JP4218142B2 - Lens device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lens device, and more particularly, to a lens device mounted on a television camera and equipped with a field angle correction function for correcting a field angle variation at the time of focusing with a zoom lens.
[0002]
[Prior art]
As a lens device mounted on a TV camera or the like, an external controller is connected by a cable, and an optical member such as a zoom lens and a focus lens mounted on the lens device is driven by a motor based on a control signal transmitted from the controller. Things are known.
[0003]
A controller (zoom controller) used for controlling the zoom lens is provided with a rotatable operation member called, for example, a thumb ring. When a cameraman rotates the operation member, zooming according to the operation amount is performed. A speed control signal for instructing the speed is transmitted to the control unit of the lens apparatus, and the zoom lens is motor-driven at the zoom speed instructed by the speed control signal.
[0004]
A zoom controller having a shot function or a limit function is known (a zoom controller having a shot function is also called a shot box). The shot function is that when the shot switch provided in the zoom controller is turned on, the zoom lens moves to the shot position specified by the shot position adjustment knob. When the shot switch is turned on, the zoom controller is moved from the lens device. A current position of the zoom lens is acquired, and a speed control signal for instructing a speed in accordance with the direction in which the difference between the current position of the zoom lens and the designated shot position is zero and the difference is sent to the control unit of the lens apparatus. Send. As a result, the control unit of the lens apparatus drives the zoom lens according to the speed control signal, so that the zoom lens moves to the shot position. The shot function is described in, for example, Japanese Patent Application Laid-Open No. 8-334474.
[0005]
The limit function is to limit the movement range of the zoom lens to a desired range, and the zoom controller acquires the current position of the zoom lens from the lens device when the operation member is operated, and the zoom lens When the current position is moving in a direction approaching the limit position set by the limit position adjustment knob, a speed control signal to be transmitted to the control unit of the lens device is a speed corresponding to the difference between the current position of the zoom lens and the limit position. 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 apparatus. Thereby, 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 the range set by the limit position. The limit function is described in, for example, JP-A-10-39193.
[0006]
On the other hand, there is known a lens apparatus equipped with a field angle correction function (see, for example, Japanese Patent Laid-Open No. 10-282396). The angle-of-view correction function prevents the angle-of-view fluctuation caused by the movement of the focus lens by moving the zoom lens when the focus lens is moved. The control unit of the lens device moves the focus lens. In conjunction with this, the zoom lens is moved to a position where the shooting angle of view is fixed. This prevents a change in the angle of view during focusing.
[0007]
[Problems to be solved by the invention]
However, conventionally, when the shot function and limit function as described above are executed, it 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, the control unit of the lens apparatus moves the zoom lens by the control based on the angle of view correction function. In the zoom controller, it is recognized that the position of the zoom lens is displaced from the shot position, or it is determined that the limit position has been exceeded 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 apparatus. The correction function will not work effectively.
[0008]
For the limit function, it is not desired to prioritize the angle of view correction until the zoom lens exceeds the limit position, but for the shot function, the zoom lens moves to the shot position and stops. In such a case, the field angle correction function may be prioritized and it may be desired to perform the field angle correction even from the shot position. Therefore, a method of invalidating the control signal supplied from the zoom controller when performing angle of view correction in order to satisfy such a requirement can be considered. However, since the restriction at the limit position originally given from the zoom controller is invalidated in this way, there arises a problem that the zoom lens moves outside the limit position due to the view angle correction.
[0009]
Conventionally, the shot function and limit function in the zoom controller and the angle of view correction function in the lens device are performed in an overlapping manner, so there is a problem in control, and there is a problem in the vicinity of the shot position and limit position. There was a problem that the movement of the zoom lens became worse.
[0010]
The present invention has been made in view of such circumstances, and enables the angle of view to be corrected even when the zoom lens is stopped at the shot position by the control based on the shot function, and the limit function is effective in the controller. Accordingly, an object of the present invention is to provide a lens device that can prevent the zoom lens from moving outside the limit position by the angle of view correction, and can operate the zoom lens satisfactorily.
[0011]
[Means for Solving the Problems]
In order to achieve the object, the invention according to claim 1 includes a focus lens and a zoom lens, and controls the movement of the zoom lens based on a control signal provided from a controller, and when the focus lens moves. 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 angle of view caused by the movement of the focus lens. A limit for obtaining a position signal indicating the position of the zoom lens output from the lens device, and limiting 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. In a lens apparatus having a function, the value of the position signal output to the controller is actually 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 changed position signal value, by changing from a value indicating the position of the zoom lens; and Limiting means for limiting a moving range of the zoom lens so 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. It is characterized by that.
