Lens device, imaging device, control method for lens device, and program

Abstract

To provide a lens device that enables faster processing without degrading image quality. [Solution] The lens device (1) includes a first lens (101) that moves during focusing, a second lens (112) that changes aberrations by inserting and removing it from the optical path, and a control unit (111) that performs autofocus by controlling the movement of the first lens using first information relating to autofocus adjustment. The control unit changes the first information depending on whether or not the second lens is inserted into the optical path.

Description

Technical Field

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

Background Art

[0002] By imaging using a lens device including a lens for focus adjustment (focus lens) and a lens for intentionally generating aberration (soft focus lens), it is possible to give a sense of blur before and after to a subject like a cinematic video, or to obtain a soft image.

[0003] Patent Document 1 discloses a technique for shortening the AF control time, including a changing means for changing the focus determination width based on a user operation, and performing focus determination based on the changed focus determination width.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the method disclosed in Patent Document 1, since the focus lens does not reach the original focus determination position, when the AF processing time is shortened, the quality of the video deteriorates.

[0006] Therefore, an object of the present invention is to provide a lens device capable of realizing high-speed AF processing.

Means for Solving the Problems

[0007] A lens device as one aspect of the present invention comprises a first lens that moves during focusing, a second lens that changes aberrations by insertion into and removal from the optical path, and a control unit that performs autofocus adjustment by controlling the movement of the first lens using first information relating to autofocus adjustment, wherein the control unit changes the first information depending on whether or not the second lens is inserted into the optical path.

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

[0009] According to the present invention, it is possible to provide a lens device that can achieve high-speed AF processing. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram showing the configuration of the imaging device in Example 1. [Figure 2] This is an explanatory diagram of the conventional phase-detection autofocus control in normal video mode. [Figure 3] This is an explanatory diagram of conventional phase-detection autofocus control in cinema video mode. [Figure 4] This is an explanatory diagram illustrating the focus position range in Example 1 that does not impair the desired cinematic image. [Figure 5] This is an explanatory diagram of the AF drive time reduction control in cinema video mode in Example 1. [Figure 6] This is a flowchart of the AF drive process in Example 1. [Figure 7] This is a diagram showing the configuration of the imaging device in Example 2. [Figure 8] This is a flowchart of the AF drive process in Example 2. [Figure 9] This diagram shows the positional relationships necessary to achieve AF control unaffected by the soft focus lens in Example 3. [Figure 10] This is an explanatory diagram of the two focus ranges in cinema video mode in Example 3. [Figure 11] It is a flowchart of the AF driving process in Example 3. [Figure 12] It is an external view of the focus control device in Example 4. [Figure 13] It is an explanatory diagram of the output timing of the AF end notification in Example 4. [Figure 14] It is a flowchart of the AF driving process in Example 4.

Modes for Carrying Out the Invention

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

[0012] (Example 1) First, referring to FIG. 1, the configuration of the imaging device 10 in Example 1 of the present invention will be described. FIG. 1 is a configuration diagram of the imaging device 10 in this embodiment. The imaging device 10 is an imaging system including a lens device 1, a camera device (camera body) 2 and a focus control device 3 that are detachable from the lens device. However, the imaging device 10 is not limited to this, and may be an imaging device including the lens device 1 and the camera device 2 (an imaging device not including the focus control device 3). Further, the imaging device 10 may be an imaging device in which the lens device 1 and the camera device 2 are integrally configured. Further, the imaging device 10 may be an imaging device in which the lens device 1 and the focus control device 3 are integrally configured.

[0013] The focus lens (first lens) 101 is disposed on the optical axis. By adjusting the position of the focus lens 101 in the optical axis direction (moving during focusing), the focus of the subject can be adjusted. The focus position detection unit 102 and the focus drive unit 103 are position detection means and drive means mechanically connected to the focus lens 101, respectively, and in this embodiment, are configured by a known encoder and motor for position detection.

[0014] The aperture mechanism unit 104 has an aperture diaphragm disposed on the optical axis. The aperture mechanism unit 104 can adjust the amount of light from the subject by adjusting the aperture. The aperture mechanism position detection unit 105 and the aperture mechanism drive unit 106 are position detection means and drive means that are mechanically connected to the aperture mechanism unit 104, respectively, and in this embodiment, they are constituted by a known encoder and motor for position detection.

