JPH11243505A - Multiple transmission system turntable system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a system to send a plurality of control signals including a power supply for a camera, a lens and the turntable and a video image of a camera through the identical coaxial cable without having the characteritcs of a video signal of the camera deteriorated. SOLUTION: A camera video signal is sent as a baseband signal from a video signal transmission circuit 19, a synchronizing signal (c), a camera remote control signal (b) are modulated by modulators 5, 6, and a truntable remote control signal (d) and a turntable remote control return signal (e) are modlulted by frequency modulators 27, 40 respectively at each predetermined frequency signal via filters 7, 16, 28, 41, and a power supply signal is conveted into a constant current signal and are multiplexed and sent through a coaxial cable 12. The transmitted modulated wave is separated into each frequency component by filters 16, 36, 31, demodulated by demodulators 17, 18, 32, 37 and restored to the oriinal signals. The power supply signal which has been sent as a constant current signal is converted into a constant voltage signal, and the result is fed to a load (camera) 24 and then fed to the turntable 45 through a large capacity capacitor circuit 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex transmission type turntable system for multiplexing and transmitting video signals, control signals, power supplies, and the like.

[0002]

2. Description of the Related Art Hitherto, as an example of a transmission system for multiplexing a power supply, a camera control signal, and a synchronizing signal with a video signal, means described in JP-A-5-83689 has been used.

[0003] These multiplex transmission systems are described below with reference to FIG.
This will be described in detail with reference to FIG.

FIG. 6 shows an example of frequency assignment of each signal transmitted through a coaxial cable of the conventional multiplex transmission system, wherein a camera video signal (a) such as a camera remote control signal (b) and a synchronization signal (c). Are modulated at frequencies outside the band of the video signal (a) of the camera.

FIG. 7 is a diagram showing an example of a waveform used for multiplex transmission in the conventional multiplex transmission system, and FIG. 8 is a diagram showing an example of a transmission waveform in a coaxial cable of the conventional multiplex transmission system. As shown in FIGS. 7 and 8, when these modulated signals and the video signal are multiplexed and transmitted, the modulated signal of the camera remote control signal (b) is converted into a vertical blanking period a-B of the video signal (a). And multiplexing in synchronization with the synchronization signal (c). As a result, since the video signal can be transmitted as it is in the baseband, deterioration of the S / N, DG (differential gain) characteristics, and DP (differential phase) characteristics of the video signal (a) is prevented.

In addition, since the modulation signal is superimposed on the vertical blanking period a-B of the video signal (a), signals other than the video signal are not affected by the jump or beat in the video period. ing.

FIG. 9 is a block diagram showing the configuration of a conventional multiplex transmission system. In FIG. 9, reference numeral 1 denotes a remote control unit for operating a camera signal separator (or camera) 13 from a remote place.
3 is connected by a coaxial cable 12. The remote control unit 1 has terminals 2, 3, and 4 for inputting and outputting a video signal (a), a synchronization signal (c), and a camera remote control signal (b) from the camera 24, respectively.

In the remote control unit 1, reference numerals 5 and 6 denote predetermined frequencies f4 and f4, respectively.
a modulator for modulating f5, a filter 7 for passing the modulated signal through only a predetermined frequency component, 8 and 9 coupling capacitors, 10 a power supply, and 11 a DC power supply from the power supply 10. A constant current circuit for converting to a power supply, and a synchronous pulse generating circuit 25 for generating a pulse synchronized with the video signal.

A camera signal separator (or camera) 1
In 3, 14 and 15 are coupling capacitors, 16 is a filter for extracting only a predetermined frequency component from a signal transmitted via the coaxial cable 12, and 17 and 18 are modulation signals at a predetermined frequency. A demodulator 19 demodulates the video signal, a video signal transmitting circuit 19 amplifies and transmits a video signal obtained on the camera signal separator (or camera) 13 side, and 20 synchronizes the camera signal separator (or camera) 13. A synchronizing circuit for outputting a synchronizing signal for taking, a camera control circuit 21, an impedance converter 22 for converting a DC power source of a constant current source into low impedance, a constant voltage circuit 23 for converting the DC power source to a stable constant voltage, 24 is a load (camera).

