JP2021085987A - Lens device, imaging device, control method, and program - Google Patents

Abstract

To provide a lens device that is advantageous in low noise.SOLUTION: A lens device (2) includes a driven member (4), a driving unit (5) that drives the driven member, a control unit (6) that controls the driving unit, and a storage unit (8) that stores the quantity about the play of the driving unit. The control unit selectively generates a first driving signal and a second driving signal that has higher control resolution than the first driving signal. From a driving start position to a first switching position, the driving unit is controlled with the second driving signal. From the first switching position, the driving unit is controlled with the first driving signal. The first switching position is determined based on the quantity stored in the storage unit.SELECTED DRAWING: Figure 3

Description

The present invention relates to a lens device, an imaging device, a control method, and a program.

Conventionally, as a drive method of a stepping motor for driving a driven member such as a diaphragm, a rectangular wave drive method such as 1-2 phase drive or 2-phase drive and a microstep drive method are known. According to the rectangular wave drive system, high torque can be generated, so that high-speed drive can be realized. However, for example, in the case of 1-2 phase drive, the stepping motor can be stopped only at 8 points in the electric angle of 360 °. Further, since the motor excitation phase changes rapidly, the drive speed may become discontinuous. On the other hand, according to the microstep drive method, the drive torque is lower than that of the rectangular wave drive method, so that high-speed drive is difficult. However, it can be stopped at points at intervals finer than the stoptable points of the square wave drive system. Further, since the change of the motor excitation phase is smooth, the driving noise is small, and the driving speed can be changed smoothly.

Patent Document 1 describes stepping that achieves both stop accuracy and high speed by driving a stepping motor with a microstep drive method for starting and stopping the drive of the aperture and a rectangular wave drive method between them. The motor control device is disclosed.

Japanese Unexamined Patent Publication No. 2016-119814

However, the stepping motor control device disclosed in Patent Document 1 is driven by a rectangular wave drive method from the 1-2 phase stop point closest to the drive start point to the point beyond. Here, there is play (mechanical play) between the parts of the diaphragm. Therefore, if the backlash is not clogged up to the nearest 1-2 phase stop point, the driving speed becomes high and the collision noise may become loud because the driving speed is discontinuous in the rectangular wave driving method.

An object of the present invention is, for example, to provide a lens device which is advantageous in terms of quietness.

The lens device as one aspect of the present invention stores a driven member, a driving unit that drives the driven member, a control unit that controls the driving unit, and an amount related to play of the driving unit. The control unit selectively generates a first drive signal and a second drive signal having a control resolution higher than that of the first drive signal, and the drive start position to the first switching position are described as described above. The drive unit is controlled by the second drive signal, the drive unit is controlled by the first drive signal from the first switching position, and the first switching position is set to the amount stored in the storage unit. Determine based on.

The image pickup device as another aspect of the present invention includes the lens device and an image pickup device that captures an image formed by the lens device.

A control method as another aspect of the present invention is a control method for controlling a drive unit that drives the driven member based on a first drive signal and a second drive signal having a control resolution higher than that of the first drive signal. From the drive start position to the first switching position, the drive unit is controlled by the second drive signal, and from the first switching position, the drive unit is controlled by the first drive signal. The first switching position is determined based on the amount of play of the drive unit.

A program as another aspect of the present invention causes a computer to execute the driving method.

Other objects and features of the present invention will be described in the following examples.

According to the present invention, for example, it is possible to provide a lens device which is advantageous in terms of quietness.

It is a block diagram of the image pickup apparatus in Example 1. FIG. It is an exploded perspective view of the aperture diaphragm in Example 1. FIG. It is a flowchart which shows the driving method in Example 1. FIG. It is a flowchart which shows the setting of the drive waveform switching position in Example 1. FIG. It is a flowchart which shows the selection of the drive waveform in Example 1. FIG. It is explanatory drawing of the data stored in the drive instruction value storage means in Example 1. FIG. It is explanatory drawing of two drive waveforms in Example 1. FIG. It is explanatory drawing of the position change of two drive waveforms in Example 1. FIG. It is explanatory drawing of the drive waveform in Example 1. FIG. It is explanatory drawing of the gear play in Example 1. FIG. It is a schematic diagram of the backlash between the blade driving member and the cover member in Example 1. It is a schematic diagram of the backlash between the blade driving member and the cover member in Example 1. It is explanatory drawing of the data stored in the storage means in Example 2. FIG. It is a flowchart which shows the driving method in Example 2. FIG. It is a flowchart which shows the setting of the drive waveform switching position in Example 2.

Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

First, the configuration of the image pickup apparatus and the aperture diaphragm in the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram of the image pickup apparatus 100. FIG. 2 is an exploded perspective view of the aperture diaphragm (aperture) 4. In this embodiment, the image pickup device 100 is a camera system such as a single-lens reflex camera having a camera body (imaging device body) 1 and a lens device (interchangeable lens) 2 that can be attached to and detached from the camera body 1. However, this embodiment is not limited to this, and can be applied to an imaging device in which a camera body and a lens device are integrally configured.

The camera body 1 has an image sensor 51 such as a CMOS sensor or a CCD sensor. The lens device 2 includes an optical system (imaging optical system) having a lens group 3 and an aperture diaphragm 4. The aperture diaphragm 4 is a diaphragm mechanism that adjusts the amount of light in the optical system, and includes a stepping motor 9, a pinion gear 10, a cover member 11, a blade drive member 13, a blade member 16 that forms an aperture, and a base member 19. The stepping motor 9 is connected to the cover member 11 by a screw (not shown). Further, the gear portion 15 of the blade drive member 13 and the pinion gear 10 press-fitted into the shaft of the stepping motor 9 mesh with each other. The blade driving member 13 has a fitting portion 14 and engages with the fitting projection 12 of the cover member 11. Therefore, when the stepping motor 9 is driven, the force is transmitted to the gear portion 15 of the blade drive member 13 via the pinion gear 10, and the blade drive member 13 rotates around the opening center of the cover member 11 as the axis of rotation. Move. Further, the hole 21 of the blade drive member 13 and the drive pin 17 of the blade member 16 are engaged, and the drive pin 18 of the blade member 16 is engaged with the cam 20 of the base member 19. Therefore, when the blade driving member 13 rotates, the blade member 16 is rotationally driven along the cam 20 to change the opening (opening diameter). The base member 19 has a circular opening and is connected to the cover member 11 by a screw (not shown).

The diaphragm drive unit (drive unit) 5 has a stepping motor 9. The aperture control unit (control unit) 6 controls the drive of the aperture drive unit 5. Specifically, the aperture control unit 6 controls the drive direction of the aperture drive unit 5 by changing the polarity of the signal (aperture drive signal) applied to the aperture drive unit 5, and increases or decreases the number of pulses of the aperture drive signal. This controls the drive position of the aperture drive unit 5. Subsequent 1-2 phase step positions indicate pulse positions at the 1-2 phase stop point of the stepping motor 9. As a result, the diaphragm control unit 6 controls the opening / closing operation amount of the plurality of blade members 16 in the aperture diaphragm 4. The aperture diaphragm 4 is provided with an aperture position detecting means (not shown) as an actual diaphragm value measuring means for detecting the positions of a plurality of blade members 16 corresponding to the open diaphragm values. In this embodiment, the diaphragm position detecting means is provided in consideration of the case where an impact or the like is received, but open control may be performed by the pulse count of the stepping motor 9.

The storage unit (drive instruction value storage means) 7 stores the drive step for each aperture value. The storage unit (mechanical backlash storage means) 8 stores the amount of backlash (mechanical backlash) between the parts of the aperture diaphragm 4 or the aperture drive unit 5, that is, a predetermined amount of play of the aperture drive unit 5 (predetermined amount of mechanical backlash). In this embodiment, the predetermined amount is the maximum value of the design value relating to the play of the aperture drive 5. The details of these will be described later.

Next, a method of driving the aperture diaphragm 4 in this embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing a driving method of the aperture diaphragm 4. Each step of FIG. 3 is mainly executed by the aperture control unit 6.

First, in step S1, the aperture control unit 6 acquires the target aperture value (target Fno) of the aperture aperture 4 as the driven member from the camera body 1. In this embodiment, for example, Fno11 is acquired as a target aperture value.

Subsequently, in step S2, the aperture control unit 6 converts the target aperture value into the target step. Here, with reference to FIG. 6, the data stored in the storage unit (drive instruction value storage means) 7 will be described. FIG. 6 is an explanatory diagram of data stored in the storage unit 7. As shown in FIG. 6, the storage unit 7 stores the drive instruction value 23 corresponding to the target aperture value 22. The aperture control unit 6 reads out the drive instruction value 23 corresponding to the target aperture value 22 of the storage unit 7 and sets it as a target step. For example, since the drive instruction value 23 whose target aperture value 22 corresponds to Fno 11 is Step 14.5, the aperture control unit 6 sets Step 14.5 as the target step. The 1st step shows the pulse position (1-2 phase position) at the 1-2 phase stop point, and the decimal part shows the position where the 1-2 phase stop point is divided.