[0012]
According to the present invention, when the control unit of the lens apparatus corrects the angle of view, if the limit function is valid in the controller, the limit position is grasped in the lens apparatus, and the angle of view is considered in consideration of the limit position. Since the correction is performed, even when the angle of view is corrected in the lens device in preference to the control signal from the controller, the problem that the zoom lens moves outside the limit position is prevented.
[0013]
According to a second aspect of the present invention, there is provided a focus lens and a zoom lens, the control for moving the zoom lens based on a control signal given from a controller, and the focus lens when the focus lens moves. A lens apparatus comprising control means for executing control based on an angle-of-view correction function for moving the zoom lens to a position that prevents a change in angle of view due to movement, the controller being output from the lens apparatus A limit function that obtains a position signal indicating the position of the zoom lens and limits the movement range of the zoom lens based on the position signal so that the zoom lens does not move outside a predetermined limit position; and the position signal The camera has a shot function for stopping the zoom lens at a predetermined shot position based on When the control unit executes control based on the angle-of-view correction function, the position of the zoom lens before the control based on the angle-of-view correction function is calculated based on the position signal value output to the controller. Position signal fixing means for fixing to the indicated value, and the position signal value to be output to the controller is changed from a value indicating the actual position of the zoom lens, and the changed position signal value is given from the controller. A limit position detecting means for detecting the limit position by detecting a change in the control signal and an outside of the limit position detected by the limit position detecting means when executing control based on the angle of view correction function. Limiting means for limiting a moving range of the zoom lens so that the zoom lens does not move. It is characterized.
[0014]
According to the present invention, when the angle of view is corrected, the position signal value output from the lens apparatus to the controller is fixed, so that the zoom lens stopped at the shot position by the control of the shot function is also displayed. Angle correction can be performed. Further, by fixing the position signal value in this way, there is a risk that the zoom lens may move beyond the limit position due to the angle of view correction. However, the limit position is detected by a predetermined means, and the zoom lens is detected on the lens device side. By controlling so as not to exceed the limit position, it is possible to prevent a problem that the zoom lens moves outside the limit position.
[0015]
In addition, 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 substantially Since the state becomes invalid, the conventional problem that the shot function or the limit function and the angle of view correction function are performed at the same time is solved, and the operation of the zoom lens is improved even near the shot position or the limit position.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of a lens apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
[0017]
FIG. 1 is a perspective view showing an embodiment of a television camera using a lens apparatus according to the present invention. As shown in the figure, the television camera 10 includes a lens device 12 and a camera main body 14, and the television camera 10 is supported by a camera platform 18 on a pedestal dolly 16. Two operating rods 22 and 23 are extended on the pan head 18, and a zoom controller 26 for operating the zoom speed and a focus controller 28 for operating the focus are attached to the ends of the operating rods 22 and 23, respectively. It is supposed to be.
[0018]
The zoom controller 26 is also called a shot box, and the zoom controller 26 is provided with a thumb ring 26A and a switch panel 26B. The thumb ring 26A can be rotated in both directions from the reference position, and the cameraman is mounted on the lens device 12 by rotating the thumb ring 26A with the thumb of the left hand and adjusting the rotation amount and the rotation direction from the reference position. The moving speed and moving direction of the zoom lens can be manipulated. By operating the thumb ring 26A, the zoom controller 26 outputs a speed control signal corresponding to the amount and direction of rotation of the thumb ring 26A to the lens device 12.
[0019]
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 the switch. Is a function that limits 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 is provided with shot switches 32A, 32B, 32C, and 32D for instructing execution of a shot by a pressing operation of a photographer in association with the shot function, and corresponds to each of the shot switches 32A to 32D. Then, shot position adjustment knobs 34A, 34B, 34C and 34D for setting the shot position are provided. Further, a speed adjustment knob 36 for setting the moving speed of the zoom lens up to the shot position at the time of executing a shot is provided.
[0020]
Further, in relation to the limit function, the switch panel 26B is provided with limit switches 38A and 38B for switching between enabling and disabling the limit functions for the wide side and the tele side by a pressing operation of the photographer. , 38B, limit position adjustment knobs 40A and 40B for setting the limit positions on the wide side and the tele side are provided. The zoom control based on these functions will be described later.
[0021]
The focus controller 28 shown in FIG. 1 is provided with a rotatable focus ring 28A. The photographer can operate the position of the focus lens mounted on the lens device 12 by rotating the focus ring 28A with the right hand and adjusting the rotation position. 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.
[0022]
A viewfinder 30 is provided on the upper surface of the camera body 14 for confirming an image being shot.
