JPH09106630A - Information-recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an information-recording medium which can prevent ID information from being detected wrongly and can determine the start position of an information part from a block number. SOLUTION: In manufacturing the information-recording medium, a plurality of blocks as a basic unit for recording of information are formed. The information has a header (D1) where ID information (ID) recording three to five block numbers are continuously provided. Moreover, each of the three to five ID information areas records count data corresponding to the number of times. The count data is used to determine a recording start position of a data- recording area from the ID information area.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an information recording medium, and more particularly to an information recording medium used for optically recording or reproducing information.

[0002]

2. Description of the Related Art CAV is used as a recording system for optical disks.
(Constant Angular Velocity) method and CLV (Consant Angular Velocity) method
tant Linear Velocity) method. In the CAV method, the number of rotations of the optical disk medium is kept constant, and recording or reproduction is performed at a constant bit rate. Therefore, it is not necessary to change the rotation speed of the rotary motor during the seek operation for positioning the light spot on a predetermined block, and high-speed seek operation is possible, but the recording capacity per track of the optical disk medium is the radial position. The total storage capacity of the optical disk medium is smaller than that of the CLV method because it is constant regardless of the above.

In the case of the CLV system, recording or reproduction is carried out at a constant bit rate while changing the rotational speed of the rotary motor so as to be inversely proportional to the radial direction of the optical disk medium. For this reason, the storage capacity per track of the optical disk medium increases in proportion to the radius, and the total storage capacity of the optical disk medium becomes 1.5 times that of the CAV method. However, since it is necessary to change the rotation speed of the rotary motor during the seek operation, the seek operation time is delayed.

MCAV (Modified Conform) is a new recording method that solves the above-mentioned drawbacks of the CAV method and CLV method.
stant Angular Velocity) method is being developed. This MCAV system keeps the rotation speed of the optical disk medium constant,
This is a method of recording or reproducing while changing the bit rate so as to be proportional to the radial position of the optical disk medium.
Therefore, it is not necessary to change the rotation speed of the rotary motor during the seek operation, and a high-speed seek operation can be performed. 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 CL.
It is the same as the V method.

[0005]

An optical disk medium used in the MCAV system is divided into a plurality of blocks along a track, and ID information is formed in advance at the beginning of each block in the manufacture of the optical disk medium and is so-called preformatted. It This ID information is detected at the time of recording or reproducing the data, and the data is recorded or reproduced in the data area provided after the ID information. When recording or reproducing by the MCAV method using an optical disc medium having such a format, the time for which the light beam scans one block is not constant, and becomes shorter toward the outer peripheral portion of the disc. That is, the relative speed between the optical disk medium and the pick-up head increases at the outer peripheral portion, and I
A situation occurs in which D information cannot be detected. Further, if the optical disc medium is scratched, dusty, or the like due to manufacturing, use, aging, or the like of the optical disc medium, the ID information cannot be detected. For this reason, data recording or reproduction is hindered. In particular, even if the ID information can be detected at the time of recording and the data can be recorded in the data area after the ID area, the I
If a situation in which the D information cannot be detected occurs, the recorded data cannot be reproduced, which causes a problem in the reliability of the device.

Therefore, an object of the present invention is to provide an information recording medium capable of preventing the ID information detection error and determining the starting position of the data part from the block number.

[0007]

According to the present invention, at the time of manufacturing, I to which 3 to 5 block numbers are recorded.
A plurality of blocks serving as a basic unit of recording information having a header in which D information is continuously provided is provided, and each of the three to five sequentially provided ID information areas is information on the number of times corresponding to a sequential number. An information recording medium is provided, characterized in that this number of times information is used to determine the recording start position of the data recording area from the ID information area.

[0008]

FIG. 2 shows an optical disk medium 1 used in the optical disk device of the present invention. For example, in the case of the 5-inch optical disk medium 1, the radius is 29 to 6
20,000 tracks are provided within 1 mm, and about 400,000 blocks are formed in the MCAV system. These blocks are formed continuously on the optical disc 1 in a spiral shape. The number of blocks per track from the innermost track to the outermost track varies from 14 to 28. The bit rate is switched in 114 steps for every 165 tracks within a radius of 30 to 60 mm, and the bit rate change rate between adjacent track steps is designed to be within 1%.

