JP2531516Y2 - Surveillance camera shutter control device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle surveillance camera, and more particularly, to a control device for opening and closing a shutter provided on a front surface of a protective case of the surveillance camera.

[0002]

2. Description of the Related Art In recent years, in order to check the rear of a vehicle such as a bus or a truck, a small surveillance camera such as a CCD camera for surveillance is mounted at the rear of the vehicle, and a monitor television is provided in a driver's seat. The surveillance camera attached to the rear of the vehicle is covered with a protective case to protect the camera from rain and dust, a shutter is provided in front of the surveillance camera's lens as an opening / closing door, and the surveillance camera is used to move the vehicle backward. When the camera is operated, the shutter is opened as necessary. Usually, the shutter is closed so that the camera and the lens of the camera are not stained.

The shutter opening / closing control mechanism normally senses that the gear lever has been moved to the reverse position and rotates the shutter driving motor, and the timer drives the shutter driving motor for the time required for opening and closing the shutter. Voltage (e.g., 2-66).
No. 342), which performs opening / closing control while detecting the opening / closing completion position of the shutter by a sliding contact or a limit switch for detecting the opening / closing position of the shutter (for example, Japanese Utility Model Application Publication No.
No. -117881), and the shutter is automatically closed when the gear lever is removed from the reverse position.

[0004]

As described above, in the device for automatically opening the shutter by moving the gear lever to the reverse position, when the gear lever is moved to the reverse position, the monitor of the vehicle is displayed on the monitor television provided in the driver's seat. If the rear is not projected, the driver may be at fault with the surveillance camera itself,
It was not possible to immediately determine whether the shutter or the shutter opening / closing mechanism had failed.

[0005] Even if the surveillance camera breaks down, the shutter is opened by putting the gear in the reverse direction, and the pedestrian or worker behind the vehicle is illusioned that the driver is confirming himself on the monitor television. However, it is easy to be careless when the vehicle moves backward, and an accident may easily occur.

[0006]

According to the present invention, a synchronizing signal is extracted by a synchronizing separation circuit from a video signal of a surveillance camera which operates when the gear lever enters a reverse position, and a start signal is input while the synchronizing signal is being input. An operation detection circuit for outputting is provided, and a switch circuit for operating an alarm device when a start signal from the operation detection circuit is not input by inputting the same power supply as the power supply of the monitoring camera is provided; and A start signal is input to a shutter drive motor starting circuit to open and close the shutter.

[0007]

[Operation] In the present invention, the synchronization signal is extracted from the video signal of the surveillance camera by the synchronization separation circuit to form a start signal. Therefore, if the surveillance camera does not operate normally, the start signal is not output and the switch circuit is turned on. As a state, the camera can be notified of an abnormality by an alarm device, and the shutter can be kept closed without operating the shutter drive motor starting circuit.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a shutter control device according to the present invention has a first terminal connected to a power supply terminal of a monitoring camera 17.
It has an input terminal 21 and a second input terminal 23 to which a video signal from the surveillance camera 17 is input. The power supply terminal of the alarm 71, the control input terminal of the switch circuit 61, and the power supply terminal of the synchronization separation circuit 27 1 is connected to the first input terminal 21, the signal input terminal of the synchronization separation circuit 27 is connected to the second input terminal 23 via the coupling capacitor 25, and the output terminal of the synchronization separation circuit 27 is connected to the operation detection circuit 31 to detect the operation. The output terminal of the circuit 31 is connected to another control input terminal of the switch circuit 61 and the shutter drive motor starting circuit 41.

As shown in FIG. 2, the power supply terminal of the monitoring camera 17 and the power supply terminal of the monitor television 19 are connected to the battery 11 via the back gear detection switch 15 and the main switch 13, and the shutter drive motor is started. The circuit 41 switches the voltage polarity from the battery 11 as appropriate and applies the battery voltage to the shutter drive motor 59.

Therefore, in the shutter control device 20, when the back gear detection switch 15 is turned on by moving the gear lever to the reverse position while the main switch 13 is turned on, the surveillance camera 17
Starts operating, the power supply voltage is applied to the alarm 71, and the synchronization separation circuit 27 also starts operating. When a video signal from the surveillance camera 17 is input, the synchronization separation circuit 27 extracts only a pulse-like synchronization signal from the video signal and sends it to the operation detection circuit 31.

