Control device, imaging device, control method, and program

Abstract

To provide a control apparatus capable of providing highly accurate focusing by switching a focusing control method in accordance with a position of an area for calculating an evaluation value relating to an in-focus level.SOLUTION: The control apparatus includes: a tilt driving unit (118) configured to perform tilt driving by changing a tilt of at least one of an image sensor (106) and an optical system; a focus driving unit (119) configured to perform focus driving by moving in an optical axis direction a focus lens (102) that constitutes at least part of the optical system; a judgment unit (114) configured to judge an evaluation value relating to an in-focus level of each of a plurality of areas in an image; a control unit (115, 116) configured to control the focus driving unit and the tilt driving unit for focusing on at least a first area and a second area in the plurality of areas; and a determination unit (113) configured to determine a control method of the control unit on the basis of a position of at least one of the first area and the second area.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control device and an imaging device that perform tilt control. [Background technology]

[0002] A commonly known technology is called the Scheimpflug principle, which adjusts the focal plane by tilting the imaging plane relative to the imaging optical axis plane that is perpendicular to the imaging optical axis system that captures the subject (hereinafter referred to as "tilt control"), thereby changing the depth of field of the captured scene. For cameras used in surveillance, there is a demand for images with a deep depth of field. Using this technology, it is possible to increase the depth of field without narrowing the aperture, thereby obtaining images in which the entire shooting area is in focus while suppressing subject blur and noise caused by insufficient light.

[0003] Patent Document 1 discloses an imaging device that performs focus control based on the defocus amounts of a plurality of focus detection areas so as to minimize the defocus amounts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-173802 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the imaging device disclosed in Patent Document 1, the control target position is calculated by calculation, and mechanical errors may prevent control to the ideal flap angle and focus position. Also, instead of controlling to the control target position calculated by calculation, a configuration is conceivable in which both the flap angle and focus position are controlled while determining the focus level of the subject. In this case, however, depending on the setting of the area for determining the focus level of the subject, it may not be possible to correctly determine the change in focus level, resulting in control to an incorrect flap angle and focus position.

[0006] Therefore, the present invention aims to provide a control device, an imaging device, a control method, and a program that enable high-precision focus adjustment by switching the focus adjustment control method depending on the position of the area in which an evaluation value related to the focus degree is calculated. [Means for solving the problem]

[0007] A control device according to one aspect of the present invention includes: a tilt driver that performs tilt drive by changing the tilt of at least one of an image sensor or an optical system; a focus driver that performs focus drive by moving a focus lens that constitutes at least a part of the optical system in the optical axis direction; a determination unit that determines an evaluation value related to a focus degree for each of a plurality of regions in an image; a control unit that controls the focus driver and the tilt driver so as to focus on at least a first region and a second region among the plurality of regions; and a determination unit that determines a control method for the control unit based on whether a difference in distance between a position of at least one of the first region or the second region and a position corresponding to a tilt axis in the image is smaller than a predetermined threshold, and the determination unit sets the control method to a first method when a difference in distance between the position of each of the first region and the second region and the position is larger than the predetermined threshold, and sets the control method to a second method when a difference in distance between the position of at least one of the first region or the second region and the position is smaller than the predetermined threshold. the control unit controls the focus driving unit or the tilt driving unit based on a change in the evaluation value of each of the first area and the second area during the focus driving or the tilt driving in the first method; In the second method, the focus driving is performed to focus on an area of ​​the first area and the second area where the difference in distance is determined to be smaller than the predetermined threshold, and then the tilt driving is performed to focus on an area of ​​the first area and the second area where the difference in distance is determined to be larger than the predetermined threshold. .

