Patent Description:
A technology called the Scheimpflug principle is generally known that adjusts a focal plane by rotating an imaging plane so as to tilt the imaging plane relative to an imaging optical axis plane that is orthogonal to an imaging optical axis system for capturing an object (referred to as a "tilt control" hereinafter), and changes a depth of field for an imaging scene. Cameras for surveillance applications are demanded to capture an image with a deep depth of field. Using the above technology can increase the depth of field without narrowing an aperture stop (diaphragm) and obtain an image in which an imaging area is entirely in focus while suppressing object blurring and noise caused by a shortage of light intensity.

Japanese Patent Laid-Open No. <CIT>- <CIT> discloses an image pickup apparatus that provides focus control based on focus shift amounts of a plurality of focal detecting areas (so that the focus shift amounts are minimized).

However, the image pickup apparatus disclosed in <CIT> acquires a control target position through calculation, and may not provide control that results in an ideal tilt angle and focus position due to mechanical errors. Instead of the control for the control target position that is acquired through calculation, it is conceivable to control both the tilt angle and the focus position while an in-focus level of an object is determined. However, in this case, depending on the setting of an area for determining the in-focus level of the object, a change in in-focus level cannot be correctly determined and the control may cause an incorrect tilt angle and focus position.

Document <CIT> discloses an imaging apparatus wherein a control apparatus according to the preamble of independent claims <NUM> and <NUM> is provided, and which includes a controller configured to change a tilt angle between an image sensor and a plane orthogonal to an optical axis of an optical system by adjusting a tilt of the image sensor or the optical system, an evaluation value acquirer configured to acquire contrast evaluation values of a plurality of areas in an image by changing the tilt angle through the controller, and a determiner configured to determine the tilt angle for each of the plurality of areas based on the contrast evaluation values of the plurality of areas acquired by the evaluation value acquirer, and to determine the tilt angle based on the tilt angle of each determined area. The controller adjusts the tilt of the image sensor or the optical system based on the tilt angle determined by the determiner.

It is an object of the present invention to provide a control apparatus, an image pickup apparatus, a control method, and a program, each of which being capable of providing highly accurate focusing by switching a focusing control method according to a position of an area for calculating an evaluation value relating to an in-focus level.

This object is achieved by a control apparatus as specified in claim <NUM> or <NUM>.

Furthermore, this object is achieved by an image pickup apparatus as specified in claim <NUM>.

In addition, this object is achieved by a control method as specified in claim <NUM> or <NUM>.

Moreover, this object is achieved by a program as specified in claim <NUM>. Advantageous further developments are as set forth in the respective dependent claims.

Referring now to the accompanying drawings, a detailed description will be given of embodiments according to the present invention.

Referring now to <FIG>, a description will be given of an image pickup apparatus <NUM> according to this embodiment. <FIG> is a block diagram of the image pickup apparatus <NUM>. The image pickup apparatus <NUM> may have a structure in which a camera body and an imaging optical system (optical system) are integrated with each other, or a structure in which the imaging optical system (interchangeable lens) is attachable to and detachable from the camera body.

The imaging optical system includes a zoom lens <NUM> that moves in a direction along an optical axis OA (optical axis direction) to change a focal length, a focus lens <NUM> that moves in the optical axis direction for focusing, and an aperture stop (diaphragm) unit <NUM> that adjusts a light amount. The light that has passed through the imaging optical system forms an object image as an optical image on an image sensor <NUM> via a bandpass filter (BPF) <NUM> and a color filter <NUM>. The BPF <NUM> may be insertable into and ejectable from an optical path of the imaging optical system. The image sensor <NUM> is a CMOS sensor or a CCD sensor, and performs a photoelectric conversion for the object image that has been formed via the imaging optical system to output an analog electric signal (imaging signal). The analog electric signal that has been output from the image sensor <NUM> is gain-controlled by an AGC <NUM>, converted into a digital signal by an A/D converter <NUM>, and then input to a camera signal processing unit <NUM>.

