comparing the rotation command value with the detected rotation speed or linear velocity. The rotary motor 2 is driven based on the comparison result.

Therefore, the rotary motor 2 can rotate at an angular velocity or an image velocity proportional to the rotation command value.

FIG. 2 is a flow chart showing the main processing flow for determining the number of revolutions at the time of recording information by varying the recording power in the information recording apparatus 1 shown in FIG.
In the figure, # 1 to # 6 indicate steps.

In the flow of FIG. 2, steps # 1 to # 3
The processing itself is known, and is characterized by the processing of steps # 4 to # 6.

At step # 1, the recording power Pw is set to the lower limit L.
By varying from lim to the upper limit Ulim, test recording patterns are sequentially recorded in a predetermined trial writing area of the disc 1.

At this time, the controller 8 outputs a recording power command to the laser power control means 6 in order to vary the recording power Pw.

As the recording pattern, for example, random recording data digitally modulated based on a predetermined recording modulation method is used. Further, the variable amount (step) of the recording power Pw is indicated by Pd.

Here, an example of specific values of the power lower limit Llim, the power upper limit Ulim, and the variable amount (step) Pd will be shown. Llim = 6 mw, U1im = 10 m
It can be set as w, Pd = 0.5 mw.

In this case, it is possible to sequentially record with 9 kinds of recording power Pw.

It should be noted that the upper limit of power Ulim is preferably set near the rated value of the laser because it can deal with a wide range of disks having different sensitivities within the range where the laser is not destroyed.

At step # 2, the previously recorded trial writing area is sequentially reproduced to detect an index (called β) of reproduced signal quality.

Since the reproduction signal quality index β is obtained for each recording power Pw, a table of Pw vs β can be obtained.

The index β will be described in detail later, but the index β is a negative value when the recording power Pw is insufficient, a positive value when the recording power Pw is excessive, and is monotonic with respect to the recording power Pw. It is an index that increases.

At the next step # 3, the optimum recording power Pwo is obtained from the obtained Pw vs. β table. For example, β =
Pw that becomes 0 is the optimum power.

This optimum recording power Pwo is the same as the previous Pw.
It can be easily calculated by obtaining an appropriate approximate straight line or curve from the data in the β table.

As described above, this first embodiment is characterized by the processing of steps # 4 to # 6 below.
The controller 8 manages the control.

In step # 4, it is determined whether or not the previously obtained optimum recording power Pwo exceeds the power upper limit Ulim.

The optimum recording power Pwo is the power upper limit Ul.
If it exceeds im, the process proceeds to step # 5, the recording power Pw is set to its upper limit value Ulim, and the disc rotation speed is corrected.

For example, assuming that the normal rotation speed (or linear velocity) of the disk is fo, the rotation speed fo ′ of the disk is fo ′ = fo * (Ulim / Pwo) ² (1) Correct as follows.

Therefore, the rotation speed in this case is reduced in proportion to the square of the shortage of the recording power. In this state, the recording power Pw should be the power upper limit Ulim (Pw = Ulim).

Generally, the required recording energy of a recordable rotary optical disk is almost proportional to the square root of the linear velocity, so that if the number of rotations is lowered according to the above equation (1), good recording becomes possible. , Favorable results are obtained.

Further, as a result of the judgment in the previous step # 4,
When the optimum recording power Pwo does not exceed the power upper limit Ulim (when the power upper limit U1im value or less),
Proceeding to step # 6, the optimum recording power Pwo is set as it is as the recording power Pw and the rotation speed is also kept at the normal rotation speed (or linear velocity) fo of the disk.

In the above embodiments, the number of revolutions of the disk has been mainly described. However, in the case of a recording system with a constant linear velocity, "linear velocity" may be adopted instead of "revolution number". .

The information recording apparatus of the present invention can be applied to any system of constant rotation speed (angular velocity) or constant linear velocity. In the following description, the same applies to all cases, and the description will be made centering on the “rotation speed”, but it is also possible to apply to the “linear velocity”, and it goes without saying that both are included.

