JP4189784B2 - Lens drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lens driving device, and more particularly to a lens driving device that controls a zoom operation of an ENG lens or the like.
[0002]
[Prior art]
2. Description of the Related Art A lens drive device that is mounted on a television camera or the like uses a lens driving device that controls the speed of a variable power lens by a motor based on an operation of a zoom operation member (seesaw switch, thumb ring, etc.). Among such lens driving devices, those having a constant speed auto zoom function are known in order to easily hold the variable magnification lens at a desired speed. In constant speed auto zoom, when a predetermined switch is pressed while moving the zoom lens at a certain speed with the zoom operation member, the speed is memorized, and even if the zoom operation member is returned to the neutral position (stop position), the zoom lens Will continue to move at the memorized speed. Conventionally, as a method of canceling the constant speed auto zoom, a method of pressing the switch again or operating the zoom operation member again is employed.
[0003]
[Problems to be solved by the invention]
However, when the constant-speed auto zoom is canceled by pressing a switch or by operating the zoom operation member as in the past, the moving speed of the zoom lens at the moment when the constant-speed auto zoom is canceled. Sometimes suddenly changed, resulting in an unnatural zoom operation.
[0004]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a lens driving device capable of suitably canceling the constant speed auto zoom.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a lens driving device that motor-drives a zoom lens in a lens barrel at a direction and speed according to the operation of a zoom operation member.
When the execution of constant speed auto zoom is instructed when the variable magnification lens is moved, constant speed auto zoom execution means for holding the variable magnification lens at a constant speed, and the variable speed lens is fixed by the constant speed auto zoom execution means. When the speed is maintained, the constant speed auto zoom is canceled when a speed exceeding the moving speed of the zoom lens is instructed by the operation of the operating member. And a constant-speed automatic zoom canceling means.
[0006]
According to the present invention, when the operation of the zoom operation member is in the same direction as the movement direction of the zoom lens and exceeds the movement speed of the zoom lens during the constant speed auto zoom operation, the constant speed auto zoom is performed. Since this is canceled, it is possible to prevent a situation in which the moving speed of the zoom lens changes suddenly when the constant-speed auto zoom is canceled, and the zoom operation when the constant-speed auto zoom is canceled is suitably performed. .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of a lens driving device according to the present invention will be described in detail with reference to the accompanying drawings.
1 and 2 are a plan view and a rear view showing the external appearance of an ENG lens to which a drive unit to which the present invention is applied is mounted. An ENG lens 1 shown in these drawings is an inner focus type zoom lens used for a broadcast television camera such as an ENG camera. The lens barrel 2 is provided with a focus ring 4, a zoom ring 6, and an iris ring 8. The extender device 10 is provided at the rear end of the lens barrel 2.
[0008]
A drive unit 12 for driving the focus ring 4, zoom ring 6 and iris ring 8 is provided on the side of the lens barrel 2. Reference numeral 14 denotes a lens hood, and 15 denotes a lens hood mounting knob.
Although the internal structure of the lens barrel 2 is not illustrated, as is well known, a fixed focus lens, a moving focus lens, a variable power lens, an iris, a relay lens, and the like are provided in the lens barrel in order from the front. , The extender 10 is disposed behind it. When the focus ring 4 is rotated, the moving focus lens is moved back and forth along the optical axis to perform focus adjustment, and when the zoom ring 6 is rotated, the zoom lens is moved back and forth along the optical axis. Move to perform zoom adjustment. In addition, the iris diameter is adjusted by rotating the iris ring 8.
[0009]
The drive unit 12 has a case 18, and the case 18 is attached to the side portion of the lens barrel 2 via screws 20 and 20. A focus drive motor (not shown) is disposed in the case 18, and the focus drive motor meshes with the focus ring 4 via a gear transmission mechanism (not shown) to rotationally drive the focus ring 4. Note that some drive units 12 are not equipped with a focus drive motor, and in this embodiment, the focus drive motor may not be installed. Further, a zoom drive motor is disposed in the case 18, and this zoom drive motor meshes with the zoom ring 6 through a gear transmission mechanism (not shown) to drive the zoom ring 6 to rotate. Similarly, an iris drive motor (not shown) is disposed in the case 18, and the iris drive motor meshes with the iris ring 8 via a gear transmission mechanism (not shown) to drive the iris ring 8 to rotate. .
[0010]
On the upper surface of the case 18, a zoom seesaw control switch 22 (hereinafter referred to as a seesaw switch), an iris auto / manual mode switch 24, an iris momentary switch 25, a return switch 26 and the like are provided. A preset switch 34 and a preset position memory switch 36 are provided near the mounting screws 20 and 20.
