JPH09167371A - Recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always perform recording with a good laser output by reproducing a signal recorded immediately before and controlling a laser output based on the measuring of an actual error rate while an optical pickup is on standby during a recording period. SOLUTION: While an optical pickup 2 is on standby for recording during a recording period, a laser output is controlled. A specified amount of information to be recorded in a DRAM 12 is recorded in a magneto-optical disk 21, the used amount of the DRAM is compared with a reference capacity and when it is within the reference capacity, a signal is reproduced considering that the controlling of a laser output is possible. If the error rate of the reduced signal exceeds a reference error rate, a laser output is increased by a specified value and the signal of a recording unit in the DRAM 12 is recorded in the disk 21. If the error rate of this reproduced signal is larger than the previous error rate, the laser output is decreased. By controlling the laser output to be lower than the reference error rate, good recording always can be obtained.

Description

Detailed Description of the Invention

[0001]

[0001]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus such as a mini disk recorder for intermittently recording.

[0003]

[0002]

[0004]

2. Description of the Related Art Recently, a mini disk recorder (hereinafter referred to as MD recorder) capable of recording and reproducing signals has been developed. When this MD recorder records with the same recording laser output, the error rate of the recording signal changes due to changes in the disk temperature. Therefore, in order to reduce the error rate of the recording signal as much as possible, the laser output is controlled during recording. More specifically, a temperature sensor in which the output voltage changes due to a temperature change near the disk is used to control the laser output by using this output voltage as a laser output control signal. This temperature sensor obtains the characteristics of the optimum laser output with respect to the disk temperature from the data measured in advance using a certain predetermined disk, and selects one having an output voltage characteristic that can perform control close to this characteristic. I am using.

[0005]

[0003]

[0006]

However, in the above-mentioned method, the number of components such as the temperature sensor increases, making it difficult to downsize the MD recorder and increasing the cost. Further, it is very difficult to select a temperature sensor that controls the ideal laser output characteristic, and it is difficult to control with high accuracy.

[0007]

Further, when the temperature sensor is at the reference temperature,
It is necessary to make adjustments so as to output a predetermined control voltage, which will increase the number of production processes, and even if adjustments are made during production, if the characteristics of the temperature sensor change over time, laser output control will be adversely affected. Will have an effect.

[0008]

Further, the optimum laser output characteristic with respect to the disk temperature is based on the data measured using a predetermined optical disk, and cannot be said to be the optimum laser output for all the optical disks having a characteristic variation to some extent.

[0009]

Therefore, the present invention has been made to deal with such a situation, and does not use parts such as a temperature sensor,
When the optical pickup is on standby during recording, the signal recorded immediately before is reproduced, and laser output control is performed based on the actual error rate measurement result and the like.

[0010]

[0007]

[0011]

According to a first aspect of the present invention, in order to achieve the above object, in a recording apparatus, there is a recording standby time during which the signal is not recorded during the signal recording period. And a recording pickup for recording a signal stored in the storage means or a signal obtained by compressing the signal on a recording medium, and a control means for controlling a laser output of the recording pickup. The control means controls the laser output during the recording standby of the recording pickup.

[0012]

According to a second aspect of the present invention, the control means of the recording apparatus according to the first aspect comprises a reproducing means for reproducing a signal recorded on the recording medium, and a signal reproduced by the reproducing means. An error rate detecting unit for detecting an error rate is provided, and the control unit controls the laser output based on the error rate detected by the error rate detecting unit.

[0013]

According to a third aspect of the present invention, the control means of the recording apparatus according to the first aspect comprises a reproducing means for reproducing a signal recorded on the recording medium, and a signal reproduced by the reproducing means. RF signal level detecting means for detecting an RF signal level, and the control means controls the laser output based on the RF signal level detected by the RF signal level detecting means.

[0014]

[0010]

[0015]

According to the inventions of claims 1 to 3,
In a recording apparatus that performs intermittent recording, the laser output control of the recording pickup is performed during recording standby during the recording period.
A good laser output can always be obtained without being affected by the difference in characteristics of various recording disks and the influence of ambient temperature.

[0016]

[0011]

[0017]

【Example】

(First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the basic structure of an embodiment of the MD recorder according to the present invention. The MD 20 has a magneto-optical disk 21 having a magnetic film and a cartridge 22 for protecting the magneto-optical disk 21. A guide groove is formed on the magneto-optical disk 21, and the guide groove is formed so as to wobble (meander) at a frequency FM-modulated by ADIP (ADdress In Pregroove) indicating absolute time information.

