JP2001051182A - Lens device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit correction of the angle of view, even when a zoom lens is stopped on a shot position, and to prevent movement of the lens to the outside of a limit position caused by correction of the angle of view, by executing correction of the angle of view, taking the limit position into consideration. SOLUTION: When position control based on a correcting function of the angle of view is executed, the value of a position signal outputted from a CPU 50 to a zoom controller 26 is fixed on a stop position before execution of the position control based on the correcting function of the angle of view. Hereby, in the case where the zoom controller 26 stops a zoom lens 60 on a shot position by position control based on a shot function, even when the CPU 50 moves the zoom lens 60 by the correcting function of the angle of view, such a speed control signal as to reset the zoom lens 60 to the shot position relative to the CPU 50 is not given from the zoom controller 26. When detecting a limit position, the CPU 50 limits a movement range so that the zoom lens 60 is not moved to the outside of the limit position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens device,
In particular, the present invention relates to a lens device mounted on a television camera and having an angle-of-view correction function of correcting a change in angle of view during focusing with a zoom lens.

[0002]

2. Description of the Related Art As a lens device mounted on a television camera or the like, an external controller is connected by a cable, and optical members such as a zoom lens and a focus lens mounted on the lens device are controlled based on a control signal transmitted from the controller. And those driven by a motor.

A controller (zoom controller) used for controlling the zoom lens is provided with a rotatable operation member called, for example, a thumb ring. When the operation member is turned by a cameraman, the amount of operation is reduced. A speed control signal for commanding a corresponding zoom speed is transmitted to the control unit of the lens device, and the zoom lens is motor-driven at the zoom speed specified by the speed control signal.

A known zoom controller is equipped with a shot function and a limit function (a zoom controller equipped with a shot function is also called a shot box). The shot function is that when a shot switch provided in the zoom controller is turned on, the zoom lens moves to a shot position designated by a shot position adjustment knob.When the shot switch is turned on, the zoom controller
The current position of the zoom lens is acquired from the lens device, and a speed control signal for instructing a speed in a direction in which the difference between the current position of the zoom lens and the designated shot position becomes zero and a speed corresponding to the difference is transmitted to the lens device. Transmit to the control unit. Thus, the control unit of the lens device drives the zoom lens according to the speed control signal, so that the zoom lens moves to the shot position. Note that the shot function is described in, for example, Japanese Patent Application Laid-Open No. 8-33467.

The limit function limits the movement range of the zoom lens to a desired range. When the operation member is operated, the zoom controller acquires the current position of the zoom lens from the lens device, and obtains the current position. When the current position of the zoom lens is moving in the direction approaching the limit position set by the limit position adjustment knob, the speed control signal transmitted to the control unit of the lens device is determined by the difference between the current position of the zoom lens and the limit position. Limit to the speed according to,
Further, when the current position of the zoom lens exceeds the limit position, a speed control signal for returning to the limit position is transmitted to the control unit of the lens device. Thus, the control unit of the lens device drives the zoom lens according to the speed control signal given from the zoom controller, so that the movement range of the zoom lens is limited to a range set by the limit position. The limit function is described in, for example,
0-39193.

On the other hand, there is known a lens device equipped with an angle-of-view correction function (for example, Japanese Patent Laid-Open No.
282396). The angle-of-view correction function is to prevent a change in the angle of view caused by the movement of the focus lens when the focus lens is moved by moving the zoom lens.The control unit of the lens device moves the focus lens. When the zoom lens is moved, the zoom lens is moved to a position where the angle of view is fixed. This prevents a change in the angle of view during focusing.

[0007]

However, conventionally,
When the shot function and the limit function as described above are being executed, there has been a problem that the angle-of-view correction function cannot be effectively operated. That is, when the zoom lens is stopped at the shot position or the limit position by the control based on the shot function or the limit function in the zoom controller, and the control unit of the lens device moves the zoom lens by the control based on the view angle correction function. The zoom controller recognizes that the position of the zoom lens has shifted from the shot position, or determines that the position has exceeded the limit position in some cases. Therefore, a speed control signal for returning the zoom lens to the shot position or the limit position is transmitted from the zoom controller to the control unit of the lens device, and eventually, the zoom lens is returned to the shot position or the limit position, and the angle of view is changed. The correction function will not operate effectively.

[0008] For the limit function, it is not desired that the zoom lens gives priority to the angle of view correction beyond the limit position, but for the shot function, the zoom lens moves to the shot position. When the camera is stopped at a predetermined position, there is a case where it is desired that the angle of view correction function is prioritized and the angle of view correction is performed even from the shot position. Therefore, a method of invalidating the control signal given from the zoom controller when performing the angle-of-view correction in order to satisfy such a request may be considered. However, in this case, the limitation at the limit position originally given by the zoom controller is also invalidated, so that a problem occurs that the zoom lens moves outside the limit position due to the angle of view correction.

Conventionally, since the shot function and the limit function of the zoom controller and the angle-of-view correction function of the lens device are performed in an overlapping manner, there is a problem in control. There is a problem that the movement of the zoom lens near the position becomes worse.

