Lens apparatus, control method, and imaging system

Abstract

The lens device includes: a zoom lens; a focusing lens; a detection unit that directly detects the position of the zoom lens; and a control unit that maintains a parameter for performing drive control of the focus lens when an amount of movement of the zoom lens based on a detection result of the detection unit is less than a predetermined threshold value, and switches the parameter when the amount of movement of the zoom lens is equal to or greater than the threshold value, and performing drive control of the focus lens based on the held or switched parameter.

Description

TECHNICAL FIELD

[0001] The present technology relates to a lens apparatus, a control method, and an imaging system, and particularly relates to a driving control technology of a focus lens. BACKGROUND

[0002] In a lens apparatus provided with a zoom lens and a focus lens, when the zoom lens moves in the optical axis direction, the focus is lost even if the focus lens does not move. Therefore, in the lens apparatus, in order to change the magnification of an image while maintaining the focus (in-focus) position, zoom tracking in which the focus lens is caused to move in accordance with the movement of the zoom lens is performed (for example, Patent Literature 1).

[0003] LIST OF CITATIONS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2018-124498 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] Further, in the technology described in Patent Literature 1, zoom tracking in which the responsiveness to the target is high is performed based on the movement of the zoom lens. Therefore, even if the zoom lens moves slightly due to mechanical blur caused by a change in the posture of the lens apparatus attributable to the user moving the lens apparatus or the like, zoom tracking in which the responsiveness is high is performed.

[0008] Then, when zoom tracking in which the responsiveness is high is performed, sound or vibration can occur. Therefore, when zoom tracking in which the responsiveness is high is performed due to the user’s unintentional slight movement of the zoom lens, the user feels uncomfortable.

[0009] The present technology was completed in view of the above circumstances, and an object thereof is to perform appropriate zoom tracking in accordance with the movement of the zoom lens.

[0010] SOLUTION TO PROBLEM

[0011] A lens apparatus according to the present technology includes a zoom lens, a focus lens, a detection unit that directly measures the position of the zoom lens, and a control unit that maintains a parameter in a case where the amount of movement of the zoom lens based on the measurement result of the detection unit is less than a predetermined threshold value, switches the parameter in a case where the amount of movement of the zoom lens is equal to or greater than the threshold value, and performs driving control of the focus lens based on the parameter maintained or switched.

[0012] With this arrangement, the lens apparatus can perform zoom tracking without switching parameters when the zoom lens moves a little due to shake or the like, and can perform zoom tracking by switching parameters when the zoom lens moves to some extent due to operation of the zoom ring or the like. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a diagram illustrating a configuration of an imaging system according to the present technology.

[0014] Figure 2 is a block diagram illustrating an internal configuration of an imaging system.

[0015] Figure 3 is a diagram for describing a configuration of a zoom lens position detection unit that detects a zoom lens position.

[0016] Figure 4 is a diagram for describing a subject position, a subject distance, a focus position, a focus distance, a focus lens position, a zoom lens position, and a focal length.

[0017] Figure 5 is a diagram for describing a cam curve.

[0018] Figure 6 is a diagram for describing a stabilization priority mode and a follow-up priority mode.

[0019] Figure 7 is a flowchart illustrating a flow of zoom tracking processing during AF processing.

[0020] Figure 8 is a diagram for describing mode switching when switching the mode according to movement of the zoom lens as a comparative example.

[0021] Figure 9 is a diagram for describing mode switching when switching the mode according to whether or not the amount of movement of the zoom lens is equal to or greater than a threshold value.

[0022] Figure 10 is a diagram for describing mode switching when switching the mode according to whether or not the amount of movement of the zoom lens is equal to or greater than a threshold value.

[0023] Figure 11 is a diagram for describing mode switching when switching the mode according to whether or not the amount of movement of the zoom lens is equal to or greater than a threshold value. DETAILED DESCRIPTION

[0024] Hereinafter, the embodiments will be described in the following order.

[0025] <1. Configuration of imaging system>

[0026] <2. Focus-related processing>

[0027] <3. Modified forms>

[0028] <4. Overview of Embodiments>

[0029] <5. The present technology>

[0030] <1. Configuration of imaging system>

[0031] Figure 1 is a diagram illustrating a configuration of an imaging system 1 according to the present technology.

[0032] The imaging system 1 is configured as a digital camera device in which an interchangeable lens 3 is detachably attached to an imaging device (body) 2. The imaging system 1 has not only a function of capturing still images but also a function of capturing moving images.

[0033] As Figure 1 illustrated, the imaging system 1 includes an imaging element 55 that captures an object image incident via the interchangeable lens 3, a display unit 61 capable of displaying a GUI such as a captured image obtained by the imaging element 55 and various operation screens, an operation unit 65 for a user to perform various operation inputs, and the like.

[0034] In addition, the imaging system 1 includes a configuration for recording a captured image obtained by the imaging element 55, a configuration for performing image signal processing on a captured image obtained by the imaging element 55, a configuration for performing communication with the interchangeable lens 3, and the like.

[0035] The interchangeable lens 3 is a lens unit in which various lenses such as Figure 2 a zoom lens 13 and a focus lens 16 as illustrated are provided.

[0036] Further, the interchangeable lens 3 includes a drive unit that drives these lenses, a control unit that outputs a drive signal to the drive unit, a mounting portion having a connection function and a communication function with respect to the imaging device 2, and the like.

[0037] Figure 2 is a block diagram illustrating an internal configuration of the imaging system 1.

[0038] As Figure 2 illustrated, the interchangeable lens 3 includes a mounting portion 11 that is detachably attached to a mounting portion 51 of the imaging device 2. The mounting portion 11 has a plurality of terminals for electrical connection with the imaging device 2.

[0039] Further, the interchangeable lens 3 includes a lens-side control unit 12, a zoom lens 13, a camera shake correction lens 14, an aperture 15, a focus lens 16, and a detection unit 17.

[0040] The interchangeable lens 3 further includes a zoom ring 21, a camera shake control unit 22, an aperture control unit 23, a focus lens drive unit 24, an operation unit 31, a memory 32, and a power supply control unit 33.

[0041] The lens side control unit 12 includes, for example, a microcomputer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like, and performs overall control of the interchangeable lens 3 by the CPU reading a program stored in a predetermined storage device such as the ROM or the memory 32 into the RAM and executing the program.

[0042] The lens side control unit 12 performs various kinds of control according to an instruction from the imaging device (main body) 3 supplied via a predetermined communication terminal of the mounting portion 11 or a user operation received by the zoom ring 21 and the operation unit 31.

[0043] For example, the lens side control unit 12 controls the camera shake correction lens 14 to correct camera shake. Specifically, based on an amount of camera shake detected by the camera shake detection sensor in the detection unit 17, the lens side control unit 12 determines a drive condition (a drive direction, a drive amount, a drive speed, and the like) of the camera shake correction lens 14 in a direction to eliminate the amount of camera shake, and outputs the determined drive condition to the camera shake control unit 22 together with a movement command.

[0044] The camera shake detection sensor in the detection unit 17 includes, for example, two or one of a gyro sensor and a three-axis acceleration sensor. The gyro sensor is used to detect a deviation (shake) in a direction corresponding to a pitch or a yaw as a correction direction of the camera shake correction lens 14. The three-axis acceleration sensor is used to detect a deviation (shake) between an X-axis direction and a Y-axis direction when an optical axis direction is defined as a Z-axis.

