Control device, camera device, control method and storage medium

Abstract

The present invention provides a control device, an imaging device, a control method and a storage medium. The control device includes: a tilt drive unit configured to perform tilt drive; a focus drive unit; a control unit configured to control the focus drive unit and the tilt drive unit to focus on at least a first area and a second area among a plurality of areas in an image; and a first determination unit configured to determine a control method of the control unit based on whether the difference between the position of at least one of the first area and the second area and the position corresponding to the tilt axis in the image is less than a predetermined threshold.

Description

Technical Field

[0001] The present invention relates to a control device and an imaging device each of which performs tilt control. Background Art

[0002] As is well known, the technique called the Scheimpflug principle adjusts the focal plane (hereinafter referred to as "tilt control") by rotating the imaging plane so that the imaging plane is tilted relative to the imaging optical axis plane orthogonal to the imaging optical axis system for photographing the subject, and changes the depth of field for the imaging scene. Cameras for monitoring applications need to capture images with a deep depth of field. Using the above technique, the depth of field can be increased without narrowing the aperture stop (aperture), and an image in which the imaging area is fully focused can be obtained while suppressing the blur and noise of the subject caused by insufficient light intensity.

[0003] Japanese Patent Laid-Open (“JP”) 2017-173802 discloses an imaging apparatus that provides focus control (minimizes the focus shift amount) based on the focus shift amounts of a plurality of focus detection areas.

[0004] However, the imaging device disclosed in JP 2017-173802 acquires the control target position by calculation, and may not provide control that produces an ideal tilt angle and focus position due to mechanical errors. Instead of controlling the control target position acquired by calculation, it may be considered to control both the tilt angle and the focus position while determining the focus level of the subject. However, in this case, depending on the setting of the area for determining the focus level of the subject, the change in the focus level cannot be correctly determined, and the control may result in an erroneous tilt angle and focus position. Summary of the invention

[0005] The present invention provides a control device, an imaging device, a control method, and a storage medium, each of which can provide high-precision focusing by switching a focus control method according to the position of an area for calculating an evaluation value related to a focus level.

[0006] A control device according to one aspect of the present invention includes: a tilt drive unit, which is configured to perform tilt drive by changing the tilt of at least one of an image sensor and an optical system; a focus drive unit, which is configured to perform focus drive by moving a focus lens constituting at least a part of the optical system along an optical axis direction; at least one processor; and at least one memory, which is coupled to at least one processor storing instructions, which, when executed by the at least one processor, enables the at least one processor to function as a control unit, the control unit being configured to control the focus drive unit and the tilt drive unit to focus on at least a first area and a second area among multiple areas in an image; and a first determination unit, which is configured to determine a control method of the control unit based on whether a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis in the image is less than a predetermined threshold.

[0007] According to another aspect of the present invention, an imaging device includes an image sensor and the above-mentioned control device. A control method corresponding to the control device and a non-transitory computer-readable storage medium storing a program for causing a computer to execute the control method also constitute another aspect of the present invention.

[0008] According to another aspect of the present invention, a control method is configured to control a tilt drive unit and a focus drive unit, wherein the tilt drive unit is configured to perform tilt drive by changing the tilt of at least one of an image sensor and an optical system, and the focus drive unit is configured to perform focus drive by moving a focus lens constituting at least a part of the optical system along an optical axis direction, and the control method includes the following steps: controlling the focus drive unit and the tilt drive unit to focus on at least a first area and a second area among multiple areas in an image; and determining the control method in the control based on whether the distance between the position of at least one area among the first area and the second area and the position corresponding to the tilt axis in the image is less than a predetermined threshold.

[0009] A non-transitory computer-readable storage medium according to still another aspect of the present invention is used to store a program for causing a computer to execute the above control method.

[0010] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a block diagram of an image pickup apparatus according to various embodiments.

[0012] Figure 2 The tilt control in each embodiment is described.

[0013] FIG. 3A to FIG. 3C The tilt angle correction amount and the focus position correction amount in each embodiment are described.

[0014] Figure 4 The subsequent control based on the change of the evaluation value in each embodiment is described.

[0015] Figure 5 The tilt driving direction in each embodiment is described.

[0016] Figure 6 Schematic diagram of the positional relationship between the image sensor and point A and point B in each embodiment.

[0017] Fig. 7A and Figure 7B Describe the scenarios in various embodiments.

[0018] FIG. 8A to FIG. 8C The change of the evaluation value of the scene in each embodiment is described.

[0019] Fig. 9 A flow chart showing a control method according to the first embodiment.

[0020] Fig.10 A focus control method according to the first embodiment is described.

[0021] Fig.11A and Fig. 11B A flow chart showing a control method according to the second embodiment is shown.

[0022] Fig.12 The next control based on the change of the evaluation value in the second embodiment is described.

[0023] FIG. 13A to FIG. 13M A control method according to the second embodiment is described.

