JPS6184169A - Stop control method of lens for cctv camera - Google Patents

Abstract

PURPOSE:To perform switching from remote control to automatic control by applying a control voltage continuously for a specific time even after a stop diameter is reduced to a minimum or completely closed state. CONSTITUTION:A stop driving circuit 3 and a switching circuit 4 which performs automatic/remote switching and controls a stop are incorporated in the lens side of a television camera, and an automatic and a remote control system are switched with a control voltage applied to a solid wire 7 lead out of the switching circuit. Further, a position detection signal is fed back to the driving circuit 3 from a position element H during remote control to fix the stop, and a remote control signal is increased or decreased according to the time when the remote control signal is applied. On the other hand, the signal is applied continuously for the specific time even after the stop diameter is reduce to a minimum or completely closed state by adjusting the voltage of the remote control signal, thereby switching the remote control to the automatic control.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for controlling the aperture of a lens for a CCTV camera.

“Prior art” As a conventional technology, the applicant has already applied for
As stated in Patent Application No. 172753, White: 1? controls the aperture of the lens using the image signal from the television camera. l + aperture control and remote aperture control, which sets the aperture arbitrarily regardless of the image signal from the TV camera, can be switched between the remote aperture control and the remote aperture control, where the aperture can be controlled by switching at the center line. controllable CCTV
There was no way to control the aperture of camera lenses.

``Problems to be Solved by the Invention'' It is said that the conventional aperture control device using a moving magnet type or moving coil type servometer as a drive source is excellent in terms of responsiveness, reliability, and economy. However, for example, if the power supply is stopped, the aperture may move due to shock or vibration, and if you try to fix this mechanically,
Not only is there a loss of freedom in designing the arrangement and configuration of various parts of the mechanism, but there is also the problem that remote control is not easy.

"Means for Solving the Problem" Therefore, in the above-mentioned patent application, the applicant proposed an aperture control device for a moving magnet type or moving coil type servometer that includes an aperture drive circuit and automatic or remote switching via this drive circuit. An automatic control circuit and a remote control circuit that control the aperture are built into the TV camera, and the control method can be switched between automatic and remote by applying a control voltage to a single wire drawn out from this circuit. A CC that can feed back a position detection signal to the drive circuit using a built-in position detection element to electrically fix the aperture.
An aperture control device for a TV camera lens was presented.

The present invention relates to an improvement thereof, in which the aperture control during remote control is performed by adjusting the DC voltage depending on the application time, and the aperture diameter is kept at the minimum or completely closed state by adjusting the DC voltage. Since then, it has continued to be applied to history (5
The object of the present invention is to provide a CCT camera lens aperture method that switches from remote control to automatic control after a certain period of time.

"Function" Not only can the aperture control method be easily switched between automatic and remote using a single line, but also the aperture control operation during remote control can be performed, for example, by simply pressing an operation button. Also,
You can switch from remote control to automatic control by simply pressing and holding in the direction of the aperture.

"Embodiment" Fig. 1 shows a block circuit diagram of an embodiment of the present invention.
Symbols are components built into the lens side, and ■ are components on the control side. As is clear from the figure, in the first control rule ■, only the single-wire remote control line 2 is provided in addition to the ground Komaizumi 1, and all other circuit parts are connected to the lens example I.
is incorporated into.

FIGS. 2(A) and 2(B) show the structure of a movable magnet type servometer according to the present invention, where 10 is a movable magnet that opens and closes the aperture by its rotation, θ is the rotation range of the movable magnet 10, and 11
12 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 damp the aperture operation; 13;
is a magnetic sensor for position detection built into the servometer, which is activated by the magnetic flux of the movable magnet 10 and detects the rotational position of the movable magnet.

