JPH0611141B2 - Cable television communication system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cable television communication system for distributing low-speed data communication between television devices which are receiving images in a cable television system for distributing video information by a cable. It is about.

(Prior Art) As a conventional method of this kind, I of Nippon Telegraph and Telephone Corporation is used.
There is an NS model system video distribution system.

FIG. 3 is a block diagram showing its configuration. 1, 1'is an image receiving device, 2, 2'is a video line, 3 is a video transmitting device, 4,
Reference numeral 4'denotes a low-speed data line, 5 a transmission control device, 6 a control line, and 7 a video transmission center.

In order for the image receiving device 1 to receive and reproduce the image signal from the image transmission center 7, the image receiving device 1 transmits a viewing request signal to the transmission control device 5 via the low-speed data line 4, and the transmission control device 5 controls. The video transmission device 3 is activated via the line 6. The low-speed data line 4 is used intermittently because it sends a signal only when first requesting a program to be watched, when changing a program, and when watching a number. Since the image receiving device 1'also performs reception under the same control, the low speed data line 4'is still used intermittently.

(Problems to be Solved by the Invention) For these reasons, the image receiving devices 1 and 1 ′ have low-speed data lines 4 and 4 ′, but the utilization efficiency of the low-speed data lines 4 and 4 ′ is low.

An object of the present invention is to enable communication between image receiving devices during an image receiving operation via a low-speed data line having a margin in terms of utilization efficiency.

(Means for Solving the Problems) The present invention adds a data transmission / reception device that can be connected to a plurality of image receiving devices to a cable television system using a video transmission center in which a plurality of image receiving devices are connected by a video line and a low-speed data line. It is characterized by doing.

(Operation) Under the control of the data transmitting / receiving device, low-speed data communication is performed between the image receiving devices via the low-speed data line.

(Embodiment) FIG. 1 is an embodiment of the present invention, in which 1 and 1'are image receiving devices, 2 and 2'are video lines, 3 is a video transmitting device, and 4,
4'is a low-speed data line, 5 is a transmission control device, 6 is a control line, 7 is a video transmission center, which is the same as in FIG. 3, 8 and 8'is a low-speed data signal branching / synthesizing device, 9 ，
Reference numeral 9'denotes a data communication line branched from the low-speed data lines 4, 4 ', 10 a data transmitter / receiver, and 11 a line connecting the transmission controller 5 and the data transmitter / receiver 9. In this case, the low-speed data signal branching / synthesizing devices 8 and 8'are transmission control devices such as a viewing request signal and a program selection signal among the information from the image receiving devices 1 and 1'on the low-speed data lines 4 and 4 '. 5, a function of extracting information other than the information to be notified to 5 and branching it to the data communication lines 9, 9 ',
This is a device having a function of synthesizing the information transmitted from the data transmitting / receiving device 10 via 9'and the channel number information of the program transmitted from the transmission control device 5 and transmitting the synthesized information to the image receiving devices 1 and 1 '.

The method of activating the video transmitting device 3 for the image receiving device 1 to receive and reproduce the video signal from the video transmitting center 7 is the same as that in FIG. 3, and the transmission control device 5 receives the image from the image receiving devices 1, 1 ', etc. It is possible to recognize which image receiving device the operating image receiving device is.

In order to transmit low-speed data information from the image receiving device 1 to the image receiving device 1'through the low speed data lines 4 and 4'while the image receiving devices 1 and 1'are both receiving images, the data is input by the image receiving device 1 and the destination is received. The address and message information are converted into low-speed data information, a flag code to be delivered to the data transmitting / receiving device 10 is added, and the low-speed data signal branch /
The data is sent to the synthesizing device 8, and the destination address and the message information are delivered to the data transmitting / receiving device 10 through the data communication line 9. The data transmitting / receiving device 10 reads the number of the image receiving device 1 ', which is the incoming address added to the beginning of the received low-speed data information, and transmits via the line 11 whether the image receiving device 1'is in the image receiving operation. Access the controller 5 to confirm. After confirming that the image receiving device 1 ′ is in the image receiving operation, the data transmitting / receiving device 10 internally connects the data communication line 9 to the data communication line 9 ′, and the low-speed data information received from the image receiving device 1 is data-transmitted. Send to line 9 '. The low-speed data information sent on the data communication line 9'is combined with the signal from the transmission control device 5 by the low-speed data signal branching / combining device 8'and sent to the image receiving device 1'through the low-speed data line 4 '. . However, when the image receiving device 1'is not in the image receiving operation, the low-speed data information addressed to the image receiving device 1'is discarded by the data transmitting / receiving device 10.

