Imaging device, information processing device, control method for imaging device, and program

Abstract

To achieve focus control in a more suitable mode even in a situation in which control in an imaging direction is performed.SOLUTION: An imaging apparatus 100 comprises: an imaging optical system that includes at least a focus lens 2; an image pickup device 6; a control unit 15 that controls a focal position; a pan driving unit 11 and a tilt driving unit 12 that control an imaging direction; a distance measuring device 18 that acquires distance information on a distance between the imaging apparatus 100 and a subject; and a storage unit 13 that stores the distance information. When the imaging direction is changed from a first imaging direction to a second imaging direction, the control unit 15 causes a distance transition calculation unit 14 to calculate, according to a transition in change of the imaging direction, a transition of the distance between the imaging apparatus 100 and the subject based on the distance information associated with the imaging direction. The control unit 15 controls the focal position according to a result of calculation of the transition of the distance.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to an imaging device, an information processing device, a control method for an imaging device, and a program.

Background Art

[0002] Conventionally, in a situation where the imaging direction is controlled in the pan direction or the tilt direction, a technique related to autofocus control for more quickly focusing on a subject is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the present invention is to realize focus control in a more suitable manner even in a situation where the imaging direction is controlled.

Means for Solving the Problems

[0005] The imaging device according to the present invention includes an imaging optical system configured to be able to control at least a focus position, an imaging element that photoelectrically converts a subject image formed through the imaging optical system, an imaging unit that images a subject, a first control unit that controls the focus position, a second control unit that controls the imaging direction of the imaging unit, an acquisition unit that acquires distance information regarding the distance between the imaging unit and the subject, and a storage unit that stores the imaging direction and the distance information in association with each other. The first control unit When the imaging direction is changed from the first imaging direction to the second imaging direction, including at least the distance between the imaging means and the subject in the third imaging direction imaged during the change from the first imaging direction to the second imaging direction tracks the change in the distance between the imaging unit and the subject derived based on the distance information stored in the storage means and controls the focus position according to the result of the change in the distance. derivation according to the result of during the change from the first imaging direction to the second imaging direction the change in the distance.

Effects of the Invention

[0006] According to the present invention, it is possible to realize focus control in a more suitable manner even in a situation where the imaging direction is controlled.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0008] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0009] <Example of the Configuration of the Imaging Device> Referring to FIG. 1, an example of the configuration of the imaging device according to the present embodiment will be described. The imaging device 100 according to the present embodiment includes an imaging optical system configured by a plurality of optical elements and forming an optical image of an object (subject). The imaging optical system included in the imaging device 100 according to the present embodiment includes at least a configuration for adjusting the focus position (in other words, a configuration for controlling the position for focusing). As a specific example, the imaging optical system may include a focus lens 2 for performing focus adjustment by moving in the optical axis direction as a configuration for adjusting the focus position. Further, the imaging optical system may include at least one of a zoom lens (varifocal lens) 1 for changing the focal length (in other words, controlling the zoom ratio) and an aperture unit 3 for adjusting the amount of light.

[0010] The focus drive unit 16 schematically shows a configuration (for example, an actuator or the like) for controlling the position of the focus lens 2 in order to realize the focus adjustment of the imaging optical system. Further, the zoom drive unit 17 schematically shows a configuration for controlling the position of the zoom lens 1 in order to realize the adjustment of the focal length (adjustment of the zoom ratio) of the imaging optical system. Note that the optical elements shown as the zoom lens 1 and the focus lens 2 can also be substituted by a plurality of configurations of two or more groups.

[0011] The optical image (subject image) formed by the imaging optical system is guided to the imaging element 6 through an infrared cut filter (IRCF) 4 and a color filter 5 and forms an image, and is photoelectrically converted into an electrical signal by the imaging element 6. Further, an optical element such as the infrared cut filter 4 may be configured to be movable forward and backward with respect to the optical path of the imaging optical system.

[0012] The electrical signal (video signal) output from the imaging device 6 according to the imaging result is adjusted in gain by the AGC (Automatic Gain Control) 7, A / D converted from an analog signal to a digital signal by the A / D converter 8, and input to the signal processing unit 9. The signal processing unit 9 performs desired image processing on the input digital video signal, outputs the video signal after the image processing to the communication unit 10, and calculates an evaluation value for use in autofocus control using the video signal before or after the image processing. Examples of autofocus control methods include a method using a focus evaluation value (contrast) and a method using phase difference.

