JP2012141516A - Imaging device and imaging program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device and an imaging program which are capable of easily auto-focusing while having a tilt function, and allows a user to accurately recognize a focus target area.SOLUTION: An imaging device comprises: a displacement detection part for detecting displacement from a reference position where an optical axis of an optical system is orthogonal to a light receiving surface of an imaging part; a focus candidate area decision part for deciding a candidate area on which a focus control is performed in the imaging part according to a detection result of the displacement detection part; a display part capable of displaying an image corresponding to image data generated by the imaging part; and a display control part which displays an area corresponding to the candidate area decided by the focus candidate area decision part and the image on the display part.

Description

  The present invention relates to an imaging apparatus and an imaging program for imaging a subject and generating electronic image data.

  2. Description of the Related Art Conventionally, in an imaging apparatus that captures a subject and generates electronic image data, by using a photographing lens or a mount adapter having a tilt function, the optical axis of the photographing lens is tilted with respect to the imaging element to There is known a technique capable of shooting while adjusting the depth of field and performing exposure correction according to the tilt amount (see, for example, Patent Document 1).

  In addition, in an imaging apparatus having a tilt function, a technique for detecting a tilt amount or a shift amount of a lens and switching exposure control automatically and manually based on the detection result is also known (see, for example, Patent Document 2). .

JP 2001-194700 A Japanese Patent No. 3165433

  However, in the above-described prior art, when the tilt operation is performed, it is difficult to automatically perform focusing because the closest focusing distance changes due to the influence of aberration. Further, the user cannot accurately grasp in which area of the image the automatic focusing process (AF process) is performed.

  The present invention has been made in view of the above, and it is possible to easily perform automatic focusing while having a tilt function, and it is possible for a user to accurately grasp a region to be focused. An object is to provide an imaging device and an imaging program that can be used.

  In order to solve the above-described problems and achieve the object, an imaging apparatus according to the present invention receives an optical system having a lens group including one or a plurality of lenses and light collected by the optical system. An imaging unit that generates electronic image data and is capable of displacing the optical axis of the optical system, wherein a position where the optical axis is orthogonal to a light receiving surface of the imaging unit is a reference position A displacement amount detection unit that detects a displacement amount from the reference position, and a focus candidate region determination unit that determines a candidate region for performing focus control in the imaging unit based on a detection result of the displacement amount detection unit A display unit capable of displaying an image corresponding to the image data generated by the imaging unit, and a display control for causing the display unit to display a region corresponding to the candidate region determined by the focus candidate region determining unit together with the image And equipped with And wherein the door.

  In the imaging device according to the present invention, in the above invention, the display control unit notifies that the displacement limit has been reached when the displacement amount detected by the displacement amount detection unit has reached a limit value. Displacement limit warning information is displayed on the display unit.

  In the image pickup apparatus according to the present invention, in the above invention, the display control unit is configured such that the distance from the optical system to the in-focus position is smaller than the closest distance determined according to the amount of displacement of the optical axis of the optical system. In this case, close limit warning information for notifying that the in-focus position is closer than the close limit is displayed on the display unit.

  The imaging apparatus according to the present invention is the imaging apparatus according to the above-described invention, wherein the auxiliary light irradiating unit that irradiates auxiliary light toward the visual field region of the imaging apparatus, the amount of displacement of the optical axis of the optical system, and the in-focus state And a light control unit that adjusts an irradiation amount of the auxiliary light irradiation unit according to a distance to the position.

  The imaging apparatus according to the present invention is characterized in that, in the above invention, the optical system is detachable from a main body of the imaging apparatus.

  An imaging program according to the present invention includes an optical system having a lens group including one or a plurality of lenses, and an imaging unit that receives light collected by the optical system and generates electronic image data. A displacement amount for detecting a displacement amount from the reference position, with a position where the optical axis is orthogonal to the light receiving surface of the imaging unit as a reference position. Based on the detection result of the detection step, the displacement amount detection step, a focus candidate region determination step for determining a candidate region for performing focus control in the imaging unit, and a candidate region determined in the focus candidate region determination step A display step of displaying an area corresponding to the image data together with an image corresponding to the image data.

  According to the present invention, a candidate region for focus control in the imaging unit is determined based on the amount of displacement from the reference position of the optical axis of the optical system having the tilt function, and a region corresponding to the candidate region is displayed on the display unit Therefore, automatic focusing can be easily performed while having the tilt function, and the user can accurately grasp the region to be focused.