By the processing in the above steps # 1 to # 6, particularly in the latter half steps # 4 to # 6, the laser power is controlled so as not to exceed the power upper limit Ulim value, and as a result, laser damage is also prevented. .

The optimum recording state is realized by selecting the recording power Pw on the one hand and the rotation speed on the other hand.

Next, the reproduction signal quality index β described above will be described in detail.

FIG. 3 is a waveform diagram for explaining the β value as one of the indexes of the reproduced signal quality. (1) is an insufficient recording power, (2) is an appropriate value, and (3) is an excessive value. It is a figure which shows a case. In the figure, the horizontal axis represents time t, and the vertical axis represents the high frequency signal (reproduction signal) HF Signal, where A1 represents the level of the upper envelope and A2 represents the level of the lower envelope.

The reproduction signal is detected by a signal called a high frequency signal HF Signa1 as shown on the vertical axis of FIG.

There are generally a plurality of types of recording marks, from short marks to long marks.

In FIG. 3, this high frequency signal HF Si
AC-couple gna1 (a signal that cuts off the DC component),
The waveform when reproduced is schematically shown.

For example, as shown in FIG. 3 (1), when the recording power is insufficient, the level A1 of the upper envelope and the level A2 of the lower envelope are shifted to the lower side, and vice versa. Three
As in (3), when the recording power is excessive, the level A1 of the upper envelope and the level A2 of the lower envelope are shifted to the upper side.

Here, the β value is defined as an equation (2) of β = (A1 + A2) / (Al−A2) (2), where the shift amount is normalized by the amplitude.

Therefore, if proper, β = 0.

Instead of such an index β value, it is also possible to use an index of the reproduced signal secondary high frequency component, as described in the prior art (Japanese Patent Laid-Open No. 5-109077).

In short, it is sufficient to use a method in which the optimum recording power Pwo can be obtained from the reproduced signal in the test writing area recorded while changing (swing) the power.

<Second Embodiment> In this second embodiment as well, the hardware configuration is the same as that in FIG. 1 described above, and the control (algorithm) by the controller 8 is performed in the first embodiment described above. It is only different from.

Next, the operation of the second embodiment will be described.
Shown in the flow.

FIG. 4 is a flowchart showing the main processing flow in the information recording apparatus shown in FIG. 1 when the recording power is changed and the number of rotations is determined during information recording according to the second embodiment. In the figure, # 11 to # 16 indicate steps.

The processing from step # 11 to step # 14 is the same as step # 1 to step # 4 in FIG.

That is, from step # 11 to step #
By the processes up to 13, the optimum recording power Pwo can be obtained.

Then, in step # 14, it is judged whether or not the obtained optimum recording power Pwo exceeds the power upper limit Ulim.

In the second embodiment, if the optimum recording power Pwo exceeds the power upper limit Ulim as a result of the judgment in step # 14, the process proceeds to step # 15, and the linear velocity (or rotation speed) is set. Decrease by a certain value.

After that, the process returns to step # 11 again,
The same process is repeated until the optimum recording power Pwo does not exceed the power upper limit Ulim.

When the optimum recording power Pwo does not exceed the power upper limit Ulim by such processing, this loop is exited and the recording power is set to Pwo in step # 16.

The other processing is the same as that shown in FIG.

Therefore, the optimum recording power is the upper limit Ul.
Within a range not exceeding im, the required number of rotations is lowered to obtain a good recording state.

The effect of this second embodiment is that the value obtained directly from the Pw vs. β table is adopted as the optimum power, so that the optimum power more accurate than the algorithm for performing the processing of FIG. That is, the recording state can be obtained.

Further, in the processing described with reference to FIG. 2 and FIG. 4 above, when the recording power is insufficient, the power is limited to the upper limit, so that laser destruction does not occur, and
Moreover, it is possible to obtain the effects of maximally utilizing the laser power and not unnecessarily slowing the recording speed.