[0013] Note that the signal processing unit 9 may change the image processing performed on the input video signal according to the state of the imaging optical system. As a specific example, when the infrared cut filter 4 is inserted on the optical axis of the imaging optical system, the signal processing unit 9 may control the image processing performed on the input video signal so that a color image is output by operating in the day mode. On the other hand, when the infrared cut filter 4 is not inserted on the optical axis of the imaging optical system, the signal processing unit 9 may control the image processing performed on the input video signal so that a black-and-white image is output by operating in the night mode.

[0014] The pan (PAN) drive unit 11 and the tilt (TILT) drive unit 12 schematically show a configuration (such as an actuator) related to the control of the imaging direction of the imaging device 100 according to the present embodiment. Specifically, the pan drive unit 11 controls the imaging direction of the imaging device 100 along the pan direction by rotating the imaging device 100 in the pan direction, for example. In other words, the pan drive unit 11 controls the pan angle of the imaging device 100. Also, the tilt drive unit 12 controls the imaging direction of the imaging device 100 along the tilt direction by rotating the imaging device 100 in the tilt direction, for example. In other words, the tilt drive unit 12 controls the tilt angle of the imaging device 100.

[0015] The distance measurement device 18 schematically shows a device that executes processing related to the measurement of the distance between the imaging device according to the present embodiment and the subject. Note that the method is not particularly limited as long as it is possible to measure the distance between the imaging device and the subject. For example, the distance measurement device 18 may use a plurality of imaging devices such as a so-called stereo camera, etc., and utilize the parallax between images according to the imaging results of each of the plurality of imaging devices, and measure the distance between the target imaging device and the subject based on the principle of triangulation. As another example, the distance measurement device 18 may measure the distance between the target imaging device and the subject by using a so-called laser rangefinder or a so-called radar. For example, the distance measurement device 18 may utilize the phase difference between the emitted laser and its reflected light for distance measurement. The distance measurement device 18 may transmit information according to the measurement result of the distance between the imaging device and the subject to a control unit 15 described later via communication established by the communication unit 10.

[0016] The monitoring device 19 acquires a video signal output from the signal processing unit 9 via communication established by the communication unit 10, and presents the image to the user by displaying an image based on the video signal on a predetermined output device such as a display. Further, the monitoring device 19 may control the operations of the focus drive unit 16 and the zoom drive unit 17 by transmitting instructions related to various imaging to the control unit 15 described later via communication established by the communication unit 10. Further, the monitoring device 19 may control the operations of the pan drive unit 11 and the tilt drive unit 12 by transmitting instructions related to the control of the imaging direction (for example, commands related to pan drive and tilt drive) to the pan drive unit 11 and the tilt drive unit 12 via communication established by the communication unit 10.

[0017] The control unit 15 controls various operations related to imaging of the imaging device 100 according to the present embodiment. For example, the control unit 15 may perform focus adjustment of the imaging optical system by controlling the position of the focus lens 2 by driving the focus driving unit 16. As a more specific example, the control unit 15 may control the focus position based on at least one of the driving direction, driving speed, response speed, driving range related to the movement of the focus lens, and the presence or absence of the driving. As another example, the control unit 15 may adjust the focal length of the imaging optical system by driving the zoom driving unit 17. Further, the control unit 15 may adjust the imaging direction of the imaging device 100 by driving at least one of the pan driving unit 11 and the tilt driving unit 12 via the communication unit 10.

[0018] Further, the control unit 15 may obtain information (hereinafter, also referred to as "distance information") corresponding to the measurement result of the distance between the imaging device and the subject from the distance measurement device 18, and use the distance information for various controls. In this case, the control unit 15 may hold the distance information by storing the acquired distance information in the storage unit 13. The storage unit 13 is a storage area for storing various information. Further, the control unit 15 may sequentially output distance information corresponding to the measurement result of the distance between the imaging device and the subject described above to a distance transition calculation unit 14 described later, so that the distance transition calculation unit 14 calculates the transition of the distance between the imaging device and the subject. In this case, the control unit 15 may use the calculation result of the transition of the distance between the imaging device and the subject by the distance transition calculation unit 14 for various controls. Note that the details of this control will be described separately later.

