JPS60201571A - Information recording and reproducing system - Google Patents

Abstract

PURPOSE:To form an optical information recording and reproducing system with ease of information management where the amount of recorded information, i.e., the number of bits has no limitation, general-purpose performance and the recorded information has a low error rate by recording the number of bits of input information in a sector as management information to each sector. CONSTITUTION:A series of input information fed from an input device 310 is led to an encoder 312 at recording while the number of bits of input information is counted by a sector bit number counter 311 and error correction coding is supplied. The error correction code is added with a check bit in l-bit generated based on a prescribed rule to an input in R-bit for example and becomes a code word in a code length (m=R+l)-bit. Thus, since the number of bits of the recorded input information to each sector is managed in the unit of sector, no limitation is imposed on the amount of handled information and the general- purpose performance as a large capacity memory is improved remarkably and the system copes with any input of information form.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optical information recording and reproducing method for optically recording and reproducing C information using a laser beam.

[Technical background of the invention and its problems]

Recently, a so-called optical disk device C1 has been attracting attention as a main device for recording and reproducing information with high density and large capacity. For example, this can be done by narrowing down the laser beam to a diameter of about 1 μm,
Irradiates a disk-shaped recording medium called an optical disk, with a width of 0.6
Bits of ~1 .mu.m and length of 1 to 2 .mu.m are formed on a recording medium, recorded in C, and then reproduced in C using a similar laser beam with reduced power.

Large-capacity memories such as optical disk devices have versatility in the format of information handled, such as data length, and it is important to know how quickly and accurately the recorded information can be reproduced with a low error rate, and how easy it is to manage the recorded information. The existence of such products is one of the important factors for popularization. To do this, the encoded input information is divided into information units consisting of a certain number of bits, and error processing is performed on these units to improve the error rate of C as a system. Furthermore, management information consisting of sector control signals and address information, etc. It is effective to add the following to form a fixed recording unit called C sector, and to record and reproduce signals using the sector size.

FIG. 1 schematically shows the sector structure adopted in conventional magnetic disks and optical disk devices, in which each sector consists of an information signal 101. Address signal 102 indicating the address of the sector, address signal 10
cue signals 103, 9 and synchronization signal 10 indicating the start of 2
Consists of 4.

As mentioned above, in optical disk devices, the bit size is μm.
Because it has a storage capacity that is 10 to 100 times larger than conventional magnetic memory devices, its use as an electronic file device for document images and still images is expanding. However, since the bit size is small, on the order of μm, even defects such as dust and scratches on the order of μm on the optical disk can cause errors, and the error rate of the recording medium itself is as low as 10 to 10. Also, according to our research (1166 National Conference of the Institute of Electronics and Communication Engineers, 1986)
;Study of error correction method suitable for optical disk memory),
On optical discs manufactured under normal conditions, there are not only random double-sided defects on the μm order, but also 10 in some cases.
It is known that there are even burst-like defects of 0 μm or more. Although the error characteristics of optical disks are basically random, including large bursts, it is important to randomize large errors from the system side using interleaving and to use error correction methods using random error correction codes. By using these methods in combination, the error rate in the system can be dramatically reduced.

Here, an error correction code is, for example, a code length m(
=R+z) bit code word. If such encoding is performed, upon reproduction, by checking the 'C variation pattern according to the above encoding law, a code error up to the A bit occurring at any position in 'C1 can be detected and corrected. It becomes possible to do so. Typical examples of such coding include Hamming code, BCH code, etc., and the number A of bi'sotos capable of error correction is called error correction ability. Interleaving means, as shown in FIG.
This refers to rearranging data at intervals of bits. As a result, there was a large gap on the optical disk, and it was interleaved and recorded (N numbers were consecutive and C was missing [However, when gain interleaved and C was returned to the original signal, the adult defects were dispersed [ The influence of defects can be reduced.In other words, if the number of error bits is distributed to each codeword by dinterleaving and is less than the error correction capability A bit, all errors caused by large defects can be corrected. .

In this way, by using error correction codes and interleaving together, it is possible to dramatically reduce the error rate systematically, but recording signals on a recording medium requires the product mXn of the error correction code length m bits and the interleaving length n bits. C is carried out using bits as the basic unit (segment), so the number of information bits in each sector is equal to the number of information bits included in that segment.
= RX must be an integer multiple of n bits (block).

On the other hand, electronic file devices that handle long form images and still images
Information is Document Painting II! Alternatively, a series of information signals can be set for each still image. The amount of information in each image, such as an image and a document filled with small characters, is undefined and varies greatly.

