JP2001285826A - Data transmission equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide data transmission equipment capable of providing program information corresponding to the desire of each receiver with comparatively simple constitution. SOLUTION: The equipment has a record reproduction means for recording and reproducing data on a prescribed recording medium and is provided with a data sending part which sorts the requests of plural receivers to the respective time slots of plural time slots in the case of reading recorded data on the recording medium in accordance with requests from receivers, and reads the recorded data from the different recording areas of the recording medium by each time slot to generate plural pieces of data in accordance with the requests from the plural receivers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission apparatus, and is suitably applied to, for example, a data transmission apparatus for transmitting video data according to a request of a receiver.

[0002]

2. Description of the Related Art Conventionally, as this type of data transmission device,
There are CATV (cable television) and a captain system using a telephone network. In CATV, a video tape recorder (VTR), which is a storage device of sequential access, generally uses a video tape recorder (VTR) to unilaterally provide a program to a receiver.

[0003]

By the way, in the CATV, the program information reproduced from the VTR is provided to a plurality of receivers as described above, so that the program information is received at a time desired by the receivers. As a result, it was not possible to supply the program desired by the receiver, and as a result, there was still an insufficient problem in meeting the demands of the receiver.

For example, even if a receiver selects a desired program, this program is provided unilaterally to a plurality of receivers regardless of the request of the receiver.
Recipients had the inconvenience of not being able to watch the program from the beginning.

[0005] As one method of solving such a problem,
It is conceivable to provide desired program information at a desired time of the receiver in response to a request from the receiver by using the same number of VTRs and video tapes as the number of receivers. In addition, there has been a problem that a large operation cost is required.

[0006] Combining a large-scale disk array with a high-performance work station may provide program information according to a request of a receiver. However, this method also has a problem that the configuration becomes very complicated. There was. In this method, a large margin is required for a storage device and a workstation in order to immediately respond to a request from a large number of recipients and to secure a constant transmission rate, and the number of recipients that can be received at the same time is required. There is a problem that a large cost burden is required to remove the restrictions.

The present invention has been made in view of the above points, and has as its object to propose a data transmission apparatus capable of providing program information according to each receiver's desire with a relatively simple configuration. It is.

[0008]

According to the present invention, there is provided a data transmission apparatus for transmitting data corresponding to a request from a receiver via a predetermined transmission line, a predetermined recording medium. It controls the operation of the sending units 4A1 to 4AL, 10A1 to 10Am, and the sending units 4A1 to 4AL, 10A1 to 10Am, which record data thereon and transmit the data from the top to the receiver in response to a request from the receiver. A control unit 6 is provided. When the number of recipients reaches a predetermined number, the control unit 6 sends data to the transmission units 4A1 to 4AL, 1
Sending unit 4A by copying within 0A1-10Am
The number of output channels of 1 to 4AL and 10A1 to 10Am is increased.

As a result, in the data transmission apparatus 1, the copy from the preceding section to the succeeding section in the sending sections 4A1 to 4AL and 10A1 to 10Am is performed when the request of the n-th receiver is made to the preceding section. When a request is received from the (n + 1) -th receiver for the data in the preceding stage, the receiver is immediately assigned to the latter by responding to the request from the latter in response to the receiver. Data can be provided.

In the present invention, the transmitting units 4A1 to 4A-4
AL, 10A1 to 10Am are the first sending units 4A1 to 4A4.
AL and second transmission units 10A1 to 10Am, and the first transmission units 4A1 to 4AL to the second transmission units 10A1 to 10Am.
The data is copied to 10 Am, so that the sending unit 4A
The number of output channels 1 to 4AL and 10A1 to 10Am is increased.