[0019]

As shown in FIG. 1, this MD recorder 10
Reference numeral 0 has a spindle motor 1 for rotationally driving the magneto-optical disk body 21, an actuator (not shown) and a polarization beam splitter, and irradiates the rotating magneto-optical disk 21 with a laser beam. In the magnetic film 21, the polarization plane slightly rotates according to the magnetization direction of the magneto-optical disk body 21 due to the magnetic Kerr effect, and the amount of light of the beam reflected and returned corresponding to the polarization plane is used. R for magneto-optical signal
An optical pickup 2 for outputting as an F signal (RF: Radio Frequency), an RF amplifier 7 for amplifying the RF signal to an appropriate level, and an unrecorded information by detecting a wobbling frequency from the RF signal. Also in the above, the ADIP decoder 6 capable of detecting the absolute position in the magneto-optical disk body 21, the EFM decoder 9 for extracting an EFM signal (EFM: Eight to Fourteen Modulation) from the amplified RF signal, and the Curie by the laser beam. A magnetic head 3 for recording information by applying an external magnetic field to the position of the magnetic film heated above the temperature, a head magnetic field control circuit 5 for controlling the external magnetic field output from the magnetic head 3, and about 1 Mbit Recording / playback information data is temporarily stored, and during recording, the recording data is not recorded due to vibration or defects (scratches, dirt, etc.) As a buffer to prevent a certain period of time missing, also during playback, the DRAM (Dynamic Random Access Memory) 12 as a buffer to prevent a sound skipping due to vibration,
A DRAM control circuit 11 for limiting the input / output of data to / from the DRAM 12, an A / D converter 15 for converting an analog information signal input from the outside during information recording into a digital information signal, and the converted digital information. A data compression encoder 13 for compressing the data amount of a signal to about ⅕ by utilizing the minimum audible limit characteristic of human ear and the masking effect, and a signal read from the MD 20 at the time of signal reproduction and EFM demodulated A data compression decoder 14 for decompressing data, a D / A converter 16 for converting the decoded digital audio signal into an analog signal, and a carriage 4 for moving the optical pickup 2 in the radial direction of the magneto-optical disk 21.
A servo control circuit 8 for servo-controlling the spindle motor 1, the carriage 4, and an actuator (not shown), a system controller 10 for controlling each part of the MD recorder 100, and an operation command from the outside to the system controller 10. Key input unit 18 for displaying, a display unit 17 for displaying the reproduction state of the MD recorder 100, and an electric power for a laser beam that the optical pickup 2 irradiates the magneto-optical disk body 21 during recording and reproduction. A laser output control circuit 19 for controlling the output (laser output) is provided, and these units are connected as shown.

[0020]

With this configuration, the servo control circuit 8 receives the RF signal from the RF amplifier, extracts a control signal for controlling the carriage 4 and an actuator (not shown), sends the control signal, and emits a laser beam. Focus control is performed to keep the objective lens and the magneto-optical disk 21 at a constant distance, and tracking servo control is performed so that the laser beam does not deviate from the recording track axis of the magneto-optical disk 21. Further, the servo control circuit 8 uses the EF from the EFM decoder 9.
Spindle servo control is performed by sending a control signal for rotating the spindle motor 1 at a constant speed based on a clock signal included in the M signal. The system controller 10 can send a control signal to each part of the recorder based on an operation command input from the outside to the key input part 18 to perform a high speed search operation, a random access play operation, or the like.

[0021]

Next, prior to the explanation of the operation of the present embodiment, FIG.
The “recording standby time” during the recording period in the MD recorder will be described with reference to FIG. As shown in FIG. 2, the recording of the MD recorder uses a method of compressing the input information and recording the compressed data. At this time, since the information to be recorded is compressed, the predetermined unit of information to be recorded is M
The time for recording the compressed predetermined unit of information on the magneto-optical disk 21 is shorter than the time for being input to the D recorder. That is, the information recording rate is higher than the information input rate. Therefore, even during the recording of information, a recording standby time T shown by T1 to T3 in FIG. 2 in which the optical pickup 2 does not record on the magneto-optical disk 21 occurs. The present invention uses this recording standby time T to control the laser output of the optical pickup 2.

[0022]

Next, FIG. 3 shows an error rate judging circuit not shown in FIG. The error rate judgment circuit
The EFM decoder 9 shown in FIG. 1 and the EFM decoder 9
Error rate counter 31 for adding the number of error corrections based on the error correction information obtained when decoding from
And a comparison circuit 32 that compares the error rate measured by the error rate counter 31 with the reference error rate, and the system controller 10 to which the comparison result of the comparison circuit 32 is input.

[0023]

Next, the operation of this embodiment will be described with reference to FIG. A predetermined amount of information to be recorded in the DRAM 12 is recorded on the magneto-optical disk 21 (step 1). Next, the system controller 10 and the DRAM control circuit 11 first compare the used capacity of the DRAM 12 with a predetermined reference capacity (step 2). This is to determine whether or not there is time for performing laser output control, which will be described later. That is, during the average time required for laser output control, it is determined whether or not there is a free space that can hold the input signal without overflowing the DRAM 12. If the capacity of the DRAM 12 is equal to or larger than the predetermined reference capacity (step 2: NO), step 1 is performed. If the capacity of the DRAM 12 is less than the reference capacity (step 2: YES), the step 1 recording signal (the meaning of the signal recorded in step 1, the same applies to the similar portions hereinafter) is reproduced (step 3).

