JPH05274817A - Record decision method and data recorder - Google Patents

Abstract

PURPOSE:To perform an accurate verify by performing the timing adjustment of read data and delayed data and comparing them, based on the synchronizing signal read with data. CONSTITUTION:The output signal on the light receiving surface of a sensor is inputted in a control circuit via a binary circuit 85 from the differential amplifier of an arithmetic circuit and is verified. When a controller ODC 1 confirms the address of a sector to be recorded, the controller takes out data from a buffer RAM 2 by a synchronizing signal 12 detected by a synchronizing detection circuit 8 from reflection light from a disk, transmits the data to a comparison/decision circuit 14 and detects errors. Record data 10 is inputted in a delay circuit 11 and it is inputted as a signal 13 synchronized with reproduced data 15 in the comparison/decision circuit 14. In the decision circuit 14, a decision is performed by a prescribed judgment reference and a result signal 16 is supplied to the ODC 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recording data on a recording medium and determining the quality of the recording at the same time, and a data recording apparatus for executing this method.

[0002]

2. Description of the Related Art Conventionally, there are known various data recording devices for recording data on a recording medium and reading the recorded data as needed. In recent years, since a large amount of information can be recorded at a high density, an optical data recording device that records by irradiating an optical recording medium with a light beam has been particularly attracting attention. A magneto-optical disk device will be described below as an example of such a data recording device.

FIG. 16 is a schematic diagram showing a configuration example of a conventional magneto-optical disk device. Here, reference numeral 71 indicates a magneto-optical disk as a recording medium. The disk 71 is rotated by a motor (not shown) and moves in the direction of arrow D. An optical head and a magnetic head 82 are arranged at positions substantially opposite to each other with the disk 71 in between.
The optical head includes a light source 72 such as a semiconductor laser, a collimator lens 73, a beam splitter 74, an objective lens 75,
It contains a condenser lens 76, an analyzer 86, a photodetector 77, and the like.

In the apparatus having the above structure, the light beam emitted from the light source 72 passes through the collimator lens 73 and the beam splitter 74 and is focused by the objective lens 75 on the recording layer (magnetic film) of the magneto-optical disk 71. The temperature of the portion of the magnetic film irradiated with the light beam rises to near the Curie temperature, and the coercive force decreases. On the other hand, a magnetic field in the direction perpendicular to the film surface is applied by the magnetic head 82 in the vicinity of the light beam irradiation portion of the magnetic film. Then, in the above-mentioned portion where the coercive force is lowered by the irradiation of the light beam, the magnetization direction is oriented in the same direction as the applied magnetic field. The magnetic field applied from the magnetic head 82 is the magnetic head driver 81.
Is controlled so that the direction is reversed according to the data to be recorded. Therefore, in the portion scanned by the light beam with the movement of the disk 71, data is recorded as a succession of magnetic domains with upward magnetization and downward magnetization.

The data recorded as described above is read out after recording, and an error is detected. Then, the quality of recording is judged from the number of detected errors. Such an operation is usually called verification.
If the verification determines that the recording is defective,
Data is re-recorded in a portion where bad recording is performed or a portion different from this portion.

At the time of the above verification, the light source 72 of the optical head emits a light beam having a power smaller than that at the time of recording, and the data recording portion of the disk 71 is scanned by this light beam. The reflected light of the light beam from the disk 71 has its polarization direction modulated by the magneto-optical effect such as the Kerr effect according to the recorded data.
The reflected light is separated from the optical path of the irradiation beam by the beam splitter 74 and is condensed by the condenser lens 76.
The reflected light that has passed through the condenser lens 76 is transmitted through the analyzer 86, converted into intensity-modulated light in accordance with the recorded data, and detected by the photodetector 77. The output signal of the photodetector 77 is binarized through a binarization circuit 78, and is input to a magneto-optical disk drive controller (hereinafter referred to as ODC) 80 through a data separator 79.
ODC80 is a microprocessor unit (MPU)
83 and a small computer system interface (SCSI) control circuit 84. OD
In C80, the data read from the disc is checked for errors. Then, when the error is equal to or less than the predetermined criterion, the recording operation is ended.
If the error exceeds the criterion, it is determined that the recording is defective, and the ODC 80 causes the data to be re-recorded.

FIG. 17 is a block diagram showing a configuration example of the ODC. Here, the ODC performs data flow control, modulation, demodulation, synchronization processing, etc., and an error correction code (ECC) circuit generates a parity at the time of recording to correct an error occurring in the data and reproduces it. Sometimes the parity generated during recording is used to correct the error in the data read from the disk.

In FIG. 17, the ODC is a DMA interface (I / F) via a DMA controller 25.
It is connected by 24 to the aforementioned SCSI control circuit 84. Further, the ODC is connected to the aforementioned MPU 83 by the MPU-I / F 21 via the MPU-I / F circuit 22. The ODC also includes the ECC circuit 26 and DRAM.
It is composed of a controller 83, a buffer RAM 84, and a formatter circuit 27. Each of these units is connected to each other by an internal bus 23. The formatter circuit 27 also includes a synchronization signal generation circuit, a synchronization signal detection circuit, a modulation circuit, and a demodulation circuit.

When recording data in the apparatus shown in FIGS. 16 and 17, the ECC circuit 26 first adds an error correction code to the data sent from the SCSI control circuit 84. The data to which the error correction code has been added is coded into a code for recording by the formatter circuit 27, and further a synchronization signal necessary for reproduction is added to the recording signal 28.
Is sent to the magnetic head driver 81. The magnetic head driver 81 drives the magnetic head 82 in accordance with the transmitted recording signal 28 to record data on the magneto-optical disk 71.

