Lens device and imaging apparatus

Abstract

To provide a lens device that can reduce an unintended change in optical performance items during the drive of a movable optical group.SOLUTION: A lens device has: a plurality of lens group that are movable along an optical axis; a driving unit that can drive the plurality of lens groups independently of each other; an acquisition unit that acquires one or more kinds of first optical performance selected from a plurality of optical performance items through a selection input unit; and a control unit that sets a driving path for the driving unit to drive the plurality of lens groups on the basis of one or more target values for each of the one or more kinds of first optical performance.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] 2. Description of the Related Art It is known that in a zoom lens, a focus operation causes the angle of view of an image to change due to the driving of the focus lens. When shooting a scene in which the focus in the image is changed from one subject to another without operating the zoom lens, the image may move due to the change in the angle of view caused by the focus operation.

[0003] Patent Document 1 discloses a technique for suppressing changes in the angle of view by operating not only the focus lens but also the zoom lens during focus operation. Patent Document 2 discloses a technique for controlling the positions of the zoom lens and the focus lens so that even when zooming and focusing are performed simultaneously, the change in the angle of view is caused only by the zoom operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-282396 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-145931 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the configuration of Patent Document 1 does not allow control that prioritizes suppression of unintended changes in optical performance items other than changes in the angle of view during focus operation. The same is true for Patent Document 2. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a lens device that can reduce unintended changes in optical performance items when a movable optical group is driven. [Means for solving the problem]

[0006] In order to achieve the above object, the lens device of the present invention is characterized by having a plurality of lens groups movable along an optical axis, a drive unit capable of driving the plurality of lens groups independently of one another, an acquisition unit that acquires one or more first optical performances selected from a plurality of optical performance items via a selection input unit, and a control unit that sets a drive trajectory for driving the plurality of lens groups by the drive unit based on one or more target values ​​for each of the one or more first optical performances. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a lens device that can reduce unintended changes in optical performance items when a movable optical group is driven. [Brief explanation of the drawings]

[0008] [Figure 1] 1 shows a system configuration of a lens apparatus and a camera apparatus according to a first embodiment. [Figure 2] FIG. 10 is a diagram showing an example of a liquid crystal display when a first optical performance is selected in the first embodiment. [Figure 3] FIG. 10 is a diagram showing an example of a liquid crystal display when a first optical performance is selected in the first embodiment. [Figure 4] FIG. 10 is a diagram showing an example of a liquid crystal display when the second optical performance is selected in the first embodiment. [Figure 5] 10A and 10B are diagrams illustrating an example of a liquid crystal display when a target value of a first optical performance is set in Example 1. [Figure 6] 10 is a flowchart of an optical performance selection mode in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. [Example]

[0010] The system configuration of an image capturing apparatus 300 according to a first embodiment of the present invention will be described with reference to FIG. An imaging device 300 according to the first embodiment includes a lens device 101 and a camera device 201 that captures an image formed by the lens device 101. The lens device 101 includes a fixed lens group 102, a first movable lens group 103, an aperture stop unit 104, a second movable lens group 105, and a third movable lens group 106.

[0011] Furthermore, the lens device 101 includes a zoom ring (not shown), a zoom detection sensor 107 that detects the rotation of the zoom ring, a lens data storage unit 108, and a lens CPU (lens control unit) 109. The lens data storage unit 108 stores a plurality of sensitivities and drive trajectories of optical performance items of each lens group. The lens CPU 109 is a control unit that performs drive control and calculations for the entire lens.

[0012] The lens CPU 109 outputs commands to a first lens group driver 110, a second lens group driver 112, and a third lens group driver 113 to control the driving of the first movable lens group 103, the second movable lens group 105, and the third movable lens group 106 in the direction of the optical axis X. The lens CPU 109 also outputs commands to an aperture diaphragm driver 111 to drive the aperture diaphragm unit 104 and control the aperture size. A position sensor (not shown) is provided for each lens group, making it possible to detect the position of each lens group.

[0013] The lens device 101 and the camera device 201 are detachably fixed to each other via a mount 114 to form an imaging device 300. An image of a subject captured within the lens device 101 is formed on an imaging element 202 held in the camera device 201, and an image is captured by the imaging element 202.

[0014] The camera device 201 includes a camera CPU (camera control unit) 203, a release button 204, a main power supply 205, an image recording medium 206, a liquid crystal display unit 207, an operation dial 208, an operation switch 209, a finder 210, and the like.