[0019] The distance transition calculation unit 14 calculates the transition of the distance between the imaging device and the subject based on the information corresponding to the measurement result of the distance between the imaging device and the subject sequentially output from the control unit 15. Thereby, for example, when the distance between the imaging device and the subject changes due to a change in the subject existing within the angle of view of the imaging device as the imaging direction of the imaging device changes, it is possible to calculate the transition of the change in the distance.

[0020] For example, FIG. 2 is a diagram showing an example of the appearance of the imaging device according to the present embodiment, and shows an example of the appearance of a PTZ camera capable of PAN / TILT / ZOOM control that can be applied as the imaging device. In the example shown in FIG. 2, the case where the pan and tilt mechanisms are integrated with the imaging device is shown, but it does not necessarily limit the configuration of the imaging device according to the present embodiment. As a specific example, an imaging system capable of pan control and tilt control may be configured by combining an electric pan-tilt head and an imaging device. Note that various instructions are transmitted from the control unit 15, the monitoring device 19, etc. to the pan driving unit 11 and the tilt driving unit 12, and the pan driving unit 11 and the tilt driving unit 12 are driven, so that pan control and tilt control of the imaging device 100 can be realized.

[0021] Here, with reference to FIG. 3, an example will be described regarding the output imaging angle when controlling the PAN / TILT / ZOOM position of the PTZ camera and the entire imaging angle that the PTZ camera can image. Each of Pa, Pb, and Pc schematically shows an example of an image obtained according to the imaging result by the PTZ camera. P0 schematically shows an image within the range that can be imaged by the PTZ camera according to the pan control range (hereinafter also referred to as the "pan range") and the tilt control range (hereinafter also referred to as the "tilt range"). That is, the image P0 corresponds to an image obtained by sequentially imaging while controlling the imaging direction of the PTZ camera within the pan range and the tilt range, and then connecting a series of images according to the imaging result. In the following description, for convenience, the imaging range corresponding to the image P0, that is, the range that the imaging device (PTZ camera) can image determined according to the pan range and the tilt range, is also referred to as the "entire imaging angle".

[0022] For imaging devices installed using a tripod or the like, or imaging devices fixed to a ceiling or wall surface, etc., it can basically be assumed that the overall angle of view does not change (in other words, the overall angle of view is fixed). In this embodiment, on the basis of such a premise, the distance between the imaging device and the subject is measured at each angle of view corresponding to the imaging direction, such as angles of view Pa, Pb, and Pc, and distance information corresponding to the overall angle of view P0 is created based on the measurement results of the distances corresponding to each of the series of angles of view.

[0023] Specifically, after the PTZ camera (imaging device according to this embodiment) is installed, in response to an instruction from a user (photographer) via the monitoring device 19, a trigger related to the creation of distance information is applied to the imaging device 100. By sending instructions to the pan drive unit 11, tilt drive unit 12, and control unit 15 respectively via the communication unit 10, after focusing at a desired angle of view, distance information corresponding to the measurement result of the distance between the subject and the PTZ camera by the distance measurement device 18 is acquired.

[0024] In addition, in FIG. 1, an example of the case where the distance measurement device 18 is externally attached to the imaging device 100 is shown, but it does not necessarily limit the configuration of the imaging device according to this embodiment. As a specific example, the imaging device 100 and the distance measurement device 18 may be integrally configured. Also, as another example, among a series of components of the imaging device 100 shown in FIG. 1, some of the components may be provided outside the imaging device 100. As a more specific example, components that are the main bodies of various controls, such as the control unit 15, etc., may be realized by another device different from the imaging device 100. In this case, the other device corresponds to an example of an "information processing device" that controls the operation of the imaging device 100.

[0025] <Processing> With reference to FIGS. 4 to 7, an example of the processing of the imaging device according to this embodiment will be separately described for the processing related to the storage of distance information and the processing related to focus control using the distance information.

[0026] (Storage of distance information) First, with reference to FIG. 4, an example of the process related to the acquisition of distance information will be described. FIG. 4 shows an example of a process of measuring the distance between the imaging device and the subject according to the position related to the pan-tilt control (hereinafter, also referred to as the "pan-tilt position"), and storing the distance information corresponding to the result of the measurement.