[0024] Fig.14 The relationship between the distance of the evaluation value acquisition region from the tilt axis and the evaluation value change amount in each embodiment is shown. DETAILED DESCRIPTION

[0025] Now, referring to the drawings, a detailed description will be given of embodiments according to the present invention.

[0026] Reference Figure 1 , a description will be given of an image pickup apparatus 100 according to this embodiment. Figure 1 : is a block diagram of the imaging apparatus 100. The imaging apparatus 100 may have a structure in which a camera body and an imaging optical system (optical system) are integrated with each other, or a structure in which an imaging optical system (interchangeable lens) is attachable to and detachable from a camera body.

[0027] The imaging optical system includes a zoom lens 101 that moves in the direction of the optical axis OA (optical axis direction) to change the focal length, a focus lens 102 that moves in the optical axis direction to adjust the focus, and an aperture stop (aperture) unit 103 that adjusts the amount of light. The light that has passed through the imaging optical system forms a subject image as an optical image on the image sensor 106 via a band pass filter (BPF) 104 and a color filter 105. The BPF 104 can be inserted into the optical path of the imaging optical system and can exit from the optical path of the imaging optical system. The image sensor 106 is a CMOS sensor or a CCD sensor, and performs photoelectric conversion on the subject image formed via the imaging optical system to output an analog electric signal (imaging signal). The analog electric signal output from the image sensor 106 is gain-controlled by the AGC 107, converted into a digital signal by the A / D converter 108, and then input to the camera signal processing unit 109.

[0028] The camera signal processing unit 109 performs various image processing on the digital camera signal to generate a video signal. The video signal is output to the monitoring monitoring device 111 connected to the camera apparatus 100 by wired or wireless communication via the communication unit 110. Upon receiving an instruction from the user, the monitoring monitoring device 111 outputs a control signal such as a command to each of the evaluation value acquisition area setting unit 112, the tilt control unit 115, the focus control unit 116, and the zoom control unit 117 in the camera apparatus 100 via the communication unit 110.

[0029] The evaluation value acquisition area setting unit 112 sets an area to be focused (evaluation value acquisition area) based on an instruction from the communication unit 110. The focus method determination unit (first determination unit) 113 determines a focus control method according to the area set by the evaluation value acquisition area setting unit 112. The evaluation value calculation unit (second determination unit) 114 acquires (calculates or determines) an evaluation value related to contrast in the area set by the evaluation value acquisition area setting unit 112 from the A / D converter 108 or the camera signal processing unit 109.

[0030] The tilt control unit (control unit) 115 instructs the tilt drive unit 118 on the tilt setting position based on the focus method determined by the focus method determination unit 113 and the evaluation value calculated (determined) by the evaluation value calculation unit 114. The focus control unit (control unit) 116 instructs the focus drive unit 119 on the focus setting position based on the focus method determined by the focus method determination unit 113 and the evaluation value calculated by the evaluation value calculation unit 114. The zoom control unit 117 instructs the zoom drive unit 120 on the zoom setting position based on the instruction from the communication unit 110.

[0031] The tilt drive unit 118 drives the image sensor 106 based on the tilt setting position instructed by the tilt control unit 115. The focus drive unit 119 drives the focus lens 102 based on the focus setting position instructed by the focus control unit 116. The zoom drive unit 120 drives the zoom lens 101 based on the zoom setting position instructed by the zoom control unit 117.

[0032] Reference Figure 2 , Figure 3A and Figure 3B , a description of tilt control will be given. Figure 2 Tilt control is described, and an example of tilt control is shown, which brings the faces of two subjects, subject A and subject B, in focus within the imaging angle of view at different distances from the imaging device 100. The principle of tilt control is called the Scheimpflug principle, in which when the optical system principal plane 201 and the imaging plane 202 intersect each other at a point (Scheimpflug point 204), the focal plane 203 also intersects them at the point. According to the Scheimpflug principle, the tilt angle α is calculated by the following formula (1), in which F is the focal length, L is the subject distance, and θ is the depression angle.

[0033] α=tan -1 (f / Ltanθ) (1)

[0034] This allows all objects on a plane, from short distances to long distances, to be focused.

[0035] FIG. 3A to FIG. 3C A target scene for tilt control and a tilt angle correction amount α and a focus position correction amount β suitable for the scene are described. Figure 3A The scene in shows two subjects, a subject A and a subject B, located at different distances from the imaging apparatus 100. Figure 3B against Figure 3A The scene shown schematically shows the relationship between the position of the image sensor 106, the focus position of the subject A (point A), and the focus position of the subject B (point B). The vertical position of each of the subjects A and B represents the image height, and the horizontal distance of each of the subjects A and B from the image sensor 106 represents the defocus amount. In order to focus on both the subject A and the subject B, as shown in FIG. Figure 3C As shown, the image sensor 106 may be driven with a tilt angle correction amount α (tilt angle α), and the focus lens 102 may be driven with a focus position correction amount β so that the imaging plane 202 is aligned with (contains) point A and point B.

