Optical Member Control Device, Imaging Device, Control Method, and Storage Medium

Abstract

The present invention provides an optical member control device, an imaging device, a control method, and a storage medium. The optical member control device includes a first optical member and a second optical member that are arranged to be movable on the same plane intersecting the optical path of light incident on an imaging element, and when moving to insert either the first optical member or the second optical member into the optical path and retract the other of the first optical member and the second optical member from the optical path, controls such that after starting to move the optical member to be retracted from the optical path and before completing the movement, starts to move the optical member to be inserted into the optical path.

Description

Technical Field

[0001] The present invention relates to an optical member control device, a imaging device, a control method, and a storage medium, and particularly to a technique for controlling the operation of an optical member. Background Art

[0002] As an example of an optical member control device that controls an optical member (the optical member changes the characteristics of an optical image incident on an image sensor) in an imaging device such as a digital camera, for example, there is an optical member control device that moves a plurality of separately movable filters having different optical characteristics (for example, a neutral density (ND) filter, an infrared (IR) cut-off filter, etc.) separately to insert these filters into the optical path or remove them from the optical path. By using the optical member control device, by arranging an appropriate filter on the optical path according to the shooting environment or shooting intention, a user can shoot an image under optimal conditions.

[0003] Japanese Patent Application Laid-Open No. 2019-66801 proposes an optical member control device in which a plurality of filters are arranged in a plane orthogonal to the optical axis of an imaging optical system, and by arranging two filters in the same plane, the size and thickness of the optical member control device are reduced.

[0004] However, if two filters are arranged in the same plane as described in Japanese Patent Application Laid-Open No. 2019-66801, switching of the filters on the optical path is performed by an exclusive operation (in the exclusive operation, after waiting for a filter to retract from the optical path, movement of another filter is started), and this operation takes longer time compared with the case of moving a single filter. In this case, the switching time can be reduced by moving one filter to the outside of the optical path and simultaneously moving another filter to the optical path, but there is a possibility that the filters come into contact with or collide with each other. Summary of the Invention

[0005] The present invention has been made in view of the above problems, and the present invention realizes the following technique: when at least two optical members move in the same plane intersecting the optical axis, the time taken to switch the optical members can be reduced and the possibility that the optical members come into contact with or collide with each other can be reduced.

[0006] In order to solve the above problems, the present invention provides an optical member control device, which includes: a first optical member and a second optical member, the first optical member and the second optical member being arranged to be movable on the same plane intersecting the optical path of light incident on the imaging element; a driving unit capable of independently moving the first optical member and the second optical member; and a control unit configured to control the movement of the first optical member and the second optical member, wherein, when moving to insert either the first optical member or the second optical member into the optical path and retract the other of the first optical member and the second optical member from the optical path, the control unit performs control such that after starting to move the optical member to be retracted from the optical path and before completing the movement, start moving the optical member to be inserted into the optical path.

[0007] In order to solve the above problems, the present invention provides a control method for an optical member control device, the optical member control device having a first optical member, a second optical member, and a driving unit, the first optical member and the second optical member being arranged to be movable on the same plane intersecting the optical path of light incident on the imaging element, the driving unit being capable of independently moving the first optical member and the second optical member, the control method including: controlling the movement of the first optical member and the second optical member, wherein, in the control, when moving to insert either the first optical member or the second optical member into the optical path and retract the other of the first optical member and the second optical member from the optical path, perform control such that after starting to move the optical member to be retracted from the optical path and before completing the movement, start moving the optical member to be inserted into the optical path.

[0008] In order to solve the above problems, the present invention provides a non-transitory computer-readable storage medium storing a program for causing a computer to execute a control method for an optical member control device, the optical member control device having a first optical member, a second optical member, and a driving unit, the first optical member and the second optical member being arranged to be movable on the same plane intersecting the optical path of light incident on the imaging element, the driving unit being capable of independently moving the first optical member and the second optical member, the control method including: controlling the movement of the first optical member and the second optical member, wherein, in the control, when moving to insert either the first optical member or the second optical member into the optical path and retract the other of the first optical member and the second optical member from the optical path, perform control such that after starting to move the optical member to be retracted from the optical path and before completing the movement, start moving the optical member to be inserted into the optical path.

[0009] In order to solve the above problems, the present invention provides an imaging device, which includes: an imaging element; and an optical member control device. The optical member control device includes: a first optical member and a second optical member, the first optical member and the second optical member are arranged to be movable on the same plane intersecting the optical path of the light incident on the imaging element, and can be inserted into the optical path and retracted from the optical path; a driving unit capable of independently moving the first optical member and the second optical member; and a control unit configured to control the movement of the first optical member and the second optical member, wherein when moving to insert either one of the first optical member and the second optical member into the optical path and retract the other one of the first optical member and the second optical member from the optical path, the control unit performs control such that after starting to move the optical member to be retracted from the optical path and before completing the movement, start moving the optical member to be inserted into the optical path.

[0010] In order to solve the above problems, the present invention provides an imaging device, which includes: an imaging element, wherein the imaging device is configured such that an optical member control device can be attached to and detached from the imaging device, and the optical member control device includes: a first optical member and a second optical member, the first optical member and the second optical member are arranged to be movable on the same plane intersecting the optical path of the light incident on the imaging element, and can be inserted into the optical path and retracted from the optical path; a driving unit capable of independently moving the first optical member and the second optical member; and a control unit configured to control the movement of the first optical member and the second optical member, wherein when moving to insert either one of the first optical member and the second optical member into the optical path and retract the other one of the first optical member and the second optical member from the optical path, the control unit performs control such that after starting to move the optical member to be retracted from the optical path and before completing the movement, start moving the optical member to be inserted into the optical path.

