JPH01185721A - Multiaccess filing device - Google Patents

Abstract

PURPOSE:To realize low cost and miniaturization by providing a memory circuit having the optimum memory capacity on a multiaccess filing device provided with (m) reproducing devices and (n) output terminals. CONSTITUTION:The (m) (m=1, 2, 3...) reproducing devices (T1-Tm) to repro duce information from an information storage medium, the memory circuit 4 to store the information reproduced by the reproducing devices (T1-Tm), a write circuit 7 to write the information from the reproducing devices (T1-X) on the memory circuit 4, a readout circuit 13 to perform the readout of the information from the memory circuit 4, and the (n) output terminals (w1-wn) to send the information reproduced by the reproducing devices (T1-Tm) and the information read out from the memory circuit 4 to a user answering to a request are provided. And the capacity in which the capacity required for the storage of reproducing information per one time from an information record ing medium is multiplied by either a smaller number out of the quotient of n/2 or (m) is set as the memory capacity of the memory circuit 4. In such a way, it is possible to realize the miniaturization and the low cost of a system.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is for use in a center system that immediately cues and provides information such as videos and music in response to individual requests from multiple users. This invention relates to a multi-access file device.

(Problems to be Solved by Prior Art and Invention) Conventionally, in information provision services using center systems, the only services that can immediately search in response to individual requests are database services using character codes with a small amount of information, telephone services using voice messages, etc. limited to. For videos and music that contain a huge amount of information, it is not possible to immediately locate the beginning and send it in response to individual requests, and if a duplicate request is received for a request that is already being sent, the information may be sent from the middle. I have no choice but to release it.

Therefore, multi-access file devices equipped with memory circuits have been proposed for center systems that provide video and music services as well, in order to enable immediate cueing. By providing a memory circuit, it becomes possible to cue and service multiple requests for the same title.

However, for example, in a center system that sends out music recorded on compact discs in response to requests, if each compact disc player, which is a playback device, is equipped with memory equivalent to (the amount of information for) a compact disc, the number of Requires 100 megabytes of memory. A.D.
It may be possible to compress the amount of information using a compression method such as PCM, but this increases the total memory capacity of the entire system, making the system larger and more expensive.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a multi-access file device for a center system that transmits information in response to requests from multiple users, as shown in FIG. 1, m units (m
=1.2.3,...), a memory circuit 4 that stores information reproduced by the reproduction apparatuses T1 to Tm, and a memory circuit 4 that stores the information reproduced by the reproduction apparatuses T1 to Tm.
a write circuit 7 for writing information from the memory circuit 4; a read circuit 13 for reading information from the memory circuit 4; and a read circuit 13 for reading information from the memory circuit 4;
It has n (n=1.2, 3°...) output terminals W1 to Wn which send out the information reproduced by Tm to Tm and the information read from the memory circuit 4 to the user in response to a request. The storage capacity of the memory circuit 4 is calculated by multiplying the capacity required to store information reproduced once from the information recording medium by the quotient of n/2 or m, whichever is smaller. This provides a multi-access file device with the following functions.

(Function) The memory circuit has an optimal memory capacity for m playback devices and n output terminals, and there is no excess memory capacity due to a shortage of output terminals, and there is no surplus memory capacity due to a shortage of output terminals. There is no surplus at the output end.

(Embodiment) An embodiment of the multi-access file device according to the present invention will be described below with reference to the drawings.

Figure 1 is a block diagram of a multi-access file device.
FIG. 2 shows a center service system comprised of the above multi-access file device.

First, an overview of the center service system will be explained with reference to FIG.

This service system has, for example, 100 users in their homes and terminal devices F1 to F100, and each user requests a desired music title from center A by operating the terminal devices F1 to F100. be able to. Further, the terminal devices F1 to F100 have a function of receiving and receiving music information provided from the center A and outputting it to an audio device so that the user can listen to the music. Requests from the terminal devices F1 to F100 and music information services from Center 8 are performed via communication lines E1 to E100, and the terminal devices MF1 to F100 are connected to Center A by a switch. The multi-access file device 1 in the center A is connected to an exchange through communication lines 01-C20 via communication control devices 81-B20.

Next, a multi-access file device will be explained with reference to FIG. The multi-access file device M1 in the center A is a compact disc stocker 12 that stores human-sized compact discs (information recording media).
as a music information file. When a request from a certain user is input to the request input terminal S1 of the multi-access file device 1 via the terminal device F1, communication line l1IE1, conversion 'IaD, communication line C1, and communication control means B1 shown in FIG. , requests to the input terminal S1 are sent to the refnis 1~ controlled by the CPU 15.
The information is transferred to the reception means 6, where the address of the terminal device, the title of the song, etc. are identified.

The CPU 15 stores a usage status table cm of the compact disk stocker 12 stored in the main memory @17.
, and confirm that the compact disc with the requested title is stored at address X in the compact disc stocker 12. Next, CPIJ15
refers to the usage status table dm of the compact disc drives (playback devices) T1-Tm stored in the main storage device 17, and selects, for example, the disc drive T2 if there is a compact disc drive currently in use. Then, the CPU 15 controls the autochanger control circuit 14, and the autochanger 11 takes out the compact disc of the requested title from address X of the compact disc stocker 12, loads it into the compact disc drive T2, and plays it.

