JP2590273B2 - Superimposing device for character information - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention superimposes information related to a local viewer on a normal broadcast for each relay station whose area is an area by text information in a television broadcast. To a superimposing device.

2. Description of the Related Art In television broadcasting, for example, it is widely practiced to transmit textual information (hereinafter referred to as character information) by superimposing and displaying, for example, extraordinary news and weather information on a normal broadcast screen. ing. Such text information is superimposed on a baseband video signal using a superimposing device at the broadcasting station, and is broadcast from a transmitting station. Therefore, such text information broadcasting is received in an area where the main video signal of the broadcasting station is broadcast, for example, in a wide area such as the Kanto region or the Kinki region, and its contents are intended for a fairly wide audience. ing.

[Problems to be Solved by the Invention] On the other hand, among such character information, information relating only to viewers in a limited area such as a specific city or town, for example, a preliminary bulletin for mayoral election or regional weather information With regard to, if such information is superimposed on the video of the broadcast station and broadcast, distant viewers who are hardly related to the information can inevitably be shown the video. In such a case, it can be said that the character information is a disturbing image for the viewer. Therefore, particularly local information, such as information about construction outages in small areas, information about breakdowns or interruptions in relay stations, notices of public broadcasts and entertainments, and other information unrelated to viewers in other areas may cause inconvenience to those viewers. It could not be broadcast as textual information.

The present invention is particularly useful in a relay station, in a simple and low-cost manner, in which information related only to a viewer in a limited area of the above-mentioned relay station is automatically selected by a relay station device according to an instruction from a musician, and character information is obtained. It is an object of the present invention to provide a superimpose apparatus for superimposing on a normal broadcast video.

[Means for Solving the Problems] The character information superimposing apparatus for broadcasting a character signal to which an address signal is added for each television relay station according to the first aspect of the present invention is a television broadcasting system in which a broadcasting station performs music. Teletext production apparatus for adding an address signal designating at least one relay station distant from a broadcasting station to a teletext signal using a vertical blanking period of a video signal of the type described above. , An IF conversion circuit that generates an intermediate frequency signal, a VA separation circuit that separates the intermediate frequency signal into an audio intermediate frequency signal and a video intermediate frequency signal, and a television broadcast wave received at a relay station, and the above-mentioned address signal is accompanied. Teletext receiver for detecting a text signal, an address deco. Which generates an output when detecting the address of the relay station and a predetermined control signal in the address signal. A switching means driven by the output of the address decoder; a modulator for modulating a video intermediate frequency signal by the character signal when being driven by the switching means; a modulated video intermediate frequency signal and an audio intermediate frequency A mixing circuit that mixes the signals; and a transmission unit that converts the mixed intermediate frequency television signal to a predetermined frequency and transmits the signal.

Further, the superimposing apparatus for broadcasting a character signal to which an address signal is added for each television relay station according to the second aspect of the present invention uses a vertical blanking period of a video signal of a television broadcast at a music station of a broadcasting station. Teletext production apparatus for adding an address signal designating at least one relay station located at a position distant from a broadcast station to a teletext signal of a teletext to be transmitted, an IF receiving a television broadcast wave at the relay station and generating an intermediate frequency signal A conversion circuit, a VA separation circuit that separates the intermediate frequency signal into an audio intermediate frequency signal and a video intermediate frequency signal, a teletext receiver that receives a television broadcast wave at a relay station and detects a text signal with the address signal, An address decoder that generates an output when the address of its own relay station is detected in the address signal, and converts the character information produced by the relay station to a character signal A character signal input device, a first switch means that is selectively driven by the output of the address decoder or the output of the character signal input device, and a second switch for selecting either the character signal or the character signal output from the character signal input device. 2, a modulator for modulating a video intermediate frequency signal by a character signal selected by the switch means, a mixing circuit for mixing the modulated video intermediate frequency signal and audio intermediate frequency signal, and a mixed intermediate frequency television signal To a predetermined frequency for transmission.

[Operation] A broadcast station sends an image with an address during a vertical blanking period of a video signal, and character information generated by a character signal received and decoded by a relay station corresponding to the address is the image of the relay station. It is superimposed on the intermediate frequency signal of the signal and broadcast.

