JPS6184167A - Radio transmission system for television signal - Google Patents

Abstract

PURPOSE:To improve operativity and mobility and prevent the delay of a video signal by turning on the driving power source for image pickup elements of a video camera simultaneously with the power source for a transmitting circuit, and holding it in the on state. CONSTITUTION:When a push button switch SW is pressed, a contact S is made and the driving power source for image pickup elements of the video camera is turned on simultaneously with power supply to respective transmitting circuits. The power source is held on once turned on, and the image pickup elements are heated and run sufficiently all the time and an inveriably optimum image is converted photoelectrically. Therefore, when the push button switch SW is pushed, a remote operation signal for the start of VTR is transmitted by radio and a normal video signal is transmitted by radio at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention provides a method for starting/receiving a video tape recorder (hereinafter abbreviated as VTR) in addition to a video signal and an audio signal.
It is concerned with a system for wirelessly transmitting television signals that can also wirelessly transmit a remote control signal that causes a stop.

(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, VTR
If you want to visualize Deno J on a TV receiver, set the VTR's R.
Connect the F output terminal and the antenna of the TV receiver with a cable. 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. The RF signal converted for a specific channel in this way becomes a television signal. The television signal received by the television receiver is separated into a video signal and an audio signal, and each of the separated signals is processed to create an image on a CRT and to obtain audio as well.

According to the conventional method, the image cast by a video camera is
When recording on a TR, the video camera and VTR are connected with a cable, so if you are transporting the record outdoors,
I had to carry the TR around on my shoulder. V
TR is extremely heavy compared to a television camera. Therefore,
In the method of hanging the VTR on your shoulder and casting a shadow,
Separate behavior was poor, and it was especially difficult when children were involved.

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, performs RF modulation, converts the modulated RF multiplied signals for a specific television channel, and transmits them wirelessly from a whip antenna. ing.

In this case, the transmission power output from the antenna becomes a problem, but at a position 10100II away from the source, 15
Article 6 of the NTf Wave Law stipulates that radio waves with a strength of less than μv/Il can be used without permission regardless of frequency or type of radio wave.

(Problem to be Solved by the Invention) The wireless transmitter described above is used to transmit television signals to a VTR.
In the case of A-line transmission, the VTR is set in advance to a predetermined mode (recording mode), the VTR is started, and then the TV (ji number) is wirelessly transmitted.

In the case of such a tlil shadow method, a problem arises in that the VTR's radar continues to run even when the camera operation is stopped. 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 run the tape several hundred times, the tape runs will be wasted and it will be necessary to perform re-editing to cut out the blank areas later.

Such operations are extremely troublesome and inconvenient, especially when one person is performing the imaging.

Therefore, it would be convenient if, in addition to the above-mentioned television signal, a remote control signal for starting/stopping the receiving VTR is also transmitted wirelessly.

In that case, if the drive power for the video camera's image carrying element is turned on and off in conjunction with the power on and off of the transmitting circuit, the rise of the video signal will inevitably be delayed by the warming-up time of the ff1l eTIM element. However, the rise of the video signal is delayed compared to the start signal of the VTR.

The present invention has been made in view of these points, and its purpose is to improve operability and mobility by making it possible to wirelessly transmit VTR start/stop signals in addition to television signals. To realize a wireless transmission system for television signals that can prevent video signal delays by transmitting a video signal simultaneously with a VTR start signal.

(Means for Solving the Problems) The present invention solves the above-mentioned problems, and when video signals and audio signals are RF-modulated and transmitted wirelessly from a transmitting circuit, V
In a wireless television signal transmission system that sends remote control signals to start and stop the TR side, the driving power for the image element of the video camera was turned on at the same time as the power for the transmitter f2 circuit. The device is characterized in that it is configured to maintain the on state.

(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 video (a) and audio signals and modulates these signals with RF.The RF modulation circuit performs AM modulation on a carrier wave for the video signal, and modulates the carrier wave for the audio signal. FM modulate.And,
m transmission waves modulated by the video signal and the audio signal are output from the RF 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 two channels, the channel allocation frequency is 96 to 102 MHz, 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 1
03.25MHz, audio signal carrier frequency is 107
．． 75M)-1z.

