JP2604546Y2 - TV camera device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television camera device which transmits and receives power, video signals, and other control signals through a single coaxial cable.

[0002]

2. Description of the Related Art Normally, a television camera device is composed of a power supply device, a television camera body, and a coaxial cable for connecting the two. Then, the combination of the connected power supply device and the TV camera body is changed, for example, even if another TV camera body is connected, it will operate even if it is connected with a coaxial cable and the power is turned on. Was working.

[0003]

However, when a system is constructed using a plurality of television camera devices, a combination of a power supply device and a television camera body must be specified. For example, when performing a delicate adjustment between devices and installing a series of systems, there is a possibility that the combination of the power supply device and the TV camera body may be mistakenly connected, and it will be used without exhibiting the original performance, A malfunction may occur. For this reason, in the past, the best care was taken so as not to break the combination between devices at the time of installation.

The present invention provides a television camera device which detects whether or not a combination of a power supply device and a television camera body is intended, is connected without making the combination mistaken, and exhibits expected performance. The purpose is to:

[0005]

According to the present invention, there is provided a television camera device for supplying power to a television camera body from a power supply device using a coaxial cable.
A state in which a plurality of types of impedances higher than the coaxial cable can be set, and impedance setting means provided between the coaxial cable and the ground on the television camera body side, and the power supply device does not supply power to the television camera body The video camera body by identifying an impedance detecting means for detecting the impedance between the coaxial cable and the ground on the power supply device side, and an impedance set by the impedance setting means according to a detection result of the impedance detecting means. And identification means for identifying whether the TV camera body is a different one.

[0006] The power supply apparatus may further include a power supply permitting means for permitting the power supply device to supply power to the television camera body in accordance with the identification result of the identifying means.

[0007]

The impedance detecting means detects the impedance of the impedance setting means provided between the coaxial cable and the ground on the television camera body side, and the result is identified by the identification circuit.

The power supply permitting means operates according to the identification result of the identification circuit.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a circuit diagram showing a television camera device according to an embodiment of the present invention. FIG. 2 is a timing chart showing the operation of FIG. 1. Waveforms A, B, C, D, and E are shown in FIG.
A, B, C, D, and E of FIG.
In the figure, 1 is a power supply device, 2 is a television camera body, and both are connected by a coaxial cable 3. Power supply 1
Has a power supply circuit 4 and the power supply 1 is always supplied with power. The resistor R1 inserted into the power supply line is for detecting load current, and when the television camera body 2 is not connected, the transistor T1 is off, the collector is low, and the output of the OR gate 5 is low. Therefore, JK
The S terminal of the flip-flop 6 is low, the R terminal is high, the output Q bar is low, turning on the transistor T2,
The transistor T3 is cut off. At this time, a resistor R2 and a diode D are connected to the collector of the transistor T3.
Although a voltage appears through the resistor 1, the resistors R3 and R4 have a sufficiently larger resistance value than the resistor R2, and therefore are substantially equal to the circuit power supply V except for the voltage drop of the diode D1.

On the other hand, the television camera body 2 is
And a driving circuit 8, and a resistance block 9 as impedance means is provided between the coaxial cable 3 as a power supply line and the ground. This resistor block 9 is composed of four resistors R5, R6, R7, R8 having different values and four switches S1, S2, S3, S4, and 16 impedances can be set by setting the switches. The impedance has a higher value than that of the coaxial cable 3 at the moment when the power supply device 1 and the television camera body 2 are connected. Therefore, at this moment, the power supply circuit 4
By supplying a different power to the coaxial cable 3 and detecting the voltage generated in the coaxial cable 3, the setting state of the resistor block 9 can be known.

