JP6098690B2 - Lens barrel and camera body - Google Patents

Description

  The present invention relates to a lens barrel and a camera body.

  2. Description of the Related Art Conventionally, there has been known an image pickup apparatus that detects a focus state of an optical system by detecting a shift amount of an image plane of the optical system based on an output of a focus detection pixel provided in the image pickup element. As such an imaging device, for example, in order to prevent vignetting when performing focus detection, the aperture value of the optical system is set to a value (open side value) smaller than a predetermined aperture value, A method of performing focus detection is known (for example, 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 actually capture an image, the image plane of the optical system is changed along with the change of the aperture value. Moved, and as a result, there was a case where an image focused on the subject could not be taken.

  The problem to be solved by the present invention is to provide a lens barrel that can capture an image satisfactorily.

  The present invention solves the above problems by the following means. In the following description, reference numerals corresponding to the drawings showing the embodiment of the present invention are given and described. However, the reference numerals are only for facilitating the understanding of the invention and are not intended to limit the invention. .

[1] A camera body according to the present invention includes an imaging unit (22) that captures an image by an optical system and outputs a signal, and an image by the optical system matches the imaging unit (22) based on the signal. A detecting unit for detecting a focusing position of the optical system to be focused, and a limit value on the open side of the aperture value of the optical system when the focusing position is detected by the detecting unit, and a lens barrel having the optical system A receiving unit that receives the aperture position, a storage unit (21) that stores a limit value on the aperture side of the aperture value of the optical system when the in-focus position is detected by the detection unit, and detection of the in-focus position by the detection unit The aperture value of the optical system when performing imaging is larger than the limit value on the aperture side when the imaging aperture value when imaging is performed by the imaging unit (22) to record the signal as image data. More than the limit value on the side and the limit on the narrowing side Set within the following range, the case imaging aperture value is below the limit value of the closing side, provided with a control unit (21) to set the restriction value or more and a range of less than the imaging aperture of the open side.

[2] In the invention according to the camera body, the control unit (21) sets the aperture value of the optical system when the detection unit detects the in-focus position to be less than the imaging aperture value or the imaging aperture value. Can be configured to set to a value .

[3] In the invention according to the camera body, the control unit (21) sets an aperture value of the optical system when the detection unit detects a focus position to a value larger than an open aperture value of the optical system. Can be configured to be set to

[4] In the invention according to the camera body, the imaging unit (22) includes a plurality of imaging pixels and a plurality of focus detection pixels arranged two-dimensionally,
The detection unit is based on at least one of the signal output from the focus detection pixel and the evaluation value related to the contrast of the image by the optical system based on the signal output from the imaging pixel. The in-focus position of the optical system can be detected.

[5] In the invention relating to the camera body, the control unit (21) is configured to detect the in-focus position by the detection unit when the photographing aperture value is equal to or less than the open limit value. The aperture value of the optical system can be set to the photographing aperture value .

[6] In the invention relating to the camera body, the control unit (21) is configured to detect the in-focus position by the detection unit when the photographing aperture value is larger than a limit value on the aperture side. The aperture value of the system can be configured to be set to the limit value on the narrowing side .

[7] In the invention according to the camera body, the control unit (21) may determine the aperture value of the optical system when the detection unit detects the in-focus position by using the lens barrel via a lens adapter. When the photographic aperture value is larger than the limit value on the aperture side, the aperture value is set to the limit value on the aperture side.When the aperture value is less than or equal to the limit value on the aperture side, the aperture value is set. Can be configured to set .

[8] A lens barrel according to the present invention is a lens barrel that can be attached to and detached from the camera body, and includes an optical system including a focus adjustment optical system;
A diaphragm for limiting a light beam passing through the optical system, a moving unit for moving the focus adjusting optical system in an optical axis direction, and an in-focus position detected by the detection unit of the camera body. A storage unit (27) that stores a limit value on the open side of the aperture value, and a transmission unit that transmits the limit value on the open side to the camera body.

[9] In the invention related to the lens barrel, the storage unit (27) stores the open side limit value as the number of aperture stages from the open aperture value of the optical system.

  According to the present invention, an image can be taken satisfactorily.

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 the arrangement of the focus detection pixels 222a and 222b by enlarging the III part of FIG. FIG. 4 is an enlarged front view showing one of the imaging pixels 221. 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 an enlarged cross-sectional view showing one of the imaging pixels 221. FIG. 7A is an enlarged cross-sectional view showing one of the focus detection pixels 222a, and FIG. 7B is an enlarged cross-sectional view showing one of the focus detection pixels 222b. 8 is a cross-sectional view taken along 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 diagram illustrating an example of a relationship between the aperture value at the time of focus detection set in the first embodiment and the photographing aperture value. FIG. 11 is a flowchart showing the scan operation execution process in step S118. FIG. 12 is a block diagram illustrating a camera according to the second embodiment. FIG. 13 is a diagram illustrating an example of the relationship between the aperture value at the time of focus detection set in the second embodiment and the photographing aperture value.

  Hereinafter, embodiments of the present invention will be described with reference to 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. A digital camera 1 according to the present embodiment (hereinafter simply referred to as a camera 1) includes 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. Yes.

  The lens barrel 3 is an interchangeable lens that can be attached to and detached from the camera body 2. As shown in FIG. 1, the lens barrel 3 includes a photographic optical system including lenses 31, 32, 33 and a diaphragm 34.

