JPH0771214B2 - Television camera device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a system for driving a television camera by supplying a synchronizing signal to the camera unit from the outside, by changing the pulse width of the vertical synchronizing signal to the camera unit. The present invention relates to a television camera device adapted to send a message.

(Prior art and its problems) Conventionally, when transmitting a control signal to a camera unit, a dedicated multi-purpose cable was provided in addition to a coaxial cable for transmitting a video signal. Even in the method of superimposing the power supply and the camera drive synchronization signal on the video signal transmission coaxial cable, a multi-purpose cable must be provided to transmit the control signal. It was not possible to take advantage of this method that can be connected. Even in a 4-division camera system that requires a camera deflection size switching signal in addition to the power supply and synchronization signal, the deflection size switching operation cannot be performed simply by connecting the camera unit and the control unit with one coaxial cable. A dedicated multi-purpose cable was connected to transmit a synchronizing signal and a deflection size switching signal.

The use of a multi-fiber cable causes problems such as difficulty in obtaining the cable from the general market, poor soldering due to an increase in the number of cable terminal processing parts, and poor reliability such as incorrect connection. Also, although a manufacturer can supply a multi-purpose cable with a connector, there is a drawback in that it cannot be performed smoothly due to the distance between the installation location of the camera unit and the control unit, and the way the wires are connected.

In order to solve this, the control signals for the lens and platform are digitized and superimposed on the vertical blanking period and transmitted to the camera head, and the subcarrier synchronization information is transmitted as pulse width modulation of the horizontal synchronization signal. It has also been proposed to transmit white balance control information as pulse width modulation of H-cut pulses.

According to this, the control signal can be transmitted to and controlled by the camera head with one coaxial cable.

However, in this method, the circuit scale becomes large only to generate a pulse to represent digital information, and since the cut pulse width of H is used, it is necessary to make a slight change in the pulse width (several microseconds). ， There is a drawback that the circuit becomes complicated and the cost increases. (Object) In order to solve these drawbacks, the present invention changes the pulse width of the vertical synchronizing signal transmitted to the camera unit according to the control purpose, detects the pulse width in the camera unit, and uses it as a control signal. It is something that is done.

(Embodiment) Hereinafter, a case where the present invention is applied to a four-division camera system requiring a control signal for switching the deflection size will be described.

The four-division camera system reduces the images of four television cameras and divides them into four by projecting them on the screen of one monitor television to enlarge and scan the deflection size of the camera. However, since it is necessary to display the image of one television camera on the entire screen of one monitor television, the deflection size switching control must be performed according to each mode.

FIG. 1 is a block diagram of a 4-division camera system according to an embodiment of the present invention. The camera unit 9 and the control unit 1 are connected by one coaxial cable 8, and the coaxial cable 8 has a video signal sent from the camera unit 9 to the control unit 1 and a camera sent from the control unit 1 to the camera unit 9. The power supply for differential, the horizontal sync signal for driving the camera, and the vertical sync signal for driving the camera are superimposed. In the control unit 1, the power supply for camera operation is from the power supply circuit 16, the horizontal sync signal for camera drive is from the horizontal sync shaping circuit 5, and the vertical sync signal for camera drive is from the vertical sync shaping circuit 6. It is sent out via 7. The vertical synchronizing signal for driving the camera is a signal having a different pulse width or a normal pulse width signal as a deflection size switching signal. In the camera unit 9, the power supply / synchronization signal separation and image superimposing circuit 10 separates the power supply and the synchronization signal to drive the camera. Also, vertical sync width detection circuit
The control signal is obtained by switching the deflection size by 11. Since the deflection linearity constant is switched in accordance with the deflection size switching, the deflection circuit 13 is controlled via the deflection size / linearity correction switching circuit 12. Reference numeral 14 is an image pickup unit and a video processing circuit, and 15 is a lens.

The video signal input to the control unit 1 is synthesized by the video processing circuit 2 through the video separation circuit, the power supply, and the sync signal superimposing circuit 7 in synchronization with the sync pulse shaping circuit and the operation unit 3,
It is sent from the video output terminal 17. Reference numeral 4 is a synchronizing signal generating circuit.

