JPH09330566A - Information recording medium and information storage method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the number of recordable/reproducible contents to that suited to the average transfer speed of a disc by setting each information block to a block size so that time required for recording and reproduction is constant according to the transfer speed of a storage zone thereof. SOLUTION: The contents 101 are divided into fixed sizes of blocks 102. The sizes of a blocks 102 are varied per zone so that time required for the recoding and reproduction of the blocks in the respective zones is almost equal. The size of the blocks to be stored into the zones on the inner circumference side with a lower delay speed is made smaller while the size of the blocks to be stored into the zones on the outer circumference side with a higher delay speed is made larger. The blocks are arranged in a form arrayed radially from the center of the disc. When the recording area is used being divided by the same angle whether the blocks belong to the outer circumference area, the middle circumference and the inner circumference, the areas can be consumed at the same rate thereby enabling the maximization of the memory capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for simultaneously recording / reproducing a plurality of moving image information, audio information and the like by using an information storage device such as a magnetic disk device or an optical disk device having a ZCAV format.

[0002]

2. Description of the Related Art The modern society is advancing to a multimedia information society due to the increase in processing speed of computers, the increase in memory capacity, and the development of communication networks. Above all, there are active movements regarding the handling of moving images. For example, research and development of video-on-demand (VOD) systems on the Internet and cable television (CATV), and movements to create standards for moving picture information handling such as MPEG (Moving Picture Experts Group). Can be mentioned.

A computer is used to handle moving images.
Along with memory and communication, the performance of information storage devices such as magnetic storage devices is important. Especially the VOD of CATV
In a large-scale system such as a video server for mobile use, a large amount of moving image data is handled at once, and therefore high performance is required in terms of capacity and transfer speed. In response to the demand, in recent years, a disk array in which a plurality of magnetic disk drives are lined up has appeared, thereby increasing the capacity and increasing the transfer speed by parallel data transfer. For example, in the above video server, contents (programs) of thousands of titles are always stored, and hundreds to thousands of contents are simultaneously delivered in response to each request. Therefore, in order to satisfy the required capacity and transfer speed. Disk array is required.

On the other hand, in addition to the CATV broadcasting station,
Network environments that are not as large as broadcasters (eg 1
There is a great need to handle digital moving images in a network environment consisting of 0 to 50 computers) and in the personal computer environment of each individual. In that case, it is desirable that a single magnetic disk drive can handle a plurality of contents rather than a disk array that is usually expensive and requires a large installation area.

In recent years, the performance (capacity, transfer speed) of a single magnetic disk drive has been improved, and a moving picture coding system with a high compression rate such as MPEG can be easily mounted, resulting in the capacity As a result, the above needs can be answered to some extent. For example, MPEG1 is used for a magnetic disk drive having a capacity of about 2 gigabytes.
2 to 3 video images (transfer rate of about 1.5 megabytes per second)
It can store time and minutes. This time corresponds to 24 to 36 news contents, each of which is about 5 minutes. Also, in terms of sequential transfer speed, recent magnetic disk drives have a transfer speed of MPEG1 of 26 to 53.
Many of them have a transfer rate of about 5 to 10 megabytes per second, which is twice as much. Therefore, the magnetic disk drive satisfying these specifications has the capability of constructing the above-mentioned multimedia environment in terms of capacity and transfer speed.

However, the above-mentioned sequential transfer rate means that when data is recorded in continuous sectors and when data that is sequentially recorded in continuous sectors is reproduced (in a disk controller such as error correction). There is no processing time). Such a situation is usually possible only when handling one content.

Generally, when a plurality of contents are handled at the same time, the recording / reproducing process is performed while fragmenting each content into blocks and time sharing. At this time, recording / reproduction is performed at different positions on the disk for each block.
Therefore, during the recording / reproducing processing of each block, the head is moved to the target track (seek), and the operation of waiting for the rotation of the disk to reach the target sector (waiting for rotation) is entered. The effective transfer speed of the drive is reduced by the amount of time required for this seek and rotation, and the number of contents that can be handled simultaneously is reduced.

This is a problem particularly in the case of reproducing a plurality of contents. When recording multiple contents, write scheduling is performed using a buffer, and the seek time and rotation waiting time are designed to be as short as possible by changing the order so that the positions for storing each block are as close as possible. be able to. On the other hand, in reproduction, since it is not known which contents are accessed at the same time, in the worst case, a situation occurs in which the furthest point between disks is sought block by block.