[0015] The branching prism 107 is a branching unit that branches a part of the light from the subject. That is, the branching prism 107 branches the light that has passed through the focus lens 101 into a first light that travels toward the imaging unit 201 (soft focus lens 112 inserted in the optical path) described later and a second light that is used for autofocus adjustment. Then, the AF control unit (control unit) 111 performs autofocus adjustment by the phase difference detection method using the second light (controls the movement of the focus lens 101).

[0016] The pupil splitting mechanism 108 splits the second light branched by the branching prism 107 into two light beams for phase difference AF control. The focus detection unit 109 forms images of the pair of light beams split by the pupil splitting mechanism 108 and calculates an evaluation value necessary for AF control from the phase difference between the two formed images. Here, the smaller the phase difference, the higher the value of the evaluation value.

[0017] The lens CPU (Central Processing Unit) 110 is the control unit of the lens device 1. The lens CPU 110 acquires the current position information of the focus lens 101 and the aperture mechanism unit 104 from the focus position detection unit 102 and the aperture mechanism position detection unit 105, respectively. Then, the lens CPU 110 issues commands to the focus drive unit 103 and the aperture mechanism unit 104, and can drive and control the position of the focus lens 101 and the aperture mechanism unit 104 to the target positions.

[0018] The AF control unit 111 is located inside the lens CPU 110 and determines whether or not the lens is in focus based on the evaluation value calculated by the focus detection unit 109. If the lens is not in focus (i.e., out of focus), the AF control unit 111 uses the evaluation value and the current position information of the focus lens 101 to calculate the amount of defocus required to transition to a focused state.

[0019] The soft-focus lens (second lens) 112 is a lens that changes aberrations by inserting or removing it from the optical path (optical axis). When the soft-focus lens 112 is inserted into the optical path, it can intentionally produce spherical aberration to give a cinematic blur effect. In other words, with the soft-focus lens 112, the subject can be depicted with a soft atmosphere while in focus. This embodiment is not limited to this, and the soft-focus lens 112 may be configured to intentionally produce aberrations other than spherical aberration, such as chromatic aberration. However, in order to give a better effect on the subject, it is desirable that the soft-focus lens 112 is a lens that produces at least one of spherical aberration or chromatic aberration.

[0020] The soft focus position detection unit 113 is a detection means for detecting whether or not the soft focus lens 112 is located on the optical axis. The soft focus drive unit 114 is a drive unit for inserting the soft focus lens 112 onto the optical axis or moving it away from the optical axis. In this embodiment, the soft focus position detection unit 113 and the soft focus drive unit 114 are each composed of a known encoder and motor for position detection.

[0021] The soft focus switch unit 115 is an operating unit for the user to switch between inserting the soft focus lens 112 onto the optical axis or retracting it from the optical axis. When the lens CPU 110 detects the switching of the soft focus switch unit 115, it can issue a command to the soft focus drive unit 114. Based on the position information from the soft focus position detection unit 113, it can detect whether or not the soft focus lens 112 is located on the optical axis. The lens CPU 110 has at least two video modes, which are selected according to this position information: cinema video mode (when the soft focus lens 112 is inserted into the optical path) and normal video mode (when the soft focus lens 112 is retracted from the optical path).

[0022] In cinema video mode, a wider range of focus lens drive speeds is required compared to normal video shooting, such as scenes that require slow focusing to capture visually natural images, and scenes that require high-speed focusing like action sequences. On the other hand, in lens devices with autofocus (AF) functionality that automatically controls the focus lens, increasing the drive speed of the focus lens during AF can easily cause a hunting phenomenon where the focus lens overshoots the focus point.

[0023] The memory unit 116 is a memory unit that stores information related to AF control (parameters related to autofocus adjustment, first information), and stores parameters for each video mode. In this embodiment, the information related to AF control includes parameters related to the drive speed of the focus lens 101. The drive speed of the focus lens 101 is, for example, a target drive speed set by the user, but is not limited to this, and may be a predetermined target drive speed. The memory unit 116 is composed of a non-volatile ROM such as an EEPROM. The AF control unit 111 may not only directly obtain parameters from the memory unit 116, but may also calculate parameters by performing calculations using the data stored in the memory unit 116.

[0024] The lens-camera communication unit 117 is a communication unit that communicates with the camera device 2. The lens-controller communication unit 118 is a communication unit that communicates with the focus control device 3.