[0008] Other objects and features of the present invention will be described in the following embodiments. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a control device, an imaging device, a control method, and a program that are capable of high-precision focus adjustment by switching the focus adjustment control method depending on the position of the area for calculating the evaluation value related to the focus degree. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a block diagram of an imaging device according to each embodiment. [Figure 2] FIG. 4 is an explanatory diagram of tilt control in each embodiment. [Figure 3] 5A and 5B are diagrams illustrating amounts of correction of a swing angle and a focus position in each embodiment. [Figure 4] 10A and 10B are explanatory diagrams of subsequent control based on changes in evaluation values ​​in each embodiment. [Figure 5] 5A and 5B are explanatory diagrams of a tilt drive direction in each embodiment. [Figure 6] 3A and 3B are schematic diagrams illustrating the positional relationship between the imaging element and points A and B in each embodiment. [Figure 7] FIG. 2 is an explanatory diagram of a scene in each embodiment. [Figure 8] 10A and 10B are diagrams illustrating changes in scene evaluation values ​​in each embodiment. [Figure 9] 4 is a flowchart of a control method according to the first embodiment. [Figure 10] FIG. 2 is an explanatory diagram of a focus adjustment control method in the first embodiment. [Figure 11] 10 is a flowchart of a control method according to a second embodiment. [Figure 12] FIG. 10 is an explanatory diagram of the next control based on a change in the evaluation value in the second embodiment. [Figure 13] FIG. 10 is an explanatory diagram of a control method in the second embodiment. [Figure 14]10A and 10B are diagrams illustrating the relationship between the distance from the elevation axis of the evaluation value acquisition area and the amount of change in the evaluation value in each embodiment. DETAILED DESCRIPTION OF THE INVENTION

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

[0012] First, an imaging device 100 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram of the imaging device 100. The imaging device 100 may have either a configuration in which the camera body and the imaging optical system (optical system) are integrally configured, or a configuration in which the imaging optical system (interchangeable lens) is detachably configured with respect to the camera body.

[0013] The imaging optical system includes a zoom lens 101 that moves along an optical axis OA (optical axis direction) to change the focal length, a focus lens 102 that moves along the optical axis direction to adjust the focus, and an aperture unit 103 that adjusts the amount of light. Light passing through the imaging optical system passes through a bandpass filter (BPF) 104 and a color filter 105 to form an optical image of a subject on an imaging element 106. The BPF 104 may be movable forward and backward relative to the optical path of the imaging optical system. The imaging element 106 is a CMOS sensor or a CCD sensor that photoelectrically converts the subject image formed through the imaging optical system and outputs an analog electrical signal (image signal). The analog electrical signal output from the imaging element 106 is gain-adjusted by an AGC 107, converted into a digital signal by an AD converter 108, and then input to a camera signal processing unit 109.

[0014] The camera signal processing unit 109 performs various image processing on the digital imaging signal to generate a video signal. The video signal is output to a monitoring monitor device 111 connected to the imaging device 100 via a communication unit 110 by wired or wireless communication. In response to a user's instruction, the monitoring monitor device 111 outputs control signals such as commands via the communication unit 110 to each of an evaluation value acquisition area setting unit 112, a tilt control unit 115, a focus control unit 116, and a zoom control unit 117 of the imaging device 100.

[0015] The evaluation value acquisition area setting unit 112 sets an area to be focused on (evaluation value acquisition area) based on instructions from the communication unit 110. The focus adjustment method determination unit (determination unit) 113 determines a method of focus adjustment control according to the area set by the evaluation value acquisition area setting unit 112. The focus evaluation value calculation unit (determination unit) 114 obtains (calculates or determines) an evaluation value (focus evaluation value) related to contrast in the area set by the evaluation value acquisition area setting unit 112 from the AD converter 108 or the camera signal processing unit 109.

[0016] A tilt control unit (control unit) 115 instructs a tilt setting position to a tilt driving unit 118 based on the focus adjustment method determined by the focus adjustment method determination unit 113 and the focus evaluation value calculated (determined) by the focus evaluation value calculation unit 114. A focus control unit (control unit) 116 instructs a focus setting position to a focus driving unit 119 based on the focus adjustment method determined by the focus adjustment method determination unit 113 and the focus evaluation value calculated by the focus evaluation value calculation unit 114. A zoom control unit 117 instructs a zoom setting position to a zoom driving unit 120 based on an instruction from the communication unit 110.

[0017] The tilt driver 118 drives the image sensor 106 based on the tilt setting position instructed by the tilt control unit 115. The focus driver 119 drives the focus lens 102 based on the focus setting position instructed by the focus control unit 116. The zoom driver 120 drives the zoom lens 101 based on the zoom setting position instructed by the zoom control unit 117.