[0024]

Then, in the comparison circuit 32, it is judged whether the error rate of the reproduction signal of step 3 (the meaning of the signal reproduced in step 3, the same applies hereinafter) is less than the reference error rate (step 4). The reference error rate is set to a value lower than the maximum value (worst value) of the error rate allowable range obtained during normal recording. Therefore, if the error rate is equal to or lower than the reference error rate, good recording can be performed.

[0025]

In the comparison of the error rates in step 4, when the error rate of the reproduced signal in step 3 is less than the reference error rate (step 4: YES), the reference error rate is satisfied, and it is necessary to control the laser output. Since there is not, return to step 1. On the contrary, when it is equal to or higher than the reference error rate (step 4: NO), the laser output is increased by a predetermined value (step 5). Then, the laser output whose output has been increased is waited as the next recording power condition. And then DRA
A signal, which is a recording unit to be recorded in M12, is recorded on the disc (step 6). Then, the recording signal in step 6 is reproduced (step 7).

[0026]

Step 7 The error rate of the reproduced signal is measured, and the error rate and the error rate are measured in Step 4 and stored in the comparison circuit in Step 3.
The error rate of the reproduced signal is compared (step 8). Here, if the error rate of the reproduction signal of step 7 has improved or decreased (step 8: YES), the error rate of the reproduction signal of step 7 is compared with the reference error rate (step 9). Here, when the error rate of the reproduction signal in step 7 is less than the reference error rate (step 9: YES), the laser output control is ended and the process proceeds to step 1 to perform the above-described operation. If it is equal to or higher than the reference error rate in step 9 (step 9: NO), the process returns to step 5 and the laser output is further increased by a predetermined amount to stand by, and a signal which is the next information unit to be recorded is recorded. Step 7 is repeated until the error rate of the reproduction signal becomes less than the reference error rate.

[0027]

Further, when the error rate is deteriorated in step 8 (step 8: NO), the output is lowered by a predetermined amount from the laser output recording the signal in step 1 (step 1).
0) A signal of an information unit to be recorded next is recorded with this laser output (step 11). Further, the reason why recording is performed at a value in which the laser output is lowered by a predetermined amount from the laser output in step 1 is that the characteristics of the laser output vs. error rate have the characteristics shown in FIG. 5, and the reference error rate is the value shown by the broken line, for example. Therefore, when the laser output control range is above the broken line and the laser output is increased and the error rate deteriorates,
This is because the error rate can be improved by reducing the laser output. On the contrary, when the laser output is lowered and the error rate is deteriorated, it is clear that the error rate can be improved by increasing the laser output.

[0028]

Then, in step 11, the recording signal is reproduced (step 12). Thereafter, the error rate of the reproduction signal in step 12 is compared with the reference error rate (step 13). If the error rate of the reproduction signal in step 12 is less than the reference error rate (step 13: Y
ES), the laser output control is completed, and the process proceeds to step 1. On the contrary, if the error rate of the reproduced signal in step 12 is equal to or higher than the reference error rate (step 12: NO), the process proceeds to step 10 again, and a predetermined amount of laser output is further output from the laser output recorded the step 11 recording signal last time. The signal of the information unit to be recorded next is lowered and recorded.

This is repeated until it becomes less than the reference error rate in step 13 (step 13: YES).

[0030]

Furthermore, if a recording stop command is issued while the steps in this flowchart are being performed, the recording operation is terminated at that point, and the operations in this flowchart are also terminated.

[0031]

If the timer does not return to the step 1 even if a predetermined time has passed after entering the step 3 by the timer means (not shown), that is, if the laser output control is not finished,
You may forcibly return to step 1. Even if information is continuously input from the reference value of DRAM for this predetermined time, D
Set the time when the information in RAM does not overflow.

[0032]

In the first embodiment, the laser output control is performed according to the error rate of the signal recorded immediately before, so that the laser output control is not performed immediately after the start of recording. Therefore, in order to control the laser output immediately after the start of recording, a predetermined test signal is recorded / reproduced in a recordable area such as an unrecorded area or a recorded area that may be overwritten before the start of recording so that the error rate Measurement and laser output control may be performed. The laser output may be controlled by recording / reproducing a predetermined test signal not only before the start of recording but also during the recording period. However, since it is not preferable that the recorded test signal is reproduced during normal reproduction, the recorded test signal is erased or the U-TOC (User Tab) is used.
le Of Contents), and it is preferable to perform processing that is not played during normal playback.

[0033]

(Second Embodiment) Next, a second embodiment will be described with reference to the drawings.

In the second embodiment, laser output control is performed using the RF level.