The present invention has been made in view of such circumstances, and makes it possible to correct the angle of view even when the zoom lens is stopped at the shot position by controlling based on the shot function, and to provide a limit function in the controller. It is an object of the present invention to provide a lens device that can prevent the zoom lens from moving outside the limit position by angle-of-view correction when is enabled, and can operate the zoom lens satisfactorily. And

[0011]

According to a first aspect of the present invention, there is provided a control apparatus comprising a focus lens and a zoom lens, wherein the zoom lens is moved based on a control signal given from a controller. And a control unit that executes control based on an angle-of-view correction function that moves the zoom lens to a position that prevents a change in the angle of view due to movement of the focus lens when the focus lens moves. The controller obtains a position signal indicating the position of the zoom lens output from the lens device, and based on the position signal, controls the zoom lens so as not to move outside a predetermined limit position. In a lens device having a limit function for restricting a moving range of a zoom lens, the lens device has an output to the controller. Changing the value of the position signal from the value indicating the actual position of the zoom lens, and detecting a change in the control signal given from the controller with respect to the value of the changed position signal, thereby setting the limit position. A limit position detecting means for detecting, and a movement range of the zoom lens such that the zoom lens does not move outside the limit position detected by the limit position detecting means when performing control based on the angle-of-view correction function. And limiting means for limiting

According to the present invention, when the control unit of the lens device corrects the angle of view, when the limit function is enabled in the controller, the limit position is grasped by the lens device, and the limit position is considered. Since the angle of view is corrected by performing the correction, the problem that the zoom lens moves outside the limit position even when the angle of view is corrected in the lens device prior to the control signal from the controller is prevented.

According to a second aspect of the present invention, there is provided a control system comprising a focus lens and a zoom lens, wherein the control for moving the zoom lens based on a control signal given from a controller;
A lens device comprising: a control unit configured to execute control based on an angle-of-view correction function of moving the zoom lens to a position that prevents an angle-of-view change due to movement of the focus lens. Obtain a position signal indicating the position of the zoom lens output from
A limit function for limiting a movement range of the zoom lens so that the zoom lens does not move outside a predetermined limit position based on the position signal; and stopping the zoom lens at a predetermined shot position based on the position signal. In the lens device having a shot function to perform the control, when the control means executes the control based on the angle-of-view correction function, the control unit executes the control based on the value of the position signal output to the controller based on the angle-of-view correction function. Position signal fixing means for fixing to a value indicating the position of the previous zoom lens, and changing the value of the position signal output to the controller from a value indicating the actual position of the zoom lens, and changing the value of the changed position signal To detect the limit position by detecting a change in a control signal given from the controller. And when the control based on the angle-of-view correction function is performed, the movement range of the zoom lens is limited so that the zoom lens does not move outside the limit position detected by the limit position detection means. And limiting means for performing the operation.

According to the present invention, when correcting the angle of view, by fixing the value of the position signal output from the lens device to the controller, the zoom lens stopped at the shot position by controlling the shot function. This allows the angle of view to be corrected. Further, by fixing the value of the position signal in this manner, the zoom lens may move beyond the limit position due to the angle of view correction. However, the limit position is detected by predetermined means, and the zoom lens is moved by the lens device. By controlling the zoom lens so as not to exceed the limit position, it is possible to prevent the zoom lens from moving out of the limit position.

When the control based on the angle-of-view correction function is executed for the zoom lens stopped at the shot position or the limit position by the shot function or the limit function, the position signal is fixed and the shot function or the limit function is performed. Since the state is substantially ineffective, the conventional disadvantage that the shot function or the limit function and the angle-of-view correction function are simultaneously performed is eliminated, and the operation of the zoom lens is improved even near the shot position or the limit position.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a lens device according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an embodiment of a television camera using a lens device according to the present invention. As shown in FIG. 1, the television camera 10 includes a lens device 12 and a camera body 14. The television camera 10 is supported by a camera platform 18 on a pedestal dolly 16. Two operation rods 22 and 23 are extended from the camera platform 18, and a zoom controller 26 for operating a zoom speed and the like and a focus controller 28 for operating a focus are attached to the ends of the operation rods 22 and 23, respectively. It is supposed to be.

The zoom controller 26 is also called a shot box. The zoom controller 26 includes a thumb ring 26A and a switch panel 26.
B is provided. The thumb ring 26A can be rotated in both directions from the reference position. The photographer operates the thumb ring 26A with the thumb of the left hand to adjust the amount of rotation and the rotation direction from the reference position.
The moving speed and moving direction of the zoom lens mounted on the camera can be controlled. By the operation of the thumb ring 26A,
From the zoom controller 26, a speed control signal corresponding to the rotation amount and rotation direction of the thumb ring 26A is output to the lens device 12.

The switch panel 26B is provided to execute a shot function and a limit function. The shot function is a function for automatically moving the zoom lens to a desired position (shot position) by pressing a switch. The limit function is a function for limiting the movement range of the zoom lens to desired positions on the wide side and the tele side. As shown in FIG. 2, the switch panel 26B has shot switches 32A, 32B, 32C, and 3 that instruct the execution of a shot by a pressing operation of the photographer in connection with the shot function.
2D is provided, and shot position adjustment knobs 34A, 34B, 34C, 34D for setting the shot positions corresponding to the respective shot switches 32A to 32D are provided.
Further, a speed adjustment knob 36 for setting the moving speed of the zoom lens to the shot position at the time of executing a shot is provided.

In the switch panel 26B, the limit functions for the wide side and the tele side are enabled by the pressing operation of the cameraman in connection with the limit function.
Limit switches 38A and 38B for disabling are provided, and limit position adjustment knobs 40A and 40B for setting limit positions on the wide side and the tele side are provided corresponding to the limit switches 38A and 38B. Note that zoom control based on these functions will be described later.

The focus controller 28 shown in FIG. 1 is provided with a rotatable focus ring 28A. The photographer uses this focus ring 28A
Can be operated with the right hand to adjust the rotational position, whereby the position of the focus lens mounted on the lens device 12 can be operated. When the focus ring 28A is operated, a position control signal corresponding to the rotational position of the focus ring 28A is transmitted from the focus controller 28 to the lens device 12.

