JPH0991892A - Disk device and disk system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform data reading and data writing from and to an optical disk. SOLUTION: Heads 1 to 4 read out data from or write data to the whole of areas A, B of a disk 21. Heads 5 to 16 read out data from or write data to only the area B. Data having a low frequency of access by a user are written to the area A of the disk 21 and data having a high frequency of access are written to the area B. Since a large number of heads cover the area B. The probability of establishment of 'busy' is made minim to requests from plural users.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a disk device for reading data recorded on a disk such as an optical disk, a magnetic disk, a magneto-optical disk (MO), or writing data on the disk, and the disk device. Regarding the disk system.

[0002]

2. Description of the Related Art In recent years, there has been a data distribution service using a disc in response to a request for various data (karaoke, movie, mail order catalog, etc.) from a user such as a general household. Then, a disk system has been realized in which the user accesses the data at any time to view the data.

An optical disk 111 is one of the data storage media in this system, but as shown in FIG. 12, due to the structure of the optical disk 111, this optical disk 11 is used.
Heads 101, 102, 1 that can access the same data or a plurality of data recorded inside 1 at substantially the same time
There is a limit to the number of 03, 104. Therefore, the disk 1
It is impossible for a plurality of users exceeding the number of heads 101 to 104 to access the data recorded in the vicinity of the inner circumference of 11 at substantially the same time, which results in busy. Then, there is a drawback that the user has to wait until the other head becomes empty.

As a solution to this problem, if a plurality of optical disks containing the same data are prepared, the probability of busyness can be reduced. However, on the contrary, the total number of discs becomes enormous, and the number of disc devices required increases as the number of optical discs increases. Further, for the information supply side and the user, there is a big drawback that the cost is increased and the service is deteriorated such that the access time becomes long.

[0005]

As described above, since the conventional disk system occupies the data (karaoke, etc.) desired by the user who is accessing the data, other users can watch the data during that time. Instead, it becomes busy.

Further, if a plurality of disks storing the same data can reduce the probability of busyness, the total number of disks will become enormous and the number of necessary disk devices will increase, resulting in a system scale. Becomes larger,
Not economical. And for the information supply side and the user,
It has a big drawback that it causes cost increase and leads to service degradation such as long access time.

Further, the disk-shaped optical disk has a limitation in the number of heads that can be moved to the innermost circumference at the same time due to its structure, and there is a physical space limit in order to avoid interference between the heads.

Further, the data recorded on the same disk is not always equal in access frequency to each head, and in some cases there is data that is not accessed at all or a head that is not in operation, which is inefficient and economical. It was not desirable, and it led to deterioration of service for users.

Therefore, according to the present invention, the disk can be efficiently used.
It is an object of the present invention to provide a disk device capable of reading and writing data.

Another object of the present invention is to provide a disk system that changes the recording position of the data on the disk according to the data access frequency.

[0011]

[Means for Solving the Problems]

(First Disk Device) At least one first read head or first write head capable of moving in a first movement range from the innermost circumference to the outermost circumference in the radial direction of the data recordable area of the disk. The second from the arbitrary middle position in the radial direction of the data recordable area to the outermost circumference
At least one second read head or second write head that is movable in the moving range of
The number of the second read heads or the write heads is larger than that of the first read heads or the write heads.

(Second Disk Device) At least one or more first reading which is movable in the first moving range from the innermost circumference in the radial direction of the data recordable area of the disk to an arbitrary first intermediate position. A head or a first write head, and at least one or more second read head movable in a second movement range from an arbitrary first intermediate position in the radial direction of the data recordable area to the outermost circumference. Alternatively, the second write head and at least one third read head or a third read head that is movable in a third movement range from an arbitrary second intermediate position in the radial direction of the data recordable area to the outermost circumference. Three write heads, and the number of the second and third read heads or write heads is larger than the number of the first read heads or write heads. It is characterized in.

(Third Disk Device) One or more read heads or write heads each having a predetermined movable range are arranged spirally from the innermost circumference to the outermost circumference of the data recordable area of the disk. Characterize.

(Disk system) A system in which a plurality of users access data in a disk at any time, and at least one read head, at least one write head, and the frequency of access to the data on the disk are determined. And an access frequency calculating unit for calculating, wherein the recording position of the data on the disc is changed according to the calculation result of the access frequency calculating unit.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of a first embodiment of a disk device according to the present invention. This is used in a system or the like for providing each karaoke song online to the user at an arbitrary timing using the optical disc 21 or the like.