As a result, in this data transmission device, the first transmission units 4A1-4AL to the second transmission units 10A1-10A
Am to the first sending units 4A1 to 4A
L starts at the request of the n-th receiver, and the data of the first sending units 4A1 to 4AL is (n
+1) When a receiving request is received from the second receiver, the receiver is immediately assigned to the second transmitters 10A1 to 10Am, so that the receivers are immediately transmitted to the second transmitters 10A1 to 10A1.
It is possible to provide data according to a request from 10 Am.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a data transmission apparatus as a whole, which can provide desired program information such as a movie program to each recipient in response to a reception request sent from the recipient over a telephone line LIN. Has been made.

The data transmission apparatus 1 includes program information SR1, SR2,..., SR (k-
1), the SRk is transmitted to the first transmission unit group 4 via the switch 3
,..., 4AL
-1, 4AL selectively.

Here, the program library 2 includes a plurality of VTRs.
Is automatically loaded and reproduced by a cassette in which desired program information is recorded in each VTR based on a control signal S1 from the program control unit 5. Different program information SR1 to SRk can be simultaneously output from the output channels.

The switch 3 is a (k × L) matrix switch composed of k inputs and L outputs,
Program information SR1 to SRk sent from program library 2
Is selectively output to the sending units 4A1 to 4AL in response to the control signal S2 from the program control unit 5.

Each of the sending sections 4A1 to 4AL has one input channel and (n + 1) output channels. Each of the sending units 4A1 to 4AL has a large-capacity storage device,
The input program information is temporarily stored in a storage device, and is read out and output based on a control signal S3 from the program transmission control section 6.

Out of the (n + 1) output channels of the sending sections 4A1 to 4AL, n are allocated to the receiver, and the other output channel is connected to the switch 7.

The program information output from the sending units 4A1 to 4AL for the receiver is added with ID information (identification information) corresponding to the receiver by the formatters 8A1 to 8AL, and is also input to the subsequent input format of the data exchange 9. After being converted to a suitable format, it is provided to each recipient via the data exchange 9 and the telephone line LIN. Thereby, in the data transmission device 1, for example, the transmission unit 4A1
Can provide the same program information to n receivers, and, for example, from the transmitting unit 4AL to the transmitting unit 4
The program information having contents different from the program information of A1 can be provided to n recipients.

Further, the data transmission apparatus 1 includes a second transmission unit group 1
0, and the second sending unit group 10
Transmission units 10A1 to 10 having the same configuration as A1 to 4AL
Am.

(N + 1) of each of the sending units 10A1 to 10Am
The n output channels are allocated for the receiver, and the other output channel is connected to the switch 7. The program information output for the receiver from the sending units 10A1 to 10Am is stored in the format 11A.
ID information corresponding to the receiver is added by 1 to 11 Am, and after being converted into a format suitable for the input format of the subsequent data exchange 9, it is provided to each recipient via the data exchange 9 and the telephone line LIN. Is done.

The switcher 7 has a matrix structure of {(L + m) × m}, and switches the connection based on a control signal S4 from the program transmission control unit 6 so that the first transmission unit group 4 and the second transmission unit The program information output from the group 10 is sent to the sending units 10A1 to 10Am- of the second sending unit group 10.
It is adapted to selectively supply 1 or 10 Am.

As a result, in the data transmission apparatus 1, as shown in FIG.
Sending units 4A1 to 4A for program information of L-1 or 4A
If there are a large number of requests (that is, n or more requests) that cannot be fulfilled by one of the 4ALs, the sending unit 4A
The program information of 1 to 4AL-1 or 4AL is temporarily sent to the empty sending units 10A1 to 10Am-1 of the second sending unit group 10.
Alternatively, the number of receivers that can provide the program information can be doubled (2n) by providing the information through 10 Am.

The sending units 4A1 to 4A1 of the first sending unit group 4
A sending unit 4A1 for the AL-1 or 4AL program information
４4AL-1 or 4AL and one sending unit 10A1 to 10Am-1 or 10Am of the second sending unit group 10, there were a large number of requests (that is, 2n or more requests) that could not be satisfied by two sending units. In this case, the output units 10A1 to 10Am-1 or 10Am of the second transmission unit group 10 are connected to another transmission unit 10A1 to 10Am-1 or 10Am in a subsequent stage, so that the number of output channels of the program information is changed. Are sequentially increased.