[0035]

FIG. 6 shows a block diagram of the RF level determination circuit. The RF amplifier 7 and the system controller 10 of this circuit are those shown in FIG. In addition to this configuration, a detection circuit 61 for detecting the output from the RF amplifier.
And a window comparator 62 for determining whether the detected output is within a predetermined range, and the output detected by the detection circuit are input, compared with a reference value, and compared with the reference value of the output. Comparing circuit 63 for comparing the size of all
An RF level determination circuit is configured by the determination circuit 64 that inputs the outputs of the comparison circuit 63 and the window comparator 62, and the determination result of the determination circuit 64, and the system controller 10 that controls the laser output.

[0036]

Next, a second embodiment will be described with reference to FIGS.

When a recording command is input to the MD recorder, a predetermined amount of information to be recorded in the DRAM 12 is recorded on the magneto-optical disk 21 (step 21). Next, by the system controller 10 and the DRAM control circuit 11,
First, the used capacity of the DRAM 12 is compared with a predetermined reference capacity to determine whether the amount of information stored in the DRAM 12 is less than or equal to the predetermined reference capacity (step 22). If the information amount is equal to or larger than the reference capacity (step 22: NO), the signal of the information unit to be recorded next on the disc is recorded (step 21). When it is determined in step 22 that the amount of information is less than the reference capacity (step 22: Y
ES) proceeds to step 23 and reproduces the recording signal in step 21 (step 23).

[0038]

In step 23, the RF signal level of the reproduced signal is judged by the window comparator to be within the reference range (step 24). The reference range of this window comparator is set to a range smaller than the allowable RF signal level range which is the range of the RF signal level when good recording is performed. When it is determined that the determination result of step 24 is within the reference range (step 24: YES), the process returns to step 21. On the contrary, when it is determined that the value is out of the reference range (step 24: N
O), it is determined whether the RF signal level is equal to or higher than the reference value (step 25), and when it is equal to or higher than the reference value (step 25: YES), the laser output is controlled to be decreased by a predetermined amount (step 26). This is because the RF signal level is higher than the reference range, so that the laser output is lowered and recorded so as to approach the reference range.

On the contrary, when it is less than the reference value (step 25: NO), the laser output is controlled to be increased by a predetermined amount (step 27). And after laser output control,
Return to step 24.

The reason why the laser output changes depending on the RF signal level is that the RF level characteristic also has a peak at the optimum point and deteriorates from the optimum point, as in the error rate shown in FIG.

[0041]

Furthermore, if a recording stop command is issued while the steps in this flowchart are being performed, the recording operation is terminated at that point, and the operations in this flowchart are also terminated.

[0042]

It should be noted that the time counting means (not shown) does not return to step 21 even after a lapse of a predetermined time after entering step 23, that is, if the laser output control is not finished, the process is forced to return to step 21. Is also good. This predetermined time is set to the time when the information in the DRAM does not overflow even if the information is continuously input from the reference value of the DRAM.

[0043]

In the second embodiment, the laser output control is performed according to the RF signal level of the signal recorded immediately before, so that the laser output control is not performed immediately after the start of recording. Therefore, in order to optimally control the laser output immediately after the start of recording, a predetermined test signal is recorded and reproduced in a recordable area such as an unrecorded area or a recorded area that may be overwritten before the recording is started. The signal level may be measured and the laser output may be controlled. The laser output may be controlled by recording / reproducing a predetermined test signal not only at the start of recording but also during the recording period. However, since it is not preferable that the recorded test signal is reproduced during normal reproduction, the recorded test signal is erased or the U-TOC is deleted.
It is preferable to perform processing that is managed on the (User Table Of Contents) and that is not reproduced during normal reproduction.

[0044]

Further, M shown in the first and second embodiments
Since the D recorder is compressing and recording, the predetermined unit of information to be recorded is longer than the time when it is input to the MD recorder.
Although the time for recording the compressed predetermined unit of information on the magneto-optical disk 21 is shorter and the recording standby time is generated, the present invention is limited to a recording apparatus for performing compressed recording such as an MD recorder. However, the present invention can be applied to any recording apparatus that generates a recording standby time during the recording period.

[0045]

Further, in the first and second embodiments, M
Although the description has been made using the magneto-optical disk of D, the present invention is not limited to this, and can be applied to any optical disk recording medium.

[0046]

[0034]

[0047]

As described above, by controlling the laser output during the recording standby time during the recording operation, recording can always be performed with a good laser output.

[Brief description of the drawings]

FIG. 1 Basic configuration of MD recorder

FIG. 2 is a diagram illustrating a recording standby time during recording.

[FIG. 3] Error rate determination circuit

FIG. 4 is an operation flowchart of the first embodiment.

FIG. 5: Characteristic diagram of laser output vs. error rate

FIG. 6 RF level determination circuit

FIG. 7 is an operation flowchart of the second embodiment.