[0045] The camera shake control unit 22 moves the camera shake correction lens 14 based on the movement command supplied from the lens side control unit 12 so as to achieve the indicated drive condition.

[0046] Further, in a case where the power supply is turned off, the lens side control unit 12 performs control to mechanically lock the camera shake correction lens 14. In a state where the power is supplied from the imaging device 2 to the interchangeable lens 3, the position of the camera shake correction lens 14 is held at a predetermined position by control via the camera shake control unit 22. On the other hand, if the power supply is turned off, the camera shake control unit 22 stops the position control so that the camera shake correction lens 14 drops by a predetermined amount in the direction of gravity.

[0047] Accordingly, the lens-side control unit 12 mechanically locks the camera shake correction lens 14 via the camera shake control unit 22 according to the timing of the power supply turn-off, thereby preventing the camera shake correction lens 14 from descending. The camera shake control unit 22 mechanically locks the camera shake correction lens 14 based on the fixed command supplied from the lens-side control unit 12.

[0048] Further, the lens-side control unit 12 controls the aperture 15 (aperture diameter) according to the instruction or the like from the imaging device 2 supplied via the predetermined communication terminal of the mounting portion 11. Specifically, the lens-side control unit 12 acquires the aperture diameter of the aperture 15 detected by the aperture detection sensor in the detection unit 17, issues a command to the aperture control unit 23 so as to achieve the aperture value (F value) instructed by the imaging device 2, and drives the aperture 15. The aperture control unit 23 drives the aperture 15 so as to achieve the aperture diameter instructed from the lens-side control unit 12.

[0049] Further, the lens-side control unit 12 controls the position of the focus lens 16 based on the instruction from the imaging device 2 supplied via the predetermined communication terminal of the mounting portion 11, the current position of the focus lens 16 from the detection unit 17, or the like. Specifically, the lens-side control unit 12 acquires the current position of the focus lens 16 from the detection unit 17, determines a drive condition for moving the focus lens 16 to a predetermined position based on the acquisition result, and outputs the determined drive condition to the focus lens drive unit 24 together with a movement command. The focus lens drive unit 24 moves the focus lens 16 in the optical axis direction so as to achieve the instructed drive condition.

[0050] Here, the focus lens 16 is configured as a "focus lens group" including one or a plurality of optical elements. In the case where the focus lens group includes a plurality of optical elements, the optical elements are integrally displaced according to focus adjustment.

[0051] Note that this similarly applies to the zoom lens 13. In other words, the zoom lens 13 is configured as a "zoom lens group" including one or a plurality of optical elements, and in the case where the zoom lens group includes a plurality of optical elements, the optical elements are integrally displaced according to zoom adjustment.

[0052] In this example, the zoom lens 13 and the focus lens 16 are configured as one zoom lens group and one focus lens group, respectively. However, the zoom lens 13 and the focus lens 16 can be configured as a plurality of zoom lens groups and a plurality of focus lens groups, respectively.

[0053] In addition, the lens-side control unit 12 performs a process of transmitting the position of the zoom lens 13 (hereinafter, referred to as "zoom lens position") and the position of the focus lens 16 (hereinafter, referred to as "focus lens position") detected by the detection unit 17 to the imaging device 2 (body-side control unit 52).

[0054] The detection unit 17 generally represents a configuration for detecting a state of the interchangeable lens 3 such as a position of the zoom lens 13, the camera shake correction lens 14, and the focus lens 16, and an aperture of the aperture 15. In the detection unit 17, the position of the lens can be detected by, for example, a magnetic sensor, a photodiode array, a potentiometer, a reflective encoder, or the like.

[0055] Figure 3 is a view for describing a configuration of the zoom lens position detection unit 44 that detects a position of the zoom lens. Note that, in Figure 3 , a portion necessary to describe a configuration of the zoom lens position detection unit 44 among components constituting the interchangeable lens 3 is extracted and illustrated. Further, the zoom lens position detection unit 44 is one of the detection units 17.

[0056] As illustrated in A in Figure 3 , the zoom lens 13 is fixed to the compression ring 41 inside the interchangeable lens 3. The cam pin 42 is connected to the compression ring 41 so as to project toward the outer peripheral surface. For example, three cam pins 42 are attached at equal intervals in the circumferential direction of the compression ring 41, and are inserted into the cam groove 43a formed in the cam ring 43.

[0057] Further, the cam ring 43 is rotatably housed in the interchangeable lens 3, and the zoom ring 21 (see Figure 1 ) for manually setting a zoom magnification is arranged rotatably along the outer peripheral surface.

[0058] The zoom lens 13 is held by the cam ring 43 via the compression ring 41 and the cam pin 42. When the user rotates the zoom ring 21, the cam ring 43 provided inside the interchangeable lens 3 rotates. When the cam ring 43 rotates, the zoom lens 13 moves in the optical axis direction.

[0059] The zoom lens position detection unit 44 is a reflective absolute linear optical encoder, and includes an encoder module 44a having a light emission unit and a light reception unit, and a pattern seal 44b on which a pattern illustrated in B in Figure 3 is formed.

[0060] The encoder module 44a is fixed at a predetermined position of the interchangeable lens 3. The pattern seal 44b is attached to the outer peripheral surface of the compression ring 41 at a position facing the encoder module 44a.

[0061] As illustrated in B in Figure 3 , the pattern seal 44b is attached to the compression ring 41 so that Figure 3 the left-right direction in B is along the optical axis direction of the zoom lens 13. In the pattern seal 44b, in a direction orthogonal to the optical axis direction (the up-down direction in B), a plurality of patterns are arranged at equal intervals in the circumferential direction. Figure 3The scale pattern formed in B in FIG. 6 is formed in the vertical direction (the direction of the optical axis) in B in FIG. 6.

[0062] In Figure 3 The scale pattern 45 formed on the upper side in B in FIG. 6 is a pattern for detecting the absolute position of the zoom lens 13, and is formed in the optical axis direction with patterns having different widths and intervals.

[0063] In Figure 3 The scale pattern 46 formed on the lower side in B in FIG. 6 is a pattern for detecting the relative position of the zoom lens 13, and is formed in the optical axis direction with patterns having the same width at equal intervals.

[0064] The encoder module 44a optically reads the pattern of the pattern seal 44b by irradiating the pattern seal 44b with light from the light emitting unit, and receiving the light returned after the emitted light is reflected by the pattern seal 44b by the light receiving unit. Then, the encoder module 44a detects the position (absolute value and relative position) of the zoom lens 13 based on the read pattern.

[0065] Here, in the interchangeable lens 3, for example, it is assumed that the position of the zoom lens 13 is indirectly detected by detecting the position of the cam ring 43 connected via the cam pin 42. In this case, it can become difficult to accurately detect the position of the zoom lens 13 due to the play between the cam pin 42 and the cam groove 43a, or the like.

[0066] Therefore, in the interchangeable lens 3, the position of the zoom lens 13 can be directly detected by using the zoom lens position detection section 44. Here, direct detection means directly detecting the position of the zoom lens 13 without other connecting mechanisms (for example, the cam pin 42 and the cam ring 43).

