JPH112753A - Lens operation switching device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens operation switching device for camera capable of being switched to a manual made and executing manual operation of a cameraman instantaneously when an operation ring is operated when the lens operation of the camera is performed in an automatic mode. SOLUTION: When a focus lens 12 is driven by a drive motor 14, and photographing is performed by autofocus, when a focus ring 24 is operated by the cameraman, its rotational speed is inputted to a CPU 22 by a tachometer 28. The CPU 22 turns the switch 27 of the source line of the drive motor 14 off to stop forcedly the drive motor 14 when the rotational speed is a prescribed rotational speed or above to enable the manual operation of the focus lens 12 by the focus ring 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera lens operation switching device, and more particularly to a camera lens operation switching device provided with an auto mode and a manual mode for camera lens operation.

[0002]

2. Description of the Related Art Conventionally, adjustment of focus and zoom magnification of a lens unit of a television camera or the like has been performed by manual driving or motor driving. JP-A-5-150291
Japanese Patent Application Laid-Open Publication No. H11-264,086 discloses a video camera that does not require a switching operation from an auto mode to a manual mode in a focus adjustment operation mode. That is, when the manual focus adjusting device is rotated in the auto mode, the manual focus adjusting device is automatically switched from the automatic mode to the manual mode so that the focus can be manually adjusted without operating the switching operation member. Thus, even when shooting in the automatic mode, the photographer can quickly adjust the focus to his / her intended focus.

[0003]

However, the operation mode described in Japanese Patent Laid-Open No. 5-150291 is to drive the lens by a motor in both the auto mode and the manual mode. The lens is driven by a motor. Therefore, there is a problem in that fine adjustment of the lens position is difficult even when the mode is switched to the manual mode, and power is consumed even in the manual mode.

On the other hand, in the case of a camera capable of operating a lens by manual driving and motor driving, conventionally, switching between manual driving and motor driving lens operation is mechanically performed by a clutch mechanism. However, with such a clutch mechanism, it was difficult to instantaneously switch from motor drive to manual drive lens operation.

The present invention has been made in view of such circumstances, and even when a lens operation is performed by a motor drive, a lens operation switching of a camera can be performed immediately and preferentially and immediately by a manual drive. It is intended to provide a device.

[0006]

According to the present invention, there is provided an automatic mode in which a lens of a camera is driven by a drive motor to adjust a position of the lens, and a drive of the lens by the drive motor. A manual mode for stopping and adjusting the position of the lens by manual operation of an operation member, wherein the lens operation switching device for a camera capable of performing a lens operation by switching between the auto mode and the manual mode. Operation detection means for detecting the presence or absence of operation of the member; and, when the lens operation is performed in the auto mode, when the operation detection means detects that the operation member has been operated, the lens operation is performed in the manual mode. And lens operation switching means for switching to

According to the present invention, for example, when photographing is performed in an auto mode in which a lens is driven by a driving motor, the operation member is manually operated by a cameraman, and the operation detecting means detects the operation. The operation switching means switches from the auto mode to the manual mode to enable manual lens operation. As a result, the manual operation of the cameraman is preferentially performed, and the cameraman can immediately perform the lens operation by manual driving without the time and effort of the mode switching operation when necessary.

According to the second aspect of the present invention, the operation amount of the operation member is detected, and when the detected operation amount is equal to or more than a predetermined value, it is determined that the operation member has been operated, and the operation mode is switched from the auto mode. Since the mode is switched to the manual mode, for example, when the photographer is shooting with an operating member such as an operating ring to support the camera, even if the operating ring moves slightly due to vibration, the mode is accidentally switched from the auto mode to the manual mode. The switching is prevented, and the operability of the lens operation is improved.

