JPS61125284A - Radio transmitting-receiving system of television signal - Google Patents

Abstract

PURPOSE:To attain remote control of a VTR by transmitting intermittently a television signal from a sending side and by processing this signal at receiving side and using it as a start/stop signal of the VTR. CONSTITUTION:Power source +B supplies power to a transmitting circuit while a contact S is pressed down by an external operation. In the state, a RF modulation circuit 1 receives a video signal input and audio signal input and modulates each carrier with these input signals. The VTR receives the RF signal with an antenna 4 sent from the transmitting circuit, generates a d.c. signal and activates a relay to make it a VTR start signal. Therefore, the start/stop signal at VTR side keeps start state as long as the contact S is pressed down, and the video signals and audio signals sent from the transmitting circuit are recorded consecutively.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention wirelessly transmits a video signal and an audio signal (television signal) on the transmitting side, and separates the television signal and converts it into a video signal on the receiving side. The present invention also relates to a wireless transmission/reception system for television signals that processes video signals so that they can be used as start/stop signals for VTRs in addition to being used as audio signals.

(Prior Art) Conventionally, when the output of a video camera or VTR is visualized on a television receiver, the video camera or the like and the television receiver are usually connected by a cable. For example, if the output of a VTR is to be visualized on a television receiver, a cable is used to connect the RF output terminal of the VTR and the antenna input of the television receiver. 115, the VTR performs RFG modulation on the video signal and audio signal, converts it into one or two channels of V)-IF, and sends it to the television receiver. In this way, the RF double signal television signal is converted for a specific channel. On the television receiver side, the received television signal is separated into a video signal and an audio signal, and each of the separated signals is processed to create an image on the CRT-1- and also obtain audio.

According to the conventional method, images taken with a video camera are
When recording to R, the video camera and VTR are connected by a cable, so if you are shooting outdoors, the VT
I had to carry R around my shoulder. VTR
is extremely heavy compared to a television camera. Therefore, VTR
The method of shooting by carrying the camera over your shoulder has poor mobility;
This was especially difficult when children were photographed.

In order to eliminate such problems, a simple wireless transmitter for television signals that transmits RF multiplied signals wirelessly has recently been developed. This device receives video and audio signals output from a VTR or video camera, R[modulates them], converts the modulated RF signal for a specific television channel, and transmits it wirelessly from a whip antenna. It has become.

In this case, the transmission power output from the antenna becomes a problem, but at a position 100m away from the source, it is 15μV.
Radio waves with a strength of less than /m can be used without permission, regardless of frequency or type of N-wave (Article 6 of the Radio Law).

(Problem to be Solved by the Invention) When transmitting TV No. 48 wirelessly to a VTR using the wireless transmitter described above, the VTR is set to a predetermined mode (recording mode) in advance, and the VTR is started. TV signals are then transmitted wirelessly. In this type of shooting method, even when the camera operation is stopped, the VT
A problem arises in that the tape on the R side continues to run.

Therefore, every time I turn off the TV camera, I turn off the TV camera.
It is also necessary to stop the R tape running. It is possible to leave the tape running, but this will result in unnecessary tape running.
You will need to re-edit to cut out the blank parts later.

Such operations are extremely troublesome and inconvenient, especially when a person is photographing alone.

The present invention has been made in view of these points, and its purpose is to enable the transmitting side to wirelessly transmit television signals, and to enable the receiving side to reproduce the television signals. In addition to obtaining images and sounds, video signals can also be
The object of the present invention is to realize a wireless transmission/reception system for television signals with improved operability and mobility by enabling remote control of start/stop of V-R from the transmitting side.

(Iζth Means for Solving the Problems) The present invention, which solves the above-mentioned problems, wirelessly transmits video signals and audio signals from a transmitting circuit on the transmitting side, and transmits the signals transmitted from the transmitting side on the receiving side. A wireless transmission/reception system for television signals that receives and demodulates the received signals to obtain a video signal and an audio signal. obtains the original video signal from the signal transmitted from the transmitting circuit, and depending on the presence or absence of the video signal, the video tape recorder (VTR)
This feature is characterized in that it can also be used as a signal to control the start and stop of.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is an RF modulation circuit that receives a video signal and an audio signal and performs RF modulation on these signals.