[0067] With this arrangement, even in a structure in which play or the like occurs between the cam pin 42 and the cam groove 43a, in the interchangeable lens 3, the position of the zoom lens 13 can be accurately detected by the zoom lens position detection section 44.

[0068] Returning to Figure 2 The focus lens drive unit 24 can include, for example, an ultrasonic motor, a DC motor, a linear actuator, a stepping motor, a piezo element (piezoelectric element), or the like as a drive source of the lens.

[0069] The operation unit 31 corresponds to a focus ring or the like for manually setting the focus lens 16, receives a manual operation by the user, and supplies an operation signal corresponding to the received operation to the lens side control unit 12. Further, the zoom ring 21 is also one of the operation units 31.

[0070] The memory 32 is constituted by, for example, a nonvolatile memory such as an electrically erasable programmable (EEP) ROM, and can be used to store an operation program of the lens-side control unit 12 and various kinds of data.

[0071] Data of the cam curve is stored in the memory 32, which will be described later.

[0072] The power supply control unit 33 detects a power amount of a power supply supplied from the imaging device 2, optimally allocates the power amount to the respective units (the lens-side control unit 12 and various kinds of drive units) in the interchangeable lens 3 based on the detected power amount, and supplies the power.

[0073] The imaging device 2 on the main body side is provided with a mounting portion 51 to which the interchangeable lens 3 is detachably attached. The mounting portion 51 has a plurality of terminals for electrically connecting with the mounting portion 11 of the interchangeable lens 3.

[0074] If the interchangeable lens 3 is mounted on the mounting portion 51 of the imaging device 2, the corresponding terminals are electrically and physically connected between the mounting portion 51 and the mounting portion 11 of the interchangeable lens 3. Examples of the terminals to be connected include a terminal for supplying power (power supply terminal), a terminal for transmitting an instruction or data (communication terminal), a terminal for transmitting a synchronization signal (synchronization signal terminal), and the like.

[0075] The imaging device 2 further includes a main body-side control unit 52, a shutter 53, a shutter control unit 54, an imaging element 55, an analog-digital converter (ADC) 56, a frame memory 57, an image signal processing unit 58, a recording unit 59, a recording medium 60, a display unit 61, a memory 62, a power supply control unit 63, a power supply unit 64, an operation unit 65, and a communication unit 66.

[0076] The main body-side control unit 52 includes a microcomputer (including a CPU), a ROM, a RAM, and the like, and performs overall control of the imaging device 2 and the interchangeable lens 3 by the CPU reading a program stored in a predetermined storage device such as a ROM or the memory 62 into the RAM and executing the program.

[0077] The memory 62 is constituted by, for example, a nonvolatile memory such as an EEPROM, and can be used to store an operation program of the main body-side control unit 52 and various kinds of data.

[0078] The main body-side control unit 52 causes the imaging element 55 to perform an imaging process based on an operation signal representing an operation of a user supplied from the operation unit 65. Further, the main body-side control unit 52 transmits a predetermined command to the interchangeable lens 3 via the mounting portion 51 to drive the focus lens 16 and the like.

[0079] Further, the body side control unit 52 can acquire information indicating, for example, a zoom lens position and a focus lens position from the interchangeable lens 3.

[0080] A shutter 53 is arranged on a front surface (object side) of the imaging element 55 and is opened and closed under the control of a shutter control unit 54. When the shutter 53 is in a closed state, light of an object passing through the optical system of the interchangeable lens 3 is blocked. The shutter control unit 54 detects the opening / closing state of the shutter 53 and supplies information indicating the detection result to the body side control unit 52. The shutter control unit 54 drives the shutter 53 to the open state or the closed state based on the control of the body side control unit 52.

[0081] The imaging element 55 is configured as an image sensor including, for example, a charge-coupled device (CCD) sensor, a complementary metal-oxide semiconductor (CMOS) sensor, or the like, and outputs a received light signal obtained by imaging an object.

[0082] In a case where the imaging element 55 includes a CCD sensor or a CMOS sensor, an electronic shutter can be used, and thus the shutter 53 can be omitted. In a case where the shutter 53 is omitted, the shutter control unit 54 for control is also omitted.

[0083] The imaging element 55 includes pixels (RGB pixels) for capturing an image and pixels for acquiring detection information by a phase difference method, that is, phase difference detection pixels for acquiring phase difference information between a pair of images (phase difference information between a pair of images formed by pupil division).

[0084] In the imaging element 55, the phase difference detection pixels are discretely arranged on a pixel array surface in which the RGB pixels are two-dimensionally arranged in a predetermined array pattern such as a Bayer array.

[0085] A received light signal obtained by photoelectric conversion of the RGB pixels in the imaging element 55 is converted into a digital signal by the ADC 56, temporarily held in the frame memory 57, and then input to the image signal processing unit 58.

[0086] In the Figure 2 In the

[0087] Meanwhile, a received light signal obtained by photoelectric conversion of the phase difference detection pixels in the imaging element 55 is converted into a digital signal by the ADC 56 and supplied to the body side control unit 52.

[0088] In the Figure 2In the present embodiment, a signal obtained by digitally converting the received light signal of the phase difference detection pixel is referred to as a "phase difference pixel signal Sp".

[0089] The body side control unit 52 analyzes the phase difference between the pair of images on the basis of the phase difference pixel signal Sp supplied via the ADC 56, and calculates the focus offset amount, that is, the defocus amount DF, with respect to a subject to be focused (a focus target object).

[0090] The body side control unit 52 performs focus-related processing on the basis of the defocus amount DF calculated in this way, which will be described later.

[0091] The image signal processing unit 58 applies predetermined image signal processing to the captured image input via the frame memory 57. Here, examples of the image signal processing include demosaicing processing, white balance (WB) adjustment, gamma correction processing, and the like.

[0092] The image signal processing unit 58 applies image signal processing to the captured image input via the frame memory 57 as a raw image, and then converts the captured image into image data in a predetermined file format, and records the image data in the recording medium 60 via the recording unit 59.

[0093] Further, the image signal processing unit 58 converts the captured image to which the image signal processing has been applied into an image signal in accordance with a predetermined display format, supplies the image signal to the display unit 61, and displays the captured image.

[0094] The recording medium 60 includes a nonvolatile memory, and the recording unit 59 is configured to be able to write data to the recording medium 60 and read data recorded in the recording medium 60. Here, the recording medium 60 can be detachably attached to the imaging device 2.

[0095] The display unit 61 includes a panel-type display device such as a liquid crystal panel or an organic EL panel, and can display an image.

[0096] The display unit 61 is mounted on a rear surface of the imaging device 2 opposite to a front surface on which the mounting portion 51 is arranged, and can perform display of a so-called through image, display of an image read from the recording medium 60, display of a GUI as various operation screens, and the like.

[0097] The power supply control unit 63 supplies power supplied from the power supply unit 64 to each unit of the imaging device 2 including the body side control unit 52. Further, the power supply control unit 63 calculates the amount of power that can be supplied to the power supply of the interchangeable lens 3 on the basis of the operation state of the imaging device 2, and supplies power to the interchangeable lens 3 via the mounting portion 51.