[0015] The release button 204 has a two-stage depression configuration, with the first stage being referred to as a half-press and the second stage being a full press. When the release button 204 is half-pressed, preparations for starting shooting are made, such as returning from shooting standby, starting image stabilization processing, starting autofocus, and starting metering. When the release button 204 is fully pressed, an image is captured and an instruction to record the image to the image recording medium 206 is issued.

[0016] In addition, power is supplied from the camera device 201 to the lens device 101 and shooting information is communicated between the lens CPU 109 and the camera CPU 203 via a contact block (not shown) provided on the mount 114.

[0017] Next, the lens system section that is characteristic of this patent will be described with reference to FIGS.

[0018] In the lens apparatus 101, various optical sensitivity information, which compiles a plurality of optical performance items that represent optical performance, such as focus sensitivity, spherical aberration sensitivity, field curvature sensitivity, angle of view variation sensitivity, and chromatic aberration sensitivity, is stored for each lens group in a lens data storage unit 108. Here, the sensitivity indicates the amount of change in the state of each optical performance when each lens group that can be moved in the optical axis direction is moved by a unit length in the optical axis direction.

[0019] The lens data storage unit 108 also stores a drive locus table indicating the basic drive locus and a drive speed table indicating the basic drive speed of each lens group during focusing and zooming. During focusing and zooming, the drive locus table and drive speed table are read from the lens data storage unit 108, and the target position of each lens group is set. The lens CPU 109 drives each lens group by outputting a command to the drive unit of each lens group based on the set target position.

[0020] FIG. 2 shows a first pattern of the liquid crystal display when optical performance is selected in this embodiment. In this embodiment, five optical performance items, namely, focus, spherical aberration, field curvature, angle of view variation, and chromatic aberration, are defined as candidates for optical performance that can be selected as the first optical performance. For each first optical performance, an optical performance item for which sensitivity information is stored in the lens data storage unit 108 can be selected. In this embodiment, a selection is made from five optical performance items, but field curvature sensitivity may be broken down into sagittal field curvature and meridional field curvature and subdivided, or another optical performance item that changes as a result of movement of a lens that is movable in the optical axis direction may be added.

[0021] The camera device 201 has a selection input unit, which allows a user to select a desired optical performance item from a menu screen on the liquid crystal display unit 207, which serves as a touch panel, thereby selecting multiple desired first optical performance items. Here, the first optical performance refers to an optical performance item for which suppression of unintended changes is prioritized when controlling to minimize unintended changes in optical performance due to movement of the focus optical system in the optical axis direction during focus operation, for example. The first optical performance corresponds to, for example, at least one of spherical aberration, field curvature, angle of view variation, and chromatic aberration. Here, control to minimize changes is not limited to control that does not allow changes, but may also be control that limits the amount of change within a predetermined allowable range.

[0022] 2, when making a selection, arrow A is moved to a position representing the selection item on the first optical performance-1 screen, and the selection and confirmation are made by operating the liquid crystal display unit 207 of the camera device 201. After selecting the first item on the first optical performance-1 screen, the screen moves to a second first optical performance selection screen (first optical performance-2), and arrow B is moved to a position representing the selection item as shown in FIG.

[0023] In this embodiment, it is possible to set priorities for items other than the selected first optical performance. The liquid crystal display unit 207 having a touch panel function is used as a priority setting means, and the second optical performance and its order are selected for the items other than the optical performance item selected as the first optical performance.

[0024] As shown in FIG. 4, by operating the liquid crystal display unit 207 of the camera device 201, it is possible to move the arrow C to a position representing a selection item, and to make a selection and confirm it. By making it possible to set the priority of the second optical performance, it is possible to control to some extent how aberrations occur, even if it is not possible to eliminate changes in aberrations of the second optical performance.

[0025] In principle, it is not possible to control as the first optical performance more optical performance items than the number of independently driveable lens groups. However, by making it possible to set priorities as the second optical performance for optical performance items for which unintended changes should be minimized as much as possible, it is possible to control the second optical performance other than the first optical performance so as to prioritize and minimize unintended changes in performance. Furthermore, as shown in FIG. 5, by operating a scroll bar 211 on the liquid crystal display unit 207 as a target value setting means, the target value for the first optical performance can be arbitrarily set to the minimum value (0), a predetermined value on the positive side, or a predetermined value on the negative side.

