JPH0998404A - Video on-demand device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly provide a terminal equipment with service by setting error correction ability corresponding to the reception state of the terminal equipment. SOLUTION: Data A which are the data of a video source compressed by a compression encoding device 53a1 for instance are divided, an HDR (header) 2 is added by a first redundant data adder 53b1, redundant data CC 2 which are variable length are added, packet data are constituted, they are divided into a fixed length further and the HDR is added. Further, the redundant data CC are added to the HDR 2, the data A and the data B by a second redundant data adder 53d. In this case, the redundant data are added in over two stages, the redundant data CC are the fixed length, the error correction ability is set relatively low and information to be added is reduced as much as possible. Also, the redundant data CC 2 are variable for the respective terminal equipments 711-71n and controlled in a redundant data controller 49 by the reception states of the terminal equipments 711-71n.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video-on-screen which monitors a terminal device and provides a smooth service to the terminal device used in various states based on the information.
Demand device.

[0002]

2. Description of the Related Art As is well known, in CATV (cable television) broadcasting facilities, coaxial broadcasting or optical cable is used as a transmission medium to perform general broadcasting such as satellite broadcasting and terrestrial broadcasting and pay broadcasting. These days,
The method of transmitting an image by AM modulation and the method of transmitting audio by FM, which is analog, tends to replace the method using digital technology.

FIG. 15 shows a conventional C using digital technology.
1 shows a configuration of a video-on-demand device of an ATV system. In FIG. 15, reference numeral 11 is CATV.
At the broadcasting station, a plurality of terminal devices 311 are connected via the cable 21.
It is connected to ~ 31n and bidirectional communication is possible. The plurality of terminal devices 311 to 31n are connected to the television receivers 321 to 32n, respectively. The upstream signal transmitted from any one of the plurality of terminal devices 311 to 31n is supplied to the demodulator 12 in the CATV broadcasting station 11.

Here, the terminal device 311 will be described as an example. The demodulator 12 demodulates the upstream signal from the terminal device 311 to convert it into a digital signal, and supplies this digital signal to the error corrector 13. The error corrector 13 removes an error in transmission of the digital signal,
The digital signal is supplied to the upstream data collector 14.

The upstream data collector 14 includes an error corrector 13
Data regarding the terminal device 311 is collected and stored from the digital signal from the device, and the system operation is managed so as to be transmitted to the requesting terminal device 311. Further, the upstream data collector 14 gives a control signal based on a request from the terminal device 311 to the plurality of compression encoding devices 15a1 to 15a2 of the video transmission device 151. Further, control signals are similarly given to a plurality of other video transmission devices 152 to 15m. That is, the upstream data collector 14
Is the compression encoding device 1 for the terminal devices 311 to 31n.
This means that 5a1 to 15a2 are allocated. Further, the upstream data collector 14 provides the terminal controller 16 with program information such as frequency and channel number allocated at the same time as or before the allocation of the compression encoding devices 15a1 to 15a2.

[0006] The terminal controller 16 performs status polling and control on the requesting terminal device 311. That is, the control data from the terminal controller 16 is modulated to a specific frequency by the data modulator 17 and transmitted to the terminal device 311. The data modulator 17 generally uses a PSK (Phase Shiht Keying) system and an FSK (Frequenque).
cy Shift Keying) method.

On the other hand, in the video sending device 151,
The television signals supplied to the input terminals 181 to 18n are supplied to the compression encoding devices 15a1 to 15an, respectively. Compression encoding devices 15a1 to 15an
Compresses the supplied television signal in order to effectively use the transmission band. Then, the plurality of television signals compressed by the compression encoding devices 15a1 to 15an are multiplexed in the same band by the multiplexing device 15b. The multiplexer 15b also simultaneously multiplexes program information about television signals. The television signal multiplexed by the multiplexer 15b is supplied to the redundant data adder 15c.

The redundant data adder 15c adds redundant data to the supplied television signal in order to protect against an error on the line. In addition, the redundant data adder 15
c is usually also used in a method such as interleaving so as to effectively perform error correction. The length of the redundant data at this time is fixed on the system.

Then, the television signal to which the redundant data is added is modulated with the redundant data by the modulator 15d and mapped to a specific frequency. This modulator 1
5d includes QAM (Quadrature Amplitude Modulation)
Modulation method, VSB (Vestigial Sideband Modulation) modulation method is mainly used. The television signal output from the modulator 15d is transmitted to the terminal devices 311 to 31n.

FIG. 16 shows details of the terminal device 311, for example. That is, in the cable input terminal 31a,
The television signal S1 is supplied. Then, of the television signal S1, the data modulated and mapped by the modulator 15d is selected by the tuner 31b, and the signal S2 as a result of the selection is supplied to the data demodulator 31c. The data demodulator 31c performs, for example, QAM demodulation processing on the input signal S2, and the demodulated signal S3 obtained by this is supplied to the FEC 31d.

The FEC 31d detects error data generated during transmission from the demodulated signal S3 from the redundant data added by the redundant data adder 15c and corrects it. Then, the corrected signal S4 is supplied to the demultiplexer 31e. Further, the FEC 31d supplies the corrected signal S5 to the microcomputer 31f.

The demultiplexer 31e separates a plurality of multiplexed data from the supplied signal S5, acquires a necessary television signal S5, and outputs it to the compression decoder 31g. In addition, the demultiplexer 31e selects the television signal supplied to the input terminals 181 to 18n, gives the channel number to the microcomputer 31f, and outputs the channel number of the selected television signal to the LED (Light). Emitting Diode) 31k. The microcomputer 31f instructs the demultiplexer 31e how much to separate the multiplexed data.

The compression decoder 31g restores the video / audio from the supplied television signal S5 and supplies the television signal S6 to one input end of the on-screen display device 31h.