Here, if the design value is stored as the drive instruction value 23, even if the aperture aperture 4 is driven at the position of the drive instruction value 23, the actual aperture diameter (actual aperture value) is the target aperture value due to mechanical tolerances and the like. The diameter may be different from 22. Therefore, the storage unit 7 measures the actual aperture diameter when driven to each step, and stores the step at which the target aperture value 22 and the actual aperture diameter are closest to each other as the drive instruction value 23. As a result, the error between the actual aperture diameter and the target aperture value 22 can be reduced, so that high aperture accuracy can be realized.

Subsequently, in step S3 of FIG. 3, the aperture control unit 6 calculates the total drive amount. The aperture drive position at the start of aperture drive is stored in a current position storage means (not shown). The diaphragm control unit 6 subtracts the diaphragm position at the start of diaphragm drive from the target step to calculate the total drive amount.

Here, two drive waveforms of the stepping motor 9 will be described with reference to FIGS. 7 and 8. FIG. 7 is an explanatory diagram of the two drive waveforms. FIG. 8 is an explanatory diagram of the position change of the two drive waveforms. The diaphragm control unit 6 controls the stepping motor 9 by generating a drive signal according to the drive step. In this embodiment, the aperture control unit 6 uses a rectangular wave signal (first drive signal) for 1-2 phase drive, 2-phase drive, etc. and a sine wave signal (second drive signal) for microstep drive as drive signals. It is possible to generate two types of drive signals (drive signals).

FIG. 7 shows a schematic diagram of the drive voltage waveforms of the 1-2 phase drive system and the microstep drive system. In FIG. 7, the vertical line indicates the position of the 1-2 phase stop point. The lower side in FIG. 7 shows the 1-2 phase drive as the rectangular wave drive 27, and the upper side in FIG. 7 shows the drive waveform of the microstep drive 24. Black circles indicate the excitation positions at the 1-2 phase stop points. In the square wave drive 27, the two signals of the A phase 28 and the B phase 29 change abruptly at the 1-2 phase stop point. In the microstep drive 24, the two signals of the A phase 25 and the B phase 26 change smoothly.

FIG. 8 shows changes in the drive positions of the rectangular wave drive and the microstep drive. In FIG. 8, the horizontal axis represents time and the vertical axis represents position. Since the rectangular wave drive 30 can generate high torque, high-speed drive is possible. On the other hand, since the microstep drive 31 has a lower drive torque than the rectangular wave drive 30, it is difficult to drive at high speed. Further, in the rectangular wave drive 27, the stepping motor 9 can be stopped only at eight points in the electric angle of 360 °. In addition, the drive speed may become discontinuous due to the rapid change in the excitation phase. On the other hand, in the microstep drive 24, it is possible to stop with a finer resolution than the 1-2 phase drive stop point. For example, it is possible to stop the 1-2 phase drive stop point at a position divided by 256. Further, since the change in the excitation phase is smooth, driving noise is small and smooth driving can be realized.

Subsequently, in step S4 of FIG. 3, the diaphragm control unit 6 sets the switching position of the drive waveform in order to switch the drive waveform for driving the stepping motor 9 according to the drive step. Here, the setting of the switching position of the drive waveform will be described with reference to FIGS. 4 and 9. FIG. 4 is a flowchart showing the setting of the drive waveform switching position. Each step of FIG. 4 is mainly executed by the aperture control unit 6. FIG. 9 is an explanatory diagram of the drive waveform.

In this embodiment, as shown in FIG. 9, the drive waveform is switched at two positions, the first switching position 32 and the second switching position 33. First, in step S41 of FIG. 4, the aperture control unit 6 reads out the amount of mechanical play (a predetermined amount related to the play of the aperture drive unit 5) stored in the storage unit 8. In this embodiment, the storage unit 8 stores the amount of mechanical backlash (predetermined amount) as the number of drive steps. The details of the amount of mechanical backlash will be described later. Subsequently, in step S42, the aperture control unit 6 sets the first switching position 32. In this embodiment, the aperture control unit 6 determines the first switching position 32 based on the amount of mechanical play (predetermined amount) stored in the storage unit 8. Subsequently, in step S43, the aperture control unit 6 sets the second switching position 33. The details of these will be described later.

