JPS60115069A - Recording and reproducing device of optical information - Google Patents

Abstract

PURPOSE:To attain the track jump and the error recovery of a sector address with high reliability and high stability for an optical disk containing spiral tracks, by obtaining the prescribed constitution of an index field and each sector. CONSTITUTION:An index field 11 of a disk 10 contains an index mark 12 and a jumping area 13 where a track is sent back and an original track is retraced. The mark 12 is detected without using any special detection element to perform a track jump with high stability and high reliability. While each sector 14 contains a sector mark 15, address field 16, data field 17, etc. Both marks 15 and 12 serve as a substitute function of the field 16. Thus a sector address error is recovered easily and assuredly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical information recording and reproducing apparatus that records and reproduces digital data signals on an optical disk by narrowing a laser beam to a finely focused laser beam;
In particular, the present invention relates to track tracing and address detection of an optical information recording/reproducing device using an optical disk having a spiral guide track.

Conventional Structures and Problems Optical disks are attracting attention as high-density, large-capacity digital memories because they can record signals by concentrating laser light into a minute spot on the order of 1 .mu.m, and are capable of almost non-contact recording and reproduction.

In order to achieve a track pitch on the order of μm, an optical disc has a groove-shaped guide track formed in advance, and while this guide track is traced with a minute spot light, the energy of the laser light is used to create holes in the recording layer or form a change in reflectance. heat recorded.

Optical discs that record digital data signals use a disc format in which each guide track is divided into a plurality of sectors, similar to magnetic discs, allowing users to randomly access each sector.

This disc format is simultaneously written in a laser cutting machine when forming guide tracks on a photoresist-coated master disc. After this master disk is developed, it is nickel plated. This nickel plating is applied to the master disk and becomes the nickel master disk.

The nickel mask has a photoresist image transferred to it.
Injection processing is performed using a glass molding machine to produce the formatted replica disk, and a recording layer is formed by depositing a recording material on this replica disk. Next, a protective layer is formed on the recording layer to form an optical disc.

FIG. 1 is an external view of a conventional example of the disc format of an optical disc.

In FIG. 1, an optical disc 1 has a guide trunk having a plurality of sectors 2. It is divided into SO to Sn at equal intervals, and formatted so that each sector 2 has addresses 3 and AO to An at the beginning.

Address 3 consists of a track address and a sector address, and the same track address is recorded in Ao to 8n of address 3 on the same guide track, and S□-3 of each sector 2.
A sector address corresponding to n is recorded. In order to increase the guide track density of the optical disc 1, the grooves are formed as spiral grooves with good pitch accuracy.

FIG. 2 is an external view of another conventional optical diffuser.

The optical disc 4 is divided into a plurality of sectors 5, S'O to S'n at equal intervals, and each sector has a sector separator SP, s of the same structure recorded at the beginning thereof. The shunted guide trunk is formed with an address 7 in which address signals of each track are recorded.

The optical disc 4 has an index A8 .corresponding to the track address 7 on its innermost circumference. An index B9 corresponding to the sector separator 6 is cut. Index A8 and index B9 are detected by specially provided index detection elements as changes in the amount of reflected light. Intex 88 is used to create jumping timing for retracing the spiral guide track, and index B9 is counted by a counter. The output of this counter is initialized with index A8, latched in a register at the timing of sector separators sp and e, and applied to each sector ts and S' of the optical disc 4.
The sector address corresponds to o-8'n.

Sector separators SP, e, index 88, and index BS are signals formed using uneven grooves, and burst signals are used.

As mentioned above, in optical information recording and reproducing devices using conventional format optical discs, ■ Track jumping of the spiral guide track is insufficiently stable, resulting in long access times ■ Stable jumping cannot be achieved. To obtain this, a special detection element is required.■ There is no function to recover from errors that occur in sector addresses. Even if they were, there were some problems that they were insufficient.

OBJECTS OF THE INVENTION The present invention is directed to providing an optical information recording and reproducing apparatus that has stable and reliable track jumping and sector address error recovery functions for optical discs having spiral guide tracks. shall be.

Structure of the Invention The present invention has a spiral guide track, and the guide track has an index field consisting of a first identification signal followed by a jumping area, and a plurality of sectors, and this sector has a second identification signal at the beginning thereof. A circuit for separately detecting a first identification signal and a second identification signal using an optical disk consisting of a sector header area consisting of an identification signal and an address field, and a data field for recording data; A circuit that performs one-track retrace jumping (an operation of returning one track to the original track) of the spiral track in the jumping area in response to an identification signal, an address read error check circuit for the address field, and an error detection signal of this error check circuit. and a circuit for substituting a count output of a count circuit that counts the second identification signal starting from the first identification signal as a read sector address of the address field.