[0036] Reference Figures 4 to 6An example of a control determination condition will be given, which is used to determine the next control by changing the evaluation values ​​of two (front and rear) areas while slightly driving the focus position and the tilt angle, so that both the subject A and the subject B located in the two areas gradually approach the in-focus state. Figure 4 The next control determined based on the change in the evaluation value will be described. Figure 5 Describes the tilt drive direction.

[0037] exist Figure 4 In the above, “tilt + drive” and “tilt - drive” are defined as the Figure 5 Tilt drive in plus (+) and minus (-) directions shown. Figure 6 Schematically showing the Figure 4 The determination conditions shown in the figure are used to determine the positional relationship between the image sensor 106 and the points A and B when the control for focusing on the points A and B is performed. Since the tilt drive and the focus drive change the relative positional relationship between the image sensor 106 and the focus lens 102, the image sensor 106 or the focus lens 102 can be driven. Figure 6 As shown, in the case of fine tilt driving or fine focus driving, by determining the next control based on the evaluation value change, it is possible to focus on point A and point B.

[0038] Fig. 7A and Figure 7B The scenario in this embodiment is described. Fig. 7A A scene of tilt control is shown in which the subject B is located near a position corresponding to the tilt axis 301 in the captured image. Figure 7B against Fig. 7A The illustrated scene schematically shows the relationship between the position of the image sensor 106, the in-focus position of subject A (point A), and the in-focus position of subject B (point B). The vertical position of each of subjects A and B represents the image height, and the horizontal distance of each of subjects A and B from the image sensor 106 represents the defocus amount.

[0039] FIG. 8A to FIG. 8C Describes changes in rating values ​​in a scene. Fig. 8A The positional relationship between the tilt axis 301 , tilt angles 801 to 803 , and point A and point B is shown. Figure 8B and Figure 8C 801, 802, and 803, respectively, show changes in the evaluation values ​​at point A and point B. Figure 8B and Figure 8C , the horizontal axis represents the inclination angle, and the vertical axis represents the evaluation value.

[0040] In FIG. 8 , the evaluation values ​​804, 805, and 806 for point A and Figure 8C The evaluation values ​​807, 808, and 809 for point B correspond to the evaluation values ​​for tilt angle 801, tilt angle 802, and tilt angle 803, respectively. For point A, the tilt + drive makes the positions of point A and the image sensor 106 close to each other, and as shown in FIG. Figure 8B On the other hand, for point B located on the tilt axis 301, as shown in Figure 8C As shown, the tilt drive does not change the evaluation value. Therefore, the tilt drive does not change the evaluation value on the tilt axis 301, and if based on Figure 4 If the control is performed based on the determination conditions shown, the control for the focus state may not be performed due to erroneous determination. In various embodiments, the tilt axis 301 is located at (but not limited to) a specific position in the image, such as the horizontal direction of the center part.

[0041] In the following respective embodiments, a description will be given of a method of switching the focus control method in a case where both the tilt angle and the focus position are controlled while determining the focus level of a subject, and an evaluation value acquisition area for the evaluation value of the focus control is located on the tilt axis 301. Thus, high-precision focusing can be performed.

[0042] First embodiment

[0043] Reference Fig. 9 , a description will be given of the control method (focus control) according to the first embodiment. Fig. 7A and Figure 7B As shown, this embodiment relates to a focus control method in a scene where a subject is located at a position corresponding to the tilt axis 301 in a captured image. Fig. 9 A flow chart showing a control method according to this embodiment is shown.

[0044] First, in step S901, the evaluation value acquisition area setting unit 112 determines whether there are multiple subjects with different image heights in the scene. The subject can be detected by subject detection in the camera device 100, or the determination can be made based on instructions (operations) from the user via the monitoring monitoring device 111. If it is determined that there are no multiple subjects with different image heights, the process enters step S902. If it is determined in step S901 that there are no multiple subjects with different image heights, it is not necessary to increase the depth of field by tilt control. Therefore, in step S902, the focus control unit 116 performs automatic focus (AF) control for a certain subject and enters step S911.

[0045] On the other hand, in the case where it is determined in step S901 that there are multiple subjects with different image heights, the process proceeds to step S903. In the case where it is determined in step S901 that there are multiple subjects with different image heights, the scene needs to use tilt control to increase the depth of field. Therefore, in step S903, the evaluation value acquisition area setting unit 112 sets two areas with different image heights among the multiple subjects as evaluation value acquisition areas. The evaluation value acquisition area can be an area where the subject is detected by subject detection or an area specified by the user.