Next, the amount of mechanical backlash stored in the storage unit 8 of this embodiment will be described with reference to FIGS. 10 to 12. FIG. 10 is an explanatory view of the gear backlash, and shows an enlarged view of the meshing portion between the pinion gear 10 and the gear portion 15 of the blade drive member 13. There is backlash 34 (backlash, play) between the pinion gear 10 and the gear portion 15 of the blade drive member 13. Therefore, when the stepping motor 9 is driven, the backlash 34 is clogged and the teeth of the gear portion 15 collide with each other, so that a collision sound is generated.

11 and 12 are schematic views of play in the fitting portion between the cover member 11 and the blade drive member 13. Although the fitting projection 12 of the cover member 11 and the fitting portion 14 of the blade drive member 13 are engaged with each other, there is play (play) due to the component tolerance. As shown in FIG. 11, consider a case where the blade driving member 13 is closer to the left side of the paper surface and the gear portion 15 of the blade driving member 13 receives a force 35 on the lower right side of the paper surface. In this case, as shown in FIG. 12, the blade driving member 13 moves to the lower right in FIG. 12 and collides with the fitting projection 12 of the cover member 11 at the position 46. When the parts collide with each other in this way, a collision sound is generated.

Further, there is also play (play) between the drive pin 17 of the blade member 16 and the hole 21 of the blade drive member 13 due to the component tolerance. Further, there is play between the drive pin 18 of the blade member 16 and the cam 20 of the base member 19 due to the component tolerance. Therefore, when the blade driving member 13 rotates, a collision noise is generated between the parts. The storage unit 8 stores the values when these mechanical backlash amounts are maximized within the tolerance range by converting them into the number of drive steps of the stepping motor 9. For example, the backlash of the gear portion 15 is 2 steps, the backlash between the blade driving member 13 and the cover member 11 is 0.5 step, and the backlash between the blade member 16 and the base member 19 and the blade driving member 13 is 0. In the case of 5 steps, the total maximum amount of mechanical backlash is stored as 3 steps. The value to be stored as the amount of mechanical play may be a decimal value. Further, the amount related to the play of the drive unit may be an amount considering only the gear backlash or an amount considering the backlash and the gear backlash between the blade drive member 13 and the cover member 11. Further, although the amount of mechanical backlash is set to the maximum amount within the tolerance range, the maximum amount of backlash measured by the part or the design center value may be used.

Subsequently, in step S6 of FIG. 3, the diaphragm control unit 6 selects the drive waveform of the stepping motor 9. Here, the selection of the drive waveform will be described in detail with reference to FIG. FIG. 5 is a flowchart showing the selection of the drive waveform. Each step of FIG. 5 is mainly executed by the aperture control unit 6. The aperture control unit 6 selects a drive waveform according to each drive amount count (step S8 in FIG. 3).

First, in step S501, the aperture control unit 6 determines whether or not the drive amount count is smaller than the first switching position 32. If the drive amount count is smaller than the first switching position 32, the process proceeds to step S502. In step S502, the aperture control unit 6 selects the microstep drive 36. That is, as shown in FIG. 9, the aperture control unit 6 is driven by the microstep drive 36 from the drive start position 37 to the first switching position 32. Here, the first switching position 32 is on the 1-2 phase stop point. This is because when the drive waveform is switched at a point other than the 1-2 phase stop point, the speed changes discontinuously, causing step-out or discontinuous change in the amount of light. This also applies to the second switching position 33, and the second switching position 33 is also on the 1-2 phase stop point. Further, in the first switching position 32, when the minimum resolution of the position where the rectangular wave drive signal can be stopped is one step, the number of drive steps is 38 + X (X: 0 step ≤ X <1 step) from the drive start position 37. At a distance. Here, X is the range 39, which corresponds to the range of driving to the 1-2 phase stop point when the position of the distance of the mechanical backlash amount 38 from the drive start position 37 is not on the 1-2 phase stop point. Here, since the rectangular wave drive suddenly changes the excitation of the motor, the speed of the motor may be discontinuous and steep. On the other hand, since the microstep drive smoothly changes the excitation of the motor, the drive of the motor is smooth and the discontinuous speed change is small. In this embodiment, the microstep drive 36 is set from the drive start position 37 to the first switching position 32, so that the drive when the mechanical backlash is clogged and a collision between parts occurs is set to the microstep drive 36. As a result, it is possible to prevent the speed of the motor from becoming steep at the time of a component collision and reduce the collision noise between the components.