The operation detecting circuit 31 to which the synchronizing signal is inputted is constituted by, for example, an integrating hold circuit 33 and a Schmitt circuit 37. A pulse-like synchronizing signal is inputted to the integrating and holding circuit 33, The output level of the Schmitt circuit 37 outputs a low-level start signal when the output level of the Schmitt circuit 37 reaches the threshold value of the Schmitt circuit 37. When the input of the synchronizing signal to the integration hold circuit 33 is stopped, the Schmitt circuit 37 changes its output to the H level. And the output of the start signal is stopped.

The switch circuit 61 to which the start signal is input is composed of an AND circuit 63, a switching transistor 65, and an appropriate limiting resistor.
One input terminal of the AND circuit 63 is connected to the first input terminal 21.
The other input terminal is connected to the output terminal of the Schmitt circuit 37, the output terminal of the AND circuit 63 is connected to the base of the switching transistor 65 via a resistor, and the switching transistor 65 has an emitter grounded, The collector is connected to the alarm 71.

Therefore, when a voltage is input to the AND circuit 63 from the first input terminal 21 and the start signal from the operation detecting circuit 31 is not input, the switch circuit 61 turns on the switching transistor 65 to turn on the alarm circuit. 71 is to sound an alarm sound. Further, the shutter drive motor starting circuit 41 includes, for example, as shown in FIG.
It comprises an inverter, a pulse generator, a relay switch and a holding circuit, and a shutter rotational position detecting switch. The output terminal of the Schmitt circuit 37 in the operation detecting circuit 31 is connected to the first pulse generator 43 via the inverter 42.
The output terminal of the Schmitt circuit 37 is directly connected to the second pulse generator 44, the output terminal of the first pulse generator 43 is connected to the control terminal of the first relay switch 45, and the output of the second pulse generator 44 is A terminal is connected to a control terminal of the second relay switch 46, and a common terminal of the first relay switch 45 is connected to one input terminal of the shutter drive motor 59 via the shutter position detection switch 51, and is connected to the second relay switch 46.
Is connected to the other input terminal of the shutter drive motor 59, the B terminals of the first relay switch 45 and the second relay switch 46 are grounded, and the A terminals are respectively connected via holding circuits 47 and 48. It is connected to the power supply battery 11.

The shutter position detection switch 51 is
As shown in FIG. 4, an insulating portion 57 is formed on the surface of a disk conductor that rotates in accordance with the rotation of the shutter, and three contacts are brought into contact with each other. As shown in FIG. Then, the first contact 52 contacts the insulating portion 57 and the second contact 5
3 and the third contact 54 are short-circuited, and at the shutter open / close intermediate position, all of the first contact 52 to the third contact 54 are short-circuited to each other as shown in FIG. As shown in FIG. 4C, the second contact 53 contacts the insulating portion 57, and the first contact 52 and the third contact 54 are short-circuited.

Accordingly, when an L-level start signal is input to the shutter drive motor starting circuit 41, the first pulse generator 43 via the inverter 42 generates a pulse signal to connect the common terminal of the first relay switch 45 to the common terminal. A terminal, and the shutter position detection switch 51 is connected to C in FIG.
Since the first contact 52 and the third contact 54 are short-circuited, the drive motor 59 is rotated forward, and the first relay switch 45 is controlled by the holding circuit 47 to output the pulse from the first pulse generator 43. The rotation of the shutter drive motor 59 is continued even after the signal stops, and when the shutter reaches the open position, the first contact 52 of the shutter position detection switch 51 contacts the insulating portion 57 as shown in FIG. Then, the rotation of the motor is stopped, and the common terminal of the first relay switch 45 is returned to the connection to the B terminal.

When the input of the start signal from the operation detection circuit is stopped, the second pulse generator 44 outputs a pulse signal to connect the common terminal of the second relay switch 46 to the A terminal, and When the drive motor 59 is rotated in the reverse direction, the shutter is brought to the completely closed position, and the second contact 52 of the shutter position detection switch 51 as shown in FIG.
When the contact is made with the insulating portion 57, the rotation of the motor is stopped and the connection of the common terminal of the second relay switch 46 is returned to the B terminal.

