Control device, lens device, imaging device, control method, and program

Abstract

To provide a control device capable of exercising zoom tracking control and driving a focus lens to a target position in a time close to a designated arrival time even when the zoom position changes in the middle of time-designated focusing operation.SOLUTION: When the position of a zoom lens changes in the middle of driving a focus lens, a control device (106), while driving the focus lens in order to reduce a focus variation on the basis of locus information that indicates a relationship between the position of a zoom lens and the position of the focus lens that is focused at the position, drives the focus lens at a drive speed updated on the basis of drive information including at least two of designated information pieces: a target position, an arrival time, and a drive speed. When the updated drive speed is out of range of a prescribed speed region, the control device (106) limits the drive speed with a threshold for defining the prescribed speed region, and updates the arrival time of the focus lens on the basis of the threshold and a remaining drive amount representing the difference between the target position and the current position of the focus lens.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a control device, a lens device, an imaging device, a control method, and a program. [Background technology]

[0002] Zoom tracking control is known as a technique for reducing the fluctuation of the focus position for the same subject caused by the movement of a variable magnification lens. Patent Document 1 discloses a control device that drives a focus lens based on the correction amount by zoom tracking control and the correction amount by control for maintaining focus on a moving object. With this control device, even when a moving object is photographed while zooming, it is possible to maintain high-precision focus on the moving object while reducing focus fluctuation caused by zoom fluctuation.

[0003] By the way, there is known a time-specified focus drive, which performs focus drive by specifying the drive amount (target position) and drive time of the focus lens. This drive method makes it possible to slowly focus on a certain subject over a predetermined time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-66556 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the control device disclosed in Patent Document 1, when a zoom operation is performed during time-specified focus drive, the focus drive speed dynamically updated while performing zoom tracking control may not be realized due to actuator constraints.

[0006] Therefore, an object of the present invention is to provide a control device that can drive a focus lens to a target position in a time close to the specified arrival time while performing zoom tracking control, even if the zoom position changes during time-specified focus drive. [Means for solving the problem]

[0007] A control device as one aspect of the present invention is a control device that controls the driving of a focus lens to reduce focus fluctuations associated with movement of a variable magnification lens, and has an acquisition means for acquiring trajectory information indicating the relationship between the position of the variable magnification lens and the position of the focus lens that focuses at that position, and a control means for driving the focus lens based on the trajectory information and driving information including at least two specified pieces of information: a target position, an arrival time, and a driving speed, and when the position of the variable magnification lens changes while driving the focus lens, the control means drives the focus lens at the driving speed updated based on the driving information while driving the focus lens to reduce the focus fluctuations based on the trajectory information, and when the updated driving speed is outside a predetermined speed range, the control means limits the driving speed to a threshold value that defines the predetermined speed range, and updates the arrival time of the focus lens based on the threshold value and a remaining driving amount that is the difference between the target position and the current position of the focus lens.

[0008] Other objects and features of the present invention are illustrated in the following examples. Effect of the Invention

[0009] According to the present invention, a control device can be provided that can drive a focus lens to a target position in a time close to the specified arrival time while performing zoom tracking control, even if the zoom position changes during time-specified focus drive. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a configuration diagram of an imaging system in each embodiment. [Diagram 2] 5A and 5B are diagrams illustrating the relationship between the zoom position and the focus position in each embodiment. [Diagram 3] 5A to 5C are explanatory diagrams of a method for calculating a focal position of a focus lens in each embodiment. [Figure 4] 11A and 11B are explanatory diagrams for updating the focus drive speed and the arrival time when a zoom operation is performed during time-specified focus drive in the first embodiment. [Diagram 5] 4 is a flowchart showing a control method in the first embodiment. [Figure 6] 13A and 13B are explanatory diagrams of updates of focus drive speed and arrival time when a zoom operation is performed during time-specified focus drive in the second embodiment. [Figure 7] 13 is an explanatory diagram of switching of focus driving methods when a zoom operation is performed during time-specified focus driving in the third embodiment. FIG. [Figure 8] 13 is a flowchart showing a control method in the third embodiment. [Figure 9] 13 is an explanatory diagram of a prediction of a time-specified focus drive update in a case where a time-specified zoom drive command is received during time-specified focus drive in the fourth embodiment. FIG. [Figure 10] 13 is a flowchart showing a control method in the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0012] First, an imaging system 10 in each embodiment will be described with reference to Fig. 1. Fig. 1 is a configuration diagram of the imaging system 10. The imaging system 10 is a lens-interchangeable camera system including a lens device (interchangeable lens) 100 and a camera body (imaging device) 200 to which the lens device 100 is removably attached, and is capable of taking still images and moving images. The lens device 100 and the camera body 200 are mechanically and electrically connected via a mount (not shown), and power is supplied and mutual communication between the lens device 100 and the camera body 200 is performed through terminals provided on the mount. However, each embodiment is not limited thereto, and can also be applied to an imaging device in which the lens device and the camera body are integrally configured.

[0013] The lens device 100 has an optical system 101 capable of forming a subject image on an image sensor 201 of a camera body 200. The optical system 101 has a variable magnification lens 102, an aperture (aperture stop) 103, and a focus lens 104, and is a zoom lens with a variable focal length. The variable magnification lens 102 can be moved in a direction along an optical axis OA (optical axis direction) by operating a zoom operation unit 105 to change the focal length of the lens device 100 (variable magnification). The zoom operation unit 105 has a mechanism for manually moving the variable magnification lens 102, such as a zoom ring, or a mechanism for electrically moving the variable magnification lens 102 by an actuator. The zoom position detection unit 108 is a position sensor for detecting the position of the variable magnification lens 102. For the zoom position detection unit 108, a sensor with a simple configuration and high durability, such as a potentiometer, can be used. The zoom position detection unit 108 detects the position of the variable magnification lens 102 and outputs a detection signal to a lens control unit (control device) 106.

[0014] The aperture 103 has aperture blades (not shown), and adjusts the amount of light by moving the aperture blades via an actuator operated by an aperture driver 109. The focus lens 104 adjusts the in-focus state (focus state) by moving in the optical axis direction via an actuator operated by a focus driver 110.

[0015] The focus position detection unit 111 has a position sensor that detects the position of the focus lens 104, and outputs a signal corresponding to a state quantity such as the position or speed of the actuator to the lens control unit 106. As the position sensor, an optical encoder or the like can be used that is configured with an optical scale having a light-dark pattern and an optical sensor including a light receiving unit that receives light emitted from a light emitting unit and reflected by the optical scale. Also, speed information can be generated from position information of the actuator obtained by the position sensor.

[0016] The lens control unit 106 is a computer having a CPU (Central Processing Unit). The lens control unit 106 transmits drive signals to the aperture drive unit 109, the focus drive unit 110, and the zoom operation unit 105, and controls the drive of the aperture 103, the focus lens 104, and the variable magnification lens 102. The lens control unit 106 controls the drive of the focus lens 104 to reduce focus fluctuations caused by the movement of the variable magnification lens 102. The lens control unit 106 has an acquisition unit 106a and a control unit 106b. The acquisition unit 106a acquires trajectory information indicating the relationship between the position of the variable magnification lens 102 and the position of the focus lens 104 that is focused at that position. The control unit 106b drives the focus lens 104 based on the trajectory information and drive information including at least two pieces of designated information: a target position, a reaching time, and a drive speed.

[0017] The memory 107 is a storage means configured with a ROM (Read Only Memory) or a RAM (Random Access Memory), etc. The memory 107 stores, for example, trajectory information indicating the relationship between the zoom position and the in-focus position of the focus lens 104 that is in focus at the zoom position. The memory 107 also stores information such as the maximum and minimum speeds at which the focus lens 104 can be driven.

[0018] The camera body 200 has an image sensor 201 , a signal processing unit 202 , a recording processing unit 203 , an electronic viewfinder 204 , a display unit 205 , a defocus detection unit 206 , a camera control unit 207 , and a memory 208 .

[0019] The image sensor 201 converts light from the optical system 101 (subject image formed by the optical system 101) into an electrical signal by photoelectric conversion, and outputs the electrical signal to a signal processor 202. The image sensor 201 has pixels for imaging as well as pixels for detecting a focus position. The signal processor 202 performs various processes such as amplification of the input electrical signal, noise removal, and color correction, and outputs image data to a recording processor 203. The recording processor 203 records the input image data. The recorded image data is displayed on an electronic viewfinder 204 or a display unit 205.

[0020] The defocus detection unit 206 detects the phase difference between signals of a pair of subject images obtained by light incident on focus detection pixels of the image sensor 201 via a microlens that performs pupil division. The defocus detection unit 206 also determines the amount of defocus based on the detected phase difference, and outputs the amount of defocus to the camera control unit 207.

[0021] The camera control unit 207 is a computer having a CPU, and is electrically connected to each of the recording processing unit 203, the defocus detection unit 206, and the memory 208. The camera control unit 207 reads and executes a program recorded in the memory 208, and also communicates information necessary for autofocus control with the lens control unit 106. The camera control unit 207 also controls the camera body 200 in response to inputs from a camera operation unit such as a shooting switch and various setting switches (not shown).

[0022] The optical system 101 is an inner focus (rear focus) type zoom lens. In an inner focus type zoom lens, when the zoom position is changed (magnification is changed) in a state where the lens is focused on a certain subject distance, the position of the image plane changes and the image becomes out of focus. For this reason, the lens control unit 106 uses trajectory information stored in the memory 107 to drive and control the focus lens 104 in order to correct the change in the image plane position during the magnification change operation (zoom operation). Such drive control of the focus lens 104 is called zoom tracking control.

[0023] Next, the relationship between the zoom position and the in-focus position (focus position) of focus lens 104 that is in focus at the zoom position for each subject distance will be described with reference to Fig. 2. Fig. 2 is a diagram showing the relationship between the zoom position and the focus position. In Fig. 2, the horizontal axis indicates the zoom position, and the vertical axis indicates the focus position. The solid curves in Fig. 2 indicate the relationship between the zoom position and the focus position for ensuring focusing accuracy at each subject distance. Memory 107 stores curves corresponding to each of a number of representative subject distances.

[0024] When the subject distance coincides with the representative subject distance shown in Fig. 2, it is possible to obtain the focus position using trajectory information corresponding to the representative subject distance. On the other hand, when the subject distance is different from the representative subject distance shown in Fig. 2, it is possible to obtain the focus position by calculation (linear interpolation) using trajectory information corresponding to a representative subject distance near that subject distance. Note that in each embodiment, the memory 107 stores curves as trajectory information, but it may also store data of representative points that allow these curves to be drawn by approximation.

[0025] Next, with reference to Figs. 3(a) and (b), a method for calculating the in-focus position of the focus lens 104 when the subject distance is different from the representative subject distance will be described. Figs. 3(a) and (b) are explanatory diagrams of a method for calculating the in-focus position of the focus lens 104. In Figs. 3(a) and (b), the horizontal axis indicates the zoom position, and the vertical axis indicates the focus position. Fig. 3(a) shows the entire trajectory information, and Fig. 3(b) shows an enlarged view of a part of Fig. 3(a) (a part surrounded by a frame in Fig. 3(a)). Hereinafter, a method for calculating a focus position at a zoom position y between a wide-side (wide-angle side) zoom position x and a telephoto side (telephoto side) zoom position z at a subject distance A' between subject distances A and B will be described.

[0026] First, data on the focus position at subject distance A and the focus position at subject distance B at wide-side zoom position x is read out, and a ratio b / a of the difference a in the focus positions at subject distances A and B to the difference b in the focus positions at subject distances A and A' is calculated. Then, the focus position at subject distance A' at wide-side zoom position x is calculated using the focus positions at subject distances A and B and the ratio b / a.

[0027] Next, data on the focus position at subject distance A and subject distance B at telephoto zoom position z is read out. The ratio b' / a' of the difference a' in focus positions at subject distances A and B and the difference b' in focus positions at subject distances A and A' is the same as the ratio b / a. Then, the focus position at subject distance A' at telephoto zoom position z is calculated using the focus positions at subject distances A and B and the ratio b' / a' (=b / a).

[0028] Finally, a zoom movement amount l, which is the difference between the wide-side zoom position x and the zoom position y, and a zoom movement amount m, which is the difference between the zoom position y and the telephoto side zoom position z, are calculated. Then, the focus position at the zoom position y at the subject distance A' is calculated using the focus positions at the wide-side and telephoto side zoom positions x and z at the subject distance A' and the ratio of the movement amounts l / (l+m).

[0029] Next, the focus driving means in each embodiment will be described. The lens control unit 106 receives driving information including at least two pieces of designation information, a target focus position, a focus driving speed, and a time to reach the target focus position, through communication with the camera control unit 207, and drives the focus lens 104 based on the driving information. In each of the following embodiments, a control method will be described using time-designated focus driving, which designates a target focus position and a time to reach the target focus position, as an example, but each embodiment is not limited thereto. EXAMPLES

[0030] First, a first embodiment of the present invention will be described. This embodiment relates to a control method for updating the focus drive speed within a threshold range while performing zoom tracking control when the zoom position changes during time-specified focus drive, and dynamically updating the arrival time when the drive speed is limited by the threshold.

[0031] Fig. 4 is an explanatory diagram of updating of focus drive speed and arrival time when zoom operation is performed during time-specified focus drive in this embodiment. In Fig. 4, the horizontal axis indicates time and the vertical axis indicates focus position. Here, an example is described in which zoom operation is performed during time-specified focus drive in which the focus position is driven from position Fs to position Fe in arrival time Tf.

[0032] When a zoom operation is performed, zoom tracking drive is performed immediately. After that, a target focus position Fe' at the changed zoom position is calculated from the trajectory information stored in the memory 107, and the target position is updated. Here, a focus drive speed that reaches the focus position Fe' in the remaining drive time is calculated, and the drive speed is updated to satisfy the time specification. However, if the drive speed to be updated exceeds the maximum speed at which the actuator can be driven or falls below the minimum speed, it cannot be realized due to the constraints of the actuator. Therefore, the drive speed is updated to the maximum speed if it exceeds the maximum speed, or to the minimum speed if it falls below the minimum speed, and the arrival time Tf' is calculated from the updated drive speed and the remaining drive amount, and the arrival time is updated to the time that can be reached at the maximum speed or the minimum speed.

[0033] FIG. 5 is a flowchart showing a control method in this embodiment, illustrating the update process of the drive speed and arrival time (drive information) during time specified focus drive.

[0034] First, in step S501, the lens control unit 106 monitors a change in the zoom position using the zoom position detection unit 108, and determines whether or not a zoom operation has been performed. If a zoom operation has been performed, the process proceeds to step S502. On the other hand, if a zoom operation has not been performed, the process ends this flow without updating the drive information.

[0035] In step S502, the lens control unit 106 determines a zoom tracking correction amount using the changed zoom position detected by the zoom position detection unit 108 and the trajectory information stored in the memory 107, and performs zoom tracking drive. Then, in step S503, the lens control unit 106 updates the target focus position to a value corresponding to the changed zoom position using the trajectory information stored in the memory 107. Then, in step S504, the lens control unit 106 calculates a drive speed for reaching the target focus position in a designated arrival time. The drive speed is calculated based on the remaining drive time, which is the difference between the designated arrival time and the elapsed time, and the remaining drive amount, which is the difference between the target focus position updated in step S503 and the current focus position detected by the focus position detection unit 111.

[0036] Next, in step S505, the lens control unit 106 determines whether or not the drive speed calculated in step S504 is within a predetermined speed range. In this embodiment, the upper and lower thresholds (upper limit speed and lower limit speed) that define the predetermined speed range are set to the maximum speed and minimum speed at which the actuator can be driven, respectively. Note that in this embodiment, it is determined whether or not the drive speed is within a predetermined speed range defined by the maximum speed and the minimum speed, but a different threshold may be set. If the drive speed is within the predetermined speed range, the process proceeds to step S506. On the other hand, if the drive speed is not within the predetermined speed range, the process proceeds to step S507.

[0037] In step S506, the lens control unit 106 updates the driving speed calculated in step S504 as a new driving speed, and ends this flow.

[0038] In step S507, the lens control unit 106 updates the drive speed calculated in step S504 to a threshold value (maximum speed or minimum speed). That is, if the drive speed is equal to or lower than the minimum speed, the lens control unit 106 updates the minimum speed as a new drive speed, or if the drive speed is equal to or higher than the maximum speed, the lens control unit 106 updates the maximum speed as a new drive speed. Next, in step S508, the lens control unit 106 calculates and updates the arrival time using the remaining drive amount and the drive speed (threshold value) updated in step S507, and ends this flow. Here, the remaining drive amount corresponds to the difference between the target focus position updated in step S503 and the current focus position detected by the focus position detection unit 111.

[0039] According to this embodiment, even if the zoom position changes during time-specified focus drive, the drive speed is updated within the constraints of the actuator while performing zoom tracking control, and focus drive can be performed to the specified arrival position in a time close to the specified arrival time.

[0040] In this embodiment, the control method of this embodiment has been described using the time-specified focus drive as an example, but is not limited thereto. For example, the control method of this embodiment may be applied when a zoom operation is performed during focus drive in which the target position and drive speed are specified as drive information. In this case, the arrival time can be calculated from the information on the target position and drive speed. Therefore, as described above, by dynamically updating the drive speed and arrival time while observing the constraints of the actuator, the focus can be driven to the specified arrival position in a time close to the specified arrival time. EXAMPLES

[0041] Next, a description will be given of a second embodiment of the present invention. This embodiment relates to a method for calculating and updating the subsequent drive speed and arrival time (drive information) based on the initially specified arrival time when a further zoom operation is performed after the arrival time has been updated by the control method of the first embodiment.

[0042] Fig. 6 is an explanatory diagram of updating of focus drive speed and arrival time (drive information) when zoom operation is performed during time-specified focus drive in this embodiment. In Fig. 6, the horizontal axis indicates time, and the vertical axis indicates focus position. In this embodiment as well, an example will be described in which zoom operation is performed during time-specified focus drive in which the focus position is driven from Fs to Fe in arrival time Tf. The specified drive information is stored in memory 107.

[0043] As in the first embodiment, when zoom operation 1 is performed, if the drive speed to be updated after zoom tracking drive is equal to or higher than the maximum speed or equal to or lower than the minimum speed, the drive speed is updated to the maximum speed or minimum speed, and the arrival time is also updated to Tf'. This switches to time-specified focus drive that reaches the target position Fe' at the arrival time Tf'. After that, when further zoom operation 2 is performed, after zoom tracking drive, the target focus position Fe" at the changed zoom position is calculated from the trajectory information, and the target position is updated again.

[0044] Here, the drive speed for driving to the target focus position Fe″ is calculated using the remaining drive amount, which is the difference between the initially specified reach time Tf stored in memory 107 and the elapsed time, rather than the reach time Tf′ updated after zoom operation 1. If the recalculated drive speed is within the range between the maximum speed and the minimum speed, it is updated again as the new drive speed.

[0045] This makes it possible to realize time-specified focus drive that reaches the target focus position in the initially specified arrival time Tf. If the recalculated drive speed is out of range, the drive speed is updated again to the maximum or minimum speed, as in the first embodiment, and the arrival time is updated again accordingly. This makes it possible to drive the focus to the specified arrival position in an arrival time as close as possible to the specified arrival time while observing the constraints of the actuator.

[0046] Similarly, if a further zoom operation is performed after zoom operation 2, a new drive speed is calculated based on the initially specified arrival time Tf, so that the focus can be driven to the specified arrival position in an arrival time as close as possible to the specified arrival time.

[0047] In this embodiment, the update process of the drive speed and arrival time during time-specified focus drive is basically the same as that in the flowchart of Fig. 5. However, when calculating a new drive speed in step S504, a drive speed that will reach the target focus position in the initially specified arrival time stored in memory 107 is calculated, rather than the arrival time updated after the previous zoom operation. EXAMPLES

[0048] Next, a third embodiment of the present invention will be described. This embodiment relates to a control method for switching time-specified focus drive to intermittent drive that repeats drive and stop when the drive speed calculated to satisfy the specified time while performing zoom tracking control falls below the minimum speed of the actuator.

[0049] Fig. 7 is an explanatory diagram of switching of focus drive methods when a zoom operation is performed during time-specified focus drive in this embodiment. In Fig. 7, the horizontal axis indicates time, and the vertical axis indicates focus position. In this embodiment as well, an example will be described in which a zoom operation is performed during time-specified focus drive in which the focus position is driven from position Fs to position Fe in arrival time Tf.

[0050] When a zoom operation is performed, zoom tracking drive is performed immediately. After that, the target focus position Fe' at the changed zoom position is calculated from the trajectory information stored in the memory 107, and the target position is updated. Here, if the remaining drive amount, which is the difference between the target focus position Fe' and the current position, becomes significantly smaller due to the update of the target position, the focus drive speed that reaches Fe' in the remaining drive time falls below the minimum speed of the actuator and cannot be realized. Therefore, by performing intermittent drive that repeats drive and stop, the focus is driven to satisfy the drive speed calculated from the specified target focus position and arrival time, and drive that satisfies the specified arrival time can be realized. Here, the cycle of performing intermittent drive may or may not match the cycle of zoom tracking drive.

[0051] If the drive speed to be updated is equal to or lower than the minimum speed of the actuator, the time-specified focus drive may be switched to intermittent drive as in this embodiment, or the drive may be performed at the minimum speed as in embodiment 1 and the arrival time may be updated by switching between these under specified conditions.

[0052] FIG. 8 is a flow chart showing a control method in this embodiment, illustrating the switching of the driving method and the updating of the driving information in the above-mentioned case.

[0053] First, in step S801, the lens control unit 106 monitors a change in the zoom position using the zoom position detection unit 108, and determines whether or not a zoom operation has been performed. If a zoom operation has been performed, the process proceeds to step S802. On the other hand, if a zoom operation has not been performed, the process ends this flow without updating the drive information.

[0054] In step S802, the lens control unit 106 determines a zoom tracking correction amount using the changed zoom position detected by the zoom position detection unit 108 and the trajectory information stored in the memory 107, and performs zoom tracking drive. Then, in step S803, the lens control unit 106 updates the target focus position to a value corresponding to the changed zoom position using the trajectory information stored in the memory 107. Then, in step S804, the lens control unit 106 calculates a drive speed for reaching the target focus position in a designated arrival time. The drive speed is calculated based on the remaining drive time, which is the difference between the designated arrival time and the elapsed time, and the remaining drive amount, which is the difference between the target focus position updated in step S803 and the current focus position detected by the focus position detection unit 111.

[0055] Next, in step S805, the lens control unit 106 determines whether the drive speed calculated in step S804 is equal to or greater than the minimum speed of the actuator. If the drive speed is equal to or greater than the minimum speed, the process proceeds to step S806. On the other hand, if the drive speed is smaller than the minimum speed, the process proceeds to step S807.

[0056] In step S806, the lens control unit 106 updates the driving speed calculated in step S804 as a new driving speed, and ends this flow.

[0057] In step S807, the lens control unit 106 determines whether or not intermittent drive is enabled. If intermittent drive is enabled, the process proceeds to step S808. On the other hand, if intermittent drive is disabled, the process proceeds to step S809.

[0058] In step S808, the lens control unit 106 switches the drive method of the time specified focus drive to intermittent drive that satisfies the drive speed calculated in step S804, and ends this flow.

[0059] In step S809, the lens control unit 106 updates the drive speed with the minimum speed of the actuator. Then, in step S810, the lens control unit 106 calculates and updates the arrival time using the remaining drive amount and the drive speed updated in step S809, and ends this flow. The remaining drive amount corresponds to the difference between the target focus position updated in step S803 and the current focus position detected by the focus position detection unit 111.

[0060] According to this embodiment, when the drive speed to be updated is equal to or lower than the minimum speed of the actuator, it is possible to switch between time-specified focus drive being intermittent drive, or driving at the minimum speed to update the arrival time.

[0061] Here, an example of the predetermined condition for determining whether or not to perform intermittent drive is the shooting mode (still image mode or video mode) of the camera body 200. For example, in the still image mode, intermittent drive is performed while giving priority to focusing at an expected position at a predetermined time during time-specified focus drive. In the video mode, intermittent drive is not performed, and drive is performed at the lowest speed without intermittent drive, giving priority to moving the image plane smoothly and not causing discomfort in the image, and drive is performed to update the arrival time. In addition, the predetermined condition for determining whether or not to perform intermittent drive may be determined by an instruction from the camera body 200, a user setting, the lens attitude (lens attitude difference), or the environmental temperature.

[0062] In this embodiment, the zoom lens is operated during time-specified focus drive, but this embodiment can be applied to lens devices other than zoom lenses. In that case, for example, when a speed equal to or lower than the minimum speed of the actuator is specified as drive information, intermittent drive may be performed to satisfy the specified speed. EXAMPLES

[0063] Next, a fourth embodiment of the present invention will be described. In the control method of this embodiment, when a time-specified zoom drive command is received during time-specified focus drive, if performing the zoom drive would prevent the time-specified focus drive from being completed within the specified time, the zoom drive is not performed. Here, the time-specified zoom drive refers to electrically driving the variable magnification lens 102 by an actuator by specifying the zoom drive amount and the arrival time (drive information).

[0064] In this embodiment, the lens control unit 106 functions as a first control means and a second control means. The first control means drives the focus lens 104 based on trajectory information and drive information including at least two pieces of designation information: a target position, a time to reach the target position, and a drive speed (focus preset drive). The second control means drives the variable magnification lens 102 by designating a target position and a time to reach the target position (zoom preset drive).

[0065] Fig. 9 is an explanatory diagram of a prediction of a time-specified focus drive update when a time-specified zoom drive command is received during time-specified focus drive in this embodiment. In Fig. 9, the horizontal axis indicates time, and the vertical axis indicates focus position. This embodiment will be described taking as an example a case where a time-specified zoom drive command is received to move the variable magnification lens 102 by a predetermined drive amount in time Tz during time-specified focus drive that drives the focus position from position Fs to position Fe in arrival time Tf. Even when time-specified zoom drive is performed, zoom tracking drive is performed to drive the focus so as to suppress fluctuations in the focus position.

[0066] Here, at the stage where a time-specified zoom drive command is received, the target focus position Fe' and focus position Fz at the end of zoom drive can be calculated in advance. This can be calculated based on the drive information of the time-specified zoom drive command, the drive information of the time-specified focus drive, the trajectory information stored in the memory 107, and the current position information that can be detected by the zoom position detection unit 108 and the focus position detection unit 111. This makes it possible to calculate the drive speed for satisfying the arrival time of the time-specified focus drive with the remaining time when time-specified zoom drive is performed based on the specified drive information.

[0067] If the new focus drive speed required to satisfy the time specification is a speed that cannot be realized due to the constraints of the actuator, the focus drive cannot be completed within the specified arrival time. In this embodiment, when a time-specified zoom drive command is received that makes it impossible to satisfy the specified time for the time-specified focus drive, the zoom drive is not performed. This allows control that prioritizes the time-specified focus drive reaching the specified position within the specified time.

[0068] FIG. 10 is a flowchart showing a control method in this embodiment, and shows the process of determining whether or not to perform zoom drive when a time-specified zoom drive command is received during time-specified focus drive.

[0069] First, in step S1001, the lens control unit 106 receives a time-specified zoom drive command that specifies the zoom drive amount and zoom reach time (drive information) as drive information. Next, in step S1002, the lens control unit 106 determines whether the remaining time (remaining focus drive time), which is the difference between the reach time and the elapsed time of the time-specified focus drive, is greater than the zoom reach time. If the remaining time is greater than the zoom reach time, the process proceeds to step S1003. On the other hand, if the remaining time is less than the zoom reach time, the flow ends without performing zoom drive.

[0070] In step S1003, the lens control unit 106 calculates the focus target position at the zoom position after the time-specified zoom drive ends. The zoom target position can be calculated using the current zoom position and zoom drive amount that can be detected by the zoom position detection unit 108, and the focus target position after reaching the zoom target position is obtained using the trajectory information stored in the memory 107.

[0071] Next, in step S1004, the lens control unit 106 calculates a position (anticipated focus position) where the focus is expected to reach when the time specified zoom drive ends. This is a value obtained by adding the zoom tracking drive amount and the drive amount that is to be driven by the time specified focus drive during zoom drive to the current focus position that can be detected by the zoom position detection unit 108. Next, in step S1005, the lens control unit 106 calculates a drive speed for reaching the focus target position calculated in step S1003 in the remaining time of the time specified focus drive at the time when the time specified zoom drive ends.

[0072] Next, in step S1006, the lens control unit 106 judges whether the drive speed calculated in step S1005 falls within a range of a predetermined speed region defined by a threshold value. In this embodiment, the threshold value is set to the maximum and minimum speed at which the actuator can be driven, and whether the drive speed falls within the range defined by these two threshold values ​​is judged, but a different threshold value may be set. If the drive speed falls within the range of the predetermined speed region, the flow proceeds to step S1007. On the other hand, if the drive speed does not fall within the range of the predetermined speed region, the flow ends without performing zoom drive. In step S1007, the lens control unit 106 starts time-specified zoom drive based on the specified zoom drive amount and zoom arrival time.

[0073] According to this embodiment, a control method can be realized in which a time-specified zoom drive command that cannot satisfy the time specification for focus drive is not accepted, while simultaneously performing time-specified zoom drive when the time specification can be satisfied.

[0074] (Other Examples) The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0075] According to each embodiment, it is possible to provide a control device or the like that can drive the focus lens to the target position in a time close to the specified arrival time while performing zoom tracking control even if the zoom position changes during time-specified focus drive.

[0076] The disclosure of each embodiment includes the following configurations and methods. (Configuration 1) A control device that controls driving of a focus lens to reduce focus fluctuations caused by movement of a variable magnification lens, an acquisition means for acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a control means for driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; The control means When the position of the variable magnification lens changes during the driving of the focus lens, the focus lens is driven at the driving speed updated based on the driving information while driving the focus lens to reduce the focus fluctuation based on the trajectory information; A control device characterized in that, when the updated drive speed is outside a predetermined speed range, the drive speed is limited by a threshold value that defines the predetermined speed range, and the arrival time of the focus lens is updated based on the threshold value and a remaining drive amount, which is the difference between the target position and the current position of the focus lens. (Configuration 2) the threshold value is an upper limit speed of the predetermined speed region, The control device according to configuration 1, characterized in that, when the updated drive speed exceeds the upper limit speed, the control means updates the arrival time to a time that the focus lens can reach by driving at the maximum speed. (Configuration 3) the threshold value is a lower limit speed of the predetermined speed region, The control device according to configuration 1 or 2, characterized in that, when the updated drive speed falls below the lower limit speed, the control means updates the arrival time to a time that the focus lens can reach by driving at the lowest speed. (Configuration 4) The control device described in any one of configurations 1 to 3, characterized in that after the arrival time has been updated, if the position of the variable magnification lens changes again while the focus lens is being driven, the control means updates the drive speed and the arrival time of the focus lens again so that they match the arrival time specified based on the drive information. (Configuration 5) A control device that controls driving of a focus lens to reduce focus fluctuations caused by movement of a variable magnification lens, an acquisition means for acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a control means for driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; when the position of the variable magnification lens changes during driving of the focus lens, the control means drives the focus lens to reduce the focus fluctuation based on the trajectory information, and drives the focus lens at the drive speed updated based on the drive information; The control device is characterized in that, when the drive speed updated based on the drive information is smaller than the minimum speed at which an actuator that drives the focus lens can be driven, the control means performs intermittent drive by repeatedly driving and stopping the focus lens so that the drive speed corresponds to the updated drive speed. (Configuration 6) 6. The control device according to configuration 5, wherein the control means performs the intermittent drive in the same cycle as the drive of the focus lens for reducing focus fluctuation accompanying movement of a variable magnification lens. (Configuration 7) 6. The control device according to configuration 5, wherein the control means performs the intermittent drive at a cycle different from that of the drive of the focus lens for reducing focus fluctuation accompanying movement of a variable magnification lens. (Configuration 8) a control means for driving the focus lens based on driving information including at least two pieces of designation information of a target position, a time to reach the target position, and a driving speed of the focus lens; when the drive speed calculated from the drive information is lower than a minimum speed at which an actuator that drives the focus lens can be driven, the control unit limits the updated drive speed to the minimum speed; A control device characterized by determining, based on information about an imaging device or information about a lens device, whether to update the arrival time of the focus lens based on the minimum speed and a remaining drive amount, which is the difference between the target position and the current position of the focus lens, or to perform intermittent drive that repeatedly drives and stops the focus lens so that the speed corresponds to the updated drive speed. (Configuration 9) 9. The control device according to configuration 8, wherein the information about the imaging device includes information about a user setting or a shooting mode. (Configuration 10) 9. The control device according to configuration 8, wherein the information about the lens device includes information about a temperature or a lens attitude. (Configuration 11) A control device that controls driving of a focus lens to reduce focus fluctuations caused by movement of a variable magnification lens, an acquisition means for acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a first control means for driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; a second control means for driving the variable magnification lens by specifying a target position and a time to reach the target position; The first control means is When the second control means drives the variable magnification lens while driving the focus lens, the second control means drives the focus lens at the drive speed updated based on the drive information while controlling the drive of the focus lens to reduce the focus fluctuation based on the trajectory information; A control device which does not drive the variable magnification lens when the updated drive speed is outside a predetermined speed range. (Configuration 12) an optical system including a focus lens; 12. A lens device comprising the control device according to any one of configurations 1 to 11. (Configuration 13) An imaging element; 12. An imaging device comprising the control device according to any one of configurations 1 to 11. (Method 1) A control method for controlling driving of a focus lens in order to reduce focus fluctuation accompanying movement of a variable magnification lens, comprising: an acquisition step of acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a control step of driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; In the control step, When the position of the variable magnification lens changes during the driving of the focus lens, the focus lens is driven at the driving speed updated based on the driving information while driving the focus lens to reduce the focus fluctuation based on the trajectory information; A control method characterized by: if the updated drive speed is outside a predetermined speed range, limiting the drive speed by a threshold value that defines the predetermined speed range; and updating the arrival time of the focus lens based on the threshold value and a remaining drive amount that is the difference between the target position and the current position of the focus lens. (Method 2) A control method for controlling driving of a focus lens in order to reduce focus fluctuation accompanying movement of a variable magnification lens, comprising: an acquisition step of acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a control step of driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; In the control step, When the position of the variable magnification lens changes during the driving of the focus lens, the focus lens is driven at the driving speed updated based on the driving information while driving the focus lens to reduce the focus fluctuation based on the trajectory information; A control method characterized by performing intermittent driving of the focus lens by repeatedly driving and stopping the focus lens so that the drive speed updated based on the drive information is equal to the minimum speed at which an actuator that drives the focus lens can be driven, when the drive speed updated based on the drive information is smaller than the minimum speed at which an actuator that drives the focus lens can be driven. (Method 3) acquiring drive information including at least two pieces of designation information of a target position of a focus lens, a time to reach the target position, and a drive speed; and a control step of driving the focus lens based on the driving information, In the control step, If the drive speed calculated from the drive information is lower than a minimum speed at which an actuator that drives the focus lens can be driven, the updated drive speed is limited to the minimum speed; A control method characterized by determining whether to update the arrival time of the focus lens based on the minimum speed and a remaining drive amount, which is the difference between the target position and the current position of the focus lens, based on information about an imaging device or information about a lens device, or to perform intermittent drive that repeatedly drives and stops the focus lens so that the speed corresponds to the updated drive speed. (Method 4) A control method for controlling driving of a focus lens in order to reduce focus fluctuation accompanying movement of a variable magnification lens, comprising: an acquisition step of acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a first control step of driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed, using a first control means; a second control step of driving the variable magnification lens by specifying a target position and a time to reach the target position using a second control means; In the first control step, When the second control means drives the variable magnification lens while the first control means is driving the focus lens, the second control means drives the focus lens at the drive speed updated based on the drive information while controlling the drive of the focus lens to reduce the focus fluctuation based on the trajectory information; A control method comprising the steps of: not driving the variable magnification lens when the updated drive speed is outside a predetermined speed range. (Configuration 14) A program for causing a computer to execute the control method according to any one of Methods 1 to 4.

[0077] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0078] 102 Variable Magnification Lens 104 Focus Lens 106 Lens control unit (control device) 106a Acquisition method 106b Control means

Claims

1. A control device that controls driving of a focus lens to reduce focus fluctuations caused by movement of a variable magnification lens, an acquisition means for acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a control means for driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; The control means When the position of the variable magnification lens changes during the driving of the focus lens, the focus lens is driven at the driving speed updated based on the driving information while driving the focus lens to reduce the focus fluctuation based on the trajectory information; A control device characterized in that, when the updated drive speed is outside a predetermined speed range, the drive speed is limited by a threshold value that defines the predetermined speed range, and the arrival time of the focus lens is updated based on the threshold value and a remaining drive amount, which is the difference between the target position and the current position of the focus lens.

2. The threshold value is an upper limit speed of the predetermined speed region, 2. The control device according to claim 1, wherein, when the updated drive speed exceeds the upper limit speed, the control means updates the arrival time to a time that the focus lens can reach by driving at a maximum speed.

3. the threshold value is a lower limit speed of the predetermined speed region, 2. The control device according to claim 1, wherein the control means updates the arrival time to a time that the focus lens can reach by driving at a minimum speed when the updated drive speed falls below the lower limit speed.

4. The control device described in claim 1, characterized in that if the position of the variable magnification lens changes again while the focus lens is being driven after the arrival time has been updated, the control means updates the drive speed and the arrival time of the focus lens again so that they match the arrival time specified based on the drive information.

5. A control device that controls driving of a focus lens to reduce focus fluctuations caused by movement of a variable magnification lens, an acquisition means for acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a control means for driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; when the position of the variable magnification lens changes during driving of the focus lens, the control means drives the focus lens to reduce the focus fluctuation based on the trajectory information, and drives the focus lens at the drive speed updated based on the drive information; The control device is characterized in that, when the drive speed updated based on the drive information is smaller than the minimum speed at which an actuator that drives the focus lens can be driven, the control means performs intermittent drive by repeatedly driving and stopping the focus lens so that the drive speed corresponds to the updated drive speed.

6. 6. The control device according to claim 5, wherein the control means performs the intermittent drive in the same cycle as the drive of the focus lens for reducing focus fluctuation accompanying movement of a variable magnification lens.

7. 6. The control device according to claim 5, wherein the control means performs the intermittent drive at a cycle different from that of the drive of the focus lens for reducing focus fluctuation accompanying movement of a variable magnification lens.

8. a control means for driving the focus lens based on driving information including at least two pieces of designation information of a target position, a time to reach the target position, and a driving speed of the focus lens; when the drive speed calculated from the drive information is lower than a minimum speed at which an actuator that drives the focus lens can be driven, the control unit limits the updated drive speed to the minimum speed; A control device characterized by determining, based on information about an imaging device or information about a lens device, whether to update the arrival time of the focus lens based on the minimum speed and a remaining drive amount, which is the difference between the target position and the current position of the focus lens, or to perform intermittent drive that repeatedly drives and stops the focus lens so that the speed corresponds to the updated drive speed.

9. The control device according to claim 8 , wherein the information about the imaging device includes information about a user setting or a shooting mode.

10. The control device according to claim 8 , wherein the information about the lens device includes information about a temperature or a lens attitude.

11. A control device that controls driving of a focus lens to reduce focus fluctuations caused by movement of a variable magnification lens, an acquisition means for acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a first control means for driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; a second control means for driving the variable magnification lens by specifying a target position and a time to reach the target position; The first control means is When the second control means drives the variable magnification lens while driving the focus lens, the second control means drives the focus lens at the drive speed updated based on the drive information while controlling the drive of the focus lens to reduce the focus fluctuation based on the trajectory information; A control device which does not drive the variable magnification lens when the updated drive speed is outside a predetermined speed range.

12. an optical system including a focus lens; A lens device comprising the control device according to claim 1 .

13. An imaging element; An imaging device comprising the control device according to claim 1 .

14. A control method for controlling driving of a focus lens in order to reduce focus fluctuation accompanying movement of a variable magnification lens, comprising: an acquisition step of acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a control step of driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; In the control step, When the position of the variable magnification lens changes during the driving of the focus lens, the focus lens is driven at the driving speed updated based on the driving information while driving the focus lens to reduce the focus fluctuation based on the trajectory information; A control method characterized by: if the updated drive speed is outside a predetermined speed range, limiting the drive speed by a threshold value that defines the predetermined speed range; and updating the arrival time of the focus lens based on the threshold value and a remaining drive amount that is the difference between the target position and the current position of the focus lens.

15. A control method for controlling driving of a focus lens in order to reduce focus fluctuation accompanying movement of a variable magnification lens, comprising: an acquisition step of acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a control step of driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed; In the control step, When the position of the variable magnification lens changes during the driving of the focus lens, the focus lens is driven at the driving speed updated based on the driving information while driving the focus lens to reduce the focus fluctuation based on the trajectory information; A control method characterized by performing intermittent driving of the focus lens by repeatedly driving and stopping the focus lens so that the drive speed updated based on the drive information is equal to the minimum speed at which an actuator that drives the focus lens can be driven, when the drive speed updated based on the drive information is smaller than the minimum speed at which an actuator that drives the focus lens can be driven.

16. acquiring drive information including at least two pieces of designation information of a target position of a focus lens, a time to reach the target position, and a drive speed; and a control step of driving the focus lens based on the driving information, In the control step, If the drive speed calculated from the drive information is lower than a minimum speed at which an actuator that drives the focus lens can be driven, the updated drive speed is limited to the minimum speed; A control method characterized by determining whether to update the arrival time of the focus lens based on the minimum speed and a remaining drive amount, which is the difference between the target position and the current position of the focus lens, based on information about an imaging device or information about a lens device, or to perform intermittent drive that repeatedly drives and stops the focus lens so that the speed corresponds to the updated drive speed.

17. A control method for controlling driving of a focus lens in order to reduce focus fluctuation accompanying movement of a variable magnification lens, comprising: an acquisition step of acquiring trajectory information indicating a relationship between a position of the variable magnification lens and a position of the focus lens that is focused at the position; a first control step of driving the focus lens based on the trajectory information and drive information including at least two pieces of designation information of a target position, a time to reach the target position, and a drive speed, using a first control means; a second control step of driving the variable magnification lens by specifying a target position and a time to reach the target position using a second control means; In the first control step, When the second control means drives the variable magnification lens while the first control means is driving the focus lens, the second control means drives the focus lens at the drive speed updated based on the drive information while controlling the drive of the focus lens to reduce the focus fluctuation based on the trajectory information; A control method comprising the steps of: not driving the variable magnification lens when the updated drive speed is outside a predetermined speed region.

18. A program causing a computer to execute the control method according to any one of claims 14 to 17.

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