JP2019095809A - Imaging apparatus - Google Patents

Abstract

To provide an imaging apparatus capable of excellently photographing an image.SOLUTION: The imaging apparatus includes an imaging part which captures the image by an optical system having a diaphragm and a focus adjustment lens and outputs a signal, a detection part which detects the focusing position of the optical system where the image by the optical system is focused on the imaging part on the basis of the signal, a lens movement instruction part which instructs the movement of the focus adjustment lens, a setting part which sets the diaphragm value of the diaphragm, and a control part which performs control for moving the focus adjustment lens on the basis of the focusing position detected by setting the diaphragm value to a range of a first value or more and a second value larger than the first value or less and for performing imaging by setting the diaphragm value of the diaphragm to a third value larger than the second value and control for moving the focus adjustment lens on the basis of the focusing position detected by setting the diaphragm value to a range of the first value or more and a fourth value smaller than the second value or less and for performing imaging by setting the diaphragm value of the diaphragm to the fourth value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging device.

  2. Description of the Related Art Conventionally, there has been known an image pickup apparatus which detects a focus state of an optical system by detecting a shift amount of an image plane of an optical system based on an output of focus detection pixels provided in an image pickup device. As such an imaging device, for example, in order to prevent occurrence of vignetting when performing focus detection, the aperture value of the optical system is set to a value smaller than a predetermined aperture value (value on the open side), A method for performing focus detection is known (e.g., Patent Document 1).

JP, 2010-217618, A

  However, in the prior art, when the aperture value of the optical system is changed from the aperture value at the time of focus detection to the imaging aperture value in order to capture an image in real time, the image plane of the optical system As a result, there was a case where it was not possible to shoot an image in which the subject was in focus.

  The problem to be solved by the present invention is to provide an imaging device capable of capturing an image well.

  The present invention solves the above-mentioned subject by the following solution means. Although the following description will be made with reference to the reference numerals corresponding to the drawings showing the embodiments of the present invention, these reference numerals are for the purpose of facilitating the understanding of the present invention and are not intended to limit the present invention. .

[1] An image pickup apparatus according to the present invention is an image pickup section for picking up an image by an optical system having a diaphragm and a focusing lens and outputting a signal, and an image by the optical system based on the signal A detection unit for detecting the in-focus position of the optical system to be focused, a lens movement instruction unit for instructing the movement of the focusing lens, a setting unit for setting the diaphragm value of the diaphragm, and the diaphragm value The focus adjustment lens is moved based on the in-focus position detected by setting it in a range of 1 value or more and a second value or less larger than the first value, and the aperture value of the diaphragm is set to the second value Control to perform imaging by setting to a third value larger than the above, and the in-focus position detected by setting the aperture value to a range not less than the first value and not more than the fourth value smaller than the second value To move the focusing lens based on the Set 4 values and a control unit that performs a control to perform imaging.
[2] In the imaging device according to the present invention, the first value can be a predetermined value determined by the optical system.
[3] In the imaging device according to the present invention, the second value may be a predetermined value determined by the imaging device.
[4] In the imaging device according to the present invention, the first value may be a limit value on the open side of the diaphragm when the focus position is detected by the detection unit.
[5] In the imaging device according to the present invention, the second value may be a limit value on the stop side of the diaphragm when the focus position is detected by the detection unit.
[6] In the imaging device according to the present invention, the focusing lens is moved based on the in-focus position detected by setting the aperture value to the fourth value, and the aperture value of the aperture is adjusted to a fourth value. It can be configured to perform imaging without changing from the value.
[7] In the imaging device according to the present invention, the imaging unit includes a plurality of imaging pixels and a plurality of focus detection pixels arranged in a two-dimensional shape, and the detection unit is the focus detection pixel A shift amount of an image position by light fluxes passing through different parts of the pupil of the optical system based on the signal output from the image system, and an image contrast by the optical system based on the signal output by the imaging pixel The focusing position of the optical system can be detected based on at least one of the evaluation values regarding.
[8] The imaging device according to the present invention may include a communication unit that communicates with the lens barrel having the optical system, and may receive the first value from the lens barrel via the communication unit.
[9] The imaging device according to the present invention can be configured to have a storage unit that stores the second value.

  According to the present invention, an image can be captured well.

FIG. 1 is a block diagram showing a camera according to the first embodiment. FIG. 2 is a front view showing a focus detection position on the imaging surface of the imaging device shown in FIG. FIG. 3 is a front view schematically showing an arrangement of the focus detection pixels 222a and 222b by enlarging a portion III of FIG. FIG. 4 is a front view showing one of the imaging pixels 221 in an enlarged manner. FIG. 5A is an enlarged front view showing one of the focus detection pixels 222a, and FIG. 5B is an enlarged front view showing one of the focus detection pixels 222b. FIG. 6 is a cross-sectional view showing one of the imaging pixels 221 in an enlarged manner. FIG. 7A is an enlarged sectional view showing one of the focus detection pixels 222a, and FIG. 7B is an enlarged sectional view showing one of the focus detection pixels 222b. FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. FIG. 9 is a flowchart showing the operation of the camera according to the present embodiment. FIG. 10 is a view showing an example of the relationship between the aperture value at the time of focus detection set in the first embodiment and the imaging aperture value. FIG. 11 is a flowchart showing the scan operation execution process of step S118. FIG. 12 is a block diagram showing a camera according to the second embodiment. FIG. 13 is a diagram showing an example of the relationship between the aperture value at the time of focus detection set in the second embodiment and the imaging aperture value.

  Hereinafter, embodiments of the present invention will be described based on the drawings.

First Embodiment
FIG. 1 is a main part configuration diagram showing a digital camera 1 according to an embodiment of the present invention. The digital camera 1 (hereinafter simply referred to as the camera 1) of the present embodiment is composed of a camera body 2 and a lens barrel 3, and the camera body 2 and the lens barrel 3 are detachably coupled by a mount unit 4 There is.

  The lens barrel 3 is an interchangeable lens that is detachable from the camera body 2. As shown in FIG. 1, the lens barrel 3 incorporates a photographing optical system including lenses 31, 32, 33 and a diaphragm 34.

  The lens 32 is a focus lens, and can move in the direction of the optical axis L1 to adjust the focal length of the imaging optical system. The focus lens 32 is provided so as to be movable along the optical axis L1 of the lens barrel 3, and its position is adjusted by the focus lens drive motor 36 while its position is detected by the encoder 35.

  The specific configuration of the moving mechanism along the optical axis L1 of the focus lens 32 is not particularly limited. For example, a rotary cylinder is rotatably inserted into a fixed cylinder fixed to the lens barrel 3, and a helicoid groove (helical groove) is formed on the inner peripheral surface of the rotary cylinder, and the focus lens 32 is fixed. The end of the lens frame is fitted in the helicoid groove. Then, by rotating the rotary cylinder by the focus lens drive motor 36, the focus lens 32 fixed to the lens frame moves rectilinearly along the optical axis L1.