In the RF modulation circuit, the video signal performs AM modulation on a carrier wave,
The A-dio signal FM modulates the carrier wave. Then, the LJ carrier wave modulated by the video signal and audio signal is R
It is output from the F modulation circuit 1. Here, the channel number of the television receiver is determined by the frequency band of the modulated carrier wave. For example, in the case of 2 channels, the channel allocation frequency is 96 to 102 M l-I
Z, the video signal carrier frequency is 97°25MH2,
The A-dio signal@carrier frequency is 101°75MHz. When this becomes 3 channels, the video signal @ carrier frequency becomes 103.25 M1-IZ1 audio A signal carrier frequency becomes 107.75 MHz.

2 is an amplifier that amplifies the output of the RF modulation circuit, and 3 is an antenna connected to the amplifier. As antenna 3,
For example, a whip antenna as described above is used.

RF modulation circuit 1. The amplifier 2 and the anti-no 3 constitute an RF signal transmission circuit. S is a contact connected to power supply +B. The contact S can be turned on and off by external operation. Power is supplied to the transmitting circuit via contact S.

4 is a receiving antenna that receives RF (No. 8), 5 is a frequency conversion circuit that separates a video signal and an audio signal from the RF multiplied signal picked up by the receiving antenna 4, and 6 is an intermediate that amplifies the output of the frequency conversion circuit 5. It is a frequency amplification circuit.

7 is a buffer that receives the output of the intermediate frequency amplifier circuit 6; D
8 is a rectifier diode that rectifies the output of the buffer 7, and 8 is a waveform shaping circuit that shapes the rectified output (direct current) by the diode D. RL is a relay driven by the output of the waveform shaping circuit 8, and the other end of the relay R[- is grounded. The operation of the device configured as described above will be explained as follows.

First, the operation on the transmitting side will be explained.

When contact S is pressed by external operation,
The power supply element [3 supplies power to the transmitting circuit. In this state, the RF modulation circuit 1 receives a video signal input and an audio signal input, and modulates each carrier wave Sl with these input signals. That is, the video signal performs AM modulation on the first carrier wave, and the audio signal performs FM modulation on the second carrier wave. Here, the frequencies of the first carrier wave and the second carrier wave are 4°5M! It is determined that the frequency is -1zmf.

For example, in the case of two channels, the video signal carrier frequency is determined to be 97.25 MHz, and the audio signal carrier frequency is determined to be 101.75M+-12.

Note that the video signal and audio signal input to the RF modulation circuit 1 may be from a VTR or a video camera. The video modulation signal and the audio A modulation signal output from the RF modulation circuit 1 are amplified by the following amplifier 2, and then wirelessly transmitted from a common antenna 3.

The output of the transmitting circuit is wirelessly transmitted and transmitted to, for example, a VTR. On the VTR side, the RF signal sent from the transmitting circuit
The signal is received by the double signal antenna 4, separated into a video signal system and an audio signal system by the subsequent frequency conversion circuit 5, and then demodulated to reproduce the video signal and audio signal and reproduce them as images and audio. On the other hand, the separated video signal is rectified and smoothed to create a DC signal, which operates a relay to turn on a contact, and the contact signal is used as a VTR start signal.

As long as contact S is pressed, the transmitting circuit shown in FIG. 1 continues to transmit signals, so the start/stop signal on the VTR side continues to maintain its start state. Therefore, the tape continues to run and continuously records the video and audio signals sent from the first transmission circuit.

Here, if contact S is set to A), power supply to the transmitting circuit +B
Since the supply of signal is cut off, the signal is no longer transmitted. On the VTR side, which receives the signal from the transmitting circuit and generates the VTR start signal, 1q of DC voltage for driving the relay is no longer available, so the relay is turned off. As a result, the contacts are also turned off. The relay contact is turned off by VTR star 1~. / This means that the stop signal has become a stop signal, so the tape running of the VTR is stopped. Of course,
Since the transmission of video and audio signals is also stopped, no recording occurs.

Next, the operation on the receiving side will be explained.

The receiving device shown in FIG. 1 receives the RF multiplied signal transmitted from the transmitting device as described above and generates a start/stop signal for the VTR. The signal received by the antenna 4 is separated into a video signal and an audio signal by a frequency conversion circuit 5. The separated video signal is amplified by an intermediate frequency amplification circuit 6 and then buffered by a buffer 7.