Here, on the lens side I of the block circuit diagram of FIG. TG is a tacho generator consisting of a braking coil 12, which feeds back a speed control signal for controlling the aperture speed to the motor M via a speed 3M return circuit. H is a position detection element consisting of a magnetic sensor 13, which feeds back an aperture position detection signal to the drive circuit 3 via a position feedback circuit to electrically control the aperture by fixing the movable magnet when performing remote control to be described later. It is configured so that it can be fixed in place.

Reference numeral 4 denotes an automatic/remote switching circuit consisting of an automatic control circuit, a remote control circuit, and a switch circuit for switching these circuits with respect to the base i+11 voltage. As shown in FIG. 3, the automatic/remote switching circuit 4 includes an automatic control circuit 6 which rectifies the image signal from the television camera inputted to the automatic terminal 5 and supplies it to the drive circuit 3 as an automatic control signal, and a remote switching circuit 6. The remote control circuit 8 supplies the remote control signal from the control signal input line 7 to the drive circuit 3, and the automatic control circuit 6 and the drive circuit 3 depending on whether the remote control signal is large or small with respect to a preset reference voltage. A switch circuit 9 selectively switches between a switch SW1 between the remote control circuit 8 and the position feedback circuit, and switches SW2 and SW3 between the remote control circuit 8 and the position feedback circuit. In the case of the embodiment, when the remote control signal from the human power line 7 is lower than a predetermined reference voltage, it is assumed that there is no remote control signal, and the switch circuit 9 closes the switch SWI while opening the switch SW2 and the switch SW3 to perform automatic control. circuit 6
Aperture control is performed by automatic control based on the image signal from the television camera by connecting the drive circuit 3 to the drive circuit 3, and when the remote control signal from the input line 7 is higher than a predetermined reference voltage, the switch SWI of the automatic control circuit is opened. , closes the switch SW2 of the remote control circuit 8 and the switch SW3 of the position feedback circuit, supplies a remote control signal to the drive circuit 3, and remotely controls the aperture to an arbitrary aperture position, completely independent of the image signal from the television camera. It is configured so that it can be used.

14 is a DA conversion circuit that supplies a remote control signal to the remote control circuit 4 via the input line 7;
The controller is configured to supply the remote control circuit 8 with a DC control signal that increases or decreases in response to the supply time of the diaphragm opening signal 10 or the diaphragm closing signal - 2 from the remote control line 2. be. Therefore, for example, in Figure 4, the time To
When the position control signal of input line 7 is Vo, remote control line 2
When an aperture opening signal of +■ is continuously supplied to the terminal 15 of the terminal 15 until time T4, the automatic control circuit operates until the reference voltage becomes 1 at the elapsed time T1, and then the switch circuit 9 switches to remote control and the elapsed time Fully open aperture voltage at T2■2
The remote control signal is supplied to the drive circuit 3, and the aperture continues to be opened continuously until the voltage of the remote control signal reaches (4), which indicates the aperture is fully open, at the subsequent elapsed time T4. At the intermediate elapsed time T3, the voltage of the remote control signal is ■3 and the aperture is in the intermediate aperture state.In this state, if the terminal 15 is set to neutral and the +■ aperture opening signal is cut off, the intermediate aperture state is maintained. The Rukoto. Conversely, remote control line 2
If a diaphragm closing signal of 1 is applied to the terminal 15 of the diaphragm continuously from T4 to To at time intervals, for example, with a remote control signal of voltage 4 of fully open diaphragm being supplied to the drive circuit, The voltage of the remote control signal gradually decreases from V4, the iris continues to close, and in the time interval up to T2, the voltage of the remote control signal becomes 2, which is when the iris is fully open, and further, in the time up to TI, the voltage reaches the reference voltage. V1, and then the switch circuit is switched by the diaphragm closing signal of <-V, and a control signal from the automatic control circuit is supplied to the drive circuit.

FIG. 5 continuously shows the relationship between the supply time of the remote control signal to the remote control line 2 and the state of the diaphragm. When the diaphragm is currently in the automatic control state, time T.

