JP7612339B2 - Image capture device and method for controlling image capture device - Google Patents

Description

The present invention relates to an imaging device and a control method for the imaging device, and in particular to an imaging device having a tilt mechanism that tilts the imaging sensor, and a control method for the imaging device.

A technique known in the art is to tilt the image sensor relative to the optical axis of the lens (sensor tilt).

When the image sensor is perpendicular to the optical axis (without tilting), it can only focus on subjects that are a specific distance away along the optical axis. In other words, since the focal plane is perpendicular to the optical axis, in a scene with depth, it is not possible to focus on subjects from the foreground to the background.

On the other hand, by tilting (tilting) the image sensor with respect to the optical axis, the focal plane can be tilted with respect to the optical axis, and the focal plane can be made to be a plane other than a plane perpendicular to the optical axis. In this case, it is possible to focus on subjects at different distances in the optical axis direction. In other words, it is possible to focus on a plane where there are distant and close subjects. Therefore, by tilting the image sensor according to the distribution of subject distances within the angle of view, it is possible to focus on subjects from closer to the front to subjects further back, compared to when the image sensor is not tilted.

Such technology is disclosed, for example, in Patent Document 1. Patent Document 1 discloses a method of performing sensor tilt photography by adjusting the inclination of the image sensor so that the focus is on multiple specified areas.

JP 2016-042194 A

However, the conventional technology disclosed in the above-mentioned Patent Document 1 was not able to adjust the position of the focal plane by translating the focal plane to match the ground or the like using sensor tilt.

For example, suppose the sensor tilt angle is set so that the focus is on a horizontal surface such as a road or the ground. From that state, it is not possible to change the position of the focal plane while maintaining the tilt of the focal plane so that the focus is on a horizontal surface that is a specified height above the road or ground by shifting the position of the focal plane in parallel. Without sensor tilt, it is possible to shift the position of the focal plane in parallel in the depth direction simply by moving the focus lens, but moving only the focus lens while tilting the sensor changes the tilt of the focal plane. If the tilt of the focal plane changes, it may become difficult to achieve the effect of sensor tilt, which is to expand the range in focus in the depth direction by tilting the focal plane in the depth direction.

Furthermore, even if the focal plane can be moved in parallel to match the ground or other object by tilting the sensor, the range of subjects that can be captured in the depth direction on the focal plane may be narrowed. In other words, tilting the sensor may result in a narrower range of subjects that fit within the angle of view, even if you try to focus on a wide range of subjects from the front to the back.

The object of the present invention is to provide an imaging device and a control method for an imaging device that can adjust the position of the focal plane by translating the focal plane while maintaining the subject area when the focal plane is not perpendicular to the optical axis.

In order to achieve the above-mentioned object, the imaging device of the present invention comprises a sensor driving unit that tilts an imaging sensor with respect to a plane perpendicular to the optical axis of the imaging optical system, a focus lens driving unit that changes the position of a focus lens in the imaging optical system, a change unit that changes the imaging direction of the imaging means , and a control unit that controls the position of the focus lens, the imaging direction , and the angle of the imaging sensor so that a first tilt focus plane and a second tilt focus plane after changing the position of the first tilt focus plane are parallel , and the control unit changes the imaging direction so that the distance of the second tilt focus plane included in the imaging range in the direction of the second tilt focus plane is approximately equal to the distance of the first tilt focus plane included in the imaging range in the direction of the first tilt focus plane .

The present invention provides an imaging device and a control method for an imaging device that can adjust the position of the focal plane by translating the focal plane while maintaining the subject area when the focal plane is not perpendicular to the optical axis.

