JP7427368B2 - Control device, imaging device, control method, and program - Google Patents

Description

The present invention relates to an imaging device having aperture information of an imaging optical system.

2. Description of the Related Art Conventionally, imaging apparatuses are known that calculate information for focus detection using aperture information that limits transmitted light of an imaging optical system. Patent Document 1 discloses that aperture data regarding the distance to each aperture of the optical system is acquired, and the distance of the center of gravity of the overlapping region where the distance measuring pupil of the focus detection optical system and the exit pupil of the interchangeable lens overlap with each other is calculated, An imaging device is disclosed that converts an amount of image shift into an amount of defocus based on a center of gravity distance. Patent Document 2 discloses that the lens stores information regarding the incident angle range of the imaging light flux, the camera body stores information regarding the light receiving sensitivity characteristics of the focus detection pixels, and based on this information, the information for focus adjustment control is stored. An imaging device that calculates information is disclosed.

Patent No. 5045801 Japanese Patent Application Publication No. 2016-118697

Incidentally, as apertures that limit the light flux passing through the imaging optical system, there are various apertures such as not only a plurality of lens apertures and aperture apertures but also a shutter aperture included in a camera body. Additionally, when an adapter unit that adjusts the optical path length or a converter lens unit that converts the focal length is installed between the photographic lens and the camera body, the aperture of each unit also limits the light flux that passes through the imaging optical system. It is possible. However, Patent Document 1 and Patent Document 2 do not disclose a method for deriving aperture information for each of a plurality of detachable units.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a control device, an imaging device, a control method, and a program that can calculate aperture information of each of a plurality of detachable units with high precision.

A control device according to one aspect of the present invention acquires first aperture information and second aperture information regarding the shape of an aperture that defines the outer edge of a luminous flux passing through each of a first unit and a second unit that are detachable from an imaging device. and a calculating means that calculates synthetic aperture information based on the first aperture information and the second aperture information.

An imaging device according to another aspect of the present invention includes an imaging element and the control device.

A control method according to another aspect of the present invention provides first aperture information and second aperture information regarding the shape of an aperture that defines the outer edge of a luminous flux passing through each of a first unit and a second unit that are detachable from an imaging device. and calculating synthetic aperture information based on the first aperture information and the second aperture information.

A program according to another aspect of the present invention causes a computer to execute the control method.

Other objects and features of the invention are explained in the following embodiments.

According to the present invention, it is possible to provide a control device, an imaging device, a control method, and a program that can calculate aperture information of each of a plurality of detachable units with high precision.

FIG. 1 is a block diagram of an imaging device in this embodiment. FIG. 2 is a block diagram of an imaging apparatus in which a detachable unit is installed between a lens unit and a camera body according to the present embodiment. FIG. 3 is a schematic explanatory diagram of aperture information in this embodiment. FIG. 2 is a schematic explanatory diagram of a method of calculating aperture information in this embodiment. FIG. 2 is a schematic explanatory diagram of a method of calculating aperture information in this embodiment. FIG. 3 is a schematic explanatory diagram when aperture information in this embodiment is expressed as information regarding the distance from the center position of the diaphragm. FIG. 3 is a diagram showing a situation in which a light beam passing through an imaging optical system in this embodiment is blocked by a part of the camera body. 3 is a flowchart showing a method for acquiring aperture information in this embodiment. It is an example of the attribute information of opening information in this embodiment. FIG. 7 is an explanatory diagram of aperture information depending on the amount of defocus in this embodiment. FIG. 3 is an explanatory diagram of the aperture information of each unit and the shape of the aperture that defines the outer edge of the light beam passing through the imaging optical system in the present embodiment. FIG. 3 is a block diagram showing communication information and arithmetic processing units of each unit in this embodiment.

Embodiments of the present invention will be described in detail below with reference to the drawings.

(Configuration of imaging device 10)
First, with reference to FIG. 1, the configuration of the imaging device in this embodiment will be described. FIG. 1 is a block diagram of an imaging device 10 (single-lens reflex digital camera with interchangeable lenses) in this embodiment. The imaging device 10 is a camera system that includes a lens unit (lens device as a first unit) 100 and a camera body 120. The lens unit 100 is detachably attached to the camera body 120 via a mount M shown by a dotted line in FIG. However, this embodiment is not limited to this, and can also be applied to an imaging device (digital camera) in which a lens unit (imaging optical system) and a camera body are integrally configured. Furthermore, the present embodiment is not limited to digital cameras, but can also be applied to other imaging devices such as video cameras.

The lens unit 100 includes a first lens group 101 as an optical system, an aperture 102, a second lens group 103, a focus lens group (hereinafter simply referred to as "focus lens") 104, and a drive/control system. In this way, the lens unit 100 is a photographic lens (imaging optical system) that includes the focus lens 104 and forms a subject image.

The first lens group 101 is disposed at the tip of the lens unit 100 and is held movable in the optical axis direction OA. The diaphragm 102 adjusts the amount of light during photographing by adjusting its aperture diameter, and also functions as a shutter for adjusting the exposure time during still image photographing. The diaphragm 102 and the second lens group 103 are movable together in the optical axis direction OA, and achieve a zoom function in conjunction with the forward and backward movements of the first lens group 101. The focus lens 104 is movable in the optical axis direction OA, and the subject distance (focusing distance) on which the lens unit 100 focuses changes depending on its position. By controlling the position of the focus lens 104 in the optical axis direction OA, focus adjustment (focus control) that adjusts the focusing distance of the lens unit 100 is possible.

