JPS63252085A - monitoring device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a monitoring device that monitors images taken by a camera such as an entrance intercom with a television or a security surveillance camera using a display such as a cathode ray tube.

2. Description of the Related Art Recently, monitoring devices that monitor images captured by a video camera on a display have become popular.

Hereinafter, a conventional monitoring device as described above will be explained with reference to the drawings.

FIG. 3 is a block diagram of a conventionally commonly used monitoring device. In FIG. 3, 1 is a monitor device including a power supply device and a display device. 2 is a camera, 3 is a camera power supply circuit that supplies power to the camera, 4 is a display power supply circuit that displays images from the camera on a display, and 6 is a monitor that processes images from the camera and displays them on the display 6. This is a display circuit. When voltage is supplied to the camera 2 from the camera power supply circuit 3, the camera 2 is turned on, and the video signal of the camera 2 is displayed on the display 6 via the monitor display circuit 6. At this time, the display power supply circuit 4 needs to be in the ON state. Conventionally, the display power supply circuit 4 has always been in an ON state, or has been turned ON at the same time as the camera power supply circuit 3 is turned ON.

Problems to be Solved by the Invention However, if the display power supply circuit 4 is always on, unnecessary power is constantly supplied, which is not only uneconomical but also affects the lifespan of the display 6. , and it is unnatural that the display device is working even though the camera is not working. On the other hand, if the display power supply circuit 4 is turned on at the same time as the camera power supply circuit 3 is turned on, the power supply line to the camera may be disconnected or short-circuited, or the camera may operate abnormally and cause excessive current. The display device will work even when the video is flowing.

In view of the above problems, the present invention provides a monitoring device in which power to a display device is turned on only when power is being normally supplied to the camera.

Means for Solving the Problem To achieve this object, the inventive monitoring device includes a camera power supply circuit that supplies power to the camera, and detects the voltage of the camera power supply circuit and the power supply point to the camera; A power switch circuit is provided that controls turning on of power to the monitor display circuit according to the voltage.

Effect: With this configuration, the monitor display circuit operates only when power is being supplied to the camera normally, eliminating the need for the monitor display device to operate when no image is being displayed, resulting in an unnatural feeling. It is economical because it eliminates the problem and does not consume unnecessary power.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 1 shows a monitoring device of the present invention.

In Fig. 1, 1 is a camera power supply circuit 3 that supplies power to the camera, detects the voltage at the power supply point to the camera, and turns on/off the power to the monitor display circuit according to the detected voltage.
This monitor device includes a power switch circuit 7 for turning off the camera, a monitor display circuit 6 for processing images from the camera, and a display 6 for displaying images from the camera. 2 is a camera.

The operation of the monitoring device configured as described above will be explained below.

In FIG. 1, when the camera power supply circuit 3 is turned on and power is supplied to the camera 2, the camera power supply circuit 3 and the camera 2
The voltage at the connection point becomes a predetermined value.

The power switch circuit 7 detects this voltage and, when a predetermined voltage is detected, supplies power to the monitor display circuit 6 and can display the video signal of the camera 2 on the display 6. If the connection between the camera power supply circuit 3 and the camera 2 is disconnected or short-circuited, the voltage at the connection point of the camera power supply circuit 3 will not reach the predetermined value, so the power switch circuit 7 will not be able to supply power to the monitor display circuit 6. The intended purpose is achieved.

FIG. 2 shows an embodiment of the monitoring device of the present invention.

In Figure 2, L is a coil, R4-R45 are resistors, and C
is a capacitor, Q1 to Q5 are transistors, 1C1 to I
C5 [Comparator, SW is a switch.

Reference characters 1 and B are power supply points, and C is a power supply point to the monitor display circuit 6.

D is the output point of the video signal. Further, 2 is a camera.

The operation of the embodiment of the monitoring device configured as described above will be described below.

In FIG. 2, when the switch SW is turned on, the transistor Q5 is turned on, causing the voltage at the + side terminal of the comparator IC to be lower than that at the one side terminal.

This lowers the potential at the output terminal of comparator IC, and transistor Q2. Q1 is turned on and voltage is supplied to camera 2. At this time, the collector current of the transistor Q becomes constant, and the collector voltage of the transistor Q1 becomes a predetermined voltage due to the load of the camera 2. When the camera 2 is in the ON state, the video signal is superimposed on the power supply line, passes through the capacitor C, and is output to the terminal. When the camera 2 is in normal operation, the collector voltage of the transistor Q is the voltage across the terminals of the resistors R4, R,. , R4, is the middle of the voltage range divided by R4, that is, the terminal voltage R4,/(R1+R10I-
R2,) to (R10+RH) / (R9+R10+
RH), the output voltages of the comparators IC2 and IC5 become high, turning on the transistors Q5 and Q4, and supplying power to the terminal C to the monitor display circuit 6.

If camera 2 malfunctions or the power supply terminal to camera 2 is disconnected or short-circuited, the collector voltage of transistor Q will be out of the voltage range mentioned above, and comparator E C2 or Comparator I
C, the output of one of the transistors Q5. Q4 is in the OFF state, and power is not supplied to the terminal C to the monitor display circuit 6.

Effects of the Invention As described above, the present invention detects the voltage at the point where power is supplied to the camera and controls the operation of the monitor display circuit according to the detected voltage. Since only the monitor display works, there is no wasted power consumption, and there is no unnatural feeling such as the monitor being on even though no image is displayed, so its practical effects are great. There is.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a monitoring device of the present invention, FIG. 2 is an electrical connection diagram of the same essential parts, and FIG. 3 is a block diagram of a conventional monitoring device. 1...Monitor device, 2...Camera,
3... Camera power supply circuit, 4... Power switch circuit, 6... Monitor display circuit, 6... Display, L... Coil , R7-R15...Resistor, C...Capacitor, Q1-Q5...Transistor, IC4
~ Engineering C5...Comparator, SW...Switch, A, B...Power terminal, C......
Power supply terminal, C...Video output terminal. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 21 2 L D Figure 3!

Claims (1)

[Claims] A camera power supply circuit that supplies power to the camera, and a monitor display circuit that detects the voltage between the camera power supply circuit and the power supply point to the camera, and controls the power supply to process the imaging output of the camera according to the voltage. A monitoring device comprising a power switch circuit.