On the other hand, the above-mentioned microcomputer 31f
Is the remote control light-receiving unit 31i that responds to the user's input operation.
Thus, the requested menu mode is operated to be displayed on the television screen. This menu mode is created based on the program information sent from the CATV broadcast station 11, and includes a channel selection menu, a selected channel, and the like. Then, the responded menu mode made by the remote control light receiving unit 31i is the screen control circuit 3
It is output to 1j.

The screen control circuit 31j generates graphics or the like for displaying on the screen of the television receiver 321 based on the menu mode output from the microcomputer 31f, and outputs the signal S7 to the on-screen display device. It is supplied to the other input end of 31h. The on-screen display device 31h uses the television signal S6.
A channel selection menu, a selected channel, etc., which is the signal S7, are superimposed on and output to the television receiver 321. here,
To switch from the program being broadcast to the menu screen,
Switching control is performed by the screen control circuit 31j.

The signal output from the data modulator 17 and the program information for selection output from the upstream data collector 14 via the demodulator 12 are the data demodulator 3
The signal is received by 1l and supplied to the microcomputer 31f. Then, the user selects a desired program with a remote controller or the like based on the program information displayed on the screen of the television receiver 321. The request signal for the selected program is transmitted to the CATV broadcasting station 11 via the upstream data modulator 31m. The upstream data modulator 31m modulates status data transmitted at the request of the terminal controller 16 or a request signal and transmits the modulated status data to the upstream data collector 14.

Then, program information such as a channel number is transmitted from the CATV broadcasting station 11, and the terminal device 311
The program requested by the program information can be received. At this time, the program information multiplexed on the television signal by the multiplexer 15b is also used.

In the video-on-demand apparatus configured as described above, since the programs are allocated to each of the terminal devices 311 to 31n, it is possible to pause, rewind, fast-forward, etc. of the video at the request of the user. VTR (Video Tape Reco
rder) It is strongly required to be used like.

By the way, in the conventional video-on-demand apparatus as described above, although the VTR-like performance is desired, the CATV broadcasting station 11 side and the terminal apparatus 3 are provided.
Due to a problem such as the distance from the 11 to 31n side, the terminal device 311
Even though the states of ~ 31n are different, the system is built around the CATV broadcasting station 11.

Specifically, even if an error occurs in the cable 21 connecting the CATV broadcasting station 11 and the terminal devices 311 to 31n and a clear image cannot be obtained, the user pays the normal fee. . Further, even if the line environment on the side of the terminal devices 311 to 31n where the system is vastly expanded changes, enormous cost and time are required to improve the system once constructed. If such inconvenience is usually mere data, the terminal devices 311 to 31 1
Although the problem can be solved by a restoration process such as retransmission at the request of n, it is impossible to retransmit information such as a video signal, which has many time constraints.

Further, even if a power failure or the like occurs while requesting or viewing a pay program, the character similar to VTR is lost. After the power failure is restored, it stops like that of a dedicated VTR, and cannot recover from that point.

Also, in a normal use state, the VTR-like performance is likely to be lost. that is,
In the terminal devices 311 to 31n, when it is desired to temporarily watch a free program while receiving a pay broadcast, the CATV broadcasting station 1
Since the state cannot be detected on the one side, even if the program is unilaterally advanced and the reception of the pay broadcast is resumed, the program may have already ended. This state also occurs when a menu such as program information is selected during pay broadcasting. It also occurs due to an erroneous operation of the remote controller.

[0023]

As described above, since the conventional video-on-demand device is built around the CATV broadcasting station, it is suitable for the terminal device used in various environments or forms. In addition, there is a problem that it is difficult to provide a service and an unnecessary fee is charged to the user. Further, there is an inconvenience that a good service cannot be obtained for a user when a screen is hidden or switched due to an erroneous operation such as a remote control during pay broadcasting.

An object of the present invention is that the transmitting side monitors the receiving state of the terminal device by using the uplink, so that the transmitting side can smoothly operate the terminal device in accordance with the terminal device used in various environments or forms. It is to provide a video-on-demand device that can provide services.

[0025]

A video according to the present invention
The on-demand device includes a transmission unit, a plurality of terminal devices,
One end side is connected to the transmission unit, and the other end side is provided with a bidirectional transmission cable connected to a plurality of terminal devices, the transmission unit,
A first input terminal to which a plurality of television signals are input, a compression unit that compresses the plurality of television signals input to the first input terminal, and a plurality of the television signals compressed by the compression unit Even by the first redundant data adding means for adding a plurality of stages of variable-length redundant data, the multiplexing means for multiplexing a plurality of television signals to which the redundant data has been added by the first redundant data adding means, and the multiplexing means. Second redundant data adding means for adding redundant data with a fixed length to the multiplexed television signal in addition to the redundant data of the first redundant data adding means, and a transmitting section side for exchanging information with the terminal device. Control so as to vary the redundant data length of the first redundant data adding means based on the request signal included in the information received by the bidirectional communication means and the transmitting side bidirectional communication means. And the redundant data length variable control unit that,
The terminal device includes a second input terminal to which the television signal transmitted from the transmitter is input, and a television input to the second input terminal. First transmission error correction means for detecting and correcting a transmission error using redundant data added to a signal in a fixed length, and measuring means for measuring the number of times the transmission error cannot be corrected by the first transmission error correction means. A second transmission error correction means for correcting a transmission error that could not be corrected by using the variable length redundant data added to the output of the first transmission error correction means, and the number of times measured by the measurement means. It is provided with terminal-side bidirectional communication means for transmitting information to the transmission-side bidirectional communication means and for receiving information from the transmission-side bidirectional communication means.