The drive/control system includes a zoom actuator 111, an aperture actuator 112, a focus actuator 113, a zoom drive circuit 114, an aperture drive circuit 115, a focus drive circuit 116, a lens MPU 117, and a lens memory 118. The zoom drive circuit 114 uses the zoom actuator 111 to drive the first lens group 101 and the third lens group 103 in the optical axis direction OA, and controls the angle of view of the optical system of the lens unit 100 (performs a zoom operation). . Further, the zoom drive circuit 114 has a function as a position detection unit that uses the zoom actuator 111 to detect the current position (zoom state) of the first lens group 101 and the third lens group 103. The diaphragm drive circuit 115 drives the diaphragm 102 using the diaphragm actuator 112, and controls the aperture diameter and opening/closing operation of the diaphragm 102. The focus drive circuit 116 drives the focus lens 104 in the optical axis direction OA using the focus actuator 113 to control the focusing distance of the optical system of the lens unit 100 (performs focus control). Further, the focus drive circuit 116 has a function as a position detection unit that detects the current position (focus state) of the focus lens 104 using the focus actuator 113.

A lens MPU (processor, transmitter) 117 performs all calculations and controls related to the lens unit 100, and controls a zoom drive circuit 114, an aperture drive circuit 115, and a focus drive circuit 116. Further, the lens MPU 117 is connected to the camera MPU 125 through a plurality of channels of the mount M, and communicates commands and data. For example, the lens MPU 117 detects the position of the focus lens 104 and notifies lens position information in response to a request from the camera MPU 125. This lens position information includes the position of the focus lens 104 in the optical axis direction OA, the position and diameter of the exit pupil in the optical axis direction OA when the optical system is not moving, and the position of the lens frame that limits the light flux of the exit pupil. It includes information such as the position and diameter in the optical axis direction OA. Further, the lens MPU 117 controls the zoom drive circuit 114, the aperture drive circuit 115, and the focus drive circuit 116 in response to a request from the camera MPU 125.

A lens memory (storage means) 118 stores optical information (aperture information) necessary for automatic focus adjustment (AF control). Lens MPU 117 transmits optical information (aperture information) to camera MPU 125 periodically or all at once in response to a request from camera MPU 125 . Further, the camera MPU 125 controls the operation of the lens unit 100 by executing a program stored in the built-in nonvolatile memory or the lens memory 118, for example.

The camera body 120 includes a shutter unit 131, an optical low-pass filter 121, an image sensor 122, and a drive/control system. The shutter unit 131 has a rectangular opening, and adjusts the amount of photographing light using the slit width of two light-shielding films running inside the opening. The optical low-pass filter 121 and the imaging device 122 function as an imaging unit (imaging means) that photoelectrically converts a subject image (optical image) formed through the lens unit 100 and outputs image data. In this embodiment, the image sensor 122 photoelectrically converts a subject image formed through an imaging optical system, and outputs an imaging signal and a focus detection signal as image data. Further, in this embodiment, the first lens group 101, the diaphragm 102, the second lens group 103, the focus lens 104, and the optical low-pass filter 121 constitute an imaging optical system.

The optical low-pass filter 121 reduces false colors and moiré in captured images. The image sensor 122 is composed of a CMOS image sensor and its peripheral circuit, and has m pixels in the horizontal direction and n pixels in the vertical direction (m and n are integers of 2 or more). The image sensor 122 of this embodiment has a pupil division pixel that has a pupil division function and can perform focus detection (phase difference AF) using a phase difference detection method using image data (image signal). The image processing circuit 124 generates data for phase difference AF and image data for display, recording, and contrast AF (TVAF) based on the image data output from the image sensor 122.

The drive/control system includes an image sensor drive circuit 123, an image processing circuit 124, a camera MPU 125, a display 126, an operation switch group (operation SW) 127, a memory 128, and a phase difference AF section 129 (imaging surface phase difference focus detection section). and a TVAF section 130 (TVAF focus detection section). The image sensor drive circuit 123 controls the operation of the image sensor 122, performs A/D conversion on an image signal (image data) output from the image sensor 122, and transmits the converted image signal to the camera MPU 125. The image processing circuit 124 performs general image processing performed in a digital camera, such as γ conversion, white balance adjustment processing, color interpolation processing, and compression encoding processing, on the image signal output from the image sensor 122. The image processing circuit 124 also generates a signal for phase difference AF.

The camera MPU 125 (processor, control device) performs all calculations and controls related to the camera body 120. That is, the camera MPU 125 controls the image sensor drive circuit 123, the image processing circuit 124, the display 126, the operation switch group 127, the memory 128, the phase difference AF section 129, and the TVAF section 130. The camera MPU 125 is connected to the lens MPU 117 via the signal line of the mount M, and communicates commands and data with the lens MPU 117. The camera MPU 125 issues a request to the lens MPU 117 to acquire the lens position and drive the lens with a predetermined drive amount, and also issues a request from the lens MPU 117 to acquire optical information specific to the lens unit 100 .

The camera MPU 125 includes a ROM 125a that stores a program for controlling the operation of the camera body 120, a RAM 125b (camera memory) that stores variables, and an EEPROM 125c that stores various parameters. Further, the camera MPU 125 executes focus detection processing based on a program stored in the ROM 125a. In the focus detection process, a known correlation calculation process is performed using a pair of image signals obtained by photoelectrically converting an optical image formed by a light flux that has passed through different pupil areas (pupil partial areas) of the imaging optical system. . The camera MPU 125 also includes an acquisition means 125d and a calculation means 125e. The operation of each of these means will be described later. Note that at least a part of the means of the camera MPU 125 (a part of the acquisition means 125d or the calculation means 125e) may be provided in other parts such as the phase difference AF section 129.

The display 126 is composed of an LCD or the like, and displays information regarding the photographing mode of the imaging device 10, a preview image before photographing, a confirmation image after photographing, a focus state display image at the time of focus detection, and the like. The operation switch group 127 includes a power switch, a release (shooting trigger) switch, a zoom operation switch, a shooting mode selection switch, and the like. The memory (recording means) 128 is a removable flash memory and records captured images.

