Optical apparatus and control method therefor

Abstract

To provide an optical apparatus capable of reducing focus deviation when a position of a zoom end is deviated.SOLUTION: An optical apparatus includes: an acquisition section that can acquire a position of a zoom lens group; and a storage section that stores position characteristics data indicating a relation among a position of a focus group, a subject distance, and a position of the zoom lens group. The position characteristics data in a first region between a wide angle end and a zoom position separated from the wide angle end to a telephoto side by a predetermined distance and a second region between a telephoto end and a zoom position separated from the telephoto end to a wide angle side by a predetermined distance is represented using a coefficient of a polynomial of a position of the zoom lens group with respect to a position of the focus group corresponding to the subject distance. When the position of the zoom lens group is closer to the wide angle side than the wide angle end, the position of the focus group is calculated using the position characteristics data in the first region. When the position of the zoom lens group is closer to the telephoto side than the telephoto end, the position of the focus group is calculated using the position characteristics data in the second region.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to optical instruments. [Background technology]

[0002] Conventionally, there is known a lens device that can control the position of the focus lens so as to focus during zooming by storing the position where the zoom ring is butted as the zoom end position and associating the focus position with the stored position as a reference. However, if the zoom end position deviates from the ideal position due to an error when butting to store the zoom end position, the focus lens position cannot be calculated correctly, and the zoom focus accuracy deteriorates.

[0003] Patent document 1 discloses a configuration capable of performing good focus control even when the in-focus position corresponding to the position of the focus lens or the target drive amount of the focus lens is in a margin area outside the optical infinity position and the closest position.

[0004] Patent document 2 discloses a configuration that prohibits changing the telephoto end position to the telephoto end position in a low temperature state when the telephoto end position has been changed to the telephoto end position in a high temperature state, the current temperature is lower than a reference temperature, and the current position coincides with the telephoto end position in a high temperature state. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-134322 A [Patent Document 2] Patent No. 4857256 Summary of the Invention [Problem to be solved by the invention]

[0006] The configuration of Patent Document 1 complements the position in the marginal area by having data outside a specified area in the subject distance direction, but it cannot interpolate the focus position error caused by the zoom position shift in the focal length (zoom position) direction.

[0007] The configuration of Patent Document 2 is premised on the zoom lens being driven electrically, and cannot be applied to a configuration in which the position of the zoom lens is determined in response to the operation of a manual zoom ring.

[0008] An object of the present invention is to provide an optical device capable of reducing focus deviation that occurs when the zoom end position is shifted. [Means for solving the problem]

[0009] An optical device according to one aspect of the present invention has a focus group movable in an optical axis direction, a zoom lens group whose focal length can be changed, an acquisition unit capable of acquiring the position of the zoom lens group, and a memory unit that stores position characteristic data indicating the relationship between the position of the focus group, the subject distance, and the position of the zoom lens group, wherein the position characteristic data in a first region between the wide-angle end and a zoom position a predetermined distance away from the wide-angle end to the telephoto side, and a second region between the telephoto end and a zoom position a predetermined distance away from the telephoto end to the wide-angle side are expressed using polynomial coefficients of the position of the zoom lens group relative to the position of the focus group corresponding to the subject distance, and when the position of the zoom lens group is on the wide-angle side of the wide-angle end, the position of the focus group is calculated using the position characteristic data in the first region, and when the position of the zoom lens group is on the telephoto side of the telephoto end, the position of the focus group is calculated using the position characteristic data in the second region. Effect of the Invention

[0010] According to the present invention, it is possible to provide an optical device capable of reducing focus deviation caused when the zoom end position is shifted. [Brief description of the drawings]

[0011] [Figure 1]1 is a schematic diagram of a camera system according to a first embodiment. [Diagram 2] FIG. 11 is a diagram showing position characteristic data. [Diagram 3] 11A and 11B are diagrams illustrating the relationship between the zoom position and the focus lens position when the zoom end adjustment position is shifted. [Figure 4] 11 is a diagram showing the zoom position near the wide-angle end and the position characteristic data of the close cam in the first embodiment. FIG. [Diagram 5] 5 is a diagram showing a focus lens position and a zoom focus adjustment value with respect to a zoom position in the first embodiment. FIG. [Figure 6] FIG. 11 is a diagram showing a zoom focus adjustment value with respect to a zoom position in the second embodiment. [Figure 7] 10 is a flowchart showing a target position calculation method during zoom tracking control in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same components, and duplicated descriptions will be omitted. EXAMPLES