According to the invention, when the lens operation is switched from the auto mode to the manual mode, the lens operation switching means forcibly shuts off a power supply line of the drive motor. As a result, the switching of the lens operation between the manual operation and the drive motor can be performed instantaneously as compared with the case where the switching is performed by, for example, a clutch mechanism.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a camera lens operation switching device according to the present invention. Lens part 1 of the camera shown in FIG.
The position of the 0 focus lens 12 is adjusted by a servo mechanism (automatic mechanism) and a manual mechanism. The servo mechanism mainly includes a drive motor 14, a motor drive circuit 16, a position sensor 18, an A / D converter 20, a CPU 22
Consists of The drive motor 14 is a motor drive circuit 16
The focus lens 12 is rotated by the drive current output from the camera and moves the position of the focus lens 12. The position sensor 18 detects the position of the focus lens 12, and outputs the detected position to A /
CPU (Central Processing Unit) 22 via D converter 20
To enter. The CPU 22 outputs the input position of the focus lens 12 to the motor drive circuit 16, and the motor drive circuit 16 outputs the position to the drive motor 14 based on the detected position of the focus lens 12 so that the focus lens 12 is at the target position. Drive current to be controlled. Thus, the focus lens 12 is positioned at the target position. The target position of the focus lens 12 is, for example,
It is generated by autofocus or generated by an operation unit such as a switch and input to the motor drive circuit 16.

On the other hand, the manual mechanism is operated by the focus ring 24, interrupts the driving force of the drive motor 14, and causes the focus ring 24 to move the focus lens 12 in the front-rear direction by the rotational force of the manual operation.
Next, a switching control mechanism between the servo mechanism and the manual mechanism will be described. Hereinafter, a control mode in which the focus mechanism 12 is operated by the servo mechanism is referred to as a servo mode (auto mode), and a control mode in which the focus mechanism is operated by the manual mechanism is referred to as a manual mode. The CPU 22 is connected to a servo switch 26 for switching between a servo mode and a manual mode. The servo switch 26 is turned on by a switch operation of a cameraman, and the CPU 22 sequentially switches between the servo mode and the manual mode each time the servo switch 26 is turned on. When the servo switch 26 is pressed to set the servo mode, the CPU 22 turns on the switch 27 of the servo mechanism to make the drive motor 14 and the motor drive circuit 16 conductive, and the servo mechanism turns the focus lens 12 on. Enables drive control.

On the other hand, when the manual mode is set by pressing the servo switch 26 in the servo mode, the switch 27 of the servo mechanism is turned off to cut off the current of the drive motor 14 and stop the operation of the servo mechanism. Manual operation using the focus ring 24. The CPU 22 is provided with the servo switch 2.
In addition to the switch operation of No. 6, in the case of the servo mode, the mode is switched to the manual mode when the focus ring 24 is rotated at a rotation speed higher than a predetermined speed.
Therefore, the focus ring 2 has the focus ring 2
4 is provided with a tachometer 28 for detecting the rotation speed.
The rotational speed detected by the tachometer 28 is input to the CPU 22 via the A / D converter 30.

When the CPU 22 detects in the servo mode that the focus ring 24 has been rotated at a predetermined speed (switching speed) or more, the CPU 22 turns off the switch 27 of the servo mechanism to reduce the drive current of the drive motor 14. Shut off and automatically switch from servo mode to manual mode. As a result, even in the servo mode, if the photographer operates the focus ring 24 as necessary, it is possible to forcibly switch to the manual mode without switching to the manual mode by the servo switch 26, thereby improving the operability of the cameraman. Can be achieved. Also,
Since the mode is switched to the manual mode by interrupting the drive current of the drive motor 14, the switching speed is higher than the mechanical switching by a conventional clutch or the like.

The switching speed of the focus ring 24 when switching from the servo mode to the manual mode can be arbitrarily set by the sensitivity switching means 32. That is, it is possible to arbitrarily set the detection sensitivity as to whether or not the operation of switching to the manual mode by the focus ring 24 has been performed. For example, when the detection sensitivity is set to be high, the switching speed is low, and it is possible to switch to the manual mode even by a slight operation of the focus ring 24. On the other hand, when the detection sensitivity is set low, the switching speed is high and the focus ring 2
The manual mode cannot be switched unless the key 4 is operated to a certain extent.

The CPU 22 refers to the detection sensitivity set by the sensitivity switching means 32 and refers to the focus ring 2.
It is determined whether or not the value of the output signal output from the tachometer 28 has exceeded a set value determined by the detection sensitivity in accordance with the rotation speed of Step 4. If the set value is exceeded,
Switch to manual mode. Thus, a desired sensitivity is taken into consideration in consideration of a problem that the focus mode is switched from the servo mode to the manual mode just by touching the focus ring 24 and a problem that the mode is not switched to the manual mode unless the focus ring is rotated at a high speed. Can be adjusted.