Here, regarding the relationship between the index β of the reproduced signal quality and the recording power Pw described with reference to FIG.
Add a description.

FIG. 5 is a characteristic diagram showing the relation between the recording power Pw and the index β, [1] is a diagram for explaining that there are a plurality of relations of Pw and β, and (2) when the linear velocity is small. P
It is a figure explaining that the characteristic of w vs. β shifts to the upper direction. The horizontal axis of the figure shows the recording power Pw, and the vertical axis shows the index β.

FIG. 5A shows that there are a plurality of relationships of Pw and β depending on the difference in recording sensitivity of the disc and the ambient temperature.

In FIG. 5A, three characteristic curves are shown. Which characteristic is obtained is determined by the difference in recording sensitivity of the disc, the ambient temperature and the like.

Further, FIG. 5 (2) shows that when the linear velocity is changed and the linear velocity is decreased, the characteristic curve of Pw vs. β is shifted upward.

For example, when the optimum recording power Pwo is obtained for the bottom plot having the highest linear velocity, the power upper limit Ulim is exceeded.

Therefore, if the recording power Pw is set in this state, there is a risk of laser breakage.

Therefore, when the linear velocity is slowed down, the plot is shifted upward as shown by the characteristic curve in the center, for example, and the optimum recording power Pwo comes below the power upper limit Ulim.

The control (algorithm) by the controller 8 shown in FIGS. 2 and 4 described above utilizes the characteristics shown in FIG. 5 (2).

[0119] <First Example> destination of the first and second embodiments, performs test writing recording power by varying, has been described a case of determining the rotational speed of the recording information by a result .

In the first reference example , the recording power is kept constant, the number of revolutions of the disk is varied, and the trial writing is performed.
The feature is that the number of rotations at the time of recording information is determined by the result.

The reason why the test writing is performed by changing the rotation speed of the disk and the rotation speed at the time of information recording is determined based on the result is the same as in the first and second embodiments. .

That is, the first reason is that, as described above, a good recording mark can be formed even if the optimum recording power differs due to the difference in recording sensitivity of the disc and the difference in ambient temperature. This is because.

The second reason is to prevent laser breakage even if the optimum recording power exceeds the laser rating due to the difference in recording sensitivity between disks and the difference in ambient temperature.

The third reason is to perform high-speed recording when the recording power has a margin due to the difference in recording sensitivity of the disc and the difference in ambient temperature.

In the first reference example as well, the hardware configuration is the same as that of FIG. 1, but in this case, the recording power Pw
Is a predetermined value. For example, it is set near the power upper limit Ulim as described above.

FIG. 6 is a flowchart showing the main processing flow in the information recording apparatus shown in FIG. 1 for varying the rotation speed of the disc according to the first reference example to determine the rotation speed at the time of information recording. . In the figure, # 21 to # 23 indicate steps.

In step # 21, the linear velocity (or rotation speed) is varied from the lower limit Llim to the upper limit Ulim,
Test recording patterns are sequentially recorded in a predetermined trial writing area of the disk 1.

At step # 22, the previously recorded trial writing areas are sequentially reproduced to obtain a table of "linear velocity" vs. "reproduction signal quality index (β)".

At the next step # 23, the optimum linear velocity Vo is calculated from the obtained table of "linear velocity" vs. "index (β) of reproduction signal quality".

As a method of calculating the optimum Vo, an appropriate approximation method as described in the control (algorithm) of FIG. 2 can be used.

The value of Vo thus obtained is used as a linear velocity to issue a rotation command, and actual data recording is performed.

By such control, the power upper limit Uli
It becomes possible to record at an optimum linear velocity near m.

In this case, when the normal linear velocity (or the number of rotations) is set and the recording power Pw has a margin,
In terms of performance, it should be possible to record at even higher linear velocities.