A method for suppressing a decrease in the effective transfer rate when reproducing such a plurality of contents has been proposed ("O
n Configuring a Single Disk Continuous Media Serve
r ", Proceedings of ACM SIGMETRICS and PERFORMANCE '
95, p.37-p.46). This is to divide the disk into multiple areas in the radial direction, record blocks of the same size while shifting the areas one by one, and then shift to the opposite direction when recording to the end area. To go. That is, R (1), R (2), ...
Block A of content A is divided into n areas of (n)
(1), A (2), ..., A (n-1), A (n), A (n + 1),
, A (n + 2), ... R (1), R (2), ..., R (n
-1), R (n), R (n), R (n-1), ...
The recording start block may be from any area, and the area may be shifted first.

When a reproduction request for the content B is issued while reproducing the content A, the content A in the area in which the first block B (1) of the content B is stored
The reproduction of the content B is made to wait until the block is reproduced (wait until the area movement direction at the time of reproduction also coincides). Then, the contents A and B always reproduce the blocks in the same area, and the seek time can be shortened by the amount that the worst seek distance can be shortened, and the effective drive transfer speed increases. , It is possible to increase the number of contents that can be handled at the same time.

In this area division storage method, the number of contents that can be handled at the same time can be increased in exchange for the fact that the response time at the time of reproducing a plurality becomes longer as the number of areas is increased (waiting until the same block is reached). In addition, the buffer size can be reduced as much as the block length can be shortened. The system designer determines the balance of the number of contents that can be handled at the same time as the buffer size according to the usage environment.

[0012]

Many of the magnetic disk drives in recent years use the ZCA in order to increase the recording capacity and transfer speed.
It uses the V format. This is a system in which the disc is divided into a plurality of zones in the radial direction to reduce the difference in recording density between the zones. Unlike the CLV system used for compact discs, the rotation speed of the disc is constant. This is because if the disk rotation speed is changed according to the recording radius as in the CLV system, the time required to change the rotation speed during seek is extremely long (10 times or more of the head seek time), and random access is extremely deteriorated. Is.
The linear frequency varies depending on the radius, which is dealt with by changing the clock frequency during recording and reproduction.

As a result, the recording capacity per track increases as the track length increases toward the outer circumference of the disk. Also, the transfer speed becomes faster as the linear speed becomes faster toward the outer circumference of the disk. In the conventional CAV format, the recording density and transfer rate were determined by the inner circumference conditions,
By adopting the ZCAV format, it is possible to improve the overall performance due to the higher recording density and transfer rate on the outer peripheral side. Generally, when the ratio of the innermost radius to the outermost radius of the recording area on the disc is 1: 2, the ZCAV format has a recording capacity of about 1.5 times as much as the CAV format, and the transfer rate is 2 at maximum. Doubled, there is a significant performance improvement effect.

However, a moving image requiring a constant transfer rate is not compatible with the ZCAV format in which the transfer rate changes. Generally, when a moving image is handled by a ZCAV format drive, the number of contents that can be handled at the same time is limited so that recording / reproduction can be done in time on the inner circumference side where the transfer speed is slow. Then, in the zone on the outer peripheral side, the blocks can be reproduced in a short time, and conversely, there is extra time and wasted time. Therefore, the effect of the ZCAV format cannot be utilized regarding the transfer speed.

Further, in the above-mentioned area division storage system, not only the transfer speed but also the capacity cannot utilize the effect of the ZCAV format. That is, as to the transfer rate, the number of contents that can be handled simultaneously is limited by the transfer rate in the inner circumference, as in the above case (details will be described later). Further, regarding the capacity, since the same amount is used in each area, the capacity in which the content can be stored is determined in the zone having the smallest capacity. Generally, in the ZCAV format, the zones are set by dividing the radius at equal intervals in order to secure the maximum storage capacity.
Large storage capacity per zone. Therefore, when contents are stored in the ZCAV format drive by the area division storage method, new contents cannot be recorded when the innermost area is full, and unused sectors are left in other zones. Remain. As a result, the effectively used capacity is the same as the CAV method in which the recording capacity per track is set by the recording density of the inner circumference of the disc.