FIG. 1 is a perspective view illustrating a configuration of a side facing a subject of the imaging apparatus according to the first embodiment of the present invention. FIG. 2 is a perspective view showing the configuration of the side (back side) facing the photographer of the imaging apparatus according to the first embodiment of the present invention. FIG. 3 is a block diagram illustrating a configuration of the imaging apparatus according to the first embodiment of the present invention. FIG. 4 is a diagram illustrating an example of aberration information of the lens unit stored in the aberration information storage unit of the imaging apparatus according to the first embodiment of the present invention. FIG. 5 is a diagram illustrating another example of the aberration information of the lens unit stored in the aberration information storage unit of the imaging apparatus according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view schematically illustrating a configuration of a main part of the lens unit in the imaging apparatus according to the first embodiment of the present invention. FIG. 7 is a diagram schematically illustrating a method of operating the lens unit in the imaging apparatus according to the first embodiment of the present invention. FIG. 8 is a diagram schematically illustrating an outline of a lens unit that operates by the operation illustrated in FIG. FIG. 9 is a diagram schematically illustrating aberrations that occur on the light receiving surface of the imaging unit in the imaging apparatus according to the first embodiment of the present invention. FIG. 10 schematically illustrates an example (first example) of aberration caused by the displacement of the optical axis of the lens unit with respect to the direction orthogonal to the light receiving surface of the imaging unit in the imaging apparatus according to the first embodiment of the present invention. FIG. FIG. 11 schematically illustrates an example of aberration (second example) caused by the displacement of the optical axis of the lens unit with respect to the direction orthogonal to the light receiving surface of the imaging unit in the imaging apparatus according to the first embodiment of the present invention. FIG. FIG. 12 schematically illustrates an example of aberration (third example) caused by the change of the optical axis of the lens unit with respect to the direction orthogonal to the light receiving surface of the imaging unit in the imaging apparatus according to the first embodiment of the present invention. FIG. FIG. 13 is a diagram illustrating an example of an image generated by the imaging apparatus according to the first embodiment of the present invention. FIG. 14 is a diagram schematically illustrating a relationship between the tilt state of the optical system of the imaging apparatus according to the first embodiment of the present invention and a candidate area for focusing control in the imaging unit. FIG. 15 is a diagram schematically illustrating a relationship between a deviation angle with respect to an optical axis of the optical system of the imaging apparatus according to the first embodiment of the present invention and aberration. FIG. 16 is a flowchart illustrating an outline of processing performed by the imaging apparatus according to the first embodiment of the present invention. FIG. 17 is a diagram illustrating an example of both displacement warning information displayed by the display unit of the imaging apparatus according to the first embodiment of the present invention. FIG. 18 is a diagram schematically illustrating focus control candidate areas in the imaging unit of the imaging apparatus according to the first embodiment of the present invention. FIG. 19 is a diagram illustrating an example of focus control candidate areas displayed on the display unit of the imaging apparatus according to the first embodiment of the present invention. FIG. 20 is a diagram illustrating an example of the close warning information displayed by the display unit of the imaging apparatus according to the first embodiment of the present invention. FIG. 21 is a diagram illustrating a configuration of a main part of a lens unit of the imaging apparatus according to the second embodiment of the present invention. FIG. 22 is a diagram schematically illustrating the operation of the lens unit of the imaging apparatus according to the second embodiment of the present invention. FIG. 23 is a diagram schematically illustrating a relationship between the tilt state of the optical system of the imaging apparatus according to the second embodiment of the present invention and the focus control candidate area in the imaging unit. FIG. 24 is a diagram illustrating the configuration of the front side of an imaging apparatus according to another embodiment of the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the drawings. The present invention is not limited to the embodiments described below.

(Embodiment 1)
FIG. 1 is a perspective view illustrating a configuration of a side facing the subject (front side) of the imaging apparatus according to the first embodiment of the present invention. FIG. 2 is a perspective view illustrating a configuration (back side) facing the photographer of the imaging apparatus according to the first embodiment. FIG. 3 is a block diagram illustrating a configuration of the imaging apparatus according to the first embodiment of the present invention. An imaging apparatus 1 illustrated in FIGS. 1 to 3 is a digital single-lens reflex camera, and includes a main body unit 2 and a lens unit 3 that can be attached to and detached from the main body unit 2. The imaging device 1 can also be equipped with accessories 4 such as an electronic viewfinder (EVF) and an electronic flash.

  As shown in FIGS. 1 to 3, the main body 2 includes an imaging unit 201, an imaging drive unit 202, a signal processing unit 203, an auxiliary light irradiation unit 204, an attitude detection unit 205, a timer 206, A first communication unit 207, a second communication unit 208, an operation input unit 209, a display unit 210, a touch panel 211, a storage unit 212, a power supply unit 213, a power supply unit 214, a main body control unit 215, Have

  The imaging unit 201 is configured using an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) that receives the light collected by the lens unit 3 and converts it into an electrical signal, and a shutter. .

  The imaging drive unit 202 has a function of driving the imaging device and the shutter according to the release signal. For example, the imaging drive unit 202 causes the signal processing unit 203 to output image data (analog signal) from the imaging device at a predetermined timing.

  The auxiliary light irradiation unit 204 is configured using a xenon lamp, an LED (Light Emitting Diode), or the like. The auxiliary light irradiation unit 204 irradiates auxiliary light (strobe light) toward the field of view imaged by the imaging device 1.

  The posture detection unit 205 is configured using an acceleration sensor. The posture detection unit 205 detects the posture state of the imaging device 1 by detecting the acceleration of the imaging device 1. Specifically, the posture detection unit 205 detects the posture (tilt angle) of the imaging device 1 with respect to the horizontal plane.

  The timer 206 has a timekeeping function and a shooting date / time determination function. The timer 206 outputs the date / time data to the main body control unit 215 in order to add the date / time data to the captured image data.

  The first communication unit 207 is a communication interface for performing communication with the lens unit 3 attached to the main body unit 2. The second communication unit 208 is a communication interface for performing communication with the accessory communication unit 401 of the accessory 4 attached to the main body unit 2.

  As shown in FIGS. 1 and 2, the operation input unit 209 inputs a power switch 209 a that switches the power state of the imaging apparatus 1 to an on state or an off state, and a still image release signal that gives a still image shooting instruction. A switch 209b, a shooting mode switching switch 209c for inputting a switching signal for giving an instruction for switching various shooting modes set in the imaging apparatus 1, and an instruction signal for giving an instruction for selecting or determining various settings for the imaging apparatus 1 are input. An operation switch 209d, a menu switch 209e for inputting an instruction signal for giving an instruction to display an operation menu screen set in the imaging apparatus 1, and a moving image switch 209f for inputting a moving image release signal for giving an instruction to shoot a moving image. . In the following description, a surface on which the power switch 209a and the like are provided in FIG. 1 is referred to as an upper surface, and a direction perpendicular to the surface is referred to as an up-down direction. A direction parallel to the upper surface and perpendicular to the vertical direction is referred to as a horizontal direction.

  The display unit 210 is realized using a display panel made of liquid crystal, organic EL (Electro Luminescence), or the like. In addition to the image data generated by the imaging unit 201, the display unit 210 appropriately displays operation information of the imaging device 1 and information related to shooting.

  The touch panel 211 is provided on the display screen of the display unit 210. The touch panel 211 detects a position touched by the user based on information displayed on the display unit 210 and receives an input of an operation signal corresponding to the detected touch position. In general, the touch panel includes a resistance film method, a capacitance method, an optical method, and the like. In the first embodiment, any type of touch panel is applicable.