A plurality of (16 in this example) read and write heads 1 to 16 are provided on an optical disk 21 as a recording medium. Each head 1 to 16
As shown in FIG. 2, is composed of a laser diode 25 and a condenser lens 27. The optical track groove (not shown) of the optical disk 21 may be concentric or spiral.

Further, the heads 1 to 16 are moved in the radial direction of the optical disc 21 by a pulse motor 23 arranged on the outer peripheral side of the optical disc 21 to be tracking-controlled.

FIG. 2 also shows a tracking control system for each head 1 to 16. Each head 1 to 16 is attached to a head block 29. The head block 29 is slidably supported by a pair of guide rails 31 and 33. A screw hole is provided in the head block 29, and the shaft 35 of the pulse motor 23 is inserted into this screw hole.
Are in mesh with each other. Therefore, when the pulse motor 23 rotates, the shaft 35 also rotates, but the head block 29
Since it is supported by the guide rails 31 and 33, it does not rotate and can slide in the radial direction of the optical disk 21 and move to another track. This pulse motor 23
The head is moved to the optical disk 21 by the forward or reverse rotation of
Is slid in the inner peripheral direction or the outer peripheral direction. And 16
Heads 1 to 16 and a pulse motor 23 corresponding to each head (including a shaft 35 and guide rails 31 and 33)
Are arranged radially from the center of the optical disk 21 as shown in FIG.

The method for driving the heads 1 to 16 is not limited to the above, and any method that can be freely driven in the radial direction of the optical disk 21 may be used.

In this embodiment, 16 heads 1 to 16 are used.
Among them, there are a total of four heads 1 to 4 driven from the outermost circumference to the innermost circumference of the recordable area of the optical disk 21.
On the other hand, a total of 12 heads 5 to 16 are driven from the outermost circumference to the innermost circumference.

The disk 21 of this embodiment is a disk having a recording medium on one side, and the recording surface is divided into an inner peripheral recording area A and an outer peripheral recording area B. That is, the heads 1 to 4 can access the tracks (not shown) recorded in the recording areas A and B. And
All the heads 5 to 16 can access the track recorded in the recording area B.

Further, these heads 1 to 16 can independently access each other and simultaneously access each track to read out data and conversely write data.
The optical disc 21 may be a disc having recording media on both sides.

The drive method of the optical disk 21 includes a CLV (constant linear velocity) method and a CAV (constant angular velocity) method. Alternatively, there is an MCAM (improved constant angular velocity) method that changes the recording rate of information while keeping the rotation speed of the optical disk 21 constant to achieve both a substantially constant recording density and high-speed access. In this embodiment, the CAV method will be described.

FIG. 5 shows a configuration of a first embodiment of a disc system using the above-mentioned disc device, and FIG. 9 shows a flow chart for explaining a music rewriting operation. Incidentally, ST91 to ST97 indicate operation steps.

The disk system is composed of users U1 to Un.
(N is an integer of 1 or more), the transmission / reception control unit 71, the control device 7
3, access frequency calculation means 75, and the disk device 77 described above. The transmission / reception control unit 71 controls the user U.
Determine the priority of requests from 1 to Un. Also, only requests with the same password will be accepted. Further, the read song is transmitted to the user who made the request, and the busy display instruction is transmitted to the user.
Further, the disk device 77 includes a writing unit 79 (heads 1 to 16 and the like) and a reading unit 81 (heads 1 to 16).
Etc.), and the optical disk 21 is arranged therein.

When a plurality of users U1 to Un request a song (ST91), the request information is transmitted to the transmission / reception control unit 71 and then to the control device 73. The request information is the access frequency calculation means 75.
Thus, the frequency of how many requests (accesses) have been made within a predetermined time for each song desired by the user is calculated and stored (ST92). Based on this calculation result, the control device 73 is supposed to control the reading or writing from the optical disc 21.

This control is performed as follows, as described above. In FIG. 1, it is assumed that the karaoke piece a is recorded in the recording area A on the inner circumference of the optical disk 21 and the karaoke piece b is recorded in the recording area B on the outer circumference of the disk.
The heads that can be accessed from the outermost circumference to the innermost circumference of the disk, that is, both the area B and the area A have a total of 1 to 4 heads.
Individual. Further, there are a total of 12 heads 5 to 16 that can access only the area B.

