JPH10134352A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a recording power to a proper level for recording information in a phase transition type disk. SOLUTION: Since a laser power during recording is a pulse light, a light is not received if a light receiving element of a high band is not used. Thus, in order to detect the laser power during the recording so as to optimize the laser power during recording, a CPU 11 outputs a mask signal (WDC) and causes a semiconductor laser driving circuit 13 to mask its recording operation so as to continuously emit laser lights for a specified time. Then, information is reproduced by a peak detecting circuit 14 and a bottom detecting circuit 16 and its signal amplitude is detected. Then, the signal amplitude is compared with a pre-recorded reference amplitude, a recording power objective signal is outputted to a semiconductor laser control circuit 10 and the recording power is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus capable of adjusting the laser power so that recording can be performed with an optimum laser power when information is recorded on a phase change type information recording medium.

[0002]

2. Description of the Related Art In order to record information on an information recording medium (hereinafter, simply referred to as a disk), laser light emitted from a semiconductor laser device is focused on a disk and pits are formed on the disk. Is being done.

In this case, if the laser power (hereinafter, the laser power at the time of recording is referred to as recording power) fluctuates, pits may not be formed properly. Therefore, control is performed to keep the recording power constant. Have been done.

However, if the recording characteristics fluctuate due to variations in the disk characteristics, the inclination of the disk with respect to the optical system, and changes in the temperature due to changes in the disk characteristics and the oscillation characteristics of the semiconductor laser element, the pits are properly formed even if the recording power is constant. No longer formed.

Therefore, Japanese Patent Application Laid-Open No. 6-76288 discloses that
There is disclosed a method of receiving reflected light from a disk during data recording and adjusting recording power based on the reflected light.

That is, in this method, a test writing area is provided on a disk and test writing is performed as appropriate. This trial writing
This is performed while changing the recording power, and at the same time, the intensity of the reflected light from the disk is measured and stored. In measuring the reflected light intensity, the reflected light at the time of forming a pit having a high recording power is used as necessary.

After the trial writing, the area is reproduced, the recording power at which the asymmetry of the reproduced signal at that time is minimized is determined as the optimum recording power, and the reflected light intensity at the time of the trial writing with the recording power is determined as the target value.

Then, the recording power is adjusted so that the reflected light intensity during the actual recording of data becomes the target value determined in advance.

[0009]

However, the above-described method has a problem that it can be applied to a write-once disk or the like, but cannot be applied to a phase-change disk.

This will be described with reference to the driving waveform of the semiconductor laser device shown in FIG. 8A is for a write-once disc, and FIG. 8B is for a phase-change disc. In the drawing, Pr indicates a reproducing power, Pw indicates a recording power, and Pe indicates an erasing power. The erasing power is used when data is overwritten, and in this specification, the erasing power is described as the erasing power.

As can be easily understood by comparing FIGS. 8A and 8B, the pulse width at the time of recording is shorter in the phase change type disc than in the write-once type disc.

For this reason, the frequency of the reflected light from the phase-change type disk at the time of recording increases, and the reflected light cannot be detected unless a light receiving element having a wide band is used. Therefore, like the method in the above-mentioned publication,
It becomes difficult to adjust the recording power by receiving reflected light during data recording.

In this case, two laser spots are formed on a disk by using two laser sources, and one preceding laser spot is set to have a pulse width as shown in FIG. And the other laser spot is D
Although it is possible to overcome the above-mentioned difficulties by making it possible to receive light with a normal light receiving element as C lighting, this configuration newly raises a problem that the cost of the optical disk device increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical disk apparatus capable of adjusting the recording power so that recording can be performed with an optimum recording power without increasing the cost.

[0015]

According to a first aspect of the present invention, a laser beam from a laser source is focused on an information recording medium to form a laser spot, and information is recorded on the information recording medium. A pickup means for emitting a laser beam with a predetermined pulse width and continuously emitting a laser beam when reproducing or erasing recorded information; a reproducing means for reproducing recorded information; and a reproducing means for reproducing recorded information. Detecting means for detecting the recording state, masking the information recording operation, causing the pickup means to continuously emit laser light for a predetermined time, and causing the detecting means to detect the recording state of the information recorded immediately before the mask; Control means for controlling the pickup means based on the detection result to adjust the laser power at the time of recording.

That is, since the laser beam at the time of recording is a pulse beam, it cannot be received unless a high-band light receiving element is used. Therefore, in order to evaluate the laser power at the time of recording and adjust the laser power to an optimal laser power, the control means masks the information recording operation and causes the pickup means to continuously emit laser light for a predetermined time. Then, the recording state of the information recorded immediately before the mask is detected by the detecting means, and the appropriateness of the laser power is determined based on the detection result to adjust the laser power at the time of recording.

According to a second aspect of the present invention, the information recording medium has a packet area in which information is recorded in a packet format, and a linking area provided between the packet areas, and the pickup means includes the linking area. The control means causes the detection means to detect a recording state while scanning the area.