Next, when verifying is performed, the data recording portion of the disk is again scanned with the light beam as described above, and the signal recorded by the photodetector 77 is read. The read signal is binarized by the binarization circuit 78, and the clock-synchronized reproduction signal 29 is taken out by the data separator 79. The reproduced signal 29 extracted is the ODC8.
It is sent to the formatter circuit 27 in 0, and various sync signals are detected by the sync signal detection circuit. Also, the reproduction signal 29
Is separated into data and sync signal, and only data ECC
It is input to the circuit 26. Note that the sync signal used here can be detected even if there is some error.
It consists of a pattern with some degree of redundancy,
Further, even if it is not detected, it is designed so that there is no inconvenience in reproducing the data by interpolation or the like.

The ECC circuit 26 performs a syndrome calculation of the input data to detect an error. Then, the number of detected errors is counted, and when the number is equal to or less than the preset determination standard, the recording is determined to be good,
If the number of errors exceeds the judgment standard, the recording is judged to be defective.

On the other hand, as described above, recording and verifying are not performed by scanning the disk twice with a light beam,
A so-called direct verify method has been proposed in which verify is performed simultaneously with recording. For such direct verification, a method using a plurality of light beams as described in JP-A-58-17546 and JP-A-62-62.
There is known a method using reflected light of a recording light beam as described in JP-A-54857 or JP-A-3-73448.

[0013]

If the above-mentioned method of judging the quality of recording is applied to the direct verify using the plurality of light beams, the following problems will occur. That is, in this direct verify,
The recording / reproducing light beam and the verifying light beam are
They are arranged with a predetermined distance in the scanning direction of the light beam. Then, the data recorded by the preceding recording / reproducing light beam is read by the following verifying light beam, and the read data is compared with the data delayed by the time corresponding to the predetermined distance. Perform verification. Here, if the timings of the read data and the delayed data deviate from each other due to fluctuations in the rotation speed of the disc, correct verification may not be possible.

Further, when the optical adjustment is performed so that the image formation state of the recording / reproducing light beam among the plurality of light beams is optimized, the verify operation is performed due to various aberrations such as field curvature aberration of the optical system. The imaging state of the working light beam is worse than that of the recording / reproducing light beam. The signal / noise (S / N) ratio of the signal read by the verifying light beam in such an imaging state is about 2 dB as compared with the S / N ratio of the signal reproduced by the recording / reproducing light beam. descend. When the initial performance of the disk and the device is maintained, such a decrease in the S / N ratio does not pose a problem, but in consideration of the change over time, in the worst case, normal reproduction does not pose a problem. The recorded state may be determined to be defective during verification.

For example, when a long distance code (LDC) is used for ECC, the byte error rate before correction, which is generally required to satisfy the error rate after error correction of 1 × 10 ⁻¹² , is 2 × 10. It will be about ^-3 . This value corresponds to the limit of reproduction with time using the recording / reproducing light beam. On the other hand, the data read out by the verifying light beam has an error rate of about 7 × 10 ⁻³ , which is worse by the 2 dB reduction. In this case, assuming that the number of data in one sector is 639 bytes, even if there is no defect in the disk, 4 to 5 errors will occur per sector, and a sector that has no problem in normal reproduction is It may be determined as a defective sector.

On the other hand, when the verification is carried out by using the reflected light of the recording light beam from the disk, the data read from the reflected light indicates the data that would be recorded in principle. Errors due to defects on the disc are difficult to detect, and there is a high possibility that they will be overlooked even if there is actually a defect on the disc. Therefore, when the quality of recording is determined by the verification using the reflected light of the recording light beam in this way, the determination result at the time of verification is the actual recording state, contrary to the case of using the plurality of light beams. Could be better than.

An object of the present invention is to solve the above-mentioned problems of the prior art and to execute a recording judgment method and a recording judgment method capable of accurately judging the quality of recording when verifying is performed at the same time as recording. It is to provide a data recording device of.

[0018]

The above object of the present invention is to record optical data on a recording medium by scanning an optical recording medium with a first light beam, and at the same time, the medium is followed by a first light beam. In the method of detecting an error by scanning data with two light beams to read data and comparing the read data with the data obtained by delaying the recording data, a synchronization signal is added to the data to generate a first signal. Timing of data read by the light beam and reading the data and sync signal recorded on the medium by the second light beam, and the data read based on the read sync signal and the data delayed from the recorded data It is achieved by adjusting.

Further, the above object of the present invention is to record data on a recording medium and, at the same time, to judge the quality of recording, read the recorded data from the medium and detect an error in the read data. At the same time, it is achieved by detecting the defect of the medium in which the data is recorded and judging the quality of the recording based on the result of both the error detection and the defect detection.

In the determination of the quality of the recording, for example, when the results of both the error detection and the defect detection are below a predetermined determination criterion, the recording is determined to be good, and at least one of the error detection and the defect detection is performed. When the result exceeds the criterion, the recording is determined to be defective.

Further, the data recording apparatus for executing the above-mentioned recording determination method has means for recording data on a recording medium, means for reading recorded data from the medium at the same time as recording, and an error of the read data. Means for detecting
It is composed of means for detecting defects in the medium in which the data is recorded, and means for judging the quality of recording based on the results of both error detection and defect detection.