FIG. 2 shows another embodiment of the present invention. 1, 1'is an image receiving device, 2, 2'is a video line, 3 is a video transmitting device, 4,
4'is a low-speed data line, 5 is a transmission control device, 6 is a control line, 7 is a video transmission center, which is the same as in FIG. 3, 8 and 8'is a low-speed data signal branching / synthesizing device, 9 ，
9'is a data communication line, 10 is a data transmission / reception device, 11 is a line as in FIG. 2, 12 is a storage device, and 13 is a storage device.
Is a line connecting the data transmitting / receiving device 10 and the storage device 12.

A method of activating the video transmission device 3 for the image reception device 1 to receive and reproduce a video signal from the video transmission center 7, and the transmission control device 5 determines which one of the image reception devices 1 and 1 ′ is receiving the image. That is, the image receiving device 1 of the transmission source of the low-speed data information and the image receiving device 1 ′ of the transmission destination of the low speed data information
The method for transmitting and receiving low-speed data when both are receiving images is the same as in FIG. The example of the present invention is different from the example of the invention of FIG. 1 in that the image receiving device 1 ′ as a transmission destination is provided with means for sending low-speed data information from the image receiving device 1 to the image receiving device 1 ′ even when the image receiving device 1 ′ is not in the image receiving operation. . Hereinafter, a method of transmitting low-speed data information from the image receiving device 1 to the image receiving device 1'when the image receiving device 1 is in the image receiving operation and the image receiving device 1'is not in the image receiving operation will be described. A low-speed data signal branching / synthesizing device using the low-speed data line 4 by converting the destination address and message information input in the image receiving device 1 into low-speed data information and attaching a flag code to be delivered to the data transmitting / receiving device 10. Then, the destination address and the message information are delivered to the data transmitting / receiving device 10 through the data communication line 9. The data transmitting / receiving device 10 reads the number of the image receiving device 1 ', which is the incoming address added to the beginning of the received low-speed data information, and transmits via the line 11 whether the image receiving device 1'is in the image receiving operation. Access the controller 5 to confirm. After confirming that the image receiving device 1'is not in the image receiving operation, the data transmitting / receiving device 10 internally connects the data communication line 9 to the line 13 and transmits the low-speed data information received from the image receiving device 1 to the storage device 12 and temporarily stores it. Let After that, the data transmission / reception device accesses the transmission control device 5 after a certain period of time to access the image reception device 1 '.
Check whether or not is in the image receiving operation. After confirming that the image receiving device 1'is in the image receiving operation, the data transmitting / receiving device 10 reads out low-speed data information addressed to the image receiving device 1'from the storage device 12 via the line 13 to the data communication line 9'at low speed. The data information of is transmitted. The low speed data information is then sent to the image receiving device 1'through the low speed data signal branching / synthesizing device 8'and the low speed data line 4 '. As described above, in the example of the invention shown in FIG. 2, it is possible to perform communication of low-speed data information regardless of whether or not the image receiving device 1 ', which is the destination of the low-speed data information, is receiving an image. . Further, when all low-speed data information received by the data transmission / reception device 10 is temporarily stored in the storage device 12 and transmitted to the image receiving device 1 ′ of the called party, only the reception of the low-speed data information is first received. The signal is sent to the device 1'and then a low speed signal is received from the image receiving device 1'through the low speed data line 4 ', the low speed data signal branching / synthesizing device 8'and the data communication line 9'. A method of transmitting data information to the image receiving device 1'is also possible. In order to realize this method, in FIG. 3, a flag which should be delivered to the data transmitting / receiving apparatus 10 by converting the destination address inputted in the image receiving apparatus 1, that is, the number of the image receiving apparatus 1'and the message information into low speed data information. A code is attached and sent to the low-speed data signal branching / synthesizing device 8 using the low-speed data line 4, and the destination address and message information are delivered to the data transmitting / receiving device 10 through the data communication line 9. The data transmission / reception device 10 reads the incoming address added to the beginning of the low-speed data information composed of the received destination address and the message information, that is, the number of the image receiving device 1 ', and determines whether the image receiving device 1'is in the image receiving operation. It is confirmed by accessing the transmission control device 5 via the line 11. When it is confirmed that the image receiving device 1'is in the image receiving operation, the data transmitting / receiving device 10 determines the data communication line 9
Is internally connected to the line 13, and the low-speed data information received from the image receiving device 1 is transmitted to the storage device 12 to be temporarily stored. At the same time, the data transmission / reception device 10 internally generates a code string serving as notification information indicating that the message information addressed to the image receiving device 1'is received and stored, and the code string is sent to the data communication line 9'as low speed data information. Send out. The low-speed data information transmitted on the data communication line 9'is the low-speed data signal branch /
It is sent to the image receiving device 1'through the synthesizing device 8'and the low-speed data line 4 ', and the notification information is reproduced and displayed on the image receiving device 1'. When the callee who has read the display of the image receiving apparatus 1'want to receive the message information addressed to himself, the callee inputs a specific receiving number code to the image receiving apparatus 1 '. This specific receiving number code is a number that has already been registered in the data transmission / reception device 10, and the low-speed data line 4 ', low-speed data transmission line 10' can be transmitted in the same manner as the low-speed data information is delivered to the data transmission / reception device 10. Data transmission / reception device via signal branching / combining device 8'and data communication line 9 '
It will be sent to 10. The data transmission / reception device 10 determines whether the number code for reception received from the image receiving device 1 ′ matches the number registered in advance, and if they match, the data is temporarily stored in the storage device 12 via the line 13. The stored destination address and information message are searched, and only the information message addressed to the image receiving device 1'is retrieved and sent to the data communication line 9'as low speed data information. The low-speed data information sent on the data communication line 9'is transmitted to the image receiving device 1'through the low-speed data signal branching / synthesizing device 8'and the low-speed data line 4 ', and reproduced and displayed on the image receiving device 1'. It In this way, all the information messages between the image receiving devices 1 and 1'can be temporarily stored, and the receiving image receiving device 1'side can be first notified only of the arrival of the information and then received. It is also possible to perform confidential low-speed data communication.