The output of the buffer 7 is rectified by a rectifying diode D,
converted to direct current. This DC 18 waveform shaping circuit 8
After the waveform is shaped by , relay R1- is driven. When relay RL is activated, its internal contacts are turned on. This internal contact is turned on and off by the start/off of the VTR, respectively.
Used as a stop signal. In this case, the internal contact is on, so the VTR starts, and the VTR (not shown)
The tape continues running. A video signal and an A-dio signal are recorded on the tape while it is running.

On the other hand, when the contact S becomes A) on the transmitting side, the supply of the power supply 1B to the transmitting circuit is stopped, and the RF multiplied signal transmission is stopped. Due to this binding, the DC voltage rectified by the rectifier diode D on the receiving circuit side becomes approximately OV, and the relay R1 cannot be driven.

This binding causes the contact point of relay RL to become A), which notifies the VTR of the stop of tape running. The VTR stops tape running. That is, the receiving circuit shown in the figure receives the wireless signal, generates a start/stop signal for the VTR, and
It can be given to R.

The transmitter H position shown in FIG. 1 can be made compact so that it can be integrated with a television camera.

FIG. 2 is a diagram showing an example of the appearance of a television camera and the device of the present invention. In the figure, 20 is a wireless transmitter according to the present invention, and 30 is a video camera. The wireless transmitter @20 and the video camera 30 are connected to the wireless transmitter 2 as shown in FIG.
0 side]-shaped angle 21, the video camera 3
After inserting it into the zero-side accessory release 31 in the direction of the arrow, turn the knob 22 to fix it.

In FIG. 2, numeral 3 is an antenna for transmitting the output of the first transmission circuit shown in FIG. 1; 23 is a power switch;
4 is a lamp that lights up to let you know that the computer is in operation;
25 is a connector, and 26 is a cable connected to the connector 25. The cable 26 is connected to a signal output terminal (not shown) of the video camera 30 and transmits the video signal and audio signal from the video camera 30 to the wireless transmitter 20. 27 is a power pack that is powered on to operate the wireless transmitter 1F20. As for the power supply voltage,
For example, 12V is used. Note that the power source used does not need to be externally connected as a power supply back as shown in the figure, and may be embedded within the main body of the wireless transmitter.

Although the contact S shown in FIG. 1 may be provided on the wireless transmitter 20 side, it is more convenient to provide it on the video camera 30 side and link it with the camera's start button.

FIG. 4 is a diagram showing an example of the external shape of a wireless receiving device according to the present invention. In the figure, 40 is a radio receiving device, 50 is a VT
It is R. 41 is a power switch, 42 is a pilot lamp that lights up when the ll source switch 41 is turned on, and 43 is a VTR.
A receiving lamp 44 lights up when a control signal is received, and 44 is a plug for taking out the start 7/stop signal of the VTR 50. Plug 44 is connected to remote signal input jack 51 of VTR 50.

In the above description, an example has been described in which the sending circuit controls the transmission and stopping of the RF signal by turning on and off the contact S to supply or stop the power source 1B. However, the present invention is not necessarily limited to this. For example, as shown in FIG.
A contact S may be provided between the & modulator circuit 1 and the amplifier 2 to control transmission and stop of the RF multiplied signal. That is, when the contact S is turned on, the output of the RF modulation circuit 1 is input to the amplifier 2 and is wirelessly transmitted from the antenna 3. On the other hand, contact S
When turned off, the output of the RF modulation circuit 1 is no longer input to the amplifier 2, and the RF multiplied signal wireless transmission is stopped.

Further, according to the present invention, as described above, the carrier wave is constantly transmitted without intermittent transmission of the RF multiplied signal, and the television signal (video A audio signal) is applied to the RF modulation circuit. The same purpose can be achieved with or without addition. FIG. 6 is a block diagram showing another embodiment of the present invention. The receiving side circuit is omitted. In the figure, 61 is a carrier wave generation circuit that generates a carrier wave, 62 is a buffer amplifier circuit that receives a video signal (video signal) and an audio signal (sound signal) output from a video camera (not shown), and S W + and SW
Reference numeral 2 denotes a switch that interlocks and connects the video signal and A-dio signal buffered by the buffer amplifier circuit 62. 63 receives the output of the carrier wave generation circuit 61 (transmission carrier wave) and the video signal and A-di A signal sent via the switches SW+ and SWz;
This is an RFF modulation circuit that RF modulates these signals using a carrier wave. In the RFF modulation circuit, a video signal is subjected to AM modulation on a carrier wave, and an audio signal is subjected to FM modulation on a carrier wave. Then, W! is modulated by a video signal and an audio signal. The transmitted wave is output from the RFF modulation circuit 63.

