JPH0642720B2 - CCTV camera lens aperture control method - Google Patents

Description

The present invention relates to a diaphragm control method for a CCTV camera lens.

"Conventional Technology" As a conventional technology, the applicant has already applied for the Showa 58
Patent Application No. 172753 (Patent Application Publication Sho 60-64)
No. 581), the automatic aperture control for controlling the aperture of the lens using the image signal from the television camera,
A remote-controllable C which can easily and remotely switch the aperture control to set the aperture arbitrarily regardless of the image signal from the television camera, especially by switching with a single line.
There was no aperture control method for the CTV camera lens.

“Problems to be Solved by the Invention” A diaphragm control device using a conventional moving magnet type or moving coil type servometer as a drive source has been considered to be excellent in responsiveness, reliability and economy. However, for example, if the power supply is stopped, there is a problem that the diaphragm will move due to shock and vibration, and if this is mechanically fixed, not only will the design freedom be lost in the arrangement and configuration of each part of the mechanism. However, there was a problem that remote control was not easy.

Therefore, in the above-mentioned patent application, the applicant discloses a diaphragm control device for a movable magnet type or a movable coil type servometer, and an automatic control circuit and a remote control circuit for automatically or remotely switching the diaphragm control circuit through this driving circuit. A control circuit is built into the lens side of the TV camera, and the control system can be switched between automatic and remote by the control voltage applied to the single wire drawn from this, and at the time of remote control, the diaphragm position detection element built into the servo meter. In this way, an aperture control device for a CCTV camera lens is presented in which the aperture position detection signal is fed back to the drive circuit to electrically fix the aperture.

[Means for Solving Problems] The present invention relates to an improvement thereof, including an aperture drive circuit,
A lens side in a diaphragm control device of a movable magnet type or a movable coil type servo meter in which an automatic control circuit and a remote control circuit for automatically or remotely switching the diaphragm to control the diaphragm via the drive circuit are built in the lens side of the television camera. A control switching signal added to the control system switching line drawn from the aperture control device to the control side makes it possible to instantly switch the aperture control system automatically and remotely, and at the time of remote control, it detects the aperture position built in the servo meter. A method for controlling the aperture of a lens for a CCTV camera, wherein an aperture is electrically fixed by returning an aperture position detection signal to an aperture drive circuit by an element, wherein aperture control during remote control is performed on the lens side. Supply of diaphragm opening signal or diaphragm closing signal added to the remote control line drawn from the diaphragm controller to the control side The DC control signal which increases or decreases correspondingly is applied to the remote control circuit while the DC control signal to be applied is smaller than a predetermined reference voltage capable of remote control. It is intended to provide a diaphragm control method for a lens for a CCTV camera, which is characterized by switching to

[Operation] According to the aperture control method for a lens for a CCTV camera according to the present invention, an automatic control is performed by adding a control switching signal to a control system switching line drawn from the aperture control device built in the lens side of the TV camera to the control side. The remote control system can be switched instantaneously and the aperture can be electrically fixed by feeding back the aperture position detection signal to the aperture drive circuit by the aperture position detection element built into the servo meter during remote control. With remote control,
By applying to the remote control circuit a DC control signal that increases or decreases according to the supply time of the throttle opening signal or the throttle closing signal applied to the remote control line different from the control method switching line drawn to the control side. The diaphragm can be opened and closed, and, for example, when the DC control signal to be applied to the remote control circuit is smaller than a predetermined reference voltage that can be remotely controlled immediately after switching from the automatic diaphragm control to the remote diaphragm control,
Since the remote control is switched to the automatic aperture control, there is an effect that the automatic aperture control can be immediately switched to the aperture control state and the aperture control state can be maintained and continued without falling into the aperture control disabled state.

[Embodiment] FIG. 1 shows a block circuit diagram of an embodiment of the present invention.
Is a component built into the lens side, and II is a component on the control side. As is apparent from the figure, in addition to the ground wire 1, the control side II is provided with a single line remote diaphragm control line 2 and only a control system switching line 16 for instantaneously and automatically switching the diaphragm control system. All the circuit parts of are incorporated in the lens side I.

