JP2002197793A - Disk recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an erroneous position from being detected as a record terminating end when a position traced by an optical head is skipped due to disturbance such as impact or the read of a disk is temporarily interrupted. SOLUTION: When the restart of record of recording data is judged, recorded data on a disk just before record interruption are read, and a record starting position to restart the record on the disk is detected by a record starting position detecting means 23. A comparison means 26 compares the recording data read from the disk with record data created by an encoder 11. The encoder 11 operates considering a bit clock extracted from the recording data read when recording data recorded on the disk are read as an operating clock. The record starting position detecting means 23 judges whether a detected record starting position is normal or abnormary on the basis of the comparison output of the comparison means 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk recording apparatus capable of continuously adding recording data to the end of a recording just before recording when recording on the disk is interrupted.

[0002]

2. Description of the Related Art As a disk recording device for recording digital recording data on a disk using a light beam from an optical head, a CD (Compact Disc) family CD-ROM is known.
R (Recordable) drive and CD-RW (ReWritable)
Drives are well known.

In such a disk recording device,
A buffer RAM for temporarily storing data transferred from a host device such as a personal computer is provided.
The data read from the AM is signal-processed to recording data in a form to be written to the disk by the encoder, and writing to the disk is performed.

[0004] By the way, since the writing speed has been increased, data transferred from a host device cannot keep up with the writing to the disk, and a buffer underrun occurs in the buffer RAM. When a buffer underrun occurs in the buffer RAM, generation of recording data is stopped, and recording on the disk is interrupted.

Even if the recording on the disk is interrupted, new data is transferred to the buffer RAM, and when the generation of the recording data by the encoder is resumed, the data is continuously connected to the recording data already recorded on the disk. If the recording data can be added to the recorded recording data so as to be substantially seamlessly connected to the disk, the buffer R
A buffer underrun error, which is a recording error caused by an AM buffer underrun, can be avoided, and a disk recording apparatus that avoids such a buffer underrun error has been realized.

[0006]

By the way, as a particularly important technique for realizing such a disk recording apparatus, recording data is added to recorded recording data so as to be substantially seamlessly connected to the disk. That is,
For this purpose, it is necessary to detect the end of recording recorded on the disc when resuming recording on the disc.

The end of the recording is detected by reading the recorded data recorded on the disk immediately before the interruption of the recording, referring to the last address and the synchronization signal stored therein, and determining a fixed length corresponding to the data length based on the synchronization signal. This can be achieved by measuring the time, but if the trace position is skipped by the optical head due to a shock or other disturbance while reading the disk, or if the reading of the disk is temporarily interrupted, the wrong position is detected as the end of recording In some cases, recording is restarted from an incorrect position.

[0008] When recording is restarted from an incorrect position, a gap occurs where overwriting or reproduction is impossible at the additional recording portion of the disk, and in the case of a write-once disk, the disk is wasted.

[0009]

According to the present invention, when recording resumption of recording data is judged by recording judging means for judging recording resumption and resumption of recording of recording data on a disc, the data is already recorded on the disc immediately before the interruption of recording. The recording start position at which the recording data is read and the recording is resumed on the disk is detected by the recording start position detection means, and the recording data read from the disk and the recording data generated by the encoder are compared by the comparison means, The encoder operates using a bit clock extracted from the read recording data when the recording data recorded on the disk is read, as an operation clock, and the recording start position detecting means detects the recording start position based on the comparison output of the comparing means. Is determined to be normal or abnormal.

[0010]

FIG. 1 is a circuit block diagram showing an embodiment of a CD-R drive as a disk recording apparatus according to the present invention.

In FIG. 1, reference numeral 1 denotes an optical head which emits a laser beam for tracing a signal track of a disk and writes and reads recording data on the disk.

An R 2 amplifies an RF signal of a received light output obtained by the optical head 1 and binarizes the RF signal.
The F-amplifier 3 feeds back various light-receiving outputs obtained by the optical head 1, focuses the laser beam emitted from the optical head 1 on the signal surface of the disk, and causes the laser beam to follow the signal track of the disk. A head servo circuit that performs tracking control and performs thread feed control for sending the optical head 1 itself in the radial direction of the disk.

Reference numeral 4 denotes a CD-DA decoder unit 5 for demodulating the binarized data of the RF signal output from the RF amplifier 2 in a range defined by the signal format of the CD-DA disk, and the CD-DA decoder An encoder comprising a CD-ROM decoder unit 6 for performing demodulation processing on the demodulated data demodulated by the unit 5 in a range defined by the signal format of the CD-ROM disk.

