JP2017102332A - Lens device and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to control the drive of an actuator with a reduced time lag until photographing.SOLUTION: A lens device comprises: optical systems (101, 102, 103, 104, and 114) including a plurality of movable parts (105 and 106); driving means (107, 108, and 113) that drive the plurality of movable parts; and control means (111) that controls the driving speed to drive the movable parts on the basis of the amount of drive (L1 and L2) of the respective plurality of movable parts so as to reduce a difference in time required to reach target positions (1b and 2b) between the respective plurality of movable parts.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens device and an imaging device to which the lens device can be attached and detached.

  The photographic lens includes a plurality of actuators, but there is an upper limit to the total power that can be used by all the actuators. For this reason, power that can be used by each actuator is individually determined in advance so that the total power is not exceeded even when a plurality of actuators are driven simultaneously.

  Patent Document 1 discloses a control device that controls a zoom lens for a television camera having a plurality of current consumption means that receive power from the camera side and perform an operation according to an external operation to consume current. The control device sets a limit value indicating the upper limit of the current that can be supplied from the camera side, and thereby controls the operation of each current consumption means within the range of the limit value.

Japanese Patent No. 3873321

  However, since the control device disclosed in Patent Document 1 performs drive control with a predetermined power for each actuator, even if there is an actuator that is not driven and there is a margin in the total power, this should be utilized. I can't.

  In addition, if the drive amount of each actuator is large or small, the arrival time at the target position does not match. However, in the release operation when the camera captures a subject image, exposure is started after all of the actuators that have received the drive instruction have reached the target position. For this reason, exposure is started after the arrival of the actuator having the latest arrival time. As a result, the time lag until shooting becomes longer, and the shooting timing desired by the photographer cannot be realized.

  Moreover, the control apparatus disclosed by patent document 1 performs control so that a specific combination is not operated simultaneously among several current consumption means, when the set limit value is smaller than a predetermined electric current value. Therefore, it takes a long time for all of the power consuming means to complete the desired operation.

  The present invention realizes actuator drive control with a small shooting time lag without mounting a large battery or the like.

  A lens apparatus according to one aspect of the present invention has a small time difference until each of a plurality of movable units reaches a target position, an optical system including a plurality of movable units, a driving unit that drives the plurality of movable units. As described above, the control unit includes a control unit that controls a driving speed for driving the movable unit based on a driving amount of each of the plurality of movable units.

  According to the present invention, it is possible to realize drive control of an actuator with a small shooting time lag.

1 is a block diagram of an imaging system in Embodiment 1 of the present invention. It is a figure explaining the relationship between the drive electric power of the actuator in Example 1, and drivable speed. It is a figure explaining the relationship between the drive electric power of the actuator in Example 1, and drivable speed. It is a figure explaining the acceleration / deceleration pattern of the actuator in Example 1. FIG. It is a figure explaining the acceleration / deceleration pattern of the actuator in Example 1. FIG. FIG. 6 is a diagram illustrating a relationship between a driving amount and a driving time according to the driving power of the actuator in the first embodiment. It is a figure which shows the imaging | photography sequence from the conventional imaging | photography instruction | indication to imaging | photography exposure. 6 is a diagram illustrating a shooting sequence from a shooting instruction to shooting exposure in Embodiment 1. FIG. 3 is a flowchart illustrating an imaging process of the imaging system in Embodiment 1. 1 is a block diagram of an imaging apparatus in Embodiment 1. FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, regarding an imaging system including an interchangeable lens imaging device (hereinafter referred to as a camera body) that is Embodiment 1 of the present invention and an interchangeable lens device (hereinafter referred to as an interchangeable lens) that can be attached to the camera. This will be described with reference to FIG.

  The camera body 200 and the interchangeable lens 100 shown in FIG. 1 are coupled (attached) to each other by a bayonet mechanism via a mount 300. The mount 300 has a conductive terminal on the inner side, and the conductive terminal is used for communication between each other and supply of lens power from the camera body 200 to the interchangeable lens 100.

  The camera body 200 is an imaging device such as a digital still camera or a video camera that generates image data by imaging (photoelectric conversion) a subject image (optical image) formed by the imaging optical system of the interchangeable lens 100 by the imaging element 201. is there.