DESCRIPTION OF THE EMBODIMENTS FIG. 3 shows an external view of the disc format of an optical disc used in the optical information recording/reproducing apparatus of the present invention. In FIG. 3, 10 is an optical disc, 11 is an index field, and 12 is an index mark (IDM).
), 13 is jumping area (JG), 14 is sector S
``0~S//n115 is sector mark (SM'), 1e
The id address field, DoA'10-A"n, 1, is data 7, Do-Dn.

The address field 16 is composed of a track address, a sector address, and an error detection code.

FIG. 4 1-1: Track data format of the optical disc shown in FIG. 8.

In FIG. 4, the same numbers and symbols as in FIG. 3 represent the same things. 18 indicates the period of one rotation of the disk,
19 is a sector header of sector 14, S"0 to S"n. EOT indicates the end of the track.

FIG. 5 is a block diagram of an embodiment of the optical information recording/reproducing apparatus of the present invention.

In FIG. 5, 20 is a disk motor, 21 is a motor drive circuit, 22 is an optical head, 23 is a linear motor, and 24
is a linear motor drive circuit, 25 is a head amplifier, 26 is a focus servo circuit, 27 is a tracking servo circuit, 28 is a jumping circuit, 29 is a laser drive circuit,
3o is an equalizer circuit, 31 is a modulation circuit, 32 is a demodulation circuit, 33 is a scramble buffer 7.34 is an error correction circuit, 3B is an f-tava sofa, 36 is an index mark/sector mark detection circuit, 37 is an address reading circuit, 38 39 is an error detection lunch, 39 is an alternative sector address counter, 40 is a multiplexer, 41 is a sector control circuit, and 42 is a control section.

The operation of the optical information recording/reproducing apparatus of this embodiment configured as described above will be described below.

The optical disc 10, which is being rotated at a constant rotation speed by the disc motor 2o, is turned into light by a minute spot light from the nozzle 22, which causes the focus servo circuit 26 and the tracking servo circuit 2 to
7 is used to trace the guide trunk. Since the guide track is a spiral trunk, in this state the optical head 22 follows the direction of the spiral track,
Under the control of the linear motor 23 and the linear motor drive circuit 24, the guide trunk always moves so as to be directly above the optical head 22.

In order to have the optical path 22 trace the river trunk, it is necessary to return one track each time the optical disk 1o rotates once. The jumping circuit 28 performs this movement. .

Index mark 1' recorded on the optical disc 10
12Tt (Sector mark/sector mark detection circuit 3
6, and output as an index mark signal 102 and a sector signal 0;

The index mark signal 102 is sent to the jumping circuit 28
At this timing, the jumping area 130
In the meantime, by slightly moving the diaphragm lens of the optical head 22 in the disk radial direction using an actuator, one trunk jump is performed and returned to the original position. This jumping is checked by reading the track address output 103 of the address reading circuit 370 and the error detection signal 108 by a control section 42 composed of a microcomputer to check whether or not the jumping has been performed correctly.

By doing so, highly reliable spiral trunk glue tracing is achieved.

Next, the operation of recording data onto an optical disc will be explained.

First, the optical head 22 is transported at high speed to a designated guide track by the linear motor 23. Next, input data 1
00 is transferred from the system side to the data buffer 36,
An error correction code is added to the data in the error correction circuit 34 and stored in the scramble buffer 33. The scramble buffer 33 has the function of interleaving data recorded on the optical disc 10. This interleaving is performed to randomize burst errors occurring on the optical disc.

The sector control circuit 41 detects a designated sector position within one trunk. When the optical head 22 starts tracing a designated sector, a write sector gate signal 106 is output and the modulation circuit 31 is activated.

The data in the scramble buffer 33 is digitally modulated by the modulation circuit 31, and applied to the laser drive circuit 29 to drive the semiconductor laser built into the optical head 22, modulating the intensity of the minute spot light and recording on the optical disk 10VC.

Next, data reading will be explained.

To read data, a read sector gate signal 107 from the sector control circuit 41 is applied to the demodulation circuit 32 to start demodulation. The reproduced signal whose waveform has been shaped by the equalizer 30 is demodulated by the demodulation circuit 32 and written to the scramble buffer 33.

The scramble buffer 33 is read in the direction of dinterleaving, error detection and error correction are performed in the error correction circuit 34, and the data is written into the data buffer 35. The data in the data buffer 36 is transferred to the system side as output data 100.