[0025] The camera device 2 converts light from the lens device 1 into an image signal using an imaging unit 201 equipped with an image sensor, and adjusts the image using an image signal processing unit 202. The camera CPU 203 is the control unit of the camera device 2 and can communicate with the lens device 1 via the camera communication unit 204.

[0026] The focus control device 3 is connectable to the lens device 1 and is an operating device for controlling focus. The focus controller CPU 301 is the control unit of the focus control device 3. The AF / MF switch 302 is an operating unit for switching between automatic and manual operation. The focus handle operating unit 303 is an operating unit used for manual operation. The AF switch unit 304 is an operating unit for starting AF operation. The focus controller CPU 301 can transmit operation signals from the AF / MF switch 302, the focus handle operating unit 303, and the AF switch unit 304 to the lens device 1 via the focus controller communication unit 305. The focus controller CPU 301 can also display the completion notification of AF operation received from the lens device 1 on the AF focus confirmation display unit 306. The AF focus confirmation display unit 306 is a notification unit that notifies the end of operation (end of AF operation). In this embodiment, the notification unit may not only turn light on / off, but also notify by changing the color of the light or by sound. In this embodiment, the focus control operation is assigned to the focus control device 3, but it may also be configured in the lens device 1.

[0027] Next, with reference to Figure 2, we will describe the case where conventional phase-detection AF control is performed in the normal video mode of this embodiment. Figure 2 is an explanatory diagram of conventional phase-detection AF control in normal video mode.

[0028] Images A and B are a pair of images formed by the focus detection unit 109. The amount of defocus is calculated from the evaluation value calculated from the phase difference between images A and B in Figure 2 (before AF) and the current position information read by the focus position detection unit 102, and the AF operation is started. In Figure 2 (during AF operation 1), the evaluation value is higher than (before AF), but it is still not sufficient, so the fine-tuning control is being applied. In Figure 2 (during AF operation 2), the evaluation value is even higher than (during AF operation 1), but the focus lens 101 is still outside the focus range, so the fine-tuning control is being applied further. In Figure 2 (AF completed), the focus lens 101 is within the focus range, and the AF control is complete. The image shown in Figure 2 (normal video mode footage) shows the image contrast when in focus, and the user can clearly see the letters "ABC".

[0029] Next, referring to Figure 3, we will explain the case where the phase-detection AF control described in Figure 2 is applied to the cinema video mode. Figure 3 is an explanatory diagram of conventional phase-detection AF control in cinema video mode. The operation of (before AF), (during AF operation 1), (during AF operation 2), and (after AF completion) in Figure 3 is the same as that described in Figure 2. The image shown in Figure 3 (Cinema Video Mode Image) is how the image appears in cinema video mode when the focus lens 101 is within the focus range. By passing the image through the soft-focus lens 112, the sharpness of the letters "ABC" becomes softer than in Figure 2, and the image can be finished as a cinema image.

[0030] Next, with reference to Figure 4, the focus range that does not impair the desired cinematic image will be explained. Figure 4 is an explanatory diagram of the focus range that does not impair the desired cinematic image in Example 1. The soft focus lens 112 has spherical aberration, which increases the depth of field, making focusing easier, and allows for both bokeh and focus, thus widening the focus range. Therefore, the image contrast is the same in Figure 4 (during AF operation 2) and (after AF completion), and even if the focus lens 101 is not within the best focus range, it is within the focus range that can be in focus in cinema video mode. In the following explanation, the focus range in normal video mode (first focus range) will be referred to as the "best focus range". Also, the focus range in cinema video mode (second focus range) will be referred to as the "image focus range". The second focus range is wider than the first focus range.

[0031] Next, with reference to Figure 5, the AF drive time reduction control in the cinema video mode in this embodiment will be explained. Figure 5 is an explanatory diagram of the AF drive time reduction control in the cinema video mode in Embodiment 1. To shorten the AF drive time, one can consider increasing the drive speed of the focus lens 101 during AF. On the other hand, if the drive speed is increased, the focus lens 101 is more likely to overshoot the focus range, causing a hunting phenomenon and giving the user an unnatural image. However, in cinema video mode, as explained with reference to Figure 4, the focus range is widened, so the range in which hunting is acceptable is also widened, and it is possible to increase the AF drive speed compared to normal video mode.