  The storage unit 212 is realized using a semiconductor memory such as a flash memory or a DRAM (Dynamic Random Access Memory) that is fixedly provided inside the imaging apparatus 1. The storage unit 212 stores various programs for operating the imaging apparatus 1, the imaging program according to the first embodiment, various data and parameters used during the execution of the above-described program, and the like. The storage unit 212 stores image data and information such as information on the lens unit 3 that can be attached to the main body unit 2 and information on correction of image data according to the type of the lens unit 3. Note that the storage unit 212 may include a computer-readable storage medium such as a memory card mounted from the outside.

  The power supply unit 213 is configured using a battery that is detachably attached to the imaging apparatus 1. The power supply unit 214 supplies power from the power supply unit 213 to each component of the imaging apparatus 1 (including the lens unit 3 and the accessory 4 to be mounted). The power supply unit 214 may supply power supplied from an external power source (not shown) to each component of the imaging device 1.

  The main body control unit 215 is configured using a CPU (Central Processing Unit) or the like. The main body control unit 215 controls the operation of the imaging apparatus 1 by performing instructions, data transfer, and the like corresponding to each part of the imaging apparatus 1 according to an instruction signal, a switching signal, and the like from the operation input unit 209 and the touch panel 211. Control. The main body control unit 215 includes an image processing unit 215a, a face detection unit 215b, a state determination unit 215c, a focus candidate area determination unit 215d, a shooting control unit 215e, a light control unit 215f, and a display control unit 215g. Have

  The image processing unit 215 a performs various types of image processing on the image data input from the signal processing unit 203 and outputs the processed image data to the storage unit 212. Specifically, the image processing unit 215a performs image processing including at least edge enhancement, white balance, color correction, and γ correction on the image data.

  The face detection unit 215b detects the face of a person included in the image corresponding to the image data by pattern matching. Note that the face detection unit 215b may detect not only a person's face but also a face such as a dog or a cat. Furthermore, the face detection unit 215b may detect a human face using a known technique other than pattern matching.

  The state determination unit 215 c determines the state of the lens unit 3 based on information regarding the state of the lens unit 3 input from the first communication unit 207.

  The focus candidate area determination unit 215d determines a candidate area (hereinafter referred to as “focus candidate area”) for which the imaging unit 201 performs focus control based on the determination result of the state determination unit 215c.

  The shooting control unit 215e performs control to start a shooting operation in the imaging device 1 when a still image release signal is input. Here, the photographing operation in the imaging apparatus 1 refers to an operation in which the signal processing unit 203 and the image processing unit 215a perform predetermined processing on the image data output from the imaging unit 201 by driving the imaging driving unit 202. The image data processed in this way is recorded in the storage unit 212 by the main body control unit 215. Note that the imaging control unit 215e may perform control to start the imaging operation in the imaging device 1 in accordance with the determination result of the state determination unit 215c.

  The dimmer 215f adjusts the irradiation amount of the auxiliary light emitted by the auxiliary light irradiation unit 204 when the imaging device 1 performs shooting based on the amount of displacement of the lens unit 3 from the predetermined reference position.

  When the instruction signal is input from the menu switch 209e, the display control unit 215g displays the operation menu screen on the display unit 210. Further, the display control unit 215g causes the display unit 210 to display an area corresponding to the focus candidate area in the imaging unit 201.

  The main body unit 2 having the above configuration may be provided with a voice input / output function, a communication function for performing communication via the Internet, and the like.

  The lens unit 3 is a tilt lens (tilt lens) that can swing in all directions with reference to a direction in which the optical axis of the optical system 301 is orthogonal to the light receiving surface of the imaging unit 201.

  The lens unit 3 includes an optical system 301, a lens driving unit 302, a position detection unit 303, an inclination detection unit 304, an aperture driving unit 305, a lens operation unit 306, a lens communication unit 307, and a lens storage unit 308. And a lens control unit 309.

  The optical system 301 includes a lens group 301a including one or a plurality of lenses, a focus mechanism 301b that adjusts the focus of the lens group 301a, and an optical axis of the optical system 301 that can swing with respect to the light receiving surface of the imaging unit 201. An inclination mechanism 301c for inclining and an aperture mechanism 301d for limiting the amount of incident light collected by the lens group 301a are provided.

  The lens driving unit 302 is configured by using a DC motor, a stepping motor, or the like. The lens driving unit 302 drives the focus mechanism 301b, thereby moving the lens group 301a of the optical system 301 along the optical axis. The focus of the system 301 is adjusted.

  The position detection unit 303 detects the position of the lens group 301a in the optical axis direction. The inclination detection unit 304 detects a displacement amount (inclination amount) from the reference position with a position where the optical axis of the optical system 301 and the light receiving surface of the imaging unit 201 are orthogonal to each other as a reference position. In this sense, in the first embodiment, the inclination detection unit 304 functions as a displacement amount detection unit.

  The aperture driving unit 305 is configured using a stepping motor or the like. The aperture driving unit 305 adjusts the amount of light incident on the imaging unit 201 by driving the aperture mechanism 301d.

  As shown in FIG. 1, the lens operation unit 306 is a focus ring provided around the lens barrel of the lens unit 3, and receives a signal for operating the lens group 301 a in the optical system 301. The lens operation unit 306 may be a push switch or the like.

  The lens communication unit 307 is a communication interface for communicating with the first communication unit 207 of the main body unit 2 when the lens unit 3 is attached to the main body unit 2.

  The lens storage unit 308 stores a control program and various parameters for determining the position and movement of the lens group 301a of the optical system 301. The lens storage unit 308 includes an aberration information storage unit 308 a regarding various aberrations of the lens unit 3. Further, the lens storage unit 308 includes tilt angle limit value information of the lens unit 3, closest distance limit information, constraint condition information that restrains movement of the lens unit 3, focus position information corresponding to the tilt angle of the optical system 301, The focus position information determined by the extendable range of the lens unit 3, the tilt angle of the optical system 301 and the extension amount of the lens unit 3 are stored.

  FIG. 4 is a diagram illustrating an example of aberration information of the lens unit 3 stored in the aberration information storage unit 308a. As shown in FIG. 4, in the aberration information table T1, a deviation angle φ from the optical axis when an image formed at a position away from the optical system 301 by a focal length is viewed from the center of the optical system 301 (= The relationship between the angle of view φ when the optical axis direction is 0 ° and the aberration (for example, the amount of field curvature and astigmatism difference) s is described. For example, when the deviation angle φ is 5 °, the aberration s is described as 0.1 mm.

