JPH06267202A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To efficiently record and reproduce data by using one of ECC circuits as an ECC coding circuit for writing-in information and the other ECC circuit as an ECC decoding circuit for detecting errors of reading-out information at the time of recording operation, and using both ECC circuits as the ECC decoding circuit at the time of reproducing operation. CONSTITUTION:In recording operation, this information is read by an optical disk drive 7 immediately after writing for a real time RAW check of recording information, transferred to an ECC circuit 4 via a demodulation circuit 6, and detection processing for errors is performed. A control circuit 11 performs rerecording or alternation processing from results of the RAW check according to the following way. That is, if the number of errors are less than allowable numbers, writing is made normal, and if it exceeds allowable numbers, writing is made abnormal. Next, in a switching state of a switch at the time of reproducing a control circuit 11 makes the ECC circuit 3 and the ECC circuit 4 function as a ECC composite circuit when a host device 1 issues a reproducing instruction, and switches an input of a switch 8 to a (a) side, an input of a switch 9 to a (d) side, and an input of a switch 10 to a (f) side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for a recording medium such as an optical disk or a magneto-optical disk for writing and reading information by using light.

[0002]

2. Description of the Related Art For example, an optical disk (including a magneto-optical disk) can record and reproduce data through a transparent substrate in a non-contact manner, so that the recording layer can be sealed and the environment resistance is excellent. However, the optical disc generally has a higher bit error rate of the recording medium during recording than the magnetic disc. Therefore, when recording digital information on an optical disc,
An error correction code is added in advance by an ECC circuit to information to be recorded, which is output from a higher-level device such as a computer or an image processing device, and is written as a digital signal multiplexed with a synchronization code and a control code through a modulation circuit. Writing to the optical disc by means. Then, after this writing, in order to confirm whether or not the written information can be correctly read by setting the device in the reproduction mode,
RAW check (Read After Write)
Confirmation work of the reliability of the recorded information called is performed.

For a general RAW check, a well-known error detection method using an error correction code is used. That is, the information recorded on the recording medium with the error correction code added at the time of recording is read by the reading means, demodulated by the demodulation circuit, and then subjected to the decoding process by the ECC circuit to be subjected to the error correction code. Error detection is performed. If the number of detected errors is less than or equal to the predetermined number of errors set in advance by the system, it is possible to confirm that the recorded information can be read correctly.

Further, when the recording / reproducing apparatus carries out normal reproduction, the ECC circuit performs error detection and correction processing on the read information after demodulation by means of an error correction code, and sends it to the upper apparatus together with the correction information and the error detection information. Forward.

[0005]

As described above, in the case of performing the RAW check at the time of data recording in the batch processing, the device is set to the reproduction mode after writing by the writing means,
Since the light beam for reading must be moved again to the write information writing start position for reading, the light beam must pass through the area on the recording medium more than once, and the entire recording process Takes longer.

For this reason, recently, in order to perform information writing at the time of recording at a high transfer rate and improve the performance seen from a host device such as a host computer, a writing beam and a reading beam immediately following the writing beam are used. By using an optical head such as a multi-beam optical head (Japanese Patent Laid-Open No. 61-153830) that also combines the above, read data that is taken out in real time during recording is immediately checked for RAW by matching bit correspondence with delayed write data. A device or a device (Japanese Patent Laid-Open No. 3-157875) for performing RAW check by collating write information coded by the ECC circuit and its real-time read data by another data verify circuit without using the ECC circuit. Proposed.

However, in these conventional apparatuses, the real-time RAW check at the time of recording increases the transfer rate at the time of recording as viewed from the host apparatus, but the data transfer rate for error correction at the time of reproduction is the same as before. That is, at the time of reproduction, the EC of the read information
Although it is necessary to detect and correct an error by C decoding processing, the error correction processing time in particular becomes long in proportion to the number of errors in the number of correction bits. It takes more time than processing. In the above-mentioned proposed conventional apparatus, since the read information is directly subjected to the error detection processing by continuous serial transfer, the error correction processing by the ECC circuit or another controller is permitted to be executed in real time. The time is still the same, so the real-time correction capability during playback is unchanged.

Further, in the conventional apparatus, although the error correction processing performance at the time of reproducing information has not been improved at all, the cost for the hardware for performing the RAW check in real time is lower than that of the conventional apparatus. In particular, when an optical disk recording / reproducing device of this kind is considered as an external storage device of various information processing devices, if the allowable time allocated for error correction processing becomes shorter as the information recording density in the near future increases, the However, there is a problem that the speed of extracting the information is limited.

Therefore, according to the present invention, the information transfer rate can be increased by the real-time RAW check using the ECC code at the time of recording, as well as the real-time error correction processing of the read information at the time of reproduction within a limited time. It is an object of the present invention to provide an information recording / reproducing apparatus capable of performing real-time ECC processing at the time of reproduction even if the allocation time for error correction becomes short.