  The lens 32 is a focus lens, and can adjust the focal length of the photographing optical system by moving in the direction of the optical axis L1. 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 rotating cylinder is rotatably inserted into a fixed cylinder fixed to the lens barrel 3, a helicoid groove (spiral groove) is formed on the inner peripheral surface of the rotating cylinder, and the focus lens 32 is fixed. The end of the lens frame is fitted into the helicoid groove. Then, by rotating the rotating cylinder by the focus lens drive motor 36, the focus lens 32 fixed to the lens frame moves straight along the optical axis L1.

  As described above, the focus lens 32 fixed to the lens frame by rotating the rotary cylinder with respect to the lens barrel 3 moves straight in the direction of the optical axis L1, but the focus lens drive motor 36 as the drive source is the lens. The lens barrel 3 is provided. The focus lens drive motor 36 and the rotary cylinder are connected by a transmission composed of a plurality of gears, for example, and when the drive shaft of the focus lens drive motor 36 is driven to rotate in any one direction, it is transmitted to the rotary cylinder at a predetermined gear ratio. Then, when the rotating cylinder rotates in any one direction, the focus lens 32 fixed to the lens frame moves linearly in any direction of the optical axis L1. When the drive shaft of the focus lens drive motor 36 is rotated in the reverse direction, the plurality of gears constituting the transmission also rotate in the reverse direction, and the focus lens 32 moves straight in the reverse direction of 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 optical axis L1 direction correlates with the rotation angle of the rotating cylinder, and can be obtained by detecting the relative rotation angle of the rotating cylinder with respect to the lens barrel 3, for example.

  As the encoder 35 of this embodiment, an encoder that detects the rotation of a rotating disk coupled to the rotational drive of the rotating cylinder with an optical sensor such as a photo interrupter and outputs a pulse signal corresponding to the number of rotations, or a fixed cylinder And the contact point of the brush on the surface of the flexible printed wiring board provided on either one of the rotating cylinders, and the brush contact provided on the other, the amount of movement of the rotating cylinder (in either the rotational direction or the optical axis direction) A device that detects a change in the contact position according to the detection circuit using a detection circuit can be used.

  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 closest end) to the end on the subject side (also referred to as the infinite end) by the rotation of the rotating 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 to be described later via the lens control unit 37, and the focus lens drive motor 36 calculates the focus calculated based on this information. The driving position of the lens 32 is driven by being sent from the camera control unit 21 via the lens control unit 37.

  The diaphragm 34 is configured such that the aperture diameter around the optical axis L1 can be adjusted in order to limit the amount of light flux that passes through the photographing optical system and reaches the image sensor 22 and to adjust the blur amount. The adjustment of the aperture diameter by the diaphragm 34 is performed, for example, by sending an aperture diameter corresponding 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 aperture 34 is detected by an aperture sensor (not shown), and the lens controller 37 recognizes the current aperture diameter.

  In the present embodiment, the lens control unit 37 stores in advance the limit value on the open side of the aperture value of the optical system when detecting the focus state of the optical system in the memory 39 as the open side limit value. Yes. Here, for example, when the aperture value at the time of detecting the focus state of the optical system is F1.4 and the imaging aperture value at the time of actual imaging of the image is F2.8, the main imaging is performed after the focus detection. In addition, when the aperture value of the optical system is changed from F1.4, which is the aperture value at the time of focus detection, to F2.8, which is the photographing aperture value, the focal point is changed due to the movement of the image plane accompanying the change of the aperture value. The focus position detected at the time of detection deviates from the depth of field of the optical system at the time of actual shooting of the image, and it may not be possible to capture a focused image on the subject that was in focus at the time of focus detection. . In particular, this tendency increases as the aperture value of the optical system becomes a value on the open side. Therefore, in such a case, for example, by restricting the aperture value at the time of detecting the focus state of the optical system to F2 instead of F1.4, the amount of image plane movement due to 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 imaging aperture value, an image in focus on the subject can be captured. In this way, the open side limit value is an open aperture value of the optical system that can capture a good image even when the aperture value of the optical system is changed from the aperture value at the time of focus detection to the shooting aperture value. This limit value is stored in the lens control unit 37 in advance as a unique value for each lens barrel 3.

  In the present embodiment, the lens control unit 37 stores the open side limit value as the number of aperture stages from the open aperture value. For example, when the open side limit value is F2 as the aperture value (F value), the open aperture value is F1.2, and the aperture value of the optical system is changed from the open aperture value F1.2 to the open side limit value. When the number of aperture stages of the aperture 34 for changing to a certain F2 is 2, the camera control unit 37 stores the open side limit value as 2 stages. Thus, by storing the open side limit value as the number of aperture stages 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 Based on the above, it is possible to obtain the open side limit value according to the lens position of the zoom lens, 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 number of aperture stages are examples, and are not limited to these values.

  On the other hand, the camera body 2 is provided with an imaging element 22 that receives the light beam L1 from the photographing optical system on a planned focal plane of the photographing optical system, and a shutter 23 is provided on the front surface thereof. The image sensor 22 is composed of a device such as a CCD or CMOS, converts the received optical signal into an electrical signal, and sends it to the camera control unit 21. The captured 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 a release button ( When (not shown) is fully pressed, the photographed image information is recorded in the memory 24 that is a recording medium. As the memory 24, any of a removable card type memory and a built-in type memory can be used. An infrared cut filter for cutting infrared light and an optical low-pass filter for preventing image aliasing noise are disposed in front of the imaging surface of the image sensor 22. Details of the structure of the image sensor 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 through an electric signal contact unit 41 provided in the mount unit 4, receives lens information from the lens control unit 37, and defocuses to the lens control unit 37. Send information such as volume and aperture diameter. The camera control unit 21 reads out the pixel output from the image sensor 22 as described above, generates image information by performing predetermined information processing on the read out pixel output as necessary, and generates the generated image information. Is output to the liquid crystal driving circuit 25 and the memory 24 of the electronic viewfinder 26. The camera control unit 21 controls the entire camera 1 such as correction of image information from the image sensor 22 and detection of a focus adjustment state and an aperture adjustment state of the lens barrel 3.