[0032] Next, with reference to Figure 6, the AF drive process (control method for the lens device 1) in this embodiment will be described. Figure 6 is a flowchart of the AF drive process in this embodiment.

[0033] First, in step S601, the lens CPU 110 of the lens device 1 starts the AF drive process. Next, in step S602, the lens CPU 110 determines whether or not it is in cinema video mode. That is, the lens CPU 110 uses the soft focus position detection unit 113 to determine (detect) whether or not the soft focus lens 112 is located on the optical axis (optical path). If the lens CPU 110 determines that the soft focus lens 112 is located on the optical axis, it selects (sets) cinema video mode as the video mode. On the other hand, if the lens CPU 110 determines that the soft focus lens 112 is not located on the optical axis, it selects (sets) normal video mode as the video mode. If the video mode is cinema video mode, the process proceeds to step S603. On the other hand, if the video mode is normal video mode, the process proceeds to step S604.

[0034] In step S603, the lens CPU 110 reads parameters related to the focus drive speed corresponding to the cinema video mode from the memory unit 116 and changes the focus drive speed setting according to those parameters.

[0035] In step S604, the AF control unit 111 calculates the defocus amount using the evaluation value calculated by the focus detection unit 109 and the current position information detected by the focus position detection unit 102. The lens CPU 110 then performs AF drive by outputting a drive command to the focus drive unit 103 based on the defocus amount calculated by the AF control unit 111.

[0036] Next, in step S605, similar to step S604, the AF control unit 111 calculates the amount of defocus and determines whether or not it is within the focus range. If it is determined to be within the focus range, the process proceeds to step S606 and the AF drive process ends. On the other hand, if it is determined to be outside the focus range, the process returns to step S604. In step S604, the AF control unit 111 performs AF fine-tuning control to bring the focus lens 101 within the focus range. Note that in the flowchart of Figure 6, "focus range" refers to the best focus position focus range (first focus range) in normal video mode and the image focus range (second focus range) in cinema video mode.

[0037] As described above, in this embodiment, the AF control unit 111 changes the parameters related to autofocus adjustment depending on whether or not the soft focus lens 112 is inserted into the optical path. Preferably, the AF control unit 111 performs autofocus adjustment using the parameters obtained from the memory unit 116.

[0038] Preferably, the parameters include parameters relating to the driving speed of the focus lens 101. More preferably, the driving speed of the focus lens 101 when the soft focus lens 112 is inserted into the optical path is faster than the driving speed of the focus lens 101 when the soft focus lens 112 is retracted from the optical path.

[0039] According to this embodiment, it is possible to achieve faster AF drive speed and shorter AF processing time without degrading the desired image quality.

[0040] (Example 2) Next, with reference to Figure 7, the configuration of the imaging device 10a in Embodiment 2 of the present invention will be described. Figure 7 is a configuration diagram of the imaging device 10a in this embodiment. The imaging device 10a is an imaging system comprising a lens device 1a and a camera device (camera body) 2, a focus control device 3, and a zoom control device 4 that are detachable from the lens device. However, the imaging device 10a is not limited to this, and may also be an imaging device comprising a lens device 1 and a camera device 2 (an imaging device that does not include at least one of the focus control device 3 or the zoom control device 4). The imaging device 10a may also be an imaging device in which the lens device 1 and the camera device 2 are integrally configured. Furthermore, the imaging device 10a may have the lens device 1 and at least one of the focus control device 3 or the zoom control device 4 integrally configured.

[0041] The imaging device 10a of this embodiment differs from the imaging device 10 of Embodiment 1 in that it includes a lens device 1a instead of the lens device 1, and also includes a zoom control device 4. The lens-controller communication unit 118 communicates with the focus control device 3 and the zoom control device 4. The lens device 1a of this embodiment differs from the lens device 1 of Embodiment 1 in that it includes a zoom lens (third lens) 119, a zoom position detection unit 120, and a zoom lens drive unit 121.

[0042] The zoom lens 119 is located on the optical axis, and its focal length can be changed by adjusting its position in the direction of the optical axis. The angle of view can be set by adjusting the focal length. The zoom position detection unit 120 and the zoom lens drive unit 121 are a position detection means and a drive means mechanically connected to the zoom lens 119, respectively, and in this embodiment they are composed of a known encoder and motor for position detection. In this embodiment, the memory unit 116 stores the drive speed of the focus lens 101 according to the position of the zoom lens 119 as information related to AF control.

