JP4685183B2 - Optical apparatus and imaging system - Google Patents

Description

  The present invention relates to an optical device such as a lens device used for television photography.

  In a lens apparatus used for television photography or the like, a phenomenon occurs in which the angle of view changes when the focus lens is driven to focus after setting the angle of view by zooming the subject. When the focus lens is driven to the infinity side, the field angle is large, and when the focus lens is driven to the close side, the field angle is small.

  For this reason, recently, an angle-of-view correction function for driving a zoom lens in conjunction with the focus lens may be employed in order to suppress or correct a change in the angle of view caused by operating the focus lens.

  In a lens apparatus having such an angle of view correction function, it is necessary to read the zoom lens position and the focus lens position when the apparatus is stopped, and to maintain the angle of view when the focus lens is driven to a new position. The zoom lens correction position is calculated, and the zoom lens is driven and controlled to the obtained correction position.

  The field angle correction function is realized by precise lens position control by an electric actuator such as a zoom lens motor. For this reason, a lens apparatus having an angle of view correction function is configured on the assumption that at least a zoom lens is electrically driven. Therefore, a lens apparatus having an angle-of-view correction function is not configured to be manually zoomed.

  However, when the zoom lens is driven with a function other than the angle of view correction function, for example, in a shooting situation that requires instantaneous determination of the angle of view, there are cases where the electric zoom cannot be used, and comfortable drawing can be obtained under various shooting conditions. For this purpose, not only electric driving of the zoom lens but also manual driving is required.

  Therefore, the lens device is provided with a switching operation unit for switching between a state in which the zoom lens can be electrically driven (hereinafter referred to as an electric zoom mode) and a state in which the zoom lens can be manually driven (hereinafter referred to as a manual zoom mode). It is also conceivable that a clutch or the like for connecting / disconnecting the driving force transmission path between the motor and the zoom lens is operated by operating the.

  However, for example, after the angle of view is determined in the manual zoom mode, the switching operation unit must be switched to the electric zoom mode every time in order to use the angle of view correction function. It cannot respond quickly.

  Therefore, the present invention can drive a movable part such as a zoom lens both electrically and manually, while performing a state and electric drive for manually driving the movable part without performing a special mode switching operation. An object of the present invention is to provide an optical device capable of switching the device state to a state for performing.

  In order to achieve the above object, in the present invention, a focus lens and a zoom lens that constitute an optical system, a state for electrically driving the zoom lens, and a state for manually driving the zoom lens are provided. In an optical device that has a switchable drive mechanism and performs electric drive control of the zoom lens in accordance with the drive of the focus lens, the drive mechanism is set to a state for causing the zoom lens to be manually driven And when the focus lens is driven, control means for switching the drive mechanism to a state for electrically driving the zoom lens and a state for causing the drive mechanism to electrically drive the zoom lens are set. Discriminating whether or not the electric driving control of the zoom lens according to the driving of the focus lens is finished It is provided and the stage. When the determination unit determines that the electric driving control of the zoom lens has been completed, the control unit switches the driving mechanism to a state for causing the zoom lens to be manually driven.

  This provides an optical device capable of smoothly correcting the angle of view without performing a special mode switching operation.

It is a schematic block diagram showing the lens drive mechanism in the zoom lens apparatus which is embodiment of this invention. It is an operation | movement flowchart of the said zoom lens apparatus.

  FIG. 1 shows the configuration of a zoom lens apparatus (optical apparatus) that is an embodiment of the present invention. This zoom lens device is used for television photography and the like.

  In FIG. 1, reference numeral 1 denotes a zoom lens, which is held by a zoom lens barrel 2 and is movable in the optical axis direction (left-right direction in FIG. 1). The zoom lens barrel 2 is provided with at least three roller members 3 projecting radially outward, and each roller member 3 includes a linear groove 4a formed in a fixed tube 4 as a housing. The curved groove 5 a formed in the rotary cylinder 5 is engaged.

  A connecting pin 6 is provided on the rotary cylinder 5 so as to protrude outward in the radial direction, and engages with the zoom operation ring 7 through a groove 4 b formed in the fixed cylinder 4.