[0022]

1 is a schematic diagram showing the configuration of a first embodiment in which the present invention is applied to a magneto-optical disk device. Here, reference numeral 46 indicates a magneto-optical disk as a recording medium. The disk 46 is rotated by a motor (not shown) and moves in the direction of arrow D. An optical head and a magnetic head 47 are arranged at positions substantially opposite to each other with the disk 46 interposed therebetween. The optical head is a semiconductor laser 3 which is a light source.
1, collimator lens 32, diffraction grating 33, optical path bending mirror 34, beam splitter 35, objective lens 3
8, a laser power automatic control sensor 37, a servo sensor 40, a Wollaston prism 41, an RF signal detection sensor 42, etc. are built-in. Further, reference numerals 36 and 39 denote condenser lenses for forming optimum images on the sensors 37 and 40, respectively.

In the above-mentioned device, the light beams emitted from the semiconductor laser 31 are made 0 by the diffraction grating 33, respectively.
It is divided into three light beams corresponding to the second-order diffracted light and the ± first-order diffracted light. Then, the divided light beams are condensed by the objective lens 38 and imaged on the disk 46 as three beam spots 43, 44, 45. These beam spots are arranged in the longitudinal direction of the tracks provided on the disc, that is, in the scanning direction of the light beam. FIG. 2 is a diagram showing the arrangement of these beam spots on the disc. The distance between the spots 43 and 44 is about 15 μm. The diffraction grating 33 is formed such that the ratio of the light intensity of the spot 43 and the light intensity of the spots 44 and 45 is 5: 1. Of these spots, the spot 43 is used for recording and normal reproduction, and the spot 44 is used for verification. Spot 45 is not used.

From the moving direction D of the disc shown in FIG. 1, it can be seen that the beam spot 43 precedes and the beam spot 44 follows in the scanning direction of the light beam. At the time of recording the data, the data is recorded on the disk 46 at the preceding spot 43, the data recorded at the subsequent spot 44 is read, and the verification is performed. Since the spots 43 and 44 are arranged at a distance of about 15 μm as described above, the recording signal and the read signal have a time difference corresponding to the time when the spot moves over this distance. Occurs.

Next, the verify operation in this device will be described. Data recording by beam spot 43
This is performed in the same process as that described as the prior art. The recorded data is the beam spot 44
Scanned in. The reflected light of the beam spot 44 passes through the objective lens 38 again and is separated from the optical path of the light beam with which the disk 46 is irradiated by the beam splitter 35. The separated reflected light passes through the Wollaston prism 41 and is detected by the RF signal detection sensor 42. The output signal of the sensor 42 is subjected to a predetermined calculation by the calculation circuit 87, and the reproduction signal (RF signal) S _RF is taken out.

FIG. 3 is a diagram for explaining the detection system from the Wollaston prism 41 to the arithmetic circuit 87 in more detail. In FIG. 3, the reflected light 9 from the beam spot 44 is
Only 5 is shown. The reflected light 95 is split by the Wollaston prism 41 into two lights 91 and 92 whose polarization directions are orthogonal to each other. Here, the crystal axis of the Wollaston prism 41 is arranged so as to form an angle of 45 ° with respect to the polarization direction of the light before being modulated in the polarization direction, that is, the polarization direction of the light beam incident on the disc. Therefore, the light divided by the Wollaston prism 41 is converted into light whose intensity is modulated according to the information recorded on the disc, and the phases of the signal components of the light 91 and 92 are different by 180 °. ..

The sensor 42 has light-receiving surfaces 42a and 42a.
and the modulated light 91 and 92 are
It is incident on the light receiving surfaces 42a and 42b, respectively. The output signals of these light receiving surfaces are input to the arithmetic circuit 87. The arithmetic circuit 87 includes a differential amplifier 93 and an adder 94. The differential amplifier 93 differentiates the output signals of the light receiving surfaces 42a and 42b. As described above, since the signal components of the modulated lights 91 and 92 have mutually inverted phases, fluctuations in the reflected light intensity due to changes in the reflectance of the disk are canceled out, and the differential amplifier 93 outputs the RF signal S _RF. Is output. On the other hand, the adder 94 adds the output signals of the light receiving surfaces 42a and 42b. Therefore, the signals corresponding to the information on the disc are canceled out, and the sum signal S corresponding to the reflectance of the disc is added from the adder.
_SUM is output.

The signal from the arithmetic circuit 87 is input to the control circuit 49 and is verified. FIG. 4 is a block diagram showing a configuration example of the control circuit 49. In FIG. 4, the magneto-optical disk controller (ODC) 1 has the same configuration as that of FIG. 17 except for the synchronization signal detecting section. The ODC 1 is connected to the buffer RAM 2 for temporarily storing data. When recording data, the address of the sector to be recorded on the disk is confirmed, and the sync signal 1 detected from the reflected light from the disk is detected.
Data is taken out from the buffer RAM 2 in synchronization with 2.
An error correction code is added to the data by the ECC circuit in the ODC 1. The data to which the error correction code is added is modulated (1-7 modulation in this embodiment) into a signal format to be recorded on the disk by the modulation circuit and sent to the magnetic head driver 48. The magnetic head driver 48 drives the magnetic head 47 according to the transmitted recording signal, and the magneto-optical disk 46.
Record the data in.

R sent from the above-mentioned differential amplifier 93
The F signal S _RF is converted into a digital signal by the binarization circuit 85 and input to the data separator 5. In the data separator 5, a clock (VCO
A clock) is generated and sent together with the reproduced data to the synchronization signal detection circuit 8 and the demodulation circuit in the ODC 1. The demodulation circuit converts the signal modulated at the time of recording into the original NZR (non-return to zero) signal, removes portions such as data marks for synchronization and resync, and compares / determines circuit 14 as reproduction data 15. Send to.