The phase difference AF unit (defocus amount calculation means) 129 performs focus detection processing using a phase difference detection method based on the image signal of the focus detection image data obtained from the image sensor 122 and the image processing circuit 124. More specifically, the image processing circuit 124 generates a pair of image data formed by a light beam passing through a pair of pupil regions of the imaging optical system as focus detection data, and the phase difference AF unit 129 generates a pair of image data as focus detection data. The amount of defocus is detected based on the amount of deviation of image data. In this way, the phase difference AF unit 129 of this embodiment performs phase difference AF (imaging surface phase difference AF) based on the output of the image sensor 122 without using a dedicated AF sensor.

The TVAF unit 130 performs focus detection processing using a contrast detection method based on the TVAF evaluation value (contrast information of image data) generated by the image processing circuit 124. During focus detection processing using the contrast detection method, the focus lens 104 is moved and the focus lens position where the evaluation value (focus evaluation value) reaches its peak is detected as the in-focus position.

In this way, the imaging device 10 of the present embodiment can perform the imaging plane phase difference AF and TVAF in combination, and depending on the situation, these can be used selectively or in combination. can. The phase difference AF unit 129 and the TVAF unit 130 function as a focus control unit that controls the position of the focus lens 104 using the respective focus detection results. When distance measuring means other than the imaging plane phase difference AF and TVAF are provided, these distance measuring means may also be used in combination.

(Configuration of an imaging device in which a detachable unit is attached between the lens unit 100 and the camera body 120)
Next, an imaging device configured by attaching a detachable unit (accessory) between the lens unit 100 and the camera body 120 will be described. FIG. 2 is a block diagram of the imaging devices 10a and 10b in which a detachable unit is attached between the lens unit 100 and the camera body 120. FIG. 2A shows an imaging device 10a in which an adapter 700, which does not have optical power and is used to adjust the optical path length of the imaging optical system, is attached as an accessory between the lens unit 100 and the camera body 120. show. FIG. 2(b) shows an imaging device 10b in which a converter lens unit 600 as an accessory is attached between the lens unit 100 and an adapter 700 in addition to the configuration of FIG. 2(a). Note that in FIG. 2, components similar to those in FIG. 1 are given the same reference numerals, and their descriptions will be omitted. In this embodiment, at least one of the camera body 120, the adapter 700, and the converter lens unit 600 constitutes a second unit.

As shown in FIG. 2(a), the adapter 700 includes an adapter mechanical member 701 including a conversion mount and an adapter memory 702. The adapter mechanical member 701 has a function of converting mounts so that they can be attached and detached when the standards of the mount M2 of the lens unit 100 and the mount M1 of the camera body 120 are different. The adapter memory 702 stores optical information (aperture information) necessary for automatic focus adjustment (AF control). The adapter memory 702 stores aperture information (second aperture information) formed by the adapter 700, unlike the aperture information (first aperture information) stored in the lens memory 118. The camera MPU 125 is configured to be able to acquire optical information (second aperture information) from the adapter memory 702.

As shown in FIG. 2(b), the converter lens unit 600 is a photographic lens that includes a converter lens 601 and a converter memory 602, and changes the focal length of the lens unit 100 that forms an optical image of a subject. Note that in the following description, the lens unit 100 will be referred to as a "master lens 100" to distinguish it from the converter lens 601. When the converter lens unit 600 is attached, the first lens group 101, the second lens group 103, and the converter lens 601 realize a zoom function. Converter memory 602 stores in advance optical information (aperture information) necessary for automatic focus adjustment. Lens MPU 117 or camera MPU 125 is configured to be able to acquire optical information (second aperture information) stored in converter memory 602. Note that the converter lens unit 600 and the adapter 700 may be provided with a separate MPU or the like to enable predetermined processing and calculations.

(Aperture information dependent on image height)
Next, with reference to FIG. 3, an overview of aperture information that depends on the image height will be described. In the following explanation, the aperture information of the master lens 100 will be explained, but the aperture information of the converter lens unit 600 and adapter 700 is also stored in different memories, but is formed by a circular aperture centered on the optical axis. The same applies to the aperture information.

FIG. 3 is a schematic explanatory diagram of the shape of the aperture (aperture information) that defines the outer edge of the light beam passing through the imaging optical system (imaging optical system). FIG. 3A shows the relationship between the lens member 301 that defines the underlined light flux at the center image height, the lens member 302 that defines the overlined light flux, and the aperture shape 311. FIG. 3B shows the relationship between the lens member 303 that defines the underlined light flux at the peripheral image height, the lens member 304 that defines the overlined light flux, and the aperture shape 312. The aperture shapes 311 and 312 are perpendicular to the optical axis and projected onto a plane of z=DS. Ds is the aperture shape calculation distance.

FIG. 3(a) shows a state when the focus detection area is set to the central image height ((x, y)=(0, 0)). In the case of the central image height in FIG. 3A, the aperture shape is defined by the lens member 301 and the lens member 302 arranged in the same xy plane, and the aperture shape is circular. FIG. 3(b) shows a state when the focus detection area is set to the peripheral image height ((x, y)=(-10, 0)). In the case of the peripheral image height of FIG. 3(b), the aperture shape is not defined by the lens members 301 and 302, but by the lens members 303 and 304, and the shape is no longer circular. Although FIG. 3B shows an example in which the aperture is defined by two lens members 303 and 304, the aperture may be defined by a plurality of lens members. In that case, the opening shape becomes more complicated.

Next, a method for calculating aperture information will be described with reference to FIGS. 4 to 6. FIG. 4 is a schematic explanatory diagram of a method of calculating aperture information. FIG. 4(a) shows how the aperture shape 312 in FIG. 3(b) is expressed as aperture information, and FIG. 4(b) and FIG. 4(c) show evaluation values used when calculating the aperture information. (shape parameter).