The object of the present invention is to solve the above problems in the area division storage system by utilizing the characteristics of the magnetic disk drive of the ZCAV format so that the number of contents that can be simultaneously recorded / reproduced is equal to the average transfer speed. To increase the storage capacity to the maximum, increase the number to match the average transfer rate.

[0017]

An information recording medium according to the present invention has a Z provided with a plurality of zones having different transfer rates.
In an information recording medium having a CAV format and dividing information that needs to be continuously transferred at a predetermined speed into a plurality of blocks and storing the divided information in each of the plurality of zones, each block is stored in the zone in which the block is stored. It is characterized by having a block size such that the time required for recording and reproducing becomes substantially constant according to the transfer speed.

More specifically, in the information recording medium according to the present invention, a plurality of areas each consisting of one or a predetermined number of continuous zones are set, and a plurality of blocks are stored in adjacent areas one by one in time series order. Only the outermost area and the innermost area store two blocks that are continuous in time series. The information recorded may be time-series information such as moving picture information or audio information. This information recording medium is used by being loaded in an information storage device having a recording / reproducing head.

Further, according to the information storage method of the present invention, time series information that needs to be continuously transferred at a predetermined speed to an information recording medium having a ZCAV format in which a plurality of zones having different transfer speeds are provided. In the information storage method of dividing a plurality of blocks into a plurality of blocks and storing the plurality of blocks, the plurality of zones are divided into a plurality of areas each including one or a predetermined number of consecutive zones, and the block size of each block is divided into a plurality of zones. It is characterized in that it is stored in such a size that the time required for recording and reproducing becomes substantially constant according to the transfer speed.

Each block of the time-series information is stored in time-series order by shifting one area on the inner circumference side or the outer circumference side,
When the innermost or outermost area is reached, two blocks are stored in that area, and then stored in the opposite direction while shifting by one area at a time. At this time, the number N of regions and the i-th region R
The block size B (i) in (i), the transfer rate X (i) in the area R (i), the predetermined block in the area R (i) are recorded or reproduced, and then the next block is recorded or reproduced. The time S (i) required up to, the maximum number M of information to be recorded / reproduced at the same time, and the required transfer rate C of information are set so as to satisfy the following equation.

[0021]

[Equation 2]

The difference in transfer rate and block size is absorbed by the buffer. When a new reproduction request for other information is made while recording or reproducing information on the information recording medium, the first block of reproduction request information and the block of information being recorded or reproduced are stored in the same area. The operation of delaying the start of reproduction of other information until the time when the movement direction of the next area matches and then recording or reproducing multiple blocks of information stored in the same area. repeat.

When another information recording request is generated during recording or reproducing of information, recording of the block of recording request information is started from the same area as the block of information being recorded or reproduced, and then the same area is recorded. After recording or reproducing a plurality of stored information blocks, the operation of moving the area is repeated. If another information recording request occurs during recording or reproduction of information, wait until the processing of the recording or reproduction information in the area specified by the system issuing the recording or reproduction request arrives, After that, after recording or reproducing a plurality of blocks of information stored in the same area, the operation of moving the area is repeated.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. FIG. 1 shows a method of dividing content into blocks, where the horizontal axis is time. In the conventional area division storage method corresponding to the CAV format, as shown in (a), the content 101 is divided into blocks 102 of a certain size. On the other hand, in the present invention, as shown in (b), the size of the block 103 is changed for each zone so that the time required to record or reproduce the block in each zone becomes substantially equal. That is, the blocks stored in the inner zone having the slower transfer rate are made smaller in size, and the blocks stored in the outer zone having the faster transfer rate are made larger in size.

In a normal magnetic disk drive, data is processed in fixed units called sectors. Therefore, it is desirable to set the block size to an integral multiple of the sector size in order to prevent useless areas in the sector. However, in general, in order to satisfy both the condition that the time required for recording and reproducing the block size in the ZCAV format is constant and the condition that the block size is an integral multiple of the sector size at the same time, the block size must be made very large. Particularly in the ZCAV format in which the number of sectors in one track increases by 1 as it goes to the outer circumference side for each zone, the block size must be one track circumference in order to satisfy the above two conditions.

