JP5047769B2 - CCTV camera system - Google Patents

Description

  The present invention relates to a CCTV camera system, and more particularly, to a CCTV camera system having a manual aperture adjustment and an aperture opening / closing speed adjustment function in a DC drive type automatic aperture.

Conventional CCTV cameras are equipped with a lens equipped with an aperture device and a camera equipped with an image pickup device as detachable separate bodies, and a plurality of types of lenses and cameras can be prepared so that combinations can be selected according to applications. The configuration is common. The control system of the aperture device mounted on the lens of such a conventional CCTV camera includes a video drive system in which an aperture control circuit is built in the lens side (a system in which an aperture control circuit is built in the lens side), and an aperture control circuit. A DC drive system built in the camera side (a system that does not have an aperture control circuit on the lens side) is known (Patent Document 1).
Japanese Patent Laid-Open No. 60-64581

  The DC drive method has come to be used in many cases because it has an advantage that the backlight correction of the subject can be properly processed on the CCTV camera body side. However, in the DC drive system, there has been no CCTV camera that allows the user to switch the aperture control between automatic control and manual control according to the shooting situation.

  When a CCTV camera is used for traffic monitoring or the like, it may receive the color of the vehicle body or reflected light of a vehicle that passes in an instant. Therefore, if the aperture is sensitively followed, an unfavorable situation occurs such as a flickering image. In order to cope with such a situation, the diaphragm may be adjusted so as to move slowly. However, the CCTV camera lens automatic diaphragm is generally controlled by using a drive coil and a control coil. The control voltage detected by the control coil is amplified by an amplifier circuit such as an operational amplifier and controlled at a constant speed. It is used for. Therefore, if the amplification degree of the control voltage is increased, the offset voltage of the amplifier circuit is also amplified. Therefore, if the amplification degree is increased too much, the operation of the diaphragm is affected.

  The present invention has been made in view of the problems of the prior art, and provides a CCTV camera system that enables adjustment of aperture opening / closing speed, switching between manual operation, and automatic aperture control in a DC drive system. Objective.

The present invention that achieves such an object includes a lens having a diaphragm unit that includes a diaphragm sensor that holds the diaphragm at a degree of opening and closing according to the level of the diaphragm driving signal and detects the degree of opening and closing of the diaphragm ; possible, the automatic iris control circuit and the camera is built to output the iris drive signal based on the picked-up video signal; CCTV camera system comprising a; and the remote diaphragm control unit for outputting a remote signal for aperture control The lens further includes a lens-side diaphragm control circuit that inputs the remote signal and outputs the diaphragm driving signal, and a switching circuit that switches between the lens-side diaphragm control circuit and the automatic diaphragm control circuit of the camera. The lens-side aperture control circuit, when selected by the switching circuit, sets the aperture of the aperture unit to the remote signal The aperture drive signal is output so as to maintain the corresponding open / closed degree, and the automatic aperture control circuit of the camera outputs the aperture drive signal so that the open / closed degree of the aperture of the aperture unit corresponds to the level of the remote signal. And an aperture setting circuit for outputting an aperture drive signal based on a video signal input from the camera, and a level based on the aperture drive signal output by the aperture setting circuit for the remote signal. And a remote signal output circuit that outputs while increasing or decreasing the aperture opening / closing speed .

The remote aperture control device further includes manual setting means for manually setting the aperture signal, and an auto / manual switching circuit for switching the aperture signal input to the remote signal output circuit between the manual setting means and the aperture setting circuit. It is preferable to provide.
In addition, the remote aperture control device includes a speed adjustment circuit that adjusts a change speed for increasing or decreasing the level of the remote signal, and the remote signal output circuit is configured to transmit the remote signal at a speed set by the speed adjustment circuit. It is preferable to adjust the level up or down.

  The remote signal output circuit adjusts the level of the remote signal up or down at a speed set by the speed adjustment circuit to a level corresponding to the aperture signal while the aperture signal is being input.