[0013] FIG. 1 is a schematic diagram of an interchangeable lens camera (camera system) of this embodiment. The interchangeable lens camera has a lens device (interchangeable lens) 100 and a camera body 200 as optical devices. The lens device 100 and the camera body 200 are mechanically and electrically connected via a mount (not shown), and perform power supply and mutual communication via terminals provided on the mount. Note that this embodiment will be described taking as an example an interchangeable lens camera in which the lens device 100 is detachably attached to the camera body 200, but the present invention can also be applied to a lens-integrated imaging device in which the lens device 100 and the camera body 200 are integrated. In this case, the lens-integrated imaging device functions as an optical device. (Interchangeable lens configuration) The lens device 100 has an optical system 101 that includes a plurality of lenses and forms an optical image on an image sensor 201 using light from outside the lens. The optical system 101 includes a variable magnification lens (zoom lens group) 102, an aperture 103, and a focus lens (focus group) 104. The variable magnification lens 102 moves in the optical axis direction in response to an operation on a zoom operation unit 110, and is capable of changing the focal length of the lens device 100. A zoom position detection unit (acquisition unit) 111 is capable of acquiring the position (zoom position) of the variable magnification lens 102 using a potentiometer sensor or the like. The acquired zoom position is transmitted to a lens control unit 105. The aperture 103 is composed of aperture blades, and is driven by an aperture drive unit 106, and is capable of adjusting the amount of light that passes through the optical system 101 and enters the image sensor 201.

[0014] The focus lens 104 is configured to be movable in the optical axis direction by a focus lens driving means 107 having an actuator. By moving the focus lens 104 in the optical axis direction, it is possible to focus the optical image formed on the image sensor 201 and adjust the aberration. The actuator has a small ultrasonic motor such as a NanoUSM (Nano Ultra Sonic Motor), and moves itself linearly on a slider by vibration energy of ultrasonic waves to move the focus lens connected to a rack member. The focus lens position detection unit 108 has a position detection sensor including a fixed part and a movable part, emits LED light from the fixed part, and receives light reflected by a scale of a different pattern of the movable part with a photodiode of the fixed part. With such a configuration, the focus lens position detection unit 108 detects the absolute position of the focus lens 104 and transmits the detected position data to the lens control unit 105.

[0015] Memory (storage unit) 109 is a storage unit configured with a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and stores position characteristic data of focus lens 104. The position characteristic data is position data of focus lens 104 that indicates the same subject distance for each focal length, and is optically determined so as to achieve good focusing and reduced aberration.

[0016] Lens control unit 105 is a computer including a CPU. Lens control unit 105 transmits information such as the amount of drive received through communication with camera body 200 to aperture drive unit 106 and focus lens drive means 107, and controls the position of focus lens 104, the opening of aperture 103, and the like through closed-loop control. (Camera body explanation) The camera body 200 has an image sensor 201, a signal processing unit 202, a recording processing unit 203, a defocus detection unit 204, a camera control unit 205, a memory 206, an electronic viewfinder 207, and a display unit 208. The image sensor 201 converts an optical image formed through the optical system 101 into an electrical signal using photoelectric conversion and transmits it to the signal processing unit 202. The signal processing unit 202 receives the electrical signal, which is the result of the photoelectric conversion, from the image sensor 201 and converts it into a digital signal. The signal processing unit 202 also performs image processing on the digital signal and transmits the image data to the recording processing unit 203. The recording processing unit 203 displays the image data transmitted as a digital signal on the electronic viewfinder 207 or the display unit 208.

[0017] A defocus detection unit 204 detects the amount of defocus and transmits it to a camera control unit 205. The pixels of the image sensor 201 can also be used for focus detection, and the amount of defocus can be detected by measuring the phase difference between the photoelectric conversion results of adjacent pixels that divide the pupil region.

