JPS63220482A - Information recording medium - Google Patents

Abstract

PURPOSE:To surely detect a bit of ID information at every block and to evade the dissipation of a data due to the impossibility of reproduction, by providing three - five ID information areas on every block. CONSTITUTION:Plural blocks having headers in which the ID information are provided successively storing the three - five block numbers and which become the fundamental unit of the recording of the information are provided. For example, when four pieces of ID information are received on every block, possibility in which neither ID information is detected out of the four pieces of ID information is equal to or less than the possibility in which a data error is mixed in one block, and a sufficient reading rate can be obtained by quadruplicating the ID information for practical use. And when an optical disk device is set in a recording mode, the bit of ID information detected normally out of the four pieces of ID information is inputted to a control circuit 30 sequentially via a shift register 11 for an ID, and the control circuit 30, in the case of receiving two or more pieces of ID information, inputs a signal to indicate the start of a recording operation to a recording/reproduction operation timing circuit 18. In such a way, it is possible to surely perform the detection of the bit of ID information.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Application Field) The second invention relates to an information recording medium, particularly an information recording medium used for optically recording or reproducing information.

(Conventional technology) As a recording method for optical discs, CAV (Consta
nt Angular Velocity) method and CLV (Constant Linear Vcloc) method
lty) method.

In the CAV system, the rotational speed of the optical disk medium is kept constant, and recording or reproduction is performed at a constant bit rate. Therefore, there is no need to change the rotation speed of the rotary motor during a seek operation to position the light spot to a predetermined block, and high-speed seek operations are possible. is constant regardless of the radial position, so the total storage capacity of the optical disk medium is smaller than that of the CLV system.

In the case of the CLV method, recording or reproduction is performed at a constant bit rate while changing the number of revolutions of a rotary motor in inverse proportion to the radial direction of the optical disc medium. For this reason, the storage capacity per track of the destination disk medium increases in proportion to the radius, and the total storage capacity of the optical disk medium is CA
This is 1.5 times that of the V method. However, since it is necessary to change the rotational speed of the rotary motor during the seek operation, the seek operation time becomes slow.

] MCA V (Modll'1e
dConsLanL Angu! ar VeloclL
y) A method has been developed. The MCAV method is a method in which recording or reproduction is performed while keeping the rotational speed of the optical disk medium constant and changing the bit rate in proportion to the radial position of the optical disk medium. Therefore, there is no need to change the rotational speed of the rotary motor during the seek operation, and a high-speed seek operation can be performed. Furthermore, since the storage capacity per track of the optical disk medium increases in proportion to the radius, the total storage capacity of the optical disk medium is the same as that of the CLV system.

(Problems to be Solved by the Invention) An optical disk medium used in the MCAV system is divided into a plurality of blocks along a track, and ID information is preformed at the beginning of each block during the manufacturing of the optical disk medium. Preformatted. This ID information is detected when recording or reproducing data, and data is recorded or reproduced in a data area provided after the ID information.

When recording or reproducing by the MCAV method using an optical disk medium having such a format, the time it takes for the light beam to scan one block is not constant, and becomes shorter toward the outer periphery of the disk. That is, the relative speed between the optical disk medium and the pickup head becomes faster at the outer circumferential portion, resulting in a situation where ID information cannot be detected. In addition, if the optical disk medium becomes scratched or dented due to manufacturing, use, or aging, the ID
Information becomes undetectable. This causes problems in data recording or reproduction. In particular, even if ID information can be detected during recording and data can be recorded in the data area after the ID area, if a situation occurs where ID information cannot be detected during playback, the recorded data will not be able to be played back, and the reliability of the device will be affected. A problem arises.

Therefore, an object of the present invention is to provide an information recording medium that prevents ID information detection errors.

rStructure of the Invention] (Means for Solving the Problems) According to this invention, the basic unit for recording information has a header in which ID information in which 3 to 5 block numbers are stored is consecutively provided. An information recording medium is provided that is characterized by being provided with a plurality of blocks.