As described above, in the data transmission apparatus 1, the sending units 10A1 to 10Am-1 or 10A which are connected in succession as the number of requests for certain program information increases.
By increasing the number of m, the number of recipients that can receive at the same time can be increased by effectively using the sending unit.

Here, each sending section 4A1 of the first sending section group 4
-4AL and each of the transmission units 10A1-1 of the second transmission unit group 10
0Am is configured as shown in FIG.

That is, the sending units 4A1 to 4AL and 10A
1 to 10 Am input the program information from the switch 3 or 7 via the input interface 20 to the buffer memory 21.
To enter.

Sending units 4A1-4AL and 10A1-10
Am can record the output of the buffer memory 21 on a predetermined recording medium by a recording / reproducing unit 23 via a recording / reproducing interface 22 and simultaneously output from a plurality of output channels via an output interface 24. It has also been made possible.

In the case of the embodiment, a magneto-optical disc capable of recording, for example, program information for one movie is used as a recording medium, and the recording / reproducing section 23 records program information on this magneto-optical disc. A disk recording / reproducing apparatus capable of performing high-speed reproduction is also used. As a result, the recording / reproducing unit 23 can access a desired recording area of the recording medium at a high speed in response to a request from the receiver and reproduce the desired information at a high speed.

The program information read from the recording / reproducing unit 23 is expanded in the time axis direction by the buffer memory 21 to be reduced to a predetermined transmission rate, and then transmitted to a plurality of receivers (through the output interface 24). (within n people).

The writing and reading operations of the program information by the recording / reproducing unit 23 are controlled by the CPU 26 using the ROM 25 and the RAM 27.

When the program information is already recorded on the recording medium, the recording / reproducing section 23 divides the unit time (1 second in the embodiment) into n time slots as shown in FIG. Then, by assigning each time slot to each receiver, and accessing the different position of the recording medium at high speed and reading out the recording data at this position at high speed for each time slot, the same The program information can be provided with a time difference.

As a result, in the data transmission device 1, the program information can be provided to each receiver from the beginning.

That is, the recording / reproducing unit 23 sets the unit time to T
If [sec] is set, a desired area of the recording medium is accessed at high speed by T / n [sec], and T [sec] of one receiver is obtained.
Play minute data at high speed.

The recording / reproducing unit 23 stores the program information from the program library 2 or another transmitting units 4A1 to 4A on a recording medium.
L, while recording the program information from 10A1 to 10Am, it is also possible to transmit the program information having a time difference to each receiver.

In this case, as shown in FIG. 5, the recording / reproducing section 23 divides the unit time into n time slots, reads out the recorded data in (n-1) time slots, and reads the remaining data. In one time slot, the program library 2 or another transmitting unit 4A1-4AL, 10A1-10
The program information from Am is recorded.

Here, the unit time is T (seconds), and the recording / reproducing unit 2
3, the maximum access time to the recording medium is ta (second), the data write / read rate of the recording / reproducing unit is r (byte / second), and the data amount transmitted to the receiver within the unit time T is d (byte). Then, each of the sending units 4A1 to 4AL or 1
The number of time slots S of 0A1 to 10Am is expressed by the following equation:

[0038]

(Equation 1)

Can be selected.

In the data transmission apparatus 1, the transmission units 4A1 to 4AL and 10A1 to 10Am are connected in series, and transmission data is transmitted to a large number of recipients via the plurality of transmission units 4A1 to 4AL and 10A1 to 10Am. At this time, the copying of data from the upstream transmission unit to the downstream transmission unit is started when the request of the nth receiver is sent to the upstream transmission unit.

Thus, in the data transmission device 1,
When a (n + 1) -th receiver receives a request for the data of the preceding transmission unit, the receiver is immediately assigned to the subsequent transmission unit, thereby immediately requesting the receiver from the subsequent transmission unit. It is possible to provide data according to.