  The camera body 200 includes an imaging device 201, an A / D conversion circuit 202, a signal processing circuit 203, a recording unit 204, and a camera microcomputer 205 as a camera control unit and a power supply control unit. In addition, the camera body 200 includes a display unit 206 and an LBI storage unit 220 as a storage medium.

  The imaging element 201 is configured by a photoelectric conversion element such as a CCD sensor or a CMOS sensor that photoelectrically converts a subject image formed by the interchangeable lens 100. The analog electrical signal output from the image sensor 201 is converted into a digital signal by the A / D conversion circuit 202, and the digital signal is input to the signal processing circuit 203. The signal processing circuit 203 performs various kinds of image processing on the input digital signal to generate a video signal. The signal processing circuit 203 also generates focus information indicating the focus state of the image and generating luminance information indicating the exposure state. The video signal output from the signal processing circuit 203 is sent to the recording unit 204 and recorded, or sent to the display unit 206 and displayed as a finder video.

  The camera microcomputer 205 performs control and setting related to imaging in response to input from an imaging instruction switch and setting switch (not shown). Further, the camera microcomputer 205 sends a zoom drive request, an aperture drive request, a focus drive request, other requests to the lens microcomputer (hereinafter, lens microcomputer) 111 via the camera communication unit 208 and the communication terminal of the mount 300, or Send instructions. As described above, the camera microcomputer 205 controls the entire imaging system.

  The camera power supply unit 209 converts the power from the battery 210 built in the camera body 200 into voltages necessary for each part of the camera body 200 such as the camera microcomputer 205, the signal processing circuit 203, and the display unit 206. Supply. The camera power supply unit 209 also supplies power to the interchangeable lens 100 electrically connected to the camera body 200 via a power supply terminal provided on the mount 300. Further, the camera power supply unit 209 controls the interruption and restart of the power supply to the interchangeable lens 100 according to the instruction of the power management control in the camera microcomputer 205.

  The interchangeable lens 100 includes, in order from the subject OB side, a field lens 101, a zooming lens 102 for zooming, an aperture unit 114 for adjusting the amount of light, an afocal lens 103, and a focus lens 104 for focusing. An imaging optical system. The variable power lens 102 adjusts the focal length of the entire interchangeable lens 100. The focus lens 104 adjusts the imaging state of the subject image. In addition to these, a vibration correction lens for image stabilization may be included.

  The variable power lens 102 and the focus lens 104 are respectively held by lens holding frames 105 and 106 that are movable in the optical axis direction (the arrow direction in the figure). The lens holding frames 105 and 106 (movable parts) move according to the driving of the stepping motors 107 and 108.

  The aperture unit 114 includes aperture blades 114a and 114b that are movable in the opening and closing direction. The diaphragm blades 114 a and 114 b move according to the driving of the diaphragm actuator 113.

  The lens microcomputer 111 transmits various information and data to the camera microcomputer 205 in response to a transmission request from the camera microcomputer 205 which is a microcomputer on the camera body 200 side. In addition, the lens microcomputer 111 performs control described later in response to various requests and instructions from the camera microcomputer 205.

  When the lens power supply unit 140 receives the lens power supplied from the camera body 200 via the mount 300, the lens power unit 140 converts the voltage necessary for each unit such as the lens microcomputer 111 and the drive circuits 119 to 121 by a voltage conversion circuit (not shown). To do. The lens power supply unit 140 has a configuration capable of controlling power supplied to each unit of the drive circuits 119 to 121, and supplies power to each unit based on power distribution information instructed from the power distribution setting unit 115. Control the amount.

  Next, control performed in the lens microcomputer 111 will be described.

  The lens microcomputer 111 drives the drive circuit 119 of the stepping motor 107 in response to an operation of a zoom switch (not shown) provided in the interchangeable lens 100. Further, the lens microcomputer 111 may drive the drive circuit 119 of the stepping motor 107 in response to a zoom drive request received from the camera microcomputer 205 via the lens communication unit 112. Zooming can be performed by moving the variable magnification lens 102 with these configurations.

  Further, the lens microcomputer 111 drives the drive circuit 120 of the stepping motor 108 in response to an operation of a focus operation ring (not shown) provided in the interchangeable lens 100 or a focus drive request received from the camera microcomputer 205 through the lens communication unit 112. To do. With this configuration, focusing can be performed by moving the focus lens 104.