[0027] In S401, the control unit 15 initializes the target position of the pan-tilt position in response to an instruction from the monitoring device 19 via the communication unit 10. In S402, the control unit 15 drives the pan drive unit 11 and the tilt drive unit 12 in response to an instruction from the monitoring device 19 via the communication unit 10, thereby shifting the pan-tilt position to the target position.

[0028] After the pan-tilt position reaches the target position, in S403, an instruction related to autofocus is sent from the monitoring device 19 to the control unit 15 via the communication unit 10. In S404, the control unit 15 determines whether the focus is in focus on the subject. As long as the control unit 15 determines in S404 that the focus is not in focus on the subject, the autofocus control is continued and the determination in S404 is executed again. Then, when the control unit 15 determines in S404 that the focus is in focus on the subject, the process proceeds to S405.

[0029] In S405, the control unit 15 acquires distance information corresponding to the measurement result of the distance between the imaging device 100 and the subject from the distance measurement device 18 via the communication unit 10 (in other words, the distance measurement result at the timing of focusing), and stores the distance information in the storage unit 13.

[0030] In S406, the control unit 15 updates the target position of the pan-tilt position in response to an instruction from the monitoring device 19 via the communication unit 10. As a result, the pan-tilt position (in other words, the angle of view corresponding to the pan-tilt position) that is the target of the acquisition of distance information is updated.

[0031] In S407, the control unit 15 determines whether the storage of the distance information has been completed for a series of viewing angles (for example, the overall viewing angle). If the control unit 15 determines in S407 that the storage of the distance information for a series of viewing angles has not been completed, the process proceeds to S402. In this case, the processes after S402 will be executed again. Then, if the control unit 15 determines in S407 that the storage of the distance information for a series of viewing angles has been completed, the series of processes shown in FIG. 4 is terminated. That is, by completing the series of processes shown in FIG. 4, the storage unit 13 stores distance information corresponding to the measurement results of the distances between the imaging device 100 and the subject for each of the series of viewing angles.

[0032] Here, with reference to FIG. 5, an example of the transition of the change in the distance between the imaging device and the subject associated with the pan-tilt control will be described. First, FIG. 5(A) will be described. P51 schematically shows the viewing angle of the imaging device before the pan-tilt control is performed. Also, P52 schematically shows the viewing angle of the imaging device when the pan-tilt position reaches the target position with the pan-tilt control.

[0033] T51 schematically shows the trajectory of the pan-tilt position when the pan-tilt position is controlled to move from the position corresponding to the viewing angle P51 (starting position) to the position corresponding to the viewing angle P52 (target position) with the pan-tilt control. Hereinafter, for the sake of making the features of the technology according to the present disclosure clearer, each description will be made assuming that the pan-tilt position moves linearly from the starting position to the target position. Also, the imaging direction corresponding to the starting position corresponds to an example of the "first imaging direction", and the imaging direction corresponding to the target position corresponds to an example of the "second imaging direction".

[0034] P53 schematically shows the viewing angle corresponding to the pan-tilt position existing in the process of the pan-tilt position moving along the locus T51. At the viewing angles P51 and P52, the subject existing within the viewing angle with respect to the imaging device is in a so-called close-up state where it is at a relatively close position. In contrast, at the viewing angle P53, it is in a so-called long-shot state, and the subject existing within the viewing angle with respect to the imaging device is at a position farther than those at the viewing angles P51 and P52.

[0035] When the driving speed of the pan-tilt control is low, since the time for capturing a long shot becomes relatively long, even if focus control is performed so as to focus on the long shot, there are often no particular problems manifested. On the other hand, in a situation where the driving speed of the pan-tilt control is relatively fast, for example, after focus control is started to match the long shot, a close-up subject immediately appears within the viewing angle and is switched to focus control to match the subject. In such a situation, a phenomenon may occur where the image according to the imaging result is visually recognized as being blurry. Also, when the long shot is a subject with relatively low contrast such as the sky or mountains, the time required to focus tends to be longer. Therefore, also in this case, a phenomenon may occur where the image according to the imaging result is visually recognized as being blurry.

