JP3697683B2 - Imaging apparatus and monitoring system including the imaging apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus that performs monitoring by displaying a captured image of a person or a vehicle captured by a television camera installed indoors or outdoors on a screen of a monitor apparatus, and a monitoring system including the imaging apparatus.
[0002]
[Prior art]
A security camera device has been proposed as an example of a surveillance system that installs a plurality of television cameras in a building or the like and monitors a person intrusion (see Japanese Patent Publication No. 8-31195).
The security camera device includes a control unit that sequentially switches and transmits imaging signals from a plurality of television cameras installed in a building every predetermined period, and a focus movement detection unit that detects a change in imaging focus of the television camera. I have. Each television camera has a built-in focus adjustment unit and a distance measuring circuit.
The security camera device configured as described above obtains the distance between the subject and the camera by transmitting and receiving infrared rays or ultrasonic waves from each television camera toward the subject. Further, the in-focus position is detected by the automatic focus adjustment circuit, and the subject is focused by driving the lens system.
Then, when an object or a person who has not existed within the imaging range of the camera has entered since the start of the focusing operation, the focus position detection means detects a change in the imaging focus of the television camera.
Then, the control means stops the sequential switching operation of the imaging signals, and only the captured video of the television camera whose focus has changed is displayed on the screen of the CRT constituting the monitor device for centralized monitoring. Therefore, it is possible to immediately detect a person's intrusion without relying on the monitoring of the manager.
[0003]
[Problems to be solved by the invention]
By the way, the conventional security camera device centrally monitors the captured video of only the television camera in which the change in the imaging focus is detected. However, while the change in the imaging focus is not detected, some image is displayed on the CRT screen. continuing.
In this way, if an image is continuously displayed on a CRT with high power consumption even during a period in which the imaging target does not change at all, the power supply is not stopped even after the power is turned on, and this waste of power has been extremely wasteful. .
In addition, when an image signal from a television camera is recorded on a magnetic tape by a VTR (video tape recorder), the recording amount of the magnetic tape may be reduced if there is a case where recording is continued while the imaging target does not change at all. There is a problem that the volume of the recording medium becomes enormous, leading to waste of time as well as waste of the tape as a storage medium, and deterioration of each part of the device can be accelerated.
[0004]
The present invention was devised in view of the above problems, and receives a focus signal for moving a focusing lens to a focus position, and stops the image display of the display means when there is no change in the imaging target, thereby consuming power. An object of the present invention is to provide a display device that can reduce the waste of a recording medium by reducing recording and signal recording of a recording means.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 of the present invention is a control for outputting a signal voltage for moving a focusing lens of an imaging unit to a focus position in response to a focus signal from a focus sensor. A motor drive unit having a terminal unit, a monitor device connected to the video terminal unit of the imaging unit, a display unit for receiving an image signal output from the monitor device and displaying an image, and an output from the control terminal unit A signal detection unit that detects the signal voltage and outputs the detection signal as a control signal, and receives the control signal output from the signal detection unit to turn on the monitor device and display an image on the display unit On the other hand, when the control signal is no longer input, the built-in timer starts counting for a fixed time, and when the predetermined time elapses, the monitor device is turned off. To stop the reflect images to the display unit is operated, the control unit If this from the signal detection unit at a time is receiving the control signal which is again turned on the monitor device to repeat the above process It is characterized by having.
[0006]
The invention according to claim 2 is characterized in that the display section is a cathode ray tube monitor or a liquid crystal display device .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the illustrated examples. FIG. 1 is an electrical block diagram showing a schematic configuration of an imaging apparatus according to the present invention, FIG. 2 is an explanatory diagram showing control means of the imaging apparatus, and FIG. 3 shows a monitoring system provided with the imaging apparatus. Electrical block diagram , FIG. 4 is a flowchart for explaining the operation of image display .
[0008]
This surveillance system 1 is a security camera device that monitors a person by installing a plurality of television cameras as imaging devices 2 in a building, and includes a camera control unit 3, a signal switching unit 4, a motor control signal detection circuit (hereinafter referred to as a “motor control signal detection circuit”). (Abbreviated as a signal detection circuit) 5 and a monitor device 8 incorporating a control unit 9 and the like.
The television camera 2 uses a conventionally well-known video camera, and in this example, 4 units 2A to 2D are arranged in various places of the building. This television camera 2 is provided with a focusing lens 11 on the front end side of the imaging lens 10 built in the main body case.
The focusing lens 11 is moved in the optical axis direction by a motor 15 and a drive mechanism 16 to change the focal position. The motor 15 rotates forward and backward in response to a control signal from the motor drive unit 14 and rotates the drive mechanism 16 formed of a gear to move the focusing lens 11 forward and backward.
[0009]
Although not shown, the motor drive unit 14 includes a signal conversion unit, one input port 14a, two output ports 14b and 14c, and the like, and operates according to a command signal from the camera control unit 3 to provide a motor. A signal for controlling the rotation of 15 is output.