[0098] For example, the power supply unit 64 includes a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery. Note that the power supply unit 64 can also be configured to be able to receive a power supply from a commercial AC power source via an AC adapter or the like.

[0099] The operation unit 65 comprehensively represents an operator for allowing a user to perform an operation input to the imaging device 2, such as various hardware keys such as a shutter button, a mode dial, and a zoom button, and a touch panel configured to be able to detect a touch operation on a display screen of the display unit 61.

[0100] The operation unit 65 accepts an operation of a user, and supplies an operation signal according to the operation to the main body side control unit 52.

[0101] For example, the communication unit 66 performs wireless or wired communication with an external device.

[0102] Here, in the following description, focus-related processing including AF processing and zoom tracking processing will be described, but in this specification, “subject position”, “subject distance”, “focus position (focusing position)”, “focusing distance”, “focus lens position”, and “zoom lens position” are used as terms related to focus-related processing.

[0103] Reference will now be made to Figure 4 the definitions of these terms will be described. Figure 4 is a diagram for describing a subject position, a subject distance, a focus position, a focusing distance, a focus lens position, and a zoom lens position.

[0104] As Figure 4 illustrated, the “subject position” literally indicates a position where a subject exists, and the “subject distance” indicates a distance from the imaging system 1 to the subject. Note that the “subject distance” strictly corresponds to a distance from a focal point of the interchangeable lens 3 to the “subject position”.

[0105] The “focus position” indicates a position that is focused on, and can be rewritten as a “focusing position”. The “focusing distance” means a distance from the imaging system 1 to the focus position.

[0106] Here, as understood with reference to Figure 4 , the subject distance and the focusing distance are distances to a position outside the interchangeable lens 3, and are values represented by actual distances such as 2 m, 3 m, 4 m,... for example.

[0107] As Figure 4The "focus lens position" means the position of the focus lens 16 within the movable range of the focus lens 16 in the interchangeable lens 3, and the "zoom lens position" similarly means the position of the zoom lens 13 within the movable range of the zoom lens 13 in the interchangeable lens 3, as illustrated.

[0108] Here, the defocus amount DF obtained by the image plane phase difference method indicates the amount of shift between the "subject position" and the "focus position" when the "subject position" is the position of the object to be focused. Figure 4 The "subject position" is the position of the object to be focused, and the "focus position" is the position of the focus lens 16 in the interchangeable lens 3. The defocus amount DF is the amount of shift between the "subject position" and the "focus position" when the "subject position" is the position of the object to be focused.

[0109] Note that, in the following description, information directly indicating the position of the zoom lens 13 will be given as an example of the "zoom lens position". However, the "zoom lens position" is not necessarily limited to information directly indicating the position of the zoom lens 13, and information related to the position of the zoom lens 13 and capable of being uniquely converted into information about the position of the zoom lens 13 can also be used as the "zoom lens position".

[0110] Furthermore, using information directly indicating the distance to the subject as an example of the "subject distance" will be described. However, the "subject distance" is not necessarily limited to information directly indicating the distance to the subject distance, and information related to the distance to the subject distance and capable of being uniquely converted into information about the distance to the subject can also be used as the "subject distance".

[0111] Here, a cam curve used in the focus-related processing will be described.

[0112] Figure 5 is a diagram for describing a cam curve. The cam curve is data indicating the correspondence relationship of the zoom lens position with respect to a plurality of focus distances and the focus lens position, and is stored in the memory 32 of the interchangeable lens 3.

[0113] In the imaging system 1, for example, when the imaging device 2 is powered on in a state where the interchangeable lens 3 is attached to the imaging device 2, the data of the cam curve stored in the memory 32 is transmitted to the imaging device 2 and stored in the memory 62. With this arrangement, both the imaging device 2 and the interchangeable lens 3 can hold the same cam curve. Note that it is sufficient that both the imaging device 2 and the interchangeable lens 3 hold the same cam curve, and this same cam curve is pre-stored in the memory 32 and the memory 62.

[0114] In the imaging system 1, for example, when the imaging device 2 is powered on in a state where the interchangeable lens 3 is attached to the imaging device 2, the data of the cam curve stored in the memory 32 is transmitted to the imaging device 2 and stored in the memory 62. With this arrangement, both the imaging device 2 and the interchangeable lens 3 can hold the same cam curve. Note that it is sufficient that both the imaging device 2 and the interchangeable lens 3 hold the same cam curve, and this same cam curve is pre-stored in the memory 32 and the memory 62. Figure 5In the illustrated graph, the horizontal axis represents the zoom lens position (Wide side to Tele side), and the vertical axis represents the focus lens position (imaging element side to object side), and the zoom lens position and the focus lens position corresponding to a plurality of focus distances (1 m, 3 m, 5 m, 7 m, inf) are illustrated.

[0115] For example, in a case where the focus distance is 7 m and the zoom lens position is Zml, the focus lens position for focusing on an object is Fcl.

[0116] Further, even if the focus distance is the same as 7 m, in a case where the zoom lens position is changed and the zoom lens position is set to Zm2, the focus lens position for focusing on an object is changed to Fc2.

[0117] Further, even if the zoom lens position is Zml without change, in a case where the object distance is changed from 7 m to 10 m, the focus lens position for focusing on an object is changed from Fcl to Fc3.

[0118] In this way, information about the zoom lens position and the focus distance is given by the cam curve, whereby information about the focus lens position corresponding to a combination of the zoom lens position and the focus distance can be acquired. Further, by being provided with information about the zoom lens position and the focus lens position, information about the focus distance corresponding to a combination of the zoom lens position and the focus lens position can also be acquired.

[0119] <2. Focus-related processing>

[0120] Next, focus-related processing that performs drive control of the focus lens 16 will be described. In the present embodiment, AF processing and zoom tracking processing are provided as the focus-related processing. However, the focus-related processing can include processing other than the AF processing and the zoom tracking processing.

[0121] The AF processing is processing of moving the focus lens 16 in the optical axis direction in order to focus on an arbitrary object automatically, and is performed, for example, when a shutter button is half-pressed, which is so-called. With this arrangement, even if a predetermined object moves, the object can be focused on at all times while the shutter button is half-pressed.

[0122] The zoom tracking processing is processing of moving the focus lens 16 in the optical axis direction in order to achieve a change in magnification of an image while maintaining a state of focus in accordance with a movement of the zoom lens 13.

[0123] Here, the imaging system 1 is provided with a plurality of modes for performing drive control of the focus lens 16 when performing the focus-related processing (the AF processing and the zoom tracking processing).

[0124] In the imaging system 1, one of a plurality of modes is set, and drive control of the focus lens 16 is performed based on a parameter defined in the set mode. Note that the parameter indicates a value and a condition necessary to determine a drive condition (drive direction, drive amount, drive speed, etc.) of the focus lens 16 in order to perform the drive control of the focus lens 16.

[0125] In the present embodiment, a stabilization priority mode and a follow-up priority mode are provided as the plurality of modes.

[0126] Figure 6 is a diagram for describing the stabilization priority mode and the follow-up priority mode. In Figure 6 , the target focus position in the stabilization priority mode is indicated by a thick solid line, and the moving locus of the focus lens 16 during control in the stabilization priority mode is indicated by a thick dashed line. Further, in Figure 6 , the target focus position in the follow-up priority mode is indicated by a thin solid line, and the moving locus of the focus lens 16 during control in the follow-up priority mode is indicated by a thin dashed line.