  In such a configuration, when the zoom operation ring 7 is rotated, the rotary cylinder 5 rotates integrally with the zoom operation ring 7, and the roller member 3 provided on the zoom lens barrel 2 is connected to the linear groove 4 a of the fixed cylinder 4. It moves along the curved groove 5a of the rotating cylinder 5. Thereby, the zoom lens 1 moves in the optical axis direction within the fixed cylinder 4. The operating ends of the zoom operation ring 7 and the zoom lens 1 are determined by the operating range of the connecting pin 6 that rotates about the optical axis through the groove 4b of the fixed cylinder 4.

  In addition, a drive unit 8 is disposed in the vicinity of the fixed cylinder 4. Inside the drive unit 8, a CPU (main control means) 31, a zoom motor (electric drive source) 9, a zoom lens position detection potentiometer 10, a focus The motor 23, the potentiometer 22 for detecting the focus lens position, the drive circuits 28, 30, 32, and the like are housed.

  On the input shaft of the potentiometer 10, a position detection gear 11 that meshes with an operation gear portion 7 a provided on the zoom operation ring 7 is attached. Therefore, when the zoom operation ring 7 rotates, the input rotation of the potentiometer 10 corresponding to the rotation amount is obtained, and the position of the zoom lens 1 can be detected by the detection signal from the potentiometer 10. Note that, by detecting the position through the potentiometer 10, when the zoom lens 1 is electrically driven, the impact force and the impact sound when the zoom lens 1 (zoom lens barrel 2) hits the operation end are alleviated. The zoom lens 1 can be decelerated.

  The driving force of the zoom motor 9 is transmitted to the intermediate gear 14 via the gear head 12 and the motor output gear 13. A face gear portion 14a is formed on the end face of the intermediate gear 14, and the face gear portion 15a of the connecting gear 15 is located opposite to the face gear portion 14a. The connection gear 15 meshes with an operation gear portion 7 b provided on the zoom operation ring 7. The zoom motor 9 is driven and controlled by a zoom drive circuit 28 that has received a position control signal from the CPU 31.

  Further, an electromagnetic clutch 16 is attached to a position on the opposite side of the intermediate gear 14 on the support shaft 15 b of the connecting gear 15. By controlling the electromagnetic clutch 16 on and off, the connecting gear 15 slides in the axial direction (longitudinal direction) of the support shaft 15b, and the face gear portion 14a of the intermediate gear 14 and the face gear portion 15a of the connecting gear 15 are engaged. Can be switched off.

  Since the connection gear 15 meshes with the operation gear portion 7b of the operation ring 7, by controlling the electromagnetic clutch 16 to be ON, the intermediate gear 14 and the connection gear 15 can be connected and rotated integrally. The driving force of the motor 9 can be transmitted to the zoom operation ring 7 and driven to rotate. Thereby, the zoom lens 1 (zoom lens barrel 2) is electrically driven in the optical axis direction. In the description of the present embodiment, the state of the drive mechanism for electrically driving the zoom lens 1 in this way is referred to as an electric zoom mode.

  Further, by controlling the electromagnetic clutch 16 to be OFF, the intermediate gear 14 and the connecting gear 15 can be disengaged so that the driving force of the zoom motor 9 is not transmitted to the zoom operation ring 7. In this case, when the zoom operation ring 7 is manually rotated, the zoom lens 1 can be manually driven comfortably without applying a load on the zoom motor 9. In the description of the present embodiment, the state of the drive mechanism for manually driving the zoom lens 1 in this way is referred to as a manual zoom mode.

  ON / OFF control of the electromagnetic clutch 16 is performed by a clutch drive circuit 32 that receives a signal from the CPU 31.

  In addition, the zoom lens apparatus according to the present embodiment has a field angle correction function for electrically driving the zoom lens 1 in the optical axis direction in order to correct a field angle variation caused by driving a focus lens 18 to be described later along the optical axis direction. Yes. This angle-of-view correction function works effectively when the clutch drive circuit 32 that receives a signal from the CPU 31 controls the electromagnetic clutch 16 to be ON, that is, sets the motorized zoom mode.