[0023]
FIG. 3 is a block diagram showing the configuration of the lens apparatus according to the present invention. In the drawing, the configuration of blocks related to the control of the zoom lens 60, the focus lens 80, and the iris 100 mounted on the lens device 12 is shown. The CPU 50 mounted on the lens device 12 includes the zoom controller 26 and Processing related to control of the zoom lens 60, the focus lens 80, and the iris 100 is executed based on a control signal supplied from the focus controller 28 or the camera body 14.
[0024]
First, the control of the zoom lens 60 will be described. As 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 or the limit function that is commanded on the switch panel 26B of the zoom controller 26. Position control based on this, or position control based on the view angle correction function mounted on the lens device 12 is performed.
[0025]
The speed control based on the operation of the thumb ring 26A of the zoom controller 26 is a control for moving the zoom lens 60 at a speed corresponding to the operation amount when the cameraman operates the thumb ring 26A of the zoom controller 26. 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 an analog signal as a speed control signal for instructing the moving speed (zoom speed) of the zoom lens 60. Is output from. The speed control signal is converted into a digital signal by the A / D converter 40 in the lens device 12 and input to the CPU 50. The configuration of the zoom controller 26 will be described later.
[0026]
When the CPU 50 acquires the speed control signal from the zoom controller 26, the CPU 50 sends a control signal for instructing the rotational speed of the zoom drive motor 56 (the moving speed of the zoom lens 60) to the D / A converter 52 based on the speed control signal. The output signal is converted into an analog signal by the D / A converter 52 and supplied to the zoom control circuit 54.
[0027]
When the control signal is given from the CPU 50 as described above, the zoom control circuit 54 acquires the actual rotation speed of the zoom drive motor 56 from the tachometer 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 instructed 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 drive 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 26 </ b> A of the zoom controller 26.
[0028]
Position control based on the shot function commanded on the switch panel 26B of the zoom controller 26 is performed when any of the shot switches 32A to 32D provided on the switch panel 26B of the zoom controller 26 is pressed as described with reference to FIG. In this control, the zoom lens 60 is moved to the shot position set by the shot position adjustment knobs 34A to 34D corresponding to the pressed shot switches 32A to 32D. When any of the shot switches 32A to 32D is pressed, the zoom controller 26 detects the shot position set by the shot position adjustment knobs 34A to 34D corresponding to the pressed shot switches 32A to 32D, and The current position of the zoom lens 60 is acquired from the CPU 50 of the lens device 12 via the D / A converter 42. Note that the CPU 50 acquires the current position of the zoom lens 60 via the A / D converter 64 by the potentiometer 62.
[0029]
The zoom controller 26 outputs to the lens device 12 a speed control signal for instructing a speed according to the direction in which the difference between the current position of the zoom lens 60 acquired from the CPU 50 and the shot position is zero. In the lens device 12, the speed control signal is converted into a digital signal by the A / D converter 40 and input to the CPU 50.
[0030]
When the CPU 50 acquires the speed control signal from the zoom controller 26, the rotational speed of the zoom driving motor 56 (the moving speed of the zoom lens 60) based on the speed control signal, as in the case of speed control based on the operation of the thumb ring 26A. Is output to the zoom control circuit 54. As a result, the zoom driving motor 56 is driven, and the zoom lens 60 moves at a speed commanded by the speed control signal from the zoom controller 26. Since the zoom controller 26 outputs a 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.
[0031]
Position control based on the limit function commanded on the switch panel 26B of the zoom controller 26 is performed when the limit switch 38A and the limit switch 38B provided on the shot panel 26B of the zoom controller 26 are turned on as described in FIG. The limit function on the wide side and the tele side is made effective, and the limit on the wide side and the tele side is limited based on the limit position adjustment knob 40A and the limit position adjustment knob 40B provided corresponding to each of the limit switch 38A and the limit switch 38B. Set the position. When the zoom lens 60 is controlled based on the operation of the thumb ring 26A or the shot function, the zoom lens 60 exceeds the limit position and is outside the limit position (for the limit position on the wide side, on the wide side from the limit position). This is a control that limits the movement range of the zoom lens 60 so that the limit position on the tele side does not move to the tele side relative to the limit position. When any of the limit switches 38A, 38B is pressed, the zoom controller 26 detects the set positions of the limit position adjusting knobs 40A, 40B corresponding to the pressed limit switches 38A, 38B, and The limit position is set as the wide-side or tele-side limit position corresponding to the pressed limit switches 38A and 38B. If one or both of the limit switches 38A and 38B are not turned on, the limit position on the side that is not turned on is set to the wide end or the tele end (the wide end or the tele end is the mechanical end). To do.