  As described above, the focus lens 32 fixed to the lens frame moves rectilinearly in the direction of the optical axis L1 by rotating the rotary cylinder with respect to the lens barrel 3, but the focus lens drive motor 36 as its drive source is a lens The lens barrel 3 is provided. The focus lens drive motor 36 and the rotary cylinder are connected by, for example, a transmission composed of a plurality of gears, and when the drive shaft of the focus lens drive motor 36 is rotationally driven in either direction, it is transmitted to the rotary cylinder with a predetermined gear ratio. Then, when the rotary cylinder rotates in any one direction, the focus lens 32 fixed to the lens frame moves rectilinearly in any direction of the optical axis L1. When the drive shaft of the focus lens drive motor 36 is driven to rotate in the reverse direction, the gears constituting the transmission also rotate in the reverse direction, and the focus lens 32 moves rectilinearly in the direction opposite to the optical axis L1. .

  The position of the focus lens 32 is detected by the encoder 35. As described above, the position of the focus lens 32 in the direction of the optical axis L1 is correlated with the rotation angle of the rotary cylinder, and therefore can be determined by detecting the relative rotation angle of the rotary cylinder with respect to the lens barrel 3, for example.

  The encoder 35 according to the present embodiment detects a rotation of a rotating disk connected to the rotational drive of the rotating cylinder by an optical sensor such as a photo interrupter and outputs a pulse signal according to the number of rotations, or a fixed cylinder The encoder contacts on the surface of the flexible printed wiring board provided on either one of the rotating cylinder and the brush contact on the other are brought into contact with each other, and the moving amount of the rotating cylinder (in either the rotational direction or the optical axis direction) It is possible to use one that detects a change in the contact position according to (a) by a detection circuit.

  The focus lens 32 can move in the direction of the optical axis L1 from the end on the camera body side (also referred to as the near end) to the end on the subject side (also referred to as the infinite end) by rotation of the rotary cylinder described above. it can. Incidentally, the current position information of the focus lens 32 detected by the encoder 35 is sent to the camera control unit 21 described later via the lens control unit 37, and the focus lens drive motor 36 calculates the focus based on this information. The drive position of the lens 32 is driven by being sent from the camera control unit 21 via the lens control unit 37.

  The aperture 34 is configured to adjust the aperture diameter centered on the optical axis L1 in order to limit the light amount of the light flux passing through the imaging optical system and reaching the imaging device 22 and to adjust the blur amount. Adjustment of the aperture diameter by the aperture stop 34 is performed, for example, by transmitting the aperture diameter according to the aperture value calculated in the automatic exposure mode from the camera control unit 21 via the lens control unit 37. Further, the aperture diameter corresponding to the set photographing aperture value is input from the camera control unit 21 to the lens control unit 37 by manual operation by the operation unit 28 provided in the camera body 2. The aperture diameter of the diaphragm 34 is detected by a diaphragm aperture sensor (not shown), and the lens controller 37 recognizes the current aperture diameter.

  Further, in the present embodiment, the lens control unit 37 stores in advance in the memory 39 the open limit value of the aperture value of the optical system when detecting the focus state of the optical system as the open limit value. There is. Here, for example, when the f-number at the time of detecting the focus state of the optical system is F1.4 and the shooting f-number at the time of main photographing of the image is F2.8, the main photographing is performed after focus detection. When the f-number of the optical system is changed from F1.4, which is the f-number at the time of focus detection, to F2.8, which is the shooting f-number, the image plane moves with the change of the f-number. The focus position detected at the time of detection may deviate from the depth of field of the optical system at the time of main shooting of the image, and an image in focus on the subject in focus at the time of focus detection may not be shot. . In particular, this tendency becomes greater as the aperture value of the optical system becomes a value on the open side. Therefore, in such a case, for example, by limiting the aperture value at the time of detecting the focus state of the optical system to F2 instead of F1.4, the image plane movement amount accompanying the change of the aperture value is suppressed. Even when the aperture value of the optical system is changed from the aperture value at the time of detecting the focus state to the photographing aperture value, it is possible to capture an image in focus on the subject. In this way, even when the aperture value of the optical system is changed from the aperture value at the time of focus detection to the imaging aperture value, the open-side limit value can be used to successfully capture an image. The limit value on the side is stored in advance in the lens control unit 37 as a unique value for each lens barrel 3.

  Further, in the present embodiment, the lens control unit 37 stores the open side limit value as the number of aperture steps from the open aperture value. For example, when the open limit value is F2 as the f-number (F value), the open f-number is F1.2 and the f-number of the optical system is changed from the open f-number F1.2 to the open-end limit value. When the number of stages of the diaphragm 34 for changing to a certain F2 is two, the camera control unit 37 stores the open side limit value as two stages. Thus, by storing the open-side limit value as the number of aperture steps from the open aperture value, for example, even when the lens position of the zoom lens is changed, the open aperture value according to the lens position of the zoom lens The open-side limit value corresponding to the lens position of the zoom lens can be obtained based on the above, and it is not necessary to store the open aperture value for each lens position of the zoom lens. The above-described open aperture value, open side limit value, and aperture stage number are merely examples, and the present invention is not limited to these values.

  On the other hand, in the camera body 2, an imaging element 22 for receiving the light flux L1 from the imaging optical system is provided on a planned focal plane of the imaging optical system, and a shutter 23 is provided on the front surface thereof. The imaging device 22 is configured of a device such as a CCD or a CMOS, converts the received light signal into an electric signal, and sends it to the camera control unit 21. The photographed image information sent to the camera control unit 21 is sequentially sent to the liquid crystal drive circuit 25 and displayed on the electronic viewfinder (EVF) 26 of the observation optical system, and the release button (provided in the operation unit 28) When the full depression (not shown) is performed, the photographed image information is recorded in the memory 24 which is a recording medium. The memory 24 can use any of a removable card type memory and a built-in type memory. An infrared cut filter for cutting infrared light and an optical low pass filter for preventing aliasing noise of an image are disposed in front of the imaging surface of the image sensor 22. Details of the structure of the imaging device 22 will be described later.

  A camera control unit 21 is provided in the camera body 2. The camera control unit 21 is electrically connected to the lens control unit 37 by the electric signal contact unit 41 provided in the mount unit 4, receives lens information from the lens control unit 37, and defocuses the lens control unit 37. Send information such as the amount and aperture diameter. In addition, as described above, the camera control unit 21 reads out the pixel output from the imaging device 22 and generates image information by performing predetermined information processing on the read out pixel output as necessary, and the generated image information Are output to the liquid crystal drive circuit 25 and the memory 24 of the electronic viewfinder 26. Further, the camera control unit 21 controls the entire camera 1 such as correction of image information from the image pickup device 22 and detection of a focusing state of the lens barrel 3, an aperture adjusting state, and the like.

  Further, in addition to the above, the camera control unit 21 detects the focus state of the photographing optical system by the phase detection method based on the pixel data read from the imaging device 22 and detects the focus state of the optical system by the contrast detection method. Do. In addition, the detection method of a focus state is mentioned later.

  In addition, when performing focus detection, the camera control unit 21 stores in advance in the memory 29 the limit value on the stop side of the aperture value of the optical system as the stop side limit value. When the focus detection is performed, this narrowing-side limit value is, for example, the narrowing-side value among aperture values that can effectively prevent occurrence of vignetting and can obtain good focus detection accuracy. be able to. Then, the camera control unit 21 controls the exposure at the time of focus detection based on the open-side limit value received from the lens control unit 37 and the narrow-down side limit value stored in the memory 29. The details of the exposure control at the time of focus detection will be described later.