  In the zoom lens device of the present embodiment, the zoom lens 1 can be electrically driven other than when the angle of view correction function is activated. For example, the CPU 31 is operated according to an operation of a zoom electric operation member 17 provided on the exterior surface of the drive unit 8 or a zoom demand 34 attached to a tripod that supports the zoom lens device and a camera (not shown) to which the zoom lens device is attached. The electromagnetic clutch 16 is ON-controlled by the clutch drive circuit 32. Further, the speed of the zoom motor 9 is controlled according to the operation amount of the zoom electric operation member 17 and the like, and thereby the speed of the zoom lens 1 is controlled.

  Further, the focus lens 18 is held by a focus lens barrel 19 and can move in the optical axis direction (left-right direction in FIG. 1). A helicoid screw portion 19 a is formed on the outer peripheral surface of the focus barrel 19 and is engaged with the helicoid screw portion 4 c of the fixed barrel 4. Further, a focus operation ring 20 that rotates about the optical axis is attached to the fixed cylinder 4, and the focus operation ring 20 and the focus lens barrel 19 are connected by a connecting pin 21. For this reason, when the focus operation ring 20 is rotated, the focus lens 18 can be driven in the optical axis direction.

  The output of the focus motor 23 is transmitted to the intermediate gear 26 via the gear head 24 and the focus motor output gear 25. The intermediate gear 26 meshes with a gear portion 20 a formed on the focus operation ring 20. For this reason, when the focus motor 23 is rotationally operated, the rotation is transmitted to the focus operation ring 20 and is rotationally driven, and the focus lens 18 (focus barrel 19) can be electrically driven in the optical axis direction.

  The focus motor 23 is focus control data (for example, data indicating the position of the focus lens 18) from a focus demand (operation means) 29 attached to the tripod, and a signal for instructing driving of the focus lens 18 according to the change. Is driven by the focus drive circuit 30 in accordance with a position control signal generated from the CPU 31.

  Further, the focus gear output gear 25 and the intermediate gear 26 can be disengaged by moving the intermediate gear 26 in the Z direction in the figure by a switching lever (not shown). In this state, the focus operation ring 20 is manually operated. Then, the focus lens 18 can be manually driven comfortably without applying a load on the focus motor 23.

  A potentiometer 22 has a position detection gear 22a attached to its input shaft. The position detection gear 22a meshes with a gear 20a formed on the focus operation ring 20. Therefore, when the focus operation ring 20 rotates, an input rotation of the potentiometer 22 corresponding to the rotation amount is obtained, and the position of the focus lens 18 can be detected by a detection signal from the potentiometer 22. It should be noted that, by detecting the position through the potentiometer 22, when the focus lens 18 is electrically driven, the impact force and the impact sound when the focus lens 18 (focus lens barrel 19) hits its operating end are alleviated. The focus lens 18 can be decelerated.

  Next, the angle-of-view correction operation in the zoom lens apparatus will be described with reference to the flowchart of FIG. In the present embodiment, two modes can be selected: a mode in which the view angle correction function works (view angle correction mode) and a mode in which the view angle correction function does not work (non-view angle correction mode). Specifically, the view angle correction mode is set when the view angle correction mode selection switch 27 is turned on, and the non-view angle correction mode is set when the view angle correction mode selection switch 27 is turned off.

  The flowchart of FIG. 2 starts from a state in which the angle of view is determined by manual driving of the zoom lens 1 (manual zoom mode). First, in step 51, the position of the focus lens 18 (hereinafter referred to as the focus position) and the position of the zoom lens 1 (hereinafter referred to as the zoom position) are read by the CPU 31 through the potentiometers 22 and 10, respectively.

  Next, in step 52, the CPU 31 reads correction data used to calculate the zoom position for maintaining the angle of view with respect to the focus position change from the data memory unit 33.

