JPS61102826A - Wireless transmitting equipment for television signal - Google Patents

Abstract

PURPOSE:To improve operability and maneuvability at the time of video camera photographing by transmitting wirelessly a control signal which starts and stops VTR, besides an RF modulating signal of a video signal and an audio signal. CONSTITUTION:When a contact of switches SW1 and SW2 is on, a video modu lating signal and an audio modulating signal outputted from an RF modulating circuit 1 are amplified subsequently through the switch SW1 by an amplifier 2, and after that, transmitted wirelessly from a common antenna 3. On the other hand, a high frequency signal modulated by the output of a modulating wave oscillating circuit 4 is supplied through a multiplying circuit 6 and a power amplifier 7 to an antenna 8, and a VTR remote operation signal is trans mitted wirelessly. At the VTR side, an RF signal sent from the first transmitting circuit is received,demodulated and the video signal and the audio signal are reproduced, the VTR remote operation signal sent from the second transmitting circuit is demodulated and used as a VTR start signal. If the switches SW1 and SW2 are on, the first and second transmitting circuits continue to transmit the signal, and therefore, the VTR side continues to maintain a start condition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a wireless television signal transmitting device that can wirelessly transmit television signals to a television receiver or a video tape recorder. The present invention relates to a television signal wireless transmitter capable of wirelessly transmitting not only video signals and audio signals but also radio control signals that can remotely start and stop a video tape recorder (hereinafter simply referred to as VTR).

(Prior Art) Conventionally, when the output of a video camera or VTR is visualized for television viewing, the video camera or the like and the television receiver are usually connected by a cable. For example, when 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. That is, a VTR performs RF modulation on video and audio signals, converts them into one or two channels of VHF, and sends them to a television receiver. In this way, the RF double signal television signal is converted for a specific channel. At the TV receiver WA side, the received TV signal is separated into a video signal and an audio signal, and each separated signal is processed to create an image on a CRT 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 on my shoulder. VTR
is extremely heavy compared to a television camera. Therefore, VTR
The method of throwing the camera over the shoulder and casting a 1ft shadow had poor mobility and was particularly difficult when photographing children.

In order to eliminate such problems, a simple method of wirelessly transmitting television signals using RF double signal wireless transmission has recently been developed. This device receives video and audio signals output from a VTR or video camera, performs RF modulation, converts the modulated RF multiplied 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 1001111 away from the source, 15
Radio waves with a strength of μV/m or less can be used without permission, regardless of frequency or type of radio waves (Article 6 of the Radio Law).

(Problem to be Solved by the Invention) When transmitting a television signal to a VTR wirelessly using the wireless transmitter described above, the VTR must be set in a predetermined mode (recording mode) in advance, and the VTR must be started. It is designed to transmit television signals wirelessly. In the case of this method of imaging, even when the camera operation is stopped, the VTR
A problem arises in that the tape continues to run. Therefore, every time the television camera is stopped, it is necessary to also stop the tape running on the VTR. Although it is possible to leave the tape running, the tape running will be wasted, and it will be necessary to perform re-editing to cut out the blank areas later.

Such operations become extremely troublesome and inconvenient when a person is taking pictures alone.

The present invention has been made in view of these points, and its purpose is to improve operability and photographing efficiency by wirelessly transmitting VTR start/stop signals in addition to television signals. The purpose of this invention is to realize narrow-band wireless transmission of television signals.

<Means for Solving the Problems> The present invention, which solves the above-mentioned problems, includes a first transmitting circuit that wirelessly transmits a video signal and an audio signal after RF modulation, and a high frequency signal that is modulated at a modulation frequency. The device is characterized in that it further comprises a second transmitting circuit for wirelessly transmitting, and is configured such that signals wirelessly transmitted from these first and second transmitting circuits can be turned on and off by external operation.

<Examples> Hereinafter, examples 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 modulates the carrier wave by AMR,
The audio signal is FM modulated on a carrier wave. Then, the carrier wave modulated by the video signal and audio signal is RF
It is output from the 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 2ch 1r channel, the channel allocation frequency is 96~102MH2,
The video signal carrier frequency is 97°25 MHz, and the audio signal carrier frequency is 101°75 MHz. When this becomes 3 channels, the video signal carrier frequency is 103.25MHz and the audio signal carrier frequency is 1
07.75MHz.