In this embodiment, the aperture shape is expressed by the position and size of two circles as the aperture information. In FIG. 4A, the aperture shape 312 is expressed by aperture information 411 (position c1, radius r1) and aperture information 412 (position c2, radius r2). The aperture information 411 is calculated by fitting the area from the point 401 of the aperture shape 312 clockwise to the point 402, and the aperture information 412 is calculated by fitting the area from the point 401 of the aperture shape 312 to the point 402 counterclockwise. It is calculated by

Points 401 and 402 are discrete points of the second derivative of the distance from the predetermined position to the aperture shape 312. In FIG. 4(b), the horizontal axis is the rotation angle θ in FIG. 4(a), and the vertical axis is the distance r from (X, Y)=(0,0) to the opening shape 312 in FIG. 4(a). are shown respectively. In FIG. 4(c), the horizontal axis represents the rotation angle θ in FIG. 4(a), and the vertical axis represents the value obtained by differentiating the distance r twice with respect to the rotation angle θ. Points (discrete points) 401 and 402 in FIG. 4(c) correspond to points 401 and 402 in FIG. 4(a), and these discrete points determine the fitting range when calculating the aperture information. Ru. Points where the distance change from a predetermined position is discontinuous appear as discrete points of the second derivative of the distance change, so by using such discrete points, the aperture shape can be expressed for each area as one aperture information. Can be separated.

Next, with reference to FIG. 5, a method for calculating aperture information when an aperture is defined by a plurality of lens members and the aperture shape becomes more complicated will be described. FIG. 5 is a schematic explanatory diagram of a method of calculating aperture information. FIG. 5(a) shows how the aperture shape 313 in FIG. 3(b), in which the aperture is defined by a plurality of lens members, is expressed as aperture information, and FIG. 5(b) and FIG. 5(c) show the aperture information. The evaluation value (shape parameter) used in the calculation of is shown.

In this embodiment, the aperture information is expressed by the position and size of two circles representing the aperture shape. In FIG. 5A, the aperture shape 313 is expressed by aperture information 511 (position c1, radius r1) and aperture information 512 (position c2, radius r2). The aperture information 511 is calculated by fitting the area from the point 501 of the aperture shape 313 clockwise to the point 504, and the aperture information 512 is calculated by fitting the area from the point 502 of the aperture shape 313 to the point 503 counterclockwise. It is calculated by

Points 501 to 504 are discrete points of the second-order differential of the distance from the predetermined position to the aperture shape 313. In FIG. 5(b), the horizontal axis represents the rotation angle θ in FIG. 5(a), and the vertical axis represents the distance r from (X, Y)=(0,0) in FIG. 5(a) to the opening shape 313. are shown respectively. In FIG. 5(c), the horizontal axis represents the rotation angle θ in FIG. 5(a), and the vertical axis represents the value obtained by differentiating the distance r twice with respect to the rotation angle θ. Points (discrete points) 501 to 504 in FIG. 5(c) correspond to points 501 to 504 in FIG. 5(a), respectively, and these discrete points determine the fitting range when calculating the aperture information. It has been decided. During focus detection, accuracy of the upper and lower lines of the aperture shape is required, so the area from point 501 of the aperture shape 313 clockwise to point 504, and the area from point 502 to point 503 counterclockwise. Fitting.

In this embodiment, priority is given to the accuracy of the overline and underline, but the fitting range of the circle may be determined from discrete points where the degree of discontinuity of change is large and the second derivative value is large among the discrete points. . Further, in this embodiment, fitting is performed in a region, but calculation may be performed by fitting from several points within a region determined using discrete points. Furthermore, in this embodiment, the fitting region is set based on the discrete points of the second derivative of the distance from the predetermined position, but the fitting region is set based on the change point of the radius of curvature of the aperture shape, and the aperture information is calculated. It's okay. Furthermore, in this embodiment, fitting is performed based on discrete points of the second-order differential of the distance from a predetermined position, but regarding the width at each Y coordinate (the difference between The aperture information may be calculated so that the difference is minimized. Alternatively, the aperture information may be calculated such that the difference between the area of the aperture shape and the area of the aperture information (the area of the common portion of the aperture information 511 and the aperture information 512) is minimized.

Further, in this embodiment, the aperture shape is expressed using two pieces of aperture information, but the aperture shape may be expressed using three or more pieces of aperture information. In that case, although the storage capacity of the lens memory 118 increases, the accuracy of expressing the aperture shape using the aperture information can be improved. Further, in this embodiment, the aperture information is stored in the lens memory 118 and acquired from the lens memory 118, but the aperture information may be stored in the memory 128 and acquired from the memory 128. Alternatively, the aperture shape may be stored on the network, the aperture information may be calculated using the calculation method described in this embodiment, and acquired by communicating with the lens unit 100 or the camera body 120. With the above configuration, it is possible to express the aperture shape with a simple configuration without lowering the accuracy of the aperture information.

Further, different methods can be considered as the method of expressing the aperture information. In the above description, the aperture information is expressed and held by the position (c1, c2) and size (r1, r2) of the circle, but the information is not limited to this. Next, a case where aperture information is held as information regarding the distance from the center position of the aperture 102 of the imaging optical system will be described.

FIG. 6 is a schematic explanatory diagram when aperture information is expressed as information regarding the distance from the center position of the aperture 102, and how the aperture information is expressed as information regarding the distance from the center position of the aperture 102 regarding the aperture shape 312. It shows. In FIG. 6, c3 is the center position of the aperture 102, and a1 and a2 indicate distances (aperture information) from the center position of the aperture 102, respectively. The distances a1 and a2 can be calculated by the following equations (1) and (2), respectively, based on the position c1, the size r1, the positions c3, c2, the size r2, and the position c3.

a1=r1-(c1-c3)...(1)
a2=r2+(c2-c3)...(2)
In this way, by storing the positions c1 and c2 and the sizes r1 and r2 as distances a1 and a2, the storage capacity of the lens memory 118 can be reduced.