[0127] The stabilization priority mode is a mode in which the focus lens 16 moves toward a target focus lens position (hereinafter, target focus lens position) irrespective of the control period of the lens-side control unit 12. In other words, the stabilization priority mode is a mode in which the focus lens 16 only needs to reach the target focus lens position.

[0128] Therefore, as Figure 6 illustrated, in the stabilization priority mode, the delay request during drive is low, and the moving locus of the focus lens 16 is somewhat separated from the target focus position, while the maximum speed to be set is high. However, in the stabilization priority mode, overshoot is highly required.

[0129] The stabilization priority mode is mainly set during the AF processing.

[0130] The follow-up priority mode is a mode in which the lens-side control unit 12 specifies the target focus lens position for each control period, and moves the focus lens 16 to the specified target focus lens position within the control period. In other words, the follow-up priority mode is a mode in which the focus lens 16 is caused to follow the target focus lens position specified for each control period as needed. Therefore, as Figure 6 illustrated, in the follow-up priority mode, the delay request during drive is high, and the focus lens 16 is caused to follow the target focus lens position with almost no delay, while the maximum speed to be set is low.

[0131] The follow-up priority mode is mainly set during the zoom tracking processing. Note that, as will be described in detail later, in the zoom tracking processing, the stabilization priority mode can be set under certain conditions.

[0132] [2.1. AF processing in stabilization priority mode]

[0133] Next, AF processing in the stabilization priority mode when the zoom lens 13 is not moved will be described.

[0134] In the AF processing, drive control of the focus lens 16 is performed in accordance with the parameters of the stabilization priority mode.

[0135] Specifically, the lens side control unit 12 transmits information on the zoom lens position and the focus lens position detected by the detection unit 17 to the imaging device 2 as needed. After acquiring the information on the zoom lens position and the focus lens position, the body side control unit 52 calculates the focus distance with reference to the cam curve based on the zoom lens position and the focus lens position. For example, in the example of Figure 5 , if the zoom lens position is Zml and the focus lens position is Fcl, the body side control unit 52 calculates that the focus distance is 7 m.

[0136] Further, the body side control unit 52 analyzes the phase difference between a pair of images based on the phase difference pixel signal Sp supplied at predetermined intervals via the ADC 56 to calculate the defocus amount DF.

[0137] Then, the body side control unit 52 adds the calculated focus distance to the defocus amount DF to calculate the distance to the in-focus target object (subject distance) as the target focus distance.

[0138] After calculating the target focus distance, the body side control unit 52 transmits information indicating the target focus distance to the imaging device 2. The lens side control unit 12 receives the information indicating the target focus distance transmitted from the imaging device 2.

[0139] Further, the lens side control unit 12 acquires the current zoom lens position and the current focus lens position detected by the detection unit 17.

[0140] Then, the lens side control unit 12 refers to the cam curve based on the current zoom lens position and the target focus distance received from the interchangeable lens 3, and calculates the target focus lens position for focusing on the in-focus target object. For example, in the example of Figure 5 , if the zoom lens position is Zml and the target focus distance is 3 m, the lens side control unit 12 calculates that the target focus position is Fc3.

[0141] Subsequently, the lens side control unit 12 determines a drive condition for moving the focus lens 16 to the target focus lens position based on the current focus lens position and the target focus lens position. Then, the lens side control unit 12 outputs the determined drive condition to the focus lens drive unit 24 together with the movement command.

[0142] With this arrangement, in the interchangeable lens 3, the focus lens 16 is driven so that the focus lens position coincides with the target focus lens position, and autofocus is achieved.

[0143] Note that, in the above description, the process of obtaining the target focus distance from the defocus amount DF is performed on the imaging device 2 side, and the process of obtaining the target focus lens position from the target focus distance is performed on the interchangeable lens 3 side. However, the processes can be performed by the imaging device 2 or the interchangeable lens 3. For example, the process of obtaining the target focus lens position from the defocus amount DF can be performed only by one of the imaging device 2 and the interchangeable lens 3.

[0144] [2.2. Zoom tracking process in follow-up priority mode]

[0145] Next, the zoom tracking process in the follow-up priority mode will be described.

[0146] In the zoom tracking process, the drive control of the focus lens 16 is mainly performed in accordance with the parameters of the above-described follow-up priority mode.

[0147] Specifically, the lens side control unit 12 transmits information on the zoom lens position and the focus lens position detected by the detection unit 17 to the imaging device 2 as needed. After acquiring the information on the zoom lens position and the focus lens position, the body side control unit 52 calculates the focus distance with reference to the cam curve based on the zoom lens position and the focus lens position. For example, in the example of FIG. 8, if the zoom lens position is Zml and the focus lens position is Fcl, the body side control unit 52 calculates that the focus distance is 7 m. Figure 5

[0148] Further, the body side control unit 52 analyzes the phase difference between a pair of images based on the phase difference pixel signal Sp supplied at predetermined intervals via the ADC 56 to calculate the defocus amount DF.

[0149] Then, the body side control unit 52 adds the calculated focus distance to the defocus amount DF to calculate the distance to the in-focus subject (subject distance) as the target focus distance.

[0150] ​After the target focus distance is calculated, the body-side control unit 52 calculates a target position of the moving focus lens 16 for each control period of the lens-side control unit 12. As the target position, a position that minimizes the amount of delay during driving of the focus lens 16 (e.g., 0.5 depth or less) is calculated.

[0151] The body-side control unit 52 transmits information indicating the target position to the imaging device 2. The lens-side control unit 12 receives the information indicating the target position transmitted from the imaging device 2.

[0152] Further, the lens-side control unit 12 acquires the current zoom lens position and the current focus lens position detected by the detection unit 17 for each control period.

[0153] Then, the lens-side control unit 12 calculates a target focus lens position for focusing on the target position with reference to the cam curve based on the current zoom lens position and the target position received from the interchangeable lens 3 for each control period.

[0154] Subsequently, the lens-side control unit 12 determines a driving condition for moving the focus lens 16 to the target focus lens position based on the current focus lens position and the target focus lens position for each control period. Then, the lens-side control unit 12 outputs the determined driving condition to the focus lens driving unit 24 together with a moving command.

[0155] With this arrangement, in the interchangeable lens 3, the focus lens 16 is driven as needed to coincide the focus lens position with the target focus lens position for each control period, and zoom tracking is achieved.

[0156] Here, as described above, the zoom lens 13 is held by the cam ring 43 via the compression ring 41 and the cam pin 42, and a gap is formed between the cam pin 42 and the cam groove 43a.

[0157] Therefore, when the user moves the imaging system 1 in, for example, the upward direction or the downward direction and the posture of the imaging system 1 changes, the zoom lens 13 can move a small amount due to jitters or the like attributable to the gap between the cam pin 42 and the cam groove 43a.

[0158] Then, for example, when the zoom lens 13 moves a small amount due to a change in the posture of the imaging system 1 during AF processing, if the mode is switched from the stabilization priority mode to the follow-up priority mode, the mode is frequently switched, and the responsiveness of the zoom lens 13 changes due to a difference in driving control in different modes, a sound or a vibration is generated, and an uncomfortable feeling can be given to the user.

