JPH04227196A - Catv system - Google Patents

Abstract

PURPOSE:To perform the confirmation of a television signal transmitted to a terminal side with one coaxial cable comprising a communication line at a center device side. CONSTITUTION:A terminal video image confirming part 13 equipped with a terminal controller 12 which transmits the television signal received by an antenna 1 to the center device 4 side via the communication line 3 and transmits channel information and a control signal to the terminal side, and a monitor receiver 15 which displays the video signal sent from the terminal side is provided. A video image monitoring device 7 which sends out the television signal on a prescribed channel to the center device 4 side is provided at the terminal side. The video image monitoring device 7 performs channel selection and the on/off control of a power source based on the channel information and a control signal sent from the terminal controller 12, and sends out the signal to the terminal video image confirming part 13 by using a channel of prescribed frequency band, and displays a channel image sent from the video image monitoring device on a receiver 19 for up signal at the terminal video image confirming part 13.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CATV system having a function of checking a television image of a terminal.

0002

2. Description of the Related Art Conventionally, as a CATV system having a function of checking television images of this type of terminal, there is one disclosed, for example, in Japanese Patent Publication No. 60-53954. In this CATV system, a separate auxiliary transmission line is drawn out from the center equipment side in order to check the image on the terminal side.
The signal sent from the center device was fed back through the auxiliary transmission line, and the image was checked on a monitor receiver installed on the center device side.

0003

[Problems to be Solved by the Invention] However, in the conventional CATV system described above, an auxiliary transmission line is separately drawn out from the center equipment side in order to check the image on the terminal side, but the main line for transmitting signals As the length of the auxiliary transmission line increases, the length of the auxiliary transmission line increases accordingly, which poses a problem in that the cost of installing the auxiliary transmission line increases.

[0004] The present invention solves the above-mentioned conventional problems, and enables the center equipment to check the television signal transmitted to the terminal side using a single coaxial cable constituting the communication line, thereby eliminating the need to lay an auxiliary transmission line. The purpose is to provide a CATV system with

[0005]

[Means for Solving the Problems] The present invention, which achieves the above objects and solves the conventional problems, transmits a television signal received by an antenna via a communication line and distributes it to each terminal.
In an ATV system, a terminal image confirmation unit is provided on the center device side, which includes a terminal control device that transmits channel information and control signals to the terminal side, and a monitor receiver that displays the TV signal sent from the terminal side. A television image monitoring device is provided that sends the television signal of the channel to the center device, and the television image monitoring device selects a channel based on the channel information and control signal sent from the terminal control device, and transmits the signal at a predetermined frequency. The channel information is transmitted to the terminal image checking unit using a channel in the band, and the terminal image checking unit displays the channel information sent from the television image monitoring device on the monitor receiver.

[0006] According to a second aspect of the invention, the center device is provided with a monitor receiver for monitoring the television signal received by the antenna, and the monitor receiver is arranged close to the monitor receiver of the terminal image confirmation section. It is characterized by

[0007]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a CATV according to an embodiment of the present invention.
FIG. 1 is a block diagram showing the configuration of the system.

[0008] This CATV system includes an antenna 1 that receives TV radio waves, a head end 2 that rearranges the received TV signals into designated TV channels and outputs them with the same level, and transmits the TV signals output from the head end 2. a communication line 3 for checking images of television signals, a center device 4 for checking images of television signals, and various amplifiers 5 and 6 provided on the communication line 3.
, an image monitoring device 7 provided on the terminal side. The television signal received by the antenna 1 is transmitted via the communication line 3, amplified by amplifiers 5 and 6 along the way, and sent to each branched terminal. At the terminal, for example, the transmitted television signal is demodulated and displayed on a television receiver.

The center device 4 is composed of a center image confirmation section 11, a terminal control device 12, and a terminal television image confirmation section 13. The center image confirmation unit 11
It monitors the television signal sent from the antenna 1 via the head end 2, and consists of a set converter 14 and a monitor receiver 15. The set converter 14 is provided between the head end 2 and the monitor receiver 15, has a function of receiving all the television channels transmitted by the CATV system, and includes a remote control receiving section 41 and a channel switch 42. That is, CAT
In the V system, approximately 60 channels of signals are used, and the set converter 14 functions as a tuner for these channels. This set converter 14
performs AV output on a predetermined channel (for example, VHF 2 channel) to the monitor receiver 15 by remote control using the remote controller 30. Then, the state of the television signal is confirmed by visually observing the image on the monitor receiver 15. In addition, the remote controller 30
By turning the power ON/OFF, the set converter 14 and the monitor receiver 15 can be turned ON/OFF.