  FIG. 5 is a diagram illustrating another example of the aberration information of the lens unit 3 stored in the aberration information storage unit 308a. As shown in FIG. 5, the aberration information table T2 describes the relationship between the above-described deviation angle φ and the magnification of R (red), G (green), and B (blue) with respect to the ideal image height. For example, when the deviation angle is 5 °, the magnifications of R, G, and B with respect to the ideal image height are described as 98%, 96%, and 93%, respectively. When the deviation angle φ is 10 °, the magnifications of R, G, and B with respect to the ideal image height are described as 96%, 92%, and 85%, respectively. In general, the light having a smaller wavelength has a higher refractive index. For this reason, the distortion aberration of the B component having the smallest wavelength among the three components of R, G, and B is the largest. Furthermore, the distortion aberration (chromatic aberration) for each color increases as the deviation angle φ increases.

  The lens control unit 309 is configured using a CPU (Central Processing Unit) or the like. The lens control unit 309 controls the operation of the lens unit 3 according to the instruction signal from the main body unit 2.

  Here, with reference to FIG. 6, the structure of the principal part of the lens part 3 is demonstrated. FIG. 6 is a cross-sectional view schematically showing the configuration of the main part of the lens unit 3. In FIG. 6, the left side is the subject side (hereinafter referred to as the front), and the right side is the side attached to the main body 2 (hereinafter referred to as the rear).

As shown in FIG. 6, the lens unit 3 rotates the first frame 31 that holds the lens group 301a and the diaphragm mechanism 301d, the second frame 32 that holds the frame 31 movably in the front-rear direction, and the point O ₁ . It has the 3rd frame 33 which hold | maintains the 2nd frame 32 so that rocking is possible as a center. A position detection unit 303 is provided inside the second frame 32, and an inclination detection unit 304 is provided inside the third frame 33.

  The position detection unit 303 is configured by a reflective displacement sensor or the like. Specifically, the position detection unit 303 includes a photo interrupter 303a having a light emitting element and a light receiving element, and a reflecting member 303b having a reflectance that varies depending on the position. The photo interrupter 303 a is provided on the inner peripheral side of the second frame 32, and the reflecting member 303 b is provided on the outer peripheral side of the first frame 31. The position detection unit 303 calculates the amount of extension of the first frame 31 by reflecting the light irradiated by the photo interrupter 303a by the reflecting member 303b and causing the photo interrupter 303a to receive the light reflected by the reflecting member 303b. The position of the lens group 301a in the optical axis direction is detected from the extended amount. The position detection unit 303 may use various position sensors.

The tilt detection unit 304 detects the tilt angle of the second frame 32 with respect to the point O _1, whereby the optical axis of the optical system 301 is directed from the position where the optical axis of the optical system 301 and the light receiving surface of the imaging unit 201 are orthogonal to each other. Detect the direction you are doing. The inclination detection unit 304 includes a photo interrupter 304a and a reflection member 304b. The tilt detection unit 304 may use various position sensors. Further, the second frame 32 and the reflecting member 304b may be integrally formed.

  The lens unit 3 having the above configuration is focused only in the vicinity of the optical axis of the optical system 301, and the periphery thereof is blurred radially. Further, in the lens unit 3, the parallax on the side opposite to the side on which the optical axis is inclined becomes the largest.

  A method of operating the lens unit 3 configured as described above will be described. FIG. 7 is a diagram schematically illustrating a method for operating the lens unit 3. FIG. 8 is a diagram schematically illustrating an outline of the lens unit 3 that operates by the operation illustrated in FIG. 7.

  As shown in FIGS. 7 and 8, when the user operates the lens operation unit 306 to adjust the focus of the optical system 301 (FIG. 7A), the lens control unit according to the operation amount of the lens operation unit 306. 309 feeds the first frame 31 forward (FIG. 8A). Thereby, the lens unit 3 adjusts the focus of the optical system 301. Thereafter, the tilt mechanism 301c tilts the first frame 31 according to the operation of the lens barrel by the user (FIG. 7B) (FIG. 8B). Thereby, the lens unit 3 can change the optical axis of the optical system 301 from a position orthogonal to the light receiving surface of the imaging unit 201. The lens control unit 309 can automatically adjust the focus and focus.

  Next, a change in aberration that occurs when the optical axis of the lens unit 3 is displaced with respect to the light receiving surface of the imaging unit 201 will be described. FIG. 9 to FIG. 12 are diagrams for schematically explaining aberrations caused by the displacement of the optical axis of the lens unit 3 with respect to the direction orthogonal to the light receiving surface of the imaging unit 201. 9 to 12 show a case where the lens group 301a is composed of one lens. Hereinafter, a state where the optical axis of the optical system 301 passes through the center of the light receiving surface of the imaging unit 201 and is at a position orthogonal to the light receiving surface of the imaging unit 201 is referred to as an “initial state”.

As shown in FIG. 9, when the distance from the light receiving surface of the imaging unit 201 to the two subjects E11 and E12 is the same (d ₁ ), the subject E11 is focused on the lens group 301a that is not sufficiently corrected for aberrations. In this case, an aberration s ₁ occurs in the image of the subject E12 formed in the imaging unit 201, and thus the image of the subject E12 is blurred. However, by utilizing this aberration as one of the expressions, it is possible to change the expression of the image to be captured.

As shown in FIG. 10, when the lens group 301a with respect to the light receiving surface of the imaging unit 201 is inclined at an inclination angle θ (for example, θ = 5 °), an image of the subject E12 further enters from the periphery of the optical axis L _1. Therefore, the aberration s _{2 of the} subject E12 formed in the imaging unit 201 is larger than the aberration s ₁ (s ₁ <s ₂ ). As a result, the image to be picked up has a further enhanced difference between the subject E11 and the subject E12. Actually, off-axis aberration also occurs for the subject E11, but in FIG. 10, the tilt angle θ from the initial state of the lens group 301a is small enough to have little effect on the image of the subject E11. It is supposed to be.