[0046] Next, in step S904, the focusing method determination unit 113 determines whether any one of the two evaluation value acquisition areas set in step S903 exists near the position corresponding to the tilt axis in the captured image. In the case where it is determined that neither of the two evaluation value acquisition areas exists near the position corresponding to the tilt axis in the captured image, the process proceeds to step S905. On the other hand, in the case where it is determined that any one of the two evaluation value acquisition areas exists near the position corresponding to the tilt axis in the captured image, the process proceeds to the focus control method surrounded by the dotted line (steps S906 to S910). It can be determined whether the evaluation value acquisition area exists near the position corresponding to the tilt axis in the captured image by calculating the distance difference between the position of the evaluation value acquisition area and the position of the tilt axis (rotation axis of the tilt drive unit) and by determining whether the difference is less than a predetermined threshold. The predetermined threshold can be set according to the depth of field determined based on the focal length, the subject distance, and the F value. The predetermined threshold can be set smaller as the depth of field is shallower, and set larger as the depth of field is deeper. That is, in a case where the depth of field is shallower than a predetermined depth of field, the predetermined threshold is a first threshold, and in a case where the depth of field is deeper than the predetermined depth of field, the predetermined threshold is a second threshold greater than the first threshold.

[0047] In the case where it is determined in step S904 that neither of the two evaluation value acquisition areas exists near the position corresponding to the tilt axis in the captured image, the flow proceeds to step S905. In step S905, the tilt control unit 115 and the focus control unit 116 determine the value of the image to be acquired based on the tilt axis. Figure 4 The conditions shown are determined as follows Figure 6 Thus, control can be performed so that the subject A and the subject B located in the two evaluation value acquisition areas are in focus.

[0048] On the other hand, in the case where it is determined in step S904 that any one of the two evaluation value acquisition areas exists near the position corresponding to the tilt axis in the captured image, the process proceeds to step S906. In step S906, the evaluation value calculation unit 114 and the focus control unit 116 perform AF in the evaluation value acquisition area determined to exist near the position corresponding to the tilt axis in the captured image, and perform control for fixing the focus position (single-shot AF). Next, in step S907, the focus control unit 116 determines whether the evaluation value acquisition area existing near the tilt axis is in a focused state on the subject, that is, whether the single-shot AF is completed. In the case where it is determined that it is not in a focused state on the subject, it can be considered that the subject has moved from the evaluation value acquisition area set in step S903. Therefore, steps S901 to S907 are repeated.

[0049] On the other hand, in the case where it is determined that the subject is in focus, the process proceeds to step S908. In step S908, in an evaluation value acquisition area different from the evaluation value acquisition area in the two evaluation value acquisition areas that exists near the position corresponding to the tilt axis in the captured image, the tilt control unit 115 and the evaluation value calculation unit 114 search for the evaluation value peak while changing the tilt angle (perform a tilt search). Next, in step S909, the tilt control unit 115 determines the tilt angle when the evaluation value is maximum based on the tilt search result in step S908. Next, in step S910, the tilt control unit 115 performs tilt control based on the tilt angle determined in step S909.

[0050] Reference Fig.10 , will give Fig. 9 Description of the process of steps S906 to S910 (focus control method) shown. Fig.10 The process of steps S906 to S910 is shown. The vertical position of each of the subjects A and B represents the image height, and the horizontal distance of each of the subjects A and B from the image sensor 106 represents the defocus amount. By performing single-shot AF for the evaluation value acquisition area set to the subject B at a position corresponding to the tilt axis in the captured image, and by performing tilt search in the evaluation value acquisition area set to the subject A, tilt control can be performed so that point A and point B are in focus.

[0051] Next, in Fig. 9 In step S911 in the evaluation value calculation unit 114, it is determined whether both evaluation value acquisition areas are in focus (whether they are in focus state). In the case where at least one of the two evaluation value acquisition areas is not in focus, steps S901 to S911 are repeated. On the other hand, in the case where both evaluation value acquisition areas are in focus, the process is terminated.

[0052] Therefore, even in the case where the evaluation value acquisition area is set to a position corresponding to the tilt axis in the captured image, this embodiment can provide high-precision focusing.

[0053] Second embodiment

[0054] Reference Fig.11A and Fig. 11B , a description will be given of a control method (focus control) according to the second embodiment. Fig. 7A and Figure 7B As shown, this embodiment relates to a focus control method in a scene where a subject exists on a tilt axis 301 . Fig.11A and Fig. 11B A flow chart of the control method according to this embodiment is shown. Fig.11A and Fig. 11B Steps S1101 to S1105 in Fig. 9 Steps S901 to S905 in are the same, so their description will be omitted.

[0055] In the case where it is determined in step S1104 that any one of the two evaluation value acquisition areas exists near the position corresponding to the tilt axis in the captured image, the flow enters the focus control method (steps S1106 to S1117) surrounded by the dotted line. Steps S1106 to S1117 show a focus control method for determining the next control based on the evaluation value changes of the two (front and rear) evaluation value acquisition areas in the case of fine focus driving toward the infinite end or side (far) and the near (short distance) end or side (near).