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

Each block serves as a basic unit for recording information, has a minimum of 1435 bytes, and is formatted as shown in FIG. That is, it has a pre-format portion D1 and a data portion D2 that form the header A. The preformat section D1 is composed of, for example, 48 bytes, and has a 16-byte preamble VFO and four ID area IDs following it (each ID is composed of 8 bytes including 1-byte synchronization information). Each ID area I
D is a block number (No.), ID number (ID), CR
C) Store DMY. The data part has a recorded flag (16
Byte), VFO (16 bytes), data, ECC, resynchronization code (1306 bytes), PO (2 bytes), post field (POST FIELD: 32 bytes), and block gab (GAP: 15 bytes).

As shown in FIG. 2, the optical disc medium 1 is provided with an alternative area a for recording, for example, 1000 tracks, which is used as an alternative to the defective area while recording defect management information in the inner peripheral portion of the recording area Ia. A user area (user recording area) as a recording area used by the user
b is provided.

As shown in the circuit of FIG. 3, the optical disk medium 1 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 the reproduction signal amplification circuit 3
Is connected to the reproduction signal binarization circuit 4 via. The reproduction signal binarization circuit 4 converts the reproduction signal into a digital signal (2-7 code modulation signal).

A laser drive circuit 5 is connected to the drive input section of the optical head 2 for receiving a modulation signal from the modulation circuit 6 and driving a semiconductor laser of the optical head 2. The output of the reproduction signal binarization circuit 4 is the reproduction synchronization clock extraction circuit 7
The demodulation circuit 8 and the address mark detection circuit 9 are connected. The reproduction 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 NRs the 2-7 code modulation signal by the demodulation clock.
It is a circuit that demodulates to a Z signal. The address mark detection circuit 9 is a circuit which is provided immediately before the ID information and detects an address mark including an irregular pattern which is out of the 2-7 code conversion rule.

The output of the demodulation circuit 8 is a recorded flag detection circuit 10, an ID shift register 11, and a CRC detection circuit 12.
And a recording / reproducing switching circuit 15. C
The output of the RC detection circuit 12 is connected to the output of the address mark detection circuit 9 and the ID detection timing circuit 13.
The output of the ID detection timing circuit 13 is connected to the timing shift signal input terminal 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 the ID comparator 16 and the ID counter 17. ID
The output of the comparator 16 is connected to the recording / reproducing timing circuit 18 together with the output of the ID counter 17. The output of the recording / reproducing timing circuit 18 is connected to the laser driving circuit 5, the modulating circuit 6, the recording / reproducing switching circuit 15 and the ID number counter 17. 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 recording / reproducing ID register 14 and the other input terminals of the recording / reproducing timing circuit 18. Post-field content register 1
9, CRC generation circuit, postamble pattern generation circuit 21, resynchronization code pattern generation circuit 22, VFO pattern generation circuit 23, address mark pattern generation circuit 2
4, the recorded flag pattern generation circuit 25, the data buffer 26, and the error correction code addition / error correction circuit 27 are connected to the recording / reproduction switching circuit 15. The data buffer 26, the data transfer circuit 28, and the control circuit 30 are coupled to an external device via the external interface 29.

In the above apparatus, when the optical disk medium 1 is rotated by a rotation mode (not shown), for example, at 925 rpm, and the optical head 2 is driven by the laser drive circuit 5, the optical head 2 is ejected. The guide groove of the optical disk medium is tracked by the laser spot. Recording and reproduction are performed in block units, and a seek operation is performed to position the light spot in a predetermined block. In this seek operation, the reproduction signal obtained from the optical head 2 is amplified by the reproduction signal amplifier circuit 3 and converted into a 2-7 code-modulated digital signal by the reproduction signal binarization circuit 4. The digital signal is demodulated into the NRZ signal by the demodulation circuit 8 in synchronization with the synchronization clock extracted from the reproduction signal by the reproduction synchronization clock extraction circuit 7. Further, the digital reproduction signal is input to the address mark detection circuit 9 and I
When the address mark immediately before the D information is detected, the ID detection operation timing circuit 13 is driven. The ID detection operation timing circuit 13 receives a signal from the CRC detection circuit 12, and this CRC detection circuit 12 performs a CRC check using the CRC set for the ID and 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 ID detection operation timing circuit 13. The ID detection operation timing circuit 13 is I
The D detection operation timing signal is input to the ID shift register 7. In response to this signal, the ID shift register 7 transfers the count data of the ID information included in the stored contents to the count 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 drives the optical head and the driving means (not shown) for driving the objective lens in the optical head to drive the light spot to the target of the target track. Move to a block. Further, the control circuit 30 records / reproduces the ID information of the target block in order to confirm whether the input ID information is the ID information of the target block.
And set this setting ID information to the ID shift register 1
It is input to the comparator 16 for comparison with the input ID information of 1.

