JPS61202375A - Optical record card - Google Patents

Abstract

PURPOSE:To retrieve easily and quickly the recorded information and also to attain the detection and correction with high accuracy to errors, by providing a retrieval information block where the interleave length is decreased and at the same time the error detection/correction capacity is improved. CONSTITUTION:An optical recording medium 2 contains the retrieval information blocks 4 in advance of plural information blocks 3. Each block 4 where the retrieval information is recorded has two tracks, for example, and the same contents are recorded to both tracks. At the same time, the six of 24 words of each track are defined as the parity words consisting of the read Solomon codes, for example, for error detection/correction processing. Then the triple error correction coding process is applied with an inter-code distance 7. The block 4 is capable of the deinterleave processing in a short time in a read mode since the interleave length is equal to 0 for a signal track. Thus the contents can be retrieved easily and a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical recording card comprising an optical recording medium provided on the card.

[Summary of the invention]

The present invention records a plurality of blocks of information on an optical recording medium provided on a card, records search information in advance of each block, and shortens the interleaving length of this search information. This shortens the time required for reading and allows information retrieval of each block to be performed easily and quickly.

[Conventional technology]

In recent years, bank cards, credit cards,
For use as identification cards, other memory cards, etc.
2. Description of the Related Art So-called optical memory cards or optical recording cards, which have an optical recording medium as an information recording medium, are becoming popular.

This optical recording card 1For example, as shown in Fig. 4,
At least one strip-shaped optical recording medium 102 is arranged parallel to the longitudinal direction of the card on a rectangular card substrate 1o1. Inside this medium 102, a plurality of trunks T are arranged in parallel in a wooden structure and are arranged in a direction perpendicular to the longitudinal direction of the card. Further, in each trunk T, an information signal is recorded in an optically readable manner as an array of pinot +-p as shown in FIG. In FIG. 5, one track T is composed of, for example, a synchronizing signal portion 103 and an information data portion lLi4.

By the way, such an optical recording card has a capacity of several M, for example.
It has a relatively large storage capacity of about two bits, and can record a relatively large number of types or large amounts of information, but when such high-density recording is performed, slight scratches may occur on the card's recording medium. Bit errors, burst errors, etc. occur due to the occurrence of dust or adhesion of dust. For this reason,
Error detection and correction encoding processing such as addition of parity words for error detection and correction and interleaving processing are generally performed.

[Problems to be Solved by the Invention] However, optical recording cards generally have slow access speeds, and if the interleaving length is increased to prevent burst errors, decoding processing time such as dinterleaving processing during reading increases. The disadvantage is that it takes a long time to retrieve the recorded contents, and searching for recorded contents cannot be performed easily and quickly. Further, if the interleaving length is shortened, the dinterleaving processing time is shortened, but there is a drawback that it becomes vulnerable to burst errors.

In view of these circumstances, the present invention provides an optical recording card that allows recorded information to be searched easily and quickly, and that is capable of powerfully detecting and correcting errors. With the goal.

[Means for solving problems]

In order to solve the above-mentioned problems, an optical recording card according to the present invention is an optical recording card in which a strip-shaped optical recording medium is arranged along the relative movement direction of the card when reading recorded contents. Information is recorded on a recording medium divided into a plurality of information blocks, search information is recorded in advance of each of the information blocks, and the interleave length of error detection and correction encoding processing applied to the search information is shortened. It is also characterized by providing a search information block with enhanced error detection and correction capabilities.

[For production]

The recorded contents of each search information block, which is provided in advance of each information block, require short interleaving processing time, and have improved error detection and correction capabilities, making them resistant to errors and fast. In addition, it becomes possible to search recorded contents with high reliability.

〔Example〕

Preferred embodiments of the present invention will be described below with reference to the drawings.

In the optical recording card 1 shown in FIG. 1, the card longitudinal direction (
At least one strip-shaped optical recording medium 2 is disposed parallel to the arrow direction), and a plurality of recording tracks perpendicular to the longitudinal direction (arrow direction) of the optical recording medium 2 are parallel to each other. Records are being formed. In this optical recording medium 2, various general information, for example, in the case of a bank card, deposit information, deposit and withdrawal history information, etc. are recorded divided into a plurality of information blocks 3.
1) preceding each of the plurality of information blocks 3, search information for searching the recorded contents of each block;
A search information block 4 is provided in which information such as a title, label, address, etc., is recorded.

Furthermore, if necessary, at the beginning position of the optical recording medium 2,
Basic information 1 that corresponds to the content of the above general information and can also be independent information 1 For example, TO
An information block 5 is provided in which C (total of content) data, ID (identification) data, etc. are recorded, and this information block 5 also includes a search information block 6 as described above.
is provided in advance.

8. Of course, each of these pieces of information is recorded in the information data section 104 of each track T in FIG. 5 mentioned above.

Here, each information block 3 in which the general information is recorded has, for example, an l block of 256 words, and at least the information data portion (104 in FIG. 5) of one track is 24 words.
It has become a word. When recording information, 24 words of data for one track are recorded, for example, as shown in FIG.

Interleaving processing is performed to separate every 3 words by 32 tracks, and 4 of the 24 words are used as parity words (shaded area in Figure 2) for error detection and correction, for example, in a Reed-Solomon code. This constitutes a double error correction code with a distance of 5. When trying to decode one track of information recorded in information block 3 after such interleaving processing,
It is necessary to read at least 225 tracks for the dinterleaving process, making it unsuitable for high-speed access such as searching.

On the other hand, for each search information block 4 in which the above-mentioned search information is recorded, one block has, for example, two tracks, and search information of the same content is recorded on each track (so-called double writing).