If the block size is large, the buffer must be large, and the worst response time to the reproduction request becomes long, which deteriorates the system performance. The optimum block size is determined from the viewpoint of balance between the time required for recording / reproduction and the time required for head seek and rotation waiting, and from the viewpoint of shortening the worst response time to a reproduction request, as described later. Therefore, it is better to slightly deviate from the above two conditions in order to make the optimum conditions as close as possible. However, the smaller the sector size is, the smaller the size of the empty area formed in the sector immediately after each block in the zone where the block size is not an integral multiple of the sector.

FIG. 2 shows a method of storing each content block according to the present invention. Here, for the sake of simplicity, it is assumed that the number of disks in the drive is one and only one side is used. It can be considered to be exactly the same when there are a plurality of discs and both sides are used. The block size will be described as an integral multiple of the sector 212. In the example of the figure, there are eight kinds of contents A to H, 204 displayed at the top of FIG. 2 is a block of content A, 205 is a block of content B, 206 is a block of content C, and 207 is a content D. Block of 208
Is a block of content E, 209 is a block of content F, 210 is a block of content G, 21
1 represents each block of the content H.

Similar to the conventional area division storage method, the recording area of the disk is divided into a plurality of areas 200 in the radial direction. This area 200 is ZCAV format zone 2
03 may be the same as zone 03 and area 200
The number of divisions of may be changed. However, when the number of divisions of zones and areas is changed, the above blocks (204 to 21)
1) The size is changed not for each area 200 but for each zone 203 so that the time required for recording / reproducing each block is substantially equal. Regarding the location where each content block is recorded, the area to be recorded for each block is shifted to the inner circumference side or the outer circumference side one by one, as in the conventional area division storage method. And the innermost area of the disc,
Alternatively, when the outermost area is reached, two blocks are recorded in that area, and then the area to be recorded is shifted in the opposite direction. This zigzag recording operation is repeated until there are no content blocks to be recorded.

FIG. 3 shows how the content blocks of the present invention are stored on a ZCAV format disc. Under the condition that the time required to record / reproduce each block is constant, the arcs of each block (306) on the disk 301 have the same central angle. That is, when the blocks of content are arranged as shown in FIG. 3, the blocks are arranged radially from the center of the disc. Each block has an outer peripheral area 303, a middle peripheral area 304,
If the recording areas are used at the same angle regardless of the inner peripheral area 305, the respective areas are consumed at the same rate. Finally, the recording area is used up evenly in all areas, and no unnecessary empty area remains in the specific area, and the storage capacity can be maximized. In addition, in FIG. 3, one section 302 divided by a broken line represents a sector.

FIG. 4 shows another example in which the content block of the present invention is stored in the ZCAV format disc. In FIG. 3, the blocks are arranged at the same angle in order to make the size of the blocks easy to understand, but this is not necessary. Since the length of each content recorded on the disc 401 is not uniform, when the unused area on the disc is getting smaller, the radial areas are not necessarily neat and the empty areas do not always remain at equal intervals.
Further, as recording and deletion are repeated, the free area on the disc will be present at random positions. Therefore, the area 403 in which each content block 406 is recorded
Only items up to 405 are uniquely determined by the order, but the content block may be recorded at any vacant position in the area.

However, when it is known that the transfer rates of the contents to be handled are all equal (for example, when all contents are in the MPEG1 format) and no other information is recorded on this disc, each recording sector in the same zone. Arrangement is made so that the interval between 402 is an integral multiple of the block size in that zone. By doing so,
Even if a lot of data is accumulated on the disk, the free area does not become smaller than the block unit in each zone, so one block is not fragmented and the transfer rate above a certain level can be maintained. .

FIG. 5 shows a time chart showing a disc operation state when a plurality of contents are reproduced on the CAV format disc by using the conventional divided area storage system, and a transition of the amount of information in the buffer at that time. FIG. 5 (a)
This shows a reproducing operation on the disc when another reproducing request is generated while reproducing one content.
The horizontal axis represents time, and the vertical axis represents areas 501 provided on the disc.
Is represented. Since each block size and disk transfer speed are constant, the time required to play each block (5
04, 505) is constant. When the content being reproduced is one, each time the block is reproduced, the head is sought to the adjacent area, and rotation is waited until the block comes (506). When the head reaches the innermost or outermost area, two blocks in the same area are reproduced, and then seek is performed in the opposite direction. This zigzag operation is repeated until the end of the content or a command such as stop from the host side.