A viewfinder 30 is provided on the upper surface of the camera body 14 for checking an image being shot.

FIG. 3 is a block diagram showing the configuration of the lens device according to the present invention. The zoom lens 60, the focus lens 80, and the
The block configuration related to the control of the iris 100 is shown, and the CPU 50 mounted on the lens device 12 includes:
Zoom controller 26 and focus controller 2
8, or a process related to control of the zoom lens 60, the focus lens 80, and the iris 100 based on a control signal given from the camera body 14.

First, the control of the zoom lens 60 will be described. For the control of the zoom lens 60, the speed control based on the operation of the thumb ring 26A of the zoom controller 26, the shot function commanded on the switch panel 26B of the zoom controller 26, or Position control based on the limit function or position control based on the angle-of-view correction function mounted on the lens device 12 is performed.

The thumb ring 26 of the zoom controller 26
The speed control based on the operation A is a control in which, when the photographer operates the thumb ring 26A of the zoom controller 26, the zoom lens 60 is moved at a speed corresponding to the operation amount. As shown in FIG. 3, the operation amount of the thumb ring 26A is detected by a potentiometer in the zoom controller 26, and the operation amount is used as a speed control signal for instructing the moving speed (zoom speed) of the zoom lens 60, and the analog signal is used as the speed control signal. Output from Then, the speed control signal is converted into a digital signal by the A / D converter 40 in the lens device 12, and
It is input to the CPU 50. The zoom controller 26
Will be described later.

When the CPU 50 obtains the speed control signal from the zoom controller 26, the CPU 50 converts the control signal for instructing the rotation speed of the zoom drive motor 56 (movement speed of the zoom lens 60) based on the speed control signal into D / A conversion. Vessel 5
2 and the D / A converter 52 converts the control signal into an analog signal and supplies the analog signal to the zoom control circuit 54.

As described above, the zoom control circuit 54
When a control signal is given from U50, the actual rotation speed of the zoom drive motor 56 is obtained from the tachogenerator 58. Then, a voltage is applied to the zoom drive motor 56 so that the difference between the rotation speed of the zoom drive motor 56 commanded by the control signal from the CPU 50 and the actual rotation speed of the zoom drive motor 56 becomes zero. As a result, the zoom driving motor 56 rotates at the rotation speed commanded by the CPU 50, and the zoom lens 60 moves at the speed commanded by the thumb ring 26A of the zoom controller 26.

The position control based on the shot function commanded on the switch panel 26B of the zoom controller 26 is performed by the shot switch 3 provided on the switch panel 26B of the zoom controller 26 as described with reference to FIG.
When any one of 2A to 32D is pressed, the zoom lens 60 is moved to a shot position set by the shot position adjustment knobs 34A to 34D corresponding to the pressed shot switches 32A to 32D.
The zoom controller 26 includes shot switches 32A to
When any of 32D is pressed, the shot position set by the shot position adjustment knobs 34A to 34D corresponding to the pressed shot switches 32A to 32D is detected, and the CPU 50 of the lens device 12 sends the zoom lens 60 Is obtained via the D / A converter 42. Note that the CPU 50 determines the current position of the zoom lens 60 by the potentiometer 62 and the A / D converter 64.
Are getting through.

The zoom controller 26 outputs a speed control signal to the lens device 12 in a direction in which the difference between the current position of the zoom lens 60 obtained from the CPU 50 and the shot position is zero and a speed corresponding to the difference is provided to the lens device 12. I do. In the lens device 12, the speed control signal is transmitted to the A / D converter 4
The signal is converted into a digital signal by 0 and input to the CPU 50.

When the CPU 50 obtains the speed control signal from the zoom controller 26, the CPU 50 determines the rotation speed of the zoom drive motor 56 (the speed of the zoom lens 60) based on the speed control signal as in the case of the speed control based on the operation of the thumb ring 26A. A control signal for instructing (moving speed) is output to the zoom control circuit 54. Thereby, the zoom driving motor 5
6 is driven, and the zoom lens 60 moves at the speed commanded by the speed control signal from the zoom controller 26. Further, since the zoom controller 26 outputs the speed control signal so that the zoom lens 60 stops at the shot position as described above, the zoom lens 60 moves to the shot position and stops.

The position control based on the limit function instructed on the switch panel 26B of the zoom controller 26 is performed by the limit switch 3 provided on the shot panel 26B of the zoom controller 26 as described with reference to FIG.
8A and the limit switch 38B are turned on, the limit functions on the wide side and the tele side are enabled,
Limit position adjustment knobs 4 provided corresponding to each of the limit switch 38A and the limit switch 38B.
0A, the limit positions on the wide side and the tele side are set based on the limit position adjustment knob 40B. Then, when controlling the zoom lens 60 based on the operation of the thumb ring 26A or the shot function, the zoom lens 60 is moved beyond the limit position and outside the limit position (for the limit position on the wide side, the position on the wide side is shifted from the limit position on the wide side). Good,
The zoom lens 60 is moved so as not to move to the tele side limit position (to the tele side from the limit position).
Is a control for restricting the moving range of the image. When one of the limit switches 38A and 38B is pressed, the zoom controller 26 presses the pressed limit switch 38.
A, 38B corresponding to the limit position adjustment knob 40A,
The set position of 40B is detected, and the set position is set as a wide-side or tele-side limit position corresponding to the pressed limit switches 38A and 38B. When one or both of the limit switches 38A and 38B are not turned on, the limit position on the side not turned on is set to the wide end or the tele end (the wide end or the tele end is a mechanical end). I do.

