JPS62262232A - Optical recording medium - Google Patents

Abstract

PURPOSE:To improve the efficiency of read access by recording a data by dividing it into plural small areas and adding a mark to identify its data area to each data area. CONSTITUTION:In expressing a data in several bits or several tens of bits, e.g., per one column and arranging the data in a line, the data is expressed by a suitable code, e.g., an MFM code, and 1-bit of data is expressed by 2-bit of the MFM code. Since 16-bit is used for one line in the MFM code, 8-bit, i.e., 1 byte data is recorded on a line, and one data sector 6 is formed in the unit of several tens of lines each of which bits are recorded. A mark 8 is added to identify the sector 6 to the data 7 in the sector 6. Information such as a number in ascending order is recorded as the mark 8, the sector 6 is identified by reading the mark 8 at reading and mis-reading of the mark 8 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an optical recording medium called, for example, an optical memory card.

(Prior Art) Conventionally, an optical memory card as shown in FIG. 5 has been used for recording or reading data using, for example, a laser beam. That is, a stripe 2 serving as a data recording area is provided at a predetermined portion on the surface of the card base 1 along its longitudinal direction. In the stripe 2, a plurality of reference lines (reference lines) 3 indicating divisions of recording data are provided along the longitudinal direction, and the space between these reference lines 3 is called a band 4. In each band 4, optical data 5 is arranged and recorded in a matrix.

That is, each piece of data is determined by, for example, making a hole in the stripe 2 using a laser beam (this is called a bit), and for example, +1++ when the hole is made and 0° when it is not made.

Record it digitally. Then, each pit is expressed by, for example, one column of several bits, and by arranging them in a column, a set of data is recorded. The recorded data is read out by using, for example, a laser beam as a light source, and receiving reflected light from the stripe 2 by a CCD type line sensor or the like.

However, with such conventional optical memory cards, data can only be read continuously, and even in order to read intermediate data, the entire data for one column must be read. For this reason, there was a drawback that the efficiency of successive access was extremely low. Furthermore, if the data is destroyed due to scratches or the like, all the data will be lost and the reliability of the card will be significantly reduced.

(Problems to be Solved by the Invention) As mentioned above, there is a drawback that the efficiency of read access is very low, and there is also a drawback that the reliability of the card is significantly reduced if the data is destroyed.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks, and provides an optical recording medium in which the efficiency of read access is significantly improved, and even if data is destroyed, there is only minimal loss, and reliability is significantly improved. The purpose is to

[Structure of the Invention] (Means for Solving the Problems) The optical recording medium of the present invention records data divided into a plurality of small areas, and further includes a method for identifying the data area in each data area. A mark is added.

(Function) Data can be read in small data flj area units, and data areas can be easily identified, making access easier, significantly improving read access efficiency, and preventing data from being destroyed. However, the loss can be minimized, and the reliability as an optical recording medium is significantly improved.

(Embodiment) The present invention will be described below with reference to an embodiment shown in FIG. Note that the same parts as in FIG. 5 are given the same reference numerals, and the explanation thereof will be omitted, and only the different parts will be explained in detail. In this embodiment, data is expressed using, for example, several bits to several tens of bits per column and arranged in one column. At this time, the data is an appropriate code, for example, MFM%P.
W.M.

Expressed using a code such as NRZ. For example, MF~1
In code, 1 bit of data is expressed using 2 bits.

In the example shown in FIG. 1, the MFM code uses 16 bits per column, so 8 pits, or 1 byte, of data can be recorded in one column. The bits recorded in columns in this way are defined as one data area in units of several tens of columns. This data area is called a sector and is represented by the reference numeral 6 in FIG.

For data 7 in sector 6, this sector 6
A mark 8 is added for identification. The mark 8 records information such as an ascending number, and the sector 6 can be identified by reading the mark 8 at the time of reading. In the example in Figure 1, the number is recorded four times, and this J
: This prevents misreading of mark 8.

Note that information representing the position of the sector 6 may be used as the information recorded as the mark 8. By doing so, it is possible to prevent erroneous reading of the sector 6, and even if the data is destroyed due to scratches or the like and becomes unreadable, other parts can be read accurately. Specifically, as shown in FIG. 2, for example, each band 4 is assigned 1, 2, 3, . . . in ascending order from the bottom.・・・
. . , and each sector 6 is numbered 1, 2, 3, etc. in ascending order from the left side within band 4. ..., each sector 6 is uniquely determined by the band number @9 and sector number 10, and this is recorded as mark 8.

Further, the data 7 area and the mark 8 area may be separated. By doing this, mark 8
identification becomes easier. Specifically, as shown in FIG. 3, for example, a column 11 in which nothing is recorded is provided between the data 7 ii and the mark 8 area.

Furthermore, as shown in FIG. 4, by adding a code 12 to the mark 8 that is different from the code representing the data 7, misreading of the mark 8 can be prevented. In the example shown in FIG. 4, a special code that does not appear in the MFM code used in data 7 is used.

In this way, data is divided into sectors and recorded,
Furthermore, by adding a mark to identify the sector, it is possible to read data sector by sector, and the sector can also be identified in the cylinder, making access easier and significantly improving the efficiency of read access. At the same time, even if data is destroyed, only minimal loss is caused, and the reliability of the card is significantly improved.

[Effects of the Invention] As detailed above, according to the present invention, there is provided an optical recording medium in which read access efficiency is significantly improved, even if data is destroyed, there is only minimal loss, and reliability is significantly improved. can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIGS. 2 to 4 are block diagrams showing other embodiments of the present invention, and Section 5 shows an example of a conventional optical memory card. FIG. 1...Card base, 2...Strive, 3...Reference line, 4...
-Band, 6... Sector, 7... Data, 8... Mark, 9... Band number, 10... Sector number.

Claims (1)

[Claims] (1) An optical system having a plurality of data areas in which optical data is arranged and recorded in a matrix, and each data area has a mark for identifying the area. recoding media. (2) The optical recording medium according to claim 1, wherein the mark includes information indicating the position of the data area. (3) The optical recording medium according to claim 1, wherein the mark is distinguishable from data in the data area. (4) The optical recording medium according to claim 1, wherein the mark uses a code that does not appear in the data in the data area.