The speed adjustment circuit includes a pulse generation circuit that outputs a pulse signal at a manually set cycle, and the remote signal output circuit adjusts the level of the remote signal in synchronization with the pulse signal output by the pulse generation circuit. Adjust up and down step by step.
The remote signal output circuit includes an electronic volume, and the electronic volume increases and decreases the level of the remote signal in synchronization with the pulse signal output from the pulse generation circuit.

  Actually, the aperture unit includes a control coil that detects the opening / closing speed of the aperture, and the aperture control circuit and the automatic aperture control circuit of the camera are configured to open / close the aperture based on a control signal output by the control coil. The aperture drive signal is adjusted so that the speed is constant.

According to the present invention, it is possible to manually control the aperture even if the aperture control method of the camera is a DC drive method. In addition, it is possible to perform external aperture automatic control by an external control device, and it is possible to adjust the aperture opening / closing speed in both manual control and external aperture automatic control.
In the case of automatic aperture control, an automatic aperture built in the camera can be used, so that the aperture control circuit on the lens side can be simplified and the cost can be reduced.

The present invention will be described based on the embodiments shown in the accompanying drawings. FIG. 1 is a block diagram showing main circuits of a CCTV camera device to which the present invention is applied. This camera device includes a DC drive type CCTV lens 100, a DC drive type camera 200, and a remote aperture control device 300.

The lens 100 includes a photographing lens group L including first and second lens groups L1 and L2, a diaphragm unit 110, a diaphragm control circuit 120, and a switching circuit 130. The aperture unit 110 is disposed in the optical path of the photographic lens group L, and includes an aperture blade 111 that controls the amount of transmitted light, a drive coil M that opens and closes the aperture blade (aperture) 111, and an aperture that is driven to open and close by the drive coil M. A control coil (generator coil) G for generating a control signal (voltage) corresponding to the opening / closing speed of the blade 111 to detect the opening / closing speed, and a hall element as an aperture sensor for detecting the opening / closing degree (opening / closing amount) of the aperture blade 111 113 is provided. The diaphragm blade 111 is spring-biased in the normally closed direction. When the drive coil M is not energized, the diaphragm blade 111 is fully closed. When the drive coil M is energized, the diaphragm blade 111 is driven by the magnetic force generated by the drive coil M. 111 is driven in the opening direction against the spring biasing force, and is held at a position where the magnetic force and the spring biasing force are balanced.

When a remote signal is input from the outside, the aperture control circuit 120 outputs a drive signal for driving the aperture blade 111 to open and close. This diaphragm control circuit 120 controls the drive signal based on the control signal from the control coil G so that the opening / closing speed of the diaphragm blade 111 is constant, and further, based on the opening / closing degree detection signal detected by the Hall element 113, The drive signal is controlled so that the aperture blade 111 is held at the aperture position corresponding to the signal level.

  The switching circuit 130 switches the opening / closing drive of the aperture blade 111 between the aperture control circuit 120 and the automatic aperture control circuit 220 of the camera 200. The switching circuit 130 switches to remote control by the aperture control circuit 120 when a remote signal is input, and switches to automatic aperture control by the automatic aperture control circuit 220 when no remote signal is input.

  The camera 200 receives a subject image formed by the photographing lens group L of the attached lens 100, converts the image into an electrical video signal and outputs the video signal, and the video output by the imaging device 210. Based on the signal (luminance signal) and the control signal from the control coil G of the lens 100, an automatic aperture control circuit that generates a drive signal for driving the aperture unit 110 so that the video signal (luminance signal) falls within a predetermined level. 220. The video signal output from the image sensor 210 is usually visualized by a monitor television, but is further output to the remote aperture controller 300 in this embodiment. As the image pickup element 210, a CCD type or CMOS type monochrome or color image sensor is usually used. The signal input to the remote aperture control device 300 may be a signal generated based on the video signal.