That is, the control means masks the information recording operation, and the recorded information is lost while the pickup means continuously emits the laser beam for a predetermined time. In order to prevent this, an information recording medium on which information is recorded in a packet format is characterized in that a mask is performed when the pickup means reaches a linking area.

According to a third aspect of the present invention, the pickup means has a multiple spot forming section for forming at least two or more laser spots from one laser beam, and the control means is preset in the pickup means. The test writing is performed in the test writing area that has been
The recording state of the information recorded in the test writing area is detected by using the reflected light having a high light intensity among the reflected lights of the laser spot.

That is, when recording or reproducing information by forming at least two or more laser spots from one laser beam on an information recording medium by a multiple spot forming unit,
When the optimum recording power is detected by reproducing the test writing area, the reproduction is performed using the reflected light of the laser spot having a high light intensity, thereby increasing the S / N ratio of the reproduced signal. .

According to a fourth aspect of the present invention, when the control means masks the information recording operation and causes the pickup means to continuously emit a laser beam for a predetermined time, the laser for reproducing the recorded information is reproduced. It is characterized by continuous light emission with power.

That is, when the information recording operation is masked, the pickup means emits laser light continuously for a predetermined time, and when reproducing the recorded information, the laser is emitted with the laser power at the time of reproduction. Features.

According to a fifth aspect of the present invention, when the control means masks the information recording operation and causes the pickup means to continuously emit laser light for a predetermined time, the erased laser for erasing the recorded information is used. It is characterized by continuous light emission with power.

That is, when the information recording operation is masked, the pickup means emits laser light continuously for a predetermined time, and when reproducing the recorded information, the laser is emitted with the laser power at the time of erasure. Features.

According to a sixth aspect of the present invention, the pickup means includes: a laser source driving unit for controlling and driving the laser source;
A laser power detection unit that monitors a laser power emitted from the laser source and outputs a laser power monitor signal when at least continuous emission of laser light is performed, and the control unit receives the laser power from the detection unit. An arithmetic control unit for calculating a recording power target value signal, which is a target value of laser power at the time of recording, based on a detection result of the information recording state;
A laser control unit that compares the target recording power value signal with the laser power monitor signal and outputs a laser power control signal to the laser source driving unit so that the laser power becomes the target recording power value. It is characterized by the following.

That is, in order to monitor the laser power of the laser light emitted from the laser source, a laser power detection unit is provided, and a laser source driving unit that supplies a predetermined power to the laser source and drives the laser source is used as the pickup means. Provide. An arithmetic control unit for evaluating the laser power based on the detection result of the recording state of the information received from the detecting means, thereby calculating a recording power target value signal which is a target value of the laser power at the time of recording; A laser control unit that outputs a laser power control signal to the laser source driving unit so that the value signal is compared with the laser power monitor signal so that the laser power becomes a target value.

According to a seventh aspect of the present invention, the laser power when the laser source driving section causes the laser source to emit continuous laser light is controlled based on a laser power control signal from the laser control section. Or the laser power at the time of erasing.

That is, the laser control section outputs a laser power control signal indicating the laser power at the time of reproduction or the laser power at the time of erasing to the laser source drive section, and the laser source drive section performs the operation based on the laser power control signal. The laser light is continuously emitted.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram of a phase change disk device according to the present embodiment, and FIG. 2 is a diagram showing a positional relationship between a track and a laser spot formed on the phase change disk. As will be described later,
On the disc, a main spot and two leading and trailing sapots are formed.

The optical disk device has a pickup means, a detection means, a control means and the like. The pick-up means includes a semiconductor laser element 4 for emitting laser light, a part of the laser light emitted from the semiconductor laser element 4, receiving a part of the laser light, converting it into an electric signal, and outputting this as a laser power monitor signal. Element 5, a signal detecting light receiving element 6 for receiving reflected light from the disk 1 and converting it into an electric signal
And the like.

Since the signal output from the signal detecting light receiving element 6 is a current signal, the detecting means converts the signals from the IV converters 7 to 9 and 9 from the IV converter 9 for converting the current signal into a voltage signal. A peak detection circuit 14 for detecting a peak value, and a bottom detection circuit 1 for detecting a bottom value of a signal from the IV converter 9
6, an A / D converter 15 for converting a signal from the peak detection circuit 14 to a digital signal, an A / D converter 17 for converting a signal from the bottom detection circuit 16 to a digital signal, and the like.

The control means outputs a mask signal (WDC) for continuously emitting a laser beam by masking the recording operation at the time of recording, and also outputs A / D converters 15 and 17.
CPU 11, which determines an optimum recording power based on a signal from the CPU and outputs a recording power target signal based on the determination;
A D / A converter 12 for converting a recording power target signal into an analog signal, a semiconductor laser control circuit 10 for outputting a laser driving current control signal for causing the semiconductor laser element 4 to emit a laser beam having an optimum recording power, and a laser driving current It has a semiconductor laser drive circuit 13 for driving the semiconductor laser element 4 based on a control signal, an AND gate 18 to which a gate signal and a mask signal (WDC) are inputted, and an AND gate 19 to which a data signal and a mask signal (WDC) are inputted. ing.