Here, the schedule management unit 12 of the data transmission device 1 controls the entire data transmission device 1 by executing a processing procedure as shown in FIG.

That is, the schedule management unit 12 enters from step SP0, and receives the received signal S5 indicating the program request from the receiver from the data exchange 9 in step SP1.
Is input, in the following step SP2, the step S
It is determined whether the program requested in P1 is present in any of the transmission units 4A1 to 4AL-1 or 4AL of the first transmission unit group 4.

The schedule management section 12 executes step SP2.
If a positive result is obtained in step, the process proceeds to step SP3.
On the other hand, the schedule management unit 12 proceeds to step SP2.
If a negative result is obtained in step SP4, the program proceeds to step SP4 and the program requested in step SP1 is sent to the second transmission unit group 1.
0, any of the sending units 10A1 to 10Am-1 or 10
It is determined whether or not it is Am, and if an affirmative result is obtained, the process moves to step SP3.

The schedule management unit 12 executes step SP3
, Sending units 4A1 to 4A4 in which a requested program is recorded
The AL or the empty time slot of 10A1 to 10Am is assigned to the receiver.

The schedule management unit 12 proceeds to the next step S
In P5, the sending sections 4A1 to 4AL or 10A1 to 10A to which the time slots have been assigned in step SP3.
Formatter 8A1-8AL or 11A1 corresponding to m
After instructing .about.11Am the receiver ID and the time slot number, the operation proceeds to step SP6.

On the other hand, if a negative result is obtained in step SP4, the schedule management unit 12 proceeds to step SP7 and there are the sending units 4A1 to 4AL-1 or 4AL not used in the first sending unit group 4. If a positive result is obtained here, the process proceeds to step SP8 to determine whether or not the output channel of the program library 2 is empty. The schedule management unit 12 executes step SP8.
If a positive result is obtained in step SP9, the process moves to step SP9 and the first
The requested program is transferred from the program library 2 to the vacant transmission units 4A1 to 4AL-1 or 4AL of the transmission unit group 4 of (3), and the process proceeds to step SP6.

On the other hand, if the negative result is obtained in step SP7 or the negative result is obtained in step SP8, the schedule management unit 12 moves to step SP10 to indicate that the service cannot be performed due to congestion. Is transmitted to the requester via the data exchange 9, and the process proceeds to step SP6.

The schedule management section 12 executes step SP6.
In step 2, when the management information obtained from the program control unit 5 and the program transmission control unit 6 is fetched, the process returns to step SP1 to repeat the above-described processing.

The program control unit 5 includes a schedule management unit 12
7 to control the program library 2 and the switch 3 based on the control signal from the first transmitting unit 4 so that the transmitting units 4A1 to 4A of the first transmitting unit group 4 are controlled.
L to selectively transfer program information.

That is, the program control unit 5 executes step SP1
In step SP12, it is determined in step SP12 whether or not an instruction from the schedule management unit 12 has been received. If a positive result is obtained, the control signal S1 instructs to step SP13 to transfer the requested program. To the program library 2.

Next, in step SP14, the program control unit 5 sends the output channel of the program library 2 to which the requested program is output and the vacant sending units 4A1 to 4A1 to the switch 3.
After instructing the connection of the 4AL-1 or 4AL input channel, the process proceeds to step SP15.

On the other hand, if a negative result is obtained in step SP12, the program control section 5 proceeds to step SP15. In step SP15, the program control unit 5 sends the program library 2 and the switch 3 to the schedule management unit 12.
When the management information is transmitted, the process returns to step SP12 to repeat the above processing.

The program transmission control section 6 executes a processing procedure as shown in FIG. 8 based on a control signal from the schedule management section 12 so that the switch 7 and the transmission section 4 are executed.
A1 to 4AL and 10A1 to 10Am are controlled.