On the other hand, if the drive amount count is larger than the first switching position 32 in step S501, the process proceeds to step S503. In step S503, the aperture control unit 6 determines whether or not the drive amount count is smaller than the second switching position 33. If the drive amount count is smaller than the second switching position 33, the process proceeds to step S504. In step S504, the aperture control unit 6 selects the rectangular wave drive 40. That is, as shown in FIG. 9, the aperture control unit 6 is driven by the rectangular wave drive 40 from the first switching position 32 to the second switching position 33. Since the rectangular wave drive 40 has a large drive torque, it can be driven at high speed. As a result, the driving time of the aperture diaphragm 4 can be shortened, and the frame speed of the image pickup apparatus 100 can be increased.

On the other hand, if the drive amount count is larger than the second switching position 33 in step S503, the process proceeds to step S502. In step S502, the aperture control unit 6 selects the microstep drive 41. Here, the total number of drive steps from the drive start position to the drive target position is taken as the total step. At this time, the second switching position 33 is the total step-luminance change prevention distance (arbitrary step) 42-Y (arbitrary step: number of 0 or more, Y: 0 step ≤ Y <1 step) from the drive start position 37. Is at a distance. The brightness change prevention distance 42 is stored in a brightness change prevention distance storage means (not shown), and may be set to 0. Y is the range 43, which corresponds to the range from the drive start position 37 to the 1-2 phase stop point when the position 44, which is the distance of the total drive step-brightness change prevention distance 42, is not on the 1-2 phase stop point. To do.

In this way, the aperture control unit 6 switches to the microstep drive 41 several steps before the target position 45 to perform smooth drive. If the square wave drive is performed at this time, a sudden change in brightness occurs due to a steep change in speed. Here, since the speed is slow near the target position 45, this sudden change in brightness may be noticeable. On the other hand, by driving smoothly with the microstep drive 41, it is possible to reduce a sudden change in brightness. Further, by stopping smoothly, the phenomenon that the blade driving member 13 and the blade member 16 continue to vibrate after the driving of the stepping motor 9 is stopped due to the inertial force can be reduced, and the diameter accuracy can be improved. In addition, since the drive stop position can be stopped at a fine division position, the diameter accuracy can be improved. By controlling these drive waveforms, it is possible to reduce collision noise, achieve high-speed drive, and achieve high caliber accuracy.

Subsequently, in step S6 of FIG. 3, the aperture control unit 6 sets the drive speed. Specifically, the aperture control unit 6 performs acceleration / deceleration drive according to the number of drive steps up to the target step. That is, it accelerates from the start of driving to half of the total driving amount, and then decelerates thereafter. Acceleration and deceleration parameters with respect to the number of such drive steps are stored in acceleration / deceleration instruction value storage means (not shown). As a result, the maximum speed can be achieved while preventing the stepping motor 9 from stepping out. Further, the drive speed stored in the acceleration / deceleration instruction value storage means is stored as a parameter of a speed that does not step out for each torque of the drive signal.

Subsequently, in step S7 of FIG. 3, the aperture control unit 6 performs drive control. That is, the diaphragm control unit 6 controls the diaphragm drive unit 5 according to the drive waveform selected in step S5 and the drive speed set in step S6. Subsequently, in step S8, the aperture control unit 6 counts the driving amount. Specifically, the aperture control unit 6 counts and stores the drive amount from the start of drive to the current position. Using this drive amount count, the aperture control unit 6 selects the drive waveform in step S5, sets the drive speed in step S6, and determines the arrival at the target step in step S9.

Subsequently, in step S9, the aperture control unit 6 determines whether or not the target step has been reached. Specifically, the aperture control unit 6 compares the drive amount count with the total drive amount calculated in step S3, and determines whether or not the target step has been reached. When the target step is reached, the drive ends. On the other hand, if the target step has not been reached, the process returns to step S5.

According to this embodiment, it is possible to reduce collision noise, drive at high speed, and achieve high caliber accuracy.

Next, Example 2 of the present invention will be described. This embodiment is different from the first embodiment in that the setting of the amount of mechanical backlash is changed depending on whether or not the driving direction of the aperture diaphragm 4 matches the driving direction immediately before.