The camera signal processing unit <NUM> performs various image processing for the digital imaging signal to generate a video signal. The video signal is output to a surveillance monitor apparatus <NUM> that is connected to the image pickup apparatus <NUM> by wire or wireless communication via a communication unit <NUM>. Upon receiving an instruction from a user, the surveillance monitor apparatus <NUM> outputs a control signal such as a command to each of an evaluation value acquiring area setting unit <NUM>, a tilt control unit <NUM>, a focus control unit <NUM>, and a zoom control unit <NUM> in the image pickup apparatus <NUM> via the communication unit <NUM>.

The evaluation value acquiring area setting unit <NUM> sets an area (evaluation value acquiring area) to be focused based on an instruction from the communication unit <NUM>. The focusing method determining unit (first determination unit) <NUM> determines a focusing control method according to the area that has been set by the evaluation value acquiring area setting unit <NUM>. The evaluation value calculating unit (second determination unit) <NUM> acquires (calculates or determines) an evaluation value relating to a contrast in the area that has been set by the evaluation value acquiring area setting unit <NUM> from the A/D converter <NUM> or the camera signal processing unit <NUM>.

The tilt control unit (control unit) <NUM> instructs a tilt driving unit <NUM> on a tilt set position based on the focusing method that has been determined by the focusing method determining unit <NUM> and the evaluation value that has been calculated (determined) by the evaluation value calculating unit <NUM>. The focus control unit (control unit) <NUM> instructs a focus driving unit <NUM> on a focus set position based on the focusing method that has been determined by the focusing method determining unit <NUM> and the evaluation value that has been calculated by the evaluation value calculating unit <NUM>. The zoom control unit <NUM> instructs a zoom driving unit <NUM> on a zoom set position based on the instruction from the communication unit <NUM>.

The tilt driving unit <NUM> drives the image sensor <NUM> based on the tilt set position that has been instructed by the tilt control unit <NUM>. The focus driving unit <NUM> drives the focus lens <NUM> based on the focus set position that has been instructed by the focus control unit <NUM>. The zoom driving unit <NUM> drives the zoom lens <NUM> based on the zoom set position that has been instructed by the zoom control unit <NUM>.

Referring now to <FIG>, <FIG>, a description will be given of tilt control. <FIG> explains the tilt control, and illustrates an example of the tilt control such that faces of two objects A and B are in focus which are located within an imaging angle of view at different distances from the image pickup apparatus <NUM>. The principle of tilt control is called the Scheimpflug principle, in which when an optical system principal plane <NUM> and an imaging plane <NUM> intersect each other at one point (Scheimpflug point <NUM>), a focal plane <NUM> also intersects them at that point. From the Scheimpflug principle, a tilt angle α is calculated by the following expression (<NUM>) where F is a focal length, L is an object distance, and θ is a depression angle.

Thereby, all objects from a short distance to a long distance on a certain plane can be focused.

<FIG> explain a target scene for the tilt control, and a tilt angle correcting amount α and a focus position correcting amount β suitable for the scene. The scene in <FIG> illustrates two objects A and B located at different distances from the image pickup apparatus <NUM>. <FIG> schematically illustrates a relationship among a position of the image sensor <NUM>, an in-focus position of the object A (point A), and an in-focus position of the object B (point B) for the scene illustrated in <FIG>. A vertical position of each of the object A and B represents an image height, and a horizontal distance of each of the object A and B from the image sensor <NUM> represents a defocus amount. In order to focus on both the objects A and B, the image sensor <NUM> may be driven by the tilt angle correcting amount α (tilt angle α) and the focus lens <NUM> may be driven by the focus position correcting amount β so that the imaging plane <NUM> is aligned with (contains) the points A and B as illustrated in <FIG>.

Referring now to <FIG>, a description will be given of an example of a control determination condition for gradually bringing both the objects A and B located in the two areas closer to in-focus states by determining the next control based on evaluation value changes of the two, front and back, areas, in a case where the focus position and the tilt angle are slightly driven. <FIG> explains the next control that is determined based on the evaluation value change. <FIG> explains a tilt driving direction.