[0043] The zoom control device 4 is connectable to the lens device 1 and is an operating unit for controlling the zoom. The zoom controller CPU 401 is the control unit of the zoom control device 4 and can transmit operation signals from the zoom handle operating unit 402 used for zoom operation to the lens device 1 via the zoom controller communication unit 403. In this embodiment, the zoom control operation is performed by the zoom control device 4, but it may also be configured in the lens device 1.

[0044] In a system that generates cinematic images using a soft-focus lens 112, it is known that at a focal length known as the F-drop period (described later), the optical soft-focus effect is not produced. The F-drop period refers to the period during which the F-number (maximum aperture) becomes darker when the aperture of the aperture mechanism 104 is at its maximum. Since the F-number is a value obtained by dividing the focal length of the lens by the effective aperture of the lens, theoretically it becomes darker as you move from wide-angle to telephoto. However, in reality, it remains constant from wide-angle to near the telephoto end, and beyond a certain point towards the telephoto end, the maximum aperture drops, and the amount of light decreases. In this embodiment, the maximum aperture is taken into consideration, the position of the zoom lens 119 is read from the zoom position detection unit 120, and the setting of the AF drive speed is changed according to the focal length of the lens. For example, the AF control unit 111 slows down the drive speed when the position of the zoom lens 119 is on the telephoto side of a predetermined position compared to when the position of the zoom lens 119 is on the wide-angle side of a predetermined position.

[0045] Next, with reference to Figure 8, the AF drive process according to the focal length in this embodiment will be described. Figure 8 is a flowchart of the AF drive process in this embodiment. Note that steps S601, S602, and S604-S606 in Figure 8 are the same as those described in Figure 9 in Embodiment 1, so their explanation will be omitted.

[0046] If it is determined in step S602 that the video mode is cinema video mode, the process proceeds to step S801. On the other hand, if it is determined that the video mode is normal video mode, the process proceeds to step S604.

[0047] In step S801, the lens CPU 110 acquires the position of the zoom lens 119 (zoom lens position, focal length) detected using the zoom position detection unit 120. Subsequently, in step S802, the lens CPU 110 acquires the drive speed of the focus lens 101 (focus drive speed) corresponding to the focal length from the memory unit 116 and changes the setting to that focus drive speed.

[0048] In this embodiment, the AF control unit 111 changes parameters according to the position of the zoom lens 119. More preferably, when the position of the zoom lens 119 is on the telephoto side of a predetermined position, the AF control unit 111 slows down the drive speed compared to when the position of the zoom lens 119 is on the wide-angle side of a predetermined position.

[0049] According to this embodiment, it is possible to achieve faster AF drive speed and shorter AF processing time, taking into account the F-drop period during which it is difficult to produce the image effect of a soft-focus lens.

[0050] (Example 3) Next, with reference to Figures 9 to 11, Embodiment 3 of the present invention will be described. In cinema video mode, even if the position of the focus lens 101 is not within the range of the best focus position, it is not a problem as long as it is within the focusing range in cinema video mode. However, if the focus lens 101 is outside the range of the best focus but remains within the focusing range of cinema video mode, then immediately after the user switches from cinema video mode to normal video mode, the image will not be in focus in normal video mode. Therefore, in this embodiment, even when AF is being driven in cinema video mode, the camera is driven to the range of the best focus.

[0051] The lens device 1(1a) in this embodiment is identical in configuration to that of Embodiment 1 or Embodiment 2. On the other hand, the positional relationship between the optical components related to AF control (focus lens 101, branching prism 107, pupil division mechanism 108, focus detection unit 109) and the soft focus lens 112 is limited. In this embodiment, in addition to the information described in Embodiment 1 or Embodiment 2, the memory unit 116 can also store drive speed parameters within the image focusing range, which will be described later, as information related to AF control.

[0052] Figure 9 shows the positional relationship for achieving AF control unaffected by the soft focus lens 112. In AF control, the focus lens 101 is positioned in front of (on the object side of) the focus detection unit 109, the branching prism 107 for guiding light to the focus detection unit 109, and the pupil division mechanism 108. In order for the image to be in focus when switching to normal video mode, the AF control must be configured to be unaffected by the soft focus lens 112. Therefore, as shown in Figure 9, the optical components involved in AF control (focus lens 101, branching prism 107, pupil division mechanism 108, and focus detection unit 109) are positioned in front of (on the object side of) the soft focus lens 112. In other words, in this embodiment, the branching prism 107 is positioned between the focus lens 101 and the soft focus lens 112 in the optical path, so that the AF control is unaffected by the presence or absence of the soft focus lens 112.