The detection sensitivity (switching speed) of whether or not the operation to switch to the manual mode by the focus ring 24 is set in two stages according to the operating condition of the focus lens 12. That is, while the focus lens 12 is being moved by the servo mechanism, the forced switching to the manual mode by the focus ring 24 is rarely performed, so that the forced switching to the manual mode due to an erroneous operation of the focus ring 24 can be prevented. Because of the weight, the detection sensitivity of the operation of the focus lens 12 is set to be low (the switching speed is high).

On the other hand, when the focus lens 12 is stopped, there is a high possibility that the manual mode is forcibly switched, and when the focus ring 24 is operated, the mode is shifted to the manual mode as smoothly as possible. Therefore, the detection sensitivity of the operation of the focus lens 12 is set to be high (the switching speed is small) because emphasis is placed on.

FIG. 2 shows an example of setting the detection sensitivity of the operation of the focus ring 24. The graph shown in the figure is a graph showing the output voltage of the tachometer with respect to the rotation speed of the focus ring 24. The point O on the graph is a point when the focus ring 24 is stopped, and the tachometer output at that time is a value indicated by ref. On the graph shown in FIG. 3, points A and B are shown in the forward and reverse directions of the focus ring 24. Point A indicates a set point of the detection sensitivity when the focus lens 12 is operating,
Point B indicates a set point of the detection sensitivity when the focus lens 12 is stopped, and point A and point B are symmetrical with respect to the point O in consideration of the normal rotation and the reverse rotation of the focus lens 12, respectively. Is set.

In this detection sensitivity setting example, when the focus lens 12 is in operation, the focus ring 24
Is operated in the forward or reverse direction at a speed higher than the switching speed corresponding to the point A, and a value exceeding the output value corresponding to the point A from the tachometer 28 (the output value corresponding to the point A in the positive and negative directions with ref as the origin). If the output value exceeds
2 switches to manual mode.

On the other hand, when the focus lens 12 is stopped, the focus ring 24 is operated in the forward or reverse direction at a speed higher than the switching speed corresponding to the point B, and the tachometer 2 is rotated.
A value exceeding the output value corresponding to point B from 8 (a value exceeding the output value corresponding to point B in the positive and negative directions with ref as the origin)
Is output, the CPU 22 switches to the manual mode. The output of the tachometer 28 is linear with respect to the rotation speed of the focus ring 12, and the amount of change in the output value of the tachometer 28 with respect to the same rotation speed of the focus ring 12 in the forward and reverse directions around the point O ( re
The difference between the value of f and the output value) is equal. Therefore, when the sensitivity setting unit sets the detection sensitivity to point A, for example, the CPU 22 sets the absolute value of the difference between the output value corresponding to point A and the ref value as the detection sensitivity setting value, and sets the detected tachometer 28 When the absolute value of the difference between the output value and the ref value exceeds the set value, it is determined to switch to the manual mode.

As described above, the detection sensitivity (switching speed) of whether or not the operation for switching to the manual mode by the focus ring 24 is performed is such that the focus lens 12 is stopped compared to when the focus lens 12 is operating. The case is set so as to be higher (smaller). next,
The processing procedure of the CPU of the lens operation switching device configured as described above will be described with reference to the flowchart of FIG. First, the CPU 22 performs initial settings such as parameters for starting the following processing (step S10). Then, it is determined whether the current drive control (focus control) of the focus lens 12 is performed by a servo mechanism or a manual mechanism (step S12). That is, it is determined whether the mode is the servo mode or the manual mode. First, the case where the mode is determined to be the manual mode will be described.

If it is determined that the operation mode is the manual mode, the switch 27 of the servo mechanism is turned off to cut off the power supply line of the drive motor 14 to enable the manual operation (step S16). Then, the timer for monitoring the focus driving operation is stopped (step S18). This timer is used in the servo mode, and this process works effectively when the mode is switched from the servo mode to the manual mode.