As shown in FIG. 11, when the distance d ₁ from the imaging unit 201 to the subject E11 is smaller than the distance d ₂ from the imaging unit 201 to the subject E12 (d ₁ <d ₂ ), the image of the subject E12 is Since the light is incident from a position farther from the optical axis L ₁ than in the case shown in FIG. 10, the aberration s _{3 of the} subject E12 formed in the imaging unit 201 is further larger than the aberration s ₂ (s ₂ < s _3). Also in FIG. 11, the inclination angle θ from the initial state of the lens group 301a is set to be small enough to hardly affect the image of the subject E11.

Also, as shown in FIG. 12, the distance d ₃ from the imaging unit 201 to the subject E11 is smaller than the distance d ₁ (d ₁ <d ₃ ), and the lens group 301a after tilting from the initial state. If the subject E11 on the optical axis L ₁ is positioned and to focus the lens 301a to the subject E11, becomes a difference between the object E11 and the subject E12 (aberration s ₄₎ has more been further emphasized.

  FIG. 13 is a diagram illustrating an image change example corresponding to a change in the optical axis of the optical system 301. An image W11 illustrated in FIG. 13A is an image captured by focusing on the face of a person who is a subject with the lens group 301a in the initial state. An image W12 shown in FIG. 13B is an image that is captured by focusing on the face of a person with the lens group 301a tilted from the initial state. When comparing the image W11 and the image W12, the periphery of the person's face spreads radially and blurs in both images (indicated by broken lines), but the blur amount (aberration) of the image W12 is larger than that of the image W11. It has become. As described above, in the case of the optical system 301, when the lens group 301a is tilted from the initial state, an image in which the difference between the vicinity of the optical axis and the periphery thereof is further emphasized can be captured.

By the way, when the optical system 301 having the above-described properties is applied, the focus candidate area in the imaging unit 201 changes according to the inclination angle θ from the initial state. FIG. 14 is a diagram schematically illustrating the relationship between the displacement of the optical system 301 from the reference position and the focus candidate area in the imaging unit 201. In Figure 14, the feed amount Z ₁ and the optical system 301 in an initial state vertically and tilted rotated by the inclination angle θ with a plane parallel state (hereinafter, referred to as "inclined state") feed amount Z ₁ of the same The case is shown. The distance on the optical axis between the point O ₁ and the imaging unit 201 when the optical system 301 is in the initial state is Z ₂ , and the optical axis between the point O ₁ and the imaging unit 201 when the optical system 301 is in the inclined state Let Z _{3 be the} upper distance. At this time,
Z ₃ = Z ₂ · arccos θ (1)
Is true.

In the initial state, the distance from the optical system 301 to the in-focus position (hereinafter referred to as the in-focus distance) when focusing on the subject located on the optical axis is D ₁ ,
D ₁ = α (Z ₁ + Z ₂ ) (2)
Suppose that Here, α is a positive constant determined according to the characteristics of the lens group 301a. On the other hand, the focusing distance D ₂ in the inclined state is
D ₂ = D ₁ · (Z ₁ + Z ₂ ) / (Z ₁ + Z ₃ ) (3)
Given in. Here, since Z ₂ > Z ₃ , D ₁ > D ₂ . As described above, the focusing distance of the lens unit 3 is changed by changing the tilt angle θ without changing the extension amount. Specifically, in the lens unit 3, when the feeding amount is constant, the focusing distance becomes shorter as the tilt angle θ is larger, and the subject located closer can be focused. When the lens unit 3 having such characteristics is applied, it is necessary to correct the focus distance and adjust the amount of auxiliary light emitted by the auxiliary light irradiation unit 204 according to the focus distance. In the imaging device 1, the light control unit 215f adjusts the amount of auxiliary light irradiation based on the state of the lens unit 3 at the time of shooting.

In FIG. 14, the vertical distance ΔY between the intersection P between the optical axis of the optical system 301 in the initial state and the imaging unit 201 and the intersection Q between the optical axis of the optical system 301 in the tilted state and the imaging unit 201 is an inclination angle. Using θ
ΔY = Z ₂ · tan θ (4)
Given in.

FIG. 15 is a diagram schematically showing the relationship between the deviation angle φ with respect to the optical axis of the optical system 301 and the aberration s. As shown in FIG. 15, the aberration s increases as the deviation angle φ increases. Therefore, in the first embodiment, in order to determine a focus candidate region suitable for the automatic focusing process, an upper limit value s _{max of} aberration is set in advance, and the deviation angle is set so as to satisfy this upper limit value. The allowable value φ _k of φ is determined. For example, s _max can be set to 0.2 mm, and φ _k can be defined as −10 ° <φ _k <10 °. In this way, the focusing range of the vertical direction of the image pickup unit 201 around the [Delta] Y, is set to ΔY ± ΔY _k. Where ΔY _k is
ΔY _k = Z ₂ · tan | φ _k | (5)
Given in.

  In the above description, only the vertical direction of the imaging device 1 has been described. However, the focus candidate area determination unit 215d similarly sets the focusing range in the horizontal direction of the imaging device 1, thereby forming a rectangular shape. The focus candidate area to be formed can be determined.

  In the imaging apparatus 1 having the above configuration, it is possible to mount a lens unit other than the lens unit 3 that is a tilt lens. Therefore, in the following description, the lens units that can be attached to the imaging apparatus 1 are collectively referred to as “lens unit 3G”. The lens unit 3G includes at least a lens communication unit 307 and a lens control unit 309.

  Next, an operation performed by the imaging apparatus 1 having the above configuration will be described. FIG. 16 is a flowchart illustrating an outline of processing performed by the imaging apparatus 1.

  In FIG. 16, a case where the imaging device 1 is set to the shooting mode will be described (step S101: Yes). In this case, the display control unit 215g displays the live view image on the display unit 210 (step S102). Further, the lens control unit 309 communicates the lens state of the lens unit 3G with the main body control unit 215 (step S103).

  Subsequently, the main body control unit 215 determines whether the lens unit 3G attached to the main body unit 2 is a tilt lens based on a signal input from the lens control unit 309 (step S104). When the lens unit 3G attached to the main body unit 2 is a tilt lens (step S104: Yes), the imaging device 1 proceeds to step S105 described later. On the other hand, when the lens unit 3G attached to the main body unit 2 is not a tilt lens (step S104: No), the imaging device 1 proceeds to step S118 described later.