2 (A) and 2 (B) show the structure of the movable magnet type servometer according to the present invention, 10 is a movable magnet which opens and closes the diaphragm by its rotation, θ is the rotation range of the movable magnet 10, 11
Is a drive coil that rotationally drives the movable magnet 10, 12 is a braking coil that works integrally with the drive coil 11 to detect the speed of the movable magnet, and damps the diaphragm operation.
Is a magnetic sensor for detecting the diaphragm position incorporated in the servo meter, which operates by the magnetic flux of the movable magnet 10 to detect the rotational position of the movable magnet.

Here, on the lens side I in the block circuit diagram of FIG. 1, M is a diaphragm drive motor composed of a drive coil 11, which operates based on the diaphragm control signal from the drive circuit 3. TG
Is a tacho-generator composed of a braking coil 12, which feeds back a speed control signal for controlling the throttle speed to the motor M via a speed feedback circuit. H is the magnetic sensor 1
With the diaphragm position detection element composed of 3, the diaphragm position detection signal is fed back to the drive circuit 3 via the position feedback circuit when the remote diaphragm control described later is performed, and the diaphragm is electrically fixed by fixing the movable magnet. It is configured so that it can be done.

Reference numeral 4 denotes an automatic / remote switching circuit including an automatic diaphragm control, a remote diaphragm control, and a switch circuit for switching these circuits with respect to a reference voltage. Automatic / remote switching circuit 4
As shown in FIG. 3, an automatic control circuit 6 for direct-current rectifying an image signal from the television camera input to the auto terminal 5 and supplying it to the drive circuit 3 as an automatic aperture control signal, and a control switching signal input line 16. The switch SW between the automatic control circuit 6 and the drive circuit 3 depends on whether the control switching signal is larger or smaller than the preset reference voltage.
1 or a remote control signal supply line 7 and a switch circuit 9 for selectively switching the switches SW2 and SW3 of the position feedback circuit. In the case of the embodiment, the control switching signal input line 1
When the changeover switch SW4 of 6 is open, the switch circuit 9 closes the switch SW1 while the switch SW9 is closed.
2 and the switch SW3 are opened to connect the automatic control circuit 6 and the drive circuit 3 to perform aperture control by automatic control based on the image signal from the television camera, and the switch SW4 is closed to output the remote switching signal Vc from the terminal 17. When input, the switch SW1 of the automatic aperture control circuit is opened, and the switch SW2 of the remote control signal supply line 7 and the switch S of the position feedback circuit S
W3 is closed and a remote control signal is supplied to the drive circuit 3 so that the aperture can be controlled to an arbitrary aperture position regardless of the image signal from the television camera.

Therefore, the configuration of the circuit for closing the switch SW2 of the remote control signal supply line 7 and the switch SW3 of the position feedback circuit to supply the remote control signal to the drive circuit 3 constitutes the remote control circuit according to the present invention. Become.

That is, the switch SW4 constitutes means for instantaneously switching between the automatic control circuit and the remote control circuit.

Reference numeral 14 is a DA conversion circuit that supplies a remote control signal to the drive circuit 3 via the remote control signal supply line 7 during remote aperture control.
A remote control signal supply line 7 is supplied with a DC control signal that increases or decreases in accordance with the supply time of the control signal of the diaphragm opening signal + V or the diaphragm closing signal -V from the remote control line 2 of the control side II. Is configured.