1 is a configuration diagram of an imaging apparatus according to a first embodiment of the present invention. FIG. 1 is a diagram illustrating a part of the principle of a first embodiment of the present invention. FIG. 1 is a diagram illustrating a part of the principle of a first embodiment of the present invention. 4 is a flowchart showing a part of a processing flow according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a captured image according to the present invention. FIG. 11 is a configuration diagram of an imaging apparatus according to a second embodiment of the present invention. FIG. 13 is a diagram illustrating part of the principle of a second embodiment of the present invention. FIG. 13 is a configuration diagram of an imaging apparatus according to a third embodiment of the present invention. FIG. 13 is a diagram illustrating part of the principle of a third embodiment of the present invention. FIG. 13 is a diagram illustrating part of the principle of a fourth embodiment of the present invention. FIG. 13 is a diagram illustrating part of the principle of a fourth embodiment of the present invention. FIG. 2 is a diagram illustrating an example of an operation screen of the imaging device of the present invention. FIG. 13 is a diagram illustrating part of the principle of a sixth embodiment of the present invention. FIG. 13 is a diagram illustrating part of the principle of a sixth embodiment of the present invention. FIG. 13 is a configuration diagram of an imaging apparatus according to a sixth embodiment of the present invention. FIG. 13 is a diagram illustrating part of the principle of a sixth embodiment of the present invention. 1A and 1B are diagrams illustrating a part of the principle of an imaging device of a comparative example. 11A and 11B are diagrams illustrating an example of a captured image of an imaging device of a comparative example.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

Below, an imaging device according to a first embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 is a configuration diagram showing an example of the functional configuration of an imaging device according to the present invention.

In this embodiment, the focus lens position and sensor tilt angle are preset so that the focus is on a reference plane (reference plane), such as a road or the ground. Then, by specifying the amount of change in the position of the focus plane, the focus plane is translated from the reference plane by an amount equivalent to the change. The amount of change in the position of the focus plane is, for example, the distance from the reference plane.

The imaging device 1000 includes an optical unit 1001, a control unit 1002, and a drive unit 1003.

The optical unit 1001 is composed of a lens 101 and an image sensor 102, and captures input light such as reflected light from a subject, converts it into an image signal, and outputs it.

The lens 101, which serves as an imaging optical system, focuses input light and forms a subject image on the imaging sensor 102. The lens 101 may also be composed of multiple lenses, and in this embodiment, the lens 101 can be moved to focus on a subject at a specified subject distance.

The image sensor 102 converts the subject image formed on an imaging surface consisting of multiple imaging elements arranged two-dimensionally into an electrical signal, thereby generating and outputting an image signal of the subject.

The control unit 1002, which serves as a control unit, is made up of an imaging direction change unit 103, a focus position change unit 104, and a sensor angle change unit 105.

The imaging direction change unit 103, which serves as a range change unit, acquires an instruction to change the position of the focal plane (a focal plane change instruction), and calculates the amount of change in the tilt angle based on the amount of change in the position of the focal plane. The imaging direction change unit 103 instructs the tilt drive unit 106 to change the orientation of the imaging device 1000 by the calculated amount of change. The imaging direction change unit 103 also outputs the amount of change in the tilt angle to the focal position change unit 104. Note that the focal plane change instruction is the amount of change in the position of the focal plane, and is an amount that indicates the distance from the reference plane.

The focal position change unit 104 calculates the position of the focus lens based on the amount of change in the tilt angle and the amount of change in the position of the focal plane acquired from the shooting direction change unit 103, and instructs the focus drive unit 107 to drive the focus lens to the calculated position. The focal position change unit 104 also outputs the position of the focus lens to the sensor angle change unit 105.

The sensor angle change unit 105 calculates the elevation angle of the image sensor 102 based on the amount of change in the tilt angle obtained from the shooting direction change unit 103 and the position of the focus lens obtained from the focus position change unit 104. The sensor angle change unit 105 instructs the sensor drive unit 108 to drive the image sensor 102 to achieve the calculated elevation angle.

The drive unit 1003 consists of a tilt drive unit 106, a focus drive unit 107, and a sensor angle change unit 108.