(Aperture information with non-continuous dependence on image height)
Next, with reference to FIG. 7, an outline of aperture information in which image height does not depend continuously will be described. In the following explanation, the aperture information of the camera body 120 will be explained, but the aperture information of the adapter 700 is also stored in different memories, but vignetting can be affected depending on the thickness of the photographing light beam (F number) and the incident angle. The same applies to aperture information whose presence or extent differs.

FIG. 7 is a diagram illustrating a situation in which the light flux that has passed through the imaging optical system (imaging optical system) is blocked (vignetted) by a part of the camera body 120. FIG. 7A shows how the light flux passing through the imaging optical system reaches the central image height, and FIG. 7B shows how it reaches the peripheral image height.

In FIG. 7, 905 indicates (a part of) the housing of the camera body 120, and 906 indicates (the end of) the opening of the shutter unit 131. In FIG. 7, luminous fluxes 902 and 904 indicate luminous fluxes when the F number (aperture value) of the imaging optical system is small, and luminous fluxes 901 and 903 indicate luminous fluxes when the F number of the imaging optical system is larger.

As shown in FIG. 7A, with respect to the light beam 902, vignetting occurs due to the housing 905, but no vignetting occurs due to the shutter aperture 906. On the other hand, regarding the light beam 901, no vignetting occurs at both the housing 905 and the shutter aperture 906. As shown in FIG. 7B, the light beam 904 is vignetted at both the housing 905 and the shutter opening 906. On the other hand, the light beam 903 is not vignetted at both the housing 905 and the shutter opening 906.

In this way, vignetting that occurs within the camera body 120 can be divided into an image height range in which vignetting does not occur and an image height range in which vignetting occurs. Further, depending on the F number (aperture value) of the imaging optical system, vignetting may not occur over the entire range of image height. Therefore, in this embodiment, such aperture information is not stored for each image height, but the coordinates of the end of the aperture are stored. For example, with the intersection of the image sensor 122 and the optical axis as the origin, and based on the coordinate axes shown in FIG. 7, the aperture of the housing 905 and the aperture 906 of the shutter are stored as three-dimensional coordinate positions of rectangular apertures. This makes it possible to reduce the amount of information that needs to be stored with respect to the above-mentioned aperture information that depends on the image height.

(How to obtain aperture information)
Next, a method for acquiring aperture information in this embodiment will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart showing a method for acquiring aperture information. Note that each step in FIG. 8 is mainly executed by the lens MPU 117 or the camera MPU 125. In FIG. 8, a method for acquiring aperture information will be described based on the configuration of the imaging device 10b shown in FIG. 2(b), but the configuration of the imaging device 10 in FIG. The same applies to the assumed method of acquiring aperture information. Furthermore, the process related to the method of acquiring aperture information is performed without aperture information belonging to units that are not attached.

First, in step S801, the camera MPU 125 acquires the mounting status of the master lens 100, converter lens unit 600, adapter 700, and camera body 120, the presence or absence of aperture information each has, and attribute information of each aperture information.

FIG. 9 is an example of attribute information of aperture information. FIG. 9 shows aperture information and attribute information regarding the imaging device 10b in which the converter lens unit 600 and the adapter 700 are attached between the master lens 100 and the camera body 120 shown in FIG. 2(b).

The aperture information (first aperture information) of the master lens 100 changes depending on the positions (lens states) of the focus lens and zoom lens, and the image height of the focus detection area. Since the converter lens unit 600 does not have a movable part as a lens, the aperture information does not depend on the lens state and is information that depends only on the image height of the focus detection area. The aperture information of the adapter 700 and the aperture information of the camera body (casing) 120 are information that does not depend on any of the lens state, image height, and defocus (defocus amount), respectively. The aperture information of the shutter aperture (first aperture information) is aperture information that depends on defocus. Note that the relationship between the aperture information of the shutter aperture and defocus will be described later. The aperture information of the converter lens unit 600, the aperture information of the adapter 700, and the aperture information of the camera body (casing) 120 are each second aperture information.

Although FIG. 9 shows three types of attribute information (lens state, image height, and defocus), the types of attribute information are not limited to these. For example, when vibration isolation is performed by swinging a part of the imaging optical system or the image sensor, the attribute information may include whether or not the aperture information changes due to the vibration isolation operation. Further, information regarding the opening shape, such as whether the opening shape is circular or rectangular, may be included as attribute information.

Further, in step S801 in FIG. 8, after acquiring the attribute information, the camera MPU 125 associates the aperture information obtained according to the wearing situation with the attribute information.

Subsequently, in step S802, aperture information (acquisition frame information) for determining the acquisition method and processing method of aperture information thereafter is determined. In this embodiment, each of the master lens 100, converter lens unit 600, adapter 700, and camera body 120 has aperture information and is stored. In order to process these aperture information sequentially, the camera MPU 125 selects any one of the aperture information as the aperture information to be processed.

Subsequently, in step S803, the camera MPU 125 determines whether or not the processing target aperture information changes with respect to the lens state. As shown in FIG. 9, the camera MPU 125 checks the attribute information stored together with the aperture information. If the aperture information changes depending on the lens state, the process advances to step S804. In step S804, the camera MPU 125 sets a communication acquisition method for processing target aperture information. Since this aperture information changes depending on the lens state, the camera MPU 125 selects a method of acquiring aperture information by communicating at predetermined intervals. After setting the acquisition method in step S804, the camera MPU 125 thereafter acquires processing target aperture information via communication at predetermined intervals, and updates and stores the acquired information in a predetermined area of the RAM 125b.