[0036] Next, FIG. 5(B) will be described. FIG. 5(B) is a graph showing an example of the change in the distance between the imaging device and the subject when the pan-tilt position is moved from the start position to the target position. In FIG. 5(B), the horizontal axis relatively shows the change in the pan-tilt position. The vertical axis shows the distance between the imaging device and the subject. Also, T52 is a graph showing the change in the distance between the imaging device and the subject when pan-tilt control is performed so that the pan-tilt position changes along the locus T51 in the example shown in FIG. 5(A). As shown in the graph T52, it can be seen that at the pan-tilt position corresponding to the angle of view P53, it temporarily becomes a long shot and the distance between the imaging device and the subject becomes long. In other words, at the pan-tilt position corresponding to the angle of view P53, the distance between the imaging device and the subject temporarily changes more than the change in the distance between the imaging device and the subject at the start position and the target position respectively.

[0037] (Auto Focus Control) Next, with reference to FIG. 6, as an example of auto focus control when pan-tilt control is performed, an outline of control for changing the settings related to auto focus according to the transition of the pan-tilt position will be described. Note that the horizontal axis and the vertical axis in each of FIGS. 6(A) and 6(B) are the same as the horizontal axis and the vertical axis in FIG. 5(B).

[0038] First, FIG. 6(A) will be described. FIG. 6(A) shows an example in which when the pan-tilt position is moved from the start position to the target position, the period during which the distance between the imaging device and the subject temporarily changes is relatively short (for example, when the period related to the change is equal to or less than the threshold). In FIG. 6(A), the graph T61 shown by the dashed line is a graph schematically showing the transition of the position at which the imaging device according to the present embodiment focuses. Specifically, in the example shown in FIG. 6(A), as the pan-tilt position moves, the distance between the imaging device and the subject changes from a so-called close-up state where the distance is relatively short to a so-called long-shot state where the distance is relatively long temporarily, and the period during which the long-shot state is temporarily reached is relatively short. Therefore, the imaging device suppresses the control to focus on the long shot during the period when the long-shot state is temporarily reached.

[0039] Next, FIG. 6(B) will be described. FIG. 6(B) shows an example in which when the pan-tilt position is moved from the start position to the target position, the period during which the distance between the imaging device and the subject temporarily changes is relatively long (for example, when the period related to the change exceeds the threshold). In FIG. 6(B), the graph T62 shown by the dashed line is a graph schematically showing the transition of the position at which the imaging device according to the present embodiment focuses. Specifically, in the example shown in FIG. 6(B), as the pan-tilt position moves, the distance between the imaging device and the subject changes from a close-up state where the distance is relatively short to a long-shot state where the distance is relatively long temporarily, and the period during which the long-shot state is temporarily reached is relatively long. Therefore, the imaging device focuses on the long shot during the period when the long-shot state is temporarily reached.

[0040] Incidentally, the period during which the distance between the imaging device and the subject temporarily changes may vary depending on the speed related to the control of the pan-tilt position and the zoom ratio. Therefore, for example, the distance transition calculation unit 14 may calculate the period during which the distance to the subject temporarily changes based on these parameters. In this case, the distance transition calculation unit 14 may acquire information regarding the current pan-tilt position from the pan drive unit 11 and the tilt drive unit 12 via the communication unit 10, and acquire information regarding the current zoom ratio from the control unit 15. Further, the distance transition calculation unit 14 may acquire information corresponding to the measurement result of the distance between the imaging device 100 and the subject from the distance measurement device 18 via the communication unit 10. Then, based on the acquired series of information, the distance transition calculation unit 14 may calculate the period during which the distance between the imaging device and the subject temporarily changes.

[0041] By calculating the period during which the distance between the imaging device and the subject temporarily changes as described above, for example, when the period is within 1 second, it is also possible to suppress the focus control so as to obtain the locus shown by the graph T61. Note that the distance threshold for determining whether or not to suppress the focus control may be changed according to an instruction from a user (for example, a photographer), for example. Also, even when the focus control is performed so as to obtain the locus shown by the graph T62, by using the distance information stored in the storage unit 13 for the focus control, it is possible to prevent, for example, focus search in the opposite direction and realize smooth focus transition.

[0042] Next, with reference to FIG. 7, an example of a process of changing the setting related to the focus control according to the transition of the pan-tilt position as shown in FIG. 6 will be described.