When the CRC detection circuit 12 outputs a signal without error and the comparator 16 outputs a signal indicating the match between the ID information of the target block and the read ID information, the recording / reproducing operation timing circuit 18 records. / Timing signals necessary for reproduction operation are input to the laser drive circuit 5, the modulation circuit 6, the recording / reproduction switching circuit 15 and the ID number counter 16. The operation of the recording / reproducing operation timing circuit 18 is preset by the control circuit 30. Therefore, the CRC detection circuit 12 and the ID comparator 16 are accordingly set.
Even if the operation signal is input from the recording / reproducing operation timing circuit 18, if the control circuit 30 sets the state in which the operation is prohibited.

When the seek operation as described above, that is, the operation of moving the light spot to the target block or the recording or reproduction of the data in the target block, it is necessary to correctly detect the ID information. An error may occur in ID information detection due to scratches, stains during use, deterioration of the recording area due to aging, and the like. Generally, the error rate of an optical disk is 1 × 10
^-5 to 1 × 10 ^-4 errors / bit, so 8
The probability that an error will be included in ID information composed of bytes (= 64 bits) is 64 × 1 × 10 ⁻⁵ to 64 × 1 × 10 ^−4.
The error occurrence rate after correction of the data portion, which has been corrected by the error correction method, is far higher than 10 ⁻¹² errors / byte. For this reason, in the present invention, the ID information is quadruple multiplexed and recorded on the optical disc medium 1. Quadruple I
By recording the D information, the incidence of ID detectors is significantly reduced. The table below shows the error occurrence rates for three examples in which the number of ID information is 4, 3, and 2.

[0021]

[Table 1]

If four blocks of ID information are provided in each block as shown in the above table, if the probability that an error is mixed in one ID area is 5 × 10 ⁻³ , then four blocks of ID information will be obtained. The probability that no ID information can be detected is (5 × 10 ^-3 ) ⁴
= 6.25 × 10 ^-10 . This value is equal to or less than the probability that data errors are mixed in one block, which is 10 ⁻⁹ to 10 ⁻¹⁰ , or less, and a practically sufficient read rate can be obtained by quadrupling the ID information. The probability that the three pieces of ID information will be defective is 0.19 if expressed as the number of blocks per surface.
It is a block, which is also practically acceptable.

When three pieces of ID information are provided in one block, the probability that two pieces of ID information cannot be detected is 2 per side.
This is 9.14 blocks, and the probability that even one of the three pieces of ID information cannot be detected is 0.05 block per surface. Within this range, there is no practical problem. However, when only two pieces of ID information are provided in one block, the error occurrence rate is 3886.7 / side, which is considerably large. Therefore, it is necessary to provide three or more pieces of ID information in one block. However, if the ID information is increased, the total storage capacity of data is reduced, so it is preferable to provide the ID information in the range of 3 to 5.

In the above-mentioned ID information detection, in particular, in order to ensure the detection of the ID information at the time of reproduction as described above, it is necessary to make the ID detection condition at the time of recording stricter than that at the time of reproduction. Therefore, it is necessary to detect at least two pieces of ID information at the time of recording, and if two pieces of ID information cannot be detected, recording of data in the block is prohibited, and the data is stored in the alternative area a as necessary. An alternative process of recording is performed.

The above-mentioned prohibition and substitution processing is controlled by the control circuit 30. That is, when the optical disk device is set to the recording mode, the correctly detected ID information of the four pieces of ID information is sequentially input to the control circuit 30 via the ID shift register 11. The control circuit 30 has two or more I's.
When the D information is received, a signal instructing the start of the recording operation is input 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. In response to the control signal, the recording / reproducing switching circuit 15 selectively sends the data in the postamble pattern generating circuit 21, the reproducing sync code pattern generating circuit 22, the VFO pattern generating circuit 23 and the data buffer 26 to the modulating circuit 6. Lead.

The data buffer 26 is a data transfer circuit 28.
The recording data from No. 2 is stored and an error correction code is added to the recording data by the error correction code addition / error correction circuit 27. Error correction code addition / error correction circuit 27
Thus, in the case of read-after-write at the time of recording, the correction can be performed by the normal error correction ability at the time of reproduction by performing the correction with the weak correction ability and performing the strict check.