That is, the output signal from the focus sensor 13 is guided to the input port 14 a of the motor drive unit 14. The focus sensor 13 outputs a focusing signal, and a signal from a photoelectric conversion unit (not shown) is guided.
This focus sensor 13 calculates the defocus amount (image plane shift amount) when the light beam of the subject image divided by the beam splitter 12 in the imaging lens 11 enters, and drives a signal for focusing on the imaging focus by a motor. To the input port 14a of the unit 14.
[0010]
The motor drive unit 14 receives a focus signal, generates a signal voltage (“H” and “L” level) for moving the focusing lens 11 to the imaging focus, and outputs two output ports 14b and 14c as control signals. The signals are supplied to the motor 15 and the signal detection circuit 5 connected to the (control terminal unit).
The motor 15 is configured to rotate forward (right rotation) or reverse (left rotation) in response to an H level or L level control signal output from the output port 14b.
The signal detection circuit 5 detects an H level or an L level appearing at the output port 14c, and sends the detection signal to the control unit 9 side of the monitor device 8 as an on / off control signal.
[0011]
The monitor device 8 includes a control unit 9, an audio signal processing unit, a video signal processing unit, and the like. A CRT 7 is connected to the video signal processing unit, and images of the TV cameras 2A to 2D are captured on the screen of the CRT 7. It is supposed to be projected on. Note that a liquid crystal display device having an LCD screen may be employed instead of the CRT 7.
The control unit 9 controls the operation of the entire apparatus, and includes a CPU, a ROM, and a RAM. The input port 9a and the output port 9b include a key input unit 6, the camera control unit 3, and a signal switching unit 4. The CRT 7 and the video signal processing unit are connected in one direction or bidirectionally depending on each function.
The camera control unit 3 is connected to each of the four television cameras 2A to 2D, and is connected to the output of the control unit 9, and receives a selection command signal from the control unit 9 to receive each television camera. A command signal for turning on and off 2A to 2D is output.
[0012]
The signal switching unit 4 includes first to fourth fixed contacts 4a to 4d and a movable contact 4e. The first fixed contact 4a is connected to the video terminal unit 2a of the first TV camera 2A, and the video of the second TV camera 2B. A second fixed contact 4b is connected to the terminal 2a, a third fixed contact 4c is connected to the video terminal 2a of the third TV camera 2C, and a fourth fixed contact 4d is connected to the video terminal 2a of the fourth TV camera 2D. ing.
The movable contact 4e is connected to a video signal processing unit of the monitor device 8, and a switching signal from the control unit 9 is guided to the movable contact 4e.
In the signal switching unit 4 thus connected, the movable contact 4e is switched and connected to one of the first to fourth fixed contacts 4a to 4d by the switching signal, and the images of the first to fourth TV cameras 2A to 2D are connected. The imaging signal sent from the terminal unit 2a is transmitted to the video signal processing unit side.
This video signal processing unit is configured to perform signal processing for receiving a captured image signal from the television camera 2 and displaying a captured image on the screen of the CRT 7.
[0013]
Next, an image display operation of the monitoring system provided with the imaging device will be described.
When the operator performs an on operation with the key input unit 6, the control unit 9 receives the operation signal and sends a command signal to the camera control unit 3 and the signal switching unit 4.
The camera control unit 3 supplies a voltage to each of the television cameras 2A to 2D based on the command signal and turns on each of them. Along with this, imaging of all the television cameras 2 </ b> A to 2 </ b> D is started, and the imaging signals are sent to the signal switching unit 4.
The signal switching unit 4 switches and connects the movable contact 4e to the four fixed contacts 4a to 4d at a predetermined time interval set in advance, and sequentially switches the imaging signals sent from the TV cameras 2A to 2D to perform video signal processing. To the control unit 9 side.
Along with this, the control unit 9 turns on the monitor device 8 and sequentially displays images captured by the television cameras 2A to 2D on the screen of the CRT 7.
[0014]
After such imaging and image display are started, when no object or person enters the imaging range of any of the television cameras 2A to 2D, they enter the focus sensor 13 of each television camera 2A to 2D. The defocus amount does not change.
Therefore, since the focus signal is not sent from the focus sensor 13 to the motor drive unit 14, the motor 15 does not rotate, and no control signal is output from the signal detection circuit 5.
When this control signal is not input, the control unit 9 turns off the monitor device 8 within a preset time, and stops displaying an image on the screen of the CRT 7. Thereby, when there is no change in the imaging target after the start of imaging and image display, the monitor device 8 and the CRT 7 are not operated, so that power consumption can be reduced.
[0015]
During such standby, the control unit 9 continues to determine whether or not the autofocus operation has been started (step S11).
Here, when an object or person that has not existed in the imaging range of any of the television cameras 2A to 2D enters, the amount of defocus entering the focus sensor 13 of the television camera changes. The focus sensor 13 sends a focus signal to the motor drive unit 14 in accordance with a change in the defocus amount.
The motor drive unit 14 outputs a control signal for rotating the motor 15 forward (right) or reverse (left) based on the focus signal.