The flow of acquiring aperture information will be explained in more detail. First, when the aperture information to be acquired is aperture information regarding the master lens 100, the camera MPU 125 acquires the current lens state (zoom state and focus state) of the master lens 100. Subsequently, the camera MPU 125 acquires aperture information according to the acquired zoom state and focus state. The lens memory 118 stores aperture information for each zoom state in which the zoom range is divided into a plurality of parts, for each focus state in which the focus range is divided into a plurality of parts, and for each image height in which the image height range is divided into a plurality of parts. Therefore, aperture information in the current zoom state and focus state is calculated and obtained by linear interpolation from aperture information in neighboring states.

Similarly, if the aperture information to be acquired is aperture information regarding converter lens unit 600, camera MPU 125 acquires the aperture information of converter lens unit 600. Converter memory 602 stores aperture information for each image height obtained by dividing the image height range into a plurality of parts.

On the other hand, if it is determined in step S803 that the aperture information does not change depending on the lens state, the process advances to step S805. In step S805, the camera MPU 125 selects a method for acquiring aperture information all at once at a certain timing. The camera MPU 125 acquires aperture information, for example, during initial communication when the lens unit 100, adapter 700, etc. are attached to the camera body 120. After setting the acquisition method in step S805, the camera MPU 125 acquires the processing target aperture information acquired in the initial communication, and stores the acquired information in a predetermined area of the RAM 125b. In this way, by changing the communication method according to the attribute information of the aperture information, it is possible to reduce the amount of information communicated every predetermined period.

After determining the aperture information acquisition method, the process advances to step S806. In step S806, the camera MPU 125 determines whether the processing target aperture information changes with respect to the focus detection area (image height) that is the target of focus adjustment. As shown in FIG. 9, the camera MPU 125 checks the attribute information stored together with the aperture information. If the aperture information does not depend on the image height and does not change, the process advances to step S807. In step S807, as described with reference to FIG. 7, the camera MPU 125 acquires aperture information as a three-dimensional coordinate position from the RAM 125b. Thereafter, the process advances to step S809, and the camera MPU 125 performs conversion into aperture information according to the image height. As described with reference to FIG. 7, the camera MPU 125 uses the image height of the center of the focus detection area as a viewpoint as the three-dimensional coordinate position of the stored rectangular aperture, and moves the camera MPU 125 to a plane on the aperture shape calculation distance Ds. Four straight lines are projected to define a rectangular opening.

On the other hand, if the processing target aperture information changes with respect to the image height in step S806, the process advances to step S808. In step S808, the camera MPU 125 reads out aperture information corresponding to the image height near the center of the focus detection area from the RAM 125b. The camera MPU 125 calculates and obtains aperture information corresponding to the image height of the focus detection area by performing linear interpolation from aperture information of nearby image heights. In this embodiment, the aperture information of the image height of the set focus detection area is obtained by calculating by linear interpolation, but the aperture information of the neighboring image height is obtained as the aperture information of the set image height. You may.

Furthermore, although the present embodiment has been described assuming that the aperture information is used for focus detection, the aperture information may be used for exposure adjustment, image processing, and the like. Even in this case, similarly to the present embodiment, aperture information for the image height to be processed is set, and the corresponding aperture information is acquired through interpolation processing and the like.

Subsequently, in step S810, the camera MPU 125 determines whether or not the processing target aperture information changes depending on the defocus amount. If the aperture information changes depending on the defocus amount, the process advances to step S811. In step S811, the camera MPU 125 converts the aperture information into aperture information according to the defocus amount, and acquires the converted aperture information.

Next, with reference to FIG. 10, aperture information that depends on the amount of defocus will be described. FIG. 10 is an explanatory diagram of aperture information that depends on the amount of defocus, and shows that the light flux passing through the imaging optical system is blocked (vignetted) by a part of the camera body 120 depending on the amount of defocus. FIG. FIG. 10(a) shows the same state as FIG. 7(b), and shows that the light beam 904 that has passed through the imaging optical system is eclipsed by the housing 905 and focused on the image sensor 122. . FIG. 10B shows that the light beam passing through the imaging optical system is defocused to a position shifted in the positive direction of the Z-axis from the top of the image sensor 122 (def>0). As a result, the light beam 904 is eclipsed on one side by the shutter aperture 906, and the light beam outside the light beam 904-2 (in the positive direction of the X-axis) does not reach the image sensor 122. Similarly, FIG. 10(c) shows that the light beam passing through the imaging optical system is defocused in the opposite direction (def<0) with respect to FIG. 10(b). In this case, as in FIG. 10(b), vignetting occurs at the shutter aperture 906, and the light flux outside the light flux 904-3 (in the negative direction of the X-axis) does not reach the image sensor 122. In this way, the manner in which vignetting occurs in an aperture located close to the image sensor 122 differs depending on the magnitude and sign of the defocus amount. Therefore, in this embodiment, aperture information that depends on the amount of defocus is converted in accordance with the amount of defocus.

The conversion method is similar to the conversion of aperture information (three-dimensional coordinate position of a rectangular aperture) whose dependence on image height is not continuous, as described above. Specifically, the position of the viewpoint corresponding to the center image height of the focus detection area is moved in the Z-axis direction by an amount corresponding to the amount of defocus, and the viewpoint corresponding to the amount of defocus is calculated. Then, the stored three-dimensional coordinate position of the rectangular aperture is projected onto a plane on the aperture shape calculation distance Ds using the viewpoint corresponding to the defocus amount, and four straight lines defining the rectangular aperture are drawn. calculate.

Note that in this embodiment, the position of the viewpoint used for projecting the rectangular aperture is moved in the Z-axis direction in accordance with the amount of defocus. However, if the principal ray angle of the luminous flux is known, the viewpoint corresponding to the amount of defocus may be moved parallel to the traveling direction of the principal ray. Thereby, it is possible to calculate aperture information with higher accuracy.