Next, the operation of transmitting the video signal, synchronization signal, camera remote control signal, and power supply of the camera will be described. First, the video signal (a) obtained on the camera signal separator (or camera) 13 side is video-amplified by the video signal transmission circuit 19, passes through the coaxial cable 12 via the coupling capacitor 14, and passes through the remote control unit 1. The video signal (a) transmitted to the remote control unit 1 is transmitted as it is in the baseband.

Next, the synchronizing signal (c) and the camera remote control signal (b) will be described. The synchronizing signal (c) and the camera remote control signal (b) input to the input terminals 3 and 4 are modulated by modulators 5 and 6 at predetermined frequencies f4 and f5.
The modulated signal transmitted to the coaxial cable 12 passes through the coupling capacitor 15 and then enters the filter 16 where it is separated into individual signals, and the demodulator 1
The signals are demodulated into the original synchronizing signal and the camera remote control signal by 7 and 18.

FIG. 6 shows the frequency allocation for modulating the synchronization signal (c) and the camera remote control signal (b). The video signal (a) of the camera is a base band, and the frequency is DC. ~ 8MHz, sync signal (c)
Has a center of 28.6 MHz (frequency f4), and the camera remote control signal (b) has a center of 14.3 MHz.
MHz (frequency f5), and they are sufficiently spaced so as not to buffer each other.

[0013]

However, in the above-mentioned conventional multiplex transmission system, only the video signal (a), synchronization signal (c), power supply and remote control signal (b) of the camera are transmitted as shown in FIG. Therefore, in a system in which a camera is mounted on a turntable, there is a problem that a remote control signal for the turntable and its power must be separately supplied.

In the multiplex transmission method described above, the coaxial cable 1
If the multiplexed power supplied by the book is supplied to a device such as a turntable at the same time as the camera, the impedance of the coaxial cable changes abruptly because an inrush current flows when the turntable or the like operates. Therefore, there is a problem that the level of the video signal of the camera changes or noise enters, and there is a problem that power cannot be supplied simultaneously to the camera and the turntable.

The present invention has been made to solve such a conventional problem, and a single coaxial cable can be used to transmit a video signal of a camera.
An object of the present invention is to provide a multiplex transmission type turntable system capable of supplying not only a synchronization signal and a camera remote control signal but also a turntable remote control signal, a lens remote control signal, a camera power supply, and a turntable power supply. It is.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the object, the present invention provides a lens remote control signal in addition to a conventional signal other than a video signal such as a camera remote control signal and a synchronization signal. Are modulated at frequencies outside the band of the video signal, and these signals and the video signal of the camera are multiplexed and transmitted.

The conventional camera remote control signal is amplitude-modulated as described in the conventional example and multiplexed within the blanking period of the video signal to eliminate the influence on the video signal. Since the control signal of the table continuously communicates bidirectionally between the turntable and the turntable control unit (the turntable control panel), the processing during the video blanking period is delayed by the movement of the turntable. Problem arises.

Further, if the amplitude-modulated rotary control remote control signal is multiplexed in the video period, there is a problem that the video signal separated by the filter may be damaged or noise at a point where the amplitude of the amplitude modulation changes greatly. In addition, the frequency is modulated and the video signal is multiplexed uniformly so that the amplitude of the modulated wave of the control signal does not change, thereby eliminating the influence on the video signal.

In order to supply power to the turntable, the inrush current and switch noise when the turntable starts to move and the drive noise of the motor of the turntable do not affect the multiplex transmission path. Equipped with a filter.