Further, the video-on-demand apparatus according to the present invention is a bidirectional transmission cable in which a transmitting section, a plurality of terminal apparatuses, one end side is connected to the transmitting section, and the other end side is connected to a plurality of terminal apparatuses. And a first input terminal to which a plurality of television signals are input, a compression unit that compresses the plurality of television signals input to the first input terminal, and a compression unit that compresses the plurality of television signals. A plurality of television signals, at least redundant data are added in a plurality of stages to the redundant data adding means, and the redundant data adding means is provided with a multiplexing means for multiplexing the plurality of television signals to which the redundant data is added. The device uses a second input terminal to which the television signal transmitted from the transmitter is input, and redundant data added to the television signal input to the second input terminal. A transmission error correction unit that detects and corrects a transmission error and a measurement unit that measures the number of times the transmission error correction unit cannot correct the transmission error are provided, and the measurement result of the measurement unit is provided in either the transmission unit or the terminal device. Based on the above, a billing discount means for discounting billing is provided.

Further, the video-on-demand apparatus according to the present invention is a bidirectional transmission cable in which a transmitting section, a plurality of terminal apparatuses, one end side is connected to the transmitting section, and the other end side is connected to a plurality of terminal apparatuses. And a first transmitting unit for transmitting the ON / OFF state of the power source to the transmitting unit,
A second transmitting unit that periodically transmits a status corresponding to a reception state from the transmitting unit to the transmitting unit, wherein the transmitting unit includes a signal generating unit that transmits a television signal to a plurality of terminal devices; Storage means for storing the state of the terminal device, first recognition means for recognizing the power-on state of the plurality of terminal devices, and second recognition means for recognizing the regular status from the plurality of terminal devices. A determination means for determining the non-response time of the status, and a control means for controlling the transmission of the television signal based on the non-response time determined by the determination means are provided.

The video-on-demand apparatus according to the present invention is a bidirectional transmission cable in which a transmitting section, a plurality of terminal apparatuses, one end side is connected to the transmitting section, and the other end side is connected to a plurality of terminal apparatuses. The terminal device is provided with a detecting means for detecting the screen hiding of the pay broadcast program due to menu display or general channel viewing, and based on the detection result of the detecting means, an automatic stop instruction signal is sent to the transmitting part. And a returning means for returning from the suspended state.

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

In FIG. 1, reference numeral 41 is a CATV broadcasting station, and a plurality of terminal devices 711 to 711 are connected via a cable 61.
It is connected to 71n, and bidirectional communication is possible. The plurality of terminal devices 711 to 71n are connected to television receivers 721 to 72n, respectively. The upstream signal transmitted from any one of the plurality of terminal devices 711 to 71n is supplied to the demodulator 42 in the CATV broadcasting station 41.

Here, the terminal device 711 will be described as an example. The demodulator 42 demodulates the upstream signal from the terminal device 711 to convert it into a digital signal and supplies this digital signal to the error corrector 43. The error corrector 43 removes an error in transmission of the digital signal,
The digital signal is supplied to the upstream data collector 44.

The upstream data collector 44 is an error corrector 43.
Data regarding the terminal device 711 is collected and stored from the digital signal from the device, and operation management of the system is performed so as to be transmitted to the requesting terminal device 711. Then, the upstream data collector 44 stores the upstream status regarding the reception status of the terminal device 711 in the reception status memory 45. This reception state memory 45 is used by the microprocessor 4
It is managed by 6. In addition, the reception state memory 45
Supplies the upstream status regarding the reception status of the terminal device 711 to the charging management device 47. Billing management device 47
Is the terminal device 71 stored in the reception state memory 45.
The service response charge is calculated and managed based on the upstream status regarding the reception state of 1.

The billing management device 47 also includes a terminal device 71.
By giving a control signal based on the reception state of 1 to the compression controller 48 and the redundant data controller 49, for example, a plurality of compression encoding devices 53a1 in the video transmission device 531.
To 53an and first redundant data adders 53b1 to 53b
One of n is controlled. The same control is performed for the other plurality of video transmission devices 532 to 53m.

On the other hand, in the output of the upstream data collector 44, the no-response period of the terminal device 711 is measured by the no-response memory 50, and the measurement result is stored in the no-response memory 50. The terminal no-response memory 50 is
It is managed by the microprocessor 46. The measurement result stored in the terminal no-response memory 50 is supplied to the terminal controller 51. The terminal controller 51 performs status polling and control on the terminal device 711. That is, the control data and the message data from the terminal controller 51 are modulated to a specific frequency by the data modulator 52 and transmitted to the terminal device 711.

On the other hand, in the video transmission device 531 described above,
The television signals supplied to the input terminals 541 to 54n are supplied to the compression encoding devices 53a1 to 53an, respectively. Compression encoding devices 53a1 to 53an
Compresses the supplied television signal in order to effectively use the transmission band. Further, the compression encoding devices 53a1 to 53an selectively perform compression processing based on the control signal from the compression controller 48. Then, the plurality of television signals compressed by the compression encoding devices 53a1 to 53an are supplied to the first redundant data adders 53b1 to 53bn, respectively.

First redundant data adders 53b1 to 53bn
Adds a plurality of stages of variable length redundant data to the input television signal. In addition, the first redundant data adder 5
3b1 to 53bn selectively add redundant data of variable length based on a control signal from the redundant data controller 49. Then, the first redundant data adder 53b1
The television signals output from ~ 53bn are multiplexed in the same band by the multiplexer 53c. The multiplexer 53c also simultaneously multiplexes program information about television signals.

The television signal multiplexed by the multiplexer 53c is supplied to the second redundant data adder 53d. The second redundant data adder 53d adds redundant data with a fixed length to the multiplexed television signal.
Then, the television signal to which the redundant data is added by the second redundant data adder 53d is changed by the modulator 53e.
The redundant data is modulated, mapped to a specific frequency, and transmitted to the terminal devices 711 to 71n.