The CD-DA decoder section 5 separates various data from the binary data of the input RF signal,
Eight to Fourteen Modulation (FM) data is converted to EFM
In addition to demodulation, a frame synchronization signal indicating the head of a frame of the EFM data (EFM frame) and a subcode synchronization signal in a subcode composed of 98 EFM frames are detected. Is demodulated.

The CD-ROM decoder section 6 has a CD-ROM decoder.
CD-ROM specified in the signal format of ROM disk
In addition to performing synchronization detection of ROM data, an error detection code (EDC) for an error detection code for CD-ROM data is used.
e) and ECC (Error Correction Cod) of the error correction code.
Perform error detection and error correction according to e).

Reference numeral 9 denotes an interface for controlling data exchange with a host device such as a personal computer connected to the outside via a connection terminal 10. Reference numeral 11 denotes input data input to the interface 9 for recording data to be recorded on a disk. It is an encoder that modulates.

The encoder 11 adds a sync, a header, an EDC of an error detection code for CD-ROM data, and an EC of an error correction code to input data based on the CD-ROM standard.
C-ROM encoder unit 12 for adding C,
A CD encoded by the ROM encoder unit 12
-ROM data is CD-DA based on the CD-DA standard.
CIRC (Cross Interleave)
d-Solomon Code) processing, and a CD-DA encoder unit 13 that adds a subcode, performs EFM processing, and adds a frame synchronization signal.

Reference numeral 14 denotes a control for converting the EFM data output from the encoder 11 into a pulse signal set to an optimum level for recording on a disk based on the recording data and controlling a laser beam generated from the optical head 1. A head output control circuit 15 for generating an output is a laser drive circuit for driving a laser light source of the optical head 1 to perform recording on a disk in accordance with a control output from the head output control circuit 14.

Reference numeral 16 caches input data input by the interface 9 and is used when the encoder 11 performs a modulation process on recording data to be recorded on the disk, and caches data read from the disk. This is a buffer RAM used when demodulating data.

Reference numeral 17 denotes an RF amplifier 2 by a push-pull method.
Demodulates the 22.05kHz wobble signal included in the pre-groove of the disc from the push-pull signal generated by the above, and demodulates the ATIP (AbsoluteTime In Pre-groove) address of the time information address from the wobble signal This is a wobble decoder including an ATIP demodulation circuit 18.

Reference numeral 19 denotes a system control circuit for performing system control relating to recording and reproduction of a disk. The system control circuit 19 selectively refers to the subcode address of the absolute time information in the subcode (sub Q data) demodulated by the CD-DA decoder unit 5 and the ATIP address demodulated by the ATIP demodulation circuit 18. Access control means 20 for controlling access by means of a buffer RAM
A buffer control means 21 for controlling writing and reading of data to and from the disk 16 according to the data storage capacity of the buffer RAM 16 by the buffer control means 21 or by a command from a host device connected to the connection terminal 10 Recording determining means 22 for determining the interruption of data recording and for resuming the recording of recording data on the disc; and when the recording determining means 22 determines that the recording is to be resumed, the recording is interrupted and recorded on the disc. Recording start position detecting means 2 for detecting a position continuing to the end of the recorded data as the recording start position of the disk
3, an address memory 24 for storing the last subcode address immediately before the recording interruption when the recording judging means 22 judges that the recording is interrupted, and a new disc code when the recording to the disc is resumed after the recording interruption of the disc. A synchronization setting unit for synchronizing recording data to be recorded with recording data already recorded on the disk.

A comparison circuit 26 compares the recording data read from the disk with the recording data generated by the encoder 11.

The comparison circuit 26 sets each record data to be compared to corresponding record data by a subcode frame, a subcode synchronization signal and a frame synchronization signal.

Here, the connection bit for connecting the symbols of the EFM data which is the recording data is DSV (Digital).
Sum Variation), which varies depending on the previous symbol pattern. Therefore, when recording is resumed after recording interruption, the combined bits generated by the encoder 11 are stored in the encoder 11 and are considered before the recording interruption. Varies by.

For this reason, the comparison circuit 26 compares the symbols of the EFM data, which is the recording data, but does not compare the connection bits connecting the symbols.

The recording start position detecting means 23 determines whether the detection of the recording start position is normal or abnormal based on the comparison output from the comparing circuit 26. When it is determined that the recording start position is abnormal, the recording start position The detecting means 23 is controlled so as to repeatedly detect the recording start position.

Reference numeral 27 denotes a system clock generation circuit for generating a system clock which is an operation clock for all operations related to recording and reproduction of the disk. The system clock generation circuit 27 is extracted from EFM data output from the RF amplifier 2. And a reference clock for crystal oscillation accuracy.

Next, the recording operation of the disk recording apparatus thus configured will be described.

