JPS6374175A - Information recording carrier - Google Patents

Abstract

PURPOSE:To reproduce recorded information accurately at a high speed and also to simplify the constitution of a demodulation circuit for reproduction of information, by providing an identifying area to each block and using a signal that can be reproduced by the same demodulation system as other areas to form said identifying area. CONSTITUTION:An information recording carrier includes information tracks 4 consisting of information bit strings arrayed in a line toward an arrow head C. Each track 4 includes 100 bits and all data excluding a reference R line 37 are modulated by an MFM modulation system and recorded. The 49 tracks 4 continuous toward an arrow head A form a block 32 and upper two tracks of the block 32 are defined as a block identifying area 33. The area 33 includes a block mark track 33a and a subblock mark track 33b and a block mark 45 is added to a data area 39 of both tracks 33a and 33b respectively. The mark 45 records continuously two missing clocks consisting of 8 bits respectively. Furthermore the mark 45 can be detected by a circuit that demodulates the information on a track 35. Thus the blocks can be surely identified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an information recording carrier, and particularly to an information recording Q carrier with an improved recording area format.

[Prior Art] Conventionally, record carriers used for recording information using a light beam and reproducing the recorded information using a light beam have various shapes such as a card shape, a disk shape, and a tape shape. What is known? Among them, optical information recording carriers (hereinafter referred to as "optical cards") shaped like carts are used.
) is expected to be in great demand as a recording medium that is easy to manufacture, portable, and easily accessible.

An example of the recording format of such an optical card is shown in the schematic plan view of FIG. No. 5I2I is a partially enlarged view thereof.

In these figures, a recording area 2 is provided on an optical cart 1 which is a record carrier, and this recording area 2 is connected to a band 3.
are arranged in multiple rows. In these hunts 3, a large number of information tracks 4 (for example, about 4,600 per L band) are arranged, and each track 4 has an information capacity of about several tens to 100 bits (for example, 46 bits). As shown in FIG. 5, this information track 4 is composed of a start bit 20, a stop bit 21, a track number area 22, and a data area 23 (including a parity bit for error correction).

Further, each band is separated by a reference line (hereinafter referred to as R line) 5. Furthermore, the optical card
In the corner is the home position HP which is the access reference position.
is provided.

Note that arrow A indicates the moving direction of the optical card l during reproduction, and arrow C indicates the information reading scanning direction by the optical head during reproduction.

FIG. 6 is a schematic diagram of an apparatus for reproducing information tracks having the above recording format.

In the same figure, the optical cart 1 is rotated by the rotation mechanism 6 to
The information recorded on the optical card 1 is read and reproduced track by track by the optical head 11. Light from a light source 7 such as an LED is focused by a lens system 8 and illuminates the optical cart 1. This optical card
The image of the track is formed on a one-dimensional sensor array 10 by an imaging optical system 9. Thus, an electrical signal corresponding to the information recorded on track 4 is output from sensor array IO. To access the target track on the optical cart L, first move the optical head 11 in the direction of arrow C with reference to the home position HP, and count the number of R lines 5 read by the optical head 11 at this time. Select band 3 to which the target track belongs 6 Next,
Track number area 22 of the information track imaged on the sensor array 10 as the optical cart l moves in the six directions of the arrow
The track number of the target track is detected, and the information in the data area 23 of the track is reproduced.

[Problems to be Solved by the Invention] Incidentally, it is desirable that the data information recording capacity of the above-mentioned optical card be as large as possible.

However, as the number of information tracks included in one hand increases, the number of bits in the track number area 22 for identifying the tracks has to be increased, and the number of bits in the data area decreases and becomes redundant or expensive. .

Furthermore, it is desirable that the playback speed of the above-mentioned optical cart be as fast as possible, especially in the case of information, image information, or audio information, where a plurality of the above-mentioned information tracks are required as the minimum unit of the information. In particular, it is preferable to increase the playback speed.

However, as described above, when the number of bits in the track number area 22 increases, the number of bits in the data area 23 decreases, and thus the number of tracks required to record the minimum unit of information increases, resulting in an increase in information reproduction. speed decreases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an information recording carrier having a format that has a large data information capacity by reducing redundancy and improves access speed, thereby making it possible to increase reproduction speed.

A further object of the present invention is to provide an information recording carrier that satisfies the above objects and can simplify the demodulation circuit used when reproducing information.

[Means for Solving the Problems] The above conventional problem is that the information track of the present invention is arranged in a plurality of rows in a direction substantially perpendicular to the length direction of the information track. a hand is formed, a plurality of the bands are arranged in parallel in the length direction of the information track,
In an information recording carrier in which each band is formed by a set of blocks consisting of a plurality of consecutive tracks constituting the hand, each block has an area for identifying the block. The present invention is solved by an information recording carrier characterized in that the area is provided with a single signal and cannot be reproduced by the same bitonal system as the other areas.