[0043] In S701, the control unit 15 determines whether the operation mode related to the focus control is the autofocus mode. If the control unit 15 determines in S701 that it is not the autofocus mode, it waits for an instruction until the operation mode is changed to the autofocus mode. Then, when the control unit 15 determines in S701 that it is in the autofocus mode, the process proceeds to S702.

[0044] In S702, the control unit 15 checks the driving states of the pan driving unit 11 and the tilt driving unit 12, and determines whether the pan driving unit 11 and the tilt driving unit 12 have received an instruction related to the control of the pan-tilt position. If the control unit 15 determines in S702 that the pan driving unit 11 and the tilt driving unit 12 have not received an instruction related to the control of the pan-tilt position, the process proceeds to S701. In this case, the processes of S701 and S702 will be executed again. On the other hand, if the control unit 15 determines in S702 that the pan driving unit 11 and the tilt driving unit 12 have received an instruction related to the control of the pan-tilt position (in other words, the pan driving unit 11 and the tilt driving unit 12 are in a driving state), the process proceeds to S703.

[0045] In S703, the control unit 15 acquires information on the current pan-tilt position from the pan driving unit 11 and the tilt driving unit 12. Also, the control unit 15 acquires information on the zoom position according to the control states of the focus driving unit 16 and the zoom driving unit 17.

[0046] In S704, the control unit 15 acquires the pan-tilt position (target position) that is the target of the pan-tilt control. At this time, the control unit 15 may acquire information on the position related to the control of the pan driving unit 11 and the tilt driving unit 12 corresponding to the target position from the pan driving unit 11 and the tilt driving unit 12.

[0047] In S705, the distance change calculation unit 14 calculates the change in the distance between the imaging device and the subject based on the information on the current pan-tilt-zoom position acquired in S703 and the information on the target pan-tilt position acquired in S704.

[0048] In S706, based on the calculation result of the change in the distance between the imaging device and the subject in S705, the control unit 15 changes the settings related to autofocus and then ends the series of processes shown in FIG. 7. Note that the series of processes shown in FIG. 7 is repeatedly executed until the pan-tilt position reaches the target position. As a result, it becomes possible to change the settings related to autofocus according to the change in the pan-tilt position.

[0049] As described above, the imaging device according to the present embodiment stores distance information corresponding to the measurement result of the distance from the subject for each pan-tilt position, and uses the distance information to calculate the change in the pan-tilt position associated with pan-tilt control. Furthermore, the imaging device performs focus control (in other words, control of the focus position) according to the calculation result of the change in the pan-tilt position. Thereby, for example, even in a situation where the distance between the imaging device and the subject temporarily changes, it is possible to prevent the manifestation of image blurring by temporarily suppressing the focus control and to realize smooth focus control.

[0050] Although the preferred embodiments of the present invention have been described above, they do not necessarily limit the application scope of the present invention, and various modifications and changes are possible without departing from the gist thereof. In addition, in the above description, attention has been paid to the case where a so-called lens-integrated imaging device in which the imaging optical system and the main body of the imaging device are integrated is used, but the configuration of the imaging device according to the present embodiment is not limited. As a specific example, the present invention can also be applied to an imaging system (optical device) including an imaging device main body and an imaging optical system (so-called interchangeable lens) detachably configured for the imaging device.

[0051] <Modification Example> Referring to FIGS. 8 and 9, a modified example of the imaging device according to the present embodiment will be described below. In this modified example, an example of control when the distance between the imaging device and the in-focus subject is different from the distance information stored for the pan-tilt position at that time will be described. Note that in this modified example, the description will focus on the parts different from the above-described embodiment, and detailed descriptions of the parts substantially the same as those of the embodiment will be omitted.

[0052] First, FIG. 8 will be described. FIG. 8 is an explanatory diagram for explaining an outline of control for changing settings related to autofocus according to the transition of the pan-tilt position as an example of autofocus control when pan-tilt control is performed.