In the first reference example , since the linear velocity as high as possible is set near the upper limit Ulim of the recording power, high speed recording can be performed.

In the flow of FIG. 6 described above, since the variable control of the recording power is not performed, the device configuration is simpler than that of the device of FIG. 1, and the cost is reduced accordingly. Further, it is possible to easily change the flow shown in FIG. 2 to “if the recording power Pw has a margin, increase the number of rotations”.

For example, step # 4 (a process of determining whether the previously obtained optimum recording power Pwo does not exceed the power upper limit Ulim) and step # 6 (the optimum recording power Pwo is maintained as it is as the recording power Pw). age,
The processing that keeps the rotation speed fo the normal rotation speed fo)
And delete, and after the process of step # 3,
You can move to 5.

The process of step # 5 is a process of setting the recording power Pw to the upper limit value Ulim and correcting the disc rotation speed.

When the power has a margin, the recording power Pwo <power upper limit Ulim is always satisfied.
m / Pwo)> 1 and the rotation speed is increased.

By the way, if the linear velocity is increased, the index β
The value of decreases.

This relationship is shown in FIG.

FIG. 7 is a characteristic diagram showing the relationship between the linear velocity and the index β. The horizontal axis of the figure shows the linear velocity, and the vertical axis shows the index β.

As shown in FIG. 7, the reproduction signal quality index β has a characteristic that it decreases on the contrary when the linear velocity increases.

The characteristic shown in FIG. 7 corresponds to the "linear velocity" vs. "β" used in the control (algorithm) shown in FIG.
Value ”.

As already described many times, in the embodiment of the present invention, the case where the index β of the reproduction signal quality is used is mainly explained, but the β value is not limited to such a value. , It is possible to use different playback signal quality indicators.

However, since this β value can be measured by a simple envelope detection circuit and a microcomputer, the device can be much simpler than the method of measuring the second harmonic or the reproduction error rate and using it as an index. It is possible to configure.

Therefore, it goes without saying that utilizing this β value is a very preferable method in practical use.

< Second Reference Example > In the first and second embodiments and the first reference example described above, trial writing is performed by changing the recording power or the disk rotation speed. The case where the number of rotations at the time of recording information is determined by the result has been described.

The second reference example is characterized in that, during the recording operation, one or both of the recording power and the rotational speed of the disc are changed according to the result of comparison between the level of the reproduction signal from the recording mark and a predetermined value. have.

Therefore, during recording of actual information, the difference in recording sensitivity in the disc, the variation in laser wavelength,
Even if the recording efficiency fluctuates due to a beam positioning error or the like, an effect that a good recording mark can be always formed can be obtained.

Specifically, B indicating the mark formation state
The level is set as a reference, the recording actually performed is reproduced, and the reproduced signal level is sampled and compared with this B level.

FIG. 8 shows the second embodiment of the information recording apparatus of the present invention.
It is a functional block diagram which shows an example of the principal part structure about a reference example . Reference numerals in the figure are the same as those in FIG. 1, and 11 is B.
Level detecting means, 12 a comparator, 13 a first integrator,
14 is a second integrator, 15 is a controller, Pw
Indicates a target power command, and V indicates a rotation command value.

The information recording apparatus shown in FIG. 8 is the same as that shown in FIG.
Blocks 11 to 14 are provided instead of the upper and lower amplitude detection means 5. The controller 15
The basic control operation is almost the same as that of the controller 8 of FIG. 1, but the control is different, and therefore different reference numerals are given.

The B level detecting means 11 samples the reproduction signal level when the laser is emitting light at the recording power level and outputs a signal of B level.

As described above, the B-level signal is a signal indicating the mark formation state. For example, when the mark formation is insufficient, the B level becomes a high level, and conversely,
When the mark formation is excessive, the B level becomes a low level.

The optimum recording state is when the B level is a predetermined value.