On the turntable side, in order to reduce the influence of the inrush current flowing through the coaxial cable at the start of the turntable and the noise at the start and end of the turntable operation on the multiplex transmission line, the operation at the start and end of the movement is performed. The voltage control circuit is controlled by a microcomputer inside the turntable to gradually increase and decrease the current, and the voltage applied to the horizontal operation motor and the vertical operation motor is controlled.

According to the present invention, a camera, a lens and a turntable can be remotely controlled with a single coaxial cable, and in addition to these remote controls, power can be supplied to the camera, lens and turntable.

Conventionally, in addition to a coaxial cable for connection between a camera and a remote control unit, an AC adapter or the like is separately prepared on the turntable side to supply power to the turntable and to rotate the turntable and the other. Although it was necessary to connect the stand control panel with a cable, all power supply and control could be performed with only one coaxial cable, which significantly improved the efficiency of construction work and reduced the need for AC power. It has the effect that a turntable can be installed.

[0023]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG.

FIG. 1 is a block diagram showing the configuration of a multiplex transmission type turntable system according to an embodiment of the present invention. In FIG. 1, reference numerals 1 to 25 denote blocks having the same functions as those of the conventional example shown in FIG. Here, in the remote control unit 1, reference numeral 26 denotes an input terminal of a turntable remote control signal (d) including a lens remote control signal.
4, a turntable remote control signal (d) including a lens remote control signal is input. Reference numeral 27 denotes a modulator for frequency-modulating the input signal at a center frequency of 11.7 MHz.
A filter that allows only a 7-MHz modulated wave to pass through, and 29 is a coupling capacitor for multiplexing the modulated wave coaxially. 30 is a coupling capacitor for extracting the frequency-modulated turntable remote control return signal (e) returned from the camera signal separator (or camera) 13; 31
Is a filter for separating the frequency-modulated turntable remote control return signal (e) returned from the camera signal separator (or camera) 13, 32 is a demodulator for demodulating the signal, 33
Is an output terminal of the demodulated turntable remote control return signal (e), which is output to the turntable control panel 34. A control panel 34 for controlling the turntable is provided.
, The turntable 45 is controlled by the turntable remote control signal (d) and the turntable remote control return signal (e).

In the camera signal separator (or camera) 13, reference numeral 35 denotes a coupling capacitor for extracting the rotary base remote control signal (d) frequency-modulated by the modulator 27 of the remote control unit 1, and reference numeral 36 denotes only the frequency. A filter 37 is a demodulator for demodulating the frequency-modulated turntable remote control signal (d). An output terminal 38 is connected to the turntable 45 at an output terminal of the turntable remote control signal (d).

Reference numeral 39 denotes an input terminal of a turntable remote control return signal (e) sent from the turntable 45 to the turntable control panel 34, which is connected to the turntable 45.

40 is a modulator for frequency-modulating the turntable remote control return signal (e), 41 is a filter for passing the frequency-modulated signal of the turntable remote control return signal (e),
Reference numeral 42 denotes a coupling capacitor for multiplexing the coaxial cable 12 with another signal.

Reference numeral 43 denotes a large-capacitance capacitor circuit including a filter for preventing the power supplied by the coaxial cable 12 from affecting the video signal of the camera. The power distributed here is supplied to the turntable 4 through the turntable power supply terminal 44.
5.

FIG. 2 shows the operating characteristics of the turntable 45 of FIG. 1. The starter ST is controlled to move slowly at the time of start ST, and is controlled to stop slowly at the time of stop SP. ing.

FIG. 3 is a block diagram showing the inside of the turntable 45 of FIG. 1. The output terminal 38 of the turntable remote control signal (d) and the input terminal 39 of the turntable remote control return signal (e) in FIG. Have. Reference numeral 451 denotes a microcomputer that receives start and stop signals based on the two control signals (d) and (e). The microcomputer controls the voltage control circuit 452 from the start and stop signals, and controls the horizontal operation motor 453 for moving the turntable 45 in the horizontal direction and the vertical operation motor 454 for moving the turntable 45 in the vertical direction.