When executing control for moving the zoom lens 60 based on the operation of the thumb ring 26A, the shot function, or the angle-of-view correction function, the zoom controller 26 sets the limit position in the moving direction to the target position. Determined as Then, the current position of the zoom lens 60 is obtained from the CPU 50 of the lens device 12 via the D / A converter 42, and when the difference between the target position determined as described above and the current position becomes smaller than a predetermined value ( When the position of the zoom lens 60 approaches within a predetermined distance from the limit position), the speed control signal given to the CPU 50 of the lens device 12 is limited to a speed corresponding to the difference between the target position and the current position. Thereby, the CPU 50 sets the thumb ring 2
As in the case of the speed control based on the operation of 6A, a control signal for instructing the rotation speed of the zoom drive motor 56 (movement speed of the zoom lens 60) is output to the zoom control circuit 54 based on the speed control signal. , Thumb Ring 26
Regardless of the operation A or the like, the zoom lens 60 is decelerated near the limit position and stops at a position not exceeding the limit position. Note that when the zoom lens 60 is located outside the limit position, the zoom controller 26 performs control to move the zoom lens 60 to the limit position, similarly to the position control based on the shot function.

The position control based on the angle-of-view correction function is, for example, a control that can be enabled or disabled by a predetermined switch provided in the lens device 12 or the like. When the position control is enabled, the position control is executed by the CPU 50. You. After moving the zoom lens 60 based on the speed control signal from the zoom controller 26, the CPU 50 stops the zoom lens 60 when the stop (0) is commanded by the speed control signal to stop the zoom lens 60.
Are obtained from potentiometers 62 and 82 via A / D converters 64 and 84, respectively, and the position of zoom lens 60 and the position of focus lens 80 are stored.

As described later, when the focus lens 80 is moved based on an instruction from the focus controller 28 (or based on an autofocus signal transmitted from the camera body 14), the focus lens 80 The position of the zoom lens 60 that keeps the shooting angle of view constant with respect to the moving position is determined as a target position.
The position of the zoom lens 60 that makes this shooting angle of view constant is
The stored zoom lens 60 and focus lens 80
And the position of the focus lens 80 after the movement is calculated by a predetermined arithmetic expression. When the target position is determined in this manner, the CPU 50 obtains a difference between the target position and the current position of the zoom lens 60, and outputs a control signal for instructing a speed in a direction in which the difference becomes zero and for a speed corresponding to the difference.
The signal is output to the A converter 52, the control signal is converted into an analog signal by the D / A converter 52, and given to the zoom control circuit 54. As a result, the zoom lens 60 is moved to a position where the change in the angle of view due to the movement of the focus lens 80 is prevented under the control of the zoom control circuit 54 described above.

The position control based on the angle-of-view correction function is performed when the thumb ring 26A of the zoom controller 26 is at the neutral position or when the zoom lens 60 is moved to the shot position by executing the shot function. Is executed when the zoom lens 60 is stopped. When executing the position control based on the angle-of-view correction function, the value of the position signal output from the CPU 50 to the zoom controller 26 becomes a value indicating the stop position before executing the position control based on the angle-of-view correction function. Fixed. Thus, when the zoom controller 26 stops the zoom lens 60 at the shot position by the position control based on the shot function, even when the CPU 50 moves the zoom lens 60 by the view angle correction function,
The speed control signal for returning the zoom lens 60 to the shot position with respect to 0 is not supplied from the zoom controller 26, and the angle-of-view correction function is effectively executed.

The CPU 50 of the lens device 12 intentionally fluctuates the value of the position signal of the zoom lens 60 transmitted to the zoom controller 26 from the value indicating the current position of the zoom lens 60, and responds to the fluctuation with the zoom controller. Whether the zoom controller 26 is performing control based on the operation of the thumb ring 26A by detecting the state of the change in the speed control signal given from the
Alternatively, it is detected whether control based on the shot function is being performed. That is, the value of the position signal is increased and decreased from the value of the current position and transmitted to the zoom controller 26, and the value of the speed control signal given from the zoom controller 26 is changed depending on whether the position signal is increased or decreased. If there is almost no change, the control of the zoom controller 26 is independent of the position of the zoom lens 60 and the thumb ring 2
It can be determined that the control based on the operation of 6A is being executed.

On the other hand, the value of the position signal is increased and decreased from the value of the current position and transmitted to the zoom controller 26, and a speed control signal given from the zoom controller 26 when the position signal is increased or decreased. When the value increases on the one hand and decreases on the other hand, the control of the zoom controller 26 is related to the position of the zoom lens 60, and it can be determined that the control based on the shot function is being executed.

It should be noted that such determination of the control contents of the zoom controller 26 can be performed even when the zoom lens 60 is stopped or moving.

The CPU 50 determines that the zoom controller 26 is performing control based on the shot function in this manner, and fixes the position signal value for performing the angle-of-view correction as described above. A value range (hereinafter, referred to as a dead zone) that is regarded as instructing a stop is set on both the positive and negative sides of the value of 0 instructing a stop in the same manner as in the case of 0. That is, even when the position signal is fixed at the shot position, the position signal may be displaced from the shot position due to a fluctuation error of the position signal or the like, and a speed control signal for commanding movement may be given from the zoom controller 26. In this case, the CPU 50 cannot determine whether the speed control signal is caused by the operation of the thumb ring 26A or the speed control signal is caused by an error in the position signal. In addition, the operation of the thumb ring 26A must take precedence over the angle of view correction. For this reason, even when a speed control signal is given due to an error in the position signal, the CPU 50 must follow the speed control signal, and the angle of view cannot be properly corrected. . However, as described above, by setting the dead zone where the speed control signal is regarded as instructing the stop to be on both the positive and negative sides of the value of 0, the angle of view can be corrected without following the speed control signal caused by the error. Will be able to Note that the range set as the dead zone is determined in consideration of the fluctuation range of the value of the speed control signal caused by an error in the position signal or the like.