[0018] The camera control unit 205 is a computer including a CPU, and is electrically connected to the recording processing unit 203, the defocus detection unit 204, and the memory 206. The camera control unit 205 reads and executes programs recorded in the memory 206, and communicates information necessary for autofocus control with the lens control unit 105. The camera control unit 205 also controls the camera body 200 in response to inputs from a camera operation unit such as a shooting switch and various setting switches (not shown). (About zoom tracking drive) The control when the zoom operation unit 110 is operated by the user (control during zoom operation) will be described. The zoom operation unit 110 is configured to be rotatable on the side of the lens device 100 like a zoom ring, for example, and an internal zoom encoder or the like may move in conjunction with the rotational motion to drive the variable magnification lens 102 according to a designed cam. When the variable magnification lens 102 is driven, the zoom position detection unit 111 obtains the zoom position and notifies the lens control unit 105 of the current zoom position.

[0019] FIG. 2 is a diagram showing position characteristic data indicating the position (cam data) of the focus lens 104 on the same subject distance trajectory for each zoom position. For example, a case will be described in which the current zoom position is the most telephoto (Tele end), the subject distance is the closest (MOD), and the zoom is moved to the widest zoom position (Wide end) by zoom operation. The current position of the focus lens 104 is the Tele end, MOD, which is the position Pt in FIG. 2. The lens control unit 105 monitors the zoom position detection unit 111 at a predetermined control cycle. When the zoom position detection unit 111 acquires the position of the variable magnification lens 102, the lens control unit 105 refers to the position characteristic data and moves the focus lens 104 to a position corresponding to the current zoom position and subject distance using the focus lens driving means 107.

[0020] Note that the memory 109 does not store the positions of the focus lens 104 at all subject distances and zoom positions as position characteristic data. Since there is a limit to the storage capacity, only position data of the focus lens 104 at some representative subject distances is stored as position characteristic data, as shown by the solid line in FIG. 2. The zoom position direction is also shown by a solid line, but this is a finite amount of data. If the required data does not exist in the position characteristic data, the ratio (cam interpolation ratio) between adjacent cam data is calculated and stored. If the cam interpolation ratio is calculated, an appropriate position of the focus lens 104 can be calculated even if the zoom position changes, and the same subject distance can be tracked for each control cycle.

[0021] 2 in response to the user's zoom operation, and reaches position Pw. This type of control is called zoom tracking control. (Zoom end adjustment and zoom focus adjustment) As shown in FIG. 2, in order to perform zoom tracking control accurately, it is necessary to have a one-to-one correspondence between the zoom position and the focus lens position at the same subject distance. However, when considering assembly errors and mechanical tolerances, the positions of both ends of the variable magnification lens 102 have errors for each lens device 100. In other words, they are not uniquely determined as design values. Therefore, the zoom ring is abutted against the telephoto end and the wide-angle end for each lens device 100, and the values ​​of the zoom sensor at the telephoto end and the wide-angle end at that time are stored in the memory 109. This operation is called zoom end adjustment. After performing the zoom end adjustment, the telephoto end and the wide-angle end adjusted at the zoom end may be equally divided into a predetermined number of zoom divisions to perform zoom tracking control. The positions of the adjustment ends determined by the zoom end adjustment are respectively called the adjusted telephoto end Zta and the adjusted wide-angle end Zwa.

[0022] Next, the zoom focus adjustment will be described. The zoom focus adjustment is performed after the zoom end adjustment is performed. First, the zoom ring is operated to move the variable magnification lens 102 to the zoom position with the highest resolution of the object distance, which is the adjusted telephoto end Zta in this embodiment. After that, a subject at a specific object distance is projected on the lens, and the focus lens 104 is moved so as to focus on the object using a focusing device such as a camera. In this embodiment, the object at this time is an object at an infinite distance such as a chart using a collimator that can converge parallel light. After focusing at the adjusted telephoto end Zta, the current position Fta of the focus lens 104 is calculated. Also, the designed infinity position Fti at the adjusted telephoto end Zta is obtained from the position characteristic data. Here, the zoom focus adjustment value Ata at the adjusted telephoto end Zta is calculated using the following formula (1).