Based on the above configuration, laser light emitted from the semiconductor laser element 4 is condensed by an objective lens (not shown) to form a laser spot 3 on the phase-change disk 1.

At this time, the laser beam emitted from the semiconductor laser element 4 is divided into three parts by a grating or the like (not shown), so that the laser spot 3 is divided into the main spot 21, the preceding spot 22 and the following spot as shown in FIG. The spot 23 is composed of three spots.

The main spot 21 is configured to have a higher light intensity than the preceding and following spots 22 and 23.

The disk 1 is provided with spiral tracks from the inner circumference to the outer circumference.
The main spot 21 and the succeeding spot 23 are arranged on the track in this order with the preceding spot 22 at the head. The preceding spot 22 is located at the center of the track,
The leading spot 22 and the trailing spot 23 are located so as to straddle adjacent tracks, respectively.

The reflected light of the main spot 21 from the disk 1 is received by the signal detection light-receiving element 6 and is reflected by the IV.
The current and voltage are converted by the converter 7 and sent to a reproducing system (not shown).

Similarly, the reflected light of the preceding spot 22 and the reflected light of the following spot 23 are received by the signal detection light-receiving element 6 and converted into current and voltage by the IV converters 8 and 9, respectively, to form a servo system (not shown). Sent.

On the other hand, a part of the laser light emitted from the semiconductor laser element 4 enters the laser light detecting light receiving element 5, is photoelectrically converted by the laser detecting light receiving element 5, and is transmitted to the semiconductor laser control circuit 10. It is output as a power monitor signal.

The semiconductor laser control circuit 10 compares the recording power target value signal with the laser power monitor signal, and sends a signal to the semiconductor laser driving circuit 13 so that the laser power monitor signal matches the recording power target value signal. Outputs a laser drive current control signal. The semiconductor laser drive circuit 13 drives the semiconductor laser device 4 based on the laser drive current control signal.

A gate signal is input to the AND gate 18, a data signal is input to the AND gate 19, and a mask signal (WDC) is input to the AND gates 18 and 19 from the CPU 11. The outputs of the AND gates 18 and 19 are input to the semiconductor laser action circuit 13.

Each of the AND gates 18 and 19 outputs an "L" level signal when one of the two inputs is at the "L" level. Therefore, when the mask signal (WDC) is at the “H” level, the gate signals and data signals input to the AND gates 18 and 19 are directly input from the AND gates 18 and 19 to the semiconductor laser drive circuit 13 and the mask signal When (WDC) is at “L” level, an “L” level signal is input to the semiconductor laser drive circuit 13 regardless of the gate signal and the data signal.

Thus, when the mask signal is at the "H" level, the semiconductor laser drive circuit 13 modulates the data signal to drive the semiconductor laser element 4 into a laser element drive waveform as shown in FIG. I do.

Next, the power adjustment of the recording power will be described. As described above, at the time of data recording, the laser light is pulse-modulated and emitted. Therefore, the reflected light of the leading spot 22 and the trailing spot 23 from the disk 1 fluctuates drastically, and it is impossible to properly receive and photoelectrically convert the light unless a high-band light receiving element is used. That is, it is not possible to determine whether the recording power is appropriate based on the reflected light.

Then, in order to judge whether the recording power is appropriate or not,
The CPU 11 outputs an “L” level mask signal (WDC) to the AND gates 18 and 19 for a predetermined period during recording, stops the pulse modulation of the laser light, and causes the semiconductor laser element 4 to continuously emit the laser light. As a result, the leading spot 22 and the trailing spot 23 become laser light whose light intensity does not fluctuate.

That is, when the mask signal (WDC) goes to the "L" level, the signal levels output from the AND gates 18 and 19 also go to the "L" level, and the semiconductor laser drive circuit 13 stops the modulation and continues the laser operation. The semiconductor laser device 4 is driven so as to output light.

As the power of the continuous laser light, a reproducing power, an erasing power, or the like can be used.
Hereinafter, such a continuous laser beam is referred to as a DC laser.

As described above, in the state of the DC laser, the data recorded immediately before the mask signal is set to the "L" level is reproduced.

At this time, the reproduced signal received by the signal detection light-receiving element 6 is output to the peak detection circuit 14 and the bottom detection circuit 16 via the IV converter 9, and the peak detection circuit 14 and the bottom detection circuit At 16 the peak and bottom values are detected. The peak value and the bottom value are converted into digital signals by A / D converters 15 and 17,
Sent to 1.