[Function] As described above, in the present invention, since an area for identifying the block is provided in each block as described above, when searching for a target track, first the information recording is performed. A block containing the track of interest can be identified from the entire carrier and then the track of interest can be searched within the block. in this way,
By using a block as a unit area for information access and making it possible to accurately identify each block as described above, the number of bits in the track number area of each track can be small, and moreover, it is possible to easily identify the target track. When searching, first identifying each block enables quick information access. Furthermore, since the area for identifying the occupied block can be reproduced using the same demodulation method as other areas, the demodulation circuit used to reproduce information can be simplified.

[Example] Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a partially enlarged schematic diagram showing a recording format of an embodiment of an information recording carrier according to the present invention, and FIG. 2 is a partially enlarged schematic diagram showing a part of the recording format of FIG.

In FIG. 1, reference numeral 4 indicates an information track consisting of information bit strings arranged in a line in the direction of arrow C. Each information track 4 consists of 100 bits.

In this embodiment, each of the information tracks 4 includes a 20-bit preamble section 36, a 6-bit R line 37, a 1-bit start bit 38. 48 bits (i.e. 6 bytes) of data area 39. 16 bits (2 bytes) of error correction code 40. 3 bits of track number 41. 4 bits of data parity 42. 2 bits of dummy bits 43. All data except for the R line 37 is modulated and recorded using the MFM modulation method.

Further, in this embodiment, the information tracks 4 configured as described above are arranged in parallel in the direction of arrow A, as shown in FIG. Each of the 49 consecutive blocks constitutes one block 32, and a plurality of these blocks 32 are arranged in the direction of the arrow to constitute the bunt 3. Furthermore, whether the illustration is omitted or such band 3 or arrow C
A plurality of recording areas are arranged in the direction.

In each block 32, one end in the direction of arrow A, that is, the top two tracks in FIG. 1, are used as a block identification area 33, and each block can be identified.

The block identification area 33 consists of a block mark track 33a and a sub-block mark track 33b, as shown in FIG. It consists of a data area 48 with a hand number of 46.8 bits and a block number of 47.16 bits.

In the block mark 45, two consecutive missing clocks "A1." consisting of 8 bits shown in FIG. 3 are recorded with a total of 16 bits (2 bytes). The missing clock "A1." in the MF14 is a known one on floppy disks, etc., and the data is "AI□", but it is 4.5
The signal is not inverted between bits, the clock is lost, and this pattern cannot be found in the signal pattern obtained by the normal 1st complementary modulation method, so it can be distinguished from other format data on the optical card, and the clock is lost. Identification can be performed reliably. Furthermore, blocks can be detected by demodulating the pattern of the block mark 45 using a demodulation circuit for demodulating other format data or information recorded in the data track 34, thereby simplifying the demodulation circuit. It becomes possible. Zaranimata, truck 33a,
Are the track numbers 41 of 33b both set to "7"?
The data area 48 of the track 33a contains 2 bytes of "OOu", and the data area of the track 33b:!&48 contains "F".
2 bytes of "F++" are recorded, and the block mark track and sub-block mark track are distinguished from each other by 1IT.

The error correction codes 40 in the tracks 33a and 33b, like the other data tracks 34, can perform single error correction on the data in the data area 39, and can further ensure block identification. .

Note that single error correction is performed for each track, but interleaving is performed for the data track 34, and the data area 39 and An interleaved double-correction error correction code is recorded in the area of the error correction code 40 to improve the data error rate.

The track 33 in which block arcs are recorded needs to be played back in real time in order to perform high-speed access, so only single correction is performed and no interleaving is performed.

In addition, there are a total of 43 data tracks 34 in the block 32, and the data 39 in each track is 6 bytes, so the data content H1 in the l block is 258 bytes, but as a unit that is easy to input data. In order to obtain 256 bytes/block, the last two bytes of the data 39 of the last track in the data track 34 are dummy data and "OOH" is recorded therein.

Next, an example of a method for reproducing the information record BkFU body will be described in detail. Here, an optical card is used as the information storage Q carrier having the recording format shown in FIG.
A reproducing device shown in FIG. 6 is used as a device for reading information from the optical card.

In the same manner as described with respect to FIGS. 4-5 above.

First, the optical head 11 is moved in the direction of arrow C to access the band containing the target block. Next, the optical card 1 is moved in the direction of arrow A, and the sensor array 10 of the optical head 11 sequentially reproduces the data in the track 4.

To explain in detail how to reproduce the data in the track 4, as shown in FIG. 2, the preamble 36 first reproduces the reference clock, and the R line 37 obtains the on-track timing. Next, the start point of the data is detected using the start bit 38, and the data 39 is loaded. An error correction code 40 is added to the data 39, and the data is reproduced almost in real time while improving the error rate of the data 39. The data parity 42 has a total of 4 bits of 1)a parity recorded for every 2 bytes of data 39 and error correction code 40, and the reproduction result of the data parity 42 is combined with the information on the R line 37 mentioned above. Used to select on-track signals. Then, by reproducing the track number 41, track transition is detected together with the information on the R line 37.