  A case where the lens unit 3G attached to the main body unit 2 is a tilt lens (the lens unit 3 described above) in step S104 (step S104: Yes) will be described. Hereinafter, in steps S <b> 105 to S <b> 110 showing processing when the lens unit 3 </ b> G is a tilt lens, the lens unit 3 </ b> G is described as the lens unit 3. In this case, the state determination unit 215c determines whether or not a tilt operation for tilting the lens unit 3 has been performed (step S105). Specifically, the state determination unit 215c determines whether the tilt detection unit 304 of the lens unit 3 has detected the tilt of the optical system 301. When the tilt operation of the lens unit 3 is performed (step S105: Yes), the lens control unit 309 acquires tilt information including the tilt amount as the displacement amount detected by the tilt detection unit 304 from the tilt detection unit 304. (Step S106). On the other hand, when the tilt operation of the lens unit 3 is not performed (step S105: No), the imaging apparatus 1 proceeds to step S118 described later.

  After step S106, the lens control unit 309 refers to the lens storage unit 308 to determine whether the tilt of the lens unit 3, that is, the tilt angle, has reached a limit (displacement limit) (step S107). As a result of the determination, if the tilt of the lens unit 3 has reached the limit (step S107: Yes), the lens control unit 309 sends a signal indicating that the tilt of the lens unit 3 has reached the limit to the main body control unit 215. Send. Based on the signal received from the lens control unit 309, the display control unit 215g causes the display unit 210 to display information (displacement limit warning information) notifying that the tilt of the lens unit 3 has reached the limit (step S108). ). FIG. 17 is a diagram illustrating a display example of warning information displayed by the display unit 210 in this case. In the case illustrated in FIG. 17, a message “Inclination limit” is displayed on the display unit 210. By notifying the tracking limit of the mechanism and various sensors in this way, it is possible to prevent focusing on the optical axis without obtaining an image and to prevent the user from performing excessive operations. You can do it.

  As a result of the determination by the lens control unit 309 in step S107, if the inclination of the lens unit 3 has not reached the limit value (step S107: No), the imaging apparatus 1 proceeds to step S109 described later.

In step S109, the focus candidate area determination unit 215d determines a focus candidate area in the imaging unit 201 (step S109). At this time, the in-focus candidate area determination unit 215d determines in-focus candidate areas around the point Q of the imaging unit 201 by using, for example, equations (1) to (5). FIG. 18 is a diagram schematically illustrating a focus candidate area in the imaging unit 201. The focus candidate area PD shown in FIG.
PD = {(X, Y) | ΔX−ΔX _k <X <ΔX + ΔX _k , ΔY−ΔY _k <Y <ΔY + ΔY _k }
Given in. Here, ΔX _k is obtained in the same manner as ΔY _k described above (see Expression (5)).

  Thereafter, the display control unit 215g causes the display unit 210 to display the focus candidate area determined by the focus candidate area determination unit 215d on the live view image (step S110). FIG. 19 is a diagram illustrating a display example of the focus candidate areas displayed by the display unit 210. Specifically, FIG. 19 shows a display example when the optical axis of the optical system 301 is inclined upward with respect to the light receiving surface of the imaging unit 201. The display unit 210 displays the focus candidate area PD1 so as to overlap the live view image W21. As a result, the user can accurately grasp the focus candidate area in the image.

  After step S110, the main body control unit 215 and the lens control unit 309 cooperate to automatically perform focusing control by using an image signal or the like of the focusing candidate area (step S111). In the first embodiment, the imaging apparatus 1 performs focus determination only in the focus candidate area. Note that step S111 may be performed in parallel with step S110.

  Subsequently, the lens control unit 309 refers to the lens storage unit 308 and determines whether or not the focus distance is smaller than the closest distance (step S112). In the first embodiment, the feeding amount of the optical system 301 corresponding to the closest distance is set smaller than the feeding amount at the mechanical limit unless the inclination of the lens unit 3 reaches the limit.

  As a result of the determination by the lens control unit 309, when the in-focus distance is smaller than the closest distance (step S112: Yes), the lens control unit 309 transmits a signal to that effect to the main body control unit 215. The main body control unit 215 that has received the signal causes the display control unit 215g to display the near limit warning information indicating that the in-focus position is closer than the close limit on the display unit 210 (step S113). FIG. 20 is a diagram illustrating a display example of the close warning information displayed by the display unit 210. In the case illustrated in FIG. 20, a message “Closest limit” is displayed on the display unit 210. As a result, it is possible to avoid wasting labor and time such as trying to shoot at a distance where the user cannot focus. As a result, the user can take a picture without missing a photo opportunity by quick determination.

  On the other hand, as a result of the determination by the lens control unit 309, when the in-focus distance is equal to or greater than the closest distance (step S112: No), the main body control unit 215 records the in-focus distance in the storage unit 212 in association with the tilt angle. (Step S114).

  After step S113 or S114, when the release switch 209b is pressed and a still image release signal is input (step S115: Yes), the imaging apparatus 1 performs shooting under the control of the shooting control unit 215e (step S116). ). Thereafter, the main body control unit 215 records the image data acquired by photographing in the storage unit 212 (step S117). Here, when the imaging apparatus 1 is set to the auxiliary light automatic light emission mode, the main body control unit 215 performs control to cause the auxiliary light irradiation unit 204 to emit light according to the brightness of the visual field area of the optical system 301. At this time, if the lens unit 3G is a tilt lens and the result of determination in step S112 is that the in-focus distance is equal to or greater than the closest distance, the dimming unit 215f includes the lens unit 3 stored in the storage unit 212. The dose is adjusted according to the focus distance and the tilt angle.

  In step S115, when a still image release signal is not input via the release switch 209b (step S115: No), the imaging apparatus 1 proceeds to step S122 described later.