[0011] According to the present invention, when at least two optical members move on the same plane intersecting the optical axis, the time spent on switching the optical members can be reduced and the possibility of the optical members contacting or colliding with each other can be lowered.

[0012] Other features of the present invention will become clear from the following description of exemplary embodiments with reference to the drawings. Description of the Drawings

[0013] Figure 1 is an exploded perspective view showing the external structure of the optical member control device according to the present embodiment.

[0014] Figure 2 is a block diagram showing the internal configuration of the optical member control device according to the first embodiment.

[0015] Figure 3A and Figure 3B is a graph showing the relationship between the movement amount of the filter and the detection position in the first embodiment.

[0016] Figure 4 is a flowchart showing the control process related to the operation for switching the filter in the first embodiment.

[0017] Figure 5 is a block diagram showing the internal configuration of the optical member control device according to the second embodiment.

[0018] Figure 6A and Figure 6B is a graph showing the relationship between the movement amount of the filter and the detection position in the second embodiment.

[0019] Figure 7A and Figure 7B is a flowchart showing the control process related to the operation for switching the filter in the second embodiment. DETAILED DESCRIPTION

[0020] Hereinafter, embodiments will be described in detail with reference to the drawings. Note that the following embodiments are not intended to limit the scope of the present invention. In the embodiments, a plurality of features are described, but it is not limited that the present invention requires all of these features, and these features can be appropriately combined. In addition, in the drawings, the same or similar components are given the same reference numerals, and their repeated descriptions are omitted.

[0021] [First Embodiment]

[0022] Hereinafter, an embodiment applied to a filter device built in a imaging device (such as a digital camera) or additionally attached to the imaging device will be described as the optical member control device of the present invention with reference to the drawings.

[0023] In the present embodiment, the subject side in the optical axis direction of the imaging device will be referred to as the front side or the front, and the opposite side will be referred to as the rear side or the back. In addition, when observing the imaging device in the normal position from the front side, the up-down direction and the left-right direction of the imaging device are defined.

[0024] As Figure 1 shown, the filter device 10 includes a hollow frame-shaped holding member 101, a first drive unit 102, a second drive unit 103, a first filter unit 104, and a second filter unit 105.

[0025] The first filter unit 104 includes filters 106 and 108 as independently movable optical members, and the driving unit 102 includes motors 107 and 109. The motor 107 converts the electric power supplied from a motor driver (described later) into power, and converts the power into a driving force for the filter 106 through a power transmission mechanism such as gears, so that the filter 106 can move in the vertical direction. Similarly, using the power of the motor 109, the filter 108 can move in the vertical direction. Note that in the present embodiment, the center of the optical axis of the lens is shown by the optical axis R. In addition, the first filter unit 104 and the second filter unit 105 have similar configurations, and thus the configuration of the first filter unit 104 is described below and the description of the second filter unit 105 is omitted.

[0026] Figure 2 An example of the functional blocks of the filter device 10 and the imaging device 20 to which the filter device 10 is attached is shown.

[0027] In the case where the imaging device 20 is a digital camera, the imaging device 20 includes functions for photographing an image of a subject, generating image data, storing the image data as an image file in a storage device, or outputting the image data to a display device or an external device. However, these components and functions are known, and thus details thereof are not described in the present embodiment.

[0028] Since appropriate filters are arranged on the optical path according to the shooting environment, shooting intention, etc., the imaging device 20 can capture images under optimal shooting conditions.

[0029] Note that except during the switching operation described later, the filters 106 and 108 stop at predetermined positions, and the stop position on the optical path (the position where the filter intersects the optical path (at a right angle)) is defined as the insertion position, and the stop position outside the optical axis is defined as the retracted position.

[0030] In addition to the filters 106 and 108 and the motors 107 and 109, the filter device 10 further includes a position detection unit 110 for detecting the position of the filter 106 and a position detection unit 111 for detecting the position of the filter 108. The filter 106 can move in the vertical direction as described above, and the position detection unit 110 includes a retracted position side switch that is turned on when the filter 106 moves to the retracted position and an inserted position side switch that is turned on when the filter 106 moves to the inserted position. The position detection unit 111 has a similar configuration to the position detection unit 110 and can detect the retracted position and the inserted position of the filter 108. Note that the components constituting the position detection units 110 and 111 are not limited to switches that turn on or off, and a configuration may also be employed in which a light interrupter is used to detect the position based on light reception / blocking, or a Hall effect element is used to detect the position, the Hall effect element detecting a change in the magnetic field of a magnet included in the filter.

[0031] The imaging device 20 adjusts the amount of light of the subject image incident on the imaging element 201 (described later) by inserting the filter 106 or 108 into the optical axis and / or retracting the filter 106 or 108 from the optical axis. The insertion and retraction of the filters 106 and 108 can be performed according to an operation by the user who is performing imaging or by automatic exposure control of the imaging device 20.