As described above, the CPU 50 of the lens device 12 intentionally changes the value of the position signal of the zoom lens 60 transmitted to the zoom controller 26, and the speed given from the zoom controller 26 as a response to the change. The limit position is detected by detecting a change in the control signal. That is, the zoom controller 26
Is changed to a value indicating a position wider than the current position of the zoom lens 60, a speed control signal given from the zoom controller 26 instructs movement to the tele side. Sometimes zoom lens 6
It can be determined that there is a wide-side limit position between the current position of 0 and the position transmitted as the position signal.
When the value of the position signal is changed to a value indicating a position on the telephoto side of the current position of the zoom lens 60, and the speed control signal given from the zoom controller 26 instructs movement to the wide side, the zoom It can be determined that there is a wide-side limit position between the current position of the lens 60 and the position transmitted as the position signal. If the position signal is transmitted with a smaller amount of change from the current position, the current position of the zoom lens 60 when the existence of the limit position is detected as described above may be determined as the limit position. If the value of the position signal is changed in the same direction as the moving direction when the lens 60 is moving, it is possible to detect when the speed control signal commands movement in the opposite direction to the moving direction. The position transmitted as the position signal at the time of the detection can be determined as the limit position. Also, by gradually changing the value of the position signal to the tele side or the wide side and detecting when a speed control signal for commanding movement in the direction opposite to the direction of the change is given, the position signal is detected at the time of the detection. Can be determined as the limit position.

When the limit position is detected in this manner, the CPU 50 limits the moving range of the zoom lens 60 so that the zoom lens 60 does not move outside the limit position when the zoom lens 60 is moved by correcting the angle of view. . If it is determined that the zoom lens 60 has stopped at the limit position, the zoom controller
The dead zone is set as the range of values in which the speed control signal given from 6 instructs stop. Thereby, the same problem as described above can be solved.

Next, focus control will be described.
Focus control is performed based on the operation of the focus ring 28A of the focus controller 28 shown in FIG. The operation of the focus ring 28A is detected by a potentiometer of the focus controller 28, and the operation amount is output from the focus controller 28 by an analog signal as a position control signal for instructing the position (focus position) of the focus lens 80. Then, the speed control signal is converted into a digital signal by the A / D converter 44 in the lens device 12, and
It is input to the CPU 50.

The CPU 50 includes a focus controller 2
When the position control signal is acquired from 8, the focus position designated by the position control signal is set as the target position. Also,
The current position of the focus lens 80 is determined by the potentiometer 8
2 through the A / D converter 84. Then, the difference between the target position of the focus lens 80 and the current position is 0.
Is output to the D / A converter 72, and the D / A converter 72 converts the control signal into an analog signal and supplies the analog signal to the focus control circuit 74. .

When the focus control circuit 74 obtains the control signal output from the CPU 50 as described above, it obtains the actual rotation speed of the focus drive motor 76 from the tacho generator 78. The focus driving motor 76 instructed by the control signal from the CPU 50
Is applied to the focus driving motor 76 such that the difference between the rotation speed of the focus driving motor 76 and the actual rotation speed of the focus driving motor 76 becomes zero. Thus, the focus driving motor 76 rotates at the rotation speed commanded by the CPU 50, and the focus lens 80 moves to the focus position commanded by the focus controller 28.

Next, the iris control will be described.
The control of the iris 100 is performed based on a control signal transmitted from the camera body 14, for example. CPU 50
When a position control signal indicating the position (aperture diameter) of the iris 100 is given from the camera body 14, the position indicated by the position control signal is set as a target position, and the current position (aperture diameter) of the iris 100 is set as a potentiometer 102. From A /
Obtained via the D converter 104. And Iris 1
The difference between the target position of 00 and the current position is obtained, and the difference is 0
Is output to the D / A converter 92, and the D / A converter 92 converts the control signal into an analog signal and supplies the analog signal to the iris control circuit 94. .

As described above, the iris control circuit 94
When the control signal is given from the PU 50, the actual rotation speed of the iris drive motor 94 is obtained from the tachogenerator 98. The difference between the rotation speed of the iris drive motor 96 commanded by the control signal from the CPU 50 and the actual rotation speed of the iris drive motor 96 is 0.
A voltage is applied to the iris drive motor 96 such that As a result, the iris drive motor 96 is
The iris 10 is rotated at the commanded rotation speed from 0.
The aperture diameter of 0 is changed.

Next, the internal configuration of the zoom controller 26 will be described. FIG. 4 is a diagram showing the internal configuration. The signal shown in the figure is the speed control signal given from the zoom controller 26 to the CPU 50 of the lens device 12, and the signal shown in the figure is the current position of the zoom lens 60 given from the lens device 12 to the zoom controller 26. Is a position signal indicating the position.

As shown in the figure, the operation amount of the thumb ring 26A is converted into a voltage signal by the potentiometer 120. Then, the voltage signal is amplified at a predetermined magnification by the amplifier 122 and input to the input terminal 1 of the switching circuit 124.