The tilt drive unit 106 is a tilt drive mechanism that changes the tilt direction of the imaging device 1000, and changes the shooting direction (tilt direction) of the imaging device based on instructions from the imaging direction change unit 103.

The focus lens driving unit 107 is a focus lens driving mechanism that drives the focus lens included in the lens 101, and drives the lens 101 based on instructions from the focus position changing unit 104.

The sensor angle change unit 108 is a tilt drive mechanism that changes the tilt angle of the image sensor 102, and drives the image sensor 102 to change the tilt angle of the image sensor 102 based on instructions from the sensor angle change unit 105. In other words, the sensor angle change unit 108 tilts the image sensor 102 with respect to a plane perpendicular to the optical axis of the lens 102.

Next, the amount of change in the tilt angle, the position of the focus lens, and the elevation angle will be specifically explained with reference to Figures 2 and 3. Figure 2 shows the state where the focal plane is aligned with the reference plane. Figure 3 shows the state where the focal plane has been translated a distance H from the reference plane.

Given the subject distance (a), the angle (θ) between the optical axis and the perpendicular to the reference plane, the angle of view (ω), and the focal length (f), the tilt angle (α) when aligning the focal plane with the reference plane and the position of the focus lens (b) can be expressed as follows:

Furthermore, the distance (Ln) to the near end and the distance (Lf) to the far end of the focal plane range (subject area) included within the angle of view of the imaging device are expressed as follows:

Next, referring to Figure 3, we will explain the state in which the focal plane has been translated a distance H from the reference plane.

The amount of change (φ) in the tilt angle is calculated so that the distance (Ln') to the front end of the range (subject area) of the focal plane included in the angle of view of the imaging device, where the focal plane is translated by a distance H from the reference plane, is equal to Ln when the focus is set on the reference plane. Specifically, the imaging direction change unit 103 calculates the amount of change (φ) in the tilt angle according to the amount of change (H) in the position of the focal plane so as to satisfy the following formula.

If the focal plane is translated a distance H from the reference plane, the subject distance (A'), the angle between the optical axis and the reference plane (θ'), the angle of view (ω), and the focal length (f) are given, the distance (Ln') to the near end of the focal plane range (subject area) can be expressed as follows:

Next, the focal position change unit 104 calculates the position (B') of the focus lens when the focal plane is translated by a distance H as follows:

Furthermore, the sensor angle change unit 105 calculates the elevation angle (αp') when the focal plane is translated by a distance H as follows:

In this embodiment, the shooting direction change unit 103, the focal position change unit 104, and the sensor angle change unit 105 calculate each control amount based on the above-mentioned formula, but the method of calculating each control amount is not limited to this. The control amount calculated based on the formula may be stored as table data in advance, and each control amount corresponding to the change amount of the focal plane position may be read from the table data. The formula for calculating each control amount is also not limited to the above-mentioned one, and may be, for example, a more simplified version of the above-mentioned formula. Each control amount may be calculated without using a formula. For example, a control amount obtained experimentally may be stored as table data. When installing the imaging device in an actual installation location, a preferred control amount may be determined while checking the captured image, and stored in the table data.

Next, an example of the processing flow of the imaging device according to this embodiment will be described with reference to FIG. 4. FIG. 4 is a flowchart showing part of the processing flow of the imaging device according to this embodiment.

In S101, the shooting direction change unit 103 calculates and stores the distance (W1) in the direction of the focal plane within the range of the angle of view of the imaging device from the focal plane before changing the position of the focal plane.

In S102, the drive unit 1002 determines whether or not there is an instruction to change the focal plane, and if there is an instruction to change the focal plane, the process proceeds to S103.

In S103, the imaging direction change unit 103 calculates the distance (W2) in the focal plane direction of the range of the focal plane after changing the position of the focal plane that is included in the angle of view of the imaging device.

In S104, the shooting direction change unit 103 calculates the difference between W1 and W2, and determines whether the difference is equal to or greater than a predetermined value. If the difference is equal to or greater than a predetermined value, the process proceeds to S105; if not, the process proceeds to S107.