Next, the operation when the power supply device 1 and the television camera body 2 are connected will be described. The power supply device 1 has four resistors R9 and R4 having different values, similarly to the television camera body 2.
10, R11, R12 and four switches S5, S6, S
7, a resistor block 10 composed of S8 is provided. The resistors R9, R10, R11 and R12 are respectively resistors R
5, R6, R7, and R8 have the same value. And
The voltage divided by the resistor R2, the diode D1, and the resistor block 9 and supplied from a power supply different from the power supply circuit 4 is
Resistance R13, R14, diode D2, resistance block 1
The voltages divided by 0 are compared with the comparators 11 and 12. If the set impedances of the resistance blocks 9 and 10 are the same and sufficiently larger than that of the coaxial cable 3, the ends 9a and 10a of each resistance block have substantially the same voltage.
The voltage divided by the resistor block 9 is set so that the voltage at both ends of the resistor R14 is divided up and down. If the set impedances of the resistor blocks 9 and 10 are the same, the outputs of the comparators 11 and 12 become Both go low, N
The output of the OR gate 13 becomes high (waveform A), and the resistance R
A high is input to the OR gate 5 slightly later than the timing when the power supply device 1 and the television camera main body 2 are connected by the integrating circuit constituted by 15 and the capacitor C1. Accordingly, the output of the OR gate 5 becomes high (waveform B), and high is input to the S terminal of the JK flip-flop 6.

On the other hand, the output of the NOR gate 13 is a resistor R
The hysteresis amplifier 14 passes through an integrating circuit constituted by a resistor 15 and a capacitor C1 and an integrating circuit constituted by a resistor R16 and a capacitor C2 (waveform C).
Is input to the CK terminal of the JK flip-flop 6 through the inverter 15 (waveform D), and changes from low to high later than the timing when the power supply device 1 and the television camera body 2 are connected. At the timing of changing from low to high, the states of the Q and Q bar terminals of the JK flip-flop 6 are inverted, that is, Q bar changes from low to high (waveform E),
The transistor T2 is turned on, and power is supplied to the television camera body 2 side. Then, by the voltage drop by the resistor R1 provided for detecting the load current,
Transistor T1 turns on, collector goes high and OR
The output to gate 5 goes high. Therefore, even if the coaxial cable functions as a signal line and the output of the NOR gate 13 becomes low due to a decrease in impedance (point a of the waveform A), the output of the OR gate 5 remains high. The output Q bar remains high until the next fall signal is input to the CK terminal.

If the set impedances of the resistance blocks 9 and 10 are different, that is, if the combination of the power supply device 1 and the television camera body 2 is not intended, the output of the NOR gate 13 becomes low and the output of the OR gate 5 becomes low. Does not go high. Therefore, power is not supplied from the power supply device 1 to the television camera body 2.

Next, when the power supply device 1 and the television camera body 2 are connected in an intended combination and the connection is released while power is being supplied, the load current decreases, the transistor T1 turns off, and the collector output Is low, and both inputs of the OR gate 5 are low. Therefore, the input to the S terminal of the JK flip-flop 6 becomes low (waveform B), and Q
The output of the bar terminal is low (waveform E), the transistor T3 is turned off, and the power supply from the power supply device 1 to the television camera body 2 is cut off.

[0016]

According to the present invention, whether or not the combination of the power supply device and the TV camera body is intended is identified by detecting the set impedance even if the TV camera body is the same model, It is possible to provide a television camera device which is connected without making a mistake in the combination and exhibits expected performance, and the effect is great.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a television camera device according to an embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply device 2 TV camera main body 3 Coaxial cable 4 Power supply circuit 9, 10 Resistor block 11, 12 Comparator T3 transistor (power supply permission means)

Claims (2)

(57) [Scope of request for utility model registration] 1. A television camera device for supplying power to a television camera body from a power supply device using a coaxial cable, wherein a plurality of types of impedances higher than that of the coaxial cable can be set, and the coaxial cable and the ground are set on the television camera body side. Impedance setting means provided therebetween; impedance detection means for detecting the impedance between the coaxial cable and the ground on the power supply device side in a state where the power supply device does not supply power to the television camera body; A television camera device comprising: identification means for identifying whether the video camera body is a different television camera body by identifying the impedance set by the impedance setting means in accordance with the detection result of the detection means. . 2. The power supply apparatus according to claim 1, further comprising a power supply permitting unit that permits the power supply device to supply power to the television camera body in accordance with a result of the identification by the identification unit. Television camera device.