The predetermined B level is set as a target level, and the actual B level is compared by the comparator 12.

The comparison result is sent to the first integrator 13 and the second integrator 14.

First, one of the first integrators 13 detects the detection B.
The level is integrated and the target power command Pw is output.

In this state, when the detected B level becomes lower than the target B level, the target power command Pw is decreased to control so that the mark formation will not become excessive.

Therefore, the detected B level is raised and coincides with the target B level.

The other second integrator 14 integrates the target B level and outputs the rotation command value V.

When the detected B level becomes lower than the target B level, the rotation command value V increases and the disc rotates faster, and control is performed so that mark formation does not become excessive.

Therefore, the detected B level is raised and coincides with the target B level.

Each of the first integrator 13 and the second integrator 14 stops the integration in response to a holding command from the controller 15, and holds the immediately preceding integrated value.

When the hold command is released, integration is performed.

The controller 15 inputs the output (Pw) of the first integrator 13 and the output (V) of the second integrator 14, and the first and second integrators 13 and 14 are also input. In response, each holding command is output.

In this state, the first and second integrators 13 and 14 are set in accordance with the current recording power (Pw) and rotation speed (V).
One of the two is operated and the other is brought into the holding state.

That is, the current recording power (Pw) and rotation speed (V) are monitored, and when they differ from the power target value,
Depending on the result of comparison between the detected B level and the target B level, either the recording power (Pw) or the rotation speed (V) is variably controlled.

More specifically, the recording power (Pw)
Is about to exceed the upper limit Ulim, the first integrator 13 is held so that the power does not rise further, and the second integrator 14 is turned on to start the integration.

As a result, the number of rotations is reduced and the recording state is brought into an appropriate state.

After that, when the recording state becomes excessive, the rotation speed starts to increase, and when a certain rotation speed (for example, the first normal rotation speed) is reached, the second integrator 14 is brought into the holding state, The first integrator 13 is turned on to start integration.

This relationship is shown in the state transition diagram shown in FIG.
become that way.

FIG. 9 is a state transition diagram of the controller 15 according to the second reference example . In the figure, S1 and S2 are states, int1 is the first integrator 13, int2 is the second integrator 14, and Ulim is the upper limit value of the power Pw, Vn.
Indicates a normal rotation speed (nominal).

As shown in FIG. 9, the controller 15 of FIG. 8 has a sequential circuit configuration of two states S1 and S2.

First, in state S1, int1 (first integrator 13) is turned on and int2 (second integrator 14) is held.

When the relationship between the target power command Pw and the power upper limit Ulim is Pw <Ulim, the state S
If Pw ≧ Ulim, the state is set to S2.

In state S2, conversely, int1 (first integrator 13) is held, int2 (second integrator 14) is held.
Turn on.

In this state S2, the relationship between the rotation command value V and the actual rotation speed (detected rotation speed) is maintained while V <Vn (first normal rotation speed), and the relationship between the two is V ≧ V
When it becomes n, the state S1 is set.

By the controller 15 performing such an operation, the power Pw is controlled by the comparison result between the target B level and the detected B level until the power Pw reaches the upper limit Ulim, and the power Pw is the upper limit Uli.
When m 2 is reached, the rotation speed V can be controlled according to the result of comparison between the target B level and the detected B level.

When the relationship between the recording power Pw and the rotational speed V in this case is shown in a waveform diagram, it changes as shown in FIG.

FIG. 10 shows the recording power Pw and the rotation speed V based on the state transition of the controller 15 in the second reference example .
It is a waveform diagram showing the relationship of. The horizontal axis of the figure is time t, the waveform Pw is the recording power Pw, V is the rotation speed V, and S1 and S
2 indicates a state, Ulim indicates an upper limit value of power, and Vn indicates a normal rotation speed.

As is apparent from FIG. 10, initially, the rotation speed V is constant and the recording power Pw is sequentially increased.