  Next, in step 53, it is determined whether or not the focus control data from the focus demand 29 has changed. If there is no change, the flow process ends. On the other hand, if there is a change in the focus control data, the process proceeds to step 54 where the CPU 31 sends a signal to the clutch drive circuit 32 to turn on the electromagnetic clutch 16. As a result, the zoom lens apparatus automatically switches from the manual zoom mode to the electric zoom mode.

  In step 55, the CPU 31 first calculates the position (focus position command) to which the focus lens 18 should be moved from the focus control data from the focus demand 29, and the correction read from the focus position command and the data memory unit 33. Based on the data, a position (zoom position command) to which the zoom lens 1 should be moved is calculated in order to maintain the angle of view (reference angle of view) before the focus control data changes.

  Further, in step 56, the position control calculation of the focus lens 18 is performed from the focus position command calculated in step 55 and the current focus position read in step 51, and the calculation result is sent to the focus control circuit 30 to obtain the focus lens. 18 is driven. At the same time, the position control calculation of the zoom lens 1 is performed from the zoom position command calculated in step 55 and the current zoom position read in step 51, and the calculation result is sent to the zoom control circuit 28. Drive. As a result, the field angle fluctuation accompanying the driving of the focus lens 1 is corrected, and focusing is performed while the field angle is maintained constant.

  Subsequently, at step 57, the current fluctuation value of the zoom motor 9 (that is, the load state of the zoom motor 9) is detected, and when the predetermined fluctuation value is exceeded within a predetermined time, the CPU 31 determines the angle of view of the zoom lens 1. Assuming that the zoom operation ring 7 is manually operated during the correction drive, in order to give priority to this manual operation, a signal is sent to the clutch drive circuit 32 to turn off the electromagnetic clutch 16. As a result, the zoom lens device automatically switches to the manual zoom mode. Further, the driving of the zoom lens 1 by the zoom motor 9 is stopped and the flow ends. On the other hand, if the current fluctuation value of the zoom motor 9 does not exceed the predetermined fluctuation value within the predetermined time, the angle-of-view correction driving of the zoom lens 1 is continued as it is, and the routine proceeds to step 59.

  In step 59, it is determined whether or not the focus control data from the focus demand 29 has changed during the field angle correction drive of the zoom lens 1. If the focus control data has changed, the process returns to step 55 to calculate the focus position command and zoom position command corresponding to the new focus control data, and drive the focus lens 18 and drive the angle of view correction of the zoom lens 1.

  On the other hand, if there is no change in the focus control data during the view angle correction drive of the zoom lens 1, the process proceeds to step 59, where the CPU 31 determines whether or not the view angle correction drive of the zoom lens 1 is completed. Specifically, if the zoom lens 1 is not operating within a predetermined time based on the difference calculation of the detection value of the potentiometer 10, it is considered that the zoom operation has been completed, and the process proceeds to step 60.

  In step 60, the CPU 31 turns off the electromagnetic clutch 16 through the clutch drive circuit 32, switches the zoom lens device from the electric zoom mode to the manual zoom mode, and ends the process.

  As described above, in the present embodiment, when the view angle correction mode is set and the manual zoom mode is set, when the change in the focus control data from the focus demand 29 is detected, the manual zoom mode is automatically set. Switches to the electronic zoom mode. Therefore, according to the present embodiment, during shooting in the manual zoom mode, the field angle correction function can be quickly activated without performing a special operation for switching from the manual zoom mode to the electric zoom mode. Shooting can be started.

  In the present embodiment, when the angle-of-view correction driving of the zoom lens 1 is completed, the electric zoom mode is automatically switched to the manual zoom mode. For this reason, according to this embodiment, after performing focusing in a state where the angle of view is maintained, quick operation by manual operation of the zoom lens 1 is performed without performing a special operation for switching from the electric zoom mode to the manual zoom mode. You can change the frame.