[Explanation of symbols]

 1 Spindle Motor 2 Optical Pickup 3 Magnetic Head 4 Carriage 5 Head Magnetic Field Control Circuit 6 ADIP Decoder 7 RF Amplifier 8 Servo Control Circuit 9 EFM Decoder 10 System Controller 11 DRAM Control Circuit 12 DRAM 13 Data Compression Encoder 14 Data Compression Decoder 15 A / D Converter 16 D / A converter 17 Display section 18 Key input section 19 Laser output control circuit 20 MD 21 Magneto-optical disk 22 Cartridge 31 Error rate counter 32 Comparison circuit 61 Detection circuit 62 Window comparator 63 Comparison circuit 64 Judgment circuit 100 MD recording / reproducing apparatus

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[Procedure amendment]

[Submission date] December 16, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Detailed description of the invention

[Correction method] Change

[Correction contents]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus such as a mini disk recorder for intermittently recording.

[0002]

2. Description of the Related Art Recently, a mini disk recorder (hereinafter referred to as MD recorder) capable of recording and reproducing signals has been developed. When this MD recorder records with the same recording laser output, the error rate of the recording signal changes due to changes in the disk temperature. Therefore, in order to reduce the error rate of the recording signal as much as possible, the laser output is controlled during recording. More specifically, a temperature sensor in which the output voltage changes due to a temperature change near the disk is used to control the laser output by using this output voltage as a laser output control signal. This temperature sensor obtains the characteristics of the optimum laser output with respect to the disk temperature from the data measured in advance using a certain predetermined disk, and selects one having an output voltage characteristic that can perform control close to this characteristic. I am using.

[0003]

However, in the above-mentioned method, the number of components such as the temperature sensor increases, making it difficult to downsize the MD recorder and increasing the cost. Further, it is very difficult to select a temperature sensor that controls the ideal laser output characteristic, and it is difficult to control with high accuracy.

Further, when the temperature sensor is at the reference temperature,
It is necessary to make adjustments so as to output a predetermined control voltage, which will increase the number of production processes, and even if adjustments are made during production, if the characteristics of the temperature sensor change over time, laser output control will be adversely affected. Will have an effect.

Further, the optimum laser output characteristic with respect to the disk temperature is based on the data measured using a predetermined optical disk, and cannot be said to be the optimum laser output for all the optical disks having a characteristic variation to some extent.

Therefore, the present invention has been made to deal with such a situation, and does not use parts such as a temperature sensor,
When the optical pickup is on standby during recording, the signal recorded immediately before is reproduced, and laser output control is performed based on the actual error rate measurement result and the like.

[0007]

According to a first aspect of the present invention, in order to achieve the above object, in a recording apparatus, there is a recording standby time during which the signal is not recorded during the signal recording period. And a recording pickup for recording a signal stored in the storage means or a signal obtained by compressing the signal on a recording medium, and a control means for controlling a laser output of the recording pickup. The control means controls the laser output during the recording standby of the recording pickup.

According to a second aspect of the present invention, the control means of the recording apparatus according to the first aspect comprises a reproducing means for reproducing a signal recorded on the recording medium, and a signal reproduced by the reproducing means. An error rate detecting unit for detecting an error rate is provided, and the control unit controls the laser output based on the error rate detected by the error rate detecting unit.

According to a third aspect of the present invention, the control means of the recording apparatus according to the first aspect comprises a reproducing means for reproducing a signal recorded on the recording medium, and a signal reproduced by the reproducing means. RF signal level detecting means for detecting an RF signal level, and the control means controls the laser output based on the RF signal level detected by the RF signal level detecting means.

[0010]

According to the inventions of claims 1 to 3,
In a recording apparatus that performs intermittent recording, the laser output control of the recording pickup is performed during recording standby during the recording period.
A good laser output can always be obtained without being affected by the difference in characteristics of various recording disks and the influence of ambient temperature.

[0011]

(First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the basic configuration of an embodiment of the MD recorder according to the present invention. The MD 20 has a magneto-optical disk 21 having a magnetic film and a cartridge 22 for protecting the magneto-optical disk 21. A guide groove is formed on the magneto-optical disk 21,
This guide groove shows ADIP (ADdre) indicating absolute time information.
It is formed so as to wobble (meander) at a frequency that is FM-modulated by ss InPregroove.