FIG. 2 shows details of the terminal device 711, for example.

That is, at the cable input terminal 71a,
The television signal S10 is supplied. Then, of the television signal S10, the data modulated and mapped by the modulator 53e is selected by the tuner 71b, and the signal S11 as a result of the selection is supplied to the data demodulator 71c. It should be noted that the tuner 71b is provided in the video transmission device 531.
Channels of television signals from ~ 53 m are selected. The data demodulator 71c performs, for example, QAM demodulation processing on the input signal S11, and the demodulated signal S12 obtained by this is supplied to the second FEC 71d.

The second FEC 71d detects a transmission error using the redundant data added to the fixed length of the demodulated signal S12, and outputs the signal S13 containing the corrected and multiplexed data to the demultiplexer 71e. Also, the second FEC7
The transmission error that cannot be corrected by 1d is counted by the second error counter 71f, and the result is sent to the microcomputer 71g and stored in the error memory 71n.

The demultiplexer 71e separates the multiplexed data from the supplied signal S13, acquires the necessary television signal S14, and outputs it to the first FEC 71h. In addition, the demultiplexer 71e selects the television signal supplied to the input terminals 541 to 54n, notifies the microcomputer 71g of the channel number, and causes the LED 71p to display the channel number.

The first FEC 71h detects and corrects a transmission error using the variable-length redundant data of the input television signal S14. Transmission errors that cannot be corrected by the first FEC 71h are counted by the first error counter 71i, and the result is counted by the microcomputer 71g.
And is stored in the error memory 71n. The error memory 71 stores the count results of the second error counter 71f and the first error counter 71i for each program. The first FEC 71h is controlled by the FEC controller 71j.

On the other hand, the microcomputer 71g has a second error counter 71f and a first error counter 71i.
The count result of the transmission error received from is supplied to the FEC controller 71j. That is, the first FEC 71h
Is controlled by the FEC controller 71j to correct a transmission error that could not be corrected by the second FEC 71d. Television signal S corrected by the first FEC 71h
15 is supplied to the compression decoder 71k.

The compression decoder 71k restores the video / audio of the supplied television signal S15 and restores the television signal S16 to the on-screen display device 71l.
Supply to one input terminal.

On the other hand, the microcomputer 71g
Is the remote control light receiving unit 71q that responds to the user's input operation.
Thus, the requested menu mode is operated to be displayed on the television screen. This menu mode is created based on the program information sent from the CATV broadcasting station 41, and includes a channel selection menu, a selected channel, and the like. Then, the responded menu mode made by the remote control light receiving unit 71q is the screen control circuit 7
Output to 1m. Also, microcomputer 71g
Picks up a message from the message memory 71r and outputs it to the screen control circuit 71m.

The screen control circuit 71m generates graphics or the like for displaying on the screen of the television receiver 721 based on the menu mode output from the microcomputer 71g, and outputs the signal S17 to the on-screen display device. It is supplied to the other input terminal of 71l.
The on-screen display device 71h uses the television signal S
16, the channel selection menu, the selected channel, the message, etc., which are the signals S17, are superimposed, and the television receiver 721
Output to Here, the switching from the broadcast program to the menu screen or the message screen is controlled by the screen control circuit 71m. Further, the on-screen display device 71h returns a signal such as an interrupt to the microcomputer 71g when the display screen completely overlaps the television signal.

Further, the microcomputer 71g includes
A power-on detector 71o and a time counter 71s are added. Among them, the power-on detector 71o detects that the microcomputer 71g is powered on and notifies the microcomputer 71g of the detection result. Further, the time counter 71s is a counter that can be arbitrarily started and cleared from the microcomputer 71g, and after measuring a predetermined time, the microcomputer 71g
Notify g of timeout.

Further, the signal output from the data modulator 52 and the program information for selection output from the upstream data collector 44 via the demodulator 42 are the data demodulator 7
It is received at 1t and supplied to the microcomputer 71g. Then, the user selects a desired program with a remote controller or the like based on the program information displayed on the screen of the television receiver 721. The request signal for the selected program is transmitted to the CATV broadcasting station 41 via the upstream data modulator 71u. The upstream data modulator 71u modulates the status data transmitted at the request of the terminal controller 51, a request signal or the like and transmits the modulated status data to the upstream data collector 44.

Then, the program information such as the channel number is transmitted from the CATV broadcasting station 41, and the terminal device 711 becomes
The program requested by the program information can be received. At this time, the program information multiplexed on the television signal by the multiplexer 53c is also used.

Further, the microcomputer 71g sends the count result of the transmission errors stored in the error memory 71n to the CATV broadcasting station 4 via the upstream data modulator 71u.
The data is transmitted to one upstream data collector 44.

FIG. 3 shows a packet system which is one system of multiplexing in a television signal. In FIG. 3, reference numeral 81 in the drawing denotes dataA, which is data of a video source compressed by the compression encoding device 53a1, for example. The data A81 is divided in a specific unit, and further, the HDR (header) is added by the first redundant data adder 53b1.
2 is added and redundant data C of variable length
C2 is added to form packet data 82. The packet data 82 is further divided into fixed lengths and HDR is added. At this time, HDR is also added to the HDR2 itself and packetized. Then, the data A divided into the fixed length is multiplexed with the data B by the multiplexer 53c to form the packet data 83.

Further, HDR2, dataA, data
The redundant data CC is added to B by the second redundant data adder 53d. In FIG. 3, dataA and data
Two types of data, B and B, are multiplexed, but actually d
Also in ataA, the video signal and the audio signal are separately packetized. Further, in the multiplexer 53c, it is general that the multiplexing information of the multiplexed data is simultaneously multiplexed.