[0032]
The zoom controller 26 determines the limit position in the moving direction as a target position when executing the control to move the zoom lens 60 based on the operation of the thumb ring 26A, the shot function, or the angle of view correction function. Then, the current position of the zoom lens 60 is acquired from the CPU 50 of the lens device 12 via the D / A converter 42, and 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 of the limit position), the speed control signal given to the CPU 50 of the lens device 12 is limited to a speed according to the difference between the target position and the current position. As a result, the CPU 50 sends a control signal for instructing the rotation speed of the zoom drive motor 56 (the moving 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. By outputting to 54, the zoom lens 60 is decelerated in the vicinity of the limit position regardless of the operation of the thumb ring 26A or the like, and stops at a position not exceeding the limit position. Note that when the zoom lens 60 is outside the limit position, the zoom controller 26 performs control to move the zoom lens 60 to the limit position as in the position control based on the shot function.
[0033]
The position control based on the angle-of-view correction function is, for example, control that is switched between valid and invalid by a predetermined switch provided in the lens device 12 or the like. When the position control is valid, the CPU 50 executes the position control. The CPU 50 moves the zoom lens 60 based on the speed control signal from the zoom controller 26 and then instructs the stop (0) by the speed control signal to stop the zoom lens 60 when the zoom lens 60 is stopped. The position and the position of the focus lens 80 are acquired from the potentiometers 62 and 82 via the A / D converters 64 and 84, respectively, and the position of the zoom lens 60 and the position of the focus lens 80 are stored.
[0034]
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 is moved to the moving position. On the other hand, the position of the zoom lens 60 that makes the shooting angle of view constant is determined as the target position. The position of the zoom lens 60 that makes the shooting angle of view constant is calculated by a predetermined arithmetic expression from the stored positions of the zoom lens 60 and the focus lens 80 and the position of the focus lens 80 after the movement. When the target position is determined in this way, 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 corresponding to the difference in a direction in which the difference becomes zero. The signal is output to the A converter 52, and the control signal is converted into an analog signal by the D / A converter 52 and supplied to the zoom control circuit 54. As a result, the zoom lens 60 moves to a position where the change in the angle of view accompanying the movement of the focus lens 80 is prevented by the control of the zoom control circuit 54 described above.
[0035]
As for the position control based on the angle of view correction function described above, zooming is performed as in the case where the thumb ring 26A of the zoom controller 26 is in the neutral position or after the zoom lens 60 is moved to the shot position by executing the shot function. This is executed when the lens 60 is stopped. When the position control based on the angle of view correction function is executed, the value of the position signal output from the CPU 50 to the zoom controller 26 becomes a value indicating the stop position before the position control based on the angle of view correction function is executed. 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, the CPU 50 zooms with respect to the CPU 50 even when the CPU 50 moves the zoom lens 60 by the angle of view correction function. A speed control signal for returning the lens 60 to the shot position is not given from the zoom controller 26, and the angle-of-view correction function is effectively executed.
[0036]
Further, 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 from the value indicating the current position of the zoom lens 60 and gives it from the zoom controller 26 as a response to the change. By detecting the change of the speed control signal, it is detected whether the zoom controller 26 is executing control based on the operation of the thumb ring 26A or control based on the shot function. 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 obtained when the position signal is increased and decreased. If there is almost no change, it can be determined that the control of the zoom controller 26 is independent of the position of the zoom lens 60 and that the control based on the operation of the thumb ring 26A is being executed.
[0037]
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 the value of the speed control signal given from the zoom controller 26 is increased depending on whether the position signal is increased or decreased. On the other hand, when it increases 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.
[0038]
Note that the control content of the zoom controller 26 can be determined even when the zoom lens 60 is stopped or moving.
[0039]
When the CPU 50 determines that the zoom controller 26 performs control based on the shot function in this way and fixes the value of the position signal to correct the angle of view as described above, the CPU 50 instructs the stop of the speed control signal. As in the case of 0, a range of values (hereinafter referred to as a dead zone) that is considered to be commanded to stop is set on both the positive and negative sides of the 0 value. 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 variation error of the position signal, and a speed control signal for instructing 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 position signal error. In addition, the operation of the thumb ring 26A must have priority over the field angle correction. For this reason, even when the speed control signal is given due to the error of the position signal, the CPU 50 must follow the speed control signal, and the angle of view may not be appropriately corrected. . However, as described above, the angle of view can be corrected without following the speed control signal caused by the error by setting the dead zone that the speed control signal regards as a stop command on both the positive and negative sides of the value of 0. Will be able to. 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 the error of the position signal or the like.