As shown in FIG. 1, this MD recorder 10
Reference numeral 0 has a spindle motor 1 for rotationally driving the magneto-optical disk body 21, an actuator (not shown) and a polarization beam splitter, and irradiates the rotating magneto-optical disk 21 with a laser beam. In the magnetic film 21, the polarization plane slightly rotates according to the magnetization direction of the magneto-optical disk body 21 due to the magnetic Kerr effect, and the amount of light of the beam reflected and returned corresponding to the polarization plane is used. R for magneto-optical signal
An optical pickup 2 for outputting as an F signal (RF: Radio Frequency), an RF amplifier 7 for amplifying the RF signal to an appropriate level, and a wobbling frequency detected from the RF signal when information is not recorded Also in the above, the ADIP decoder 6 capable of detecting the absolute position in the magneto-optical disc body 21 and the EFM signal (EFM: Eight to
EFM decoder 9 for extracting the Fourteen Modulation), a magnetic head 3 for applying an external magnetic field to the position of the magnetic film heated to a Curie temperature or higher by a laser beam to record information, and an output from the magnetic head 3. The head magnetic field control circuit 5 for controlling the external magnetic field and the recording / reproducing information data of about 1 Mbit are temporarily stored, and during recording, the recording signal is not lost due to vibration or defects (scratches, dirt, etc.) of the magneto-optical disk. A DRAM (Dynamic Random Acces) as a buffer for preventing a certain period of time and as a buffer for preventing skipping due to vibration during playback.
s Memory) 12, a DRAM control circuit 11 for limiting the input and output of data to and from the DRAM 12, and an A / D converter 15 for converting an analog information signal input from the outside during information recording into a digital information signal. , A data compression encoder 13 for compressing the data amount of the converted digital information signal to about ⅕ using the minimum audibility limit characteristic of human ear and the masking effect, and read from MD 20 at the time of signal reproduction. E
A data compression decoder 14 for decompressing the FM demodulated signal, a D / A converter 16 for converting the decoded digital audio signal into an analog signal,
A carriage 4 for moving the optical pickup 2 in the radial direction of the magneto-optical disk 21, a spindle motor 1,
A servo control circuit 8 for servo-controlling the carriage 4 and an actuator (not shown), and the MD
A system controller 10 for controlling each part of the recorder 100, a key input part 18 for giving an operation command to the system controller 10 from the outside, and a display part 17 for displaying a reproduction state of the MD recorder 100 and the like.
And a laser output control circuit 19 for controlling the electric output (laser output) for the laser beam with which the optical pickup 2 irradiates the magneto-optical disk body 21 during recording and reproduction. Connected as shown.

With this configuration, the servo control circuit 8 receives the RF signal from the RF amplifier, extracts a control signal for controlling the carriage 4 and an actuator (not shown), sends the control signal, and emits a laser beam. Focus control is performed to keep the objective lens and the magneto-optical disk 21 at a constant distance, and tracking servo control is performed so that the laser beam does not deviate from the recording track axis of the magneto-optical disk 21. Further, the servo control circuit 8 uses the EF from the EFM decoder 9.
Spindle servo control is performed by sending a control signal for rotating the spindle motor 1 at a constant speed based on a clock signal included in the M signal. The system controller 10 can send a control signal to each part of the recorder based on an operation command input from the outside to the key input part 18 to perform a high speed search operation, a random access play operation, or the like.

Next, prior to the explanation of the operation of the present embodiment, FIG.
The “recording standby time” during the recording period in the MD recorder will be described with reference to FIG. As shown in FIG. 2, the recording of the MD recorder uses a method of compressing the input information and recording the compressed data. At this time, since the information to be recorded is compressed, the predetermined unit of information to be recorded is M
The time for recording the compressed predetermined unit of information on the magneto-optical disk 21 is shorter than the time for being input to the D recorder. That is, the information recording rate is higher than the information input rate. Therefore, even during the recording of information, a recording standby time T shown by T1 to T3 in FIG. 2 in which the optical pickup 2 does not record on the magneto-optical disk 21 occurs. The present invention uses this recording standby time T to control the laser output of the optical pickup 2.

Next, FIG. 3 shows an error rate judging circuit not shown in FIG. The error rate judgment circuit
The EFM decoder 9 shown in FIG. 1 and the EFM decoder 9
Error rate counter 31 for adding the number of error corrections based on the error correction information obtained when decoding from
And a comparison circuit 32 that compares the error rate measured by the error rate counter 31 with the reference error rate, and the system controller 10 to which the comparison result of the comparison circuit 32 is input.

Next, the operation of this embodiment will be described with reference to FIG. A predetermined amount of information to be recorded in the DRAM 12 is recorded on the magneto-optical disk 21 (step 1). Next, the system controller 10 and the DRAM control circuit 11 first compare the used capacity of the DRAM 12 with a predetermined reference capacity (step 2). This is to determine whether or not there is time for performing laser output control, which will be described later. That is, during the average time required for laser output control, it is determined whether or not there is a free space that can hold the input signal without overflowing the DRAM 12. If the capacity of the DRAM 12 is equal to or larger than the predetermined reference capacity (step 2: NO), step 1 is performed. If the capacity of the DRAM 12 is less than the reference capacity (step 2: YES), the step 1 recording signal (the meaning of the signal recorded in step 1, the same applies to the following) is reproduced (step 3).