[0011]
The seesaw switch 22 is swingably installed with respect to the neutral position, and when the seesaw switch 22 is pressed to the tele (T) side or the wide (W) side, the zoom ring 6 rotates to the tele side or the wide side. It is supposed to be. Further, the zoom speed can be adjusted by the pressing amount (operation amount) of the seesaw switch 22, and the larger the pressing amount, the higher the zoom speed.
[0012]
The preset switch 34 and the preset position memory switch 36 are provided so that the preset function can be executed on the drive unit 12. When the preset switch 34 and the preset position memory switch 36 are pressed at the same time, the zoom lens at that time is changed. The position (zoom position) is stored in the memory as a preset position, and when only the preset switch 34 is pressed, the zoom lens is moved to the preset position stored in the memory.
[0013]
A grip band 28 is provided on the side surface of the case 18, and the photographer can hold the lens barrel 2 by inserting the right hand (four fingers other than the thumb) into the grip band 28. Yes. In addition, a VTR switch 30 and a quick zoom & constant speed auto zoom switch 32 are disposed on the rear surface of the case 18 (see FIG. 2), and these switches 30 and 32 can be operated by the photographer with the thumb of the right hand. Yes.
[0014]
The VTR switch 30 is a switch for operating start / end of recording when recording (recording) an image being shot on a video tape.
The quick zoom & constant speed auto zoom switch 32 is a switch that is used to execute both the quick zoom and constant speed auto zoom functions. When the zoom lens is stopped, when the switch 32 is pressed, When the quick zoom function is activated and the switch 32 is pressed while the seesaw switch 22 is being operated (when the zoom lens is moving), the constant speed auto zoom function is activated. In the quick zoom, while the switch 32 is being pressed, the zoom lens is moved in the direction toward the telephoto end at a predetermined zoom speed (high speed), and when the switch 32 is released, the original zoom position (the quick zoom switch 32 is pressed) This is a function in which the zoom lens is returned to the zoom position at a predetermined zoom speed.
[0015]
On the other hand, in the constant speed auto-zoom, when the switch 32 is pressed, the moving speed (zoom speed) of the variable power lens driven based on the operation of the seesaw switch 22 is constant at the speed when the switch 32 is pressed. It is a function to hold. Therefore, even if the pressing operation of the seesaw switch 22 is canceled by pressing the switch 32 when the seesaw switch 22 is pressed to the tele (T) side or the wide (W) side to achieve a desired zoom speed, the zoom can be performed. The speed is kept constant. A method of canceling the constant speed auto zoom will be described later.
[0016]
A zoom maximum speed adjustment knob 38 is provided on the rear surface of the case 18, and the zoom speed (maximum zoom speed) when the seesaw switch 22 is pushed in most deeply is appropriately changed by rotating the knob 38. be able to. For example, the zoom maximum speed is set to be higher as the zoom maximum speed adjustment knob 38 is rotated in the clockwise direction in the figure, and conversely, the zoom maximum speed is set to be lower as it is rotated in the counterclockwise direction. Further, the zoom speed at the time of preset reproduction when the preset switch 34 is pressed is also varied according to the set position of the zoom maximum speed adjustment knob 38.
[0017]
Also, reference numeral 39 shown in FIG. 2 denotes an extender switching lever. By rotating the lever 39, a double extender can be inserted into and removed from the photographing optical path.
FIG. 3 is a block diagram showing a configuration of a circuit for driving the zoom ring 6 by a motor in the drive unit 12. The seesaw switch 22 is connected to, for example, a rotary shaft of an incremental rotary encoder 50 (hereinafter referred to as encoder 50), and when the seesaw switch 22 is operated, the number and phase (two-phase pulse) according to the pushing direction and the pushing amount. The encoder 50 outputs a pulse of the phase of the pulses between the phases when output. The pulses output from the encoder 50 are counted by the counter 52, and the pushing direction and the pushing amount of the seesaw switch 22 are given to the CPU 54 as numerical values within a predetermined range. The CPU 54 determines the rotation direction and rotation speed of the zoom drive motor 60 (hereinafter referred to as the motor 60) based on the numerical value given from the counter 52. At this time, the CPU 54 obtains the setting position (analog voltage) of the zoom maximum speed adjustment knob 38 output from the potentiometer 68 via the A / D converter 70, and when the pushing amount of the seesaw switch 22 becomes maximum. The rotational speed of the motor 60 is determined so that the zoom speed becomes the maximum speed set by the zoom maximum speed adjustment knob 38.