Here, the redundant data is added in two stages. The redundant data CC has a fixed length and the error correction capability is set relatively low to reduce the amount of added information as much as possible. Also, the redundant data CC2 is variable for each of the terminal devices 711 to 71n, and the terminal devices 711 to 7n are variable.
The redundant data controller 49 controls the reception state of 1n. The redundant data length at this time is described in HDR2.

That is, according to the above means, the line can be effectively used by setting the error correction capability corresponding to the reception state of the terminal devices 711 to 71n. Further, even if the system is expanded or the line conditions are changed, optimization can be performed each time.

FIG. 4 shows the second FEC 71 of the terminal device 711.
7 shows the input / output characteristics of the data error rate in d and the first FEC 71h. In FIG. 4, reference numeral T in the figure
Indicates an error correctable byte. Here, regarding the relationship between the redundant data length and the error correctable byte length, in the case of the Reed-Solomon code, it is a well-known technique to set the redundant data length to twice the error correctable byte length.

Here, paying attention to the fact that the error correction capability is improved by increasing the redundant data length, the redundant data length is variably set for each of the terminal devices 711 to 71n.
Further, for example, the terminal device 711 having a very good reception state does not require the redundant data CC2. On the contrary, in the terminal device 712 having a very poor reception state, the redundant data C
The data length of C2 becomes longer, and the amount of information tends to increase. Therefore, there is no problem if the transmission information amount has a margin, but it is generally difficult to perform the same service in the same band.

In order to solve the above problem, the compression controller 48 controls, for example, the compression encoding device 53a2 to control the information amount as much as the information amount increases. For a method of controlling this information amount, for example, MP
It is clearly defined by the EG (Moving Picture Coding Experts Group).

Here, the reception status of the terminal devices 711 to 71n can be easily known by transmitting the count result of the first error counter 71i to the CATV broadcasting station 41 by the upstream data modulator 71u. At this time, sufficient error protection for upstream data is required. The method is to reduce the data rate and set the redundant data relatively long.

FIG. 5 shows the input / output characteristics of the data error rate in the first FEC 71h for the service charge discount. The output data of the first FEC 71h passes through the compression decoder 71k and the television receiver 72.
It is output to 1. The compression decoder 71k generally allows some input error, but if it exceeds a certain boundary, the screen of the television receiver 721 will be greatly disturbed. In particular, when decompressing digitally compressed data, if an error occurs, the screen will be disturbed in a block manner.

Here, for example, the terminal device 711 measures the number of times the output data error rate exceeds a certain boundary,
We will provide a mechanism for charging according to the number of times. In FIG. 5, the shaded area in the figure is the range to be discounted. Further, in FIG. 5, the allowable output data error rate is set to 10E-9 or less. Then, the number of crossing the boundary is measured by the first error counter 71i. In this measurement, the output of the first FEC 71h, which is the final stage of the two-stage FEC configuration, is counted.
Even if the FEC is one stage, it is enough that the number of errors immediately before decoding the compression can be counted.

Here, the counter value measured by the first error counter 71i is first determined by the microcomputer 71.
By g, it is stored in the error memory 71n for each program periodically or while the program is being watched. Then, at the end of the program, the upstream data modulator 71u causes the CATV broadcasting station 41
Is sent to the billing management device 47, and billing processing is performed.
The discount rate is determined, for example, based on the discount map shown in FIG. Further, when the billing process is completed, the microprocessor 46 clears the reception state of the corresponding program in the reception state memory 45. At the same time, the microprocessor 46 sends control data to the terminal device 711 by giving an instruction signal to the terminal controller 51. As a result, the counter value of the corresponding program in the error memory 71n of the terminal device 711 is cleared.

That is, according to the above means, even if the screen of the television receiver 721 is disturbed due to some reason that the line does not function normally while receiving the pay broadcast, it is possible to respond to it. Billing is possible. Therefore, the user will not be charged with the viewing fee illegally, and the program provider can appropriately respond to the request from the user.

FIG. 7 shows a second embodiment of the present invention.

In FIG. 7, the same parts as those in FIG. The difference from FIG. 2 is that a prepaid card 71v and a discount map 71w are added to the microcomputer 71g instead of the error memory 71n. It is also different in that the upstream data modulator 71u is deleted. That is, the microcomputer 71g charges by subtracting the amount of money of the prepaid card 71v purchased in advance. The counter value from the first error counter 71i is stored in the discount map 71w. The discount for billing is performed based on the discount map 71w. The discount map 71w is again shown in FIG.
It can be updated by downloading from the terminal controller 51 shown in FIG.

FIG. 8 shows the microprocessor 4 in the CATV broadcasting station 41 according to the third embodiment of the present invention.
6 is a flowchart for explaining the operation of No. 6. In this embodiment, when the power of the terminal devices 711 to 71n is cut off due to a power failure or the like while watching the video-on-demand service, the watching is continued and unnecessary charges are generated. It is a means to prevent.

That is, the microprocessor 46 executes the status reception process for each of the terminal devices 711 to 71n in step S80, and thereby in step S81.
Then, read the status from the upstream data collector 44,
The terminal address is recognized and it is confirmed whether or not the status for a certain terminal device 711 is received. Then, when the status is received (YES), the microprocessor 46, in step S82, the terminal device 71.
Check the power-on status of 1.

If the power-on status cannot be confirmed (NO), the microprocessor 46 confirms the viewing request status in step S83. Here, if the status of the viewing request is confirmed (YES),
The microprocessor 46 starts the distribution of the program to the terminal device 711 at step S87, and thereafter at step S81.
Then, the process is returned to the above process, and writing to the reception state memory 45 is executed. During distribution, the viewing flag is set to 1.