The recording / reproducing switching circuit 15 receives the ID number counter 17, and the ID number counter 17 is loaded with the ID number of the last detected ID information. This ID count value corresponds to the distance (for example, the 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 from the number of times.

When the ID number counter 17 counts up to the number value corresponding to the data recording start position, the recording timing signal is supplied to the switching circuit 15. At this time, the postamble pattern generation circuit 21, the resynchronization code pattern generation circuit 22, the VFO pattern generation circuit 2
3 and the data in the data buffer 26 are input to the modulation circuit 6, and the laser drive circuit 5 drives the semiconductor laser of the optical head 2 according to the modulation signal. Data is written from a data recording start position of a predetermined block of the optical disk medium 1 by a laser beam generated from a semiconductor laser.

When the writing of data to the data section is completed,
Move to read after write. That is, the optical disc medium 1
When the light spot reaches the block after one round, I
The D information is read, the start position of the recorded flag area is determined, and the recorded flag output from the recorded flag pattern generation circuit 25 is written in the recorded flag area. In addition, the start position of the post field is determined from the ID information, and the ID field counter 17,
The data from the CRC generation circuit 20 and the address mark pattern generation circuit 24 is written. The post-field content register 19 is input with data by the control circuit 30.

By writing the recorded flag, duplicate writing to the same block is prevented. That is, when the recorded block is designated again in the recording mode, the recording flag is read and recorded in the recorded flag register 10. The control circuit 10 checks the flag of the recorded flag register 10 and prohibits recording when it detects the recorded flag. When deleting data recorded in a block, a deletion flag is written in the postfield.

When only one ID information is detected, writing of data to the corresponding block is prohibited,
Alternative processing is performed. When performing the alternative process, the control circuit 30 sets the alternative track number and the alternative block number of 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 in the alternative block through the same operation as the above recording operation.

When reading the data stored in the optical disk medium 1 as described above, the reproduction mode is set and the ID information of the block to be reproduced is input. This input ID information is recorded in the recording / reproduction ID register 14. On the other hand, the ID information reproduced from the optical disc 1 is the ID
It is stored in the shift register 11 for use. Shift register 1
1 transfers the ID information to the control circuit 30 each time the correct ID information is input. When the control circuit 30 detects one piece of ID information, the control circuit 30 executes the reproduction mode. That is,
The read position is determined by the number of times of the detected ID information,
Data reading is started. In this case, only the data in the data section and the data error correction code are stored in the data buffer 26.
And is ECC-checked by the error correction code addition / error correction circuit 27.

The reproduction signal is input to the demodulation circuit 8 via the reproduction signal amplification circuit 3 and the reproduction signal binarization circuit 4. ID
When the comparator 16 outputs a coincidence signal between the reproduction ID information and the set target ID information, the recording / reproduction operation timing circuit 18 outputs a control signal to the recording / reproduction switching circuit 15 in response to the coincidence signal. The switching circuit 15 guides the demodulated signal of the demodulation circuit 8 to the data buffer 28. In many cases, the reproduction data of the data buffer 26 is output to the host computer via the external interface 29.

[0034]

As described above, in the MCAV type optical disc device, by providing 3 to 5 ID information areas in each block, the ID information in each block can be reliably detected and data loss due to unreproducible data loss. It can be avoided. In addition, even when a plurality of ID information, that is, which block number among a plurality of block numbers is detected, the start position of the data part from the detected block number can be determined.

[Brief description of the drawings]

FIG. 1 is a diagram showing a block format of an information recording medium used in an optical disc device according to an embodiment of the present invention.

FIG. 2 is a plan view of an optical disc medium having an alternative area.

FIG. 3 is a block circuit diagram of an optical disk device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical disk medium, 2 ... Optical head, 6 ... Modulation circuit, 8 ... Demodulation circuit, 10 ... Recorded flag register, 11 ... ID shift register, 13 ... ID detection operation timing circuit, 14 ... Recording / reproduction ID register, 15 ... Recording / reproducing switching circuit, I6 ... ID comparator, 17 ... ID counter, 18 ... Recording / reproducing timing circuit, 26 ... Data buffer, 30 ... Control circuit.

Claims (1)

[Claims] 1. At the time of manufacturing, a plurality of blocks, which is a basic unit of information recording, having a header in which ID information in which 3 to 5 block numbers are recorded are continuously provided, are provided, and The five I provided in sequence
An information recording medium characterized in that each of the D information areas sequentially records the number of times information corresponding to the number of times, and the number of times information is used to determine the recording start position of the data recording area from the ID information area.