  A case where the lens unit 3G attached to the main body unit 2 is not a tilt lens in step S104 (step S104: No) will be described. In this case, a focus operation for adjusting the focus of the lens unit 3G is performed (step S118: Yes), and a predetermined time (for example, 3 seconds) has not elapsed since the focus operation was performed (step S119: No) ) The lens control unit 309 adjusts the focus of the lens unit 3G according to the operation amount of the focus operation (step S120). On the other hand, when the focus operation of the lens unit 3G is performed (step S118: Yes) and a predetermined time has elapsed since the focus operation was performed (step S119: Yes), the lens control unit 309 performs the body control. In cooperation with the unit 215, AF control of the lens unit 3G is performed (step S121). If the focus operation is not performed in step S118 (step S118: No), the imaging device 1 proceeds to step S121. After step S120 or S121, the imaging apparatus 1 proceeds to step S115 described above.

  In step S122, when the power switch 209a is pressed (step S122: Yes), the main body control unit 215 performs control to turn off the power (step S123). Thereafter, the imaging apparatus 1 ends a series of processes.

  In step S122, when the power switch 209a is not pressed (step S122: No), when the lens unit 3G is replaced with another lens unit 3G (step S124: Yes), the main body control unit 215 is newly mounted. Lens type information is obtained from the lens unit 3G (step S125). Thereafter, the imaging apparatus 1 returns to step S101. On the other hand, when the power switch 209a is not pressed (step S122: No), if the lens unit 3G is not replaced with another lens unit 3G (step S124: No), the imaging device 1 returns to step S101.

  Next, a case where the shooting mode is not set in step S101 (step S101: No) will be described. In this case, when the imaging device 1 is set to the reproduction mode (step S126: Yes), the display control unit 215g displays a file list on the display unit 210 (step S127).

  Subsequently, when a file to be enlarged and displayed is selected via the operation input unit 209 or the touch panel 211 (step S128: Yes), the display control unit 215g reproduces and displays the selected file on the display unit 210 ( Step S129).

  Thereafter, when another image file is newly selected (step S130: Yes), the imaging device 1 returns to step S129. On the other hand, when another image file is not selected (step S130: No), the imaging apparatus 1 proceeds to step S131.

  In step S131, when an instruction to end image reproduction is input through the operation input unit 209 or the touch panel 211 (step S131: Yes), the imaging device 1 proceeds to step S122. On the other hand, when an instruction to end image reproduction is not input (step S131: No), the imaging apparatus 1 returns to step S127.

  If no file is selected in step S128 (step S128: No), the imaging apparatus 1 proceeds to step S131.

  In step S126, when the imaging device 1 is not set to the reproduction mode (step S126: No), the imaging device 1 returns to step S101.

  According to the first embodiment of the present invention described above, the focus control candidate region in the imaging unit is determined based on the displacement amount from the reference position of the optical axis of the optical system having the tilt function, and the candidate region is defined as the candidate region. Since the corresponding area is displayed on the display unit, automatic focusing can be easily performed while the tilt function is provided, and the user can accurately grasp the area to be focused.

  Further, according to the first embodiment, since the displacement limit warning information and the close limit warning information are displayed on the display unit according to the state of the lens unit (optical system), only a normal lens having no tilt function is used. Users with no tilt can learn how to use a lens with a tilt function and get used to the lens with a tilt function quickly.

  In the first embodiment of the present invention, the optical axis of the optical system 301 can be tilted with respect to the direction orthogonal to the light receiving surface of the imaging unit 201. For example, the optical axis of the optical system 301 is It may be movable while maintaining the angle formed with the light receiving surface 201.

(Embodiment 2)
FIG. 21 is a diagram illustrating a configuration of a main part of a lens unit included in the imaging apparatus according to Embodiment 2 of the present invention. The lens unit 6 shown in FIG. 21 includes a first frame 61 that holds the lens group 601a and the diaphragm 601d, a second frame 62 that holds the first frame 61, and the second frame 62 that has the point O ₂ as the center of rotation. It has the 3rd frame 63 hold | maintained so that rocking | swiveling in an azimuth | direction, and the 4th frame 64 holding the 3rd frame 63 so that a movement in the front-back direction is possible. In addition, an inclination detection unit 603 is provided inside the third frame 63, and a position detection unit 604 is provided inside the fourth frame 64. Similar to the tilt detection unit 304 of the lens unit 3, the tilt detection unit 603 includes a photo interrupter 603a and a reflection member 603b. The position detection unit 604 includes a photo interrupter 604a and a reflection member 604b, like the position detection unit 303 of the lens unit 3. In Embodiment 2, the lens group 601a is composed of one lens, but the lens group 601a may be configured using a plurality of lenses.

  The optical system 601 of the lens unit 6 includes a focus mechanism 601b and a tilt mechanism 601b corresponding to the focus mechanism 301b and the tilt mechanism 301c, respectively, in addition to the lens group 601a and the diaphragm mechanism 601d. Similarly to the lens unit 3, the lens unit 6 includes a lens driving unit 302, a diaphragm driving unit 305, a lens operation unit 306, a lens communication unit 307, a lens storage unit 308, and a lens control unit 309.

  The operation of the lens unit 6 having the above configuration will be described. FIG. 22 is a diagram schematically illustrating the operation of the lens unit 6. As shown in FIG. 22, in the lens unit 6, the focus is adjusted by moving the first frame 61 and the second frame 62 in the front-rear direction (FIG. 22A). The movement of the first frame 61 and the second frame 62 can be automatically performed under the control of the lens control unit 309 or can be performed by the user operating the lens operation unit 306. is there. Further, when the user operates the lens barrel of the lens unit 6 to tilt the first frame 61 and the second frame 62, the optical axis of the optical system 601 is displaced (FIG. 22B).

FIG. 23 is a diagram schematically illustrating the relationship between the tilted state of the optical system 601 and the focus candidate area of the imaging unit 201. In FIG. 23, between the feed amount W ₁ in the initial state and the feed amount W ₂ in the tilted state where the lens group 601a is tilted by the tilt angle ψ,
W ₂ = W ₁ · arccosψ (6)
Is true.