[0018] Next, tilt control will be described with reference to Figures 2 and 3. Figure 2 is an explanatory diagram of tilt control, showing an example of performing tilt control on two subjects A and B that are at different distances from the imaging device 100, so that the focus is at the same height as the faces of the two subjects A and B. The principle of tilt control is called the Scheimpflug principle, which states that when the optical system principal plane 201 and the imaging plane 202 intersect at a certain point (Scheimpflug point 204), the focal plane 203 also intersects at that point. According to the Scheimpflug principle, the tilt angle α is calculated using the focal length f, the subject distance L, and the depression angle θ according to the following equation (1).

[0019]

number

[0020] This makes it possible to focus on all subjects from close distances to long distances on a certain plane.

[0021] FIG. 3 is an explanatory diagram of a scene subject to tilt control and a tilt angle correction amount α and focus position correction amount β appropriate for the scene. The scene in FIG. 3(a) shows two subjects A and B at different distances from the imaging device 100. FIG. 3(b) schematically shows the relationship between the position of the image sensor 106 and the in-focus position of subject A (point A) and the in-focus position of subject B (point B) for the scene in FIG. 3(a). To focus on both subjects A and B, the image sensor 106 is driven by the tilt angle correction amount α (tilt angle α) and the focus lens 102 is driven by the focus position correction amount β so that the imaging plane 202 is aligned with points A and B, as shown in FIG. 3(c).

[0022] Next, with reference to Figures 4 to 6, examples of control judgment conditions will be described in which the next control is determined based on changes in the evaluation values ​​of two areas, the front and the back, when the focus position and the tilt angle are slightly driven, and both of subjects A and B present in the two areas are gradually brought closer to focus. Figure 4 is an explanatory diagram of the next control based on changes in the evaluation values. Figure 5 is an explanatory diagram of the tilt drive direction.

[0023] In FIG. 4, "tilt+drive" and "tilt-drive" are defined as the directions shown in FIG. 5. FIG. 6 is a schematic diagram of the positional relationship between the image sensor 106 and points A and B when control is performed to focus on points A and B based on the determination conditions shown in FIG. 4. The tilt drive and focus drive change the relative positional relationship between the image sensor 106 and the focus lens 102, so either the image sensor 106 or the focus lens 102 may be driven. As shown in FIG. 6, the next control is determined based on the change in the evaluation value when the tilt or focus is slightly driven, thereby enabling focusing on points A and B.

[0024] 7(a) and (b) are explanatory diagrams of scenes in this embodiment. Fig. 7(a) shows a scene of tilt control when subject B is present near tilt axis 301. Fig. 7(b) schematically shows the relationship between the position of image sensor 106 and the in-focus position of subject A (point A) and the in-focus position of subject B (point B) for the scene in Fig. 7(a).

[0025] Figures 8(a) to 8(c) are explanatory diagrams of changes in evaluation values ​​in a scene. Figure 8(a) shows the positional relationship between the tilt axis 301, tilt angles 801 to 803, and points A and B. Figures 8(b) and 8(c) show changes in evaluation values ​​when the tilt angle is changed to 801, 802, and 803 at points A and B, respectively. In Figures 8(b) and 8(c), the horizontal axis represents the tilt angle, and the vertical axis represents the evaluation value (focus evaluation value).

[0026] Evaluation values ​​804, 805, and 806 for point A in FIG. 8(b) and evaluation values ​​807, 808, and 809 for point B in FIG. 8(c) correspond to evaluation values ​​for the tilt angles 801, 802, and 803, respectively. For point A, tilt driving brings point A closer to the position of the image sensor 106, and the evaluation value increases as shown in FIG. 8(b). On the other hand, for point B on the tilt axis 301, tilt driving does not change the evaluation value as shown in FIG. 8(c). Thus, tilt driving does not change the evaluation value on the tilt axis 301, and if control is performed based on the determination conditions shown in FIG. 4, there is a possibility that control to achieve a focused state will be erroneously determined. Note that in each embodiment, the tilt axis 301 is located at a specific position in the image (e.g., in the horizontal direction at the center), but this is not limited thereto.