FIG. 4 continuously shows the relationship between the supply time of the remote control signal to the remote control line 2, the state of the diaphragm, and the control changeover switch SW4. At the time T0, the switch SW4 is in the automatic control state of the diaphragm. It is open. Here, when the switch SW4 is closed at time T1, the switch SW1 of the automatic control circuit 6 is opened and at the same time the switch SW on the remote control side is opened.
2 and the switch SW3 are closed, remote control is performed, and the diaphragm is in a diaphragm state corresponding to the power supply voltage V3 maintained by the DA conversion circuit 14 until that time. Next, when the diaphragm opening signal + V is applied to the terminal 15 of the remote control line 2 until time T2, the DA conversion circuit 14 increases the voltage corresponding to time, and the diaphragm continues to open correspondingly. Now, at the voltage V4 at time T2, if the diaphragm closing signal -V is applied to the terminal 15 up to time T3, the DA conversion circuit 1
On the contrary, 4 reduces the supply voltage, and gradually closes the diaphragm until time T3, and becomes the diaphragm state corresponding to the supply voltage V5 at that time. At this time T3, the control changeover switch SW
When 4 is opened, the change-over switch SW9 becomes the switch S
At the same time as closing W1, switch SW2 and switch S
W3 is opened, and the automatic aperture control based on the image signal of the TV camera is instantly switched. After that time T4
When the switch SW4 is closed again, remote throttling control is performed again, and the throttling state corresponding to the supply voltage V5 that was maintained at the time of the remote throttling control at time T3 is returned to, and the open signal + V is applied to the remote control line 2. If it continues to be applied, at time T5, the diaphragm is fully opened with the voltage V6 for fully opening the diaphragm. Then, if the changeover switch SW4 is opened again at time T5, the automatic aperture control is instantaneously switched.

The DA conversion circuit 14 outputs the output voltage (that is, the remote control signal) by the switch SW5 as shown in FIG.
2 and the aperture open voltage V6 so that there is no time delay in the range where automatic control is switched to remote control (that is, the dead range of the aperture is eliminated).

Here, the present invention relates to the switch circuit 9 and the DA conversion circuit 1.
4, a control method changeover switch SW5 for stopping the function of the control changeover switch SW4 and controlling the switch circuit 9 only by the remote control signal from the DA conversion circuit 14 to perform remote control and automatic control is provided. is there.

That is, by controlling the switch SW5, it is possible to perform the aperture control by selecting a control method for instantly switching the remote / automatic control, and a control method for switching the remote / automatic control only by the remote control signal. Configured.

When the control method changeover switch SW5 is changed over to the side of only the remote control signal, the input from the control changeover signal supply line 16 to the switch circuit 9 is cut off, and the remote control signal is fed from the remote control signal input line 7 to the line 8 and. It is supplied to the switch circuit 9 via the switch SW5.

At this time, the switch circuit 9 may switch the switch SW1 of the automatic control circuit 6 or the switch SW of remote control depending on whether the remote control signal is higher or lower than a preset reference voltage.
2 and SW3 are selectively switched. In the case of the embodiment, if the remote control signal from the remote control signal supply line 7 is smaller than the predetermined reference voltage, the switch circuit 9
Closes the switch SW1 while opening the switches SW2 and SW3 to connect the automatic control circuit 6 and the drive circuit 3, and the diaphragm control is automatically controlled based on the image signal from the television camera. When the voltage is higher than the predetermined reference voltage, the switch circuit 9 opens the switch SW1 and simultaneously switches SW2 and SW3 on the remote control side.
Is closed to control the remote aperture by the remote control signal.

Therefore, for example, in FIG.
When the remote control signal of V0 is V0, the terminal 15 of the remote control line 2
When the + V aperture opening signal is continuously supplied to the time T4, the automatic control circuit 6 operates until the reference voltage V1 is reached at the elapsed time T1, and then the switch circuit 9 is switched to the remote control to change the aperture at the elapsed time T2. The remote control signal of the fully closed voltage V2 is supplied to the drive circuit 3, and the subsequent elapsed time T4
Until the voltage of the remote control signal reaches V4 with the throttle fully open,
The diaphragm will continue to open. When the elapsed time T3 on the way is reached, the voltage of the remote control signal is V3, and the intermediate diaphragm state is reached. In this state, the terminal 15 is made neutral and + V.
If the diaphragm opening signal of is cut off, the diaphragm state in the middle of the voltage V3 is maintained as it is. Conversely, remote control line 2
When a diaphragm closing signal of -V is applied to the terminal 15 of, for example, continuously from T4 to T0 at time intervals in the state where the remote control signal of the voltage V4 of the diaphragm full opening is supplied to the drive circuit, The voltage of the control signal gradually decreases from V4, the diaphragm continues to close, the voltage of the remote control signal becomes V2 of the diaphragm fully closed in the time interval up to T2, and the voltage reaches the reference voltage V1 in the time up to T1. Then, the switch circuit is switched by the subsequent -V diaphragm closing signal, and the control signal from the automatic control circuit is supplied to the drive circuit.

