JPS5932031B2 - tv jiyoung camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a camera control unit section (hereinafter referred to as CCU).
Regarding the television camera, which is separated into a camera head section (hereinafter referred to as HD
) and vertical drive pulses (hereinafter referred to as VD) can be transmitted from the CCU to the camera head through a single connection line, reducing the number of cores required for the coupling cable between the CCU and the camera head. It is an object of the present invention to provide a departure camera in which the weight and cost of a camera head including a coupling cable can be reduced.

A conventional television camera separated into a CCU and a camera head section will be explained using FIG. 2.

The synchronization signal generator 2 on the CCUI side is an HD as shown in Figure 1a.
and generates a VD as shown in FIG.
Each signal was transmitted to the camera head section 6 separately. Therefore, the coupling cable 3 needs to have a large number of core wires, which is one obstacle to reducing the weight of the camera head section 6 including the coupling cable 3. The present invention has been made in view of the above points, and one embodiment thereof will be described below based on the drawings.

In FIG. 3, □ is a CCU, and the HD shown in FIG. 1a generated by the synchronization signal generator 8 in the CCU 7 is
The pulse wave is differentiated by a differentiator 9 and is applied to an adder 10 as a pulse wave shown in FIG. 5a. Further, D shown in FIG. 1b has a high frequency component removed by a low-pass filter (hereinafter referred to as LPF) 11 and becomes a waveform as shown in FIG. 5b, and the adder 10 has a waveform shown in FIG. Outputs a composite pulse as shown in
The composite pulse is transmitted to the camera head 14 via the core wire 13 of the coupling cable 12. The reason why only the high frequency component of HD and the low frequency component of D are combined to form a composite pulse in this way is that when HD and D are separated from the composite pulse in the camera head section 14, mutual influence between each pulse is eliminated; This is to enable easy separation. In the camera head section 14, by passing the composite pulse through a high-pass filter (hereinafter referred to as HPF) 15, only the HD differential wave as shown in FIG. 5d is separated.

At this time, a slight differential wave of D also appears, but as mentioned above, the high-frequency components of D are removed to obtain a composite pulse, so
The effect is slight. If a composite pulse is created without removing the high-frequency components of VD, its differential wave (high-frequency component) will appear even if it passes through HPF15, and it will not be possible to obtain only the HD differential wave without this influence. cannot be formed. The HD differential wave separated from the composite pulse is shaped into a waveform by a switching circuit 16,
A horizontal pulse equivalent to HD as shown in FIG. 5h is obtained. On the other hand, the composite pulse passes through the LPF 17, thereby removing the HD differential wave and extracting only the D low frequency component as shown in FIG. 5e. At this time HD
The influence of the differential wave also appears, but since the composite pulse is formed using the HD as the differential wave, this influence is small and can be almost ignored. If a composite pulse is formed using the pulse as it is without differentiating HD, the effect will be large, and since the relationship between D and HD differs for each vertical scanning period (hereinafter referred to as 1) in order to perform interlaced scanning, the The influence appears at the start of D differently for each one, and the pulse period of D is different for each one, resulting in the inconvenience that the interlace is shifted. The output of the LPF 17 is waveform-shaped by the switching circuit 18 to obtain a vertical pulse equivalent to D as shown in FIG. Since the high frequency component of VD is removed and sent from the CCU 7 side, the obtained vertical pulse is slightly delayed from the original VD, but this does not have any adverse effect. FIG. 4 is a circuit diagram showing the main parts of the block diagram of FIG. 3.

The voltage VD shown in Figure 1b is led to the terminal 19, and the high frequency component is removed by the LPF consisting of the resistor R and capacitor C2 via the coupling capacitor C, resulting in the waveform shown in Figure 5b. , via resistor R2 to the base of transistor Trl biased by resistors R3 and R4.
On the other hand, the HD shown in Fig. 1a is led to the terminal 20, and is differentiated by a differentiating circuit composed of a capacitor C3 and resistors R2, R3, and R4, and is added to the signal from which the high frequency component of b is removed. As a result, a composite pulse shown in FIG.
4 to the camera head section by one core wire 22 of the coupling cable 21. The composite pulse transmitted to the camera head section passes through a coupling capacitor C5, and the HD differential pulse is removed by an LPF consisting of a resistor R6 and a capacitor C6, resulting in the waveform shown in Figure 5e, and is biased by a resistor R7. Switching transistor Tr2
The transistor T,2 is made conductive at a level below the broken line A of the waveform shown in FIG. 5e, and a vertical voltage equivalent to D shown in FIG. Get a pulse.