[0053] Figure 10 is an explanatory diagram of the two focus ranges in cinema video mode. In this embodiment, the control method in cinema video mode includes not only the image focus range but also the best focus range in the focus range. If the image is within the image focus range, no change will be seen in the image, but by moving the focus lens 101 to the best focus range without stopping AF control, it is possible to instantly provide a sharp image when switching to normal video mode. Also, when switching from normal video mode to cinema video mode, as long as the image is within the best focus range in normal video mode, it is possible to instantly provide cinema video footage even if the soft focus lens 112 is on the optical axis (optical path).

[0054] In cinema video mode, there is no need to increase the drive speed of the focus lens 101 as long as it is within the image focus range. Therefore, by keeping the drive speed low, the focus lens 101 can be moved precisely to the best focus range. As a result, once the focus lens 101 enters the image focus range, it will not leave the image focus range until the AF drive processing is complete, and will be brought to the best focus position.

[0055] Next, with reference to Figure 11, the AF drive process in this embodiment, depending on whether the image is in or out of focus range, will be described. Figure 11 is a flowchart of the AF drive process in this embodiment.

[0056] First, in step S601, the lens CPU 110 of the lens device 1 starts the AF drive process. Next, in step S602, it performs the same processing as in Figure 6 described in Example 1. That is, if the video mode is cinema video mode, it proceeds to step S801. On the other hand, if the video mode is normal video mode, it proceeds to step S1104. In step S801, the lens CPU 110 performs the same processing as in Figure 8 described in Example 2. Next, in step S802, it performs the same processing as in Figure 8 described in Example 2.

[0057] Next, in step S1101, the AF control unit 111 calculates the amount of defocus and determines whether the amount of defocus is within the image focus range. If the amount of defocus is within the image focus range, the process proceeds to step S1103. On the other hand, if the amount of defocus is outside the image focus range, the process proceeds to step S1102.

[0058] In step S1102, the lens CPU 110 performs AF drive towards image focusing by outputting an AF drive command to the focus drive unit 103 based on the defocus amount calculated by the AF control unit 111, and then proceeds to step S1101.

[0059] In step S1103, the lens CPU 110 obtains the drive speed of the focus lens 101 within the image focusing range from the memory unit 116 and changes the setting to that drive speed.

[0060] In step S1104, the AF control unit 111 calculates the amount of defocus and determines whether the amount of defocus is within the best focus range. If the amount of defocus is within the best focus range, the process proceeds to step S606 and the AF drive process ends. On the other hand, if the amount of defocus is outside the best focus range, the process proceeds to step S1105.

[0061] In step S1105, the lens CPU 110 outputs an AF drive command to the focus drive unit 103 based on the defocus amount calculated by the AF control unit 111, and proceeds to step S1104.

[0062] In this embodiment, the parameters include a parameter relating to a first focusing range set to best focus, and a parameter relating to a second focusing range that is wider than the first focusing range (for setting the desired image). Preferably, the parameters include a parameter relating to the drive speed of the focus lens 101 within the second focusing range, and a parameter relating to the drive speed of the focus lens 101 outside the second focusing range. More preferably, the drive speed within the second focusing range is faster than the drive speed outside the second focusing range.

[0063] According to this embodiment, it is possible to instantly provide the user with video suitable for their needs, even immediately after switching video modes.

[0064] (Example 4) Next, with reference to Figures 12 to 14, Embodiment 4 of the present invention will be described. The lens device 1(1a) can determine focus from the AF control unit 111, and can display a notification of completion of AF operation on the AF focus display unit 306. In this embodiment, this role is assigned to the focus control device 3, but it may also be assigned to the lens device 1.

[0065] From a user's perspective, the longer the notification display on the AF focus indicator 306 is delayed, the more stressed they become. In this embodiment, the property that the desired cinematic image is produced if the image is within the focus range in cinema video mode is utilized to output the AF focus notification quickly.

[0066] Figure 12 is an external view of the focus control device 3. The AF / MF switch 302, focus handle operating section 303, AF switch section 304, and AF focus confirmation indicator section 306 are user interfaces for operating the focus lens 101, as described in Embodiment 1. In this embodiment, the AF focus confirmation indicator section 306 is composed of an LED (light-emitting diode) and is designed to light up when the AF operation is completed.