[0018]
When the rotational direction and rotational speed of the motor 60 are determined in this way, the CPU 54 generates a speed control signal (motor drive signal) based on this and outputs the speed control signal to the D / A converter 56. The speed control signal is converted into an analog signal by the D / A converter 56 and then input to the amplifier 58. The rotational speed indicated by the speed control signal and the actual rotational speed of the motor 60 fed back by the tachometer 62 are obtained. A voltage corresponding to the difference is applied from the amplifier 58 to the motor 60. As a result, the motor 60 is driven with the rotation direction and rotation speed set by the CPU 54. Accordingly, the zoom ring 6 connected to the motor 60 is rotated at a rotation direction and speed corresponding to the pushing direction and the pushing amount of the seesaw switch 22, and the zoom lens 64 is moved by this rotation.
[0019]
Further, the CPU 54 similarly detects operations of various operation members 72 other than the seesaw switch 22 disposed in the case 18 of the drive unit 12 and executes various processes according to those operations. 3 shows only the seesaw switch 22, the zoom maximum speed adjustment knob 38, and the quick zoom & constant speed auto zoom switch 32. Here, the quick zoom & constant speed auto zoom switch 32 is pressed. The processing of the CPU 54 at that time will be described.
[0020]
As described above, the quick zoom & constant speed auto zoom switch 32 is a switch that is used for both the quick zoom function and the constant speed auto zoom function, and this switch is used when the zoom lens 64 is stopped. Pressing 32 activates the quick zoom function, and pressing this switch 32 during operation of the seesaw switch 22 (when the zoom lens is moving) activates the constant speed auto zoom function. It has become.
[0021]
When the CPU 54 detects that the quick zoom & constant speed auto zoom switch 32 (hereinafter simply referred to as the switch 32) is pressed while the variable magnification lens 64 is stopped, the CPU 54 executes the quick zoom operation. That is, while the switch 32 is being pressed, a speed control signal is output to the D / A converter 56 so that the zoom lens 64 moves to the tele side at a predetermined speed (high speed), and the motor 60 is rotated. Further, the position (zoom position) of the zoom lens 64 when the switch 32 is pressed is acquired from the potentiometer 74 via the A / D converter 76, and the zoom position is stored in the memory 78. Subsequently, when detecting that the pressing of the switch 32 is released, the CPU 54 reads out the original zoom position (the zoom position at the time when the quick zoom switch 32 is pressed) from the memory 78, and the zoom lens at the zoom position. A speed control signal is output to the D / A converter 56 so that 64 moves at a predetermined speed, and the motor 60 is rotated. Thus, when the zoom lens 64 is stopped, pressing the switch 32 allows the zoom lens 64 to be moved to the tele side at a high speed while the switch 32 is being pressed, and by releasing the switch 32. The zoom lens 64 can be returned to the original zoom position.
[0022]
On the other hand, when the CPU 54 drives the motor 60 based on the operation of the seesaw switch 22 as described above and detects that the switch 32 is pressed, the CPU 54 executes a constant speed auto zoom operation. That is, when it is detected that the switch 32 has been pressed, the speed control signal data output to the D / A converter 54 at that time is fixed, and unless the constant speed auto zoom is canceled, the speed control signal Is continuously output to the D / A converter 56. As a result, the rotation of the motor 60 is maintained at the speed at which the switch 32 is pressed, and the variable power lens 64 is continuously moved at a constant speed.
[0023]
Next, the case of canceling the constant speed auto zoom will be described. The constant speed auto zoom can be canceled by operating the seesaw switch 22 in the direction opposite to the moving direction of the zoom lens 64. Further, the constant-speed auto zoom can be canceled by operating the seesaw switch 22 in the same direction as the direction in which the zoom lens 64 is moving and exceeding the moving speed of the zoom lens 64. It has become.
[0024]
When the CPU 54 monitors the operation of the seesaw switch 22 while performing the constant speed auto zoom operation as described above, and detects that the seesaw switch 22 has been operated, the seesaw switch 22 22 is compared with the moving direction of the variable magnification lens 64 that is moved by constant-speed auto zoom. As a result, when it is detected that the pushing direction of the seesaw switch 22 is opposite to the moving direction of the zoom lens 64, the constant speed auto zoom is canceled. In other words, the CPU 54 generates a speed control signal that has been held constant until then based on the operation of the seesaw switch 22 and outputs it to the D / A converter 56.
[0025]
On the other hand, when the pushing direction of the seesaw switch 22 is operated in the same direction as the moving direction of the zooming lens 64, the moving speed of the zooming lens 64 corresponding to the pushing amount of the seesaw switch 22 (or the rotation of the motor 60). Speed) and the moving speed of the variable magnification lens 64 (or the rotational speed of the motor 60) by constant-speed auto zoom are compared. As a result, when it is detected that the moving speed of the zoom lens 64 corresponding to the pressing amount of the seesaw switch 22 exceeds the moving speed of the zoom lens 64 by the constant speed auto zoom, the constant speed auto zoom is canceled. .