(Operation) By providing 3 to 5 ID information, the ID information can be detected reliably.

(Embodiment) FIG. 2 shows an optical disk medium 1 used in the optical disk device of the present invention. For example, in the case of a 5-inch optical disk medium 1, 20,000 tracks are provided between the 29th and 61st radii, and approximately 400,000 blocks are formed in the MCAV system. These blocks are continuously formed in a spiral shape on the optical disc 1. The number of blocks per track from the innermost track to the outermost track is 14 to 2.
Changes up to 8. The bit rate is switched in 114 steps every 165 tracks within a radius of 30 to 60 mm, and the rate of change in bit rate between adjacent tracks is designed to be within 1%.

A block header A is provided at the start position of each block, for example, when the optical disk medium 1 is manufactured.

Each block is basically the 111th place for recording information, consists of a minimum of 1435 bytes, and is formatted as shown in FIG. That is, it has a preformat section D1 and a data section D2 that constitute the header A. The preformat section D1 is composed of 48 bytes, for example, and has 16 bytes.
Byte preamble VFO followed by four I
It has a D area ID (each ID consists of 8 bytes including 1 byte of synchronization information). Each ID area ID has a block number (No.), ID number (ID), and CRC.

Remember DMY. The data section includes a recorded flag (16 bytes), VFO (16 bytes), and data.

FCC, resynchronization code (1306 bytes), PO (2 bytes), post field (PO5TF I ELD
: 32 bytes) and a block gap (GAP: 15 bytes).

As shown in FIG. 3, the optical disk medium 1 records defect management information on the inner circumferential portion of the recording area 1a, and is provided with a substitute area a of, for example, 10001-racks, which is used as a substitute for the defective area.

Further, a user area (user recording area) b is provided as a recording area used by the user.

As shown in the circuit shown in FIG. 4, the optical disk medium 1 shown in "-" is read and written by the optical head 2. As is well known, the optical head 2 includes a semiconductor laser, an optical system, a tracking system, a focusing system, and a photoelectric sensor.

The output of the optical head 2 is connected to a reproduction signal binarization circuit 4 via a reproduction signal amplification circuit 3. Playback signal binarization circuit 4
converts the reproduced signal into a digital signal (2-7 code modulated signal).

A laser drive circuit 5 is connected to a drive input section of the optical head 2 in order to receive a modulation signal from a modulation circuit 6 and drive a semiconductor laser of the optical head 2 . The output of the reproduced signal binarization circuit 4 is transmitted to the reproduced synchronization clock extraction circuit 7 and the demodulation circuit 8! lI2 and address mark detection circuit 9 are connected. The regenerated synchronization clock extraction circuit 7 is a circuit that generates a demodulation clock from the 2-7 code modulation signal, and the demodulation circuit 8
converts the 2-7 code modulated signal into NRZ using the 1 week clock.
This is a circuit that demodulates the signal. Address mark detection circuit 9
is a circuit that detects an address mark that is provided immediately before ID information and includes an irregular pattern that deviates from the 2-7 code conversion convention.

The output of the demodulation circuit 8 is sent to a recorded flag detection circuit 10, an ID shift register 11. It is connected to the CRC detection circuit 12 and the recording/reproduction switching circuit 15.

The output of the CRC detection circuit 12 is sent to the address mark detection circuit 9.
It is connected to the ID detection timing circuit 13 together with the output of . The output of the ID detection timing circuit 13 is connected to the timing signal input terminals of the -ID shift register 11, the CRC detection circuit 12, and the comparator 16.

The output of the ID shift register 11 is connected to an ID comparator 16 and an ID number counter 17. The output of the ID comparator 1B is connected to the recording/reproduction timing circuit 18 together with the output of the ID number counter 17. The output of the recording/reproduction timing circuit 18 is transmitted to the laser drive circuit 5, the modulation circuit 6, the recording/reproduction switching circuit 15, and the ID number counter I7.
connected to. The recorded flag detection circuit 10 is connected to the control circuit 30 together with the ID shift register 11.