  The operation unit 28 is a shutter release button and an input switch for the photographer to set various operation modes of the camera 1 and can switch between an auto focus mode and a manual focus mode. The various modes set by the operation unit 28 are sent to the camera control unit 21, and the operation of the entire camera 1 is controlled by the camera control unit 21. Further, the shutter release button includes a first switch SW1 which is turned on when the button is half pressed, and a second switch SW2 which is turned on when the button is fully pressed.

  Next, the image sensor 22 according to the present embodiment will be described.

  FIG. 2 is a front view showing the imaging surface of the imaging device 22, and FIG. 3 is a front view schematically showing the arrangement of the focus detection pixels 222a and 222b by enlarging a portion III of FIG.

  As shown in FIG. 3, in the imaging device 22 of the present embodiment, a plurality of imaging pixels 221 are two-dimensionally arranged on a plane of an imaging surface, and a green pixel G having a color filter transmitting a green wavelength region And a red pixel R having a color filter transmitting the red wavelength region and a blue pixel B having a color filter transmitting the blue wavelength region are what is called a Bayer arrangement. That is, two green pixels are arranged on one diagonal line in adjacent four pixel groups 223 (a dense square lattice array), and one red pixel and one blue pixel are arranged on the other diagonal line. The imaging element 22 is configured by repeatedly arranging the pixel group 223 two-dimensionally on the imaging surface of the imaging element 22 in units of the pixel group 223 in which the Bayer arrangement is performed.

  The arrangement of the unit pixel groups 223 may be, for example, a close hexagonal lattice arrangement, as well as the close square lattice shown in the drawing. Further, the configuration and arrangement of the color filter are not limited to this, and an arrangement of complementary color filters (green: G, yellow: Ye, magenta: Mg, cyan: Cy) can also be adopted.

  FIG. 4 is an enlarged front view showing one of the imaging pixels 221, and FIG. 6 is a sectional view. One imaging pixel 221 includes a microlens 2211, a photoelectric conversion unit 2212, and a color filter (not shown), and as shown in the cross-sectional view of FIG. 6, the photoelectric conversion unit is formed on the surface of the semiconductor circuit substrate 2213 of the imaging device 22. 2212 is fabricated, and a microlens 2211 is formed on the surface. The photoelectric conversion unit 2212 is shaped so as to receive the imaging light flux passing through the exit pupil (for example, F1.0) of the imaging optical system by the microlens 2211 and receives the imaging light flux.

  In addition, focus detection pixel arrays 22a, 22b, and 22c in which focus detection pixels 222a and 222b are arranged instead of the imaging pixels 221 described above at the center of the imaging surface of the imaging element 22 and at three positions symmetrical with respect to the center. Is provided. Then, as shown in FIG. 3, in one focus detection pixel row, a plurality of focus detection pixels 222a and 222b are arranged adjacent to each other and alternately arranged in one horizontal row (22a, 22c, 22c). There is. In the present embodiment, the focus detection pixels 222a and 222b are densely arranged without providing a gap at the positions of the green pixel G and the blue pixel B of the imaging pixel 221 in Bayer arrangement.

  The positions of the focus detection pixel arrays 22a to 22c shown in FIG. 2 are not limited to the illustrated positions, but may be one or two, or may be disposed at four or more positions. it can. Further, at the time of actual focus detection, the photographer selects a desired focus detection pixel row as a focus detection position by manually operating the operation unit 28 from among the plurality of arranged focus detection pixel rows 22a to 22c. It can also be done.

  FIG. 5A is an enlarged front view of one of the focus detection pixels 222a, and FIG. 7A is a cross-sectional view of the focus detection pixel 222a. 5B is an enlarged front view showing one of the focus detection pixels 222b, and FIG. 7B is a cross-sectional view of the focus detection pixel 222b. The focus detection pixel 222a includes a micro lens 2221a and a semicircular photoelectric conversion unit 2222a as shown in FIG. 5A, and as shown in the cross sectional view of FIG. The photoelectric conversion portion 2222a is formed on the surface of the semiconductor circuit substrate 2213, and the micro lens 2221a is formed on the surface. Further, as shown in FIG. 5B, the focus detection pixel 222b is composed of a micro lens 2221b and a photoelectric conversion unit 2222b, and as shown in the cross sectional view of FIG. 7B, the semiconductor of the imaging device 22 is The photoelectric conversion portion 2222b is formed on the surface of the circuit board 2213, and the micro lens 2221b is formed on the surface. The focus detection pixels 222a and 222b are arranged adjacent to each other and alternately in a horizontal row, as shown in FIG. 3, to form the focus detection pixel rows 22a to 22c shown in FIG.

  The photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b have shapes that receive light beams passing through a predetermined area (for example, F2.8) of the exit pupil of the photographing optical system by the micro lenses 2221a and 2221b. Be done. Further, no color filter is provided in the focus detection pixels 222a and 222b, and the spectral characteristics thereof are obtained by integrating the spectral characteristics of the photodiode performing photoelectric conversion and the spectral characteristics of the infrared cut filter (not shown). ing. However, one of the same color filters as the imaging pixel 221, for example, a green filter may be provided.

  Although the photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b shown in FIGS. 5A and 5B are semicircular, the shape of the photoelectric conversion units 2222a and 2222b is not limited thereto. And other shapes, for example, an oval shape, a rectangular shape, and a polygonal shape.

  Here, a so-called phase difference detection method for detecting the focus state of the photographing optical system based on the pixel outputs of the focus detection pixels 222a and 222b described above will be described.

  FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 3 and is disposed in the vicinity of the photographing optical axis L1 and the focus detection pixels 222a-1, 222b-1, 222a-2, 222b-2 adjacent to each other are It shows that light beams AB1-1, AB2-1, AB1-2, and AB2-2 emitted from the focusing pupils 341 and 342 of the exit pupil 34 are respectively received. Although FIG. 8 illustrates only one of the plurality of focus detection pixels 222a and 222b located in the vicinity of the photographing optical axis L1, other focus detection pixels other than the focus detection pixels shown in FIG. 8 are shown. Similarly, the light beams emitted from the pair of distance measuring pupils 341 and 342 are also received.

  Here, the exit pupil 34 is an image set at the position of the distance D in front of the microlenses 2221 a and 2221 b of the focus detection pixels 222 a and 222 b disposed on the planned focal plane of the photographing optical system. The distance D is a value uniquely determined according to the curvature of the micro lens, the refractive index, the distance between the micro lens and the photoelectric conversion part, and the like, and this distance D is referred to as a distance measurement pupil distance. The distance measuring pupils 341 and 342 refer to images of the photoelectric conversion units 2222 a and 2222 b respectively projected by the micro lenses 2221 a and 2221 b of the focus detection pixels 222 a and 222 b.

  In FIG. 8, the arrangement direction of the focus detection pixels 222 a-1, 222 b-1, 222 a-2 and 222 b-2 coincides with the arrangement direction of the pair of distance measurement pupils 341 and 342.