  In addition to the above, the camera control unit 21 detects the focus state of the photographing optical system by the phase detection method and the focus state of the optical system by the contrast detection method based on the pixel data read from the image sensor 22. Do. A method for detecting the focus state will be described later.

  In addition, the camera control unit 21 stores in advance in the memory 29 the limit value on the aperture side of the aperture value of the optical system when performing focus detection as the limit value on the aperture side. This narrowing limit value is the most narrow value among the narrowing values that can effectively prevent the occurrence of vignetting and obtain good focus detection accuracy when performing focus detection. be able to. Then, the camera control unit 21 controls the exposure at the time of performing focus detection based on the open side limit value received from the lens control unit 37 and the aperture side limit value stored in the memory 29. Details of 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. 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. The shutter release button includes a first switch SW1 that is turned on when the button is half-pressed and a second switch SW2 that 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 image sensor 22, and FIG. 3 is a front view schematically showing the arrangement of the focus detection pixels 222a and 222b by enlarging the III part of FIG.

  As shown in FIG. 3, the imaging element 22 of the present embodiment includes a green pixel G having a color filter in which a plurality of imaging pixels 221 are two-dimensionally arranged on the plane of the imaging surface and transmit a green wavelength region. A red pixel R having a color filter that transmits a red wavelength region and a blue pixel B having a color filter that transmits a blue wavelength region are arranged in a so-called Bayer Arrangement. That is, in four adjacent pixel groups 223 (dense square lattice arrangement), two green pixels are arranged on one diagonal line, and one red pixel and one blue pixel are arranged on the other diagonal line. The image sensor 22 is configured by repeatedly arranging the pixel group 223 on the imaging surface of the image sensor 22 in a two-dimensional manner with the Bayer array pixel group 223 as a unit.

  The unit pixel group 223 may be arranged in a dense hexagonal lattice arrangement other than the dense square lattice shown in the figure. Further, the configuration and arrangement of the color filters 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 cross-sectional view. One imaging pixel 221 includes a micro lens 2211, a photoelectric conversion unit 2212, and a color filter (not shown), and a photoelectric conversion unit is formed on the surface of the semiconductor circuit substrate 2213 of the image sensor 22 as shown in the cross-sectional view of FIG. 2212 is built in and a microlens 2211 is formed on the surface. The photoelectric conversion unit 2212 is configured to receive an imaging light beam that passes through an exit pupil (for example, F1.0) of the photographing optical system by the micro lens 2211, and receives the imaging light beam.

  In addition, focus detection pixel rows 22a, 22b, and 22c in which focus detection pixels 222a and 222b are arranged in place of the above-described imaging pixels 221 at the center of the image pickup surface of the image pickup element 22 and three positions that are symmetrical from the center. Is provided. As shown in FIG. 3, one focus detection pixel column includes a plurality of focus detection pixels 222 a and 222 b that are alternately arranged adjacent to each other in a horizontal row (22 a, 22 c, 22 c). Yes. In the present embodiment, the focus detection pixels 222a and 222b are densely arranged without providing a gap at the position of the green pixel G and the blue pixel B of the image pickup pixel 221 arranged in the Bayer array.

  Note that the positions of the focus detection pixel rows 22a to 22c shown in FIG. 2 are not limited to the illustrated positions, and may be any one or two, or may be arranged at four or more positions. it can. In actual focus detection, the photographer manually operates the operation unit 28 from among a plurality of focus detection pixel rows 22a to 22c, and selects a desired focus detection pixel row as a focus detection position. You can also.

  FIG. 5A is an enlarged front view showing one of the focus detection pixels 222a, and FIG. 7A is a cross-sectional view of the focus detection pixel 222a. FIG. 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. As shown in FIG. 5A, the focus detection pixel 222a includes a micro lens 2221a and a semicircular photoelectric conversion unit 2222a. As shown in the cross-sectional view of FIG. A photoelectric conversion portion 2222a is formed on the surface of the semiconductor circuit substrate 2213, and a micro lens 2221a is formed on the surface. The focus detection pixel 222b includes a micro lens 2221b and a photoelectric conversion unit 2222b as shown in FIG. 5B, and a semiconductor of the image sensor 22 as shown in a cross-sectional view of FIG. 7B. A photoelectric conversion unit 2222b is formed on the surface of the circuit board 2213, and a microlens 2221b is formed on the surface. Then, as shown in FIG. 3, these focus detection pixels 222a and 222b are alternately arranged adjacent to each other in a horizontal row, thereby forming 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 such a shape that the microlenses 2221a and 2221b receive a light beam that passes through a predetermined region (eg, F2.8) of the exit pupil of the photographing optical system. Is done. Further, the focus detection pixels 222a and 222b are not provided with color filters, and their spectral characteristics are the total of the spectral characteristics of a photodiode that performs photoelectric conversion and the spectral characteristics of an infrared cut filter (not shown). ing. However, it may be configured to include one of the same color filters as the imaging pixel 221, for example, a green filter.

  In addition, although the photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b illustrated in FIGS. 5A and 5B have a semicircular shape, the shapes of the photoelectric conversion units 2222a and 2222b are not limited thereto. Other shapes such as an elliptical shape, a rectangular shape, and a polygonal shape can also be used.