[0026] By setting the target value for the selected first optical performance to the minimum value, the user can set the second-priority optical performance to an advantageous value, making it possible to meet a variety of user needs with a single lens. Furthermore, by allowing separate settings for video shooting and still image shooting, it is possible to select the optical performance item that suits the shooting situation as the first optical performance, and this can be automatically reflected when changing modes.

[0027] It is also possible to change the target values ​​for the first optical performance to the positive or negative side. Therefore, for example, in the past, technology that broadens the range of expression by allowing the user to change spherical aberration was only realized in some interchangeable lenses, but by adopting the present invention, the effect of broadening the range of expression can be realized in many interchangeable lenses. Furthermore, it is also possible to set an optical performance item other than spherical aberration as the first optical performance, making it possible to realize photographic expressions that have never been seen before.

[0028] Next, the process of setting the drive locus and drive speed of each lens group by the control unit (lens CPU 109) will be described with reference to the flowchart of FIG. First, when processing starts, the process proceeds to step S1, where it is determined whether or not the optical performance selection mode is selected. If the optical performance selection mode is selected, the process proceeds to step S2, and if the optical performance selection mode is not selected, the process proceeds to step S9.

[0029] In step S9, the basic drive locus and basic drive speed of each lens group stored in advance in the memory unit 108 of the lens device 101 are read, and the system transitions to a shooting mode in which focus and zoom drive are performed in accordance with the basic drive locus and basic drive speed. Here, the basic drive locus and basic drive speed are set in advance in accordance with predetermined calculation rules as basic information regarding the movement of each lens group during focusing and zooming when the optical performance selection mode is not selected, although the basic drive locus and basic drive speed may be set by appropriately changing them as necessary.

[0030] In step S2, a first optical performance is selected. The first optical performance is selected from, for example, the five optical performance items mentioned above (focus, spherical aberration, field curvature, angle of view variation, and chromatic aberration). In this embodiment, the first movable lens group 103, the second movable lens group 105, and the third movable lens group 106 move during focusing, so the number of optical performance items that can be selected as the first optical performance is two or less. After the first optical performance is selected in step S2, the process proceeds to step S3.

[0031] In this embodiment, the first optical performance is selected on the LCD display unit 207, which is a touch panel provided on the camera device 201, and the lens CPU (acquisition unit) 109 acquires information on the selected first optical performance through communication via the mount 114. In step S3, a target value for the selected first optical performance is set by operating the scroll bar 211, as described with reference to Fig. 5, and the target value for the first optical performance is set and confirmed. In this embodiment, the target value is set using a variable scroll bar, but it may also be possible to input a numerical value or select a mode with a preset value.

[0032] Next, the process proceeds to step S4, where a second priority optical performance is selected from among the optical performance items other than the first optical performance selected in step S3. Next, proceeding to step S5, various optical sensitivity information of each lens group required for calculating the drive trajectory and drive speed of each lens group so that each of the first optical performances is set to a predetermined value or so that the change is kept within a predetermined range is read from the lens data storage unit 108. Next, the process proceeds to step S6, where the basic drive locus and basic drive speed of each lens group required for the above calculation are read from the lens data storage unit .

[0033] Next, proceeding to step S7, the lens CPU 109 as a drive trajectory setting means calculates the drive speed and drive trajectory of each lens group based on the first optical performance, the target values ​​of each of the first optical performances, various optical sensitivity information, the basic drive trajectory, and the basic drive speed. Here, the drive speed and drive trajectory of each lens group are obtained by correcting the basic drive trajectory and basic drive speed in accordance with the target value of each first optical performance, but they may also be calculated from information only about the first optical performance, the target value of the first optical performance, and various optical sensitivity information.

[0034] When calculating the drive speed of each lens group in step S7, the drive speed of each lens group must be set taking into account the minimum and maximum drive speeds at which each actuator constituting the drive unit of the lens group can be driven.

[0035] If the drive unit is configured with an actuator that has a high minimum drive speed and cannot be driven at low speeds, synchronized drive will not be possible when driving each lens group simultaneously, and there is a risk of intermittent drive occurring, where one lens group is driven first and then waits for the other lens groups to follow. In such cases, there is a concern that the effects of intermittent drive will be visible in the video when shooting video, making the video look unnatural. Therefore, by calculating the drive speed required for each actuator of the drive unit in synchronous drive to be set to a drive speed equal to or higher than the minimum drive speed of each actuator, it becomes possible to drive all lens groups smoothly.