In S105, the imaging direction change unit 103 calculates the change in tilt angle.

In S106, W1 stored in the imaging direction change unit 103 is updated to W2 calculated in S103.

In S107, the focal position change unit 104 calculates the position of the focus lens included in the lens 101.

In S108, the sensor angle change unit 105 calculates the sensor angle (tilt amount).

Then, the tilt driver 106 changes the tilt direction of the imaging device based on the calculated change amount (φ) of the tilt angle. The focus driver 107 moves the focus lens to the focus lens position (B'). The sensor driver 108 rotates the imaging sensor 102 to the flap angle (αp'). Specifically, the control unit 1002 simultaneously moves the tilt driver 106, the focus driver 107, and the sensor driver 108 according to the change amount of the focal plane position from the user. The control unit 1002 may also shift the timing of the start of operation so that the change in the tilt direction of the imaging device 1000, the change in the focus lens position, and the change in the flap angle are completed simultaneously.

With the above configuration, the imaging device of this embodiment controls the distance in the focal plane direction of the focal plane included in the angle of view of the imaging device by making the focal plane position, the tilt angle of the imaging device, and the angle of the sensor have a predetermined relationship according to the amount of change in the focal plane position. More specifically, the distance in the focal plane direction of the focal plane included in the angle of view of the imaging device before changing the focal plane position and the distance in the focal plane direction of the focal plane included in the angle of view of the imaging device after changing the focal plane position are controlled to be approximately constant.

As a result, the imaging device of this embodiment is able to translate the position of the focal plane while keeping the distance (subject area) of the focal plane included in the angle of view of the imaging device in the focal plane direction substantially constant.

In addition, when the position of the focal plane is changed, if the size of the subject area changes by a predetermined amount or more, the tilt driver 106 controls to change the tilt angle. This makes it possible to prevent the angle of view from changing frequently.

The effects of the present invention will be described below with reference to a comparative example. As shown in FIG. 17, if the imaging direction is kept fixed when the position of the focal plane is moved, the subject area will become narrower and the position of the subject area will also change. In such a case, as shown in FIG. 18, the distance in the depth direction of the subject that can be imaged for a specific focal plane will become narrower. In other words, even if an attempt is made to focus on a wide range of subjects from the front to the back by tilting the sensor, the depth of the subject that fits within the angle of view itself will become narrower, which may undermine the effect of sensor tilt.

For example, when the focus plane is the ground as in the left image of Figure 18, it is possible to focus on subjects between 10m and 30m above the road surface. However, when the focus plane is translated to the height of a person's face as in the right image of Figure 18, it is only possible to focus on subjects between 10m and 20m away. In other words, by translating the focus plane, the range of subjects that can be focused on (subject area) becomes narrower.

On the other hand, in the imaging device of the present invention, as shown in Figure 5, when the position of the focal plane is moved, the imaging direction is changed accordingly. Therefore, as shown in the right diagram of Figure 5, even if the position of the focal plane is translated to the height of a human face, it is possible to focus on a subject (a human face) at a distance of 10 to 30 m, just as if the focal plane was the ground.

The following describes an example of a use case envisioned by the present invention.

For example, one use case for a surveillance camera to which the present invention is applied is one in which the position of the focal plane is automatically changed depending on the surveillance purpose. For example, assume that an aisle through which people pass is being photographed, as shown in Figure 5. If the surveillance purpose is to photograph people, such as searching for suspicious people, the focal plane is moved to the height of the person's face, as shown in the right diagram of Figure 5. On the other hand, if the surveillance purpose is to photograph objects on the road, such as searching for suspicious objects or lost property, the focal plane is moved to the road (ground), as shown in the left diagram of Figure 5. By implementing in this way, an appropriate captured image can be obtained for each surveillance purpose.