S W r is a first switch that amplifies the output of the RF modulation circuit 1 by 17 ivt, 2 is an amplifier that amplifies the output of the R,F modulation circuit 1, and 3 is a first antenna connected to the amplifier 2. As the antenna 3, for example, a whip antenna as described above is used. RF modulation circuit 1. The amplifier 2 and the antenna 3 constitute an RF signal transmission circuit (first transmission circuit).

4 is a modulated wave oscillation circuit that oscillates a modulated wave, X is a crystal oscillator, and 5 is a high frequency oscillation circuit using the crystal oscillator X as an oscillator. As the oscillation frequency of the modulated wave oscillation circuit 4, for example, 12KH2 is used, and as the oscillation frequency of the crystal oscillator X, for example, <40/3)M)-12 is used. 6 is a multiplier circuit that multiplies the oscillation frequency of the oscillation circuit 5, SW
2 is a second switch that connects the output of the multiplier circuit 6 in synchronization with the first switch S W 1; 7 is a power amplifier that amplifies the output of the multiplier circuit 6; and 8 is connected to the power amplifier 7. This is the second antenna. Multiplier circuit 6
For example, a magnification of 3 (8) is used, and therefore, the frequency transmitted from the antenna 8 is 40 MH2. This constitutes a VTR remote control signal transmitting circuit (second transmitting circuit).11+8 is supplied to these first and second transmitting circuits.The operation of the device configured in this way will be explained below. For example, as follows.

First, the operation when the contacts of the first and second switches SW+ and S to V2 are in the on state will be described.

The RF modulation circuit 1 receives video signal input and audio signal input, and modulates respective carrier waves with these input signals. That is, the video signal is AM-modulated on the first carrier wave,
The audio signal FM modulates the second carrier wave. Here, the frequency of the first carrier wave and the second carrier wave is 4.5MHzf
It is determined that the frequency is t+f.

For example, in the case of 2 channels, the video signal m
The transmission frequency is 97.25 MHz, and the audio signal carrier frequency is determined to be 101.75 MH2. still,
The video and audio signals input to the RF modulation circuit 1 may be from a VTR or a video camera. A video modulation signal and an audio modulation signal outputted from the RF modulation circuit 1 are amplified by an amplifier 2 following the switch SW 1, and then wirelessly transmitted from a common antenna 3.

On the other hand, the output (modulated wave) of the modulated wave oscillation circuit 4 modulates the high frequency signal output of the high frequency oscillation circuit 5.

The high frequency signal modulated by the modulated wave is sent to a multiplier circuit 6.
After frequency transmission 8 is performed, the signal is amplified by a power amplifier 7 and supplied to an antenna 8.

An ig1 frequency signal (VTR remote control signal) modulated by a modulated wave is wirelessly transmitted from the antenna 8.

The outputs of these first and second transmitting circuits are 7! ! 1 and transmitted to, for example, a VTR. On the VTR side, the first
The RF multiplied signal sent from the transmitting circuit is received, separated into a video signal system and an audio signal system, and then demodulated to reproduce the video signal and audio signal and reproduce them as images and audio. Also, the VT sent from the second transmitting circuit
Demodulate the R3m interval operation signal to reproduce a 12KHz modulated wave, rectify this modulated wave to create a DC signal, operate the relay with this DC signal to turn on the contact, and use the contact signal as the VTR start signal. We are using.

As long as the contacts of the first and second switches SWI and SW2 are on, the first and second transmitting circuits continue to transmit signals, so the VTR side continues to maintain the start state. Therefore, the tape continues to run and continuously records the video and audio signals sent from the first transmission circuit.

Now, when the contacts of the first and second switches SW+, SW are turned off, the RF modulation signal and the control signal are no longer supplied to the antenna 3.8, respectively, and therefore the signal transmission is stopped. As a result, V which receives the signal from the second transmitting circuit and creates the VTR start signal
On the TR side, the relay is turned off because the DC power needed to drive the relay is no longer available. As a result, the contacts are also turned off. When the relay contact is off, it means that the VTR start/stop signal has become a stop signal, so V
TR tape running stops. Of course, since the transmission of video and audio signals is also stopped, no recording is performed.