  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. The focus detection pixels 222 a-1, 222 b-1, 222 a-2, and 222 b-2 that are arranged in the vicinity of the photographing optical axis L 1 It shows that light beams AB1-1, AB2-1, AB1-2, and AB2-2 irradiated from the distance measuring pupils 341 and 342 of the exit pupil 34 are received, respectively. 8 illustrates only the focus detection pixels 222a and 222b that are located in the vicinity of the photographing optical axis L1, but other focus detection pixels other than the focus detection pixels illustrated in FIG. 8 are illustrated. In the same manner, the light beams emitted from the pair of distance measuring pupils 341 and 342 are respectively received.

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

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

  As shown in FIG. 8, the microlenses 2221a-1, 2221b-1, 2221a-2, and 2221b-2 of the focus detection pixels 222a-1, 222b-1, 222a-2, and 222b-2 are photographic optical systems. Near the planned focal plane. The shapes of the photoelectric conversion units 2222a-1, 2222b-1, 2222a-2, 2222b-2 arranged behind the micro lenses 2221a-1, 2221b-1, 2221a-2, 2221b-2 are the same as 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 projection shape forms the distance measurement pupils 341, 342.

  In other words, on the exit pupil 34 at the distance measurement distance D, the microlens and the photoelectric conversion unit in each focus detection pixel so that the projection shapes (the distance measurement pupils 341 and 342) of the photoelectric conversion unit of each focus detection pixel match. Is determined, and the projection direction of the photoelectric conversion unit in each focus detection pixel is thereby 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 that passes through the distance measuring pupil 341 and goes to the microlens 2221a-1. A signal corresponding to the intensity of the image to be output is output. Similarly, the photoelectric conversion unit 2222a-2 of the focus detection pixel 222a-2 passes through the distance measuring pupil 341, and the intensity of the image formed on the microlens 2221a-2 by the light beam AB1-2 toward the microlens 2221a-2. The signal corresponding to is output.

  Further, the photoelectric conversion unit 2222b-1 of the focus detection pixel 222b-1 passes through the distance measuring 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 measuring pupil 342, and the intensity of the image formed on the microlens 2221b-2 by the light beam AB2-2 toward the microlens 2221b-2. The signal corresponding to is output.

  Then, a plurality of the above-described two types of focus detection pixels 222a and 222b are arranged in a straight line as shown in FIG. 3, and the outputs of the photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b are converted into the distance measurement pupil 341, respectively. Of the pair of images formed on the focus detection pixel row by the focus detection light fluxes that pass through each of the distance measurement pupil 341 and the distance measurement pupil 342. Data on the distribution is obtained. Then, by applying an image shift detection calculation process such as a correlation calculation process or a phase difference detection process to the intensity distribution data, an image shift amount by a so-called phase difference detection method can be detected.

  Then, a conversion calculation is performed on the obtained image shift amount according to the center-of-gravity interval of the pair of distance measuring pupils, thereby obtaining a current focal plane with respect to the planned focal plane (the focal point corresponding to the position of the microlens array on the planned focal plane). The deviation of the focal plane at the detection position, that is, the defocus amount can be obtained.

  The calculation of the image shift amount by the phase difference detection method and the calculation of the defocus amount based thereon 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 a focus evaluation value based on the read pixel output. This focus evaluation value can be obtained, for example, by extracting a high-frequency component of an image output from the imaging pixel 221 of the image sensor 22 using a high-frequency transmission filter and integrating the extracted high-frequency components to detect a focus voltage. It can also be obtained by extracting high-frequency components using two high-frequency transmission filters having different cutoff frequencies and integrating them 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 in which the position of the focus lens 32 is determined as the in-focus position. Note that this in-focus position is obtained when, for example, when the focus evaluation value is calculated while driving the focus lens 32, the focus evaluation value rises twice and then moves down twice. Can be obtained by performing an operation such as interpolation using the focus evaluation value.

  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 camera 1 is turned on.

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

  In step S102, the camera control unit 21 performs processing for setting the aperture value (F value) of the optical system to the aperture value for performing focus detection. Specifically, the camera control unit 21 first receives from the lens control unit 37 the open side limit value of the aperture value of the optical system when detecting the focus state of the optical system as the open side limit value. At the same time, the limit value on the aperture side of the aperture value of the optical system when detecting the focus state of the optical system is acquired from the memory 29 as the limit value on the aperture side. In the present embodiment, since the open side limit value is stored in the memory 39 as the number of apertures from the aperture value, the camera control unit 21 sets the aperture value from the aperture value to the aperture value. Based on this, the limit value (F value) on the open side of the aperture value of the optical system when performing focus detection is obtained as the open side limit value.

  Then, the camera control unit 21 sets the aperture value of the optical system for performing focus detection based on the acquired open side limit value and aperture side limit value. Specifically, the camera control unit 21 reduces the aperture value of the optical system when the imaging aperture value set for actual imaging of the image is closer to the aperture side than the aperture side limit value. Set to the side limit value. Here, FIG. 10 is a diagram illustrating an example of the relationship between the aperture value set for performing focus detection and the imaging aperture value. In the example shown in FIG. 10, in the lens barrel 3 having an open aperture value of F1.2 and a maximum aperture value (maximum F value) of F16, the open side limit value is acquired as F2.8, and the aperture side The scene where the limit value is acquired as F5.6 is shown. 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 closer to the aperture than the aperture limit value F5.6. The camera control unit 21 sets the aperture value of the optical system to F5.6, which is the aperture limit value. In the example shown in FIG. 10B, since the photographing aperture value is F8, as in FIG. 10A, the camera control unit 21 sets the aperture value of the optical system to the aperture-side limit value. Set to a certain F5.6.