On the other hand, from the composite pulse, the HD differential wave is extracted by the HPF constituted by the capacitor C7 and the base bias resistor R9 of the switching transistor Tr, and the broken line of the negative side pulse of the differential wave shown in FIG. The transistor Tr3 is made conductive at a level below 100 Ω, and the terminal 23 of the capacitor C8 connected between the collector of the transistor Tr3 and the ground is connected to the power supply voltage V.

Charge to c. Similarly, from the composite pulse, the HD differential wave is taken out by the HPF constituted by the capacitor C9 and the base bias resistor RlO of the switching transistor Tr4, and the positive side pulse dashed line of the differential wave shown in FIG. The transistors T and 4 are made conductive at the level above C, and the negative pulse of the HD differential wave is applied to the power supply voltage V
The potential of the terminal 23 of the capacitor C8, which had been charged to cc, is returned to the ground potential. By this operation, a horizontal pulse having the same pulse width as HD is obtained at the terminal 23, as shown in FIG. 5h. As explained above, according to the present invention, the camera control unit section converts the horizontal drive pulse and vertical drive pulse obtained by the synchronization signal generator into waveforms, mixes them, and sends them to the camera head section as a composite pulse. In addition to providing the first means, the second means for separating and forming the horizontal drive pulse and the vertical one drive pulse from the composite pulse is provided in the camera head section, so that the coupling cable connecting the camera control unit section and the camera head section is The number of core wires in the camera head can be reduced, and the weight and cost of the camera head including the coupling cable can be reduced.

In addition, when the present invention is applied to a simple TV camera aimed at home use, the number of fibers in the coupling cable that was previously required is reduced to a coaxial cable for video signals, a shielded wire for audio signals, and a power supply. There used to be a total of 6 wires: a wire, a ground wire, a core wire for vertical drive pulses, and a core wire for horizontal drive pulses, but this was reduced to 5 wires, and the percentage of reduction was large, resulting in a remarkable effect. is obtained.

[Brief explanation of drawings]

Fig. 1a is a waveform diagram of horizontal and driving pulses, b is a waveform diagram of one vertical driving pulse, Fig. 2 is a block diagram showing a conventional example, and Figs. 3 and 4 show an embodiment of the present invention. , FIG. 3 is a block diagram thereof, FIG. 4 is a circuit diagram of its main parts, and FIG. 5 is a signal waveform diagram of each part in FIGS. 3 and 4. 7...Camera control unit section, 8...
... Synchronization signal generator, 9 ... Differentiator, 10
...Adder, 11,17...Low pass filter, 12,21...Coupling cable, 13,22
... Core wire, 14 ... Camera head section,
15...High-pass filter, 16,18...
Switching circuit, 19, 20, 23...terminal, C4~C,...capacitor, R,~R,O・
...Resistor, Trl to Tr4...Transistor.

Claims (1)

[Scope of Claims] 1. A television camera separated into a camera control unit section and a camera head section, wherein the camera control unit section receives horizontal drive pulses and vertical drive pulses obtained from a synchronization signal generator. A first means is provided which converts the waveform and then mixes it and sends it to the camera head section as a composite pulse, and the camera head section separates and separates a horizontal drive pulse and a vertical drive pulse from the composite pulse.
A television camera characterized in that it is provided with a second means for shaping. 2. The first means forms a composite pulse by adding the pulse waveform obtained by differentiating the horizontal drive pulse and the pulse waveform obtained by removing the high frequency component of the vertical drive pulse. , a horizontal drive pulse is formed by the differential wave of the horizontal drive pulse obtained by removing the low frequency component of the compound pulse, and a vertical drive pulse is formed by the low frequency component obtained by removing the high frequency component of the compound pulse. A television camera according to claim 1, characterized in that: 3 The means for forming a horizontal drive pulse using a differential wave of a horizontal drive pulse horizontally drives a first switch connected between a first power source and the other end of a capacitor whose one end is kept at an arbitrary DC potential. Driven by a negative pulse of a differential wave of the pulse, and connected between the other end of the capacitor and a second power source having a lower potential than the first power source by a positive pulse of the differential wave. Claim 2, characterized in that by driving the second switch, a horizontal pulse having the same pulse width as the original horizontal drive pulse is obtained at the other end of the capacitor. Television camera as described in section.