2 is an amplifier that amplifies the output of the RF modulation circuit, and 3 is a first antenna connected to the amplifier.

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 R[13 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, 12 KHz is used, and as the oscillation frequency of the crystal oscillator X, for example, (40/3) MHz is used. 6 is a multiplier circuit that multiplies the oscillation frequency of the excavation circuit 5; 7 is a power amplifier that amplifies the output of the multiplier circuit 6; and 8 is a second antenna connected to the power amplifier 7.

For example, 3 times is used as the multiplication factor of the multiplier circuit 6, and therefore, the frequency transmitted from the antenna 8 is 40 MHz. Modulated wave oscillation circuit 4. High frequency oscillation circuit 5. Multiplier circuit6. The power amplifier 7 and antenna 8 constitute a VTR remote control signal transmission circuit (second transmission circuit).

SW is a pushbutton switch, RL is the pushbutton switch S
This is a relay connected to W. One end of the internal contact of the pushbutton switch SW is grounded, and the other end is connected to the excitation coil of the relay RL. The other end of relay RL is connected to power supply 1B. S is a contact connected to the power supply +B, and the contact S is an internal contact of the relay RL. The internal contact of the pushbutton switch SW is always off and turns on only when pressed. Power is supplied to each transmitting circuit via a contact S. The contact S is always off, and is turned on when the pushbutton switch SW is pressed.

Furthermore, although not shown, the power supply for driving the image pickup element of the video camera is turned on at the same time as the power supply for the transmission circuit shown in the figure, and once turned on, it is configured to remain on. That is, the fill image element is always sufficiently heat-run so that it can always perform photoelectric conversion of an optimal image. The operation of the device configured as described above will be explained as follows.

When the pushbutton switch SW is pressed, the relay R is energized, the power supply contact S is turned on, and power is supplied to the first and second transmitting circuits. In this state, the RF modulation circuit 1 receives a video signal input and an audio signal input, and modulates each carrier wave with these input signals. That is, the video signal is AM-modulated on the first carrier wave, and the audio signal is FM-modulated on the second carrier wave. Here, the first carrier wave and the second 11F
The frequency of the second wave transmission is determined to be 4.5Mf-1zPA.

For example, in the case of two channels, the video A signal carrier frequency is determined to be 97.25 MHz, and the audio signal carrier frequency is determined to be 101.75 MH2. Note that the video signal and audio signal input to the RF modulation circuit 1 may be from a VTR or from a video camera. The modulated signal is amplified by a subsequent amplifier 2 and then wirelessly transmitted through 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 the frequency is multiplied by the power amplifier 7, the signal is amplified by the power amplifier 7 and supplied to the antenna 8.

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

The outputs of the first and second transmitting circuits are wirelessly transmitted and transmitted to, for example, a VTR. On the VTR side, the RF multiplied signal sent from the first transmitting circuit is received, separated into a video signal system and an audio signal system, and demodulated to reproduce the video signal and audio signal and reproduce them as images and audio. do. Also, the VTR sent from the second transmitting circuit
Demodulates the remote control signal and reproduces the 12KHz modulated wave,
This modulated wave is rectified to create a DC signal, which operates a relay to turn on the contact, and converts the contact signal to V
It is used as a TR start signal.

Here, as described above, power is always supplied to the image carrying element of the video camera regardless of whether the contact S is on or off. Therefore, the lively aM child is always ready to output the optimum image (FI number).Therefore, when the push button switch SW is pressed and the remote control signal to start the VTR is transmitted wirelessly, at the same time a normal video signal is transmitted wirelessly. Therefore, there is no problem such as the video signal being recorded with a delay when the VTR starts.

As long as the pushbutton switch SW is pressed, the first and second transmitting circuits continue to transmit signals, so the start/stop signal on the VTR side maintains the start state and increases vct. Therefore, the tape continues to run and continuously records the video and audio signals sent from the first transmission circuit.