[Embodiment] FIGS. 1 and 2 are block diagrams showing a first embodiment of the present invention. FIG. 1 shows a configuration of broadcasting equipment in a broadcasting station. In the figure, a performance room 7 is provided with facilities for producing a broadcast program using video, audio, and the like.
A broadcast program source 1 is a program sent through a camera, a VTR, and a broadcast network in a studio, and its signal is switched and selected by a master switcher 2 and sent to a teletext inserter 3. The teletext inserter 3 receives a text signal produced by the teletext production device 4 via the teletext transmission device 5. The text signal includes an address indicating a relay station to receive the text information. Both of these signals are coded based on the teletext standard and broadcast in the teletext inserter 3 during the vertical blanking period of the video signal. Appended to the signal. According to the standard transmission method for Teletext Television (Ministry of Posts and Telecommunications),
For teletext, 14H, 15 of vertical blanking period in video signal
H, 16H, 21H and 277H, 278H, 279H, 284H horizontal scanning periods are allocated. In addition, timing control for controlling the timing of displaying the superimpose on the screen includes, for example, 19H and 2H in the vertical blanking period, which is an operation signal between broadcast stations.
A NETQ signal of 0H can also be used. Although the NETQ signal is a signal used for exchanging programs between broadcast stations, no problem occurs because the broadcast station and the relay station do not use the NETQ signal.

The television broadcast signal to which the address and the text information are added by the teletext inserter 3 is a studio for communicating between the performance place 7 and a transmission place 8 provided, for example, on the top of a mountain.
It is transmitted to a transmitting station 8 by a transmitter link transmitter 6 (hereinafter abbreviated as an STL transmitter). The frequency of the STL transmitter 6 is, for example, 3.5 GHz microwave. The transmitting station 8 receives the signal of the STL transmitter 6 and receives a signal of a predetermined carrier frequency.
For example, the signal is converted to 205.25 MHz, amplified in power, and transmitted from the transmitting antenna 9 as a broadcast wave.

FIG. 2 shows a block diagram of the relay station in this embodiment. The broadcast wave transmitted from the transmitting station 8 is received by the receiving antenna 11 and amplified by the amplifier 12 to a predetermined level. The output of the amplifier 12 is input to the IF conversion circuit 13 and the teletext receiver 21. In the IF conversion circuit 13, the frequency of the received radio wave is converted to a predetermined intermediate frequency, for example, 19.5 MHz (center frequency). The converted intermediate frequency is separated into an audio intermediate frequency signal and a video intermediate frequency signal by the VA separation circuit 14 of the VA equalizer 10, and is amplified by the audio IF amplification circuit 15 and the video IF amplification circuit 17, respectively. Switch means
Reference numeral 26 denotes switching means for selecting whether or not to superimpose a character signal on the video broadcasted from the relay station. Mixed with. The output of mixing circuit 16 is
Converted to a predetermined broadcast frequency by the UHF conversion circuit 18,
The power is amplified by the amplifier 19 and transmitted from the transmission antenna 20.

On the other hand, the character broadcast receiver 21 receives the character information and the address information transmitted during the vertical blanking period of the video signal, the address is decoded by the address decoder 23, and the character information is decoded by the character signal processing circuit 22. You. The address decoder 23 generates an output when the input address information is that of the own relay station,
26 is switched to contact 26B. As a result, the output of the video IF amplification circuit 17 is input to the modulator 24, where the video signal is modulated by the character signal output from the character signal processing circuit 22, and the two signals are mixed. The output of the modulator 24 is input to the filter 25, and a sideband newly generated by superposition of the character signal is removed. The output of the filter 25 is combined with the audio signal again in the mixing circuit 16 to become a television broadcast signal, and the UHS conversion circuit 1
After being converted to a predetermined frequency by 8, the signal is amplified and transmitted from the transmitting antenna 20. FIG. 3A shows the waveform of the video intermediate frequency signal. When this signal is modulated by the character signal shown in FIG. 3 (b), a signal having the waveform shown in FIG. 3 (c) is obtained, and this signal is applied to the mixing circuit 16 via the filter 25 and the switch means 26.

FIG. 4 is a circuit example of the modulator 24. The character signal output 30A of the character signal processing circuit 22 input to the terminal 30 is connected to the variable resistor 3
The level is adjusted by 1 and applied to the cathode of the PIN diode 37 via the parallel connection of the coil 33 and the resistor 34. The video intermediate frequency signal of the video IF amplification circuit 17 is applied to the cathode of the PIN diode 37 from the terminal 35 via the capacitor 36. A constant voltage is applied to the PIN diode 37 in the forward direction by a DC power supply 45 connected between the terminal 44 and the ground.

As is generally known, the impedance of a PIN diode changes in response to a forward bias current.
In the circuit shown in FIG. 4, the bias current of the PIN diode is reduced by the positive character information signal 30A applied to the terminal 30, and the impedance of the PIN diode 37 is increased. As a result, the video intermediate frequency signal input terminal 35 and the filter
The impedance between the output terminals 39 connected to 25 increases, and the level of the output video intermediate frequency signal decreases.
When the level of the video signal decreases, the received screen becomes white, but the value of the resistor 38 sets the white level of the video intermediate frequency signal to a predetermined value. The coil 41 and the capacitor 42 are for blocking high frequencies,
40 prevents direct current from flowing into the filter 25.