Then, the recording power Pw is the upper limit Ul.
When im is reached, the recording power Pw becomes constant and the rotation speed V decreases.

When the rotation speed V decreases, the recording power Pw has a margin, so that the rotation speed V once decreases to the lowest level but increases thereafter.

When the rotation speed V returns to the normal rotation speed Vn, it becomes constant thereafter, and the recording power Pw falls from the upper limit Ulim.

The state during this time is as shown in the state transition diagram of FIG. 9, and the state changes as S1 → S2 → S1 → S2.

As described above, when the recording power is insufficient,
When the rotation speed of the disk decreases and the recording power has a margin, the rotation speed of the disk increases, so that the recording power can always be set to a level close to the upper limit.

In the above example , the B level is used to detect the mark formation status during recording, but the B level is necessarily used for the mark formation status during recording. That is not necessary.

For example, first, the second conventional technique (Japanese Patent Laid-Open No. Hei 4-
No. 10237), the recording laser beam control method has an initial intensity (VA: before the mark formation process) of the reproduction signal during the emission of the recording pulse as shown in FIGS. 1 and 2. The amount (modulation degree) obtained by normalizing the difference from the latter half intensity (VB: after the mark formation process) with the initial intensity (VA) is used.

Also in the information recording apparatus of the present invention, instead of the amount of B level described above, the initial intensity (V) of the reproduction signal during the emission of the recording pulse used in the second prior art.
It is apparent that the same effect can be obtained by using the amount (modulation degree) obtained by normalizing the difference between A) and the latter half intensity (VB: after the mark formation process) by the initial intensity (VA).

< Third Reference Example > In the above second reference example , the case where the rotation speed V serving as the criterion for the state S2 is the normal rotation speed Vn has been described.

In this third reference example , this rotation speed V is
It is characterized in that it is set to Vn2, which is higher than the normal rotation speed Vn.

In the third reference example as well, the hardware configuration is the same as that shown in FIG. 8, but the control by the controller 15 is different.

As in the third reference example , the rotation speed V, which is the criterion for the state S2, is set higher than the normal rotation speed (V
n2> Vn), when the recording power Pw is limited to the upper limit Ulim thereof and then there is a margin in the recording power Pw, the rotation speed V is increased from the normal Vn instead of lowering the recording power Pw. Therefore, it is possible to perform recording at high speed.

This relationship is shown in the state transition diagram shown in FIG.
It becomes like 1.

FIG. 11 is a state transition diagram of the controller 15 according to the third reference example . The reference numerals in the figure are the same as those in FIG. 9, and Vn2 indicates a reference rotation speed higher than the normal rotation speed.

The state transition diagram of FIG. 11 is almost the same as the state transition diagram of FIG. 9 described above, but the rotation speed V serving as a criterion for the state S2 is Vn higher than the normal rotation speed Vn.
It is 2.

The state S1 is the same as that shown in FIG.
The (first integrator 13) is turned on and the int2 (second integrator 14) is held.

When the relationship between the target power command Pw and the power upper limit Ulim is Pw <Ulim, the state S
If Pw ≧ Ulim, the state is set to S2.

In the state S2, conversely, int1 (first integrator 13) is held and int2 (second integrator 14) is held.
Turn on.

In this state S2, the relationship between the rotation command value V and the actual rotation speed Vn2 is maintained while V <Vn2, and when the relationship between them becomes V ≧ Vn2, the state S1 is set.

By the controller 15 performing such an operation, the power Pw is controlled by the comparison result between the target B level and the detected B level until the power Pw reaches the upper limit Ulim, and the power Pw is the upper limit Uli.
When m 2 is reached, the rotation speed V can be controlled according to the result of comparison between the target B level and the detected B level.

With this setting, after the recording power Pw is limited by the power upper limit Ulim, if the recording power has a margin, the recording power Pw is not lowered but the disc rotation speed is set to be higher than the normal rotation speed Vn. It becomes possible to raise.