When the viewing request status cannot be confirmed (NO), the microprocessor 46 confirms the viewing stop status in step S84. here,
When the status of the viewing stop is confirmed (YES), the microprocessor 46 determines in step S88 that the terminal device 7
The distribution of the program to No. 11 is stopped, and thereafter the process returns to step S81 and the writing to the reception state memory 45 is executed. The watching flag at this time is 0. If the viewing stop status cannot be confirmed (NO), the microprocessor 46 confirms the temporary stop status in step S85. When the pause status is confirmed (YES), the microprocessor 46 interrupts the distribution of the program to the terminal device 711 and writes the interruption position in the reception state memory 45 in step S813.
At this time, the watching flag indicates 2. If the pause status cannot be confirmed (NO), the microprocessor 46 confirms the restart status in step S86.

If the restart status is confirmed (YES), the microprocessor 46 proceeds to step S8.
At 18, the automatic resumption process of the program distribution to the terminal device 711 is executed, and it is written in the reception state memory 45. If the restart status cannot be confirmed (NO), the microprocessor 46 returns to step S81 and executes the writing process to the reception state memory 45.

On the other hand, if the power-on status is recognized in step S82 (YES), the microprocessor 46 confirms in step S815 whether or not the viewing of the terminal device 711 is suspended. And
When the viewing is not suspended (NO), the microprocessor 46 returns to step S81 and writes in the reception state memory 45. If the viewing is suspended (YES), the microprocessor 46
In step S816, the no-response counter T0 that measures the time when there is no response from the terminal device 711 is driven for a certain period.

When it is determined that there is no response for a long time, that is, the response-free counter T0 is T0> Tmax (YES), the microprocessor 46 proceeds to step S8.
In step 19, distribution of the program to the terminal device 711 is stopped, and thereafter, the process returns to step S81, and the writing process to the reception state memory 45 is executed.

Further, the no-response counter T0 is T0> Tma.
When it is determined that the value is not x (NO), the microprocessor 46 determines in step S817 that there is no response counter T0.
Determines whether T0> Tmid. If it is determined that the no-response counter T0 is T0> Tmid (YES), the microprocessor 46 proceeds to step S
In 820, the continuation confirmation process is executed, and thereafter, step S81.
Is returned to. In addition, the no-response counter T0 is T0> Tmi
When it is determined that it is not d (NO), the microprocessor 46, in step S818, executes the automatic restart process of the program distribution to the terminal device 711, and thereafter, the reception state memory 4
Write processing to 5 is executed.

Next, in step S81, the terminal device 711.
If there is no status from (NO), the microprocessor 46 determines in step S89 whether the terminal device 711 is watching the program. When it is determined that the program is not being viewed (YES), the microprocessor 46
In step S814, the no-response counter T0 is set to clear, and then the process returns to step S81 to execute the writing process to the reception state memory 45. If it is determined that the program is being viewed (NO), the microprocessor 46
Executes the initialization processing of the no-response counter T0 in step S810, and in step S811, the terminal device 71
For 1, it is determined whether the viewing is stopped.

If it is determined that the system is in the stopped state (YES), the microprocessor 46 proceeds to step S8.
The value is returned to 1, and thereafter the writing process to the reception state memory 45 is executed. If it is determined that the stop state is not set (NO), the microprocessor 46 proceeds to step S81.
In step 2, when the no-response counter T0 has exceeded Tover, the process proceeds to step S813, and otherwise returns to step S81. In the above flowchart, Tmax and Tmid can be set in the reception state memory 45 for each of the terminal devices 711 to 71n, and the difference in response interval depending on the terminal type can be absorbed.

In addition, the reception state memory 45, as shown in FIG.
It manages the status for each n. This device management table is
It can be rewritten according to the reception status of the terminal devices 711 to 71n.

Next, FIG. 10 shows the detailed operation of step S820 shown in FIG. First, when started, the microprocessor 46 makes an inquiry to the terminal device 711 to send a continuation confirmation message and clear the no-response counter T1 in step S91.

Then, the microprocessor 46 confirms the status from the terminal device 711 in step S92. Here, when the status from the terminal device 711 is not confirmed (NO), the microprocessor 46 executes the initialization processing of the no-response counter T1 in step S93. Then, in step S94, if the no-response counter T1 has exceeded Tover2 (YES), the microprocessor 46 determines in step S95 the terminal device 7
The program distribution to 11 is automatically stopped, and if not (NO), the process returns to step S92.

Further, in step S92, the terminal device 711
If the status is confirmed (YES), the microprocessor 46 determines in step S96 that the terminal device 71
It is determined from 1 whether there is a request to stop viewing. When it is determined that there is a request to stop viewing (YE
S), the microprocessor 46 executes the process of step S95, and when it is determined that it is not the request to stop viewing (NO), the microprocessor 46 determines whether there is a request to restart from the terminal device 711 in step S97.

When there is a request for restart (YE
S), the microprocessor 46, in step S98,
When the program distribution restart processing is executed and there is no request for restart (N
O), the process returns to step S92.

In the above flow chart, when the microprocessor 46 makes a continuous inquiry to the terminal device 711, the screen of the television receiver 721 displays the screen shown in FIG.
A continuation message will be displayed, as shown in.

That is, according to the third embodiment, when the pay broadcast cannot be normally watched due to a power failure during the reception of the pay broadcast, the pay is automatically paid. Broadcast distribution can be stopped, and unnecessary charges can be prevented from being imposed. Also, when recovering from a power outage, if there is a momentary interruption, distribution will continue automatically.
If you return after some time, let me confirm the continuation,
For example, if you return after a long time
It is possible to control delivery by the return time.