[0023] Ata=Fti-Fta (1) Thereafter, the variable magnification lens 102 is moved in order to a plurality of predetermined adjusted zoom positions. Focusing is performed in the same manner at each adjusted zoom position, and a zoom focus adjustment value is calculated. The calculated zoom focus adjustment value is stored in memory 109, and when determining a control target position of the focus lens 104 by zoom tracking control, the target position is calculated by adding the zoom focus adjustment value of the target zoom position to the target design position. A detailed explanation will be given later. The above is the zoom focus adjustment value.

[0024] Here, we will explain the case where the adjusted telephoto end Zta is wider than the ideal telephoto end Zti, and similarly the adjusted wide-angle end Zwa is closer to the telephoto end Zwi than the ideal wide-angle end Zwi. Zoom end adjustment may be performed manually or with a zooming machine during the production process. In such cases, the above situation may occur due to various factors such as butting errors, assembly errors, and mechanical tolerances.

[0025] FIG. 3 is a diagram showing the relationship between the zoom position and the focus lens position when the zoom end adjustment position is shifted. FIG. 3(a) shows the design position and ideal position of the focus lens 104 when the zoom end adjustment position is shifted, and the zoom focus adjustment value when the zoom focus adjustment is performed. If the zoom end adjustment is adjusted inside the ideal zoom end, it will be controlled at the design position shown in FIG. 3(a), and a deviation from the ideal position will occur. However, by performing the zoom focus adjustment, the focus position at each zoom adjustment position will be close to the ideal position. Therefore, the zoom focus adjustment value at each adjustment zoom position will be the value indicated by the arrow in FIG. 3(a), and will track the actual control position indicated in the actual control position in FIG. 3(b). As shown in FIG. 3(b), in the area from the adjustment wide-angle end Zwa to the adjustment telephoto end Zta, it follows a trajectory close to the ideal position. However, in the area from the ideal wide-angle end Zwi to the adjusted wide-angle end Zwa and in the area from the adjusted telephoto end Zta to the ideal telephoto end Zti, it is not possible to track the ideal trajectory, and focus deviation from the ideal position occurs.

[0026] The problem that occurs in this case will be described using as an example the case where the zoom position is the ideal telephoto end Zti. Assume that AF operation is performed in this case and focusing is achieved at position Ft7. Ideally, this is the position where the cam with a subject distance of 0.7 m should be tracked. However, if the zoom end adjustment position shifts and the focus lens 104 is located at position Ft7 at the ideal telephoto end Zti, the lens control unit 105 recognizes that the subject distance is MOD. If zoom tracking control is performed on the wide-angle side in this state, the subject distance will track the cam with the MOD, resulting in a tracking error.

[0027] In order to reduce this error, in this embodiment, a method of holding position characteristic data is devised. FIG. 4 is a diagram showing the zoom position near the wide-angle end and the position characteristic data of the close cam. The ideal position of the focus lens 104 in the area between the adjusted wide-angle end Zwa and the zoom position Zwd on the telephoto side by a predetermined zoom position change amount (predetermined distance) D from the adjusted wide-angle end Zwa has a value as an optical design value. Polynomial approximation of the zoom position is performed for the ideal position of the focus lens 104 from the zoom position Zwd to the adjusted wide-angle end Zwa. In this embodiment, polynomial approximation is performed using the fourth-order least squares method. Therefore, for example, the control position Fw of the focus lens 104 from the zoom position Zwd to the adjusted wide-angle end Zwa is expressed by the following formula (2).

[0028] Fw=a w z 4 +b w z 3 +c w z 2 +d w z+e w (2) Here, a w ~e w is the approximation coefficient, and z is the zoom position.