[0159] Therefore, in the zoom tracking processing performed during the AF processing (stability priority mode) in the present embodiment, the mode is switched based on the amount of movement of the zoom lens 13.

[0160] [2.3. Zoom tracking processing during AF processing]

[0161] Figure 7 is a flowchart illustrating a flow of the zoom tracking processing during the AF processing.

[0162] As described above, when the AF processing starts, the stability priority mode is set as the mode, and the drive control of the focus lens 16 is performed based on the parameters of the stability priority mode.

[0163] Then, when the zoom tracking processing during the AF processing starts, as Figure 7 illustrated, in step S1, the lens-side control unit 12 acquires the current zoom lens position detected by the zoom lens position detection unit 44. Then, the lens-side control unit 12 compares the acquired current zoom lens position with the previously acquired zoom lens position to determine whether or not the zoom lens 13 is moved.

[0164] Here, since it is simply determined whether or not the zoom lens 13 is moved, the determination is made without distinguishing between the movement of the zoom lens 13 based on the operation of the zoom ring 21 and the movement of the zoom lens 13 due to the change in posture.

[0165] Then, in a case where the zoom lens 13 is not moved (NO in step S1), in step S2, the lens-side control unit 12 stores the zoom lens position as the zoom lens base position. Further, in step S3, the lens-side control unit 12 sets the stability priority mode. That is, the parameters of the stability priority mode are maintained.

[0166] On the other hand, in a case where the zoom lens 13 is moved (YES in step S1), in step S4, the lens-side control unit 12 calculates the absolute value of the difference between the current zoom lens position detected by the zoom lens position detection unit 44 and the zoom lens base position as the amount of movement of the zoom lens 13.

[0167] In step S5, the lens-side control unit 12 determines whether or not the amount of movement of the zoom lens 13 is equal to or greater than a predetermined threshold value.

[0168] Here, the threshold value is set to the maximum value of the amount of movement of the zoom lens 13 due to the mechanical tolerance of each unit of the zoom lens 13. Therefore, when the zoom lens 13 is moved due to the change in posture of the imaging system 1, the amount of movement of the zoom lens 13 does not become equal to or greater than the threshold value.

[0169] Therefore, it can be said that whether the movement of the zoom lens 13 is determined in step S5 based on the operation of the zoom ring 21 or the movement of the zoom lens 13 is due to the posture change.

[0170] If the amount of movement of the zoom lens 13 is smaller than the threshold value (NO in step S5), that is, if the movement of the zoom lens 13 is due to the posture change, the lens-side control unit 12 skips step S6, and maintains the current mode (the stabilization priority mode).

[0171] On the other hand, in a case where the amount of movement of the zoom lens 13 is equal to or larger than the threshold value (YES in step S5), that is, in a case where the movement of the zoom lens 13 is based on the operation of the zoom ring 21, in step S6, the lens-side control unit 12 switches from the stabilization priority mode to the follow-up priority mode. That is, the parameter is switched to the parameter of the follow-up priority mode. Further, the lens-side control unit 12 notifies the imaging device 2 of the fact that the mode has been switched.

[0172] In step S7, the lens-side control unit 12 performs zoom tracking of the drive control for the zoom lens 13 based on the parameter of the set mode (the stabilization priority mode or the follow-up priority mode).

[0173] Therefore, when the stabilization priority mode is set, even if the zoom lens 13 moves a small amount, a process similar to the AF process in the stabilization priority mode is performed. Further, when the mode is switched to the follow-up priority mode, a process similar to the zoom tracking process in the follow-up priority mode is performed.

[0174] As can be seen from this flowchart, the amount of movement of the zoom lens 13 is the amount of change from the position where the zoom lens 13 is stopped (the zoom lens base position). Therefore, even if the zoom ring 21 is rotated slowly, it is possible to prevent the amount of movement of the zoom lens 13 from remaining below the threshold value.

[0175] Further, when the amount of movement of the zoom lens 13 exceeds the threshold value even once, the follow-up priority mode is maintained until the zoom lens 13 is stopped (until NO in step S1). With this arrangement, it is possible to maintain the follow-up priority mode even when the rotation speed of the zoom ring 21 changes.

[0176] Figure 8 is a diagram for describing the mode switching when the mode is switched according to the movement of the zoom lens 13, which is a comparative example. Figure 9 to Figure 11 is a diagram for describing the mode switching when the mode is switched according to whether the amount of movement of the zoom lens 13 is equal to or larger than the threshold value.

[0177] Note that, Figure 8 A in FIG. 1, Figure 9 A in FIG. 2, Figure 10 A in FIG. 3, andFigure 11 A in the diagram illustrates the movement of the zoom lens 13. Figure 8 B in Figure 9 B in Figure 10 B and Figure 11 B in the diagram illustrates the mode switching based on the movement of the zoom lens 13.

[0178] In this embodiment, the mode is switched depending on whether the amount of movement of the zoom lens 13 is equal to or greater than a threshold. However, the mode switching in the case where the mode is switched while the zoom lens 13 is moving will be described as a comparative example.

[0179] In the case of switching modes when the zoom lens 13 moves even slightly, if the zoom lens 13 moves slightly due to a change in the posture of the imaging system 1 (e.g.) Figure 8 As shown in Figure A), the mode frequently switches from stable priority mode to follower priority mode (e.g., Figure 8 (As illustrated in Figure B). Then, if the mode switches frequently, different drive controls are executed, resulting in sound or vibration.

[0180] Therefore, in this embodiment, since the mode can remain unchanged until the amount of movement of the zoom lens 13 becomes equal to or greater than the threshold, even if the zoom lens 13 moves slightly due to a change in the posture of the imaging system 1 (e.g., ...), Figure 9 As shown in Figure A), the mode does not switch (e.g., Figure 9 (As shown in Figure B). This arrangement can reduce the generation of sound or vibration.

[0181] On the other hand, such as Figure 10 and Figure 11 As illustrated, when the zoom lens 13 is moved by the operation of the zoom ring 21, the mode switches to follow-priority mode, and highly responsive zoom tracking can be performed with a small offset relative to the movement of the zoom lens 13.

[0182] In particular, since the mode switches when the amount of movement from the stopped state of zoom lens 13 becomes equal to or greater than a threshold, it avoids the situation where the mode does not switch even when zoom ring 21 is operated slowly. Figure 11 As shown in the diagram.

[0183] <3. Modified Format>

[0184] It should be noted that the embodiments are not limited to the specific examples described above, and may have configurations as various modifications.

[0185] For example, in the above embodiment, the mode is switched in a case where the movement amount of the zoom lens 13 is equal to or greater than the threshold value during the zoom tracking processing in the AF processing. However, the mode can be switched in a case where the movement amount of the zoom lens 13 is equal to or greater than the threshold value in the zoom tracking processing that is not in the AF processing. For example, in all cases where the zoom tracking processing is performed, the mode can be switched similarly to the zoom tracking processing during the AF processing described above.