Another use case for an industrial camera to which the present invention is applied is image inspection (visual inspection) of products manufactured in a factory or the like. For example, consider a case in which products are stored stacked vertically to save space in the factory, and these products are photographed with a camera and inspected using image analysis or other means to prevent the inclusion of defective products. As shown in FIG. 3, the imaging device of the present invention can take images while moving the height of the focal plane vertically. This allows for high-quality images that are focused according to the position and height of the stacked products to be obtained, improving the accuracy of image analysis. Furthermore, since products can be installed by stacking them vertically, multiple products can be inspected without moving them.

Next, an imaging device according to a second embodiment of the present invention will be described with reference to FIG. 6. In the first embodiment, the imaging range is changed by changing the orientation of the imaging device 1000 using the imaging direction change unit 103, but in the second embodiment, the focal length is changed by changing the position of the zoom lens using the angle of view change unit 203. Note that the same functional units as those in the first embodiment are given the same reference numerals, and their description will be omitted. FIG. 6 is a configuration diagram showing an example of the functional configuration of the imaging device according to this embodiment.

The lens 201 includes a focus lens and a zoom lens. By moving the position of the focus lens, it is possible to focus on a subject at a specified subject distance. In addition, by moving the position of the zoom lens, it is possible to change the focal length and change the angle of view.

The angle of view change unit 203, which serves as a range change unit, receives an instruction to change the position of the focal plane (a focal plane change instruction), calculates the angle of view based on the amount of change in the position of the focal plane, and instructs the zoom lens drive unit 206 to drive the zoom lens to obtain the calculated angle of view. The angle of view change unit 203 also outputs the angle of view to the focal position change unit 104.

The zoom lens driving unit 206 is a zoom mechanism that changes the angle of view of the imaging device 1000, and changes the focal length by moving the position of the zoom lens based on instructions from the angle of view changing unit 203.

The angle of view (ωz) after the focal plane has moved is determined as follows. As shown in FIG. 7, when the reference plane is in focus and the angle of view is (ω), the near end (Ln) and the far end (Lf) of the subject area are taken as the ends. Then, the focal plane is moved by H, and the angle of view is changed to (ωz) as the ends on the near side (Lnz) and the far side (Lfz) of the subject area are taken as the ends on the far side (Lfz). In addition, the focal length after the angle of view is changed to (ωz) is taken as (fz). Then, the angle of view (ωz) after the focal plane has moved is determined so as to satisfy the following formula.

By satisfying the above formula, the size of the subject area after the focal plane is moved can be controlled to be equal to or larger than the size of the subject area before the focal plane is moved, as shown in Figure 7.

Next, referring to FIG. 8, an imaging device according to a third embodiment of the present invention will be described. In this embodiment, as a means for changing the position of the focal plane, a mechanism (tilt mechanism) that changes the orientation of the imaging device is controlled to change the tilt angle. Also, as a means for changing the imaging range of the imaging device, the focal length is changed by changing the position of the zoom lens. FIG. 8 is a configuration diagram showing an example of the functional configuration of an imaging device according to this embodiment. Note that the same reference numerals are used for the same functional units as in embodiment 1 or embodiment 2, and their description will be omitted.

The focal position change unit 304 calculates the change amount (Ψ) of the orientation of the imaging device based on the change amount of the focal plane position, and instructs the tilt drive unit 307 to drive the imaging direction by the calculated change amount. The focal position change unit 304 also outputs the change amount (Ψ) of the imaging device to the sensor angle change unit 105.

The tilt drive unit 307 is a tilt drive mechanism that changes the orientation of the imaging device, and changes the position of the focal plane by changing the orientation of the imaging device based on instructions from the focal position change unit 304.

With the above configuration, as shown in FIG. 9, when the orientation of the imaging device is changed to change the position of the focal plane, the angle of view is changed by moving the zoom lens included in the lens 201 according to the amount of change in the orientation of the imaging device. This makes it possible to control the size of the subject area after the focal plane is moved so that it is equal to or larger than the size of the subject area before the focal plane is moved.