[0036] Furthermore, if the drive unit is configured with an actuator that has a low maximum drive speed and cannot drive at high speed, the lens groups cannot be driven synchronously when driven simultaneously, which may result in a delay in the drive of the lens groups by the drive unit, which may result in a deterioration in image quality in terms of aberrations, focus, and angle of view when shooting video. Therefore, by calculating the drive speed required for each actuator of the drive unit in synchronous drive to be set to a drive speed equal to or lower than the maximum drive speed of each actuator, it becomes possible to drive all the lens groups simultaneously.

[0037] Furthermore, in this embodiment, the drive locus and drive speed are set by calculation, but the present invention is not limited to this. All tables of drive locus and drive speed corresponding to the selected first optical performance and target value may be prepared and stored in the storage unit 108, and the tables may be read out and used. Next, in step S8, the drive locus and drive speed calculated in step S7 are set, and the process ends.

[0038] In step S9, which branches off from step S1, the basic drive locus and basic drive speed of each lens group are read from the lens data storage unit 108, and the process proceeds to step S10. As described above, the basic drive locus and basic drive speed are set in advance in accordance with predetermined calculation rules as basic information related to the movement of each lens group during focusing and zooming when the optical performance selection mode is not selected. In step S10, the basic drive locus and basic drive speed read out in step S9 are set as drive information for each lens group during focusing and zooming, and the process ends.

[0039] During subsequent focusing or zooming, each lens group is driven in accordance with the set drive locus and drive speed, thereby enabling the drive of each lens group to be achieved in accordance with the selected optical parameters.

[0040] In the optical performance selection mode, the lens groups whose drive locus and drive speed are changed may be either two or three of the three movable lens groups. Furthermore, although this embodiment has been described as having two selectable first optical performances, the range of application can be further expanded by making it possible to select up to the same number of first optical performances as the number of lens groups that can be moved in the optical axis direction.

[0041] Alternatively, since focus, which is an optical performance item, is likely to always be selected as the first optical performance item, one or more selectable first optical performance items other than focus may be selected. In this embodiment, the calculation processing of the drive locus and drive speed is performed on the lens device 101 side, but it may also be performed on the camera device 201 side.

[0042] Although it has been described that the selection of the first optical performance, the setting of a target value for the first optical performance, and the selection of the second optical performance are set on the LCD display unit 207 in the camera device 201 and input to the lens device 101 via a mount having an input unit from the camera device (external device), the present invention is not limited to this. The settings may also be made using a user interface provided in a device other than the camera device 201, for example, in the lens device 101 or in a drive unit connected to the lens device that drives the movable lens group.

[0043] Furthermore, although the configuration is such that the user can select a target value corresponding to the first priority optical performance, it is also possible to configure the configuration such that the target value is set in advance in the lens device 101 or the camera device 201, and the user can simply set the first optical performance from the optical performance items.

[0044] The disclosure of this embodiment includes the following configuration. (Configuration 1) a plurality of lens groups movable along an optical axis; a drive unit capable of driving the plurality of lens groups independently of one another; an acquisition unit that acquires one or more first optical performance items selected from a plurality of optical performance items via a selection input unit; and a control unit that sets a drive locus along which the drive unit drives the plurality of lens groups, based on one or more target values ​​for each of the one or more first optical performances. (Configuration 2) The lens device according to configuration 1, characterized in that it has the selection input section. (Configuration 3) 3. The lens device according to configuration 1 or 2, further comprising a target value setting means for setting the one or more target values. (Configuration 4) 4. The lens device according to any one of configurations 1 to 3, wherein the one or more target values ​​are preset target values. (Configuration 5) 3. The lens device according to configuration 1 or 2, further comprising a second input section for receiving the one or more target values ​​from an external device. (Configuration 6) The control unit 6. The lens device according to any one of configurations 1 to 5, wherein the drive loci of the plurality of lens groups are set by calculation based on the one or more target values. (Configuration 7) The lens device according to any one of configurations 1 to 5, wherein the control unit has a table of the drive loci of the plurality of lens groups, the table being set based on the one or more target values. (Configuration 8) a priority setting means for setting a priority as a second optical performance for optical performance items other than the one or more first optical performance items among the plurality of optical performance items, 8. The lens device according to any one of configurations 1 to 7, wherein the control unit sets a drive locus for driving the plurality of lens groups based on the priority order. (Configuration 9) the plurality of lens groups includes three or more lens groups, 9. The lens device according to any one of configurations 1 to 8, wherein the plurality of driving means are three or more driving means that respectively drive the three or more lens groups. (Configuration 10) The lens device according to any one of configurations 1 to 9, wherein the control unit sets the drive locus of the plurality of lens groups so that the drive speed of each of the plurality of drive means is equal to or greater than the minimum drive speed of each of the plurality of drive means. (Configuration 11) The lens device according to any one of configurations 1 to 10, wherein the control unit sets the drive locus of the plurality of lens groups so that the drive speed of each of the plurality of drive means is equal to or less than the maximum drive speed of each of the plurality of drive means. (Configuration 12) 4. The lens device according to configuration 3, wherein the target value setting means allows a user to arbitrarily set the target value within a predetermined range of values. (Configuration 13) 4. The lens device according to configuration 3, wherein the target value setting means sets the target value within a predetermined range. (Configuration 14) 14. The lens device according to any one of configurations 1 to 13, wherein the driving locus is a driving locus during focusing. (Configuration 15) 14. The lens device according to any one of configurations 1 to 13, wherein the drive locus is a drive locus during zooming. (Configuration 16) An imaging device comprising: a lens device according to any one of configurations 1 to 15; and a camera device having an imaging element that captures an image formed by the lens device. (Configuration 17) the camera device includes the selection input unit and a target value setting unit that sets the one or more target values ​​for each of the one or more first optical performances, 17. The imaging device according to claim 16, wherein the lens device has an input unit that receives the selected one or more first optical performances and the one or more target values ​​from the camera device. [Explanation of symbols]