[0032] The imaging device 20 includes an operation detection unit 200. The operation detection unit 200 detects user operation information and outputs the user operation information to the exposure control unit 204. The user operation information is, for example, information related to an operation such as pressing an operation member provided in the imaging device 20 or an operation performed on a remote controller connected to the imaging device 20. The insertion and retraction of the filter or the light reduction amount can be directly set by a user operation. The imaging element 201 includes an image sensor that converts a subject image into an electrical signal, such as a CCD or a CMOS.

[0033] The photometric unit 202 detects luminance information based on the captured image signal output from the imaging element 201, and outputs the detected luminance information to the exposure control unit 204. The exposure control unit 204 includes a processor such as a CPU and a memory, and determines the target light reduction amount of the filter using the information output from the photometric unit 202 or the information output from the operation detection unit 200. The imaging device 20 can select a variety of exposure modes, and the user can, for example, set the exposure mode by operating a menu screen. If the imaging device 20 is set to a mode in which the exposure is automatically controlled to be appropriate, the target light reduction amount to be achieved using the filters 106 and 108 is determined based on the difference between the luminance value detected by the photometric unit 202 and a predetermined appropriate value, so that the luminance value of the subject image incident on the imaging element 201 becomes an appropriate value. In the case of a mode in which the user determines the luminance value of the subject image by manually operating an operation member, the target light reduction amount of the filter is determined based on the user operation information detected by the operation detection unit 200.

[0034] Here, a method for determining the target light reduction amount of the filter in the exposure control unit 204 will be described.

[0035] The light reduction amount of the filter currently inserted into the optical path is obtained from the light reduction amount calculation unit 207. For example, assume that the filter 106 is an ND filter having a visible light transmittance of about 25% and reducing the light amount by an amount corresponding to two grades, and the filter 108 is an ND filter having a visible light transmittance of about 6.3% and reducing the light amount by an amount corresponding to four grades. Note that reducing the light amount by an amount corresponding to one grade means halving the light amount. If the filter 106 is in the inserted position, the exposure control unit 204 can obtain information indicating that the light reduction amount corresponds to two grades from the light reduction amount calculation unit 207. If the user performs an operation to further reduce the light amount by an amount corresponding to two grades, a request for an additional reduction by an amount corresponding to two grades is issued from the operation detection unit 200. The exposure control unit 204 outputs the target light reduction amount of the filter corresponding to four grades to the target position calculation unit 205 based on the information indicating an additional reduction by an amount corresponding to two grades (the additional reduction requested by the user for the current light reduction amount of the filter corresponding to two grades). Note that, as described above, in the case of the automatic exposure mode, the exposure control unit 204 determines the target light reduction amount of the filter by adding the difference between the current luminance value and the appropriate luminance value to the current light reduction amount obtained from the light reduction amount calculation unit 207, or subtracting the difference from the current light reduction amount. However, a device for reducing the light amount of the subject image incident on the imaging element 201 can also be used in combination with a mechanism other than the filter. For example, an aperture that reduces the light amount incident on the imaging element 201 by narrowing the optical path can be used.

[0036] The target position calculation unit 205 calculates insertion information or retraction information for each filter based on the target light reduction amount obtained from the exposure control unit 204. In the above example, the light reduction amount corresponding to four levels is input as the target value to be achieved using the filters. Therefore, the target position is determined to retract the filter 106 that reduces the light amount by an amount corresponding to two levels and insert the filter 108 that reduces the light amount by an amount corresponding to four levels, and the target position is output to the filter control unit 208. The filter control unit 208 includes a processor such as a CPU and a memory, and controls to move the filter to the target position of each filter input from the target position calculation unit 205. As will be described later, the filter control unit 208 controls the selective movement of the filter and the timing of starting the retraction movement and insertion movement of the filter. When starting the movement of the filter 106 or 108, the filter control unit 208 outputs the target drive amount to the drive waveform generation unit 209. The drive waveform generation unit 209 obtains the target drive amount and outputs a motor drive waveform to the motor driver 210.

[0037] Here, an example of the operation of each unit when retracting the filter 106 and inserting the filter 108 will be described.

[0038] It is assumed that the motors 107 and 109 are stepping motors. The filter control unit 208 outputs the number of drive pulses / drive speed. Based on the configuration of the filter device 10, the number of drive pulses required to move the filter between the insertion position and the retraction position is determined in advance. The drive waveform generation unit 209 generates a sine wave for controlling the rotation angle of the stepping motor according to the input number of pulses. By shifting the phases of sine wave A and sine wave B by 90° and advancing the phase of sine wave A relative to sine wave B, the stepping motor can be rotated forward, and by advancing the phase of sine wave B relative to sine wave A, the stepping motor can be rotated backward. Both the motor driver 210 and the motor driver 212 include an H-bridge circuit. Since sine waves C and D that are opposite in phase to the input sine waves A and B are generated, and sine waves A to D are input to the motors 107 and 109, a magnetic force is generated by the stator coils of the stepping motor and the rotor is magnetized, thereby rotating the motor.