In this example, when the block A (i) stored in the area R (p) of the content A is being reproduced,
A reproduction request for another content B whose start block storage position is indicated by 510 has been issued (507). If the first block B (0) of the content B is stored in the area R (q) and the second block B (1) is stored in the area R (q + 1), the content A continues to be reproduced and the area R (q The reproduction of the block A (j-1) stored in (-1) is finished, and the reproduction of the content B is started at the stage of reproducing the block A (j) stored in the area R (q) ( 508).
Then, after that, blocks A (j + 1) and B (1), A (j + 2) and B that are simultaneously reproduced with both contents A and B
Since (2), ..., A (j + m) and B (m) are all stored in the same area, the seek distance is short and the overhead time due to seek and rotation waiting is short. Content B
Content B playback start time 50 from playback request time 507
The time 509 up to 8 is the reproduction response time of the content B.

FIG. 5B shows the change over time in the amount of information in the buffer. In this method, the block size and the buffer size are designed so that the time required to reproduce the content block in each area is equal to the time required to send the reproduced block to the outside of the drive. By doing this, the amount of data reproduced from the disc within the processing time of each area is equal to the amount of data sent out of the drive,
No data will be left in the drive buffer or run out. Therefore, set the buffer amount to (block size) ×
(Maximum number of simultaneous processing contents) and optimization (minimization) can be achieved. Also, under this condition, the block size and the worst response time are also minimized. In FIG. 5B,
A broken line 513 represents the disk transfer rate, and a straight line 514 that descends to the lower right represents the content transfer rate. The increase rate of the amount of information in the buffer is smaller than the disk transfer rate 513 because information is taken into the buffer and data is sent from the buffer at the same time.

FIG. 6 shows a time chart showing a disk operation state when a plurality of contents are reproduced on a ZCAV format disk by using the conventional divided area storage system, and a transition of the amount of information in the buffer at that time. FIG. 6A is a diagram corresponding to FIG. 5A and shows a state in which the content A and the content B are simultaneously reproduced. Figure 6
(B) shows a time change of the amount of information in the buffer.

In the ZCAV format disc, the time (604, 605) required for reproducing a block of a certain length changes according to the disc transfer rate 610, and becomes shorter in the outer peripheral area. In the figure, 604 indicates the reproduction processing time of the block of the content A, 605 indicates the reproduction processing time of the content B, and the arrow 606 connecting them represents the seek and rotation waiting time. On the other hand, the processing time in each area 601 is made constant so that the buffer does not become excessive or insufficient in each area. As a result, the number of contents that can be processed simultaneously is determined in the area on the inner circumference side where the reproduction time is long, and in the area on the outer circumference side, there is an extra time due to the shorter reproduction time, resulting in dead time 607. In the figure, 601 represents the content transfer speed.

FIG. 7 shows a time chart showing a disk operation state when reproducing a plurality of contents according to the present invention, and a transition of the amount of information in the buffer at that time. Figure 7
FIG. 6A is a diagram corresponding to FIG.
And content B are being reproduced at the same time. FIG. 7B shows the change over time in the amount of information in the buffer.
The reproduction according to the present invention is the same as the conventional divided area storage method in that it performs a zigzag operation between the innermost area and the outermost area of the disc. However, the reproduction processing time 704 of the block of the content A and the reproduction processing time 705 of the block of the content B are substantially constant in any area 701 regardless of the inner circumference or the outer circumference, and as shown in FIG. Only time will not be spared. In the figure, 7
Reference numeral 06 represents a time required from the reproduction of one content block to the reproduction of the next content block, such as head seek and rotation waiting time. Also, the upward-sloping broken line X (i) is the disc transfer speed in the area R (i), and the downward-sloping line segment C is
Indicates the content transfer rate from the buffer.

However, this method causes excess and shortage of buffers in each area. Therefore, the block size and the buffer size are determined so that there is no excess or deficiency of the buffer during one cycle of the zigzag operation. That is, the block size B (i) in the i-th area R (i) is the area division number N,
Transfer rate X (i) in area R (i), total time S (i) for head seek, rotation wait, settling, etc. required to process each area, maximum number M of contents to be recorded / reproduced simultaneously, and It is designed so that the relationship of the following equation holds with the required transfer rate C of the content.