In the above description, a case where a VTR is used on the receiving side is taken as an example, but a TV receiver mi may be used instead. In this case, the RF modulated signal sent from the first transmission circuit can be reproduced as images and audio by setting the TV receiver (11m) to a predetermined channel. The VTR start/stop signal sent from the circuit will not pose a direct threat.However, if the cathode ray tube is preheated, the VT
It would be useful if the R start/stop signal was used as an on/off signal for the television receiver.

As described above, according to the present invention, it is possible to remotely control the start/stop of a VTR, so there is no need to carry around a TR, and mobility is greatly improved. Since the wireless transmitter shown in FIG. 1 can be made compact, 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, 1
o is a wireless transmitter according to the present invention, and 2o is a video camera. The wireless transmission wave u1o and the video camera 20 are connected by connecting an L-shaped angle 11 provided on the wireless transmitter 1o side to an accessory shoe 2 on the video camera 2o side, as shown in FIG.
1 in the direction of the arrow, and then turn the knob 12 further to secure it.

In FIG. 2, 3 is a first antenna that transmits the output of the first transmitting circuit shown in FIG. 1, 8 is a second antenna that transmits the output of the second transmitting circuit, and 13 is a '2II source. A switch, 14 is a lamp that lights up to notify that it is on air, 15 is a connector, and 16 is a cable connected to the connector 15. Cable 16 is video camera 2
It is connected to a signal output terminal (not shown) of the video camera 2°, and transmits the video signal and audio signal from the video camera 2° to the wireless transmitter 10. Reference numeral 17 denotes a power back that is turned on to operate the wireless transmitter 10. For example, 12V is used as the power supply voltage. Note that the power source to be used does not need to be installed as a power supply back as shown in the figure, and may be buried within the main body of the wireless transmitter.

Also, the first and second switches SVV+ mentioned above.

If the on/off operation of SW2 is linked with the start/stop operation of the start/stop button on the video camera side, the operability will be further improved.

In the above explanation, an example was given in which the on/off of transmission of the wireless transmission circuit is controlled using the switches SWi and SWz, but it does not necessarily have to be controlled by on/off of the switches, and other devices having similar functions It can be anything as long as it is something. For example, a control voltage may be simultaneously applied to the RF modulation circuit 1 and the modulated wave oscillation circuit 4 to start or stop the modulation operation and the oscillation operation. Alternatively, the wireless transmission operation may be controlled by turning on and off the voltage +B supplied to the circuit shown in FIG. In addition, in the second transmitting circuit, the output of the high frequency oscillation circuit 5 was multiplied by the multiplier circuit 6 to obtain the desired frequency, but if the desired frequency in the oscillation circuit 5 was less than 40 MH
2) may be directly oscillated. However, in general,
A method in which the target frequency is obtained by multiplying the oscillation frequency by a multiplier circuit is more stable because the oscillation frequency of the oscillation circuit itself can be lower. Further, in the above-described embodiment, the case where the modulated wave frequency is 12 KHz and the carrier wave is 40 MHz is taken as an example, but it is not necessary to limit the frequency to these, and any frequency may be used. Further, the carrier wave of the first transmitting circuit does not have to be limited to the VHF band, and a frequency of the UHF band can be used.

(Effect of R Light) As explained in detail above, according to the present invention, the normal R light
In addition to the F modulation signal, by wirelessly transmitting a control signal for starting and stopping the VTR, it is possible to greatly improve the operability and mobility when using a television camera for decoy recording.

[Brief explanation of drawings]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention, and FIG.
The figure shows an example of the external appearance of a television camera and the device of the present invention.
FIG. 3 is a diagram showing the state in which the television camera and the present invention are attached. 1...RF modulation circuit 2...Amplifier 3.8...
Antenna 4...Modulated wave oscillation circuit 5...High frequency oscillation circuit 6...Multiplier circuit 7...Power amplifier 1
0... Wireless transmitter 11... Angle 12.
...Knob 13...'Til switch 14...Lamp 15...Connector 16...Cable 17...
...Power back 20...Video camera 21...
Accessory shoe

Claims (1)

[Claims] A first transmitting circuit that wirelessly transmits a video signal and an audio signal after RF modulation, and a second transmitting circuit that wirelessly transmits a high frequency signal after modulating the high frequency signal at a modulation frequency. and a television signal wireless transmitter, characterized in that the signal wirelessly transmitted from the second transmitter circuit can be turned on and off.