In the present invention, as described below, a pulse having a different width from the normal horizontal drive signal (HD) and vertical drive signal (VD) is used as the horizontal and vertical synchronizing signals. The reason for this will be described first. To do.

The widths of the normal horizontal drive signal (HD) and the vertical drive signal (VD) are 0.1H and 9H (H: 63.5 μs), respectively. If it is superimposed on one coaxial cable as it is, HD pulses will not be mixed during the VD period. If a sync signal generating IC is used, a decoded sync signal can be obtained, but since the circuit is genlocked by the supply of HD and VD from the outside, the circuit becomes complicated and the cost increases. In order to improve these points, in the embodiment of the present invention, the sync signal used has a width of VD slightly smaller than H / 2 in the first control state, and is twice the above in the second control state. It is less than 1H. Moreover, the width of HD is set to about 1 μs due to the separation of synchronization. By doing this, it is possible to obtain superposed waves of HD and VD with a simple circuit configuration.

Next, the synchronizing signal supplied to the camera unit in this embodiment will be described with reference to FIG. In Figure 2,
(A) and (B) show superimposed waveforms of the horizontal drive signal (HD) and the vertical drive signal (VD) in the case of odd fields and (C) and (D). It should be noted that (A) and (C) are waveforms when an image of one of the television cameras is monitored by one monitor television, that is, when a video signal of a screen of a normal size is obtained (hereinafter, referred to as a normal mode). The waveforms of (B) and (D) are the waveforms when the images of four television cameras are simultaneously monitored by one monitor television, that is, the normal waveforms from each television camera.
Waveforms for obtaining a video signal of a 1/4 size screen (hereinafter referred to as 4-division mode) are shown.

In any mode, HD21a to 21d are set to about 1 μs, VDs 22a to 22d are set to about 28 μs in the normal mode and doubled to about 56 μs in the four-division mode. In the even field in the 4-division mode, the positive HD cut pulse 23 is inserted between the VD pulse widths. The falling position of this pulse is normal
It is shifted by the HD pulse width from the HD trailing position, but it is 1μ
Since the difference is about s, the video signal will not be abnormal.

FIG. 3 shows an example of a circuit for obtaining the above-mentioned HD and VD superimposed waves. The waveforms of the respective parts in FIG. 3 are shown by the symbols corresponding to FIG. 4 in the case of even fields. Also, the fourth
In the figure, (F), (H), and (K) show waveforms in the normal mode, and (G), (I), (L), and (M) show waveforms in the four-division mode.

First, in the normal mode, (E) and (F) HD and VD are respectively applied to the input terminals 31 and 32, the polarities are inverted by the inverters 33 and 34, respectively, and the waveform of (H) is passed through the NOR circuit 35. Is obtained. The waveform (E) is also inverted in polarity by the inverter 38 to form the waveform (J), and the waveform (F) is the resistance 36,
With the circuit consisting of the capacitor 37, the pulse width of HD (about 1
μs), and the polarity is inverted by the inverter 39 to form the waveform (K). Waveform (J) and (K) AND circuit 4
Although added to 0, no waveform appears in the output due to the phase relationship. The outputs of the NOR circuit 35 and the AND circuit 40 are applied to the OR circuit 41, and the same waveform as that of the waveform (H), that is, the waveform as shown in FIG. 2C is obtained at the output terminal 42.

On the other hand, in the 4-split mode, the waveform (G) is applied to the VD input terminal 32.
Is added to obtain a waveform (I) at the output of the NOR circuit 35 and a waveform (L) at the output of the inverter 39. Since (J) and (L) have a common portion, a waveform (M) appears in the output of the AND circuit 40. The waveforms (I) and (M) pass through the OR circuit 41, and the waveform as shown in FIG.

The above is the case of the even field, but in the case of the odd field, the waveforms of FIGS. 4 (F) and 4 (G) are advanced by 1/2 horizontal period, and the output terminal 42 is shown in FIG. Waveforms as shown in A) and (B) are obtained.