[0039] The A / D converter 203 converts the analog signal output from the position detection unit 110 into digital data and outputs the digital data to the filter position calculation unit 206. Similarly, the A / D converter 211 converts the analog signal output from the position detection unit 111 into digital data and outputs the digital data. The filter position calculation unit 206 converts the data output from the A / D converters 203 and 211 into position information in at least three modes, i.e., the insertion position of the filter 106 or 108, the retraction position of the filter 106 or 108, and the position during movement that is neither the insertion position nor the retraction position (i.e., the position is indeterminate). Except for including information indicating an indeterminate position, the information output from the filter position calculation unit 206 is information of the same type (insertion position / retraction position) as the information output from the target position calculation unit 205. The light attenuation amount calculation unit 207 outputs the light attenuation amount of the filter currently in the insertion position based on the information indicating insertion or retraction related to the filters 106 and 108. For example, if the filter 106 is in the insertion position, the current light attenuation amount corresponding to two levels is output, if the filter 108 is in the insertion position, the current light attenuation amount corresponding to four levels is output, and if the filters 106 and 108 are in the retraction position, the current light attenuation amount corresponding to zero levels is output.

[0040] Next, operations performed when switching the filter will be described with reference to Figure 3A , Figure 3B and Figure 4 describes operations performed when switching the filter according to the first embodiment.

[0041] Figure 3A and Figure 3B show examples of the relationship between the movement amount and the detection position when switching the filters 106 and 108 according to the first embodiment. Figure 4 shows an example of the control process performed when switching the filters 106 and 108 according to the first embodiment.

[0042] In the present embodiment, as described above, it is assumed that the filter 106 reduces the light amount by an amount corresponding to two levels, and the filter 108 reduces the light amount by an amount corresponding to four levels. Example operations performed in the following case will be described. In this case, in the initial state, the filter 106 is in the insertion position and the filter 108 is in the retraction position, and through a user operation or the automatic exposure control of the imaging device 20, the filter 106 retracts and the filter 108 is inserted to reduce the light amount by an amount corresponding to four levels.

[0043] In Figure 3AIn this figure, the vertical axis indicates the amount of movement of the filters 106 and 108, and the horizontal axis indicates the time points. The curve shown by the dashed line shows the movement trajectory of the filter 106, and the curve shown by the solid line shows the movement trajectory of the filter 108. In Figure 3B this figure, the vertical axis indicates the position detection result of the filter, and the horizontal axis indicates the time points. The curve shown by the dashed line shows the position detection result of the filter 106, and the curve shown by the solid line shows the position detection result of the filter 108.

[0044] At the time point t1, the exposure control unit 204 sets target values corresponding to four levels of light attenuation, and in response to the setting of the target values, the retraction movement of the filter 106 is started. Note that there is no delay between the output of the target value from the exposure control unit 204 and the start of the movement of the filter. After starting the movement of the filter 106, at the time point t2, the insertion position side switch of the position detection switch is turned off. As a result, the position detection result related to the filter 106 indicates that the filter is moving, that is, the position is uncertain. Here, there is a delay between the time point t1 when the filter 106 starts to move and the time point when the position detection result changes from the state of detecting insertion to the state of being position-uncertain because: the number of drive pulses output from the filter control unit 208 for inserting or retracting the filter is set to be a predetermined amount larger than the value corresponding to the position where the switch is turned on to drive the filter an additional amount. This process is performed to prevent the following situation: if the filter is stopped when the switch is turned on, the ON state of the switch may be cancelled and the position may become uncertain due to vibrations or the like being applied to the imaging device 20. Note that in the above configuration, the filter control unit 208 outputs a predetermined number of drive pulses, but this configuration also includes a process for correcting the number of drive pulses based on the position detection result, such as the following situation: initially, the number of drive pulses is output to start moving the filter, and thereafter, if it is confirmed that the insertion position or the retraction position is detected, the above additional drive pulses are generated and the filter stops.

[0045] Since the retraction movement of the filter 106 is detected at the time point t2, the insertion movement of the filter 108 is started. Then, the retraction movement of the filter 106 is completed at the time point t3, and the insertion movement of the filter 108 is completed at the time point t4. Note that as described above, after the position detection switch is turned on, the filters 106 and 108 move an additional amount. Therefore, in Figure 3B this figure, the filter 106 is detected to be in the retracted position at a time point before the time point t3 when the movement is completed, and the filter 108 is detected to be in the inserted position at a time point before the time point t4 when the movement is completed.

[0046] As described above, the movement of the filter 108 starts at the time point t2 when the retraction movement of the filter 106 is detected. Therefore, the delay caused by the movement of the two filters is only the time period between t2 and t1. Accordingly, the time taken to switch the filters in response to a user operation or the automatic exposure control of the imaging device 20 can be reduced. On the contrary, if the insertion movement of the filter 108 starts at the time point t1, the control responsiveness is improved, but the filter 108 may contact or collide with the filter 106. Various factors can be considered as the collision factors, such as an error in the timing of outputting a drive waveform to the motor, a delay in the start of movement due to a clearance in a power transmission mechanism (such as gears, etc.), and a decrease in drive torque. In the present embodiment, since the movement of the filter 108 starts at the time point t2 when the retraction movement of the filter 106 is detected, the possibility of the above contact and collision can be reduced.

[0047] Next, with reference to Figure 4 a control process performed by a filter control unit (hereinafter referred to as "control unit") 208 according to the present embodiment to implement an operation for switching the filters will be described.

[0048] Note that as a result of the filter control unit 208 controlling each unit by executing a program stored in a memory, the processing shown in Figure 4 is implemented.