[0029] Even if the ideal position of the focus lens 104 from the ideal wide-angle end Zwi to the adjusted wide-angle end Zwa has not been calculated by design, the zoom position from the ideal wide-angle end Zwi to the adjusted wide-angle end Zwa can be substituted into the zoom position of equation (2). This makes it possible to calculate a position that extends the slope of the ideal position of the focus lens 104 from the zoom position Zwd to the adjusted wide-angle end Zwa. Therefore, even if the zoom end adjustment position is shifted, it is possible to calculate a position of the focus lens 104 that is closer to the value at which the focus is focused. Therefore, it is not necessary to hold the ideal position of the focus lens 104 on the wide-angle side of the zoom position Zwd as actual position data, and the approximation coefficient a w ~e w It is only necessary to store the position information and calculate the position by polynomial calculation whenever necessary during control.

[0030] Furthermore, if the zoom position acquired by the zoom position detection unit 111 is on the telephoto side of the adjusted telephoto end Zta acquired by the zoom end adjustment, there is a possibility that the correct in-focus position of the focus lens 104 cannot be calculated by the zoom tracking control. Therefore, similarly to the method on the wide-angle side described above, the ideal position of the area between the adjusted telephoto end Zta and a zoom position Ztd on the wide-angle side from the adjusted telephoto end Zta by a predetermined zoom position change amount is approximated by a polynomial, and the approximation coefficients are held. If the acquired zoom position is on the telephoto side further than the adjusted telephoto end Zta, the target position of the focus lens 104 is calculated using the held approximation coefficients and the zoom position.

[0031] As described above, in this embodiment, when the zoom position at the time of zoom end adjustment deviates from the zoom position at the time of performing zoom tracking control, a position closer to the ideal position can be calculated using the inclination of the focus lens 104 near the zoom end. This makes it possible to reduce out-of-focus when AF is performed and then zoom tracking control is performed when the zoom end is deviated. In addition, it is possible to reduce out-of-focus when zooming to the wider angle side or telephoto side than the wide angle side or telephoto side adjusted by the zoom tracking control. Furthermore, since only the approximation coefficients of the polynomial approximation need to be held as the position characteristic data of the focus lens 104 near the zoom end, the data capacity can be reduced compared to the conventional method of holding actual position data. EXAMPLES

[0032] In the first embodiment, a method for calculating a target position of the focus lens 104 when the zoom end adjustment position is shifted, using the inclination of the position of the focus lens 104 relative to the zoom position for each subject distance near the zoom end, has been described. However, the method of the first embodiment may not have sufficient accuracy. In the present embodiment, the method for calculating the target position of the focus lens 104 near the end is different. In the present embodiment, only the configurations different from the first embodiment will be described, and the description of the common configurations will be omitted. (How to calculate adjustment values ​​near the zoom end) FIG. 5(a) shows the positional relationship between the zoom position near the wide-angle end and the focus lens 104 in the first embodiment. FIG. 5(b) shows the relationship between the zoom position and the zoom focus adjustment value corresponding to FIG. 5(a). In the first embodiment, the design position of the focus lens 104 from the zoom position Zwd to the adjusted wide-angle end Zwa is approximated to calculate the control position of the focus lens 104 from the ideal wide-angle end Zwi to the adjusted wide-angle end Zwa. However, the zoom focus adjustment value, which is the difference between the ideal position and the design position in the region from the ideal wide-angle end Zwi to the adjusted wide-angle end Zwa and the region from the adjusted telephoto end Zta to the ideal telephoto end Zti, is not taken into consideration. As shown in FIG. 5(b), the zoom focus adjustment value in the region from the ideal wide-angle end Zwi to the adjusted wide-angle end Zwa is a constant value. In this case, the error between the control position and the ideal position may be large in the lens device 100 designed to have a large gradient of the design value near the end or in the lens device 100 with a large assembly error.

[0033] In this embodiment, the zoom focus adjustment value near the zoom end is also polynomial-approximated in the same manner as the design position. Fig. 6 is a diagram showing the zoom focus adjustment value with respect to the zoom position in this embodiment.

[0034] A polynomial approximation of the zoom position is performed using, for example, the least square error method for the zoom focus adjustment value acquired between the adjusted wide-angle end Zwa and the zoom position Zwd on the telephoto side by a predetermined zoom position change amount D from the adjusted wide-angle end Zwa. The zoom focus adjustment value Adj is calculated using the following formula (3).