If you continue to supply the signal 10 in the opening direction to terminal 15,
Immediately before time T2, the diaphragm switches to the remote control state, and the diaphragm is fully closed at voltage 2, and continues to open in the fully open direction at voltage 2 until time T4. Conversely, at time T4, when a signal -■ in the closing direction is applied to the terminal 15, the diaphragm operates in the closing direction, and at time T5, the voltage decreases to fully closed voltage 2, and the diaphragm becomes fully open. If the signal 1 continues to be applied, the output of the DA conversion circuit becomes less than the reference voltage 1, and the switch circuit 9 is activated to automatically control the aperture. Also, if the remote control signal is switched to +■ in the open direction, the output of ■2 with reference voltage ■1 or higher is output from the DA conversion circuit at time T6, and the remote control state is established, and the +■ signal is continued until time T7. When the diaphragm is applied, the diaphragm opens to the diaphragm state of the intermediate voltage (3), and if the signal -2 in the closing direction is then supplied, the diaphragm fully closes and switches to the automatic control state after time T8 or more has elapsed.

"Effects of the Invention" As described above, according to the aperture control method for a CCTV camera lens according to the present invention, in the aperture control device of a moving magnet type or moving coil type servometer, the aperture drive circuit and the aperture control method via this drive circuit can be used. An automatic control circuit and a remote control circuit that control the aperture automatically or remotely are built into the lens side of the television camera, and the control system can be switched between automatic and remote by applying a control voltage to a single wire drawn out from this circuit. At the same time, during remote control, a position detection signal is fed back to the drive circuit using a position detection element built into the servometer, making it possible to electrically fix the aperture, and applying a remote control signal to control the aperture during remote control. The voltage of the remote control signal is adjusted depending on the time, and the voltage of the remote control signal is adjusted to minimize or completely close the aperture, and then the application is continued for a certain period of time. Since this is a CCTV camera lens aperture method that switches from remote control to automatic control, it is possible to easily switch between automatic i1i control and remote control of the aperture using a single line. The aperture can be controlled continuously by pressing and holding the button selected in the opening or closing direction, and can be fixed at any desired position by pressing the hand from the button, etc., and the aperture can be closed after opening. It has the advantage of being able to automatically switch to automatic control by providing a remote control signal in the direction of control.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing an embodiment of the method of the present invention;
2(A) and 2(B) show a movable magnet type servometer according to the present invention, (A) is a schematic front cross-sectional view, (B) is a schematic side cross-sectional view, and FIG. FIG. 4 is an explanatory diagram illustrating the operating state according to the method of the present invention, and FIG. 5 is an explanatory diagram illustrating the operating state according to the method of the present invention. ■... Lens side circuit part ■... Control side circuit part M... Aperture drive motor TG... Tacho generator H... Position detection element 2... Remote control line 3... Drive circuit 4 ...Auto/remote switching circuit 5...Image signal input terminal 6...Automatic control circuit 7...Remote control signal input line 8...Remote control circuit 9...Switch circuit 10...Movable Magnet 11... Drive circuit 12... Braking coil 13... Magnetic sensor 14... DA conversion circuit 15... Remote signal terminal

Claims (1)

[Claims] This is an aperture control device for a moving magnet type or moving coil type servometer, in which an aperture drive circuit, an automatic control circuit and a remote control circuit that control the aperture automatically or remotely via this drive circuit are connected to the lens side of a television camera. The control system can be switched between automatic and remote by applying a control voltage to the single wire drawn out from the servometer, and during remote control, a position detection signal is fed back to the drive circuit using a position detection element built into the servometer. , the diaphragm can be electrically fixed, and the diaphragm can be controlled by controlling the diaphragm during remote control by adjusting the DC voltage depending on the application time; A method for controlling the aperture of a CCTV camera lens in such a way that if the application is continued for a certain period of time, the control switches from remote control to automatic control.