Therefore, the recording operation can be performed at a higher speed than in the case of the second reference example .

The relationship between the recording power Pw and the rotation speed V in this case is shown in the waveform diagram of FIG.

FIG. 12 shows the recording power Pw and the rotation speed V based on the state transition of the controller 15 in the third reference example .
It is a waveform diagram showing the relationship of. The horizontal axis of the figure and the symbols of the waveforms are the same as in FIG. 10, and Vn2 indicates a reference rotation speed higher than the normal rotation speed.

Also in the case of FIG. 12, during the state S1,
This is similar to FIG. 10 above.

In this state S1, when the recording power Pw reaches the upper limit Ulim, the state is switched to the state S2, the recording power Pw becomes constant, and the rotation speed V decreases.

In this state S2, if the recording power Pw has a margin, the disc rotation speed V is increased.

In this case, even if the normal rotation speed Vn is reached, if the recording power Pw has a margin, the rotation speed V is further increased and the preset switching reference rotation speed V is set.
The rotation speed V can be increased until n2 is reached.

Here, if the reference rotational speed Vn2 is set sufficiently large, it is possible to rotate as fast as possible with the recording power Pw stuck to the upper limit Ulim (maximum power).

Therefore, the recording operation can be performed at high speed.

If the reference rotational speed Vn2 is set to a too large value, head positioning control becomes a problem, so it goes without saying that a value as large as possible is selected according to the performance of the apparatus.

[0214] of the third reference example, and previously described above in the first
In the second reference example , a case has been described in which either the recording power Pw or the rotation speed V is variably controlled according to the comparison result between the target B level and the detected B level.

However, both the recording power Pw and the rotation speed V can be variably controlled at the same time depending on the comparison result between the target B level and the detected B level.

In this case, the first integrator 1 shown in FIG.
Both 3 and the second integrator 14 are turned on.

At this time, the integral gain of the first integrator 13 is
If it is set higher than the integral gain of the second integrator 14, the recording power Pw follows a rapid change in the recording power demand (that is, a change in the B level), and a slow change in the recording power demand occurs. Can be configured so that the rotary motor follows (change of the rotation speed V). It should be noted that the recording power Pw has an upper limit Ul in order to prevent laser destruction.
It goes without saying that an im is provided.

According to this structure, basically, the operation for increasing the rotation speed V as much as possible is realized in the state where the recording power Pw reaches the upper limit Ulim.

When the recording power demand changes rapidly (in this case, the recording power Pw changes in the direction of lowering), the recording power Pw is promptly controlled. It is possible to maintain a good recording state.

Also in this third reference example , instead of the amount of B level, the initial intensity (VA) and the latter half intensity (VA) of the reproduction signal during the emission of the recording pulse used in the second conventional technique ( Since it is possible to use the amount (modulation degree) obtained by normalizing the difference between VB: after the mark formation process) with the initial intensity (VA), the information recording apparatus of the present invention can be used in the case of the present reference example . It is not limited.

[0221]

According to the present invention, the disc rotation speed is determined based on the result of trial writing with the recording power varied.

Therefore, even if the optimum recording power is different due to the difference in the recording sensitivity of the disc and the difference in the ambient temperature, it is possible to adjust the rotation speed and form a good recording mark.

Further, when the recording power is insufficient, the number of revolutions decreases, so that a disc outside the range covered by the laser power can be used, and many types of discs can be handled and compatibility is improved. Be improved.

Furthermore, it is possible to use a low-power laser and to widen the power efficiency allowable range due to variations in the emission optical system. As a result, it is possible to use inexpensive parts and Cost reduction is also realized.

In addition, if the recording power has a margin, the number of rotations is increased, so that high speed recording can be performed.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an example of an embodiment of the main configuration of an information recording apparatus of the present invention.

FIG. 2 is a flow chart showing a main processing flow of determining the number of rotations at the time of information recording by varying the recording power in the information recording apparatus shown in FIG.