[0027] In the following, in each embodiment, a method for switching the focus adjustment control method when controlling both the swing angle and the focus position while determining the focus level of the subject and the evaluation value acquisition area for the evaluation value used in the focus adjustment control is on the swing axis 301 will be described. This allows for highly accurate focus adjustment.

[0028] (First embodiment) First, a control method (focus adjustment control) in the first embodiment will be described with reference to Fig. 9. This embodiment relates to a focus adjustment control method in a scene where a subject is present on the tilt axis 301, as shown in Fig. 7. Fig. 9 is a flowchart of the control method in this embodiment.

[0029] First, in step S901, the evaluation value acquisition area setting unit 112 determines whether multiple subjects with different image heights exist in the scene. Here, the subjects may be detected by subject detection in the imaging device 100, or the determination may be made according to a user instruction (operation) from the surveillance monitor device 111. If it is determined that multiple subjects with different image heights do not exist, the process proceeds to step S902. If it is determined in step S901 that multiple subjects with different image heights do not exist, the scene does not require deepening the depth of field by tilt control. Therefore, in step S902, the focus control unit 116 performs autofocus (AF) control on one subject, and the process proceeds to step S911.

[0030] On the other hand, if it is determined in step S901 that multiple subjects with different image heights exist, the process proceeds to step S903. If it is determined in step S901 that multiple subjects with different image heights exist, this is a scene in which it is necessary to deepen the depth of field by tilt control. Therefore, in step S903, the evaluation value acquisition area setting unit 112 sets two areas of the multiple subjects with different image heights as evaluation value acquisition areas. The evaluation value acquisition areas may be areas in which subjects are detected by subject detection, or areas specified by the user.

[0031] Next, in step S904, the focus adjustment method determination unit 113 determines whether either of the two evaluation value acquisition areas set in step S903 is located near the tilt axis. If it is determined that neither of the two evaluation value acquisition areas is located near the tilt axis, the process proceeds to step S905. On the other hand, if it is determined that either of the two evaluation value acquisition areas is located near the tilt axis, the process proceeds to the focus adjustment control method (steps S906 to S910) surrounded by the dotted line. Whether or not an evaluation value acquisition area is located near the tilt axis can be determined by calculating the difference in distance between the position of the evaluation value acquisition area and the position of the tilt axis (the rotation axis of the tilt drive unit) and determining whether this difference is smaller than a predetermined threshold. The predetermined threshold may also be set based on the depth of field determined based on the focal length, subject distance, and F-number. The predetermined threshold may also be set smaller as the depth of field is shallower and larger as the depth of field is deeper. That is, the predetermined threshold is a first threshold when the depth of field is shallower than the predetermined depth of field, and is a second threshold greater than the first threshold when the depth of field is deeper than the predetermined depth of field.

[0032] If it is determined in step S904 that neither of the two evaluation value acquisition areas is located near the tilt axis, the process proceeds to step S905. In step S905, the tilt control unit 115 and the focus control unit 116 perform control as shown in Fig. 6 based on the determination conditions shown in Fig. 4. This allows control so that both subjects A and B located in the two evaluation value acquisition areas are in focus.

[0033] On the other hand, if it is determined in step S904 that either of the two evaluation value acquisition areas is located near the tilt axis, the process proceeds to step S906. In step S906, the focus evaluation value calculation unit 114 and the focus control unit 116 perform AF in the evaluation value acquisition area determined to be located near the tilt axis to perform control to fix the focus (one-shot AF). Subsequently, in step S907, the focus control unit 116 determines whether or not the subject is in focus in the evaluation value acquisition area located near the tilt axis, i.e., whether or not one-shot AF has been completed. If it is determined that the subject is not in focus, it is considered that the subject has moved from the evaluation value acquisition area set in step S903. Therefore, steps S901 to S907 are repeated.