The music information from the compact disc drive T2 passes through the compression circuit U2 as digital data and is sent to the ADPCM.
etc. can be compressed.

Thereafter, the compressed music information is written into the memory circuit 4 under the control of the memory write circuit 7.

The CPtJ 15 refers to the usage status table Mm of the memory circuit 4 stored in the main memory @ 17, determines the write start address y and the write capacity ff1z, and supplies them to the memory write circuit 7. The memory write circuit 7 successively generates write addresses for the memory circuit 4 from this write start address y, and writes the music information from the compression circuit U2 to the memory circuit 4.

At that time, the music information is sent from the compact disk drive T2, compressed by the compression circuit U2, and the memory write circuit 7
Writing to the memory circuit 4 by the data is performed almost synchronously, with no delay other than the time delay passing through each circuit.

While performing this write operation, the CPLJ 15 gives a read start address y' and a read capacity Z' to the memory read circuit 13 in order to send information to the user, and reads from the memory circuit 4. Ru.

Writing/reading to/from the memory circuit 4 is performed as shown in FIGS. 3(a) to 3(a).
As shown in the timing diagram shown in (C), the time during which one word of the playback information signal from the compact disc is sent out is defined as one data cycle, and during this one data cycle, a write cycle to the memory is performed. Once, the read cycle from the memory is performed j times (J is an integer of 2 or more). Note that the value of j can be increased as the memory access time (or cycle time) becomes shorter.

The data read from the address y' of the memory circuit 4 is
Under the control of the CPU 15, one of the j decompression circuits ■1 to Vj (for example, ■3) is assigned, and the music is input to the decompression circuit V3, decompressed, and passed through the audio switch circuit 8 as the original music information. , is output to one of the output terminal groups W1 to wn.

The CPU 15 controls the audio switch control circuit 16 so that the output @W1 corresponding to the terminal bag @F1 that has made the request is connected to the expansion circuit v3. Note that the input terminal S1 and the output terminal W1 are a pair and correspond to the communication control means B1 shown in FIG. 2, and the communication line C1 and the converter D
1 communication 1! The requested music information is provided to the user's terminal device F1 via E1.

At this time, if another user inputs a request from the request input terminal $2 for the same title being played on the compact disc drive T2, the CPU 15
refers to m, dm, and Mn in the table in the main storage device 17, confirms that the disk drive T2 is currently playing, and confirms that the compressed information is stored from address y in the memory circuit 4. Discern. Then, for example, the vacant expansion circuit (1) is assigned, readout and expansion from the memory circuit 4 is started, and the audio switch 8 is connected so as to send music information to the output terminal W2. Similarly, 3
Even if the lifts of the 4th, 4th, .

On the other hand, if there is a request for another title, multiple access to this title is also possible by allocating another area of the memory circuit 4.

Also, depending on the usage status of the memory circuit 4, the CPU 15
Accordingly, the information reproduced from the reproduction devices F71 to Tm is directly inputted to the audio switch circuit 8 without passing through the memory circuit 4, and is outputted to the output terminal groups W1 to wn.

Then, information from the playback devices T1 to Tm is written in the memory circuit 4, and information is read from the memory circuit 4 and transmitted, and information from the playback devices fiT1 to Tm is written without going through the memory circuit 4. The case where the data is sent directly is determined and managed by the CPLJ15.

As long as there is free space in the allocation of the memory circuits 4, when the drive (playback device) enters the play state, data is written to the memory circuits 4 one after another. If it becomes necessary to put another drive into the play state after all the memory circuits 4 have been allocated to the drive currently being played, the CPU 1
5 refers to a table rm of request frequencies by title stored in the main memory 17.

The CPtJ 15 checks the title of the music information currently stored in the memory circuit 4 and the request frequency of the tiles to be played next, determines the priority, and stores the music information in the memory circuit 4.
Decide on 0 allocation. That is, when a title with a low request frequency has already been allocated to the memory circuit 4 and a title with a high request frequency is to be brought into play next, the latter is given priority and the memory area allocated to the former is allocated. rewrite.

By using the table rm of request frequencies by title, memory circuits are always allocated efficiently, and even duplicate requests can be immediately (at any time) searched and sent.

Here, m playback devices T1 to Tm and n output ends W1
In a multi-access file device with ~wn,
The optimal memory capacity of the memory circuit 4 will be explained.

First, let's assume that the number of compact disc drives (playback devices) is 20 and the number of outputs (ends) is 20. , it will be explained that the memory capacity of the memory circuit 4 required for multi-access changes.

FIG. 4 is a diagram showing changes in required memory capacity. Note that one unit of memory capacity 1 is a capacity corresponding to one compact disc (the capacity of information reproduced once from an information recording medium), and when compression is performed, it follows the compression rate.