  The remote aperture control device 300 detects the video signal input from the camera 200 by the detection circuit 311 and converts it into a DC voltage. The comparison circuit 313 compares the DC voltage with the reference voltage, and the polarity according to the comparison result. The aperture setting signal is output. The comparison circuit 313 changes the polarity of the aperture setting signal according to the magnitude of the DC voltage with respect to the reference voltage. The detection circuit 311 and the comparison circuit 313 constitute an aperture setting circuit 310.

  The aperture setting signal output from the comparison circuit 313 is input to the auto / manual switching circuit 320. The auto / manual switching circuit 320 outputs either the output of the comparison circuit 313 or the manual operation signal to the pulse generation circuit 330. The manual operation signal is set by the aperture operation switch 351, and the auto / manual switching signal is set by the manual switching switch 352. The aperture operation switch 351 and the manual changeover switch 352 are provided as operation panels on the outer surface of the remote aperture control device 300.

The aperture setting signal or manual operation signal output from the auto / manual switching circuit 320 is converted into an up / down signal by the pulse generation circuit 330 and output to the electronic volume 340. This up / down signal is a signal for setting a driving direction (opening direction or closing direction) from the current position (opening / closing degree) of the diaphragm blade 111 . Further, the pulse generation circuit 330 outputs a control pulse signal having a period corresponding to the speed adjustment signal set by the speed adjustment circuit 331.

The electronic volume 340 constitutes a remote signal output circuit that outputs a remote signal for operating the aperture control circuit 120 of the lens 100. The electronic volume 340 sets the direction in which the level (output voltage) of the remote signal is increased or decreased according to the up / down signal, and each time the control pulse signal is received, the remote control signal is transmitted in the set up or down direction. Increase or decrease the output level (output voltage). Note that the level of the remote signal is related to the degree of opening / closing of the diaphragm blade 111 of the diaphragm unit 110, and the diaphragm control circuit 120 drives the diaphragm blade 111 to open / close to hold the degree of opening / closing according to the level of the remote signal. .

  The speed adjustment circuit 331 changes the speed adjustment signal in response to the operation of the speed adjustment switch 353 provided on the operation panel 350. That is, the user can manually adjust the aperture opening / closing speed of the aperture unit 110 by operating the speed adjustment switch 353 in both cases of aperture auto and aperture manual control.

  The remote signal output from the electronic volume 340 is output to the lens 100 via the external control on / off switch 354. The external control on / off switch 354 is provided so that the user can perform a switching operation.

  The remote signal output from the remote aperture control device 300 and input to the lens 100 is input to the aperture control circuit 120 and the switching circuit 130. Then, the switching circuit 130 switches the connection between the drive coil M and the control coil G from the camera 200 to the aperture control circuit 120. The diaphragm control circuit 120 is driven based on the position signal of the diaphragm blade input from the Hall element 113, the remote signal (its polarity and level) input from the remote diaphragm control device 300, and the speed control signal input from the control coil G. A signal is generated and output, and the drive coil M is driven via the switching circuit 130.

"Automatic aperture control by DC drive system"
When the external control on / off switch 354 is off, the switching circuit 130 is switched to camera control and the remote signal is cut off. Therefore, the switching circuit 130 is switched to automatic aperture control that connects the drive coil and the control coil to the automatic aperture control circuit 220 of the camera 200. Accordingly, the drive signal output from the automatic aperture control circuit 220 of the camera 200 is output to the drive coil M, and the control signal output from the control coil G is output to the automatic aperture control circuit 220 of the camera 200 to perform automatic aperture control. The drive signal is adjusted by the circuit 220. This operation is automatic aperture control by a normal DC drive system.