  In addition, when the photographing aperture value set for the actual photographing of the image is the same value as the aperture-side limit value or a value closer to the open side than the aperture-side limit value, the camera control unit 21 Set the aperture value to the shooting aperture value. For example, in the example shown in FIG. 10C, since the photographing aperture value is F5.6, which is the same as the narrowing-side limit value, the camera control unit 21 sets the aperture value of the optical system to F5. Set to 6. In the example shown in FIG. 10D, the photographing aperture value is set to F4, and F4 as the photographing aperture value is a value on the open side with respect to F5.6 which is the narrowing limit value. The camera control unit 21 sets the aperture value of the optical system to F4 that is the shooting aperture value. Similarly, in the examples shown in FIGS. 10E to 10G, as with FIG. 10D, since the photographing aperture value is a value closer to the open side than the limit value on the narrowing side, the camera control unit 21 sets the aperture value of the optical system to the photographing aperture value.

  In step S103, the camera control unit 21 generates a through image, and the through image is displayed by the electronic viewfinder 26 of the observation optical system. Specifically, an exposure operation is performed by the imaging element 22, and pixel data of the imaging pixel 221 is read 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 driving circuit 25 and displayed on the electronic viewfinder 26 of the observation optical system. As a result, the user can view 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 regions, and performs multi-division metering (multi-pattern metering) in which metering is performed for each of the divided regions, and the luminance value Bv of the entire shooting screen is calculated. Is done. Then, at least one of the light receiving 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 shooting screen so that proper exposure is obtained on the entire shooting 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 reception sensitivity Sv and exposure time Tv, for example, the exposure to the image sensor 22 is controlled by setting the shutter speed of the shutter 23, the sensitivity of the image sensor 21, and the like.

  In step S105, the camera control unit 21 determines whether or not an appropriate exposure has been obtained on the entire shooting screen by the exposure control in step S104. If only the change in the light receiving sensitivity Sv and the exposure time Tv does not provide proper exposure of the entire shooting screen, the process proceeds to step S106. If proper exposure is obtained as a whole, the process proceeds to step S108.

  In step S106, it is determined that a proper exposure cannot be obtained over the entire photographing screen only by changing the light receiving sensitivity Sv and the exposure time Tv, so the camera control unit 21 changes the aperture Av. Specifically, when the photographing aperture value is a value closer to the aperture side than the aperture side limit value, the camera control unit 21 sets the aperture value of the optical system between the open side limit value and the aperture side limit value. The aperture Av is changed based on the luminance value Bv of the entire shooting screen so that it is within the range. For example, in the example shown in FIG. 10A, since the photographing aperture value F16 is a value closer to the aperture than the aperture limit value F5.6, the camera control unit 21 uses the aperture of the optical system. The aperture Av is changed so that the value falls within the range from the open limit value F2.6 to the narrow limit value F5.6, and exposure control is performed so that proper exposure is obtained over the entire shooting screen. I do. The same applies to the example shown in FIG.

  Further, when the photographing aperture value is the same value as the aperture-side limit value or a value closer to the open side than the aperture-side limit value, the camera control unit 21 sets the aperture value of the optical system to the aperture-side limit value and the imaging. The aperture Av is changed based on the brightness value Bv of the entire shooting screen so that it is within the range of the aperture value. For example, in the example shown in FIG. 10C, since the shooting aperture value F5.6 is the same value as the aperture limit value F5.6, the camera control unit 21 determines the aperture value of the optical system. However, the aperture Av is changed so that it falls within the range from F2.6, which is the open side limit value, to F5.6, which is the shooting aperture value. In the example shown in FIG. 10D, since the photographing aperture value F4 is a value closer to the open side than the aperture-side limit value F5.6, the camera control unit 21 does not use the aperture of the optical system. The aperture Av is changed so that the value falls within the range from F2.6, which is the open limit value, to F4, which is the shooting aperture value.

  The camera control unit 21 keeps the aperture value of the optical system as the shooting aperture value when the shooting aperture value is the same value as the open limit value or a value closer to the open side than the open limit value. To do. For example, in the example shown in (E) of FIG. 10, since the shooting aperture value F2.6 is the same value as the open-side limit value F2.6, the camera control unit 21 uses the aperture value of the optical system. Is set to F2.6 which is the photographing aperture value. The same applies to the examples shown in FIGS. In the present embodiment, for example, as shown in FIGS. 10A to 10D, the camera control unit 21 can change the aperture Av within a predetermined aperture value range. Even when the brightness value Bv of the entire shooting screen changes again, the aperture Av is changed to the open side with a slight margin so that the aperture Av does not have to be changed again.

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

  In step S108, the camera control unit 21 performs a defocus amount calculation process using a phase difference detection method. Specifically, first, a light beam from the optical system is received by the image sensor 22, and each focus detection pixel 222 a configuring the three focus detection pixel rows 22 a to 22 c of the image sensor 22 by the camera control unit 21. , 222b, a pair of image data corresponding to the pair of images is read out. In this case, when a specific focus detection position is selected by a manual operation of the photographer, only data from focus detection pixels corresponding to the focus detection position may be read. Then, the camera control unit 21 performs image shift detection calculation processing (correlation calculation processing) based on the read pair of image data, and images at the focus detection positions corresponding to the three focus detection pixel rows 22a to 22c. The shift amount is calculated, and the image shift amount is converted into a defocus amount. Further, the camera control unit 21 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 matching degree and contrast of the pair of image data.