The CPU 11 obtains the maximum amplitude of the reproduced signal (hereinafter, such amplitude is referred to as signal amplitude) from the peak value and the bottom value, and judges the quality of the recorded signal (ie, evaluates the recording power). The determination is made by comparing the maximum amplitude of the reproduction signal (hereinafter, referred to as a reference amplitude) stored when the laser power is optimized by trial writing or the like.

It should be noted that the peak detection circuit 14
A reset signal is output to the bottom detection circuit 16. The reset signal is a signal for causing the peak detection circuit 14 and the bottom detection circuit 16 to reset the peak value and the bottom value detected so far. Therefore,
The peak value and the bottom value used for the determination by the CPU 11 are signals received after outputting the reset signal.

When the CPU 11 determines that the signal amplitude is smaller than the reference amplitude, the CPU 11 controls to increase the recording power, and when it determines that the signal amplitude is greater than the reference amplitude, controls to decrease the recording power. I do.

FIG. 3 is a flowchart showing the power adjustment processing of the recording power by the CPU 11. In step S1, the mask signal (WDC) is set to the "L" level, and in step S2, the peak detection circuit 14 and the bottom detection circuit 1 are set.
6 waits for the detection of the peak value and the bottom value to end.

Thereafter, in step S3, the CPU 11
The peak value and the bottom value are read from the D converters 15 and 17, the mask signal (WDC) is set to the “H” level in step S4, and the recording operation is restored, and the process proceeds to step S5.

Then, in step S5, the CPU 11 calculates a signal amplitude from the read peak value and bottom value, and
Proceed to step S6.

It is determined whether or not the signal amplitude calculated in step S6 is larger than the reference amplitude. If the signal amplitude is large, the flow advances to step S8 to reduce the recording power and then to step S10. On the other hand, if the signal amplitude is equal to or smaller than the reference amplitude, the process proceeds to step S7.

In step S7, it is determined whether or not the signal amplitude is smaller than the reference amplitude. If the signal amplitude is small, the process proceeds to step S9, where the recording power is increased and step S9 is performed.
Go to 10.

On the other hand, if the signal amplitude is not smaller than the reference amplitude in step S7, that is, if the signal amplitude is equal to the reference amplitude (when the recording power is appropriate), the process directly proceeds to step S10.

In step S10, a wait state is set for a predetermined time. In this wait state, the recording data is lost during the confirmation of the recording power, so that the frequency of the confirmation processing is adjusted to reduce the amount of lost data.

Thereafter, in step S11, it is confirmed whether or not the recording is completed. If not, the flow returns to step S1.
When the recording is completed, the recording power adjustment processing is also terminated.

As described above, even if the pickup has only one light source, the quality of the recording mark during recording can be detected, and the recording power can be adjusted.

During the operation for checking the recording power, the data is lost. However, the time for the checking operation is sufficiently shortened, and
Error correction can be performed by increasing the confirmation interval.

Further, if the above-mentioned recording power is checked in the linking section, it is possible to prevent the recording data from being lost. This linking part is, for example, a CD-R
When logically dividing a track provided on the disk 1 into a plurality of pieces to form a packet and performing recording for each packet, the packet is not used for recording user data provided between packets. It is an area.

Next, a second embodiment will be described with reference to the drawings. In addition, about the same structure as 1st Embodiment, description is abbreviate | omitted suitably using the same code | symbol.

Data can be reproduced by the reflected light of the trailing spot 23. However, as can be seen from FIG. 2, the trailing spot 23 is not located at the center of the track, so that the influence of noise can be obtained. It is easy to receive and the light intensity is weak.

Therefore, in the present embodiment, the reliability is improved by detecting the recording power using the reflected light of the main spot having a high light intensity.

For this reason, as shown in FIG. 4, the A terminal connected to the IV converter 7 for outputting the received light signal by the reflected light of the main spot 21 and the received light signal by the reflected light of the succeeding spot 23 are output. A common terminal C is provided with a switch 41 connected to the peak detection circuit 14 and the bottom detection circuit 16.

With this configuration, when the recording power is determined, the common terminal C is connected to the A terminal, and the light receiving signal from the IV converter 7 by the main spot 21 is transmitted to the peak detection circuit 14 and the bottom detection circuit 15. To make a trial writing. Then, the test write area is reproduced, and the recording power at which the signal amplitude of the reproduced signal at that time becomes the largest is set as the optimum recording power.

Thereafter, the common terminal C of the switch 41 is connected to the terminal B, and the trailing spot 23 from the IV converter 9 is connected.
Are set to be input to the peak detection circuit 14 and the bottom detection circuit 16. Then, the area recorded with the previously determined optimum recording power is reproduced again, and the signal amplitude obtained from the peak detection circuit 14 or the like is stored as the reference amplitude. The recording power is confirmed and adjusted in accordance with the procedure described in the first embodiment with respect to the reference amplitude thus obtained.

As a result, it is possible to adjust the recording power with high reliability.