The sync signal detection circuit 8 detects the address mark recorded in the preformatted portion, the data mark recorded in the data portion, and the resync mark, and ODC is performed.
1 and the timing adjustment delay circuit 11. The data mark pattern is 24 bits, and is composed of a reproducible pattern even if some of all patterns are partially damaged due to a defect of the disk. Therefore, when the data mark is detected, the data mark detection unit detects the quality of the data mark, that is, how many bits out of 24 bits match, and compares it with a preset reference value. Then, when the number of matched bits does not reach the reference value, the synchronization pattern determination signal 9 indicating that the recording is defective is sent to the comparison / determination circuit 14.

The resync mark is composed of 16 bits, and is detected by matching all the patterns, and there are 39 resync marks for every 15 bytes in one sector. The pattern comparison is performed within a detection window generated based on the data mark. If the detection pulse is not detected in the detection window, an interpolation pulse is inserted to generate an error signal indicating that the detection pulse is not detected in the window. Further, even if it is detected in the window, if it is not detected at the expected position, an error signal is similarly generated. This error signal is input to a counter that is reset for each sector, and the number of errors in one sector is counted. When the count value exceeds the predetermined reference value, the sector is determined to be defective, and the synchronization pattern determination signal 9 indicating the defect is sent to the comparison / determination circuit 14.

The reproduced data input to the ODC 1 is sent to the comparison / determination circuit 14 together with the recorded data, and an error is detected by comparing these data. At this time, the record data 10 is input to the timing adjustment delay circuit 11 and delayed with the reproduced sync signal as a reference. Then, the signal 1 synchronized with the reproduction data 15
3 is input to the comparison / determination circuit 14.

Next, the error detection in the comparison / judgment circuit and the judgment of the quality of recording will be described. FIG. 5 is a block diagram showing a configuration example of the comparison / determination circuit 14 of FIG. In FIG. 5, reference numeral 17 is a comparison circuit, and reference numeral 18 is S.
P converter, reference numeral 19 indicates a deinterleave control circuit, reference numeral 20 indicates an error counter, reference numeral 21 indicates a verify determination circuit, and reference numeral 22 indicates a register. In this embodiment, data having a sector structure as shown in FIG. 6 is recorded. Here, the sector indicates a data recording unit.
For example, in the case of a disc-shaped recording medium, a plurality of tracks are spirally formed on the recording surface, and each track is divided into a plurality of sectors in the circumferential direction. The example of FIG. 6 shows the data section of the ISO format of a 3.5-inch magneto-optical disk.

In FIG. 6, each square column is represented by a symbol described therein, SB1, SB2, SB3 are data marks, RS1, RS2, ..., RS39 are resync codes, 1, 2, ..., 512 are data. , UV1, ..., UV4
Is vendor unique data, CRC-1, ..., CR
C-4 is a cyclic code for error checking, E1.1,
E2.1, ..., E5.16 respectively indicate error correcting parity codes. The data of FIG. 6 is composed of the following five interleaves excluding the data mark and the resync code. Interleave 1: 1,6,11,16, ..., 511, (UV4), E1.1, E1.
2, ..., E1.16 Interleave 2: 2,7,12,17, ..., 512, CRC-1, E2.1, E2.
2, ..., E2.16 Interleave 3: 3,8,13,18, ..., 508, (UV1), CRC-2, E3.
1, E3.2, ..., E3.16 Interleave 4: 4,9,14,19, ... 509, (UV2), CRC-3, E4.
1, E4.2,…, E4.16 Interleave 5: 5,10,15,20,… 510, (UV3), CRC-4, E5.1, E5.2,
, E5.16 Each interleave is composed of 120 bytes, and is capable of correcting an error of up to 8 bytes using 16 bytes of ECC parity.

In the circuit of FIG. 5, the recording data 13 is
The comparison circuit 1 is sent from the ODC 1 of FIG. 4 and is synchronized with the reproduced data by the timing adjustment circuit 11 such as a FIFO.
Input to 7. On the other hand, the reproduction data 15 is subjected to the synchronization process and the demodulation process as described above, and the bit sequence is the same as that of the record data, and is input to the comparison circuit 17 from the ODC 1. The comparison circuit 17 performs bit comparison between the recorded data 13 and the reproduced data 15. Here, the bit in which the error is detected becomes 1. Then, serial-parallel (S
P) The converter 18 converts the bit stream of the comparison result output from the comparison circuit 17 from serial data to parallel data. Parallel data is in units of bytes (8 bits). In the deinterleave control circuit 19, both the data comparison result and the disc defect detection result are synchronized with each other for interleaving.

From the output of the deinterleave control circuit 19, the error counter 20 counts the number of errors detected by the data comparison. Here, the error counter 20 is formed to count two values, that is, the number of errors in each interleave and the total number of errors generated in all interleaves in one sector. On the other hand, the register 22 is preset with a reference value of the number of errors for judging whether the recording is good or defective (verify error) by comparing with the detected number of errors. Corresponding to the error counter, two values are set as the reference value, that is, a permissible value of the number of errors in each interleave and a permissible value of the total number of errors in all interleaves in one sector.