First, when there is one drive in play in response to a request from one user, the maximum number of free output fractions is 1.
9, and 19 more users can service the same request. In this case, it is sufficient to have the memory capacity of one compact disc. When there are two drives playing, there is a possibility that 18 other people will make requests for the two titles being played. In this case, a memory capacity equivalent to two compact discs is required. In other words, the drive being played is 1
Up to the 0th drive, the required memory capacity increases in accordance with the number of drives being played.

However, when the number of drives being played reaches 11, the number of available outputs is 9. Therefore, since there are nine requests that may be duplicated, the required memory capacity is equivalent to nine compact discs. When there are 19 drives in play, there is only one free output end, so the memory required is one compact disc. In other words, from the 11th drive in play, the required memory capacity decreases as the number of free outputs decreases, and when all 20 drives are in play, O
Become.

Therefore, as is clear from FIG. 4, the maximum required storage capacity is the equivalent of 10 compact discs.

Next, the change in memory capacity required when the number of outputs is increased from 20 to 100 while the number of drives remains 20 will be explained with reference to FIG.

When the number of output fractions is 20, the required memory capacity is equivalent to 10 compact discs, as shown in FIG. When the number of output fractions is 21, the required memory capacity is maximum when there are 10 drives playing and 11 free output fractions, or when 11 drives are playing and the number of free output fractions is 11. When there are 10 discs, the memory capacity required at this time is equivalent to 10 compact discs. That is, as the number of output fractions increases, the required memory capacity increases.

As is clear from FIGS. 4 and 5, the memory capacity required for the memory circuit 4 is maximum when the number of drives in play is closest to the number of vacant outputs, and the memory capacity at that time is n/ It is equal to the product of the quotient of 2 (n is the number of output ends) multiplied by the capacity of one compact disc.

However, as can be seen from FIG. 5, if the number of output fractions becomes 40 or more, the required memory capacity will not exceed 20 compact discs.

This is because there are only 20 drives.

Therefore, at this time, the memory capacity i required for the metric circuit 4 is equal to m (m is the number of playback devices) multiplied by the capacity 1 for one compact disc. As is clear from the above explanation, the multi-access file device 1 having m playback devices T1 to Tm and n output terminals W1 to wn is equipped with a memory circuit 4 to instantly (at any time) cue. When multiple access is performed using a compact disk drive, the optimal memory capacity ω of the memory circuit 4 is set to the smaller of n/2 (an integer, n is the output fraction) and m (m is the number of drives). This is the capacity multiplied by the amount of information equivalent to one page (if compressed, it depends on the compression rate).

If the number is too large, even if information is stored in the memory circuit 4, there is no free space at the output terminals W1 to Wn, so service cannot be provided.If it is too small, the output terminals QWI to Wn are not available. Even if the playback devices T1 to Tm are installed, the information cannot be stored in the memory, so the service cannot be provided.

Furthermore, this multi-access file device has a compression circuit 3 and an expansion circuit 5, and stores the compressed information in the memory circuit 4, so the memory capacity is a fraction of the actual amount of information, which is equivalent to one compact disc. can be configured with a small memory capacity without using a large memory capacity.

Note that the playback device may be a record player, video cassette player, digital audio deck, etc.
The data decompression circuit may be located not in the center equipment but on the terminal equipment side. In addition, the output terminal is not only a communication line but also a CATV
It may be connected to the terminal device via cable broadcasting, or directly to the terminal device.

(Effects of the Invention) As detailed above, according to the invention, a multi-access file device having m playback devices and n output terminals is provided with a memory circuit having an optimal memory capacity. Therefore, a surplus of memory capacity will not be generated due to a shortage of output terminals, and a surplus of output terminals will not be generated due to a shortage of memory on a cruise ship. Therefore, the memory circuit allows a multi-access file device capable of immediate cueing to be constructed at a lower cost and in a smaller size.

[Brief Description of the Drawings] Fig. 1 is a block diagram showing an embodiment of a multi-access file device according to the present invention, and Fig. 2 is a configuration diagram showing a center server service system constituted by the multi-access file device. , Figure 3 is a timing diagram for explaining the write/read timing of the memory circuit, and Figure 4 explains that the memory capacity required for multi-access changes depending on the number of playback devices being played. FIG. 5 is an explanatory diagram for explaining that the memory capacity required for multi-access changes depending on the number of output terminals. 1...Multi-access file Hff1, 4...Memory circuit, 7...Memory write circuit, 13...Memory read circuit, ■1~
Tm…Playback device (compact disc drive), W1
~Wn...Output end. Yz diagram

Claims (1)

[Claims] In a multi-access file device for a center system that sends out information in response to requests from multiple users, m units (m = 1, 2, 3) that reproduce information from an information storage medium are provided.
,...), a memory circuit for storing information reproduced by the reproduction apparatus, a writing circuit for writing information from the reproduction apparatus into the memory circuit, and reading information from the memory circuit. n (n=1, 2) for transmitting information reproduced by the reproduction device and information read from the memory circuit to a user in response to a request;
, 3,...) output terminals, and the capacity required to store the information reproduced once from the information recording medium is multiplied by the smaller of the quotient of n/2 or m. A multi-access file device characterized in that the capacity is the storage capacity of the memory circuit.