The VD waveform is delayed by the HD pulse width (about 1 μs) by the circuit consisting of the resistor 36 and the capacitor 37 because the phase of the input VD pulse (falling edge) and the phase of the HD pulse (falling edge) match. This is to prevent the positive pulse of HD from appearing in the output of the AND circuit 40 in the odd field.

In the above description, the width of the VD pulse is set to about 56 μs in the case of the 4-division mode, but even if the width is further widened to 1 horizontal scanning period (63.5 μs) or more, the cutting pulse is inserted at the HD pulse position, There is no problem in operation.

As described above, HD and VD superimposed pulses having different VD pulse widths in the normal mode and the 4-division mode are sent to the camera unit 9, and the difference in the widths is detected by the detection circuit 11 of the camera unit and used as a control signal.

In the 4-split mode, both horizontal and vertical sync signals are supplied to the four camera units as signals with a specified phase shift.

Further, in the above-mentioned embodiment, the power supply, the video signal and the synchronizing signal are superposed on the coaxial cable, but when the necessary power is supplied to each of the camera unit and the control unit, the coaxial cable is obviously used. There is no need to superimpose power supplies.

(Effect) According to the television camera device of the present invention, even when it is necessary to control the camera unit as in a 4-division camera system, a general multipurpose cable is not used between the camera unit and the control unit, This connection is possible with a single coaxial cable.

For this reason, workability such as cable acquisition, wiring, terminal processing, etc. is improved, and eventually cost can be reduced.

Further, the control signal can be transmitted to the camera unit by changing the width of the vertical synchronizing signal. Therefore, the vertical pulse change is several hundreds of microseconds, the accuracy is about 1/100 as compared with the horizontal synchronization method, the stability is stable, the circuit is simple and the cost is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a 4-division television camera system according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of a sync signal waveform according to the present invention, and FIGS. 3 and 4 are embodiments of the present invention. It is a figure for explaining. 1: Control unit, 2: Video synthesis process circuit, 3: Synchronous pulse shaping circuit and operation unit, 4: Synchronous signal generation circuit, 5: Horizontal synchronization shaping circuit, 6: Vertical synchronization shaping circuit, 7: Video separation and power supply synchronization Signal superimposing circuit, 8: Coaxial cable, 9: Camera section, 10: Power sync signal separation and image superimposing circuit, 11: Vertical sync width detection circuit, 12: Deflection size, linearity correction switching circuit, 13: Deflection circuit, 14 : Imaging unit and video process circuit, 15: Lens, 16: Power supply circuit, 17: Video output terminal, 18: Camera unit supplied sync signal waveform (when one camera is used), 19: Camera unit supplied sync signal waveform (4 cameras) Hour), 2
0: Horizontal sync signal, 21: Vertical sync signal (with one camera), 22:
Vertical sync signal (when using 4 cameras), 23: Notch pulse, 24:
Video signal.

Claims (3)

[Claims] 1. A camera unit and a camera control unit having a horizontal / vertical synchronizing signal generating circuit are connected by a single coaxial cable,
In a television camera device for driving a camera unit by supplying a synchronization signal from the camera control unit to the camera unit via the coaxial cable, a shaping circuit capable of changing the pulse width of the vertical synchronization signal is provided to the camera control unit. A pulse width detection circuit for the vertical synchronization signal is provided in the camera unit, and the pulse width of the vertical synchronization signal supplied to the camera unit is changed by the shaping circuit according to the camera control signal.
A television camera device, wherein the detection circuit detects a pulse width of a vertical synchronization signal to control the camera unit. 2. The camera control section is provided with a circuit for superimposing a power supply for driving the camera and a synchronizing signal, and the camera section is provided with a circuit for separating the power supply and the synchronizing signal, and the camera control is performed via the coaxial cable. The television camera device according to claim 1, wherein a power source and a synchronization signal are superimposed and transmitted from the camera unit to the camera unit, separated by the camera unit, and used for driving the camera unit. 3. The television camera device reduces all images of four television cameras or one of them.
The television camera device according to claim 1 or 2, wherein the television camera device is a four-division television camera device that selects a single video image and displays it on a single monitor television.