[0056] Fig.12 An example of the determination condition in the focus control method in this embodiment is shown, and the next control based on the change of the evaluation value is explained. Figure 4 The determination condition of the first embodiment shown in FIG. 1 is that the next control is not determined based on the change in the evaluation value in the case of tilt driving. This is because FIG. 8A to FIG. 8C As shown, when the evaluation value acquisition area exists at a position corresponding to the tilt axis in the captured image, the evaluation value of the evaluation value acquisition area does not change due to tilt driving, determination using the evaluation value leads to error, and the next control cannot be correctly determined. Fig.12 The determination condition shown determines the next control based on which of a predetermined amount of fine focus drive (focus Fardriving) to the infinite end and a predetermined amount of fine focus drive (focus Neardriving) to the near (short distance) end will increase the evaluation value of each evaluation value acquisition area. FIG. 13A to FIG. 13MThe control method according to this embodiment is described, and schematically shown based on Fig.12 The situation in which the determination conditions are controlled to focus on points A and B.

[0057] exist Fig.11A and Fig. 11B In step S1106, the evaluation value calculation unit 114 calculates (acquires) the current evaluation value R in each of the two evaluation value acquisition areas set in step S1103. The current evaluation value R is FIG. 13B to FIG. 13L The dashed line in the figure shows the evaluation value before the focus drive. Figure 13L As shown, the current evaluation value R is used to end the determination processing (S1111), and the end determination processing is used to stop the focusing operation when the state before the focusing drive is already in the focus state on point A and point B, and the evaluation value is reduced in either the focus far drive or the focus near drive.

[0058] Next, in step S1107, the focus control unit 116 provides a predetermined amount of fine focus drive. At this time, the image sensor 106 may be driven instead of driving the focus lens 102. Fig. 13B , Fig.13D , Fig.13F , Fig.13H , Fig.13J and Figure 13L , the image sensor 106 shown by the solid line on the far side of the image sensor 106 shown by the dotted line represents the image sensor 106 as a result of the fine far drive of the predetermined amount.

[0059] Next, in Fig.11A In step S1108 shown in FIG. 1 , after the focus far drive in step S1107, the evaluation value calculation unit 114 acquires the evaluation value Rfar of each of the two evaluation value acquisition areas set in step S1103. Next, in step S1109, the focus control unit 116 provides a predetermined amount of fine focus near drive. At this time, the focus lens 102 or the image sensor 106 can be driven similarly to the case of the focus far drive. Fig. 13B , Fig.13D , Fig.13F , Fig.13H , Fig.13J and Figure 13L , the image sensor 106 shown in a solid line on the near side of the image sensor 106 shown in a dotted line represents the image sensor 106 as a result of a predetermined amount of fine focus near drive.

[0060] Next, in step S1110, after the focus near drive in step S1109, the evaluation value calculation unit 114 obtains the evaluation value Rnear of each of the two evaluation value acquisition areas set in step S1103. Next, in step S1111, the evaluation value calculation unit 114 compares the current evaluation value R of each of the two evaluation value acquisition areas obtained in step S1106 with the respective Rfar and Rnear obtained in steps S1108 and S1110. The evaluation value calculation unit 114 determines whether the evaluation value is increased by the focus far drive or the focus near drive of any one of the two evaluation value acquisition areas. In the case where the evaluation values ​​of all the evaluation value acquisition areas are not increased by the focus far drive or the focus near drive ( Figure 13L ), the position before focus drive becomes the appropriate focus position.

[0061] In the case where it is determined in step S1111 that the evaluation values ​​of the two evaluation value acquisition areas have not increased by the focus far drive or the focus near drive (Rfar≤R and Rnear≤R), the flow proceeds to step S1112. In step S1112, the focus control unit 116 returns to the state before the focus drive ( Figure 13M On the other hand, in the case where it is determined in step S1111 that the evaluation value of either of the two evaluation value acquisition areas increases by focus far drive or focus near drive (Rfar≥R or Rnear≥R), the flow proceeds to step S1113.

[0062] In step S1113, the evaluation value calculation unit 114 determines the focus direction (evaluation value increase direction) in which the evaluation value of each of the two evaluation value acquisition areas increases based on the evaluation values ​​Rfar and Rnear acquired in steps S1108 and S1110. Fig.12 The control to be performed next is determined by the determination conditions shown. Fig. 13B , Fig.13D , Fig.13F and Fig.13H In the case of focus far drive and focus near drive, the evaluation value of the front evaluation value acquisition area becomes larger in focus near drive, and the evaluation value of the rear evaluation value acquisition area becomes larger in focus far drive. Fig.12 The determination conditions shown in the figure, the next control to be performed becomes tilt + drive. Fig.13J In this case, the evaluation values ​​of both the front evaluation value acquisition region and the rear evaluation value acquisition region become larger in the focus close drive. In this case, the next control to be performed is the focus close drive.