In <FIG>, "tilt + driving" and "tilt - driving" are defined as tilt driving in plus (+) and minus (-) direction illustrated in <FIG>. <FIG> schematically illustrates a positional relationship between the image sensor <NUM> and the points A and B in a case where control is made for focusing on the points A and B based on the determination condition illustrated in <FIG>. Since the tilt driving and the focus driving change the relative positional relationship between the image sensor <NUM> and the focus lens <NUM>, either the image sensor <NUM> or the focus lens <NUM> may be driven. As illustrated in <FIG>, focusing on the points A and B is available by determining the next control based on the evaluation value change in the case of fine tilt or focus driving.

<FIG> explain a scene in this embodiment. <FIG> illustrates the scene for tilt control in a case where the object B is located near a position corresponding to a tilt axis <NUM> in a captured image. <FIG> schematically illustrates a relationship between the position of the image sensor <NUM>, the in-focus position of the object A (point A), and the in-focus position of the object B (point B) for the scene illustrated in <FIG>. A vertical position of each of the object A and B represents an image height, and a horizontal distance of each of the object A and B from the image sensor <NUM> represents a defocus amount.

<FIG> explain an evaluation value change in a scene. <FIG> illustrates a positional relationship among the tilt axis <NUM>, tilt angles <NUM> to <NUM>, and the points A and B. <FIG> illustrate evaluation value changes at the points A and B, respectively, in a case where the tilt angle is changed to the tilt angles <NUM>, <NUM>, and <NUM>. In <FIG>, a horizontal axis indicates the tilt angle, and a vertical axis indicates the evaluation value.

Evaluation values <NUM>, <NUM>, and <NUM> for the point A in <FIG> and evaluation values <NUM>, <NUM>, and <NUM> for the point B in <FIG> correspond to the evaluation values for the tilt angles <NUM>, <NUM>, and <NUM>, respectively. For the point A, the tilt + driving brings the positions of the point A and the image sensor <NUM> closer to each other, and the evaluation value is increased as illustrated in <FIG>. On the other hand, for the point B located on the tilt axis <NUM>, the tilt driving does not change the evaluation value as illustrated in <FIG>. Thus, the tilt driving does not change the evaluation value on the tilt axis <NUM>, and if control is made based on the determination condition illustrated in <FIG>, control for the in-focus state may not be made due to an erroneous determination. In each embodiment, the tilt axis <NUM> is located at, but is not limited to, a specific position, such as a horizontal direction of a central part, in the image.

In each of the following embodiments, a description will be given of a method of switching the focusing control method in a case where both the tilt angle and the focus position are controlled while an in-focus level of an object is determined, and the evaluation value acquiring area of the evaluation value for the focusing control is located on the tilt axis <NUM>. Thereby, highly accurate focusing is available.

Referring now to <FIG>, a description will be given of a control method (focusing control) according to a first embodiment. As illustrated in <FIG>, this embodiment relates to a focusing control method in a scene in which an object is located at a position corresponding to the tilt axis <NUM> in a captured image. <FIG> illustrates a flowchart of the control method according to this embodiment.

First, in the step S901, the evaluation value acquiring area setting unit <NUM> determines whether or not there are a plurality of objects having different image heights in the scene. The object may be detected by the object detection in the image pickup apparatus <NUM>, or the determination may be made according to the instruction (operation) from the user via the surveillance monitor apparatus <NUM>. If it is determined that there are not the plurality of objects having different image heights, the flow proceeds to the step S902. If it is determined in the step S901 that there are not the plurality of objects having different image heights, it is unnecessary to increase the depth of field by the tilt control. Therefore, in the step S902, the focus control unit <NUM> performs autofocus (AF) control for one certain object, and proceeds to the step S911.

On the other hand, in the case where it is determined in the step S901 that there are the plurality of objects having different image heights, the flow proceeds to the step S903. In the case where it is determined in the step S901 that there are the plurality of objects having different image heights, this scene needs to increase the depth of field using the tilt control. Therefore, in the step S903, the evaluation value acquiring area setting unit <NUM> sets two areas having different image heights among the plurality of objects to evaluation value acquiring areas. The evaluation value acquiring area may be either an area in which the object is detected by the object detection or an area designated by the user.