  Further, as shown in FIG. 8, the microlenses 2221a-1, 2221b-1, 2221a-2, 2221b-2 of the focus detection pixels 222a-1, 222b-1, 222a-2, 222b-2 have a photographing optical system. It is placed near the planned focal plane of. The shape of each of the photoelectric conversion units 2222a-1, 2222b-1, 2222a-2, 2222b-2 disposed behind the microlenses 2221a-1, 2221b-1, 2221a-2, 2221b-2 is The light is projected onto the exit pupil 34 separated from the lenses 2221a-1, 2221b-1, 2221a-2, 2221b-2 by the distance measurement distance D, and the projected shapes form distance measurement pupils 341, 342.

  That is, on the exit pupil 34 located at the distance measurement distance D, the micro lens and photoelectric conversion portion in each focus detection pixel are matched so that the projection shapes (distance measurement pupils 341 and 342) of the photoelectric conversion portion in each focus detection pixel match. The relative positional relationship of is determined, whereby the projection direction of the photoelectric conversion unit at each focus detection pixel is determined.

  As shown in FIG. 8, the photoelectric conversion unit 2222a-1 of the focus detection pixel 222a-1 is formed on the microlens 2221a-1 by the light beam AB1-1 which passes through the distance measurement pupil 341 and is directed to the microlens 2221a-1. Output a signal corresponding to the intensity of the image being Similarly, the photoelectric conversion unit 2222a-2 of the focus detection pixel 222a-2 passes through the distance measurement pupil 341, and the intensity of the image formed on the microlens 2221a-2 by the light beam AB1-2 directed to the microlens 2221a-2. Output a signal corresponding to

  Further, the photoelectric conversion unit 2222b-1 of the focus detection pixel 222b-1 passes through the distance measurement pupil 342, and the intensity of the image formed on the microlens 2221b-1 by the light beam AB2-1 directed to the microlens 2221b-1 Output the corresponding signal. Similarly, the photoelectric conversion unit 2222b-2 of the focus detection pixel 222b-2 passes through the distance measurement pupil 342, and the intensity of the image formed on the microlens 2221b-2 by the light beam AB2-2 directed to the microlens 2221b-2. Output a signal corresponding to

  Then, a plurality of the above-described two types of focus detection pixels 222a and 222b are linearly arranged as shown in FIG. 3, and the output of the photoelectric conversion units 2222a and 2222b of each focus detection pixel 222a By combining the output groups corresponding to each of the focus detection pupil 342 and the focus detection pupil 342, the intensities of the pair of images formed on the focus detection pixel array by the focus detection light beams passing through the focus detection pupil 341 and the focus detection pupil 342 respectively. Data on the distribution is obtained. Then, by performing image shift detection calculation processing such as correlation calculation processing or phase difference detection processing on the intensity distribution data, it is possible to detect an image shift amount by a so-called phase difference detection method.

  Then, a conversion operation according to the distance between the center of gravity of the pair of distance measuring pupils is performed on the obtained image shift amount to obtain a current focal plane with respect to the planned focal plane The deviation of the focal plane at the detection position, that is, the defocus amount can be determined.

  The calculation of the image shift amount by the phase difference detection method and the calculation of the defocus amount based on this are executed by the camera control unit 21.

  Further, the camera control unit 21 reads the output of the imaging pixel 221 of the imaging element 22, and calculates the focus evaluation value based on the read pixel output. The focus evaluation value can be obtained, for example, by extracting a high frequency component of the image output from the imaging pixel 221 of the image sensor 22 using a high frequency transmission filter and integrating the same to detect a focus voltage. Alternatively, high-frequency components can be extracted by using two high-frequency transmission filters having different cutoff frequencies, and integration can be performed to detect the focus voltage.

  Then, the camera control unit 21 sends a control signal to the lens control unit 37 to drive the focus lens 32 at a predetermined sampling interval (distance) to obtain a focus evaluation value at each position, and the focus evaluation value is maximum. The focus detection by the contrast detection method is performed to obtain the position of the focus lens 32 as the in-focus position. It should be noted that, for example, when the focus evaluation value is calculated while driving the focus lens 32, the in-focus position is further lowered twice after the focus evaluation value rises twice. It can obtain | require by performing calculations, such as an interpolation method, using the focus evaluation value of.

  Next, an operation example of the camera 1 according to the present embodiment will be described. FIG. 9 is a flowchart showing an operation example of the camera 1 according to the present embodiment. The following operation is started when the power of the camera 1 is turned on.

  First, in step S101, the camera control unit 21 determines whether a moving image is captured. In the present embodiment, the camera control unit 21 is configured such that, for example, when the photographer presses a moving image shooting button provided on the operation unit 28 and shooting of a moving image is started, or in the moving image shooting mode Thus, when a button (for example, a shutter release button) for starting shooting of a moving image is pressed and shooting of a moving image is started, it can be determined that shooting of a moving image is being performed. If it is determined that moving image capturing is being performed, the process proceeds to step S121. If it is determined that moving image capturing is not performed, the process proceeds to step S102.

  In step S102, the camera control unit 21 sets an aperture value (F value) of the optical system to an aperture value for performing focus detection. Specifically, the camera control unit 21 first receives the open limit value of the aperture value of the optical system from the lens control unit 37 when detecting the focus state of the optical system as the open side limit value. At the same time, when the focus state of the optical system is detected, the limit value on the stop side of the aperture value of the optical system is acquired from the memory 29 as the limit side limit value. In the present embodiment, since the open side limit value is stored in the memory 39 as the number of steps from the open aperture value, the camera control unit 21 calculates the open aperture value and the number of steps from the open aperture value. Based on the open-side limit value (F value) of the aperture value of the optical system at the time of focus detection, the open-side limit value is determined.

  Then, the camera control unit 21 sets the aperture value of the optical system for performing focus detection on the basis of the acquired open side limit value and the narrowing side limit value. Specifically, the camera control unit 21 narrows down the aperture value of the optical system when the shooting aperture value set for the main shooting of the image is a value on the narrowing side rather than the narrowing limit value. Set to the side limit value. Here, FIG. 10 is a diagram showing an example of the relationship between the aperture value set to perform focus detection and the imaging aperture value. In the example shown in FIG. 10, in the lens barrel 3 in which the open aperture value is F1.2 and the maximum aperture value (maximum F value) is F16, the open side limit value is acquired as F2.8, and the narrowing side It shows a scene where the limit value is obtained as F5.6. For example, in the example shown in FIG. 10A, the shooting aperture value is set to F16, and the shooting aperture value F16 is a value on the narrowing side rather than the narrowing limit value F5.6. The camera control unit 21 sets the aperture value of the optical system to F5.6, which is the stop-side limit value. Further, in the example shown in (B) of FIG. 10, since the imaging aperture value is F8, the camera control unit 21 sets the aperture value of the optical system to the narrowing limit value as in (A) of FIG. Set to F5.6.