When a plurality of users U1 to Un access almost simultaneously, the following cases are possible. One is when there are requests for the same song at about the same time, and the other is when there are requests for different songs at about the same time. Here, the former will be described.

For example, if the song a recorded in the area A is accessed by a plurality of users at substantially the same time and the number of users is less than or equal to a predetermined value (here, within 4) (Y in ST93).
In the case of ES, and the case of YES in ST94), heads 1 to 4 can be assigned.

When the number of users exceeds 5, (ST9
In case of NO in 3 and in case of NO in ST96), the number of accessible heads is exceeded, so that it becomes busy. After that, when access to song a becomes more frequent,
The busy time becomes longer, and the users U1 to Un have to wait considerably.

Therefore, in the disk system of the present invention,
By rewriting the song a from the area A to the area B having a large number of accessible heads, the busy state is eliminated (ST97). Specifically, the reading means 81 (heads 1 to 4 and the like) reads the song a from the optical disk 21, and the writing means 79 (heads 1 to 16 and the like) writes it to the optical disk 21.

On the other hand, when the music b recorded in the area B is accessed by five or more users U1 to Un at approximately the same time (NO in ST93, YES in ST96), access is possible. Head is 1 to 16 of 16
Since it is an individual, it can be supported.

Then, when the access from the users U1 to Un is reduced and the frequency of substantially simultaneous accesses within a predetermined time is 4 times or less (in the case of YES in ST93, S
(Corresponding to NO in T94), heads 5 to 16
There is a high probability that there will be vacancies.

Therefore, in the disk system of the present invention,
By rewriting the song b from the area B to the area A having a small number of accessible heads, the heads can be efficiently allocated (ST95). Specifically, the optical disc 2 is read by the reading means 81 (heads 1 to 16, etc.).
The song b is read from 1 and written on the optical disc 21 by the writing means 79 (heads 1 to 4).

As described above, the disk system of the present invention calculates the number of requests (access frequency) within a predetermined time, and based on the relationship between the calculation result and the number of heads, the establishment of busy is minimized or the heads that are empty are used. The writing position of the software is rewritten every predetermined time so that there is no such problem. As a result, the configuration is always optimal in terms of both software and hardware with respect to the requests from the users U1 to Un.

As described above, in the disk device 77, the total number of heads 1 to 16 is 16, four in area A, and a total of 16 in area B.
Although the configuration has been described in which each individual can access, the number of heads is not limited to this. Although the heads 1 to 16 are both read and write heads, they may be separate read and write heads.

Further, instead of dividing the optical disk 21 into two areas A and B, for example, one area may be used, and the frequently accessed software may be arranged sequentially from the inner circumference to the outer circumference, or vice versa. Even if it is divided into three or more regions, it does not matter.

FIG. 3 shows a second disk device 77 of the present invention.
The following shows an example. In this example, the heads 1 to 4 do not cover the entire radius of the disk 21, but cover the middle to the outermost circumference. Then, new heads 41 to 44 are provided to cover the optical disc 21 from the middle to the innermost circumference. That is, there are a total of 4 heads 41 to 44 that can access only the area A, and a total of 16 heads that can access only the area B, that is, 1 to 16. Also in this disc device 77, the same effect as described above can be obtained by rewriting the recording position according to the frequency of access by the user to the recorded music. Although not shown, the heads 41 to 44 are also driven by the pulse motor.

The movement of the heads 1 to 4 does not have to coincide with the movement axis of the heads 41 to 44 as shown in FIG. 3, and may be shifted. Further, the moving range of the heads 1 to 4 may be the same as that of the heads 5 to 6.

FIG. 4 shows another third embodiment of the disk device 77 of the present invention. In this example, the heads 51 to 6
3 are spirally arranged from the inner circumference to the outer circumference of the optical disk. Although the drive range of each head is not shown (55, 57, 59, 61, 63), it has a predetermined range in the radial direction, and the drive range is increased by a predetermined amount from the inner circumference to the outer circumference. The head is arranged with a so-called drive range on a spiral as it shifts. It should be noted that the number of heads to cover increases as the position approaches the outer circumference of the optical disc 21.

Next, FIG. 6 shows a second embodiment of the disk system of the present invention using the disk device 77 of the present invention. Here, n disk devices 77 of the present invention (n is an integer of 1 or more) are prepared. And n optical disks 2
1 is arranged in each disk device. It should be noted that some of the n optical disks 21 may have the same contents. With this configuration, the users U1 to U
The request from n can be wide or the waiting time can be shortened.