"External aperture manual control"
When the external control on / off switch 354 is on, the remote signal (voltage) set by the electronic volume 340 is output to the aperture control circuit 120 and the switching circuit 130 of the lens 100, and the switching circuit 130 Switching to the control circuit 120 switches to external aperture manual control (remote aperture manual control). The drive signal output from the aperture control circuit 120 is output to the aperture drive coil M via the switching circuit 130, and the control signal output from the aperture control coil G is supplied to the aperture control circuit 120 via the switching circuit 130. Is output. The aperture control circuit 120 generates and outputs a drive signal for driving the drive coil M based on the remote signal output from the remote aperture control device 300 and the position signal output from the hall element 113.

"External aperture auto control"
This CCTV camera system can execute external aperture auto control (remote aperture auto control) by the remote aperture control device 300 instead of aperture auto control by the normal DC drive system. In the external aperture automatic control, the aperture opening / closing speed can be adjusted. When switching to the external aperture auto control, the manual changeover switch 352 is set to OFF, and the external control ON / OFF changeover switch 354 is set to ON. As a result of the above operation, the switching circuit 130 of the lens 100 is switched to the aperture control circuit 120, and the auto / manual switching circuit 320 of the remote aperture control device 300 is switched to the aperture automatic control operated by the output of the comparison circuit 313. With the external aperture auto control switched as described above, the opening / closing control of the aperture blade 111 is performed so that the luminance of the video signal output from the camera 200 becomes an appropriate value.

  In the external aperture automatic control, the aperture opening / closing speed can be adjusted by operating the speed adjustment switch 353. When the speed adjustment switch 353 is operated, the pulse cycle generated by the pulse generation circuit 330 changes. When the pulse period becomes shorter, the level (voltage) change speed of the remote signal output from the electronic volume 340 becomes faster and the aperture opening / closing speed becomes faster. When the pulse period becomes longer, the level (voltage) change speed of the remote signal output from the electronic volume 340 becomes slower, and the aperture opening / closing speed becomes slower.

  According to this embodiment, the external control ON / OFF switch 354 can be switched from automatic aperture control based on the DC drive signal on the camera 200 side to external aperture auto control or remote aperture manual control based on the remote aperture control device 300. In addition, the aperture opening / closing speed can be set manually.

  According to the present embodiment, the level change speed of the voltage (remote signal) output from the electronic volume 340 is changed by changing the frequency of the pulse generated by the pulse generation circuit 330. Thereby, the response speed of the diaphragm can be changed without considering the offset of the operational amplifier of the diaphragm control circuit 120.

  Examples of the circuit configurations of the aperture control circuit 120 and the switching circuit 130 of the lens 100 are shown in FIGS. 2 and 3 show the first and second embodiments (switching circuits 130A and 130B) of the switching circuit 130 that is automatically switched by a remote signal, and FIG. 4 is a switching circuit 130 that is switched by a switching signal different from the remote signal. This is Example 3 (switching circuit 130C).

  In FIG. 2, reference numerals SW1 to SW4 are changeover switches (relay switches), and are switched to the connection with the camera 200 while the remote signal is not input (while the remote signal is at the ground level). When a remote signal (positive level) is input, the connection to the aperture control circuit 120 is switched.

  In the second embodiment shown in FIG. 3, reference numerals SW11 to SW19 are switch circuits, and while the remote signal is not input (while the remote signal is at the ground level), SW11 is turned off and SW12 to SW15 are turned on. When SW6 to SW9 are turned off and the connection to the camera 200 is switched and a remote signal (positive level) is input, SW11 is turned on, SW12 to SW15 are turned off, and SW6 to SW9 are turned on. Thus, the connection to the aperture control circuit 120 is switched.

  The third embodiment shown in FIG. 4 is a modification of the first embodiment, and the selector switches SW1 to SW4 are switched in response to the input of a switching signal different from the remote signal. In the embodiment of FIG. 1, the on / off signal of the external control on / off switch 354 may be set as the switching signal.