[0026]
As described above, the constant speed auto zoom can be canceled by operating the seesaw switch 22 so as to exceed the moving speed of the variable magnification lens 64 during the constant speed auto zoom operation. At this time, if the seesaw switch 22 is operated in the same direction as the moving direction of the zoom lens 64 to gradually increase the push-in amount, the zooming rate is rapidly increased when the constant-speed auto zoom is released. A situation in which the moving speed of the lens 64 changes can be prevented.
[0027]
FIG. 4 is a flowchart showing the processing procedure of the CPU 54. After performing the initial setting (step S10), the CPU 54 detects whether or not the seesaw switch 22 is operated (step S12). In the case of NO, a required process based on the operation of the operation member other than the seesaw switch 22 is executed (step S14), and the process returns to step S10. On the other hand, in the case of YES, it is determined whether or not the constant speed auto zoom is in operation (step S16). If NO at this time, it is then determined whether or not the switch 32 has been turned on (step S18). If NO again, normal zoom operation processing is executed based on the operation of the seesaw switch 22 (step S18). Step S20), the process returns to step S12. On the other hand, if “YES” in the step S18, the constant speed auto zoom is started (step S22). That is, the moving speed of the zoom lens 64 when the switch 32 is turned on is maintained. Then, the process returns to step S12.
[0028]
If YES is determined in step S16, that is, if the seesaw switch 22 is operated during the constant speed auto zoom, the CPU 54 then moves the seesaw switch 22 in the same direction as the movement of the zoom lens 64 by the constant speed auto zoom. It is determined whether or not it has been operated in the direction (step S24). At this time, if NO, that is, if operated in the opposite direction, the constant-speed auto zoom is canceled (step S26), and the process returns to step S12. On the other hand, if YES in step S24, that is, if the seesaw switch 22 is operated in the same direction as the moving direction of the zoom lens 64 by the constant speed auto zoom, the operation amount is subsequently changed by the constant speed auto zoom. It is determined whether or not the moving speed of the lens 64 has been exceeded (step S28). If NO, the process returns to step S12 without releasing the constant speed auto zoom. On the other hand, if YES, the constant speed auto zoom is canceled (step S30), and the process returns to step S12.
[0029]
Through the above processing, when the seesaw switch 22 is operated in the direction opposite to the moving direction of the variable power lens 64 during the constant speed auto zoom operation, the moving speed exceeds the moving direction in the same direction as the moving direction of the variable power lens 64. When the seesaw switch 22 is operated, the constant speed auto zoom is released. The constant speed auto zoom may be canceled when the switch 32 is pressed during the constant speed auto zoom operation.
[0030]
In the above embodiment, the case where the present invention is applied to the drive unit attached to the ENG lens has been described. However, the present invention is also applied to an external controller (zoom demand, etc.) used by being connected to the lens device. The same can be applied.
[0031]
【The invention's effect】
As described above, according to the lens driving device of the present invention, the operation of the zoom operation member is performed in the same direction as the moving direction of the zoom lens and the zoom lens of the zoom lens during the constant speed auto zoom operation. When the moving speed is exceeded, the constant-speed auto zoom is canceled, so the situation that the moving speed of the zoom lens changes suddenly when the constant-speed auto zoom is canceled can be prevented. The zoom operation is preferably performed.
[Brief description of the drawings]
FIG. 1 is a plan view showing an external appearance of an ENG lens to which a drive unit to which the present invention is applied is attached.
FIG. 2 is a rear view showing an external appearance of an ENG lens to which a drive unit to which the present invention is applied is attached.
FIG. 3 is a block diagram showing a configuration of a circuit for driving a zoom ring by a motor in a drive unit.
FIG. 4 is a flowchart showing a processing procedure of a CPU when canceling a constant-speed auto zoom.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... ENG lens, 2 ... Lens barrel, 6 ... Zoom ring, 12 ... Drive unit, 22 ... Zoom seesaw control switch (seesaw switch), 32 ... Quick zoom & constant speed auto zoom switch, 38 ... Zoom maximum speed adjustment knob 54 ... CPU, 64 ... variable magnification lens

Claims (1)

In the lens driving device that drives the zoom lens in the lens barrel at a direction and speed according to the operation of the zoom operation member,
Constant speed auto zoom execution means for holding the variable power lens at a constant speed when execution of constant speed auto zoom is instructed during movement of the variable power lens;
When the variable power lens is held at a constant speed by the constant speed auto zoom execution means, the movement direction of the variable power lens is greater than the moving speed of the variable power lens by operating the operation member. When a speed is instructed, constant speed auto zoom canceling means for canceling the constant speed auto zoom,
A lens driving device comprising:

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