FIG. 7 shows a third embodiment of the disk system of the present invention using the disk device 77 of the present invention. Here, there is one disk device 77 of the present invention, but n optical disks 21 are prepared. And user U
In response to a request from 1 to Un, one optical disk 21 is selected, and the recorded content is read or written.

Next, FIG. 8 shows a fourth embodiment of the disk system of the present invention using the disk device 77 of the present invention. Then, FIG. 10 shows a flowchart for explaining the operation of this embodiment. Incidentally, ST101 to ST10
Reference numeral 3 indicates a step of operation.

Also in the embodiment, it is possible to rewrite the recording position of the music recorded on the optical disk 21 according to the number of requests (access frequency). The number of requests (access frequency) is calculated (ST101), and rewriting is sequentially performed according to this. For example, when the access frequency to the song c recorded on the optical disk 21 is equal to or less than a predetermined value within a predetermined time (including a case where there is no access at all)
(Corresponding to YES in ST102), another song d stored in the external storage device 83 is read out and replaced with the song c (ST103).

As a result, songs frequently accessed by the user can always be distributed using the main optical disk 21, and the service to the user can be improved. Also,
The inefficiency due to the empty head is eliminated, and the waiting time can be minimized as compared with the conventional system in which there is no requested song and the media are always taken out and delivered from other media.

The external storage device 83 may be any of the same optical disk, magnetic disk, magneto-optical disk (MO), etc., or may be plural. It goes without saying that a plurality of disk devices 77 may be configured as in the example of FIG.

Further, FIG. 11 shows a typical relationship between the karaoke songs a, b, c and the access frequency to them for each predetermined time period. A modified example of the disk system of the present invention will be described with reference to this figure.

The horizontal axis represents time and the vertical axis represents access frequency. And from morning to evening (8 to 16 o'clock), from evening to late night (16 to 24 o'clock), from late night to morning (2
It is understood by the access frequency calculation means 75 that the music pieces a, b, and c each have a typical access frequency as shown in the figure in each time zone (from 4:00 to 8:00).

According to the result of this calculation, rewriting is performed almost immediately before entering the time zone from morning to evening, and a disc in which the song c is recorded in the area A of the optical disk 21 and the songs a and b are recorded in the area B of the optical disk 21. By preparing, the users U1 to U
In response to a request from n, it is possible to provide a distribution service with a minimum amount of wasted time.

Similarly, rewriting is performed almost immediately before entering the time zone from evening to midnight to prepare an optical disk 21 in which area a of the optical disk 21 is recorded with music a and area B is recorded with music b and c. To do.

Further, rewriting is performed almost immediately before entering the time zone from midnight to morning, and the song b is written in the area A of the optical disc.
, The optical disc 2 in which the songs a and c are recorded in the area B, respectively.
Prepare 1.

This minimizes the probability of busy,
The service to the user can be improved.

In the CLV (constant linear velocity) system, a problem occurs especially when a plurality of heads access at substantially the same time. However, the rotation speed is set to match one of the heads.
If the signal processing means capable of changing the data transfer rate from each of the other heads is provided, the present invention can be realized.
The same effect can be obtained.

Further, the recording medium used in the above-mentioned disk device 77 is the optical disk 21, but it is not limited to this, and a magnetic disk or a magneto-optical disk (MO).
And so on.

[0056]

According to the disk device of the present invention, it is possible to efficiently read and write data from the disk.

According to the disc system of the present invention using the disc device of the present invention, the following effects can be obtained.

Data with high access frequency is recorded in the outer peripheral area of the disk where a large number of heads can be arranged, and data with low access frequency is recorded in the inner peripheral area of the disk. As a result, the appropriate number of heads can be assigned according to the access frequency of the same data or different types of data, the probability of busy is minimized, and it is not necessary to prepare a huge amount of disks or heads. The amount of investment in hardware does not increase significantly, the device can be downsized, and distribution services and cost performance can be improved.

Further, since the data in the disc whose access frequency becomes less than or equal to the predetermined value within the predetermined time is rewritten with the data read from another recording medium, it is possible to prepare the data with many requests at all times. Service is improved.

