JPH05284484A - Television modulator - Google Patents

Abstract

PURPOSE:To provide a television modulator being able to display a time without any broadcast or various messages of a next broadcast time on its screen even at a time when no broadcast is executed. CONSTITUTION:The television modulator installed to a center equipment side of the CATV system, applying high frequency modulation to a video signal inputted from an input section and outputting a modulated signal to a CATV transmission line is provided with a video signal detection circuit 12 detecting the presence of the input of the video signal and sending a resulting detection signal, a video signal transmission means 13 sending a predetermined pattern or the like as a video signal, a changeover means 11 connecting selectively an output section to an input section or the video signal transmission means 13, and a central processing unit 9 controlling the changeover means 11 and the video signal transmission means 13 based on the detection signal from the video signal detection circuit 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television modulator used in a CATV system, and in particular, displays various indications such as a notice to the viewer and the next broadcasting time on the screen even when the broadcasting is not in progress. A television modulator that can be used.

[0002]

2. Description of the Related Art A television modulator is used for commercial television broadcasting such as satellite broadcasting or VT on the center side as shown in FIG.
Various local programs such as movies and documents by R, laser discs, etc. are placed on a CATV transmission line and delivered on several tens of channels, so that a video signal is high-frequency modulated and sent to the CATV transmission line. That is, as shown in FIG. 3, for example, satellite broadcasting has two channels,
In VTR broadcasting, signals from various sources such as 13 channels are high-frequency modulated and sent to the CATV terminal side. Also, in each terminal, the signal can be demodulated by the CATV converter to watch various broadcasts.

Here, the conventional television modulator 1 of this type is
As shown in FIG. 4, an input unit 5 for inputting a video signal, a high frequency modulation circuit 4 for modulating the video signal input from the input unit 5 at a high frequency (hereinafter abbreviated as RF modulation circuit), and outputting a modulated video signal. An output unit 2 and a channel display unit 7 for displaying the channel currently transmitting the program,
An output channel switch 8 for switching the transmission channel, and a central processing unit 9 (hereinafter CP) for controlling these
(Abbreviated as U). On the side of the center device, the VTR 6 is connected to the input section 5 of the television modulator 1 by connecting it to a VTR 6 or a laser disk (not shown).
CAT by modulating the high frequency of the video signal sent from
The output section 2 outputs to the V transmission line 3 through a predetermined channel. As a result, various programs can be transmitted from the various sources to the CATV transmission line 3, and the viewer can freely select programs over various channels transmitted from the CATV center device side. You can enjoy

[0004]

However, in the television modulator as described above, when the video signal is not transmitted during the rewinding of the VTR on the side of the center device, the channel of the channel concerned is not used. There was a problem that only the carrier wave was output to the terminal side and the noise screen was displayed on the TV. Such a situation not only makes the viewer uncomfortable, but the viewer who just turned on the TV at that time seems to start sending again after a few minutes even if it is the VTR rewinding time. Even in this case, there is a risk that the user may recognize that the channel is not currently being sent. Further, particularly in the case of performing pay broadcasting, there is a problem that in such a case, a situation such as a complaint from a viewer or refusal to pay the fee may occur. The present invention solves the above problems,
It is an object of the present invention to provide a television modulator capable of displaying various indications such as the effect and the next broadcast time on the screen even when the VTR rewinding is not broadcast.

[0005]