[0053] As a specific example, FIG. 8(A) shows an example of focus control when, in a state of being in focus on a moving subject Obj81, the pan-tilt position is controlled following the movement of the subject Obj81. Specifically, in the example shown in FIG. 8(A), the pan-tilt position is controlled while maintaining the state of being in focus on the subject Obj81. Therefore, in this case, regardless of the transition of the pan-tilt position, the state where the distance between the imaging device and the subject is different from the distance information stored for the pan-tilt position at that time is maintained. The graph T81 shown by the dashed line is a graph schematically showing the transition of the position at which the imaging device according to the present embodiment focuses. In this case, the stored distance information is not used, and normal focus control is applied so as to follow the locus shown by the graph T81.

[0054] As another example, FIG. 8(B) shows an example of focus control when the subject Obj82 moves out of the frame as the pan-tilt position is controlled from a state where the imaging device is focused on the stationary subject Obj82. Specifically, in the example shown in FIG. 8(B), when the subject Obj82 is located within the angle of view, the distance between the imaging device and the subject is different from the distance information stored for the pan-tilt position at that time. On the other hand, when the subject Obj82 is located outside the angle of view, the distance between the imaging device and the subject is the same as the distance information stored for the pan-tilt position at that time. The graph T82 shown by the dashed line is a graph schematically showing the transition of the position where the imaging device according to the present embodiment focuses. In this case, focus control following the trajectory shown by the graph T82 is applied. Specifically, when the subject Obj82 is located within the angle of view, normal focus control is applied to focus on the subject Obj82. On the other hand, after the subject Obj82 moves out of the frame, focus control using distance information is applied in the same manner as the example described with reference to FIG. 6(A).

[0055] Next, with reference to FIG. 9, an example of a process for changing the settings related to focus control according to the transition of the pan-tilt position as shown in FIG. 8 will be described. Note that since the processes of S901 to S903 are substantially the same as the processes of S701 to S703 shown in FIG. 7, detailed description thereof is omitted.

[0056] In S904, the control unit 15 obtains the distance information by reading out the distance information corresponding to the current pan-tilt position from the storage unit 13.

[0057] In S905, the control unit 15 determines whether the distance between the imaging device and the focused subject matches the distance information obtained in S904. When the control unit 15 determines in S905 that the distance to the focused subject does not match the distance information acquired in S904, the process proceeds to S901. In this case, the processes after S901 will be executed again. On the other hand, when the control unit 15 determines in S905 that the distance to the focused subject matches the distance information acquired in S904, the process proceeds to S906. Note that in S905, the determination is made based on the distance between the imaging device and the subject, but other conditions may be applied to this determination. As a specific example, the above determination may be made by using a combination with functions related to detection of a face, a human body, etc., or functions related to tracking of an object.

[0058] The processes of S906 to S908 are substantially the same as the processes of S704 to S706 shown in FIG. 7. That is, the distance change calculation unit 14 calculates the change in the distance between the imaging device 100 and the subject during the control of the pan / tilt position. Further, the control unit 15 changes the settings related to autofocus based on the calculation result of the change in the distance, and then ends the series of processes shown in FIG. 9. Note that the series of processes shown in FIG. 9 is repeatedly executed until the pan / tilt position reaches the target position. Thereby, it becomes possible to change the settings related to autofocus according to the change in the pan / tilt position.

[0059] As described above, the imaging device according to the present embodiment stores distance information corresponding to the measurement result of the distance to the subject for each pan / tilt position, and uses the distance information to calculate the change in the pan / tilt position accompanying the pan / tilt control. Moreover, the imaging device performs focus control (in other words, control of the focus position) according to the calculation result of the change in the pan / tilt position. Thereby, for example, even in a situation where the distance between the imaging device and the subject temporarily changes, it is possible to prevent the manifestation of image blurring by temporarily suppressing the focus control and to realize smooth focus control.

[0060] As described above, the preferred embodiments of the present invention have been explained, but it does not necessarily limit the application scope of the present invention, and various modifications and changes are possible without departing from the gist thereof. Also, in the above, the description has been made focusing on the case where a so-called lens-integrated imaging device in which the imaging optical system and the main body of the imaging device are integrated is used, but it does not limit the configuration of the imaging device according to the present embodiment. As a specific example, the present invention can also be applied to an imaging system (optical device) composed of an imaging device main body and an imaging optical system (so-called interchangeable lens) configured to be detachable from the imaging device.