[0039]

(Equation 3)

Then, in the outer peripheral area, the amount of data read from the disk is larger than the amount of data sent out of the drive, and the data gradually accumulates in the buffer,
On the contrary, in the area of the inner circumference, the amount of data read from the disc is smaller than the amount of data sent out of the drive, and the data accumulated in the buffer is gradually released. The amount of data read from the disc and the amount of data sent to the outside of the drive become the closest to each other when the disc is being reproduced almost in the middle range. That is, the number of contents that can be handled simultaneously is determined by the condition of the middle circumference (the average value of the drive), and in principle, the number of contents can be increased by nearly 50% as compared with the conventional divided area storage method (in the inner and outer circumferences). When the transfer rate ratio is 2.)

Although the disk operation during reproduction of a plurality of contents has been described with reference to FIG. 7, the disk operation during recording of a plurality of contents is similar to this. However, in the case of recording, if there is a request, recording is immediately started from the area being processed at that time. Alternatively, if it is necessary to start recording from a certain specific area, the recording data may be buffered and waited until the process in progress at that time reaches the desired area, as in FIG.

Next, the calculation results of the required buffer capacity and the worst response time in the present invention will be described in comparison with the conventional divided area storage method and the non-divided area storage method (when no measures are taken). To do. The calculation conditions are as follows: as the performance of the disk drive, the data transfer rate is 4.7 megabytes per second on the inner circumference side, 9.0 megabytes per second on the outer circumference side, the rotation speed is 6300 rpm, and the format efficiency is 8
5%, sector length 512 bytes, average seek time 9.
The settling time (time until recording / playback after seek) was set to 8 milliseconds and 1.5 milliseconds, and the rotation waiting time was set to one rotation, which is the worst case. Content transfer speed is M
Assuming PEG2, it was set to 6 megabits per second. For the sake of simplicity, the seek time is assumed to be proportional to the square root of the seek distance, and there is no miss seek. The number of regions is the same as the number of zones, and is 2 to suppress the worst response time. Further, the overhead time required for the disk controller and the interface between the drive and the host was calculated as 0. In addition, in response to a request for recording, it is assumed that recording will be started immediately from the area currently being processed,
The amount of buffer was calculated.

FIG. 8 shows the calculation result regarding the required buffer capacity, and FIG. 9 shows the calculation result regarding the worst response time. In both cases, the horizontal axis indicates the number of contents to be processed simultaneously. In the figure, 801 and 901 show the case of the non-divided area storage system, 802 and 902 show the case of the conventional divided area storage system, and 803 and 903 show the case of the present invention. When the number of contents is small, there is little difference between the present invention and the prior art in required buffer capacity and worst response time. This is because there is a large difference between the transfer speed of the drive and the transfer speed of all the contents when the number of contents is small, so if you design to minimize the buffer size and worst response time, both will be This is because there is no difference in seeking and spending most of the time waiting for rotation. on the other hand,
When the number of contents is large, both the required buffer capacity and the worst response time of the present invention shown by 803 and 903 are much smaller than the conventional techniques shown by 801, 802, 901, 902, and the performance is improved. There is. This difference reflects the difference between the maximum number of contents determined by the minimum value of the disk transfer speed and the average value.
Therefore, the present invention generally improves the performance of the ZCAV format disc over the conventional divided area storage method.

Although a magnetic disk drive has been described as an example here, the performance of an information storage device such as an optical disk (including a magneto-optical disk and a phase change disk) can be similarly improved by the present invention. it can. Further, in the case of a system which records / reproduces information simultaneously not only on a single information storage medium but also on a plurality of information storage media having different transfer speeds (for example, a distribution in which a plurality of information storage media are connected via a network). In the case of a system), the present invention can be applied and implemented.