Next, an imaging device according to a fourth embodiment of the present invention will be described with reference to Figures 10 and 11. In this embodiment, the functional configuration is the same as in the first to third embodiments.

First, at least a portion of the focal plane included in the angle of view is set as the subject area. Then, when the focal position changing unit 104 or the focal position changing unit 304 changes the position of the focal plane, the position of the focal plane is restricted to a predetermined range so that the range equivalent to the subject area of the focal plane after the focal plane change falls within the angle of view.

When changing the position of the focal plane, the focal position change unit 104 limits the amount of movement of the focus lens so that the range equivalent to the subject area of the focal plane after the focal plane change falls within the angle of view. Specifically, as shown in FIG. 10, the focus lens position (b) is limited so as not to be larger than BM. This limits the amount of movement of the focal plane from the reference plane to less than the "upper height limit" in FIG. 10. Note that BM in such a case can be calculated under the condition that the above Lf, when the amount of movement of the focal plane is H, is greater than or equal to the distance (Df) to the far end of the subject area.

When changing the position of the focal plane, the focal position change unit 304 limits the change in the orientation (tilt angle) of the imaging unit so that the range corresponding to the subject area of the focal plane before the focal plane change falls within the angle of view. Specifically, as shown in FIG. 11, the change in the orientation of the imaging unit (φ) is limited to not exceed φM. This limits the amount of movement of the focal plane from the reference plane to less than the "upper height limit" in FIG. 11. Note that φM in such a case can be calculated under the condition that Ln, when the amount of movement of the focal plane is H, is less than the distance (Dn) to the near end of the subject area.

By implementing the above, it is possible to change the position of the focal plane within a range in which the subject area falls within the angle of view. In other words, it is possible to prevent the subject area from moving outside the angle of view when changing the position of the focal plane.

Next, with reference to FIG. 12, we will explain an imaging device according to a fifth embodiment of the present invention.

Figure 12 is a diagram showing an example of the operation screen of the imaging device of the present invention. As shown in Figure 12, the operation screen of the imaging device of the present invention is provided with a viewer for captured images and a focus adjustment function. The focus adjustment function as an instruction unit allows the position of the focus plane to be adjusted by pressing a button on the screen. The focus adjustment function buttons include two buttons, Far and Near, which are operated when the focus plane and the optical axis are perpendicular (no tilt), and two buttons, High and Low, which are operated when the focus plane and the optical axis are not perpendicular (tilt). The Far and Near buttons translate the focus plane in opposite directions. The High and Low buttons translate the focus plane in opposite directions. The method of translating the focus plane when the High and Low buttons are operated (when tilt is present) is as in the above-mentioned embodiment.

With the four buttons as described above prepared, in this embodiment, control is performed so that only one of the Far/Near button or the High/Low button is enabled (operable). In other words, when the focal plane and the optical axis are perpendicular (no tilt), the Far/Near button is enabled and the High/Low button is disabled (not operable). On the other hand, when the focal plane and the optical axis are not perpendicular (tilt), the Far/Near button is disabled and the High/Low button is enabled.

The Far/Near button changes the position of the focus lens, and if only the focus lens is moved while the sensor is tilted, the inclination of the focal plane will change, which may result in a change in the depth of field. Therefore, in this embodiment, when the focal plane and the optical axis are not perpendicular (tilt is present), the Far/Near button is disabled and the High/Low button is enabled.

This prevents the tilt of the focal plane from being unintentionally changed when tilting the sensor, and allows the position of the focal plane to be constantly shifted in parallel depending on the state of the sensor tilt.

Next, a use case of an imaging device according to a sixth embodiment of the present invention will be described with reference to Figures 13 and 14.