If you release your hand from the pushbutton switch SW and stop pressing it, the relay RL will not be energized and the contact S will be turned off. As a result, the power supply to the transmitting circuit is cut off, so that no signal is transmitted. V that receives the signal from the second transmitter circuit and creates the VTR start signal
On the TR side, the DC voltage for driving the relay can no longer be obtained, so the relay is turned off. 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, the case where a VTR is used on the receiving side is taken as an example, but television reception 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 television set to a predetermined channel. In this case, the VTR start/stop signal sent from the second transmitting circuit becomes meaningless.

However, it would be useful if the cathode ray tube was preheated and the start/stop signal of the VTR was used as the on/off signal for the television set. That is, the video can be displayed on the TV screen at the same time as the start.

As described above, according to the present invention, it is possible to remotely control the start/stop of a VTR, which eliminates the need to carry a VTR and greatly improves mobility. 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
0 is a wireless transmitter according to the present invention, and 20 is a video camera. The S-line transmitter 10 and the video camera 20 are connected to each other as shown in FIG. I(VA'1:ti(ci) After inserting the L-shaped angle 11 provided on the equipment 10 side into the accessory shoe 21 on the video camera 2o side in the direction of the arrow, further turn the knob 12 to fix it.

43 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 power supply. A switch 14 is a lamp that lights up to indicate that it is on air, 15 is a connector, and 16 is a cable connected to the connector 15. The cable 16 is connected to a signal output terminal (not shown) of the video camera 20, and
The video signal and audio signal from 0 are sent to the wireless transmission deviceff
Tell f10. 17 is the first power source for operating the wireless transmitter 10. The Tf source is booming. For example, 12V is used as the power supply voltage. It should be noted that the power source used does not need to be installed as a power supply back as shown in the figure, but may be embedded within the wireless transmitting R stomach body.

The pushbutton switch SW shown in FIG. 1 is the wireless transmitter 1.
Although it is possible to move the jl to the 0 side, it is convenient to provide it on the video camera 20 side and link it with the camera's start button.

In the above description, the case where the relay R1- is turned on and the power supply contact S is turned on when the pushbutton switch SW is pressed is taken as an example, but the present invention is not necessarily limited to this. The contact of the pushbutton switch SW may be of 44 configuration, which is always on and turns off when pressed. When pushbutton switch f SW is not pressed, contact S
is on and the circuit shown continues to transmit the RF multiplier signal and the VTR remote control signal. Next, when the pushbutton switch SW is pressed, the contact S is turned off, so as shown in the figure, the power supply to the circuit is cut off, and transmission naturally stops. 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 the excavation circuit 5 directly oscillated the desired frequency (>40 MHz). However, in general, formula 6, which obtains the target frequency by multiplying the oscillation frequency by a multiplier circuit, is more stable because the oscillation frequency of the oscillation circuit itself can be lower. Although the case where the modulation wave frequency is 12 KHz and the carrier wave is 40 MHz is taken as an example, it is not necessary to limit it to these frequencies, and any frequency may be used. Also, the carrier wave of the first transmitting circuit is also 1-IF. There is no need to limit the frequency to the UHF band, and a UHF band frequency 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, a control signal to start/stop the VTR is also transmitted wirelessly, making it possible to improve the operability of the TV camera. JJ performance can be greatly improved. Further, according to the present invention, one of the video cameras
Since power is constantly supplied to the image stop element, a complete video signal can be transmitted as soon as the video camera is started.
This prevents the video signal from being recorded with a delay in the receiving VTR.

[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...Power switch 14...Lamp 1
5...Connector 16...-Cable 17...
Power supply back 20...Video camera 21...Accessory shoe X...Crystal oscillator SW...Push button switch S...Contact RL...Relay disconnected

Claims (1)

[Claims] When video signals and audio signals are RF modulated and wirelessly transmitted from a transmitting circuit, a remote control signal is sent to start/stop the VTR side in conjunction with the start/stop of the video camera. 1. A radio transmission system for television signals, characterized in that the transmitting system is configured such that after turning on the driving power of the image pickup element of the video camera at the same time as the power of the transmitting circuit, the turned-on state is maintained.