The output of the control circuit 30 is connected to the other input terminals of the recording/reproducing ID register 14 and the recording/reproducing timing circuit 18. Post field content register 19, CRC generation circuit, postamble pattern generation circuit 21, resynchronization code pattern generation circuit 22, VFO pattern generation circuit 2
3. Address mark pattern generation circuit 24, recorded flag pattern generation circuit 25, data buffer 26, and error correction code addition/error correction circuit 27 are connected to recording/reproduction switching circuit I5. External interface 2
9, data buffer 26, data transfer circuit 28, and control circuit 30 are coupled to external devices.

In the above apparatus, when the optical disk medium 1 is rotated by a rotary motor (not shown) at, for example, 925 rpm, and the optical head 2 is driven by the laser drive circuit 5, the laser spot from the optical head 2 causes the optical disk medium to be The guide groove is tracked. Recording and reproduction are performed block by block, and a seek operation is performed to position the light spot in a predetermined block. In this seek operation, the reproduced signal obtained from the optical helad 2 is amplified by the reproduced signal amplification circuit 3, and the reproduced signal binarized circuit 4 converts the reproduced signal into 2-
It is converted into a 7 code modulated digital signal. The digital signal is demodulated into an NRZ signal by the demodulation circuit 8 in synchronization with the synchronization clock extracted from the reproduced signal by the reproduction synchronization clock extraction circuit 7. Further, when the digital reproduction signal is input to the address mark detection circuit 9 and the address mark immediately before the ID information is detected, the ID6 output operation timing circuit 13 is driven. The ID detection operation timing circuit 13 receives a signal from the CRC detection circuit 12,
A CRC check is performed using this CRC output circuit 12D and the CRC set for the number of times. If the result of this CRC check is determined to be incorrect, the ID information is discarded. If the result of the ID check is correct, a signal is output to the IDI output operation timing circuit 13. The ID output operation timing circuit 13 inputs the ID output operation timing signal to the ID shift register 7.

In response to this signal, the ID shift register 7 transfers the number data of the ID information included in the stored contents to the number counter 17 and also transfers the stored contents to the control circuit 30.

The control circuit 30 recognizes the current position of the light spot from the ID information, and moves the light spot to the target block of the target track by driving a driving means (not shown) that drives the optical head and the objective lens in the optical head. let In addition, the control circuit 30 sets the ID information of the target block in the recording/playback ID register 14 in order to confirm whether the manually entered ID information is the ID information of the target block, and uses this set ID information for the ID. Input ID of shift register 11
input to comparator IB for comparison with information.

When the CRC detection circuit I2 outputs an error-free signal and the comparator 16 outputs a signal indicating that the ID information of the target block matches the read ID information, the recording/reproducing operation timing circuit 18 determines the recording/reproducing operation. The timing signals necessary for this are manually input to the laser drive circuit 5, modulation circuit 6, recording/reproduction switching circuit 15, and ID number counter 1G. Furthermore, this recording/playback operation timing circuit! 8 is preset by the control circuit 30, and therefore,
Even if the operation signals are manually input from the CRC detection circuit 12 and the ID comparator 16, the recording/reproduction operation timing circuit 18 will not operate if the control circuit 30 has set a state in which operation is prohibited.

] - When performing a seek operation as described above, that is, an operation of moving a light spot to a target block or recording or reproducing data in a target block, it is necessary to correctly detect ID information, but it is necessary to detect ID information correctly during the manufacturing of optical disc media. Errors may occur in ID information detection due to scratches, dirt during use, or deterioration of the recording area due to aging. In general, the error rate of optical discs +11X10''!1
~lX10'4 errors/bit, so 8
The probability that 10 pieces of information consisting of bytes (-64 bits) contain an error is 64XIX10'5 ~ 64XI
The error rate is about 104, which is much higher than the :J correction error rate of 1 (1-12 errors/byte) in the data section using an error correction technique.For this reason, in this invention, the ID information is quadrupled. It is multiplexed and recorded on the optical disk medium 1.By recording ID information in 4 cities, the incidence of ID detection errors is considerably reduced.The table below shows the number of ID information in 4 cities.
．． The error occurrence rates for three examples with 3.2 are shown.