[0063] In steps S1114 to S1117, the focus control unit 116 or the tilt control unit 115 provides a predetermined amount of fine focus drive or fine tilt drive ( Fig. 13C , Fig.13E , Figure 13G , Fig.13I and Figure 13K ). After step S1114, S1115, S1116 or S1117, the process proceeds to step S1118. In step S1118, the evaluation value calculation unit 114 determines whether both evaluation value acquisition areas are in focus (whether they are in a focused state). In the case where at least one of the two evaluation value acquisition areas is not in a focused state, steps S1101 to S1118 are repeated. On the other hand, in the case where both evaluation value acquisition areas are in a focused state, the process terminates.

[0064] This embodiment can provide high-precision focusing even in the case where the evaluation value acquisition area is set near the position corresponding to the tilt axis.

[0065] In each embodiment, the focusing method is switched based on the result of determination whether the evaluation value acquisition area exists near the position corresponding to the tilt axis in the captured image. However, in each embodiment, even in the case where it is once determined that the evaluation value acquisition area does not exist near the position corresponding to the tilt axis in the captured image, the focusing method can be switched by making this determination based on the size of the evaluation value change amount caused by the tilt drive.

[0066] Fig.14 The relationship between the distance of the evaluation value acquisition area from the position corresponding to the tilt axis and the evaluation value change amount is shown. Fig.14 In FIG. 1 , the horizontal axis represents the distance of the evaluation value acquisition area from the position corresponding to the tilt axis, and the vertical axis represents the evaluation value change amount. Fig.14 As shown, the amount of change in the evaluation value increases as the distance of the evaluation value acquisition area from the position corresponding to the tilt axis in the captured image increases. Therefore, the evaluation value acquisition area close to the position corresponding to the tilt axis in the captured image has a smaller predetermined threshold value for the evaluation value change, and the evaluation value acquisition area far from the position corresponding to the tilt axis has a larger predetermined threshold value for the evaluation value change. Thus, it can be determined whether there is no expected evaluation value change for the position of the evaluation value acquisition area, that is, whether the evaluation value is not suitable for focus control. In this case, by switching to a focusing method that does not determine the evaluation value through tilt control, high-precision focusing can be provided.

[0067] As described above, in various embodiments, the control device includes a tilt drive unit 118, a focus drive unit 119, a control unit (tilt control unit 115 and focus control unit 116), and a first determination unit (focusing method determination unit 113). The tilt drive unit performs tilt drive by changing the tilt of at least one of the image sensor 106 and the optical system (imaging optical system). The focus drive unit performs focus drive by moving the focus lens 102 constituting at least a part of the optical system in the optical axis direction. The control device may further include a second determination unit (evaluation value calculation unit 114) that determines an evaluation value (evaluation value related to contrast) related to the focus level of each of the multiple regions in the image. The control unit controls the focus drive unit and the tilt drive unit to focus on each of at least the first region and the second region (at least two evaluation value acquisition regions) among the multiple regions. The first determination unit determines the control method of the control unit based on whether the distance difference between the position of at least one of the first region and the second region and the position corresponding to the tilt axis in the image is less than a predetermined threshold.

[0068] The predetermined threshold may be set based on the depth of field. When the depth of field is shallower than the predetermined depth of field, the predetermined threshold may be a first threshold, and when the depth of field is deeper than the predetermined depth of field, the predetermined threshold may be a second threshold greater than the first threshold.

[0069] In a case where the distance difference between the position of at least one of the first area and the second area and the position corresponding to the tilt axis is greater than a predetermined threshold, the first determination unit may set the control method to the first method. On the other hand, in a case where the distance difference between the position of at least one of the first area and the second area and the position corresponding to the tilt axis is less than a predetermined threshold, the first determination unit may set the control method to the second method. In the first method, the control unit may control the focus drive unit or the tilt drive unit based on a change in the evaluation value of the first area and the second area during the focus drive or the tilt drive.

[0070] In the second method, the control unit may perform control based on a change in the evaluation value of at least one of the first area and the second area during focus driving, and the control unit may perform control based on a change in the evaluation value of an area in which the distance difference between the first area and the second area is determined to be greater than a predetermined threshold value during tilt driving. In the second method, the control unit may perform control to focus on an area in which the distance difference between the first area and the second area is determined to be less than the predetermined threshold value by focus driving, and then perform control to focus on an area in which the distance difference between the first area and the second area is determined to be greater than the predetermined threshold value by tilt driving.

[0071] In the second method, the control unit may control the focus drive unit and the tilt drive unit based on the change in evaluation values ​​of each area in the first area and the second area during the focus drive. In the case where the change in evaluation value caused by the focus drive and the tilt drive is greater than the predetermined evaluation value change, the control unit may determine that there is an evaluation value change. In the case where the distance difference is a first difference, the predetermined evaluation value change caused by the tilt drive may be a first evaluation value change. In the case where the distance difference is a second difference greater than the first difference, the predetermined evaluation value change caused by the tilt drive may be a second evaluation value change greater than the first evaluation value change. In the case where it is determined that there is no evaluation value change caused by the tilt drive, the control unit may set the second method. The first area and the second area may be at least one of an area specified by a user and an area in which a subject is detected by subject detection.