That is, the program transmission control section 6 determines in step S
In step SP21, it is determined in step SP21 whether or not there has been an instruction from the schedule management unit 12 to transfer the program information of the program library 2 to the transmission units 4A1 to 4AL-1 or 4AL. If a negative result is obtained here, the process proceeds to step SP21. Move to SP22. On the other hand, if a positive result is obtained in step SP21, then in step SP23,
After giving an instruction to input the program information from the program library 2 to the specified sending units 4A1 to 4AL-1 or 4AL, the process proceeds to step SP22.

In step SP22, the program transmission control section 6 transmits the program from the schedule management section 12 to the transmission sections 4A1 to 4A.
It is determined whether or not an instruction to assign a receiver to L or 10A1 to 10Am has been given. If a negative result is obtained here, the process proceeds to step SP24 and all the sending units 4A1 to 4AL are sent.
And information of 10A1 to 10Am.

On the other hand, if an affirmative result is obtained in step SP22, the operation moves to step SP25, and data is output to the designated sending sections 4A1 to 4AL or 10A1 to 10Am using the empty time slots. To indicate that

The program transmission control section 6 proceeds to the next step SP26.
In step S25, the sending unit 4A1 specified in step SP25
4AL or 10A1 to 10Am, or the sending unit 4A1 to 4AL or 10A1 to 10A in which the same program is entered.
It is determined whether or not there is an empty time slot in m. If a positive result is obtained here, the process proceeds to step SP24, and if a negative result is obtained in step SP26, the process proceeds to step SP27.

In step SP27, the program transmission control section 6 judges whether or not there are any unused transmission sections 4A1 to 4AL-1 or 4AL. If a negative result is obtained here, the program shifts to step SP14. If a positive result is obtained, the process moves to step SP28.

In step SP28, the program transmission control section 6 transmits the control signal S4 to the switch 7 to thereby instruct the transmission sections 4A1 to 4AL or 10A1 to 10A1 specified.
The 0th output channel of 0Am is sent to the empty sending units 10A1-1.
Instructs connection to the 0 Am input channel.

As described above, the program transmission control section 6 executes the transmission sections 4A1 to 4AL in steps SP25 to SP28.
Or, if the output channels of 10A1 to 10Am cannot respond to the reception request, the transmission units 4A1 to 4AL or 10A
Sending units 10A1 to 10Am sequentially after A1 to 10Am
Are connected in series to increase the number of output channels.

The program transmission control section 6 proceeds to the next step SP24
In all the sending units 4A1 to 4AL and 10A1 to
After the information of 10 Am has been fetched, the information fetched in step SP24 is sent to the schedule management unit 12 as management information in step SP29.
Returning to step 21, the above-described processing is repeated.

In the above configuration, when the data transmission apparatus 1 receives a program request from the first receiver, first, the transmission section 4A
It is determined whether or not this program exists in 1 to 4AL or 10A1 to 10Am, and any of the transmission units 4A1 to 4AL or 1
When a requested program is received at 0A1 to 10Am, a receiver is assigned to an empty time slot of the transmission units 4A1 to 4AL or 10A1 to 10Am.

On the other hand, which transmitting unit 4A1-4AL
Or, when there is no requested program in 10A1 to 10Am,
Sending units 4A1 to 4AL in empty state from program library 2
Alternatively, while transmitting and copying the requested program to 10A1 to 10Am, the transmitting units 4A1 to 4AL or 10A1 to 10A
Am sends the requested program to the first recipient.

In the data transmission apparatus 1, when a request for the same program is received from the second receiver with a time difference from the first receiver, the second receiver is assigned to the first receiver. Sending unit 4A1-4AL or 10A1-10
Assign to another time slot of Am.

At this time, the data transmission device 1 accesses the recording position corresponding to the time at which the program request was made at a high speed and reads out the recording data at a high speed for each time slot.

As a result, the data transmission apparatus 1 can provide a plurality of recipients with program information having a time difference corresponding to the requested time.