  In addition, when the shooting aperture value set for the main shooting of the image is the same value as the narrowing-down limit value or a value on the open side more than the narrow-down limit, the camera control unit 21 Set the aperture to the shooting aperture. For example, in the example shown in FIG. 10C, since the shooting aperture value is F5.6, which is the same as the stop-side limit value, the camera control unit 21 sets the aperture value of the optical system to the shooting aperture value F5. Set to 6. Further, in the example shown in (D) of FIG. 10, the shooting aperture value is set to F4, and the shooting aperture value F4 is a value more on the open side than F5.6, which is the narrowing limit value. The camera control unit 21 sets the aperture value of the optical system to F4, which is a shooting aperture value. Similarly, also in the examples shown in (E) to (G) of FIG. 10, as in the case of (D) of FIG. 10, the shooting aperture value is a value on the open side more than the narrowing limit value. 21 sets the aperture value of the optical system to the photographing aperture value.

  In step S103, generation of a through image by the camera control unit 21 and display of the through image by the electronic viewfinder 26 of the observation optical system are performed. Specifically, an exposure operation is performed by the imaging device 22, and reading of pixel data of the imaging pixel 221 is performed by the camera control unit 21. Then, the camera control unit 21 generates a through image based on the read pixel data, and the generated through image is sent to the liquid crystal drive circuit 25 and displayed on the electronic viewfinder 26 of the observation optical system. As a result, the user can visually recognize the moving image of the subject through the eyepiece lens 27.

  In step S104, the camera control unit 21 divides the shooting screen into a plurality of areas, performs multi-division photometry (multi-pattern photometry) that performs photometry for each divided area, and calculates the luminance value Bv of the entire shooting screen. Be done. Then, at least one of the light reception sensitivity Sv and the exposure time Tv is changed by the camera control unit 21 based on the calculated luminance value Bv of the entire photographing screen so that the appropriate exposure can be obtained over the entire photographing screen. In step S104, at least one of the light receiving sensitivity Sv and the exposure time Tv is changed while the aperture Av corresponding to the aperture value set in step S102 is fixed. Then, based on the changed light receiving sensitivity Sv and exposure time Tv, for example, the shutter speed of the shutter 23, the sensitivity of the imaging device 21 and the like are set to control the exposure of the imaging device 22.

  In step S105, the camera control unit 21 determines whether or not the proper exposure has been obtained over the entire photographing screen by the exposure control in step S104. If the entire photographed screen does not have a proper exposure only by changing the light receiving sensitivity Sv or the exposure time Tv, the process proceeds to step S106, while changing at least one of the light receiving sensitivity Sv and the exposure time Tv If the appropriate exposure is obtained overall, the process proceeds to step S108.

  In step S106, it is determined that the proper exposure can not be obtained over the entire shooting screen only by changing the light reception sensitivity Sv and the exposure time Tv. Therefore, the camera control unit 21 changes the aperture Av. Specifically, when the shooting aperture value is a value on the narrowing side rather than the narrowing-side limit value, the camera control unit 21 determines that the aperture value of the optical system is the open-side limit value and the narrowing-side limit value. The aperture Av is changed based on the luminance value Bv of the entire shooting screen so as to be within the range. For example, in the example shown in FIG. 10A, since the imaging aperture value F16 is a value on the narrowing side rather than the narrowing limit value F5.6, the camera control unit 21 sets the aperture of the optical system to The aperture Av is changed so that the value is within the range from F2.6, which is the open side limit value, to F5.6, which is the narrowing side limit value, and exposure control is performed so that appropriate exposure can be obtained over the entire shooting screen. I do. The same is true for the example shown in FIG.

  Further, when the shooting aperture value is the same value as the narrowing limit value or a value on the opening side more than the narrowing limit value, the camera control unit 21 sets the aperture value of the optical system to the open limit value and shooting. The aperture Av is changed based on the luminance value Bv of the entire shooting screen so as to be within the range with the aperture value. For example, in the example shown in (C) of FIG. 10, since the shooting aperture value F5.6 is the same value as F5.6 which is the narrowing-down limit value, the camera control unit 21 determines the aperture value of the optical system. The aperture Av is changed so as to be within the range from F2.6, which is the open-side limit value, to F5.6, which is the shooting aperture value. Further, in the example shown in FIG. 10D, since the imaging aperture value F4 is a value more on the open side than F5.6, which is the narrowing-down limit value, the camera control unit 21 determines that the diaphragm of the optical system The aperture Av is changed so that the value falls within the range from F2.6, which is the open-side limit value, to F4, which is the shooting aperture value.

  When the shooting aperture value is the same as the opening limit value or a value on the opening side more than the opening limit value, the camera control unit 21 assumes that the aperture value of the optical system remains the shooting aperture value. Do. For example, in the example illustrated in (E) of FIG. 10, since the imaging aperture value F2.6 is the same value as the open side limit value F2.6, the camera control unit 21 determines the aperture value of the optical system. Is set to F2.6, which is the shooting aperture value. The same applies to the examples shown in (F) to (G) of FIG. Further, in the present embodiment, for example, as shown in (A) to (D) of FIG. 10, the camera control unit 21 can change the aperture Av within the range of a predetermined aperture value. Even when the luminance value Bv of the entire photographing screen changes again, the diaphragm Av is changed slightly to the open side with some margin so that the diaphragm Av need not be changed again.

  In step S107, the light reception sensitivity Sv and the exposure time Tv are determined by the camera control unit 21 so that the appropriate exposure can be obtained over the entire shooting screen with the aperture Av changed in step S106. Specifically, as in step S104, the camera control unit 21 performs multi-pattern photometry on the entire shooting screen, and calculates the luminance value Bv of the entire shooting screen. Then, based on the calculated brightness value Bv and the aperture Av changed in step S106, the camera control unit 21 determines and determines the light reception sensitivity Sv and the exposure time Tv at which the appropriate exposure can be obtained over the entire shooting screen. The exposure to the image sensor 22 is controlled based on the light receiving sensitivity Sv and the exposure time Tv, and the aperture Av changed in step S106.

  Then, in step S108, the camera control unit 21 performs calculation processing of the defocus amount by the phase difference detection method. Specifically, first, light reception from the optical system is performed by the imaging device 22, and each focus detection pixel 222 a constituting the three focus detection pixel arrays 22 a to 22 c of the imaging device 22 by the camera control unit 21. , 222b to read a pair of image data corresponding to the pair of images. In this case, when a specific focus detection position is selected by the manual operation of the photographer, only data from focus detection pixels corresponding to the focus detection position may be read out. Then, the camera control unit 21 executes image shift detection calculation processing (correlation calculation processing) based on the read pair of image data, and images at focus detection positions corresponding to the three focus detection pixel arrays 22a to 22c. The shift amount is calculated, and the image shift amount is converted into the defocus amount. The camera control unit 21 also evaluates the reliability of the calculated defocus amount. For example, the camera control unit 21 can determine the reliability of the defocus amount based on the degree of coincidence or contrast of the pair of image data.

  In step S109, the camera control unit 21 determines whether the shutter release button provided on the operation unit 28 has been half-pressed (the first switch SW1 is turned on). If the shutter release button has been half-pressed, the process proceeds to step S110. On the other hand, when the shutter release button is not pressed halfway, the process returns to step S103, and the display of the through image, the exposure control, and the calculation of the defocus amount are repeatedly executed until the shutter release button is pressed halfway. .