  The lens microcomputer 111 drives the drive circuit 121 of the aperture actuator 113 in response to the aperture drive request received from the camera microcomputer 205 through the lens communication unit 112. Thereby, the amount of light can be adjusted by moving the diaphragm blades 114a and 114b in the opening and closing direction. The positions of the diaphragm blades 114a and 114b are detected by a hall element (not shown), and a detection signal from the hall element is input to the lens microcomputer 111 via an amplifier circuit and an A / D conversion circuit. The lens microcomputer 111 controls the driving of the driving circuit 121 based on the input signal.

  In order to perform drive control of the zoom lens 102, the focus lens 104, the diaphragm unit 114, and the like, the lens microcomputer 111 includes a drive characteristic information storage unit 116 that stores drive characteristic information of each drive unit in advance.

  The drive characteristic information in the present embodiment is information related to the drive control of the actuator, and is information representing the driveable speed (maximum drive speed) SPmax with respect to the drive power W supplied to the drive circuit, for example. Information representing an acceleration / deceleration pattern corresponding to the drive power W supplied to the drive circuit, or information representing time information required for completion of drive with respect to the drive power W and drive amount supplied to the drive circuit may be used.

  First, information representing the driveable speed SPmax with respect to the drive power W supplied to the drive circuit in the drive characteristic information described above will be described with reference to FIGS. 2 and 3.

  2 and 3 show two typical drive characteristic information of the stepping motor used in the lens apparatus. In either case, the horizontal axis represents the drive power W supplied to the drive circuit, and the vertical axis represents the drivable speed SPmax. Both the actuator Act1 (hereinafter referred to as Act1) and the actuator Act2 (hereinafter referred to as Act2) shown in FIG. 2 and FIG. 3 increase the drivable speed as the drive power is increased.

  However, the increasing characteristic of Act1 shown in FIG. 2 tends to be linear, whereas the increasing characteristic of Act2 shown in FIG. 3 is not linear. In Act2, the increase ratio of the drivable speed SP with respect to the increase in drive power decreases as the drive power increases. That is, Act2 is an actuator having a characteristic that the rate of increase in the driveable speed with respect to the increase in drive power decreases as the drive power increases.

  By using this drive characteristic information, it is possible to optimally distribute the drive power to the drive circuit of the actuator from the relationship with the drive speed of the actuator.

  Next, information representing an acceleration / deceleration pattern according to the drive power W supplied to the drive circuit in the drive characteristic information described above will be described with reference to FIGS. 4 and 5.

  FIGS. 4 and 5 show changes in the driving speed with respect to the driving from the current position to the target position in the acceleration period Pu after the driving starts, the constant speed period Pc thereafter, and the deceleration period Pd until the driving ends. In either case, the horizontal axis represents time, and the vertical axis represents drive speed. FIG. 4 and FIG. 5 are different in drive power W supplied to the drive circuit, and FIG. 4 shows drive characteristics when the drive power W supplied is higher than that in FIG.

  In the acceleration period Pu from the drive start time t0 to the time t1, the drive speed is increased to the maximum speed SPmax determined for each drive power W according to a specified speed increase coefficient.

  Next, in the constant speed period Pc from time t1 to deceleration start time t2, the driving speed SPmax corresponding to the driving power W is maintained. Here, the deceleration start time t2 is obtained based on the target position and the driving amount required for the deceleration period.

  Next, in the deceleration period Pd from the deceleration start time t2 to the drive end time t3, the drive speed is decreased according to a specified speed decrease coefficient, and reaches the target position at time t3.

  According to the above drive control, the total area of the figures indicated by the acceleration period Pu, the constant speed period Pc, and the deceleration period Pd corresponds to the drive amount. Further, since the drivable speed SPmax increases as the drive power W increases, the acceleration period Pu and the deceleration period Pd can also be shortened by increasing the speed increase coefficient during acceleration and the speed decrease coefficient during deceleration.

  By using this drive characteristic information, it is possible to optimally distribute the drive power to the drive circuit of the actuator even in drive control including acceleration / deceleration.

  Next, of the above-described drive characteristic information, information representing time information required to complete the drive with respect to the drive power W and drive amount supplied to the drive circuit will be described with reference to FIG.