  In step S109, the camera control unit 21 determines whether the shutter release button provided in the operation unit 28 is half-pressed (the first switch SW1 is turned on). If the shutter release button is pressed halfway, the process proceeds to step S110. On the other hand, if the shutter release button has not been pressed halfway, the process returns to step S103, and display of a through image, exposure control, and 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 or not the defocus amount can be calculated by the phase difference detection format. If the defocus amount can be calculated, it is determined that distance measurement is possible and the process proceeds to step S111. On the other hand, if the defocus amount cannot be calculated, it is determined that 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, it is treated that the defocus amount cannot be calculated, and the process proceeds to step S115. I will do it. In the present embodiment, for example, when the subject has a low contrast, the subject is an ultra-low brightness subject, or the subject is an ultra-high brightness subject, it is determined that the reliability of the defocus amount is low. .

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

  In step S112, the camera control unit 21 determines whether or not 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. On the other hand, if the second switch SW2 is not on, the process returns to step S103.

  In step S113, the camera control unit 21 performs processing for setting the aperture value of the optical system to the shooting aperture value in order to perform the actual shooting of the image. For example, in the example shown in FIG. 10A, 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 actually take an image. From within the range of F5.6 which is the limit value on the narrowing side) to F16 which is the shooting aperture value. Similarly, also in the examples shown in FIGS. 10B to 10G, the aperture value of the optical system is changed from the aperture value for performing focus detection to the imaging aperture value for actually capturing an image. In subsequent step S <b> 114, the image is captured by the image sensor 22 with the aperture value set in step S <b> 113, and image data of the captured image is stored in the memory 24.

  On the other hand, if it is determined in step S110 that the defocus amount cannot be calculated, the process proceeds to step S115 in order to obtain an exposure suitable for focus detection. In step S115, exposure control for focus detection is performed by the camera control unit 21 so that an exposure suitable for focus detection is obtained. Specifically, the camera control unit 21 performs spot photometry in predetermined areas including the focus detection areas (focus detection pixel rows 22a, 22b, and 22c shown in FIG. 2) based on the output of the image sensor 22, A luminance value SpotBv within a predetermined area including the focus detection area is calculated. Then, the camera control unit 21 receives the light sensitivity Sv, the exposure time Tv, and the exposure time Sv so as to obtain an exposure suitable for focus detection (for example, an exposure one step brighter than the appropriate exposure) based on the calculated luminance value SpotBv. The aperture Av is determined. In exposure control for focus detection in step S115, as in steps S104 to S107, the camera control unit 21 preferentially changes the light receiving sensitivity Sv and the exposure time Tv, and sets the light receiving sensitivity Sv and the exposure time Tv. The aperture Av is changed based on the open-side limit value and the aperture-side limit value acquired in step S102 only when the exposure suitable for focus detection cannot be obtained only by the change. That is, as in the example illustrated in FIGS. 10A to 10B, the camera control unit 21 determines the aperture of the optical system when the photographing aperture value is a value closer to the aperture than the aperture limit value. 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 aperture side limit value. Also, as shown in FIGS. 10C to 10D, when the photographing aperture value is the same value as the aperture-side limit value or a value closer to the open side than the aperture-side limit value, the aperture of the optical system Based on the luminance value SpotBv in the predetermined area including the focus detection area, the aperture Av is changed so that the value falls within the range between the open side limit value and the photographing aperture value. Further, FIG. As shown in (G), when the photographing aperture value is the same value as the open side limit value or a value closer to the open side than the open side limit value, the aperture value of the optical system remains the shooting aperture value. And

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

  In step S118, the camera control unit 21 performs a scan operation execution process for executing a scan operation. Here, the scan operation is a predetermined calculation of the defocus amount and the focus evaluation value by the phase difference detection method by the camera control unit 21 while the focus lens 32 is scan-driven by the focus lens drive motor 36. Thus, 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. Hereinafter, the scan operation execution process according to the present embodiment will be described with reference to FIG. 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 a scan operation start process. 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 focus. 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 may be performed from the close end to the infinite 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. The phase difference detection method calculates the defocus amount, evaluates the reliability of the calculated defocus amount, and drives the focus lens 32 to drive the pixel output from the imaging pixel 221 of the imaging element 22 at a predetermined interval. Reading is performed, and based on this, a focus evaluation value is calculated, thereby acquiring a focus evaluation value at a different focus lens position, thereby detecting a focus position by a contrast detection method.

  In step S202, it is determined whether or not the defocus amount has been calculated by the phase difference detection method as a result of the scanning operation performed by the camera control unit 21. 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 cannot be calculated, it is determined that distance measurement is not possible and the process proceeds to step S203. .

  In step S203, it is determined whether the in-focus position has been detected by the contrast detection method as a result of the scanning operation performed by the camera control unit 21. If the in-focus position can be detected by the contrast detection method, the process proceeds to step S207. If the in-focus position cannot be detected, the process proceeds to step S204.

  In step S <b> 204, the camera control unit 21 determines whether the scan operation has been performed for the entire driveable range of the focus lens 32. If the scan operation is not performed for the entire driveable range of the focus lens 32, the process returns to step S202, and steps S202 to S204 are repeated to perform the scan operation, that is, while the focus lens 32 is scan-driven. 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 continuously performed. On the other hand, if the scan operation has been completed for the entire driveable range of the focus lens 32, the process proceeds to step S208.

  As a result of executing the scanning operation, if it is determined in step S202 that the defocus amount can be calculated by the phase difference detection method, the process proceeds to step S205. In step S205, the defocus amount is calculated by the phase difference detection method. A focusing operation based on the defocus amount is performed.

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

  As a result of executing the scanning operation, if it is determined in step S203 that the in-focus position has been detected by the contrast detection method, 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 scanning operation is stopped by the camera control unit 21, a lens driving process 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 driving 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 focus is in-focus.