As described above, in the shutter control device 20 according to the present embodiment, the back gear detection switch 15 is turned on with the gear lever in the reverse position, the surveillance camera 17 operates, and the surveillance camera 17 outputs a video signal. Then, the sync separation circuit 27 extracts the sync signal from the video signal,
An L level start signal is output from the operation detection circuit 31 and the shutter drive motor 59 is rotated forward by the shutter drive motor start circuit 41 to open the shutter.
A level start signal closes the AND circuit 63 of the switch circuit 61 and does not operate the alarm 71, and no video signal is output from the monitoring camera 17 even though the back gear detection switch 15 is turned on. In this case, the output of the operation detection circuit 31 is maintained at the H level, the AND circuit 63 in the switch circuit 61 sets the output to the H level in combination with the power supply voltage applied to the monitoring camera 17, and is connected in series with the alarm 71. By turning on the switching transistor 65, an alarm sound is emitted from the alarm 71, and the shutter drive motor starting circuit 41
Is to keep the shutter closed without operating.

In the above-described embodiment, even when the operation detection circuit 31 outputs the L-level start signal, the switch detection circuit 31 outputs the H-level start signal even when the operation detection circuit 31 outputs the H-level start signal. The shutter drive motor starting circuit 41 can be similarly operated by incorporating an inverter into the shutter drive motor starting circuit 41 as appropriate and performing level inversion. The shutter driving motor starting circuit 41 receives a start signal from a timer and a forward / reverse switch circuit. It is also possible to output a forward rotation signal to the motor only for a certain period of time from the point in time, and to output a reverse rotation signal to the motor for a certain period of time after the stop of the start signal.

As shown in FIG. 5, the switch circuit 61 is connected between the AND circuit 63 and the first input terminal 21 by a voltage of 0.5.
A delay circuit 69 of about one second to several seconds is inserted, and the monitoring camera 1
If the camera 7 requires a certain amount of time from power-on to video signal output, the alarm 71 may not be activated by mistake. Note that the alarm 71 is not limited to a sounding type such as a buzzer, and can also blink an alarm lamp.

Further, an inverter 42 and an AND circuit 63,
And supply of electric power for operating the Schmitt circuit 37 is:
The power is supplied by directly connecting to the battery or by connecting to the battery 11 via the main switch 13, and the power supply terminal of the alarm 71 is connected to the first terminal.
Not only the connection to the input terminal 21, but also the connection directly to the main switch 13 in a state of being connected in series with the switch circuit 61 or to the battery 11 together with the shutter drive motor starting circuit 41 is possible.

[0021]

The surveillance camera shutter control device according to the present invention extracts the synchronizing signal from the video signal and controls the shutter drive motor. Therefore, when the surveillance camera breaks down, the shutter is not opened and the shutter is opened behind the vehicle. It does not give the illusion that the surveillance camera is working.

When a video signal including a normal synchronizing signal is not output from the surveillance camera, the switch circuit is turned on to activate the alarm device, so that the driver can be clearly informed of the failure of the camera.

[Brief description of the drawings]

FIG. 1 is a block diagram of a shutter control device of a surveillance camera according to the present invention.

FIG. 2 is a diagram showing a circuit example of a surveillance camera using the shutter control device according to the present invention.

FIG. 3 is a diagram illustrating an example of a shutter drive motor starting circuit.

FIG. 4 is a diagram showing an example of a contact point of a shutter position detection switch.

FIG. 5 is a diagram showing another embodiment of the switch circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Battery 15 Back gear detection switch 17 Surveillance camera 19 Monitor television 20 Shutter control device 21 First input terminal 23 Second input terminal 27 Synchronous separation circuit 31 Operation detection circuit 41 Shutter drive motor starting circuit 59 Shutter drive motor 61 Switch circuit 71 Alarm

Claims (1)

(57) [Scope of request for utility model registration] 1. A first terminal connected to a power terminal of a surveillance camera.
An input terminal, a second input terminal to which a video signal from the surveillance camera is input, a synchronization separation circuit connected to the second input terminal for extracting a synchronization signal from the video signal, and a synchronization separation circuit connected to the synchronization separation circuit; An operation detection circuit that outputs a start signal while the synchronization signal from the synchronization separation circuit is being input, and a forward rotation signal to the shutter drive motor at the start of the start signal output connected to the operation detection circuit, and a start signal A shutter drive motor starting circuit that outputs a reverse rotation signal to the shutter drive motor at the end of output; and a switch that is connected to the first input terminal and the operation detection circuit and that is turned on when a start signal is not input when power is supplied to the monitoring camera. A shutter of the surveillance camera, wherein the switch circuit is connected in series with an alarm connected to a power supply. The control device.