Next, the operation of transmitting the turntable remote control signal (d) will be described. First, in FIG. 1, a turntable remote control signal (d) is input from the turntable control panel 34 to the input terminal 26 of the turntable remote control signal. The input rotary table remote control signal (d) is modulated by the frequency modulator 27 to become a frequency modulated wave having a center frequency of 11.7 MHz shown in FIG. The signal passes through a filter 28 that passes only this modulation frequency, is multiplexed with another signal through a coupling capacitor 29 for multiplexing to the coaxial cable 12, and transmitted to the camera signal separator (or camera) 13 side by the coaxial cable 12. Is done. On the camera signal separator (or camera) 13 side, the light is separated by a filter 36 that passes only this modulated wave through a coupling capacitor 35. The signal is demodulated by the demodulator 37, output from the output terminal 38 of the turntable remote control signal (d), and sent to the turntable 45.

A turntable remote control return signal (e) is output from the turntable 45 and is input from the input terminal 39 of the turntable remote control return signal (e). The input rotary base remote control return signal (e) has a center frequency of 11.2 MH shown in FIG.
The signal is frequency-modulated by a frequency modulator 40 of z, passes through a filter 41 that passes only the modulation frequency, passes through a coupling capacitor 42, is multiplexed with other signals into the coaxial cable 12, and is transmitted to the remote control unit 1 side. .

On the remote control unit 1 side, the signal is separated from the coaxial cable 12 through a coupling capacitor 30 by a filter 31 that allows only the above-mentioned modulated wave to pass. Thereafter, the signal is demodulated by the demodulator 32 and output from the output terminal 33 of the turntable remote control return signal (e), and is input to the turntable control panel 34.

Since the conventional camera remote control signal and camera synchronization signal are amplitude-modulated, the rising and falling components of the modulated wave at the point where the modulation amplitude changes significantly generate scratches and noise in the camera image. Therefore, processing is performed within the camera image blanking so that the image of the camera is not affected. However, if the control of the turntable is performed only during the blanking period of the camera, the operation of the turntable will be delayed, so real-time processing is indispensable. Therefore, the turntable remote control signal (d) and the turntable remote control return signal (e) of the turntable are sent to the coaxial cable by using frequency modulation and keeping the level multiplexed on the coaxial cable constant. It does not affect the video signal (baseband) of the camera in use. FIG. 4 shows the frequency assignment of each signal, and FIG. 5 shows the transmission waveform of each signal.

Next, the operation of the power supply supplied to the turntable 45 will be described. The power supplied from the remote control unit 1 by the method shown in the conventional example is supplied to the turntable power supply terminal 4.
4, when the turntable starts to operate due to the large-capacity capacitor circuit 43 including the filter
Due to the inrush current at the time of stop, the impedance of the coaxial cable instantaneously increases, thereby eliminating noise and the like in the image of the camera transmitted by the coaxial cable. Further, noise of the motor from the turntable 45 is also removed by a large-capacity capacitor circuit 43 including a filter.

On the other hand, the operation of the turntable 45 will be described. In FIG. 3, a start and stop signal of the turntable is input to the microcomputer 451 by a turntable remote control signal (d) from the output terminal 38. As described in the above description, the microcomputer 451 controls the voltage control circuit 452 to eliminate the noise generated by the sudden inrush current,
As shown in FIG. 2, a voltage is gradually applied to the horizontal operation motor 453 and the vertical operation motor 454 to perform the slow start ST, and the voltage is gradually reduced to perform the slow stop SP. The control curve is as shown in FIG.

The large-capacitance capacitor circuit including the above-described filter and the slow start / slow stop control of the turntable do not cause a sudden change in the current flowing through the coaxial cable.
This eliminates the effects of noise, etc., on the video signal of the camera flowing through the coaxial cable, making it possible to supply power to the turntable. The power supply to both the camera and the turntable is made possible with a single coaxial cable without having to prepare separate power supplies for the turntable and the camera.