The verify determination circuit 21 compares the count value of the error counter 20 with the reference value stored in the register 22 to determine whether or not the recording is defective, and the determination signal 16 is synchronized. The result is sent to ODC1 together with the signal determination result. An example of the judgment criteria of the verify judgment circuit 21 is as follows. 1) If there is interleaving in which three or more errors occur, the sector is determined to be defective (NG). 2) If the total number of errors detected in each interleave (the number of errors in a sector) is 15 or more, the sector is NG.
And

Needless to say, the above reference values are not limited to 3 and 15 and can be set freely. Alternatively, the determination may be made only under the condition 1) or only the condition 2).

In the above embodiment, since the error is detected without using the ECC circuit, the judgment can be made at the time when the sector data is read as shown in FIG. Is possible.

In the above embodiment, the quality of the recording is judged by the detection level of the data error and the detection level of the synchronizing signal. However, the defect of the medium is detected and the number of the detected defects is also taken into consideration. If you judge whether the recording is good or not,
Further accurate determination becomes possible. This example will be described below.

FIG. 8 is a block diagram showing a second embodiment of the control circuit 49. In this embodiment, except for this control circuit, the configuration is similar to that of the first embodiment as shown in FIGS. In FIG. 8, the same members as those in FIG. 4 are designated by the same reference numerals.

In FIG. 8, the magneto-optical disk controller (ODC) 1 is the same as that shown in FIG.
Is configured similarly to. The ODC 1 is connected to the buffer RAM 2 for temporarily storing data. When recording the data, when the address of the sector to be recorded on the disk is confirmed, the data is taken out from the buffer RAM 2 in synchronization with the synchronization signal 12 detected from the reflected light from the disk, and the ECC circuit in the ODC 1 The error correction code is added to the data. The data to which the error correction code is added is modulated (1-7 modulation in this embodiment) into a signal format to be recorded on the disk by the modulation circuit and sent to the magnetic head driver 48. The magnetic head driver 48 is
The magnetic head 47 is driven according to the sent recording signal to record data on the magneto-optical disk 46.

R sent from the above-mentioned differential amplifier 93
The F signal S _RF is converted into a digital signal by the binarization circuit 85 and input to the data separator 5. In the data separator 5, a clock (VCO
A clock) is generated and sent together with the reproduced data to the synchronization signal detection circuit 8 and the demodulation circuit in the ODC 1. The demodulation circuit converts the signal modulated at the time of recording into the original NZR (non-return to zero) signal, removes portions such as data marks for synchronization and resync, and compares / determines circuit 14 as reproduction data 15. Send to.

The sync signal detection circuit 8 detects the address mark recorded in the preformatted portion, the data mark recorded in the data portion, and the resync mark, and the ODC is performed.
1 and the timing adjustment delay circuit 11. The data mark pattern is 24 bits, and is composed of a reproducible pattern even if some of all patterns are partially damaged due to a defect of the disk. Therefore, when the data mark is detected, the data mark detection unit detects the quality of the data mark, that is, how many bits out of 24 bits match, and compares it with a preset reference value. Then, when the number of matched bits does not reach the reference value, the synchronization pattern determination signal 9 indicating that the recording is defective is sent to the comparison / determination circuit 14.

The resync mark is composed of 16 bits, and is detected by matching all the patterns, and there are 39 resync marks for every 15 bytes in one sector. The pattern comparison is performed within a detection window generated based on the data mark. If the detection pulse is not detected in the detection window, an interpolation pulse is inserted to generate an error signal indicating that the detection pulse is not detected in the window. Further, even if it is detected in the window, if it is not detected at the expected position, an error signal is similarly generated. This error signal is input to a counter that is reset for each sector, and the number of errors in one sector is counted. When the count value exceeds the predetermined reference value, the sector is determined to be defective, and the synchronization pattern determination signal 9 indicating the defect is sent to the comparison / determination circuit 14.

The reproduced data input to the ODC 1 is sent to the comparison / determination circuit 14 together with the recorded data, and an error is detected by comparing these data. At this time, the record data 10 is input to the timing adjustment delay circuit 11 and delayed with the reproduced sync signal as a reference. Then, the signal 1 synchronized with the reproduction data 15
3 is input to the comparison / determination circuit 14.

On the other hand, the sum signal S _SUM output from the adder 94 of FIG. 3 is input to the disk defect detection circuit 18 to detect a disk defect. FIG. 9 is a block diagram showing a configuration example of the disk defect detection circuit. In FIG. 9, reference numeral 61 is a differentiator, and reference numeral 62 is a voltage comparator for comparing the output of the differentiator with a reference level for disk defect detection set by a voltage source 63. Further, the AND gate 64 removes the signal of the preformat section and sends the disc defect detection signal 66 to the comparison / determination circuit 14.

Next, the operation of the disk defect detection circuit will be described. FIG. 10 is a diagram showing signal waveforms at various parts of the disk defect detection circuit. Generally, the sum signal S _SUM of the RF signal detecting sensor has a signal form including a DC fluctuation, as indicated by reference numeral 50 in FIG. Reference numeral 51 is a signal waveform obtained by stretching the signal 50 in the time axis direction. When there is a defect on the disk, it can be considered that the reflectance is high or low with respect to the normal portion of the medium. Therefore, when the beam spot scans over this defect, a waveform as indicated by reference numeral 52 appears on the signal 51. By passing this signal 51 through the differentiator 61, the DC component is removed, and a signal such as 53 is provided so that it can be detected regardless of whether the variation of the reflectance is large or small. By passing the signal 53 through the comparator 62, a signal such as reference numeral 56 is output.