Further, when the rank of the data access frequency is different depending on the time zone, the data recording position is changed in advance just before entering the predetermined time zone according to the calculation result of the access frequency for each predetermined time zone. Therefore, it is possible to provide a delivery service with a minimum of wasted time.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of a disk device of the present invention.

FIG. 2 is a diagram showing a tracking control system of each head of the disk device shown in FIG.

FIG. 3 is a diagram showing a configuration of a second embodiment of a disk device of the present invention.

FIG. 4 is a diagram showing a configuration of a third embodiment of a disk device of the present invention.

FIG. 5 is a diagram showing a first embodiment of a disk system of the present invention using the disk device of the present invention.

FIG. 6 is a diagram showing a second embodiment of the disk system of the present invention using the disk device of the present invention.

FIG. 7 is a diagram showing a third embodiment of the disk system of the present invention using the disk device of the present invention.

FIG. 8 is a diagram showing a fourth embodiment of the disk system of the present invention using the disk device of the present invention.

9 is a flow chart for explaining the operation of the disk system of FIG.

10 is a flow chart for explaining the operation of the disk system of FIG.

FIG. 11: Karaoke songs a, b, and
It is a graph which shows the typical relationship of c and the access frequency with respect to these.

FIG. 12 is a diagram showing a configuration of a conventional disk device.

[Explanation of symbols]

 1 to 16 ... Head 21 ... Optical disk 23 ... Pulse motor 25 ... Laser diode 27 ... Focusing lens 29 ... Head block 31, 33 ... Guardrail 35 ... Shaft 41 to 44 ... Head 51 to 63 ... Head U1 to Un ... User 71 ... Transmission / reception control unit 73 ... Control device 75 ... Access frequency calculation means 77 ... Disk device 79 ... Writing means 81 ... Read means 83 ... External storage device.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location // G11B 7/00 9464-5D G11B 7/00 Q

Claims (9)

[Claims] 1. A first read head or a first read head capable of moving in a first moving range from an innermost circumference to an outermost circumference in a radial direction of a data recordable area of a disc.
Writing head, and at least one or more second reading head or second writing head movable in a second movement range from an arbitrary intermediate position in the radial direction of the data recordable area to the outermost circumference. A disk device comprising: 2. A first read head or a first read head capable of moving in a first movement range from a radially innermost circumference of a data recordable area of a disc to an arbitrary first intermediate position. A write head, and at least one or more second read heads or second write heads that are movable in a second movement range from an arbitrary first intermediate position in the radial direction of the data recordable area to the outermost circumference. A head, and at least one third read head or third write head capable of moving in a third movement range from an arbitrary second intermediate position in the radial direction of the data recordable area to the outermost circumference. , And the number of the second and third read heads or write heads is larger than the number of the first read heads or write heads. Disk apparatus. 3. The disk device according to claim 2, wherein the arbitrary first intermediate position and the second intermediate position in the radial direction of the data recordable area are the same. 4. A disk device, wherein one or more read heads or write heads each having a predetermined movable range are spirally arranged from the innermost circumference to the outermost circumference of a data recordable area of the disk. . 5. A system in which a plurality of users access data in a disc at arbitrary times, and at least one read head, at least one write head, and an access frequency to data of the disc are calculated. A disk system comprising: an access frequency calculating means, wherein a recording position of the data on the disk is changed according to a calculation result of the access frequency calculating means. 6. The data having a high access frequency is sequentially recorded on the disc from the innermost circumference to the outermost circumference of the data recordable area of the disc, and the movable length or the movable range becomes closer to the outer circumference of the disc. 6. The disk system according to claim 5, wherein the read heads or the write heads that are small are arranged in an increased number. 7. A read head that sequentially records frequently accessed data on the disk from the innermost circumference to the outermost circumference of a data recordable area of the disk, and reads the data as the data approaches the outer circumference of the disk. 6. The disk system according to claim 5, wherein the number of write heads for writing the data is increased. 8. When the recording medium has another recording medium storing other data, and the frequency of accessing the data in the disc becomes a predetermined value or less within a predetermined time, the other recording medium is changed to the other recording medium. 6. The disk system according to claim 5, wherein the data in the disk is read and replaced with the data in the disk. 9. When the rank of the access frequency to each data in the disk is different depending on the time zone, the recording position of each data is changed in advance according to the access frequency in the time zone before entering each time zone. The disk system according to any one of claims 5 to 7, wherein the disk system is stored in advance.