In this way, the data in the tracks are sequentially regenerated, and when the sync clock "AI, . . ." is detected from the first two bytes l- in the data 39, the start of a block is recognized. Next, the hunt is confirmed using the band number 46, the block number is detected from the block number field 47, it is determined whether the block number belongs to the target block, and if it is the target block, the hunt is detected. The information of the data area in the block is reproduced. On the other hand, if the block is not the target block, the next block mark is detected without reproducing the information of the data area of the block, and the same operation is performed thereafter.

In this embodiment, since the block identification area is recorded over two tracks 33a and 33b, it is necessary to ensure block identification in addition to error correction and parity check within the tracks. Further, since the 2-bit track numbers 41 of the two tracks 33a and 33b are the same and their distinction is made by error-correcting the 16-bit data 48, as described above, block identification becomes even more reliable.

Note that once the block identification area 33 of a certain block 32 is detected, the number and direction of blocks before the next block or target block change.

The speed of transport of the optical head 11 and the transport of the optical cart 1 to a desired block can be increased, thereby shortening the access time to the target block.

Furthermore, since the block identification area is provided in 2 blocks and the bunt number 47 can also be obtained as information, reliability is increased when performing block access to the bunt 3 in the vertical direction C1 and the creation direction across the band. , it is important to further reduce access time.

Further, the target block can be detected by counting the number of times the block identification area 33 is detected using a counter, and this is combined with the detection of the block number in the block number area 47 and the hand number in the band number area 46. By using them together, it is possible to further increase the reliability of detecting the target block.

Furthermore, in the above embodiment, an example is shown in which the block number is recorded in the block number area 47 with a number of bits that can identify all the blocks in band 3. If the target block is detected in combination with counting the number of times, even if the number of bits in the block number area 47 is reduced, the accuracy of detecting the target block will not be reduced.

1. According to the above embodiment, the reliability of identification in the middle of blocks is improved, and error correction is performed twice in the error correction area 40 in each track 4 and in the error correction area 35 in each block. This makes it possible to strengthen error correction.

Further, in the above embodiment, it is possible to reduce the increase in redundancy caused by the error correction area. That is, in this embodiment, since error correction is performed for each block, it is not necessary to complete the error correction within each track 4, so the error correction area 40 does not need to be so long.

In the embodiment described in Section J, the case where the identification area 33 consists of two tracks is exemplified, but in the present invention, the number of tracks in the identification area 33 is not limited to this, and the number of tracks in the identification area 33 is not limited to this. If required, the number of tracks may be increased to widen the range of the identification area 33; conversely, if an increase in data capacity is required, the number of tracks in the identification area 33 may be reduced. It is also a round trip. Further, an identification area may be provided in at least one track at the beginning and at least one track at the end of each block.

Further, in the above embodiment, the block arc 45 is data "A1." containing a missing clock in the MFM modulation method.
However, the present invention is not limited to this, and as long as the pattern (bit pattern) does not appear in other areas, the modulation method, data, position and number of missing clocks, etc. can be freely selected. .

In addition, in the above embodiment, one block is composed of 49 tracks, but in the present invention, an appropriate number of tracks may be used in consideration of the type of information to be recorded, the number of bits of the track number area, etc. It can be configured by the number of tracks.

Furthermore, the present invention is not applicable only to the above-mentioned optical card, but can be applied to any information recording carrier having a recording area constituted by the above-mentioned tracks and hands.

[Effects of the Invention] According to the present invention as described above, a block is used as a priority area for information access, and the block can be accurately identified. Therefore, the reliability of data reproduction is improved, and the track number area is This makes it possible to increase the data information recording capacity and quickly access the target block. That is, recorded information can be reproduced at high speed and accurately.

Furthermore, according to the present invention, it is possible to simplify the demodulation circuit used when reproducing information.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the recording format of the information storage Q carrier according to the present invention, and FIG. 2 is a partially enlarged diagram thereof.
FIG. 3 is a diagram for explaining the missing clock "A1." according to the embodiment of the present invention, FIG. 4 is a schematic diagram showing the recording format of a conventional information recording carrier, and the fifth [4 is FIG. 4 is a partially enlarged view of the format (recording shown in A), and FIG. 6 is a schematic diagram of the optical card recording/reproducing apparatus. 3...Hand, 4...Information track, 32...Block, 33...Block identification area. Agent Patent Attorney Minoru Yamashita Children Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) Information tracks formed by arranging information one-dimensionally are arranged in a plurality of rows in a direction substantially perpendicular to the length direction of the information tracks to form bands, and the bands extend in the length direction of the information tracks. In an information recording carrier formed by a set of blocks arranged in parallel and each band consisting of a plurality of consecutive tracks whose number is equal to or less than the number constituting the band,
An information recording carrier characterized in that each block is provided with an area for identifying the block, and the area is composed of a signal that can be reproduced using the same demodulation method as the other areas. (2) The information recording carrier according to claim 1, wherein the signal recorded in the area consists of a signal pattern that does not appear in the other areas.