As one example thereof, an example in which four types of magnetic disk devices having different transfer rates are used is shown in FIG.
0 is shown. Four types of magnetic disk devices A, B, C, D
Are connected to the disk controller device 1002. At the time of data recording, the data to be recorded sent from an external device via the cable 1003 is divided by the disk controller device 1002 for each magnetic disk device and sent to each device via the cable 1004. Further, at the time of data reproduction, the data read from each magnetic disk device via the cable 1004 is combined and combined by the disk controller device 1002 and sent out to the cable 1003 as one data content. That is, division of data to each magnetic disk device,
The synthesis is controlled by the disk controller device 1002.
The ratio of the transfer rates of the four types of magnetic disk devices A, B, C, D is a: b: c: d. For the sake of simplicity, the transfer within each magnetic disk device A, B, C, D is performed. It is assumed that the speed is constant.

FIG. 11 shows a disk controller device 10.
The data division method in 02 is shown. Similar to FIG. 1B, a block size of data proportional to the transfer speed is assigned to each magnetic disk device A, B, C, D. That is, here, the block size ratio of the data for the magnetic disk devices A, B, C, and D is a: b: c: d. Regarding the order of allocating blocks, it is not necessary to consider the time required for the seek of the head in the case of recording in consecutive sectors in the magnetic disk device, and therefore, it may be in an appropriate order unlike the case of FIG. It is preferable to assign the order so that the overhead time such as waiting for rotation in each magnetic disk device is as short as possible. In this example, A → B → C → D
→ A → B → ...

FIG. 12 shows a time chart regarding the data reproduction from the magnetic disk devices A, B, C and D in the disk controller device 1002 during the data reproduction and the data amount in the buffer. In this example, the disk controller device and each magnetic disk device A, B,
Since C and D are connected by the common cable 1004, the data read from each magnetic disk device is sequentially sent to the disk controller device 1002 and temporarily stored in a buffer inside the disk controller device.
The disk controller device 1002 links and combines the data in the buffer and sends the data to the cable 1003 so that the transfer rate becomes constant. That is, as in the case of FIG. 7, the difference in transfer rate between the magnetic disk devices A, B, C, and D is adjusted by a buffer in the disk controller device, and a constant transfer speed is maintained outside the disk controller. There is. At the time of recording, the disk controller 1002 performs a flow that is completely opposite to this flow.

Although all the information storage devices are magnetic disk devices in this example, some or all of them may be other information storage devices such as optical disk devices. . Further, although the transfer speed in each magnetic disk device is constant, it is possible to include a device adopting the ZCAV method and having a non-constant transfer speed. In this case, data division may be performed as a different magnetic disk device for each area having a different transfer speed in one device. In this case, it is better to determine the order of allocating blocks in consideration of the movement time of the head within the disk.

[0049]

As described above, according to the present invention,
The number of contents that can be handled at the same time is increased by up to about 50% as compared with the conventional area division storage method, and the storage capacity can be maximized.

[Brief description of drawings]

FIG. 1 is a diagram showing a method of dividing a content into blocks.

FIG. 2 is a diagram showing a content block storage system.

FIG. 3 is a diagram showing an example in which content blocks are stored on a ZCAV format disc.

FIG. 4 is a diagram showing another example in which content blocks are stored on a ZCAV format disc.

FIG. 5 is a time chart showing a disk operation state when reproducing a plurality of contents in a CAV format disc by a conventional divided area storage system, and a diagram showing a transition of the amount of information in the buffer at that time.

FIG. 6 is a time chart showing a disk operation state when reproducing a plurality of contents in a ZCAV format disc by a conventional divided area storage system, and a diagram showing a transition of the amount of information in the buffer at the time of reproduction.

FIG. 7 is a diagram showing a time chart showing a disk operation state during reproduction of a plurality of contents according to the present invention and a transition of the amount of information in the buffer at the time of reproduction.

FIG. 8 is a diagram comparing the present invention with a conventional example in terms of required buffer capacity.

FIG. 9 is a diagram comparing the present invention with a conventional example regarding the worst response time.

FIG. 10 is a diagram showing an example in which a plurality of magnetic disk devices having different transfer rates are used.

FIG. 11 is a diagram showing a data division method in the disk controller device.

FIG. 12 is a diagram showing a time chart regarding data reproduction from each magnetic disk device and the amount of data in the buffer.