  In step S110, the camera control unit 21 determines whether the defocus amount has been calculated by the phase difference detection method. If the defocus amount can be calculated, it is determined that distance measurement is possible, and the process proceeds to step S111. If the defocus amount can not be calculated, it is determined that the distance measurement is not possible, and the process proceeds to step S115. . In the present embodiment, even if the defocus amount can be calculated, if the reliability of the calculated defocus amount is low, the defocus amount can not be calculated and the process proceeds to step S115. To be. In the present embodiment, for example, it is determined that the reliability of the defocus amount is low when the contrast of the subject is low, when the subject is an ultra-low-brightness subject, or when the subject is an ultra-high-brightness subject, .

  In step S111, the camera control unit 21 calculates the lens driving amount necessary to drive the focus lens 32 to the in-focus position based on the defocus amount calculated in step S108. The lens drive amount is sent to the focus lens drive motor 36 via the lens control unit 37. As a result, the focus lens drive motor 36 drives the focus lens 32 based on the calculated lens drive amount.

  In step S112, the camera control unit 21 determines whether the shutter release button has been fully pressed (the second switch SW2 is turned on). If the second switch SW2 is on, the process proceeds to step S113. If the second switch SW2 is not on, the process returns to step S103.

  In step S113, in order to perform the main photographing of the image, the camera control unit 21 performs a process of setting the aperture value of the optical system to the photographing aperture value. For example, in the example shown in (A) of FIG. 10, the camera control unit 21 sets the aperture value of the optical system to the aperture value at the time of focus detection (F2.8 which is the open side limit value) in order to capture an image. From the above, within the range of F5.6 which is the narrowing-down limit value), the shooting aperture value is changed to F16. Similarly, also in the examples shown in (B) to (G) of FIG. 10, the aperture value of the optical system is changed from the aperture value for performing focus detection to the imaging aperture value for performing the main photographing of the image. Then, in the subsequent step S114, the image pickup device 22 performs the main photographing of the image with the aperture value set in step S113, and the image data of the photographed image is stored in the memory 24.

  On the other hand, if it is determined in step S110 that the defocus amount can not be calculated, the process proceeds to step S115 in order to obtain an exposure suitable for focus detection. In step S115, the camera control unit 21 performs exposure control for focus detection so as to obtain an exposure suitable for focus detection. Specifically, the camera control unit 21 performs spot photometry in a predetermined area including the focus detection areas (the focus detection pixel arrays 22a, 22b, and 22c shown in FIG. 2) based on the output of the imaging device 22, and The luminance value SpotBv in a predetermined area including the focus detection area is calculated. Then, the camera control unit 21 determines the light receiving sensitivity Sv, the exposure time Tv, and the like so that an exposure suitable for focus detection (for example, an exposure brighter than the appropriate exposure) can be obtained based on the calculated brightness value SpotBv. Determine the aperture Av. In the exposure control for focus detection in step S115, as in steps S104 to S107, the camera control unit 21 preferentially changes the light reception sensitivity Sv and the exposure time Tv to obtain the light reception sensitivity Sv and the exposure time Tv. The aperture Av is changed based on the open side limit value and the narrowing side limit value acquired in step S102 only when the change is not sufficient to obtain an exposure suitable for focus detection. That is, as shown in (A) and (B) of FIG. 10, the camera control unit 21 controls the aperture of the optical system when the photographing aperture value is a value on the narrowing side rather than the narrowing limit value. The aperture Av is changed based on the luminance value SpotBv in a predetermined area including the focus detection area so that the value is within the range between the open-side limit value and the narrow-down side limit value. Further, as shown in (C) to (D) of FIG. 10, when the imaging aperture value is the same value as the narrowing limit value or a value on the opening side than the narrowing limit value, the aperture of the optical system The aperture Av is changed based on the luminance value SpotBv in the predetermined area including the focus detection area so that the value is within the range between the open-side limit value and the imaging aperture value, and further, (E) in FIG. As shown in (G), when the shooting aperture value is the same value as the opening limit value or a value closer to the opening limit than the opening limit value, the aperture value of the optical system remains the shooting aperture value. I assume.

  In step S116, the camera control unit 21 calculates the defocus amount based on the image data obtained by the exposure suitable for focus detection, and in the subsequent step S117, the camera control unit 21 is suitable for focus detection. Based on the image data obtained by the exposure, it is determined whether the defocus amount has been calculated. If the defocus amount can be calculated, the process proceeds to step S111, and drive processing of the focus lens 32 is performed based on the calculated defocus amount. On the other hand, when the defocus amount can not be calculated even if the image data obtained by the exposure suitable for focus detection is used, the process proceeds to step S118, and a scan operation execution process described later is performed. Also in step S117, as in step S110, even when the defocus amount can be calculated, if the reliability of the calculated defocus amount is low, the defocus amount can not be calculated. .

  In step S118, the camera control unit 21 performs a scan operation execution process for executing a scan operation. Here, with the scan operation, while the focus lens drive motor 36 scans and drives the focus lens 32, the camera control unit 21 determines the calculation of the defocus amount by the phase difference detection method and the calculation of the focus evaluation value. At the same time, the detection of the in-focus position by the phase difference detection method and the detection of the in-focus position by the contrast detection method are simultaneously performed at predetermined intervals. In the following, with reference to FIG. 11, a scan operation execution process according to the present embodiment will be described. FIG. 11 is a flowchart showing a scan operation execution process according to the present embodiment.

  First, in step S201, the camera control unit 21 performs processing for starting a scanning operation. Specifically, the camera control unit 21 sends a scan drive start command to the lens control unit 37, and the lens control unit 37 drives the focus lens drive motor 36 based on the command from the camera control unit 21 to perform focusing. The lens 32 is scan driven along the optical axis L1. The direction in which the scan drive is performed is not particularly limited, and the scan drive of the focus lens 32 may be performed from the infinite end to the close end, or even from the close end to the infinity end. Good.

  Then, while driving the focus lens 32, the camera control unit 21 reads out a pair of image data corresponding to the pair of images from the focus detection pixels 222a and 222b of the image sensor 22 at predetermined intervals. While the defocus amount is calculated and the reliability of the calculated defocus amount is evaluated by the phase difference detection method, the pixel output of the imaging pixel 221 of the imaging element 22 is performed at predetermined intervals while driving the focus lens 32. Based on this read out, the focus evaluation value is calculated, and the focus evaluation value at different focus lens positions is acquired, thereby detecting the in-focus position by the contrast detection method.

  In step S202, as a result of performing the scan operation, the camera control unit 21 determines whether the defocus amount has been calculated by the phase difference detection method. If the defocus amount can be calculated, it is determined that distance measurement is possible, and the process proceeds to step S205. On the other hand, if the defocus amount can not be calculated, it is determined that the distance measurement is not possible, and the process proceeds to step S203. .

  In step S203, as a result of performing the scan operation, the camera control unit 21 determines whether the in-focus position has been detected by the contrast detection method. If the in-focus position can be detected by the contrast detection method, the process proceeds to step S207. On the other hand, if the in-focus position can not be detected, the process proceeds to step S204.