Then, in the comparison circuit 32, it is judged whether or not the error rate of the reproduction signal in step 3 (the meaning of the signal reproduced in step 3, the same applies hereinafter) is less than the reference error rate (step 4). The reference error rate is set to a value lower than the maximum value (worst value) of the error rate allowable range obtained during normal recording. Therefore, if the error rate is equal to or lower than the reference error rate, good recording can be performed.

In the comparison of the error rates in step 4, when the error rate of the reproduced signal in step 3 is less than the reference error rate (step 4: YES), the reference error rate is satisfied, and it is necessary to control the laser output. Since there is not, return to step 1. On the contrary, when it is equal to or higher than the reference error rate (step 4: NO), the laser output is increased by a predetermined value (step 5). Then, the laser output whose output has been increased is waited as the next recording power condition. And then DRA
A signal, which is a recording unit to be recorded in M12, is recorded on the disc (step 6). Then, the recording signal in step 6 is reproduced (step 7).

Step 7 The error rate of the reproduced signal is measured, and the error rate and the error rate are measured in Step 4 and stored in the comparison circuit in Step 3.
The error rate of the reproduced signal is compared (step 8). Here, if the error rate of the reproduction signal of step 7 has improved or decreased (step 8: YES), the error rate of the reproduction signal of step 7 is compared with the reference error rate (step 9). Here, when the error rate of the reproduction signal in step 7 is less than the reference error rate (step 9: YES), the laser output control is ended and the process proceeds to step 1 to perform the above-described operation. If it is equal to or higher than the reference error rate in step 9 (step 9: NO), the process returns to step 5 and the laser output is further increased by a predetermined amount to stand by, and a signal which is the next information unit to be recorded is recorded. Step 7 is repeated until the error rate of the reproduction signal becomes less than the reference error rate.

Further, when the error rate is deteriorated in step 8 (step 8: NO), the output is lowered by a predetermined amount from the laser output recording the signal in step 1 (step 1).
0) A signal of an information unit to be recorded next is recorded with this laser output (step 11). Further, the reason why recording is performed at a value in which the laser output is lowered by a predetermined amount from the laser output in step 1 is that the characteristics of the laser output vs. error rate have the characteristics shown in FIG. 5, and the reference error rate is the value shown by the broken line, for example. Therefore, when the laser output control range is above the broken line and the laser output is increased and the error rate deteriorates,
This is because the error rate can be improved by reducing the laser output. On the contrary, when the laser output is lowered and the error rate is deteriorated, it is clear that the error rate can be improved by increasing the laser output.

Then, in step 11, the recording signal is reproduced (step 12). Thereafter, the error rate of the reproduction signal in step 12 is compared with the reference error rate (step 13). If the error rate of the reproduction signal in step 12 is less than the reference error rate (step 13: Y
ES), after finishing the laser output control, the process proceeds to step 1. On the contrary, if the error rate of the reproduced signal in step 12 is equal to or higher than the reference error rate (step 12: NO), the process proceeds to step 10 again, and a predetermined amount of laser output is further output from the laser output recorded the step 11 recording signal last time. The signal of the information unit to be recorded next is lowered and recorded. This is less than the reference error rate in step 13 (step 13: YE
Repeat until S).

Furthermore, if a recording stop command is issued while the steps in this flowchart are being performed, the recording operation is terminated at that point, and the operations in this flowchart are also terminated.

If the timer does not return to step 1 even if a predetermined time has passed after step 3 is entered, that is, if the laser output control is not finished, the timer means is not shown.
You may forcibly return to step 1. Even if information is continuously input from the reference value of DRAM for this predetermined time, D
Set the time when the information in RAM does not overflow.

In the first embodiment, the laser output control is performed according to the error rate of the signal recorded immediately before, so that the laser output control is not performed immediately after the start of recording. Therefore, in order to control the laser output immediately after the start of recording, a predetermined test signal is recorded / reproduced in a recordable area such as an unrecorded area or a recorded area that may be overwritten before the start of recording so that the error rate Measurement and laser output control may be performed. The laser output may be controlled by recording / reproducing a predetermined test signal not only before the start of recording but also during the recording period. However, since it is not preferable that the recorded test signal is reproduced during normal reproduction, the recorded test signal is erased or U-TOC (User).
It manages on Table Of Contents),
It is preferable to perform processing such that the normal reproduction is not performed.

(Second Embodiment) Next, a second embodiment will be described with reference to the drawings. In the second embodiment, laser output control is performed using the RF level.

FIG. 6 shows a block diagram of the RF level determination circuit. The RF amplifier 7 and the system controller 10 of this circuit are those shown in FIG. In addition to this configuration, a detection circuit 61 for detecting the output from the RF amplifier.
And a window comparator 62 for determining whether the detected output is within a predetermined range, and the output detected by the detection circuit are input, compared with a reference value, and compared with the reference value of the output. Comparing circuit 63 for comparing the size of all
An RF level determination circuit is configured by the determination circuit 64 that inputs the outputs of the comparison circuit 63 and the window comparator 62, and the determination result of the determination circuit 64, and the system controller 10 that controls the laser output.