[0049] In step S100, the control unit 208 acquires information related to the target position of the filter 106 from the target position calculation unit 205 and acquires information related to the current position from the filter position calculation unit 206. The target position of the filter 106 is the retracted position, and the current position of the filter 106 is the inserted position.

[0050] In step S101, the control unit 208 acquires information related to the target position and the current position of the filter 108. The target position of the filter 108 is the inserted position, and the current position of the filter 108 is the retracted position.

[0051] In step S102, the control unit 208 determines whether there is a filter that needs to be moved. This determination is made to reduce unnecessary processing by ending the processing immediately when there is no filter that needs to be moved. Since it is determined whether there is a filter that needs to be inserted or a filter that needs to be retracted in steps S103 and S105 described later, the processing in step S102 is not essential. In the present processing, since there is a difference between the target position and the current position for both the filters 106 and 108, the processing proceeds to step S103.

[0052] In step S103, the control unit 208 determines whether there is a filter that needs to be moved to the retracted position. If there is a filter that needs to be moved to the retracted position, the process proceeds to step S104, and if there is no filter that needs to be moved to the retracted position, the process proceeds to step S105. In this process, the filter 106 needs to be moved to the retracted position, so the process proceeds to step S104.

[0053] In step S104, the control unit 208 outputs a driving amount for retraction to the drive waveform generation unit 209. Then, using the sine wave output from the drive waveform generation unit 209, the motor 107 is rotated by a predetermined amount via the motor driver 210, and the filter 106 continuously moves until the filter reaches the retracted position. After the driving amount is output in step S104, the process proceeds to step S105.

[0054] In step S105, the control unit 208 determines whether there is a filter that needs to be moved to the inserted position. If there is a filter that needs to be moved to the inserted position, the process proceeds to step S106, and if there is no filter that needs to be moved to the inserted position, the process ends. In this process, the filter 108 needs to be moved to the inserted position, so the process proceeds to step S106.

[0055] In step S106, the control unit 208 again acquires the position information related to the filter 106 that has started the retraction movement in step S104. As described in step S106, it is necessary to acquire the position information related to the filter 106 in order to Figure 3A and Figure 3B as described, match the start timing of the movement of the filter 108 with the start timing of the detection of the retraction movement of the filter 106.

[0056] In step S107, the control unit 208 determines whether the filter 106 has started to move from the inserted position based on the information acquired in step S106. Specifically, if the insertion position side switch of the position detection unit 110 has been turned off and information indicating position uncertainty can be acquired from the filter position calculation unit 206, it is determined in step S107 that the movement has started. When it is determined that the movement has started, the control unit 208 proceeds to step S108. If the insertion position side switch of the position detection unit 110 is in the ON state, the control unit returns to step S106 and performs the process in step S106 again.

[0057] Note that, for ease of description, unless it is determined in step S107 that the movement has started, the process of step S106 is repeated in this embodiment. However, if the start of the movement cannot be detected in step S106, different types of processing may also be performed as long as the movement of the filter 108 starts after the movement of the filter 106 starts. For example, if it is determined in step S107 that the start of the movement cannot be detected, the process may also end and the process may start again from step S106 after a predetermined period of time.

[0058] Alternatively, if it is determined in step S107 that the start of the movement cannot be detected, the process may also be temporarily suspended (i.e., enter the sleep state), and the process may start again from step S106 as an interrupt process triggered by a change in the detection result of the filter position calculation unit 206. In step S108, the drive amount for insertion is output to the drive waveform generation unit 209. Then, using the sine wave output from the drive waveform generation unit 209, the motor 109 is rotated by a predetermined amount via the motor driver 212, and the filter 108 continuously moves until the filter reaches the insertion position. After the drive amount is output in step S108, the process ends.

[0059] Here, the filter device 10 includes the first filter unit 104 and the second filter unit 105, and the above processing can also be applied to the case where the filter units are used in combination. For example, assume that there is a filter that needs to be retracted in the first filter unit and there is also a filter that needs to be retracted in the second filter unit. In this case, in step S104, the drive waveforms for the retraction movement are output for the two filters, and if the start of the movement is detected for the two filters in step S107, the process proceeds to step S108. If the start timing of the retraction movement and the insertion movement is synchronized between the filter units arranged in the front-back direction along the optical axis (instead of on the same plane as described above), it is possible to prevent the filter units arranged in the front-back direction from moving separately, and the movement of the filter units will not make the user feel unnatural.

[0060] According to the first embodiment, when at least two filters move on the same plane, the time taken for switching the filters determined by user operation or automatic exposure control can be reduced, and the possibility of contact and collision between the filters can be reduced.

[0061] [Second Embodiment]

[0062] Next, the processing for switching the filter according to the second embodiment will be described.

[0063] In the second embodiment, retry control is added to the process of switching filters according to the first embodiment to detect a failure in the movement of the filter and execute the movement again. As a result, the possibility of contact and collision between the filters can be further reduced compared to the process in the first embodiment.

[0064] Figure 5 FIG. 4 is a block diagram showing the device configuration in the second embodiment, which is an example of a configuration obtained by adding an error detection unit 300 to the Figure 2 configuration shown. Since the filter position detection unit 301 and the drive waveform generation unit 303 also output to the error detection unit 300, and the filter control unit 302 performs additional processing when an error occurs based on the result output from the error detection unit 300, the filter position detection unit 301, the drive waveform generation unit 303, and the filter control unit 302 are denoted by reference numerals different from those of the corresponding units in the first embodiment. However, the description of the same processing as that performed in the first embodiment will be omitted in the second embodiment.