  In step S204, the camera control unit 21 determines whether the scan operation has been performed on the entire drivable range of the focus lens 32 or not. When the scan operation is not performed for the entire drivable range of the focus lens 32, the process returns to step S202, and the steps S202 to S204 are repeated to perform the scan operation, that is, to drive the focus lens 32 while scanning. The operation of simultaneously executing the calculation of the defocus amount by the phase difference detection method and the detection of the in-focus position by the contrast detection method at predetermined intervals is continued. On the other hand, if execution of the scan operation has been completed for the entire drivable range of the focus lens 32, the process proceeds to step S208.

  When it is determined in step S202 that the defocus amount has been calculated by the phase difference detection method as a result of executing the scan operation, the process proceeds to step S205, and the phase difference detection method is calculated in step S205. A focusing operation is performed based on the defocus amount.

  That is, in step S205, after the stop processing of the scanning operation is first performed by the camera control unit 21, the lens drive necessary to drive the focus lens 32 to the in-focus position from the calculated defocus amount The amount is calculated, and the calculated lens driving amount is sent to the lens drive motor 36 via the lens control unit 37. Then, the lens drive motor 36 drives the focus lens 32 to the in-focus position based on the lens drive amount calculated by the camera control unit 21. When driving of the focus lens 32 to the in-focus position is completed, the process proceeds to step S206, and in step S206, the camera control unit 21 determines that the in-focus state is achieved.

  If it is determined in step S203 that the in-focus position has been detected by the contrast detection method as a result of performing the scan operation, the process proceeds to step S207, and based on the in-focus position detected by the contrast detection method The drive operation of the focus lens 32 is performed.

  That is, after the processing for stopping the scanning operation is performed by the camera control unit 21, the lens driving processing for driving the focus lens 32 to the in-focus position is performed based on the in-focus position detected by the contrast detection method. . When the drive of the focus lens 32 to the in-focus position is completed, the process proceeds to step S206, and the camera control unit 21 determines that the in-focus state is achieved.

  On the other hand, if it is determined in step S204 that the execution of the scan operation has been completed for the entire drivable range of the focus lens 32, the process proceeds to step S208. In step S208, as a result of performing the scan operation, focus detection can not be performed by any of the phase difference detection method and the contrast detection method, so the scan operation end processing is performed, and then in step S209. The process proceeds, and the camera control unit 21 determines that focusing is impossible.

  Then, after the scan operation execution process of step S118 is completed, the process proceeds to step S119, and it is determined by the camera control unit 21 whether or not the in-focus state is obtained based on the result of the in-focus determination in the scan operation execution process. To be done. In the scan operation execution process, when it is determined that the image is in focus (step S206), the process proceeds to step S112. On the other hand, if it is determined that the in-focus state can not be obtained (step S209), the process proceeds to step S120, and the in-focus state is displayed in step S120. The out-of-focus indication is performed, for example, by the electronic viewfinder 26.

  If it is determined in step S101 that shooting of a moving image is being performed, the process proceeds to step S121. In step S121, the camera control unit 21 performs exposure control so as to obtain an exposure suitable for capturing a moving image. Specifically, in order to give priority to the appearance of a moving image, the camera control unit 21 performs multi-pattern photometry to calculate the brightness value Bv of the entire shooting screen, and based on the calculated brightness value Bv, over the entire shooting screen. The light receiving sensitivity Sv and the exposure time Tv are determined so as to obtain a proper exposure. In particular, during shooting of a moving image, exposure control is performed by changing only the light reception sensitivity Sv and the exposure time Tv while the aperture Av is fixed.

  Then, in step S122, the camera control unit 21 detects the focus state of the optical system, and the focus adjustment of the focus lens 32 is performed according to the detected focus state. Specifically, based on the captured image data, the camera control unit 21 calculates the defocus amount as in steps S111 and S115 to S120, and determines whether the defocus amount has been calculated. Then, when the defocus amount is calculated, the focus lens 32 is driven based on the calculated defocus amount, and when the defocus amount is not calculated, the scan operation execution processing is performed. . Then, the process proceeds to step S123, the moving image is actually shot by the image pickup element 22, and the image data of the moving image shot by the camera control unit 21 is stored in the memory 24.

  As described above, in the present embodiment, the open limit value of the aperture value of the optical system at the time of focus detection is stored in the lens barrel 3 as the open side limit value, and the focus detection is performed. The limit value on the narrowing side of the aperture value of the optical system at the time of performing is stored in the camera body 2 as the narrowing limit value. Then, the camera control unit 21 sets the aperture value of the optical system at the time of focus detection based on the open side limit value received from the lens barrel 3 and the narrowing side limit value acquired from the memory 29. . Specifically, when the shooting aperture value at the time of main imaging of the image is a value on the narrowing side rather than the narrowing limit value, the aperture value of the optical system at the time of focus detection is the open side limit value. It sets in the range of and the narrowing-down limit value. As described above, in the present embodiment, the aperture value of the optical system at the time of focus detection is limited to a value on the narrowing side rather than the open side limit value, so that the aperture of the optical system can be photographed. Even when the aperture value at focus detection is changed to the shooting aperture value for capturing an image, the movement amount of the image plane of the optical system accompanying the change of the aperture value of the optical system should be equal to or less than a predetermined value. As a result, the in-focus position detected in the focus detection can be made within the range of the depth of field of the optical system at the time of main photographing of the image, and the image in focus on the subject can be photographed. Can.

  Further, in the present embodiment, when the shooting aperture value at the time of main photographing of the image is a value on the narrowing side rather than the narrowing limit value, the aperture value of the optical system at the time of focus detection is the narrowing side. By limiting to the value on the open side rather than the limit value, the occurrence of vignetting at the time of focus detection can be effectively prevented, and the focus state of the optical system can be appropriately detected. Furthermore, in the present embodiment, when the shooting aperture value is a value on the open side more than the narrowing limit value, the aperture value of the optical system at the time of focus detection is the open side limit value and the shooting aperture value. By setting in the range of, the aperture value of the optical system at the time of performing focus detection is limited so as not to be a value on the side of reduction rather than the imaging aperture value, whereby the image is captured when the image is captured. The depth of field at the time of main shooting becomes shallower than the depth of field at the time of focus detection, and the subject focused at the time of focus detection at the time of main shooting of an image Deviation from the depth of field can be effectively prevented, and as a result, an image in focus on the subject can be photographed well.

Second Embodiment
Next, a second embodiment of the present invention will be described based on the drawings. The camera 1a according to the second embodiment is the same as the camera 1 according to the first embodiment except that the lens barrel 3a is attached to the camera body 2 via the lens adapter 5 as shown in FIG. It has the same configuration and performs the same operation as the camera 1 according to the first embodiment except for the points described below.

  That is, in the camera 1 a according to the second embodiment, the lens barrel 3 a can be attached to the camera body 2 via the lens adapter 5. Here, the lens barrel 3a has the same configuration as the lens barrel 3 of the first embodiment, except that the open side limit value is not stored in the memory 39. Then, in the second embodiment, for example, by mounting the lens barrel 3a to the camera body 2 via the lens adapter 5, the adapter control unit 51 transmits the camera control unit 21 and the lens control unit 37. A signal indicating that the lens adapter 5 has been mounted is transmitted, whereby the electric signal contact portion 41 provided in the mount portion 4 and the electric signal contact portion 61 provided in the mount portion 6 are transmitted. The information such as the aperture value of the optical system can be transmitted and received between the lens control unit 37 and the camera control unit 21.