Next, in the step S904, the focusing method determining unit <NUM> determines whether any of the two evaluation value acquiring areas set in the step <NUM> exists near the position corresponding to the tilt axis in the captured image. In a case where it is determined that neither of the two evaluation value acquiring areas exists near the position corresponding to the tilt axis in the captured image, the flow proceeds to the step S905. On the other hand, in a case where it is determined that any of the two evaluation value acquiring areas exists near the position corresponding to the tilt axis in the captured image, the flow proceeds to a focusing control method (steps S906 to S910) enclosed by a dotted line. Whether or not the evaluation value acquiring area exists near the position corresponding to the tilt axis in the captured image can be determined by calculating a difference in distance between the position of the evaluation value acquiring area and the position of the tilt axis (rotation axis of the tilt driving unit) and by determining whether the difference is smaller than a predetermined threshold. The predetermined threshold may be set based on a depth of field that is determined based on a focal length, an object distance, and an F-number. The predetermined threshold may be set smaller as the depth of field is shallower and set larger as the depth of field is deeper. That is, the predetermined threshold is a first threshold in a case where the depth of field is shallower than the predetermined depth of field, and the predetermined threshold is a second threshold larger than the first threshold in a case where the depth of field is deeper than the predetermined depth of field.

In a case where it is determined in the step S904 that neither of the two evaluation value acquiring areas exists near the position corresponding to the tilt axis in the captured image, the flow proceeds to the step S905. In the step S905, the tilt control unit <NUM> and the focus control unit <NUM> perform control as illustrated in <FIG> based on the determination condition illustrated in <FIG>. Thereby, control can be made such that the objects A and B located in the two evaluation value acquiring areas are in the in-focus state.

On the other hand, in a case where it is determined in the step S904 that any of the two evaluation value acquiring areas exists near the position corresponding to the tilt axis in the captured image, the flow proceeds to step S906. In the step S906, the evaluation value calculating unit <NUM> and the focus control unit <NUM> perform AF in the evaluation value acquiring area that has been determined to exist near the position corresponding to the tilt axis in the captured image, and perform control that fixes a focus position (one-shot AF). Next, in the step S907, the focus control unit <NUM> determines whether or not the evaluation value acquiring area existing near the tilt axis is in the in-focus state on the obj ect, that is, whether or not the one-shot AF is completed. In a case where it is determined that it is not in the in-focus state on the object, it is conceivable that the object has moved from the evaluation value acquiring area set in the step S903. Therefore, the steps S901 to S907 are repeated.

On the other hand, in a case where it is determined that it is in the in-focus state on the object, the flow proceeds to the step S908. In the step S908, the tilt control unit <NUM> and the evaluation value calculating unit <NUM> search an evaluation value different from the evaluation value acquiring area existing near the position corresponding to the tilt axis in the captured image among the two evaluation value acquiring areas, for an evaluation value peak while changing the tilt angle (perform tilt searching). Next, in the step S909, the tilt control unit <NUM> determines a tilt angle when the evaluation value is maximum, based on a tilt searching result in the step S908. Next, in the step S910, the tilt control unit <NUM> performs the tilt control based on the tilt angle that has been determined in the step S909.

Referring now to <FIG>, a description will be given of a procedure of the steps S906 to S910 (focusing control method) illustrated in <FIG>. <FIG> illustrates the procedure of the steps S906 to S910. A vertical position of each of the object A and B represents an image height, and a horizontal distance of each of the object A and B from the image sensor <NUM> represents a defocus amount. Tilt control can be made such that the points A and B are in focus by performing the one-shot AF for the evaluation value acquiring area that has been set to the object B located at the position corresponding to the tilt axis in the captured image, and by performing tilt searching in the evaluation value acquiring area that has been set to the object A.

Next, in the step S911 in <FIG>, the evaluation value calculating unit <NUM> determines whether or not both of the two evaluation value acquiring areas are in focus (whether or not they are in the in-focus states). In a case where at least one of the two evaluation value acquiring areas is not in focus, the steps S901 to S911 are repeated. On the other hand, in a case where both of the two evaluation value acquiring areas are in focus, this flow is terminated.

This embodiment can thus provide highly accurate focusing even in a case where an evaluation value acquiring area is set to a position corresponding to a tilt axis in a captured image.