It is a figure which shows the principal part of embodiment of the CCTV camera system of this invention with a block. It is a circuit diagram which shows Example 1 of the circuit structure in the lens of embodiment of the CCTV camera system. It is a circuit diagram which shows Example 2 of the circuit structure in the lens of embodiment of the same CCTV camera system. It is a circuit diagram which shows Example 3 of the circuit structure in the lens of embodiment of the same CCTV camera system.

Explanation of symbols

100 Lens 110 Aperture unit 111 Aperture blade (aperture)
113 Hall element (aperture sensor)
120 Aperture control circuit (lens side aperture control circuit)
130 switching circuit 200 camera 210 image sensor 220 automatic aperture control circuit ( automatic aperture control circuit of camera)
300 Remote diaphragm control device 310 Aperture setting circuit 311 Detection circuit 313 Comparison circuit 320 Auto / manual switching circuit 330 Pulse generation circuit 331 Speed adjustment circuit 340 Electronic volume (remote signal output circuit)
351 Aperture setting switch (manual setting means)
352 Manual changeover switch 353 Speed adjustment switch 354 External control on / off changeover switch G Control coil M Drive coil

Claims (7)

A lens having a built-in diaphragm unit having a diaphragm sensor for detecting the degree of opening / closing of the diaphragm, which holds the diaphragm at a degree of opening / closing according to the level of the diaphragm driving signal ; A CCTV camera system comprising : a camera having an automatic aperture control circuit that outputs the aperture drive signal ; and a remote aperture control device that outputs a remote signal for aperture control ,
The lens further includes a lens-side diaphragm control circuit that inputs the remote signal and outputs the diaphragm drive signal, and a switching circuit that switches between the lens-side diaphragm control circuit and the automatic diaphragm control circuit of the camera. thing,
The lens-side aperture control circuit, when selected by the switching circuit, outputs an aperture driving signal so as to hold the aperture of the aperture unit at an opening / closing degree corresponding to the remote signal;
The automatic aperture control circuit of the camera outputs an aperture driving signal so that an aperture degree of the aperture unit corresponds to a level of the remote signal; and
The remote aperture control device includes an aperture setting circuit that outputs an aperture drive signal based on a video signal input from the camera, and an aperture opening / closing speed up to a level based on the aperture drive signal output by the aperture setting circuit. Remote signal output circuit that outputs while up or down,
CCTV camera system characterized by   2. The CCTV camera system according to claim 1, wherein the remote aperture control device further includes manual setting means for manually setting the aperture signal, and the manual setting means and the aperture setting circuit for inputting an aperture signal to be input to the remote signal output circuit. CCTV camera system with auto / manual switching circuit for switching between 3. The CCTV camera system according to claim 1 , wherein the remote aperture control device includes a speed adjustment circuit that adjusts a changing speed for increasing or decreasing a level of the remote signal, and the remote signal output circuit includes the remote signal output circuit. A CCTV camera system that adjusts the level of the remote signal up or down at a speed set by a speed adjustment circuit. 4. The CCTV camera system according to claim 3 , wherein the remote signal output circuit outputs the remote signal at a speed set by the speed adjustment circuit to a level corresponding to the aperture signal while the aperture signal is input. CCTV camera system that adjusts the level up or down. 5. The CCTV camera system according to claim 3 , wherein the speed adjustment circuit has a pulse generation circuit that outputs a pulse signal at a manually set cycle, and the remote signal output circuit is output by the pulse generation circuit. A CCTV camera system that adjusts the level of the remote signal stepwise in synchronization with a pulse signal. 6. The CCTV camera system according to claim 5 , wherein the remote signal output circuit includes an electronic volume, and the electronic volume increases and decreases the level of the remote signal in synchronization with the pulse signal output from the pulse generation circuit. . The CCTV camera system according to any one of claims 1 to 6 , wherein the aperture unit includes a control coil that detects an opening / closing speed of the aperture, and the aperture control circuit and the automatic aperture control circuit of the camera are configured to perform the control. A CCTV camera system that adjusts the aperture drive signal so that the aperture opening / closing speed is constant based on a control signal output by a coil.

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