[0067] Figure 13 is an explanatory diagram of the timing of the AF termination notification output. In cinema video mode, if the amount of defocus is within the image focus range described in Example 3, virtually no change occurs in the image. Therefore, it is possible to notify the user of the AF termination when the amount of defocus enters the image focus range.

[0068] Next, the AF drive process in this embodiment will be described with reference to Figure 14. Figure 14 is a flowchart of the AF drive process in this embodiment. Note that Figure 14 differs from Figure 11 described in Embodiment 3 in that step S1401 is inserted between steps S1101 and S1103. The other steps are the same as in Figure 11, so their explanation will be omitted.

[0069] If the amount of defocus in step S1101 is inside the image focus range, proceed to step S1401. On the other hand, if the amount of defocus is outside the image focus range, proceed to step S1102.

[0070] In step S1401, the lens CPU 110 communicates with the lens-controller communication unit 118 and the focus controller communication unit 305. The lens CPU 110 then displays an AF completion notification on the AF focus indicator unit 306 via the focus controller CPU 301, and proceeds to step S1103.

[0071] In this embodiment, the AF focus indicator 306 provides notification when it detects that the focus lens 101 is within the range of the second focus range. Preferably, the AF control unit 111 drives the focus lens 101 within the range of the first focus range after the AF focus indicator 306 has provided notification.

[0072] According to this embodiment, it is possible to display the completion notification of the AF operation earlier, thereby reducing stress on the user.

[0073] (Other examples) The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0074] According to each embodiment, it is possible to provide a lens device, an imaging device, a control method for the lens device, and a program that can achieve high-speed AF processing.

[0075] Each embodiment's disclosure includes the following configuration and method. (Composition 1) The first lens moves during focusing, A second lens that modifies aberrations by insertion and removal from the optical path, The system includes a control unit that performs autofocus adjustment by controlling the movement of the first lens using first information relating to autofocus adjustment, The lens device is characterized in that the control unit changes the first information depending on whether or not the second lens is inserted into the optical path. (Configuration 2) It further has a storage unit for storing the first information, The lens device according to configuration 1, characterized in that the control unit performs the automatic focus adjustment using the first information obtained from the storage unit. (Composition 3) The lens apparatus according to configuration 1 or 2, characterized in that the first information includes information regarding the driving speed of the first lens. (Composition 4) The lens device according to configuration 3, characterized in that the driving speed of the first lens when the second lens is inserted into the optical path is faster than the driving speed of the first lens when the second lens is retracted from the optical path. (Composition 5) The lens device according to configuration 3 or 4, characterized in that the aforementioned drive speed is a target drive speed set by the user. (Composition 6) It further has a third lens that changes the focal length, The lens device according to any one of configurations 1 to 5, characterized in that the control unit changes the first information according to the position of the third lens. (Composition 7) The first information includes information regarding the driving speed of the first lens, The lens device according to configuration 6, characterized in that the control unit slows down the drive speed when the position of the third lens is on the telephoto side of the predetermined position compared to when the position is on the wide-angle side of the predetermined position. (Composition 8) The lens device according to configuration 1 or 2, characterized in that the first information includes information regarding a first focusing range to be set to the best focus range and information regarding a second focusing range that is wider than the first focusing range. (Composition 9) The lens apparatus according to configuration 8, characterized in that the first information includes information regarding the driving speed of the first lens within the range of the second focusing range and information regarding the driving speed of the first lens outside the range of the second focusing range. (Composition 10) The lens device according to configuration 9, characterized in that the drive speed within the range of the second focusing range is faster than the drive speed outside the range of the second focusing range. (Composition 11) The device further includes a branching section that splits the light that has passed through the first lens into a first beam of light directed toward the imaging unit and a second beam of light used for the autofocus adjustment. The lens device according to any one of configurations 1 to 10, characterized in that the control unit performs automatic focus adjustment using the second light in a phase difference detection manner. (Composition 12) The lens device according to configuration 11, characterized in that the branching portion is arranged between the first lens and the second lens in the optical path. (Composition 13) It further includes a notification unit that notifies the end of operation, The lens device according to any one of configurations 10 to 12, characterized in that the notification unit makes the notification when it is detected that the first lens is within the range of the second focusing range. (Composition 14) The lens device according to configuration 13, characterized in that the control unit drives the first lens within the range of the first focusing range after the notification unit has made the notification. (Composition 15) The lens apparatus according to any one of configurations 1 to 14, characterized in that the second lens is a lens that imparts at least one of spherical aberration and chromatic aberration. (Composition 16) An imaging device characterized by having a lens device as described in any of configurations 1 to 15 and an imaging unit. (Method 1) A control method for a lens device having a first lens that moves during focusing, a second lens that changes aberrations by inserting or removing it from the optical path, and a control unit that performs autofocus adjustment by controlling the movement of the first lens using first information relating to autofocus adjustment, A step of determining whether the second lens is inserted into the optical path, A method for controlling a lens device, characterized by comprising the step of changing the first information depending on whether or not the second lens is inserted into the optical path. (Composition 17) A program characterized by causing a computer to execute the lens device control method described in Method 1.