As shown in the table above, when four pieces of ID information are provided in each block, if the probability that an error will occur in one ID area is 5×10', then the four pieces of ID information will be 1
The probability of not being detected is (5X10-3)4-"6,2
It becomes 5X10-10.

This value is the probability that a data error will occur in one block.
It is equivalent to or lower than 0-9 to IQ-10, and a practically sufficient reading rate can be obtained by quadrupling the ID information. Furthermore, the probability that three pieces of ID information become defective is 0.19 blocks when expressed as the number of blocks per page, which is also acceptable in practice.

When three pieces of ID information are provided in one block, the probability that two pieces of ID information cannot be detected is 29.14 blocks per page, and the probability that one of the three pieces of ID information cannot be detected is 0 per page. .05 block. Within this range, there is no practical problem.

However, if only two pieces of ID information are provided in one block, the error rate will be as high as 3886.7/plane. Therefore, it is necessary to provide three or more pieces of ID information in one block. However, increasing the ID information reduces the total storage capacity of data, so
It is preferable to provide ID information in a range of five pieces.

In the detection of the above-mentioned ID information, in particular, as mentioned earlier, the ID j-? ! In order to ensure the detection of information, it is necessary to make II) detection conditions during recording stricter than during playback. Therefore, it is necessary to detect at least two pieces of ID information during recording, and if two pieces of ID information cannot be detected, recording of data to that block is prohibited, and if necessary, data can be transferred to alternative area a. Alternative processing to record is performed.

The above prohibition and alternative processing is controlled by the control circuit 30. That is, when the optical disk device is set to the recording mode, correctly detected ID information among the four pieces of ID information is sequentially input to the control circuit 30 via the ID shift register 11. When the control circuit 30 receives two or more pieces of 10 information, it inputs a signal instructing the start of the recording operation to the recording/reproducing operation timing circuit 18. The recording/reproducing operation timing circuit 18 inputs a control signal for recording to the recording/reproducing switching circuit 15. Recording/reproduction switching circuit 15 responds to the control signal to control postamble pattern generation circuit 21 . Reproduction synchronization code pattern generation circuit 22
, VFO pattern generation circuit 23 and data buffer 26
data is selectively guided to the modulation circuit 6.

The data buffer 2B stores the recording data from the data transfer circuit 28, and an error correction code is added to the recording data by the error correction code addition/error correction circuit 27. The error correction code addition/error correction circuit 27 performs correction using a weak correction ability and performs a strict check in the case of read-after-write during recording, so that correction can be performed using the normal error correction ability during reproduction.

The recording/reproduction switching circuit 15 has an ID number counter 1
7, but this ID number counter 17 is loaded with the ID number of the last detected ID information. This I
The D times value corresponds to the distance (for example, number of bytes) from the detected final ID information recording position to the data recording start position. Therefore, the data recording start position can be determined based on this number of times.

When the ID number counter 17 counts up to the number corresponding to the data recording start position, a recording timing signal is supplied to the switching circuit 15.

At this time, the data of the postamble pattern generation circuit 2L, the resynchronization code pattern generation circuit 22, the VFO pattern generation circuit 23, and the data buffer 26 are input to the modulation circuit 6, and according to this modulation signal, the data of the resynchronization code pattern generation circuit 22, the VFO pattern generation circuit 23, and the data buffer 26 are input to the drives the semiconductor laser of the optical head 2. Data is written from a data recording start position in a predetermined block of the optical disk medium 1 by a laser beam generated from a semiconductor laser.