[0035] Adj=a adjw z 4 +b adjw z 3 +c adjw z 2 +d adjw z+e adjw (3) When the zoom position acquired by the zoom position detection unit 111 is between the ideal wide-angle end Zwi and the adjusted wide-angle end Zwa, the approximation coefficient a of the zoom focus adjustment value near the wide-angle end adjw ~e adjwand the zoom position. This makes it possible to calculate the zoom focus adjustment value from the ideal wide-angle end Zwi to the adjusted wide-angle end Zwa while maintaining the gradient of the zoom focus adjustment value from the adjusted wide-angle end Zwa to the zoom position Zwd. This makes it possible to reduce zoom focus deviation when zoom tracking control is performed.

[0036] 7 is a flowchart showing a method for calculating a target position of focus lens 104 during zoom tracking control in this embodiment. The zoom position acquired by zoom position detection unit 111 is monitored at regular control cycles, and if the acquired current zoom position Z has changed from the previous control cycle, it is necessary to calculate and control the target position of focus lens 104 by zoom tracking control.

[0037] In step S701, the lens control unit 105 determines whether the zoom position Z is between the adjusted wide-angle end Zwa and a zoom position Zwd on the telephoto side by a predetermined zoom position change amount from the adjusted wide-angle end Zwa. If the camera control unit 205 determines that the zoom position Z is between the adjusted wide-angle end Zwa and the zoom position Zwd, it executes the process of step S702. If the camera control unit 205 determines that the zoom position Z is not between the adjusted wide-angle end Zwa and the zoom position Zwd, it executes the process of step S704.

[0038] In step S702, the lens control unit 105 calculates the design position of the focus lens 104 at the zoom position Z. Since approximation coefficients obtained by polynomial approximation of the design position of the area between the adjusted wide-angle end Zwa and the zoom position Zwd are held in the memory 109, the lens control unit 105 calculates the design position Fw of the focus lens 104 from the approximation coefficients and the zoom position using equation (2).

[0039] In step S703, the lens control unit 105 calculates the zoom focus adjustment value ADJw at the zoom position Z. Since the approximation coefficients obtained by polynomial approximation of the zoom focus adjustment values ​​in the area between the adjusted wide-angle end Zwa and the zoom position Zwd are held in the memory 109, the lens control unit 105 calculates the zoom focus adjustment value ADJw from the approximation coefficients and the zoom position using equation (3).

[0040] In step S704, the lens control unit 105 determines whether the zoom position Z is between the adjusted telephoto end Zta and a zoom position Ztd that is a predetermined zoom position change amount away from the adjusted telephoto end Zta on the wide-angle side. If the camera control unit 205 determines that the zoom position Z is between the adjusted telephoto end Zta and the zoom position Ztd, it executes the process of step S705. If the camera control unit 205 determines that the zoom position Z is not between the adjusted telephoto end Zta and the zoom position Ztd, it executes the process of step S707.

[0041] In step S705, the lens control unit 105 calculates the design position of the focus lens 104 at the zoom position Z using the method described in step S702.

[0042] In step S706, the lens control unit 105 calculates the zoom focus adjustment value ADJw at the zoom position Z using the method described in step S703.

[0043] In the processing of steps S707 and S708, the zoom position Z is between the zoom positions Zwd and Ztd, and the design position of the focus lens 104 is held as a real number position as position characteristic data in the memory 109. The zoom focus adjustment value is also held in the memory 109. Therefore, in steps S707 and S708, the lens control unit 105 extracts the design position and the zoom focus adjustment value from the memory 109.