[0034] On the other hand, if it is determined that the subject is in focus, the process proceeds to step S908. In step S908, the tilt control unit 115 and the focus evaluation value calculation unit 114 search for an evaluation value peak (tilt search) while changing the tilt angle in one of the two evaluation value acquisition areas that is different from the evaluation value acquisition area located near the tilt axis. Next, in step S909, the tilt control unit 115 determines the tilt angle at which the evaluation value is maximized based on the result of the tilt search in step S908. Next, in step S910, the tilt control unit 115 performs tilt control based on the tilt angle determined in step S909.

[0035] Now, the procedure of steps S906 to S910 (focus adjustment control method) in Fig. 9 will be described with reference to Fig. 10. Fig. 10 is a diagram showing the procedure of steps S906 to S910. By performing one-shot AF in an evaluation value acquisition area set for subject B present on the tilt axis and performing tilt search in an evaluation value acquisition area set for subject A, it is possible to perform tilt control so as to focus on points A and B.

[0036] 9, the focus evaluation value calculation unit 114 determines whether or not both of the two evaluation value acquisition areas are in focus (whether or not they are in focus). If at least one of the two evaluation value acquisition areas is not in focus, steps S901 to S911 are repeated. On the other hand, if both of the two evaluation value acquisition areas are in focus, this flow ends.

[0037] According to this embodiment, even when the evaluation value acquisition area is set on the tilt axis, it is possible to perform high-precision focus adjustment.

[0038] (Second embodiment) Next, a control method (focus adjustment control) in the second embodiment will be described with reference to Fig. 11. This embodiment relates to a focus adjustment control method in a scene in which a subject is present on the tilt axis 301, as shown in Fig. 7. Fig. 11 is a flowchart of the control method in this embodiment. Note that steps S1101 to S1105 in Fig. 11 are the same as steps S901 to S905 in Fig. 9, respectively, and therefore description thereof will be omitted.

[0039] If it is determined in step S1104 that either of the two evaluation value acquisition areas is near the tilt axis, the process proceeds to the focus adjustment control method (steps S1106 to S1117) enclosed by the dotted line. Steps S1106 to S1117 are a focus adjustment control method that determines the next control based on the change in the evaluation value of the two evaluation value acquisition areas in the front and back when the focus is slightly driven to the far and near positions.

[0040] FIG. 12 is an example of a determination condition in the focus adjustment control method of this embodiment, and is an explanatory diagram of the next control based on a change in the evaluation value. Unlike the determination conditions of the first embodiment shown in FIG. 4, this embodiment does not determine the next control based on a change in the evaluation value when tilt driving is performed. This is because, as shown in FIG. 8, if an evaluation value acquisition area exists on the tilt axis, the evaluation value in that evaluation value acquisition area does not change due to tilt driving, and a determination using this evaluation value will result in an erroneous determination, making it impossible to correctly determine the next control. The determination conditions in FIG. 12 determine the next control based on whether driving the focus to the far or near position in each evaluation value acquisition area increases the evaluation value when the focus is slightly driven to the far and near positions by a predetermined amount. FIG. 13 is an explanatory diagram of the control method of this embodiment, and is a schematic diagram of a case where control is performed to focus on points A and B based on the determination conditions of FIG. 12.

[0041] In step S1106 of Fig. 11, the focus evaluation value calculation unit 114 calculates (acquires) a current evaluation value R for each of the two evaluation value acquisition regions set in step S1103. The current evaluation value R is the evaluation value in the state before focus driving, as indicated by the dotted lines in Fig. 13(b) to (l). The current evaluation value R is used in an end determination process (S1111) for stopping the adjustment operation when the state before focus driving is already in focus with respect to points A and B, as shown in Fig. 13(l), and the evaluation value decreases whether focus driving is performed to the far or near side.

[0042] Next, in step S1107, the focus control unit 116 slightly drives the focus to the far side by a predetermined amount. At this time, the image sensor 106 may be driven instead of the focus lens 102. In Figures 13(b), (d), (f), (h), (j), and (l), the solid-line image sensor 106 located on the far side of the dotted-line image sensor 106 indicates the image sensor 106 whose focus has been slightly driven to the far side by a predetermined amount.