[Advantages of the Invention] As described above, according to the aperture control method for a CCTV camera lens according to the present invention, an aperture drive circuit and an automatic control circuit for automatically or remotely switching the aperture to control the aperture via the drive circuit, and A control switching signal applied to a control system switching line drawn from the aperture control device on the lens side to the control side in the aperture control device of a movable magnet type or movable coil type servometer in which a remote control circuit is built in on the lens side of a television camera. With this, the aperture control system can be switched instantly between automatic and remote, and during remote control, the aperture position detection element built into the servo meter feeds the aperture position detection signal back to the aperture drive circuit to electrically control the aperture. A method for controlling the aperture of a lens for a CCTV camera, which is fixed to, wherein aperture control during remote control is performed on the lens side. While applying by applying to the remote control circuit a DC control signal that increases or decreases corresponding to the supply time of the aperture open signal or the aperture close signal applied to the remote control line drawn from the aperture control device to the control side, When the DC control signal to be applied is smaller than a predetermined reference voltage that can be remotely controlled, the remote diaphragm control is switched to the automatic diaphragm control, so that a control switching signal is added to the control method switching line. , It is possible to instantly switch the aperture control method to automatic control and remote control, for example, it is possible to instantly switch the aperture control method from manual remote aperture control to automatic aperture control. In this case, there is no problem, When the control system is instantly switched from automatic aperture control to remote aperture control, the DC control signal to be applied to the remote control circuit is remote controlled. When the voltage is lower than a predetermined predetermined reference voltage, there is a problem that the remote diaphragm control is disabled and the automatic diaphragm control cannot be performed. However, as described above, the present invention should be applied to the remote control circuit during the remote diaphragm control. When the DC control signal is lower than a predetermined reference voltage that allows remote control, it has a configuration that switches from remote control to automatic aperture control. There is an effect that the aperture control system can be switched to automatic control and remote control by adding a control switching signal to the control system switching line at any time without anxiety.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing an embodiment of the method of the present invention,
2A and 2B show a movable magnet type servometer according to the present invention, FIG. 2A being a schematic front sectional view thereof, FIG. 2B being a schematic side sectional view, and FIG. FIG. 4 is an explanatory diagram for explaining an operating state according to the method of the present invention, and FIG. 5 is an explanatory diagram for similarly explaining an operating state according to the method of the present invention. I ... Lens side circuit part II ... Control side circuit part M ... Aperture drive motor TG ... Tacho-generator H ... Aperture position detection element SW5 ... Control method switch 2 ... Remote control line 3 ... Drive circuit 4 …… Automatic / remote switching circuit 5 …… Image signal input terminal 6 …… Automatic control circuit 7 …… Remote control signal supply line 9 …… Switch circuit 10 …… Movable magnet 11 …… Drive circuit 12 …… Brake coil 13 ...... Magnetic sensor 14 ...... DA conversion circuit 15 ...... Remote signal terminal 16 ...... Control method switching (signal input) line

Claims (2)

[Claims] 1. A movable magnet type or a movable coil in which a diaphragm drive circuit and an automatic control circuit and a remote control circuit for automatically or remotely switching the diaphragm to control the diaphragm are built in the lens side of a television camera. Type servometer, the aperture control system on the lens side in the aperture control system of the lens side makes it possible to instantly switch the aperture control system automatically and remotely by a control switching signal added to the control system switching line drawn to the control side. A method for controlling the aperture of a CCTV camera lens, wherein an aperture position detection signal is fed back to an aperture drive circuit by an aperture position detection element built into a servo meter to electrically fix the aperture. Aperture control is applied to the remote control line pulled out from the aperture control device on the lens side to the control side. A DC control signal that increases or decreases according to the supply time of the signal or the diaphragm closing signal is applied to the remote control circuit, while the DC control signal to be applied is smaller than a predetermined reference voltage that can be remotely controlled. And a method for controlling the aperture of a lens for a CCTV camera, characterized by switching from remote aperture control to automatic aperture control. 2. A CCTV camera according to claim 1, wherein the aperture control at the time of the remote control is performed by increasing or decreasing the DC voltage according to the time to apply to the single-line remote control line by the DA conversion circuit. Control method for lens