[0044] In step S709, the lens control unit 105 calculates the target position of the focus lens 104 by adding the design position of the focus lens 104 and the zoom focus adjustment value. As described above, in this embodiment, the zoom focus adjustment value as well as the design position are taken into consideration when the zoom end is shifted. This allows for more accurate zoom tracking control. Therefore, it is possible to reduce zoom focus shifts when the zoom end adjustment position is shifted. [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-mentioned 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. It can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0045] The disclosure of this embodiment includes the following configurations and methods. (Configuration 1) A focus group movable in an optical axis direction; A group of zoom lenses whose focal length is changeable; an acquisition unit capable of acquiring a position of the zoom lens group; a storage unit that stores position characteristic data indicating a relationship between a position of the focus lens group, a subject distance, and a position of the zoom lens group; the position characteristic data in a first region between a wide-angle end and a zoom position a predetermined distance away from the wide-angle end to the telephoto side, and in a second region between a telephoto end and a zoom position a predetermined distance away from the telephoto end to the wide-angle side, are expressed using polynomial coefficients of a position of the zoom lens group with respect to a position of the focus group corresponding to the subject distance, when the position of the zoom lens group is on the wide-angle side of the wide-angle end, the position of the focus group is calculated using the position characteristic data in the first area, an optical device according to claim 1, wherein when the position of the zoom lens group is on the telephoto side of the telephoto end, the position of the focus group is calculated using the position characteristic data in the second area. (Configuration 2) The optical device described in configuration 1, characterized in that a method of storing the position characteristic data in the first area and the second area is different from a method of storing the position characteristic data in a third area different from the first area and the second area. (Configuration 3) 3. The optical device according to configuration 2, wherein the position characteristic data in the third area is a position of the focus lens group and a position of the zoom lens group corresponding to the subject distance. (Configuration 4) the storage unit stores information about an adjustment value that is a difference between a position of the focus group corresponding to a position of the zoom lens group at a predetermined subject distance in the position characteristic data and an ideal position of the focus group; the information about the adjustment values ​​in the first region and the second region is expressed using polynomial coefficients of the adjustment values ​​corresponding to the subject distance; when the position of the zoom lens group is on the wide-angle side of the wide-angle end, the adjustment value is calculated using information about the adjustment value in the first region, The optical device described in any one of configurations 1 to 3, characterized in that when the position of the zoom lens group is on the telephoto side of the telephoto end, the adjustment value is calculated using information about the adjustment value in the second area. (Configuration 5) The optical device described in configuration 4, characterized in that a method of storing information regarding the adjustment value in the first region and the second region is different from a method of storing information regarding the adjustment value in a third region different from the first region and the second region. (Configuration 6) 6. The optical device according to configuration 5, wherein the information relating to the adjustment value in the third region is the position of the zoom lens and the adjustment value corresponding to the subject distance. (Configuration 7) when the position of the zoom lens group is on the wide-angle side of the wide-angle end, the position of the focus group is calculated using the position characteristic data in the first area and information related to the adjustment value in the first area, The optical device described in any one of configurations 4 to 6, characterized in that when the position of the zoom lens group is on the telephoto side of the telephoto end, the position of the focus group is calculated using the position characteristic data in the second area and information regarding the adjustment value in the second area. (Configuration 8) 8. The optical device according to any one of configurations 1 to 7, wherein the optical device is a lens device that is detachably attached to an imaging device. (Configuration 9) 8. The optical device according to any one of configurations 1 to 7, wherein the optical device is an imaging device having an imaging element for capturing an image. (Method 1) 1. A method for controlling an optical device having a focus group movable in an optical axis direction, a zoom lens group whose focal length is changeable, an acquisition unit capable of acquiring a position of the zoom lens group, and a storage unit that stores position characteristic data indicating a relationship between a position of the focus group, a subject distance, and a position of the zoom lens group, comprising: the position characteristic data includes polynomial coefficients of a position of the zoom lens group relative to a position of the focus group in a first region between a wide-angle end and a zoom position a predetermined distance away from the wide-angle end on the telephoto side, and in a second region between a telephoto end and a zoom position a predetermined distance away from the telephoto end on the wide-angle side, the first region corresponding to the subject distance; calculating a position of the focus group using the coefficient corresponding to the first region when the position of the zoom lens group is on the wide-angle side of the wide-angle end; and when the position of the zoom lens group is on the telephoto side of the telephoto end, calculating the position of the focus group using the coefficient corresponding to the second region. (Configuration 10) A program for causing a computer to execute a process according to the control method described in Method 1.