A magnified view of the defective portion of the signal 51 is shown in FIG.
It becomes like the signal 54 of 1. This signal 54 is a differentiator 6
1 is converted into a signal 58. If the threshold value of the comparator, that is, the reference level for detecting the disk defect is set as indicated by reference numeral 59, the reference numeral 60 indicates the defective portion.
A pulse signal as shown in is output.

The output signal 56 of the comparator 62 is input to the AND gate 64. A signal 55 of low level in the preformat section and high level of the data section is input to the AND gate 64 from the ODC 1. The AND gate 64 removes the influence of the light intensity fluctuation of the preformat section by taking the logical product of the signal 56 and the signal 55. Therefore, the output signal 57 of the AND gate 64
Is a defect detection signal having a high level pulse only in the portion corresponding to the defect of the disk.

Next, the error detection and the quality judgment of recording in the comparison / judgment circuit of the second embodiment will be described. FIG. 12 is a block diagram showing a configuration example of the comparison / determination circuit 14 of FIG. 12, the same members as those in FIG. 5 are designated by the same reference numerals. In FIG. 12, reference numeral 17
Is a comparison circuit, 18 is an SP converter, 19 is a deinterleave control circuit, 20 and 27 are error counters, 21 is a verify determination circuit, 22 and 28 are registers, and 26 is a delay circuit. .. Also in this embodiment, as in the previous embodiment, data having a sector structure as shown in FIG. 6 is recorded.

In the circuit of FIG. 12, recording data 13
Is sent from the ODC 1 of FIG. 8 and is input to the comparison circuit 17 in synchronization with the reproduced data by the timing adjustment circuit 11 such as a FIFO. On the other hand, the reproduction data 15 is subjected to the synchronization process and the demodulation process as described above, and the bit sequence is the same as that of the record data, and is input to the comparison circuit 17 from the ODC 1. The comparison circuit 17 performs bit comparison between the recorded data 13 and the reproduced data 15. Here, the bit in which the error is detected becomes 1. Then, the serial-parallel (SP) converter 18 converts the bit stream of the comparison result output from the comparison circuit 17 from serial data to parallel data. Parallel data is in units of bytes (8 bits).

On the other hand, the disk defect detection signal 66 sent from the disk defect detection circuit 18 of FIG. 8 is byte-synchronized with the comparison result signal (error detection signal) after SP conversion by the delay circuit 26, and the deinterleave control circuit. 1
9 is input. In the deinterleave control circuit 19, both the data comparison result and the disc defect detection result are synchronized with each other for interleaving.

From the output of the deinterleave control circuit 19, the error counters 20 and 27 count the number of errors detected by data comparison and the number of detected defects, respectively. Here, the error counter 20
Is formed so as to count two values of the number of errors in each interleave and the total number of errors generated in all interleaves in one sector. Similarly, the error
The counter 27 counts the number of defects in each interleave and the total number of defects existing in all interleaves in one sector. On the other hand, the register 22 is preset with a reference value of the number of errors for judging whether the recording is good or defective (verify error) by comparing with the detected number of errors. Corresponding to the error counter, two values are set as the reference value, that is, a permissible value of the number of errors in each interleave and a permissible value of the total number of errors in all interleaves in one sector. Similarly, the register 28 is preset with a reference value of the number of defects for judging whether the recording is good or bad by comparing with the number of detected defects. There are two reference values stored in the register 28: an allowable value for the number of defects in each interleave and an allowable value for the total number of defects existing in all interleaves in one sector.

The verify determination circuit 21 includes the count values of the error counters 20 and 27 and the registers 22 and 2.
The reference value stored in 8 is compared to determine whether or not the recording is defective, and this determination signal 16 is sent to the ODC 1 together with the determination result of the synchronization signal. An example of the judgment criteria of the verify judgment circuit 21 is as follows. 1) If either the number of bytes in which an error is detected per interleave or the number of bytes in which a defect is detected is 6 bytes or more, the sector is determined to be defective (NG). 2) Even if the number of bytes in which an error is detected per interleave is 4 bytes or more, if the number of bytes in which a defect is detected is 2 or less, the recording is good (verify OK).
And 3) If either the total number of bytes in which an error is detected or the total number of bytes in which a defect is detected is 20 bytes or more, the sector is determined to be NG. 4) If the total number of bytes in which an error is detected per sector is 15 bytes or more, but the total number of bytes in which a defect is detected is 10 or less, the verification is OK.

Table 1 is a summary of the above criteria for judging the quality of recording.

[0057]

[Table 1]

In the present embodiment, the threshold values of the error and the defect for judging the recording quality are 6 bytes and 3 per interleave, and 20 bytes and 11 per sector.
However, it is needless to say that these threshold values are not limited to this example and can be freely set. Alternatively, the determination may be made based only on the number of errors and the number of defects per interleave. Similarly, the determination can be made based on only the number of errors and the number of defects per sector.

As a development of this embodiment, a third error counter is further provided, and it is detected in the deinterleave control circuit that the detected error and defect are at the same position (byte unit). It may be done. Here, the detection result of the same position is input to the third error counter, and the verify determination is performed based on this count value and the count values of the above two counters. This example corrects the count value of errors caused by defects,
It is intended to more accurately judge the quality of recording.

In the above embodiments, direct verification using a plurality of light beams was taken as an example, but the present invention is so-called one-beam direct verification in which data is reproduced from the reflected light of the recording beam by the medium to perform verification. It can also be applied. FIG. 13 is a schematic diagram showing a third embodiment of such a data recording apparatus of the present invention. 13, the same members as those in FIG. 16 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 13, reference numeral 88 indicates a magneto-optical disk which is a recording medium. This disk 88 has a magnetic recording layer formed by exchange-coupling a high coercive force layer having a high Curie temperature and a low coercive force layer having a low Curie temperature. The principle of direct verification using a medium having such a two-layer recording layer is described in detail in, for example, Japanese Patent Application No. 3-175159. The disk 88 is rotated by a motor (not shown) and moves in the direction of arrow D.