[0072] Other embodiments

[0073] The embodiments of the present invention may also be implemented by providing software (program) for performing the functions of the above-described embodiments to a system or device via a network or various storage media, and a computer or a central processing unit (CPU) or a microprocessing unit (MPU) of the system or device reads and executes the program.

[0074] The present invention provides a control device, an imaging device, a control method, and a storage medium, each of which can provide high-precision focusing by switching a focus control method according to the position of an area for calculating an evaluation value related to a focus level.

[0075] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A control device, comprising: a tilt driving unit configured to perform tilt driving by changing a tilt of at least one of the image sensor and the optical system; a focus driving unit configured to perform focus driving by moving a focus lens constituting at least a part of the optical system in an optical axis direction; a control unit configured to control the focus drive unit and the tilt drive unit to focus on at least a first area and a second area among a plurality of areas in an image; a first determining unit configured to determine a control method of the control unit based on whether a distance between a position of at least one of the first area and the second area and a position corresponding to a tilt axis in the image is less than a predetermined threshold; as well as a second determining unit configured to determine an evaluation value related to a focus level of each of the plurality of areas, The method is characterized in that, when the distance between the position of at least one of the first area and the second area and the position corresponding to the tilt axis is greater than the predetermined threshold, the first determining unit sets the control method to the first method, wherein, when a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis is less than the predetermined threshold, the first determining unit sets the control method to the second method, wherein, in the first method, the control unit controls the focus driving unit or the tilt driving unit based on changes in evaluation values ​​of the first area and the second area during the focus driving or the tilt driving, Wherein, in the second method, the control unit controls through the focusing drive to focus on an area in which the distance between the first area and the second area is determined to be less than the predetermined threshold, and then controls through the tilting drive to focus on an area in which the distance between the first area and the second area is determined to be greater than the predetermined threshold.

2. The control device according to claim 1, characterized in that The predetermined threshold is set based on the depth of field.

3. The control device according to claim 2, characterized in that In the case where the depth of field is shallower than a predetermined depth of field, the predetermined threshold is a first threshold, Wherein, when the depth of field is deeper than the predetermined depth of field, the predetermined threshold is a second threshold greater than the first threshold.

4. The control device according to claim 1, characterized in that The control unit determines that there is an evaluation value change in a case where an evaluation value change amount caused by the focus drive and the tilt drive is larger than a predetermined evaluation value change amount.

5. The control device according to claim 4, characterized in that in a case where the distance is a first distance, the predetermined evaluation value change amount caused by the tilt drive is a first evaluation value change amount, Here, in a case where the distance is a second distance greater than the first distance, the predetermined evaluation value change amount caused by the tilt driving is a second evaluation value change amount greater than the first evaluation value change amount.

6. The control device according to claim 1, characterized in that The control unit sets the second method in a case where it is determined that there is no change in the evaluation value caused by the tilt driving.

7. The control device according to claim 1, characterized in that The first area and the second area are at least one of an area designated by a user and an area in which a subject is detected through subject detection.

8. A camera device, comprising: Image sensor; as well as A control device according to any one of claims 1 to 7. 9 . The image pickup apparatus according to claim 8 , further comprising an image pickup optical system as the optical system.

10. A control method, configured to control a tilt drive unit and a focus drive unit, wherein the tilt drive unit is configured to perform tilt drive by changing the tilt of at least one of an image sensor and an optical system, and the focus drive unit is configured to perform focus drive by moving a focus lens constituting at least a part of the optical system along an optical axis direction, the control method comprising the following steps: controlling the focus drive unit and the tilt drive unit to focus on at least a first area and a second area among a plurality of areas in an image; determining a control method in the controlling based on whether a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis in the image is less than a predetermined threshold; as well as determining an evaluation value associated with a focus level of each of the plurality of areas, The method is characterized in that, in determining the control method, when the distance between the position of at least one of the first area and the second area and the position corresponding to the tilt axis is greater than the predetermined threshold, the control method is set to the first method, wherein, in determining the control method, when a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis is less than the predetermined threshold, the control method is set to the second method, wherein, in the first method, the focus driving unit or the tilt driving unit is controlled based on changes in evaluation values ​​of the first area and the second area during the focus driving or the tilt driving, In the second method, control is performed by the focusing drive to focus on an area whose distance between the first area and the second area is determined to be less than the predetermined threshold, and then control is performed by the tilting drive to focus on an area whose distance between the first area and the second area is determined to be greater than the predetermined threshold. 11 . A non-transitory computer-readable storage medium storing a program for causing a computer to execute the control method according to claim 10 .