In order to solve the above-mentioned problems, the present invention is provided on the center device side of a CATV system, an input section for inputting a video signal, and a high-frequency modulation circuit for high-frequency modulating the video signal. And a television modulator having an output section for outputting a signal modulated by the high frequency modulation circuit, a video signal transmitting means for transmitting a predetermined pattern as a video signal, the output section and the input section or the video signal transmitting means. And a central processing unit for controlling the switching means. According to the second aspect of the invention, a video signal detection circuit is provided between the input section and the output section to detect the presence or absence of the input of the video signal, and sends the detection signal to the CPU, and the switching means is controlled by the detection signal. It is configured to do. Further, the video signal sending means is a pattern generator circuit in the invention of claim 3, an on-screen display circuit in the invention of claim 4, and an external input signal circuit in the invention of claim 5. The configuration is as follows.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. The configuration of a television modulator according to an embodiment of the present invention is shown in FIG. In FIG. 1, 1 is the television modulator. As shown in FIG. 1, the television modulator 1 has an input unit 5,
In addition to the configuration of the conventional TV modulator including the output unit 2, the RF modulation circuit 4, the channel display unit 7, the output channel switch 8, and the CPU 9, the video changeover switch 11, the video signal detection circuit 12, the pattern generator 13, and the time management unit. 14, a clock 15, and an external input unit 16. A VTR 6 and a laser disk (not shown) are connected to the input section 5, and a CATV transmission line 3 is connected to the output terminal 6.

Here, the RF modulation circuit 4 performs high frequency modulation on the video signal as described above, and is connected to the output unit 2. The pattern generator 13 sends out a predetermined pattern or the like as a video signal, and operates according to a command from the CPU 9. In this case, the pattern may be predetermined or may be appropriately input and may be arbitrarily changed. Then, the time management unit 14 and the clock 15 for managing the transmission time and the like are provided.
Is provided. Further, in this embodiment, the external input section 16 is provided, and an arbitrary pattern can be directly input from the outside.

On the other hand, in front of the RF modulator circuit 4, a video selector switch 11 is provided as a switching means, and the connection to the output section 2 side is made to the input section 5 side and the pattern generator 13 and the external input section 16 side. Selectively switch.
It should be noted that this switching is performed by a command from the CPU 9. Further, a video signal detection circuit 12 is provided between the video changeover switch 11 and the input unit 5 to determine whether or not a video signal is included in the signal currently flowing, that is, whether or not a video image is currently flowing. Has been. The video detection circuit 12 notifies the CPU 9 of the presence or absence of a video signal by sending a detection symbol. As a result, the CPU
Reference numeral 9 issues a video signal transmission command to the pattern generator 13. In this embodiment as well, like the conventional television modulator, an output channel switch 8 for selecting an output channel and a channel display portion 7 showing the currently output channel are provided.

Next, the operation of the embodiment configured as described above will be described. Usually in a CATV system,
In addition to so-called commercial television broadcasting such as VHF, UHF, and satellite broadcasting, local programs such as movies and area information, which are unique to each station, are also transmitted. On the side of the center device, a satellite broadcast receiver, a VTR, a laser disk, etc. are connected to the television modulator 1 and an appropriate channel is selected by operating the output channel switch 8 to transmit various programs. ing.

Now, let us consider a channel on which a movie is being played by video reproduction from the center device side of the CATV system. Normally, during the time period when this channel is broadcasting, the video signal is high-frequency modulated by the television modulator 1 and sent out to the terminal side through the CATV transmission line 3 together with the carrier wave. Normally, while the video is being sent, the video signal detection circuit 12 detects the video signal and notifies the CPU 9 that the video signal is currently being detected, that is, the video is being broadcast. .. In response to this, the CPU 9 receives the video changeover switch 1
1 is instructed to connect the RF modulation circuit 4 and the input unit 5 side. The video signal thus modulated is sent to the CATV transmission line 3 via the output unit 2.

On the other hand, when the video tape is finished and the temporary broadcast is interrupted to rewind the tape, the following operation is performed. That is, at this time, the video signal detection circuit 12 detects that the input signal does not include the video signal and notifies the CPU 9 of that. In response to this, the CPU 9 issues a command to the video selector switch 11 to switch the video selector switch 11 to the pattern generator 13 side. Also,
At the same time, the pattern generator 13 is caused to send out a pattern or the like stored in advance as a video signal.
As a result, a video signal including this pattern is output from the output unit 2 to the CATV transmission line 3 and the pattern is displayed on the television on the terminal side.