[0186] Further, in the above embodiment, the threshold value is set to a maximum value of the movement amount of the zoom lens 13 based on a mechanical tolerance of holding each unit of the zoom lens 13. That is, the mode is not switched due to the movement of the zoom lens 13 attributed to the posture change, but is switched due to the movement of the zoom lens 13 based on the operation of the zoom ring 21.

[0187] However, the threshold value is not limited to this. For example, the threshold value can be set so that the mode is not switched when the movement amount of the zoom lens 13 based on the operation of the zoom ring 21 is small.

[0188] Further, in the above embodiment, the reflection type absolute linear optical encoder is used as the zoom lens position detection unit 44 that directly measures the position of the zoom lens 13. However, the zoom lens position detection unit 44 can be another sensor as long as the position of the zoom lens 13 can be directly measured.

[0189] <4. SUMMARY OF THE EMBODIMENTS>

[0190] As described above, the lens apparatus (interchangeable lens 3) of the present embodiment includes a zoom lens 13, a focus lens 16, a detection unit (zoom lens position detection unit 44) that directly detects the position of the zoom lens 13, and a control unit (lens side control unit 12) that, in a case where the movement amount of the zoom lens 13 based on the detection result of the detection unit is less than a predetermined threshold value, maintains a parameter of performing drive control of the focus lens 16, switches the parameter in a case where the movement amount of the zoom lens 13 is equal to or greater than the threshold value, and performs the drive control of the focus lens 16 based on the maintained or switched parameter.

[0191] With this arrangement, the interchangeable lens 3 can perform zoom tracking while maintaining the parameter of the AF processing, for example, and can not switch the parameter when the zoom lens 13 is slightly moved due to the posture change or the like, and can perform zoom tracking by switching the parameter when the zoom lens 13 is moved to some extent due to the operation of the zoom ring 21 or the like.

[0192] Accordingly, in the interchangeable lens 3, since the parameter is not switched when the zoom lens 13 moves a little due to a change in posture or the like, generation of sound or vibration can be reduced, and the user is not given an uncomfortable feeling. Further, the interchangeable lens 3 can perform appropriate zoom tracking in accordance with the movement of the zoom lens 13.

[0193] A plurality of modes (a stabilization priority mode and a follow priority mode) defining parameters are provided, the mode is maintained in a case where the movement amount of the zoom lens 13 is less than a threshold value, and the mode is switched in a case where the movement amount of the zoom lens 13 is equal to or greater than a predetermined threshold value.

[0194] With this arrangement, in the interchangeable lens 3, the optimum mode is set in accordance with the movement amount of the zoom lens 13, and driving control of the zoom lens 13 can be performed with the parameter in accordance with the set mode.

[0195] A first mode (a stabilization priority mode) indicating a target position (a target focus position) that does not depend on a control cycle and a second mode (a follow priority mode) indicating a target position (a target focus position) for each control cycle are provided, the first mode is maintained in a case where the movement amount of the zoom lens 13 is less than a threshold value, and the mode is switched to the second mode in a case where the movement amount of the zoom lens 13 is equal to or greater than a predetermined threshold value.

[0196] With this arrangement, when the zoom lens 13 moves a little due to a change in posture or the like, the interchangeable lens 3 performs zoom tracking with the parameter of the stabilization priority mode without switching the mode. Further, when the zoom lens 13 moves to some extent due to the operation of the zoom ring 21 or the like, the interchangeable lens 3 can switch the mode, and perform zoom tracking with the parameter of the follow priority mode. Accordingly, when the zoom lens 13 moves to some extent due to the operation of the zoom ring 21 or the like, the interchangeable lens 3 can achieve highly accurate zoom tracking with less delay of the focus lens 16.

[0197] The movement amount is a change amount with respect to a position at which the zoom lens 13 is stopped.

[0198] With this arrangement, even when the zoom lens 13 moves extremely slowly, if the movement amount (change amount) of the zoom lens 13 is equal to or greater than the threshold value, the interchangeable lens 3 can perform zoom tracking by switching the parameter. That is, the interchangeable lens 3 can detect the zoom operation regardless of the speed of the operation of the zoom ring 21.

[0199] The parameter after the switching is maintained until the zoom lens 13 is stopped after the movement amount of the zoom lens 13 becomes equal to or greater than the threshold value.

[0200] With this arrangement, in the interchangeable lens 3, the parameter is maintained as long as the movement amount of the zoom lens 13 does not stop after the movement amount of the zoom lens 13 once becomes equal to or greater than the threshold value, and thus, the parameter is maintained even if the zoom speed changes during the zoom operation, and highly accurate zoom tracking can be continued with less delay of the focusing lens 16.

[0201] The control unit (lens side control unit 12) switches the parameter in a case where the movement amount of the zoom lens 13 during autofocus for focusing on a predetermined subject is equal to or greater than a predetermined threshold value.

[0202] With this arrangement, in a case where the movement amount of the zoom lens 13 is smaller than a predetermined value, zoom tracking can be performed using the parameter during autofocus, and an uncomfortable feeling such as sound or vibration given to the user can be reduced.

[0203] The first mode is set during autofocus for focusing on a predetermined subject, and the second mode is set in a case where the movement amount of the zoom lens 13 during autofocus is equal to or greater than a predetermined threshold value.

[0204] With this arrangement, the interchangeable lens 3 can perform zoom tracking using the parameter of the stabilization priority mode without switching the parameter when the zoom lens 13 is slightly moved due to a change in posture or the like, and can perform zoom tracking using the parameter of the follow-up priority mode by switching the mode when the zoom lens 13 is moved to some extent due to operation of the zoom ring 21 or the like. Thus, the interchangeable lens 3 can reduce an uncomfortable feeling given to the user, and can achieve highly accurate zoom tracking with less delay of the focusing lens 16.

[0205] The detection unit (zoom lens position detection unit 44) can detect the absolute position and the relative position of the zoom lens 13.

[0206] With this arrangement, the interchangeable lens 3 can accurately detect the position of the zoom lens 13.

[0207] The threshold value is set to a maximum value of the movement amount of the zoom lens 13 that occurs based on mechanical tolerances of the units (the pressure ring 41, the cam pin 42, and the cam ring 43) that hold the zoom lens 13.

[0208] With this arrangement, it is possible to make the movement amount of the zoom lens 13 due to a change in posture of the imaging system 1 smaller than the threshold value, and it is possible to prevent the parameter (mode) from being switched.

[0209] Further, the method for controlling the lens apparatus includes, in a case where the amount of movement of the zoom lens 13 based on the detection result of the detection unit that directly detects the position of the zoom lens 13 is less than a predetermined threshold value, maintaining a parameter for performing drive control of the focus lens 16 and switching the parameter in a case where the amount of movement of the zoom lens 13 is equal to or greater than the threshold value, and performing the drive control of the focus lens 16 based on the maintained or switched parameter.

[0210] Further, the imaging system 1 is an imaging system 1 including a lens apparatus (interchangeable lens 3) and an imaging apparatus 2, wherein the lens apparatus includes a zoom lens 13, a focus lens 16, a detection unit that directly detects the position of the zoom lens 13, and a control unit that maintains a parameter for performing drive control of the focus lens 16 in a case where the amount of movement of the zoom lens 13 based on the detection result of the detection unit is less than a predetermined threshold value, switches the parameter in a case where the amount of movement of the zoom lens 13 is equal to or greater than the threshold value, and performs the drive control of the focus lens 16 based on the maintained or switched parameter, and the imaging apparatus includes an imaging element that captures an object image incident via the lens apparatus.