[0061] <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 recording medium, and having one or more processors in a computer of the system or device read and execute the program. Further, it can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

Explanation of Reference Numerals

[0062] 100 Imaging device 1 Zoom lens 2 Focus lens 6 Image sensor 11 Pan drive unit 12 Tilt drive unit 14 Distance change calculation unit 15 Control unit 18 Distance measurement device

Claims

1. Imaging means for imaging a subject, comprising: an imaging optical system configured to be able to control at least a focus position; and an imaging element that photoelectrically converts a subject image formed through the imaging optical system. First control means for controlling the focus position. Second control means for controlling the imaging direction of the imaging means. Acquisition means for acquiring distance information regarding the distance between the imaging means and the subject. Storage means for storing the imaging direction and the distance information in association with each other. And comprising: The first control means: Deriving, based on the distance information stored in the storage means, the transition of the distance between the imaging means and the subject when the imaging direction changes from the first imaging direction to the second imaging direction, including at least the distance between the imaging means and the subject in a third imaging direction imaged during the change from the first imaging direction to the second imaging direction; Controlling the focus position during the change from the first imaging direction to the second imaging direction according to the derivation result of the transition of the distance. An imaging device.

2. The first control means: During the process until the imaging direction changes from the first imaging direction to the second imaging direction, When the distance between the imaging means and the subject temporarily changes more than the change between the distance between the imaging means and the subject in the first imaging direction and the distance between the imaging means and the subject in the second imaging direction, When the period related to the temporary change in the distance between the imaging means and the subject is shorter than a threshold value, suppressing the control of the focus position according to the temporary change in the distance. The imaging device according to claim 1.

3. The second control means controls at least one of the pan angle and the tilt angle of the imaging means. The imaging device according to claim 1 or 2.

4. The distance information is distance information corresponding to a distance measurement result by a sensor of a phase difference method, a laser method, or a radar method, and distance information derived based on the positions of at least some of the optical elements included in the imaging optical system, and is at least any one of The imaging device according to any one of claims 1 to 3.

5. The first control means controls the focus position based on at least any one of the drive direction, drive speed, response speed, and drive range related to the drive of the positions of at least some of the optical elements included in the imaging optical system, and the presence or absence of the drive. The imaging device according to any one of claims 1 to 4.

6. The imaging optical system is configured to be able to control the zoom ratio, The second control means changes the parameter based on the drive speed related to the change of the imaging direction and the zoom ratio. The imaging device according to claim 5.

7. When the distance at which focusing is achieved is different from the distance indicated by the distance information stored in association with the imaging direction at the timing of the focusing, the first control means suppresses the control of the focus position according to the derivation result of the transition of the distance between the imaging means and the subject. The imaging device according to any one of claims 1 to 6.

8. First control means for controlling the focus position of an imaging device that images a subject with at least an imaging optical system configured to be able to control the focus position and an imaging element that photoelectrically converts a subject image formed through the imaging optical system; second control means for controlling the imaging direction of the imaging device; acquisition means for acquiring distance information regarding the distance between the imaging device and the subject; Storage means for associating and storing the imaging direction and the distance information; provided with; The first control means; derives the transition of the distance between the imaging device and the subject at the time when the imaging direction is changed from the first imaging direction to the second imaging direction, including at least the distance between the imaging device and the subject in a third imaging direction imaged during the change from the first imaging direction to the second imaging direction, based on the distance information stored in the storage means, controls the focus position during the change from the first imaging direction to the second imaging direction according to the derivation result of the transition of the distance; An information processing apparatus.

9. A control method for an imaging device that images a subject with an imaging optical system configured to be able to control at least a focus position and an imaging element that photoelectrically converts a subject image formed through the imaging optical system, a first control step of controlling the focus position; a second control step of controlling the imaging direction of the imaging device; an acquisition step of acquiring distance information regarding the distance between the imaging device and the subject; a storage step of associating and storing the imaging direction and the distance information; including; In the first control step, derives the transition of the distance between the imaging device and the subject at the time when the imaging direction is changed from the first imaging direction to the second imaging direction, including at least the distance between the imaging device and the subject in a third imaging direction imaged during the change from the first imaging direction to the second imaging direction, based on the distance information stored in the storage step, controls the focus position during the change from the first imaging direction to the second imaging direction according to the derivation result of the transition of the distance; A control method for an imaging device.

10. A program for causing a computer to function as each means of the information processing apparatus according to claim 8.

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