When recording is requested by the host device connected to the connection terminal 10, the recording operation of the disc is started in response to the request. In this case, the system clock generation circuit 27 is switched to a state for generating a reference clock, and each circuit of the recording system is operated in synchronization with the reference clock.

When data for requesting recording is transmitted from a host device connected to the connection terminal 10, the data is received by the interface 9 and written into the buffer RAM 16.

When the storage amount of the data written in the buffer RAM 16 reaches the data amount at which the encoding process is started by the encoder 11, the data is read from the buffer RAM 16 and recorded on the disk by the encoder 11 in EFM frame units. Recorded data (EF
M data).

When the trace position by the optical head 1 reaches the recording start position of the disk, the encoder 11
The recording data is sequentially output in frame units, and the address data of the ATIP address demodulated by the ATIP demodulation circuit 18 corresponding to the output recording data is sequentially updated in the address memory 24 provided in the system control circuit 19. It is memorized.

The laser drive circuit 15 drives the laser light source of the optical head 1 based on the recording data output from the encoder 11 by the head output control circuit 14, whereby the recording data is recorded on the disk.

By the way, the amount of data received by the interface 9 becomes insufficient with respect to the capacity of the recording data recorded on the disk, and the data amount of the encoder 11 is smaller than the average data transfer rate at which the recording data is output from the encoder 11. When the average data transfer rate of input data input to the buffer RAM 16 becomes low, the data capacity stored in the buffer RAM 16 decreases.

If this state continues, the buffer RAM
It is determined that the data capacity stored in the buffer RAM 16 is smaller than a predetermined amount, and the buffer RAM 16 is in a buffer underrun state, and the recording determination unit 22 determines to stop recording on the disk.

During the recording on the disk, a recording break occurs, and the next data to be recorded is received by the interface 9 and the buffer RA
Until the data capacity stored in M16 reaches the data capacity at which the encoding process is started by the encoder 11, the recording determination unit 22 determines to stop recording on the disk.

When the recording judging means 22 judges that the recording on the disk is interrupted, the output of the recording data from the encoder 11 is stopped, and the laser output circuit 15 is controlled by the head output control circuit 14. The control output is stopped, the emission of the laser beam set for recording from the optical head 1 is stopped, and the recording on the disk is interrupted.

In the state where the recording on the disk is interrupted, the reference clock is continuously supplied to the encoder 11 from the system clock generation circuit 27 as the operation clock.

Next, when the data to be recorded is received by the interface 9 and the data capacity stored in the buffer RAM 16 reaches the data capacity at which new recording data is generated by the encoder 11, the recording judging means 22 discs A determination is made to resume recording on the.

When the recording judging means 22 judges that the recording on the disk is to be resumed, when new data is inputted to the encoder 11, the encoder 11 is turned on by the internal RAM.
28, a CIRC interleave length (maximum of 108 EFM frames) is secured for newly input data, and data subsequent to the last data output from the encoder 11 immediately before the recording is interrupted is encoded. I do.

When it is determined by the recording determining means 22 that recording on the disk should be resumed, the light output of the optical head 1 is set to the reproduction level output by the head output control circuit 14 and stored immediately before the recording is stopped. The ATIP address is searched with reference to the last subcode address to access the vicinity of the last end of the recorded data already recorded on the disk.

When the recording judging means 22 judges that the recording on the disc should be resumed, the synchronization setting means 2
5, the operation of synchronizing the recording data generated from the encoder 11 with the recording data already recorded on the disk is executed, and the system clock generating circuit 27 outputs the bit clock extracted from the recording data output from the RF amplifier 2. Is generated, the encoding operation by the encoder 11 is performed in synchronization with the bit clock, and the data synchronization of the recording data output from the encoder 11 with respect to the recording data already recorded on the disk. Is taken.

At the time of synchronization, the subcode address of the recording data output from the encoder 11 is made to correspond to the subcode address demodulated from the recording data recorded on the disk. The sub-code synchronization signal given by the encoder 11 is synchronized with the sub-code synchronization signal detected from the recorded data recorded in the sub-code.

When the recording data output from the encoder 11 is synchronized with the recording data already recorded on the disk, if the normal operation is continued, the encoder 11 is synchronized with the bit clock. This is maintained by performing the encoding process, that is, performing the encoding process in synchronization with the reading of the recorded data recorded on the disc.

Here, the internal RAM 28 of the encoder 11
The recording data immediately before the interruption of recording is stored in a predetermined number, and the stored recording data is compared with the recording data already recorded on the disk by the comparing circuit 26 in bit units.