[0211] Note that the effects described in this specification are merely illustrative and not limiting, and other effects can be provided.

[0212] <5. The present technology>

[0213] Note that the present technology can also adopt the following configurations.

[0214] (1) A lens apparatus including:

[0215] a zoom lens;

[0216] a focus lens;

[0217] a detection unit that directly detects the position of the zoom lens; and

[0218] a control unit that, in a case where the amount of movement of the zoom lens based on the detection result of the detection unit is less than a predetermined threshold value, maintains a parameter for performing drive control of the focus lens, switches the parameter in a case where the amount of movement of the zoom lens is equal to or greater than the threshold value, and performs the drive control of the focus lens based on the maintained or switched parameter.

[0219] (2) The lens apparatus according to (1), wherein,

[0220] a plurality of modes that define the parameter are provided,

[0221] the mode is maintained in a case where the amount of movement of the zoom lens is less than the threshold value, and the mode is switched in a case where the amount of movement of the zoom lens is equal to or greater than the threshold value.

[0222] (3) The lens apparatus according to (2), wherein

[0223] a first mode indicating a target position not depending on a control cycle and a second mode indicating a target position for each control cycle are provided,

[0224] the first mode is maintained in a case where the movement amount of the zoom lens is less than a threshold value, and the mode is switched to the second mode in a case where the movement amount of the zoom lens is equal to or greater than the threshold value.

[0225] (4) The lens apparatus according to any one of (1) to (3), wherein

[0226] the movement amount is a change amount with respect to a position at which the zoom lens is stopped.

[0227] (5) The lens apparatus according to any one of (1) to (4), wherein

[0228] the control unit maintains the parameter after the switching until the zoom lens is stopped after the movement amount of the zoom lens becomes equal to or greater than the threshold value.

[0229] (6) The lens apparatus according to any one of (1) to (5), wherein

[0230] the control unit switches the parameter in a case where the movement amount of the zoom lens is equal to or greater than the threshold value during autofocus for focusing on a predetermined subject.

[0231] (7) The lens apparatus according to (3), wherein

[0232] the first mode is set during autofocus for focusing on a predetermined subject, and the second mode is set in a case where the movement amount of the zoom lens is equal to or greater than the threshold value during the autofocus.

[0233] (8) The lens apparatus according to any one of (1) to (7), wherein

[0234] the detection unit is capable of detecting an absolute position and a relative position of the zoom lens.

[0235] (9) The lens apparatus according to any one of (1) to (8), wherein

[0236] the threshold value is set to a maximum value of the movement amount of the zoom lens generated based on mechanical tolerances of units that hold the zoom lens.

[0237] (10) A control method comprising:

[0238] In a case where the movement amount of the zoom lens based on the detection result of the detection unit of the position of the zoom lens is smaller than a predetermined threshold, a parameter for performing the drive control of the focus lens is maintained;

[0239] the parameter is switched in a case where the movement amount of the zoom lens is equal to or larger than the threshold, and

[0240] the drive control of the focus lens is performed based on the maintained or switched parameter.

[0241] (11) An imaging system including a lens device and an imaging device, wherein

[0242] the lens device includes:

[0243] a zoom lens,

[0244] a focus lens,

[0245] a detection unit that directly detects a position of the zoom lens, and

[0246] a control unit that, in a case where a movement amount of the zoom lens based on a detection result of the detection unit is smaller than a predetermined threshold, maintains a parameter for performing the drive control of the focus lens, in a case where the movement amount of the zoom lens is equal to or larger than the threshold, switches the parameter, and performs the drive control of the focus lens based on the maintained or switched parameter, and

[0247] the imaging device includes:

[0248] an imaging element that captures an object image incident via the lens device.

[0249] List of Reference Signs

[0250] 1 Imaging system

[0251] 2 Imaging device

[0252] 3 Interchangeable lens

[0253] 12 Lens-side control unit

[0254] 13 Zoom lens

[0255] 16 Focus lens

[0256] 24 Focus lens drive unit

[0257] 55 Imaging element

Claims

1. A lens apparatus comprising: a zoom lens; a focus lens; a detection unit that directly detects a position of the zoom lens; and a control unit that, in a case where an amount of movement of the zoom lens based on a detection result of the detection unit is smaller than a predetermined threshold value, holds a parameter used to perform drive control of the focus lens, switches the parameter in a case where the amount of movement of the zoom lens is equal to or larger than the threshold value, and performs the drive control of the focus lens based on the held or switched parameter.

2. The lens apparatus according to claim 1, wherein a plurality of modes that define the parameter are provided, the modes are held in a case where the amount of movement of the zoom lens is smaller than the threshold value, and the modes are switched in a case where the amount of movement of the zoom lens is equal to or larger than the threshold value.

3. The lens apparatus according to claim 2, wherein a first mode that indicates a target position that does not depend on a control period and a second mode that indicates a target position for each control period are provided, the first mode is held in a case where the amount of movement of the zoom lens is smaller than the threshold value, and the mode is switched to the second mode in a case where the amount of movement of the zoom lens is equal to or larger than the threshold value.

4. The lens apparatus according to claim 1, wherein the amount of movement is an amount of change with respect to a position at which the zoom lens is stopped.

5. The lens apparatus according to claim 1, wherein the control unit holds the parameter after the switching until the zoom lens is stopped after the amount of movement of the zoom lens becomes equal to or larger than the threshold value.

6. The lens apparatus according to claim 1, wherein the control unit switches the parameter in a case where the amount of movement of the zoom lens is equal to or larger than the threshold value during autofocus for focus on a predetermined subject.

7. The lens apparatus according to claim 3, wherein the first mode is set during autofocus for focus on a predetermined subject, and the second mode is set in a case where the amount of movement of the zoom lens is equal to or larger than the threshold value during the autofocus.

8. The lens apparatus according to claim 1, wherein the detection unit is capable of detecting an absolute position and a relative position of the zoom lens.

9. The lens apparatus according to claim 1, wherein the threshold value is set to a maximum value of the amount of movement of the zoom lens that is generated based on mechanical tolerances of units that hold the zoom lens.

10. A control method comprising: in a case where an amount of movement of a zoom lens based on a detection result of a detection unit that directly detects a position of the zoom lens is smaller than a predetermined threshold value, holding a parameter used to perform drive control of a focus lens; in a case where the amount of movement of the zoom lens is equal to or larger than the threshold value, switching the parameter; and performing the drive control of the focus lens based on the held or switched parameter.

11. An imaging system comprising a lens apparatus and an imaging apparatus, wherein the lens apparatus comprises: ​ ​ A zoom lens, A focus lens, A detection unit that directly detects a position of the zoom lens, and A control unit that, in a case where an amount of movement of the zoom lens based on a detection result of the detection unit is less than a predetermined threshold value, maintains a parameter used to perform drive control of a focus lens, switches the parameter in a case where the amount of movement of the zoom lens is equal to or greater than the threshold value, and performs drive control of the focus lens based on the maintained or switched parameter, and The imaging device includes: An imaging element that captures an object image that has been incident via the lens device.

Images