In this case, as shown in FIG. 2A, the pattern generator 13 displays a fixed phrase such as "currently rewinding the video tape. Please wait for a while" and the next broadcast time. Then, the message pattern as shown in FIG. The content of this pattern can be changed appropriately via the CPU 9. Also, an appropriate message pattern can be directly input from the external input unit 16. This allows the viewer to know that broadcasting is currently suspended.

As described above, the CPU 9 also issues a command to display the pattern as shown in FIG. 2 to the time management unit 14 and the clock 15, so that the time when the pattern flows, the current time, the next broadcast time, etc. To manage. That is, if the time until the video tape is rewound and re-started is known in advance, only that time, and the CP
When U9 specifies the next broadcast time, the pattern is controlled to flow until that time. When the broadcast on the day has ended, the video signal detection circuit 12 notifies the CPU 9 that no video signal is detected, as described above. In response to this, the CPU 9 causes the pattern generator 13 to send the pattern at the end of the broadcast from the pattern, taking into consideration the current time and the like. In this case,
The display as shown in (c) is made to inform the viewer that there is no broadcast today and the next broadcast time.

Next, when the delivery is started again, the following operation is performed. That is, when the video signal flows again, the video signal detection circuit 12 detects it and notifies the CPU 9 to that effect. Accordingly, the CPU 9 stops the video signal transmission of the pattern generator 13 and connects the video changeover switch 11 to the input section 5 again. As a result, the video signal is sent to the CATV transmission line 3.

As described above, in the present embodiment, the message or the like is sent by the pattern generator 13, but the sending means is not limited to this, and the on-screen display circuit is used to display it as a telop on the television screen. Also good. Also in this case, the circuit is the CPU 9
Needless to say, the display contents can be appropriately changed by being controlled by.

[0016]

As described above, in the television modulator according to the present invention, the video signal transmitting means and the video which is selectively switched between the means and the input section for inputting the video signal and is connected to the output section. By providing the change-over switch, there is an effect that a pattern including a predetermined message flows without the noise screen flowing as it is even during the time when the video tape is not being fed and released. Therefore, a noise screen that is unpleasant to the viewer is not shown, and even if the viewer starts watching TV when the broadcast is interrupted, the broadcast is not currently being performed and the next time the broadcast starts. You can immediately see what. Furthermore, C
The broadcasting side of ATV is also free from the troubles of complaints and refusal to pay. Further, in the present invention, the video signal detection circuit is provided to determine whether or not the video signal is included in the television modulator. There is also an effect that a predetermined pattern is all automatically transmitted without having to perform the work of transmitting the pattern one by one.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a television modulator according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a pattern transmitted from the television modulator according to the present invention when transmission / reception is interrupted.

FIG. 3 is a system configuration diagram showing a usage mode of a television modulator in a CATV system.

FIG. 4 is a block diagram of a conventional television modulator.

[Explanation of symbols]

 1 TV Modulator 9 Central Processing Unit (CPU) 11 Video Changeover Switch (Switching Means) 12 Video Signal Detection Circuit 13 Pattern Generator (Video Signal Sending Means) 16 External Input Section (External Input Signal Circuit)

Claims (5)

[Claims] 1. A CATV system center device, an input section for inputting a video signal, a high frequency modulating circuit for high frequency modulating the video signal, and an output for outputting a signal modulated by the high frequency modulating circuit. In a television modulator including a section, a video signal sending means for sending a predetermined pattern as a video signal, a switching means for selectively connecting the output section and the input section or the video signal sending means, the switching means, and A television modulator comprising a central processing unit for controlling a video signal transmitting means. 2. A video signal detection circuit for detecting the presence or absence of a video signal input between the input section and the output section and sending the detection signal to the central processing unit, and controlling the switching means by the detection signal. The television modulator according to claim 1, wherein: 3. The television modulator according to claim 1, wherein the video signal transmitting means is a pattern generator circuit. 4. The video signal transmitting means is an on-screen display circuit.
TV modulator according to. 5. The television modulator according to claim 1, wherein the video signal transmitting means is an external input signal circuit.