A third embodiment of the present invention will be described with reference to the drawings. In addition, about the same structure as 1st and 2nd embodiment, description is abbreviate | omitted suitably using the same code | symbol.

The optical disk device according to this embodiment is
This is a modification of the gate circuit and the semiconductor laser drive circuit according to the first and second embodiments.

The gate circuit according to the present embodiment has an AND gate 19 to which a data signal and a mask signal (WDC) are input.

The semiconductor laser driving circuit 13 includes a reproducing current driving circuit 51 for outputting a reproducing current between the power supply and the semiconductor laser element 4, a recording current driving circuit 55 for outputting a recording current, and an erasing for outputting an erasing current. The current drive circuits 53 are provided in parallel.

A recording current switch 54 is connected in series between the recording current drive circuit 55 and the semiconductor laser element 4, and an erase current switch 52 is connected in series between the erase current drive circuit 53 and the semiconductor laser element 4. It is connected to the.

A laser drive current control signal is input from the semiconductor laser control circuit 10 to the reproduction current drive circuit 51, the recording current drive circuit 55, and the erase current drive circuit 53. A reproducing current, a recording current, and an erasing current corresponding to the signal are output.

A gate signal is input to the erase current switch 52 and ON / OFF operation is performed by the gate signal. An output of the AND gate 19 is input to the recording current switch 54 and an output of the AND gate 19 is input. ON based on
/ OFF operation.

The above-described configuration is different from the gate circuits according to the first and second embodiments in that the AND gate 18 is omitted, and the gate signal and the signal from the AND gate 19 are respectively used as the erase current. The difference is that the input is made to the switch 52 and the recording current switch 54.

With the above configuration, for example, the mask signal (WD
Even when C) is at the “L” level, the signal output from the AND gate 19 does not match the signal level of the gate signal, and the erase current switch 52 and the write current switch 54 can be operated independently. become.

When a laser drive current control signal is input from the semiconductor laser control circuit 10 to the playback current drive circuit 51, a playback current is output to the semiconductor laser device 4 by the laser drive current control signal, and the semiconductor laser device 4 Emits a laser beam having a reproducing power.

Similarly, at the time of erasing (including overwriting), the laser drive current control signal from the semiconductor laser control circuit 10 is input to the erase current drive circuit 53, and the erase current is controlled by the laser drive current control signal. The drive circuit 53 operates. When an “H” level gate signal is input in such a state, the erase current switch 52 operates and the erase current is supplied from the erase current drive circuit 53 to the semiconductor laser device 4.

At this time, since the reproducing current is supplied from the reproducing current driving circuit 51 to the semiconductor laser element 4, the semiconductor laser element 4 oscillates with the total current of the erasing current and the reproducing current and has a laser having the erasing power. It emits light.

Further, at the time of recording, a laser drive current control signal is inputted from the semiconductor laser control circuit 10 to the recording current drive circuit 55, and a data signal is inputted from the AND gate 19 to the recording current switch 54. 54 is ON / OFF according to the level of the data signal
It works. When the recording current switch 54 is
In the case of N, the recording current is output from the recording current drive circuit 55, and the total current of the reproducing current and the erasing current is supplied to the semiconductor laser element 4.

As described above, the recording current switch 5
4 is turned on / off by a data signal, the current supplied to the semiconductor laser element 4 varies depending on the on / off operation of the recording current switch 54, that is, the level value of the data signal. As a result, the laser light emitted from the semiconductor laser element 4 becomes a laser pulse modulated by the data signal.

Here, when the CPU 11 outputs an "L" level mask signal (WDC) to detect the recording power, the level of the signal output from the AND gate 19 becomes "L" level and the recording is performed. The current switch 54 is OF
F operation is performed.

Therefore, in this case, the semiconductor laser element 4 emits a laser beam with the erasing power, and the laser beam becomes a DC laser.

As a result, it is possible to check and adjust the recording power according to the procedure described in the first and second embodiments.

A fourth embodiment of the present invention will be described with reference to the drawings. In addition, about the same structure as 1st-3rd embodiment, description is abbreviate | omitted suitably using the same code | symbol.

FIG. 6 shows a partial configuration diagram of an optical disk device according to the present embodiment. The optical disk device has a control circuit which is different from that of the optical disk device according to the above-described first or second embodiment. Has been added.

The semiconductor laser control circuit 10 converts the laser power monitor signal output from the laser beam detection light receiving element 5 into an IV conversion circuit 61, and converts the signal from the IV conversion circuit 61 into a reference voltage. A comparison circuit for reproduction 62 that outputs a signal corresponding to the comparison result in comparison with Vref, and a reproduction that samples / holds the signal from the comparison circuit for reproduction 62 and outputs a reproduction current control signal to the reproduction current drive circuit 51. Signal from the S / H circuit 64 and the IV conversion circuit 61
The erasing comparator 63 compares the recording power target value signal output from the CPU 11 via the / A converter 12 and outputs a signal corresponding to the comparison result.
3 to output an erase current control signal to the erase current drive circuit 53, output an erase S / H circuit 65 to an amplifier 66, which will be described later, and output the erase S / H circuit 65 from the erase S / H circuit 65. An amplifier 66 for amplifying the signal and outputting a recording current control signal to the recording current drive circuit 55 is provided.