[0065] If a drive waveform has been output from the drive waveform generation unit 303 but the filter has not reached the target position, the error detection unit 300 determines that an error has occurred and outputs the error detection result to the filter control unit 302. There are various factors that can cause an error, such as insufficient torque due to a failure of the motor 107 or 109, malfunction in the gears that transmit the power generated by the rotation of the motor to move the filter up or down, malfunction in the switches of the position detection units 110 or 111, or deformation of the holding member 101 due to dropping and contact with the filter to hinder the movement of the filter, etc.

[0066] The drive waveform generation unit 303 can output a sine wave signal according to the number of drive pulses to the motor drivers 210 or 212, and output the number of drive pulses that have currently been output as a drive waveform to an external unit. The drive waveform generation unit 303 outputs the number of pulses that have currently been output to the error detection unit 300. When the number of drive pulses that have been output and obtained from the drive waveform generation unit 303 has reached the number of drive pulses that are predetermined to be required for moving from the insertion position to the retraction position, and if the position information related to the filter 106 obtained from the filter position detection unit 301 does not indicate the retraction position, the error detection unit 300 determines that an error has occurred and outputs information indicating the occurrence of the error to the filter control unit 302. When receiving the information indicating the occurrence of the error from the error detection unit 300, the filter control unit 302 outputs the number of drive pulses required for movement to the drive waveform generation unit 303 again. The process of moving the filter to the retraction position again is defined as retry control. If an error occurs even when retry control is executed, after the retry control is repeated a predetermined number of times, a failure is notified to the user, and the output from the motor drivers 210 or 212 is stopped to prevent current from flowing to the motor.

[0067] In the second embodiment, the timing at which the movement of the filter 108 starts in the retry control is different from the timing in normal operation. In normal operation, the movement of the filter 108 starts at the timing when the start of the movement of the filter 106 is detected, but in the retry control, the movement of the filter 108 starts after the filter 106 is detected to have moved to the retraction position. This is because, even if the movement of the filter 106 can start in the retry control, due to an abnormality occurring during the operation of the filter 106, the filter 106 may not be able to normally complete the movement to the retraction position. If an error occurs, the possibility that the filter 106 stops at an intermediate position is higher than in normal operation, so it is necessary to strengthen the measures to avoid collisions between the filters.

[0068] Here, reference will be made to Figure 6A and Figure 6B Describe the operations performed when switching between the filters 106 and 108 according to the second embodiment. In this embodiment, it is assumed that the movement of the filter 106 cannot start in the first drive process, but can start in the subsequent retry control.

[0069] Similar to Figure 3A and Figure 3B Similar, Figure 6A and Figure 6B show the relationship between the movement trajectories and the position detection waveforms when switching between the filters 106 and 108 according to the second embodiment. In Figure 6AIn [the figure], the vertical axis indicates the amount of movement of the filters 106 and 108, and the horizontal axis indicates the time points. The curve shown by the dashed line shows the movement trajectory of the filter 106, and the curve shown by the solid line shows the movement trajectory of the filter 108. In Figure 6B In [the figure], the vertical axis indicates the position detection result of the filter, and the horizontal axis indicates the time points. The curve shown by the dashed line shows the position detection result of the filter 106, and the curve shown by the solid line shows the position detection result of the filter 108. The time points t1 to t4 are the same as those in Figure 3A and Figure 3B If the filter operates normally, the filter 106 starts to move at the time point t1 of the output drive waveform, as described with reference to Figure 3A and Figure 3B . However, if the filter 106 cannot start to move for some reason, the detection result of the filter position detection unit 301 at the time point t1 as shown in Figure 6A and Figure 6B will not change from the insertion position. At this time point, the error detection unit 300 does not detect the occurrence of an error. At the time point t4, the number of drive pulses of the information that has been output from the drive waveform generation unit 303 has reached the number of drive pulses required for the retraction drive, but the position of the filter does not change from the insertion position. Therefore, the error detection unit 300 detects the occurrence of an error at this time point and notifies the filter control unit 302 of the occurrence of the error. When receiving the information indicating the occurrence of an error, the filter control unit 302 transfers to the retry control process. In the retry control, as described above, the timing at which the filter 108 starts to move is different from the timing during normal operation. At the time point t5, the filter control unit 302 outputs the number of drive pulses to the drive waveform generation unit 303 in the retry control process, and the filter 106 starts to move at the time point t5. At the time point t5, the insertion position side switch of the filter 106 is turned off, and the filter position detection unit 301 outputs position information indicating an uncertain position related to the filter 106. During normal operation, the movement of the filter 108 starts at the time point t6, but in the retry control, the movement of the filter 108 does not start until the filter 106 reaches the retracted position again. At the time point t7, the retracted position side switch of the filter 106 is turned on, that is, the filter position detection unit 301 outputs position information indicating the retracted position related to the filter 106. Therefore, at the time point t7, the filter control unit 302 starts to move the filter 108 to the insertion position.

[0070] Next, with reference to Figure 7A and Figure 7BDescribe the control process performed by the filter control unit (hereinafter referred to as "control unit") 302 according to this embodiment to achieve the operation for switching the filter. Note that in Figure 7A and Figure 7B In the processing shown, different reference numerals are used from those used in Figure 4 to represent steps different from those in the processing shown in Figure 4 . The following describes steps different from those described with reference to Figure 4 .