[0040]
Similarly to the above, the CPU 50 of the lens device 12 intentionally changes the position signal value of the zoom lens 60 transmitted to the zoom controller 26, and the speed control signal given from the zoom controller 26 as a response to the change. The limit position is detected by detecting the change. That is, when the value of the position signal transmitted to the zoom controller 26 is changed to a value indicating the position on the wide side of the current position of the zoom lens 60, the speed control signal given from the zoom controller 26 moves to the tele side. , It can be determined that there is a limit position on the wide side between the current position of the zoom lens 60 and the position transmitted as the position signal, while the value of the position signal is determined from the current position of the zoom lens 60. When the speed control signal given from the zoom controller 26 is commanded to move to the wide side when the tele-side position is changed to a value indicating the tele-side position, the current position of the zoom lens 60 and the position signal are transmitted. It can be determined that there is a limit position on the wide side between the positions. If the position signal is transmitted by reducing the amount of change from the current position, the current position of the zoom lens 60 when the presence of the limit position is detected as described above may be determined as the limit position. When the lens 60 is moving, the value of the position signal is changed in the same direction as the moving direction, and the time when the speed control signal instructs to move in the direction opposite to the moving direction is detected. The position transmitted as the position signal at the time of detection can also be determined as the limit position. In addition, by gradually changing the value of the position signal to the tele side or the wide side and detecting when a speed control signal commanding movement in the direction opposite to the direction of the change is given, the position signal at the time of detection is detected. The position transmitted as can be determined as the limit position.
[0041]
When the limit position is detected in this way, the CPU 50 restricts the movement 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 field angle correction. When it is determined that the zoom lens 60 is stopped at the limit position, the dead zone is set as a range of values instructed by the speed control signal supplied from the zoom controller 26 as described above. As a result, the same problems as described above can be solved.
[0042]
Next, focus control will be described. The 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 the potentiometer of the focus controller 28, and the operation amount is output from the focus controller 28 as an analog signal as a position control signal for instructing the position (focus position) of the focus lens 80. The speed control signal is converted into a digital signal by the A / D converter 44 in the lens device 12 and input to the CPU 50.
[0043]
When the CPU 50 acquires the position control signal from the focus controller 28, the CPU 50 sets the focus position commanded by the position control signal as the target position. Further, the current position of the focus lens 80 is acquired from the potentiometer 82 via the A / D converter 84. Then, a control signal is output to the D / A converter 72 in a direction in which the difference between the target position of the focus lens 80 and the current position becomes zero and a speed corresponding to the difference is output to the D / A converter 72. The control signal is converted into an analog signal and supplied to the focus control circuit 74.
[0044]
When the focus control circuit 74 acquires the control signal output from the CPU 50 as described above, the focus control circuit 74 acquires the actual rotation speed of the focus drive motor 76 from the tacho generator 78. Then, a voltage is applied to the focus driving motor 76 so that the difference between the rotational speed of the focus driving motor 76 instructed by the control signal from the CPU 50 and the actual rotational speed of the focus driving motor 76 becomes zero. As a result, the focus drive 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.
[0045]
Next, the iris control will be described. The iris 100 is controlled based on, for example, a control signal transmitted from the camera body 14. When a position control signal indicating the position (aperture diameter) of the iris 100 is given from the camera body 14, the CPU 50 sets the position indicated by the position control signal as a target position, and also sets the current position (aperture diameter) of the iris 100 to a potentiometer. Obtained from 102 via the A / D converter 104. Then, a difference between the target position of the iris 100 and the current position is obtained, and a control signal for instructing a speed corresponding to the difference in a direction in which the difference becomes 0 is output to the D / A converter 92 to perform D / A conversion. The controller 92 converts the control signal into an analog signal and supplies it to the iris control circuit 94.
[0046]
When the control signal is given from the CPU 50 as described above, the iris control circuit 94 acquires the actual rotation speed of the iris drive motor 94 from the tacho generator 98. A voltage is applied to the iris driving motor 96 so that the difference between the rotational speed of the iris driving motor 96 instructed by the control signal from the CPU 50 and the actual rotational speed of the iris driving motor 96 becomes zero. As a result, the iris driving motor 96 is rotated at the rotation speed commanded by the CPU 50, and the iris diameter of the iris 100 is changed.
[0047]
Next, the internal configuration of the zoom controller 26 will be described. FIG. 4 is a diagram showing its internal configuration. The signal (1) shown in the figure is the speed control signal given from the zoom controller 26 to the CPU 50 of the lens apparatus 12, and the signal (2) shown in the figure is given from the lens apparatus 12 to the zoom controller 26. 3 is a position signal indicating the current position of the zoom lens 60.
[0048]
As shown in the figure, the operation amount of the thumb ring 26A is converted into a voltage signal by the potentiometer 120. 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.