Referring now to <FIG> and <FIG>, a description will be given of a control method (focusing control) according to a second embodiment. As illustrated in <FIG>, this embodiment relates to a focusing control method in a scene in which an object exists on the tilt axis <NUM>. <FIG> and <FIG> illustrate a flowchart of the control method according to this embodiment. Since the steps S1101 to S1105 in <FIG> and <FIG> are the same as the steps S901 to S905 in <FIG>, a description thereof will be omitted.

In a case where it is determined in the step S1104 that any of the two evaluation value acquiring areas exists near the position corresponding to the tilt axis in the captured image, the flow proceeds to the focusing control method (steps S1106 to S1117) enclosed by a dotted line. The steps S1106 to S1117 illustrate the focusing control method for determining the next control based on evaluation value changes of the two, front and back, evaluation value acquiring areas, in a case of fine focus driving toward an infinity end or side (Far) and a close (short distance) end or side (Near).

<FIG> illustrates an example of a determination condition in the focusing control method in this embodiment, and explains the next control based on the evaluation value change. In this embodiment, unlike the determination condition of the first embodiment illustrated in <FIG>, the next control is not determined based on an evaluation value change in the case of the tilt driving. This is because, as illustrated in <FIG>, in a case where the evaluation value acquiring area exists at the position corresponding to the tilt axis in the captured image, the evaluation value of the evaluation value acquiring area is not changed by the tilt driving, the determination using this evaluation value causes an error, and the next control cannot be correctly determined. The determination condition illustrated in <FIG> determines the next control based on which of fine focus driving to the infinity end (focus Far driving) or fine focus driving to the close (short-distance) end (focus Near driving) by a predetermined amount increases the evaluation value of each evaluation value acquiring area. <FIG> explain the control method according to this embodiment, and schematically illustrate a case where control is made for focusing on the points A and B based on the determination condition of <FIG>.

In the step <NUM> in <FIG> and <FIG>, the evaluation value calculating unit <NUM> calculates (acquires) a current evaluation value R in each of the two evaluation value acquiring areas set in the step S1103. The current evaluation value R is an evaluation value in a state before the focus driving illustrated by dotted lines in <FIG>. As illustrated in <FIG>, the current evaluation value R is used for end determination processing (S1111) for stopping the focusing operation in a case where a pre-focus driving state has already been in the in-focus state on the points A and B and the evaluation value decreases in any of the focus Far driving and the focus Near driving.

Next, in the step S1107, the focus control unit <NUM> provides fine focus Far driving by a predetermined amount. At this time, the image sensor <NUM> may be driven instead of the focus lens <NUM>. In <FIG>, the image sensor <NUM> illustrated by solid lines on the Far side of the image sensor <NUM> illustrated by dotted lines represents the image sensor <NUM> as a result of the fine Far driving by the predetermined amount.

Next, in the step S1108 illustrated in <FIG>, after the focus Far driving in the step S1107, the evaluation value calculating unit <NUM> acquires an evaluation value Rfar of each of the two evaluation value acquiring areas that have been set in the step S1103. Next, in the step S1109, the focus control unit <NUM> provides fine focus Near driving by a predetermined amount. At this time, either the focus lens <NUM> or the image sensor <NUM> may be driven similarly to the case of the focus Far driving. In <FIG>, the image sensor <NUM> illustrated by the solid lines on the Near side of the image sensor <NUM> illustrated by the dotted lines represents the image sensor <NUM> as a result of the fine focus Near driving by the predetermined amount.

Next, in the step S1110, after the focus Near driving in the step S1109, the evaluation value calculating unit <NUM> acquires the evaluation value Rnear of each of the two evaluation value acquiring areas set in the step S1103. Next, in the step S1111, the evaluation value calculating unit <NUM> compares the current evaluation value R acquired in the step S1106 with each of Rfar and Rnear acquired in the steps S1108 and S1110 of each of the two evaluation value acquiring areas. The evaluation value calculating unit <NUM> determines whether or not the evaluation value is increased by the focus Far or Near driving of any of the two evaluation value acquiring areas. In a case where the evaluation values of all the evaluation value acquiring areas are not increased by the focus Far or Near driving (<FIG>), the pre-focus driving position becomes a proper focus position.