[0046] 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]

[0047] 100 Lens device (optical equipment) 102 Variable magnification lenses (zoom lenses) 104 Focus lens (focus group) 109 Memory (storage unit) 111 Zoom position detection unit (acquisition unit)

Claims

1. A focus group movable in an optical axis direction; A group of zoom lenses whose focal length is changeable; an acquisition unit capable of acquiring a position of the zoom lens group; a storage unit that stores position characteristic data indicating a relationship between a position of the focus lens group, a subject distance, and a position of the zoom lens group; the position characteristic data in a first region between a wide-angle end and a position of the zoom lens group that is a predetermined distance away from the wide-angle end on the telephoto side, and in a second region between a telephoto end and a position of the zoom lens group that is a predetermined distance away from the telephoto end on the wide-angle side, are expressed using polynomial coefficients of the position of the zoom lens group with respect to the position of the focus group corresponding to the subject distance, when the position of the zoom lens group is on the wide-angle side of the wide-angle end, the position of the focus group is calculated using the position characteristic data in the first area, an objective lens unit configured to calculate a position of the focus lens unit using the position characteristic data in the second area when the zoom lens unit is positioned on the telephoto side of the telephoto end;

2. 2. The optical device according to claim 1, wherein a method of storing the position characteristic data in the first area and the second area is different from a method of storing the position characteristic data in a third area different from the first area and the second area.

3. 3. The optical device according to claim 2, wherein the position characteristic data in the third area is a position of the focus lens group and a position of the zoom lens group corresponding to the subject distance.

4. the storage unit stores information about an adjustment value that is a difference between a position of the focus group corresponding to a position of the zoom lens group at a predetermined subject distance in the position characteristic data and an ideal position of the focus group; the information about the adjustment values ​​in the first region and the second region is expressed using polynomial coefficients of the adjustment values ​​corresponding to the subject distance; when the position of the zoom lens group is on the wide-angle side of the wide-angle end, the adjustment value is calculated using information about the adjustment value in the first region, 3. The optical device according to claim 1, wherein when the position of the zoom lens group is on the telephoto side of the telephoto end, the adjustment value is calculated using information about the adjustment value in the second region.

5. 5. The optical device according to claim 4, wherein a method of storing information regarding the adjustment value in the first region and the second region is different from a method of storing information regarding the adjustment value in a third region different from the first region and the second region.

6. 6. The optical device according to claim 5, wherein the information relating to the adjustment value in the third region is a position of the zoom lens and the adjustment value corresponding to the subject distance.

7. when the position of the zoom lens group is on the wide-angle side of the wide-angle end, the position of the focus group is calculated using the position characteristic data in the first area and information about the adjustment value in the first area, 5. The optical device according to claim 4, wherein when the position of the zoom lens group is on the telephoto side of the telephoto end, the position of the focus group is calculated using the position characteristic data in the second area and information regarding the adjustment value in the second area.

8. 3. The optical device according to claim 1, wherein the optical device is a lens device that is detachably mounted to an image pickup device.

9. 3. The optical device according to claim 1, wherein the optical device is an imaging device having an imaging element for capturing an image.

10. 1. A method for controlling an optical device having a focus group movable in an optical axis direction, a zoom lens group whose focal length is changeable, an acquisition unit capable of acquiring a position of the zoom lens group, and a storage unit that stores position characteristic data indicating a relationship between a position of the focus group, a subject distance, and a position of the zoom lens group, comprising: the position characteristic data includes polynomial coefficients of the position of the zoom lens group relative to the position of the focus group in a first region between a wide-angle end and a position of the zoom lens group that is a predetermined distance away from the wide-angle end on the telephoto side, and in a second region between a telephoto end and a position of the zoom lens group that is a predetermined distance away from the telephoto end on the wide-angle side, the first region corresponding to the subject distance; calculating a position of the focus group using the coefficient corresponding to the first region when the position of the zoom lens group is on the wide-angle side of the wide-angle end; and when the position of the zoom lens group is on the telephoto side of the telephoto end, calculating the position of the focus group using the coefficient corresponding to the second region.

11. A program for causing a computer to execute a process according to the control method according to claim 10.

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