12. A control device comprising: a tilt driving unit configured to perform tilt driving by changing a tilt of at least one of the image sensor and the optical system; a focus driving unit configured to perform focus driving by moving a focus lens constituting at least a part of the optical system in an optical axis direction; a control unit configured to control the focus drive unit and the tilt drive unit to focus on at least a first area and a second area among a plurality of areas in an image; a first determining unit configured to determine a control method of the control unit based on whether a distance between a position of at least one of the first area and the second area and a position corresponding to a tilt axis in the image is less than a predetermined threshold; as well as a second determining unit configured to determine an evaluation value related to a focus level of each of the plurality of areas, The method is characterized in that, when the distance between the position of at least one of the first area and the second area and the position corresponding to the tilt axis is greater than the predetermined threshold, the first determining unit sets the control method to the first method, wherein, when a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis is less than the predetermined threshold, the first determining unit sets the control method to the second method, wherein, in the first method, the control unit controls the focus driving unit or the tilt driving unit based on changes in evaluation values ​​of the first area and the second area during the focus driving or the tilt driving, Wherein, in the second method, the control unit performs control based on the change of the evaluation value of at least one of the first area and the second area during the focusing drive, and the control unit performs control based on the change of the evaluation value of an area whose distance between the first area and the second area during the tilting drive is determined to be greater than the predetermined threshold.

13. A control method, configured to control a tilt drive unit and a focus drive unit, wherein the tilt drive unit is configured to perform tilt drive by changing the tilt of at least one of an image sensor and an optical system, and the focus drive unit is configured to perform focus drive by moving a focus lens constituting at least a part of the optical system along an optical axis direction, the control method comprising the following steps: controlling the focus drive unit and the tilt drive unit to focus on at least a first area and a second area among a plurality of areas in an image; determining a control method in the controlling based on whether a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis in the image is less than a predetermined threshold; as well as determining an evaluation value associated with a focus level of each of the plurality of areas, The method is characterized in that, in determining the control method, when the distance between the position of at least one of the first area and the second area and the position corresponding to the tilt axis is greater than the predetermined threshold, the control method is set to the first method, wherein, in determining the control method, when a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis is less than the predetermined threshold, the control method is set to the second method, wherein, in the first method, the focus driving unit or the tilt driving unit is controlled based on changes in evaluation values ​​of the first area and the second area during the focus driving or the tilt driving, In which, in the second method, control is performed based on the change of the evaluation value of at least one of the first area and the second area during the focusing drive, and control is performed based on the change of the evaluation value of an area whose distance between the first area and the second area during the tilting drive is determined to be greater than the predetermined threshold.

14. A control device comprising: a tilt driving unit configured to perform tilt driving by changing a tilt of at least one of the image sensor and the optical system; a focus driving unit configured to perform focus driving by moving a focus lens constituting at least a part of the optical system in an optical axis direction; a control unit configured to control the focus drive unit and the tilt drive unit to focus on at least a first area and a second area among a plurality of areas in an image; a first determining unit configured to determine a control method of the control unit based on whether a distance between a position of at least one of the first area and the second area and a position corresponding to a tilt axis in the image is less than a predetermined threshold; as well as a second determining unit configured to determine an evaluation value related to a focus level of each of the plurality of areas, The method is characterized in that, when the distance between the position of at least one of the first area and the second area and the position corresponding to the tilt axis is greater than the predetermined threshold, the first determining unit sets the control method to the first method, wherein, when a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis is less than the predetermined threshold, the first determining unit sets the control method to the second method, wherein, in the first method, the control unit controls the focus driving unit or the tilt driving unit based on changes in evaluation values ​​of the first area and the second area during the focus driving or the tilt driving, Herein, in the second method, the control unit controls the focus driving unit and the tilt driving unit based on changes in evaluation values ​​of each of the first area and the second area during the focus driving period.

15. A control method, configured to control a tilt drive unit and a focus drive unit, wherein the tilt drive unit is configured to perform tilt drive by changing the tilt of at least one of an image sensor and an optical system, and the focus drive unit is configured to perform focus drive by moving a focus lens constituting at least a part of the optical system along an optical axis direction, the control method comprising the following steps: controlling the focus drive unit and the tilt drive unit to focus on at least a first area and a second area among a plurality of areas in an image; determining a control method in the controlling based on whether a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis in the image is less than a predetermined threshold; as well as determining an evaluation value associated with a focus level of each of the plurality of areas, The method is characterized in that, in determining the control method, when the distance between the position of at least one of the first area and the second area and the position corresponding to the tilt axis is greater than the predetermined threshold, the control method is set to the first method, wherein, in determining the control method, when a distance between a position of at least one of the first area and the second area and a position corresponding to the tilt axis is less than the predetermined threshold, the control method is set to the second method, wherein, in the first method, the focus driving unit or the tilt driving unit is controlled based on changes in evaluation values ​​of the first area and the second area during the focus driving or the tilt driving, Here, in the second method, the focus driving unit and the tilt driving unit are controlled based on changes in evaluation values ​​of each of the first area and the second area during the focus driving period. 16 . A non-transitory computer-readable storage medium storing a program for causing a computer to execute the control method according to claim 13 or 15 .

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