As described above, since data recording and reproduction is performed sector by sector, sector address detection is very important, and requires high reliability and an extremely small number of photodetection sectors.

As is well known, optical discs have a bit error rate on the order of 10-4 to 1o-5, so this address field 1
The address read error rate of 6 is on the order of 1o-3 to 1o-4, which is one order of magnitude worse than the bit error rate, and an error recovery function is required. The address field 16 must be a short record of several tens of bits (therefore, long interleaving of data is not possible);
It is difficult to perform appropriate error correction because burst errors of ~100 μm (equivalent to several 10 bits to several 100 bits) are relatively common.

In the present invention, a high sector address detection ability is realized by replacing and recovering the error in the address field 16 with an alternative sector address generated using the sector mark 15 recorded in the front part of the address field 16 of the sector header 19. It is something to do.

This operation will be explained below.

Alternative sector address counter 39 receives sector mark signal 1
01 is used as a clock input, index mark 102 is used as a load input, and sector marks 15 are counted starting from index mark 12. This count output 106
is the sector address signal 10 of the address reading circuit 37
4 and input to the multiplexer 40. The two inputs of this multiplexer 40 are the address field 1θ
The read error signal 110 is selected by the error detection signal 108 latched by the error launch 38, and one is output. That is, when the error detection signal 10B is high-pull, the counter output 105 is set to the sector address data 1, and when it is disabled, the sector address signal 104 is set to the sector address data 1.
09 is output to the sector control circuit 41 and the control unit 42. The error latch 38 is set by the read error signal 110 and reset by the sector mark signal 101.

Therefore, sector non-detection occurs when both the address field 16 and the sector mark 16 are defective, and such cases are considered to be much rarer than when only the address field is present.

As described above, according to this embodiment, reliable spiral trunk tracing operation, reliable sector detection, and low sector non-detection rate are possible.

Effects of the Invention The optical information recording and reproducing device of the present invention has
By performing a one-ton jump in the jumping area by detecting the difference, the optical disc is resistant to defects and scratches, and reliable concentric retrace of the spiral track is possible without using a special detection element. Furthermore, if an error occurs in reading the address field, the alternative sector address generated in the index mark and sector mark is used as the sector address, thereby improving the sector undetected rate of the optical disc, and resulting in the utilization of the sector of the optical disc. This will increase the rate.

Further, if the sector non-detection rate is kept constant, the manufacturing yield of optical discs can be greatly improved, and this has a great practical effect.

[Brief explanation of drawings]

FIG. 1 is an external view of a conventional optical disc, and FIG. 2 is an external view of another conventional optical disc. FIG. 3 is an external view of an optical disc used in the optical information recording/reproducing apparatus of the present invention, FIG. 4 is the track data format of FIG. 3, and FIG. 5 is an embodiment of the optical information recording/reproducing apparatus of the present invention. It is a block diagram. 10... Optical tissue, 14... Sector, 11...
...Index field, 12 Intex mark, 13...Yumping area, 16...Sector memory, 16.Address fee note, 17.Data field, 20..Disk motor, 21.
... Disc motor 1 drive circuit, 22 ... Optical head, 23 ... Linear motor, 24 ... l)
= 7 motor drive circuit, 25...head amplifier,
26... Focus servo circuit, 27... Tracking servo circuit, 28... Jumping circuit, 29... Laser drive circuit, 30... Equalizer circuit, 31... Modulation circuit , 32... Demodulation circuit, 33... Scramble buffer, 34...
Error correction circuit, s5...Data buffer, 3
6...--index mark/sector mark detection circuit, 37...address reading circuit, 38...
・Error detection ratte, 39--Alternative sector address counter, 40--Multiplexer, 41...
. . . Sector control circuit, 42 . . . Control unit. Name of agent: Patent attorney Uneo Nakao and 1 other person No. 1
Figure 3 O Figure 4

Claims (1)

[Claims] (1) An optical disc having a spiral guide track, the guide track consisting of a first identification signal, an index field consisting of a jumping area, and a plurality of sectors, and the sector has a second identification signal, a track address, When recording and reproducing data on an optical disk, which is composed of a sector header area consisting of a sector address and an address field including an error detection mountain code, and a data field for recording data, the first identification signal is used. The spiral track is retraced by returning the spiral guide track by one track in the jumping region, and the second identification signal is counted, and the count output is initialized with the first identification signal, and the count output is initialized with the first identification signal, An optical information recording/reproducing device in which an output is used in place of a sector address in the address field by detecting a read error in the address field. (2) The optical information recording according to claim 1, wherein the track address of the guide track is an address in which no error is detected by reading a plurality of address fields within one track from the first identification signal. playback device.