[0045] 101 Lens device 103 First Movable Lens Group 105 Second movable lens group 106 Third moving lens group 109 Lens CPU (control unit, acquisition unit) 110 First lens group drive unit (drive unit) 112 Second lens group drive unit (drive unit) 113 Third lens group drive unit (drive unit)

Claims

1. a plurality of lens groups movable along an optical axis; a drive unit capable of driving the plurality of lens groups independently of one another; an acquisition unit that acquires one or more first optical performance items selected from a plurality of optical performance items via a selection input unit; a control unit that sets a drive locus along which the drive unit drives the plurality of lens groups, based on one or more target values ​​for each of the one or more first optical performances.

2. The lens device according to claim 1 , further comprising the selection input unit.

3. 2. The lens device according to claim 1, further comprising a target value setting unit for setting the one or more target values.

4. 2. The lens device according to claim 1, wherein the one or more target values ​​are preset target values.

5. 2. The lens device according to claim 1, further comprising an input section for receiving the one or more target values ​​from an external device.

6. The control unit 2. The lens device according to claim 1, wherein the drive loci of the plurality of lens groups are set by calculation based on the one or more target values.

7. 2. The lens device according to claim 1, wherein the control unit has a table of the driving loci of the plurality of lens groups, the table being set based on the one or more target values.

8. a priority setting unit that sets a priority as a second optical performance for an optical performance item other than the one or more first optical performance items among the plurality of optical performance items, The lens device according to claim 1 , wherein the control unit sets a driving locus for driving the plurality of lens groups based on the priority order.

9. the plurality of lens groups includes three or more lens groups, 2. The lens apparatus according to claim 1, wherein the plurality of driving means are three or more driving means each for driving one of the three or more lens groups.

10. 2. The lens device according to claim 1, wherein the control unit sets the drive locus of the plurality of lens groups so that the drive speed of each of the plurality of drive means is equal to or greater than the minimum drive speed of each of the plurality of drive means.

11. 2. The lens device according to claim 1, wherein the control unit sets the drive locus of the plurality of lens groups so that the drive speed of each of the plurality of drive means is equal to or less than the maximum drive speed of each of the plurality of drive means.

12. 4. The lens device according to claim 3, wherein the target value setting means allows a user to arbitrarily set the target value within a predetermined range of values.

13. 4. The lens device according to claim 3, wherein the target value setting means sets the target value within a predetermined range.

14. 2. The lens device according to claim 1, wherein the driving locus is a driving locus during focusing.

15. 2. The lens device according to claim 1, wherein the driving locus is a driving locus during zooming.

16. 10. An imaging device comprising: a lens device according to claim 1; and a camera device having an imaging element for capturing an image formed by the lens device.

17. the camera device includes the selection input unit and a target value setting unit that sets the one or more target values ​​for each of the one or more first optical performances, 17. The imaging device according to claim 16, wherein the lens device comprises an input unit for receiving the selected one or more first optical performances and the one or more target values ​​from the camera device.

Images