Further, in the initial state, the focusing distance from the lens unit 301a when the subject is in focus to the focus position and D ₃ to the object located on the optical axis of the optical system 601,
D ₃ = βW ₁ (7)
Suppose that Here, β is a positive constant determined according to the characteristics of the lens group 601a. On the other hand, the focusing distance D ₄ in the inclined state is
D ₄ = D ₃ · W ₁ / W ₂ (8)
Given in. Therefore, also in the second embodiment, the focusing distance D ₄ in the inclined state is smaller than the focusing distance D ₃ in the initial state (D ₃ > D ₄ ). In the lens unit 6 as well, when the extension amount is constant, the focusing distance becomes shorter as the tilt angle ψ increases, and the subject located closer can be focused.

Furthermore, the vertical distance ΔY between the intersection R of the optical axis of the optical system 601 and the imaging unit 201 in the initial state and the intersection S of the optical axis of the optical system 601 and the imaging unit 201 in the inclined state is
ΔY = W ₁ · tanψ (9)
Given in.

  Even when the lens unit 6 having the above configuration is applied, the in-focus candidate region can be determined as in the first embodiment.

  According to the second embodiment of the present invention described above, as in the first embodiment described above, automatic focusing can be easily performed while the tilt function is provided, and the user can adjust the focus target. The area can be accurately grasped.

(Other embodiments)
FIG. 24 is a diagram illustrating the configuration of the front side of an imaging apparatus according to another embodiment of the present invention. An imaging apparatus 1-2 illustrated in FIG. 24 includes a main body unit 2 and a lens unit 7 attached to the main body unit 2. The lens unit 7 holds the optical system 701, an optical system holding unit 702 that holds the optical system 701, and holds the optical system holding unit 702 so that it can advance and retreat in the front-rear direction and swing in all directions. And a bellows-like connecting portion 703 that is connected to the head.

  When applying the lens unit 7 having the above configuration, the user determines the field of view and focuses by holding the optical system holding unit 702 and fixing the optical system 701 in a desired direction. be able to. It is also possible to further provide a fixing mechanism for fixing the connected state of the connecting portion 703 to the lens portion 7.

  By using the lens unit 7 configured in this way, the optical axis of the optical system 301 can be changed with respect to the direction orthogonal to the light receiving surface of the imaging unit 201, and the same effect as the above-described embodiment can be obtained. Play.

  In the above-described embodiment, the change in which the optical axis is tilted by the tilt lens has been described mainly. However, it goes without saying that the present invention can also be applied to a shift lens that shifts the optical axis in parallel. Nor.

  In the above-described embodiment, the imaging device 1 has been described as a digital single-lens reflex camera. It can be applied to various electronic devices.

DESCRIPTION OF SYMBOLS 1,1-2 Image pick-up device 2 Main-body part 3,3G, 6,7 Lens part 4 Accessory 31,61 1st frame 32,62 2nd frame 33,63 3rd frame 64 4th frame 201 Imaging part 202 Imaging drive part 203 Signal Processing Unit 204 Auxiliary Light Irradiation Unit 205 Attitude Detection Unit 206 Timer 207 First Communication Unit 208 Second Communication Unit 209 Operation Input Unit 209a Power Switch 209b Release Switch 209c Shooting Mode Switch 209d Operation Switch 209e Menu Switch 209f Movie Switch 210 Display unit 211 Touch panel 212 Storage unit 213 Power supply unit 214 Power supply unit 215 Main body control unit 215a Image processing unit 215b Face detection unit 215c State determination unit 215d In-focus candidate area determination unit 215e Imaging control unit 215f Dimming unit 215g Display control unit 301 601 and 701 Optical systems 301a and 601a Lens group 301b Focus mechanism 301c Tilt mechanism 301d and 601d Aperture mechanism 302 Lens drive unit 303 and 604 Position detection unit 304 and 603 Tilt detection unit 305 Diaphragm drive unit 306 and 701a Lens operation unit 307 Lens communication Unit 308 lens storage unit 308a aberration information storage unit 309 lens control unit 401 accessory communication unit 702 optical system holding unit 703 connection unit

Claims (6)

An optical system having a lens group composed of one or a plurality of lenses, and an imaging unit that receives light collected by the optical system and generates electronic image data, and displaces the optical axis of the optical system An imaging device capable of causing
A displacement amount detection unit that detects a displacement amount from the reference position with a position where the optical axis is orthogonal to the light receiving surface of the imaging unit as a reference position;
Based on a detection result of the displacement amount detection unit, a focus candidate region determination unit that determines a candidate region for performing focus control in the imaging unit;
A display unit capable of displaying an image corresponding to the image data generated by the imaging unit;
A display control unit that causes the display unit to display a region corresponding to the candidate region determined by the focus candidate region determination unit, together with the image;
An imaging apparatus comprising: The display control unit
The displacement limit warning information for notifying that the displacement limit has been reached is displayed on the display unit when the displacement amount detected by the displacement amount detection unit has reached a limit value. The imaging device described. The display control unit
When the distance from the optical system to the in-focus position is smaller than the closest distance determined according to the amount of displacement of the optical axis of the optical system, close limit warning information for informing that the in-focus position is closer than the close limit is displayed. The image pickup apparatus according to claim 1, wherein the image pickup apparatus is displayed on the display unit. An auxiliary light irradiation unit that emits auxiliary light toward the field of view of the imaging device;
A light control unit that adjusts the amount of irradiation of the auxiliary light irradiation unit according to the amount of displacement of the optical axis of the optical system and the distance from the optical system to the in-focus position;
The imaging apparatus according to claim 1, further comprising:   The imaging apparatus according to claim 1, wherein the optical system is detachable from a main body of the imaging apparatus. An optical system having a lens group composed of one or a plurality of lenses, and an imaging unit that receives light collected by the optical system and generates electronic image data, and displaces the optical axis of the optical system In an imaging device that can be
A displacement amount detecting step for detecting a displacement amount from the reference position with a position where the optical axis is orthogonal to the light receiving surface of the imaging unit as a reference position;
Based on the detection result of the displacement amount detection step, a focus candidate area determination step for determining a candidate area for performing focus control in the imaging unit;
A display step of displaying an area corresponding to the candidate area determined in the focus candidate area determining step together with an image corresponding to the image data;
The imaging program characterized by performing.

Images