The structure of the apparatus of FIG. 13 is basically the same as that of the apparatus of FIG. 16, except that the light beam emitted from the light source 72 is applied to the disk 88 to record data, and at the same time the medium of this light beam is used. The reflected light is detected. This reflected light is modulated in the polarization direction according to the data recorded on the disk by the magneto-optical effect. Therefore, this reflected light is split by the Wollaston prism 89, and the split light is split by the light receiving surface 9 of the photodetector 90.
As shown in FIG.
The data can be read in the same manner as the case of the reflected light 95 of. The outputs of the light receiving surfaces 90a and 90b are the differential amplifier 9
6 and the adder 97, and the reproduction signal S from each
_{The RF} and sum signal S _SUM are input to the control circuit 98.

The control circuit 98 basically has a structure as shown in FIG. Here, the signal from the differential amplifier 96 is input to the binarization circuit, and the signal from the adder 97 is input to the disk defect detection circuit.

In the control circuit 98, the quality of recording is determined in the same manner as in the second embodiment. However, in the control circuit 98, the criterion for determination is different from that in the second embodiment. That is, the criteria for determination are as follows. 1) If either the number of bytes in which an error is detected per interleave or the number of bytes in which a defect is detected is 6 bytes or more, the sector is determined to be defective (NG). 2) Even if the number of bytes in which an error is detected per interleave is 3 bytes or less, if the number of bytes in which a defect is detected is 4 or more, verify NG. 3) If either the total number of bytes in which an error is detected or the total number of bytes in which a defect is detected is 20 bytes or more, the sector is determined to be NG. 4) Even if the total number of bytes in which an error is detected per sector is 15 bytes or less, if the total number of bytes in which a defect is detected is 16 or more, the verify is NG.

In the present embodiment, the threshold values of the error and the defect for judging the recording quality are 6 bytes and 4 per interleave, and 20 bytes and 16 per sector.
However, it is needless to say that these threshold values are not limited to this example and can be freely set. Alternatively, the determination may be made based only on the number of errors and the number of defects per interleave. Similarly, the determination can be made based on only the number of errors and the number of defects per sector.

Table 2 summarizes the criteria for determining the quality of recording in this embodiment.

[0067]

[Table 2]

In the above embodiments, the portion where the reflectance of the medium changes abruptly is detected as a defect, but the defect can also be detected by monitoring the amplitude of the read data signal. This is because the amplitude of the read data signal in the defective portion is smaller than that in the normal portion. An example of such a medium defect detection circuit is shown in FIG. The circuit of FIG. 14 can be used by replacing the disk defect detection circuit 18 of FIG. However, in this case, not the sum signal from the adder but the reproduction signal from the differential amplifier is input to the defect detection circuit.

FIG. 15 is a diagram showing waveforms at various portions of the circuit of FIG. In the circuit of FIG. 14, first, the reproduced signal waveform as indicated by reference numeral 110 is the envelope detection circuit 101.
Entered in. The amplitude of the waveform 110 is small in the defective portion 115. The envelope detection circuit 101 outputs an envelope signal indicated by a broken line 111. The envelope signal 111 is compared in the comparator 102 with a reference value V determined by the voltage of the voltage source 103. Then, the comparator 102 outputs a signal 112 that becomes a high level when it is lower than the reference value V. Among the recorded information, the preformatted portion in which the address and the like are recorded in advance has no magneto-optical signal, so that the signal 112 is at the high level even if there is no defect. In order to remove this influence, a signal 113 which becomes a low level is sent from the ODC at a timing corresponding to the preformat section, and an AND gate obtains a logical product signal of the signal 112 and the signal 113, so that a defect 114 is generated. A defect detection signal 105 that emits a high-level pulse only in the area is obtained. This defect detection signal is sent to the comparison / determination circuit as in the case of the first embodiment.

The present invention can be applied in various ways other than the embodiments described above. For example, the present invention is not limited to the magneto-optical disk device of the embodiment, but an optical data recording device other than magneto-optical as proposed in JP-A-59-167855 or a magnetic recording device using no light beam. Can also be applied to. Further, the shape of the recording medium may be any shape such as a disk shape, a card shape, or a tape shape. The present invention includes all such applications without departing from the scope of the claims.

[0071]

As described above, the recording determination method and the data recording apparatus of the present invention read data together with data when detecting an error by comparing the data read from the medium with the delayed data. Since the timing is adjusted based on the generated synchronizing signal, accurate verification can be performed regardless of fluctuations in the rotation speed of the disk.
Further, the recording determination method and the data recording apparatus of the present invention are
The error of the data read from the recording medium is detected, the defect of the medium in which the data is recorded is detected, and the quality of the recording is judged based on the results of both the error detection and the defect detection. Therefore, an accurate determination can be made even when the verification is performed at the same time as the recording.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of a first embodiment in which the present invention is applied to a magneto-optical disk device.

FIG. 2 is a schematic view showing a state of a beam spot on a disc in the apparatus of FIG.

FIG. 3 is a schematic diagram for explaining the detection system in the apparatus of FIG. 1 in more detail.

4 is a block diagram showing a configuration example of a control circuit in the device of FIG.