[0071] Similar to the processing in the first embodiment, the filter control unit 302 determines whether there is a filter that needs to be moved based on the target position and the current position of the filters 106 and 108. If there is a filter that needs to be moved to the retracted position, the retraction movement is first started (steps S200 to S204). Thereafter, in the first embodiment, the insertion movement of the filter 108 is started at the timing when the retraction movement of the filter 106 is started. However, in the second embodiment, it is initially determined in step S206 whether a retry state is set. The retry state is a state in which, as described above, in the case where the filter cannot reach the target position even though the drive waveform required for movement is output from the drive waveform generation unit 303, a process for outputting the required drive waveform again occurs. The filter control unit 302 manages flag information indicating the retry state and makes the determination in step S206 based on whether the flag indicating the retry state is true or false. Note that the process for setting or canceling the flag indicating the retry state determined in step S206 will be described later.

[0072] If it is determined in step S206 that the retry state is set, the timing for starting the movement of the filter 108 is set after the movement of the filter 106 to the retracted position is completed. If it is determined in step S206 that the retry state is set, the control unit 302 enters step S207 and determines in step S207 whether the movement of the filter 106 has been completed. If the completion of the movement of the filter 106 is detected, the control unit 302 enters step S208, starts the process for the insertion movement of the filter 108, and enters step S209.

[0073] In steps S209 to S211, similar to the first process, the control unit 302 determines whether there is a filter that needs to be moved based on the target positions and current positions of the filters 106 and 108. The determination made in step S211 is a process for confirming that the movement of all the filters that are currently the movement targets has been completed. If it is determined in step S211 that there is no difference between the target position and the current position, that is, all the filters have reached the target position, the control unit 302 considers that the movement has been completed normally, cancels the retry state in step S212, and ends the process. When the movement has been completed normally, the retry state is cancelled as described in step S212 to avoid a situation where, due to continuing the previously set retry state, the movement of the filters starts only after always waiting for the movement of another filter to be completed, and unnecessary waiting time occurs. Based on the fact that the movement has been completed normally, the possibility of a failure is considered to be reduced, and the retry state is cancelled at the timing of confirming the normal movement.

[0074] Here, the process in step S213 is performed until the movement to the target position is completed in step S211. In step S213, the control unit 302 acquires error information from the error detection unit 300. In step S214, if there is information indicating that an error has occurred, the control unit 302 proceeds to step S215, and if there is no information indicating that an error has occurred, the control unit 302 returns to step S209 to wait for the completion of the movement. If there is information indicating that an error has occurred in step S214, the control unit 302 proceeds to step S215, sets the retry state, and ends the process. Here, the process is executed at a predetermined cycle while setting the retry state. That is, when the process is executed again, the process is performed with the retry state set, so the retraction drive process is performed until step S205, and then based on the determination made in step S206, the process proceeds to step S207, and the subsequent processes are executed.

[0075] Note that if the retry state is not set, based on the determination made in step S206, the process proceeds to step S216. In the steps after step S216, similar to the first embodiment, the process of the filter 108 is performed at the timing of starting the movement of the filter 106. However, different from the first embodiment, error determination is performed while waiting to detect the start of the movement of the filter 106. Error information is acquired in step S217, error determination is performed in step S218, and if a drive error is detected, the retry state is set in step S215 similar to the above process. However, although error detection is not particularly described in the first embodiment, if the movement cannot be started due to a failure of the motor or the like, the process will loop infinitely, so a process for exiting the loop such as error detection or timeout processing is required.

[0076] Here, the cases where an error is detected in step S214 include the following: The filter 106 stops moving during the movement of the filter 108. In this case, there is a possibility that the filter 106 collides with the filter 108. If retry control is performed in this collision state, the filter 106 may not move normally in the state where the filter 108 is in contact with the filter 106. Therefore, in the process performed in step S204, for example, while generating a drive waveform for the retraction movement of the filter 106, a drive waveform for moving the filter 108 to the retracted position again may also be generated. Thus, the filters 106 and 108 move away from each other, and the possibility of successfully performing the retry control of the filter 106 can be increased. Note that the process for driving the filters to move away from each other in the retry control will not be described because the difference between this process and Figure 7A and Figure 7B the process shown is only the following process in step S204 as described above: The drive amount for retraction of the filter 108 is also output to the drive waveform generation unit 303.

[0077] In addition, as described in the first embodiment, the filter device 10 includes the first filter unit 104 and the second filter unit 105, and the above process can also be applied to the process in the case of using the filter units in combination. For example, if an abnormality occurs when the retraction movement starts in the first filter unit 104, the retry state is also applied to the second filter unit 105. That is, if the retry state is set due to the first filter unit, the process of starting the insertion movement after waiting for the completion of the retraction movement in step S207 is also applied to the second filter unit 105. In both the first filter unit 104 and the second filter unit 105, at the timing after the filter that needs to move to the retracted position has reached the retracted position, the movement in the insertion direction starts. Even if an error occurs during the retraction movement in the first filter unit 104, this error does not affect the filter insertion operation of the second filter unit 105. However, even if the movement is completed only in the second filter unit 105 prior to the completion of the movement in the first filter unit 104, the desired light reduction amount by the user is the total light reduction amount of the first filter unit 104 and the second filter unit 105. Therefore, in terms of the function of adjusting the light reduction amount, it is meaningless to move only the second filter unit unless the movement to the target position is not completed in the first filter unit 104. In addition, if the filter units arranged in the front-back direction rather than on the same plane move separately, their movements lack unity and make the user feel unnatural. For the above reasons, the first filter unit 104 and the second filter unit 105 are not independently controlled, and the start timing of the retraction movement and the insertion movement is synchronized between the filter units.