[0049]
The switching circuit 124 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 control circuit 126 described later, and is provided in the switch panel 26B. When all of the shot switches 32A to 32D are off, the voltage signal inputted from the input terminal 1 is outputted from the output terminal 3, and when any of the shot switches 32A to 32D is turned on, the voltage is inputted from the input terminal 2. The input voltage signal is output from the output terminal 3. Therefore, when all of the shot switches 32A to 32D are OFF, the voltage signal input from the potentiometer 120 to the input terminal 1 via the amplifier 122 based on the operation of the thumb ring 26A is output from the output terminal 3 as described above. The As a result, the voltage signal is transmitted as a speed control signal to the CPU 50 of the lens device 12 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.
[0050]
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 32 </ b> A to 32 </ b> D 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 given to switch to a voltage signal. When all of the shot switches 32A to 32D are off, the instruction signal so that the signal output from the output terminal 3 of the switching circuit 124 is the voltage signal input from the input terminal 1 to the switching circuit 124. give.
[0051]
In addition, the control circuit 126 inputs a voltage signal output from the slider of the variable resistors VR1 to VR4 corresponding to the shot switch that is turned on to one input terminal of the differential amplifier 128. The variable resistors VR1 to VR4 are configured such that the positions of the sliders are changed according to the set positions of the shot position adjusting knobs 34A to 34D provided on the switch panel 26B. The voltage signal output from the child indicates the shot position to which the zoom lens 60 should move when the corresponding shot switch 32A to 32D is turned on.
[0052]
The differential amplifier 128 amplifies the difference between the voltage signals input from the two input terminals by a predetermined magnification, and outputs the amplified voltage signal from the output terminal. Thus, the voltage signal output from the sliders of the variable resistors VR1 to VR4 is input, and the position signal supplied from the lens device 12 is input to the other input terminal. Accordingly, the differential amplifier 128 outputs a voltage signal corresponding to the difference between the shot position where the zoom lens 60 should be moved and the current position of the zoom lens 60, and the voltage signal is input to the input terminal 2 of the switching circuit 124. The
[0053]
The voltage signal input to the input terminal 2 of the switching circuit 124 is output from the output terminal 3 of the switching circuit 124 when any of the shot switches 32A to 32D is on as described above, and the voltage signal is the limit circuit. The speed control signal is transmitted to the CPU 50 of the lens device 12 via 130. As a result, 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.
[0054]
The release of the execution of the shot function may be performed by pressing the shot switch that has been turned on again, or may be performed by operating the thumb ring 26A.
[0055]
When the limit switches 38A and 38B of the switch panel 26B shown in FIG. 2 are turned on, the limit circuit 130 uses the voltage signal (speed control signal) output from the output terminal 3 of the switching circuit 124 as its speed. It is a circuit for converting in a direction in which the speed commanded by the control signal decreases. When any 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 configured such that the position of the slider is varied according to the set position of the limit position adjusting knobs 40A and 40B provided on the switch panel 26B. The sliding of the variable resistors VR5 and VR6 The voltage signal output from the child indicates the limit position on the wide side and the tele side when the corresponding limit switches 38A and 38B are turned on.
[0056]
A position signal provided from the lens device 12 is input to the other input terminal of the limit circuit 130. 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 a signal indicating the limit position input from these input terminals and a position signal indicating the current position of the zoom lens 60. When the difference becomes smaller than a predetermined amount, the speed control signal supplied from the switching circuit 124 is limited to a voltage corresponding to the difference. Accordingly, even if the zoom lens 60 tries to output a speed control signal that exceeds the limit position by the operation of the thumb ring 26A or the 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 position.
[0057]
An example of a processing procedure related to the control of the zoom lens 60 in the CPU 50 of the lens apparatus 12 configured as described above will be described with reference to the flowcharts of FIGS. As shown in FIG. 5, the CPU 50 first determines whether the zoom controller 26 connected to the lens device 12 is digital or analog (step S10). The digital zoom controller transmits various information such as a speed control signal to the CPU 50 as a digital signal by serial communication. On the other hand, as shown in FIG. 3, the analog zoom controller issues a command such as a zoom speed with the voltage value of the analog voltage signal. The CPU 50 transmits a predetermined command to the zoom controller 26. If there is a response from the zoom controller 26 to the command, the CPU 50 determines that it is digital, and if there is no response, determines that it is analog. If it is determined to be digital, processing for the digital zoom controller is performed (step S12), but description of the processing is omitted here.
[0058]
On the other hand, when it is determined that the zoom controller 26 is analog, the CPU 50 performs control to drive the zoom lens 60 based on the speed control signal provided from the zoom controller 26 as described above. It is assumed that the speed control signal indicates a value (0) for commanding stop (step S13).