In a case where it is determined in the step S1111 that the evaluation values of both of the two evaluation value acquiring areas are not increased by the focus Far or Near driving (Rfar ≤ Rand Rnear ≤ R), the flow proceeds to the step S1112. In the step S1112, the focus control unit <NUM> returns to the state before the focus driving (<FIG>). On the other hand, in a case where it is determined in the step S1111 that the evaluation value of any of the two evaluation value acquiring areas is increased by the focus Far or Near driving (Rfar > R or Rnear > R), the flow proceeds to the step S1113.

In the step S1113, the evaluation value calculating unit <NUM> determines a focus direction (evaluation value increasing direction) in which the evaluation value of each of the two evaluation value acquiring areas increases, based on the evaluation values Rfar and Rnear acquired in the steps S1108 and S1110. The evaluation value calculating unit <NUM> determines control to be performed next according to the determination condition illustrated in <FIG>. In <FIG>, in the case of focus Far and Near driving, the evaluation value of the front evaluation value acquiring area becomes larger in the focus Near driving, and the evaluation value of the back evaluation value acquiring area becomes larger in the focus Far driving. In this case, based on the determination condition illustrated in <FIG>, the control to be performed next becomes tilt + driving. In <FIG>, the evaluation values of both the front and back evaluation value acquiring areas become larger in the focus Near driving. In this case, the next control to be performed is focus Near driving.

In the steps S1114 to S1117, the focus control unit <NUM> or the tilt control unit <NUM> provides fine focus or tilt driving by a predetermined amount based on the next control determined based on the determination result (<FIG>). After the steps S1114, S1115, S1116, or S1 <NUM>, the flow proceeds to the step S1118. In the step S1118, the evaluation value calculating unit <NUM> determines whether or not both of the two evaluation value acquiring areas are in focus (whether or not they are in the in-focus states). In a case where at least one of the two evaluation value acquiring areas is not in the in-focus state, the steps S1101 to S1118 are repeated. On the other hand, in a case where both of the two evaluation value acquiring areas are in the in-focus states, this flow is terminated.

This embodiment can provide highly accurate focusing even in a case where the evaluation value acquiring area is set near the position corresponding to the tilt axis.

In each embodiment, the focusing method is switched based on the determination result of whether or not the evaluation value acquiring area exists near the position corresponding to the tilt axis in the captured image. However, in each embodiment, even in a case where it is once determined that the evaluation value acquiring area does not exist near the position corresponding to the tilt axis in the captured image, the focusing method may be switched by making the determination based on the size of the evaluation value change amount caused by the tilt driving.

<FIG> illustrates a relationship between a distance of the evaluation value acquiring area from the position corresponding to the tilt axis and an evaluation value changing amount. In <FIG>, a horizontal axis represents the distance of the evaluation value acquiring area from the position corresponding to the tilt axis, and a vertical axis represents the evaluation value changing amount. As illustrated in <FIG>, the evaluation value changing amount increases as the distance of the evaluation value acquiring area from the position corresponding to the tilt axis in the captured image increases. Therefore, the evaluation value acquiring area near the position corresponding to the tilt axis in the captured image has a smaller predetermined threshold for the evaluation value change, and an evaluation value acquiring area farther from the position corresponding to the tilt axis has a larger predetermined threshold for the evaluation value change. Thereby, it is possible to determine whether or not there is no expected evaluation value change for the position of the evaluation value acquiring area, that is, whether or not the evaluation value is not suitable for the focusing control. In that case, highly accurate focusing can be provided by switching to the focusing method that does not perform the evaluation value determination through the tilt control.