The upper part of Figure 13 shows use cases of the first to fifth embodiments. As already explained, by performing sensor tilt, even when close and distant subjects exist within the imaging range, an image can be obtained in which both the close and distant subjects are in focus. As an example, in the example shown, without tilt, only subject 20 is in focus, but with tilt, subjects 10, 20, and 30 are in focus. This type of case is when the subject is photographed from a relatively long distance.

On the other hand, the lower part of FIG. 13 shows a use case of the sixth embodiment. This case is a case where a subject is photographed from a close distance, for example, a case where a product manufactured in a factory is photographed with a camera to perform an external inspection. As an example, a case is shown where subjects 11, 21, and 31 are photographed individually while changing the orientation of the imaging device when photographing at a close distance. When photographing at a close distance, only a narrow range can be photographed and only one subject can be photographed at a time, so the orientation of the imaging device is changed. Also, when photographing at a close distance, the depth of field becomes shallow. Therefore, when there is no tilt, even if there is only one subject to be photographed, there will be parts of the subject that are in focus and parts that are not, but when there is tilt, an example is shown where the entire subject being photographed is in focus.

Figure 14 also shows a use case of the sixth embodiment. This case is also one in which the subject is photographed from a close distance, for example, when products or luggage are stacked and the top item is photographed. The horizontal position of the subject is constant, and the height of the subject being photographed (height of the focal plane) is changed by changing the orientation of the imaging device. As this is a close-range photograph, the depth of field is shallow when there is no tilt, and some parts of the subject are in focus and some are not, which is similar to the example shown in the lower part of Figure 13.

With reference to FIG. 15, an imaging device according to a sixth embodiment of the present invention will be described. In the first embodiment, the imaging direction change unit 103 acquires an instruction to change the position of the focal plane (instruction to change the focal plane), and calculates the amount of change in the tilt angle based on the amount of change in the position of the focal plane. On the other hand, in the sixth embodiment, the focal plane change unit 409 acquires an instruction to change the tilt angle (instruction to change the imaging direction), and calculates the amount of change in the position of the focal plane based on the amount of change in the tilt angle. Note that the same reference numerals are used for the same functional units as in the first embodiment, and their description will be omitted. FIG. 15 is a configuration diagram showing an example of the functional configuration of an imaging device according to this embodiment.

The control unit 1002 as a control unit is composed of an imaging direction changing unit 103, a focal position changing unit 104, a sensor angle changing unit 105, and a focal plane changing unit 409.

The imaging direction change unit 103 acquires an instruction to change the tilt angle (imaging direction change instruction), and instructs the tilt drive unit 106 to change the orientation of the imaging device 1000 by the change amount of the tilt angle. Note that the imaging direction change instruction is the change amount of the tilt angle of the imaging device, and is an amount indicating the angle between the reference plane and the optical axis direction of the imaging device.

The focal position change unit 104 calculates the position of the focus lens based on the amount of change in the focal plane position obtained from the focal plane change unit 409, and instructs the focus drive unit 107 to drive the focus lens to the calculated position.

The sensor angle change unit 105 calculates the elevation angle of the image sensor 102 based on the amount of change in the position of the focal plane acquired from the focal plane change unit 409. The sensor angle change unit 105 instructs the sensor drive unit 108 to drive the image sensor 102 to achieve the calculated elevation angle.

The focal plane changing unit 409 receives an instruction to change the tilt angle (an instruction to change the imaging direction) and calculates the amount of change in the position of the focal plane based on the amount of change in the tilt angle. The focal plane changing unit 409 also outputs the calculated amount of change in the position of the focal plane to the focal position changing unit 104 and the sensor angle changing unit 105.

With the above configuration, as shown in FIG. 16, when the camera height (H) is known and the subject position (L) or the subject height (h) is a known fixed value, the position of the focal plane can be changed according to the amount of change in the tilt angle (θ) of the imaging device. In other words, since the subject distance (a) can be calculated from L and θ, or h and θ, the position of the focus lens and the tilt angle can be calculated. In other words, when the subject position is a known fixed value, the height of the focal plane can be changed to the height of the subject according to the amount of change in the tilt angle of the imaging device. Also, when the subject height is a known fixed value, the position of the focal plane can be changed to the subject position according to the amount of change in the tilt angle of the imaging device.