[0043] 11, after the focus is driven far in step S1107, the focus evaluation value calculation unit 114 acquires the evaluation value Rfar in each of the two evaluation value acquisition regions set in step S1103. Then, in step S1109, the focus control unit 116 slightly drives the focus to near by a predetermined amount. At this time, as in the case of far drive, either the focus lens 102 or the image sensor 106 may be driven. In FIGS. 13(b), (d), (f), (h), (j), and (l), the solid-line image sensor 106 located on the near side of the dotted-line image sensor 106 indicates the image sensor 106 whose focus has been slightly driven near by a predetermined amount.

[0044] Next, in step S1110, after the focus is driven to near in step S1109, the focus evaluation value calculation unit 114 acquires the evaluation value Rnear in each of the two evaluation value acquisition regions set in step S1103. Next, in step S1111, the focus evaluation value calculation unit 114 compares the current evaluation value R acquired in step S1106 with Rfar and Rnear acquired in steps S1108 and S1110, respectively, in each of the two evaluation value acquisition regions. The focus evaluation value calculation unit 114 then determines whether the evaluation value increases by focus far drive or focus near drive in either of the two evaluation value acquisition regions. If the evaluation value does not increase in any of the evaluation value acquisition regions, regardless of whether the focus is moved to far or near (FIG. 13(l)), the position before focus drive is the appropriate focus position.

[0045] If it is determined in step S1111 that the evaluation value does not increase in either the far or near direction in both of the two evaluation value acquisition regions (Rfar≦R and Rnear≦R), the process proceeds to step S1112. In step S1112, the focus control unit 116 returns the focus to the state before it was driven (FIG. 13(m)). On the other hand, if it is determined in step S1111 that the evaluation value increases in either of the two evaluation value acquisition regions by moving the focus to the far or near direction (Rfar>R or Rnear>R), the process proceeds to step S1113.

[0046] In step S1113, the focus evaluation value calculation unit 114 determines the focus direction (evaluation value increasing direction) in which the evaluation value increases in each of the two evaluation value acquisition regions based on the evaluation values ​​Rfar and Rnear acquired in steps S1108 and S1110. The focus evaluation value calculation unit 114 then determines the next control to be performed in accordance with the determination conditions in FIG. 12. In FIGS. 13(b), (d), (f), and (h), when the focus is driven to the far and near directions, the evaluation value increases with near drive in the front evaluation value acquisition region, and the evaluation value increases with far drive in the back evaluation value acquisition region. In this case, based on the determination conditions in FIG. 12, the next control to be performed is tilt+drive. Furthermore, in FIG. 13(j), the evaluation value increases with near drive in both the front and back evaluation value acquisition regions. In this case, the next control to be performed is focus near drive.

[0047] In steps S1114 to S1117, the focus control unit 116 or the tilt control unit 115 slightly drives the focus or tilt by a predetermined amount based on the next control determined based on the determination result (FIGS. 13(c), (e), (g), (i), and (k)). After step S1114, S1115, S1116, or S1117, the process proceeds to step S1118. In step S1118, the focus evaluation value calculation unit 114 determines whether or not both of the two evaluation value acquisition areas are in focus (whether or not they are in an in-focus state). If at least one of the two evaluation value acquisition areas is not in an in-focus state, steps S1101 to S1118 are repeated. On the other hand, if both of the two evaluation value acquisition areas are in an in-focus state, this flow ends.

[0048] According to this embodiment, even when the evaluation value acquisition area is set near the tilt axis, high-precision focus adjustment can be performed.

[0049] In each embodiment, the focus adjustment method is switched based on the result of determining whether the evaluation value acquisition area is located near the tilt axis. However, in each embodiment, even if it is determined that the evaluation value acquisition area is not located near the tilt axis, the focus adjustment method may be switched by additionally determining the magnitude of the change in the evaluation value due to tilt driving.