(Effects of the Invention) As described above, according to the present invention, in a cable television system in which a video signal is sent from a video transmission center by sending a viewing request from the video receiving device, a plurality of image receiving devices that are receiving images are used. Since low-speed data information can be sent and received between the image receiving devices via the low-speed data line for the viewing request signal, the low-speed data line can be used efficiently and the image signal receiving device can be used only by the communication between the center ends. There is an advantage that it can also be used for end-to-end communication and that low-speed data information communication can be performed without call loss at the time of outgoing because a low-speed data line is prepared for each image receiving device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of the present invention, FIG. 2 is a diagram showing another embodiment of the present invention, and FIG. 3 is a configuration diagram of a conventional video distribution system. 1, 1 '... image receiving device, 2, 2' ... video line, 3 ... video transmission device, 4, 4 '... low speed data line, 5 ... transmission control device, 6 ... control line, 7 ... video transmission center, 8, 8 '... Low-speed data signal branching / synthesizing device, 9, 9' ... Data communication line, 10 ... Data transmitting / receiving device, 11 ... Line, 12 ... Storage device,
13 ... line.

Claims (1)

[Claims] 1. A video signal is transmitted from a video transmission center by sending a viewing request signal from the video receiver to the video transmission center connected to a plurality of video receivers by a video line and a low speed data line. In a cable television system that is sent to an image receiving device via a video line, the data transmitting / receiving device is connected to the image receiving device via a low-speed data line and is also connected to an image transmitting center, and the data transmitting / receiving device is a video transmitting center. When the low-speed data information to be delivered from the image receiving device which is receiving the video signal from the device is received via the low-speed data line, the image transmitting center is accessed to receive the low-speed data. When it is confirmed that the low-speed data information is transmitted to the image receiving device of the delivery destination via the low-speed data line, Cable television communication system.