Next, it is determined whether the servo switch 26 has been turned on (step S18). That is, it is determined whether the servo mode has been designated. In the case of NO, the manual mode is continued, and the processing of steps S12 to S16 is repeatedly executed. On the other hand, when the servo switch 26 is turned on and the servo mode is designated, the servo mode is set (step S20), the switch 27 of the servo mechanism is turned on, the power supply line of the drive motor 14 is connected, and the servo mechanism is turned on. Is enabled (step S22).

Next, the current position of the focus lens 12 is read by the position sensor 18, and this value is set as POSI0 (step S24). Also, focus ring 2
The detection sensitivity of the operation 4 is set to the low sensitivity point A shown in FIG. 2 (step S26). Then, the process returns to step S12. As described above, when the servo mode is specified in the manual mode and the servo mode is set, it is determined in step S12 that the current control is the servo mode. Therefore, the case where the servo mode is determined in step S12 will be described.

When entering the servo mode, the CPU 22 first starts a timer for monitoring the focus driving operation (step S28). If the timer has already started, this process is not executed. Next, it is determined whether or not a timer interrupt has occurred (step S30). This interrupt is generated every time the timer elapses a predetermined time. The processing when an interrupt occurs will be described later.

Then, it is determined whether or not the output of the tachometer 28 has exceeded the set value (switching speed) of the detection sensitivity (step S32). Note that the set value is determined in step S2.
6, the low-sensitivity point A is set when the focus lens 12 is in operation. However, when the focus lens 12 is stopped in the interrupt processing described later, the high-sensitivity point B shown in FIG. 2 is set. Have been. Again,
If the output of the tachometer exceeds the set value, the mode is set to the manual mode (step S34), and the above-mentioned step S12 is performed.
Return to In this case, as described above, the switch 27 of the servo mechanism is turned off, the power supply line of the drive motor 14 is cut off, the manual operation is enabled (step S16), and the timer for monitoring the focus drive operation is stopped (step S18). .

On the other hand, if the output of the tachometer 28 does not exceed the set value in step S32, the flow returns to step S12, and the processing from step S28 is repeated. When the interruption by the timer occurs in step S30, first, the current position of the focus lens 12 is read by the position sensor 18, and
The value is set to POSI1 (step S36). Then, it is compared with POSI0 set in step S24 to determine whether or not POSI0 = POSI1 (step S3).
8). This detects whether the focus lens 12 is stopped or in operation. If POSI0 = POSI1, it is determined that the focus lens 12 is stopped,
The detection sensitivity of the operation of the focus ring 24 is set to the high sensitivity B point (step S40). On the other hand, if POSI0 is not equal to POSI1, it is determined that the focus lens 12 is operating, and the detection sensitivity of the operation of the focus ring 24 is set to the low sensitivity point A (step S42). After setting these detection sensitivities, the position POSI1 of the focus lens 12 is set.
Is substituted for POSI0 (step S44), and the position of POSI1 is set as the previous value at the time of determining the operation state of the focus lens 12 when the next interrupt occurs (step S38).

When the above interrupt processing is completed, the process returns to step S32. When the process of step S32 is performed after the end of the interrupt process, the detection sensitivity set in steps S40 and S42 is reflected in the determination value of this process. That is, when the focus lens 12 is stopped, the manual mode is set when the focus ring 24 is rotated and operated at a value equal to or higher than the set value of the low sensitivity B point, and when the focus lens 12 is in operation, the focus ring 24 is operated. The manual mode is set when the rotary operation is performed at a value higher than the set value of the high sensitivity point A.

With the lens operation switching device described above,
Even when the focus lens 12 is driven and controlled by the servo mechanism, when the photographer operates the focus ring 24, the focus lens 12 can be forcibly operated manually, and the servo switch 26 for switching to the manual operation can be used. Operation can be saved. In addition to switching the servo mechanism to the manual mechanism simply by operating the focus ring 24, the detection sensitivity of the operation of the focus ring 24 is changed in accordance with the operation state of the focus lens 12 to change the manual operation. Since the switching to the mechanism is performed, the operability of switching to the manual operation by the cameraman is improved.