In the data transmission apparatus 1, one transmission unit 4A1-4AL or 10A1
If there is a program request that cannot be satisfied by 10 to 10 Am, that is, if there is a program request that exceeds the number of time slots allocated within the unit time T of the sending units 4A1 to 4AL or 10A1 to 10Am, the sending unit 4A1-4
The program information of AL or 10A1 to 10Am is transmitted to another transmitting unit 10A1 to 10Am-1 or 10A of the second transmitting unit group 10.
m and the sending units 10A1 to 10Am-1 or 1
The program information is provided to the receiver via 0Am.

As a result, in the data transmission device 1, 1
Even if there is a program request that exceeds the capacity of one of the sending units 4A1 to 4AL or 10A1 to 10Am, the same program information can be transmitted to a large number of receivers by effectively using another sending unit 10A1 to 10Am-1 or 10Am. Can be provided with a time lag, and the limitation on the number of recipients that can be received can be eliminated.

According to the above configuration, the sending units 4A1 to 4A
L, or once the program information is recorded in 10A1 to 10Am, and when reading out the program information, the request from the receiver is distributed to each time slot of a plurality of time slots.
By making high-speed access to different recording areas of the recording medium and reading out recording data at high speed for each time slot, even if there is a program request with a time difference from each receiver, the program corresponding to this time difference The data transmission device 1 that can provide information to each receiver can be realized.

Also, one sending unit 4A1-4AL or 10
When there are a large number of program requests that cannot be fulfilled by A1 to 10Am, the sending units 10A1 to 10A according to the number of program requests.
m are connected in succession, so that the sending unit 4
A1 to 4AL and 10A1 to 10Am can be effectively used, and as a result, a data transmission device 1 with a simplified configuration can be realized.

In the above embodiment, the plurality of data transmission units 4A1 to 4AL and 10A1 to 10Am are divided into the first data transmission unit group 4 and the second transmission unit group 10, and the first transmission unit When there is a reception request exceeding the number of output channels to any of the transmission units 4A1 to 4AL or 10A1 to 10Am of the group 4 or the second transmission unit group 10, the second transmission unit group 10 is switched via the switch 7. Empty sending unit 10
A case has been described where the number of receivable recipients is increased by successively connecting A1 to 10Am-1 or 10Am at the subsequent stage. However, the present invention is not limited to this, and as shown in FIG. And a transmission unit 4A1
Depending on the availability of ~ 4AL, via the switch 31
The program library 2 may be connected to the transmission units 4A1 to 4AL, and the transmission units 4A1 to 4AL may be connected continuously. In this case, the switch 31 is represented by ｛(k +
It is sufficient to use a matrix switch of L) × L｝.

In the above-described embodiment, a magneto-optical disk is used as a recording medium of the transmitting units 4A1 to 4AL and 10A1 to 10Am, and the program information can be recorded on the magneto-optical disk as the recording / reproducing unit 23, and high-speed recording can be performed. Although the case where a disk recording / reproducing apparatus capable of reproducing is used has been described, the present invention is not limited to this, and the transmitting units 4A1-4
As the recording medium of AL and 10A1 to 10Am, a magnetic tape, a semiconductor memory, a disk array, or the like can be used, and as the recording / reproducing unit 23, a video tape recorder, a memory controller, a disk reproducing device, or the like is used accordingly. In short, various recording media and the recording / reproducing unit 23 capable of high-speed access and high-speed reading can be applied.

Further, in the above-described embodiment, a case has been described in which a cassette auto-changer having a plurality of video tape recorders mounted thereon is used as the program library 2. However, the present invention is not limited to this.
For example, a disc player or a data recorder having various configurations can be applied.

Further, in the above-described embodiment, the transmission data obtained by the data transmission device 1 is transmitted to the telephone line LI.
Although the transmission to the receiver via N has been described, the transmission path is not limited to this, and various transmission paths such as a cable television line or a satellite communication path can be used.