FIG. 12 is a flow chart for explaining the operation of the microcomputer 71g in the terminal device 711 according to the fourth embodiment of the present invention.
That is, the user starts viewing, and step S131
Then, using a remote controller or the like not shown, the CATV broadcasting station 41
When a program viewing request is issued to the microcomputer 7,
The 1g continuously outputs the terminal status to the CATV broadcasting station 41 in step S132, thereby the terminal device 71
1 plays a role of informing the CATV broadcasting station 41 that the 1 is operating normally.

Next, in step S133, the microcomputer 71g executes a determination process for recognizing from the screen control circuit 71m that the screen currently being viewed is hidden by a predetermined ratio or more. In this determination process, the screen control circuit 71m is instructed to display the menu by pressing the terminal setting menu of the remote controller, and the screen control circuit 71m is displayed.
It is to recognize that the video-on-demand screen is hidden from m. When the screen is hidden (YES), the microcomputer 71g
In step S134, the viewing stop flag is stored as 1 and used for the stop request.

When it is not determined that the screen is hidden (NO), the microcomputer 71g executes a process of recognizing that the viewing of the general channel is selected by the user's remote control operation in step S135. . Here, when it is not recognized that the viewing of the general channel is selected (NO), the microcomputer 7
1 g is returned to the process of step S132. And
When it is recognized that the viewing of the general channel is selected (YES), the microcomputer 71g switches to the general channel and stores the state as the viewing stop flag 2 in step S136.

Then, the microcomputer 71g is
In step S137, the CATV broadcasting station 41 is instructed to pause, and T3 for recognizing the pause time is set to 0. After that, the microcomputer 71g executes the process of monitoring the temporarily stopped state in step S138, and returns to the process of step S132 again.

In the above flowchart, the microcomputer 71g makes a viewing request to the CATV broadcasting station 41 by request command data, as shown in FIG.

Next, FIG. 14 shows the detailed operation of step S138 shown in FIG. That is, the microcomputer 71g executes a process of determining that the menu is deleted from the screen control circuit 71m in step S141. If it is determined that the menu has not been erased (NO), the microcomputer 7
The 1g executes a process of determining that the general channel is returned to the video-on-demand channel in step S142.

If it is not determined that the system has returned (NO), the microcomputer 71g proceeds to step S
At 143, a counter T3 for recognizing the pause time
The initialization process is executed, and the time in the pause state is counted in step S144. If the counter T3 does not exceed Tover3 (NO), the microcomputer 71g returns to the process of step S141.

If the counter T3 has exceeded Tover3 (YES), the microcomputer 71g displays the restart inquiry menu on the screen of the television receiver 721 in step S145, and in step S146.
Prompt the user to decide whether to resume or cancel.

In steps S141 and S142, the menu is erased, the general channel is restored, and step S146 is performed.
In the case of the restart instruction by the inquiry (YES), the microcomputer 71g sends a viewing restart request to the CATV broadcasting station 41 in step S147, and then in step S14.
In step 9, the viewing stop flag is set to 0, and this process ends. If it is determined that the process is stopped in step S146 (NO), the microcomputer 71g determines in step S146.
In 149, the viewing stop is sent to the CATV broadcasting station 41, and the processing ends in step S148.

In the above flowchart, step S
Even if there is no 138, step S8 shown in FIG. 8 is performed again.
By the processing of S5 and S86, the CATV broadcasting station 41 makes an inquiry about continuation.

Also, in the situation where the video-on-demand screen cannot be seen due to the menu being displayed or the general channel being pressed by the above means,
If you return, you can continue viewing from the switched screen. Further, even if the screen remains switched due to a malfunction of the remote controller, the continuous charge will not occur.

[0094]

As described above in detail, according to the present invention, the transmission side monitors the reception state of the terminal device by using the uplink so that the transmission can be performed in accordance with the terminal device used in various environments or forms. It is possible to provide a video-on-demand device in which the side can provide smooth service to the terminal device.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of a video-on-demand device according to the present invention.

FIG. 2 is a block configuration diagram showing details of a terminal device in the embodiment.

FIG. 3 is a diagram shown for explaining one method of signal multiplexing in the same embodiment;

FIG. 4 is a diagram showing an input / output characteristic of a data error rate of FEC in the same embodiment.

FIG. 5 is a diagram for explaining a charge discount area according to the embodiment.

FIG. 6 is a diagram shown for explaining a discount rate of charges in the embodiment.

FIG. 7 is a block diagram showing a second embodiment of the present invention.

FIG. 8 is a flowchart shown to explain the operation of the microprocessor according to the third embodiment of the present invention.

FIG. 9 is a diagram for explaining a terminal management table stored in a reception state memory according to the same embodiment.

10 is a flowchart shown to explain the continuation confirmation processing operation in FIG. 8 in the same embodiment. FIG.

FIG. 11 is a diagram shown for explaining a continuous inquiry screen in the same embodiment;

FIG. 12 is a flowchart shown to explain the operation of the microcomputer of the terminal device in the third embodiment of the invention.

FIG. 13 is a diagram showing a terminal device to a CATV according to the embodiment.
The figure which shows the request command data format to a broadcasting station.

FIG. 14 is a flowchart shown for explaining a viewing-and-stopped monitoring processing operation in FIG. 12 in the same embodiment.

FIG. 15 is a block diagram showing a conventional video-on-demand device.

FIG. 16 is a block configuration diagram showing details of a terminal device in the conventional device.