The driving method of this embodiment will be described with reference to FIGS. 13 to 15. FIG. 13 is an explanatory diagram of data stored in the storage unit 8. FIG. 14 is a flowchart showing a driving method. FIG. 15 is a flowchart showing the setting of the drive waveform switching position. Each step of FIGS. 14 and 15 is mainly executed by the aperture control unit 6. In FIGS. 14 and 15, the same steps as those in FIGS. 3 and 4 are indicated by the same reference numerals, and their description will be omitted.

In step S10 of FIG. 14, the diaphragm control unit 6 sets the switching position of the drive waveform in order to switch the drive waveform for driving the stepping motor 9 according to the drive step. Specifically, in this embodiment, the drive direction is stored in a drive direction storage means (not shown) at the end of drive in step S11. Then, in step S10, the aperture control unit 6 sets the switching position of the drive waveform at the time of the next drive.

First, in step S101, the aperture control unit 6 determines whether the drive is a forward drive or a reverse drive. That is, when the drive direction at the time of the previous drive stored in the drive direction storage means and the next drive direction coincide with each other, the aperture control unit 6 determines that the drive is a progressive drive. On the other hand, when these drive directions do not match, the aperture control unit 6 determines that the drive is a reverse drive.

Subsequently, in step S102, the aperture control unit 6 reads out from the storage unit 8 the amount of mechanical backlash corresponding to the drive determined in step S101. Here, when the drive is reverse drive, the amount of mechanical play at the start of drive is maximized because the play between the parts is clogged in the opposite direction. Further, when the throttle drive is stopped, the blade drive member 13 and the blade member 16 may advance beyond the stop position of the stepping motor 9 due to inertial force. Therefore, even in the case of the progressive drive, a smaller amount of mechanical play occurs than in the case of the reverse drive.

As shown in FIG. 13, the storage unit 8 stores the amount of mechanical play corresponding to each of the forward drive and the reverse drive (for example, 1 step for the forward drive and 3 steps for the reverse drive). The aperture control unit 6 uses the amount of mechanical backlash according to the driving direction when setting the next first switching position. Therefore, in the case of progressive drive, the amount of mechanical backlash can be set small, so that the shift to rectangular wave drive can be performed faster. As a result, it is possible to realize high-speed driving by shifting to rectangular wave driving faster in the forward direction while preventing the generation of collision noise.

Next, Example 3 of the present invention will be described. This embodiment is different from the first and second embodiments in that the drive speed is set. In this embodiment, the vehicle is driven from the drive start position 37 to the first switching position 32 at a low constant speed. Next, it is driven from the first switching position 32 to the second switching position 33 at a high speed and constant speed. Then, the vehicle is driven from the second switching position 33 to the target position 45 at a low constant speed.

Since the positions of the parts are not exactly the same for each drive, the amount of mechanical backlash is not always the same for each drive. Therefore, when the speed is accelerated from the drive start position 37 to the first switching position 32, the speed at the time of mechanical collision changes for each drive depending on the state of mechanical play. Therefore, the collision sound pressure changes for each drive. On the other hand, in this embodiment, since the section from the drive start position 37 to the first switching position 32 is driven at a constant speed, the speed at the time of mechanical collision is constant for each drive. That is, the sound pressure at the time of collision can be stably reduced.

Next, Example 4 of the present invention will be described. This embodiment is different from the first to third embodiments in the method of setting the amount of mechanical backlash. In this embodiment, a position sensor (not shown) is installed on the blade drive member 13.

Next, the drive waveform in this embodiment will be described. First, the microstep drive is performed from the start of the drive until the position sensor detects that the blade drive member 13 has moved. Subsequently, the blade drive member 13 is continuously driven by microstep drive from the position where the position sensor detects that the blade drive member 13 has moved to the nearest 1-2 phase stop point. Then, the rectangular wave is driven up to the second switching position 33. As a result, it is not necessary to use the maximum tolerance amount as the mechanical backlash amount, so that it is possible to shift to the rectangular wave drive immediately after the gear backlash is clogged. Therefore, it is possible to reduce the collision noise between the parts and realize high-speed driving.