Further, in the above-described embodiment, the program information is read out from all the receivers by reading the recording data from the position corresponding to the request time of the receiver for each time slot assigned to each receiver. Has been described from the top, but the present invention is not limited to this, and if there is a request from the receiver to view program information from the middle,
If the reading position is selected according to this, the program information can be provided from the position according to each receiver's request.

Further, in the above-described embodiment, when reading out data corresponding to each receiver's request at each time slot, the recording / reproducing section 23 reads out the recording data at high speed, and then reads this data in the buffer memory 21. Although the case of decompression has been described, the present invention is not limited to this, and if the program information of the program library 2 is compressed in advance in the time axis direction by the recording / reproducing unit 23 and recorded, it is necessary to read out recorded data at high speed. There is no.

Further, in the above-described embodiment, a case has been described in which the present invention is applied to the data transmission apparatus 1 for transmitting the program information from the program library 2. However, the data transmission units 4A1 to 4AL and 10A1 to 10Am The data to be transmitted is not limited to the program information, and the data transmission units 4A1 to 4A1
Even when data other than program information is transmitted via 4AL and 10A1 to 10Am, the same effect as in the above-described embodiment can be obtained.

[0074]

As described above, according to the present invention, in a data transmission apparatus for transmitting data according to a request from a receiver via a predetermined transmission path, the data is recorded on a predetermined recording medium, A transmission unit that transmits data from the beginning to the recipient in response to a request from the recipient and a control unit that controls the operation of the transmission unit are provided, and when the number of recipients reaches a predetermined number, In the case where the number of output channels of the transmission unit is increased by copying the data in the transmission unit so that the copy in the transmission unit is changed from the former stage to the latter stage, the former stage unit is copied after the start of the copy. A data transmission device which can provide data according to the request from the subsequent stage to the receiver who has requested, and thus can provide program information according to each receiver's request with a relatively simple configuration Can be realized .

Further, according to the present invention, in this data transmission apparatus, the transmitting section comprises a first transmitting section and a second transmitting section, and the data is transmitted from the first transmitting section to the second transmitting section. Is copied so as to increase the number of output channels of the transmitting unit, so that the second transmitting unit responds to the receiver who has requested the first transmitting unit after the start of the copy, according to the request. Thus, a data transmission apparatus capable of providing program information according to each receiver's desire with a relatively simple configuration can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of a data transmission device according to the present invention.

FIG. 2 is a block diagram for explaining a case where a sending unit is connected in a cascade connection.

FIG. 3 is a block diagram showing a configuration of a sending unit.

FIG. 4 is a time chart for explaining a reading operation of the transmission unit when desired recording data is present in the transmission unit.

FIG. 5 is a time chart for explaining a data writing and data reading operation performed by the transmission unit when there is no desired recording data in the transmission unit.

FIG. 6 is a flowchart showing a processing procedure of a schedule management unit.

FIG. 7 is a flowchart showing a processing procedure of a program control unit.

FIG. 8 is a flowchart showing a processing procedure of a program transmission control unit.

FIG. 9 is a block diagram showing a data transmission device according to another embodiment.

[Explanation of symbols]

1, 30 ... data transmission device, 2 ... program library,
3, 7, 31 ... switch, 4, 10 ... sending unit group,
4A1-4AL, 10A1-10Am ... Sending unit, 21
...... Buffer memory, 23 ... Recording / reproducing unit, LIN ...
telephone line.

Claims (2)

[Claims] 1. A data transmission apparatus for transmitting data according to a request from a receiver via a predetermined transmission path, wherein the data is recorded on a predetermined recording medium, and the data is transmitted in response to the request from the receiver. A sending unit that sends the data to the receiver from the beginning, and a control unit that controls the operation of the sending unit. A data transmission device, wherein the number of output channels of the transmission unit is increased by copying the data in the transmission unit. 2. The transmitting section comprises a first transmitting section and a second transmitting section, and the data is copied from the first transmitting section to the second transmitting section so that the transmitting section is copied. 2. The data transmission device according to claim 1, wherein the number of output channels is increased.