64 is an amplifier that amplifies the output of the RFF adjustment circuit 63; 65;
is an antenna connected to the amplifier 64. As the antenna 65, for example, a whip antenna as described above is used. The circuit shown in the figure constitutes an RFF signal transmitting circuit. The operation of the circuit configured as described above will be explained as follows.

First, the operation when the contacts of the switches S'A'r and SW2 are on will be described. In this case, the video signal and audio signal are input to the modulation circuit 63 via switches SW+ and SW2. RF switching circuit 63 receives video signal input and audio signal input.
These inputs (No. 8) modulate each of the m transmission waves. That is, the same A signal modulates the first carrier wave with AM, and the audio signal modulates the second carrier wave with FM. Ru.

Here, when the contacts of the switches SW+ and SWz are set to A), the video It@ and A-D A signals are sent to the RFF adjustment circuit 63.
', 'K' is input. Only a carrier wave is outputted from this combination and RFF modulation circuit 63, and this carrier wave is amplified by an amplifier 64 and then transmitted from the anti-pro 5. V
On the TR side, this carrier wave is received, but since it does not contain the video signal and the A-D signal, it cannot be rectified by a rectifier circuit, or even if it is rectified, it does not reach the specified DC level. , the VTR start relay cannot be activated. As a result, the relay contacts are turned off. When the relay contact is off, it means that the VTR star 1-7/s 1-tub signal has become a stop signal, so the VTR
tape running stops.

Also, in the above explanation, the case where a VTR was used on the receiving (Fi side) was taken as an example, but a television receiver may be used instead.In this case, the RFF tone signal sent from the transmitting circuit is If you set the TV receiver to a predetermined channel, you can retransmit the image and sound.In this case, the VTR's start/stop signals will have no direct meaning.However, if the CRT is preheated, It would be useful if the start/stop word of the VTR could be used as an on/off signal for a television receiver that displays an image immediately when the start button is pressed.

(Effects of the Invention) As described above in detail, according to the present invention, the transmitting side transmits a television signal intermittently wirelessly, and the receiving side processes this television signal and uses it as a start/stop signal for a VTR. By using it, remote control of VTRs and the like becomes possible, greatly improving operability and mobility.

[Brief explanation of drawings]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention, and FIG.
Figure 3 shows an example of the external shape of a wireless transmitter and a television camera.
4 is a diagram showing the appearance of the radio receiving device, and FIGS. 5 and 6 are block diagrams showing other embodiments of the present invention. 1.63...RFF adjustment circuit 2.64...Amplifier 3,4.65...Antinor 5...Frequency conversion circuit 6...Intermediate frequency amplification circuit 7...Buffer 8...Waveform Shaping circuit 20
...Wireless transmitter 21...Angle 22...Knob 23...Power switch 24...Lamp 25...21 Connector 26...Cable
27...Power pack 30...Video camera 31...Accessory switch 40...Wireless receiving device 41...Power switch 71
2...Pilot lamp 43...Reception lamp 44...Plug 50...
VTR51...Jack 61...Carrier wave generation circuit 62...Buffer amplifier circuit R...Relay S...Contact D...Diode SW1, SW2...Switch Patent applicant Konishiroku Photo Industry Co., Ltd. Company agent Patent attorney #+ Shima Fuji Jigai 1 name [n-]

Claims (1)

[Claims] A television signal in which the transmitting side wirelessly transmits video and audio signals from a transmitting circuit, the receiving side receives the signals transmitted from the transmitting side, and demodulates the received signals to obtain video and audio signals. In this wireless transmission/reception system, the transmitting side is configured to be able to externally control the transmission and stop of the television signal, and the receiving side obtains the original video signal from the signal transmitted from the transmitting circuit, and processes the video signal. A wireless transmission and reception system for television signals, characterized in that the signal is also used as a signal to control the start and stop of a video tape recorder (VTR) depending on the presence or absence of the signal.