[0050] FIG. 14 is a diagram showing the relationship between the distance of the evaluation value acquisition area from the tilt axis and the amount of change in evaluation value. In FIG. 14, the horizontal axis represents the distance of the evaluation value acquisition area from the tilt axis, and the vertical axis represents the amount of change in evaluation value. As shown in FIG. 14, the amount of change in evaluation value increases as the distance of the evaluation value acquisition area from the tilt axis increases. Therefore, the closer the evaluation value acquisition area is to the tilt axis, the smaller the predetermined threshold for the change in evaluation value is, and the farther the evaluation value acquisition area is from the tilt axis, the larger the predetermined threshold for the change in evaluation value is. This makes it possible to determine whether there is no expected change in evaluation value for the position of the evaluation value acquisition area, i.e., whether the evaluation value is not suitable for focus adjustment control. In this case, high-precision focus adjustment can be achieved by switching to a focus adjustment method that does not perform evaluation value determination using tilt control.

[0051] As described above, in each embodiment, the control unit includes a tilt driver 118, a focus driver 119, a calculation unit (focus evaluation value calculation unit 114), a control unit (tilt control unit 115, focus control unit 116), and a determination unit (focus adjustment method determination unit 113). The tilt driver performs tilt drive by changing the tilt of at least one of the image sensor 106 or the optical system (image pickup optical system). The focus driver performs focus drive by moving the focus lens 102, which constitutes at least a part of the optical system, in the optical axis direction. The calculation unit calculates an evaluation value related to the focus degree (evaluation value related to contrast) for each of multiple regions in the image. The control unit controls the focus driver and the tilt driver to focus on at least a first region and a second region (at least two evaluation value acquisition regions) among the multiple regions. The determination unit determines the control method for the control unit based on the position of at least one of the first region or the second region.

[0052] Preferably, the determination unit determines the control method based on a distance between a position of at least one of the first area or the second area and a position of a tilt axis corresponding to the rotation axis of the tilt drive unit. More preferably, the determination unit determines the control method based on whether a difference in distance between a position of at least one of the first area or the second area and the position of the tilt axis is smaller than a predetermined threshold.

[0053] Preferably, the determination unit sets the control method to the first method when the difference in distance between the position of each of the first and second areas and the position of the tilt axis is greater than a predetermined threshold. On the other hand, the determination unit sets the control method to the second method when the difference in distance between the position of at least one of the first or second areas and the position of the tilt axis is smaller than a predetermined threshold. More preferably, in the first method, the control unit controls the focus driver or the tilt driver based on changes in the evaluation values ​​of the first and second areas during focus drive or tilt drive.

[0054] Preferably, in the second method, the control unit performs control based on a change in the evaluation value of at least one of the first region and the second region during focus driving, and performs control based on a change in the evaluation value of a region determined to have a distance difference greater than a predetermined threshold during tilt driving. Preferably, in the second method, the control unit performs control to focus on a region determined to have a distance difference less than the predetermined threshold through focus driving, and then to focus on a region determined to have a distance difference greater than the predetermined threshold through tilt driving.

[0055] Preferably, in the second method, the control unit controls the focus drive unit and the tilt drive unit based on changes in the evaluation values ​​of the first and second regions during focus drive. Also preferably, the control unit determines that there is a change in the evaluation value when the change in the evaluation value due to focus drive and tilt drive is greater than a predetermined change in the evaluation value. Also preferably, the predetermined change in the evaluation value due to tilt drive is a first change in the evaluation value when the difference in distance is a first difference, and a second change in the evaluation value greater than the first change in the evaluation value when the difference in distance is a second difference greater than the first difference. Also preferably, the control unit sets the second method when it determines that there is no change in the evaluation value due to tilt drive.

[0056] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0057] According to each embodiment, by switching the focus adjustment control method depending on the position of the area in which an evaluation value related to the degree of focus is calculated, it is possible to provide a control device, an imaging device, a control method, and a program capable of high-precision focus adjustment.