[0010]

[Means for Solving the Problems] To achieve the above object,
The present invention relates to an information recording / reproducing apparatus capable of reading information written on a recording medium by the recording operation during the recording operation of the information on the recording medium, using ECC encoding and E
The first and second ECC circuits having both CC decoding function and one of the first and second ECC circuits at the time of recording operation are made to write information and function as an ECC encoding circuit for ECC information, and the other is It is made to function as an ECC decoding circuit for read information, and during playback operation,
Provided is an information recording / reproducing apparatus, comprising: a control unit that causes both the first and second ECC circuits to function as an ECC decoding circuit for read information.

According to a second aspect of the present invention, in the information recording / reproducing apparatus according to the first aspect, the control means reads the read information for each predetermined amount of information at the time of the reproducing operation. Switching means for alternately applying to the ECC circuit.

[0012]

In the present invention configured as described above, at the time of recording, the control means controls the first ECC circuit to the EC.
The second ECC circuit is made to function as a C encoding circuit and the second ECC circuit is made to function as a decoding circuit. Then, the information recorded on the recording medium is temporarily stored in the buffer memory from, for example, the host device, and then transferred to the first ECC circuit by the control means for each block (sector) having a predetermined number of bytes. The first ECC circuit generates and adds an error correction code to the transferred information, and the information to which the ECC information is added is written in the recording medium via the writing means such as the modulation circuit and the recording head. .

During this write operation, the read means reads the information written by the write means immediately after the track for real-time RAW check of the recorded information, and the read information is demodulated by the demodulation circuit and then the second information is read. It is transferred to the ECC circuit. The second ECC circuit decodes the ECC information in the read information, and the real-time error detection processing is thereby performed. It goes without saying that the quality of the recording sector is determined based on the number of detected errors.

On the other hand, during reproduction, the control means causes both the first ECC circuit and the second ECC circuit to function as a decoding circuit. In the present invention, since the first and second ECC circuits both have a decoding processing function, the control means can alternately input the read information from the demodulation circuit to these first and second ECCs, for example, in sector units. . That is, by alternately decoding the read information of a predetermined number of bytes by two or more ECC circuits, it is possible to distribute the time burden of error detection and error correction processing to each ECC circuit. . As a result, each ECC circuit has a time margin for at least one sector until the next sector information is transferred, and error detection and correction processing can be performed on data having a sufficient information amount during this time. . The transfer from each ECC circuit to the upper device may be performed via the buffer memory.

Further, in the invention described in claim 2, the control means comprises a switching means for alternately applying read information to the first and second ECC circuits for each predetermined amount of information at the time of reproducing operation. ing. By switching the two or more ECC circuits sequentially by this switching means to perform the decoding process, the efficiency of the switching and correction processing capability at the time of reproduction can be achieved.

That is, the information recorded on the recording medium constitutes, for example, a block in sector units, and this information is read by the reading means and demodulated by the demodulation circuit, and first, for example, the first sector. Read information is first
Is transferred to the ECC circuit. When the transfer of the read information of the first sector to the first ECC circuit is completed, the control means switches the output of the demodulation circuit from the first ECC circuit to the second ECC circuit to transfer the read information of the second sector to the first ECC circuit. EC of 2
Transfer to C circuit. During this time, the information for which the decoding process has been completed by the first ECC circuit is sent out as a reproduction output via the buffer memory.

The read information of the third sector is transferred from the demodulation circuit to the first ECC circuit which has finished transferring the read information of the first sector to the buffer memory, and the second ECC is transferred during this period.
The read information of the second sector decoded by the ECC circuit is output via the buffer memory.

Thus, these two or more ECCs
By performing the ECC encoding process on the read information by alternately using the circuits, it becomes possible to secure the allocation time for the error correction process of the read information at the time of reproduction about twice or more than the conventional time, and to record the information in the future. It becomes possible to provide a real-time correction capability that can sufficiently cope with the increase in density.

[0019]

Embodiments of the present invention will be described with reference to the drawings. The same or corresponding components in each drawing are designated by the same reference numerals.

As shown in FIG. 1, the information recording / reproducing apparatus according to the present embodiment is wholly constituted by a portion indicated by reference numeral 12. That is, a buffer memory 2 for temporarily storing recording information and reproduction information and two ECC circuits 3 having both ECC encoding and ECC decoding functions for input / output transmission to / from the host device 1 or other host device 1. , 4
A modulation circuit 5 for performing modulation such as (1-7) modulation on information to be written on an optical disc as a recording medium, and a demodulation circuit 6 for demodulating information read from the recording medium.
An optical disk drive 7 having an information recording head and an information reproducing head, switches 8, 9, 10 for switching signal transmission paths depending on recording and reproducing, and control means 11 for controlling these functions. It is configured. Further, the buffer memory 2 is connected to the host computer 1 or other host device 1, and all commands such as recording and reproduction are instructed by the host device 1. The control means 11 may be, for example, the function of the higher-level device 1, and is shown here as another functional block for the sake of explanation.

FIG. 2 is a block diagram showing a switch switching state during recording. At the time when the host device 1 issues a recording command, the control means 11 sets the ECC circuit 3 to EC.
The ECC circuit 4 is caused to function as an ECC decoding circuit while functioning as a C encoding circuit, and the connection of the switch 8 is switched to the a side, the connection of the switch 9 is switched to the c side, and the connection of the switch 10 is switched to the e side.