The switching circuit 124 includes a control circuit 126 described later.
Is a circuit that outputs one of the signals input from the input terminal 1 and the input terminal 2 from the output terminal 3 in response to an instruction signal from the external device. All of the shot switches 32A to 32D provided on the switch panel 26B are turned off. In the case of, the voltage signal input from the input terminal 1 is output from the output terminal 3, and when any of the shot switches 32A to 32D is turned on, the voltage signal input from the input terminal 2 is output from the output terminal 3. Output. Therefore, shot switch 3
When all of 2A to 32D are off, the potentiometer 120 is operated based on the operation of the thumb ring 26A as described above.
, A voltage signal input to the input terminal 1 via the amplifier 122 is output from the output terminal 3. As a result, the voltage signal is transmitted to the CPU 50 of the lens device 12 as a speed control signal via the limit circuit 130 described later, and the zoom lens 60 is driven at a speed corresponding to the operation amount of the thumb ring 26A.

On the other hand, when any of the shot switches 32A to 32D is turned on, the turned on shot switch is detected by the control circuit 126. When any of the shot switches 32A to 32D is turned on, the control circuit 126 inputs a signal output from the output terminal 3 of the switching circuit 124 to the switching circuit 124 from the input terminal 2 of the switching circuit 124. An instruction signal is provided so as to switch to the output voltage signal. The shot switch 32
When all of A to 32D are off, an instruction signal is given to the switching circuit 124 such that the signal output from the output terminal 3 of the switching circuit 124 is the voltage signal input from the input terminal 1 thereof.

The control circuit 126 inputs a voltage signal output from the slider of the variable resistors VR1 to VR4 corresponding to the turned on shot switch to one input terminal of the differential amplifier 128. The variable resistors VR1 to VR4 change the position of the slider in accordance with the set positions of the shot position adjustment knobs 34A to 34D provided on the switch panel 26B, respectively.
The voltage signal output from the slider indicates a shot position to which the zoom lens 60 should move when the corresponding shot switch 32A to 32D is turned on.

The differential amplifier 128 amplifies the difference between the voltage signals input from the two input terminals at a predetermined magnification.
The amplified voltage signal is output from the output terminal.
One input terminal is connected to the variable resistors VR1 to VR as described above.
A voltage signal output from the slider 4 is input, and a position signal provided from the lens device 12 is input to the other input terminal. Accordingly, a voltage signal corresponding to the difference between the shot position at which the zoom lens 60 should be moved and the current position of the zoom lens 60 is output from the differential amplifier 128,
The voltage signal is input to the input terminal 2 of the switching circuit 124.

The voltage signal input to the input terminal 2 of the switching circuit 124 is applied to the shot switches 32A-32 as described above.
When any one of D is on, the voltage is output from the output terminal 3 of the switching circuit 124 and the voltage signal is
0 as a speed control signal through the C
It is transmitted to PU50. Thereby, the zoom lens 60
Moves according to the speed control signal, and the position signal of the zoom lens 60 input to the differential amplifier 128 gradually approaches the shot position. As a result, the zoom lens 60 moves to the shot position and stops.

The release of the execution of the shot function may be performed by pressing the shot switch which has been turned on again, or may be performed by operating the thumb ring 26A.

The limit circuit 130 is provided with the limit switches 38A and 38 of the switch panel 26B shown in FIG.
This is a circuit for converting the voltage signal (speed control signal) output from the output terminal 3 of the switching circuit 124 in a direction in which the speed commanded by the speed control signal decreases when B is turned on. When one of the limit switches 38A and 38B is turned on, the control circuit 126 outputs a voltage signal output from the slider of the variable resistor VR5 or the variable resistor VR6 corresponding to the turned on limit switch to the limit circuit 130. Input to a predetermined input terminal (when both limit switches 38A and 38B are turned on, voltage signals output from both sliders are input). The variable resistors VR5 and VR6 are respectively connected to the switch panel 26B.
The position of the slider is changed in accordance with the set position of the limit position adjustment knobs 40A and 40B provided in the first and second variable resistors VR5 and VR6. Limit switches 38A, 38B
Indicates the limit positions on the wide side and the tele side when are turned on.

The other input terminal of the limit circuit 130 receives a position signal given from the lens device 12. The limit circuit 130 is a direction in which the difference between the limit position and the current position of the zoom lens decreases based on the signal indicating the limit position input from these input terminals and the position signal indicating the current position of the zoom lens 60. When the difference is smaller than a predetermined amount, the switching circuit 124
Is limited to a voltage corresponding to the difference. As a result, even if an attempt is made to output a speed control signal that causes the zoom lens 60 to exceed the limit position by operation of the thumb ring 26A or control based on the shot function, the speed control signal is limited by the limit circuit 130, and the zoom lens 60 is limited. Stop at the position.

C of the lens device 12 configured as described above
An example of a processing procedure regarding control of the zoom lens 60 in the PU 50 will be described with reference to the flowcharts in FIGS. As shown in FIG. 5, the CPU 50 firstly controls the zoom controller 2 connected to the lens device 12.
6 is digital or analog (Step S1)
0). The digital zoom controller converts various information such as a speed control signal into a digital signal by serial communication using a digital signal.
This is transmitted to U50. On the other hand, the analog zoom controller issues a command such as a zoom speed using a voltage value of an analog voltage signal as shown in FIG. C
The PU 50 sends a predetermined command to the zoom controller 26.
To the zoom controller 2 for the command
If there is a response from 6, it is determined that it is digital, and if there is no response, it is determined that it is analog. If it is determined to be digital, processing for a digital zoom controller is performed (step S12), but description of that processing is omitted here.

On the other hand, when it is determined that the zoom controller 26 is analog, the CPU 50 controls the driving of the zoom lens 60 based on the speed control signal given from the zoom controller 26 as described above.
It is assumed that after some control, the speed control signal indicates a value (0) for instructing a stop (step S13).