[0076] Although 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 its essence. [Explanation of symbols]

[0077] 1, 1a Lens device 101 Focus lens (first lens) 111 AF Control Unit (Control Unit) 112 Soft focus lens (second lens)

Claims

1. The first lens moves during focusing, A second lens that modifies aberrations by insertion and removal from the optical path, The system includes a control unit that performs autofocus adjustment by controlling the movement of the first lens using first information relating to autofocus adjustment, The lens device is characterized in that the control unit changes the first information depending on whether or not the second lens is inserted into the optical path.

2. The system further includes a storage unit for storing the first information, The lens device according to claim 1, characterized in that the control unit performs the autofocus adjustment using the first information obtained from the storage unit.

3. The lens apparatus according to claim 1, characterized in that the first information includes information relating to the driving speed of the first lens.

4. The lens device according to claim 3, characterized in that the driving speed of the first lens when the second lens is inserted into the optical path is faster than the driving speed of the first lens when the second lens is retracted from the optical path.

5. The lens device according to claim 3, characterized in that the aforementioned drive speed is a target drive speed set by the user.

6. It further has a third lens that changes the focal length, The lens device according to claim 1, characterized in that the control unit changes the first information according to the position of the third lens.

7. The first information includes information relating to the driving speed of the first lens, The lens device according to claim 6, characterized in that the control unit slows down the drive speed when the position of the third lens is on the telephoto side of the predetermined position compared to when the position is on the wide-angle side of the predetermined position.

8. The lens device according to claim 1, characterized in that the first information includes information regarding a first focusing range to be set to the best focus range and information regarding a second focusing range that is wider than the first focusing range.

9. The lens apparatus according to claim 8, characterized in that the first information includes information relating to the driving speed of the first lens within the range of the second focusing range and information relating to the driving speed of the first lens outside the range of the second focusing range.

10. The lens device according to claim 9, characterized in that the drive speed within the range of the second focusing range is faster than the drive speed outside the range of the second focusing range.

11. The device further includes a branching section that splits the light that has passed through the first lens into a first beam of light directed toward the imaging unit and a second beam of light used for the autofocus adjustment. The lens device according to claim 1, characterized in that the control unit performs automatic focus adjustment using a phase difference detection method with respect to the second light.

12. The lens device according to claim 11, characterized in that the branching portion is arranged between the first lens and the second lens in the optical path.

13. It further includes a notification unit that notifies the end of operation, The lens device according to claim 10, characterized in that the notification unit makes the notification when it is detected that the first lens is within the range of the second focusing range.

14. The lens device according to claim 13, characterized in that the control unit drives the first lens within the range of the first focusing range after the notification unit has made the notification.

15. The lens apparatus according to any one of claims 1 to 14, characterized in that the second lens is a lens that provides at least one of spherical aberration and chromatic aberration.

16. An imaging device comprising a lens device according to any one of claims 1 to 14 and an imaging unit.

17. A control method for a lens device having a first lens that moves during focusing, a second lens that changes aberrations by inserting and removing it from the optical path, and a control unit that performs autofocus adjustment by controlling the movement of the first lens using first information relating to autofocus adjustment, A step of determining whether the second lens is inserted into the optical path, A method for controlling a lens device, characterized by comprising the step of changing the first information depending on whether or not the second lens is inserted into the optical path.

18. A program characterized by causing a computer to execute the control method for the lens device described in claim 17.

Images