However, as mentioned above, in conventional recording and reproducing methods, a series of input information is recorded and reproduced in units of information consisting of a fixed number of bits, so the amount of information handled is limited to the number of bits of the information unit (block, There was a problem in that it was limited to an integer multiple of an integer multiple).

[Purpose of the invention]

An object of the present invention is to provide an optical information recording and reproducing method that has no limitations on the information content of recorded information, that is, the number of bits, is versatile, has a low error rate for recorded information, and is easy to manage information. be.

[Summary of the invention]

In the present invention, for an information unit consisting of a fixed number of bits,
When the focus number of input information to be recorded is less than the number of bits of the information unit, auxiliary information corresponding to the number of missing bits is added to the input information, and one information unit is always composed of a constant number of bits, and the change is managed. By adding the input information bit number of the information unit to form a C sector and recording the signal on the recording medium in sector units, the conventional drawbacks can be overcome and the object of the invention described above can be achieved.

〔Effect of the invention〕

In the present invention, each sector has input information f! Since the number of bits is recorded along with the management information, there are no restrictions on the form or content of the information, such as the size of the image to be handled or the information density of the image, and the versatility of the C is significantly improved due to the large capacity memory. Moreover, the amount of information can be managed very easily.

[Embodiments of the invention]

FIG. 3 is a schematic configuration diagram of an optical disk device to which the method of the present invention is applied. In the same figure, 3 (301 is an optical disk with a recording medium binding C, which is rotated C by a motor 302.
03 is, for example, a laser beam from a semiconductor laser that can be directly modulated to a predetermined beam diameter l/c on the optical disk 301.
This is an optical system for irradiating, recording, and reproducing information.

During recording, a series of input information given from an input device 310 is guided to an encoder 312 while counting the number of input information bits with a sector bit number counter 311, and is subjected to C1 error correction encoding. This error correction code adds, for example, t check bits generated based on a predetermined rule to an n-bit input to form a code word with a code length (m=a+z) bits. The signal C error correction encoded by the encoder 312 in this manner is led to an interleaving circuit 313, where it is subjected to C interleaving in units of, for example, Le language code words, and then stored in a sector buffer 314. The number of bits of input information transferred at this time is the block bit number B = RX, which is the basic unit for error correction encoding and interleaving processing.
If the sector bit number counter 311 displays the transferred bit number C, and the auxiliary information generation circuit 3
Bit ``0'' until the total number of pits becomes n bits by 15.
``'' is input to the CPI encoder 312 as pseudo input information.

The signal stored in the sector buffer 314 is a synchronization signal generated by the synchronization signal generation circuit 316 and a cue signal generated by the cue signal generation circuit 317.

Following the sector address 'C generated by the address signal generation circuit 318 and the number of input information bits indicated by the sector bit number counter 311, [is read out, these constitute the C1 sector, and it is given to the write processing circuit 319. . The write processing circuits 3 and 9 sequentially process these applied signals and use them as modulation signals to modulate the semiconductor laser.

A series of input information transferred from the input device 310 onto the optical disk 301 is recorded as a series of sector columns optically in the form of a so-called pit column.

On the other hand, during playback, the optical disc 301 is passed through the optical system 303 as an electric signal.The obtained playback signal is first demodulated by the readout processing circuit 321, and then synchronized and started by the synchronization circuit 322 and cue signal detection circuit 323. address signal detection circuit 324. After the address signal and the sector information signal are separated and detected by the sector information signal detection circuit 325, they are dinterleaved by the dinterleave circuit 326 and stored in the sector buffer 327. The signal stored in sector buffer 7327 is subjected to C error detection and correction processing by decoder 328. Soshi C1
Only C1 manual information is transferred to the output device 329 according to the number of input information bits recorded as a sector information signal.

FIG. 4 shows the sector structure according to this embodiment. Each sector is called a segment in which input information or input information and auxiliary information of bit "0" are subjected to error correction encoding and interleaving processing. Bit information signal 401. Address signal 40 indicating the address of the sector
2. Cue signal 403 indicating the start of address signal 402
．． It is composed of a synchronization signal 404 and a sector information signal 405 indicating the number of input information bits of the information signal 401.
There is C.