As described above, in each embodiment, the control apparatus includes the tilt driving unit <NUM>, the focus driving unit <NUM>, the control unit (tilt control unit <NUM> and focus control unit <NUM>), and the first determination unit (focusing method determining unit <NUM>). The tilt driving unit performs tilt driving by changing the tilt of at least one of the image sensor <NUM> and the optical system (imaging optical system). The focus driving unit performs focus driving by moving in the optical axis direction the focus lens <NUM>, which constitutes at least part of the optical system. The control apparatus may further include the second determination unit (evaluation value calculating unit <NUM>) that determines the evaluation value relating to the in-focus level (evaluation value regarding contrast) of each of the plurality of areas in an image. The control unit controls the focus driving unit and the tilt driving unit for focusing on each of at least the first area and the second area (at least two evaluation value acquiring areas) among the plurality of areas. The first determination unit determines the control method of the control unit based on whether or not the difference in distance between the position of at least one of the first area and the second area and the position corresponding to the tilt axis in the image is smaller than the predetermined threshold.

The predetermined threshold may be set based on a depth of field. The predetermined threshold may be the first threshold in a case where the depth of field is shallower than a predetermined depth of field, and the predetermined threshold is the second threshold larger than the first threshold in a case where the depth of field is deeper than the predetermined depth of field.

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

In the second method, the control unit may perform control based on the evaluation value change of at least one of the first area and the second area during the focus driving, and the control unit performs control based on the evaluation value change of an area of the first area and the second area during the tilt driving in which the difference in distance is determined to be larger than the predetermined threshold. In the second method, the control unit may control, through the focus driving, for focusing on an area of the first area and the second area in which the difference in distance is determined to be smaller than the predetermined threshold, and then performs control, through the tilt driving, for focusing on an area of the first area and the second area in which the difference in distance is determined to be larger than the predetermined threshold.

In the second method, the control unit may control the focus driving unit and the tilt driving unit based on the evaluation value change of each of the first area and the second area during the focus driving. The control unit may determine that there is the evaluation value change in a case where an evaluation value changing amount caused by the focus driving and the tilt driving is larger than a predetermined evaluation value changing amount. The predetermined evaluation value changing amount caused by the tilt driving may be a first evaluation value changing amount in a case where the difference in distance is the first difference. The predetermined evaluation value changing amount caused by the tilt driving may be the second evaluation value changing amount larger than the first evaluation value changing amount in a case where the difference in distance is a second difference larger than the first difference. The control unit may set the second method in a case where it is determined that there is no evaluation value change caused by the tilt driving. The first area and the second area may be at least one of an area designated by the user and an area in which an object is detected by an object detection.

Claim 1:
A control apparatus comprising:
a tilt driving unit (<NUM>) configured to perform tilt driving by changing a tilt of at least one of an image sensor (<NUM>) and an optical system;
a focus driving unit (<NUM>) configured to perform focus driving by moving in an optical axis direction a focus lens (<NUM>) that constitutes at least part of the optical system;
a control unit (<NUM>, <NUM>) configured to control the focus driving unit (<NUM>) and the tilt driving unit (<NUM>) for focusing on at least a first area and a second area in a plurality of areas in an image;
a first determination unit (<NUM>) configured to determine a control method of the control unit for controlling the focus driving unit and the tilt driving unit for focusing based on whether or not a distance between a position of at least one of the first area and the second area and a position corresponding to a tilt axis (<NUM>) in the image is smaller than a predetermined threshold, and
a second determination unit (<NUM>) configured to determine an evaluation value relating to an in-focus level of each of the plurality of areas,
wherein the first determination unit (<NUM>) is configured to set the control method to a first method in a case where the distance between the position of at least one of the first area and the second area and the position corresponding to the tilt axis (<NUM>) is larger than the predetermined threshold,
wherein the first determination unit (<NUM>) is configured to set the control method to a second method in a case where the distance between the position of at least one of the first area and the second area and the position corresponding to the tilt axis (<NUM>) is smaller than the predetermined threshold,
wherein in the first method, the control unit (<NUM>, <NUM>) is configured to control the focus driving unit (<NUM>) or the tilt driving unit (<NUM>) based on an evaluation value change of the first area and the second area during the focus driving or the tilt driving,
characterized in that in the second method, the control unit (<NUM>, <NUM>) is configured perform control, through the focus driving, for focusing on an area of the first area and the second area in which the distance is determined to be smaller than the predetermined threshold, and then to perform control, through the tilt driving, for focusing on an area of the first area and the second area in which the distance is determined to be larger than the predetermined threshold.