When a control signal indicating a change in focus signal is output from the output ports 14b and 14c, the control unit 9 that receives this control unit signal turns on the monitor device 8, and images the screen of the CRT 7 with any of the television cameras. The processed image is displayed (step S12).
[0016]
Further, since the motor 15 is rotated by the control unit signal and the drive mechanism 16 is interlocked, the focusing lens 11 moves to the imaging focus. When the focusing lens 11 stops moving at the in-focus position, the imaging signal at this time is sent to the monitor device 8 and a clear image is displayed on the screen of the CRT 7.
During this image display, the control unit 9 continues to determine the autofocus operation (step S13). Then, when the control signal is not input, time counting by the built-in timer is started, and it is determined whether or not a predetermined time has elapsed (step S14).
Here, when there is no object or person due to the resolution of the security problem and the fixed time has elapsed, the control unit 9 turns off the monitor device 8 and stops displaying the image on the screen of the CRT 7. .
Thereby, even when the image is displayed, when there is no change in the imaging target, the monitor device 8 and the CRT 7 do not operate continuously, so that power consumption is reduced accordingly.
[0017]
In the above embodiment, the case where the captured image is displayed on the CRT 7 of the monitor device 8 has been described. However, it is also possible to connect the VTR to the control unit 9 and record the image signal on the magnetic tape of the cassette. is there.
At this time, an image signal input terminal of the VTR is connected to the movable contact 4e that is switched and connected to the video terminal portion 2b, and a control signal input terminal of the VTR is connected to the control terminal portion of the output port 9b in the control portion 9. .
When connecting a VTR in this way, the control unit of this VTR is set to the automatic recording mode. That is, the control unit controls the recording of the image signal on the magnetic tape of the cassette when the control signal is input by the movement of the focusing lens 11 and stops the recording of the image signal when the control signal is not input. It is set as the structure which performs.
[0018]
Thereby, during imaging of the television cameras 2A to 2D, when there is no movement of an object or a person and the imaging target does not change, an image signal is not recorded on the magnetic tape, so that it is possible to prevent the magnetic tape from being used wastefully. Further, time is not wasted when reproducing the magnetic tape.
In the above embodiment, a video camera is used as the television camera 2 so that sound can be emitted along with video display. However, a digital camera may be installed instead of the television camera. .
This type of digital camera outputs a captured image as a digital image signal, and is a recording device that can store information in a memory and can be widely used. Can be reduced.
In addition, a handy type video camera or the like that is operated by a built-in battery can automatically stop and restart imaging, image display, and image recording based on the determination of the autofocus operation, thereby reducing waste of the battery and magnetic tape. .
[0019]
【The invention's effect】
As described above, according to the monitoring system of claim 1 of the present invention, the monitor device is turned on in response to the control signal output from the signal detection unit, and the display unit displays an image. When the control signal is no longer input, the built-in timer starts counting for a certain period of time, and when the preset period of time has elapsed, the monitor device is turned off to stop projecting the image on the display unit. When the control signal is received from the signal detection unit, the monitor device is turned on again and the above processing is repeated, so that no image is displayed on the display unit while the monitoring target is not changed. There is an effect that waste of power as in the case of performing display is greatly reduced and deterioration of each part of the device is reduced .
[0020]
According to the monitoring system of the second aspect, when the display unit is a cathode ray tube type monitor, there is an advantage that the display unit with high power consumption can be used only when necessary and the waste of power can be greatly reduced. is there. When the display unit is a liquid crystal display device, there is an advantage that power consumption can be greatly reduced and deterioration of the liquid crystal can be reduced to maintain a long life .
[Brief description of the drawings]
FIG. 1 is an electrical block diagram showing a schematic configuration of an imaging apparatus according to the present invention.
FIG. 2 is an explanatory diagram illustrating a control unit of the imaging apparatus.
FIG. 3 is an electrical block diagram illustrating a monitoring system including the imaging apparatus.
FIG. 4 is a flowchart for explaining an image display operation;
[Explanation of symbols]
2a Video terminal part 11 Focusing lens 14c Control terminal part

Claims (2)

A motor drive unit having a control terminal unit that receives a focus signal from the focus sensor and outputs a signal voltage for moving the focusing lens of the imaging unit to a focus position;
A monitor device connected to the video terminal section of the imaging section ;
A display unit for receiving an image signal output from the monitor device and displaying an image;
A signal detection unit that detects the signal voltage output from the control terminal unit and outputs the detection signal as a control signal;
In response to the control signal output from the signal detection unit, the monitor device is turned on to display the image on the display unit. On the other hand, when the control signal is not input, the built-in timer counts a predetermined time. When the preset fixed time has elapsed, the monitor device is turned off to stop projecting the image on the display unit, and at this time, when the control signal is received from the signal detection unit And a control unit that repeats the above process by turning on the monitor device again . The monitoring system according to claim 1, wherein the display unit is a cathode ray tube monitor or a liquid crystal display device.

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