The terminal control device 12 is composed of a control section 16 and a modulator 17. The control section 16 includes a remote control receiving section 61, a terminal control signal generating section 62, and a channel switch 63, and the control section 16 includes a remote control receiving section 61, a terminal control signal generating section 62, and a channel switch 63.
0 and outputs a digital signal of the channel signal to the modulator 17. Further, the modulator 17 converts the digital signal from the control unit 16 into an analog signal, and transmits it to the television image monitoring device 7 on the terminal side via the communication line 3.

The terminal television image confirmation section 13 is composed of an upstream signal demodulator 18 and an upstream signal receiver 19. The uplink signal demodulator 18 is connected to the terminal-side television image monitoring device 7.
The uplink signal receiver 19 displays the TV signal. This uplink signal receiver 19 is installed close to the monitor receiver 15 of the center image confirmation section 11 so that images can be compared.

The television image monitoring device 7 is connected to the terminal end and is composed of a demodulator 21, a set converter 22, and an upstream signal modulator 23. The demodulator 21 is the modulator 1 of the terminal control device 12.
Channel signal sent from 7 or power ON/O
An analog signal consisting of a control signal for an FF or the like is converted into a digital signal and output to the set converter 22. The set converter 22 selects a channel based on the signal from the terminal control device 12 and outputs a television signal. The upstream signal modulator 23 modulates the television signal selected by the set converter 22 using a predetermined channel in the upstream signal frequency band of 10 to 50 MHz, and sends it back to the center device 4 side.

Next, the operation of this embodiment configured as described above will be explained. By specifying a channel with the remote controller 30, the control unit 16 of the terminal control device 12 of the center device 4 outputs channel information as a digital signal. This digital signal is sent to the modulator 17
The signal is converted into an analog signal and sent out via the communication line 3. The transmitted signal is received by the demodulator 21 of the television image monitoring device 7 on the terminal side, converted into a digital signal, and transmitted to the set converter 22. The set converter 22 starts a channel switching operation upon receiving the input signal from the terminal control device 12.

[0014] Then, the set converter 22 selects a channel according to the input channel information, and
Output a signal. Further, the AV signal output from the set converter 22 is sent to the upstream signal modulator 23 for 10 to 50M.
The signal is modulated using a predetermined channel in the Hz frequency band and sent to the center device 4 side. The transmitted AV signal is received and demodulated by the upstream signal demodulator 18 of the terminal television image confirmation unit 13 of the center device 4, and displayed on the upstream signal receiver 19. At that time, remote controller 3
0, the image of the corresponding channel is displayed on the monitor receiver 15 of the center image confirmation section 11, and by comparing the screens of the upstream signal receiver 19 and the monitor receiver 15, the TV signal can be detected. You can check whether the data is being transmitted normally to the terminal side.

If the monitor receiver 15 and the upstream signal receiver 19 are configured as AV two-system input receivers, image confirmation can be performed with one receiver by switching the AV signal input.

[0016]

[Effects of the Invention] As explained above, according to the CATV system of the present invention, it is possible to check the television signal transmitted to the terminal side via the communication line through which the signal is transmitted. This has the effect of eliminating the need to lay an auxiliary transmission line. In addition, since only one uplink channel is required, the band usage efficiency is also good.

According to the second aspect of the invention, the center device is provided with a monitor receiver for monitoring the television signal received by the antenna, and the monitor receiver is placed close to the monitor receiver of the terminal image confirmation section. With this arrangement, images can be accurately confirmed by comparing the screens of both receivers.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a CATV system according to an embodiment of the present invention.

[Explanation of symbols]

1 Antenna 2 Head end 3 Communication line 4 Center device 7 Image monitoring device 11 Center image confirmation department 12 Terminal control device 13 Terminal TV image confirmation section 14 Set converter 15 Monitor receiver 16 Control section 17 Modulator 18 Upstream signal demodulator 19 Upstream signal receiver 21 Demodulator 22 Set converter 23 Upstream signal modulator 30 Remote controller

Claims (2)

[Claims] Claim 1: In a CATV system in which a television signal received by an antenna is transmitted via a communication line and distributed to each terminal, the center device includes a terminal control device that transmits channel information and control signals to the terminals. A terminal image checking unit is provided with a monitor receiver that displays a television signal sent from the terminal side, a television image monitoring device is provided on the terminal side for transmitting a television signal of a predetermined channel to a center device side, and the television image monitoring device is , selects a channel based on the channel information and control signal sent from the terminal control device, and sends the signal to the terminal image confirmation unit using a channel in a predetermined frequency band, and the terminal image confirmation unit A CATV system characterized by displaying channel information sent from a television image monitoring device on a receiver. 2. The center device is provided with a monitor receiver for monitoring television signals received by an antenna, and the monitor receiver is arranged close to the monitor receiver of the terminal image confirmation section. A CATV system according to claim 1.