Information to be written in the recording medium is stored in the host device 1.
Is temporarily stored in the buffer memory 2, and is transferred to the ECC circuit 3 by the control means 11 in a predetermined amount of information, for example, in sector units of the optical disk. An error correction code is generated and added to the information in the ECC circuit 3, and is written on a recording medium (optical disk) by the optical disk drive 7 via the modulation circuit 5.

During the recording operation, the information is read by the optical disk drive 7 immediately after being written and transferred to the ECC circuit 4 through the demodulation circuit 6 for real-time RAW check of the recording information, and the ECC circuit 4 is read. In, error detection processing is performed by decoding the error correction code.

According to the result of the RAW check performed by the ECC circuit 4, the control means 11 determines that the writing is normal if the number of errors is less than the allowable number, and rewrites it as a writing failure if it exceeds the allowable number, or Perform replacement processing.
These series of operations are continued until all the information is written. The time chart at this time is shown in FIG. Circled numbers in FIG. 3 are sector numbers.

FIG. 4 is a block diagram showing a switch change state during reproduction. When the host device 1 issues a reproduction command, the control means 11 causes the ECC circuit 3 and E
Make the CC circuit 4 function as an ECC decoding circuit, and
The input of the switch 8 is switched to the a side, the input of the switch 9 is switched to the d side, and the input of the switch 10 is switched to the f side.

The information read from the recording medium by the optical disk drive 7 is processed by the control means 11 for each sector. First, the read information of the first sector is transferred to the ECC circuit 3 via the demodulation circuit and the switch 10. When the read information of the first sector is completely transferred to the ECC circuit 3, the control unit 11 switches the input of the switch 10 to the e side, and the read information of the second sector is subsequently transferred to the ECC circuit 4.

The ECC-decoded read information of the first sector is transferred from the ECC circuit 3 to the buffer memory, and the read information of the read second sector is E.
When the transfer to the CC circuit 4 is completed, the control means 11 switches the input of the switch 8 to the b side and the input of the switch 10 to the f side again. Then, the read information of the third sector is transferred to the ECC circuit 3 again, and the second information is read by the ECC circuit 4.
ECC decoding processing of the read information of the sector is performed. The time chart at this time is shown in FIG.

In this way, the reproduced signal from the optical disk drive 7 is demodulated, and the ECC circuit 3 and the ECC circuit 4 are demodulated.
By performing the ECC decoding process by alternately transferring the data to each other, the time required for processing such as error detection and correction of the read information can be reduced to about half at maximum compared with the conventional case. In other words, for this embodiment, the real-time correction capability will be doubled up to a maximum.

Therefore, it is possible to obtain a real-time RAW check of write information at the time of recording, and it is possible to obtain an optical disk recording / reproducing apparatus which has twice the real-time error correction capability of read information at the time of reproducing.

In this embodiment, the optical disk recording / reproducing apparatus provided with two ECC circuits is taken as an example.
The number of C circuits is not limited to two, and any number may be used as needed.

[0031]

As described above in detail, according to the information recording / reproducing apparatus of the present invention, it is possible to perform the real-time RAW check at the time of recording, and it is proportional to the number of ECC circuits at the time of reproducing. By improving the error correction capability, it is possible to substantially reduce the ECC processing time at the time of reading information. Furthermore, since the time required for error correction processing is longer than the time required for error detection processing, when error correction of read information is performed in the future,
Even when the recording density on the disc side is increased and the allotted time allowed for the ECC circuit is somewhat shortened, it is possible to realize an optical disc recording / reproducing device which can sufficiently cope with the situation.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an optical disc recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a switch state at the time of recording of the optical disc recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 3 is a time chart diagram at the time of recording by the optical disc recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a switch state at the time of reproduction of the optical disc recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 5 is a time chart diagram during reproduction of the optical disk recording / reproducing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Host device 2 Buffer memory 3 1st ECC circuit 4 2nd ECC circuit 5 Modulation circuit 6 Demodulation circuit 7 Optical disk drive 8 Switch 9 switch 10 Switch 11 Control means 12 Information recording / reproducing apparatus according to the present invention

Claims (2)

[Claims] 1. An information recording / reproducing apparatus capable of reading information written on a recording medium by the recording operation during the recording operation of the information on the recording medium, wherein the information recording / reproducing apparatus has both ECC encoding and ECC decoding functions.
And a second ECC circuit, and at the time of a recording operation, one of the first and second ECC circuits functions as an ECC encoding circuit for write information, and the other functions as an ECC decoding circuit for read information to reproduce. In operation, the first and second EC
An information recording / reproducing apparatus comprising: a control unit that causes both C circuits to function as an ECC decoding circuit for read information. 2. The control means outputs read information for each of a predetermined amount of information at the time of reproduction operation to the first and second ECs.
The information recording / reproducing apparatus according to claim 1, further comprising switching means for alternately applying to the C circuit.