  Further, in the present embodiment, when the zoom operation ring 7 is manually operated during the field angle correction drive of the zoom lens 1, the motorized zoom mode is automatically switched to the manual zoom mode. Therefore, according to the present embodiment, the manual operation can be performed by interrupting the view angle correction drive of the zoom lens 1 without performing a special operation for switching from the electric zoom mode to the manual zoom mode. Further, it is possible to prevent an excessive load from being applied to the zoom motor 9.

  In the present embodiment, in the state where the non-view angle correction mode is set, the electromagnetic clutch 16 is not turned on in conjunction with the focus operation, but the zoom electric operation member 17 and the zoom demand in the manual zoom mode are not used. The electromagnetic clutch 16 is turned ON in conjunction with the operation 34, and the manual zoom mode is switched to the electric zoom mode without any special mode switching operation.

  In the above embodiment, the case where the focus control data is switched from the manual zoom mode to the electric zoom mode by inputting the focus control data from the focus demand 29 to the CPU 31 has been described. However, the zoom lens apparatus is attached to the focus control data. It may be input from a camera by communication, or may be input from a control unit arranged in an adjustment room or the like located at a location distant from these imaging systems.

  Further, in the above embodiment, when the focus control data is changed in step 53, that is, when the manual zoom mode is switched to the electric zoom mode before the actual driving of the focus lens 18 is started. However, the configuration may be such that the manual zoom mode is switched to the electric zoom mode by detecting that the drive of the focus lens 18 is started. By adopting such a configuration, the zoom lens 1 can be driven to correct the angle of view even when the focus lens 18 is manually operated. Further, for example, even when the focus operation ring 20 is pressed by a hand or the like and the focus control data or the focus position command from the focus demand 29 or the like is different from the actual focus position, the image of the zoom lens 1 is also different. Since the angle correction drive is performed according to the actual focus position, it is possible to prevent the angle of view from changing due to the view angle correction drive based on the focus position command.

  The start of driving the focus lens 18 can be detected by calculating the difference between the position detection results within a predetermined time of the potentiometer 22 that detects focus movement. Further, the CPU 31 may be configured to switch from the manual zoom mode to the electric zoom mode in accordance with the timing at which the CPU 31 sends a position control signal to the zoom drive circuit 28 for field angle correction.

  Further, it is detected that the position control signal (drive control signal) of the zoom lens 1 calculated based on the focus control data is output from the CPU 31 to the zoom drive circuit 28, and the manual zoom mode is switched to the electric zoom mode. It may be.

  Furthermore, in the above embodiment, the case where the zoom lens 1 that has been driven to correct the angle of view is detected to be stopped and switched from the electric zoom mode to the manual zoom mode has been described. However, the zoom lens 1 for the zoom drive circuit 28 from the CPU 31 is described. The completion of sending the position control signal may be detected to switch from the electric zoom mode to the manual zoom mode. Further, the change of focus control data from the focus demand 29 or the like may be detected and switched, or the drive completion of the focus lens 18 may be detected and switched.

  Further, in the present embodiment, when the zoom operation ring 7 is manually operated during the view angle correction drive of the zoom lens 1, and this manual operation is detected when the drive current (or drive power) of the zoom motor 9 fluctuates. However, the manual operation may be detected based on the back electromotive voltage (change) generated in the zoom motor 9 or the difference between the zoom position command and the actual zoom position by the potentiometer 10.

  In the present embodiment, the case where the switching between the manual zoom mode and the electric zoom mode is performed using the electromagnetic clutch 16 has been described. However, other than the electromagnetic clutch, the driving force transmission path is electrically disconnected such as a solenoid. Means capable of touching can be used.

  In the present embodiment, the case where the manual zoom mode is automatically switched to the electric zoom mode in conjunction with the driving of the focus lens 18 and the zoom lens 1 can be driven to correct the angle of view has been described. For example, the manual focus mode can be switched to the autofocus mode in conjunction with the driving of the zoom lens. Further, the first movable portion and the second movable portion referred to in the present invention may be any movable portion constituting an optical system such as a focus lens, a zoom lens, an iris (aperture), a macro, a filter disk, or the like.