At this time, first, the CPU 50 detects whether or not the control (shot operation) based on the shot function is performed by the zoom controller 26, and when the shot operation is performed, the speed control is performed as described above. A dead zone is set in a range in which the value of the signal is regarded as instructing the stop (step S14). The details of the processing in step S14 will be described later.

Next, it is determined whether or not a shot operation is being performed by detecting the shot operation in step S14 (step S16). If NO, limit detection processing is performed, and if a limit position is detected, a dead zone is set and a correction limit is set in the same manner as described above (step S18). If it is determined as YES in step S16, the process of step S18 is not performed. The details of the processing in step S18 will be described later.

Next, the CPU 50 determines whether or not there is a speed control signal from the zoom controller 26 (step S20). When the speed control signal from the zoom controller 26 instructs stop, it is determined that there is no speed control signal. At this time, the determination is made in consideration of the dead zone. That is, the value of the speed control signal given from the zoom controller 26 is equal to the value in the above step S14 or step S18
If the value is within the range set as the dead zone in,
It is determined that there is no speed control signal (0). Where YE
When determining as S, that is, when determining that there is a speed control signal, the CPU 50 transmits the current position of the zoom lens 60 as a position signal to the zoom controller 26 (step S22), and the speed control provided from the zoom controller 26. A normal process for controlling the zoom lens 60 is executed based on the signal (step S24).

On the other hand, if NO is determined in step S20, that is, if it is determined that there is no speed control signal, the CPU 50 fixes the position signal transmitted to the zoom controller 26 to the value of the stop position (step S20). S2
6) Then, a process related to the control of the angle of view correction is executed (step S28). At this time, the correction limit is considered.
That is, when the limit position is detected in step S18, the angle of view is corrected within a range where the zoom lens 60 does not exceed the limit position.

The CPU 50 repeatedly executes the processing from step S13 to step S28.

Next, the shot detection process in step S14 will be described. As shown in FIG.
The PU 50 sets the speed control signal given from the zoom controller 26 to AD (Step S40). Since the shot operation detection processing is executed when the speed control signal is 0 as shown in step S13, the AD value is 0. However, the shot operation detection processing is performed by the zoom lens. Since it is possible to perform the operation while the 60 is moving (when the speed control signal is not 0), the value of AD is not limited to 0 in consideration of such a case.

Subsequently, the CPU 50 controls the zoom lens 60
Then, a value indicating a position displaced by a predetermined amount in a predetermined direction (for example, on the tele side) with respect to the current position is transmitted as a position signal to the zoom controller 26 (step S42). That is, the value of the position signal is increased from the value indicating the current position of the zoom lens 60. Then, the value of the speed control signal given from the zoom controller 26 at this time is set to AD1 (step S44). Next, the CPU 50 sets the zoom lens 60
Is transmitted to the zoom controller 26 as a position signal indicating a position displaced by a predetermined amount in a direction opposite to the predetermined direction (for example, on the wide side) with respect to the current position (step S4).
6). That is, the value of the position signal is reduced from the value indicating the current position of the zoom lens 60. At this time, the value of the speed control signal given from the zoom controller 26 is
2 (Step S48).

Next, the CPU 50 determines whether or not both the values of AD1 and AD2 have changed by a predetermined value or more from the value of AD (step S50). If NO at this time, it is determined that a shot is not being performed (step S5).
2). On the other hand, if YES, it is determined that a shot is being taken (step S54), and a dead zone is set (step S5).
6). When the above processing is completed, the zoom controller 2
The position signal transmitted to No. 6 is returned to a value indicating the current position of the zoom lens 60 (step S58), and the shot detection process ends.

Next, the process of limit detection in step S16 will be described. As shown in FIG.
The PU 50 determines whether the speed control signal given from the zoom controller 26 instructs movement in the wide direction or movement in the tele direction (step S).
70). Since the limit detection process is executed when the speed control signal is 0 as shown in step S13, the speed control signal instructs movement in any direction only at the time of the determination in step S70. Although it is not possible to determine whether the zoom operation is performed or not, this limit detection processing can be performed while the zoom lens 60 is moving, as in the shot operation detection processing. Therefore, the processing procedure including this case is shown. is there. Therefore, the zoom lens 60
Is stopped, the determination in step S70 may be performed in the direction in which the zoom lens 60 has moved, or the following processing is performed in both the wide and tele directions. It may be.

In step S70, only the processing when it is determined that the speed control signal instructs movement in the wide direction will be described. In this case, the CPU 50
Transmits to the zoom controller 26 a value indicating a position displaced outward by a predetermined amount α (wide side) from the current position of the zoom controller 26 to the wide side as a position signal (step S72). Then, at this time, a speed control signal is read from the zoom controller 26 (step S74),
It is determined whether or not the speed control signal instructs movement to the tele side (step S76). If YES, since there is a wide-side limit position from the current position of the zoom lens 60 to a position on the wide side by a predetermined amount α, the correction of the angle of view to the wide side is prohibited (setting of a correction limit). Further, as described above, a dead zone is set, which is a range in which the value of the speed control signal is regarded as instructing the stop (step S78). If “NO” in the step S76, the process in the step S78 is not performed. Note that the above step S7
0, the above-described step S
The same processing as in step 72 to step S78 is performed.

As described above, according to the processing shown in the flowcharts of FIGS. 5 to 7, the angle of view can be corrected for the zoom lens 60 stopped at the shot position by controlling the shot function, and It is possible to prevent the angle of view from being corrected beyond the position.