  FIG. 6 shows the drive time T for each drive power W with respect to the drive amount L instructed from the camera microcomputer 205. The horizontal axis indicates the drive amount L, and the vertical axis indicates the drive time. This characteristic information can be stored as table data in addition to a format stored as a calculation function. In this case, representative data may be stored in a storage medium for the purpose of reducing the amount of stored data, and desired information may be acquired by interpolating between the stored data.

  By using this characteristic information, it is possible to easily derive the driving time T and the driving power W at that time in which driving of a plurality of actuators can be completed simultaneously according to each driving amount L instructed from the camera microcomputer 205. it can. Furthermore, the drive speed condition can be obtained from the drive time T by drive characteristic information that associates the drive time T and the drive speed SP (not shown).

  Next, a time lag from when a photographer gives a photographing instruction to when actual photographing exposure is started will be described with reference to FIGS. Here, in the actuator ACT1 (hereinafter referred to as ACT1), the current position is 1a, the drive amount instructed from the camera body 200 is L1, and the target position is 1b. In the actuator ACT2 (hereinafter referred to as ACT2), the current position is 2a, the drive amount instructed from the camera body 200 is L2, and the target position is 2b.

  First, a conventional imaging sequence based on drive control will be described with reference to FIG. In this drive control, the power distributed to each actuator on the lens side is fixed to a predetermined value so as not to exceed the total power Wmax allowed to be consumed by all actuators. That is, the drive power W1 supplied to ACT1 and the drive power W2 supplied to ACT2 are represented by the following formula (1).

Wmax ≧ fixed value W1 + fixed value W2 (1)
In this case, since the electric power supplied to each actuator is a fixed value, the maximum drive speed of each actuator is uniquely determined. Here, since the drive amount instructed to each actuator is different between L1 and L2, in this drive control, a large difference also occurs at arrival times T1 and T2 in proportion to the difference in drive amount. In other words, in this drive control, even if the drive of ACT1 is completed and there is a surplus in the total power amount, a constant power is supplied to ACT2 regardless of the drive amount.

  In order to start photographing exposure, it is necessary to reach the target position for all the actuators. Therefore, even if ACT1 reaches the target position 1b at the arrival time T1, ACT2 reaches the arrival time T2. No exposure is performed.

  On the other hand, in the present embodiment shown in FIG. 8, the driving power distributed to ACT1 and ACT2 is optimized, and the time difference of the target position arrival time for each actuator is reduced, so that the imaging delay time is longer than the driving control shown in FIG. To shorten.

  Hereinafter, the imaging sequence based on the drive control of the present embodiment will be specifically described with reference to FIG.

  The drive control in this embodiment is different from the example shown in FIG. 7, and the supply power W1 to ACT1 and the supply power W2 to ACT2 are not fixed values but are set in consideration of the drive amounts L1 and L2 of each actuator. The

  When the lens microcomputer 111 in the present embodiment receives a command of the driving amount L instructed to each driving circuit from the camera microcomputer 205, the power W, driving speed SP, and driving time T supplied to each actuator based on this command The calculation method is shown below.

  First, the drive time T of each actuator is derived from the following equation (2).

Drive time T = drive amount L / drive speed SP (2)
The drive power W of each actuator is derived from the following equation (3), which is a characteristic function that represents the actuator drive characteristic and the drive speed SP is an input value, or equation (4) using a conversion table.

Electric power W = function f1 (drive speed SP) (3)
Electric power W = Table TBL1 (drive speed SP) (4)
Here, when the driving power of the two actuators on the lens side is W1 and W2, and the total power allowed to be consumed as the driving power of these actuators is Wmax, the following formula (5) is satisfied.

Total power Wmax ≧ variable value W1 + variable value W2 (5)
Further, in order to set the time when all of the plurality of actuators complete driving to the shortest, it is necessary to distribute power so that the driving time T of these actuators is the same. That is, the drive times T1 and T2 of the two actuators satisfy the following formula (6).

Driving time T1 = Driving time T2 (6)
Based on the equations (2) to (6), the lens microcomputer 111 determines the drive speed SP or drive power of each actuator that has the shortest time to complete the drive of all the plurality of actuators within a range not exceeding the total power Wmax. W1 and W2 are calculated.