In the above-described embodiment, the switching device of the lens operation for performing the focus adjustment has been described. However, also in the case where the zoom adjustment is performed by switching between the servo mechanism and the manual mechanism, similarly to the above-described embodiment, the zoom ring is switched. The operation may be switched from the servo mechanism to the manual mechanism. In the above embodiment, the mode is switched from the servo mode to the manual mode based on the rotation speed of the focus ring 24. However, the present invention is not limited to this, and it is detected that the focus ring 24 is intentionally operated by a cameraman. If you can,
For example, a method of switching based on the amount of rotation angle in which the focus ring 24 is continuously operated may be used.

In the above embodiment, the tachometer is used as a sensor for detecting the rotation of the focus ring 24. However, the present invention is not limited to this, and a rotary encoder and a photo interrupter can be used. In the above embodiment, the focus lens 12 is driven by the drive motor 14 of the servo mechanism.
The present invention can be applied even when is not controlled by the servo mechanism. That is, when the operation mode in which the focus lens 12 is operated by the drive motor 14 is the auto mode, switching from the auto mode to the manual mode can be performed in the same manner as in the above embodiment.

[0032]

As described above, according to the present invention, when a photographer manually operates an operation member during photographing in an auto mode in which a lens is driven by a drive motor, operation detection means operates the operation member. Is detected, and the lens operation switching means switches from the auto mode to the manual mode to enable manual lens operation. As a result, the manual operation of the cameraman is preferentially performed, and the cameraman can immediately perform the lens operation by manual driving without the time and effort of the mode switching operation when necessary.

According to the second aspect of the present invention, the operation amount of the operation member is detected, and when the detected operation amount is equal to or more than the predetermined value, it is determined that the operation member has been operated, and the operation mode is changed from the auto mode. Since the mode is switched to the manual mode, for example, when the photographer is shooting with an operating member such as an operating ring to support the camera, even if the operating ring moves slightly due to vibration, the mode is accidentally switched from the auto mode to the manual mode. The switching is prevented, and the operability of the lens operation is improved.

According to the invention, when the lens operation is switched from the auto mode to the manual mode, the lens operation switching means forcibly shuts off a power supply line of the drive motor. As a result, the switching of the lens operation between the manual operation and the drive motor can be performed instantaneously as compared with the case where the switching is performed by, for example, a clutch mechanism.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a lens operation switching device of a camera according to the present invention.

FIG. 2 is a diagram illustrating a setting example of a detection sensitivity of an operation of a focus ring 24;

FIG. 3 is a flowchart showing a processing procedure of a CPU of the lens operation switching device of the camera according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Lens part 12 ... Focus lens 14 ... Drive motor 16 ... Motor drive circuit 18 ... Position sensor 20, 30 ... A / D converter 22 ... CPU 24 ... Focus ring 26 ... Servo switch 27 ... Switch 28 ... Tachometer 32 ... Sensitivity Setting means

Claims (6)

[Claims] 1. An auto mode in which a lens of a camera is driven by a drive motor to adjust the position of the lens, and the drive of the lens is stopped by the drive motor and the position of the lens is adjusted by manual operation of an operation member. A lens operation switching device for a camera that can perform a lens operation by switching between the auto mode and the manual mode, the operation detection unit detecting whether or not the operation member is operated; and the lens. When the operation is performed in the automatic mode, when the operation detecting unit detects that the operation member is operated, the lens operation switching unit that switches the lens operation to the manual mode. Camera lens operation switching device. 2. The operation detecting means detects an operation amount of the operation member, and determines that the operation member has been operated when the detected operation amount is equal to or more than a predetermined value. 2. The camera lens operation switching device according to claim 1, wherein it is determined that the operation member is not operated when the value is less than a predetermined value. 3. The operation detecting means changes the predetermined value between a case where the lens is stopped and a case where the lens is operating, and changes the predetermined value while the lens is operating. 3. The lens operation switching device for a camera according to claim 2, wherein the distance is set larger than when the lens is stopped. 4. A lens operation switching device for a camera according to claim 2, further comprising setting means for setting said predetermined value to an arbitrary value. 5. The lens operation switching device for a camera according to claim 2, wherein the operation member is an operation ring, and an operation amount of the operation member is a rotation speed of the operation ring. 6. The camera according to claim 1, wherein said lens operation switching means forcibly shuts off a power supply line of said drive motor when said lens operation is switched from said auto mode to said manual mode. Lens operation switching device.