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

  Then, after the scan operation execution process in step S118 is completed, the process proceeds to step S119, and the camera control unit 21 determines whether or not the camera is in focus based on the focus determination result in the scan operation execution process. Done. In the scan operation execution process, when it is determined that the focus is achieved (step S206), the process proceeds to step S112. On the other hand, when it is determined that focusing is not possible (step S209), the process proceeds to step S120, and in-focusing display is performed in step S120. The in-focus indication is performed by the electronic viewfinder 26, for example.

  If it is determined in step S101 that a moving image has been shot, the process proceeds to step S121. In step S121, the camera control unit 21 performs exposure control so that an exposure suitable for moving image shooting is obtained. Specifically, in order to prioritize the appearance of the moving image, the camera control unit 21 performs multi-pattern metering to calculate the luminance value Bv of the entire shooting screen, and based on the calculated luminance value Bv, The light receiving sensitivity Sv and the exposure time Tv are determined so that proper exposure can be obtained. In particular, during shooting of a moving image, exposure control is performed by changing only the light receiving sensitivity Sv and the exposure time Tv while the aperture Av is fixed.

  In step S122, the camera control unit 21 detects the focus state of the optical system and adjusts the focus of the focus lens 32 according to the detected focus state. Specifically, the camera control unit 21 calculates the defocus amount based on the captured image data, similarly to steps S111 and S115 to S120, and determines whether the defocus amount has been calculated. When the defocus amount is calculated, the focus lens 32 is driven based on the calculated defocus amount. On the other hand, when the defocus amount is not calculated, a scan operation execution process is performed. . Then, the process proceeds to step S 123, where the moving image is actually captured by the image sensor 22, and the image data of the moving image captured by the camera control unit 21 is stored in the memory 24.

  As described above, in this embodiment, the limit value on the open side of the aperture value of the optical system when performing 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 aperture side of the aperture value of the optical system when performing the above is stored in the camera body 2 as the aperture side limit value. The camera control unit 21 sets the aperture value of the optical system when performing focus detection based on the open side limit value received from the lens barrel 3 and the aperture side limit value acquired from the memory 29. . Specifically, if the shooting aperture value when the image is actually captured is a value closer to the aperture than the aperture limit value, the aperture value of the optical system when performing focus detection is set to the open side limit value. And within the range of the narrowing limit value. As described above, in the present embodiment, the aperture value of the optical system when performing focus detection is limited to a value closer to the aperture side than the open side limit value, so that the image of the aperture of the optical system is captured. Even when the value is changed from the aperture value at the time of focus detection to the imaging aperture value for the actual shooting of the 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 a predetermined value or less. As a result, the in-focus position detected in the focus detection can be set 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 subject is in focus can be photographed. Can do.

  In the present embodiment, when the photographing aperture value at the time of actual photographing of the image is a value on the narrowing side with respect to the narrowing side limit value, the aperture value of the optical system at the time of performing focus detection is set to the narrowing side. By limiting to a value closer to the open side than the limit value, it is possible to effectively prevent occurrence of vignetting at the time of focus detection, and to appropriately detect the focus state of the optical system. Furthermore, in this embodiment, when the photographing aperture value is a value closer to the open side than the aperture-side limit value, the aperture value of the optical system when performing focus detection is set to the open side limit value and the photographing aperture value. By setting within the range, the aperture value of the optical system at the time of focus detection is limited so as not to be a value closer to the aperture than the shooting aperture value. The depth of field at the time of actual shooting will be shallower than the depth of field at the time of focus detection. Deviating from the depth of field can be effectively prevented, and as a result, an image focused on the subject can be taken well.

<< Second Embodiment >>
Next, 2nd Embodiment of this invention is described based on drawing. As shown in FIG. 12, the camera 1 a according to the second embodiment is the same as the camera 1 according to the first embodiment except that the lens barrel 3 a is attached to the camera body 2 via the lens adapter 5. 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, the camera 1 a according to the second embodiment can mount the lens barrel 3 a to the camera body 2 via the lens adapter 5. Here, the lens barrel 3 a 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. In the second embodiment, for example, the lens barrel 3 a is attached to the camera body 2 via the lens adapter 5, so that the adapter control unit 51 and the lens control unit 37 are connected to the camera control unit 21. Thus, a signal indicating that the lens adapter 5 is attached is sent out, and thereby, via the electrical signal contact portion 41 provided on the mount portion 4 and the electrical signal contact portion 61 provided on the mount portion 6. 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 diagram illustrating an example of a relationship between an aperture value set at the time of focus detection and a shooting aperture value in the second embodiment. Further, in the example shown in FIG. 13, in a scene where the maximum aperture value is F1.2 and the maximum aperture value (maximum F value) is F16, the camera control unit 21 performs aperture reduction without using the open side limit value. A scene in which exposure control for focus detection is performed based only on the side limit value is shown.

  In the second embodiment, the camera control unit 21 restricts the aperture value of the optical system to the aperture side limit when the imaging aperture value for actual imaging of the image is a value closer to the aperture side than the aperture side limit value. The focus detection is performed by setting the value, and the actual photographing is performed by setting the aperture value of the optical system to the photographing aperture value. For example, in the example shown in FIG. 13A, the photographic aperture value is F16, and the photographic aperture value is a value closer to the aperture side than F5.6, which is the aperture side limit value. Is set to F5.6 which is the limit value on the narrowing side, focus detection is performed, and when the actual photographing of the image is performed, the aperture value of the optical system is changed from F5.6 which is the limit value on the narrowing side. The image is changed to F16, which is the shooting aperture value, and the actual shooting of the image is performed. Similarly, in the example shown in FIG. 13B, since the photographing aperture value F8 is a value closer to the narrowing side than F5.6, which is the narrowing side limit value, F5.6, which is the narrowing side limit value. The focus is detected at, and the actual image is taken at F8 which is the shooting aperture value.