  In other words, in this embodiment, the driving power W1 and W2 are made variable within a range not exceeding the total power Wmax based on the driving amount of each actuator, and the driving speed is set. As a result, compared to the drive control shown in FIG. 7, the drive power W1 supplied to ACT1 is reduced, and the supply power W2 to ACT2 is increased using the surplus power made available by the reduction of W1. it can. Therefore, ACT2 can be driven at a higher speed than the drive control shown in FIG. 7, and the imaging delay time can be shortened by bringing the target position arrival time of ACT2 closer to the target position arrival time of ACT1. . At this time, if the target position arrival time is the same for all actuators, the imaging delay time can be minimized.

  In order to speed up the calculation process of the lens microcomputer 111, it is preferable to store the table data of the driving power W for each driving speed SP in the driving characteristic information storage unit 116 as the actuator driving characteristic described above.

  Next, control performed by the camera microcomputer 205 and the lens microcomputer 111 for driving the actuator will be described with reference to the flowchart of FIG.

  The camera microcomputer 205 performs shooting control according to a control program on the camera side. Similarly, the lens microcomputer 111 also performs in-lens processing including drive processing of various actuators according to instructions from the camera microcomputer 205 in accordance with the lens-side control program. Further, the lens microcomputer 111 transmits lens status information indicating the processing status in the interchangeable lens 100 to the camera microcomputer 205.

  When a shooting instruction event is issued from the photographer, the lens microcomputer 111 drives and controls the focus lens 104 and the aperture 114 to positions appropriate for shooting the shooting subject. In the process, the power distribution to the drive circuits 120 and 121 of the focus lens 104 and the diaphragm 114 is within the range of power that can be used on the lens side so that the time to reach the target position is the shortest in all the actuators. , And determine the drive speed.

  In step S100, the camera microcomputer 205 determines whether a shooting instruction event from the photographer occurs. If the camera microcomputer 205 determines that an event has occurred, in step S101, the camera microcomputer 205 performs an automatic focus detection process and an automatic exposure process in order to appropriately photograph the photographic subject.

  In step S102, the camera microcomputer 205 determines a target position for driving the focus lens and the aperture based on the result calculated in step S101, and notifies the lens microcomputer of the determined target position. The camera microcomputer 205 may calculate the driving amount based on the current position information from the lens microcomputer 111 and notify the lens microcomputer 111 of the calculated driving amount.

  In step S <b> 103, the lens microcomputer 111 acquires drive characteristic information of the focus lens 104 and the diaphragm 114 from the drive characteristic information storage unit 116.

  In step S104, the lens microcomputer 111 first calculates the drive amount from the target position information notified in step S102 and the current position information by a calculation unit (not shown). Next, the driving conditions of the focus lens 104 and the diaphragm 114 are determined based on the calculated drive amount, information on the maximum speed that can be driven for each supply drive voltage, information on the acceleration / deceleration change curve, and the like with reference to the drive characteristic information. To decide. Examples of the driving conditions include power distribution to be supplied, driving speed, and acceleration / deceleration pattern. In step S102, when the camera microcomputer 205 calculates the drive amount, the drive condition is determined using the calculated drive amount.

  In step S <b> 105, the lens microcomputer 111 calculates a target position arrival time when driven by the driving conditions determined in step S <b> 104 and notifies the camera microcomputer 205 of the target position arrival time.

  In step S106, the lens microcomputer 111 starts driving the focus lens 104 and the diaphragm 114 based on the driving condition determined in step S104.

  In step S107, the camera microcomputer 205 starts an exposure preparation process in accordance with the timing of completion of driving of the focus lens 104 and the aperture 114 based on the information on the target position arrival time notified from the lens microcomputer 111 in step S105. In the present embodiment, charge control of a driving force of a mechanical shutter configured to shield light traveling from the optical lens toward the image sensor 201 with a light shielding curtain (light shielding member) is performed.

  In step S108, the camera microcomputer 205 waits for the shutter operation until the focus lens 104 and the stop 114 reach the target positions. When the completion of reaching the target position is detected, the process proceeds to step S109, and a predetermined exposure process is performed.

  When the exposure process is completed in step S109, in step S110, the camera microcomputer 205 reads out subject image data from the image sensor 201 and converts it into digital data in the A / D conversion circuit 202. Then, development processing is performed by the signal processing circuit 203 to generate a photographic image. The data of the photographic image is stored in a memory card or the like equipped as the recording unit 204, and a series of photographing processes is finished.