In phase difference method focus detection, to calculate a highly accurate defocus amount, use aperture information to derive a known baseline length, and use that baseline length to convert the detected phase difference into a defocus amount. There is a need to. Therefore, the following two methods can be considered as a method of calculating aperture information that takes into account the amount of defocus described above. The first method is to estimate the defocus amount when calculating the aperture information, based on the defocus amount obtained in advance and the subsequent drive amount of the focus lens, assuming that the subject distance has not changed. It is. The second method is to calculate the aperture information on the premise that there is no defocus amount the first time, calculate the defocus amount, and then calculate the aperture information again using the calculated defocus amount. Note that the calculation of the aperture information is not limited to two times, but may be performed multiple times, so the aperture information may be calculated three or more times.

Furthermore, when the aperture information is not calculated in consideration of the amount of defocus, it may be configured to drive the focus lens corresponding to the amount of defocus smaller than the detected amount of defocus. This makes it possible to avoid erroneous focus lens driving due to an inaccurate defocus amount. Further, the calculation of aperture information that does not depend on the image height is performed in step S809, but for the aperture information that depends on the amount of defocus, the process of step S809 can be skipped and the aperture information can be calculated in step S811. good.

If the processing target aperture information does not change in accordance with the defocus amount in step S810 of FIG. 8, step S811 is skipped. Thereafter, in step S812, the camera MPU 125 determines whether or not all of the obtainable aperture information has been obtained. If there is aperture information that has not been acquired yet, the process returns to step S802 and the above-described process is repeated for the next aperture information. On the other hand, if the acquisition of all aperture information is completed, the process advances to step S813. In step S813, the camera MPU 125 as a calculation means combines the acquired aperture information.

Here, synthesis of aperture information will be explained with reference to FIG. 11. FIG. 11 is an explanatory diagram of the aperture information of each unit (master lens 100, adapter 700, camera body 120) and the shape of the aperture that defines the outer edge of the light beam passing through the imaging optical system. Similar to FIG. 3, the shape of the aperture information described above is defined in a plane on the aperture shape calculation distance Ds, so it can be shown as shown in FIG. 11. In step S813 in FIG. 8, these aperture shapes are synthesized, and the area of the hatched part in FIG. 11 is calculated as a synthesized aperture shape (synthetic aperture information). The synthetic aperture shape (synthetic aperture information) may be created by storing all the aperture information that forms the synthetic aperture shape, or by performing fitting processing again and processing the information into two circular shapes, for example. good. After completing step S813, the camera MPU 125 ends the aperture information acquisition process.

(About calculation resources for combining communication information and aperture information)
Next, with reference to FIG. 12, calculation resources for communication of aperture information and synthesis processing of aperture information in this embodiment will be described. FIG. 12 is a block diagram showing communication information and arithmetic processing units of each unit (master lens 100, converter lens unit 600, adapter 700, camera body 120). FIG. 12 shows blocks in which information is stored and blocks that perform calculations for synthesis processing of aperture information.

FIG. 12(a) shows an example of a block that performs information storage and arithmetic processing. The camera MPU 125 acquires adapter aperture information from the adapter memory 702 and performs a synthesis process with the aperture information of the housing 905 and the shutter aperture 906. This aperture information is stored with a rectangular aperture as a three-dimensional coordinate position. Therefore, the aperture information that causes the most vignetting can be selected depending on the angle formed by the optical axis of the imaging optical system and the vector connecting the image height and the three-dimensional coordinate position of the rectangular aperture. This selection of aperture information corresponds to composing the aperture information.

Next, the camera MPU 125 obtains lens aperture information from the master lens 100 and converter lens aperture information from the converter lens unit 600, and performs synthesis processing with the already synthesized (selected) aperture information. The compositing process performed here is as described with reference to FIG. Since the aperture information, which does not have information for each image height, does not change depending on the lens state, the amount of calculation processing can be reduced by combining the aperture information in advance.

FIG. 12(b) shows an example in which the blocks that perform information storage and arithmetic processing are different. The difference from FIG. 12A is that in the master lens 100, the lens MPU 117 performs a synthesis process of the lens aperture information of the master lens 100, which has aperture information for each image height, and the converter lens aperture information of the converter lens unit 600. The point is to do it. Since the lens aperture information and converter lens aperture information each change depending on the lens state, it is necessary to notify the camera body 120 at any time. On the other hand, in FIG. 12(b), since the aperture information after the synthesis process is notified to the camera body 120, the amount of communication information can be reduced.

Note that various configurations are possible for combinations of blocks that perform information storage and arithmetic processing. If the adapter 700 or the converter lens unit 600 has a computing device, the computing device may acquire appropriate information and perform the combining process.

Furthermore, various routes are conceivable as the route for notifying the aperture information. A method in which each unit attached to the camera body 120 notifies the camera body 120 individually, or a method in which information on the converter lens unit 600 is acquired by the master lens 100 and then the master lens 100 notifies the camera body 120 all at once. etc. are possible.

Furthermore, if each unit does not have aperture information, the camera body 120 may store the aperture information. For example, some of the master lens 100, converter lens unit 600, and adapter 700 may acquire aperture information from each unit, and other information may be stored in a storage unit within the camera body 120. Even in such a case, synthetic aperture information can be calculated in the same manner as described above.

Further, in this embodiment, a case has been described in which each unit stores aperture information, but the present invention is not limited to this. If at least some of the plurality of units do not store aperture information, the camera MPU 125 cannot acquire the aperture information of that unit. In this case, the synthetic aperture information may be calculated without using the aperture information that cannot be obtained (at least part of the first aperture information and the second aperture information). In each of the imaging devices 10, 10a, and 10b shown in FIGS. 1 and 2, the number of detachable units differs, but in any case, the aperture information of the attached unit is acquired, and the synthetic aperture information is can be calculated. Note that the aperture information may be acquired from outside the image sensor 10 using a communication means or the like. Alternatively, a configuration may be adopted in which a user or the like is required to input information using a UI displayed on a display unit or the like.