[Explanation of symbols]

101 ... Content, 102 ... Content block (fixed size division), 103 ... Content block (variable size), 200 ... Area, 203 ... Zone, 212 ... Sector, 301 ... Disk, 302 ... Sector, 303 ... Peripheral area, 304 ... Middle circumference area, 305 ... Inner circumference area, 306 ...
Content block, 401 ... Disc, 402 ... Sector, 403 ... Outer peripheral area, 404 ... Middle circumference area, 405 ... Inner circumference area, 406 ... Content block, 501 ... Area,
504 ... Block playback processing time for content A, 505
... content B block playback processing time, 506 ... seek and rotation waiting time, 509 ... content B playback response time, 510 ... content B first block storage position, 51
3 ... Disk transfer speed, 514 ... Content transfer speed,
601 ... Area, 604 ... Content A block playback processing time, 605 ... Content B block playback processing time, 606 ... Seek and rotation waiting time, 607 ... Dead time, 610 ... Disk transfer speed, 611 ... Content transfer speed, 701 ... area, 704 ... block playback processing time for content A, 705 ... block playback processing time for content B, 706 ... seek and rotation waiting time, 1002
... disk controller device, 1003 ... cable, 1
004 ... Cable

Claims (12)

[Claims] 1. A ZCAV format having a plurality of zones having different transfer rates is provided, and information which needs to be continuously transferred at a predetermined rate is divided into a plurality of blocks and is divided into the plurality of zones. In the stored information recording medium,
An information recording medium characterized in that each block has a block size such that a time required for recording and reproducing becomes substantially constant according to a transfer speed of a zone in which the block is stored. 2. A plurality of areas each consisting of one or a predetermined number of continuous zones are set, and the plurality of blocks are stored in the adjacent areas one by one in a time series order, and the outermost area and the innermost area are stored. 2. Two blocks which are continuous in time series are stored only in the peripheral area.
Information recording medium as described. 3. The information recording medium according to claim 1, wherein the information is moving image information or audio information. 4. An information storage device comprising the information recording medium according to claim 1. 5. An information recording medium having a ZCAV format in which a plurality of zones having different transfer rates are provided,
In an information storage method of dividing time-series information that needs to be transferred continuously at a predetermined speed into a plurality of blocks and storing the plurality of blocks, the plurality of zones are divided into a plurality of areas each including one or a predetermined number of consecutive zones. The information storage method is characterized in that the block size of each block is stored in such a size that the time required for recording and reproduction becomes substantially constant according to the transfer speed of the zone in which the block is stored. 6. The blocks are stored in chronological order by shifting one area to the inner circumference side or the outer circumference side, and when reaching the innermost circumference area or the outermost circumference area, two blocks are stored in the area and then in the reverse direction. The information storage method according to claim 5, wherein the information is stored while being shifted by one area at a time. 7. The number N of the areas, the block size B (i) in the i-th area R (i), and the transfer rate X in the area R (i).
(i), a time S (i) required from recording or reproducing a predetermined block in the area R (i) to recording or reproducing the next block, a maximum number M of the information to be recorded / reproduced at the same time, and 7. The information storage method according to claim 5, wherein the required transfer rate C of the information satisfies the following expression. [Equation 1] 8. The information storage method according to claim 7, wherein a difference between the transfer rate and the block size is absorbed by a buffer. 9. The recording / reproducing method for an information recording medium according to claim 1, 2 or 3, wherein when a reproduction request for other information is newly made during recording or reproducing the information, the reproduction request information is recorded. The first block and the block of information being recorded or reproduced are stored in the same area, and the start of reproduction of the other information is made to wait until the movement direction of the next area matches, and then in the same area. A recording / reproducing method characterized by repeating the operation of moving the area after recording or reproducing a plurality of blocks of information stored in. 10. When another information recording request is generated during recording or reproduction of information, recording of the block of recording request information is started from the same area as the block of information being recorded or reproduced, and then the same. 9. The information storage method according to claim 5, wherein the operation of moving the area is repeated after recording or reproducing a plurality of blocks of information stored in the area. 11. When another information recording request is generated during recording or reproduction of information, the processing of the recording or reproduction information in the area designated by the system issuing the recording or reproduction request is performed. 9. The information storage according to any one of claims 5 to 8, characterized in that the operation of waiting for the arrival of the plurality of blocks of information stored in the same area is repeated and then the operation of moving the area is repeated. Method. 12. The method according to claim 5, wherein the information is moving image information or audio information.