[0078] By using the process for switching filters according to the second embodiment, even if an abnormality occurs while the filter device is starting or in the process of being driven, the possibility of contact and collision between the filters can be minimized by changing the movement control to be different from that during normal operation.

[0079] [Other Embodiments]

[0080] Embodiments of the present invention can also be implemented by the following method, that is, a software (program) that executes the functions of the above-described embodiments is provided to a system or device through a network or various storage media, and a method in which a computer or a central processing unit (CPU) or a microprocessing unit (MPU) of the system or device reads and executes the program.

[0081] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications as well as equivalent structures and functions.

Claims

1. An optical member control device, comprising: a first optical member and a second optical member, the first optical member and the second optical member being arranged to be movable on the same plane intersecting the optical path of light incident on the imaging element; a driving unit capable of independently moving the first optical member and the second optical member; a control unit configured to control the movement of the first optical member and the second optical member; and a position detection unit capable of detecting the insertion position and the retraction position of each of the first optical member and the second optical member, the insertion position of each optical member corresponding to the state in which the optical member has been inserted into the optical path, and the retraction position of each optical member corresponding to the state in which the optical member has been retracted from the optical path, wherein, when moving to insert either the first optical member or the second optical member into the optical path and retract the other of the first optical member and the second optical member from the optical path, the control unit controls such that after starting the movement of the optical member to be retracted from the optical path and before completing this movement, the movement of the optical member to be inserted into the optical path is started, when moving to insert either the first optical member or the second optical member into the optical path and retract the other of the first optical member and the second optical member from the optical path, the control unit gives the driving unit the driving amount required to move the optical member to be retracted from the optical path to a predetermined position, and if it cannot be detected that the optical member has reached the predetermined position after a predetermined period of time, the control unit performs retry control, in which the control unit again gives the driving unit the driving amount required to move the optical member to the predetermined position.

2. The optical member control device according to claim 1, wherein, in the retry control, at least after the optical member to be retracted from the optical path has moved outside the optical path, the movement of the optical member to be inserted into the optical path is started.

3. The optical member control device according to claim 1, wherein, in the case of performing the retry control, the control unit controls to move the optical member to be inserted into the optical path to the position where the optical member was located before starting the insertion.

4. The optical member control device according to claim 1, further comprising: a third optical member and a fourth optical member, the third optical member and the fourth optical member being arranged to be movable on the same plane different from the plane on which the first optical member and the second optical member move, wherein the control unit synchronizes the timings: the timing of the retraction movement from the optical path and the insertion movement to the optical path in the operation for switching the first optical member and the second optical member; and the timing of the retraction movement from the optical path and the insertion movement to the optical path in the operation for switching the third optical member and the fourth optical member.

5. The optical member control device according to claim 1, wherein, The position detection unit can at least detect the state where the first optical member is inserted into the optical path, the state where the first optical member retracts from the optical path, the state where the second optical member is inserted into the optical path, and the state where the second optical member retracts from the optical path.

6. A control method for an optical member control device, the optical member control device having a first optical member, a second optical member, and a drive unit, the first optical member and the second optical member being arranged to be movable on the same plane intersecting the optical path of light incident on an imaging element, the drive unit being capable of independently moving the first optical member and the second optical member, The control method includes: Controlling the movement of the first optical member and the second optical member, Detecting the insertion positions and retraction positions of the first optical member and the second optical member respectively, the insertion position of each optical member corresponding to the state where the optical member has been inserted into the optical path, and the retraction position of each optical member corresponding to the state where the optical member has retracted from the optical path, wherein, in the control, when moving to insert either the first optical member or the second optical member into the optical path and retract the other of the first optical member and the second optical member from the optical path, control is performed such that after starting to move the optical member to be retracted from the optical path and before completing this movement, start moving the optical member to be inserted into the optical path. wherein, in the control, when moving to insert either the first optical member or the second optical member into the optical path and retract the other of the first optical member and the second optical member from the optical path, give the drive amount required to move the optical member to be retracted from the optical path to a predetermined position, and if the optical member cannot be detected to have reached the predetermined position after a predetermined period of time, give again the drive amount required to move the optical member to the predetermined position.

7. A non-transitory computer-readable storage medium storing a program for causing a computer to execute the control method according to claim 6.

8. An imaging device, comprising: An imaging element; and The optical member control device according to any one of claims 1 to 5, wherein the first optical member and the second optical member can be inserted into the optical path and can retract from the optical path.

9. An imaging device, comprising: An imaging element, wherein the imaging device is configured such that the optical member control device according to any one of claims 1 to 5 can be attached to and detached from the imaging device, and The first optical member and the second optical member can be inserted into the optical path and can retract from the optical path.

10. A computer program product comprising a program for causing a computer to execute the control method according to claim 6.

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