FIG. 5 is a block diagram of a relay station according to a second embodiment of the present invention. In this embodiment, a switch 27 and a character signal input device 28 are further added to the configuration of the first embodiment shown in FIG. In FIG.
The output terminal of the character signal processing circuit 22 is a contact 27 of the switch means 27.
The output terminal of the character signal input device 28 provided at the relay station is connected to the contact 27B. The control output terminal 28A of the character signal input device 28 is connected to the switch means 26 and 2
When the output of the character signal input device 28 is superimposed on the video, the movable element 27C of the switch means 27 is connected to the contact 2
7B, and the mover 26C of the switch means 26 is switched to the contact 26B. The input end of the modulator 24 is a mover 27C of the switch means 27.
And by switching of the switch means 27,
Either the output of the character signal processing circuit 22 or the output of the character signal input device 28 is selected as the input.

The character signal input device 28 is composed of, for example, a personal computer or the like, and can create local information for a viewer in the area of the relay station as needed and output it as a character signal. This character signal is input to the modulator 24 via the switch means 27 and is superimposed on the video signal as in the case of the first embodiment. The character signal input device 28 can receive character information from another communication line and output it as a character signal.

[Effects of the Invention] According to the present invention, information related to a viewer in an area of a specific relay station is converted into a teletext signal, an address signal of the relay station is added, and the information is transmitted or produced at the relay station. Since the relay station receives the broadcast signal and superimposes the character signal on the video signal based on the address signal, the relay station can provide local information only to viewers who need it.

In addition, since the video signal is generated by modulating the video intermediate frequency signal with the text signal in the superimposition of the text, the video to be broadcast is not degraded. Less cost.

[Brief description of the drawings]

FIG. 1 is a block diagram of a broadcasting device according to an embodiment of the present invention, FIG. 2 is a block diagram of a relay station according to the first embodiment of the present invention, FIG. 3 (a), FIG. 3 (b) and FIG. FIG. 3 (c) is a waveform diagram showing the modulation of the video intermediate frequency signal in the relay station, FIG. 4 is a modulation circuit, and FIG. 5 is a block diagram of the relay station in the second embodiment.

Claims (2)

(57) [Claims] An address signal for designating at least one relay station located at a position distant from a broadcast station in a character signal of a teletext using a vertical blanking interval of a video signal of a television broadcast at a music station of the broadcast station. , A teletext production device that produces a broadcast signal with an additional signal, an IF conversion circuit that receives television broadcast waves at a relay station, and generates an intermediate frequency signal, and a VA that separates the intermediate frequency signal into an audio intermediate frequency signal and a video intermediate frequency signal A separation circuit, a teletext receiver for receiving a television broadcast wave at a relay station and detecting a text signal to which the address signal included in the broadcast signal is added, a self-relay included in the address signal An address decoder for generating a switching output upon detecting a station address and a predetermined control signal, and a switching means switched by the switching output of the address decoder A modulator for modulating a video intermediate frequency signal by the character signal when switched by the switch means, a mixing circuit for mixing the modulated video intermediate frequency signal and audio intermediate frequency signal, and a mixed intermediate frequency television A transmitting means for converting a signal to a predetermined frequency and transmitting the converted signal, wherein a character information superimposing apparatus for broadcasting a character signal to which an address signal is added for each television relay station. 2. An address signal designating a character signal of a teletext using a vertical blanking period of a video signal of a television broadcast at a performance station of the broadcast station to designate at least one relay station located at a position distant from the broadcast station. , A teletext production device that produces a broadcast signal with an additional signal, an IF conversion circuit that receives television broadcast waves at a relay station, and generates an intermediate frequency signal, and a VA that separates the intermediate frequency signal into an audio intermediate frequency signal and a video intermediate frequency signal A separation circuit, a teletext receiver that receives a television broadcast wave at a relay station and detects a text signal with the address signal included in the broadcast signal, and a self-relay station included in the address signal. An address decoder that generates a switching output when an address is detected, a character signal input device that converts character information produced in a relay station into a character signal, and an address. A first switch means switched by the switching output of the decoder or an output of the character signal input device; a second switch means for selecting either the character signal or a character signal output from the character signal input device; A modulator for modulating the video intermediate frequency signal by the character signal selected by the switch means, a mixing circuit for mixing the modulated video intermediate frequency signal and the audio intermediate frequency signal, and the mixed intermediate frequency television signal to a predetermined frequency Transmitting means for converting and transmitting, and a character information superimposing apparatus for broadcasting a character signal to which an address signal is added for each television relay station.