Next, a second embodiment will be described with reference to FIGS. When a recording command is input to the MD recorder, a predetermined amount of information to be recorded in the DRAM 12 is recorded on the magneto-optical disk 21 (step 21). Next, the system controller 10 and the DRAM control circuit 11 first compare the used capacity of the DRAM 12 with a predetermined reference capacity to determine whether the amount of information stored in the DRAM 12 is less than or equal to the predetermined reference capacity (step 22). If the amount of information is greater than or equal to the reference capacity (step 22: NO),
A signal of an information unit to be recorded next is recorded on the disc (step 21). In addition, when it is determined in step 22 that the amount of information is less than the reference capacity (step 22:
If YES, the process proceeds to step 23, and the recording signal of step 21 is reproduced (step 23).

In step 23, the RF signal level of the reproduced signal is judged by the window comparator to be within the reference range (step 24). The reference range of this window comparator is set to a range smaller than the allowable RF signal level range which is the range of the RF signal level when good recording is performed. When it is determined that the determination result of step 24 is within the reference range (step 24: YES), the process returns to step 21. On the contrary, when it is determined that the value is out of the reference range (step 24: N
O), it is determined whether the RF signal level is equal to or higher than the reference value (step 25), and when it is equal to or higher than the reference value (step 25: YES), the laser output is controlled to be decreased by a predetermined amount (step 26). This is because the RF signal level is higher than the reference range, so that the laser output is lowered and recorded so as to approach the reference range. On the contrary, when it is less than the reference value (step 25: NO),
The laser output is controlled to increase by a predetermined amount (step 27). Then, after the laser output control, the process returns to step 24. The reason why the laser output changes depending on the RF signal level is that the RF level characteristic also has a peak at the optimum point and deteriorates from the optimum point, like the error rate in FIG.

Furthermore, if a recording stop command is issued while the steps in this flowchart are being performed, the recording operation is terminated at that point, and the operations in this flowchart are also terminated.

It should be noted that the time counting means (not shown) does not return to step 21 even after a lapse of a predetermined time after entering step 23, that is, if the laser output control is not finished, the process is forced to return to step 21. Is also good. This predetermined time is set to the time when the information in the DRAM does not overflow even if the information is continuously input from the reference value of the DRAM.

In the second embodiment, the laser output control is performed according to the RF signal level of the signal recorded immediately before, so that the laser output control is not performed immediately after the start of recording. Therefore, in order to optimally control the laser output immediately after the start of recording, a predetermined test signal is recorded and reproduced in a recordable area such as an unrecorded area or a recorded area that may be overwritten before the recording is started. The signal level may be measured and the laser output may be controlled. The laser output may be controlled by recording / reproducing a predetermined test signal not only at the start of recording but also during the recording period. However, since it is not preferable that the recorded test signal is reproduced during normal reproduction, the recorded test signal is erased or the U-TOC is deleted.
It is preferable to perform processing that is managed on the (User Table Of Contents) and is not reproduced during normal reproduction.

Further, M shown in the first and second embodiments
Since the D recorder is compressing and recording, the predetermined unit of information to be recorded is longer than the time when it is input to the MD recorder.
Although the time for recording the compressed predetermined unit of information on the magneto-optical disk 21 is shorter and the recording standby time is generated, the present invention is limited to a recording apparatus for performing compressed recording such as an MD recorder. However, the present invention can be applied to any recording apparatus that generates a recording standby time during the recording period.

Further, in the first and second embodiments, M
Although the description has been made using the magneto-optical disk of D, the present invention is not limited to this, and can be applied to any optical disk recording medium.

[0034]

As described above, by controlling the laser output during the recording standby time during the recording operation, recording can always be performed with a good laser output.

Claims (3)

[Claims] 1. A recording apparatus having a recording standby state in which the signal is not recorded during a signal recording period, and a storage unit for storing the signal, and a signal stored in the storage unit or the signal compressed by the storage unit. A recording pickup that records the recorded signal on a recording medium, and a control unit that controls the laser output of the recording pickup, and the control unit controls the laser output during the recording standby of the recording pickup. A recording device characterized by. 2. The control means includes reproducing means for reproducing a signal recorded on the recording medium, and error rate detecting means for detecting an error rate of a signal reproduced by the reproducing means, The recording apparatus according to claim 1, wherein the control unit controls the laser output based on the error rate detected by the error rate detection unit. 3. The control means includes reproducing means for reproducing the signal recorded on the recording medium, and RF signal level detecting means for detecting the RF signal level of the signal reproduced by the reproducing means. The recording apparatus according to claim 1, wherein the control unit controls the laser output based on the RF signal level detected by the RF signal level detection unit.