Six words out of 24 words in one track are used as parity words (shaded area in the figure) using Reed-Solomon code for error detection and correction processing, and are subjected to so-called triple error correction encoding processing with an inter-code distance of 7. There is. This search information block 4 has an interleaving length of O between one track.
Therefore, the dinterleaving process at the time of reading can be performed in a short time (by just reading one track), and content searches can be performed easily and at high speed.

However, due to the short interleave length of 0.

In consideration of the vulnerability to burst errors, the same content is written twice on two tracks, and in order to prevent words with the same content from being in the same position between adjacent tracks, for example, 12 words are repeated. It is shifted cyclically. This means that groups of 3 words for 24 words in one track are sequentially A, B, C, etc.
When H, as shown in FIG. 2, A, B, C, . . . , H are arranged in one track of the search information block 4, and E, F', . G, H, A, B
,C.

They should be arranged in the order of D. Furthermore, the above G.

Six words in two groups of H are used as parity words for error detection. Therefore, even if so-called burst errors occur due to scratches or defects on the optical recording medium 2, and data reading errors occur at the same position on each track T,
Each of the double-written search information becomes a different word, and error correction can be easily and reliably performed.

That is, regarding the above search information, since 18 words in 6 groups of A and F are recorded using 48 words in 2 tracks of search information block 4, the redundancy is (
48-18)/48=0.625, or 62.59
6, and the redundancy of the information block 3 is 4/24.
;=0.167, that is, it is extremely large compared to approximately 16.796, and the error detection and correction ability is strengthened accordingly. However, information block 3-2
Compared to the 56 tracks, the search information track 4 is small with 2 trunks, and the increase in redundancy can be kept small overall.

By the way, such a determination of the search information block 4 can be made, for example, by checking the synchronization signal recording area (the synchronization signal portion 103 in FIG. 5) provided in parallel with the data recording area consisting of each information block 3 to 6 as described above. This can be done by recording a synchronization signal for determining the search information, but in addition to this, for example, a non-recorded portion 7 for at least one track is provided immediately before the search information block 4, and this non-recorded portion is 7, it may be determined that it is the search information block 4.

Regarding the recording of information block 5 in which highly important data such as the TOC data and ID data are recorded, for example, 6 words out of 24 words in one track may be used as parity words for error detection and correction. It is desirable to increase the error detection and correction ability compared to the general information block 3 by dividing the block into two and writing the same content twice.

Information recorded on the optical recording medium 2 of the optical recording card 1 as described above is read by an optical reader having a basic configuration as shown in FIG. That is, for at least one track T in the optical recording medium 2 of the optical recording card 1, the light source 11 shown in FIG.
The irradiation light from the trunk T is irradiated through the illumination lens 12, and the reflected light, that is, the reading light of the trunk T, is incident on the light detection element 14 such as a line sensor through the imaging lens 13. A light emitting diode is generally used as the light source 11, but a lamp, a laser diode, etc. may also be used. As the photodetecting element 14, a plurality of detection elements (photocells) are arranged in a straight line, such as a C0D (charge-coupled device) line sensor, and the image projected thereon is read by electrical scanning. We use what we can. A signal (track reading signal) from the photodetector element is sent to a data extraction circuit 15 via an amplifier or the like, and an information (data) signal is extracted. This data extraction circuit 1
The data from 5 is temporarily stored in a RAM (Random Access Memory) 16, which is a so-called buffer memory. The decoder 17 detects errors (including dinterleave processing) on the data stored in the RAM 15.
Error) detection and correction processing is performed, and the decoded information is sent to, for example, a second AMi f3. This RAM18
The information from is displayed on the display device 19 or the like.

Further, the optical recording card 1 is moved relative to the optical system such as the lens 12° 13 and the photodetecting element 14 in the longitudinal direction of the card (in the direction of the arrow).
It is now possible to read data about the track T at a desired position. For example, a motor 20 for moving the card 1 in the longitudinal direction of the arrow is controlled by a drive device 21, and a desired trunk T of the recording medium 2 of the card 1 is connected to the reading section of the optical system.
is located. This may be done by moving the optical system relative to the card 1 in the direction of the arrow.

The position detection device 22 detects the position of the card 1 with respect to the optical system based on a signal from the drive device 21, for example, and sends this position information to the control device 23. Control device 23
is the drive device 2 when reading the optical recording card 1.
1 and search information block 4 according to the above location information.
By determining whether or not and controlling the decoder 17,
It is possible to perform decoding processing that is appropriate for each block 3 and 4. In other words, by controlling the display device 19, the control device 23 can display information in a timely manner.

〔Effect of the invention〕

A search information block is provided in advance of each information block divided into a plurality of pieces, and this search information block contains search information that has been subjected to error detection and correction encoding processing that has a short interleave length and high error detection and correction ability. , the recorded contents of each information block can be searched easily and quickly, and the reliability of the search information can be increased without significantly increasing the overall redundancy.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing an embodiment of the present invention, FIG. 2 is a schematic plan view schematically showing the main parts of FIG. 1, and FIG. 3 is an example of an optical recording card reading device. Block Diagram,
FIG. 4 is a schematic plan view showing a general optical recording card, and FIG. 5 is a schematic plan view showing the structure of (7) 11-rack in the optical recording medium.

Claims (1)

[Claims] An optical recording card in which a strip-shaped optical recording medium is arranged parallel to the relative movement direction of the card when reading recorded contents, wherein information is divided into a plurality of information blocks on the optical recording medium. search information for searching the recorded contents of each of the information blocks is recorded in advance of each of the information blocks, and the interleaving length of the error detection and correction encoding processing applied to this search information is shortened. An optical recording card characterized by recording with enhanced error detection ability.