  In addition, when the photographing aperture value is the same value as the aperture-side limit value or a value closer to the open side than the aperture-side limit value, the camera control unit 21 changes the aperture value of the optical system to the imaging aperture value. The focus detection is performed by setting, and the image is actually shot while the aperture value of the optical system is set to the shooting aperture value. For example, in the example shown in FIG. 13C, since the photographing aperture value is F5.6 which is the same as the narrowing-side limit value, the camera control unit 21 sets the aperture value of the optical system to F5. The focus detection is performed with setting to 6, and the image is actually captured with the photographing aperture value F5.6. In the example shown in FIG. 13D, since the photographing aperture value is F4, and the photographing aperture value is a value on the open side with respect to F5.6, which is the aperture-side limit value, the camera control unit 21 The focus value is detected by setting the aperture value of the optical system to F4, which is the shooting aperture value, and the actual shooting of the image is performed with the set shooting 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 side limit value is not acquired from the lens control unit 37, the photographing aperture value is the same value as the aperture side limit value or a value closer to the open side than the aperture side limit value. In some cases, as shown in FIGS. 13C to 13F, the aperture value of the optical system is set to the shooting aperture value to perform focus detection, and the image is left set to the shooting aperture value. Perform the actual shooting. As a result, in this embodiment, since the aperture value of the optical system is not changed from the time of focus detection to the time of actual image capture, the image plane position of the optical system is different between when focus detection is performed and when an image is actually captured. Is not changed, and the in-focus position detected in the focus detection is 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 focus on the subject can be photographed.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, in the above-described embodiment, the focus adjustment of the focus lens 32 is started by half-pressing the shutter release button provided in the operation unit 28. However, the present invention is not limited to this configuration. The camera 1 may be configured to activate the focus adjustment of the focus lens 32 by connecting a personal computer and receiving a signal from the personal computer, or a signal from a remote controller corresponding to the camera 1 may be received by the camera 1. It is good also as a structure which starts the focus adjustment of the focus lens 32 by receiving. In this case, in step S110, it may be configured to determine whether a signal for starting focus adjustment of the focus lens 32 is received from a personal computer or a remote controller.

  The camera 1 of 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 a mobile phone. May be.

DESCRIPTION OF SYMBOLS 1 ... Digital camera 2 ... Camera body 21 ... Camera control part 22 ... Imaging device 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 for outputting a signal by capturing an image by the optical system,
Based on the preceding item relaxin, a detection unit image by the optical system to detect the focus position of the optical system for focusing on the imaging unit,
A receiving unit that receives the limit value on the open side of the aperture value of the optical system when the in-focus position is detected by the detection unit from a lens barrel having the optical system ;
A storage unit which memorize the closing side of the limit value of the aperture value of the optical system at the time of detecting the in-focus position by the detecting unit,
The aperture value of the optical system when the in-focus position is detected by the detection unit, and the imaging aperture value when the imaging unit performs imaging to record the signal as image data is the limit value on the aperture side If larger, set within a range not less than the limit value on the open side and not more than the limit value on the narrowing side, and if the photographing aperture value is not more than the limit value on the narrowing side, the limit value on the open side and above A control unit that is set within a range below the aperture value ;
The equipped Luke Merabodi. The camera body according to claim 1 ,
Wherein the control unit, the said aperture of the optical system when the detection of in-focus position by the detection unit, set to Luke Merabodi the shooting aperture or a value less than the shooting aperture. The camera body according to claim 1 or 2 ,
Wherein the control unit, the aperture value of the optical system, a camera body to be set to a value greater than the maximum aperture of the optical system when the detection of in-focus position by the detecting unit. A camera body according to any one of claims 1 to 3 ,
The imaging unit includes a plurality of focus detection pixels of the image pixels and multiple arrayed two-dimensionally,
The detection section before SL signal output from the focus detection pixels, and, among the evaluation values for image contrast by the optical system based on the prior SL signal output by the imaging pixels, whereas at least one A camera body for detecting a focus position of the optical system based on The camera body according to any one of claims 1 to 4 ,
Wherein the control unit set, the photographing aperture value, the open side of the limit value or less is case, the aperture value of the optical system when the detection of in-focus position by the detecting unit, the imaging aperture to Luke Merabodi. A camera body according to claim 1,
Wherein the control unit, the imaging aperture is greater than the limit value of the closing side, set the aperture value of the optical system, the closing side limit value when performing detection of the focusing position by the detecting unit to Luke Merabodi. A camera body according to claim 1,
Prior Symbol controller, the aperture value of the optical system when the detection of the focus position by the detection unit, the lens barrel through the lenses adapter is mounted, the imaging aperture value is the narrowing is greater than the side of the limit value, the set closing side of the limit value, the case imaging aperture value is below the limit value before Symbol closing side, Luke Merabodi set before Symbol shooting aperture.   A lens barrel detachable from the camera body according to claim 1,
An optical system including a focusing optical system;
  A diaphragm for limiting a light beam passing through the optical system;
  A moving unit for moving the focus adjusting optical system in the optical axis direction;
  A storage unit that stores a limit value on the open side of the aperture value of the optical system when the detection unit of the camera body detects the in-focus position;
  A lens barrel comprising: a transmission unit that transmits the open side limit value to the camera body.   The lens barrel according to claim 8, wherein
  The lens barrel in which the storage unit stores the open side limit value as the number of aperture stages from the open aperture value of the optical system.

Images