When writing of data to the data section is completed, the process moves to read-after-write. That is, when the optical disk medium 1 goes around once and the light spot reaches the same block, the ID information is read, the start position of the recorded flag area is determined, and the recorded flag pattern generation circuit 25 outputs the recorded flag area. A flag is written to the recorded flag area. Further, the start position of the post field is determined from the ID information, and data from the ID number counter 17, CRC generation circuit 20, and address mark pattern generation circuit 24 are written into this post field. Note that data is input to the post field content register 19 by the control circuit 30.

Writing the recorded flag prevents duplicate writing to the same block. That is, when a recorded block is designated again in the recording mode, the recording flag is read and recorded in the recorded flag register IO. The control circuit IO checks the flag in the recorded flag register 10, and when detecting the recorded flag, inhibits recording. When deleting data recorded in a block, a deletion flag is written in the post field.

If only one piece of ID information is detected, writing of data to the corresponding block is prohibited and alternative processing is performed. When performing alternative processing, the control circuit 30 sets an alternative track number and an alternative block number for one block in the alternative area a, and moves the light spot to the alternative block. When the ID information of the alternative block is detected, predetermined data is written into the alternative block through an operation similar to the recording operation described above.

When reading data stored on the optical disc medium 1 as described above, a reproduction mode is set and ID information of a block to be reproduced is input.

This manual ID information is recorded in the recording/reproducing ID register 14. On the other hand, ID information reproduced from the optical disc 1 is stored in the ID shift register 11.

The shift register 11 sequentially transfers the correct ID information to the control circuit 30 every time the correct ID information is input. If the control circuit 30 detects one piece of ID information, it executes the playback mode. That is, the reading position is determined based on the number of times the ID information has been detected, and data reading is started. In this case, only the data of the data portion and the data error correction code are transferred to the data buffer 2B, and subjected to an ECC check by the error correction code addition/error correction circuit 27.

The reproduced signal is inputted to the demodulation circuit 8 via the reproduced signal amplification circuit 3 and the reproduced signal binarization circuit 4.

The ID comparator 16 compares the unified ID information and the set purpose ID.
When the matching signal with the information is output, the recording/reproducing operation timing circuit 18 outputs a control signal to the recording/reproducing switching circuit 15 in response to the matching signal.

Switching circuit 15 guides the demodulated signal of demodulation circuit 8 to data buffer 2B. The reproduced data in the data buffer 2B is output to the host computer via the external interface 29 in most cases.

[Effects of the Invention] As described above, in the MCAV type optical disk device, by providing 3 to 5 ID information areas in each block, the ID information in each block can be reliably detected.
It is possible to avoid data loss due to unavailability of data.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a block format of an information recording medium used in an optical disk device according to an embodiment of the present invention, FIG. 2 is a plan view of an optical disk medium having an alternative area, and FIG. FIG. 2 is a block circuit diagram of an optical disk device according to an embodiment of the present invention. l... Optical disk medium, 2... Optical head, 6...
- Modulation circuit, 8... Demodulation circuit, lO... Recorded flag register, 11... ID shift register, 13.
... ID detection operation timing circuit, 14... Recording/playback ID register, 15... Recording/playback switching circuit, IB... ID comparator, 17... ID number counter, 18... Recording/ Playback timing circuit, 2G...
Data buffer, 30...control circuit.

Claims (3)

[Claims] (1) An information recording medium characterized by being provided with a plurality of blocks serving as a basic unit for recording information having a header in which ID information in which three to five block numbers are stored are consecutively provided. (2) Each of the ID information areas 3 to 5 provided sequentially records number information corresponding to the number of times, and this number information is used to calculate the recording start position of the data recording area from the ID information area. The information recording medium according to claim 1, characterized in that: (3) The information recording medium according to claim 1, wherein the plurality of blocks are consecutively provided in a spiral shape.