[0059]
At this time, first, the CPU 50 detects whether or not control (shot operation) based on the shot function is performed in the zoom controller 26, and when the shot operation is performed, the value of the speed control signal as described above. Is set to a dead zone which is a range that is considered to command stop (step S14). Details of the processing content of step S14 will be described later.
[0060]
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 when a limit position is detected, a dead zone is set in the same manner as described above, and a correction limit is set (step S18). When it determines with YES in step S16, the process of step S18 is not performed. Details of the processing content of step S18 will be described later.
[0061]
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 to 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, if the value of the speed control signal provided from the zoom controller 26 is a value within the range set as the dead zone in step S14 or step S18, it is determined that there is no speed control signal (0). If YES is determined here, that is, if it is determined 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 is given from the zoom controller 26. Based on the speed control signal, normal processing relating to control of the zoom lens 60 is executed (step S24).
[0062]
On the other hand, when it is determined NO in step S20, that is, when it is determined that there is no speed control signal, the CPU 50 fixes the position signal to be transmitted to the zoom controller 26 to the value of the stop position (step S26). Processing related to the control of the angle of view is executed (step S28). At this time, the correction limit is taken into consideration. That is, when the limit position is detected in step S18, the angle of view is corrected in a range where the zoom lens 60 does not exceed the limit position.
[0063]
The CPU 50 repeatedly executes the processes from step S13 to step S28.
[0064]
Next, the shot detection process in step S14 will be described. As shown in FIG. 6, the CPU 50 sets the speed control signal supplied from the zoom controller 26 to AD (step S40). Since the shot operation detection process is executed when the speed control signal is 0 as shown in step S13, the AD value is 0. However, the shot operation detection process is performed by the zoom lens. Since it is also possible to perform the operation when the motor 60 is moving (when the speed control signal is not 0), the value of AD is not limited to 0 below in consideration of such a case.
[0065]
Subsequently, the CPU 50 transmits a value indicating a position displaced by a predetermined amount in a predetermined direction (for example, the tele side) with respect to the current position of the zoom lens 60 to the zoom controller 26 as a position signal (step S42). That is, the value of the position signal is increased from the value indicating the current position of the zoom lens 60. At this time, the value of the speed control signal supplied from the zoom controller 26 is set to AD1 (step S44). Next, the CPU 50 transmits a value indicating a position displaced by a predetermined amount in a direction opposite to the predetermined direction (for example, the wide side) with respect to the current position of the zoom lens 60 to the zoom controller 26 as a position signal (step S46). That is, the value of the position signal is decreased 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 set to AD2 (step S48).
[0066]
Next, the CPU 50 determines whether or not both the AD1 and AD2 values have changed by a predetermined value or more with respect to the AD value (step S50). If NO at this time, it is determined that the shot is not being performed (step S52). On the other hand, if YES, it is determined that a shot is being performed (step S54), and a dead zone is set (step S56). When the above processing ends, the position signal transmitted to the zoom controller 26 is returned to a value indicating the current position of the zoom lens 60 (step S58), and the shot detection processing ends.
[0067]
Next, the limit detection process in step S16 will be described. As shown in FIG. 7, the CPU 50 determines whether the speed control signal given from the zoom controller 26 commands movement in the wide direction or movement in the tele direction (step S70). Since the limit detection process is executed when the speed control signal is 0 as shown in step S13, the speed control signal commands movement in any direction only at the time of determination in step S70. Although it is not possible to determine whether or not the zoom lens 60 is moving, the limit detection process can be performed while the zoom lens 60 is moving, as in the case of the shot operation detection process. is there. Therefore, when the zoom lens 60 is stopped, the determination in step S70 may be performed in the direction in which the zoom lens 60 has been moved until then. You may make it perform the process of.
[0068]
Only the processing in the case where it is determined in step S70 that the speed control signal instructs to move in the wide direction will be described. In this case, the CPU 50 moves outside the current position of the zoom controller 26 by a predetermined amount α outside the current position. A value indicating the position displaced to the wide side is transmitted as a position signal to the zoom controller 26 (step S72). At this time, a speed control signal is read from the zoom controller 26 (step S74), and it is determined whether or not the speed control signal commands movement to the tele side (step S76). If YES, since there is a limit position on the wide side between the current position of the zoom lens 60 and a position on the wide side by a predetermined amount α, field angle correction to the wide side is prohibited (correction limit setting). Further, as described above, a dead zone that is a range in which the value of the speed control signal is regarded as commanding stop is set (step S78). If NO in step S76, the process in step S78 is not performed. In addition, also when it determines with the tele direction in the said step S70, the process similar to the said step S72-step S78 is performed.
[0069]
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 the control of the shot function, and the limit position is exceeded. Thus, it is possible to prevent the angle of view from being corrected.