The control circuit receives the data signal and the mask signal (WDC) and outputs the output as a recording switch control signal (WSW).
AND gate 19 to output to 4, mask signal (WDC)
Is input through the NOT gate 20 and the CPU 11
AND gate 21 to which the erase control signal (ERC) is input from the AND gate 21 and the signal from the AND gate 21 and the gate signal are input to the erase S / H circuit 65 and the erase S / H signal (ES
R), a NAND gate 22 to which a mask signal (WDC) is input via a NOT gate 20 and an erase control signal (ERC) via a NOT gate 23, and a signal and a gate from the NAND gate 22. A gate signal is input through an AND gate 25 and a NOT gate 27 which receives an input signal and outputs an erase switch control signal (ESW) to an erase current switch 52, and a signal from the NAND gate 22 through a NOT gate 28. Is input to the reproduction S / H circuit 64 for reproduction S / H signal (RSH).
Is provided.

Based on the above configuration, a part of the laser light emitted from the semiconductor laser element 4 enters the laser light detecting / receiving element 5 and is photoelectrically converted to become a laser power monitor signal to become an IV conversion circuit 61. Is subjected to IV conversion. The IV converted laser power monitor signal is output to the comparison circuit for reproduction 62 and the comparison circuit for erasure 63.

The reproduction comparison circuit 62 compares the laser power monitor signal from the IV conversion circuit 61 with the reference voltage Vref while emitting laser light at the reproduction power.
A signal corresponding to the comparison result is output to the reproducing S / H circuit 64.

The reproduction S / H signal RSH is input from the OR gate 26 to the reproduction S / H circuit 64, and the reproduction S / H signal
A signal from the comparison circuit for reproduction 62 is sampled based on the / H signal RSH, the signal at that time is held and output to the reproduction current drive circuit 51 as a reproduction current control signal.

The erasing comparison circuit 63 outputs the signal from the IV conversion circuit 61 and the recording power target value signal from the CPU 11 via the D / A converter 12 when the laser beam is emitted at the erasing power. And outputs a signal corresponding to the comparison result to the erasing S / H circuit 65.

The erasing S / H circuit 65 receives an erasing S / H signal (ESR) from the AND gate 24, and based on the erasing S / H signal (ESR), the erasing comparison circuit 63.
Is sampled, the signal at that time is held and output to the erase current drive circuit 53 as an erase current control signal. The erase current control signal is output to the amplifier 66, amplified by the amplifier 66, and output to the recording current drive circuit 55 as a recording current control signal.

As described above, the reproduction current drive circuit 51, the erase current drive circuit 53, and the recording current drive circuit 55
The erasing and recording current control signals are output, and the reproduction current control signal controls the reproduction current to be always constant.
The erasing and recording currents are not controlled as described above, but can be adjusted and changed appropriately.

Next, the operation of the control circuit will be described with reference to the timing chart of FIG. Note that the playback S
/ H circuit 64 and erase S / H circuit 65
The sample mode is set when the signal RSH and the erase S / H signal (ESR) are at “H” level, and the hold mode is set when the signal RSH and the erase S / H signal (ESR) are at “L” level.

The section shown in FIG. 7 indicates the time of reproduction. In this section, the gate signal is at "L" level and the mask signal (WDC)
And the erase control signal (ERC) is at the “H” level.

Therefore, an "L" level signal is output from AND gate 21, and the erase S / H signal (ESR) output from AND gate 24 is both "L" level regardless of the level of the gate signal. Become. Therefore, the erasing S / H circuit 65 is in the hold mode, an erasing current control signal is output from the erasing S / H circuit 65 to the erasing current driving circuit 52, and the recording current driving circuit is output via the amplifier 66. A recording current control signal is output to 55.

The output of NAND gate 22 is "H".
Therefore, the signal input to the OR gate 26 via the NOT gate 28 becomes "L" level. On the other hand, since the gate signal is at the “L” level, the OR gate 26 eventually outputs the “H” level reproduced S / H signal RSH to the reproducing S / H signal.
This is output to the H circuit 64.

Therefore, at the time of reproduction, the reproduction S / H circuit 64
Becomes the sample mode, and the reproducing S / H circuit 64
Outputs a reproduction current control signal to the reproduction current drive circuit 51.

At this time, since the erase switch control signal (ESW) output from the AND gate 25 is at the "L" level, the erase current switch 52 is turned off and the erase current is not supplied to the semiconductor laser 4. . At the time of reproduction, since the data signal is at "L" level, the AND gate 1
The recording switch control signal (WSW) output from 9 becomes “L” level, the recording current switch 54 operates OFF, and the recording current is not supplied to the semiconductor laser 4.