  Next, an operation example of the camera 1a according to the second embodiment will be described with reference to FIG. FIG. 13 is a view showing an example of the relationship between the aperture value set at the time of focus detection and the photographing aperture value in the second embodiment. Further, in the example shown in FIG. 13, in a scene where the open aperture value is F1.2 and the maximum aperture value (maximum F value) is F16, the camera control unit 21 narrows down without using the open limit value. The scene which performs exposure control of focus detection based on only a side restriction value is shown.

  In the second embodiment, the camera control unit 21 sets the aperture value of the optical system to the narrowing side restriction when the photographing aperture value for the main photographing of the image is a value on the narrowing side rather than the narrowing side restriction value. The focus detection is performed by setting the value to a value, and the aperture value of the optical system is set to the photographing aperture value to perform main photographing. For example, in the example shown in FIG. 13A, since the imaging aperture value is F16 and the imaging aperture value is a smaller value than F5.6 which is the narrowing limit value, the aperture value of the optical system is Is set to F5.6, which is the narrowing-down limit value, to perform focus detection, and when the image is actually shot, the aperture value of the optical system is calculated from F5.6, which is the narrowing-side limit value. The actual shooting of the image is performed by changing to the shooting aperture value F16. Similarly, in the example illustrated in (B) of FIG. 13, since the imaging aperture value F8 is a value on the narrowing side rather than F5.6 that is the narrowing side limit value, the narrowing side limit value F5.6 is The focus detection is performed at step S8, and the main photographing of the image is performed at F8 which is the photographing aperture value.

  Further, the camera control unit 21 sets the aperture value of the optical system to the imaging aperture value when the imaging aperture value is the same value as the aperture limit value or a value on the open side than the aperture limit value. Focus detection is performed by setting, and the actual photographing of the image is performed while the aperture value of the optical system is set to the photographing aperture value. For example, in the example shown in FIG. 13C, since the shooting aperture value is F5.6, which is the same as the stop-side limit value, the camera control unit 21 sets the aperture value of the optical system to F5. Focus detection is performed by setting it to 6, and then the actual photographing of the image is performed with the photographing aperture value F5.6. Further, in the example illustrated in FIG. 13D, since the imaging aperture value is F4 and the imaging aperture value is a value on the open side more than F5.6, which is the narrowing-down limit value, the camera control unit 21 The focus value is set by setting the aperture value of the optical system to the photographing aperture value F4, and the main photographing of the image is performed with the set photographing aperture value. The same applies to the scene examples shown in (E) and (F) of FIG.

  As described above, in the second embodiment, when the open limit value is not acquired from the lens control unit 37, the imaging aperture value is the same as the narrowing limit value or a value on the open side than the narrowing limit value. In some cases, as shown in (C) to (F) of FIG. 13, focus detection is performed by setting the aperture value of the optical system to the imaging aperture value, and the image is still set to the imaging aperture value. Take a picture of Thus, in the present embodiment, the aperture value of the optical system is not changed from the time of focus detection to the time of actual photographing of the image, and therefore the image plane position of the optical system at the time of focus detection and the time of actual photographing of the image. Is not changed, and the in-focus position detected in focus detection falls within the range of the depth of field of the optical system at the time of actual photographing of the image, and an image in which the object is in focus can be photographed.

  The embodiments described above are described to facilitate the understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents that fall within the technical scope of the present invention.

  For example, in the embodiment described above, when the shutter release button provided on the operation unit 28 is half-pressed, the focus adjustment of the focus lens 32 is activated. However, the present invention is not limited to this configuration. A personal computer may be connected, and a signal from the personal computer may be received by the camera 1 to activate focus adjustment of the focus lens 32. Alternatively, the camera 1 may use a signal from the remote control corresponding to the camera 1 It may be configured to activate focus adjustment of the focus lens 32 by receiving. In this case, in step S110, it may be determined whether a signal for activating focus adjustment of the focus lens 32 has been received from a personal computer or a remote control.

  The camera 1 according to the above-described embodiment is not particularly limited. For example, the present invention is applied to other optical devices such as a digital video camera, a single-lens reflex digital camera, a lens integrated digital camera, and a camera for mobile phones. May be

DESCRIPTION OF SYMBOLS 1 digital camera 2 camera main body 21 camera control part 22 imaging element 221 imaging pixel 222a, 222b focus detection pixel 28 operation part 3 lens barrel 32 focus lens 36 focus lens drive motor 37 lens Control unit

Claims (9)

An imaging unit that captures an image by an optical system having a stop and a focusing lens and outputs a signal;
A detection unit that detects an in-focus position of the optical system at which an image by the optical system focuses on the imaging unit based on the signal;
A lens movement instruction unit for instructing movement of the focusing lens;
A setting unit configured to set an aperture value of the aperture;
The focus adjustment lens is moved based on the in-focus position detected by setting the aperture value to a range not less than a first value and not more than a second value larger than the first value, and the aperture value of the aperture Control for performing imaging by setting the third value to the third value larger than the second value, and detecting the aperture value within the first value or more and the fourth value range smaller than the second value or less A control unit configured to move the focusing lens based on the in-focus position and set an aperture value of the aperture to a fourth value to perform imaging.
An imaging device comprising: The imaging apparatus according to claim 1,
The imaging device, wherein the first value is a predetermined value determined by the optical system. The imaging device according to claim 1 or 2,
The imaging device, wherein the second value is a predetermined value determined by the imaging device. The imaging apparatus according to any one of claims 1 to 3, wherein
The imaging apparatus according to claim 1, wherein the first value is a limit value on an open side of the diaphragm when the focus position is detected by the detection unit. The imaging apparatus according to any one of claims 1 to 4, wherein the second value is a limit value on the stop side of the diaphragm when the focus position is detected by the detection unit. The imaging apparatus according to any one of claims 1 to 5, wherein
The imaging is performed by moving the focusing lens based on the in-focus position detected by setting the aperture value to the fourth value and changing the aperture value of the aperture from the fourth value. apparatus. The imaging apparatus according to any one of claims 1 to 6, wherein
The imaging unit includes a plurality of imaging pixels and a plurality of focus detection pixels which are two-dimensionally arranged.
The detection unit is configured to detect an amount of positional deviation of an image due to a light beam passing through different portions of the pupil of the optical system based on the signal output from the focus detection pixel, and the image output by the imaging pixel. An imaging apparatus, which detects a focus position of the optical system based on at least one of evaluation values on image contrast by the optical system based on a signal. The imaging apparatus according to any one of claims 1 to 7, wherein
A communication unit that communicates with the lens barrel having the optical system;
An imaging device which receives the first value from the lens barrel via the communication unit. The imaging apparatus according to any one of claims 1 to 8, wherein
An imaging apparatus, comprising: a storage unit that stores the second value.

Images