[0058] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0059] 113 Focus adjustment method determination unit (determination unit) 114 Focus evaluation value calculation unit (determination unit) 115 Gate control unit (control unit) 116 Focus control unit (control unit) 118 Gate drive unit 119 Focus drive unit

Claims

1. a tilt drive unit that performs tilt drive by changing the tilt of at least one of the image pickup element and the optical system; a focus driving unit that performs focus driving by moving a focus lens that constitutes at least a part of the optical system in an optical axis direction; a determination unit that determines an evaluation value related to the focus degree of each of a plurality of regions in an image; a control unit that controls the focus drive unit and the tilt drive unit so as to focus on at least a first area and a second area of ​​the plurality of areas, respectively; a determination unit that determines a control method of the control unit based on whether a difference in distance between a position of at least one of the first region or the second region and a position corresponding to a tilt axis in the image is smaller than a predetermined threshold, The determination unit If a difference in distance between the first region and the second region and the position is greater than the predetermined threshold, the control method is set to a first method; If a difference in distance between the position and at least one of the first region and the second region is smaller than the predetermined threshold, the control method is set to the second method; The control unit in the first method, the focus driving unit or the tilt driving unit is controlled based on a change in the evaluation value of each of the first area and the second area during the focus driving or the tilt driving; A control device characterized in that, in the second method, the focus drive is used to focus on an area between the first area and the second area where the difference in distance is determined to be smaller than the predetermined threshold, and then the tilt drive is used to focus on an area between the first area and the second area where the difference in distance is determined to be larger than the predetermined threshold.

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

3. The predetermined threshold value is if the depth of field is shallower than a predetermined depth of field, a first threshold value; 3. The control device according to claim 2, wherein when the depth of field is deeper than the predetermined depth of field, the second threshold value is greater than the first threshold value.

4. The control device according to any one of claims 1 to 3, characterized in that in the second method, the control unit performs control based on a change in evaluation value of at least one of the first area and the second area during the focus driving, and performs control based on a change in evaluation value of an area of ​​the first area and the second area in which the difference in distance is determined to be greater than the predetermined threshold value during the tilt driving.

5. 5. The control device according to claim 1, wherein in the second method, the control unit controls the focus drive unit and the tilt drive unit based on changes in the evaluation values ​​of the first area and the second area during the focus drive.

6. 6. The control device according to claim 1, wherein the control unit determines that the evaluation value has changed when the amount of change in the evaluation value due to the focus drive and the tilt drive is greater than a predetermined amount of change in the evaluation value.

7. The predetermined change in evaluation value due to the tilt drive is If the difference in distance is a first difference, it is a first evaluation value change amount, 7. The control device according to claim 6, wherein when the difference in distance is a second difference that is greater than the first difference, the second evaluation value change amount is greater than the first evaluation value change amount.

8. 8. The control device according to claim 1, wherein the control unit sets the second method when it is determined that there is no change in the evaluation value due to the tilt driving.

9. 9. The control device according to claim 1, wherein 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 by subject detection.

10. An imaging element; An imaging device comprising: the control device according to claim 1 .

11. 11. The imaging device according to claim 10, further comprising an imaging optical system including a focus lens.

12. A control method for controlling a tilt driver that performs tilt drive by changing the tilt of at least one of an image sensor or an optical system, and controlling a focus driver that performs focus drive by moving a focus lens that constitutes at least a part of the optical system in an optical axis direction, comprising: determining an evaluation value for the degree of focus of each of a plurality of regions in the image; determining a control method for the tilt driver and the focus driver based on whether a difference in distance between a position of at least one of a first area or a second area among the plurality of areas and a position corresponding to a tilt axis in the image is smaller than a predetermined threshold; and controlling the focus driver and the tilt driver by the control method so as to bring the first area and the second area into focus, respectively; In the step of determining the control method, If a difference in distance between the first region and the second region and the position is greater than the predetermined threshold, the control method is set to a first method; If a difference in distance between the position and at least one of the first region and the second region is smaller than the predetermined threshold, the control method is set to the second method; In the step of controlling the focus driving unit and the tilt driving unit, in the first method, the focus driving unit or the tilt driving unit is controlled based on a change in the evaluation value of each of the first area and the second area during the focus driving or the tilt driving; A control method characterized in that, in the second method, the focus drive is used to focus on an area between the first area and the second area where the difference in distance is determined to be smaller than the predetermined threshold, and then the tilt drive is used to focus on an area between the first area and the second area where the difference in distance is determined to be larger than the predetermined threshold.

13. A program causing a computer to execute the control method according to claim 12.

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