  As described above, according to the present embodiment, it is possible to realize actuator drive control capable of reducing the time lag until photographing.

  In this embodiment, the power distribution setting unit 115 of the lens microcomputer 111 instructs the lens power supply unit 140 to distribute power, and the lens power supply unit 140 supplies power to the drive circuit of each actuator based on the instruction. However, by directly instructing the drive speed from the lens microcomputer 111 to the drive circuit, it may be controlled so that the time to reach the target position in all the actuators is shortened.

  In the present embodiment, the drive control of the actuator in the configuration in which the interchangeable lens 100 can be attached to and detached from the camera body 200 with the mount 300 has been described. However, the drive control shown in the present embodiment can also be applied to an imaging apparatus in which a lens and a camera are integrated as shown in FIG.

  FIG. 10 differs from FIG. 1 in that the imaging device 1 includes a lens unit 10 and an imaging unit 20. Actuator drive control is performed by the camera microcomputer 211 in the imaging unit 20. Therefore, the power distribution setting unit 115 and the drive characteristic information storage unit 116 are provided in the camera microcomputer 211. Then, the camera microcomputer 211 instructs the lens power supply unit 140 provided in the imaging unit 20 to distribute power. The rest is the same as the configuration shown in FIG.

  Each embodiment described above is only a representative example, and various modifications and changes can be made to each embodiment in carrying out the present invention.

  An imaging device such as a digital camera or a lens device that has a high time lag until photographing can be provided.

DESCRIPTION OF SYMBOLS 101 Field lens 102 Variable magnification lens 103 Afocal lens 104 Focus lens 107 Stepping motor 108 Stepping motor 111 Lens microcomputer 113 Aperture actuator 114 Aperture unit

Claims (12)

A lens device detachable from an imaging device,
An optical system including a plurality of movable parts;
Driving means for driving the plurality of movable parts;
Drive that drives the movable unit based on the drive amount from the current position of each of the plurality of movable units to the target position so that the time difference until each of the plurality of movable units reaches the target position becomes small. And a control means for controlling the speed.   2. The control unit according to claim 1, wherein the control unit controls the driving speed by setting a distribution of driving power for driving each of the plurality of movable units based on the driving amount. Lens device.   The lens apparatus according to claim 2, wherein the control unit sets the distribution of the driving power so as not to exceed a total power that can be used by the plurality of movable parts as a whole. And further comprising storage means for storing drive characteristic information of the drive means,
The lens device according to claim 1, wherein the control unit controls the driving speed based on the driving characteristic information.   The drive characteristic information includes information indicating a driveable speed with respect to drive power supplied to the drive means, information indicating an acceleration / deceleration pattern for each drive power, or time required for completion of drive for the drive amount for each drive power. The lens apparatus according to claim 4, wherein the lens apparatus represents information.   6. The lens device according to claim 1, wherein the control unit instructs the driving unit to increase the driving speed as the driving amount increases. 6.   The lens device according to claim 1, wherein the driving amount is acquired from the imaging device.   8. The control unit according to claim 1, wherein the control unit calculates the drive amount based on target position information of the plurality of movable parts acquired from the imaging device. 9. Lens device.   9. The control unit according to claim 1, wherein the control unit controls the driving speed so that a time until all of the plurality of movable parts reach the target position is minimized. The lens device according to 1.   The plurality of movable parts include at least two of a focus unit that adjusts an imaging state of a subject image, a zoom unit that adjusts a focal length, and a diaphragm unit that adjusts the amount of light. 9. The lens device according to claim 9. An image sensor that photoelectrically converts an optical image formed via an optical system including a plurality of movable parts and outputs image data; and
A calculation unit that calculates the drive amount of each of the plurality of movable units;
Drive that drives the movable unit based on the drive amount from the current position of each of the plurality of movable units to the target position so that the time difference until each of the plurality of movable units reaches the target position becomes small. And a control means for controlling the speed. Further comprising shutter means having a light shielding member for shielding light from the optical system;
12. The imaging apparatus according to claim 11, wherein the control unit waits for the operation of the light shielding member by the shutter unit until all the plurality of movable parts reach a target position.