5 is a block diagram showing a configuration example of a comparison / determination circuit in the circuit of FIG.

FIG. 6 is a diagram for explaining a sector configuration of data determined in the first embodiment.

FIG. 7 is a diagram for explaining the difference between the present invention and the conventional method at the time of verify determination.

FIG. 8 is a block diagram showing a second embodiment of the control circuit.

9 is a block diagram showing a configuration example of a disk defect detection circuit in the circuit of FIG.

FIG. 10 is a diagram showing signal waveforms in various parts of the circuit of FIG.

FIG. 11 is an enlarged view of waveforms for explaining the state of defect detection in the circuit of FIG.

12 is a block diagram showing a configuration example of a comparison / determination circuit in the circuit of FIG.

FIG. 13 is a third example in which the present invention is applied to a magneto-optical disk device.
It is the schematic which shows the structure of an Example.

FIG. 14 is a block diagram showing another configuration example of the defect detection circuit used in the present invention.

FIG. 15 is a waveform diagram for explaining how defects are detected in the circuit of FIG.

FIG. 16 is a schematic diagram showing a configuration example of a conventional magneto-optical disk device.

17 is a block diagram showing a configuration example of a magneto-optical disk drive controller in the apparatus of FIG.

[Explanation of symbols]

 1 Magneto-optical disk drive controller 2 Buffer RAM 5 Data separator 8 Sync signal detection circuit 11 Timing adjustment delay circuit 14 Comparison / judgment circuit 18 Disk defect detection circuit

Claims (10)

[Claims] 1. An optical recording medium is scanned with a first light beam to record recording data, and at the same time, the medium is scanned with a second light beam following the first light beam to read data. A recording determination method for detecting an error by comparing the read data with the data obtained by delaying the recording data, a synchronization signal is added to the data, and the data is recorded with a first light beam; Read the data and the synchronization signal recorded on the medium by the light beam, and adjust the timing of the data read based on the read synchronization signal and the data obtained by delaying the recording data, and A recording determination method characterized by detecting an error by comparing. 2. Means for recording recording data to which a synchronizing signal is added by scanning an optical recording medium with a first light beam,
Means for reading the recorded data and sync signal by scanning the medium with a second light beam following the first light beam and comparing the read data with the delayed data of the recorded data In the data recording device, the timing of the read data and the data obtained by delaying the recording data is adjusted based on the synchronization signal read by the second light beam. A data recording device comprising means for performing. 3. At the same time as recording data on a recording medium,
In a method of determining the quality of recording, the recorded data is read from the medium, the error of the read data is detected, and the defect of the medium in which the data is recorded is detected to detect the error and the defect. A recording determination method, characterized in that the quality of recording is determined based on both results. 4. An optical recording medium is scanned with a first light beam to record data, and at the same time, the medium is scanned with a second light beam following the first light beam to determine whether recording is good or bad. In the determining method, the data recorded on the medium by the second light beam is read, an error in the read data is detected, and the defect of the medium in the portion where the data is recorded by the second light beam is detected. If the result of both the error detection and the defect detection is less than or equal to the preset determination standard, the recording is judged to be good, and at least one of the error detection and the defect detection exceeds the determination standard. A recording determination method characterized by determining recording as defective. 5. A method for determining the quality of recording by detecting the reflected light of the light beam from the medium at the same time as scanning the optical recording medium with the light beam to record data, The recorded data is read, the error of the read data is detected, the defect of the medium where the data is recorded is detected from the reflected light, and the results of both the error detection and the defect detection are preset. A recording determination method characterized in that recording is determined to be good when the determination result is equal to or less than a determination standard, and recording is determined to be defective when at least one of error detection and defect detection exceeds the determination standard. 6. A means for recording data on a recording medium, a means for reading the recorded data from the medium simultaneously with the recording, and a means for detecting an error in the read data.
In a data recording device comprising a means for judging quality of recording in accordance with a result of error detection, there is provided means for detecting a defect of a medium in a portion where the data is recorded, and the judging means includes the error detection and the defect. A data recording device, characterized in that the quality of recording is judged based on both detection results. 7. A means for recording data by scanning an optical recording medium with a first light beam, and a means for scanning and recording the medium with a second light beam following the first light beam. A data recording device comprising: a means for reading data; a means for detecting an error in the read data; and a means for judging the quality of recording in accordance with the result of error detection. A means for detecting the defect of the medium of the portion where the data is recorded from the reflected light of, the determination means, when the results of both the error detection and the defect detection is less than or equal to the preset determination criteria Good record,
A data recording apparatus, wherein recording is determined to be defective when at least one of error detection and defect detection exceeds the determination standard. 8. The data recording apparatus according to claim 7, wherein the defect detecting means detects a portion where the reflectance of the medium changes abruptly or a portion where the amplitude of the read data signal decreases from the reflected light as a defect. .. 9. A means for recording data by scanning an optical recording medium with a light beam, a means for reading recorded data from reflected light from the medium of the light beam, and an error of the read data. In a data recording device comprising a means for detecting and a means for judging the quality of recording according to the result of error detection, there is provided means for detecting a defect in the medium in which data is recorded from the reflected light, The judging means regards the recording as good when the results of both the error detection and the defect detection are equal to or lower than the preset judgment standard, and the result of at least one of the error detection and the defect detection exceeds the judgment standard. A data recording device characterized in that recording is determined to be defective. 10. The data recording apparatus according to claim 9, wherein the defect detecting means detects a portion where the reflectance of the medium changes sharply from the reflected light or a portion where the amplitude of the read data signal decreases as a defect. ..