As described above, during reproduction, only the reproduction current output from the reproduction current drive circuit 51 is applied to the semiconductor laser device 4.
Will be supplied.

At the time of recording, the gate signal goes to "H" level and recording is started. As a result, both the reproduced S / H signal RSH and the erased S / H signal (ESR) become “L” level.

Therefore, both the reproducing S / H circuit 64 and the erasing S / H circuit 65 are in the hold mode, and the reproducing current control signal and the erasing current control signal in this state are:
The current is output to the reproducing current driving circuit 51 and the erasing current driving circuit 52, and the recording current control signal from the amplifier 66 is output to the recording current driving circuit 55.

At this time, since the erase switch control signal (ESW) output from the NAND gate 25 is at the "H" level, the erase current switch 52 is turned ON, and the erase current from the erase current drive circuit 53 is supplied to the semiconductor laser. Output to element 4.

The recording switch control signal (WSW) output from the AND gate 19 is the same signal as the data signal because the mask signal is at the "H" level, and the recording current switch 54 is turned ON / OFF according to the level of the data signal.
Operate. Thus, the recording current is intermittently supplied to the semiconductor laser element 4 according to the ON / OFF operation of the recording current switch 54.

At the time of such recording, when the mask signal goes to the “L” level (corresponding to the area in FIG. 7), the reproduction S
The / H signal RSH goes low and the erase S / H signal (ESR) goes high.

Therefore, the reproducing S / H circuit 64 is in the hold mode, the erasing S / H circuit 65 is in the sample mode, and a control signal to that effect is sent to the reproducing current driving circuit 51 and the erasing current driving circuit 52. Each is output, and a control signal from the amplifier 66 is output to the recording current drive circuit 55.

At this time, the erase switch control signal (ESW) output from the AND gate 25 goes to the “H” level, so that the erase current switch 52 is turned on, and the erase current from the erase current drive circuit 53 is applied to the semiconductor. It is supplied to the laser element 4.

The recording switch control signal (WSW) output from the AND gate 19 becomes "L" irrespective of the data signal because the mask signal becomes "L" level.
Level, and the recording current switch 54 is turned off. Thereby, the recording current supplied to the semiconductor laser element 4 is cut off.

When the erasure control signal (ERC) goes low from the above state (corresponding to the region in FIG. 7), the reproduced S / H signal RSH goes high and the erase S / H signal (ESR) goes low. It becomes the “L” level.

Therefore, the reproducing S / H circuit 64 is in the sample mode, the erasing S / H circuit 65 is in the hold mode, and a control signal to that effect is sent to the reproducing current driving circuit 51 and the erasing current driving circuit 52. The recording current control signal is output from the amplifier 66 to the recording current drive circuit 55.

At this time, the erase switch control signal (ESW) output from the AND gate 25 goes to the “L” level, so that the erase current switch 52 is turned off, and the erase current drive circuit 53 sends the semiconductor laser device 4 Is erased, the erase current being supplied to the memory cell is cut off.

The recording switch control signal (WSW) output from the AND gate 19 becomes "L" regardless of the data signal because the mask signal has become "L" level.
Level, and the recording current switch 54 is turned off. Thereby, the recording current supplied to the semiconductor laser element 4 is cut off.

As described above, the recording power during recording can be confirmed and adjusted to the optimum recording power.

In each of the above embodiments, 3
Although the description has been made on the premise that two laser spots are used, when a track signal is detected by a push-pull method or the like, a laser beam is divided into two and two laser spots are formed on the disk 1 so as to be centered on the track. The present invention is also applicable when a laser spot is arranged.

Further, the detection of the recording power has been described using the signal amplitude as an example, but it may be detected by an asymmetry method or the like.

[0120]

According to the first aspect of the present invention, the recording operation of the information is masked, the laser light is continuously emitted for a predetermined time, the recording state of the recorded information is detected, and the laser power at the time of recording is adjusted. As a result, the recording power can be adjusted even with a phase change type information recording medium, and recording can be performed with the optimum recording power.

Further, since the recording state of the recorded information is detected without preparing a plurality of laser sources, etc.,
In addition to preventing cost increase, adjustment and the like are simplified and reliability is improved as compared with the case where a plurality of laser sources are used.

According to the second aspect of the present invention, the information recording operation is masked when reaching the linking area, so that the information is not lost.

According to the third aspect of the present invention, the test writing area is reproduced by using the reflected light of the laser spot having a high light intensity among the plurality of laser spots. The intensity has increased, and it has become possible to detect the optimum recording power with high accuracy.

At this time, the reproduction of the test writing area is performed by using a normal reproduction circuit, so that an increase in the cost of the apparatus can be prevented.