[Explanation of symbols]

11 ... CATV broadcasting station, 12 ... Demodulator, 13 ... Error corrector, 14 ... Upstream data collector, 151-15m ... Video sending device, 15a1-15a2 ... Compression encoding device, 1
5b ... Multiplexing device, 15c ... Redundant data adder, 15d
... modulator, 16 ... terminal controller, 17 ... data modulator, 1
81-18n ... input terminal, 21 ... cable, 311-3
1n ... terminal device, 31a ... cable input terminal, 31b ...
Tuner, 31c ... Data demodulator, 31d ... FEC, 3
1e ... Demultiplexer, 31f ... Microcomputer, 31g ... Compression decoder, 31h ... On-screen display device, 31i ... Remote control light receiving part, 31j ... Screen control circuit, 31k ... LED, 31l ... Data demodulator, 31m ...
Upstream data modulator, 321-32n ... Television receiver, 41 ... CATV broadcasting station, 42 ... Demodulator, 43 ... Error corrector, 44 ... Upstream data collector, 45 ... Reception state memory, 46 ... Microprocessor, 47 ... Billing management device,
48 ... Compression controller, 49 ... Redundant data controller, 50 ... Terminal non-responsive memory, 51 ... Terminal controller, 52 ... Data modulator, 531-53m ... Video sending device, 53a1-53a
n ... compression encoding device, 53b1 to 53bn ... first redundant data adder, 53c ... multiplexing device, 53d ... second redundant data adder, 53e ... modulator, 541-54n ... input terminal, 61 ... cable, 711- 71n ... terminal device,
71a ... Cable input terminal, 71b ... Tuner, 71c
Data demodulator 71d Second FEC 71e Demultiplexer 71f Second error counter 71g Microcomputer 71h First FEC 71i First error counter 71j FEC controller 71k Compression Decoder, 71l ... On-screen display device, 71m
... screen control circuit, 71n ... error memory, 71o ... power-on detector, 71p ... LED, 71q ... remote control light receiving section, 71r ... message memory, 71s ... time counter, 71t ... data demodulator, 71u ... upstream data modulator, 71v ... prepaid card, 71w ... discount map,
721 to 72n ... Television receiver, 81 ... data
A, 82 ... Packet data.

Claims (4)

[Claims] 1. A transmission unit, a plurality of terminal devices, and a bidirectional transmission cable, one end side of which is connected to the transmission unit and the other end side of which is connected to the plurality of terminal devices. A first input terminal to which a plurality of television signals are input; a compression unit that compresses the plurality of television signals input to the first input terminal; and a plurality of the compression units that are compressed by the compression unit. First redundant data adding means for adding a plurality of stages of at least variable length redundant data to the television signal, and multiplexing for multiplexing the plurality of television signals to which the redundant data is added by the first redundant data adding means. Means and second redundant data adding means for adding redundant data with a fixed length to the television signal multiplexed by the multiplexing means, in addition to the redundant data of the first redundant data adding means. A first redundant data adding means based on a request signal included in the information received by the transmitting side bidirectional communication means and a transmitting side bidirectional communication means for exchanging information with the terminal device. The redundant data length variable control means for controlling the redundant data length of the television to be varied, and the compression variable means for varying the compression ratio in the compression means, and the terminal device includes the television set transmitted from the transmission section. A first input terminal for receiving a signal and a first input terminal for detecting and correcting a transmission error using redundant data added to the television signal input to the second input terminal in a fixed length. Transmission error correction means, measurement means for measuring the number of times the transmission error cannot be corrected by the first transmission error correction means, and the variable length added to the output of the first transmission error correction means. Second transmission error correction means for correcting the transmission error that could not be corrected by using the long data, and the number of times measured by the measuring means is sent to the transmitting section side two-way communication means and the transmission is performed. A video-on-demand device comprising: a terminal-side two-way communication means for taking in information from a department-side two-way communication means. 2. A transmission unit, a plurality of terminal devices, a bidirectional transmission cable having one end side connected to the transmission unit and the other end side connected to the plurality of terminal devices, and the transmission unit having a plurality of A first input terminal to which a television signal is input, a compression unit that compresses the plurality of television signals input to the first input terminal, and a plurality of the television signals compressed by the compression unit The redundant data adding means for adding at least a plurality of stages of redundant data, and a multiplexing means for multiplexing the plurality of television signals to which the redundant data is added by the redundant data adding means, and the terminal device, A second input terminal to which the television signal transmitted from the transmitter is input, and redundant data added to the television signal input to the second input terminal are used. To detect a transmission error,
A transmission error correction unit for correcting the transmission error, and a measurement unit for measuring the number of times the transmission error cannot be corrected by the transmission error correction unit, and the measurement result of the measurement unit is provided in either the transmission unit or the terminal device. A video-on-demand device, characterized in that the video-on-demand device comprises: 3. A transmission unit, a plurality of terminal devices, and a bidirectional transmission cable having one end side connected to the transmission unit and the other end side connected to the plurality of terminal devices. A first transmitting means for transmitting an on / off state of a power source to the transmitting section, and a second transmitting means for periodically transmitting a status corresponding to a receiving state from the transmitting section to the transmitting section. However, the transmission unit includes a signal generation unit that transmits a television signal to the plurality of terminal devices, a storage unit that stores the states of the plurality of terminal devices, and a power-on state of the plurality of terminal devices. A first recognizing unit for recognizing, a second recognizing unit for recognizing the status periodically from a plurality of the terminal devices, a deciding unit for deciding a non-response time of the status, and a deciding unit for deciding The above Based on the response time, video-on-demand system characterized by comprising by a control means for controlling the transmission of said television signal. 4. A transmission unit, a plurality of terminal devices, and a bidirectional transmission cable, one end side of which is connected to the transmission unit, and the other end side of which is connected to a plurality of the terminal devices. Detecting means for detecting the screen hiding of the pay broadcast program due to menu display or general channel viewing, and transmitting means for automatically transmitting a pause instruction signal to the transmitting section based on the detection result of the detecting means, A video-on-demand device comprising: a recovery unit for recovering from the paused state.