The comparison output of the comparison circuit 26 is used as a criterion for determining whether or not the recorded data recorded on the disk is correctly traced and read, and the data to be compared by the comparison circuit 26 allows some error. When the comparison output is output from the comparison circuit 26 when the ranges coincide with each other, the recording start position detection unit 23 determines that the recording start position is normally detected and the comparison circuit 26 is in a normal state. When the comparison circuit 26 outputs a comparison output from the comparison circuit 26 when the data to be compared by the comparison circuit 26 does not coincide with each other beyond a range in which a certain error is allowed, the recording start position detection means 23 detects the recording start position normally. It is determined that there is no abnormal condition.

If the recording start position detecting means 23 determines that the recording start position is normal, the detection of the recording start position is continued.

The detection of the recording start position by the recording start position detecting means 23 is performed by detecting the trace position by the optical head 1 at the end of the last recorded data of the disk corresponding to the recorded last recorded data outputted immediately before the recording is stopped from the encoder 11. Is reached, and the encoder 11 operates in synchronization with the reading of the recording data already recorded on the disk. The point at which data is output is detected as the recording start position.

When the recording start position is detected by the recording start position detecting means 23, the start of recording on the disk is judged by the recording judging means 22, and the light output of the optical head 1 is changed to the recording level output by the head output control circuit 14. Is set.

Here, the recording data to be compared is monitored by the comparing circuit 26, and it is determined that the recording data to be compared is a predetermined bit before the end of the recorded final recording data. Control can be performed in consideration of the start-up time for raising the light emission output of the optical head 1 to the recording level output so that the light emission output of the optical head 1 becomes the recording level output immediately upon detection.

On the other hand, when the encoder 11 starts outputting the recording data next to the last recording data, the encoder 11 starts outputting from the recording data. Therefore, the recorded recording is synchronized with the recording data already recorded on the disk. The end of the data is substantially seamlessly connected to the disk, and the recording of the recording data continuous with the recorded data is resumed.

Here, when the start of recording on the disc is judged by the recording judging means 22, the system clock generating circuit 27 switches to a state of generating a reference clock, and the operation of recording the record data on the disc is synchronized with the reference clock. Will be done.

By the way, if the recording start position detecting means 23 determines that there is an abnormal state, an access is made again with reference to the last subcode address stored immediately before the recording is stopped, and the recording start position is detected again. Is performed.

Therefore, if the trace position of the optical head is skipped due to a disturbance such as an impact during reading of the disk, or if the reading of the disk is temporarily interrupted, the detection of the recording start position is performed again. Since the recording start position is not detected, the correct recording start position can be detected, and the recording can be restarted from the correct recording start position.

In particular, since the comparison by the comparison circuit 26 is the recording data itself, verification can be performed at the data level.

[0056]

As described above, according to the present invention, the detection of the recording start position by the recording start position detecting means is determined based on the comparison output of the comparing means as normal or abnormal. The detection error of the start position can be prevented.

In this case, since the combination bit is not compared by the comparing means, when recording is restarted after the recording is interrupted, whether the detection of the recording start position is normal or abnormal is determined by the coupling bit which may change. Not affected by judgment.

When the detection of the recording start position by the recording start position detecting means is determined to be abnormal, the recording start position is repeatedly detected again, so that when a disturbance occurs, Can also correctly detect the recording start position.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing one embodiment of a CD-R drive as an example for realizing a disk recording device according to the present invention.

[Description of Signs] 1 Optical head 4 CD-DA decoder 8 CD-ROM decoder 9 Interface 11 Encoder 14 Head output control circuit 16 Buffer RAM 17 Wobble decoder 18 ATIP demodulation circuit 19 System control circuit 22 Recording judgment means 23 Recording start position detection Means 25 Synchronization setting means 26 Comparison circuit 27 System clock generation circuit

Claims (3)

[Claims] 1. A disk recording apparatus capable of continuously adding recording data to the end of recording recorded on a disk until immediately before recording on the disk is interrupted, and according to input data. An encoder for generating recording data to be recorded on the disk, recording determining means for determining recording interruption and recording resumption of the recording data on the disk, and immediately before the recording interruption when the recording determining means determines recording resumption of recording data. The recording start position detecting means for detecting the recording start position at which the recording data already recorded on the disk is read and the recording is resumed on the disk is compared with the recording data read from the disk and the recording data generated by the encoder. Comparison means, wherein the encoder extracts the recorded data read when the recorded data recorded on the disc is read. A disc recording apparatus which operates using the output bit clock as an operation clock, and wherein the recording start position detecting means determines whether the detection of the recording start position is normal or abnormal based on the comparison output of the comparing means. . 2. The disk recording apparatus according to claim 1, wherein said comparing means does not compare the combination bits included in the recording data. 3. When the detection of the recording start position by the recording start position detecting means is judged to be abnormal by the comparison output by the comparing means, the recording start position is detected again by the recording start position detecting means. 2. The disk recording apparatus according to claim 1, wherein the step is repeated.