[0070]
As described above, in the above-described embodiment, when the angle of view correction is performed, the CPU 50 fixes the position signal to be output to the zoom controller 26, the movement of the zoom lens 60 by the angle of view correction, the shot function in the zoom controller 26, or Although a speed control signal commanding movement from the zoom controller 26 due to the limit function is prevented, the present invention is not limited to this. When performing field angle correction instead of fixing the position signal, The CPU 50 may not follow the speed control signal given from the zoom controller 26. However, since it is necessary to at least comply with the speed control signal given due to the operation of the thumb ring 26A, when a speed control signal not related to the movement of the zoom lens 60 by the angle of view correction is input, for example, If the value of the speed control signal suddenly changes, control of the zoom lens 60 according to the speed control signal is started.
[0071]
In the above embodiment, the case where an analog zoom controller is used has been described. However, the present invention can be applied to a digital zoom controller as in the above embodiment.
[0072]
【The invention's effect】
As described above, according to the lens device according to the present invention, when the angle function is corrected, if the limit function is enabled in the controller, the lens device grasps the limit position and takes the limit position into consideration. Therefore, even when the angle of view correction is performed in the lens device in preference to the control signal from the controller, the problem that the zoom lens moves outside the limit position is prevented.
[0073]
In addition, when performing field angle correction, the position signal value output from the lens device to the controller is fixed, so the field angle is corrected even for zoom lenses that are stopped at the shot position by controlling the shot function. Can be done. Further, by fixing the position signal value in this way, there is a risk that the zoom lens may move beyond the limit position due to the angle of view correction. However, the limit position is detected by a predetermined means, and the zoom lens is detected on the lens device side. By controlling so as not to exceed the limit position, it is possible to prevent a problem that the zoom lens moves outside the limit position.
[0074]
In addition, 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 substantially Since it is in an invalid state, the conventional problem that the shot function or limit function and the angle of view correction function are performed simultaneously is solved, and the zoom lens operates well even near the shot position or limit position. .
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a television camera in which a lens apparatus according to the present invention is used.
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 an embodiment of a lens apparatus according to the present invention.
FIG. 4 is a configuration diagram showing an internal configuration of a zoom controller.
FIG. 5 is a flowchart showing a processing procedure related to zooming by the CPU of the lens apparatus;
FIG. 6 is a flowchart illustrating a procedure of shot operation detection processing of a CPU of the lens apparatus.
FIG. 7 is a flowchart showing a procedure of limit detection processing of a CPU of the lens apparatus.
[Explanation of symbols]
26 ... Zoom controller, 26A ... Thumb ring, 26B ... Switch panel, 28 ... Focus controller, 30 ... Viewfinder, 32A-32D ... Shot switch, 34A-34D ... Shot position adjustment knob, 38A, 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)

A focus lens and a zoom lens, and a control for moving the zoom lens based on a control signal given from a controller; and a position that prevents a change in angle of view due to the movement of the focus lens when the focus lens moves. A lens apparatus comprising control means for executing control based on an angle of view correction function for moving the zoom lens, wherein the controller obtains a position signal indicating the position of the zoom lens output from the lens apparatus. In the lens device having a limit function for limiting the movement range of the zoom lens so that the zoom lens does not move outside a predetermined limit position based on the position signal,
By changing the value of the position signal to be output to the controller from a 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 changed position signal value, Limit position detecting means for detecting the limit position;
When performing control based on the angle of view correction function, a limiting unit that limits a moving range of the zoom lens so that the zoom lens does not move outside a limit position detected by the limit position detecting unit;
A lens device comprising: A focus lens and a zoom lens, and a control for moving the zoom lens based on a control signal given from a controller; and a position that prevents a change in angle of view due to the movement of the focus lens when the focus lens moves. A lens apparatus comprising control means for executing control based on an angle of view correction function for moving the zoom lens, wherein the controller obtains a position signal indicating the position of the zoom lens output from the lens apparatus. And a limit function for limiting 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, and the zoom lens based on the position signal. In the lens device having a shot function to stop
When the control based on the angle of view correction function is executed by the control means, the value of the position signal output to the controller is fixed to a value indicating the position of the zoom lens before the control based on the angle of view correction function is executed. Position signal fixing means for
By changing the value of the position signal to be output to the controller from a 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 changed position signal value, Limit position detecting means for detecting the limit position;
When performing control based on the angle of view correction function, a limiting unit that limits a moving range of the zoom lens so that the zoom lens does not move outside a limit position detected by the limit position detecting unit;
A lens device comprising: When the position signal is fixed by the position signal fixing means, when the control signal given from the controller changes by a predetermined value or more, the zoom lens is moved based on the control signal, and 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.

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