The above describes preferred embodiments of the present invention, but the present invention is not limited to these embodiments, and various modifications and variations are possible within the scope of the gist of the invention.

REFERENCE SIGNS LIST 1001 Optical unit 1002 Control unit 101 Lens 102 Imaging sensor 103 Imaging direction change unit 104 Focus position change unit 105 Sensor angle change unit

Claims (9)

a sensor driver that tilts the image sensor with respect to a plane perpendicular to the optical axis of the image pickup optical system;
a focus lens driving unit for changing a position of a focus lens in the imaging optical system;
A change unit that changes the imaging direction of the imaging means;
a control unit that controls a position of the focus lens, the imaging direction, and an angle of the imaging sensor so that a first tilt focus plane and a second tilt focus plane obtained after changing the position of the first tilt focus plane are parallel to each other;
The control unit changes the imaging direction so that a distance of the second tilt focus plane included in the imaging range in the direction of the second tilt focus plane is approximately equal to a distance of a range of the first tilt focus plane included in the imaging range in the direction of the first tilt focus plane. The imaging device according to claim 1, characterized in that the control unit controls the position of the focus lens, the imaging direction, and the angle of the imaging sensor based on the distance between the first and second tilt focus planes. The imaging device according to claim 2, characterized in that the control unit calculates the amount of change in the imaging direction based on the distance between the first tilt focus plane and the second tilt focus plane. The imaging device according to claim 3, characterized in that the control unit calculates the position of the focus lens based on the distance between the first and second tilt focus planes and the calculated change amount of the imaging direction. The imaging device according to claim 4, characterized in that the control unit calculates the angle of the imaging sensor based on the distance between the first and second tilt focus planes, the calculated change in the imaging direction, and the calculated position of the focus lens. The imaging device according to any one of claims 1 to 5, characterized in that the control unit calculates a difference between a distance in the first tilt focus plane direction of the first tilt focus plane included in the imaging range and a distance in the second tilt focus plane direction of a range of the second tilt focus plane included in the imaging range before changing the focus plane from the first tilt focus plane to the second tilt focus plane, and changes the imaging direction when the difference is equal to or greater than a predetermined value. 7. The imaging device according to claim 1, further comprising an instruction unit that instructs a change in the position of the first tilt focus plane. the instruction unit includes a first instruction unit that instructs an amount of change in a position of the focal plane when the focal plane is perpendicular to an optical axis of the imaging optical system, and a second instruction unit that instructs an amount of change in a position of the focal plane when the focal plane is not perpendicular to the optical axis of the imaging optical system,
The imaging device according to claim 7, characterized in that, when the focal plane is perpendicular to the optical axis of the imaging optical system, the control unit enables operation of the first indicating unit and restricts operation of the second indicating unit, and when the focal plane is not perpendicular to the optical axis of the imaging optical system, the control unit restricts operation of the first indicating unit and enables operation of the second indicating unit. A control method for an imaging device including a sensor driver that tilts an imaging sensor with respect to a plane perpendicular to an optical axis of an imaging optical system, a focus lens driver that changes a position of a focus lens in the imaging optical system, and a changer that changes an imaging direction of an imaging means, comprising:
a control step of controlling a position of the focus lens, the imaging direction, and an angle of the imaging sensor so that a first tilt focus plane and a second tilt focus plane obtained after changing the position of the first tilt focus plane are parallel to each other;
A control method for an imaging device, characterized in that, in the control step, the imaging direction is changed so that a distance in the direction of the second tilt focus plane included in the imaging range of the second tilt focus plane is approximately equal to a distance in the direction of the first tilt focus plane of a range included in the imaging range of the first tilt focus plane.

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