According to the fourth aspect of the present invention, the information recording operation is masked, and the laser beam is continuously emitted for a predetermined time by the pickup means. Since the laser is emitted by the power, when the laser light is continuously emitted, the laser power is not so strong that an abnormal area is not generated on the information recording medium.

According to the fifth aspect of the present invention, when the information recording operation is masked, the pickup means emits laser light continuously for a predetermined time, and when the recorded information is reproduced, the laser at the time of reproduction is reproduced. Since the laser is emitted by the power, when the laser light is continuously emitted, the laser power is not so strong that an abnormal area is not generated on the information recording medium.

According to the sixth aspect of the invention, the information recording operation is masked, the laser light is continuously emitted for a predetermined time, and the laser power is controlled during the period, so that the recording power and the like can be adjusted. Will be possible.

According to the invention of claim 7, since the information recording operation is masked, the laser light is continuously emitted for a predetermined time, and the laser power at the time of recording, erasing, or reproducing is controlled during the period. It is possible to adjust the laser power appropriately with high reliability.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical disc device applied to the description of a first embodiment.

FIG. 2 is a diagram showing a positional relationship of a laser spot on a track formed on a phase change disk.

FIG. 3 is a flowchart when detecting and adjusting the recording power.

FIG. 4 is a configuration diagram of an optical disc device applied to the description of a second embodiment.

FIG. 5 is a configuration diagram of an optical disc device applied to the description of a third embodiment.

FIG. 6 is a configuration diagram of an optical disc device applied to the description of a fourth embodiment.

FIG. 7 is a timing chart showing the operation timing of FIG.

8A and 8B are drive waveforms of a laser beam applied to the description of the related art and the description of the problem. FIG.
(B) is a driving waveform of the phase change type disk.

[Description of Signs] 2 Pickup 4 Semiconductor laser element 4 5 Laser light detection element 6 Signal detection light receiving element 7 to 9, 61 IV converter 10 Semiconductor laser control circuit 11 CPU 12 A / D converter 13 Semiconductor laser drive Circuit 14 Peak detection circuit 16 Bottom detection circuit 15, 17 D / A converter 18, 19 AND gate 41 Switch 51 Reproduction current drive circuit 53 Erase current drive circuit 55 Recording current drive circuit 52 Erase current switch 54 Recording current switch 62 For reproduction Comparison circuit 63 Erasure comparison circuit 64 Reproduction S / H circuit 65 Erasure S / H circuit 66 Amplifier

Claims (7)

[Claims] 1. A laser beam from a laser source is converged on an information recording medium to form a laser spot, and when recording information on the information recording medium, the laser beam is pulse-emitted with a predetermined pulse width. A pickup means for continuously emitting a laser beam when reproducing or erasing recorded information; a reproducing means for reproducing recorded information; a detecting means for detecting a recording state of the recorded information; By masking the operation, the pickup means continuously emits a laser beam for a predetermined time, the recording state of the information recorded immediately before the mask is detected by the detection means, and the pickup means is controlled based on the detection result. An optical disc device comprising: a control unit for adjusting a laser power at the time of recording. 2. The information recording medium has a packet area in which information is recorded in a packet format, and a linking area provided between the packet areas, and the pickup means scans the linking area. 2. The optical disk apparatus according to claim 1, wherein said control means causes said detection means to detect a recording state. 3. The pickup means has a multiple spot forming section for forming at least two or more laser spots from one laser beam, and the control means controls a test in a test writing area preset in the pickup means. The writing is performed, and the detecting unit detects the recording state of the information recorded in the test writing area by using reflected light having a high light intensity among reflected lights of the two or more laser spots. Item 3. The optical disk device according to item 1 or 2. 4. When the control means masks an information recording operation and causes the pickup means to continuously emit a laser beam for a predetermined time, the control means continuously emits a laser beam at a reproduction laser power for reproducing the recorded information. Claim 1 characterized by the following:
4. The optical disk device according to any one of claims 1 to 3. 5. When the control means masks an information recording operation and causes the pickup means to continuously emit a laser beam for a predetermined time, the control means continuously emits a laser beam at the erasing laser power for erasing the recorded information. The optical disk device according to any one of claims 1 to 4, wherein: 6. A laser source drive section for controlling and driving a laser source, wherein the pickup means monitors a laser power emitted from the laser source when at least laser light is continuously emitted, and outputs a laser power monitor signal. A laser power detecting unit for outputting, based on a detection result of a recording state of the information received from the detecting unit,
An arithmetic and control unit for calculating a recording power target value signal which is a target value of the laser power at the time of recording; and comparing the recording power target value signal with the laser power monitor signal so that the laser power becomes the recording power target value. 6. The optical disk device according to claim 1, further comprising: a laser control unit that outputs a laser power control signal to the laser source driving unit. 7. The laser power when the laser source driving section causes the laser source to emit laser light continuously, based on the laser power control signal from the laser control section, when reproducing information or when erasing information. 7. The optical disk device according to claim 6, wherein the laser power is: