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 designated time even when the zoom position changes in the middle of operation to drive the focus lens to the target position in a designated time.SOLUTION: A control device (105) comprises: acquisition means (105a) for acquiring tracking information that indicates a relationship between the position of a zoom lens and the position of a focus lens that is focused at the position; and control means (105b) for driving the focus lens on the basis of drive information including information related to the designated target position of the focus lens and information related to a designated arrival time. When the position of the zoom lens changes in the middle of drive of the focus lens, the control means changes the designated target position to a target position corresponding to the position of the zoom lens after the change on the basis of the tracking information, and changes the drive speed of the focus lens so that the difference between the designated arrival time and an arrival time when the position of the zoom lens has changed is minimized.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a lens control device, a lens apparatus, an imaging apparatus, 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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-66556 A Summary of the Invention [Problem to be solved by the invention]

[0004] The control device disclosed in Patent Document 1 cannot realize an operation of gradually focusing on a certain subject while slowly zooming in on the subject over a predetermined period of time when shooting a moving image.

[0005] Therefore, an object of the present invention is to provide a control device that can drive a focus lens to a target position within a specified time while performing zoom tracking control, even if the zoom position changes during the operation of driving the focus lens to a target position within a specified time. [Means for solving the problem]

[0006] 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 driving information including information regarding a designated target position of the focus lens and information regarding a designated arrival time, and when the position of the variable magnification lens changes while driving the focus lens, the control means changes the designated target position to a target position corresponding to the position of the variable magnification lens after the change based on the trajectory information, and changes the driving speed of the focus lens so that the difference between the designated arrival time and the arrival time when the position of the variable magnification lens has changed is reduced.

[0007] Other objects and features of the present invention are illustrated in the following examples. Effect of the Invention

[0008] According to the present invention, it is possible to provide a control device that can drive a focus lens to a target position within a specified time while performing zoom tracking control, even if the zoom position changes during the operation of driving the focus lens to a target position within a specified time. [Brief description of the drawings]

[0009] [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] 6A to 6C are explanatory diagrams of driving information for time-specified focus driving in each embodiment. [Diagram 5] 11A and 11B are explanatory diagrams of trajectories caused by time-specified focus driving when the zoom position does not change in each embodiment. [Figure 6]6 is an explanatory diagram of a trajectory by time specified focus driving in the first embodiment. FIG. [Figure 7] 5 is a flowchart showing control in time specified focus drive in the first embodiment. [Figure 8] 13 is an explanatory diagram of a trajectory by time specified focus driving in the second embodiment. FIG. [Figure 9] 13 is a flowchart showing control in time specified focus drive in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0011] 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.

[0012] The lens device 100 has an optical system (zoom lens) 101 capable of forming a subject image on an image sensor 201 of a camera body 200, and a lens control unit (control device) 105 capable of communicating with a camera control unit 207 of the camera body 200. The optical system 101 has a variable magnification lens 102, an aperture (aperture stop) 103, and a focus lens 104. The variable magnification lens 102 is movable along an optical axis OA in response to a user operating a zoom operation ring (not shown). The focal length of the optical system 101 is changed (magnification is changed) by the movement of the variable magnification lens 102. The focus lens 104 moves during focusing.

[0013] The lens control unit 105 is a computer having a CPU (Central Processing Unit), and is electrically connected to each of the memory (storage means) 106, the zoom position detection unit 107, the aperture driving unit 108, and the focus driving unit 109. The lens control unit 105 controls the driving of the focus lens 104 to reduce focus fluctuations accompanying the movement of the variable magnification lens 102. The lens control unit 105 has an acquisition unit 105a and a control unit 105b. The acquisition unit 105a 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 this position. The control unit 105b drives the focus lens 104 based on drive information including information on the designated target position of the focus lens 104 and information on the designated arrival time. The control unit 105b can acquire the drive information in response to the operation of a focus position storage button (operation means) (not shown) of the lens device 100. Alternatively, the control unit 105b may acquire the drive information by communication with the camera body 200.

[0014] The memory 106 is composed of a ROM (Read Only Memory) or a RAM (Random Access Memory), and stores 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.

[0015] The zoom position detection unit 107 detects the zoom position using a zoom position sensor such as a variable resistor, and outputs data related to the detected zoom position to the lens control unit 105. The data related to the zoom position is data related to the position of the variable magnification lens 102 or the operation position of the zoom operation ring, but is not limited to these. For example, the data related to the zoom position may be data related to the focal length corresponding to the position of the variable magnification lens 102 or the operation position of the zoom operation ring.

[0016] The aperture drive unit 108 has an aperture actuator such as a stepping motor or a voice coil motor for driving the aperture 103, and an aperture sensor such as a Hall element for detecting the drive position of the aperture 103. The focus drive unit 109 has a focus actuator such as a stepping motor, an ultrasonic motor, or a voice coil motor, and a focus position sensor such as an encoder for detecting the position in the optical axis direction of the focus lens 104. The aperture actuator of the aperture drive unit 108 and the focus actuator of the focus drive unit 109 are controlled by the lens control unit 105 that receives an aperture drive command or a focus drive command from the camera control unit 207.

[0017] 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 .

[0018] 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.

[0019] The defocus detection unit 206 detects the focus state (focus state) of the subject image using the image sensor 201. The defocus detection unit 206 detects the phase difference between signals of a pair of subject images obtained from light incident on pixels for detecting the focus position of the image sensor 201 via a microlens that performs pupil division, and obtains a defocus amount corresponding to the detected phase difference. The defocus amount is output to the camera control unit 207.

[0020] 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 required for autofocus control with the lens control unit 105. The camera control unit 207 also generates a focus drive command using the defocus amount acquired from the defocus detection unit 206 and position information of the focus lens 104 acquired from the lens device 100. Note that in each embodiment, autofocus control (AF control) is performed by a phase difference detection method, but is not limited to this, and AF control may be performed by a contrast detection method.

[0021] 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 105 uses trajectory information stored in the memory 106 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.

[0022] 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 106 stores curves corresponding to each of a number of representative subject distances.

[0023] 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 106 stores curves as trajectory information, but it may also store data of representative points that allow these curves to be drawn by approximation.

[0024] 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.

[0025] 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.

[0026] 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).

[0027] 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).

[0028] <Time-specified focus drive information> Next, examples (a) to (d) of drive information specified by a time-specified focus drive command will be described with reference to Fig. 4. The time-specified focus drive command is transmitted from camera body 200 to lens device 100. Note that in each embodiment, time-specified focus drive refers to an operation of driving focus lens 104 to a target position within a specified time.

[0029] Example (a) is a case where the target position (information about the target position) and the arrival time (information about the arrival time) are given (specified) directly. Example (b) is a case where the target position and the drive speed are given, and the arrival time is calculated using this information. Example (c) is a case where the drive speed and the arrival time are given, and the target position is calculated using this information. Example (d) is a case where the target position and the image plane movement speed are given, and the arrival time is calculated using sensitivity information that indicates the relationship between the drive speed and the image plane movement speed of the focus lens 104.

[0030] In each embodiment, the information about the target position or the information about the arrival time can also be said to include information about the drive speed of focus lens 104. In this case, the information about the drive speed is information about the movement speed of focus lens 104 or information about the image plane movement speed of the subject caused by the movement of focus lens 104.

[0031] The information on the specified target position is not limited to a value indicating the physical position of focus lens 104, and may be indirect information capable of identifying the physical position of the focus lens. The target position may be specified as a value indicating the subject position at a certain zoom position (a value corresponding to a specific zoom position). For example, the target position may be specified as the subject position at the TELE end (telephoto end), and may be converted into the physical target position of focus lens 104 within lens device 100 using the current zoom position and trajectory information.

[0032] The drive information may be specified as a parameter accompanying the drive command, or may be specified in advance. For example, the focus position at the time when the focus position storage command is transmitted from the camera body 200 may be stored in the lens device 100, and the lens device 100 may be driven to the stored focus position at a predetermined speed (such as maximum speed) by a focus drive command.

[0033] Alternatively, the drive information may be specified by communication from the camera body 200, or may be specified by an operation member (operation means) attached to the lens apparatus 100. For example, the lens apparatus 100 may have operation members such as a focus position storage button and a playback button, and may store the current focus position when the focus position storage button is pressed, and drive the lens apparatus 100 to the stored focus position at a determined speed when the playback button is pressed.

[0034] <Time-specified focus drive control> Next, referring to Fig. 5, a trajectory of time-specified focus drive when the zoom position does not change will be described. Fig. 5 is a diagram showing a trajectory of time-specified focus drive when the zoom position does not change. In Fig. 5, the horizontal axis indicates the zoom position, and the vertical axis indicates the focus position. Fig. 5 shows a case where focus lens 104 is driven from position F0 to position F5 from time T0 to time T5. When times T0 to T5 are equally divided into T1, T2, T3, and T4, the positions where focus lens 104 should be at times T1, T2, T3, and T4 are positions F1, F2, F3, and F4, respectively.

[0035] In each embodiment, even if the zoom position changes during time-specified focus drive, the focus drive speed is updated (changed) so that the focus is driven to the specified position over a specified time. Two embodiments of a method for updating the focus drive speed when the zoom position changes during time-specified focus drive control are described below. EXAMPLES

[0036] First, a first embodiment of the present invention will be described. This embodiment is an example in which the drive speed is updated so as to immediately perform the correction amount by the zoom tracking control.

[0037] Fig. 6 is an explanatory diagram of the trajectory of time-specified focus drive in this embodiment, and shows a method of updating the focus drive speed during time-specified focus drive. In Fig. 6, the horizontal axis indicates the zoom position, and the vertical axis indicates the focus position. Fig. 6 shows the drive trajectory when the zoom position moves from position Z to position Z' while the focus position is driven from position F0 to F5 from time T0 to T5.

[0038] At time T0, the focus lens 104 is at position F0, and the variable magnification lens is at position Z. Assume that a time-specified focus drive command is sent from the camera body 200 to specify a target position F5 and an arrival time T5, and at the same time, the zoom position is changed. First, the zoom position at time T1 is predicted using the current zoom position and the past zoom position. Using the trajectory information, the target position F5 at the predicted zoom position and the correction drive amount required for zoom tracking control are obtained. A drive amount for the time-specified drive is obtained so that the remaining drive amount excluding the zoom tracking correction drive amount moves in the remaining time. A drive speed from time T0 to time T1 is determined using the zoom tracking correction drive amount and the drive amount for the time-specified drive of the current cycle. The focus lens 104 is driven at the determined drive speed. After time T1, the focus lens 104 is driven while updating the drive speed in the same manner.

[0039] In this way, by updating the drive speed of the focus lens 104 so as to instantly move the lens by the amount of correction due to zoom tracking, it is possible to drive the focus lens 104 to a specified position over a specified time while reducing focus fluctuations due to zoom fluctuations.

[0040] 7 is a flowchart showing the drive speed update process in this embodiment. This flow is executed at predetermined time intervals (control cycles) until the time-specified focus drive is completed. The predetermined time may be constant or may change depending on the processing state.

[0041] First, in step S701, the lens control unit 105 acquires the current zoom position detected by the zoom position detection unit 107, and stores it in the memory 106. Next, in step S702, the lens control unit 105 estimates the zoom position after a predetermined time (the zoom position of the next cycle) using the current zoom position acquired in step S701 and the past zoom positions stored in the memory 106.

[0042] Next, in step S703, the lens control unit 105 updates the final target position of the focus lens 104 in the time-specified focus drive stored in the memory 106 to a value (position) corresponding to the estimated zoom position. The final target position can be updated using the zoom position after the predetermined time estimated in step S702 and the trajectory information stored in the memory 106.

[0043] Next, in step S704, the lens control unit 105 determines the correction amount by the zoom tracking control after a predetermined time (the zoom tracking correction amount corresponding to the estimated zoom position). This correction amount is determined using the zoom position after the predetermined time estimated in step S702 and the trajectory information stored in the memory 106.

[0044] Next, in step S705, the lens control unit 105 updates the remaining time of the time-specified focus drive stored in the memory 106. Next, in step S706, the lens control unit 105 determines the drive amount for the time-specified focus drive, using the final target position updated in step S703 and the zoom tracking correction amount determined in step S704.

[0045] Next, in step S707, the lens control unit 105 determines the drive speed of the focus lens 104. The drive speed can be determined using the zoom tracking correction amount determined in step S704, the drive amount for the time-specified focus drive determined in step S706, and the remaining time updated in step S705.

[0046] As described above, in this embodiment, when the position of the variable magnification lens 102 changes while the focus lens 104 is being driven, the lens control unit 105 (control means 105b) changes the designated target position to a target position corresponding to the position of the variable magnification lens 102 after the change, based on the trajectory information. Then, the lens control unit 105 changes the drive speed of the focus lens 104 so as to reduce the difference between the designated arrival time and the arrival time when the position of the variable magnification lens 102 has changed. Preferably, the lens control unit 105 changes the drive speed so that the designated arrival time matches the arrival time when the position of the variable magnification lens has changed.

[0047] Preferably, when the position of the variable magnification lens 102 changes while driving the focus lens 104, the lens control unit 105 drives the lens 102 by a drive amount necessary to reduce focus fluctuation based on the trajectory information, and changes the drive speed so as to drive the remaining drive amount excluding the drive amount in the remaining time. More specifically, it is as follows. That is, the drive amount for zoom tracking correction for the zoom position of the next period is set as the first drive amount. Also, the drive amount required in the current period to move the remaining drive amount to the final target position at the zoom position of the next period excluding the first drive amount in the remaining time is set as the second drive amount. At this time, the focus lens 104 is driven by the total drive amount of the first drive amount and the second drive amount. That is, the focus fluctuation from the current period to the next period is predicted, and the correction amount is driven in the current period. EXAMPLES

[0048] Next, a description will be given of a second embodiment of the present invention. This embodiment is an example in which the drive speed is updated so that the total drive amount, including the correction amount by the zoom tracking control, is moved in the remaining time.

[0049] Fig. 8 is an explanatory diagram of a trajectory by time-specified focus drive in this embodiment, and shows a method of updating the focus drive speed during time-specified focus drive. In Fig. 8, the horizontal axis indicates the zoom position, and the vertical axis indicates the focus position. Fig. 8, like Fig. 6, shows a drive trajectory when the zoom position moves from position Z to position Z' while the focus position is driven from position F0 to position F5 from time T0 to time T5.

[0050] At time T0, the focus lens 104 is at position F0, and the variable magnification lens 102 is at position Z. Assume that a time-specified focus drive command is sent from the camera body 200 to specify a target position F5 and an arrival time T5, and at the same time, the zoom position is changed. First, the zoom position at time T1 is predicted using the current zoom position and the past zoom position. Using trajectory information, the position F5 at the predicted zoom position is obtained. The drive speed (focus drive speed) from time T0 to time T1 is determined so as to move the remaining drive amount to the updated position F5 in the remaining time. The focus lens 104 is driven at the determined drive speed. The drive speed is determined similarly after time T1. In this embodiment, the total remaining drive amount including the correction amount of the zoom tracking control is divided by the remaining time, so that the calculation load is smaller than that of the first embodiment.

[0051] 9 is a flowchart showing the drive speed update process in this embodiment. This flow is executed at predetermined time intervals (control cycles) until the time-specified focus drive is completed. The predetermined time may be constant or may change depending on the processing state.

[0052] First, in step S901, the lens control unit 105 acquires the current zoom position detected by the zoom position detection unit 107, and stores it in the memory 106. Next, in step S902, the lens control unit 105 estimates the zoom position after a predetermined time (the zoom position of the next cycle) using the current zoom position acquired in step S901 and the past zoom positions stored in the memory 106.

[0053] Next, in step S903, the lens control unit 105 updates the final target position of the focus lens 104 in the time-specified focus drive stored in the memory 106 to a value (position) corresponding to the estimated zoom position. The final target position can be updated using the zoom position after the predetermined time estimated in step S902 and the trajectory information stored in the memory 106.

[0054] Next, in step S904, the lens control unit 105 updates the remaining time of the time specified focus drive stored in the memory 106. Next, in step S905, the lens control unit 105 determines the drive speed of the focus lens 104, using the final target position updated in step S903 and the remaining time updated in step S904.

[0055] As described above, in this embodiment, when the position of the variable magnification lens 102 changes while the focus lens 104 is being driven, the lens control unit 105 (control means 105b) changes the designated target position to a target position corresponding to the position of the variable magnification lens 102 after the change, based on the trajectory information. Then, the lens control unit 105 changes the drive speed of the focus lens 104 so as to reduce the difference between the designated arrival time and the arrival time when the position of the variable magnification lens 102 has changed. Preferably, the lens control unit 105 changes the drive speed so that the designated arrival time matches the arrival time when the position of the variable magnification lens has changed.

[0056] Preferably, when the position of the variable magnification lens 102 changes while driving the focus lens 104, the lens control unit 105 changes the drive speed so as to drive the remaining drive amount, including the drive amount necessary to reduce focus fluctuation based on the trajectory information, in the remaining time. In other words, the drive speed in the current cycle is determined so as to move the entire remaining drive amount (including the first drive amount for zoom tracking correction for the zoom position in the next cycle) to the final target position corresponding to the position of the variable magnification lens 102 in the next cycle in the remaining time.

[0057] (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.

[0058] According to each embodiment, it is possible to provide a control device or the like that can drive a focus lens to a target position within a specified time while performing zoom tracking control, even if the zoom position changes during the operation of driving the focus lens to a target position within a specified time.

[0059] 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 unit that drives the focus lens based on drive information including information on a designated target position of the focus lens and information on a designated arrival time; The control means when the position of the variable magnification lens changes during driving of the focus lens, the specified target position is changed to a target position corresponding to the position of the variable magnification lens after the change based on the trajectory information; A control device which changes a drive speed of the focus lens so as to reduce a difference between the designated arrival time and an arrival time when the position of the variable magnification lens is changed. (Configuration 2) 2. The control device according to configuration 1, wherein the control means changes the drive speed so that the designated arrival time coincides with the arrival time when the position of the variable magnification lens has changed. (Configuration 3) The control device according to configuration 1 or 2, characterized in that, when the position of the variable magnification lens changes while the focus lens is being driven, the control means drives the focus lens by a drive amount necessary to reduce the focus fluctuation based on the trajectory information, and changes the drive speed so as to drive the remaining drive amount excluding the drive amount in the remaining time. (Configuration 4) The control device according to configuration 1 or 2, characterized in that, when the position of the variable magnification lens changes while the focus lens is being driven, the control means changes the drive speed so as to drive the remaining drive amount, including the drive amount necessary to reduce the focus fluctuation based on the trajectory information, in the remaining time. (Configuration 5) 5. The control device according to any one of configurations 1 to 4, wherein the information about the target position is a value corresponding to a specific zoom position. (Configuration 6) the information on the target position or the information on the arrival time includes information on a drive speed of the focus lens, 5. The control device according to any one of configurations 1 to 4, wherein the information on the drive speed is information on a moving speed of the focus lens, or information on a moving speed of an image plane of a subject caused by the movement of the focus lens. (Configuration 7) an optical system including a variable magnification lens and a focus lens; A lens device comprising the control device according to any one of configurations 1 to 6. (Configuration 8) Further comprising an operating means, 8. The lens device according to configuration 7, wherein the control means obtains the drive information in response to operation of the operation means. (Configuration 9) An imaging element; An imaging device comprising the control device according to any one of configurations 1 to 6. (Configuration 10) 10. The imaging device according to configuration 9, wherein the control means acquires the driving information through communication with the imaging device. (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 drive information including information on a designated target position of the focus lens and information on a designated arrival time, In the control step, when the position of the variable magnification lens changes during driving of the focus lens, the specified target position is changed to a target position corresponding to the position of the variable magnification lens after the change based on the trajectory information; A control method comprising: changing a drive speed of the focus lens so as to reduce a difference between the designated arrival time and an arrival time when the position of the variable magnification lens is changed. (Configuration 11) A program for causing a computer to execute the control method according to method 1.

[0060] 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]

[0061] 102 Variable Magnification Lens 104 Focus Lens 105 Lens control unit (control device) 105a Acquisition method 105b 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 unit that drives the focus lens based on drive information including information on a designated target position of the focus lens and information on a designated arrival time; The control means when the position of the variable magnification lens changes during driving of the focus lens, the specified target position is changed to a target position corresponding to the position of the variable magnification lens after the change based on the trajectory information; A control device which changes a drive speed of the focus lens so as to reduce a difference between the designated arrival time and an arrival time when the position of the variable magnification lens is changed.

2. 2. The control device according to claim 1, wherein the control means changes the drive speed so that the designated arrival time coincides with the arrival time when the position of the variable magnification lens has changed.

3. The control device according to claim 1, characterized in that, when the position of the variable magnification lens changes while the focus lens is being driven, the control means changes the drive speed so as to drive the focus lens by the drive amount necessary to reduce the focus fluctuation based on the trajectory information, and drive the remaining drive amount excluding the drive amount in the remaining time.

4. The control device according to claim 1, characterized in that, when the position of the variable magnification lens changes while the focus lens is being driven, the control means changes the drive speed so as to drive the remaining drive amount, including the drive amount required to reduce the focus fluctuation based on the trajectory information, in the remaining time.

5. The control device of claim 1 , wherein the information regarding the target position is a value corresponding to a particular zoom position.

6. the information on the target position or the information on the arrival time includes information on a drive speed of the focus lens, 2. The control device according to claim 1, wherein the information on the drive speed is information on a moving speed of the focus lens, or information on a moving speed of an image plane of a subject caused by the movement of the focus lens.

7. an optical system including a variable magnification lens and a focus lens; A lens device comprising the control device according to claim 1 .

8. Further comprising an operating means, 8. The lens device according to claim 7, wherein the control means obtains the drive information in response to an operation of the operation means.

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

10. 10. The imaging device according to claim 9, wherein the control means acquires the driving information through communication with the imaging device.

11. 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 drive information including information on a designated target position of the focus lens and information on a designated arrival time, In the control step, when the position of the variable magnification lens changes during driving of the focus lens, the specified target position is changed to a target position corresponding to the position of the variable magnification lens after the change based on the trajectory information; A control method comprising: changing a drive speed of the focus lens so as to reduce a difference between the designated arrival time and an arrival time when the position of the variable magnification lens has changed.

12. A program causing a computer to execute the control method according to claim 11.

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