As described above, in this embodiment, the control device (camera MPU 125) includes the acquisition means 125d and the calculation means 125e. The acquisition means acquires first aperture information and second aperture information of each of a first unit and a second unit that are detachable from the imaging device (camera body 120). The calculation means calculates synthetic aperture information based on the first aperture information and the second aperture information (that is, by combining the first aperture information and the second aperture information).

Preferably, the first aperture information and the second aperture information have different attribute information from each other, and the attribute information is information regarding at least one of the lens state, image height, anti-vibration operation, and defocus amount. Preferably, when the first aperture information changes with respect to the lens state and the second aperture information does not change with respect to the lens state, the acquisition means adjusts the lens state according to the change of the lens state (every time there is a change). First aperture information corresponding to is acquired (by communication or calculation). Further, in this case, the acquisition means acquires the second aperture information all at once (through communication or calculation) at a timing different from the communication of the first aperture information. Preferably, when the first aperture information changes with respect to the defocus amount and the second aperture information does not change with respect to the defocus amount, the calculation means calculates the defocus amount using the first aperture information. Or change the image height range. For example, the calculation means varies the defocus amount or image height range depending on at least one of an aperture value (F value) and an exit pupil distance.

Preferably, at least one of the timing, frequency, information, and calculation with which the acquisition means acquires the first aperture information and the second aperture information are different from each other. Also preferably, the acquisition means acquires the first aperture information from the first unit and the second aperture information from the second unit. Preferably, when the acquisition means cannot acquire the first aperture information, the calculation means calculates the synthetic aperture information without using the first aperture information.

Preferably, the first unit is a lens unit 100 that is detachable from the imaging device (camera body 120), and the second unit is an accessory that is detachable between the imaging device and the lens unit. More preferably, the accessory is at least one of an adapter 700 that adjusts the optical path length of the imaging optical system in the lens unit, and a converter lens unit 600 that changes the focal length of the lens unit. Preferably, the first unit and the second unit limit the light flux received by the image sensor 122. The first aperture information and the second aperture information are information regarding apertures through which the first unit and the second unit limit the light flux received by the image sensor, respectively.

According to this embodiment, even if the master lens 100, converter lens unit 600, adapter 700, and camera body 120 each limit the light flux passing through the imaging optical system, the aperture information can be adjusted without reducing the accuracy of the aperture information. It becomes possible to calculate the shape.

(Other embodiments)
The present invention provides a system or device with a program that implements one or more of the functions of the embodiments described above via a network or a storage medium, and one or more processors in the computer of the system or device reads and executes the program. This can also be achieved by processing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

According to the present embodiment, it is possible to provide a control device, an imaging device, a control method, and a program that can calculate aperture information of each of a plurality of detachable units with high precision.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the invention.

125 Camera MPU (control unit)
125d Acquisition means 125e Calculation means

Claims (14)

acquisition means for acquiring first aperture information and second aperture information regarding the shape of an aperture that defines an outer edge of a luminous flux passing through each of a first unit and a second unit that are detachable from the imaging device;
A control device comprising: calculation means for calculating synthetic aperture information based on the first aperture information and the second aperture information. The first aperture information and the second aperture information have different changes in attribute information,
The control device according to claim 1, wherein the attribute information is information regarding at least one of a lens state, an image height, an anti-vibration operation, and a defocus amount. The attribute information is the lens state,
When the first aperture information changes with respect to the lens state and the second aperture information does not change with respect to the lens state, the acquisition means changes the lens state according to the change in the lens state. 3. The control device according to claim 2, wherein the corresponding first aperture information is acquired, and the second aperture information is acquired all at once at a timing different from communication of the first aperture information. The attribute information is the defocus amount,
When the first aperture information changes with respect to the defocus amount and the second aperture information does not change with respect to the defocus amount, the acquisition means converts the information into the defocus amount according to the defocus amount. 3. The control device according to claim 2, wherein the first aperture information is acquired and the second aperture information is acquired without performing conversion according to the defocus amount. 5. The control device according to claim 1, wherein at least one of timing and frequency with which the acquisition means acquires the first aperture information and the second aperture information are different from each other. The acquisition means is
acquiring the first aperture information from the first unit;
The control device according to any one of claims 1 to 5, wherein the second aperture information is acquired from the second unit. 7. If the acquisition means cannot acquire the first aperture information, the calculation means calculates the synthetic aperture information without using the first aperture information. The control device described in . The first unit is a lens unit that is detachable from the imaging device,
The control device according to any one of claims 1 to 7, wherein the second unit is an accessory that can be attached and detached between the imaging device and the lens unit. 9. The accessory according to claim 8, wherein the accessory is at least one of an adapter that adjusts the optical path length of an imaging optical system in the lens unit, and a converter lens unit that changes the focal length of the lens unit. Control device. An image sensor and
An imaging device comprising: the control device according to claim 1 . The first unit and the second unit limit the light flux received by the image sensor,
11. The first aperture information and the second aperture information are information regarding an aperture in which the first unit and the second unit respectively limit the light flux received by the image sensor. Imaging device. The first unit is a lens unit that is detachable from the imaging device,
The imaging device according to claim 10 or 11, wherein the first aperture information changes depending on a defocus amount. acquiring first aperture information and second aperture information regarding the shape of an aperture that defines an outer edge of a light beam passing through each of a first unit and a second unit that are detachable from the imaging device;
A control method comprising the step of calculating synthetic aperture information based on the first aperture information and the second aperture information. A program that causes a computer to execute the control method according to claim 13.