(Other Examples)
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

As described above, in each embodiment, the aperture control unit 6 selectively selects the first drive signal (rectangular wave drive signal) and the second drive signal (microstep drive signal) having a higher control resolution than the first drive signal. To generate. Further, the diaphragm control unit 6 controls the diaphragm drive unit 5 with a second drive signal from the drive start position to the first switching position (1-2 phase position), and from the first switching position, the first drive signal is used. The aperture drive unit 5 is controlled. Then, the aperture control unit 6 determines the first switching position based on the amount stored in the storage unit 8 (for example, the maximum value of the design value regarding the play of the aperture drive unit 5 and the number of drive steps).

Preferably, the resolution of the position that can be controlled by the first drive signal is set as one step, and the drive start position and the first switching position are separated by the amount + X steps (0 ≦ X <1). More preferably, the amount is an amount in units of one step. Further, preferably, the aperture control unit 6 controls the aperture drive unit 5 with the first drive signal from the first switching position to the second switching position, and the second drive signal from the second switching position to the drive target position. Controls the aperture drive unit 5.

Preferably, the speed of the aperture stop 4 by the first drive signal is faster than the speed of the aperture stop 4 by the second drive signal. Further, preferably, the storage unit 8 stores two quantities that are different from each other depending on whether or not the drive direction is reversed. Also preferably, the amount includes an amount relating to backlash between gears. Further, preferably, the first drive signal is a rectangular wave drive signal, and the second drive signal is a microstep drive signal. More preferably, the aperture control unit 6 determines the first switching position based on the 1-2 phase position. Further, preferably, the amount is an amount based on a design value or an actually measured value of play.

According to each embodiment, it is possible to provide a lens device, an image pickup device, a driving method, and a program capable of realizing high-speed and high-precision driving while reducing driving noise at the start of driving.

Although preferable examples of the present invention have been described above, the present invention is not limited to these examples, and various modifications and changes can be made within the scope of the gist thereof.

For example, the driven member of each embodiment is an aperture diaphragm 4, but the driven member is not limited to this. The present invention can also be applied to an optical element such as a lens as a driven member.

2 Lens device 4 Aperture diaphragm (driven member)
5 Aperture drive unit (drive unit)
6 Aperture control unit (control unit)
8 Storage unit 100 Imaging device

Claims (14)

Driven member and
A drive unit that drives the driven member and
A control unit that controls the drive unit and
It has a storage unit that stores the amount of play of the drive unit, and has a storage unit.
The control unit
The first drive signal and the second drive signal having a higher control resolution than the first drive signal are selectively generated.
From the drive start position to the first switching position, the drive unit is controlled by the second drive signal, and from the first switching position, the drive unit is controlled by the first drive signal.
A lens device characterized in that the first switching position is determined based on the amount stored in the storage unit. The resolution of the position that can be controlled by the first drive signal is set as one step, and the drive start position and the first switching position are separated by the amount + X steps (0 ≦ X <1). The lens device according to claim 1. The control unit
From the first switching position to the second switching position, the drive unit is controlled by the first drive signal.
The lens device according to claim 1 or 2, wherein the drive unit is controlled by the second drive signal from the second switching position to the drive target position. The lens device according to claim 3, wherein the speed of the driven member by the first drive signal is faster than the speed of the driven member by the second drive signal. The lens device according to any one of claims 1 to 4, wherein the storage unit stores two quantities that are different from each other depending on whether or not the drive direction is reversed. The lens device according to claim 2, wherein the amount is an amount in units of the one step. The lens device according to any one of claims 1 to 6, wherein the driven member is an aperture diaphragm. The lens device according to any one of claims 1 to 7, wherein the amount includes an amount related to backlash between gears. The first drive signal is a rectangular wave drive signal, and is
The lens device according to any one of claims 1 to 8, wherein the second drive signal is a microstep drive signal. The lens device according to claim 9, wherein the control unit determines the first switching position based on the 1-2 phase position. The lens device according to any one of claims 1 to 10, wherein the amount is an amount based on the design value or the actually measured value of the play. The lens device according to any one of claims 1 to 11.
An image sensor that captures an image formed by the lens device,
An imaging device characterized by having. A control method for controlling a drive unit that drives a driven member based on a first drive signal and a second drive signal having a control resolution higher than that of the first drive signal.
From the drive start position to the first switching position, the drive unit is controlled by the second drive signal.
From the first switching position, the drive unit is controlled by the first drive signal, and the drive unit is controlled.
The control method, characterized in that the first switching position is determined based on the amount of play of the drive unit. A program comprising causing a computer to execute the control method according to claim 13.

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