[0038]

As described above, the present invention enables remote control of a camera, a lens, and a turntable with a single coaxial cable. In addition to these remote controls, power is supplied to the camera, lens, and turntable. Made it possible. According to the present invention, in addition to a coaxial cable for connection between a camera and a remote control unit, an AC adapter or the like is separately prepared on the turntable side to supply power to the turntable, Although it was necessary to connect the stand control panel with a cable, all power supply and control can be performed with only one coaxial cable, which significantly improves the work efficiency and at the same time makes the turntable to a place where it is difficult to take AC power. Can be installed.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a multiplex transmission type turntable system according to an embodiment of the present invention.

FIG. 2 is an operation characteristic diagram of the turntable in the embodiment of the present invention.

FIG. 3 is a configuration block diagram of a turntable according to the embodiment of the present invention.

FIG. 4 is a frequency allocation diagram of each signal transmitted by the coaxial cable according to the embodiment of the present invention.

FIG. 5 is a waveform diagram used for multiplex transmission in the embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of frequency allocation of signals transmitted by a conventional multiplex transmission type coaxial cable.

FIG. 7 is an example of a waveform used for multiplex transmission in a conventional multiplex transmission system.

FIG. 8 is a diagram showing an example of a transmission waveform in a conventional multiplex transmission type coaxial cable.

FIG. 9 is a configuration block diagram of a conventional multiplex transmission system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Remote control unit 2 Camera video signal output terminal 3 Synchronization signal input terminal 4 Camera remote control signal input terminal 5, 6, 27, 40 Modulator 7, 16, 28, 31, 36, 41 Filter 8, 9, 14, 15, 29, 30, 35, 42 Coupling capacitor 10 Power supply unit 11 Constant current circuit 12 Coaxial cable 13 Camera signal separator (or camera) 17, 18, 32, 37 Demodulator 19 Camera video signal transmission circuit 20 Synchronization circuit 21 Camera control circuit 22 Impedance converter 23 Constant voltage circuit 24 Load (camera) 25 Synchronization pulse generation circuit 26 Input terminal of turntable remote control signal 33 Output terminal of turntable remote control return signal 34 Turntable control panel 38 Turn Output terminal of stand remote control signal 39 Input terminal of turntable remote control return signal 43 large-capacity capacitor circuit 44 rotary base power supply terminal 45 turntable including a filter

Claims (5)

[Claims] A remote control signal including a camera remote control signal, a synchronizing signal, a turntable remote control signal, and a lens remote control signal is modulated to a frequency outside the band of the video signal of the camera. A multiplex transmission type turntable system, wherein a signal and the video signal are multiplexed and transmitted. 2. A power supply circuit on a remote control unit side, and a turntable remote control signal including a camera video signal, a remote control signal, a synchronization signal, a turntable remote control signal, and a lens remote control signal at an output thereof. 2. The multiplex transmission type turntable system according to claim 1, wherein the control signal and the power are supplied to the camera, the lens and the turntable side by multiplexing and transmitting the signal by one coaxial cable. 3. The multiplex transmission type turntable system according to claim 1, wherein the multiplexed power supply is distributed to the camera, the lens, and the turntable via a large-capacity capacitor circuit including a filter. 4. In order to supply the multiplexed power to the camera and the turntable, the start / stop speed of the turntable is controlled, and noise due to inrush current and noise of the motor of the turntable are added to the video signal of the camera. The multiplex transmission type turntable system according to claim 1, wherein the number is reduced. 5. Control of each of a camera, a turntable and a lens,
2. The multiplexing method according to claim 1, wherein the video signal of the camera, the power supply of the camera, the lens and the turntable are multiplex-transmitted to the turntable and the camera signal separator from the remote control unit and the turntable control panel by one coaxial cable. Transmission type turntable system.