FIG. 3 is a waveform diagram illustrating a β value as one of indexes of reproduced signal quality.

FIG. 4 is a flowchart showing the main processing flow in the information recording apparatus shown in FIG. 1 when the recording power is changed and the number of rotations is determined during information recording according to the second embodiment.

FIG. 5 is a characteristic diagram showing the relationship between the recording power Pw and the index β.

FIG. 6 is a diagram showing a first reference in the information recording apparatus shown in FIG.
6 is a flowchart showing a main processing flow for determining the number of rotations at the time of recording information by changing the number of rotations of the disc according to the example.

FIG. 7 is a characteristic diagram showing a relationship between a linear velocity and an index β.
The horizontal axis of the figure shows the linear velocity, and the vertical axis shows the index β.

FIG. 8 is a functional block diagram showing an example of a main part configuration of a second reference example of the information recording apparatus of the present invention.

FIG. 9 is a state transition diagram of a controller 15 according to a second reference example .

FIG. 10 is a waveform diagram showing the relationship between the recording power Pw and the rotation speed V based on the state transition of the controller 15 in the second reference example .

FIG. 11 is a state transition diagram of a controller 15 according to a third reference example .

FIG. 12 is a waveform diagram showing the relationship between the recording power Pw and the rotation speed V based on the state transition of the controller 15 in the third reference example .

[Explanation of symbols]

1 disc 2 rotation motor 3 optical head 4 Playback signal detection means 5 Vertical amplitude detection means 6 Laser power control means 7 Rotation control means 8 controller 11 B level detection means 12 Comparator 13 First integrator 14 Second integrator 15 Controller

Continuation of the front page (56) Reference JP-A-8-7369 (JP, A) JP-A-7-73471 (JP, A) JP-A-7-57268 (JP, A) JP-A-6-176364 (JP , A) JP-A-6-76288 (JP, A) JP-A-6-36449 (JP, A) JP-A-5-225570 (JP, A) Patent 3254120 (JP, B2) (58) Fields investigated ( Int.Cl. ⁷ , DB name) G11B ^7/ 00-7/013 G11B 7/125 G11B 19/28

Claims (5)

(57) [Claims] 1. An information recording apparatus for forming an information recording mark by irradiating a disk with a light beam, and means for performing trial writing by varying the recording power of the light beam; and an optimum obtained from the result of the trial writing. Recording power is above a certain level
If the recording power is greater than
Set to, the number of revolutions of the disc during trial writing and the optimum
By calculation using the ratio of the recording power and the predetermined value ,
An information recording apparatus, comprising: a rotation speed determining unit that determines a rotation speed at the time of recording information. 2. The information recording apparatus according to claim 1 , wherein the optimum recording power is Pwo, the predetermined value is Ulim,
An information recording apparatus characterized in that when the rotational speed of the disc at the time of trial writing is fo and the rotational speed of the disc at the time of recording information is fo ', the calculation is fo' = fo * (Ulim / Pwo) ^2. . 3. The information recording apparatus according to claim 1 or 2 , wherein a detection unit that detects the number of rotations of the disc, a number of rotations detected by the detection unit and a number of rotations determined by the number of rotations determination unit. An information recording apparatus, comprising: a comparison unit that compares the two, and controls the rotation of the disk based on a comparison result by the comparison unit. 4. The information recording apparatus according to any one of claims 1 to 3, a power control means for varying the recording power of the light beam within a predetermined range, the disk is rotated at a predetermined rotational speed The optimum recording power is determined by varying the recording power within the predetermined range for trial writing, and determining the optimum recording power based on the result. An information recording apparatus, wherein when the power is out of the predetermined range, a rotation speed different from the predetermined rotation speed is set. 5. The information recording apparatus according to claim 4 , wherein the optimum recording power determination means limits the power of the light beam to within the range when the optimum recording power is outside the predetermined range. Information recording device.