FIG. 5 is a diagram showing a sector array of a series of information signals recorded in this manner on an optical disk. A series of information signals such as document images or still images is T3 = RX
5101, 5102, ~, 510z- in n bit units
The data is recorded on an optical disc as seven sector rows of 2°510z-1510fi. Each sector includes a segment 501, an address signal 5029, a cue signal 503. It is composed of a synchronization signal 504 and a sector information signal 505 indicating the number of input information bits. The address signals 502 are A, +A+'' 1. A4 + 2. in sector order.
. . , A, +Y-2°A, +'i knee 1, and the number increases and ゛C is recorded. Here sector address A, to A
, +τ-1 and the amount of information of the series of image information 'C' is nx(Σ-t)+C(C(B)),
The sector information signal of the t-14th sector 510i-1 from the first sector 510 of the sector sequence includes a total temperature of
The number of bits B indicating that is input information is recorded in binary code, and the value C indicating that the number of input information bits is C bits is recorded in the sector information signal of the seventh sector 510i. . Further, up to the C pit of the i-th sector is input information, and from the C-th +1 bit to the n bit, 1 is auxiliary information and "0" bits are added.

As described above, according to the present invention, the number of bits of input information recorded in each sector is managed for each sector, so there is no equal restriction on the information to be handled, and it can be applied to any information engraving input. The versatility of C is significantly improved by making it a large-capacity memory.

In addition, in this embodiment, the constant number of block bits B=RXrL
All error processing for the pits by C error correction coding and interleaving is performed to CI, but when the number of input information bits becomes less than n bits, auxiliary information bit 10' is automatically added and input to C. A certain amount of processing error processing is always performed, and the reliability of C can be supplementarily improved as a system.

[Other embodiments of the invention]

FIG. 6 shows another example of the sector structure based on the present invention, in which N segments of m x n pits are recorded in the same manner as in the previous embodiment and defined by the error correction code length m and the interleave length n. , 601. Sector information signal 605.~601N includes information on the number of human information bits included in the N segments. Address signal 6029 cue signal 6
03. A synchronizing signal 604 is added to make the sector C1. Here, it is recorded in the sector information signal 605. The maximum value of the number of input information bits is N pits. It is clear that the same effect as in the previous embodiment can be obtained in this manner.

Next, in these embodiments, the information signal is transferred to the sector buffer 31.
4 to the C write processing circuit 319, but C may also be transferred directly to the write processing circuit 319 without passing through the sector buffer 314. At this time, the sector information indicating the number of input information bits is calculated in the same order as shown in the above embodiment when the number of input information bits is systemically known in advance, and when the number of input information bits can be counted starting after information transfer. Synchronous signal, single start signal, address signal,
The sector will be configured on page 11 of the information No. 1B, f-Niji'C sector information signal.

The additional information may not be bits "0#", but may be all C "1", or any bit string.Especially when handling image information, the bit corresponding to white is used as additional information. The sector information signal does not necessarily have to be provided in each sector, but it is concentrated in the first sector and provided in C [
Good too.

As described above, the present invention is not limited to the above-mentioned embodiments, and can be modified in nine different ways, including the sector structure, sector information signal configuration, error processing configuration, presence/absence, etc., within the scope of the invention. It can be implemented in various forms.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the sector structure employed in conventional magnetic disk and optical disk devices. FIG. 2 is a diagram for explaining interleave processing. FIG. 3 is a schematic configuration diagram of an optical disk device to which the information recording/reproducing method according to the present invention is applied. FIG. 4 is a diagram showing a sector structure of a recording signal according to the present invention. FIG. 5 is a diagram showing a sector sequence of signals recorded on the optical disk 2 according to the present invention. FIG. 6 is a diagram showing a sector structure according to another embodiment of the recording signal according to the present invention. 311... Sector bit number counter. 315...Auxiliary information occurrence record. 405... Sector information signal. Agent Patent Attorney Noriyuki Chika (and 1 other person) Figure 1 Figure 4 Figure 5 3 Parties Figure 8 Figure 6

Claims (1)

[Claims] (1) In a method of recording digitally encoded signals in sector units, each C1 sector includes at least an information unit that includes a series of digitally encoded input information and has a fixed number of bits, and a sector. control signal, and when the number of bits of the input information is less than the number of bits of the information unit, the input information (2) the series of input information is 10'', 1
The auxiliary information is a digital signal that has been binarized into "1" (3) in which all C pits are "1" (3). Each sector includes management information for the information unit, and the management information indicates the number of input information bits in the information unit to be managed. (4) The input information constituting at least the information unit in each sector and the input information constituting the information unit. A patent claim characterized in that the auxiliary information is recorded on the recording medium after being subjected to error detection processing, error correction processing, error detection/correction processing, interleaving, or error processing consisting of a combination thereof. (5) The recording medium is disk-shaped, and information is recorded and reproduced optically by irradiation with a laser beam. Claim 1, ID 2, or 3 Alternatively, the information recording and reproducing method described in Section 4.