In the above embodiment, when performing the angle-of-view correction, the CPU 50 fixes the position signal to be output to the zoom controller 26, so that the movement of the zoom lens 60 by the angle-of-view correction and the Although the speed control signal for instructing the movement from the zoom controller 26 due to the shot function or the limit function is prevented from being given, the invention is not limited to this, and the angle of view is corrected instead of fixing the position signal. In some cases, CPU5
0 may not follow the speed control signal given from the zoom controller 26. However, thumb ring 26
Since it is necessary to follow at least the speed control signal given by the operation of A, when a speed control signal irrelevant to the movement of the zoom lens 60 due to the angle of view correction is input, for example, the sudden speed When the value of the control signal changes, the control of the zoom lens 60 according to the speed control signal is started.

In the above embodiment, the case where the analog zoom controller is used has been described.
The present invention can be applied to a digital zoom controller in the same manner as in the above embodiment.

[0072]

As described above, according to the lens device of the present invention, when the limit function is enabled in the controller when performing the angle of view correction, the limit position is grasped by the lens device. Since the angle of view is corrected in consideration of the limit position, even when the angle of view is corrected in the lens device prior to the control signal from the controller, a problem that the zoom lens moves outside the limit position is prevented. You.

When the angle of view correction is executed, the value of the position signal output from the lens device to the controller is fixed, so that the zoom lens stopped at the shot position by controlling the shot function. The angle of view can be corrected. Further, by fixing the value of the position signal in this manner, the zoom lens may move beyond the limit position due to the angle of view correction. However, the limit position is detected by predetermined means, and the zoom lens is moved by the lens device. By controlling the zoom lens so as not to exceed the limit position, it is possible to prevent the zoom lens from moving out of the limit position.

When executing control based on the angle-of-view correction function for the zoom lens stopped at the shot position or the limit position by the shot function or the limit function, the position signal is fixed and the shot function or the limit function is not performed. Since the state is substantially ineffective, the conventional problem that the shot function or the limit function and the angle-of-view correction function are simultaneously performed is eliminated, and the operation of the zoom lens is favorably performed even near the shot position or the limit position. Become like

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a television camera using a lens device according to the present invention.

FIG. 2 is a configuration diagram illustrating a configuration of an operation member disposed on a switch panel of a zoom controller.

FIG. 3 is a block diagram showing one embodiment of a lens device according to the present invention.

FIG. 4 is a configuration diagram showing an internal configuration of a zoom controller.

FIG. 5 is a flowchart illustrating a processing procedure regarding zoom of a CPU of the lens device;

FIG. 6 is a flowchart illustrating a procedure of a shot operation detection process of a CPU of the lens device.

FIG. 7 is a flowchart illustrating a procedure of a limit detection process of a CPU of the lens device;

[Explanation of symbols]

26: Zoom controller, 26A: Thumb ring, 26
B: switch panel, 28: focus controller,
Reference numeral 30: viewfinder, 32A to 32D: shot switch, 34A to 34D: shot position adjustment knob, 3
8A, 38B: Limit switch, 40A, 40B: Limit position adjustment knob, 50: CPU, 54: Zoom control circuit, 56: Zoom drive motor, 60: Zoom lens, 80: Focus lens, 100: Iris

Claims (3)

[Claims] 1. A control system comprising a focus lens and a zoom lens, wherein the zoom lens is moved based on a control signal given from a controller, and a field angle variation accompanying the movement of the focus lens when the focus lens moves. A control unit that executes control based on an angle-of-view correction function of moving the zoom lens to a position where the zoom lens is prevented, wherein the controller determines a position of the zoom lens output from the lens device. A lens device having a limit function of acquiring a position signal indicating the position of the zoom lens and restricting a movement range of the zoom lens based on the position signal so that the zoom lens does not move outside a predetermined limit position. The value of the output position signal is changed from the value indicating the actual position of the zoom lens. A limit position detecting means for detecting the limit position by detecting a change in a control signal given from the controller with respect to the value of the changed position signal; and executing control based on the angle-of-view correction function. A lens device comprising: a limiter configured to limit a movement range of the zoom lens so that the zoom lens does not move outside the limit position detected by the limit position detector. 2. A control system comprising a focus lens and a zoom lens, wherein the zoom lens is moved based on a control signal given from a controller, and a field angle variation accompanying the movement of the focus lens when the focus lens moves. A control unit that executes control based on an angle-of-view correction function of moving the zoom lens to a position where the zoom lens is prevented, wherein the controller determines a position of the zoom lens output from the lens device. A position signal indicating the position of the zoom lens based on the position signal, and a limit function for restricting a movement range of the zoom lens so that the zoom lens does not move outside a predetermined limit position. In a lens device having a shot function of stopping the camera at a predetermined shot position, When executing the control based on the angle-of-view correction function by the control unit, the value of the position signal output to the controller is fixed at a value indicating the position of the zoom lens before the control based on the angle-of-view correction function is executed. A position signal fixing unit that changes a value of the position signal output to the controller from a value indicating an actual position of the zoom lens, and a control signal given from the controller with respect to the changed position signal value. A limit position detecting unit that detects the limit position by detecting a change; and when performing control based on the angle-of-view correction function, the zoom lens is positioned outside the limit position detected by the limit position detecting unit. Limiting means for limiting the moving range of the zoom lens so that the lens does not move. Apparatus. 3. A control for moving the zoom lens based on the control signal provided by the controller when the position signal is fixed by the position signal fixing means and the control signal given by the controller changes by a predetermined value or more. 3. The lens apparatus according to claim 2, wherein the position signal fixing means returns the position signal to a value indicating the actual position of the zoom lens.