DESCRIPTION OF SYMBOLS 1 Zoom lens 2 Zoom lens barrel 3 Roller member 4 Fixed cylinder 4a Straight groove 4b Groove part 5 Rotating cylinder 5a Curved groove 6 Connecting pin 7 Zoom operation ring

Claims (13)

A focus lens and a zoom lens constituting an optical system, and a drive mechanism that can be switched between a state for electrically driving the zoom lens and a state for manually driving the zoom lens, In an optical device that performs electric drive control of the zoom lens according to driving of the focus lens,
When the drive mechanism is set to a state for manually driving the zoom lens, when the focus lens is driven, the drive mechanism is configured to electrically drive the zoom lens. Control means for switching to a state;
A discriminating unit that discriminates whether or not the electric driving control of the zoom lens according to the driving of the focus lens is finished when the driving mechanism is set to a state for causing the zoom lens to be electrically driven. And
An optical apparatus, wherein when the determination unit determines that the electric driving control of the zoom lens has been completed, the control unit switches the driving mechanism to a state for causing the zoom lens to be manually driven.   In the case where the drive mechanism is set to a state for causing the zoom lens to be manually driven, the control means moves the focus mechanism to the zoom lens in response to an instruction to drive the focus lens. The optical device according to claim 1, wherein the optical device is switched to a state for causing the electric drive to be performed.   The control means moves the focus mechanism to the zoom lens in response to the drive of the focus lens being started when the drive mechanism is set to a state for causing the zoom lens to be manually driven. The optical device according to claim 1, wherein the optical device is switched to a state for causing the electric drive to be performed.   The control means is a drive control for performing an electric drive control of the zoom lens in accordance with the drive of the focus lens when the drive mechanism is set to a state for causing the zoom lens to be manually driven. The optical apparatus according to claim 1, wherein the driving mechanism is switched to a state for electrically driving the zoom lens in response to the start of signal output.   When the driving mechanism is set to a state for causing the zoom lens to be electrically driven, the control means is configured to end the electric drive control of the zoom lens according to the drive of the focus lens. The optical apparatus according to claim 1, wherein the driving mechanism is switched to a state for causing the zoom lens to be manually driven.   In the case where the driving mechanism is set to a state for causing the zoom lens to be electrically driven, the control unit is configured to perform the driving in response to an operation for manually driving the zoom lens being performed. 6. The optical apparatus according to claim 1, wherein the mechanism is switched to a state for causing the zoom lens to be manually driven.   The control means causes the drive mechanism to manually drive the zoom lens in response to an operation for manual driving of the zoom lens being performed when the zoom lens is electrically driven. The optical device according to claim 6, wherein the optical device is switched to a state of   The control means detects that an operation for manual driving of the zoom lens has been performed based on a load state of the electric driving source of the zoom lens or a back electromotive voltage generated in the power source driving source. The optical device according to claim 6 or 7, wherein: A focus lens and a zoom lens constituting an optical system, and a drive mechanism that can be switched between a state for electrically driving the zoom lens and a state for manually driving the zoom lens, In an optical device that performs electric drive control of the zoom lens according to driving of the focus lens,
When the drive mechanism is set to a state for manually driving the zoom lens, when the focus lens is driven, the drive mechanism is configured to electrically drive the zoom lens. An optical device comprising control means for switching to a state. A determination means for determining whether or not the driving of the focus lens is completed;
The optical apparatus according to claim 9, wherein when the determination unit determines that the driving of the focus lens is completed, the control unit switches to a state for causing the zoom lens to be manually driven. A focus demand for driving the focus lens;
Means for determining whether or not the change of control data for the focus lens, which is output by the focus demand, is completed,
When the determination unit determines that the change of the control data for the focus lens output from the focus lens is completed, the control unit switches to a state for causing the zoom lens to be manually driven. The optical device according to claim 9 or 10.   The optical apparatus according to claim 1, wherein the zoom lens is electrically driven and controlled in order to correct a change in an angle of view accompanying the driving of the focus lens.   An imaging system comprising: the optical device according to any one of claims 1 to 12; and an imaging device on which the optical device is mounted to perform imaging.